Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Resizable virtual memory filesystem for Linux. |
| 3 | * |
| 4 | * Copyright (C) 2000 Linus Torvalds. |
| 5 | * 2000 Transmeta Corp. |
| 6 | * 2000-2001 Christoph Rohland |
| 7 | * 2000-2001 SAP AG |
| 8 | * 2002 Red Hat Inc. |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 9 | * Copyright (C) 2002-2011 Hugh Dickins. |
| 10 | * Copyright (C) 2011 Google Inc. |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 11 | * Copyright (C) 2002-2005 VERITAS Software Corporation. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | * Copyright (C) 2004 Andi Kleen, SuSE Labs |
| 13 | * |
| 14 | * Extended attribute support for tmpfs: |
| 15 | * Copyright (c) 2004, Luke Kenneth Casson Leighton <lkcl@lkcl.net> |
| 16 | * Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com> |
| 17 | * |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 18 | * tiny-shmem: |
| 19 | * Copyright (c) 2004, 2008 Matt Mackall <mpm@selenic.com> |
| 20 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | * This file is released under the GPL. |
| 22 | */ |
| 23 | |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 24 | #include <linux/fs.h> |
| 25 | #include <linux/init.h> |
| 26 | #include <linux/vfs.h> |
| 27 | #include <linux/mount.h> |
Andrew Morton | 250297e | 2013-04-29 15:06:12 -0700 | [diff] [blame] | 28 | #include <linux/ramfs.h> |
Hugh Dickins | caefba1 | 2009-04-13 14:40:12 -0700 | [diff] [blame] | 29 | #include <linux/pagemap.h> |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 30 | #include <linux/file.h> |
| 31 | #include <linux/mm.h> |
Paul Gortmaker | b95f1b31 | 2011-10-16 02:01:52 -0400 | [diff] [blame] | 32 | #include <linux/export.h> |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 33 | #include <linux/swap.h> |
Christoph Hellwig | e2e40f2 | 2015-02-22 08:58:50 -0800 | [diff] [blame] | 34 | #include <linux/uio.h> |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 35 | |
| 36 | static struct vfsmount *shm_mnt; |
| 37 | |
| 38 | #ifdef CONFIG_SHMEM |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | /* |
| 40 | * This virtual memory filesystem is heavily based on the ramfs. It |
| 41 | * extends ramfs by the ability to use swap and honor resource limits |
| 42 | * which makes it a completely usable filesystem. |
| 43 | */ |
| 44 | |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 45 | #include <linux/xattr.h> |
Christoph Hellwig | a569425 | 2007-07-17 04:04:28 -0700 | [diff] [blame] | 46 | #include <linux/exportfs.h> |
Christoph Hellwig | 1c7c474 | 2009-11-03 16:44:44 +0100 | [diff] [blame] | 47 | #include <linux/posix_acl.h> |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 48 | #include <linux/posix_acl_xattr.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | #include <linux/mman.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | #include <linux/string.h> |
| 51 | #include <linux/slab.h> |
| 52 | #include <linux/backing-dev.h> |
| 53 | #include <linux/shmem_fs.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | #include <linux/writeback.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | #include <linux/blkdev.h> |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 56 | #include <linux/pagevec.h> |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 57 | #include <linux/percpu_counter.h> |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 58 | #include <linux/falloc.h> |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 59 | #include <linux/splice.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | #include <linux/security.h> |
| 61 | #include <linux/swapops.h> |
| 62 | #include <linux/mempolicy.h> |
| 63 | #include <linux/namei.h> |
Hugh Dickins | b00dc3a | 2006-02-21 23:49:47 +0000 | [diff] [blame] | 64 | #include <linux/ctype.h> |
Lee Schermerhorn | 304dbdb | 2006-04-22 02:35:48 -0700 | [diff] [blame] | 65 | #include <linux/migrate.h> |
Christoph Lameter | c1f60a5 | 2006-09-25 23:31:11 -0700 | [diff] [blame] | 66 | #include <linux/highmem.h> |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 67 | #include <linux/seq_file.h> |
Mimi Zohar | 9256292 | 2008-10-07 14:00:12 -0400 | [diff] [blame] | 68 | #include <linux/magic.h> |
David Herrmann | 9183df2 | 2014-08-08 14:25:29 -0700 | [diff] [blame] | 69 | #include <linux/syscalls.h> |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 70 | #include <linux/fcntl.h> |
David Herrmann | 9183df2 | 2014-08-08 14:25:29 -0700 | [diff] [blame] | 71 | #include <uapi/linux/memfd.h> |
Lee Schermerhorn | 304dbdb | 2006-04-22 02:35:48 -0700 | [diff] [blame] | 72 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | #include <asm/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | #include <asm/pgtable.h> |
| 75 | |
Mel Gorman | dd56b04 | 2015-11-06 16:28:43 -0800 | [diff] [blame] | 76 | #include "internal.h" |
| 77 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 78 | #define BLOCKS_PER_PAGE (PAGE_SIZE/512) |
| 79 | #define VM_ACCT(size) (PAGE_ALIGN(size) >> PAGE_SHIFT) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | /* Pretend that each entry is of this size in directory's i_size */ |
| 82 | #define BOGO_DIRENT_SIZE 20 |
| 83 | |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 84 | /* Symlink up to this size is kmalloc'ed instead of using a swappable page */ |
| 85 | #define SHORT_SYMLINK_LEN 128 |
| 86 | |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 87 | /* |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 88 | * shmem_fallocate communicates with shmem_fault or shmem_writepage via |
| 89 | * inode->i_private (with i_mutex making sure that it has only one user at |
| 90 | * a time): we would prefer not to enlarge the shmem inode just for that. |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 91 | */ |
| 92 | struct shmem_falloc { |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 93 | wait_queue_head_t *waitq; /* faults into hole wait for punch to end */ |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 94 | pgoff_t start; /* start of range currently being fallocated */ |
| 95 | pgoff_t next; /* the next page offset to be fallocated */ |
| 96 | pgoff_t nr_falloced; /* how many new pages have been fallocated */ |
| 97 | pgoff_t nr_unswapped; /* how often writepage refused to swap out */ |
| 98 | }; |
| 99 | |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 100 | /* Flag allocation requirements to shmem_getpage */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 101 | enum sgp_type { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | SGP_READ, /* don't exceed i_size, don't allocate page */ |
| 103 | SGP_CACHE, /* don't exceed i_size, may allocate page */ |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 104 | SGP_WRITE, /* may exceed i_size, may allocate !Uptodate page */ |
| 105 | SGP_FALLOC, /* like SGP_WRITE, but make existing page Uptodate */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 106 | }; |
| 107 | |
Andrew Morton | b76db73 | 2008-02-08 04:21:49 -0800 | [diff] [blame] | 108 | #ifdef CONFIG_TMPFS |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 109 | static unsigned long shmem_default_max_blocks(void) |
| 110 | { |
| 111 | return totalram_pages / 2; |
| 112 | } |
| 113 | |
| 114 | static unsigned long shmem_default_max_inodes(void) |
| 115 | { |
| 116 | return min(totalram_pages - totalhigh_pages, totalram_pages / 2); |
| 117 | } |
Andrew Morton | b76db73 | 2008-02-08 04:21:49 -0800 | [diff] [blame] | 118 | #endif |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 119 | |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 120 | static bool shmem_should_replace_page(struct page *page, gfp_t gfp); |
| 121 | static int shmem_replace_page(struct page **pagep, gfp_t gfp, |
| 122 | struct shmem_inode_info *info, pgoff_t index); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 123 | static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 124 | struct page **pagep, enum sgp_type sgp, |
| 125 | gfp_t gfp, struct mm_struct *fault_mm, int *fault_type); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 126 | |
| 127 | static inline int shmem_getpage(struct inode *inode, pgoff_t index, |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 128 | struct page **pagep, enum sgp_type sgp) |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 129 | { |
| 130 | return shmem_getpage_gfp(inode, index, pagep, sgp, |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 131 | mapping_gfp_mask(inode->i_mapping), NULL, NULL); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 132 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | static inline struct shmem_sb_info *SHMEM_SB(struct super_block *sb) |
| 135 | { |
| 136 | return sb->s_fs_info; |
| 137 | } |
| 138 | |
| 139 | /* |
| 140 | * shmem_file_setup pre-accounts the whole fixed size of a VM object, |
| 141 | * for shared memory and for shared anonymous (/dev/zero) mappings |
| 142 | * (unless MAP_NORESERVE and sysctl_overcommit_memory <= 1), |
| 143 | * consistent with the pre-accounting of private mappings ... |
| 144 | */ |
| 145 | static inline int shmem_acct_size(unsigned long flags, loff_t size) |
| 146 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 147 | return (flags & VM_NORESERVE) ? |
Al Viro | 191c542 | 2012-02-13 03:58:52 +0000 | [diff] [blame] | 148 | 0 : security_vm_enough_memory_mm(current->mm, VM_ACCT(size)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 149 | } |
| 150 | |
| 151 | static inline void shmem_unacct_size(unsigned long flags, loff_t size) |
| 152 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 153 | if (!(flags & VM_NORESERVE)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 154 | vm_unacct_memory(VM_ACCT(size)); |
| 155 | } |
| 156 | |
Konstantin Khlebnikov | 7714251 | 2014-08-06 16:06:34 -0700 | [diff] [blame] | 157 | static inline int shmem_reacct_size(unsigned long flags, |
| 158 | loff_t oldsize, loff_t newsize) |
| 159 | { |
| 160 | if (!(flags & VM_NORESERVE)) { |
| 161 | if (VM_ACCT(newsize) > VM_ACCT(oldsize)) |
| 162 | return security_vm_enough_memory_mm(current->mm, |
| 163 | VM_ACCT(newsize) - VM_ACCT(oldsize)); |
| 164 | else if (VM_ACCT(newsize) < VM_ACCT(oldsize)) |
| 165 | vm_unacct_memory(VM_ACCT(oldsize) - VM_ACCT(newsize)); |
| 166 | } |
| 167 | return 0; |
| 168 | } |
| 169 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | /* |
| 171 | * ... whereas tmpfs objects are accounted incrementally as |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 172 | * pages are allocated, in order to allow large sparse files. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | * shmem_getpage reports shmem_acct_block failure as -ENOSPC not -ENOMEM, |
| 174 | * so that a failure on a sparse tmpfs mapping will give SIGBUS not OOM. |
| 175 | */ |
| 176 | static inline int shmem_acct_block(unsigned long flags) |
| 177 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 178 | return (flags & VM_NORESERVE) ? |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 179 | security_vm_enough_memory_mm(current->mm, VM_ACCT(PAGE_SIZE)) : 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | } |
| 181 | |
| 182 | static inline void shmem_unacct_blocks(unsigned long flags, long pages) |
| 183 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 184 | if (flags & VM_NORESERVE) |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 185 | vm_unacct_memory(pages * VM_ACCT(PAGE_SIZE)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 186 | } |
| 187 | |
Hugh Dickins | 759b977 | 2007-03-05 00:30:28 -0800 | [diff] [blame] | 188 | static const struct super_operations shmem_ops; |
Christoph Hellwig | f5e54d6 | 2006-06-28 04:26:44 -0700 | [diff] [blame] | 189 | static const struct address_space_operations shmem_aops; |
Helge Deller | 15ad7cd | 2006-12-06 20:40:36 -0800 | [diff] [blame] | 190 | static const struct file_operations shmem_file_operations; |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 191 | static const struct inode_operations shmem_inode_operations; |
| 192 | static const struct inode_operations shmem_dir_inode_operations; |
| 193 | static const struct inode_operations shmem_special_inode_operations; |
Alexey Dobriyan | f0f37e2 | 2009-09-27 22:29:37 +0400 | [diff] [blame] | 194 | static const struct vm_operations_struct shmem_vm_ops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 195 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 196 | static LIST_HEAD(shmem_swaplist); |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 197 | static DEFINE_MUTEX(shmem_swaplist_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 199 | static int shmem_reserve_inode(struct super_block *sb) |
| 200 | { |
| 201 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 202 | if (sbinfo->max_inodes) { |
| 203 | spin_lock(&sbinfo->stat_lock); |
| 204 | if (!sbinfo->free_inodes) { |
| 205 | spin_unlock(&sbinfo->stat_lock); |
| 206 | return -ENOSPC; |
| 207 | } |
| 208 | sbinfo->free_inodes--; |
| 209 | spin_unlock(&sbinfo->stat_lock); |
| 210 | } |
| 211 | return 0; |
| 212 | } |
| 213 | |
| 214 | static void shmem_free_inode(struct super_block *sb) |
| 215 | { |
| 216 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 217 | if (sbinfo->max_inodes) { |
| 218 | spin_lock(&sbinfo->stat_lock); |
| 219 | sbinfo->free_inodes++; |
| 220 | spin_unlock(&sbinfo->stat_lock); |
| 221 | } |
| 222 | } |
| 223 | |
Randy Dunlap | 4671181 | 2008-03-19 17:00:41 -0700 | [diff] [blame] | 224 | /** |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 225 | * shmem_recalc_inode - recalculate the block usage of an inode |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 226 | * @inode: inode to recalc |
| 227 | * |
| 228 | * We have to calculate the free blocks since the mm can drop |
| 229 | * undirtied hole pages behind our back. |
| 230 | * |
| 231 | * But normally info->alloced == inode->i_mapping->nrpages + info->swapped |
| 232 | * So mm freed is info->alloced - (inode->i_mapping->nrpages + info->swapped) |
| 233 | * |
| 234 | * It has to be called with the spinlock held. |
| 235 | */ |
| 236 | static void shmem_recalc_inode(struct inode *inode) |
| 237 | { |
| 238 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 239 | long freed; |
| 240 | |
| 241 | freed = info->alloced - info->swapped - inode->i_mapping->nrpages; |
| 242 | if (freed > 0) { |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 243 | struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); |
| 244 | if (sbinfo->max_blocks) |
| 245 | percpu_counter_add(&sbinfo->used_blocks, -freed); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | info->alloced -= freed; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 247 | inode->i_blocks -= freed * BLOCKS_PER_PAGE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 248 | shmem_unacct_blocks(info->flags, freed); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 249 | } |
| 250 | } |
| 251 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 252 | /* |
| 253 | * Replace item expected in radix tree by a new item, while holding tree lock. |
| 254 | */ |
| 255 | static int shmem_radix_tree_replace(struct address_space *mapping, |
| 256 | pgoff_t index, void *expected, void *replacement) |
| 257 | { |
| 258 | void **pslot; |
Johannes Weiner | 6dbaf22 | 2014-04-03 14:47:41 -0700 | [diff] [blame] | 259 | void *item; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 260 | |
| 261 | VM_BUG_ON(!expected); |
Johannes Weiner | 6dbaf22 | 2014-04-03 14:47:41 -0700 | [diff] [blame] | 262 | VM_BUG_ON(!replacement); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 263 | pslot = radix_tree_lookup_slot(&mapping->page_tree, index); |
Johannes Weiner | 6dbaf22 | 2014-04-03 14:47:41 -0700 | [diff] [blame] | 264 | if (!pslot) |
| 265 | return -ENOENT; |
| 266 | item = radix_tree_deref_slot_protected(pslot, &mapping->tree_lock); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 267 | if (item != expected) |
| 268 | return -ENOENT; |
Johannes Weiner | 6dbaf22 | 2014-04-03 14:47:41 -0700 | [diff] [blame] | 269 | radix_tree_replace_slot(pslot, replacement); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 270 | return 0; |
| 271 | } |
| 272 | |
| 273 | /* |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 274 | * Sometimes, before we decide whether to proceed or to fail, we must check |
| 275 | * that an entry was not already brought back from swap by a racing thread. |
| 276 | * |
| 277 | * Checking page is not enough: by the time a SwapCache page is locked, it |
| 278 | * might be reused, and again be SwapCache, using the same swap as before. |
| 279 | */ |
| 280 | static bool shmem_confirm_swap(struct address_space *mapping, |
| 281 | pgoff_t index, swp_entry_t swap) |
| 282 | { |
| 283 | void *item; |
| 284 | |
| 285 | rcu_read_lock(); |
| 286 | item = radix_tree_lookup(&mapping->page_tree, index); |
| 287 | rcu_read_unlock(); |
| 288 | return item == swp_to_radix_entry(swap); |
| 289 | } |
| 290 | |
| 291 | /* |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 292 | * Like add_to_page_cache_locked, but error if expected item has gone. |
| 293 | */ |
| 294 | static int shmem_add_to_page_cache(struct page *page, |
| 295 | struct address_space *mapping, |
Wang Sheng-Hui | fed400a | 2014-08-06 16:07:26 -0700 | [diff] [blame] | 296 | pgoff_t index, void *expected) |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 297 | { |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 298 | int error; |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 299 | |
Sasha Levin | 309381fea | 2014-01-23 15:52:54 -0800 | [diff] [blame] | 300 | VM_BUG_ON_PAGE(!PageLocked(page), page); |
| 301 | VM_BUG_ON_PAGE(!PageSwapBacked(page), page); |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 302 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 303 | get_page(page); |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 304 | page->mapping = mapping; |
| 305 | page->index = index; |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 306 | |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 307 | spin_lock_irq(&mapping->tree_lock); |
| 308 | if (!expected) |
| 309 | error = radix_tree_insert(&mapping->page_tree, index, page); |
| 310 | else |
| 311 | error = shmem_radix_tree_replace(mapping, index, expected, |
| 312 | page); |
| 313 | if (!error) { |
| 314 | mapping->nrpages++; |
| 315 | __inc_zone_page_state(page, NR_FILE_PAGES); |
| 316 | __inc_zone_page_state(page, NR_SHMEM); |
| 317 | spin_unlock_irq(&mapping->tree_lock); |
| 318 | } else { |
| 319 | page->mapping = NULL; |
| 320 | spin_unlock_irq(&mapping->tree_lock); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 321 | put_page(page); |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 322 | } |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 323 | return error; |
| 324 | } |
| 325 | |
| 326 | /* |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 327 | * Like delete_from_page_cache, but substitutes swap for page. |
| 328 | */ |
| 329 | static void shmem_delete_from_page_cache(struct page *page, void *radswap) |
| 330 | { |
| 331 | struct address_space *mapping = page->mapping; |
| 332 | int error; |
| 333 | |
| 334 | spin_lock_irq(&mapping->tree_lock); |
| 335 | error = shmem_radix_tree_replace(mapping, page->index, page, radswap); |
| 336 | page->mapping = NULL; |
| 337 | mapping->nrpages--; |
| 338 | __dec_zone_page_state(page, NR_FILE_PAGES); |
| 339 | __dec_zone_page_state(page, NR_SHMEM); |
| 340 | spin_unlock_irq(&mapping->tree_lock); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 341 | put_page(page); |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 342 | BUG_ON(error); |
| 343 | } |
| 344 | |
| 345 | /* |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 346 | * Remove swap entry from radix tree, free the swap and its page cache. |
| 347 | */ |
| 348 | static int shmem_free_swap(struct address_space *mapping, |
| 349 | pgoff_t index, void *radswap) |
| 350 | { |
Johannes Weiner | 6dbaf22 | 2014-04-03 14:47:41 -0700 | [diff] [blame] | 351 | void *old; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 352 | |
| 353 | spin_lock_irq(&mapping->tree_lock); |
Johannes Weiner | 6dbaf22 | 2014-04-03 14:47:41 -0700 | [diff] [blame] | 354 | old = radix_tree_delete_item(&mapping->page_tree, index, radswap); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 355 | spin_unlock_irq(&mapping->tree_lock); |
Johannes Weiner | 6dbaf22 | 2014-04-03 14:47:41 -0700 | [diff] [blame] | 356 | if (old != radswap) |
| 357 | return -ENOENT; |
| 358 | free_swap_and_cache(radix_to_swp_entry(radswap)); |
| 359 | return 0; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 360 | } |
| 361 | |
| 362 | /* |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 363 | * Determine (in bytes) how many of the shmem object's pages mapped by the |
Vlastimil Babka | 48131e0 | 2016-01-14 15:19:23 -0800 | [diff] [blame] | 364 | * given offsets are swapped out. |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 365 | * |
| 366 | * This is safe to call without i_mutex or mapping->tree_lock thanks to RCU, |
| 367 | * as long as the inode doesn't go away and racy results are not a problem. |
| 368 | */ |
Vlastimil Babka | 48131e0 | 2016-01-14 15:19:23 -0800 | [diff] [blame] | 369 | unsigned long shmem_partial_swap_usage(struct address_space *mapping, |
| 370 | pgoff_t start, pgoff_t end) |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 371 | { |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 372 | struct radix_tree_iter iter; |
| 373 | void **slot; |
| 374 | struct page *page; |
Vlastimil Babka | 48131e0 | 2016-01-14 15:19:23 -0800 | [diff] [blame] | 375 | unsigned long swapped = 0; |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 376 | |
| 377 | rcu_read_lock(); |
| 378 | |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 379 | radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) { |
| 380 | if (iter.index >= end) |
| 381 | break; |
| 382 | |
| 383 | page = radix_tree_deref_slot(slot); |
| 384 | |
Matthew Wilcox | 2cf938a | 2016-03-17 14:22:03 -0700 | [diff] [blame] | 385 | if (radix_tree_deref_retry(page)) { |
| 386 | slot = radix_tree_iter_retry(&iter); |
| 387 | continue; |
| 388 | } |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 389 | |
| 390 | if (radix_tree_exceptional_entry(page)) |
| 391 | swapped++; |
| 392 | |
| 393 | if (need_resched()) { |
| 394 | cond_resched_rcu(); |
Matthew Wilcox | 7165092 | 2016-03-17 14:22:06 -0700 | [diff] [blame] | 395 | slot = radix_tree_iter_next(&iter); |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 396 | } |
| 397 | } |
| 398 | |
| 399 | rcu_read_unlock(); |
| 400 | |
| 401 | return swapped << PAGE_SHIFT; |
| 402 | } |
| 403 | |
| 404 | /* |
Vlastimil Babka | 48131e0 | 2016-01-14 15:19:23 -0800 | [diff] [blame] | 405 | * Determine (in bytes) how many of the shmem object's pages mapped by the |
| 406 | * given vma is swapped out. |
| 407 | * |
| 408 | * This is safe to call without i_mutex or mapping->tree_lock thanks to RCU, |
| 409 | * as long as the inode doesn't go away and racy results are not a problem. |
| 410 | */ |
| 411 | unsigned long shmem_swap_usage(struct vm_area_struct *vma) |
| 412 | { |
| 413 | struct inode *inode = file_inode(vma->vm_file); |
| 414 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 415 | struct address_space *mapping = inode->i_mapping; |
| 416 | unsigned long swapped; |
| 417 | |
| 418 | /* Be careful as we don't hold info->lock */ |
| 419 | swapped = READ_ONCE(info->swapped); |
| 420 | |
| 421 | /* |
| 422 | * The easier cases are when the shmem object has nothing in swap, or |
| 423 | * the vma maps it whole. Then we can simply use the stats that we |
| 424 | * already track. |
| 425 | */ |
| 426 | if (!swapped) |
| 427 | return 0; |
| 428 | |
| 429 | if (!vma->vm_pgoff && vma->vm_end - vma->vm_start >= inode->i_size) |
| 430 | return swapped << PAGE_SHIFT; |
| 431 | |
| 432 | /* Here comes the more involved part */ |
| 433 | return shmem_partial_swap_usage(mapping, |
| 434 | linear_page_index(vma, vma->vm_start), |
| 435 | linear_page_index(vma, vma->vm_end)); |
| 436 | } |
| 437 | |
| 438 | /* |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 439 | * SysV IPC SHM_UNLOCK restore Unevictable pages to their evictable lists. |
| 440 | */ |
| 441 | void shmem_unlock_mapping(struct address_space *mapping) |
| 442 | { |
| 443 | struct pagevec pvec; |
| 444 | pgoff_t indices[PAGEVEC_SIZE]; |
| 445 | pgoff_t index = 0; |
| 446 | |
| 447 | pagevec_init(&pvec, 0); |
| 448 | /* |
| 449 | * Minor point, but we might as well stop if someone else SHM_LOCKs it. |
| 450 | */ |
| 451 | while (!mapping_unevictable(mapping)) { |
| 452 | /* |
| 453 | * Avoid pagevec_lookup(): find_get_pages() returns 0 as if it |
| 454 | * has finished, if it hits a row of PAGEVEC_SIZE swap entries. |
| 455 | */ |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 456 | pvec.nr = find_get_entries(mapping, index, |
| 457 | PAGEVEC_SIZE, pvec.pages, indices); |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 458 | if (!pvec.nr) |
| 459 | break; |
| 460 | index = indices[pvec.nr - 1] + 1; |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 461 | pagevec_remove_exceptionals(&pvec); |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 462 | check_move_unevictable_pages(pvec.pages, pvec.nr); |
| 463 | pagevec_release(&pvec); |
| 464 | cond_resched(); |
| 465 | } |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 466 | } |
| 467 | |
| 468 | /* |
| 469 | * Remove range of pages and swap entries from radix tree, and free them. |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 470 | * If !unfalloc, truncate or punch hole; if unfalloc, undo failed fallocate. |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 471 | */ |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 472 | static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, |
| 473 | bool unfalloc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 474 | { |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 475 | struct address_space *mapping = inode->i_mapping; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 476 | struct shmem_inode_info *info = SHMEM_I(inode); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 477 | pgoff_t start = (lstart + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 478 | pgoff_t end = (lend + 1) >> PAGE_SHIFT; |
| 479 | unsigned int partial_start = lstart & (PAGE_SIZE - 1); |
| 480 | unsigned int partial_end = (lend + 1) & (PAGE_SIZE - 1); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 481 | struct pagevec pvec; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 482 | pgoff_t indices[PAGEVEC_SIZE]; |
| 483 | long nr_swaps_freed = 0; |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 484 | pgoff_t index; |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 485 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 486 | |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 487 | if (lend == -1) |
| 488 | end = -1; /* unsigned, so actually very big */ |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 489 | |
| 490 | pagevec_init(&pvec, 0); |
| 491 | index = start; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 492 | while (index < end) { |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 493 | pvec.nr = find_get_entries(mapping, index, |
| 494 | min(end - index, (pgoff_t)PAGEVEC_SIZE), |
| 495 | pvec.pages, indices); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 496 | if (!pvec.nr) |
| 497 | break; |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 498 | for (i = 0; i < pagevec_count(&pvec); i++) { |
| 499 | struct page *page = pvec.pages[i]; |
| 500 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 501 | index = indices[i]; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 502 | if (index >= end) |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 503 | break; |
| 504 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 505 | if (radix_tree_exceptional_entry(page)) { |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 506 | if (unfalloc) |
| 507 | continue; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 508 | nr_swaps_freed += !shmem_free_swap(mapping, |
| 509 | index, page); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 510 | continue; |
| 511 | } |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 512 | |
| 513 | if (!trylock_page(page)) |
| 514 | continue; |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 515 | if (!unfalloc || !PageUptodate(page)) { |
| 516 | if (page->mapping == mapping) { |
Sasha Levin | 309381fea | 2014-01-23 15:52:54 -0800 | [diff] [blame] | 517 | VM_BUG_ON_PAGE(PageWriteback(page), page); |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 518 | truncate_inode_page(mapping, page); |
| 519 | } |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 520 | } |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 521 | unlock_page(page); |
| 522 | } |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 523 | pagevec_remove_exceptionals(&pvec); |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 524 | pagevec_release(&pvec); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 525 | cond_resched(); |
| 526 | index++; |
| 527 | } |
| 528 | |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 529 | if (partial_start) { |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 530 | struct page *page = NULL; |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 531 | shmem_getpage(inode, start - 1, &page, SGP_READ); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 532 | if (page) { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 533 | unsigned int top = PAGE_SIZE; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 534 | if (start > end) { |
| 535 | top = partial_end; |
| 536 | partial_end = 0; |
| 537 | } |
| 538 | zero_user_segment(page, partial_start, top); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 539 | set_page_dirty(page); |
| 540 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 541 | put_page(page); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 542 | } |
| 543 | } |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 544 | if (partial_end) { |
| 545 | struct page *page = NULL; |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 546 | shmem_getpage(inode, end, &page, SGP_READ); |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 547 | if (page) { |
| 548 | zero_user_segment(page, 0, partial_end); |
| 549 | set_page_dirty(page); |
| 550 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 551 | put_page(page); |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 552 | } |
| 553 | } |
| 554 | if (start >= end) |
| 555 | return; |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 556 | |
| 557 | index = start; |
Hugh Dickins | b1a3665 | 2014-07-23 14:00:13 -0700 | [diff] [blame] | 558 | while (index < end) { |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 559 | cond_resched(); |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 560 | |
| 561 | pvec.nr = find_get_entries(mapping, index, |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 562 | min(end - index, (pgoff_t)PAGEVEC_SIZE), |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 563 | pvec.pages, indices); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 564 | if (!pvec.nr) { |
Hugh Dickins | b1a3665 | 2014-07-23 14:00:13 -0700 | [diff] [blame] | 565 | /* If all gone or hole-punch or unfalloc, we're done */ |
| 566 | if (index == start || end != -1) |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 567 | break; |
Hugh Dickins | b1a3665 | 2014-07-23 14:00:13 -0700 | [diff] [blame] | 568 | /* But if truncating, restart to make sure all gone */ |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 569 | index = start; |
| 570 | continue; |
| 571 | } |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 572 | for (i = 0; i < pagevec_count(&pvec); i++) { |
| 573 | struct page *page = pvec.pages[i]; |
| 574 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 575 | index = indices[i]; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 576 | if (index >= end) |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 577 | break; |
| 578 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 579 | if (radix_tree_exceptional_entry(page)) { |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 580 | if (unfalloc) |
| 581 | continue; |
Hugh Dickins | b1a3665 | 2014-07-23 14:00:13 -0700 | [diff] [blame] | 582 | if (shmem_free_swap(mapping, index, page)) { |
| 583 | /* Swap was replaced by page: retry */ |
| 584 | index--; |
| 585 | break; |
| 586 | } |
| 587 | nr_swaps_freed++; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 588 | continue; |
| 589 | } |
| 590 | |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 591 | lock_page(page); |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 592 | if (!unfalloc || !PageUptodate(page)) { |
| 593 | if (page->mapping == mapping) { |
Sasha Levin | 309381fea | 2014-01-23 15:52:54 -0800 | [diff] [blame] | 594 | VM_BUG_ON_PAGE(PageWriteback(page), page); |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 595 | truncate_inode_page(mapping, page); |
Hugh Dickins | b1a3665 | 2014-07-23 14:00:13 -0700 | [diff] [blame] | 596 | } else { |
| 597 | /* Page was replaced by swap: retry */ |
| 598 | unlock_page(page); |
| 599 | index--; |
| 600 | break; |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 601 | } |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 602 | } |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 603 | unlock_page(page); |
| 604 | } |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 605 | pagevec_remove_exceptionals(&pvec); |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 606 | pagevec_release(&pvec); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 607 | index++; |
| 608 | } |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 609 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 610 | spin_lock(&info->lock); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 611 | info->swapped -= nr_swaps_freed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 612 | shmem_recalc_inode(inode); |
| 613 | spin_unlock(&info->lock); |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 614 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 615 | |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 616 | void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend) |
| 617 | { |
| 618 | shmem_undo_range(inode, lstart, lend, false); |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 619 | inode->i_ctime = inode->i_mtime = CURRENT_TIME; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 620 | } |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 621 | EXPORT_SYMBOL_GPL(shmem_truncate_range); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 622 | |
Yu Zhao | 44a3022 | 2015-09-08 15:03:33 -0700 | [diff] [blame] | 623 | static int shmem_getattr(struct vfsmount *mnt, struct dentry *dentry, |
| 624 | struct kstat *stat) |
| 625 | { |
| 626 | struct inode *inode = dentry->d_inode; |
| 627 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 628 | |
Hugh Dickins | d0424c4 | 2015-11-05 18:50:34 -0800 | [diff] [blame] | 629 | if (info->alloced - info->swapped != inode->i_mapping->nrpages) { |
| 630 | spin_lock(&info->lock); |
| 631 | shmem_recalc_inode(inode); |
| 632 | spin_unlock(&info->lock); |
| 633 | } |
Yu Zhao | 44a3022 | 2015-09-08 15:03:33 -0700 | [diff] [blame] | 634 | generic_fillattr(inode, stat); |
Yu Zhao | 44a3022 | 2015-09-08 15:03:33 -0700 | [diff] [blame] | 635 | return 0; |
| 636 | } |
| 637 | |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 638 | static int shmem_setattr(struct dentry *dentry, struct iattr *attr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 639 | { |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 640 | struct inode *inode = d_inode(dentry); |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 641 | struct shmem_inode_info *info = SHMEM_I(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 642 | int error; |
| 643 | |
Christoph Hellwig | db78b87 | 2010-06-04 11:30:03 +0200 | [diff] [blame] | 644 | error = inode_change_ok(inode, attr); |
| 645 | if (error) |
| 646 | return error; |
| 647 | |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 648 | if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) { |
| 649 | loff_t oldsize = inode->i_size; |
| 650 | loff_t newsize = attr->ia_size; |
npiggin@suse.de | 3889e6e | 2010-05-27 01:05:36 +1000 | [diff] [blame] | 651 | |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 652 | /* protected by i_mutex */ |
| 653 | if ((newsize < oldsize && (info->seals & F_SEAL_SHRINK)) || |
| 654 | (newsize > oldsize && (info->seals & F_SEAL_GROW))) |
| 655 | return -EPERM; |
| 656 | |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 657 | if (newsize != oldsize) { |
Konstantin Khlebnikov | 7714251 | 2014-08-06 16:06:34 -0700 | [diff] [blame] | 658 | error = shmem_reacct_size(SHMEM_I(inode)->flags, |
| 659 | oldsize, newsize); |
| 660 | if (error) |
| 661 | return error; |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 662 | i_size_write(inode, newsize); |
| 663 | inode->i_ctime = inode->i_mtime = CURRENT_TIME; |
| 664 | } |
Josef Bacik | afa2db2 | 2015-06-24 16:58:45 -0700 | [diff] [blame] | 665 | if (newsize <= oldsize) { |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 666 | loff_t holebegin = round_up(newsize, PAGE_SIZE); |
Hugh Dickins | d0424c4 | 2015-11-05 18:50:34 -0800 | [diff] [blame] | 667 | if (oldsize > holebegin) |
| 668 | unmap_mapping_range(inode->i_mapping, |
| 669 | holebegin, 0, 1); |
| 670 | if (info->alloced) |
| 671 | shmem_truncate_range(inode, |
| 672 | newsize, (loff_t)-1); |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 673 | /* unmap again to remove racily COWed private pages */ |
Hugh Dickins | d0424c4 | 2015-11-05 18:50:34 -0800 | [diff] [blame] | 674 | if (oldsize > holebegin) |
| 675 | unmap_mapping_range(inode->i_mapping, |
| 676 | holebegin, 0, 1); |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 677 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 678 | } |
| 679 | |
Christoph Hellwig | db78b87 | 2010-06-04 11:30:03 +0200 | [diff] [blame] | 680 | setattr_copy(inode, attr); |
Christoph Hellwig | db78b87 | 2010-06-04 11:30:03 +0200 | [diff] [blame] | 681 | if (attr->ia_valid & ATTR_MODE) |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 682 | error = posix_acl_chmod(inode, inode->i_mode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 683 | return error; |
| 684 | } |
| 685 | |
Al Viro | 1f895f7 | 2010-06-05 19:10:41 -0400 | [diff] [blame] | 686 | static void shmem_evict_inode(struct inode *inode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 687 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 688 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 689 | |
npiggin@suse.de | 3889e6e | 2010-05-27 01:05:36 +1000 | [diff] [blame] | 690 | if (inode->i_mapping->a_ops == &shmem_aops) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 691 | shmem_unacct_size(info->flags, inode->i_size); |
| 692 | inode->i_size = 0; |
npiggin@suse.de | 3889e6e | 2010-05-27 01:05:36 +1000 | [diff] [blame] | 693 | shmem_truncate_range(inode, 0, (loff_t)-1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 694 | if (!list_empty(&info->swaplist)) { |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 695 | mutex_lock(&shmem_swaplist_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 696 | list_del_init(&info->swaplist); |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 697 | mutex_unlock(&shmem_swaplist_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 698 | } |
Al Viro | 3ed47db | 2016-01-22 18:08:52 -0500 | [diff] [blame] | 699 | } |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 700 | |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 701 | simple_xattrs_free(&info->xattrs); |
Hugh Dickins | 0f3c42f | 2012-11-16 14:15:04 -0800 | [diff] [blame] | 702 | WARN_ON(inode->i_blocks); |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 703 | shmem_free_inode(inode->i_sb); |
Jan Kara | dbd5768 | 2012-05-03 14:48:02 +0200 | [diff] [blame] | 704 | clear_inode(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 705 | } |
| 706 | |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 707 | /* |
| 708 | * If swap found in inode, free it and move page from swapcache to filecache. |
| 709 | */ |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 710 | static int shmem_unuse_inode(struct shmem_inode_info *info, |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 711 | swp_entry_t swap, struct page **pagep) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 712 | { |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 713 | struct address_space *mapping = info->vfs_inode.i_mapping; |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 714 | void *radswap; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 715 | pgoff_t index; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 716 | gfp_t gfp; |
| 717 | int error = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 718 | |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 719 | radswap = swp_to_radix_entry(swap); |
Hugh Dickins | e504f3f | 2011-08-03 16:21:27 -0700 | [diff] [blame] | 720 | index = radix_tree_locate_item(&mapping->page_tree, radswap); |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 721 | if (index == -1) |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 722 | return -EAGAIN; /* tell shmem_unuse we found nothing */ |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 723 | |
Hugh Dickins | 1b1b32f | 2008-02-04 22:28:55 -0800 | [diff] [blame] | 724 | /* |
| 725 | * Move _head_ to start search for next from here. |
Al Viro | 1f895f7 | 2010-06-05 19:10:41 -0400 | [diff] [blame] | 726 | * But be careful: shmem_evict_inode checks list_empty without taking |
Hugh Dickins | 1b1b32f | 2008-02-04 22:28:55 -0800 | [diff] [blame] | 727 | * mutex, and there's an instant in list_move_tail when info->swaplist |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 728 | * would appear empty, if it were the only one on shmem_swaplist. |
Hugh Dickins | 1b1b32f | 2008-02-04 22:28:55 -0800 | [diff] [blame] | 729 | */ |
| 730 | if (shmem_swaplist.next != &info->swaplist) |
| 731 | list_move_tail(&shmem_swaplist, &info->swaplist); |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 732 | |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 733 | gfp = mapping_gfp_mask(mapping); |
| 734 | if (shmem_should_replace_page(*pagep, gfp)) { |
| 735 | mutex_unlock(&shmem_swaplist_mutex); |
| 736 | error = shmem_replace_page(pagep, gfp, info, index); |
| 737 | mutex_lock(&shmem_swaplist_mutex); |
| 738 | /* |
| 739 | * We needed to drop mutex to make that restrictive page |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 740 | * allocation, but the inode might have been freed while we |
| 741 | * dropped it: although a racing shmem_evict_inode() cannot |
| 742 | * complete without emptying the radix_tree, our page lock |
| 743 | * on this swapcache page is not enough to prevent that - |
| 744 | * free_swap_and_cache() of our swap entry will only |
| 745 | * trylock_page(), removing swap from radix_tree whatever. |
| 746 | * |
| 747 | * We must not proceed to shmem_add_to_page_cache() if the |
| 748 | * inode has been freed, but of course we cannot rely on |
| 749 | * inode or mapping or info to check that. However, we can |
| 750 | * safely check if our swap entry is still in use (and here |
| 751 | * it can't have got reused for another page): if it's still |
| 752 | * in use, then the inode cannot have been freed yet, and we |
| 753 | * can safely proceed (if it's no longer in use, that tells |
| 754 | * nothing about the inode, but we don't need to unuse swap). |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 755 | */ |
| 756 | if (!page_swapcount(*pagep)) |
| 757 | error = -ENOENT; |
| 758 | } |
| 759 | |
KAMEZAWA Hiroyuki | d13d144 | 2009-01-07 18:07:56 -0800 | [diff] [blame] | 760 | /* |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 761 | * We rely on shmem_swaplist_mutex, not only to protect the swaplist, |
| 762 | * but also to hold up shmem_evict_inode(): so inode cannot be freed |
| 763 | * beneath us (pagelock doesn't help until the page is in pagecache). |
KAMEZAWA Hiroyuki | d13d144 | 2009-01-07 18:07:56 -0800 | [diff] [blame] | 764 | */ |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 765 | if (!error) |
| 766 | error = shmem_add_to_page_cache(*pagep, mapping, index, |
Wang Sheng-Hui | fed400a | 2014-08-06 16:07:26 -0700 | [diff] [blame] | 767 | radswap); |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 768 | if (error != -ENOMEM) { |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 769 | /* |
| 770 | * Truncation and eviction use free_swap_and_cache(), which |
| 771 | * only does trylock page: if we raced, best clean up here. |
| 772 | */ |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 773 | delete_from_swap_cache(*pagep); |
| 774 | set_page_dirty(*pagep); |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 775 | if (!error) { |
| 776 | spin_lock(&info->lock); |
| 777 | info->swapped--; |
| 778 | spin_unlock(&info->lock); |
| 779 | swap_free(swap); |
| 780 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 781 | } |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 782 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 783 | } |
| 784 | |
| 785 | /* |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 786 | * Search through swapped inodes to find and replace swap by page. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 787 | */ |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 788 | int shmem_unuse(swp_entry_t swap, struct page *page) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 789 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 790 | struct list_head *this, *next; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 791 | struct shmem_inode_info *info; |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 792 | struct mem_cgroup *memcg; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 793 | int error = 0; |
| 794 | |
| 795 | /* |
| 796 | * There's a faint possibility that swap page was replaced before |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 797 | * caller locked it: caller will come back later with the right page. |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 798 | */ |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 799 | if (unlikely(!PageSwapCache(page) || page_private(page) != swap.val)) |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 800 | goto out; |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 801 | |
| 802 | /* |
| 803 | * Charge page using GFP_KERNEL while we can wait, before taking |
| 804 | * the shmem_swaplist_mutex which might hold up shmem_writepage(). |
| 805 | * Charged back to the user (not to caller) when swap account is used. |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 806 | */ |
Kirill A. Shutemov | f627c2f | 2016-01-15 16:52:20 -0800 | [diff] [blame] | 807 | error = mem_cgroup_try_charge(page, current->mm, GFP_KERNEL, &memcg, |
| 808 | false); |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 809 | if (error) |
| 810 | goto out; |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 811 | /* No radix_tree_preload: swap entry keeps a place for page in tree */ |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 812 | error = -EAGAIN; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 813 | |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 814 | mutex_lock(&shmem_swaplist_mutex); |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 815 | list_for_each_safe(this, next, &shmem_swaplist) { |
| 816 | info = list_entry(this, struct shmem_inode_info, swaplist); |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 817 | if (info->swapped) |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 818 | error = shmem_unuse_inode(info, swap, &page); |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 819 | else |
| 820 | list_del_init(&info->swaplist); |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 821 | cond_resched(); |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 822 | if (error != -EAGAIN) |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 823 | break; |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 824 | /* found nothing in this: move on to search the next */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 825 | } |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 826 | mutex_unlock(&shmem_swaplist_mutex); |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 827 | |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 828 | if (error) { |
| 829 | if (error != -ENOMEM) |
| 830 | error = 0; |
Kirill A. Shutemov | f627c2f | 2016-01-15 16:52:20 -0800 | [diff] [blame] | 831 | mem_cgroup_cancel_charge(page, memcg, false); |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 832 | } else |
Kirill A. Shutemov | f627c2f | 2016-01-15 16:52:20 -0800 | [diff] [blame] | 833 | mem_cgroup_commit_charge(page, memcg, true, false); |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 834 | out: |
Hugh Dickins | aaa4686 | 2009-12-14 17:58:47 -0800 | [diff] [blame] | 835 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 836 | put_page(page); |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 837 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 838 | } |
| 839 | |
| 840 | /* |
| 841 | * Move the page from the page cache to the swap cache. |
| 842 | */ |
| 843 | static int shmem_writepage(struct page *page, struct writeback_control *wbc) |
| 844 | { |
| 845 | struct shmem_inode_info *info; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 846 | struct address_space *mapping; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 847 | struct inode *inode; |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 848 | swp_entry_t swap; |
| 849 | pgoff_t index; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 850 | |
| 851 | BUG_ON(!PageLocked(page)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 852 | mapping = page->mapping; |
| 853 | index = page->index; |
| 854 | inode = mapping->host; |
| 855 | info = SHMEM_I(inode); |
| 856 | if (info->flags & VM_LOCKED) |
| 857 | goto redirty; |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 858 | if (!total_swap_pages) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 859 | goto redirty; |
| 860 | |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 861 | /* |
Christoph Hellwig | 97b713b | 2015-01-14 10:42:31 +0100 | [diff] [blame] | 862 | * Our capabilities prevent regular writeback or sync from ever calling |
| 863 | * shmem_writepage; but a stacking filesystem might use ->writepage of |
| 864 | * its underlying filesystem, in which case tmpfs should write out to |
| 865 | * swap only in response to memory pressure, and not for the writeback |
| 866 | * threads or sync. |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 867 | */ |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 868 | if (!wbc->for_reclaim) { |
| 869 | WARN_ON_ONCE(1); /* Still happens? Tell us about it! */ |
| 870 | goto redirty; |
| 871 | } |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 872 | |
| 873 | /* |
| 874 | * This is somewhat ridiculous, but without plumbing a SWAP_MAP_FALLOC |
| 875 | * value into swapfile.c, the only way we can correctly account for a |
| 876 | * fallocated page arriving here is now to initialize it and write it. |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 877 | * |
| 878 | * That's okay for a page already fallocated earlier, but if we have |
| 879 | * not yet completed the fallocation, then (a) we want to keep track |
| 880 | * of this page in case we have to undo it, and (b) it may not be a |
| 881 | * good idea to continue anyway, once we're pushing into swap. So |
| 882 | * reactivate the page, and let shmem_fallocate() quit when too many. |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 883 | */ |
| 884 | if (!PageUptodate(page)) { |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 885 | if (inode->i_private) { |
| 886 | struct shmem_falloc *shmem_falloc; |
| 887 | spin_lock(&inode->i_lock); |
| 888 | shmem_falloc = inode->i_private; |
| 889 | if (shmem_falloc && |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 890 | !shmem_falloc->waitq && |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 891 | index >= shmem_falloc->start && |
| 892 | index < shmem_falloc->next) |
| 893 | shmem_falloc->nr_unswapped++; |
| 894 | else |
| 895 | shmem_falloc = NULL; |
| 896 | spin_unlock(&inode->i_lock); |
| 897 | if (shmem_falloc) |
| 898 | goto redirty; |
| 899 | } |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 900 | clear_highpage(page); |
| 901 | flush_dcache_page(page); |
| 902 | SetPageUptodate(page); |
| 903 | } |
| 904 | |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 905 | swap = get_swap_page(); |
| 906 | if (!swap.val) |
| 907 | goto redirty; |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 908 | |
Vladimir Davydov | 37e8435 | 2016-01-20 15:02:56 -0800 | [diff] [blame] | 909 | if (mem_cgroup_try_charge_swap(page, swap)) |
| 910 | goto free_swap; |
| 911 | |
Hugh Dickins | b1dea80 | 2011-05-11 15:13:36 -0700 | [diff] [blame] | 912 | /* |
| 913 | * Add inode to shmem_unuse()'s list of swapped-out inodes, |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 914 | * if it's not already there. Do it now before the page is |
| 915 | * moved to swap cache, when its pagelock no longer protects |
Hugh Dickins | b1dea80 | 2011-05-11 15:13:36 -0700 | [diff] [blame] | 916 | * the inode from eviction. But don't unlock the mutex until |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 917 | * we've incremented swapped, because shmem_unuse_inode() will |
| 918 | * prune a !swapped inode from the swaplist under this mutex. |
Hugh Dickins | b1dea80 | 2011-05-11 15:13:36 -0700 | [diff] [blame] | 919 | */ |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 920 | mutex_lock(&shmem_swaplist_mutex); |
| 921 | if (list_empty(&info->swaplist)) |
| 922 | list_add_tail(&info->swaplist, &shmem_swaplist); |
Hugh Dickins | b1dea80 | 2011-05-11 15:13:36 -0700 | [diff] [blame] | 923 | |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 924 | if (add_to_swap_cache(page, swap, GFP_ATOMIC) == 0) { |
Hugh Dickins | 267a4c7 | 2015-12-11 13:40:55 -0800 | [diff] [blame] | 925 | spin_lock(&info->lock); |
| 926 | shmem_recalc_inode(inode); |
| 927 | info->swapped++; |
| 928 | spin_unlock(&info->lock); |
| 929 | |
Hugh Dickins | aaa4686 | 2009-12-14 17:58:47 -0800 | [diff] [blame] | 930 | swap_shmem_alloc(swap); |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 931 | shmem_delete_from_page_cache(page, swp_to_radix_entry(swap)); |
| 932 | |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 933 | mutex_unlock(&shmem_swaplist_mutex); |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 934 | BUG_ON(page_mapped(page)); |
Hugh Dickins | 9fab561 | 2009-03-31 15:23:33 -0700 | [diff] [blame] | 935 | swap_writepage(page, wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 936 | return 0; |
| 937 | } |
| 938 | |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 939 | mutex_unlock(&shmem_swaplist_mutex); |
Vladimir Davydov | 37e8435 | 2016-01-20 15:02:56 -0800 | [diff] [blame] | 940 | free_swap: |
Johannes Weiner | 0a31bc9 | 2014-08-08 14:19:22 -0700 | [diff] [blame] | 941 | swapcache_free(swap); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 942 | redirty: |
| 943 | set_page_dirty(page); |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 944 | if (wbc->for_reclaim) |
| 945 | return AOP_WRITEPAGE_ACTIVATE; /* Return with page locked */ |
| 946 | unlock_page(page); |
| 947 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 948 | } |
| 949 | |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 950 | #if defined(CONFIG_NUMA) && defined(CONFIG_TMPFS) |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 951 | static void shmem_show_mpol(struct seq_file *seq, struct mempolicy *mpol) |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 952 | { |
Lee Schermerhorn | 095f1fc | 2008-04-28 02:13:23 -0700 | [diff] [blame] | 953 | char buffer[64]; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 954 | |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 955 | if (!mpol || mpol->mode == MPOL_DEFAULT) |
Lee Schermerhorn | 095f1fc | 2008-04-28 02:13:23 -0700 | [diff] [blame] | 956 | return; /* show nothing */ |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 957 | |
Hugh Dickins | a7a88b2 | 2013-01-02 02:04:23 -0800 | [diff] [blame] | 958 | mpol_to_str(buffer, sizeof(buffer), mpol); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 959 | |
Lee Schermerhorn | 095f1fc | 2008-04-28 02:13:23 -0700 | [diff] [blame] | 960 | seq_printf(seq, ",mpol=%s", buffer); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 961 | } |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 962 | |
| 963 | static struct mempolicy *shmem_get_sbmpol(struct shmem_sb_info *sbinfo) |
| 964 | { |
| 965 | struct mempolicy *mpol = NULL; |
| 966 | if (sbinfo->mpol) { |
| 967 | spin_lock(&sbinfo->stat_lock); /* prevent replace/use races */ |
| 968 | mpol = sbinfo->mpol; |
| 969 | mpol_get(mpol); |
| 970 | spin_unlock(&sbinfo->stat_lock); |
| 971 | } |
| 972 | return mpol; |
| 973 | } |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 974 | #else /* !CONFIG_NUMA || !CONFIG_TMPFS */ |
| 975 | static inline void shmem_show_mpol(struct seq_file *seq, struct mempolicy *mpol) |
| 976 | { |
| 977 | } |
| 978 | static inline struct mempolicy *shmem_get_sbmpol(struct shmem_sb_info *sbinfo) |
| 979 | { |
| 980 | return NULL; |
| 981 | } |
| 982 | #endif /* CONFIG_NUMA && CONFIG_TMPFS */ |
| 983 | #ifndef CONFIG_NUMA |
| 984 | #define vm_policy vm_private_data |
| 985 | #endif |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 986 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 987 | static struct page *shmem_swapin(swp_entry_t swap, gfp_t gfp, |
| 988 | struct shmem_inode_info *info, pgoff_t index) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 989 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 990 | struct vm_area_struct pvma; |
Mel Gorman | 18a2f37 | 2012-12-05 14:01:41 -0800 | [diff] [blame] | 991 | struct page *page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 992 | |
Hugh Dickins | c4cc6d0 | 2008-02-04 22:28:40 -0800 | [diff] [blame] | 993 | /* Create a pseudo vma that just contains the policy */ |
| 994 | pvma.vm_start = 0; |
Nathan Zimmer | 09c231c | 2012-07-31 16:46:17 -0700 | [diff] [blame] | 995 | /* Bias interleave by inode number to distribute better across nodes */ |
| 996 | pvma.vm_pgoff = index + info->vfs_inode.i_ino; |
Hugh Dickins | c4cc6d0 | 2008-02-04 22:28:40 -0800 | [diff] [blame] | 997 | pvma.vm_ops = NULL; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 998 | pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, index); |
Lee Schermerhorn | 52cd3b0 | 2008-04-28 02:13:16 -0700 | [diff] [blame] | 999 | |
Mel Gorman | 18a2f37 | 2012-12-05 14:01:41 -0800 | [diff] [blame] | 1000 | page = swapin_readahead(swap, gfp, &pvma, 0); |
| 1001 | |
| 1002 | /* Drop reference taken by mpol_shared_policy_lookup() */ |
| 1003 | mpol_cond_put(pvma.vm_policy); |
| 1004 | |
| 1005 | return page; |
| 1006 | } |
| 1007 | |
| 1008 | static struct page *shmem_alloc_page(gfp_t gfp, |
| 1009 | struct shmem_inode_info *info, pgoff_t index) |
| 1010 | { |
| 1011 | struct vm_area_struct pvma; |
| 1012 | struct page *page; |
| 1013 | |
| 1014 | /* Create a pseudo vma that just contains the policy */ |
| 1015 | pvma.vm_start = 0; |
| 1016 | /* Bias interleave by inode number to distribute better across nodes */ |
| 1017 | pvma.vm_pgoff = index + info->vfs_inode.i_ino; |
| 1018 | pvma.vm_ops = NULL; |
| 1019 | pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, index); |
| 1020 | |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 1021 | page = alloc_pages_vma(gfp, 0, &pvma, 0, numa_node_id(), false); |
| 1022 | if (page) { |
| 1023 | __SetPageLocked(page); |
| 1024 | __SetPageSwapBacked(page); |
| 1025 | } |
Mel Gorman | 18a2f37 | 2012-12-05 14:01:41 -0800 | [diff] [blame] | 1026 | |
| 1027 | /* Drop reference taken by mpol_shared_policy_lookup() */ |
| 1028 | mpol_cond_put(pvma.vm_policy); |
| 1029 | |
| 1030 | return page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1031 | } |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 1032 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1033 | /* |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1034 | * When a page is moved from swapcache to shmem filecache (either by the |
| 1035 | * usual swapin of shmem_getpage_gfp(), or by the less common swapoff of |
| 1036 | * shmem_unuse_inode()), it may have been read in earlier from swap, in |
| 1037 | * ignorance of the mapping it belongs to. If that mapping has special |
| 1038 | * constraints (like the gma500 GEM driver, which requires RAM below 4GB), |
| 1039 | * we may need to copy to a suitable page before moving to filecache. |
| 1040 | * |
| 1041 | * In a future release, this may well be extended to respect cpuset and |
| 1042 | * NUMA mempolicy, and applied also to anonymous pages in do_swap_page(); |
| 1043 | * but for now it is a simple matter of zone. |
| 1044 | */ |
| 1045 | static bool shmem_should_replace_page(struct page *page, gfp_t gfp) |
| 1046 | { |
| 1047 | return page_zonenum(page) > gfp_zone(gfp); |
| 1048 | } |
| 1049 | |
| 1050 | static int shmem_replace_page(struct page **pagep, gfp_t gfp, |
| 1051 | struct shmem_inode_info *info, pgoff_t index) |
| 1052 | { |
| 1053 | struct page *oldpage, *newpage; |
| 1054 | struct address_space *swap_mapping; |
| 1055 | pgoff_t swap_index; |
| 1056 | int error; |
| 1057 | |
| 1058 | oldpage = *pagep; |
| 1059 | swap_index = page_private(oldpage); |
| 1060 | swap_mapping = page_mapping(oldpage); |
| 1061 | |
| 1062 | /* |
| 1063 | * We have arrived here because our zones are constrained, so don't |
| 1064 | * limit chance of success by further cpuset and node constraints. |
| 1065 | */ |
| 1066 | gfp &= ~GFP_CONSTRAINT_MASK; |
| 1067 | newpage = shmem_alloc_page(gfp, info, index); |
| 1068 | if (!newpage) |
| 1069 | return -ENOMEM; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1070 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1071 | get_page(newpage); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1072 | copy_highpage(newpage, oldpage); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1073 | flush_dcache_page(newpage); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1074 | |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1075 | SetPageUptodate(newpage); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1076 | set_page_private(newpage, swap_index); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1077 | SetPageSwapCache(newpage); |
| 1078 | |
| 1079 | /* |
| 1080 | * Our caller will very soon move newpage out of swapcache, but it's |
| 1081 | * a nice clean interface for us to replace oldpage by newpage there. |
| 1082 | */ |
| 1083 | spin_lock_irq(&swap_mapping->tree_lock); |
| 1084 | error = shmem_radix_tree_replace(swap_mapping, swap_index, oldpage, |
| 1085 | newpage); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1086 | if (!error) { |
| 1087 | __inc_zone_page_state(newpage, NR_FILE_PAGES); |
| 1088 | __dec_zone_page_state(oldpage, NR_FILE_PAGES); |
| 1089 | } |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1090 | spin_unlock_irq(&swap_mapping->tree_lock); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1091 | |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1092 | if (unlikely(error)) { |
| 1093 | /* |
| 1094 | * Is this possible? I think not, now that our callers check |
| 1095 | * both PageSwapCache and page_private after getting page lock; |
| 1096 | * but be defensive. Reverse old to newpage for clear and free. |
| 1097 | */ |
| 1098 | oldpage = newpage; |
| 1099 | } else { |
Johannes Weiner | 6a93ca8 | 2016-03-15 14:57:19 -0700 | [diff] [blame] | 1100 | mem_cgroup_migrate(oldpage, newpage); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1101 | lru_cache_add_anon(newpage); |
| 1102 | *pagep = newpage; |
| 1103 | } |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1104 | |
| 1105 | ClearPageSwapCache(oldpage); |
| 1106 | set_page_private(oldpage, 0); |
| 1107 | |
| 1108 | unlock_page(oldpage); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1109 | put_page(oldpage); |
| 1110 | put_page(oldpage); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1111 | return error; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1112 | } |
| 1113 | |
| 1114 | /* |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 1115 | * shmem_getpage_gfp - find page in cache, or get from swap, or allocate |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1116 | * |
| 1117 | * If we allocate a new one we do not mark it dirty. That's up to the |
| 1118 | * vm. If we swap it in we mark it dirty since we also free the swap |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1119 | * entry since a page cannot live in both the swap and page cache. |
| 1120 | * |
| 1121 | * fault_mm and fault_type are only supplied by shmem_fault: |
| 1122 | * otherwise they are NULL. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1123 | */ |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1124 | static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1125 | struct page **pagep, enum sgp_type sgp, gfp_t gfp, |
| 1126 | struct mm_struct *fault_mm, int *fault_type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1127 | { |
| 1128 | struct address_space *mapping = inode->i_mapping; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1129 | struct shmem_inode_info *info; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1130 | struct shmem_sb_info *sbinfo; |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1131 | struct mm_struct *charge_mm; |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 1132 | struct mem_cgroup *memcg; |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1133 | struct page *page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1134 | swp_entry_t swap; |
| 1135 | int error; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1136 | int once = 0; |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1137 | int alloced = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1138 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1139 | if (index > (MAX_LFS_FILESIZE >> PAGE_SHIFT)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1140 | return -EFBIG; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1141 | repeat: |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1142 | swap.val = 0; |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 1143 | page = find_lock_entry(mapping, index); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1144 | if (radix_tree_exceptional_entry(page)) { |
| 1145 | swap = radix_to_swp_entry(page); |
| 1146 | page = NULL; |
| 1147 | } |
| 1148 | |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 1149 | if (sgp <= SGP_CACHE && |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1150 | ((loff_t)index << PAGE_SHIFT) >= i_size_read(inode)) { |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1151 | error = -EINVAL; |
Hugh Dickins | 267a4c7 | 2015-12-11 13:40:55 -0800 | [diff] [blame] | 1152 | goto unlock; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1153 | } |
| 1154 | |
Hugh Dickins | 66d2f4d | 2014-07-02 15:22:38 -0700 | [diff] [blame] | 1155 | if (page && sgp == SGP_WRITE) |
| 1156 | mark_page_accessed(page); |
| 1157 | |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1158 | /* fallocated page? */ |
| 1159 | if (page && !PageUptodate(page)) { |
| 1160 | if (sgp != SGP_READ) |
| 1161 | goto clear; |
| 1162 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1163 | put_page(page); |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1164 | page = NULL; |
| 1165 | } |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1166 | if (page || (sgp == SGP_READ && !swap.val)) { |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1167 | *pagep = page; |
| 1168 | return 0; |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1169 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1170 | |
| 1171 | /* |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1172 | * Fast cache lookup did not find it: |
| 1173 | * bring it back from swap or allocate. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1174 | */ |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1175 | info = SHMEM_I(inode); |
| 1176 | sbinfo = SHMEM_SB(inode->i_sb); |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1177 | charge_mm = fault_mm ? : current->mm; |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1178 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1179 | if (swap.val) { |
| 1180 | /* Look it up and read it in.. */ |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1181 | page = lookup_swap_cache(swap); |
| 1182 | if (!page) { |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1183 | /* Or update major stats only when swapin succeeds?? */ |
| 1184 | if (fault_type) { |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 1185 | *fault_type |= VM_FAULT_MAJOR; |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1186 | count_vm_event(PGMAJFAULT); |
| 1187 | mem_cgroup_count_vm_event(fault_mm, PGMAJFAULT); |
| 1188 | } |
| 1189 | /* Here we actually start the io */ |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1190 | page = shmem_swapin(swap, gfp, info, index); |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1191 | if (!page) { |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1192 | error = -ENOMEM; |
| 1193 | goto failed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1194 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1195 | } |
| 1196 | |
| 1197 | /* We have to do this with page locked to prevent races */ |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1198 | lock_page(page); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1199 | if (!PageSwapCache(page) || page_private(page) != swap.val || |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1200 | !shmem_confirm_swap(mapping, index, swap)) { |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1201 | error = -EEXIST; /* try again */ |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1202 | goto unlock; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1203 | } |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1204 | if (!PageUptodate(page)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1205 | error = -EIO; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1206 | goto failed; |
| 1207 | } |
| 1208 | wait_on_page_writeback(page); |
| 1209 | |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1210 | if (shmem_should_replace_page(page, gfp)) { |
| 1211 | error = shmem_replace_page(&page, gfp, info, index); |
| 1212 | if (error) |
| 1213 | goto failed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1214 | } |
| 1215 | |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1216 | error = mem_cgroup_try_charge(page, charge_mm, gfp, &memcg, |
Kirill A. Shutemov | f627c2f | 2016-01-15 16:52:20 -0800 | [diff] [blame] | 1217 | false); |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1218 | if (!error) { |
Hugh Dickins | aa3b189 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1219 | error = shmem_add_to_page_cache(page, mapping, index, |
Wang Sheng-Hui | fed400a | 2014-08-06 16:07:26 -0700 | [diff] [blame] | 1220 | swp_to_radix_entry(swap)); |
Hugh Dickins | 215c02b | 2012-11-16 14:15:03 -0800 | [diff] [blame] | 1221 | /* |
| 1222 | * We already confirmed swap under page lock, and make |
| 1223 | * no memory allocation here, so usually no possibility |
| 1224 | * of error; but free_swap_and_cache() only trylocks a |
| 1225 | * page, so it is just possible that the entry has been |
| 1226 | * truncated or holepunched since swap was confirmed. |
| 1227 | * shmem_undo_range() will have done some of the |
| 1228 | * unaccounting, now delete_from_swap_cache() will do |
Vladimir Davydov | 93aa7d9 | 2015-02-11 15:24:59 -0800 | [diff] [blame] | 1229 | * the rest. |
Hugh Dickins | 215c02b | 2012-11-16 14:15:03 -0800 | [diff] [blame] | 1230 | * Reset swap.val? No, leave it so "failed" goes back to |
| 1231 | * "repeat": reading a hole and writing should succeed. |
| 1232 | */ |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 1233 | if (error) { |
Kirill A. Shutemov | f627c2f | 2016-01-15 16:52:20 -0800 | [diff] [blame] | 1234 | mem_cgroup_cancel_charge(page, memcg, false); |
Hugh Dickins | 215c02b | 2012-11-16 14:15:03 -0800 | [diff] [blame] | 1235 | delete_from_swap_cache(page); |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 1236 | } |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1237 | } |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1238 | if (error) |
| 1239 | goto failed; |
| 1240 | |
Kirill A. Shutemov | f627c2f | 2016-01-15 16:52:20 -0800 | [diff] [blame] | 1241 | mem_cgroup_commit_charge(page, memcg, true, false); |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 1242 | |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1243 | spin_lock(&info->lock); |
| 1244 | info->swapped--; |
| 1245 | shmem_recalc_inode(inode); |
| 1246 | spin_unlock(&info->lock); |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1247 | |
Hugh Dickins | 66d2f4d | 2014-07-02 15:22:38 -0700 | [diff] [blame] | 1248 | if (sgp == SGP_WRITE) |
| 1249 | mark_page_accessed(page); |
| 1250 | |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1251 | delete_from_swap_cache(page); |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1252 | set_page_dirty(page); |
| 1253 | swap_free(swap); |
| 1254 | |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1255 | } else { |
| 1256 | if (shmem_acct_block(info->flags)) { |
| 1257 | error = -ENOSPC; |
| 1258 | goto failed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1259 | } |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 1260 | if (sbinfo->max_blocks) { |
Hugh Dickins | fc5da22 | 2011-04-14 15:22:07 -0700 | [diff] [blame] | 1261 | if (percpu_counter_compare(&sbinfo->used_blocks, |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1262 | sbinfo->max_blocks) >= 0) { |
| 1263 | error = -ENOSPC; |
| 1264 | goto unacct; |
| 1265 | } |
Tim Chen | 7e49629 | 2010-08-09 17:19:05 -0700 | [diff] [blame] | 1266 | percpu_counter_inc(&sbinfo->used_blocks); |
Hugh Dickins | 59a16ea | 2011-05-11 15:13:38 -0700 | [diff] [blame] | 1267 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1268 | |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1269 | page = shmem_alloc_page(gfp, info, index); |
| 1270 | if (!page) { |
| 1271 | error = -ENOMEM; |
| 1272 | goto decused; |
| 1273 | } |
Hugh Dickins | 66d2f4d | 2014-07-02 15:22:38 -0700 | [diff] [blame] | 1274 | if (sgp == SGP_WRITE) |
Hugh Dickins | eb39d61 | 2014-08-06 16:06:43 -0700 | [diff] [blame] | 1275 | __SetPageReferenced(page); |
Hugh Dickins | 66d2f4d | 2014-07-02 15:22:38 -0700 | [diff] [blame] | 1276 | |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1277 | error = mem_cgroup_try_charge(page, charge_mm, gfp, &memcg, |
Kirill A. Shutemov | f627c2f | 2016-01-15 16:52:20 -0800 | [diff] [blame] | 1278 | false); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1279 | if (error) |
| 1280 | goto decused; |
Jan Kara | 5e4c0d97 | 2013-09-11 14:26:05 -0700 | [diff] [blame] | 1281 | error = radix_tree_maybe_preload(gfp & GFP_RECLAIM_MASK); |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 1282 | if (!error) { |
| 1283 | error = shmem_add_to_page_cache(page, mapping, index, |
Wang Sheng-Hui | fed400a | 2014-08-06 16:07:26 -0700 | [diff] [blame] | 1284 | NULL); |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 1285 | radix_tree_preload_end(); |
| 1286 | } |
| 1287 | if (error) { |
Kirill A. Shutemov | f627c2f | 2016-01-15 16:52:20 -0800 | [diff] [blame] | 1288 | mem_cgroup_cancel_charge(page, memcg, false); |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 1289 | goto decused; |
| 1290 | } |
Kirill A. Shutemov | f627c2f | 2016-01-15 16:52:20 -0800 | [diff] [blame] | 1291 | mem_cgroup_commit_charge(page, memcg, false, false); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1292 | lru_cache_add_anon(page); |
| 1293 | |
| 1294 | spin_lock(&info->lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1295 | info->alloced++; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1296 | inode->i_blocks += BLOCKS_PER_PAGE; |
| 1297 | shmem_recalc_inode(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1298 | spin_unlock(&info->lock); |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1299 | alloced = true; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1300 | |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 1301 | /* |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1302 | * Let SGP_FALLOC use the SGP_WRITE optimization on a new page. |
| 1303 | */ |
| 1304 | if (sgp == SGP_FALLOC) |
| 1305 | sgp = SGP_WRITE; |
| 1306 | clear: |
| 1307 | /* |
| 1308 | * Let SGP_WRITE caller clear ends if write does not fill page; |
| 1309 | * but SGP_FALLOC on a page fallocated earlier must initialize |
| 1310 | * it now, lest undo on failure cancel our earlier guarantee. |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 1311 | */ |
| 1312 | if (sgp != SGP_WRITE) { |
| 1313 | clear_highpage(page); |
| 1314 | flush_dcache_page(page); |
| 1315 | SetPageUptodate(page); |
| 1316 | } |
Hugh Dickins | 59a16ea | 2011-05-11 15:13:38 -0700 | [diff] [blame] | 1317 | } |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1318 | |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1319 | /* Perhaps the file has been truncated since we checked */ |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 1320 | if (sgp <= SGP_CACHE && |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1321 | ((loff_t)index << PAGE_SHIFT) >= i_size_read(inode)) { |
Hugh Dickins | 267a4c7 | 2015-12-11 13:40:55 -0800 | [diff] [blame] | 1322 | if (alloced) { |
| 1323 | ClearPageDirty(page); |
| 1324 | delete_from_page_cache(page); |
| 1325 | spin_lock(&info->lock); |
| 1326 | shmem_recalc_inode(inode); |
| 1327 | spin_unlock(&info->lock); |
| 1328 | } |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1329 | error = -EINVAL; |
Hugh Dickins | 267a4c7 | 2015-12-11 13:40:55 -0800 | [diff] [blame] | 1330 | goto unlock; |
Shaohua Li | ff36b801 | 2010-08-09 17:19:06 -0700 | [diff] [blame] | 1331 | } |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1332 | *pagep = page; |
| 1333 | return 0; |
Nick Piggin | d00806b | 2007-07-19 01:46:57 -0700 | [diff] [blame] | 1334 | |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 1335 | /* |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1336 | * Error recovery. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1337 | */ |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1338 | decused: |
| 1339 | if (sbinfo->max_blocks) |
| 1340 | percpu_counter_add(&sbinfo->used_blocks, -1); |
| 1341 | unacct: |
| 1342 | shmem_unacct_blocks(info->flags, 1); |
| 1343 | failed: |
Hugh Dickins | 267a4c7 | 2015-12-11 13:40:55 -0800 | [diff] [blame] | 1344 | if (swap.val && !shmem_confirm_swap(mapping, index, swap)) |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1345 | error = -EEXIST; |
| 1346 | unlock: |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1347 | if (page) { |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1348 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1349 | put_page(page); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1350 | } |
| 1351 | if (error == -ENOSPC && !once++) { |
| 1352 | info = SHMEM_I(inode); |
| 1353 | spin_lock(&info->lock); |
| 1354 | shmem_recalc_inode(inode); |
| 1355 | spin_unlock(&info->lock); |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1356 | goto repeat; |
Josef "Jeff" Sipek | d3ac7f8 | 2006-12-08 02:36:44 -0800 | [diff] [blame] | 1357 | } |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1358 | if (error == -EEXIST) /* from above or from radix_tree_insert */ |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1359 | goto repeat; |
| 1360 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1361 | } |
| 1362 | |
| 1363 | static int shmem_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
| 1364 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 1365 | struct inode *inode = file_inode(vma->vm_file); |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1366 | gfp_t gfp = mapping_gfp_mask(inode->i_mapping); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1367 | int error; |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 1368 | int ret = VM_FAULT_LOCKED; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1369 | |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 1370 | /* |
| 1371 | * Trinity finds that probing a hole which tmpfs is punching can |
| 1372 | * prevent the hole-punch from ever completing: which in turn |
| 1373 | * locks writers out with its hold on i_mutex. So refrain from |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 1374 | * faulting pages into the hole while it's being punched. Although |
| 1375 | * shmem_undo_range() does remove the additions, it may be unable to |
| 1376 | * keep up, as each new page needs its own unmap_mapping_range() call, |
| 1377 | * and the i_mmap tree grows ever slower to scan if new vmas are added. |
| 1378 | * |
| 1379 | * It does not matter if we sometimes reach this check just before the |
| 1380 | * hole-punch begins, so that one fault then races with the punch: |
| 1381 | * we just need to make racing faults a rare case. |
| 1382 | * |
| 1383 | * The implementation below would be much simpler if we just used a |
| 1384 | * standard mutex or completion: but we cannot take i_mutex in fault, |
| 1385 | * and bloating every shmem inode for this unlikely case would be sad. |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 1386 | */ |
| 1387 | if (unlikely(inode->i_private)) { |
| 1388 | struct shmem_falloc *shmem_falloc; |
| 1389 | |
| 1390 | spin_lock(&inode->i_lock); |
| 1391 | shmem_falloc = inode->i_private; |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 1392 | if (shmem_falloc && |
| 1393 | shmem_falloc->waitq && |
| 1394 | vmf->pgoff >= shmem_falloc->start && |
| 1395 | vmf->pgoff < shmem_falloc->next) { |
| 1396 | wait_queue_head_t *shmem_falloc_waitq; |
| 1397 | DEFINE_WAIT(shmem_fault_wait); |
| 1398 | |
| 1399 | ret = VM_FAULT_NOPAGE; |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 1400 | if ((vmf->flags & FAULT_FLAG_ALLOW_RETRY) && |
| 1401 | !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) { |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 1402 | /* It's polite to up mmap_sem if we can */ |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 1403 | up_read(&vma->vm_mm->mmap_sem); |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 1404 | ret = VM_FAULT_RETRY; |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 1405 | } |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 1406 | |
| 1407 | shmem_falloc_waitq = shmem_falloc->waitq; |
| 1408 | prepare_to_wait(shmem_falloc_waitq, &shmem_fault_wait, |
| 1409 | TASK_UNINTERRUPTIBLE); |
| 1410 | spin_unlock(&inode->i_lock); |
| 1411 | schedule(); |
| 1412 | |
| 1413 | /* |
| 1414 | * shmem_falloc_waitq points into the shmem_fallocate() |
| 1415 | * stack of the hole-punching task: shmem_falloc_waitq |
| 1416 | * is usually invalid by the time we reach here, but |
| 1417 | * finish_wait() does not dereference it in that case; |
| 1418 | * though i_lock needed lest racing with wake_up_all(). |
| 1419 | */ |
| 1420 | spin_lock(&inode->i_lock); |
| 1421 | finish_wait(shmem_falloc_waitq, &shmem_fault_wait); |
| 1422 | spin_unlock(&inode->i_lock); |
| 1423 | return ret; |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 1424 | } |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 1425 | spin_unlock(&inode->i_lock); |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 1426 | } |
| 1427 | |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1428 | error = shmem_getpage_gfp(inode, vmf->pgoff, &vmf->page, SGP_CACHE, |
| 1429 | gfp, vma->vm_mm, &ret); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1430 | if (error) |
| 1431 | return ((error == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 1432 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1433 | } |
| 1434 | |
| 1435 | #ifdef CONFIG_NUMA |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1436 | static int shmem_set_policy(struct vm_area_struct *vma, struct mempolicy *mpol) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1437 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 1438 | struct inode *inode = file_inode(vma->vm_file); |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1439 | return mpol_set_shared_policy(&SHMEM_I(inode)->policy, vma, mpol); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1440 | } |
| 1441 | |
Adrian Bunk | d8dc74f | 2007-10-16 01:26:26 -0700 | [diff] [blame] | 1442 | static struct mempolicy *shmem_get_policy(struct vm_area_struct *vma, |
| 1443 | unsigned long addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1444 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 1445 | struct inode *inode = file_inode(vma->vm_file); |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1446 | pgoff_t index; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1447 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1448 | index = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; |
| 1449 | return mpol_shared_policy_lookup(&SHMEM_I(inode)->policy, index); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1450 | } |
| 1451 | #endif |
| 1452 | |
| 1453 | int shmem_lock(struct file *file, int lock, struct user_struct *user) |
| 1454 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 1455 | struct inode *inode = file_inode(file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1456 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 1457 | int retval = -ENOMEM; |
| 1458 | |
| 1459 | spin_lock(&info->lock); |
| 1460 | if (lock && !(info->flags & VM_LOCKED)) { |
| 1461 | if (!user_shm_lock(inode->i_size, user)) |
| 1462 | goto out_nomem; |
| 1463 | info->flags |= VM_LOCKED; |
Lee Schermerhorn | 89e004ea | 2008-10-18 20:26:43 -0700 | [diff] [blame] | 1464 | mapping_set_unevictable(file->f_mapping); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1465 | } |
| 1466 | if (!lock && (info->flags & VM_LOCKED) && user) { |
| 1467 | user_shm_unlock(inode->i_size, user); |
| 1468 | info->flags &= ~VM_LOCKED; |
Lee Schermerhorn | 89e004ea | 2008-10-18 20:26:43 -0700 | [diff] [blame] | 1469 | mapping_clear_unevictable(file->f_mapping); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1470 | } |
| 1471 | retval = 0; |
Lee Schermerhorn | 89e004ea | 2008-10-18 20:26:43 -0700 | [diff] [blame] | 1472 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1473 | out_nomem: |
| 1474 | spin_unlock(&info->lock); |
| 1475 | return retval; |
| 1476 | } |
| 1477 | |
Adrian Bunk | 9b83a6a | 2007-02-28 20:11:03 -0800 | [diff] [blame] | 1478 | static int shmem_mmap(struct file *file, struct vm_area_struct *vma) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1479 | { |
| 1480 | file_accessed(file); |
| 1481 | vma->vm_ops = &shmem_vm_ops; |
| 1482 | return 0; |
| 1483 | } |
| 1484 | |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 1485 | static struct inode *shmem_get_inode(struct super_block *sb, const struct inode *dir, |
Al Viro | 09208d1 | 2011-07-26 03:15:03 -0400 | [diff] [blame] | 1486 | umode_t mode, dev_t dev, unsigned long flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1487 | { |
| 1488 | struct inode *inode; |
| 1489 | struct shmem_inode_info *info; |
| 1490 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 1491 | |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 1492 | if (shmem_reserve_inode(sb)) |
| 1493 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1494 | |
| 1495 | inode = new_inode(sb); |
| 1496 | if (inode) { |
Christoph Hellwig | 85fe402 | 2010-10-23 11:19:54 -0400 | [diff] [blame] | 1497 | inode->i_ino = get_next_ino(); |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 1498 | inode_init_owner(inode, dir, mode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1499 | inode->i_blocks = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1500 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 1501 | inode->i_generation = get_seconds(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1502 | info = SHMEM_I(inode); |
| 1503 | memset(info, 0, (char *)inode - (char *)info); |
| 1504 | spin_lock_init(&info->lock); |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 1505 | info->seals = F_SEAL_SEAL; |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 1506 | info->flags = flags & VM_NORESERVE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1507 | INIT_LIST_HEAD(&info->swaplist); |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 1508 | simple_xattrs_init(&info->xattrs); |
Al Viro | 72c0490 | 2009-06-24 16:58:48 -0400 | [diff] [blame] | 1509 | cache_no_acl(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1510 | |
| 1511 | switch (mode & S_IFMT) { |
| 1512 | default: |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 1513 | inode->i_op = &shmem_special_inode_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1514 | init_special_inode(inode, mode, dev); |
| 1515 | break; |
| 1516 | case S_IFREG: |
Hugh Dickins | 14fcc23 | 2008-07-28 15:46:19 -0700 | [diff] [blame] | 1517 | inode->i_mapping->a_ops = &shmem_aops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1518 | inode->i_op = &shmem_inode_operations; |
| 1519 | inode->i_fop = &shmem_file_operations; |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 1520 | mpol_shared_policy_init(&info->policy, |
| 1521 | shmem_get_sbmpol(sbinfo)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1522 | break; |
| 1523 | case S_IFDIR: |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 1524 | inc_nlink(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1525 | /* Some things misbehave if size == 0 on a directory */ |
| 1526 | inode->i_size = 2 * BOGO_DIRENT_SIZE; |
| 1527 | inode->i_op = &shmem_dir_inode_operations; |
| 1528 | inode->i_fop = &simple_dir_operations; |
| 1529 | break; |
| 1530 | case S_IFLNK: |
| 1531 | /* |
| 1532 | * Must not load anything in the rbtree, |
| 1533 | * mpol_free_shared_policy will not be called. |
| 1534 | */ |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 1535 | mpol_shared_policy_init(&info->policy, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1536 | break; |
| 1537 | } |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 1538 | } else |
| 1539 | shmem_free_inode(sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1540 | return inode; |
| 1541 | } |
| 1542 | |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 1543 | bool shmem_mapping(struct address_space *mapping) |
| 1544 | { |
Sasha Levin | f0774d8 | 2015-02-23 05:38:00 -0500 | [diff] [blame] | 1545 | if (!mapping->host) |
| 1546 | return false; |
| 1547 | |
Christoph Hellwig | 97b713b | 2015-01-14 10:42:31 +0100 | [diff] [blame] | 1548 | return mapping->host->i_sb->s_op == &shmem_ops; |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 1549 | } |
| 1550 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1551 | #ifdef CONFIG_TMPFS |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 1552 | static const struct inode_operations shmem_symlink_inode_operations; |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 1553 | static const struct inode_operations shmem_short_symlink_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1554 | |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 1555 | #ifdef CONFIG_TMPFS_XATTR |
| 1556 | static int shmem_initxattrs(struct inode *, const struct xattr *, void *); |
| 1557 | #else |
| 1558 | #define shmem_initxattrs NULL |
| 1559 | #endif |
| 1560 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1561 | static int |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1562 | shmem_write_begin(struct file *file, struct address_space *mapping, |
| 1563 | loff_t pos, unsigned len, unsigned flags, |
| 1564 | struct page **pagep, void **fsdata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1565 | { |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1566 | struct inode *inode = mapping->host; |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 1567 | struct shmem_inode_info *info = SHMEM_I(inode); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1568 | pgoff_t index = pos >> PAGE_SHIFT; |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 1569 | |
| 1570 | /* i_mutex is held by caller */ |
| 1571 | if (unlikely(info->seals)) { |
| 1572 | if (info->seals & F_SEAL_WRITE) |
| 1573 | return -EPERM; |
| 1574 | if ((info->seals & F_SEAL_GROW) && pos + len > inode->i_size) |
| 1575 | return -EPERM; |
| 1576 | } |
| 1577 | |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1578 | return shmem_getpage(inode, index, pagep, SGP_WRITE); |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1579 | } |
| 1580 | |
| 1581 | static int |
| 1582 | shmem_write_end(struct file *file, struct address_space *mapping, |
| 1583 | loff_t pos, unsigned len, unsigned copied, |
| 1584 | struct page *page, void *fsdata) |
| 1585 | { |
| 1586 | struct inode *inode = mapping->host; |
| 1587 | |
Hugh Dickins | d360244 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 1588 | if (pos + copied > inode->i_size) |
| 1589 | i_size_write(inode, pos + copied); |
| 1590 | |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 1591 | if (!PageUptodate(page)) { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1592 | if (copied < PAGE_SIZE) { |
| 1593 | unsigned from = pos & (PAGE_SIZE - 1); |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 1594 | zero_user_segments(page, 0, from, |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1595 | from + copied, PAGE_SIZE); |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 1596 | } |
| 1597 | SetPageUptodate(page); |
| 1598 | } |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1599 | set_page_dirty(page); |
Wu Fengguang | 6746aff | 2009-09-16 11:50:14 +0200 | [diff] [blame] | 1600 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1601 | put_page(page); |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1602 | |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1603 | return copied; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1604 | } |
| 1605 | |
Al Viro | 2ba5bbe | 2014-04-02 20:00:02 -0400 | [diff] [blame] | 1606 | static ssize_t shmem_file_read_iter(struct kiocb *iocb, struct iov_iter *to) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1607 | { |
Al Viro | 6e58e79 | 2014-02-03 17:07:03 -0500 | [diff] [blame] | 1608 | struct file *file = iocb->ki_filp; |
| 1609 | struct inode *inode = file_inode(file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1610 | struct address_space *mapping = inode->i_mapping; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1611 | pgoff_t index; |
| 1612 | unsigned long offset; |
Hugh Dickins | a0ee5ec | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1613 | enum sgp_type sgp = SGP_READ; |
Geert Uytterhoeven | f7c1d07 | 2014-04-13 20:46:22 +0200 | [diff] [blame] | 1614 | int error = 0; |
Al Viro | cb66a7a | 2014-03-04 15:24:06 -0500 | [diff] [blame] | 1615 | ssize_t retval = 0; |
Al Viro | 6e58e79 | 2014-02-03 17:07:03 -0500 | [diff] [blame] | 1616 | loff_t *ppos = &iocb->ki_pos; |
Hugh Dickins | a0ee5ec | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1617 | |
| 1618 | /* |
| 1619 | * Might this read be for a stacking filesystem? Then when reading |
| 1620 | * holes of a sparse file, we actually need to allocate those pages, |
| 1621 | * and even mark them dirty, so it cannot exceed the max_blocks limit. |
| 1622 | */ |
Al Viro | 777eda2 | 2014-12-17 04:46:46 -0500 | [diff] [blame] | 1623 | if (!iter_is_iovec(to)) |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 1624 | sgp = SGP_CACHE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1625 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1626 | index = *ppos >> PAGE_SHIFT; |
| 1627 | offset = *ppos & ~PAGE_MASK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1628 | |
| 1629 | for (;;) { |
| 1630 | struct page *page = NULL; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1631 | pgoff_t end_index; |
| 1632 | unsigned long nr, ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1633 | loff_t i_size = i_size_read(inode); |
| 1634 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1635 | end_index = i_size >> PAGE_SHIFT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1636 | if (index > end_index) |
| 1637 | break; |
| 1638 | if (index == end_index) { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1639 | nr = i_size & ~PAGE_MASK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1640 | if (nr <= offset) |
| 1641 | break; |
| 1642 | } |
| 1643 | |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1644 | error = shmem_getpage(inode, index, &page, sgp); |
Al Viro | 6e58e79 | 2014-02-03 17:07:03 -0500 | [diff] [blame] | 1645 | if (error) { |
| 1646 | if (error == -EINVAL) |
| 1647 | error = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1648 | break; |
| 1649 | } |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 1650 | if (page) { |
| 1651 | if (sgp == SGP_CACHE) |
| 1652 | set_page_dirty(page); |
Hugh Dickins | d360244 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 1653 | unlock_page(page); |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 1654 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1655 | |
| 1656 | /* |
| 1657 | * We must evaluate after, since reads (unlike writes) |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 1658 | * are called without i_mutex protection against truncate |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1659 | */ |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1660 | nr = PAGE_SIZE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1661 | i_size = i_size_read(inode); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1662 | end_index = i_size >> PAGE_SHIFT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1663 | if (index == end_index) { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1664 | nr = i_size & ~PAGE_MASK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1665 | if (nr <= offset) { |
| 1666 | if (page) |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1667 | put_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1668 | break; |
| 1669 | } |
| 1670 | } |
| 1671 | nr -= offset; |
| 1672 | |
| 1673 | if (page) { |
| 1674 | /* |
| 1675 | * If users can be writing to this page using arbitrary |
| 1676 | * virtual addresses, take care about potential aliasing |
| 1677 | * before reading the page on the kernel side. |
| 1678 | */ |
| 1679 | if (mapping_writably_mapped(mapping)) |
| 1680 | flush_dcache_page(page); |
| 1681 | /* |
| 1682 | * Mark the page accessed if we read the beginning. |
| 1683 | */ |
| 1684 | if (!offset) |
| 1685 | mark_page_accessed(page); |
Nick Piggin | b581003 | 2005-10-29 18:16:12 -0700 | [diff] [blame] | 1686 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1687 | page = ZERO_PAGE(0); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1688 | get_page(page); |
Nick Piggin | b581003 | 2005-10-29 18:16:12 -0700 | [diff] [blame] | 1689 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1690 | |
| 1691 | /* |
| 1692 | * Ok, we have the page, and it's up-to-date, so |
| 1693 | * now we can copy it to user space... |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1694 | */ |
Al Viro | 2ba5bbe | 2014-04-02 20:00:02 -0400 | [diff] [blame] | 1695 | ret = copy_page_to_iter(page, offset, nr, to); |
Al Viro | 6e58e79 | 2014-02-03 17:07:03 -0500 | [diff] [blame] | 1696 | retval += ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1697 | offset += ret; |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1698 | index += offset >> PAGE_SHIFT; |
| 1699 | offset &= ~PAGE_MASK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1700 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1701 | put_page(page); |
Al Viro | 2ba5bbe | 2014-04-02 20:00:02 -0400 | [diff] [blame] | 1702 | if (!iov_iter_count(to)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1703 | break; |
Al Viro | 6e58e79 | 2014-02-03 17:07:03 -0500 | [diff] [blame] | 1704 | if (ret < nr) { |
| 1705 | error = -EFAULT; |
| 1706 | break; |
| 1707 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1708 | cond_resched(); |
| 1709 | } |
| 1710 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1711 | *ppos = ((loff_t) index << PAGE_SHIFT) + offset; |
Al Viro | 6e58e79 | 2014-02-03 17:07:03 -0500 | [diff] [blame] | 1712 | file_accessed(file); |
| 1713 | return retval ? retval : error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1714 | } |
| 1715 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1716 | static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos, |
| 1717 | struct pipe_inode_info *pipe, size_t len, |
| 1718 | unsigned int flags) |
| 1719 | { |
| 1720 | struct address_space *mapping = in->f_mapping; |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1721 | struct inode *inode = mapping->host; |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1722 | unsigned int loff, nr_pages, req_pages; |
| 1723 | struct page *pages[PIPE_DEF_BUFFERS]; |
| 1724 | struct partial_page partial[PIPE_DEF_BUFFERS]; |
| 1725 | struct page *page; |
| 1726 | pgoff_t index, end_index; |
| 1727 | loff_t isize, left; |
| 1728 | int error, page_nr; |
| 1729 | struct splice_pipe_desc spd = { |
| 1730 | .pages = pages, |
| 1731 | .partial = partial, |
Eric Dumazet | 047fe36 | 2012-06-12 15:24:40 +0200 | [diff] [blame] | 1732 | .nr_pages_max = PIPE_DEF_BUFFERS, |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1733 | .flags = flags, |
| 1734 | .ops = &page_cache_pipe_buf_ops, |
| 1735 | .spd_release = spd_release_page, |
| 1736 | }; |
| 1737 | |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1738 | isize = i_size_read(inode); |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1739 | if (unlikely(*ppos >= isize)) |
| 1740 | return 0; |
| 1741 | |
| 1742 | left = isize - *ppos; |
| 1743 | if (unlikely(left < len)) |
| 1744 | len = left; |
| 1745 | |
| 1746 | if (splice_grow_spd(pipe, &spd)) |
| 1747 | return -ENOMEM; |
| 1748 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1749 | index = *ppos >> PAGE_SHIFT; |
| 1750 | loff = *ppos & ~PAGE_MASK; |
| 1751 | req_pages = (len + loff + PAGE_SIZE - 1) >> PAGE_SHIFT; |
Al Viro | a786c06 | 2014-04-11 12:01:03 -0400 | [diff] [blame] | 1752 | nr_pages = min(req_pages, spd.nr_pages_max); |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1753 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1754 | spd.nr_pages = find_get_pages_contig(mapping, index, |
| 1755 | nr_pages, spd.pages); |
| 1756 | index += spd.nr_pages; |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1757 | error = 0; |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1758 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1759 | while (spd.nr_pages < nr_pages) { |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1760 | error = shmem_getpage(inode, index, &page, SGP_CACHE); |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1761 | if (error) |
| 1762 | break; |
| 1763 | unlock_page(page); |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1764 | spd.pages[spd.nr_pages++] = page; |
| 1765 | index++; |
| 1766 | } |
| 1767 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1768 | index = *ppos >> PAGE_SHIFT; |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1769 | nr_pages = spd.nr_pages; |
| 1770 | spd.nr_pages = 0; |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1771 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1772 | for (page_nr = 0; page_nr < nr_pages; page_nr++) { |
| 1773 | unsigned int this_len; |
| 1774 | |
| 1775 | if (!len) |
| 1776 | break; |
| 1777 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1778 | this_len = min_t(unsigned long, len, PAGE_SIZE - loff); |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1779 | page = spd.pages[page_nr]; |
| 1780 | |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1781 | if (!PageUptodate(page) || page->mapping != mapping) { |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1782 | error = shmem_getpage(inode, index, &page, SGP_CACHE); |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1783 | if (error) |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1784 | break; |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1785 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1786 | put_page(spd.pages[page_nr]); |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1787 | spd.pages[page_nr] = page; |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1788 | } |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1789 | |
| 1790 | isize = i_size_read(inode); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1791 | end_index = (isize - 1) >> PAGE_SHIFT; |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1792 | if (unlikely(!isize || index > end_index)) |
| 1793 | break; |
| 1794 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1795 | if (end_index == index) { |
| 1796 | unsigned int plen; |
| 1797 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1798 | plen = ((isize - 1) & ~PAGE_MASK) + 1; |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1799 | if (plen <= loff) |
| 1800 | break; |
| 1801 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1802 | this_len = min(this_len, plen - loff); |
| 1803 | len = this_len; |
| 1804 | } |
| 1805 | |
| 1806 | spd.partial[page_nr].offset = loff; |
| 1807 | spd.partial[page_nr].len = this_len; |
| 1808 | len -= this_len; |
| 1809 | loff = 0; |
| 1810 | spd.nr_pages++; |
| 1811 | index++; |
| 1812 | } |
| 1813 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1814 | while (page_nr < nr_pages) |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1815 | put_page(spd.pages[page_nr++]); |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1816 | |
| 1817 | if (spd.nr_pages) |
| 1818 | error = splice_to_pipe(pipe, &spd); |
| 1819 | |
Eric Dumazet | 047fe36 | 2012-06-12 15:24:40 +0200 | [diff] [blame] | 1820 | splice_shrink_spd(&spd); |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1821 | |
| 1822 | if (error > 0) { |
| 1823 | *ppos += error; |
| 1824 | file_accessed(in); |
| 1825 | } |
| 1826 | return error; |
| 1827 | } |
| 1828 | |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1829 | /* |
| 1830 | * llseek SEEK_DATA or SEEK_HOLE through the radix_tree. |
| 1831 | */ |
| 1832 | static pgoff_t shmem_seek_hole_data(struct address_space *mapping, |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 1833 | pgoff_t index, pgoff_t end, int whence) |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1834 | { |
| 1835 | struct page *page; |
| 1836 | struct pagevec pvec; |
| 1837 | pgoff_t indices[PAGEVEC_SIZE]; |
| 1838 | bool done = false; |
| 1839 | int i; |
| 1840 | |
| 1841 | pagevec_init(&pvec, 0); |
| 1842 | pvec.nr = 1; /* start small: we may be there already */ |
| 1843 | while (!done) { |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 1844 | pvec.nr = find_get_entries(mapping, index, |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1845 | pvec.nr, pvec.pages, indices); |
| 1846 | if (!pvec.nr) { |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 1847 | if (whence == SEEK_DATA) |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1848 | index = end; |
| 1849 | break; |
| 1850 | } |
| 1851 | for (i = 0; i < pvec.nr; i++, index++) { |
| 1852 | if (index < indices[i]) { |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 1853 | if (whence == SEEK_HOLE) { |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1854 | done = true; |
| 1855 | break; |
| 1856 | } |
| 1857 | index = indices[i]; |
| 1858 | } |
| 1859 | page = pvec.pages[i]; |
| 1860 | if (page && !radix_tree_exceptional_entry(page)) { |
| 1861 | if (!PageUptodate(page)) |
| 1862 | page = NULL; |
| 1863 | } |
| 1864 | if (index >= end || |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 1865 | (page && whence == SEEK_DATA) || |
| 1866 | (!page && whence == SEEK_HOLE)) { |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1867 | done = true; |
| 1868 | break; |
| 1869 | } |
| 1870 | } |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 1871 | pagevec_remove_exceptionals(&pvec); |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1872 | pagevec_release(&pvec); |
| 1873 | pvec.nr = PAGEVEC_SIZE; |
| 1874 | cond_resched(); |
| 1875 | } |
| 1876 | return index; |
| 1877 | } |
| 1878 | |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 1879 | static loff_t shmem_file_llseek(struct file *file, loff_t offset, int whence) |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1880 | { |
| 1881 | struct address_space *mapping = file->f_mapping; |
| 1882 | struct inode *inode = mapping->host; |
| 1883 | pgoff_t start, end; |
| 1884 | loff_t new_offset; |
| 1885 | |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 1886 | if (whence != SEEK_DATA && whence != SEEK_HOLE) |
| 1887 | return generic_file_llseek_size(file, offset, whence, |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1888 | MAX_LFS_FILESIZE, i_size_read(inode)); |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 1889 | inode_lock(inode); |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1890 | /* We're holding i_mutex so we can access i_size directly */ |
| 1891 | |
| 1892 | if (offset < 0) |
| 1893 | offset = -EINVAL; |
| 1894 | else if (offset >= inode->i_size) |
| 1895 | offset = -ENXIO; |
| 1896 | else { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1897 | start = offset >> PAGE_SHIFT; |
| 1898 | end = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT; |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 1899 | new_offset = shmem_seek_hole_data(mapping, start, end, whence); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1900 | new_offset <<= PAGE_SHIFT; |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1901 | if (new_offset > offset) { |
| 1902 | if (new_offset < inode->i_size) |
| 1903 | offset = new_offset; |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 1904 | else if (whence == SEEK_DATA) |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1905 | offset = -ENXIO; |
| 1906 | else |
| 1907 | offset = inode->i_size; |
| 1908 | } |
| 1909 | } |
| 1910 | |
Hugh Dickins | 387aae6 | 2013-08-04 11:30:25 -0700 | [diff] [blame] | 1911 | if (offset >= 0) |
| 1912 | offset = vfs_setpos(file, offset, MAX_LFS_FILESIZE); |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 1913 | inode_unlock(inode); |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1914 | return offset; |
| 1915 | } |
| 1916 | |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 1917 | /* |
| 1918 | * We need a tag: a new tag would expand every radix_tree_node by 8 bytes, |
| 1919 | * so reuse a tag which we firmly believe is never set or cleared on shmem. |
| 1920 | */ |
| 1921 | #define SHMEM_TAG_PINNED PAGECACHE_TAG_TOWRITE |
| 1922 | #define LAST_SCAN 4 /* about 150ms max */ |
| 1923 | |
| 1924 | static void shmem_tag_pins(struct address_space *mapping) |
| 1925 | { |
| 1926 | struct radix_tree_iter iter; |
| 1927 | void **slot; |
| 1928 | pgoff_t start; |
| 1929 | struct page *page; |
| 1930 | |
| 1931 | lru_add_drain(); |
| 1932 | start = 0; |
| 1933 | rcu_read_lock(); |
| 1934 | |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 1935 | radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) { |
| 1936 | page = radix_tree_deref_slot(slot); |
| 1937 | if (!page || radix_tree_exception(page)) { |
Matthew Wilcox | 2cf938a | 2016-03-17 14:22:03 -0700 | [diff] [blame] | 1938 | if (radix_tree_deref_retry(page)) { |
| 1939 | slot = radix_tree_iter_retry(&iter); |
| 1940 | continue; |
| 1941 | } |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 1942 | } else if (page_count(page) - page_mapcount(page) > 1) { |
| 1943 | spin_lock_irq(&mapping->tree_lock); |
| 1944 | radix_tree_tag_set(&mapping->page_tree, iter.index, |
| 1945 | SHMEM_TAG_PINNED); |
| 1946 | spin_unlock_irq(&mapping->tree_lock); |
| 1947 | } |
| 1948 | |
| 1949 | if (need_resched()) { |
| 1950 | cond_resched_rcu(); |
Matthew Wilcox | 7165092 | 2016-03-17 14:22:06 -0700 | [diff] [blame] | 1951 | slot = radix_tree_iter_next(&iter); |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 1952 | } |
| 1953 | } |
| 1954 | rcu_read_unlock(); |
| 1955 | } |
| 1956 | |
| 1957 | /* |
| 1958 | * Setting SEAL_WRITE requires us to verify there's no pending writer. However, |
| 1959 | * via get_user_pages(), drivers might have some pending I/O without any active |
| 1960 | * user-space mappings (eg., direct-IO, AIO). Therefore, we look at all pages |
| 1961 | * and see whether it has an elevated ref-count. If so, we tag them and wait for |
| 1962 | * them to be dropped. |
| 1963 | * The caller must guarantee that no new user will acquire writable references |
| 1964 | * to those pages to avoid races. |
| 1965 | */ |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 1966 | static int shmem_wait_for_pins(struct address_space *mapping) |
| 1967 | { |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 1968 | struct radix_tree_iter iter; |
| 1969 | void **slot; |
| 1970 | pgoff_t start; |
| 1971 | struct page *page; |
| 1972 | int error, scan; |
| 1973 | |
| 1974 | shmem_tag_pins(mapping); |
| 1975 | |
| 1976 | error = 0; |
| 1977 | for (scan = 0; scan <= LAST_SCAN; scan++) { |
| 1978 | if (!radix_tree_tagged(&mapping->page_tree, SHMEM_TAG_PINNED)) |
| 1979 | break; |
| 1980 | |
| 1981 | if (!scan) |
| 1982 | lru_add_drain_all(); |
| 1983 | else if (schedule_timeout_killable((HZ << scan) / 200)) |
| 1984 | scan = LAST_SCAN; |
| 1985 | |
| 1986 | start = 0; |
| 1987 | rcu_read_lock(); |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 1988 | radix_tree_for_each_tagged(slot, &mapping->page_tree, &iter, |
| 1989 | start, SHMEM_TAG_PINNED) { |
| 1990 | |
| 1991 | page = radix_tree_deref_slot(slot); |
| 1992 | if (radix_tree_exception(page)) { |
Matthew Wilcox | 2cf938a | 2016-03-17 14:22:03 -0700 | [diff] [blame] | 1993 | if (radix_tree_deref_retry(page)) { |
| 1994 | slot = radix_tree_iter_retry(&iter); |
| 1995 | continue; |
| 1996 | } |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 1997 | |
| 1998 | page = NULL; |
| 1999 | } |
| 2000 | |
| 2001 | if (page && |
| 2002 | page_count(page) - page_mapcount(page) != 1) { |
| 2003 | if (scan < LAST_SCAN) |
| 2004 | goto continue_resched; |
| 2005 | |
| 2006 | /* |
| 2007 | * On the last scan, we clean up all those tags |
| 2008 | * we inserted; but make a note that we still |
| 2009 | * found pages pinned. |
| 2010 | */ |
| 2011 | error = -EBUSY; |
| 2012 | } |
| 2013 | |
| 2014 | spin_lock_irq(&mapping->tree_lock); |
| 2015 | radix_tree_tag_clear(&mapping->page_tree, |
| 2016 | iter.index, SHMEM_TAG_PINNED); |
| 2017 | spin_unlock_irq(&mapping->tree_lock); |
| 2018 | continue_resched: |
| 2019 | if (need_resched()) { |
| 2020 | cond_resched_rcu(); |
Matthew Wilcox | 7165092 | 2016-03-17 14:22:06 -0700 | [diff] [blame] | 2021 | slot = radix_tree_iter_next(&iter); |
David Herrmann | 05f65b5 | 2014-08-08 14:25:36 -0700 | [diff] [blame] | 2022 | } |
| 2023 | } |
| 2024 | rcu_read_unlock(); |
| 2025 | } |
| 2026 | |
| 2027 | return error; |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2028 | } |
| 2029 | |
| 2030 | #define F_ALL_SEALS (F_SEAL_SEAL | \ |
| 2031 | F_SEAL_SHRINK | \ |
| 2032 | F_SEAL_GROW | \ |
| 2033 | F_SEAL_WRITE) |
| 2034 | |
| 2035 | int shmem_add_seals(struct file *file, unsigned int seals) |
| 2036 | { |
| 2037 | struct inode *inode = file_inode(file); |
| 2038 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 2039 | int error; |
| 2040 | |
| 2041 | /* |
| 2042 | * SEALING |
| 2043 | * Sealing allows multiple parties to share a shmem-file but restrict |
| 2044 | * access to a specific subset of file operations. Seals can only be |
| 2045 | * added, but never removed. This way, mutually untrusted parties can |
| 2046 | * share common memory regions with a well-defined policy. A malicious |
| 2047 | * peer can thus never perform unwanted operations on a shared object. |
| 2048 | * |
| 2049 | * Seals are only supported on special shmem-files and always affect |
| 2050 | * the whole underlying inode. Once a seal is set, it may prevent some |
| 2051 | * kinds of access to the file. Currently, the following seals are |
| 2052 | * defined: |
| 2053 | * SEAL_SEAL: Prevent further seals from being set on this file |
| 2054 | * SEAL_SHRINK: Prevent the file from shrinking |
| 2055 | * SEAL_GROW: Prevent the file from growing |
| 2056 | * SEAL_WRITE: Prevent write access to the file |
| 2057 | * |
| 2058 | * As we don't require any trust relationship between two parties, we |
| 2059 | * must prevent seals from being removed. Therefore, sealing a file |
| 2060 | * only adds a given set of seals to the file, it never touches |
| 2061 | * existing seals. Furthermore, the "setting seals"-operation can be |
| 2062 | * sealed itself, which basically prevents any further seal from being |
| 2063 | * added. |
| 2064 | * |
| 2065 | * Semantics of sealing are only defined on volatile files. Only |
| 2066 | * anonymous shmem files support sealing. More importantly, seals are |
| 2067 | * never written to disk. Therefore, there's no plan to support it on |
| 2068 | * other file types. |
| 2069 | */ |
| 2070 | |
| 2071 | if (file->f_op != &shmem_file_operations) |
| 2072 | return -EINVAL; |
| 2073 | if (!(file->f_mode & FMODE_WRITE)) |
| 2074 | return -EPERM; |
| 2075 | if (seals & ~(unsigned int)F_ALL_SEALS) |
| 2076 | return -EINVAL; |
| 2077 | |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 2078 | inode_lock(inode); |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2079 | |
| 2080 | if (info->seals & F_SEAL_SEAL) { |
| 2081 | error = -EPERM; |
| 2082 | goto unlock; |
| 2083 | } |
| 2084 | |
| 2085 | if ((seals & F_SEAL_WRITE) && !(info->seals & F_SEAL_WRITE)) { |
| 2086 | error = mapping_deny_writable(file->f_mapping); |
| 2087 | if (error) |
| 2088 | goto unlock; |
| 2089 | |
| 2090 | error = shmem_wait_for_pins(file->f_mapping); |
| 2091 | if (error) { |
| 2092 | mapping_allow_writable(file->f_mapping); |
| 2093 | goto unlock; |
| 2094 | } |
| 2095 | } |
| 2096 | |
| 2097 | info->seals |= seals; |
| 2098 | error = 0; |
| 2099 | |
| 2100 | unlock: |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 2101 | inode_unlock(inode); |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2102 | return error; |
| 2103 | } |
| 2104 | EXPORT_SYMBOL_GPL(shmem_add_seals); |
| 2105 | |
| 2106 | int shmem_get_seals(struct file *file) |
| 2107 | { |
| 2108 | if (file->f_op != &shmem_file_operations) |
| 2109 | return -EINVAL; |
| 2110 | |
| 2111 | return SHMEM_I(file_inode(file))->seals; |
| 2112 | } |
| 2113 | EXPORT_SYMBOL_GPL(shmem_get_seals); |
| 2114 | |
| 2115 | long shmem_fcntl(struct file *file, unsigned int cmd, unsigned long arg) |
| 2116 | { |
| 2117 | long error; |
| 2118 | |
| 2119 | switch (cmd) { |
| 2120 | case F_ADD_SEALS: |
| 2121 | /* disallow upper 32bit */ |
| 2122 | if (arg > UINT_MAX) |
| 2123 | return -EINVAL; |
| 2124 | |
| 2125 | error = shmem_add_seals(file, arg); |
| 2126 | break; |
| 2127 | case F_GET_SEALS: |
| 2128 | error = shmem_get_seals(file); |
| 2129 | break; |
| 2130 | default: |
| 2131 | error = -EINVAL; |
| 2132 | break; |
| 2133 | } |
| 2134 | |
| 2135 | return error; |
| 2136 | } |
| 2137 | |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2138 | static long shmem_fallocate(struct file *file, int mode, loff_t offset, |
| 2139 | loff_t len) |
| 2140 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 2141 | struct inode *inode = file_inode(file); |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2142 | struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2143 | struct shmem_inode_info *info = SHMEM_I(inode); |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2144 | struct shmem_falloc shmem_falloc; |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2145 | pgoff_t start, index, end; |
| 2146 | int error; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2147 | |
Hugh Dickins | 13ace4d | 2014-06-23 13:22:03 -0700 | [diff] [blame] | 2148 | if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) |
| 2149 | return -EOPNOTSUPP; |
| 2150 | |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 2151 | inode_lock(inode); |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2152 | |
| 2153 | if (mode & FALLOC_FL_PUNCH_HOLE) { |
| 2154 | struct address_space *mapping = file->f_mapping; |
| 2155 | loff_t unmap_start = round_up(offset, PAGE_SIZE); |
| 2156 | loff_t unmap_end = round_down(offset + len, PAGE_SIZE) - 1; |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2157 | DECLARE_WAIT_QUEUE_HEAD_ONSTACK(shmem_falloc_waitq); |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2158 | |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2159 | /* protected by i_mutex */ |
| 2160 | if (info->seals & F_SEAL_WRITE) { |
| 2161 | error = -EPERM; |
| 2162 | goto out; |
| 2163 | } |
| 2164 | |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2165 | shmem_falloc.waitq = &shmem_falloc_waitq; |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 2166 | shmem_falloc.start = unmap_start >> PAGE_SHIFT; |
| 2167 | shmem_falloc.next = (unmap_end + 1) >> PAGE_SHIFT; |
| 2168 | spin_lock(&inode->i_lock); |
| 2169 | inode->i_private = &shmem_falloc; |
| 2170 | spin_unlock(&inode->i_lock); |
| 2171 | |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2172 | if ((u64)unmap_end > (u64)unmap_start) |
| 2173 | unmap_mapping_range(mapping, unmap_start, |
| 2174 | 1 + unmap_end - unmap_start, 0); |
| 2175 | shmem_truncate_range(inode, offset, offset + len - 1); |
| 2176 | /* No need to unmap again: hole-punching leaves COWed pages */ |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2177 | |
| 2178 | spin_lock(&inode->i_lock); |
| 2179 | inode->i_private = NULL; |
| 2180 | wake_up_all(&shmem_falloc_waitq); |
| 2181 | spin_unlock(&inode->i_lock); |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2182 | error = 0; |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2183 | goto out; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2184 | } |
| 2185 | |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2186 | /* We need to check rlimit even when FALLOC_FL_KEEP_SIZE */ |
| 2187 | error = inode_newsize_ok(inode, offset + len); |
| 2188 | if (error) |
| 2189 | goto out; |
| 2190 | |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2191 | if ((info->seals & F_SEAL_GROW) && offset + len > inode->i_size) { |
| 2192 | error = -EPERM; |
| 2193 | goto out; |
| 2194 | } |
| 2195 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2196 | start = offset >> PAGE_SHIFT; |
| 2197 | end = (offset + len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2198 | /* Try to avoid a swapstorm if len is impossible to satisfy */ |
| 2199 | if (sbinfo->max_blocks && end - start > sbinfo->max_blocks) { |
| 2200 | error = -ENOSPC; |
| 2201 | goto out; |
| 2202 | } |
| 2203 | |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2204 | shmem_falloc.waitq = NULL; |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2205 | shmem_falloc.start = start; |
| 2206 | shmem_falloc.next = start; |
| 2207 | shmem_falloc.nr_falloced = 0; |
| 2208 | shmem_falloc.nr_unswapped = 0; |
| 2209 | spin_lock(&inode->i_lock); |
| 2210 | inode->i_private = &shmem_falloc; |
| 2211 | spin_unlock(&inode->i_lock); |
| 2212 | |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2213 | for (index = start; index < end; index++) { |
| 2214 | struct page *page; |
| 2215 | |
| 2216 | /* |
| 2217 | * Good, the fallocate(2) manpage permits EINTR: we may have |
| 2218 | * been interrupted because we are using up too much memory. |
| 2219 | */ |
| 2220 | if (signal_pending(current)) |
| 2221 | error = -EINTR; |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2222 | else if (shmem_falloc.nr_unswapped > shmem_falloc.nr_falloced) |
| 2223 | error = -ENOMEM; |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2224 | else |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 2225 | error = shmem_getpage(inode, index, &page, SGP_FALLOC); |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2226 | if (error) { |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2227 | /* Remove the !PageUptodate pages we added */ |
Hugh Dickins | 7f55656 | 2016-07-10 16:46:32 -0700 | [diff] [blame] | 2228 | if (index > start) { |
| 2229 | shmem_undo_range(inode, |
| 2230 | (loff_t)start << PAGE_SHIFT, |
| 2231 | ((loff_t)index << PAGE_SHIFT) - 1, true); |
| 2232 | } |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2233 | goto undone; |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2234 | } |
| 2235 | |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2236 | /* |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2237 | * Inform shmem_writepage() how far we have reached. |
| 2238 | * No need for lock or barrier: we have the page lock. |
| 2239 | */ |
| 2240 | shmem_falloc.next++; |
| 2241 | if (!PageUptodate(page)) |
| 2242 | shmem_falloc.nr_falloced++; |
| 2243 | |
| 2244 | /* |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2245 | * If !PageUptodate, leave it that way so that freeable pages |
| 2246 | * can be recognized if we need to rollback on error later. |
| 2247 | * But set_page_dirty so that memory pressure will swap rather |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2248 | * than free the pages we are allocating (and SGP_CACHE pages |
| 2249 | * might still be clean: we now need to mark those dirty too). |
| 2250 | */ |
| 2251 | set_page_dirty(page); |
| 2252 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2253 | put_page(page); |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2254 | cond_resched(); |
| 2255 | } |
| 2256 | |
| 2257 | if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) |
| 2258 | i_size_write(inode, offset + len); |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2259 | inode->i_ctime = CURRENT_TIME; |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2260 | undone: |
| 2261 | spin_lock(&inode->i_lock); |
| 2262 | inode->i_private = NULL; |
| 2263 | spin_unlock(&inode->i_lock); |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2264 | out: |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 2265 | inode_unlock(inode); |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2266 | return error; |
| 2267 | } |
| 2268 | |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 2269 | static int shmem_statfs(struct dentry *dentry, struct kstatfs *buf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2270 | { |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 2271 | struct shmem_sb_info *sbinfo = SHMEM_SB(dentry->d_sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2272 | |
| 2273 | buf->f_type = TMPFS_MAGIC; |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2274 | buf->f_bsize = PAGE_SIZE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2275 | buf->f_namelen = NAME_MAX; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2276 | if (sbinfo->max_blocks) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2277 | buf->f_blocks = sbinfo->max_blocks; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2278 | buf->f_bavail = |
| 2279 | buf->f_bfree = sbinfo->max_blocks - |
| 2280 | percpu_counter_sum(&sbinfo->used_blocks); |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2281 | } |
| 2282 | if (sbinfo->max_inodes) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2283 | buf->f_files = sbinfo->max_inodes; |
| 2284 | buf->f_ffree = sbinfo->free_inodes; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2285 | } |
| 2286 | /* else leave those fields 0 like simple_statfs */ |
| 2287 | return 0; |
| 2288 | } |
| 2289 | |
| 2290 | /* |
| 2291 | * File creation. Allocate an inode, and we're done.. |
| 2292 | */ |
| 2293 | static int |
Al Viro | 1a67aaf | 2011-07-26 01:52:52 -0400 | [diff] [blame] | 2294 | shmem_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2295 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 2296 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2297 | int error = -ENOSPC; |
| 2298 | |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 2299 | inode = shmem_get_inode(dir->i_sb, dir, mode, dev, VM_NORESERVE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2300 | if (inode) { |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 2301 | error = simple_acl_create(dir, inode); |
| 2302 | if (error) |
| 2303 | goto out_iput; |
Eric Paris | 2a7dba3 | 2011-02-01 11:05:39 -0500 | [diff] [blame] | 2304 | error = security_inode_init_security(inode, dir, |
Mimi Zohar | 9d8f13b | 2011-06-06 15:29:25 -0400 | [diff] [blame] | 2305 | &dentry->d_name, |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 2306 | shmem_initxattrs, NULL); |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 2307 | if (error && error != -EOPNOTSUPP) |
| 2308 | goto out_iput; |
Mimi Zohar | 37ec43c | 2013-04-14 09:21:47 -0400 | [diff] [blame] | 2309 | |
Al Viro | 718deb6 | 2009-12-16 19:35:36 -0500 | [diff] [blame] | 2310 | error = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2311 | dir->i_size += BOGO_DIRENT_SIZE; |
| 2312 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; |
| 2313 | d_instantiate(dentry, inode); |
| 2314 | dget(dentry); /* Extra count - pin the dentry in core */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2315 | } |
| 2316 | return error; |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 2317 | out_iput: |
| 2318 | iput(inode); |
| 2319 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2320 | } |
| 2321 | |
Al Viro | 60545d0 | 2013-06-07 01:20:27 -0400 | [diff] [blame] | 2322 | static int |
| 2323 | shmem_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) |
| 2324 | { |
| 2325 | struct inode *inode; |
| 2326 | int error = -ENOSPC; |
| 2327 | |
| 2328 | inode = shmem_get_inode(dir->i_sb, dir, mode, 0, VM_NORESERVE); |
| 2329 | if (inode) { |
| 2330 | error = security_inode_init_security(inode, dir, |
| 2331 | NULL, |
| 2332 | shmem_initxattrs, NULL); |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 2333 | if (error && error != -EOPNOTSUPP) |
| 2334 | goto out_iput; |
| 2335 | error = simple_acl_create(dir, inode); |
| 2336 | if (error) |
| 2337 | goto out_iput; |
Al Viro | 60545d0 | 2013-06-07 01:20:27 -0400 | [diff] [blame] | 2338 | d_tmpfile(dentry, inode); |
| 2339 | } |
| 2340 | return error; |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 2341 | out_iput: |
| 2342 | iput(inode); |
| 2343 | return error; |
Al Viro | 60545d0 | 2013-06-07 01:20:27 -0400 | [diff] [blame] | 2344 | } |
| 2345 | |
Al Viro | 18bb1db | 2011-07-26 01:41:39 -0400 | [diff] [blame] | 2346 | static int shmem_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2347 | { |
| 2348 | int error; |
| 2349 | |
| 2350 | if ((error = shmem_mknod(dir, dentry, mode | S_IFDIR, 0))) |
| 2351 | return error; |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 2352 | inc_nlink(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2353 | return 0; |
| 2354 | } |
| 2355 | |
Al Viro | 4acdaf2 | 2011-07-26 01:42:34 -0400 | [diff] [blame] | 2356 | static int shmem_create(struct inode *dir, struct dentry *dentry, umode_t mode, |
Al Viro | ebfc3b4 | 2012-06-10 18:05:36 -0400 | [diff] [blame] | 2357 | bool excl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2358 | { |
| 2359 | return shmem_mknod(dir, dentry, mode | S_IFREG, 0); |
| 2360 | } |
| 2361 | |
| 2362 | /* |
| 2363 | * Link a file.. |
| 2364 | */ |
| 2365 | static int shmem_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) |
| 2366 | { |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 2367 | struct inode *inode = d_inode(old_dentry); |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 2368 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2369 | |
| 2370 | /* |
| 2371 | * No ordinary (disk based) filesystem counts links as inodes; |
| 2372 | * but each new link needs a new dentry, pinning lowmem, and |
| 2373 | * tmpfs dentries cannot be pruned until they are unlinked. |
| 2374 | */ |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 2375 | ret = shmem_reserve_inode(inode->i_sb); |
| 2376 | if (ret) |
| 2377 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2378 | |
| 2379 | dir->i_size += BOGO_DIRENT_SIZE; |
| 2380 | inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 2381 | inc_nlink(inode); |
Al Viro | 7de9c6ee | 2010-10-23 11:11:40 -0400 | [diff] [blame] | 2382 | ihold(inode); /* New dentry reference */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2383 | dget(dentry); /* Extra pinning count for the created dentry */ |
| 2384 | d_instantiate(dentry, inode); |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 2385 | out: |
| 2386 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2387 | } |
| 2388 | |
| 2389 | static int shmem_unlink(struct inode *dir, struct dentry *dentry) |
| 2390 | { |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 2391 | struct inode *inode = d_inode(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2392 | |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 2393 | if (inode->i_nlink > 1 && !S_ISDIR(inode->i_mode)) |
| 2394 | shmem_free_inode(inode->i_sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2395 | |
| 2396 | dir->i_size -= BOGO_DIRENT_SIZE; |
| 2397 | inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 2398 | drop_nlink(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2399 | dput(dentry); /* Undo the count from "create" - this does all the work */ |
| 2400 | return 0; |
| 2401 | } |
| 2402 | |
| 2403 | static int shmem_rmdir(struct inode *dir, struct dentry *dentry) |
| 2404 | { |
| 2405 | if (!simple_empty(dentry)) |
| 2406 | return -ENOTEMPTY; |
| 2407 | |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 2408 | drop_nlink(d_inode(dentry)); |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 2409 | drop_nlink(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2410 | return shmem_unlink(dir, dentry); |
| 2411 | } |
| 2412 | |
Miklos Szeredi | 3745677 | 2014-07-23 15:15:34 +0200 | [diff] [blame] | 2413 | static int shmem_exchange(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry) |
| 2414 | { |
David Howells | e36cb0b | 2015-01-29 12:02:35 +0000 | [diff] [blame] | 2415 | bool old_is_dir = d_is_dir(old_dentry); |
| 2416 | bool new_is_dir = d_is_dir(new_dentry); |
Miklos Szeredi | 3745677 | 2014-07-23 15:15:34 +0200 | [diff] [blame] | 2417 | |
| 2418 | if (old_dir != new_dir && old_is_dir != new_is_dir) { |
| 2419 | if (old_is_dir) { |
| 2420 | drop_nlink(old_dir); |
| 2421 | inc_nlink(new_dir); |
| 2422 | } else { |
| 2423 | drop_nlink(new_dir); |
| 2424 | inc_nlink(old_dir); |
| 2425 | } |
| 2426 | } |
| 2427 | old_dir->i_ctime = old_dir->i_mtime = |
| 2428 | new_dir->i_ctime = new_dir->i_mtime = |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 2429 | d_inode(old_dentry)->i_ctime = |
| 2430 | d_inode(new_dentry)->i_ctime = CURRENT_TIME; |
Miklos Szeredi | 3745677 | 2014-07-23 15:15:34 +0200 | [diff] [blame] | 2431 | |
| 2432 | return 0; |
| 2433 | } |
| 2434 | |
Miklos Szeredi | 46fdb79 | 2014-10-24 00:14:37 +0200 | [diff] [blame] | 2435 | static int shmem_whiteout(struct inode *old_dir, struct dentry *old_dentry) |
| 2436 | { |
| 2437 | struct dentry *whiteout; |
| 2438 | int error; |
| 2439 | |
| 2440 | whiteout = d_alloc(old_dentry->d_parent, &old_dentry->d_name); |
| 2441 | if (!whiteout) |
| 2442 | return -ENOMEM; |
| 2443 | |
| 2444 | error = shmem_mknod(old_dir, whiteout, |
| 2445 | S_IFCHR | WHITEOUT_MODE, WHITEOUT_DEV); |
| 2446 | dput(whiteout); |
| 2447 | if (error) |
| 2448 | return error; |
| 2449 | |
| 2450 | /* |
| 2451 | * Cheat and hash the whiteout while the old dentry is still in |
| 2452 | * place, instead of playing games with FS_RENAME_DOES_D_MOVE. |
| 2453 | * |
| 2454 | * d_lookup() will consistently find one of them at this point, |
| 2455 | * not sure which one, but that isn't even important. |
| 2456 | */ |
| 2457 | d_rehash(whiteout); |
| 2458 | return 0; |
| 2459 | } |
| 2460 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2461 | /* |
| 2462 | * The VFS layer already does all the dentry stuff for rename, |
| 2463 | * we just have to decrement the usage count for the target if |
| 2464 | * it exists so that the VFS layer correctly free's it when it |
| 2465 | * gets overwritten. |
| 2466 | */ |
Miklos Szeredi | 3b69ff5 | 2014-07-23 15:15:33 +0200 | [diff] [blame] | 2467 | static int shmem_rename2(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, unsigned int flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2468 | { |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 2469 | struct inode *inode = d_inode(old_dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2470 | int they_are_dirs = S_ISDIR(inode->i_mode); |
| 2471 | |
Miklos Szeredi | 46fdb79 | 2014-10-24 00:14:37 +0200 | [diff] [blame] | 2472 | if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) |
Miklos Szeredi | 3b69ff5 | 2014-07-23 15:15:33 +0200 | [diff] [blame] | 2473 | return -EINVAL; |
| 2474 | |
Miklos Szeredi | 3745677 | 2014-07-23 15:15:34 +0200 | [diff] [blame] | 2475 | if (flags & RENAME_EXCHANGE) |
| 2476 | return shmem_exchange(old_dir, old_dentry, new_dir, new_dentry); |
| 2477 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2478 | if (!simple_empty(new_dentry)) |
| 2479 | return -ENOTEMPTY; |
| 2480 | |
Miklos Szeredi | 46fdb79 | 2014-10-24 00:14:37 +0200 | [diff] [blame] | 2481 | if (flags & RENAME_WHITEOUT) { |
| 2482 | int error; |
| 2483 | |
| 2484 | error = shmem_whiteout(old_dir, old_dentry); |
| 2485 | if (error) |
| 2486 | return error; |
| 2487 | } |
| 2488 | |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 2489 | if (d_really_is_positive(new_dentry)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2490 | (void) shmem_unlink(new_dir, new_dentry); |
Miklos Szeredi | b928095 | 2014-09-24 17:56:17 +0200 | [diff] [blame] | 2491 | if (they_are_dirs) { |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 2492 | drop_nlink(d_inode(new_dentry)); |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 2493 | drop_nlink(old_dir); |
Miklos Szeredi | b928095 | 2014-09-24 17:56:17 +0200 | [diff] [blame] | 2494 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2495 | } else if (they_are_dirs) { |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 2496 | drop_nlink(old_dir); |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 2497 | inc_nlink(new_dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2498 | } |
| 2499 | |
| 2500 | old_dir->i_size -= BOGO_DIRENT_SIZE; |
| 2501 | new_dir->i_size += BOGO_DIRENT_SIZE; |
| 2502 | old_dir->i_ctime = old_dir->i_mtime = |
| 2503 | new_dir->i_ctime = new_dir->i_mtime = |
| 2504 | inode->i_ctime = CURRENT_TIME; |
| 2505 | return 0; |
| 2506 | } |
| 2507 | |
| 2508 | static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *symname) |
| 2509 | { |
| 2510 | int error; |
| 2511 | int len; |
| 2512 | struct inode *inode; |
Hugh Dickins | 9276aad | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 2513 | struct page *page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2514 | struct shmem_inode_info *info; |
| 2515 | |
| 2516 | len = strlen(symname) + 1; |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2517 | if (len > PAGE_SIZE) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2518 | return -ENAMETOOLONG; |
| 2519 | |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 2520 | inode = shmem_get_inode(dir->i_sb, dir, S_IFLNK|S_IRWXUGO, 0, VM_NORESERVE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2521 | if (!inode) |
| 2522 | return -ENOSPC; |
| 2523 | |
Mimi Zohar | 9d8f13b | 2011-06-06 15:29:25 -0400 | [diff] [blame] | 2524 | error = security_inode_init_security(inode, dir, &dentry->d_name, |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 2525 | shmem_initxattrs, NULL); |
Stephen Smalley | 570bc1c | 2005-09-09 13:01:43 -0700 | [diff] [blame] | 2526 | if (error) { |
| 2527 | if (error != -EOPNOTSUPP) { |
| 2528 | iput(inode); |
| 2529 | return error; |
| 2530 | } |
| 2531 | error = 0; |
| 2532 | } |
| 2533 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2534 | info = SHMEM_I(inode); |
| 2535 | inode->i_size = len-1; |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 2536 | if (len <= SHORT_SYMLINK_LEN) { |
Al Viro | 3ed47db | 2016-01-22 18:08:52 -0500 | [diff] [blame] | 2537 | inode->i_link = kmemdup(symname, len, GFP_KERNEL); |
| 2538 | if (!inode->i_link) { |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 2539 | iput(inode); |
| 2540 | return -ENOMEM; |
| 2541 | } |
| 2542 | inode->i_op = &shmem_short_symlink_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2543 | } else { |
Al Viro | e8ecde2 | 2016-01-14 17:52:59 -0500 | [diff] [blame] | 2544 | inode_nohighmem(inode); |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 2545 | error = shmem_getpage(inode, 0, &page, SGP_WRITE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2546 | if (error) { |
| 2547 | iput(inode); |
| 2548 | return error; |
| 2549 | } |
Hugh Dickins | 14fcc23 | 2008-07-28 15:46:19 -0700 | [diff] [blame] | 2550 | inode->i_mapping->a_ops = &shmem_aops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2551 | inode->i_op = &shmem_symlink_inode_operations; |
Al Viro | 21fc61c | 2015-11-17 01:07:57 -0500 | [diff] [blame] | 2552 | memcpy(page_address(page), symname, len); |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 2553 | SetPageUptodate(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2554 | set_page_dirty(page); |
Wu Fengguang | 6746aff | 2009-09-16 11:50:14 +0200 | [diff] [blame] | 2555 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2556 | put_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2557 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2558 | dir->i_size += BOGO_DIRENT_SIZE; |
| 2559 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; |
| 2560 | d_instantiate(dentry, inode); |
| 2561 | dget(dentry); |
| 2562 | return 0; |
| 2563 | } |
| 2564 | |
Al Viro | fceef39 | 2015-12-29 15:58:39 -0500 | [diff] [blame] | 2565 | static void shmem_put_link(void *arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2566 | { |
Al Viro | fceef39 | 2015-12-29 15:58:39 -0500 | [diff] [blame] | 2567 | mark_page_accessed(arg); |
| 2568 | put_page(arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2569 | } |
| 2570 | |
Al Viro | 6b25539 | 2015-11-17 10:20:54 -0500 | [diff] [blame] | 2571 | static const char *shmem_get_link(struct dentry *dentry, |
Al Viro | fceef39 | 2015-12-29 15:58:39 -0500 | [diff] [blame] | 2572 | struct inode *inode, |
| 2573 | struct delayed_call *done) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2574 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2575 | struct page *page = NULL; |
Al Viro | 6b25539 | 2015-11-17 10:20:54 -0500 | [diff] [blame] | 2576 | int error; |
Al Viro | 6a6c990 | 2015-11-17 10:54:32 -0500 | [diff] [blame] | 2577 | if (!dentry) { |
| 2578 | page = find_get_page(inode->i_mapping, 0); |
| 2579 | if (!page) |
| 2580 | return ERR_PTR(-ECHILD); |
| 2581 | if (!PageUptodate(page)) { |
| 2582 | put_page(page); |
| 2583 | return ERR_PTR(-ECHILD); |
| 2584 | } |
| 2585 | } else { |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 2586 | error = shmem_getpage(inode, 0, &page, SGP_READ); |
Al Viro | 6a6c990 | 2015-11-17 10:54:32 -0500 | [diff] [blame] | 2587 | if (error) |
| 2588 | return ERR_PTR(error); |
| 2589 | unlock_page(page); |
| 2590 | } |
Al Viro | fceef39 | 2015-12-29 15:58:39 -0500 | [diff] [blame] | 2591 | set_delayed_call(done, shmem_put_link, page); |
Al Viro | 21fc61c | 2015-11-17 01:07:57 -0500 | [diff] [blame] | 2592 | return page_address(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2593 | } |
| 2594 | |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2595 | #ifdef CONFIG_TMPFS_XATTR |
| 2596 | /* |
| 2597 | * Superblocks without xattr inode operations may get some security.* xattr |
| 2598 | * support from the LSM "for free". As soon as we have any other xattrs |
| 2599 | * like ACLs, we also need to implement the security.* handlers at |
| 2600 | * filesystem level, though. |
| 2601 | */ |
| 2602 | |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 2603 | /* |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 2604 | * Callback for security_inode_init_security() for acquiring xattrs. |
| 2605 | */ |
| 2606 | static int shmem_initxattrs(struct inode *inode, |
| 2607 | const struct xattr *xattr_array, |
| 2608 | void *fs_info) |
| 2609 | { |
| 2610 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 2611 | const struct xattr *xattr; |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 2612 | struct simple_xattr *new_xattr; |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 2613 | size_t len; |
| 2614 | |
| 2615 | for (xattr = xattr_array; xattr->name != NULL; xattr++) { |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 2616 | new_xattr = simple_xattr_alloc(xattr->value, xattr->value_len); |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 2617 | if (!new_xattr) |
| 2618 | return -ENOMEM; |
| 2619 | |
| 2620 | len = strlen(xattr->name) + 1; |
| 2621 | new_xattr->name = kmalloc(XATTR_SECURITY_PREFIX_LEN + len, |
| 2622 | GFP_KERNEL); |
| 2623 | if (!new_xattr->name) { |
| 2624 | kfree(new_xattr); |
| 2625 | return -ENOMEM; |
| 2626 | } |
| 2627 | |
| 2628 | memcpy(new_xattr->name, XATTR_SECURITY_PREFIX, |
| 2629 | XATTR_SECURITY_PREFIX_LEN); |
| 2630 | memcpy(new_xattr->name + XATTR_SECURITY_PREFIX_LEN, |
| 2631 | xattr->name, len); |
| 2632 | |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 2633 | simple_xattr_list_add(&info->xattrs, new_xattr); |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 2634 | } |
| 2635 | |
| 2636 | return 0; |
| 2637 | } |
| 2638 | |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 2639 | static int shmem_xattr_handler_get(const struct xattr_handler *handler, |
Al Viro | b296821 | 2016-04-10 20:48:24 -0400 | [diff] [blame] | 2640 | struct dentry *unused, struct inode *inode, |
| 2641 | const char *name, void *buffer, size_t size) |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 2642 | { |
Al Viro | b296821 | 2016-04-10 20:48:24 -0400 | [diff] [blame] | 2643 | struct shmem_inode_info *info = SHMEM_I(inode); |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 2644 | |
| 2645 | name = xattr_full_name(handler, name); |
| 2646 | return simple_xattr_get(&info->xattrs, name, buffer, size); |
| 2647 | } |
| 2648 | |
| 2649 | static int shmem_xattr_handler_set(const struct xattr_handler *handler, |
Al Viro | 5930122 | 2016-05-27 10:19:30 -0400 | [diff] [blame] | 2650 | struct dentry *unused, struct inode *inode, |
| 2651 | const char *name, const void *value, |
| 2652 | size_t size, int flags) |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 2653 | { |
Al Viro | 5930122 | 2016-05-27 10:19:30 -0400 | [diff] [blame] | 2654 | struct shmem_inode_info *info = SHMEM_I(inode); |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 2655 | |
| 2656 | name = xattr_full_name(handler, name); |
| 2657 | return simple_xattr_set(&info->xattrs, name, value, size, flags); |
| 2658 | } |
| 2659 | |
| 2660 | static const struct xattr_handler shmem_security_xattr_handler = { |
| 2661 | .prefix = XATTR_SECURITY_PREFIX, |
| 2662 | .get = shmem_xattr_handler_get, |
| 2663 | .set = shmem_xattr_handler_set, |
| 2664 | }; |
| 2665 | |
| 2666 | static const struct xattr_handler shmem_trusted_xattr_handler = { |
| 2667 | .prefix = XATTR_TRUSTED_PREFIX, |
| 2668 | .get = shmem_xattr_handler_get, |
| 2669 | .set = shmem_xattr_handler_set, |
| 2670 | }; |
| 2671 | |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2672 | static const struct xattr_handler *shmem_xattr_handlers[] = { |
| 2673 | #ifdef CONFIG_TMPFS_POSIX_ACL |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 2674 | &posix_acl_access_xattr_handler, |
| 2675 | &posix_acl_default_xattr_handler, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2676 | #endif |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 2677 | &shmem_security_xattr_handler, |
| 2678 | &shmem_trusted_xattr_handler, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2679 | NULL |
| 2680 | }; |
| 2681 | |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2682 | static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size) |
| 2683 | { |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 2684 | struct shmem_inode_info *info = SHMEM_I(d_inode(dentry)); |
Andreas Gruenbacher | 786534b | 2015-12-02 14:44:39 +0100 | [diff] [blame] | 2685 | return simple_xattr_list(d_inode(dentry), &info->xattrs, buffer, size); |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2686 | } |
| 2687 | #endif /* CONFIG_TMPFS_XATTR */ |
| 2688 | |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 2689 | static const struct inode_operations shmem_short_symlink_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2690 | .readlink = generic_readlink, |
Al Viro | 6b25539 | 2015-11-17 10:20:54 -0500 | [diff] [blame] | 2691 | .get_link = simple_get_link, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2692 | #ifdef CONFIG_TMPFS_XATTR |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 2693 | .setxattr = generic_setxattr, |
| 2694 | .getxattr = generic_getxattr, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2695 | .listxattr = shmem_listxattr, |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 2696 | .removexattr = generic_removexattr, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2697 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2698 | }; |
| 2699 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 2700 | static const struct inode_operations shmem_symlink_inode_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2701 | .readlink = generic_readlink, |
Al Viro | 6b25539 | 2015-11-17 10:20:54 -0500 | [diff] [blame] | 2702 | .get_link = shmem_get_link, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2703 | #ifdef CONFIG_TMPFS_XATTR |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 2704 | .setxattr = generic_setxattr, |
| 2705 | .getxattr = generic_getxattr, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2706 | .listxattr = shmem_listxattr, |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 2707 | .removexattr = generic_removexattr, |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2708 | #endif |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2709 | }; |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2710 | |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2711 | static struct dentry *shmem_get_parent(struct dentry *child) |
| 2712 | { |
| 2713 | return ERR_PTR(-ESTALE); |
| 2714 | } |
| 2715 | |
| 2716 | static int shmem_match(struct inode *ino, void *vfh) |
| 2717 | { |
| 2718 | __u32 *fh = vfh; |
| 2719 | __u64 inum = fh[2]; |
| 2720 | inum = (inum << 32) | fh[1]; |
| 2721 | return ino->i_ino == inum && fh[0] == ino->i_generation; |
| 2722 | } |
| 2723 | |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2724 | static struct dentry *shmem_fh_to_dentry(struct super_block *sb, |
| 2725 | struct fid *fid, int fh_len, int fh_type) |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2726 | { |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2727 | struct inode *inode; |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2728 | struct dentry *dentry = NULL; |
Hugh Dickins | 35c2a7f | 2012-10-07 20:32:51 -0700 | [diff] [blame] | 2729 | u64 inum; |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2730 | |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2731 | if (fh_len < 3) |
| 2732 | return NULL; |
| 2733 | |
Hugh Dickins | 35c2a7f | 2012-10-07 20:32:51 -0700 | [diff] [blame] | 2734 | inum = fid->raw[2]; |
| 2735 | inum = (inum << 32) | fid->raw[1]; |
| 2736 | |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2737 | inode = ilookup5(sb, (unsigned long)(inum + fid->raw[0]), |
| 2738 | shmem_match, fid->raw); |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2739 | if (inode) { |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2740 | dentry = d_find_alias(inode); |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2741 | iput(inode); |
| 2742 | } |
| 2743 | |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2744 | return dentry; |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2745 | } |
| 2746 | |
Al Viro | b0b0382 | 2012-04-02 14:34:06 -0400 | [diff] [blame] | 2747 | static int shmem_encode_fh(struct inode *inode, __u32 *fh, int *len, |
| 2748 | struct inode *parent) |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2749 | { |
Aneesh Kumar K.V | 5fe0c23 | 2011-01-29 18:43:25 +0530 | [diff] [blame] | 2750 | if (*len < 3) { |
| 2751 | *len = 3; |
Namjae Jeon | 94e07a75 | 2013-02-17 15:48:11 +0900 | [diff] [blame] | 2752 | return FILEID_INVALID; |
Aneesh Kumar K.V | 5fe0c23 | 2011-01-29 18:43:25 +0530 | [diff] [blame] | 2753 | } |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2754 | |
Al Viro | 1d3382cb | 2010-10-23 15:19:20 -0400 | [diff] [blame] | 2755 | if (inode_unhashed(inode)) { |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2756 | /* Unfortunately insert_inode_hash is not idempotent, |
| 2757 | * so as we hash inodes here rather than at creation |
| 2758 | * time, we need a lock to ensure we only try |
| 2759 | * to do it once |
| 2760 | */ |
| 2761 | static DEFINE_SPINLOCK(lock); |
| 2762 | spin_lock(&lock); |
Al Viro | 1d3382cb | 2010-10-23 15:19:20 -0400 | [diff] [blame] | 2763 | if (inode_unhashed(inode)) |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2764 | __insert_inode_hash(inode, |
| 2765 | inode->i_ino + inode->i_generation); |
| 2766 | spin_unlock(&lock); |
| 2767 | } |
| 2768 | |
| 2769 | fh[0] = inode->i_generation; |
| 2770 | fh[1] = inode->i_ino; |
| 2771 | fh[2] = ((__u64)inode->i_ino) >> 32; |
| 2772 | |
| 2773 | *len = 3; |
| 2774 | return 1; |
| 2775 | } |
| 2776 | |
Christoph Hellwig | 3965516 | 2007-10-21 16:42:17 -0700 | [diff] [blame] | 2777 | static const struct export_operations shmem_export_ops = { |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2778 | .get_parent = shmem_get_parent, |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2779 | .encode_fh = shmem_encode_fh, |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2780 | .fh_to_dentry = shmem_fh_to_dentry, |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2781 | }; |
| 2782 | |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2783 | static int shmem_parse_options(char *options, struct shmem_sb_info *sbinfo, |
| 2784 | bool remount) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2785 | { |
| 2786 | char *this_char, *value, *rest; |
Greg Thelen | 49cd0a5 | 2013-02-22 16:36:02 -0800 | [diff] [blame] | 2787 | struct mempolicy *mpol = NULL; |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 2788 | uid_t uid; |
| 2789 | gid_t gid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2790 | |
Hugh Dickins | b00dc3a | 2006-02-21 23:49:47 +0000 | [diff] [blame] | 2791 | while (options != NULL) { |
| 2792 | this_char = options; |
| 2793 | for (;;) { |
| 2794 | /* |
| 2795 | * NUL-terminate this option: unfortunately, |
| 2796 | * mount options form a comma-separated list, |
| 2797 | * but mpol's nodelist may also contain commas. |
| 2798 | */ |
| 2799 | options = strchr(options, ','); |
| 2800 | if (options == NULL) |
| 2801 | break; |
| 2802 | options++; |
| 2803 | if (!isdigit(*options)) { |
| 2804 | options[-1] = '\0'; |
| 2805 | break; |
| 2806 | } |
| 2807 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2808 | if (!*this_char) |
| 2809 | continue; |
| 2810 | if ((value = strchr(this_char,'=')) != NULL) { |
| 2811 | *value++ = 0; |
| 2812 | } else { |
Joe Perches | 1170532 | 2016-03-17 14:19:50 -0700 | [diff] [blame] | 2813 | pr_err("tmpfs: No value for mount option '%s'\n", |
| 2814 | this_char); |
Greg Thelen | 49cd0a5 | 2013-02-22 16:36:02 -0800 | [diff] [blame] | 2815 | goto error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2816 | } |
| 2817 | |
| 2818 | if (!strcmp(this_char,"size")) { |
| 2819 | unsigned long long size; |
| 2820 | size = memparse(value,&rest); |
| 2821 | if (*rest == '%') { |
| 2822 | size <<= PAGE_SHIFT; |
| 2823 | size *= totalram_pages; |
| 2824 | do_div(size, 100); |
| 2825 | rest++; |
| 2826 | } |
| 2827 | if (*rest) |
| 2828 | goto bad_val; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2829 | sbinfo->max_blocks = |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2830 | DIV_ROUND_UP(size, PAGE_SIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2831 | } else if (!strcmp(this_char,"nr_blocks")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2832 | sbinfo->max_blocks = memparse(value, &rest); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2833 | if (*rest) |
| 2834 | goto bad_val; |
| 2835 | } else if (!strcmp(this_char,"nr_inodes")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2836 | sbinfo->max_inodes = memparse(value, &rest); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2837 | if (*rest) |
| 2838 | goto bad_val; |
| 2839 | } else if (!strcmp(this_char,"mode")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2840 | if (remount) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2841 | continue; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2842 | sbinfo->mode = simple_strtoul(value, &rest, 8) & 07777; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2843 | if (*rest) |
| 2844 | goto bad_val; |
| 2845 | } else if (!strcmp(this_char,"uid")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2846 | if (remount) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2847 | continue; |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 2848 | uid = simple_strtoul(value, &rest, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2849 | if (*rest) |
| 2850 | goto bad_val; |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 2851 | sbinfo->uid = make_kuid(current_user_ns(), uid); |
| 2852 | if (!uid_valid(sbinfo->uid)) |
| 2853 | goto bad_val; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2854 | } else if (!strcmp(this_char,"gid")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2855 | if (remount) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2856 | continue; |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 2857 | gid = simple_strtoul(value, &rest, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2858 | if (*rest) |
| 2859 | goto bad_val; |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 2860 | sbinfo->gid = make_kgid(current_user_ns(), gid); |
| 2861 | if (!gid_valid(sbinfo->gid)) |
| 2862 | goto bad_val; |
Robin Holt | 7339ff8 | 2006-01-14 13:20:48 -0800 | [diff] [blame] | 2863 | } else if (!strcmp(this_char,"mpol")) { |
Greg Thelen | 49cd0a5 | 2013-02-22 16:36:02 -0800 | [diff] [blame] | 2864 | mpol_put(mpol); |
| 2865 | mpol = NULL; |
| 2866 | if (mpol_parse_str(value, &mpol)) |
Robin Holt | 7339ff8 | 2006-01-14 13:20:48 -0800 | [diff] [blame] | 2867 | goto bad_val; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2868 | } else { |
Joe Perches | 1170532 | 2016-03-17 14:19:50 -0700 | [diff] [blame] | 2869 | pr_err("tmpfs: Bad mount option %s\n", this_char); |
Greg Thelen | 49cd0a5 | 2013-02-22 16:36:02 -0800 | [diff] [blame] | 2870 | goto error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2871 | } |
| 2872 | } |
Greg Thelen | 49cd0a5 | 2013-02-22 16:36:02 -0800 | [diff] [blame] | 2873 | sbinfo->mpol = mpol; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2874 | return 0; |
| 2875 | |
| 2876 | bad_val: |
Joe Perches | 1170532 | 2016-03-17 14:19:50 -0700 | [diff] [blame] | 2877 | pr_err("tmpfs: Bad value '%s' for mount option '%s'\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2878 | value, this_char); |
Greg Thelen | 49cd0a5 | 2013-02-22 16:36:02 -0800 | [diff] [blame] | 2879 | error: |
| 2880 | mpol_put(mpol); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2881 | return 1; |
| 2882 | |
| 2883 | } |
| 2884 | |
| 2885 | static int shmem_remount_fs(struct super_block *sb, int *flags, char *data) |
| 2886 | { |
| 2887 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2888 | struct shmem_sb_info config = *sbinfo; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2889 | unsigned long inodes; |
| 2890 | int error = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2891 | |
Greg Thelen | 5f00110 | 2013-02-22 16:36:01 -0800 | [diff] [blame] | 2892 | config.mpol = NULL; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2893 | if (shmem_parse_options(data, &config, true)) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2894 | return error; |
| 2895 | |
| 2896 | spin_lock(&sbinfo->stat_lock); |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2897 | inodes = sbinfo->max_inodes - sbinfo->free_inodes; |
Tim Chen | 7e49629 | 2010-08-09 17:19:05 -0700 | [diff] [blame] | 2898 | if (percpu_counter_compare(&sbinfo->used_blocks, config.max_blocks) > 0) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2899 | goto out; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2900 | if (config.max_inodes < inodes) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2901 | goto out; |
| 2902 | /* |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 2903 | * Those tests disallow limited->unlimited while any are in use; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2904 | * but we must separately disallow unlimited->limited, because |
| 2905 | * in that case we have no record of how much is already in use. |
| 2906 | */ |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2907 | if (config.max_blocks && !sbinfo->max_blocks) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2908 | goto out; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2909 | if (config.max_inodes && !sbinfo->max_inodes) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2910 | goto out; |
| 2911 | |
| 2912 | error = 0; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2913 | sbinfo->max_blocks = config.max_blocks; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2914 | sbinfo->max_inodes = config.max_inodes; |
| 2915 | sbinfo->free_inodes = config.max_inodes - inodes; |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 2916 | |
Greg Thelen | 5f00110 | 2013-02-22 16:36:01 -0800 | [diff] [blame] | 2917 | /* |
| 2918 | * Preserve previous mempolicy unless mpol remount option was specified. |
| 2919 | */ |
| 2920 | if (config.mpol) { |
| 2921 | mpol_put(sbinfo->mpol); |
| 2922 | sbinfo->mpol = config.mpol; /* transfers initial ref */ |
| 2923 | } |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2924 | out: |
| 2925 | spin_unlock(&sbinfo->stat_lock); |
| 2926 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2927 | } |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2928 | |
Al Viro | 34c80b1 | 2011-12-08 21:32:45 -0500 | [diff] [blame] | 2929 | static int shmem_show_options(struct seq_file *seq, struct dentry *root) |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2930 | { |
Al Viro | 34c80b1 | 2011-12-08 21:32:45 -0500 | [diff] [blame] | 2931 | struct shmem_sb_info *sbinfo = SHMEM_SB(root->d_sb); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2932 | |
| 2933 | if (sbinfo->max_blocks != shmem_default_max_blocks()) |
| 2934 | seq_printf(seq, ",size=%luk", |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2935 | sbinfo->max_blocks << (PAGE_SHIFT - 10)); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2936 | if (sbinfo->max_inodes != shmem_default_max_inodes()) |
| 2937 | seq_printf(seq, ",nr_inodes=%lu", sbinfo->max_inodes); |
| 2938 | if (sbinfo->mode != (S_IRWXUGO | S_ISVTX)) |
Al Viro | 09208d1 | 2011-07-26 03:15:03 -0400 | [diff] [blame] | 2939 | seq_printf(seq, ",mode=%03ho", sbinfo->mode); |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 2940 | if (!uid_eq(sbinfo->uid, GLOBAL_ROOT_UID)) |
| 2941 | seq_printf(seq, ",uid=%u", |
| 2942 | from_kuid_munged(&init_user_ns, sbinfo->uid)); |
| 2943 | if (!gid_eq(sbinfo->gid, GLOBAL_ROOT_GID)) |
| 2944 | seq_printf(seq, ",gid=%u", |
| 2945 | from_kgid_munged(&init_user_ns, sbinfo->gid)); |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 2946 | shmem_show_mpol(seq, sbinfo->mpol); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2947 | return 0; |
| 2948 | } |
David Herrmann | 9183df2 | 2014-08-08 14:25:29 -0700 | [diff] [blame] | 2949 | |
| 2950 | #define MFD_NAME_PREFIX "memfd:" |
| 2951 | #define MFD_NAME_PREFIX_LEN (sizeof(MFD_NAME_PREFIX) - 1) |
| 2952 | #define MFD_NAME_MAX_LEN (NAME_MAX - MFD_NAME_PREFIX_LEN) |
| 2953 | |
| 2954 | #define MFD_ALL_FLAGS (MFD_CLOEXEC | MFD_ALLOW_SEALING) |
| 2955 | |
| 2956 | SYSCALL_DEFINE2(memfd_create, |
| 2957 | const char __user *, uname, |
| 2958 | unsigned int, flags) |
| 2959 | { |
| 2960 | struct shmem_inode_info *info; |
| 2961 | struct file *file; |
| 2962 | int fd, error; |
| 2963 | char *name; |
| 2964 | long len; |
| 2965 | |
| 2966 | if (flags & ~(unsigned int)MFD_ALL_FLAGS) |
| 2967 | return -EINVAL; |
| 2968 | |
| 2969 | /* length includes terminating zero */ |
| 2970 | len = strnlen_user(uname, MFD_NAME_MAX_LEN + 1); |
| 2971 | if (len <= 0) |
| 2972 | return -EFAULT; |
| 2973 | if (len > MFD_NAME_MAX_LEN + 1) |
| 2974 | return -EINVAL; |
| 2975 | |
| 2976 | name = kmalloc(len + MFD_NAME_PREFIX_LEN, GFP_TEMPORARY); |
| 2977 | if (!name) |
| 2978 | return -ENOMEM; |
| 2979 | |
| 2980 | strcpy(name, MFD_NAME_PREFIX); |
| 2981 | if (copy_from_user(&name[MFD_NAME_PREFIX_LEN], uname, len)) { |
| 2982 | error = -EFAULT; |
| 2983 | goto err_name; |
| 2984 | } |
| 2985 | |
| 2986 | /* terminating-zero may have changed after strnlen_user() returned */ |
| 2987 | if (name[len + MFD_NAME_PREFIX_LEN - 1]) { |
| 2988 | error = -EFAULT; |
| 2989 | goto err_name; |
| 2990 | } |
| 2991 | |
| 2992 | fd = get_unused_fd_flags((flags & MFD_CLOEXEC) ? O_CLOEXEC : 0); |
| 2993 | if (fd < 0) { |
| 2994 | error = fd; |
| 2995 | goto err_name; |
| 2996 | } |
| 2997 | |
| 2998 | file = shmem_file_setup(name, 0, VM_NORESERVE); |
| 2999 | if (IS_ERR(file)) { |
| 3000 | error = PTR_ERR(file); |
| 3001 | goto err_fd; |
| 3002 | } |
| 3003 | info = SHMEM_I(file_inode(file)); |
| 3004 | file->f_mode |= FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE; |
| 3005 | file->f_flags |= O_RDWR | O_LARGEFILE; |
| 3006 | if (flags & MFD_ALLOW_SEALING) |
| 3007 | info->seals &= ~F_SEAL_SEAL; |
| 3008 | |
| 3009 | fd_install(fd, file); |
| 3010 | kfree(name); |
| 3011 | return fd; |
| 3012 | |
| 3013 | err_fd: |
| 3014 | put_unused_fd(fd); |
| 3015 | err_name: |
| 3016 | kfree(name); |
| 3017 | return error; |
| 3018 | } |
| 3019 | |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3020 | #endif /* CONFIG_TMPFS */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3021 | |
| 3022 | static void shmem_put_super(struct super_block *sb) |
| 3023 | { |
Hugh Dickins | 602586a | 2010-08-17 15:23:56 -0700 | [diff] [blame] | 3024 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 3025 | |
| 3026 | percpu_counter_destroy(&sbinfo->used_blocks); |
Greg Thelen | 49cd0a5 | 2013-02-22 16:36:02 -0800 | [diff] [blame] | 3027 | mpol_put(sbinfo->mpol); |
Hugh Dickins | 602586a | 2010-08-17 15:23:56 -0700 | [diff] [blame] | 3028 | kfree(sbinfo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3029 | sb->s_fs_info = NULL; |
| 3030 | } |
| 3031 | |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 3032 | int shmem_fill_super(struct super_block *sb, void *data, int silent) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3033 | { |
| 3034 | struct inode *inode; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3035 | struct shmem_sb_info *sbinfo; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3036 | int err = -ENOMEM; |
| 3037 | |
| 3038 | /* Round up to L1_CACHE_BYTES to resist false sharing */ |
Pekka Enberg | 425fbf0 | 2009-09-21 17:03:50 -0700 | [diff] [blame] | 3039 | sbinfo = kzalloc(max((int)sizeof(struct shmem_sb_info), |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3040 | L1_CACHE_BYTES), GFP_KERNEL); |
| 3041 | if (!sbinfo) |
| 3042 | return -ENOMEM; |
| 3043 | |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3044 | sbinfo->mode = S_IRWXUGO | S_ISVTX; |
David Howells | 76aac0e | 2008-11-14 10:39:12 +1100 | [diff] [blame] | 3045 | sbinfo->uid = current_fsuid(); |
| 3046 | sbinfo->gid = current_fsgid(); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3047 | sb->s_fs_info = sbinfo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3048 | |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3049 | #ifdef CONFIG_TMPFS |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3050 | /* |
| 3051 | * Per default we only allow half of the physical ram per |
| 3052 | * tmpfs instance, limiting inodes to one per page of lowmem; |
| 3053 | * but the internal instance is left unlimited. |
| 3054 | */ |
Al Viro | ca4e051 | 2013-08-31 12:57:10 -0400 | [diff] [blame] | 3055 | if (!(sb->s_flags & MS_KERNMOUNT)) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3056 | sbinfo->max_blocks = shmem_default_max_blocks(); |
| 3057 | sbinfo->max_inodes = shmem_default_max_inodes(); |
| 3058 | if (shmem_parse_options(data, sbinfo, false)) { |
| 3059 | err = -EINVAL; |
| 3060 | goto failed; |
| 3061 | } |
Al Viro | ca4e051 | 2013-08-31 12:57:10 -0400 | [diff] [blame] | 3062 | } else { |
| 3063 | sb->s_flags |= MS_NOUSER; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3064 | } |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3065 | sb->s_export_op = &shmem_export_ops; |
Hugh Dickins | 2f6e38f | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 3066 | sb->s_flags |= MS_NOSEC; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3067 | #else |
| 3068 | sb->s_flags |= MS_NOUSER; |
| 3069 | #endif |
| 3070 | |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3071 | spin_lock_init(&sbinfo->stat_lock); |
Tejun Heo | 908c7f1 | 2014-09-08 09:51:29 +0900 | [diff] [blame] | 3072 | if (percpu_counter_init(&sbinfo->used_blocks, 0, GFP_KERNEL)) |
Hugh Dickins | 602586a | 2010-08-17 15:23:56 -0700 | [diff] [blame] | 3073 | goto failed; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3074 | sbinfo->free_inodes = sbinfo->max_inodes; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3075 | |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 3076 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 3077 | sb->s_blocksize = PAGE_SIZE; |
| 3078 | sb->s_blocksize_bits = PAGE_SHIFT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3079 | sb->s_magic = TMPFS_MAGIC; |
| 3080 | sb->s_op = &shmem_ops; |
Robin H. Johnson | cfd95a9 | 2006-06-12 21:50:25 +0100 | [diff] [blame] | 3081 | sb->s_time_gran = 1; |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3082 | #ifdef CONFIG_TMPFS_XATTR |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 3083 | sb->s_xattr = shmem_xattr_handlers; |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3084 | #endif |
| 3085 | #ifdef CONFIG_TMPFS_POSIX_ACL |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 3086 | sb->s_flags |= MS_POSIXACL; |
| 3087 | #endif |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3088 | |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 3089 | inode = shmem_get_inode(sb, NULL, S_IFDIR | sbinfo->mode, 0, VM_NORESERVE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3090 | if (!inode) |
| 3091 | goto failed; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3092 | inode->i_uid = sbinfo->uid; |
| 3093 | inode->i_gid = sbinfo->gid; |
Al Viro | 318ceed | 2012-02-12 22:08:01 -0500 | [diff] [blame] | 3094 | sb->s_root = d_make_root(inode); |
| 3095 | if (!sb->s_root) |
Al Viro | 48fde70 | 2012-01-08 22:15:13 -0500 | [diff] [blame] | 3096 | goto failed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3097 | return 0; |
| 3098 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3099 | failed: |
| 3100 | shmem_put_super(sb); |
| 3101 | return err; |
| 3102 | } |
| 3103 | |
Pekka Enberg | fcc234f | 2006-03-22 00:08:13 -0800 | [diff] [blame] | 3104 | static struct kmem_cache *shmem_inode_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3105 | |
| 3106 | static struct inode *shmem_alloc_inode(struct super_block *sb) |
| 3107 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3108 | struct shmem_inode_info *info; |
| 3109 | info = kmem_cache_alloc(shmem_inode_cachep, GFP_KERNEL); |
| 3110 | if (!info) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3111 | return NULL; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3112 | return &info->vfs_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3113 | } |
| 3114 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3115 | static void shmem_destroy_callback(struct rcu_head *head) |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 3116 | { |
| 3117 | struct inode *inode = container_of(head, struct inode, i_rcu); |
Al Viro | 84e710d | 2016-04-15 00:58:55 -0400 | [diff] [blame] | 3118 | if (S_ISLNK(inode->i_mode)) |
| 3119 | kfree(inode->i_link); |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 3120 | kmem_cache_free(shmem_inode_cachep, SHMEM_I(inode)); |
| 3121 | } |
| 3122 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3123 | static void shmem_destroy_inode(struct inode *inode) |
| 3124 | { |
Al Viro | 09208d1 | 2011-07-26 03:15:03 -0400 | [diff] [blame] | 3125 | if (S_ISREG(inode->i_mode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3126 | mpol_free_shared_policy(&SHMEM_I(inode)->policy); |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3127 | call_rcu(&inode->i_rcu, shmem_destroy_callback); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3128 | } |
| 3129 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3130 | static void shmem_init_inode(void *foo) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3131 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3132 | struct shmem_inode_info *info = foo; |
| 3133 | inode_init_once(&info->vfs_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3134 | } |
| 3135 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3136 | static int shmem_init_inodecache(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3137 | { |
| 3138 | shmem_inode_cachep = kmem_cache_create("shmem_inode_cache", |
| 3139 | sizeof(struct shmem_inode_info), |
Vladimir Davydov | 5d09705 | 2016-01-14 15:18:21 -0800 | [diff] [blame] | 3140 | 0, SLAB_PANIC|SLAB_ACCOUNT, shmem_init_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3141 | return 0; |
| 3142 | } |
| 3143 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3144 | static void shmem_destroy_inodecache(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3145 | { |
Alexey Dobriyan | 1a1d92c | 2006-09-27 01:49:40 -0700 | [diff] [blame] | 3146 | kmem_cache_destroy(shmem_inode_cachep); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3147 | } |
| 3148 | |
Christoph Hellwig | f5e54d6 | 2006-06-28 04:26:44 -0700 | [diff] [blame] | 3149 | static const struct address_space_operations shmem_aops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3150 | .writepage = shmem_writepage, |
Ken Chen | 7671932 | 2007-02-10 01:43:15 -0800 | [diff] [blame] | 3151 | .set_page_dirty = __set_page_dirty_no_writeback, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3152 | #ifdef CONFIG_TMPFS |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 3153 | .write_begin = shmem_write_begin, |
| 3154 | .write_end = shmem_write_end, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3155 | #endif |
Andrew Morton | 1c93923 | 2014-10-09 15:27:59 -0700 | [diff] [blame] | 3156 | #ifdef CONFIG_MIGRATION |
Lee Schermerhorn | 304dbdb | 2006-04-22 02:35:48 -0700 | [diff] [blame] | 3157 | .migratepage = migrate_page, |
Andrew Morton | 1c93923 | 2014-10-09 15:27:59 -0700 | [diff] [blame] | 3158 | #endif |
Andi Kleen | aa261f5 | 2009-09-16 11:50:16 +0200 | [diff] [blame] | 3159 | .error_remove_page = generic_error_remove_page, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3160 | }; |
| 3161 | |
Helge Deller | 15ad7cd | 2006-12-06 20:40:36 -0800 | [diff] [blame] | 3162 | static const struct file_operations shmem_file_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3163 | .mmap = shmem_mmap, |
| 3164 | #ifdef CONFIG_TMPFS |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 3165 | .llseek = shmem_file_llseek, |
Al Viro | 2ba5bbe | 2014-04-02 20:00:02 -0400 | [diff] [blame] | 3166 | .read_iter = shmem_file_read_iter, |
Al Viro | 8174202 | 2014-04-03 03:17:43 -0400 | [diff] [blame] | 3167 | .write_iter = generic_file_write_iter, |
Christoph Hellwig | 1b061d9 | 2010-05-26 17:53:41 +0200 | [diff] [blame] | 3168 | .fsync = noop_fsync, |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 3169 | .splice_read = shmem_file_splice_read, |
Al Viro | f6cb85d | 2014-04-05 04:38:56 -0400 | [diff] [blame] | 3170 | .splice_write = iter_file_splice_write, |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 3171 | .fallocate = shmem_fallocate, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3172 | #endif |
| 3173 | }; |
| 3174 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 3175 | static const struct inode_operations shmem_inode_operations = { |
Yu Zhao | 44a3022 | 2015-09-08 15:03:33 -0700 | [diff] [blame] | 3176 | .getattr = shmem_getattr, |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 3177 | .setattr = shmem_setattr, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3178 | #ifdef CONFIG_TMPFS_XATTR |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 3179 | .setxattr = generic_setxattr, |
| 3180 | .getxattr = generic_getxattr, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3181 | .listxattr = shmem_listxattr, |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 3182 | .removexattr = generic_removexattr, |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 3183 | .set_acl = simple_set_acl, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3184 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3185 | }; |
| 3186 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 3187 | static const struct inode_operations shmem_dir_inode_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3188 | #ifdef CONFIG_TMPFS |
| 3189 | .create = shmem_create, |
| 3190 | .lookup = simple_lookup, |
| 3191 | .link = shmem_link, |
| 3192 | .unlink = shmem_unlink, |
| 3193 | .symlink = shmem_symlink, |
| 3194 | .mkdir = shmem_mkdir, |
| 3195 | .rmdir = shmem_rmdir, |
| 3196 | .mknod = shmem_mknod, |
Miklos Szeredi | 3b69ff5 | 2014-07-23 15:15:33 +0200 | [diff] [blame] | 3197 | .rename2 = shmem_rename2, |
Al Viro | 60545d0 | 2013-06-07 01:20:27 -0400 | [diff] [blame] | 3198 | .tmpfile = shmem_tmpfile, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3199 | #endif |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3200 | #ifdef CONFIG_TMPFS_XATTR |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 3201 | .setxattr = generic_setxattr, |
| 3202 | .getxattr = generic_getxattr, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3203 | .listxattr = shmem_listxattr, |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 3204 | .removexattr = generic_removexattr, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3205 | #endif |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 3206 | #ifdef CONFIG_TMPFS_POSIX_ACL |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 3207 | .setattr = shmem_setattr, |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 3208 | .set_acl = simple_set_acl, |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 3209 | #endif |
| 3210 | }; |
| 3211 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 3212 | static const struct inode_operations shmem_special_inode_operations = { |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3213 | #ifdef CONFIG_TMPFS_XATTR |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 3214 | .setxattr = generic_setxattr, |
| 3215 | .getxattr = generic_getxattr, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3216 | .listxattr = shmem_listxattr, |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 3217 | .removexattr = generic_removexattr, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3218 | #endif |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 3219 | #ifdef CONFIG_TMPFS_POSIX_ACL |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 3220 | .setattr = shmem_setattr, |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 3221 | .set_acl = simple_set_acl, |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 3222 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3223 | }; |
| 3224 | |
Hugh Dickins | 759b977 | 2007-03-05 00:30:28 -0800 | [diff] [blame] | 3225 | static const struct super_operations shmem_ops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3226 | .alloc_inode = shmem_alloc_inode, |
| 3227 | .destroy_inode = shmem_destroy_inode, |
| 3228 | #ifdef CONFIG_TMPFS |
| 3229 | .statfs = shmem_statfs, |
| 3230 | .remount_fs = shmem_remount_fs, |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3231 | .show_options = shmem_show_options, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3232 | #endif |
Al Viro | 1f895f7 | 2010-06-05 19:10:41 -0400 | [diff] [blame] | 3233 | .evict_inode = shmem_evict_inode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3234 | .drop_inode = generic_delete_inode, |
| 3235 | .put_super = shmem_put_super, |
| 3236 | }; |
| 3237 | |
Alexey Dobriyan | f0f37e2 | 2009-09-27 22:29:37 +0400 | [diff] [blame] | 3238 | static const struct vm_operations_struct shmem_vm_ops = { |
Nick Piggin | 54cb882 | 2007-07-19 01:46:59 -0700 | [diff] [blame] | 3239 | .fault = shmem_fault, |
Ning Qu | d7c1755 | 2014-04-07 15:37:24 -0700 | [diff] [blame] | 3240 | .map_pages = filemap_map_pages, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3241 | #ifdef CONFIG_NUMA |
| 3242 | .set_policy = shmem_set_policy, |
| 3243 | .get_policy = shmem_get_policy, |
| 3244 | #endif |
| 3245 | }; |
| 3246 | |
Al Viro | 3c26ff6 | 2010-07-25 11:46:36 +0400 | [diff] [blame] | 3247 | static struct dentry *shmem_mount(struct file_system_type *fs_type, |
| 3248 | int flags, const char *dev_name, void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3249 | { |
Al Viro | 3c26ff6 | 2010-07-25 11:46:36 +0400 | [diff] [blame] | 3250 | return mount_nodev(fs_type, flags, data, shmem_fill_super); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3251 | } |
| 3252 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3253 | static struct file_system_type shmem_fs_type = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3254 | .owner = THIS_MODULE, |
| 3255 | .name = "tmpfs", |
Al Viro | 3c26ff6 | 2010-07-25 11:46:36 +0400 | [diff] [blame] | 3256 | .mount = shmem_mount, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3257 | .kill_sb = kill_litter_super, |
Eric W. Biederman | 2b8576c | 2013-01-25 16:32:10 -0800 | [diff] [blame] | 3258 | .fs_flags = FS_USERNS_MOUNT, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3259 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3260 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3261 | int __init shmem_init(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3262 | { |
| 3263 | int error; |
| 3264 | |
Rob Landley | 16203a7 | 2013-09-11 14:26:12 -0700 | [diff] [blame] | 3265 | /* If rootfs called this, don't re-init */ |
| 3266 | if (shmem_inode_cachep) |
| 3267 | return 0; |
| 3268 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3269 | error = shmem_init_inodecache(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3270 | if (error) |
| 3271 | goto out3; |
| 3272 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3273 | error = register_filesystem(&shmem_fs_type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3274 | if (error) { |
Joe Perches | 1170532 | 2016-03-17 14:19:50 -0700 | [diff] [blame] | 3275 | pr_err("Could not register tmpfs\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3276 | goto out2; |
| 3277 | } |
Greg Kroah-Hartman | 95dc112 | 2005-06-20 21:15:16 -0700 | [diff] [blame] | 3278 | |
Al Viro | ca4e051 | 2013-08-31 12:57:10 -0400 | [diff] [blame] | 3279 | shm_mnt = kern_mount(&shmem_fs_type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3280 | if (IS_ERR(shm_mnt)) { |
| 3281 | error = PTR_ERR(shm_mnt); |
Joe Perches | 1170532 | 2016-03-17 14:19:50 -0700 | [diff] [blame] | 3282 | pr_err("Could not kern_mount tmpfs\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3283 | goto out1; |
| 3284 | } |
| 3285 | return 0; |
| 3286 | |
| 3287 | out1: |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3288 | unregister_filesystem(&shmem_fs_type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3289 | out2: |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3290 | shmem_destroy_inodecache(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3291 | out3: |
| 3292 | shm_mnt = ERR_PTR(error); |
| 3293 | return error; |
| 3294 | } |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 3295 | |
| 3296 | #else /* !CONFIG_SHMEM */ |
| 3297 | |
| 3298 | /* |
| 3299 | * tiny-shmem: simple shmemfs and tmpfs using ramfs code |
| 3300 | * |
| 3301 | * This is intended for small system where the benefits of the full |
| 3302 | * shmem code (swap-backed and resource-limited) are outweighed by |
| 3303 | * their complexity. On systems without swap this code should be |
| 3304 | * effectively equivalent, but much lighter weight. |
| 3305 | */ |
| 3306 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3307 | static struct file_system_type shmem_fs_type = { |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 3308 | .name = "tmpfs", |
Al Viro | 3c26ff6 | 2010-07-25 11:46:36 +0400 | [diff] [blame] | 3309 | .mount = ramfs_mount, |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 3310 | .kill_sb = kill_litter_super, |
Eric W. Biederman | 2b8576c | 2013-01-25 16:32:10 -0800 | [diff] [blame] | 3311 | .fs_flags = FS_USERNS_MOUNT, |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 3312 | }; |
| 3313 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3314 | int __init shmem_init(void) |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 3315 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3316 | BUG_ON(register_filesystem(&shmem_fs_type) != 0); |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 3317 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3318 | shm_mnt = kern_mount(&shmem_fs_type); |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 3319 | BUG_ON(IS_ERR(shm_mnt)); |
| 3320 | |
| 3321 | return 0; |
| 3322 | } |
| 3323 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3324 | int shmem_unuse(swp_entry_t swap, struct page *page) |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 3325 | { |
| 3326 | return 0; |
| 3327 | } |
| 3328 | |
Hugh Dickins | 3f96b79 | 2009-09-21 17:03:37 -0700 | [diff] [blame] | 3329 | int shmem_lock(struct file *file, int lock, struct user_struct *user) |
| 3330 | { |
| 3331 | return 0; |
| 3332 | } |
| 3333 | |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 3334 | void shmem_unlock_mapping(struct address_space *mapping) |
| 3335 | { |
| 3336 | } |
| 3337 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3338 | void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend) |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 3339 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3340 | truncate_inode_pages_range(inode->i_mapping, lstart, lend); |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 3341 | } |
| 3342 | EXPORT_SYMBOL_GPL(shmem_truncate_range); |
| 3343 | |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 3344 | #define shmem_vm_ops generic_file_vm_ops |
| 3345 | #define shmem_file_operations ramfs_file_operations |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 3346 | #define shmem_get_inode(sb, dir, mode, dev, flags) ramfs_get_inode(sb, dir, mode, dev) |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 3347 | #define shmem_acct_size(flags, size) 0 |
| 3348 | #define shmem_unacct_size(flags, size) do {} while (0) |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 3349 | |
| 3350 | #endif /* CONFIG_SHMEM */ |
| 3351 | |
| 3352 | /* common code */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3353 | |
Al Viro | 3451538 | 2013-02-14 22:38:02 -0500 | [diff] [blame] | 3354 | static struct dentry_operations anon_ops = { |
Al Viro | 118b230 | 2013-08-24 12:08:17 -0400 | [diff] [blame] | 3355 | .d_dname = simple_dname |
Al Viro | 3451538 | 2013-02-14 22:38:02 -0500 | [diff] [blame] | 3356 | }; |
| 3357 | |
Eric Paris | c727709 | 2013-12-02 11:24:19 +0000 | [diff] [blame] | 3358 | static struct file *__shmem_file_setup(const char *name, loff_t size, |
| 3359 | unsigned long flags, unsigned int i_flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3360 | { |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 3361 | struct file *res; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3362 | struct inode *inode; |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 3363 | struct path path; |
Al Viro | 3451538 | 2013-02-14 22:38:02 -0500 | [diff] [blame] | 3364 | struct super_block *sb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3365 | struct qstr this; |
| 3366 | |
| 3367 | if (IS_ERR(shm_mnt)) |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 3368 | return ERR_CAST(shm_mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3369 | |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 3370 | if (size < 0 || size > MAX_LFS_FILESIZE) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3371 | return ERR_PTR(-EINVAL); |
| 3372 | |
| 3373 | if (shmem_acct_size(flags, size)) |
| 3374 | return ERR_PTR(-ENOMEM); |
| 3375 | |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 3376 | res = ERR_PTR(-ENOMEM); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3377 | this.name = name; |
| 3378 | this.len = strlen(name); |
| 3379 | this.hash = 0; /* will go */ |
Al Viro | 3451538 | 2013-02-14 22:38:02 -0500 | [diff] [blame] | 3380 | sb = shm_mnt->mnt_sb; |
Konstantin Khlebnikov | 66ee4b8 | 2014-08-06 16:06:32 -0700 | [diff] [blame] | 3381 | path.mnt = mntget(shm_mnt); |
Al Viro | 3451538 | 2013-02-14 22:38:02 -0500 | [diff] [blame] | 3382 | path.dentry = d_alloc_pseudo(sb, &this); |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 3383 | if (!path.dentry) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3384 | goto put_memory; |
Al Viro | 3451538 | 2013-02-14 22:38:02 -0500 | [diff] [blame] | 3385 | d_set_d_op(path.dentry, &anon_ops); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3386 | |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 3387 | res = ERR_PTR(-ENOSPC); |
Al Viro | 3451538 | 2013-02-14 22:38:02 -0500 | [diff] [blame] | 3388 | inode = shmem_get_inode(sb, NULL, S_IFREG | S_IRWXUGO, 0, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3389 | if (!inode) |
Konstantin Khlebnikov | 66ee4b8 | 2014-08-06 16:06:32 -0700 | [diff] [blame] | 3390 | goto put_memory; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3391 | |
Eric Paris | c727709 | 2013-12-02 11:24:19 +0000 | [diff] [blame] | 3392 | inode->i_flags |= i_flags; |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 3393 | d_instantiate(path.dentry, inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3394 | inode->i_size = size; |
Miklos Szeredi | 6d6b77f | 2011-10-28 14:13:28 +0200 | [diff] [blame] | 3395 | clear_nlink(inode); /* It is unlinked */ |
Al Viro | 26567cd | 2013-03-01 20:22:53 -0500 | [diff] [blame] | 3396 | res = ERR_PTR(ramfs_nommu_expand_for_mapping(inode, size)); |
| 3397 | if (IS_ERR(res)) |
Konstantin Khlebnikov | 66ee4b8 | 2014-08-06 16:06:32 -0700 | [diff] [blame] | 3398 | goto put_path; |
Al Viro | 4b42af8 | 2009-08-05 18:25:56 +0400 | [diff] [blame] | 3399 | |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 3400 | res = alloc_file(&path, FMODE_WRITE | FMODE_READ, |
Al Viro | 4b42af8 | 2009-08-05 18:25:56 +0400 | [diff] [blame] | 3401 | &shmem_file_operations); |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 3402 | if (IS_ERR(res)) |
Konstantin Khlebnikov | 66ee4b8 | 2014-08-06 16:06:32 -0700 | [diff] [blame] | 3403 | goto put_path; |
Al Viro | 4b42af8 | 2009-08-05 18:25:56 +0400 | [diff] [blame] | 3404 | |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 3405 | return res; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3406 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3407 | put_memory: |
| 3408 | shmem_unacct_size(flags, size); |
Konstantin Khlebnikov | 66ee4b8 | 2014-08-06 16:06:32 -0700 | [diff] [blame] | 3409 | put_path: |
| 3410 | path_put(&path); |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 3411 | return res; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3412 | } |
Eric Paris | c727709 | 2013-12-02 11:24:19 +0000 | [diff] [blame] | 3413 | |
| 3414 | /** |
| 3415 | * shmem_kernel_file_setup - get an unlinked file living in tmpfs which must be |
| 3416 | * kernel internal. There will be NO LSM permission checks against the |
| 3417 | * underlying inode. So users of this interface must do LSM checks at a |
Stephen Smalley | e1832f2 | 2015-08-06 15:46:55 -0700 | [diff] [blame] | 3418 | * higher layer. The users are the big_key and shm implementations. LSM |
| 3419 | * checks are provided at the key or shm level rather than the inode. |
Eric Paris | c727709 | 2013-12-02 11:24:19 +0000 | [diff] [blame] | 3420 | * @name: name for dentry (to be seen in /proc/<pid>/maps |
| 3421 | * @size: size to be set for the file |
| 3422 | * @flags: VM_NORESERVE suppresses pre-accounting of the entire object size |
| 3423 | */ |
| 3424 | struct file *shmem_kernel_file_setup(const char *name, loff_t size, unsigned long flags) |
| 3425 | { |
| 3426 | return __shmem_file_setup(name, size, flags, S_PRIVATE); |
| 3427 | } |
| 3428 | |
| 3429 | /** |
| 3430 | * shmem_file_setup - get an unlinked file living in tmpfs |
| 3431 | * @name: name for dentry (to be seen in /proc/<pid>/maps |
| 3432 | * @size: size to be set for the file |
| 3433 | * @flags: VM_NORESERVE suppresses pre-accounting of the entire object size |
| 3434 | */ |
| 3435 | struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags) |
| 3436 | { |
| 3437 | return __shmem_file_setup(name, size, flags, 0); |
| 3438 | } |
Keith Packard | 395e0dd | 2008-06-20 00:08:06 -0700 | [diff] [blame] | 3439 | EXPORT_SYMBOL_GPL(shmem_file_setup); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3440 | |
Randy Dunlap | 4671181 | 2008-03-19 17:00:41 -0700 | [diff] [blame] | 3441 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3442 | * shmem_zero_setup - setup a shared anonymous mapping |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3443 | * @vma: the vma to be mmapped is prepared by do_mmap_pgoff |
| 3444 | */ |
| 3445 | int shmem_zero_setup(struct vm_area_struct *vma) |
| 3446 | { |
| 3447 | struct file *file; |
| 3448 | loff_t size = vma->vm_end - vma->vm_start; |
| 3449 | |
Hugh Dickins | 66fc130 | 2015-06-14 09:48:09 -0700 | [diff] [blame] | 3450 | /* |
| 3451 | * Cloning a new file under mmap_sem leads to a lock ordering conflict |
| 3452 | * between XFS directory reading and selinux: since this file is only |
| 3453 | * accessible to the user through its mapping, use S_PRIVATE flag to |
| 3454 | * bypass file security, in the same way as shmem_kernel_file_setup(). |
| 3455 | */ |
| 3456 | file = __shmem_file_setup("dev/zero", size, vma->vm_flags, S_PRIVATE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3457 | if (IS_ERR(file)) |
| 3458 | return PTR_ERR(file); |
| 3459 | |
| 3460 | if (vma->vm_file) |
| 3461 | fput(vma->vm_file); |
| 3462 | vma->vm_file = file; |
| 3463 | vma->vm_ops = &shmem_vm_ops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3464 | return 0; |
| 3465 | } |
Hugh Dickins | d9d90e5 | 2011-06-27 16:18:04 -0700 | [diff] [blame] | 3466 | |
| 3467 | /** |
| 3468 | * shmem_read_mapping_page_gfp - read into page cache, using specified page allocation flags. |
| 3469 | * @mapping: the page's address_space |
| 3470 | * @index: the page index |
| 3471 | * @gfp: the page allocator flags to use if allocating |
| 3472 | * |
| 3473 | * This behaves as a tmpfs "read_cache_page_gfp(mapping, index, gfp)", |
| 3474 | * with any new page allocations done using the specified allocation flags. |
| 3475 | * But read_cache_page_gfp() uses the ->readpage() method: which does not |
| 3476 | * suit tmpfs, since it may have pages in swapcache, and needs to find those |
| 3477 | * for itself; although drivers/gpu/drm i915 and ttm rely upon this support. |
| 3478 | * |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 3479 | * i915_gem_object_get_pages_gtt() mixes __GFP_NORETRY | __GFP_NOWARN in |
| 3480 | * with the mapping_gfp_mask(), to avoid OOMing the machine unnecessarily. |
Hugh Dickins | d9d90e5 | 2011-06-27 16:18:04 -0700 | [diff] [blame] | 3481 | */ |
| 3482 | struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, |
| 3483 | pgoff_t index, gfp_t gfp) |
| 3484 | { |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 3485 | #ifdef CONFIG_SHMEM |
| 3486 | struct inode *inode = mapping->host; |
Hugh Dickins | 9276aad | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 3487 | struct page *page; |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 3488 | int error; |
| 3489 | |
| 3490 | BUG_ON(mapping->a_ops != &shmem_aops); |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 3491 | error = shmem_getpage_gfp(inode, index, &page, SGP_CACHE, |
| 3492 | gfp, NULL, NULL); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 3493 | if (error) |
| 3494 | page = ERR_PTR(error); |
| 3495 | else |
| 3496 | unlock_page(page); |
| 3497 | return page; |
| 3498 | #else |
| 3499 | /* |
| 3500 | * The tiny !SHMEM case uses ramfs without swap |
| 3501 | */ |
Hugh Dickins | d9d90e5 | 2011-06-27 16:18:04 -0700 | [diff] [blame] | 3502 | return read_cache_page_gfp(mapping, index, gfp); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 3503 | #endif |
Hugh Dickins | d9d90e5 | 2011-06-27 16:18:04 -0700 | [diff] [blame] | 3504 | } |
| 3505 | EXPORT_SYMBOL_GPL(shmem_read_mapping_page_gfp); |