Greg Kroah-Hartman | b244131 | 2017-11-01 15:07:57 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | /* |
| 3 | * mm/fadvise.c |
| 4 | * |
| 5 | * Copyright (C) 2002, Linus Torvalds |
| 6 | * |
Francois Cami | e1f8e87 | 2008-10-15 22:01:59 -0700 | [diff] [blame] | 7 | * 11Jan2003 Andrew Morton |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 8 | * Initial version. |
| 9 | */ |
| 10 | |
| 11 | #include <linux/kernel.h> |
| 12 | #include <linux/file.h> |
| 13 | #include <linux/fs.h> |
| 14 | #include <linux/mm.h> |
| 15 | #include <linux/pagemap.h> |
| 16 | #include <linux/backing-dev.h> |
| 17 | #include <linux/pagevec.h> |
| 18 | #include <linux/fadvise.h> |
Andrew Morton | ebcf28e | 2006-03-24 03:18:04 -0800 | [diff] [blame] | 19 | #include <linux/writeback.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | #include <linux/syscalls.h> |
Mel Gorman | 67d46b2 | 2013-02-22 16:35:59 -0800 | [diff] [blame] | 21 | #include <linux/swap.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | |
| 23 | #include <asm/unistd.h> |
| 24 | |
| 25 | /* |
| 26 | * POSIX_FADV_WILLNEED could set PG_Referenced, and POSIX_FADV_NOREUSE could |
| 27 | * deactivate the pages and clear PG_Referenced. |
| 28 | */ |
Dominik Brodowski | 9d5b7c9 | 2018-03-11 11:34:45 +0100 | [diff] [blame] | 29 | |
Amir Goldstein | 45cd0fa | 2018-08-27 15:56:02 +0300 | [diff] [blame^] | 30 | static int generic_fadvise(struct file *file, loff_t offset, loff_t len, |
| 31 | int advice) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | { |
Matthew Wilcox | e748dcd | 2015-02-16 15:59:12 -0800 | [diff] [blame] | 33 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | struct address_space *mapping; |
| 35 | struct backing_dev_info *bdi; |
Andrew Morton | ebcf28e | 2006-03-24 03:18:04 -0800 | [diff] [blame] | 36 | loff_t endbyte; /* inclusive */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | pgoff_t start_index; |
| 38 | pgoff_t end_index; |
| 39 | unsigned long nrpages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | |
Amir Goldstein | 45cd0fa | 2018-08-27 15:56:02 +0300 | [diff] [blame^] | 41 | inode = file_inode(file); |
| 42 | if (S_ISFIFO(inode->i_mode)) |
| 43 | return -ESPIPE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | |
Amir Goldstein | 45cd0fa | 2018-08-27 15:56:02 +0300 | [diff] [blame^] | 45 | mapping = file->f_mapping; |
| 46 | if (!mapping || len < 0) |
| 47 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | |
Shakeel Butt | 3a77d21 | 2017-09-08 16:13:05 -0700 | [diff] [blame] | 49 | bdi = inode_to_bdi(mapping->host); |
| 50 | |
| 51 | if (IS_DAX(inode) || (bdi == &noop_backing_dev_info)) { |
Masatake YAMATO | b5beb1c | 2008-02-04 22:29:31 -0800 | [diff] [blame] | 52 | switch (advice) { |
| 53 | case POSIX_FADV_NORMAL: |
| 54 | case POSIX_FADV_RANDOM: |
| 55 | case POSIX_FADV_SEQUENTIAL: |
| 56 | case POSIX_FADV_WILLNEED: |
| 57 | case POSIX_FADV_NOREUSE: |
| 58 | case POSIX_FADV_DONTNEED: |
| 59 | /* no bad return value, but ignore advice */ |
| 60 | break; |
| 61 | default: |
Amir Goldstein | 45cd0fa | 2018-08-27 15:56:02 +0300 | [diff] [blame^] | 62 | return -EINVAL; |
Masatake YAMATO | b5beb1c | 2008-02-04 22:29:31 -0800 | [diff] [blame] | 63 | } |
Amir Goldstein | 45cd0fa | 2018-08-27 15:56:02 +0300 | [diff] [blame^] | 64 | return 0; |
Masatake YAMATO | b5beb1c | 2008-02-04 22:29:31 -0800 | [diff] [blame] | 65 | } |
Carsten Otte | fe77ba6 | 2005-06-23 22:05:29 -0700 | [diff] [blame] | 66 | |
Andrey Ryabinin | a718e28 | 2018-08-17 15:46:57 -0700 | [diff] [blame] | 67 | /* |
| 68 | * Careful about overflows. Len == 0 means "as much as possible". Use |
| 69 | * unsigned math because signed overflows are undefined and UBSan |
| 70 | * complains. |
| 71 | */ |
| 72 | endbyte = (u64)offset + (u64)len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | if (!len || endbyte < len) |
| 74 | endbyte = -1; |
Andrew Morton | ebcf28e | 2006-03-24 03:18:04 -0800 | [diff] [blame] | 75 | else |
| 76 | endbyte--; /* inclusive */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | switch (advice) { |
| 79 | case POSIX_FADV_NORMAL: |
Amir Goldstein | 45cd0fa | 2018-08-27 15:56:02 +0300 | [diff] [blame^] | 80 | file->f_ra.ra_pages = bdi->ra_pages; |
| 81 | spin_lock(&file->f_lock); |
| 82 | file->f_mode &= ~FMODE_RANDOM; |
| 83 | spin_unlock(&file->f_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 84 | break; |
| 85 | case POSIX_FADV_RANDOM: |
Amir Goldstein | 45cd0fa | 2018-08-27 15:56:02 +0300 | [diff] [blame^] | 86 | spin_lock(&file->f_lock); |
| 87 | file->f_mode |= FMODE_RANDOM; |
| 88 | spin_unlock(&file->f_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | break; |
| 90 | case POSIX_FADV_SEQUENTIAL: |
Amir Goldstein | 45cd0fa | 2018-08-27 15:56:02 +0300 | [diff] [blame^] | 91 | file->f_ra.ra_pages = bdi->ra_pages * 2; |
| 92 | spin_lock(&file->f_lock); |
| 93 | file->f_mode &= ~FMODE_RANDOM; |
| 94 | spin_unlock(&file->f_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 95 | break; |
| 96 | case POSIX_FADV_WILLNEED: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 97 | /* First and last PARTIAL page! */ |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 98 | start_index = offset >> PAGE_SHIFT; |
| 99 | end_index = endbyte >> PAGE_SHIFT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | |
| 101 | /* Careful about overflow on the "+1" */ |
| 102 | nrpages = end_index - start_index + 1; |
| 103 | if (!nrpages) |
| 104 | nrpages = ~0UL; |
KOSAKI Motohiro | 3d3727c | 2012-07-31 16:42:50 -0700 | [diff] [blame] | 105 | |
| 106 | /* |
| 107 | * Ignore return value because fadvise() shall return |
| 108 | * success even if filesystem can't retrieve a hint, |
| 109 | */ |
Amir Goldstein | 45cd0fa | 2018-08-27 15:56:02 +0300 | [diff] [blame^] | 110 | force_page_cache_readahead(mapping, file, start_index, nrpages); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | break; |
Andrew Morton | 60c371b | 2006-08-05 12:14:25 -0700 | [diff] [blame] | 112 | case POSIX_FADV_NOREUSE: |
| 113 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | case POSIX_FADV_DONTNEED: |
Tejun Heo | 703c270 | 2015-05-22 17:13:44 -0400 | [diff] [blame] | 115 | if (!inode_write_congested(mapping->host)) |
Shawn Bohrer | ad8a1b5 | 2012-01-10 15:07:35 -0800 | [diff] [blame] | 116 | __filemap_fdatawrite_range(mapping, offset, endbyte, |
| 117 | WB_SYNC_NONE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | |
Mel Gorman | 441c228 | 2014-12-12 16:56:33 -0800 | [diff] [blame] | 119 | /* |
| 120 | * First and last FULL page! Partial pages are deliberately |
| 121 | * preserved on the expectation that it is better to preserve |
| 122 | * needed memory than to discard unneeded memory. |
| 123 | */ |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 124 | start_index = (offset+(PAGE_SIZE-1)) >> PAGE_SHIFT; |
| 125 | end_index = (endbyte >> PAGE_SHIFT); |
shidao.ytt | a7ab400 | 2018-01-31 16:19:55 -0800 | [diff] [blame] | 126 | /* |
| 127 | * The page at end_index will be inclusively discarded according |
| 128 | * by invalidate_mapping_pages(), so subtracting 1 from |
| 129 | * end_index means we will skip the last page. But if endbyte |
| 130 | * is page aligned or is at the end of file, we should not skip |
| 131 | * that page - discarding the last page is safe enough. |
| 132 | */ |
| 133 | if ((endbyte & ~PAGE_MASK) != ~PAGE_MASK && |
| 134 | endbyte != inode->i_size - 1) { |
Oleg Drokin | 18aba41 | 2016-06-08 15:33:59 -0700 | [diff] [blame] | 135 | /* First page is tricky as 0 - 1 = -1, but pgoff_t |
| 136 | * is unsigned, so the end_index >= start_index |
| 137 | * check below would be true and we'll discard the whole |
| 138 | * file cache which is not what was asked. |
| 139 | */ |
| 140 | if (end_index == 0) |
| 141 | break; |
| 142 | |
| 143 | end_index--; |
| 144 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | |
Mel Gorman | 67d46b2 | 2013-02-22 16:35:59 -0800 | [diff] [blame] | 146 | if (end_index >= start_index) { |
Johannes Weiner | 4dd72b4 | 2016-12-19 16:23:03 -0800 | [diff] [blame] | 147 | unsigned long count; |
| 148 | |
| 149 | /* |
| 150 | * It's common to FADV_DONTNEED right after |
| 151 | * the read or write that instantiates the |
| 152 | * pages, in which case there will be some |
| 153 | * sitting on the local LRU cache. Try to |
| 154 | * avoid the expensive remote drain and the |
| 155 | * second cache tree walk below by flushing |
| 156 | * them out right away. |
| 157 | */ |
| 158 | lru_add_drain(); |
| 159 | |
| 160 | count = invalidate_mapping_pages(mapping, |
Mel Gorman | 67d46b2 | 2013-02-22 16:35:59 -0800 | [diff] [blame] | 161 | start_index, end_index); |
| 162 | |
| 163 | /* |
| 164 | * If fewer pages were invalidated than expected then |
| 165 | * it is possible that some of the pages were on |
| 166 | * a per-cpu pagevec for a remote CPU. Drain all |
| 167 | * pagevecs and try again. |
| 168 | */ |
| 169 | if (count < (end_index - start_index + 1)) { |
| 170 | lru_add_drain_all(); |
| 171 | invalidate_mapping_pages(mapping, start_index, |
Andrew Morton | ebcf28e | 2006-03-24 03:18:04 -0800 | [diff] [blame] | 172 | end_index); |
Mel Gorman | 67d46b2 | 2013-02-22 16:35:59 -0800 | [diff] [blame] | 173 | } |
| 174 | } |
Andrew Morton | ebcf28e | 2006-03-24 03:18:04 -0800 | [diff] [blame] | 175 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 176 | default: |
Amir Goldstein | 45cd0fa | 2018-08-27 15:56:02 +0300 | [diff] [blame^] | 177 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | } |
Amir Goldstein | 45cd0fa | 2018-08-27 15:56:02 +0300 | [diff] [blame^] | 179 | return 0; |
| 180 | } |
| 181 | |
| 182 | int vfs_fadvise(struct file *file, loff_t offset, loff_t len, int advice) |
| 183 | { |
| 184 | if (file->f_op->fadvise) |
| 185 | return file->f_op->fadvise(file, offset, len, advice); |
| 186 | |
| 187 | return generic_fadvise(file, offset, len, advice); |
| 188 | } |
| 189 | EXPORT_SYMBOL(vfs_fadvise); |
| 190 | |
| 191 | int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice) |
| 192 | { |
| 193 | struct fd f = fdget(fd); |
| 194 | int ret; |
| 195 | |
| 196 | if (!f.file) |
| 197 | return -EBADF; |
| 198 | |
| 199 | ret = vfs_fadvise(f.file, offset, len, advice); |
| 200 | |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 201 | fdput(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | return ret; |
| 203 | } |
| 204 | |
Dominik Brodowski | 9d5b7c9 | 2018-03-11 11:34:45 +0100 | [diff] [blame] | 205 | SYSCALL_DEFINE4(fadvise64_64, int, fd, loff_t, offset, loff_t, len, int, advice) |
| 206 | { |
| 207 | return ksys_fadvise64_64(fd, offset, len, advice); |
| 208 | } |
| 209 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 210 | #ifdef __ARCH_WANT_SYS_FADVISE64 |
| 211 | |
Al Viro | 4a0fd5b | 2013-01-21 15:16:58 -0500 | [diff] [blame] | 212 | SYSCALL_DEFINE4(fadvise64, int, fd, loff_t, offset, size_t, len, int, advice) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | { |
Dominik Brodowski | 9d5b7c9 | 2018-03-11 11:34:45 +0100 | [diff] [blame] | 214 | return ksys_fadvise64_64(fd, offset, len, advice); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | |
| 217 | #endif |