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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/ext2/file.c
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * from
10 *
11 * linux/fs/minix/file.c
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 *
15 * ext2 fs regular file handling primitives
16 *
17 * 64-bit file support on 64-bit platforms by Jakub Jelinek
18 * (jj@sunsite.ms.mff.cuni.cz)
19 */
20
21#include <linux/time.h>
Jan Kara48bde862009-12-15 16:46:49 -080022#include <linux/pagemap.h>
Matthew Wilcoxc94c2ac2015-09-08 14:58:40 -070023#include <linux/dax.h>
Christoph Hellwig871a2932010-03-03 09:05:07 -050024#include <linux/quotaops.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include "ext2.h"
26#include "xattr.h"
27#include "acl.h"
28
Matthew Wilcox6cd176a2015-02-16 15:59:25 -080029#ifdef CONFIG_FS_DAX
Ross Zwisler5726b272015-10-13 16:25:37 -060030/*
31 * The lock ordering for ext2 DAX fault paths is:
32 *
33 * mmap_sem (MM)
34 * sb_start_pagefault (vfs, freeze)
35 * ext2_inode_info->dax_sem
36 * address_space->i_mmap_rwsem or page_lock (mutually exclusive in DAX)
37 * ext2_inode_info->truncate_mutex
38 *
39 * The default page_lock and i_size verification done by non-DAX fault paths
40 * is sufficient because ext2 doesn't support hole punching.
41 */
Matthew Wilcoxf7ca90b2015-02-16 15:59:02 -080042static int ext2_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
43{
Ross Zwisler5726b272015-10-13 16:25:37 -060044 struct inode *inode = file_inode(vma->vm_file);
45 struct ext2_inode_info *ei = EXT2_I(inode);
46 int ret;
47
48 if (vmf->flags & FAULT_FLAG_WRITE) {
49 sb_start_pagefault(inode->i_sb);
50 file_update_time(vma->vm_file);
51 }
52 down_read(&ei->dax_sem);
53
Ross Zwisler6b524992016-07-26 15:21:05 -070054 ret = dax_fault(vma, vmf, ext2_get_block);
Ross Zwisler5726b272015-10-13 16:25:37 -060055
56 up_read(&ei->dax_sem);
57 if (vmf->flags & FAULT_FLAG_WRITE)
58 sb_end_pagefault(inode->i_sb);
59 return ret;
Matthew Wilcoxf7ca90b2015-02-16 15:59:02 -080060}
61
Matthew Wilcoxe7b1ea22015-09-08 14:59:00 -070062static int ext2_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
63 pmd_t *pmd, unsigned int flags)
64{
Ross Zwisler5726b272015-10-13 16:25:37 -060065 struct inode *inode = file_inode(vma->vm_file);
66 struct ext2_inode_info *ei = EXT2_I(inode);
67 int ret;
68
69 if (flags & FAULT_FLAG_WRITE) {
70 sb_start_pagefault(inode->i_sb);
71 file_update_time(vma->vm_file);
72 }
73 down_read(&ei->dax_sem);
74
Ross Zwisler6b524992016-07-26 15:21:05 -070075 ret = dax_pmd_fault(vma, addr, pmd, flags, ext2_get_block);
Ross Zwisler5726b272015-10-13 16:25:37 -060076
77 up_read(&ei->dax_sem);
78 if (flags & FAULT_FLAG_WRITE)
79 sb_end_pagefault(inode->i_sb);
80 return ret;
Matthew Wilcoxe7b1ea22015-09-08 14:59:00 -070081}
82
Ross Zwisler5726b272015-10-13 16:25:37 -060083static int ext2_dax_pfn_mkwrite(struct vm_area_struct *vma,
84 struct vm_fault *vmf)
85{
86 struct inode *inode = file_inode(vma->vm_file);
87 struct ext2_inode_info *ei = EXT2_I(inode);
Ross Zwisler5726b272015-10-13 16:25:37 -060088 loff_t size;
Ross Zwisler80b4adc2016-01-22 15:10:50 -080089 int ret;
Ross Zwisler5726b272015-10-13 16:25:37 -060090
91 sb_start_pagefault(inode->i_sb);
92 file_update_time(vma->vm_file);
93 down_read(&ei->dax_sem);
94
95 /* check that the faulting page hasn't raced with truncate */
96 size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
97 if (vmf->pgoff >= size)
98 ret = VM_FAULT_SIGBUS;
Ross Zwisler80b4adc2016-01-22 15:10:50 -080099 else
100 ret = dax_pfn_mkwrite(vma, vmf);
Ross Zwisler5726b272015-10-13 16:25:37 -0600101
102 up_read(&ei->dax_sem);
103 sb_end_pagefault(inode->i_sb);
104 return ret;
Matthew Wilcoxf7ca90b2015-02-16 15:59:02 -0800105}
106
107static const struct vm_operations_struct ext2_dax_vm_ops = {
108 .fault = ext2_dax_fault,
Matthew Wilcoxe7b1ea22015-09-08 14:59:00 -0700109 .pmd_fault = ext2_dax_pmd_fault,
Ross Zwisler1e9d1802016-02-27 14:01:13 -0500110 .page_mkwrite = ext2_dax_fault,
Ross Zwisler5726b272015-10-13 16:25:37 -0600111 .pfn_mkwrite = ext2_dax_pfn_mkwrite,
Matthew Wilcoxf7ca90b2015-02-16 15:59:02 -0800112};
113
114static int ext2_file_mmap(struct file *file, struct vm_area_struct *vma)
115{
116 if (!IS_DAX(file_inode(file)))
117 return generic_file_mmap(file, vma);
118
119 file_accessed(file);
120 vma->vm_ops = &ext2_dax_vm_ops;
Matthew Wilcoxe7b1ea22015-09-08 14:59:00 -0700121 vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE;
Matthew Wilcoxf7ca90b2015-02-16 15:59:02 -0800122 return 0;
123}
124#else
125#define ext2_file_mmap generic_file_mmap
126#endif
127
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128/*
Jan Karaa6739af2007-07-15 23:40:22 -0700129 * Called when filp is released. This happens when all file descriptors
130 * for a single struct file are closed. Note that different open() calls
131 * for the same file yield different struct file structures.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 */
133static int ext2_release_file (struct inode * inode, struct file * filp)
134{
Martin J. Bligha686cd82007-10-16 23:30:46 -0700135 if (filp->f_mode & FMODE_WRITE) {
136 mutex_lock(&EXT2_I(inode)->truncate_mutex);
137 ext2_discard_reservation(inode);
138 mutex_unlock(&EXT2_I(inode)->truncate_mutex);
139 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 return 0;
141}
142
Josef Bacik02c24a82011-07-16 20:44:56 -0400143int ext2_fsync(struct file *file, loff_t start, loff_t end, int datasync)
Jan Kara48bde862009-12-15 16:46:49 -0800144{
145 int ret;
Christoph Hellwig7ea80852010-05-26 17:53:25 +0200146 struct super_block *sb = file->f_mapping->host->i_sb;
Jan Kara48bde862009-12-15 16:46:49 -0800147 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
148
Josef Bacik02c24a82011-07-16 20:44:56 -0400149 ret = generic_file_fsync(file, start, end, datasync);
Jan Kara48bde862009-12-15 16:46:49 -0800150 if (ret == -EIO || test_and_clear_bit(AS_EIO, &mapping->flags)) {
151 /* We don't really know where the IO error happened... */
152 ext2_error(sb, __func__,
153 "detected IO error when writing metadata buffers");
154 ret = -EIO;
155 }
156 return ret;
157}
158
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159/*
160 * We have mostly NULL's here: the current defaults are ok for
161 * the ext2 filesystem.
162 */
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -0800163const struct file_operations ext2_file_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 .llseek = generic_file_llseek,
Al Viroaad4f8b2014-04-02 14:33:16 -0400165 .read_iter = generic_file_read_iter,
Al Viro81742022014-04-03 03:17:43 -0400166 .write_iter = generic_file_write_iter,
Andi Kleen14f9f7b2008-02-06 01:40:10 -0800167 .unlocked_ioctl = ext2_ioctl,
David Howellse322ff02006-08-29 19:06:20 +0100168#ifdef CONFIG_COMPAT
169 .compat_ioctl = ext2_compat_ioctl,
170#endif
Matthew Wilcoxf7ca90b2015-02-16 15:59:02 -0800171 .mmap = ext2_file_mmap,
Christoph Hellwig907f4552010-03-03 09:05:06 -0500172 .open = dquot_file_open,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 .release = ext2_release_file,
Jan Kara48bde862009-12-15 16:46:49 -0800174 .fsync = ext2_fsync,
Jens Axboe5274f052006-03-30 15:15:30 +0200175 .splice_read = generic_file_splice_read,
Al Viro8d020762014-04-05 04:27:08 -0400176 .splice_write = iter_file_splice_write,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177};
178
Arjan van de Ven754661f2007-02-12 00:55:38 -0800179const struct inode_operations ext2_file_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180#ifdef CONFIG_EXT2_FS_XATTR
181 .setxattr = generic_setxattr,
182 .getxattr = generic_getxattr,
183 .listxattr = ext2_listxattr,
184 .removexattr = generic_removexattr,
185#endif
186 .setattr = ext2_setattr,
Christoph Hellwig4e34e712011-07-23 17:37:31 +0200187 .get_acl = ext2_get_acl,
Christoph Hellwig64e178a2013-12-20 05:16:44 -0800188 .set_acl = ext2_set_acl,
Josef Bacik68c9d702008-10-03 17:32:43 -0400189 .fiemap = ext2_fiemap,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190};