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1/*
2 * linux/fs/ext4/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 * ext4 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>
22#include <linux/fs.h>
23#include <linux/jbd2.h>
24#include <linux/mount.h>
25#include <linux/path.h>
26#include <linux/quotaops.h>
27#include "ext4.h"
28#include "ext4_jbd2.h"
29#include "xattr.h"
30#include "acl.h"
31
32/*
33 * Called when an inode is released. Note that this is different
34 * from ext4_file_open: open gets called at every open, but release
35 * gets called only when /all/ the files are closed.
36 */
37static int ext4_release_file(struct inode *inode, struct file *filp)
38{
39 if (ext4_test_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE)) {
40 ext4_alloc_da_blocks(inode);
41 ext4_clear_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
42 }
43 /* if we are the last writer on the inode, drop the block reservation */
44 if ((filp->f_mode & FMODE_WRITE) &&
45 (atomic_read(&inode->i_writecount) == 1) &&
46 !EXT4_I(inode)->i_reserved_data_blocks)
47 {
48 down_write(&EXT4_I(inode)->i_data_sem);
49 ext4_discard_preallocations(inode);
50 up_write(&EXT4_I(inode)->i_data_sem);
51 }
52 if (is_dx(inode) && filp->private_data)
53 ext4_htree_free_dir_info(filp->private_data);
54
55 return 0;
56}
57
58static void ext4_aiodio_wait(struct inode *inode)
59{
60 wait_queue_head_t *wq = ext4_ioend_wq(inode);
61
62 wait_event(*wq, (atomic_read(&EXT4_I(inode)->i_aiodio_unwritten) == 0));
63}
64
65/*
66 * This tests whether the IO in question is block-aligned or not.
67 * Ext4 utilizes unwritten extents when hole-filling during direct IO, and they
68 * are converted to written only after the IO is complete. Until they are
69 * mapped, these blocks appear as holes, so dio_zero_block() will assume that
70 * it needs to zero out portions of the start and/or end block. If 2 AIO
71 * threads are at work on the same unwritten block, they must be synchronized
72 * or one thread will zero the other's data, causing corruption.
73 */
74static int
75ext4_unaligned_aio(struct inode *inode, const struct iovec *iov,
76 unsigned long nr_segs, loff_t pos)
77{
78 struct super_block *sb = inode->i_sb;
79 int blockmask = sb->s_blocksize - 1;
80 size_t count = iov_length(iov, nr_segs);
81 loff_t final_size = pos + count;
82
83 if (pos >= inode->i_size)
84 return 0;
85
86 if ((pos & blockmask) || (final_size & blockmask))
87 return 1;
88
89 return 0;
90}
91
92static ssize_t
93ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
94 unsigned long nr_segs, loff_t pos)
95{
96 struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
97 int unaligned_aio = 0;
98 int ret;
99
100 /*
101 * If we have encountered a bitmap-format file, the size limit
102 * is smaller than s_maxbytes, which is for extent-mapped files.
103 */
104
105 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
106 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
107 size_t length = iov_length(iov, nr_segs);
108
109 if ((pos > sbi->s_bitmap_maxbytes ||
110 (pos == sbi->s_bitmap_maxbytes && length > 0)))
111 return -EFBIG;
112
113 if (pos + length > sbi->s_bitmap_maxbytes) {
114 nr_segs = iov_shorten((struct iovec *)iov, nr_segs,
115 sbi->s_bitmap_maxbytes - pos);
116 }
117 } else if (unlikely((iocb->ki_filp->f_flags & O_DIRECT) &&
118 !is_sync_kiocb(iocb))) {
119 unaligned_aio = ext4_unaligned_aio(inode, iov, nr_segs, pos);
120 }
121
122 /* Unaligned direct AIO must be serialized; see comment above */
123 if (unaligned_aio) {
124 static unsigned long unaligned_warn_time;
125
126 /* Warn about this once per day */
127 if (printk_timed_ratelimit(&unaligned_warn_time, 60*60*24*HZ))
128 ext4_msg(inode->i_sb, KERN_WARNING,
129 "Unaligned AIO/DIO on inode %ld by %s; "
130 "performance will be poor.",
131 inode->i_ino, current->comm);
132 mutex_lock(ext4_aio_mutex(inode));
133 ext4_aiodio_wait(inode);
134 }
135
136 ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
137
138 if (unaligned_aio)
139 mutex_unlock(ext4_aio_mutex(inode));
140
141 return ret;
142}
143
144static const struct vm_operations_struct ext4_file_vm_ops = {
145 .fault = filemap_fault,
146 .page_mkwrite = ext4_page_mkwrite,
147};
148
149static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
150{
151 struct address_space *mapping = file->f_mapping;
152
153 if (!mapping->a_ops->readpage)
154 return -ENOEXEC;
155 file_accessed(file);
156 vma->vm_ops = &ext4_file_vm_ops;
157 vma->vm_flags |= VM_CAN_NONLINEAR;
158 return 0;
159}
160
161static int ext4_file_open(struct inode * inode, struct file * filp)
162{
163 struct super_block *sb = inode->i_sb;
164 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
165 struct ext4_inode_info *ei = EXT4_I(inode);
166 struct vfsmount *mnt = filp->f_path.mnt;
167 struct path path;
168 char buf[64], *cp;
169
170 if (unlikely(!(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED) &&
171 !(sb->s_flags & MS_RDONLY))) {
172 sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED;
173 /*
174 * Sample where the filesystem has been mounted and
175 * store it in the superblock for sysadmin convenience
176 * when trying to sort through large numbers of block
177 * devices or filesystem images.
178 */
179 memset(buf, 0, sizeof(buf));
180 path.mnt = mnt;
181 path.dentry = mnt->mnt_root;
182 cp = d_path(&path, buf, sizeof(buf));
183 if (!IS_ERR(cp)) {
184 memcpy(sbi->s_es->s_last_mounted, cp,
185 sizeof(sbi->s_es->s_last_mounted));
186 ext4_mark_super_dirty(sb);
187 }
188 }
189 /*
190 * Set up the jbd2_inode if we are opening the inode for
191 * writing and the journal is present
192 */
193 if (sbi->s_journal && !ei->jinode && (filp->f_mode & FMODE_WRITE)) {
194 struct jbd2_inode *jinode = jbd2_alloc_inode(GFP_KERNEL);
195
196 spin_lock(&inode->i_lock);
197 if (!ei->jinode) {
198 if (!jinode) {
199 spin_unlock(&inode->i_lock);
200 return -ENOMEM;
201 }
202 ei->jinode = jinode;
203 jbd2_journal_init_jbd_inode(ei->jinode, inode);
204 jinode = NULL;
205 }
206 spin_unlock(&inode->i_lock);
207 if (unlikely(jinode != NULL))
208 jbd2_free_inode(jinode);
209 }
210 return dquot_file_open(inode, filp);
211}
212
213/*
214 * ext4_llseek() copied from generic_file_llseek() to handle both
215 * block-mapped and extent-mapped maxbytes values. This should
216 * otherwise be identical with generic_file_llseek().
217 */
218loff_t ext4_llseek(struct file *file, loff_t offset, int origin)
219{
220 struct inode *inode = file->f_mapping->host;
221 loff_t maxbytes;
222
223 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
224 maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes;
225 else
226 maxbytes = inode->i_sb->s_maxbytes;
227 mutex_lock(&inode->i_mutex);
228 switch (origin) {
229 case SEEK_END:
230 offset += inode->i_size;
231 break;
232 case SEEK_CUR:
233 if (offset == 0) {
234 mutex_unlock(&inode->i_mutex);
235 return file->f_pos;
236 }
237 offset += file->f_pos;
238 break;
239 case SEEK_DATA:
240 /*
241 * In the generic case the entire file is data, so as long as
242 * offset isn't at the end of the file then the offset is data.
243 */
244 if (offset >= inode->i_size) {
245 mutex_unlock(&inode->i_mutex);
246 return -ENXIO;
247 }
248 break;
249 case SEEK_HOLE:
250 /*
251 * There is a virtual hole at the end of the file, so as long as
252 * offset isn't i_size or larger, return i_size.
253 */
254 if (offset >= inode->i_size) {
255 mutex_unlock(&inode->i_mutex);
256 return -ENXIO;
257 }
258 offset = inode->i_size;
259 break;
260 }
261
262 if (offset < 0 || offset > maxbytes) {
263 mutex_unlock(&inode->i_mutex);
264 return -EINVAL;
265 }
266
267 if (offset != file->f_pos) {
268 file->f_pos = offset;
269 file->f_version = 0;
270 }
271 mutex_unlock(&inode->i_mutex);
272
273 return offset;
274}
275
276const struct file_operations ext4_file_operations = {
277 .llseek = ext4_llseek,
278 .read = do_sync_read,
279 .write = do_sync_write,
280 .aio_read = generic_file_aio_read,
281 .aio_write = ext4_file_write,
282 .unlocked_ioctl = ext4_ioctl,
283#ifdef CONFIG_COMPAT
284 .compat_ioctl = ext4_compat_ioctl,
285#endif
286 .mmap = ext4_file_mmap,
287 .open = ext4_file_open,
288 .release = ext4_release_file,
289 .fsync = ext4_sync_file,
290 .splice_read = generic_file_splice_read,
291 .splice_write = generic_file_splice_write,
292 .fallocate = ext4_fallocate,
293};
294
295const struct inode_operations ext4_file_inode_operations = {
296 .setattr = ext4_setattr,
297 .getattr = ext4_getattr,
298#ifdef CONFIG_EXT4_FS_XATTR
299 .setxattr = generic_setxattr,
300 .getxattr = generic_getxattr,
301 .listxattr = ext4_listxattr,
302 .removexattr = generic_removexattr,
303#endif
304 .get_acl = ext4_get_acl,
305 .fiemap = ext4_fiemap,
306};
307
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/ext4/file.c
4 *
5 * Copyright (C) 1992, 1993, 1994, 1995
6 * Remy Card (card@masi.ibp.fr)
7 * Laboratoire MASI - Institut Blaise Pascal
8 * Universite Pierre et Marie Curie (Paris VI)
9 *
10 * from
11 *
12 * linux/fs/minix/file.c
13 *
14 * Copyright (C) 1991, 1992 Linus Torvalds
15 *
16 * ext4 fs regular file handling primitives
17 *
18 * 64-bit file support on 64-bit platforms by Jakub Jelinek
19 * (jj@sunsite.ms.mff.cuni.cz)
20 */
21
22#include <linux/time.h>
23#include <linux/fs.h>
24#include <linux/iomap.h>
25#include <linux/mount.h>
26#include <linux/path.h>
27#include <linux/dax.h>
28#include <linux/quotaops.h>
29#include <linux/pagevec.h>
30#include <linux/uio.h>
31#include <linux/mman.h>
32#include "ext4.h"
33#include "ext4_jbd2.h"
34#include "xattr.h"
35#include "acl.h"
36
37#ifdef CONFIG_FS_DAX
38static ssize_t ext4_dax_read_iter(struct kiocb *iocb, struct iov_iter *to)
39{
40 struct inode *inode = file_inode(iocb->ki_filp);
41 ssize_t ret;
42
43 if (!inode_trylock_shared(inode)) {
44 if (iocb->ki_flags & IOCB_NOWAIT)
45 return -EAGAIN;
46 inode_lock_shared(inode);
47 }
48 /*
49 * Recheck under inode lock - at this point we are sure it cannot
50 * change anymore
51 */
52 if (!IS_DAX(inode)) {
53 inode_unlock_shared(inode);
54 /* Fallback to buffered IO in case we cannot support DAX */
55 return generic_file_read_iter(iocb, to);
56 }
57 ret = dax_iomap_rw(iocb, to, &ext4_iomap_ops);
58 inode_unlock_shared(inode);
59
60 file_accessed(iocb->ki_filp);
61 return ret;
62}
63#endif
64
65static ssize_t ext4_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
66{
67 if (unlikely(ext4_forced_shutdown(EXT4_SB(file_inode(iocb->ki_filp)->i_sb))))
68 return -EIO;
69
70 if (!iov_iter_count(to))
71 return 0; /* skip atime */
72
73#ifdef CONFIG_FS_DAX
74 if (IS_DAX(file_inode(iocb->ki_filp)))
75 return ext4_dax_read_iter(iocb, to);
76#endif
77 return generic_file_read_iter(iocb, to);
78}
79
80/*
81 * Called when an inode is released. Note that this is different
82 * from ext4_file_open: open gets called at every open, but release
83 * gets called only when /all/ the files are closed.
84 */
85static int ext4_release_file(struct inode *inode, struct file *filp)
86{
87 if (ext4_test_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE)) {
88 ext4_alloc_da_blocks(inode);
89 ext4_clear_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
90 }
91 /* if we are the last writer on the inode, drop the block reservation */
92 if ((filp->f_mode & FMODE_WRITE) &&
93 (atomic_read(&inode->i_writecount) == 1) &&
94 !EXT4_I(inode)->i_reserved_data_blocks)
95 {
96 down_write(&EXT4_I(inode)->i_data_sem);
97 ext4_discard_preallocations(inode);
98 up_write(&EXT4_I(inode)->i_data_sem);
99 }
100 if (is_dx(inode) && filp->private_data)
101 ext4_htree_free_dir_info(filp->private_data);
102
103 return 0;
104}
105
106static void ext4_unwritten_wait(struct inode *inode)
107{
108 wait_queue_head_t *wq = ext4_ioend_wq(inode);
109
110 wait_event(*wq, (atomic_read(&EXT4_I(inode)->i_unwritten) == 0));
111}
112
113/*
114 * This tests whether the IO in question is block-aligned or not.
115 * Ext4 utilizes unwritten extents when hole-filling during direct IO, and they
116 * are converted to written only after the IO is complete. Until they are
117 * mapped, these blocks appear as holes, so dio_zero_block() will assume that
118 * it needs to zero out portions of the start and/or end block. If 2 AIO
119 * threads are at work on the same unwritten block, they must be synchronized
120 * or one thread will zero the other's data, causing corruption.
121 */
122static int
123ext4_unaligned_aio(struct inode *inode, struct iov_iter *from, loff_t pos)
124{
125 struct super_block *sb = inode->i_sb;
126 int blockmask = sb->s_blocksize - 1;
127
128 if (pos >= ALIGN(i_size_read(inode), sb->s_blocksize))
129 return 0;
130
131 if ((pos | iov_iter_alignment(from)) & blockmask)
132 return 1;
133
134 return 0;
135}
136
137/* Is IO overwriting allocated and initialized blocks? */
138static bool ext4_overwrite_io(struct inode *inode, loff_t pos, loff_t len)
139{
140 struct ext4_map_blocks map;
141 unsigned int blkbits = inode->i_blkbits;
142 int err, blklen;
143
144 if (pos + len > i_size_read(inode))
145 return false;
146
147 map.m_lblk = pos >> blkbits;
148 map.m_len = EXT4_MAX_BLOCKS(len, pos, blkbits);
149 blklen = map.m_len;
150
151 err = ext4_map_blocks(NULL, inode, &map, 0);
152 /*
153 * 'err==len' means that all of the blocks have been preallocated,
154 * regardless of whether they have been initialized or not. To exclude
155 * unwritten extents, we need to check m_flags.
156 */
157 return err == blklen && (map.m_flags & EXT4_MAP_MAPPED);
158}
159
160static ssize_t ext4_write_checks(struct kiocb *iocb, struct iov_iter *from)
161{
162 struct inode *inode = file_inode(iocb->ki_filp);
163 ssize_t ret;
164
165 ret = generic_write_checks(iocb, from);
166 if (ret <= 0)
167 return ret;
168
169 if (unlikely(IS_IMMUTABLE(inode)))
170 return -EPERM;
171
172 /*
173 * If we have encountered a bitmap-format file, the size limit
174 * is smaller than s_maxbytes, which is for extent-mapped files.
175 */
176 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
177 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
178
179 if (iocb->ki_pos >= sbi->s_bitmap_maxbytes)
180 return -EFBIG;
181 iov_iter_truncate(from, sbi->s_bitmap_maxbytes - iocb->ki_pos);
182 }
183 return iov_iter_count(from);
184}
185
186#ifdef CONFIG_FS_DAX
187static ssize_t
188ext4_dax_write_iter(struct kiocb *iocb, struct iov_iter *from)
189{
190 struct inode *inode = file_inode(iocb->ki_filp);
191 ssize_t ret;
192
193 if (!inode_trylock(inode)) {
194 if (iocb->ki_flags & IOCB_NOWAIT)
195 return -EAGAIN;
196 inode_lock(inode);
197 }
198 ret = ext4_write_checks(iocb, from);
199 if (ret <= 0)
200 goto out;
201 ret = file_remove_privs(iocb->ki_filp);
202 if (ret)
203 goto out;
204 ret = file_update_time(iocb->ki_filp);
205 if (ret)
206 goto out;
207
208 ret = dax_iomap_rw(iocb, from, &ext4_iomap_ops);
209out:
210 inode_unlock(inode);
211 if (ret > 0)
212 ret = generic_write_sync(iocb, ret);
213 return ret;
214}
215#endif
216
217static ssize_t
218ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
219{
220 struct inode *inode = file_inode(iocb->ki_filp);
221 int o_direct = iocb->ki_flags & IOCB_DIRECT;
222 int unaligned_aio = 0;
223 int overwrite = 0;
224 ssize_t ret;
225
226 if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
227 return -EIO;
228
229#ifdef CONFIG_FS_DAX
230 if (IS_DAX(inode))
231 return ext4_dax_write_iter(iocb, from);
232#endif
233
234 if (!inode_trylock(inode)) {
235 if (iocb->ki_flags & IOCB_NOWAIT)
236 return -EAGAIN;
237 inode_lock(inode);
238 }
239
240 ret = ext4_write_checks(iocb, from);
241 if (ret <= 0)
242 goto out;
243
244 /*
245 * Unaligned direct AIO must be serialized among each other as zeroing
246 * of partial blocks of two competing unaligned AIOs can result in data
247 * corruption.
248 */
249 if (o_direct && ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) &&
250 !is_sync_kiocb(iocb) &&
251 ext4_unaligned_aio(inode, from, iocb->ki_pos)) {
252 unaligned_aio = 1;
253 ext4_unwritten_wait(inode);
254 }
255
256 iocb->private = &overwrite;
257 /* Check whether we do a DIO overwrite or not */
258 if (o_direct && !unaligned_aio) {
259 if (ext4_overwrite_io(inode, iocb->ki_pos, iov_iter_count(from))) {
260 if (ext4_should_dioread_nolock(inode))
261 overwrite = 1;
262 } else if (iocb->ki_flags & IOCB_NOWAIT) {
263 ret = -EAGAIN;
264 goto out;
265 }
266 }
267
268 ret = __generic_file_write_iter(iocb, from);
269 /*
270 * Unaligned direct AIO must be the only IO in flight. Otherwise
271 * overlapping aligned IO after unaligned might result in data
272 * corruption.
273 */
274 if (ret == -EIOCBQUEUED && unaligned_aio)
275 ext4_unwritten_wait(inode);
276 inode_unlock(inode);
277
278 if (ret > 0)
279 ret = generic_write_sync(iocb, ret);
280
281 return ret;
282
283out:
284 inode_unlock(inode);
285 return ret;
286}
287
288#ifdef CONFIG_FS_DAX
289static vm_fault_t ext4_dax_huge_fault(struct vm_fault *vmf,
290 enum page_entry_size pe_size)
291{
292 int error = 0;
293 vm_fault_t result;
294 int retries = 0;
295 handle_t *handle = NULL;
296 struct inode *inode = file_inode(vmf->vma->vm_file);
297 struct super_block *sb = inode->i_sb;
298
299 /*
300 * We have to distinguish real writes from writes which will result in a
301 * COW page; COW writes should *not* poke the journal (the file will not
302 * be changed). Doing so would cause unintended failures when mounted
303 * read-only.
304 *
305 * We check for VM_SHARED rather than vmf->cow_page since the latter is
306 * unset for pe_size != PE_SIZE_PTE (i.e. only in do_cow_fault); for
307 * other sizes, dax_iomap_fault will handle splitting / fallback so that
308 * we eventually come back with a COW page.
309 */
310 bool write = (vmf->flags & FAULT_FLAG_WRITE) &&
311 (vmf->vma->vm_flags & VM_SHARED);
312 pfn_t pfn;
313
314 if (write) {
315 sb_start_pagefault(sb);
316 file_update_time(vmf->vma->vm_file);
317 down_read(&EXT4_I(inode)->i_mmap_sem);
318retry:
319 handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
320 EXT4_DATA_TRANS_BLOCKS(sb));
321 if (IS_ERR(handle)) {
322 up_read(&EXT4_I(inode)->i_mmap_sem);
323 sb_end_pagefault(sb);
324 return VM_FAULT_SIGBUS;
325 }
326 } else {
327 down_read(&EXT4_I(inode)->i_mmap_sem);
328 }
329 result = dax_iomap_fault(vmf, pe_size, &pfn, &error, &ext4_iomap_ops);
330 if (write) {
331 ext4_journal_stop(handle);
332
333 if ((result & VM_FAULT_ERROR) && error == -ENOSPC &&
334 ext4_should_retry_alloc(sb, &retries))
335 goto retry;
336 /* Handling synchronous page fault? */
337 if (result & VM_FAULT_NEEDDSYNC)
338 result = dax_finish_sync_fault(vmf, pe_size, pfn);
339 up_read(&EXT4_I(inode)->i_mmap_sem);
340 sb_end_pagefault(sb);
341 } else {
342 up_read(&EXT4_I(inode)->i_mmap_sem);
343 }
344
345 return result;
346}
347
348static vm_fault_t ext4_dax_fault(struct vm_fault *vmf)
349{
350 return ext4_dax_huge_fault(vmf, PE_SIZE_PTE);
351}
352
353static const struct vm_operations_struct ext4_dax_vm_ops = {
354 .fault = ext4_dax_fault,
355 .huge_fault = ext4_dax_huge_fault,
356 .page_mkwrite = ext4_dax_fault,
357 .pfn_mkwrite = ext4_dax_fault,
358};
359#else
360#define ext4_dax_vm_ops ext4_file_vm_ops
361#endif
362
363static const struct vm_operations_struct ext4_file_vm_ops = {
364 .fault = ext4_filemap_fault,
365 .map_pages = filemap_map_pages,
366 .page_mkwrite = ext4_page_mkwrite,
367};
368
369static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
370{
371 struct inode *inode = file->f_mapping->host;
372 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
373 struct dax_device *dax_dev = sbi->s_daxdev;
374
375 if (unlikely(ext4_forced_shutdown(sbi)))
376 return -EIO;
377
378 /*
379 * We don't support synchronous mappings for non-DAX files and
380 * for DAX files if underneath dax_device is not synchronous.
381 */
382 if (!daxdev_mapping_supported(vma, dax_dev))
383 return -EOPNOTSUPP;
384
385 file_accessed(file);
386 if (IS_DAX(file_inode(file))) {
387 vma->vm_ops = &ext4_dax_vm_ops;
388 vma->vm_flags |= VM_HUGEPAGE;
389 } else {
390 vma->vm_ops = &ext4_file_vm_ops;
391 }
392 return 0;
393}
394
395static int ext4_sample_last_mounted(struct super_block *sb,
396 struct vfsmount *mnt)
397{
398 struct ext4_sb_info *sbi = EXT4_SB(sb);
399 struct path path;
400 char buf[64], *cp;
401 handle_t *handle;
402 int err;
403
404 if (likely(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED))
405 return 0;
406
407 if (sb_rdonly(sb) || !sb_start_intwrite_trylock(sb))
408 return 0;
409
410 sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED;
411 /*
412 * Sample where the filesystem has been mounted and
413 * store it in the superblock for sysadmin convenience
414 * when trying to sort through large numbers of block
415 * devices or filesystem images.
416 */
417 memset(buf, 0, sizeof(buf));
418 path.mnt = mnt;
419 path.dentry = mnt->mnt_root;
420 cp = d_path(&path, buf, sizeof(buf));
421 err = 0;
422 if (IS_ERR(cp))
423 goto out;
424
425 handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
426 err = PTR_ERR(handle);
427 if (IS_ERR(handle))
428 goto out;
429 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
430 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
431 if (err)
432 goto out_journal;
433 strlcpy(sbi->s_es->s_last_mounted, cp,
434 sizeof(sbi->s_es->s_last_mounted));
435 ext4_handle_dirty_super(handle, sb);
436out_journal:
437 ext4_journal_stop(handle);
438out:
439 sb_end_intwrite(sb);
440 return err;
441}
442
443static int ext4_file_open(struct inode * inode, struct file * filp)
444{
445 int ret;
446
447 if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
448 return -EIO;
449
450 ret = ext4_sample_last_mounted(inode->i_sb, filp->f_path.mnt);
451 if (ret)
452 return ret;
453
454 ret = fscrypt_file_open(inode, filp);
455 if (ret)
456 return ret;
457
458 ret = fsverity_file_open(inode, filp);
459 if (ret)
460 return ret;
461
462 /*
463 * Set up the jbd2_inode if we are opening the inode for
464 * writing and the journal is present
465 */
466 if (filp->f_mode & FMODE_WRITE) {
467 ret = ext4_inode_attach_jinode(inode);
468 if (ret < 0)
469 return ret;
470 }
471
472 filp->f_mode |= FMODE_NOWAIT;
473 return dquot_file_open(inode, filp);
474}
475
476/*
477 * ext4_llseek() handles both block-mapped and extent-mapped maxbytes values
478 * by calling generic_file_llseek_size() with the appropriate maxbytes
479 * value for each.
480 */
481loff_t ext4_llseek(struct file *file, loff_t offset, int whence)
482{
483 struct inode *inode = file->f_mapping->host;
484 loff_t maxbytes;
485
486 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
487 maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes;
488 else
489 maxbytes = inode->i_sb->s_maxbytes;
490
491 switch (whence) {
492 default:
493 return generic_file_llseek_size(file, offset, whence,
494 maxbytes, i_size_read(inode));
495 case SEEK_HOLE:
496 inode_lock_shared(inode);
497 offset = iomap_seek_hole(inode, offset, &ext4_iomap_ops);
498 inode_unlock_shared(inode);
499 break;
500 case SEEK_DATA:
501 inode_lock_shared(inode);
502 offset = iomap_seek_data(inode, offset, &ext4_iomap_ops);
503 inode_unlock_shared(inode);
504 break;
505 }
506
507 if (offset < 0)
508 return offset;
509 return vfs_setpos(file, offset, maxbytes);
510}
511
512const struct file_operations ext4_file_operations = {
513 .llseek = ext4_llseek,
514 .read_iter = ext4_file_read_iter,
515 .write_iter = ext4_file_write_iter,
516 .unlocked_ioctl = ext4_ioctl,
517#ifdef CONFIG_COMPAT
518 .compat_ioctl = ext4_compat_ioctl,
519#endif
520 .mmap = ext4_file_mmap,
521 .mmap_supported_flags = MAP_SYNC,
522 .open = ext4_file_open,
523 .release = ext4_release_file,
524 .fsync = ext4_sync_file,
525 .get_unmapped_area = thp_get_unmapped_area,
526 .splice_read = generic_file_splice_read,
527 .splice_write = iter_file_splice_write,
528 .fallocate = ext4_fallocate,
529};
530
531const struct inode_operations ext4_file_inode_operations = {
532 .setattr = ext4_setattr,
533 .getattr = ext4_file_getattr,
534 .listxattr = ext4_listxattr,
535 .get_acl = ext4_get_acl,
536 .set_acl = ext4_set_acl,
537 .fiemap = ext4_fiemap,
538};
539