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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
50
51
52 if (!IS_DAX(inode)) {
53 inode_unlock_shared(inode);
54
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;
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
82
83
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
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
115
116
117
118
119
120
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
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
154
155
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
174
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 if (!o_direct && (iocb->ki_flags & IOCB_NOWAIT))
234 return -EOPNOTSUPP;
235
236 if (!inode_trylock(inode)) {
237 if (iocb->ki_flags & IOCB_NOWAIT)
238 return -EAGAIN;
239 inode_lock(inode);
240 }
241
242 ret = ext4_write_checks(iocb, from);
243 if (ret <= 0)
244 goto out;
245
246
247
248
249
250
251 if (o_direct && ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) &&
252 !is_sync_kiocb(iocb) &&
253 ext4_unaligned_aio(inode, from, iocb->ki_pos)) {
254 unaligned_aio = 1;
255 ext4_unwritten_wait(inode);
256 }
257
258 iocb->private = &overwrite;
259
260 if (o_direct && !unaligned_aio) {
261 if (ext4_overwrite_io(inode, iocb->ki_pos, iov_iter_count(from))) {
262 if (ext4_should_dioread_nolock(inode))
263 overwrite = 1;
264 } else if (iocb->ki_flags & IOCB_NOWAIT) {
265 ret = -EAGAIN;
266 goto out;
267 }
268 }
269
270 ret = __generic_file_write_iter(iocb, from);
271
272
273
274
275
276 if (ret == -EIOCBQUEUED && unaligned_aio)
277 ext4_unwritten_wait(inode);
278 inode_unlock(inode);
279
280 if (ret > 0)
281 ret = generic_write_sync(iocb, ret);
282
283 return ret;
284
285out:
286 inode_unlock(inode);
287 return ret;
288}
289
290#ifdef CONFIG_FS_DAX
291static vm_fault_t ext4_dax_huge_fault(struct vm_fault *vmf,
292 enum page_entry_size pe_size)
293{
294 int error = 0;
295 vm_fault_t result;
296 int retries = 0;
297 handle_t *handle = NULL;
298 struct inode *inode = file_inode(vmf->vma->vm_file);
299 struct super_block *sb = inode->i_sb;
300
301
302
303
304
305
306
307
308
309
310
311
312 bool write = (vmf->flags & FAULT_FLAG_WRITE) &&
313 (vmf->vma->vm_flags & VM_SHARED);
314 pfn_t pfn;
315
316 if (write) {
317 sb_start_pagefault(sb);
318 file_update_time(vmf->vma->vm_file);
319 down_read(&EXT4_I(inode)->i_mmap_sem);
320retry:
321 handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
322 EXT4_DATA_TRANS_BLOCKS(sb));
323 if (IS_ERR(handle)) {
324 up_read(&EXT4_I(inode)->i_mmap_sem);
325 sb_end_pagefault(sb);
326 return VM_FAULT_SIGBUS;
327 }
328 } else {
329 down_read(&EXT4_I(inode)->i_mmap_sem);
330 }
331 result = dax_iomap_fault(vmf, pe_size, &pfn, &error, &ext4_iomap_ops);
332 if (write) {
333 ext4_journal_stop(handle);
334
335 if ((result & VM_FAULT_ERROR) && error == -ENOSPC &&
336 ext4_should_retry_alloc(sb, &retries))
337 goto retry;
338
339 if (result & VM_FAULT_NEEDDSYNC)
340 result = dax_finish_sync_fault(vmf, pe_size, pfn);
341 up_read(&EXT4_I(inode)->i_mmap_sem);
342 sb_end_pagefault(sb);
343 } else {
344 up_read(&EXT4_I(inode)->i_mmap_sem);
345 }
346
347 return result;
348}
349
350static vm_fault_t ext4_dax_fault(struct vm_fault *vmf)
351{
352 return ext4_dax_huge_fault(vmf, PE_SIZE_PTE);
353}
354
355static const struct vm_operations_struct ext4_dax_vm_ops = {
356 .fault = ext4_dax_fault,
357 .huge_fault = ext4_dax_huge_fault,
358 .page_mkwrite = ext4_dax_fault,
359 .pfn_mkwrite = ext4_dax_fault,
360};
361#else
362#define ext4_dax_vm_ops ext4_file_vm_ops
363#endif
364
365static const struct vm_operations_struct ext4_file_vm_ops = {
366 .fault = ext4_filemap_fault,
367 .map_pages = filemap_map_pages,
368 .page_mkwrite = ext4_page_mkwrite,
369};
370
371static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
372{
373 struct inode *inode = file->f_mapping->host;
374 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
375 struct dax_device *dax_dev = sbi->s_daxdev;
376
377 if (unlikely(ext4_forced_shutdown(sbi)))
378 return -EIO;
379
380
381
382
383
384 if (!daxdev_mapping_supported(vma, dax_dev))
385 return -EOPNOTSUPP;
386
387 file_accessed(file);
388 if (IS_DAX(file_inode(file))) {
389 vma->vm_ops = &ext4_dax_vm_ops;
390 vma->vm_flags |= VM_HUGEPAGE;
391 } else {
392 vma->vm_ops = &ext4_file_vm_ops;
393 }
394 return 0;
395}
396
397static int ext4_sample_last_mounted(struct super_block *sb,
398 struct vfsmount *mnt)
399{
400 struct ext4_sb_info *sbi = EXT4_SB(sb);
401 struct path path;
402 char buf[64], *cp;
403 handle_t *handle;
404 int err;
405
406 if (likely(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED))
407 return 0;
408
409 if (sb_rdonly(sb) || !sb_start_intwrite_trylock(sb))
410 return 0;
411
412 sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED;
413
414
415
416
417
418
419 memset(buf, 0, sizeof(buf));
420 path.mnt = mnt;
421 path.dentry = mnt->mnt_root;
422 cp = d_path(&path, buf, sizeof(buf));
423 err = 0;
424 if (IS_ERR(cp))
425 goto out;
426
427 handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
428 err = PTR_ERR(handle);
429 if (IS_ERR(handle))
430 goto out;
431 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
432 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
433 if (err)
434 goto out_journal;
435 strlcpy(sbi->s_es->s_last_mounted, cp,
436 sizeof(sbi->s_es->s_last_mounted));
437 ext4_handle_dirty_super(handle, sb);
438out_journal:
439 ext4_journal_stop(handle);
440out:
441 sb_end_intwrite(sb);
442 return err;
443}
444
445static int ext4_file_open(struct inode * inode, struct file * filp)
446{
447 int ret;
448
449 if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
450 return -EIO;
451
452 ret = ext4_sample_last_mounted(inode->i_sb, filp->f_path.mnt);
453 if (ret)
454 return ret;
455
456 ret = fscrypt_file_open(inode, filp);
457 if (ret)
458 return ret;
459
460
461
462
463
464 if (filp->f_mode & FMODE_WRITE) {
465 ret = ext4_inode_attach_jinode(inode);
466 if (ret < 0)
467 return ret;
468 }
469
470 filp->f_mode |= FMODE_NOWAIT;
471 return dquot_file_open(inode, filp);
472}
473
474
475
476
477
478
479loff_t ext4_llseek(struct file *file, loff_t offset, int whence)
480{
481 struct inode *inode = file->f_mapping->host;
482 loff_t maxbytes;
483
484 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
485 maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes;
486 else
487 maxbytes = inode->i_sb->s_maxbytes;
488
489 switch (whence) {
490 default:
491 return generic_file_llseek_size(file, offset, whence,
492 maxbytes, i_size_read(inode));
493 case SEEK_HOLE:
494 inode_lock_shared(inode);
495 offset = iomap_seek_hole(inode, offset, &ext4_iomap_ops);
496 inode_unlock_shared(inode);
497 break;
498 case SEEK_DATA:
499 inode_lock_shared(inode);
500 offset = iomap_seek_data(inode, offset, &ext4_iomap_ops);
501 inode_unlock_shared(inode);
502 break;
503 }
504
505 if (offset < 0)
506 return offset;
507 return vfs_setpos(file, offset, maxbytes);
508}
509
510const struct file_operations ext4_file_operations = {
511 .llseek = ext4_llseek,
512 .read_iter = ext4_file_read_iter,
513 .write_iter = ext4_file_write_iter,
514 .unlocked_ioctl = ext4_ioctl,
515#ifdef CONFIG_COMPAT
516 .compat_ioctl = ext4_compat_ioctl,
517#endif
518 .mmap = ext4_file_mmap,
519 .mmap_supported_flags = MAP_SYNC,
520 .open = ext4_file_open,
521 .release = ext4_release_file,
522 .fsync = ext4_sync_file,
523 .get_unmapped_area = thp_get_unmapped_area,
524 .splice_read = generic_file_splice_read,
525 .splice_write = iter_file_splice_write,
526 .fallocate = ext4_fallocate,
527};
528
529const struct inode_operations ext4_file_inode_operations = {
530 .setattr = ext4_setattr,
531 .getattr = ext4_file_getattr,
532 .listxattr = ext4_listxattr,
533 .get_acl = ext4_get_acl,
534 .set_acl = ext4_set_acl,
535 .fiemap = ext4_fiemap,
536};
537
538