Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
ac27a0ec | 2 | /* |
617ba13b | 3 | * linux/fs/ext4/file.c |
ac27a0ec DK |
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 | * | |
617ba13b | 16 | * ext4 fs regular file handling primitives |
ac27a0ec DK |
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> | |
bc0b0d6d TT |
24 | #include <linux/mount.h> |
25 | #include <linux/path.h> | |
c94c2acf | 26 | #include <linux/dax.h> |
871a2931 | 27 | #include <linux/quotaops.h> |
c8c0df24 | 28 | #include <linux/pagevec.h> |
e2e40f2c | 29 | #include <linux/uio.h> |
3dcf5451 CH |
30 | #include "ext4.h" |
31 | #include "ext4_jbd2.h" | |
ac27a0ec DK |
32 | #include "xattr.h" |
33 | #include "acl.h" | |
34 | ||
364443cb JK |
35 | #ifdef CONFIG_FS_DAX |
36 | static ssize_t ext4_dax_read_iter(struct kiocb *iocb, struct iov_iter *to) | |
37 | { | |
38 | struct inode *inode = file_inode(iocb->ki_filp); | |
39 | ssize_t ret; | |
40 | ||
728fbc0e GR |
41 | if (!inode_trylock_shared(inode)) { |
42 | if (iocb->ki_flags & IOCB_NOWAIT) | |
43 | return -EAGAIN; | |
44 | inode_lock_shared(inode); | |
45 | } | |
364443cb JK |
46 | /* |
47 | * Recheck under inode lock - at this point we are sure it cannot | |
48 | * change anymore | |
49 | */ | |
50 | if (!IS_DAX(inode)) { | |
51 | inode_unlock_shared(inode); | |
52 | /* Fallback to buffered IO in case we cannot support DAX */ | |
53 | return generic_file_read_iter(iocb, to); | |
54 | } | |
55 | ret = dax_iomap_rw(iocb, to, &ext4_iomap_ops); | |
56 | inode_unlock_shared(inode); | |
57 | ||
58 | file_accessed(iocb->ki_filp); | |
59 | return ret; | |
60 | } | |
61 | #endif | |
62 | ||
63 | static ssize_t ext4_file_read_iter(struct kiocb *iocb, struct iov_iter *to) | |
64 | { | |
0db1ff22 TT |
65 | if (unlikely(ext4_forced_shutdown(EXT4_SB(file_inode(iocb->ki_filp)->i_sb)))) |
66 | return -EIO; | |
67 | ||
364443cb JK |
68 | if (!iov_iter_count(to)) |
69 | return 0; /* skip atime */ | |
70 | ||
71 | #ifdef CONFIG_FS_DAX | |
72 | if (IS_DAX(file_inode(iocb->ki_filp))) | |
73 | return ext4_dax_read_iter(iocb, to); | |
74 | #endif | |
75 | return generic_file_read_iter(iocb, to); | |
76 | } | |
77 | ||
ac27a0ec DK |
78 | /* |
79 | * Called when an inode is released. Note that this is different | |
617ba13b | 80 | * from ext4_file_open: open gets called at every open, but release |
ac27a0ec DK |
81 | * gets called only when /all/ the files are closed. |
82 | */ | |
af5bc92d | 83 | static int ext4_release_file(struct inode *inode, struct file *filp) |
ac27a0ec | 84 | { |
19f5fb7a | 85 | if (ext4_test_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE)) { |
7d8f9f7d | 86 | ext4_alloc_da_blocks(inode); |
19f5fb7a | 87 | ext4_clear_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE); |
7d8f9f7d | 88 | } |
ac27a0ec DK |
89 | /* if we are the last writer on the inode, drop the block reservation */ |
90 | if ((filp->f_mode & FMODE_WRITE) && | |
d6014301 AK |
91 | (atomic_read(&inode->i_writecount) == 1) && |
92 | !EXT4_I(inode)->i_reserved_data_blocks) | |
ac27a0ec | 93 | { |
0e855ac8 | 94 | down_write(&EXT4_I(inode)->i_data_sem); |
c2ea3fde | 95 | ext4_discard_preallocations(inode); |
0e855ac8 | 96 | up_write(&EXT4_I(inode)->i_data_sem); |
ac27a0ec DK |
97 | } |
98 | if (is_dx(inode) && filp->private_data) | |
617ba13b | 99 | ext4_htree_free_dir_info(filp->private_data); |
ac27a0ec DK |
100 | |
101 | return 0; | |
102 | } | |
103 | ||
c197855e | 104 | static void ext4_unwritten_wait(struct inode *inode) |
e9e3bcec ES |
105 | { |
106 | wait_queue_head_t *wq = ext4_ioend_wq(inode); | |
107 | ||
e27f41e1 | 108 | wait_event(*wq, (atomic_read(&EXT4_I(inode)->i_unwritten) == 0)); |
e9e3bcec ES |
109 | } |
110 | ||
111 | /* | |
112 | * This tests whether the IO in question is block-aligned or not. | |
113 | * Ext4 utilizes unwritten extents when hole-filling during direct IO, and they | |
114 | * are converted to written only after the IO is complete. Until they are | |
115 | * mapped, these blocks appear as holes, so dio_zero_block() will assume that | |
116 | * it needs to zero out portions of the start and/or end block. If 2 AIO | |
117 | * threads are at work on the same unwritten block, they must be synchronized | |
118 | * or one thread will zero the other's data, causing corruption. | |
119 | */ | |
120 | static int | |
9b884164 | 121 | ext4_unaligned_aio(struct inode *inode, struct iov_iter *from, loff_t pos) |
e9e3bcec ES |
122 | { |
123 | struct super_block *sb = inode->i_sb; | |
124 | int blockmask = sb->s_blocksize - 1; | |
e9e3bcec | 125 | |
766b823e | 126 | if (pos >= ALIGN(i_size_read(inode), sb->s_blocksize)) |
e9e3bcec ES |
127 | return 0; |
128 | ||
9b884164 | 129 | if ((pos | iov_iter_alignment(from)) & blockmask) |
e9e3bcec ES |
130 | return 1; |
131 | ||
132 | return 0; | |
133 | } | |
134 | ||
213bcd9c JK |
135 | /* Is IO overwriting allocated and initialized blocks? */ |
136 | static bool ext4_overwrite_io(struct inode *inode, loff_t pos, loff_t len) | |
137 | { | |
138 | struct ext4_map_blocks map; | |
139 | unsigned int blkbits = inode->i_blkbits; | |
140 | int err, blklen; | |
141 | ||
142 | if (pos + len > i_size_read(inode)) | |
143 | return false; | |
144 | ||
145 | map.m_lblk = pos >> blkbits; | |
146 | map.m_len = EXT4_MAX_BLOCKS(len, pos, blkbits); | |
147 | blklen = map.m_len; | |
148 | ||
149 | err = ext4_map_blocks(NULL, inode, &map, 0); | |
150 | /* | |
151 | * 'err==len' means that all of the blocks have been preallocated, | |
152 | * regardless of whether they have been initialized or not. To exclude | |
153 | * unwritten extents, we need to check m_flags. | |
154 | */ | |
155 | return err == blklen && (map.m_flags & EXT4_MAP_MAPPED); | |
156 | } | |
157 | ||
158 | static ssize_t ext4_write_checks(struct kiocb *iocb, struct iov_iter *from) | |
159 | { | |
160 | struct inode *inode = file_inode(iocb->ki_filp); | |
161 | ssize_t ret; | |
162 | ||
163 | ret = generic_write_checks(iocb, from); | |
164 | if (ret <= 0) | |
165 | return ret; | |
166 | /* | |
167 | * If we have encountered a bitmap-format file, the size limit | |
168 | * is smaller than s_maxbytes, which is for extent-mapped files. | |
169 | */ | |
170 | if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { | |
171 | struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); | |
172 | ||
173 | if (iocb->ki_pos >= sbi->s_bitmap_maxbytes) | |
174 | return -EFBIG; | |
175 | iov_iter_truncate(from, sbi->s_bitmap_maxbytes - iocb->ki_pos); | |
176 | } | |
177 | return iov_iter_count(from); | |
178 | } | |
179 | ||
776722e8 JK |
180 | #ifdef CONFIG_FS_DAX |
181 | static ssize_t | |
182 | ext4_dax_write_iter(struct kiocb *iocb, struct iov_iter *from) | |
183 | { | |
184 | struct inode *inode = file_inode(iocb->ki_filp); | |
185 | ssize_t ret; | |
776722e8 | 186 | |
728fbc0e GR |
187 | if (!inode_trylock(inode)) { |
188 | if (iocb->ki_flags & IOCB_NOWAIT) | |
189 | return -EAGAIN; | |
190 | inode_lock(inode); | |
191 | } | |
776722e8 JK |
192 | ret = ext4_write_checks(iocb, from); |
193 | if (ret <= 0) | |
194 | goto out; | |
195 | ret = file_remove_privs(iocb->ki_filp); | |
196 | if (ret) | |
197 | goto out; | |
198 | ret = file_update_time(iocb->ki_filp); | |
199 | if (ret) | |
200 | goto out; | |
201 | ||
776722e8 JK |
202 | ret = dax_iomap_rw(iocb, from, &ext4_iomap_ops); |
203 | out: | |
ff5462e3 | 204 | inode_unlock(inode); |
776722e8 JK |
205 | if (ret > 0) |
206 | ret = generic_write_sync(iocb, ret); | |
207 | return ret; | |
208 | } | |
209 | #endif | |
210 | ||
ac27a0ec | 211 | static ssize_t |
9b884164 | 212 | ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from) |
ac27a0ec | 213 | { |
8ad2850f | 214 | struct inode *inode = file_inode(iocb->ki_filp); |
2ba48ce5 | 215 | int o_direct = iocb->ki_flags & IOCB_DIRECT; |
e142d052 | 216 | int unaligned_aio = 0; |
4bd809db | 217 | int overwrite = 0; |
8563000d | 218 | ssize_t ret; |
7608e610 | 219 | |
0db1ff22 TT |
220 | if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) |
221 | return -EIO; | |
222 | ||
776722e8 JK |
223 | #ifdef CONFIG_FS_DAX |
224 | if (IS_DAX(inode)) | |
225 | return ext4_dax_write_iter(iocb, from); | |
226 | #endif | |
91f9943e CH |
227 | if (!o_direct && (iocb->ki_flags & IOCB_NOWAIT)) |
228 | return -EOPNOTSUPP; | |
776722e8 | 229 | |
728fbc0e GR |
230 | if (!inode_trylock(inode)) { |
231 | if (iocb->ki_flags & IOCB_NOWAIT) | |
232 | return -EAGAIN; | |
233 | inode_lock(inode); | |
234 | } | |
235 | ||
213bcd9c | 236 | ret = ext4_write_checks(iocb, from); |
e142d052 JK |
237 | if (ret <= 0) |
238 | goto out; | |
239 | ||
f5ccfe1d | 240 | /* |
e142d052 JK |
241 | * Unaligned direct AIO must be serialized among each other as zeroing |
242 | * of partial blocks of two competing unaligned AIOs can result in data | |
243 | * corruption. | |
f5ccfe1d | 244 | */ |
e142d052 | 245 | if (o_direct && ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) && |
f5ccfe1d | 246 | !is_sync_kiocb(iocb) && |
e142d052 JK |
247 | ext4_unaligned_aio(inode, from, iocb->ki_pos)) { |
248 | unaligned_aio = 1; | |
f5ccfe1d TT |
249 | ext4_unwritten_wait(inode); |
250 | } | |
251 | ||
a41537e6 | 252 | iocb->private = &overwrite; |
213bcd9c | 253 | /* Check whether we do a DIO overwrite or not */ |
728fbc0e GR |
254 | if (o_direct && !unaligned_aio) { |
255 | if (ext4_overwrite_io(inode, iocb->ki_pos, iov_iter_count(from))) { | |
256 | if (ext4_should_dioread_nolock(inode)) | |
257 | overwrite = 1; | |
258 | } else if (iocb->ki_flags & IOCB_NOWAIT) { | |
259 | ret = -EAGAIN; | |
260 | goto out; | |
261 | } | |
262 | } | |
7608e610 | 263 | |
9b884164 | 264 | ret = __generic_file_write_iter(iocb, from); |
5955102c | 265 | inode_unlock(inode); |
7608e610 | 266 | |
e2592217 CH |
267 | if (ret > 0) |
268 | ret = generic_write_sync(iocb, ret); | |
e9e3bcec | 269 | |
e768d7ff AV |
270 | return ret; |
271 | ||
272 | out: | |
5955102c | 273 | inode_unlock(inode); |
e9e3bcec | 274 | return ret; |
ac27a0ec DK |
275 | } |
276 | ||
923ae0ff | 277 | #ifdef CONFIG_FS_DAX |
c791ace1 DJ |
278 | static int ext4_dax_huge_fault(struct vm_fault *vmf, |
279 | enum page_entry_size pe_size) | |
923ae0ff | 280 | { |
01a33b4a | 281 | int result; |
fb26a1cb | 282 | handle_t *handle = NULL; |
11bac800 | 283 | struct inode *inode = file_inode(vmf->vma->vm_file); |
ea3d7209 | 284 | struct super_block *sb = inode->i_sb; |
fd96b8da RD |
285 | |
286 | /* | |
287 | * We have to distinguish real writes from writes which will result in a | |
288 | * COW page; COW writes should *not* poke the journal (the file will not | |
289 | * be changed). Doing so would cause unintended failures when mounted | |
290 | * read-only. | |
291 | * | |
292 | * We check for VM_SHARED rather than vmf->cow_page since the latter is | |
293 | * unset for pe_size != PE_SIZE_PTE (i.e. only in do_cow_fault); for | |
294 | * other sizes, dax_iomap_fault will handle splitting / fallback so that | |
295 | * we eventually come back with a COW page. | |
296 | */ | |
297 | bool write = (vmf->flags & FAULT_FLAG_WRITE) && | |
298 | (vmf->vma->vm_flags & VM_SHARED); | |
01a33b4a MW |
299 | |
300 | if (write) { | |
301 | sb_start_pagefault(sb); | |
11bac800 | 302 | file_update_time(vmf->vma->vm_file); |
fb26a1cb JK |
303 | down_read(&EXT4_I(inode)->i_mmap_sem); |
304 | handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE, | |
305 | EXT4_DATA_TRANS_BLOCKS(sb)); | |
306 | } else { | |
307 | down_read(&EXT4_I(inode)->i_mmap_sem); | |
1db17542 | 308 | } |
fb26a1cb JK |
309 | if (!IS_ERR(handle)) |
310 | result = dax_iomap_fault(vmf, pe_size, &ext4_iomap_ops); | |
311 | else | |
312 | result = VM_FAULT_SIGBUS; | |
313 | if (write) { | |
314 | if (!IS_ERR(handle)) | |
315 | ext4_journal_stop(handle); | |
316 | up_read(&EXT4_I(inode)->i_mmap_sem); | |
01a33b4a | 317 | sb_end_pagefault(sb); |
fb26a1cb JK |
318 | } else { |
319 | up_read(&EXT4_I(inode)->i_mmap_sem); | |
320 | } | |
01a33b4a MW |
321 | |
322 | return result; | |
923ae0ff RZ |
323 | } |
324 | ||
c791ace1 DJ |
325 | static int ext4_dax_fault(struct vm_fault *vmf) |
326 | { | |
327 | return ext4_dax_huge_fault(vmf, PE_SIZE_PTE); | |
328 | } | |
329 | ||
923ae0ff RZ |
330 | static const struct vm_operations_struct ext4_dax_vm_ops = { |
331 | .fault = ext4_dax_fault, | |
c791ace1 | 332 | .huge_fault = ext4_dax_huge_fault, |
1e9d180b | 333 | .page_mkwrite = ext4_dax_fault, |
91d25ba8 | 334 | .pfn_mkwrite = ext4_dax_fault, |
923ae0ff RZ |
335 | }; |
336 | #else | |
337 | #define ext4_dax_vm_ops ext4_file_vm_ops | |
338 | #endif | |
339 | ||
f0f37e2f | 340 | static const struct vm_operations_struct ext4_file_vm_ops = { |
ea3d7209 | 341 | .fault = ext4_filemap_fault, |
f1820361 | 342 | .map_pages = filemap_map_pages, |
2e9ee850 AK |
343 | .page_mkwrite = ext4_page_mkwrite, |
344 | }; | |
345 | ||
346 | static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma) | |
347 | { | |
c9c7429c MH |
348 | struct inode *inode = file->f_mapping->host; |
349 | ||
0db1ff22 TT |
350 | if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) |
351 | return -EIO; | |
352 | ||
2e9ee850 | 353 | file_accessed(file); |
923ae0ff RZ |
354 | if (IS_DAX(file_inode(file))) { |
355 | vma->vm_ops = &ext4_dax_vm_ops; | |
11bd1a9e | 356 | vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE; |
923ae0ff RZ |
357 | } else { |
358 | vma->vm_ops = &ext4_file_vm_ops; | |
359 | } | |
2e9ee850 AK |
360 | return 0; |
361 | } | |
362 | ||
bc0b0d6d TT |
363 | static int ext4_file_open(struct inode * inode, struct file * filp) |
364 | { | |
365 | struct super_block *sb = inode->i_sb; | |
366 | struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); | |
367 | struct vfsmount *mnt = filp->f_path.mnt; | |
9dd78d8c | 368 | struct dentry *dir; |
bc0b0d6d TT |
369 | struct path path; |
370 | char buf[64], *cp; | |
c9c7429c | 371 | int ret; |
bc0b0d6d | 372 | |
0db1ff22 TT |
373 | if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) |
374 | return -EIO; | |
375 | ||
bc0b0d6d | 376 | if (unlikely(!(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED) && |
bc98a42c | 377 | !sb_rdonly(sb))) { |
bc0b0d6d TT |
378 | sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED; |
379 | /* | |
380 | * Sample where the filesystem has been mounted and | |
381 | * store it in the superblock for sysadmin convenience | |
382 | * when trying to sort through large numbers of block | |
383 | * devices or filesystem images. | |
384 | */ | |
385 | memset(buf, 0, sizeof(buf)); | |
3899167d AV |
386 | path.mnt = mnt; |
387 | path.dentry = mnt->mnt_root; | |
bc0b0d6d | 388 | cp = d_path(&path, buf, sizeof(buf)); |
bc0b0d6d | 389 | if (!IS_ERR(cp)) { |
044ce47f JK |
390 | handle_t *handle; |
391 | int err; | |
392 | ||
9924a92a | 393 | handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1); |
044ce47f JK |
394 | if (IS_ERR(handle)) |
395 | return PTR_ERR(handle); | |
5d601255 | 396 | BUFFER_TRACE(sbi->s_sbh, "get_write_access"); |
044ce47f JK |
397 | err = ext4_journal_get_write_access(handle, sbi->s_sbh); |
398 | if (err) { | |
399 | ext4_journal_stop(handle); | |
400 | return err; | |
401 | } | |
cf803903 DW |
402 | strlcpy(sbi->s_es->s_last_mounted, cp, |
403 | sizeof(sbi->s_es->s_last_mounted)); | |
044ce47f JK |
404 | ext4_handle_dirty_super(handle, sb); |
405 | ext4_journal_stop(handle); | |
bc0b0d6d TT |
406 | } |
407 | } | |
abdd438b | 408 | if (ext4_encrypted_inode(inode)) { |
a7550b30 | 409 | ret = fscrypt_get_encryption_info(inode); |
abdd438b TT |
410 | if (ret) |
411 | return -EACCES; | |
a7550b30 | 412 | if (!fscrypt_has_encryption_key(inode)) |
abdd438b TT |
413 | return -ENOKEY; |
414 | } | |
9dd78d8c | 415 | |
c0a37d48 | 416 | dir = dget_parent(file_dentry(filp)); |
9dd78d8c | 417 | if (ext4_encrypted_inode(d_inode(dir)) && |
a7550b30 | 418 | !fscrypt_has_permitted_context(d_inode(dir), inode)) { |
ff978b09 | 419 | ext4_warning(inode->i_sb, |
8d2ae1cb | 420 | "Inconsistent encryption contexts: %lu/%lu", |
9dd78d8c | 421 | (unsigned long) d_inode(dir)->i_ino, |
ff978b09 | 422 | (unsigned long) inode->i_ino); |
9dd78d8c | 423 | dput(dir); |
ff978b09 TT |
424 | return -EPERM; |
425 | } | |
9dd78d8c | 426 | dput(dir); |
8aefcd55 TT |
427 | /* |
428 | * Set up the jbd2_inode if we are opening the inode for | |
429 | * writing and the journal is present | |
430 | */ | |
a361293f | 431 | if (filp->f_mode & FMODE_WRITE) { |
c9c7429c | 432 | ret = ext4_inode_attach_jinode(inode); |
a361293f JK |
433 | if (ret < 0) |
434 | return ret; | |
8aefcd55 | 435 | } |
728fbc0e | 436 | |
91f9943e | 437 | filp->f_mode |= FMODE_NOWAIT; |
abdd438b | 438 | return dquot_file_open(inode, filp); |
bc0b0d6d TT |
439 | } |
440 | ||
c8c0df24 ZL |
441 | /* |
442 | * Here we use ext4_map_blocks() to get a block mapping for a extent-based | |
443 | * file rather than ext4_ext_walk_space() because we can introduce | |
444 | * SEEK_DATA/SEEK_HOLE for block-mapped and extent-mapped file at the same | |
445 | * function. When extent status tree has been fully implemented, it will | |
446 | * track all extent status for a file and we can directly use it to | |
447 | * retrieve the offset for SEEK_DATA/SEEK_HOLE. | |
448 | */ | |
449 | ||
450 | /* | |
451 | * When we retrieve the offset for SEEK_DATA/SEEK_HOLE, we would need to | |
452 | * lookup page cache to check whether or not there has some data between | |
453 | * [startoff, endoff] because, if this range contains an unwritten extent, | |
454 | * we determine this extent as a data or a hole according to whether the | |
455 | * page cache has data or not. | |
456 | */ | |
ad7fefb1 TT |
457 | static int ext4_find_unwritten_pgoff(struct inode *inode, |
458 | int whence, | |
2d90c160 | 459 | ext4_lblk_t end_blk, |
ad7fefb1 | 460 | loff_t *offset) |
c8c0df24 ZL |
461 | { |
462 | struct pagevec pvec; | |
ad7fefb1 | 463 | unsigned int blkbits; |
c8c0df24 ZL |
464 | pgoff_t index; |
465 | pgoff_t end; | |
ad7fefb1 | 466 | loff_t endoff; |
c8c0df24 ZL |
467 | loff_t startoff; |
468 | loff_t lastoff; | |
469 | int found = 0; | |
470 | ||
ad7fefb1 | 471 | blkbits = inode->i_sb->s_blocksize_bits; |
c8c0df24 ZL |
472 | startoff = *offset; |
473 | lastoff = startoff; | |
2d90c160 | 474 | endoff = (loff_t)end_blk << blkbits; |
c8c0df24 | 475 | |
09cbfeaf | 476 | index = startoff >> PAGE_SHIFT; |
3f1d5bad | 477 | end = (endoff - 1) >> PAGE_SHIFT; |
c8c0df24 ZL |
478 | |
479 | pagevec_init(&pvec, 0); | |
480 | do { | |
dec0da7b | 481 | int i; |
c8c0df24 ZL |
482 | unsigned long nr_pages; |
483 | ||
dec0da7b | 484 | nr_pages = pagevec_lookup_range(&pvec, inode->i_mapping, |
397162ff | 485 | &index, end); |
7d95eddf | 486 | if (nr_pages == 0) |
c8c0df24 | 487 | break; |
c8c0df24 ZL |
488 | |
489 | for (i = 0; i < nr_pages; i++) { | |
490 | struct page *page = pvec.pages[i]; | |
491 | struct buffer_head *bh, *head; | |
492 | ||
493 | /* | |
7d95eddf JK |
494 | * If current offset is smaller than the page offset, |
495 | * there is a hole at this offset. | |
c8c0df24 | 496 | */ |
7d95eddf JK |
497 | if (whence == SEEK_HOLE && lastoff < endoff && |
498 | lastoff < page_offset(pvec.pages[i])) { | |
c8c0df24 ZL |
499 | found = 1; |
500 | *offset = lastoff; | |
501 | goto out; | |
502 | } | |
503 | ||
504 | lock_page(page); | |
505 | ||
506 | if (unlikely(page->mapping != inode->i_mapping)) { | |
507 | unlock_page(page); | |
508 | continue; | |
509 | } | |
510 | ||
511 | if (!page_has_buffers(page)) { | |
512 | unlock_page(page); | |
513 | continue; | |
514 | } | |
515 | ||
516 | if (page_has_buffers(page)) { | |
517 | lastoff = page_offset(page); | |
518 | bh = head = page_buffers(page); | |
519 | do { | |
fcf5ea10 JK |
520 | if (lastoff + bh->b_size <= startoff) |
521 | goto next; | |
c8c0df24 ZL |
522 | if (buffer_uptodate(bh) || |
523 | buffer_unwritten(bh)) { | |
965c8e59 | 524 | if (whence == SEEK_DATA) |
c8c0df24 ZL |
525 | found = 1; |
526 | } else { | |
965c8e59 | 527 | if (whence == SEEK_HOLE) |
c8c0df24 ZL |
528 | found = 1; |
529 | } | |
530 | if (found) { | |
531 | *offset = max_t(loff_t, | |
532 | startoff, lastoff); | |
533 | unlock_page(page); | |
534 | goto out; | |
535 | } | |
fcf5ea10 | 536 | next: |
c8c0df24 ZL |
537 | lastoff += bh->b_size; |
538 | bh = bh->b_this_page; | |
539 | } while (bh != head); | |
540 | } | |
541 | ||
542 | lastoff = page_offset(page) + PAGE_SIZE; | |
543 | unlock_page(page); | |
544 | } | |
545 | ||
c8c0df24 ZL |
546 | pagevec_release(&pvec); |
547 | } while (index <= end); | |
548 | ||
dec0da7b | 549 | /* There are no pages upto endoff - that would be a hole in there. */ |
7d95eddf JK |
550 | if (whence == SEEK_HOLE && lastoff < endoff) { |
551 | found = 1; | |
552 | *offset = lastoff; | |
553 | } | |
c8c0df24 ZL |
554 | out: |
555 | pagevec_release(&pvec); | |
556 | return found; | |
557 | } | |
558 | ||
559 | /* | |
560 | * ext4_seek_data() retrieves the offset for SEEK_DATA. | |
561 | */ | |
562 | static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize) | |
563 | { | |
564 | struct inode *inode = file->f_mapping->host; | |
ad7fefb1 TT |
565 | struct extent_status es; |
566 | ext4_lblk_t start, last, end; | |
567 | loff_t dataoff, isize; | |
568 | int blkbits; | |
2d90c160 | 569 | int ret; |
c8c0df24 | 570 | |
5955102c | 571 | inode_lock(inode); |
ad7fefb1 TT |
572 | |
573 | isize = i_size_read(inode); | |
1bd8d6cd | 574 | if (offset < 0 || offset >= isize) { |
5955102c | 575 | inode_unlock(inode); |
c8c0df24 ZL |
576 | return -ENXIO; |
577 | } | |
ad7fefb1 TT |
578 | |
579 | blkbits = inode->i_sb->s_blocksize_bits; | |
580 | start = offset >> blkbits; | |
581 | last = start; | |
582 | end = isize >> blkbits; | |
583 | dataoff = offset; | |
584 | ||
585 | do { | |
2d90c160 JK |
586 | ret = ext4_get_next_extent(inode, last, end - last + 1, &es); |
587 | if (ret <= 0) { | |
588 | /* No extent found -> no data */ | |
589 | if (ret == 0) | |
590 | ret = -ENXIO; | |
591 | inode_unlock(inode); | |
592 | return ret; | |
ad7fefb1 | 593 | } |
c8c0df24 | 594 | |
2d90c160 JK |
595 | last = es.es_lblk; |
596 | if (last != start) | |
597 | dataoff = (loff_t)last << blkbits; | |
598 | if (!ext4_es_is_unwritten(&es)) | |
c8c0df24 | 599 | break; |
c8c0df24 | 600 | |
ad7fefb1 TT |
601 | /* |
602 | * If there is a unwritten extent at this offset, | |
603 | * it will be as a data or a hole according to page | |
604 | * cache that has data or not. | |
605 | */ | |
2d90c160 JK |
606 | if (ext4_find_unwritten_pgoff(inode, SEEK_DATA, |
607 | es.es_lblk + es.es_len, &dataoff)) | |
608 | break; | |
609 | last += es.es_len; | |
ad7fefb1 | 610 | dataoff = (loff_t)last << blkbits; |
2d90c160 | 611 | cond_resched(); |
ad7fefb1 | 612 | } while (last <= end); |
c8c0df24 | 613 | |
5955102c | 614 | inode_unlock(inode); |
c8c0df24 | 615 | |
ad7fefb1 TT |
616 | if (dataoff > isize) |
617 | return -ENXIO; | |
618 | ||
619 | return vfs_setpos(file, dataoff, maxsize); | |
c8c0df24 ZL |
620 | } |
621 | ||
622 | /* | |
ad7fefb1 | 623 | * ext4_seek_hole() retrieves the offset for SEEK_HOLE. |
c8c0df24 ZL |
624 | */ |
625 | static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize) | |
626 | { | |
627 | struct inode *inode = file->f_mapping->host; | |
ad7fefb1 TT |
628 | struct extent_status es; |
629 | ext4_lblk_t start, last, end; | |
630 | loff_t holeoff, isize; | |
631 | int blkbits; | |
2d90c160 | 632 | int ret; |
c8c0df24 | 633 | |
5955102c | 634 | inode_lock(inode); |
ad7fefb1 TT |
635 | |
636 | isize = i_size_read(inode); | |
1bd8d6cd | 637 | if (offset < 0 || offset >= isize) { |
5955102c | 638 | inode_unlock(inode); |
c8c0df24 ZL |
639 | return -ENXIO; |
640 | } | |
641 | ||
ad7fefb1 TT |
642 | blkbits = inode->i_sb->s_blocksize_bits; |
643 | start = offset >> blkbits; | |
644 | last = start; | |
645 | end = isize >> blkbits; | |
646 | holeoff = offset; | |
c8c0df24 | 647 | |
ad7fefb1 | 648 | do { |
2d90c160 JK |
649 | ret = ext4_get_next_extent(inode, last, end - last + 1, &es); |
650 | if (ret < 0) { | |
651 | inode_unlock(inode); | |
652 | return ret; | |
ad7fefb1 | 653 | } |
2d90c160 JK |
654 | /* Found a hole? */ |
655 | if (ret == 0 || es.es_lblk > last) { | |
656 | if (last != start) | |
657 | holeoff = (loff_t)last << blkbits; | |
658 | break; | |
ad7fefb1 | 659 | } |
ad7fefb1 TT |
660 | /* |
661 | * If there is a unwritten extent at this offset, | |
662 | * it will be as a data or a hole according to page | |
663 | * cache that has data or not. | |
664 | */ | |
2d90c160 JK |
665 | if (ext4_es_is_unwritten(&es) && |
666 | ext4_find_unwritten_pgoff(inode, SEEK_HOLE, | |
667 | last + es.es_len, &holeoff)) | |
668 | break; | |
ad7fefb1 | 669 | |
2d90c160 JK |
670 | last += es.es_len; |
671 | holeoff = (loff_t)last << blkbits; | |
672 | cond_resched(); | |
ad7fefb1 TT |
673 | } while (last <= end); |
674 | ||
5955102c | 675 | inode_unlock(inode); |
c8c0df24 | 676 | |
ad7fefb1 TT |
677 | if (holeoff > isize) |
678 | holeoff = isize; | |
679 | ||
680 | return vfs_setpos(file, holeoff, maxsize); | |
c8c0df24 ZL |
681 | } |
682 | ||
e0d10bfa | 683 | /* |
ec7268ce ES |
684 | * ext4_llseek() handles both block-mapped and extent-mapped maxbytes values |
685 | * by calling generic_file_llseek_size() with the appropriate maxbytes | |
686 | * value for each. | |
e0d10bfa | 687 | */ |
965c8e59 | 688 | loff_t ext4_llseek(struct file *file, loff_t offset, int whence) |
e0d10bfa TO |
689 | { |
690 | struct inode *inode = file->f_mapping->host; | |
691 | loff_t maxbytes; | |
692 | ||
693 | if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) | |
694 | maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes; | |
695 | else | |
696 | maxbytes = inode->i_sb->s_maxbytes; | |
e0d10bfa | 697 | |
965c8e59 | 698 | switch (whence) { |
c8c0df24 ZL |
699 | case SEEK_SET: |
700 | case SEEK_CUR: | |
701 | case SEEK_END: | |
965c8e59 | 702 | return generic_file_llseek_size(file, offset, whence, |
c8c0df24 ZL |
703 | maxbytes, i_size_read(inode)); |
704 | case SEEK_DATA: | |
705 | return ext4_seek_data(file, offset, maxbytes); | |
706 | case SEEK_HOLE: | |
707 | return ext4_seek_hole(file, offset, maxbytes); | |
708 | } | |
709 | ||
710 | return -EINVAL; | |
e0d10bfa TO |
711 | } |
712 | ||
617ba13b | 713 | const struct file_operations ext4_file_operations = { |
e0d10bfa | 714 | .llseek = ext4_llseek, |
364443cb | 715 | .read_iter = ext4_file_read_iter, |
9b884164 | 716 | .write_iter = ext4_file_write_iter, |
5cdd7b2d | 717 | .unlocked_ioctl = ext4_ioctl, |
ac27a0ec | 718 | #ifdef CONFIG_COMPAT |
617ba13b | 719 | .compat_ioctl = ext4_compat_ioctl, |
ac27a0ec | 720 | #endif |
2e9ee850 | 721 | .mmap = ext4_file_mmap, |
bc0b0d6d | 722 | .open = ext4_file_open, |
617ba13b MC |
723 | .release = ext4_release_file, |
724 | .fsync = ext4_sync_file, | |
dbe6ec81 | 725 | .get_unmapped_area = thp_get_unmapped_area, |
ac27a0ec | 726 | .splice_read = generic_file_splice_read, |
8d020765 | 727 | .splice_write = iter_file_splice_write, |
2fe17c10 | 728 | .fallocate = ext4_fallocate, |
ac27a0ec DK |
729 | }; |
730 | ||
754661f1 | 731 | const struct inode_operations ext4_file_inode_operations = { |
617ba13b | 732 | .setattr = ext4_setattr, |
99652ea5 | 733 | .getattr = ext4_file_getattr, |
617ba13b | 734 | .listxattr = ext4_listxattr, |
4e34e719 | 735 | .get_acl = ext4_get_acl, |
64e178a7 | 736 | .set_acl = ext4_set_acl, |
6873fa0d | 737 | .fiemap = ext4_fiemap, |
ac27a0ec DK |
738 | }; |
739 |