Commit | Line | Data |
---|---|---|
ac27a0ec | 1 | /* |
617ba13b | 2 | * linux/fs/ext4/file.c |
ac27a0ec DK |
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 | * | |
617ba13b | 15 | * ext4 fs regular file handling primitives |
ac27a0ec DK |
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> | |
dab291af | 23 | #include <linux/jbd2.h> |
bc0b0d6d TT |
24 | #include <linux/mount.h> |
25 | #include <linux/path.h> | |
871a2931 | 26 | #include <linux/quotaops.h> |
c8c0df24 | 27 | #include <linux/pagevec.h> |
e2e40f2c | 28 | #include <linux/uio.h> |
3dcf5451 CH |
29 | #include "ext4.h" |
30 | #include "ext4_jbd2.h" | |
ac27a0ec DK |
31 | #include "xattr.h" |
32 | #include "acl.h" | |
33 | ||
34 | /* | |
35 | * Called when an inode is released. Note that this is different | |
617ba13b | 36 | * from ext4_file_open: open gets called at every open, but release |
ac27a0ec DK |
37 | * gets called only when /all/ the files are closed. |
38 | */ | |
af5bc92d | 39 | static int ext4_release_file(struct inode *inode, struct file *filp) |
ac27a0ec | 40 | { |
19f5fb7a | 41 | if (ext4_test_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE)) { |
7d8f9f7d | 42 | ext4_alloc_da_blocks(inode); |
19f5fb7a | 43 | ext4_clear_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE); |
7d8f9f7d | 44 | } |
ac27a0ec DK |
45 | /* if we are the last writer on the inode, drop the block reservation */ |
46 | if ((filp->f_mode & FMODE_WRITE) && | |
d6014301 AK |
47 | (atomic_read(&inode->i_writecount) == 1) && |
48 | !EXT4_I(inode)->i_reserved_data_blocks) | |
ac27a0ec | 49 | { |
0e855ac8 | 50 | down_write(&EXT4_I(inode)->i_data_sem); |
c2ea3fde | 51 | ext4_discard_preallocations(inode); |
0e855ac8 | 52 | up_write(&EXT4_I(inode)->i_data_sem); |
ac27a0ec DK |
53 | } |
54 | if (is_dx(inode) && filp->private_data) | |
617ba13b | 55 | ext4_htree_free_dir_info(filp->private_data); |
ac27a0ec DK |
56 | |
57 | return 0; | |
58 | } | |
59 | ||
c197855e | 60 | static void ext4_unwritten_wait(struct inode *inode) |
e9e3bcec ES |
61 | { |
62 | wait_queue_head_t *wq = ext4_ioend_wq(inode); | |
63 | ||
e27f41e1 | 64 | wait_event(*wq, (atomic_read(&EXT4_I(inode)->i_unwritten) == 0)); |
e9e3bcec ES |
65 | } |
66 | ||
67 | /* | |
68 | * This tests whether the IO in question is block-aligned or not. | |
69 | * Ext4 utilizes unwritten extents when hole-filling during direct IO, and they | |
70 | * are converted to written only after the IO is complete. Until they are | |
71 | * mapped, these blocks appear as holes, so dio_zero_block() will assume that | |
72 | * it needs to zero out portions of the start and/or end block. If 2 AIO | |
73 | * threads are at work on the same unwritten block, they must be synchronized | |
74 | * or one thread will zero the other's data, causing corruption. | |
75 | */ | |
76 | static int | |
9b884164 | 77 | ext4_unaligned_aio(struct inode *inode, struct iov_iter *from, loff_t pos) |
e9e3bcec ES |
78 | { |
79 | struct super_block *sb = inode->i_sb; | |
80 | int blockmask = sb->s_blocksize - 1; | |
e9e3bcec | 81 | |
6e6358fc | 82 | if (pos >= i_size_read(inode)) |
e9e3bcec ES |
83 | return 0; |
84 | ||
9b884164 | 85 | if ((pos | iov_iter_alignment(from)) & blockmask) |
e9e3bcec ES |
86 | return 1; |
87 | ||
88 | return 0; | |
89 | } | |
90 | ||
ac27a0ec | 91 | static ssize_t |
9b884164 | 92 | ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from) |
ac27a0ec | 93 | { |
4bd809db | 94 | struct file *file = iocb->ki_filp; |
8ad2850f | 95 | struct inode *inode = file_inode(iocb->ki_filp); |
7ed07ba8 | 96 | struct mutex *aio_mutex = NULL; |
4bd809db | 97 | struct blk_plug plug; |
2ba48ce5 | 98 | int o_direct = iocb->ki_flags & IOCB_DIRECT; |
4bd809db | 99 | int overwrite = 0; |
8563000d | 100 | ssize_t ret; |
7608e610 | 101 | |
f5ccfe1d TT |
102 | /* |
103 | * Unaligned direct AIO must be serialized; see comment above | |
104 | * In the case of O_APPEND, assume that we must always serialize | |
105 | */ | |
106 | if (o_direct && | |
107 | ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) && | |
108 | !is_sync_kiocb(iocb) && | |
2ba48ce5 | 109 | (iocb->ki_flags & IOCB_APPEND || |
e768d7ff | 110 | ext4_unaligned_aio(inode, from, iocb->ki_pos))) { |
f5ccfe1d TT |
111 | aio_mutex = ext4_aio_mutex(inode); |
112 | mutex_lock(aio_mutex); | |
113 | ext4_unwritten_wait(inode); | |
114 | } | |
115 | ||
116 | mutex_lock(&inode->i_mutex); | |
3309dd04 AV |
117 | ret = generic_write_checks(iocb, from); |
118 | if (ret <= 0) | |
e768d7ff AV |
119 | goto out; |
120 | ||
e2b46574 ES |
121 | /* |
122 | * If we have encountered a bitmap-format file, the size limit | |
123 | * is smaller than s_maxbytes, which is for extent-mapped files. | |
124 | */ | |
12e9b892 | 125 | if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { |
e2b46574 | 126 | struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
ac27a0ec | 127 | |
3309dd04 | 128 | if (iocb->ki_pos >= sbi->s_bitmap_maxbytes) { |
f5ccfe1d | 129 | ret = -EFBIG; |
e768d7ff | 130 | goto out; |
f5ccfe1d | 131 | } |
3309dd04 | 132 | iov_iter_truncate(from, sbi->s_bitmap_maxbytes - iocb->ki_pos); |
e2b46574 ES |
133 | } |
134 | ||
a41537e6 | 135 | iocb->private = &overwrite; |
7ed07ba8 | 136 | if (o_direct) { |
3309dd04 AV |
137 | size_t length = iov_iter_count(from); |
138 | loff_t pos = iocb->ki_pos; | |
8ad2850f TT |
139 | blk_start_plug(&plug); |
140 | ||
8ad2850f | 141 | /* check whether we do a DIO overwrite or not */ |
7ed07ba8 | 142 | if (ext4_should_dioread_nolock(inode) && !aio_mutex && |
8ad2850f TT |
143 | !file->f_mapping->nrpages && pos + length <= i_size_read(inode)) { |
144 | struct ext4_map_blocks map; | |
145 | unsigned int blkbits = inode->i_blkbits; | |
146 | int err, len; | |
147 | ||
148 | map.m_lblk = pos >> blkbits; | |
149 | map.m_len = (EXT4_BLOCK_ALIGN(pos + length, blkbits) >> blkbits) | |
150 | - map.m_lblk; | |
151 | len = map.m_len; | |
152 | ||
153 | err = ext4_map_blocks(NULL, inode, &map, 0); | |
154 | /* | |
155 | * 'err==len' means that all of blocks has | |
156 | * been preallocated no matter they are | |
157 | * initialized or not. For excluding | |
158 | * unwritten extents, we need to check | |
159 | * m_flags. There are two conditions that | |
160 | * indicate for initialized extents. 1) If we | |
161 | * hit extent cache, EXT4_MAP_MAPPED flag is | |
162 | * returned; 2) If we do a real lookup, | |
163 | * non-flags are returned. So we should check | |
164 | * these two conditions. | |
165 | */ | |
166 | if (err == len && (map.m_flags & EXT4_MAP_MAPPED)) | |
167 | overwrite = 1; | |
168 | } | |
f5ccfe1d | 169 | } |
7608e610 | 170 | |
9b884164 | 171 | ret = __generic_file_write_iter(iocb, from); |
7ed07ba8 | 172 | mutex_unlock(&inode->i_mutex); |
7608e610 | 173 | |
7ed07ba8 TT |
174 | if (ret > 0) { |
175 | ssize_t err; | |
176 | ||
177 | err = generic_write_sync(file, iocb->ki_pos - ret, ret); | |
178 | if (err < 0) | |
179 | ret = err; | |
7608e610 | 180 | } |
7ed07ba8 TT |
181 | if (o_direct) |
182 | blk_finish_plug(&plug); | |
e9e3bcec | 183 | |
e768d7ff AV |
184 | if (aio_mutex) |
185 | mutex_unlock(aio_mutex); | |
186 | return ret; | |
187 | ||
188 | out: | |
189 | mutex_unlock(&inode->i_mutex); | |
7ed07ba8 TT |
190 | if (aio_mutex) |
191 | mutex_unlock(aio_mutex); | |
e9e3bcec | 192 | return ret; |
ac27a0ec DK |
193 | } |
194 | ||
923ae0ff RZ |
195 | #ifdef CONFIG_FS_DAX |
196 | static int ext4_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf) | |
197 | { | |
198 | return dax_fault(vma, vmf, ext4_get_block); | |
199 | /* Is this the right get_block? */ | |
200 | } | |
201 | ||
202 | static int ext4_dax_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) | |
203 | { | |
204 | return dax_mkwrite(vma, vmf, ext4_get_block); | |
205 | } | |
206 | ||
207 | static const struct vm_operations_struct ext4_dax_vm_ops = { | |
208 | .fault = ext4_dax_fault, | |
209 | .page_mkwrite = ext4_dax_mkwrite, | |
210 | }; | |
211 | #else | |
212 | #define ext4_dax_vm_ops ext4_file_vm_ops | |
213 | #endif | |
214 | ||
f0f37e2f | 215 | static const struct vm_operations_struct ext4_file_vm_ops = { |
2e9ee850 | 216 | .fault = filemap_fault, |
f1820361 | 217 | .map_pages = filemap_map_pages, |
2e9ee850 AK |
218 | .page_mkwrite = ext4_page_mkwrite, |
219 | }; | |
220 | ||
221 | static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma) | |
222 | { | |
2e9ee850 | 223 | file_accessed(file); |
923ae0ff RZ |
224 | if (IS_DAX(file_inode(file))) { |
225 | vma->vm_ops = &ext4_dax_vm_ops; | |
226 | vma->vm_flags |= VM_MIXEDMAP; | |
227 | } else { | |
228 | vma->vm_ops = &ext4_file_vm_ops; | |
229 | } | |
2e9ee850 AK |
230 | return 0; |
231 | } | |
232 | ||
bc0b0d6d TT |
233 | static int ext4_file_open(struct inode * inode, struct file * filp) |
234 | { | |
235 | struct super_block *sb = inode->i_sb; | |
236 | struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); | |
237 | struct vfsmount *mnt = filp->f_path.mnt; | |
238 | struct path path; | |
239 | char buf[64], *cp; | |
240 | ||
241 | if (unlikely(!(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED) && | |
242 | !(sb->s_flags & MS_RDONLY))) { | |
243 | sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED; | |
244 | /* | |
245 | * Sample where the filesystem has been mounted and | |
246 | * store it in the superblock for sysadmin convenience | |
247 | * when trying to sort through large numbers of block | |
248 | * devices or filesystem images. | |
249 | */ | |
250 | memset(buf, 0, sizeof(buf)); | |
3899167d AV |
251 | path.mnt = mnt; |
252 | path.dentry = mnt->mnt_root; | |
bc0b0d6d | 253 | cp = d_path(&path, buf, sizeof(buf)); |
bc0b0d6d | 254 | if (!IS_ERR(cp)) { |
044ce47f JK |
255 | handle_t *handle; |
256 | int err; | |
257 | ||
9924a92a | 258 | handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1); |
044ce47f JK |
259 | if (IS_ERR(handle)) |
260 | return PTR_ERR(handle); | |
5d601255 | 261 | BUFFER_TRACE(sbi->s_sbh, "get_write_access"); |
044ce47f JK |
262 | err = ext4_journal_get_write_access(handle, sbi->s_sbh); |
263 | if (err) { | |
264 | ext4_journal_stop(handle); | |
265 | return err; | |
266 | } | |
cf803903 DW |
267 | strlcpy(sbi->s_es->s_last_mounted, cp, |
268 | sizeof(sbi->s_es->s_last_mounted)); | |
044ce47f JK |
269 | ext4_handle_dirty_super(handle, sb); |
270 | ext4_journal_stop(handle); | |
bc0b0d6d TT |
271 | } |
272 | } | |
8aefcd55 TT |
273 | /* |
274 | * Set up the jbd2_inode if we are opening the inode for | |
275 | * writing and the journal is present | |
276 | */ | |
a361293f JK |
277 | if (filp->f_mode & FMODE_WRITE) { |
278 | int ret = ext4_inode_attach_jinode(inode); | |
279 | if (ret < 0) | |
280 | return ret; | |
8aefcd55 | 281 | } |
907f4554 | 282 | return dquot_file_open(inode, filp); |
bc0b0d6d TT |
283 | } |
284 | ||
c8c0df24 ZL |
285 | /* |
286 | * Here we use ext4_map_blocks() to get a block mapping for a extent-based | |
287 | * file rather than ext4_ext_walk_space() because we can introduce | |
288 | * SEEK_DATA/SEEK_HOLE for block-mapped and extent-mapped file at the same | |
289 | * function. When extent status tree has been fully implemented, it will | |
290 | * track all extent status for a file and we can directly use it to | |
291 | * retrieve the offset for SEEK_DATA/SEEK_HOLE. | |
292 | */ | |
293 | ||
294 | /* | |
295 | * When we retrieve the offset for SEEK_DATA/SEEK_HOLE, we would need to | |
296 | * lookup page cache to check whether or not there has some data between | |
297 | * [startoff, endoff] because, if this range contains an unwritten extent, | |
298 | * we determine this extent as a data or a hole according to whether the | |
299 | * page cache has data or not. | |
300 | */ | |
ad7fefb1 TT |
301 | static int ext4_find_unwritten_pgoff(struct inode *inode, |
302 | int whence, | |
303 | struct ext4_map_blocks *map, | |
304 | loff_t *offset) | |
c8c0df24 ZL |
305 | { |
306 | struct pagevec pvec; | |
ad7fefb1 | 307 | unsigned int blkbits; |
c8c0df24 ZL |
308 | pgoff_t index; |
309 | pgoff_t end; | |
ad7fefb1 | 310 | loff_t endoff; |
c8c0df24 ZL |
311 | loff_t startoff; |
312 | loff_t lastoff; | |
313 | int found = 0; | |
314 | ||
ad7fefb1 | 315 | blkbits = inode->i_sb->s_blocksize_bits; |
c8c0df24 ZL |
316 | startoff = *offset; |
317 | lastoff = startoff; | |
ad7fefb1 | 318 | endoff = (loff_t)(map->m_lblk + map->m_len) << blkbits; |
c8c0df24 ZL |
319 | |
320 | index = startoff >> PAGE_CACHE_SHIFT; | |
321 | end = endoff >> PAGE_CACHE_SHIFT; | |
322 | ||
323 | pagevec_init(&pvec, 0); | |
324 | do { | |
325 | int i, num; | |
326 | unsigned long nr_pages; | |
327 | ||
328 | num = min_t(pgoff_t, end - index, PAGEVEC_SIZE); | |
329 | nr_pages = pagevec_lookup(&pvec, inode->i_mapping, index, | |
330 | (pgoff_t)num); | |
331 | if (nr_pages == 0) { | |
965c8e59 | 332 | if (whence == SEEK_DATA) |
c8c0df24 ZL |
333 | break; |
334 | ||
965c8e59 | 335 | BUG_ON(whence != SEEK_HOLE); |
c8c0df24 ZL |
336 | /* |
337 | * If this is the first time to go into the loop and | |
338 | * offset is not beyond the end offset, it will be a | |
339 | * hole at this offset | |
340 | */ | |
341 | if (lastoff == startoff || lastoff < endoff) | |
342 | found = 1; | |
343 | break; | |
344 | } | |
345 | ||
346 | /* | |
347 | * If this is the first time to go into the loop and | |
348 | * offset is smaller than the first page offset, it will be a | |
349 | * hole at this offset. | |
350 | */ | |
965c8e59 | 351 | if (lastoff == startoff && whence == SEEK_HOLE && |
c8c0df24 ZL |
352 | lastoff < page_offset(pvec.pages[0])) { |
353 | found = 1; | |
354 | break; | |
355 | } | |
356 | ||
357 | for (i = 0; i < nr_pages; i++) { | |
358 | struct page *page = pvec.pages[i]; | |
359 | struct buffer_head *bh, *head; | |
360 | ||
361 | /* | |
362 | * If the current offset is not beyond the end of given | |
363 | * range, it will be a hole. | |
364 | */ | |
965c8e59 | 365 | if (lastoff < endoff && whence == SEEK_HOLE && |
c8c0df24 ZL |
366 | page->index > end) { |
367 | found = 1; | |
368 | *offset = lastoff; | |
369 | goto out; | |
370 | } | |
371 | ||
372 | lock_page(page); | |
373 | ||
374 | if (unlikely(page->mapping != inode->i_mapping)) { | |
375 | unlock_page(page); | |
376 | continue; | |
377 | } | |
378 | ||
379 | if (!page_has_buffers(page)) { | |
380 | unlock_page(page); | |
381 | continue; | |
382 | } | |
383 | ||
384 | if (page_has_buffers(page)) { | |
385 | lastoff = page_offset(page); | |
386 | bh = head = page_buffers(page); | |
387 | do { | |
388 | if (buffer_uptodate(bh) || | |
389 | buffer_unwritten(bh)) { | |
965c8e59 | 390 | if (whence == SEEK_DATA) |
c8c0df24 ZL |
391 | found = 1; |
392 | } else { | |
965c8e59 | 393 | if (whence == SEEK_HOLE) |
c8c0df24 ZL |
394 | found = 1; |
395 | } | |
396 | if (found) { | |
397 | *offset = max_t(loff_t, | |
398 | startoff, lastoff); | |
399 | unlock_page(page); | |
400 | goto out; | |
401 | } | |
402 | lastoff += bh->b_size; | |
403 | bh = bh->b_this_page; | |
404 | } while (bh != head); | |
405 | } | |
406 | ||
407 | lastoff = page_offset(page) + PAGE_SIZE; | |
408 | unlock_page(page); | |
409 | } | |
410 | ||
411 | /* | |
412 | * The no. of pages is less than our desired, that would be a | |
413 | * hole in there. | |
414 | */ | |
965c8e59 | 415 | if (nr_pages < num && whence == SEEK_HOLE) { |
c8c0df24 ZL |
416 | found = 1; |
417 | *offset = lastoff; | |
418 | break; | |
419 | } | |
420 | ||
421 | index = pvec.pages[i - 1]->index + 1; | |
422 | pagevec_release(&pvec); | |
423 | } while (index <= end); | |
424 | ||
425 | out: | |
426 | pagevec_release(&pvec); | |
427 | return found; | |
428 | } | |
429 | ||
430 | /* | |
431 | * ext4_seek_data() retrieves the offset for SEEK_DATA. | |
432 | */ | |
433 | static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize) | |
434 | { | |
435 | struct inode *inode = file->f_mapping->host; | |
ad7fefb1 TT |
436 | struct ext4_map_blocks map; |
437 | struct extent_status es; | |
438 | ext4_lblk_t start, last, end; | |
439 | loff_t dataoff, isize; | |
440 | int blkbits; | |
441 | int ret = 0; | |
c8c0df24 ZL |
442 | |
443 | mutex_lock(&inode->i_mutex); | |
ad7fefb1 TT |
444 | |
445 | isize = i_size_read(inode); | |
446 | if (offset >= isize) { | |
c8c0df24 ZL |
447 | mutex_unlock(&inode->i_mutex); |
448 | return -ENXIO; | |
449 | } | |
ad7fefb1 TT |
450 | |
451 | blkbits = inode->i_sb->s_blocksize_bits; | |
452 | start = offset >> blkbits; | |
453 | last = start; | |
454 | end = isize >> blkbits; | |
455 | dataoff = offset; | |
456 | ||
457 | do { | |
458 | map.m_lblk = last; | |
459 | map.m_len = end - last + 1; | |
460 | ret = ext4_map_blocks(NULL, inode, &map, 0); | |
461 | if (ret > 0 && !(map.m_flags & EXT4_MAP_UNWRITTEN)) { | |
462 | if (last != start) | |
463 | dataoff = (loff_t)last << blkbits; | |
c8c0df24 | 464 | break; |
ad7fefb1 | 465 | } |
c8c0df24 | 466 | |
ad7fefb1 TT |
467 | /* |
468 | * If there is a delay extent at this offset, | |
469 | * it will be as a data. | |
470 | */ | |
471 | ext4_es_find_delayed_extent_range(inode, last, last, &es); | |
472 | if (es.es_len != 0 && in_range(last, es.es_lblk, es.es_len)) { | |
473 | if (last != start) | |
474 | dataoff = (loff_t)last << blkbits; | |
c8c0df24 ZL |
475 | break; |
476 | } | |
477 | ||
ad7fefb1 TT |
478 | /* |
479 | * If there is a unwritten extent at this offset, | |
480 | * it will be as a data or a hole according to page | |
481 | * cache that has data or not. | |
482 | */ | |
483 | if (map.m_flags & EXT4_MAP_UNWRITTEN) { | |
484 | int unwritten; | |
485 | unwritten = ext4_find_unwritten_pgoff(inode, SEEK_DATA, | |
486 | &map, &dataoff); | |
487 | if (unwritten) | |
488 | break; | |
489 | } | |
c8c0df24 | 490 | |
ad7fefb1 TT |
491 | last++; |
492 | dataoff = (loff_t)last << blkbits; | |
493 | } while (last <= end); | |
c8c0df24 ZL |
494 | |
495 | mutex_unlock(&inode->i_mutex); | |
496 | ||
ad7fefb1 TT |
497 | if (dataoff > isize) |
498 | return -ENXIO; | |
499 | ||
500 | return vfs_setpos(file, dataoff, maxsize); | |
c8c0df24 ZL |
501 | } |
502 | ||
503 | /* | |
ad7fefb1 | 504 | * ext4_seek_hole() retrieves the offset for SEEK_HOLE. |
c8c0df24 ZL |
505 | */ |
506 | static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize) | |
507 | { | |
508 | struct inode *inode = file->f_mapping->host; | |
ad7fefb1 TT |
509 | struct ext4_map_blocks map; |
510 | struct extent_status es; | |
511 | ext4_lblk_t start, last, end; | |
512 | loff_t holeoff, isize; | |
513 | int blkbits; | |
514 | int ret = 0; | |
c8c0df24 ZL |
515 | |
516 | mutex_lock(&inode->i_mutex); | |
ad7fefb1 TT |
517 | |
518 | isize = i_size_read(inode); | |
519 | if (offset >= isize) { | |
c8c0df24 ZL |
520 | mutex_unlock(&inode->i_mutex); |
521 | return -ENXIO; | |
522 | } | |
523 | ||
ad7fefb1 TT |
524 | blkbits = inode->i_sb->s_blocksize_bits; |
525 | start = offset >> blkbits; | |
526 | last = start; | |
527 | end = isize >> blkbits; | |
528 | holeoff = offset; | |
c8c0df24 | 529 | |
ad7fefb1 TT |
530 | do { |
531 | map.m_lblk = last; | |
532 | map.m_len = end - last + 1; | |
533 | ret = ext4_map_blocks(NULL, inode, &map, 0); | |
534 | if (ret > 0 && !(map.m_flags & EXT4_MAP_UNWRITTEN)) { | |
535 | last += ret; | |
536 | holeoff = (loff_t)last << blkbits; | |
537 | continue; | |
538 | } | |
c8c0df24 | 539 | |
ad7fefb1 TT |
540 | /* |
541 | * If there is a delay extent at this offset, | |
542 | * we will skip this extent. | |
543 | */ | |
544 | ext4_es_find_delayed_extent_range(inode, last, last, &es); | |
545 | if (es.es_len != 0 && in_range(last, es.es_lblk, es.es_len)) { | |
546 | last = es.es_lblk + es.es_len; | |
547 | holeoff = (loff_t)last << blkbits; | |
548 | continue; | |
549 | } | |
14516bb7 | 550 | |
ad7fefb1 TT |
551 | /* |
552 | * If there is a unwritten extent at this offset, | |
553 | * it will be as a data or a hole according to page | |
554 | * cache that has data or not. | |
555 | */ | |
556 | if (map.m_flags & EXT4_MAP_UNWRITTEN) { | |
557 | int unwritten; | |
558 | unwritten = ext4_find_unwritten_pgoff(inode, SEEK_HOLE, | |
559 | &map, &holeoff); | |
560 | if (!unwritten) { | |
561 | last += ret; | |
562 | holeoff = (loff_t)last << blkbits; | |
c8c0df24 ZL |
563 | continue; |
564 | } | |
14516bb7 | 565 | } |
ad7fefb1 TT |
566 | |
567 | /* find a hole */ | |
568 | break; | |
569 | } while (last <= end); | |
570 | ||
c8c0df24 ZL |
571 | mutex_unlock(&inode->i_mutex); |
572 | ||
ad7fefb1 TT |
573 | if (holeoff > isize) |
574 | holeoff = isize; | |
575 | ||
576 | return vfs_setpos(file, holeoff, maxsize); | |
c8c0df24 ZL |
577 | } |
578 | ||
e0d10bfa | 579 | /* |
ec7268ce ES |
580 | * ext4_llseek() handles both block-mapped and extent-mapped maxbytes values |
581 | * by calling generic_file_llseek_size() with the appropriate maxbytes | |
582 | * value for each. | |
e0d10bfa | 583 | */ |
965c8e59 | 584 | loff_t ext4_llseek(struct file *file, loff_t offset, int whence) |
e0d10bfa TO |
585 | { |
586 | struct inode *inode = file->f_mapping->host; | |
587 | loff_t maxbytes; | |
588 | ||
589 | if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) | |
590 | maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes; | |
591 | else | |
592 | maxbytes = inode->i_sb->s_maxbytes; | |
e0d10bfa | 593 | |
965c8e59 | 594 | switch (whence) { |
c8c0df24 ZL |
595 | case SEEK_SET: |
596 | case SEEK_CUR: | |
597 | case SEEK_END: | |
965c8e59 | 598 | return generic_file_llseek_size(file, offset, whence, |
c8c0df24 ZL |
599 | maxbytes, i_size_read(inode)); |
600 | case SEEK_DATA: | |
601 | return ext4_seek_data(file, offset, maxbytes); | |
602 | case SEEK_HOLE: | |
603 | return ext4_seek_hole(file, offset, maxbytes); | |
604 | } | |
605 | ||
606 | return -EINVAL; | |
e0d10bfa TO |
607 | } |
608 | ||
617ba13b | 609 | const struct file_operations ext4_file_operations = { |
e0d10bfa | 610 | .llseek = ext4_llseek, |
aad4f8bb | 611 | .read_iter = generic_file_read_iter, |
9b884164 | 612 | .write_iter = ext4_file_write_iter, |
5cdd7b2d | 613 | .unlocked_ioctl = ext4_ioctl, |
ac27a0ec | 614 | #ifdef CONFIG_COMPAT |
617ba13b | 615 | .compat_ioctl = ext4_compat_ioctl, |
ac27a0ec | 616 | #endif |
2e9ee850 | 617 | .mmap = ext4_file_mmap, |
bc0b0d6d | 618 | .open = ext4_file_open, |
617ba13b MC |
619 | .release = ext4_release_file, |
620 | .fsync = ext4_sync_file, | |
ac27a0ec | 621 | .splice_read = generic_file_splice_read, |
8d020765 | 622 | .splice_write = iter_file_splice_write, |
2fe17c10 | 623 | .fallocate = ext4_fallocate, |
ac27a0ec DK |
624 | }; |
625 | ||
923ae0ff RZ |
626 | #ifdef CONFIG_FS_DAX |
627 | const struct file_operations ext4_dax_file_operations = { | |
628 | .llseek = ext4_llseek, | |
923ae0ff RZ |
629 | .read_iter = generic_file_read_iter, |
630 | .write_iter = ext4_file_write_iter, | |
631 | .unlocked_ioctl = ext4_ioctl, | |
632 | #ifdef CONFIG_COMPAT | |
633 | .compat_ioctl = ext4_compat_ioctl, | |
634 | #endif | |
635 | .mmap = ext4_file_mmap, | |
636 | .open = ext4_file_open, | |
637 | .release = ext4_release_file, | |
638 | .fsync = ext4_sync_file, | |
639 | /* Splice not yet supported with DAX */ | |
640 | .fallocate = ext4_fallocate, | |
641 | }; | |
642 | #endif | |
643 | ||
754661f1 | 644 | const struct inode_operations ext4_file_inode_operations = { |
617ba13b | 645 | .setattr = ext4_setattr, |
3e3398a0 | 646 | .getattr = ext4_getattr, |
ac27a0ec DK |
647 | .setxattr = generic_setxattr, |
648 | .getxattr = generic_getxattr, | |
617ba13b | 649 | .listxattr = ext4_listxattr, |
ac27a0ec | 650 | .removexattr = generic_removexattr, |
4e34e719 | 651 | .get_acl = ext4_get_acl, |
64e178a7 | 652 | .set_acl = ext4_set_acl, |
6873fa0d | 653 | .fiemap = ext4_fiemap, |
ac27a0ec DK |
654 | }; |
655 |