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1 | /* |
2 | * Copyright (C) 2007 Oracle. All rights reserved. |
3 | * |
4 | * This program is free software; you can redistribute it and/or |
5 | * modify it under the terms of the GNU General Public |
6 | * License v2 as published by the Free Software Foundation. |
7 | * |
8 | * This program is distributed in the hope that it will be useful, |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
11 | * General Public License for more details. |
12 | * |
13 | * You should have received a copy of the GNU General Public |
14 | * License along with this program; if not, write to the |
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
16 | * Boston, MA 021110-1307, USA. |
17 | */ |
18 | |
19 | #include <linux/fs.h> |
20 | #include <linux/pagemap.h> |
21 | #include <linux/highmem.h> |
22 | #include <linux/time.h> |
23 | #include <linux/init.h> |
24 | #include <linux/string.h> |
25 | #include <linux/backing-dev.h> |
26 | #include <linux/mpage.h> |
27 | #include <linux/swap.h> |
28 | #include <linux/writeback.h> |
29 | #include <linux/statfs.h> |
30 | #include <linux/compat.h> |
31 | #include "ctree.h" |
32 | #include "disk-io.h" |
33 | #include "transaction.h" |
34 | #include "btrfs_inode.h" |
35 | #include "ioctl.h" |
36 | #include "print-tree.h" |
37 | #include "tree-log.h" |
38 | #include "locking.h" |
39 | #include "compat.h" |
40 | |
41 | |
42 | /* simple helper to fault in pages and copy. This should go away |
43 | * and be replaced with calls into generic code. |
44 | */ |
45 | static noinline int btrfs_copy_from_user(loff_t pos, int num_pages, |
46 | int write_bytes, |
47 | struct page **prepared_pages, |
48 | const char __user *buf) |
49 | { |
50 | long page_fault = 0; |
51 | int i; |
52 | int offset = pos & (PAGE_CACHE_SIZE - 1); |
53 | |
54 | for (i = 0; i < num_pages && write_bytes > 0; i++, offset = 0) { |
55 | size_t count = min_t(size_t, |
56 | PAGE_CACHE_SIZE - offset, write_bytes); |
57 | struct page *page = prepared_pages[i]; |
58 | fault_in_pages_readable(buf, count); |
59 | |
60 | /* Copy data from userspace to the current page */ |
61 | kmap(page); |
62 | page_fault = __copy_from_user(page_address(page) + offset, |
63 | buf, count); |
64 | /* Flush processor's dcache for this page */ |
65 | flush_dcache_page(page); |
66 | kunmap(page); |
67 | buf += count; |
68 | write_bytes -= count; |
69 | |
70 | if (page_fault) |
71 | break; |
72 | } |
73 | return page_fault ? -EFAULT : 0; |
74 | } |
75 | |
76 | /* |
77 | * unlocks pages after btrfs_file_write is done with them |
78 | */ |
79 | static noinline void btrfs_drop_pages(struct page **pages, size_t num_pages) |
80 | { |
81 | size_t i; |
82 | for (i = 0; i < num_pages; i++) { |
83 | if (!pages[i]) |
84 | break; |
85 | /* page checked is some magic around finding pages that |
86 | * have been modified without going through btrfs_set_page_dirty |
87 | * clear it here |
88 | */ |
89 | ClearPageChecked(pages[i]); |
90 | unlock_page(pages[i]); |
91 | mark_page_accessed(pages[i]); |
92 | page_cache_release(pages[i]); |
93 | } |
94 | } |
95 | |
96 | /* |
97 | * after copy_from_user, pages need to be dirtied and we need to make |
98 | * sure holes are created between the current EOF and the start of |
99 | * any next extents (if required). |
100 | * |
101 | * this also makes the decision about creating an inline extent vs |
102 | * doing real data extents, marking pages dirty and delalloc as required. |
103 | */ |
104 | static noinline int dirty_and_release_pages(struct btrfs_trans_handle *trans, |
105 | struct btrfs_root *root, |
106 | struct file *file, |
107 | struct page **pages, |
108 | size_t num_pages, |
109 | loff_t pos, |
110 | size_t write_bytes) |
111 | { |
112 | int err = 0; |
113 | int i; |
114 | struct inode *inode = fdentry(file)->d_inode; |
115 | struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; |
116 | u64 hint_byte; |
117 | u64 num_bytes; |
118 | u64 start_pos; |
119 | u64 end_of_last_block; |
120 | u64 end_pos = pos + write_bytes; |
121 | loff_t isize = i_size_read(inode); |
122 | |
123 | start_pos = pos & ~((u64)root->sectorsize - 1); |
124 | num_bytes = (write_bytes + pos - start_pos + |
125 | root->sectorsize - 1) & ~((u64)root->sectorsize - 1); |
126 | |
127 | end_of_last_block = start_pos + num_bytes - 1; |
128 | |
129 | lock_extent(io_tree, start_pos, end_of_last_block, GFP_NOFS); |
130 | trans = btrfs_join_transaction(root, 1); |
131 | if (!trans) { |
132 | err = -ENOMEM; |
133 | goto out_unlock; |
134 | } |
135 | btrfs_set_trans_block_group(trans, inode); |
136 | hint_byte = 0; |
137 | |
138 | set_extent_uptodate(io_tree, start_pos, end_of_last_block, GFP_NOFS); |
139 | |
140 | /* check for reserved extents on each page, we don't want |
141 | * to reset the delalloc bit on things that already have |
142 | * extents reserved. |
143 | */ |
144 | btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block); |
145 | for (i = 0; i < num_pages; i++) { |
146 | struct page *p = pages[i]; |
147 | SetPageUptodate(p); |
148 | ClearPageChecked(p); |
149 | set_page_dirty(p); |
150 | } |
151 | if (end_pos > isize) { |
152 | i_size_write(inode, end_pos); |
153 | /* we've only changed i_size in ram, and we haven't updated |
154 | * the disk i_size. There is no need to log the inode |
155 | * at this time. |
156 | */ |
157 | } |
158 | err = btrfs_end_transaction(trans, root); |
159 | out_unlock: |
160 | unlock_extent(io_tree, start_pos, end_of_last_block, GFP_NOFS); |
161 | return err; |
162 | } |
163 | |
164 | /* |
165 | * this drops all the extents in the cache that intersect the range |
166 | * [start, end]. Existing extents are split as required. |
167 | */ |
168 | int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end, |
169 | int skip_pinned) |
170 | { |
171 | struct extent_map *em; |
172 | struct extent_map *split = NULL; |
173 | struct extent_map *split2 = NULL; |
174 | struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; |
175 | u64 len = end - start + 1; |
176 | int ret; |
177 | int testend = 1; |
178 | unsigned long flags; |
179 | int compressed = 0; |
180 | |
181 | WARN_ON(end < start); |
182 | if (end == (u64)-1) { |
183 | len = (u64)-1; |
184 | testend = 0; |
185 | } |
186 | while (1) { |
187 | if (!split) |
188 | split = alloc_extent_map(GFP_NOFS); |
189 | if (!split2) |
190 | split2 = alloc_extent_map(GFP_NOFS); |
191 | |
192 | spin_lock(&em_tree->lock); |
193 | em = lookup_extent_mapping(em_tree, start, len); |
194 | if (!em) { |
195 | spin_unlock(&em_tree->lock); |
196 | break; |
197 | } |
198 | flags = em->flags; |
199 | if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) { |
200 | spin_unlock(&em_tree->lock); |
201 | if (em->start <= start && |
202 | (!testend || em->start + em->len >= start + len)) { |
203 | free_extent_map(em); |
204 | break; |
205 | } |
206 | if (start < em->start) { |
207 | len = em->start - start; |
208 | } else { |
209 | len = start + len - (em->start + em->len); |
210 | start = em->start + em->len; |
211 | } |
212 | free_extent_map(em); |
213 | continue; |
214 | } |
215 | compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags); |
216 | clear_bit(EXTENT_FLAG_PINNED, &em->flags); |
217 | remove_extent_mapping(em_tree, em); |
218 | |
219 | if (em->block_start < EXTENT_MAP_LAST_BYTE && |
220 | em->start < start) { |
221 | split->start = em->start; |
222 | split->len = start - em->start; |
223 | split->orig_start = em->orig_start; |
224 | split->block_start = em->block_start; |
225 | |
226 | if (compressed) |
227 | split->block_len = em->block_len; |
228 | else |
229 | split->block_len = split->len; |
230 | |
231 | split->bdev = em->bdev; |
232 | split->flags = flags; |
233 | ret = add_extent_mapping(em_tree, split); |
234 | BUG_ON(ret); |
235 | free_extent_map(split); |
236 | split = split2; |
237 | split2 = NULL; |
238 | } |
239 | if (em->block_start < EXTENT_MAP_LAST_BYTE && |
240 | testend && em->start + em->len > start + len) { |
241 | u64 diff = start + len - em->start; |
242 | |
243 | split->start = start + len; |
244 | split->len = em->start + em->len - (start + len); |
245 | split->bdev = em->bdev; |
246 | split->flags = flags; |
247 | |
248 | if (compressed) { |
249 | split->block_len = em->block_len; |
250 | split->block_start = em->block_start; |
251 | split->orig_start = em->orig_start; |
252 | } else { |
253 | split->block_len = split->len; |
254 | split->block_start = em->block_start + diff; |
255 | split->orig_start = split->start; |
256 | } |
257 | |
258 | ret = add_extent_mapping(em_tree, split); |
259 | BUG_ON(ret); |
260 | free_extent_map(split); |
261 | split = NULL; |
262 | } |
263 | spin_unlock(&em_tree->lock); |
264 | |
265 | /* once for us */ |
266 | free_extent_map(em); |
267 | /* once for the tree*/ |
268 | free_extent_map(em); |
269 | } |
270 | if (split) |
271 | free_extent_map(split); |
272 | if (split2) |
273 | free_extent_map(split2); |
274 | return 0; |
275 | } |
276 | |
277 | /* |
278 | * this is very complex, but the basic idea is to drop all extents |
279 | * in the range start - end. hint_block is filled in with a block number |
280 | * that would be a good hint to the block allocator for this file. |
281 | * |
282 | * If an extent intersects the range but is not entirely inside the range |
283 | * it is either truncated or split. Anything entirely inside the range |
284 | * is deleted from the tree. |
285 | * |
286 | * inline_limit is used to tell this code which offsets in the file to keep |
287 | * if they contain inline extents. |
288 | */ |
289 | noinline int btrfs_drop_extents(struct btrfs_trans_handle *trans, |
290 | struct btrfs_root *root, struct inode *inode, |
291 | u64 start, u64 end, u64 locked_end, |
292 | u64 inline_limit, u64 *hint_byte) |
293 | { |
294 | u64 extent_end = 0; |
295 | u64 search_start = start; |
296 | u64 ram_bytes = 0; |
297 | u64 disk_bytenr = 0; |
298 | u64 orig_locked_end = locked_end; |
299 | u8 compression; |
300 | u8 encryption; |
301 | u16 other_encoding = 0; |
302 | struct extent_buffer *leaf; |
303 | struct btrfs_file_extent_item *extent; |
304 | struct btrfs_path *path; |
305 | struct btrfs_key key; |
306 | struct btrfs_file_extent_item old; |
307 | int keep; |
308 | int slot; |
309 | int bookend; |
310 | int found_type = 0; |
311 | int found_extent; |
312 | int found_inline; |
313 | int recow; |
314 | int ret; |
315 | |
316 | inline_limit = 0; |
317 | btrfs_drop_extent_cache(inode, start, end - 1, 0); |
318 | |
319 | path = btrfs_alloc_path(); |
320 | if (!path) |
321 | return -ENOMEM; |
322 | while (1) { |
323 | recow = 0; |
324 | btrfs_release_path(root, path); |
325 | ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino, |
326 | search_start, -1); |
327 | if (ret < 0) |
328 | goto out; |
329 | if (ret > 0) { |
330 | if (path->slots[0] == 0) { |
331 | ret = 0; |
332 | goto out; |
333 | } |
334 | path->slots[0]--; |
335 | } |
336 | next_slot: |
337 | keep = 0; |
338 | bookend = 0; |
339 | found_extent = 0; |
340 | found_inline = 0; |
341 | compression = 0; |
342 | encryption = 0; |
343 | extent = NULL; |
344 | leaf = path->nodes[0]; |
345 | slot = path->slots[0]; |
346 | ret = 0; |
347 | btrfs_item_key_to_cpu(leaf, &key, slot); |
348 | if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY && |
349 | key.offset >= end) { |
350 | goto out; |
351 | } |
352 | if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY || |
353 | key.objectid != inode->i_ino) { |
354 | goto out; |
355 | } |
356 | if (recow) { |
357 | search_start = max(key.offset, start); |
358 | continue; |
359 | } |
360 | if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) { |
361 | extent = btrfs_item_ptr(leaf, slot, |
362 | struct btrfs_file_extent_item); |
363 | found_type = btrfs_file_extent_type(leaf, extent); |
364 | compression = btrfs_file_extent_compression(leaf, |
365 | extent); |
366 | encryption = btrfs_file_extent_encryption(leaf, |
367 | extent); |
368 | other_encoding = btrfs_file_extent_other_encoding(leaf, |
369 | extent); |
370 | if (found_type == BTRFS_FILE_EXTENT_REG || |
371 | found_type == BTRFS_FILE_EXTENT_PREALLOC) { |
372 | extent_end = |
373 | btrfs_file_extent_disk_bytenr(leaf, |
374 | extent); |
375 | if (extent_end) |
376 | *hint_byte = extent_end; |
377 | |
378 | extent_end = key.offset + |
379 | btrfs_file_extent_num_bytes(leaf, extent); |
380 | ram_bytes = btrfs_file_extent_ram_bytes(leaf, |
381 | extent); |
382 | found_extent = 1; |
383 | } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { |
384 | found_inline = 1; |
385 | extent_end = key.offset + |
386 | btrfs_file_extent_inline_len(leaf, extent); |
387 | } |
388 | } else { |
389 | extent_end = search_start; |
390 | } |
391 | |
392 | /* we found nothing we can drop */ |
393 | if ((!found_extent && !found_inline) || |
394 | search_start >= extent_end) { |
395 | int nextret; |
396 | u32 nritems; |
397 | nritems = btrfs_header_nritems(leaf); |
398 | if (slot >= nritems - 1) { |
399 | nextret = btrfs_next_leaf(root, path); |
400 | if (nextret) |
401 | goto out; |
402 | recow = 1; |
403 | } else { |
404 | path->slots[0]++; |
405 | } |
406 | goto next_slot; |
407 | } |
408 | |
409 | if (end <= extent_end && start >= key.offset && found_inline) |
410 | *hint_byte = EXTENT_MAP_INLINE; |
411 | |
412 | if (found_extent) { |
413 | read_extent_buffer(leaf, &old, (unsigned long)extent, |
414 | sizeof(old)); |
415 | } |
416 | |
417 | if (end < extent_end && end >= key.offset) { |
418 | bookend = 1; |
419 | if (found_inline && start <= key.offset) |
420 | keep = 1; |
421 | } |
422 | |
423 | if (bookend && found_extent) { |
424 | if (locked_end < extent_end) { |
425 | ret = try_lock_extent(&BTRFS_I(inode)->io_tree, |
426 | locked_end, extent_end - 1, |
427 | GFP_NOFS); |
428 | if (!ret) { |
429 | btrfs_release_path(root, path); |
430 | lock_extent(&BTRFS_I(inode)->io_tree, |
431 | locked_end, extent_end - 1, |
432 | GFP_NOFS); |
433 | locked_end = extent_end; |
434 | continue; |
435 | } |
436 | locked_end = extent_end; |
437 | } |
438 | disk_bytenr = le64_to_cpu(old.disk_bytenr); |
439 | if (disk_bytenr != 0) { |
440 | ret = btrfs_inc_extent_ref(trans, root, |
441 | disk_bytenr, |
442 | le64_to_cpu(old.disk_num_bytes), 0, |
443 | root->root_key.objectid, |
444 | key.objectid, key.offset - |
445 | le64_to_cpu(old.offset)); |
446 | BUG_ON(ret); |
447 | } |
448 | } |
449 | |
450 | if (found_inline) { |
451 | u64 mask = root->sectorsize - 1; |
452 | search_start = (extent_end + mask) & ~mask; |
453 | } else |
454 | search_start = extent_end; |
455 | |
456 | /* truncate existing extent */ |
457 | if (start > key.offset) { |
458 | u64 new_num; |
459 | u64 old_num; |
460 | keep = 1; |
461 | WARN_ON(start & (root->sectorsize - 1)); |
462 | if (found_extent) { |
463 | new_num = start - key.offset; |
464 | old_num = btrfs_file_extent_num_bytes(leaf, |
465 | extent); |
466 | *hint_byte = |
467 | btrfs_file_extent_disk_bytenr(leaf, |
468 | extent); |
469 | if (btrfs_file_extent_disk_bytenr(leaf, |
470 | extent)) { |
471 | inode_sub_bytes(inode, old_num - |
472 | new_num); |
473 | } |
474 | btrfs_set_file_extent_num_bytes(leaf, |
475 | extent, new_num); |
476 | btrfs_mark_buffer_dirty(leaf); |
477 | } else if (key.offset < inline_limit && |
478 | (end > extent_end) && |
479 | (inline_limit < extent_end)) { |
480 | u32 new_size; |
481 | new_size = btrfs_file_extent_calc_inline_size( |
482 | inline_limit - key.offset); |
483 | inode_sub_bytes(inode, extent_end - |
484 | inline_limit); |
485 | btrfs_set_file_extent_ram_bytes(leaf, extent, |
486 | new_size); |
487 | if (!compression && !encryption) { |
488 | btrfs_truncate_item(trans, root, path, |
489 | new_size, 1); |
490 | } |
491 | } |
492 | } |
493 | /* delete the entire extent */ |
494 | if (!keep) { |
495 | if (found_inline) |
496 | inode_sub_bytes(inode, extent_end - |
497 | key.offset); |
498 | ret = btrfs_del_item(trans, root, path); |
499 | /* TODO update progress marker and return */ |
500 | BUG_ON(ret); |
501 | extent = NULL; |
502 | btrfs_release_path(root, path); |
503 | /* the extent will be freed later */ |
504 | } |
505 | if (bookend && found_inline && start <= key.offset) { |
506 | u32 new_size; |
507 | new_size = btrfs_file_extent_calc_inline_size( |
508 | extent_end - end); |
509 | inode_sub_bytes(inode, end - key.offset); |
510 | btrfs_set_file_extent_ram_bytes(leaf, extent, |
511 | new_size); |
512 | if (!compression && !encryption) |
513 | ret = btrfs_truncate_item(trans, root, path, |
514 | new_size, 0); |
515 | BUG_ON(ret); |
516 | } |
517 | /* create bookend, splitting the extent in two */ |
518 | if (bookend && found_extent) { |
519 | struct btrfs_key ins; |
520 | ins.objectid = inode->i_ino; |
521 | ins.offset = end; |
522 | btrfs_set_key_type(&ins, BTRFS_EXTENT_DATA_KEY); |
523 | |
524 | btrfs_release_path(root, path); |
525 | path->leave_spinning = 1; |
526 | ret = btrfs_insert_empty_item(trans, root, path, &ins, |
527 | sizeof(*extent)); |
528 | BUG_ON(ret); |
529 | |
530 | leaf = path->nodes[0]; |
531 | extent = btrfs_item_ptr(leaf, path->slots[0], |
532 | struct btrfs_file_extent_item); |
533 | write_extent_buffer(leaf, &old, |
534 | (unsigned long)extent, sizeof(old)); |
535 | |
536 | btrfs_set_file_extent_compression(leaf, extent, |
537 | compression); |
538 | btrfs_set_file_extent_encryption(leaf, extent, |
539 | encryption); |
540 | btrfs_set_file_extent_other_encoding(leaf, extent, |
541 | other_encoding); |
542 | btrfs_set_file_extent_offset(leaf, extent, |
543 | le64_to_cpu(old.offset) + end - key.offset); |
544 | WARN_ON(le64_to_cpu(old.num_bytes) < |
545 | (extent_end - end)); |
546 | btrfs_set_file_extent_num_bytes(leaf, extent, |
547 | extent_end - end); |
548 | |
549 | /* |
550 | * set the ram bytes to the size of the full extent |
551 | * before splitting. This is a worst case flag, |
552 | * but its the best we can do because we don't know |
553 | * how splitting affects compression |
554 | */ |
555 | btrfs_set_file_extent_ram_bytes(leaf, extent, |
556 | ram_bytes); |
557 | btrfs_set_file_extent_type(leaf, extent, found_type); |
558 | |
559 | btrfs_unlock_up_safe(path, 1); |
560 | btrfs_mark_buffer_dirty(path->nodes[0]); |
561 | btrfs_set_lock_blocking(path->nodes[0]); |
562 | |
563 | path->leave_spinning = 0; |
564 | btrfs_release_path(root, path); |
565 | if (disk_bytenr != 0) |
566 | inode_add_bytes(inode, extent_end - end); |
567 | } |
568 | |
569 | if (found_extent && !keep) { |
570 | u64 old_disk_bytenr = le64_to_cpu(old.disk_bytenr); |
571 | |
572 | if (old_disk_bytenr != 0) { |
573 | inode_sub_bytes(inode, |
574 | le64_to_cpu(old.num_bytes)); |
575 | ret = btrfs_free_extent(trans, root, |
576 | old_disk_bytenr, |
577 | le64_to_cpu(old.disk_num_bytes), |
578 | 0, root->root_key.objectid, |
579 | key.objectid, key.offset - |
580 | le64_to_cpu(old.offset)); |
581 | BUG_ON(ret); |
582 | *hint_byte = old_disk_bytenr; |
583 | } |
584 | } |
585 | |
586 | if (search_start >= end) { |
587 | ret = 0; |
588 | goto out; |
589 | } |
590 | } |
591 | out: |
592 | btrfs_free_path(path); |
593 | if (locked_end > orig_locked_end) { |
594 | unlock_extent(&BTRFS_I(inode)->io_tree, orig_locked_end, |
595 | locked_end - 1, GFP_NOFS); |
596 | } |
597 | return ret; |
598 | } |
599 | |
600 | static int extent_mergeable(struct extent_buffer *leaf, int slot, |
601 | u64 objectid, u64 bytenr, u64 *start, u64 *end) |
602 | { |
603 | struct btrfs_file_extent_item *fi; |
604 | struct btrfs_key key; |
605 | u64 extent_end; |
606 | |
607 | if (slot < 0 || slot >= btrfs_header_nritems(leaf)) |
608 | return 0; |
609 | |
610 | btrfs_item_key_to_cpu(leaf, &key, slot); |
611 | if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY) |
612 | return 0; |
613 | |
614 | fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); |
615 | if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG || |
616 | btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr || |
617 | btrfs_file_extent_compression(leaf, fi) || |
618 | btrfs_file_extent_encryption(leaf, fi) || |
619 | btrfs_file_extent_other_encoding(leaf, fi)) |
620 | return 0; |
621 | |
622 | extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); |
623 | if ((*start && *start != key.offset) || (*end && *end != extent_end)) |
624 | return 0; |
625 | |
626 | *start = key.offset; |
627 | *end = extent_end; |
628 | return 1; |
629 | } |
630 | |
631 | /* |
632 | * Mark extent in the range start - end as written. |
633 | * |
634 | * This changes extent type from 'pre-allocated' to 'regular'. If only |
635 | * part of extent is marked as written, the extent will be split into |
636 | * two or three. |
637 | */ |
638 | int btrfs_mark_extent_written(struct btrfs_trans_handle *trans, |
639 | struct btrfs_root *root, |
640 | struct inode *inode, u64 start, u64 end) |
641 | { |
642 | struct extent_buffer *leaf; |
643 | struct btrfs_path *path; |
644 | struct btrfs_file_extent_item *fi; |
645 | struct btrfs_key key; |
646 | u64 bytenr; |
647 | u64 num_bytes; |
648 | u64 extent_end; |
649 | u64 orig_offset; |
650 | u64 other_start; |
651 | u64 other_end; |
652 | u64 split = start; |
653 | u64 locked_end = end; |
654 | int extent_type; |
655 | int split_end = 1; |
656 | int ret; |
657 | |
658 | btrfs_drop_extent_cache(inode, start, end - 1, 0); |
659 | |
660 | path = btrfs_alloc_path(); |
661 | BUG_ON(!path); |
662 | again: |
663 | key.objectid = inode->i_ino; |
664 | key.type = BTRFS_EXTENT_DATA_KEY; |
665 | if (split == start) |
666 | key.offset = split; |
667 | else |
668 | key.offset = split - 1; |
669 | |
670 | ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
671 | if (ret > 0 && path->slots[0] > 0) |
672 | path->slots[0]--; |
673 | |
674 | leaf = path->nodes[0]; |
675 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
676 | BUG_ON(key.objectid != inode->i_ino || |
677 | key.type != BTRFS_EXTENT_DATA_KEY); |
678 | fi = btrfs_item_ptr(leaf, path->slots[0], |
679 | struct btrfs_file_extent_item); |
680 | extent_type = btrfs_file_extent_type(leaf, fi); |
681 | BUG_ON(extent_type != BTRFS_FILE_EXTENT_PREALLOC); |
682 | extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); |
683 | BUG_ON(key.offset > start || extent_end < end); |
684 | |
685 | bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); |
686 | num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); |
687 | orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi); |
688 | |
689 | if (key.offset == start) |
690 | split = end; |
691 | |
692 | if (key.offset == start && extent_end == end) { |
693 | int del_nr = 0; |
694 | int del_slot = 0; |
695 | other_start = end; |
696 | other_end = 0; |
697 | if (extent_mergeable(leaf, path->slots[0] + 1, inode->i_ino, |
698 | bytenr, &other_start, &other_end)) { |
699 | extent_end = other_end; |
700 | del_slot = path->slots[0] + 1; |
701 | del_nr++; |
702 | ret = btrfs_free_extent(trans, root, bytenr, num_bytes, |
703 | 0, root->root_key.objectid, |
704 | inode->i_ino, orig_offset); |
705 | BUG_ON(ret); |
706 | } |
707 | other_start = 0; |
708 | other_end = start; |
709 | if (extent_mergeable(leaf, path->slots[0] - 1, inode->i_ino, |
710 | bytenr, &other_start, &other_end)) { |
711 | key.offset = other_start; |
712 | del_slot = path->slots[0]; |
713 | del_nr++; |
714 | ret = btrfs_free_extent(trans, root, bytenr, num_bytes, |
715 | 0, root->root_key.objectid, |
716 | inode->i_ino, orig_offset); |
717 | BUG_ON(ret); |
718 | } |
719 | split_end = 0; |
720 | if (del_nr == 0) { |
721 | btrfs_set_file_extent_type(leaf, fi, |
722 | BTRFS_FILE_EXTENT_REG); |
723 | goto done; |
724 | } |
725 | |
726 | fi = btrfs_item_ptr(leaf, del_slot - 1, |
727 | struct btrfs_file_extent_item); |
728 | btrfs_set_file_extent_type(leaf, fi, BTRFS_FILE_EXTENT_REG); |
729 | btrfs_set_file_extent_num_bytes(leaf, fi, |
730 | extent_end - key.offset); |
731 | btrfs_mark_buffer_dirty(leaf); |
732 | |
733 | ret = btrfs_del_items(trans, root, path, del_slot, del_nr); |
734 | BUG_ON(ret); |
735 | goto release; |
736 | } else if (split == start) { |
737 | if (locked_end < extent_end) { |
738 | ret = try_lock_extent(&BTRFS_I(inode)->io_tree, |
739 | locked_end, extent_end - 1, GFP_NOFS); |
740 | if (!ret) { |
741 | btrfs_release_path(root, path); |
742 | lock_extent(&BTRFS_I(inode)->io_tree, |
743 | locked_end, extent_end - 1, GFP_NOFS); |
744 | locked_end = extent_end; |
745 | goto again; |
746 | } |
747 | locked_end = extent_end; |
748 | } |
749 | btrfs_set_file_extent_num_bytes(leaf, fi, split - key.offset); |
750 | } else { |
751 | BUG_ON(key.offset != start); |
752 | key.offset = split; |
753 | btrfs_set_file_extent_offset(leaf, fi, key.offset - |
754 | orig_offset); |
755 | btrfs_set_file_extent_num_bytes(leaf, fi, extent_end - split); |
756 | btrfs_set_item_key_safe(trans, root, path, &key); |
757 | extent_end = split; |
758 | } |
759 | |
760 | if (extent_end == end) { |
761 | split_end = 0; |
762 | extent_type = BTRFS_FILE_EXTENT_REG; |
763 | } |
764 | if (extent_end == end && split == start) { |
765 | other_start = end; |
766 | other_end = 0; |
767 | if (extent_mergeable(leaf, path->slots[0] + 1, inode->i_ino, |
768 | bytenr, &other_start, &other_end)) { |
769 | path->slots[0]++; |
770 | fi = btrfs_item_ptr(leaf, path->slots[0], |
771 | struct btrfs_file_extent_item); |
772 | key.offset = split; |
773 | btrfs_set_item_key_safe(trans, root, path, &key); |
774 | btrfs_set_file_extent_offset(leaf, fi, key.offset - |
775 | orig_offset); |
776 | btrfs_set_file_extent_num_bytes(leaf, fi, |
777 | other_end - split); |
778 | goto done; |
779 | } |
780 | } |
781 | if (extent_end == end && split == end) { |
782 | other_start = 0; |
783 | other_end = start; |
784 | if (extent_mergeable(leaf, path->slots[0] - 1 , inode->i_ino, |
785 | bytenr, &other_start, &other_end)) { |
786 | path->slots[0]--; |
787 | fi = btrfs_item_ptr(leaf, path->slots[0], |
788 | struct btrfs_file_extent_item); |
789 | btrfs_set_file_extent_num_bytes(leaf, fi, extent_end - |
790 | other_start); |
791 | goto done; |
792 | } |
793 | } |
794 | |
795 | btrfs_mark_buffer_dirty(leaf); |
796 | |
797 | ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, 0, |
798 | root->root_key.objectid, |
799 | inode->i_ino, orig_offset); |
800 | BUG_ON(ret); |
801 | btrfs_release_path(root, path); |
802 | |
803 | key.offset = start; |
804 | ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*fi)); |
805 | BUG_ON(ret); |
806 | |
807 | leaf = path->nodes[0]; |
808 | fi = btrfs_item_ptr(leaf, path->slots[0], |
809 | struct btrfs_file_extent_item); |
810 | btrfs_set_file_extent_generation(leaf, fi, trans->transid); |
811 | btrfs_set_file_extent_type(leaf, fi, extent_type); |
812 | btrfs_set_file_extent_disk_bytenr(leaf, fi, bytenr); |
813 | btrfs_set_file_extent_disk_num_bytes(leaf, fi, num_bytes); |
814 | btrfs_set_file_extent_offset(leaf, fi, key.offset - orig_offset); |
815 | btrfs_set_file_extent_num_bytes(leaf, fi, extent_end - key.offset); |
816 | btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes); |
817 | btrfs_set_file_extent_compression(leaf, fi, 0); |
818 | btrfs_set_file_extent_encryption(leaf, fi, 0); |
819 | btrfs_set_file_extent_other_encoding(leaf, fi, 0); |
820 | done: |
821 | btrfs_mark_buffer_dirty(leaf); |
822 | |
823 | release: |
824 | btrfs_release_path(root, path); |
825 | if (split_end && split == start) { |
826 | split = end; |
827 | goto again; |
828 | } |
829 | if (locked_end > end) { |
830 | unlock_extent(&BTRFS_I(inode)->io_tree, end, locked_end - 1, |
831 | GFP_NOFS); |
832 | } |
833 | btrfs_free_path(path); |
834 | return 0; |
835 | } |
836 | |
837 | /* |
838 | * this gets pages into the page cache and locks them down, it also properly |
839 | * waits for data=ordered extents to finish before allowing the pages to be |
840 | * modified. |
841 | */ |
842 | static noinline int prepare_pages(struct btrfs_root *root, struct file *file, |
843 | struct page **pages, size_t num_pages, |
844 | loff_t pos, unsigned long first_index, |
845 | unsigned long last_index, size_t write_bytes) |
846 | { |
847 | int i; |
848 | unsigned long index = pos >> PAGE_CACHE_SHIFT; |
849 | struct inode *inode = fdentry(file)->d_inode; |
850 | int err = 0; |
851 | u64 start_pos; |
852 | u64 last_pos; |
853 | |
854 | start_pos = pos & ~((u64)root->sectorsize - 1); |
855 | last_pos = ((u64)index + num_pages) << PAGE_CACHE_SHIFT; |
856 | |
857 | if (start_pos > inode->i_size) { |
858 | err = btrfs_cont_expand(inode, start_pos); |
859 | if (err) |
860 | return err; |
861 | } |
862 | |
863 | memset(pages, 0, num_pages * sizeof(struct page *)); |
864 | again: |
865 | for (i = 0; i < num_pages; i++) { |
866 | pages[i] = grab_cache_page(inode->i_mapping, index + i); |
867 | if (!pages[i]) { |
868 | err = -ENOMEM; |
869 | BUG_ON(1); |
870 | } |
871 | wait_on_page_writeback(pages[i]); |
872 | } |
873 | if (start_pos < inode->i_size) { |
874 | struct btrfs_ordered_extent *ordered; |
875 | lock_extent(&BTRFS_I(inode)->io_tree, |
876 | start_pos, last_pos - 1, GFP_NOFS); |
877 | ordered = btrfs_lookup_first_ordered_extent(inode, |
878 | last_pos - 1); |
879 | if (ordered && |
880 | ordered->file_offset + ordered->len > start_pos && |
881 | ordered->file_offset < last_pos) { |
882 | btrfs_put_ordered_extent(ordered); |
883 | unlock_extent(&BTRFS_I(inode)->io_tree, |
884 | start_pos, last_pos - 1, GFP_NOFS); |
885 | for (i = 0; i < num_pages; i++) { |
886 | unlock_page(pages[i]); |
887 | page_cache_release(pages[i]); |
888 | } |
889 | btrfs_wait_ordered_range(inode, start_pos, |
890 | last_pos - start_pos); |
891 | goto again; |
892 | } |
893 | if (ordered) |
894 | btrfs_put_ordered_extent(ordered); |
895 | |
896 | clear_extent_bits(&BTRFS_I(inode)->io_tree, start_pos, |
897 | last_pos - 1, EXTENT_DIRTY | EXTENT_DELALLOC, |
898 | GFP_NOFS); |
899 | unlock_extent(&BTRFS_I(inode)->io_tree, |
900 | start_pos, last_pos - 1, GFP_NOFS); |
901 | } |
902 | for (i = 0; i < num_pages; i++) { |
903 | clear_page_dirty_for_io(pages[i]); |
904 | set_page_extent_mapped(pages[i]); |
905 | WARN_ON(!PageLocked(pages[i])); |
906 | } |
907 | return 0; |
908 | } |
909 | |
910 | static ssize_t btrfs_file_write(struct file *file, const char __user *buf, |
911 | size_t count, loff_t *ppos) |
912 | { |
913 | loff_t pos; |
914 | loff_t start_pos; |
915 | ssize_t num_written = 0; |
916 | ssize_t err = 0; |
917 | int ret = 0; |
918 | struct inode *inode = fdentry(file)->d_inode; |
919 | struct btrfs_root *root = BTRFS_I(inode)->root; |
920 | struct page **pages = NULL; |
921 | int nrptrs; |
922 | struct page *pinned[2]; |
923 | unsigned long first_index; |
924 | unsigned long last_index; |
925 | int will_write; |
926 | |
927 | will_write = ((file->f_flags & O_SYNC) || IS_SYNC(inode) || |
928 | (file->f_flags & O_DIRECT)); |
929 | |
930 | nrptrs = min((count + PAGE_CACHE_SIZE - 1) / PAGE_CACHE_SIZE, |
931 | PAGE_CACHE_SIZE / (sizeof(struct page *))); |
932 | pinned[0] = NULL; |
933 | pinned[1] = NULL; |
934 | |
935 | pos = *ppos; |
936 | start_pos = pos; |
937 | |
938 | vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE); |
939 | current->backing_dev_info = inode->i_mapping->backing_dev_info; |
940 | err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode)); |
941 | if (err) |
942 | goto out_nolock; |
943 | if (count == 0) |
944 | goto out_nolock; |
945 | |
946 | err = file_remove_suid(file); |
947 | if (err) |
948 | goto out_nolock; |
949 | file_update_time(file); |
950 | |
951 | pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL); |
952 | |
953 | mutex_lock(&inode->i_mutex); |
954 | BTRFS_I(inode)->sequence++; |
955 | first_index = pos >> PAGE_CACHE_SHIFT; |
956 | last_index = (pos + count) >> PAGE_CACHE_SHIFT; |
957 | |
958 | /* |
959 | * there are lots of better ways to do this, but this code |
960 | * makes sure the first and last page in the file range are |
961 | * up to date and ready for cow |
962 | */ |
963 | if ((pos & (PAGE_CACHE_SIZE - 1))) { |
964 | pinned[0] = grab_cache_page(inode->i_mapping, first_index); |
965 | if (!PageUptodate(pinned[0])) { |
966 | ret = btrfs_readpage(NULL, pinned[0]); |
967 | BUG_ON(ret); |
968 | wait_on_page_locked(pinned[0]); |
969 | } else { |
970 | unlock_page(pinned[0]); |
971 | } |
972 | } |
973 | if ((pos + count) & (PAGE_CACHE_SIZE - 1)) { |
974 | pinned[1] = grab_cache_page(inode->i_mapping, last_index); |
975 | if (!PageUptodate(pinned[1])) { |
976 | ret = btrfs_readpage(NULL, pinned[1]); |
977 | BUG_ON(ret); |
978 | wait_on_page_locked(pinned[1]); |
979 | } else { |
980 | unlock_page(pinned[1]); |
981 | } |
982 | } |
983 | |
984 | while (count > 0) { |
985 | size_t offset = pos & (PAGE_CACHE_SIZE - 1); |
986 | size_t write_bytes = min(count, nrptrs * |
987 | (size_t)PAGE_CACHE_SIZE - |
988 | offset); |
989 | size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >> |
990 | PAGE_CACHE_SHIFT; |
991 | |
992 | WARN_ON(num_pages > nrptrs); |
993 | memset(pages, 0, sizeof(struct page *) * nrptrs); |
994 | |
995 | ret = btrfs_check_data_free_space(root, inode, write_bytes); |
996 | if (ret) |
997 | goto out; |
998 | |
999 | ret = prepare_pages(root, file, pages, num_pages, |
1000 | pos, first_index, last_index, |
1001 | write_bytes); |
1002 | if (ret) { |
1003 | btrfs_free_reserved_data_space(root, inode, |
1004 | write_bytes); |
1005 | goto out; |
1006 | } |
1007 | |
1008 | ret = btrfs_copy_from_user(pos, num_pages, |
1009 | write_bytes, pages, buf); |
1010 | if (ret) { |
1011 | btrfs_free_reserved_data_space(root, inode, |
1012 | write_bytes); |
1013 | btrfs_drop_pages(pages, num_pages); |
1014 | goto out; |
1015 | } |
1016 | |
1017 | ret = dirty_and_release_pages(NULL, root, file, pages, |
1018 | num_pages, pos, write_bytes); |
1019 | btrfs_drop_pages(pages, num_pages); |
1020 | if (ret) { |
1021 | btrfs_free_reserved_data_space(root, inode, |
1022 | write_bytes); |
1023 | goto out; |
1024 | } |
1025 | |
1026 | if (will_write) { |
1027 | btrfs_fdatawrite_range(inode->i_mapping, pos, |
1028 | pos + write_bytes - 1, |
1029 | WB_SYNC_ALL); |
1030 | } else { |
1031 | balance_dirty_pages_ratelimited_nr(inode->i_mapping, |
1032 | num_pages); |
1033 | if (num_pages < |
1034 | (root->leafsize >> PAGE_CACHE_SHIFT) + 1) |
1035 | btrfs_btree_balance_dirty(root, 1); |
1036 | btrfs_throttle(root); |
1037 | } |
1038 | |
1039 | buf += write_bytes; |
1040 | count -= write_bytes; |
1041 | pos += write_bytes; |
1042 | num_written += write_bytes; |
1043 | |
1044 | cond_resched(); |
1045 | } |
1046 | out: |
1047 | mutex_unlock(&inode->i_mutex); |
1048 | if (ret) |
1049 | err = ret; |
1050 | |
1051 | out_nolock: |
1052 | kfree(pages); |
1053 | if (pinned[0]) |
1054 | page_cache_release(pinned[0]); |
1055 | if (pinned[1]) |
1056 | page_cache_release(pinned[1]); |
1057 | *ppos = pos; |
1058 | |
1059 | /* |
1060 | * we want to make sure fsync finds this change |
1061 | * but we haven't joined a transaction running right now. |
1062 | * |
1063 | * Later on, someone is sure to update the inode and get the |
1064 | * real transid recorded. |
1065 | * |
1066 | * We set last_trans now to the fs_info generation + 1, |
1067 | * this will either be one more than the running transaction |
1068 | * or the generation used for the next transaction if there isn't |
1069 | * one running right now. |
1070 | */ |
1071 | BTRFS_I(inode)->last_trans = root->fs_info->generation + 1; |
1072 | |
1073 | if (num_written > 0 && will_write) { |
1074 | struct btrfs_trans_handle *trans; |
1075 | |
1076 | err = btrfs_wait_ordered_range(inode, start_pos, num_written); |
1077 | if (err) |
1078 | num_written = err; |
1079 | |
1080 | if ((file->f_flags & O_SYNC) || IS_SYNC(inode)) { |
1081 | trans = btrfs_start_transaction(root, 1); |
1082 | ret = btrfs_log_dentry_safe(trans, root, |
1083 | file->f_dentry); |
1084 | if (ret == 0) { |
1085 | ret = btrfs_sync_log(trans, root); |
1086 | if (ret == 0) |
1087 | btrfs_end_transaction(trans, root); |
1088 | else |
1089 | btrfs_commit_transaction(trans, root); |
1090 | } else { |
1091 | btrfs_commit_transaction(trans, root); |
1092 | } |
1093 | } |
1094 | if (file->f_flags & O_DIRECT) { |
1095 | invalidate_mapping_pages(inode->i_mapping, |
1096 | start_pos >> PAGE_CACHE_SHIFT, |
1097 | (start_pos + num_written - 1) >> PAGE_CACHE_SHIFT); |
1098 | } |
1099 | } |
1100 | current->backing_dev_info = NULL; |
1101 | return num_written ? num_written : err; |
1102 | } |
1103 | |
1104 | int btrfs_release_file(struct inode *inode, struct file *filp) |
1105 | { |
1106 | /* |
1107 | * ordered_data_close is set by settattr when we are about to truncate |
1108 | * a file from a non-zero size to a zero size. This tries to |
1109 | * flush down new bytes that may have been written if the |
1110 | * application were using truncate to replace a file in place. |
1111 | */ |
1112 | if (BTRFS_I(inode)->ordered_data_close) { |
1113 | BTRFS_I(inode)->ordered_data_close = 0; |
1114 | btrfs_add_ordered_operation(NULL, BTRFS_I(inode)->root, inode); |
1115 | if (inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT) |
1116 | filemap_flush(inode->i_mapping); |
1117 | } |
1118 | if (filp->private_data) |
1119 | btrfs_ioctl_trans_end(filp); |
1120 | return 0; |
1121 | } |
1122 | |
1123 | /* |
1124 | * fsync call for both files and directories. This logs the inode into |
1125 | * the tree log instead of forcing full commits whenever possible. |
1126 | * |
1127 | * It needs to call filemap_fdatawait so that all ordered extent updates are |
1128 | * in the metadata btree are up to date for copying to the log. |
1129 | * |
1130 | * It drops the inode mutex before doing the tree log commit. This is an |
1131 | * important optimization for directories because holding the mutex prevents |
1132 | * new operations on the dir while we write to disk. |
1133 | */ |
1134 | int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync) |
1135 | { |
1136 | struct inode *inode = dentry->d_inode; |
1137 | struct btrfs_root *root = BTRFS_I(inode)->root; |
1138 | int ret = 0; |
1139 | struct btrfs_trans_handle *trans; |
1140 | |
1141 | /* |
1142 | * check the transaction that last modified this inode |
1143 | * and see if its already been committed |
1144 | */ |
1145 | if (!BTRFS_I(inode)->last_trans) |
1146 | goto out; |
1147 | |
1148 | mutex_lock(&root->fs_info->trans_mutex); |
1149 | if (BTRFS_I(inode)->last_trans <= |
1150 | root->fs_info->last_trans_committed) { |
1151 | BTRFS_I(inode)->last_trans = 0; |
1152 | mutex_unlock(&root->fs_info->trans_mutex); |
1153 | goto out; |
1154 | } |
1155 | mutex_unlock(&root->fs_info->trans_mutex); |
1156 | |
1157 | root->log_batch++; |
1158 | filemap_fdatawrite(inode->i_mapping); |
1159 | btrfs_wait_ordered_range(inode, 0, (u64)-1); |
1160 | root->log_batch++; |
1161 | |
1162 | if (datasync && !(inode->i_state & I_DIRTY_PAGES)) |
1163 | goto out; |
1164 | /* |
1165 | * ok we haven't committed the transaction yet, lets do a commit |
1166 | */ |
1167 | if (file && file->private_data) |
1168 | btrfs_ioctl_trans_end(file); |
1169 | |
1170 | trans = btrfs_start_transaction(root, 1); |
1171 | if (!trans) { |
1172 | ret = -ENOMEM; |
1173 | goto out; |
1174 | } |
1175 | |
1176 | ret = btrfs_log_dentry_safe(trans, root, dentry); |
1177 | if (ret < 0) |
1178 | goto out; |
1179 | |
1180 | /* we've logged all the items and now have a consistent |
1181 | * version of the file in the log. It is possible that |
1182 | * someone will come in and modify the file, but that's |
1183 | * fine because the log is consistent on disk, and we |
1184 | * have references to all of the file's extents |
1185 | * |
1186 | * It is possible that someone will come in and log the |
1187 | * file again, but that will end up using the synchronization |
1188 | * inside btrfs_sync_log to keep things safe. |
1189 | */ |
1190 | mutex_unlock(&dentry->d_inode->i_mutex); |
1191 | |
1192 | if (ret > 0) { |
1193 | ret = btrfs_commit_transaction(trans, root); |
1194 | } else { |
1195 | ret = btrfs_sync_log(trans, root); |
1196 | if (ret == 0) |
1197 | ret = btrfs_end_transaction(trans, root); |
1198 | else |
1199 | ret = btrfs_commit_transaction(trans, root); |
1200 | } |
1201 | mutex_lock(&dentry->d_inode->i_mutex); |
1202 | out: |
1203 | return ret > 0 ? EIO : ret; |
1204 | } |
1205 | |
1206 | static struct vm_operations_struct btrfs_file_vm_ops = { |
1207 | .fault = filemap_fault, |
1208 | .page_mkwrite = btrfs_page_mkwrite, |
1209 | }; |
1210 | |
1211 | static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma) |
1212 | { |
1213 | vma->vm_ops = &btrfs_file_vm_ops; |
1214 | file_accessed(filp); |
1215 | return 0; |
1216 | } |
1217 | |
1218 | struct file_operations btrfs_file_operations = { |
1219 | .llseek = generic_file_llseek, |
1220 | .read = do_sync_read, |
1221 | .aio_read = generic_file_aio_read, |
1222 | .splice_read = generic_file_splice_read, |
1223 | .write = btrfs_file_write, |
1224 | .mmap = btrfs_file_mmap, |
1225 | .open = generic_file_open, |
1226 | .release = btrfs_release_file, |
1227 | .fsync = btrfs_sync_file, |
1228 | .unlocked_ioctl = btrfs_ioctl, |
1229 | #ifdef CONFIG_COMPAT |
1230 | .compat_ioctl = btrfs_ioctl, |
1231 | #endif |
1232 | }; |
1233 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
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jz-3.6-rc2-pwm
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jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9