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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 <linux/slab.h> |
32 | #include "ctree.h" |
33 | #include "disk-io.h" |
34 | #include "transaction.h" |
35 | #include "btrfs_inode.h" |
36 | #include "ioctl.h" |
37 | #include "print-tree.h" |
38 | #include "tree-log.h" |
39 | #include "locking.h" |
40 | #include "compat.h" |
41 | |
42 | |
43 | /* simple helper to fault in pages and copy. This should go away |
44 | * and be replaced with calls into generic code. |
45 | */ |
46 | static noinline int btrfs_copy_from_user(loff_t pos, int num_pages, |
47 | int write_bytes, |
48 | struct page **prepared_pages, |
49 | const char __user *buf) |
50 | { |
51 | long page_fault = 0; |
52 | int i; |
53 | int offset = pos & (PAGE_CACHE_SIZE - 1); |
54 | |
55 | for (i = 0; i < num_pages && write_bytes > 0; i++, offset = 0) { |
56 | size_t count = min_t(size_t, |
57 | PAGE_CACHE_SIZE - offset, write_bytes); |
58 | struct page *page = prepared_pages[i]; |
59 | fault_in_pages_readable(buf, count); |
60 | |
61 | /* Copy data from userspace to the current page */ |
62 | kmap(page); |
63 | page_fault = __copy_from_user(page_address(page) + offset, |
64 | buf, count); |
65 | /* Flush processor's dcache for this page */ |
66 | flush_dcache_page(page); |
67 | kunmap(page); |
68 | buf += count; |
69 | write_bytes -= count; |
70 | |
71 | if (page_fault) |
72 | break; |
73 | } |
74 | return page_fault ? -EFAULT : 0; |
75 | } |
76 | |
77 | /* |
78 | * unlocks pages after btrfs_file_write is done with them |
79 | */ |
80 | static noinline void btrfs_drop_pages(struct page **pages, size_t num_pages) |
81 | { |
82 | size_t i; |
83 | for (i = 0; i < num_pages; i++) { |
84 | if (!pages[i]) |
85 | break; |
86 | /* page checked is some magic around finding pages that |
87 | * have been modified without going through btrfs_set_page_dirty |
88 | * clear it here |
89 | */ |
90 | ClearPageChecked(pages[i]); |
91 | unlock_page(pages[i]); |
92 | mark_page_accessed(pages[i]); |
93 | page_cache_release(pages[i]); |
94 | } |
95 | } |
96 | |
97 | /* |
98 | * after copy_from_user, pages need to be dirtied and we need to make |
99 | * sure holes are created between the current EOF and the start of |
100 | * any next extents (if required). |
101 | * |
102 | * this also makes the decision about creating an inline extent vs |
103 | * doing real data extents, marking pages dirty and delalloc as required. |
104 | */ |
105 | static noinline int dirty_and_release_pages(struct btrfs_trans_handle *trans, |
106 | struct btrfs_root *root, |
107 | struct file *file, |
108 | struct page **pages, |
109 | size_t num_pages, |
110 | loff_t pos, |
111 | size_t write_bytes) |
112 | { |
113 | int err = 0; |
114 | int i; |
115 | struct inode *inode = fdentry(file)->d_inode; |
116 | u64 num_bytes; |
117 | u64 start_pos; |
118 | u64 end_of_last_block; |
119 | u64 end_pos = pos + write_bytes; |
120 | loff_t isize = i_size_read(inode); |
121 | |
122 | start_pos = pos & ~((u64)root->sectorsize - 1); |
123 | num_bytes = (write_bytes + pos - start_pos + |
124 | root->sectorsize - 1) & ~((u64)root->sectorsize - 1); |
125 | |
126 | end_of_last_block = start_pos + num_bytes - 1; |
127 | err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block, |
128 | NULL); |
129 | if (err) |
130 | return err; |
131 | |
132 | for (i = 0; i < num_pages; i++) { |
133 | struct page *p = pages[i]; |
134 | SetPageUptodate(p); |
135 | ClearPageChecked(p); |
136 | set_page_dirty(p); |
137 | } |
138 | if (end_pos > isize) { |
139 | i_size_write(inode, end_pos); |
140 | /* we've only changed i_size in ram, and we haven't updated |
141 | * the disk i_size. There is no need to log the inode |
142 | * at this time. |
143 | */ |
144 | } |
145 | return err; |
146 | } |
147 | |
148 | /* |
149 | * this drops all the extents in the cache that intersect the range |
150 | * [start, end]. Existing extents are split as required. |
151 | */ |
152 | int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end, |
153 | int skip_pinned) |
154 | { |
155 | struct extent_map *em; |
156 | struct extent_map *split = NULL; |
157 | struct extent_map *split2 = NULL; |
158 | struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; |
159 | u64 len = end - start + 1; |
160 | int ret; |
161 | int testend = 1; |
162 | unsigned long flags; |
163 | int compressed = 0; |
164 | |
165 | WARN_ON(end < start); |
166 | if (end == (u64)-1) { |
167 | len = (u64)-1; |
168 | testend = 0; |
169 | } |
170 | while (1) { |
171 | if (!split) |
172 | split = alloc_extent_map(GFP_NOFS); |
173 | if (!split2) |
174 | split2 = alloc_extent_map(GFP_NOFS); |
175 | |
176 | write_lock(&em_tree->lock); |
177 | em = lookup_extent_mapping(em_tree, start, len); |
178 | if (!em) { |
179 | write_unlock(&em_tree->lock); |
180 | break; |
181 | } |
182 | flags = em->flags; |
183 | if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) { |
184 | if (testend && em->start + em->len >= start + len) { |
185 | free_extent_map(em); |
186 | write_unlock(&em_tree->lock); |
187 | break; |
188 | } |
189 | start = em->start + em->len; |
190 | if (testend) |
191 | len = start + len - (em->start + em->len); |
192 | free_extent_map(em); |
193 | write_unlock(&em_tree->lock); |
194 | continue; |
195 | } |
196 | compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags); |
197 | clear_bit(EXTENT_FLAG_PINNED, &em->flags); |
198 | remove_extent_mapping(em_tree, em); |
199 | |
200 | if (em->block_start < EXTENT_MAP_LAST_BYTE && |
201 | em->start < start) { |
202 | split->start = em->start; |
203 | split->len = start - em->start; |
204 | split->orig_start = em->orig_start; |
205 | split->block_start = em->block_start; |
206 | |
207 | if (compressed) |
208 | split->block_len = em->block_len; |
209 | else |
210 | split->block_len = split->len; |
211 | |
212 | split->bdev = em->bdev; |
213 | split->flags = flags; |
214 | ret = add_extent_mapping(em_tree, split); |
215 | BUG_ON(ret); |
216 | free_extent_map(split); |
217 | split = split2; |
218 | split2 = NULL; |
219 | } |
220 | if (em->block_start < EXTENT_MAP_LAST_BYTE && |
221 | testend && em->start + em->len > start + len) { |
222 | u64 diff = start + len - em->start; |
223 | |
224 | split->start = start + len; |
225 | split->len = em->start + em->len - (start + len); |
226 | split->bdev = em->bdev; |
227 | split->flags = flags; |
228 | |
229 | if (compressed) { |
230 | split->block_len = em->block_len; |
231 | split->block_start = em->block_start; |
232 | split->orig_start = em->orig_start; |
233 | } else { |
234 | split->block_len = split->len; |
235 | split->block_start = em->block_start + diff; |
236 | split->orig_start = split->start; |
237 | } |
238 | |
239 | ret = add_extent_mapping(em_tree, split); |
240 | BUG_ON(ret); |
241 | free_extent_map(split); |
242 | split = NULL; |
243 | } |
244 | write_unlock(&em_tree->lock); |
245 | |
246 | /* once for us */ |
247 | free_extent_map(em); |
248 | /* once for the tree*/ |
249 | free_extent_map(em); |
250 | } |
251 | if (split) |
252 | free_extent_map(split); |
253 | if (split2) |
254 | free_extent_map(split2); |
255 | return 0; |
256 | } |
257 | |
258 | /* |
259 | * this is very complex, but the basic idea is to drop all extents |
260 | * in the range start - end. hint_block is filled in with a block number |
261 | * that would be a good hint to the block allocator for this file. |
262 | * |
263 | * If an extent intersects the range but is not entirely inside the range |
264 | * it is either truncated or split. Anything entirely inside the range |
265 | * is deleted from the tree. |
266 | */ |
267 | int btrfs_drop_extents(struct btrfs_trans_handle *trans, struct inode *inode, |
268 | u64 start, u64 end, u64 *hint_byte, int drop_cache) |
269 | { |
270 | struct btrfs_root *root = BTRFS_I(inode)->root; |
271 | struct extent_buffer *leaf; |
272 | struct btrfs_file_extent_item *fi; |
273 | struct btrfs_path *path; |
274 | struct btrfs_key key; |
275 | struct btrfs_key new_key; |
276 | u64 search_start = start; |
277 | u64 disk_bytenr = 0; |
278 | u64 num_bytes = 0; |
279 | u64 extent_offset = 0; |
280 | u64 extent_end = 0; |
281 | int del_nr = 0; |
282 | int del_slot = 0; |
283 | int extent_type; |
284 | int recow; |
285 | int ret; |
286 | |
287 | if (drop_cache) |
288 | btrfs_drop_extent_cache(inode, start, end - 1, 0); |
289 | |
290 | path = btrfs_alloc_path(); |
291 | if (!path) |
292 | return -ENOMEM; |
293 | |
294 | while (1) { |
295 | recow = 0; |
296 | ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino, |
297 | search_start, -1); |
298 | if (ret < 0) |
299 | break; |
300 | if (ret > 0 && path->slots[0] > 0 && search_start == start) { |
301 | leaf = path->nodes[0]; |
302 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1); |
303 | if (key.objectid == inode->i_ino && |
304 | key.type == BTRFS_EXTENT_DATA_KEY) |
305 | path->slots[0]--; |
306 | } |
307 | ret = 0; |
308 | next_slot: |
309 | leaf = path->nodes[0]; |
310 | if (path->slots[0] >= btrfs_header_nritems(leaf)) { |
311 | BUG_ON(del_nr > 0); |
312 | ret = btrfs_next_leaf(root, path); |
313 | if (ret < 0) |
314 | break; |
315 | if (ret > 0) { |
316 | ret = 0; |
317 | break; |
318 | } |
319 | leaf = path->nodes[0]; |
320 | recow = 1; |
321 | } |
322 | |
323 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
324 | if (key.objectid > inode->i_ino || |
325 | key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end) |
326 | break; |
327 | |
328 | fi = btrfs_item_ptr(leaf, path->slots[0], |
329 | struct btrfs_file_extent_item); |
330 | extent_type = btrfs_file_extent_type(leaf, fi); |
331 | |
332 | if (extent_type == BTRFS_FILE_EXTENT_REG || |
333 | extent_type == BTRFS_FILE_EXTENT_PREALLOC) { |
334 | disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); |
335 | num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); |
336 | extent_offset = btrfs_file_extent_offset(leaf, fi); |
337 | extent_end = key.offset + |
338 | btrfs_file_extent_num_bytes(leaf, fi); |
339 | } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { |
340 | extent_end = key.offset + |
341 | btrfs_file_extent_inline_len(leaf, fi); |
342 | } else { |
343 | WARN_ON(1); |
344 | extent_end = search_start; |
345 | } |
346 | |
347 | if (extent_end <= search_start) { |
348 | path->slots[0]++; |
349 | goto next_slot; |
350 | } |
351 | |
352 | search_start = max(key.offset, start); |
353 | if (recow) { |
354 | btrfs_release_path(root, path); |
355 | continue; |
356 | } |
357 | |
358 | /* |
359 | * | - range to drop - | |
360 | * | -------- extent -------- | |
361 | */ |
362 | if (start > key.offset && end < extent_end) { |
363 | BUG_ON(del_nr > 0); |
364 | BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE); |
365 | |
366 | memcpy(&new_key, &key, sizeof(new_key)); |
367 | new_key.offset = start; |
368 | ret = btrfs_duplicate_item(trans, root, path, |
369 | &new_key); |
370 | if (ret == -EAGAIN) { |
371 | btrfs_release_path(root, path); |
372 | continue; |
373 | } |
374 | if (ret < 0) |
375 | break; |
376 | |
377 | leaf = path->nodes[0]; |
378 | fi = btrfs_item_ptr(leaf, path->slots[0] - 1, |
379 | struct btrfs_file_extent_item); |
380 | btrfs_set_file_extent_num_bytes(leaf, fi, |
381 | start - key.offset); |
382 | |
383 | fi = btrfs_item_ptr(leaf, path->slots[0], |
384 | struct btrfs_file_extent_item); |
385 | |
386 | extent_offset += start - key.offset; |
387 | btrfs_set_file_extent_offset(leaf, fi, extent_offset); |
388 | btrfs_set_file_extent_num_bytes(leaf, fi, |
389 | extent_end - start); |
390 | btrfs_mark_buffer_dirty(leaf); |
391 | |
392 | if (disk_bytenr > 0) { |
393 | ret = btrfs_inc_extent_ref(trans, root, |
394 | disk_bytenr, num_bytes, 0, |
395 | root->root_key.objectid, |
396 | new_key.objectid, |
397 | start - extent_offset); |
398 | BUG_ON(ret); |
399 | *hint_byte = disk_bytenr; |
400 | } |
401 | key.offset = start; |
402 | } |
403 | /* |
404 | * | ---- range to drop ----- | |
405 | * | -------- extent -------- | |
406 | */ |
407 | if (start <= key.offset && end < extent_end) { |
408 | BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE); |
409 | |
410 | memcpy(&new_key, &key, sizeof(new_key)); |
411 | new_key.offset = end; |
412 | btrfs_set_item_key_safe(trans, root, path, &new_key); |
413 | |
414 | extent_offset += end - key.offset; |
415 | btrfs_set_file_extent_offset(leaf, fi, extent_offset); |
416 | btrfs_set_file_extent_num_bytes(leaf, fi, |
417 | extent_end - end); |
418 | btrfs_mark_buffer_dirty(leaf); |
419 | if (disk_bytenr > 0) { |
420 | inode_sub_bytes(inode, end - key.offset); |
421 | *hint_byte = disk_bytenr; |
422 | } |
423 | break; |
424 | } |
425 | |
426 | search_start = extent_end; |
427 | /* |
428 | * | ---- range to drop ----- | |
429 | * | -------- extent -------- | |
430 | */ |
431 | if (start > key.offset && end >= extent_end) { |
432 | BUG_ON(del_nr > 0); |
433 | BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE); |
434 | |
435 | btrfs_set_file_extent_num_bytes(leaf, fi, |
436 | start - key.offset); |
437 | btrfs_mark_buffer_dirty(leaf); |
438 | if (disk_bytenr > 0) { |
439 | inode_sub_bytes(inode, extent_end - start); |
440 | *hint_byte = disk_bytenr; |
441 | } |
442 | if (end == extent_end) |
443 | break; |
444 | |
445 | path->slots[0]++; |
446 | goto next_slot; |
447 | } |
448 | |
449 | /* |
450 | * | ---- range to drop ----- | |
451 | * | ------ extent ------ | |
452 | */ |
453 | if (start <= key.offset && end >= extent_end) { |
454 | if (del_nr == 0) { |
455 | del_slot = path->slots[0]; |
456 | del_nr = 1; |
457 | } else { |
458 | BUG_ON(del_slot + del_nr != path->slots[0]); |
459 | del_nr++; |
460 | } |
461 | |
462 | if (extent_type == BTRFS_FILE_EXTENT_INLINE) { |
463 | inode_sub_bytes(inode, |
464 | extent_end - key.offset); |
465 | extent_end = ALIGN(extent_end, |
466 | root->sectorsize); |
467 | } else if (disk_bytenr > 0) { |
468 | ret = btrfs_free_extent(trans, root, |
469 | disk_bytenr, num_bytes, 0, |
470 | root->root_key.objectid, |
471 | key.objectid, key.offset - |
472 | extent_offset); |
473 | BUG_ON(ret); |
474 | inode_sub_bytes(inode, |
475 | extent_end - key.offset); |
476 | *hint_byte = disk_bytenr; |
477 | } |
478 | |
479 | if (end == extent_end) |
480 | break; |
481 | |
482 | if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) { |
483 | path->slots[0]++; |
484 | goto next_slot; |
485 | } |
486 | |
487 | ret = btrfs_del_items(trans, root, path, del_slot, |
488 | del_nr); |
489 | BUG_ON(ret); |
490 | |
491 | del_nr = 0; |
492 | del_slot = 0; |
493 | |
494 | btrfs_release_path(root, path); |
495 | continue; |
496 | } |
497 | |
498 | BUG_ON(1); |
499 | } |
500 | |
501 | if (del_nr > 0) { |
502 | ret = btrfs_del_items(trans, root, path, del_slot, del_nr); |
503 | BUG_ON(ret); |
504 | } |
505 | |
506 | btrfs_free_path(path); |
507 | return ret; |
508 | } |
509 | |
510 | static int extent_mergeable(struct extent_buffer *leaf, int slot, |
511 | u64 objectid, u64 bytenr, u64 orig_offset, |
512 | u64 *start, u64 *end) |
513 | { |
514 | struct btrfs_file_extent_item *fi; |
515 | struct btrfs_key key; |
516 | u64 extent_end; |
517 | |
518 | if (slot < 0 || slot >= btrfs_header_nritems(leaf)) |
519 | return 0; |
520 | |
521 | btrfs_item_key_to_cpu(leaf, &key, slot); |
522 | if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY) |
523 | return 0; |
524 | |
525 | fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); |
526 | if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG || |
527 | btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr || |
528 | btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset || |
529 | btrfs_file_extent_compression(leaf, fi) || |
530 | btrfs_file_extent_encryption(leaf, fi) || |
531 | btrfs_file_extent_other_encoding(leaf, fi)) |
532 | return 0; |
533 | |
534 | extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); |
535 | if ((*start && *start != key.offset) || (*end && *end != extent_end)) |
536 | return 0; |
537 | |
538 | *start = key.offset; |
539 | *end = extent_end; |
540 | return 1; |
541 | } |
542 | |
543 | /* |
544 | * Mark extent in the range start - end as written. |
545 | * |
546 | * This changes extent type from 'pre-allocated' to 'regular'. If only |
547 | * part of extent is marked as written, the extent will be split into |
548 | * two or three. |
549 | */ |
550 | int btrfs_mark_extent_written(struct btrfs_trans_handle *trans, |
551 | struct inode *inode, u64 start, u64 end) |
552 | { |
553 | struct btrfs_root *root = BTRFS_I(inode)->root; |
554 | struct extent_buffer *leaf; |
555 | struct btrfs_path *path; |
556 | struct btrfs_file_extent_item *fi; |
557 | struct btrfs_key key; |
558 | struct btrfs_key new_key; |
559 | u64 bytenr; |
560 | u64 num_bytes; |
561 | u64 extent_end; |
562 | u64 orig_offset; |
563 | u64 other_start; |
564 | u64 other_end; |
565 | u64 split; |
566 | int del_nr = 0; |
567 | int del_slot = 0; |
568 | int recow; |
569 | int ret; |
570 | |
571 | btrfs_drop_extent_cache(inode, start, end - 1, 0); |
572 | |
573 | path = btrfs_alloc_path(); |
574 | BUG_ON(!path); |
575 | again: |
576 | recow = 0; |
577 | split = start; |
578 | key.objectid = inode->i_ino; |
579 | key.type = BTRFS_EXTENT_DATA_KEY; |
580 | key.offset = split; |
581 | |
582 | ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
583 | if (ret > 0 && path->slots[0] > 0) |
584 | path->slots[0]--; |
585 | |
586 | leaf = path->nodes[0]; |
587 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
588 | BUG_ON(key.objectid != inode->i_ino || |
589 | key.type != BTRFS_EXTENT_DATA_KEY); |
590 | fi = btrfs_item_ptr(leaf, path->slots[0], |
591 | struct btrfs_file_extent_item); |
592 | BUG_ON(btrfs_file_extent_type(leaf, fi) != |
593 | BTRFS_FILE_EXTENT_PREALLOC); |
594 | extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); |
595 | BUG_ON(key.offset > start || extent_end < end); |
596 | |
597 | bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); |
598 | num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); |
599 | orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi); |
600 | memcpy(&new_key, &key, sizeof(new_key)); |
601 | |
602 | if (start == key.offset && end < extent_end) { |
603 | other_start = 0; |
604 | other_end = start; |
605 | if (extent_mergeable(leaf, path->slots[0] - 1, |
606 | inode->i_ino, bytenr, orig_offset, |
607 | &other_start, &other_end)) { |
608 | new_key.offset = end; |
609 | btrfs_set_item_key_safe(trans, root, path, &new_key); |
610 | fi = btrfs_item_ptr(leaf, path->slots[0], |
611 | struct btrfs_file_extent_item); |
612 | btrfs_set_file_extent_num_bytes(leaf, fi, |
613 | extent_end - end); |
614 | btrfs_set_file_extent_offset(leaf, fi, |
615 | end - orig_offset); |
616 | fi = btrfs_item_ptr(leaf, path->slots[0] - 1, |
617 | struct btrfs_file_extent_item); |
618 | btrfs_set_file_extent_num_bytes(leaf, fi, |
619 | end - other_start); |
620 | btrfs_mark_buffer_dirty(leaf); |
621 | goto out; |
622 | } |
623 | } |
624 | |
625 | if (start > key.offset && end == extent_end) { |
626 | other_start = end; |
627 | other_end = 0; |
628 | if (extent_mergeable(leaf, path->slots[0] + 1, |
629 | inode->i_ino, bytenr, orig_offset, |
630 | &other_start, &other_end)) { |
631 | fi = btrfs_item_ptr(leaf, path->slots[0], |
632 | struct btrfs_file_extent_item); |
633 | btrfs_set_file_extent_num_bytes(leaf, fi, |
634 | start - key.offset); |
635 | path->slots[0]++; |
636 | new_key.offset = start; |
637 | btrfs_set_item_key_safe(trans, root, path, &new_key); |
638 | |
639 | fi = btrfs_item_ptr(leaf, path->slots[0], |
640 | struct btrfs_file_extent_item); |
641 | btrfs_set_file_extent_num_bytes(leaf, fi, |
642 | other_end - start); |
643 | btrfs_set_file_extent_offset(leaf, fi, |
644 | start - orig_offset); |
645 | btrfs_mark_buffer_dirty(leaf); |
646 | goto out; |
647 | } |
648 | } |
649 | |
650 | while (start > key.offset || end < extent_end) { |
651 | if (key.offset == start) |
652 | split = end; |
653 | |
654 | new_key.offset = split; |
655 | ret = btrfs_duplicate_item(trans, root, path, &new_key); |
656 | if (ret == -EAGAIN) { |
657 | btrfs_release_path(root, path); |
658 | goto again; |
659 | } |
660 | BUG_ON(ret < 0); |
661 | |
662 | leaf = path->nodes[0]; |
663 | fi = btrfs_item_ptr(leaf, path->slots[0] - 1, |
664 | struct btrfs_file_extent_item); |
665 | btrfs_set_file_extent_num_bytes(leaf, fi, |
666 | split - key.offset); |
667 | |
668 | fi = btrfs_item_ptr(leaf, path->slots[0], |
669 | struct btrfs_file_extent_item); |
670 | |
671 | btrfs_set_file_extent_offset(leaf, fi, split - orig_offset); |
672 | btrfs_set_file_extent_num_bytes(leaf, fi, |
673 | extent_end - split); |
674 | btrfs_mark_buffer_dirty(leaf); |
675 | |
676 | ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, 0, |
677 | root->root_key.objectid, |
678 | inode->i_ino, orig_offset); |
679 | BUG_ON(ret); |
680 | |
681 | if (split == start) { |
682 | key.offset = start; |
683 | } else { |
684 | BUG_ON(start != key.offset); |
685 | path->slots[0]--; |
686 | extent_end = end; |
687 | } |
688 | recow = 1; |
689 | } |
690 | |
691 | other_start = end; |
692 | other_end = 0; |
693 | if (extent_mergeable(leaf, path->slots[0] + 1, |
694 | inode->i_ino, bytenr, orig_offset, |
695 | &other_start, &other_end)) { |
696 | if (recow) { |
697 | btrfs_release_path(root, path); |
698 | goto again; |
699 | } |
700 | extent_end = other_end; |
701 | del_slot = path->slots[0] + 1; |
702 | del_nr++; |
703 | ret = btrfs_free_extent(trans, root, bytenr, num_bytes, |
704 | 0, root->root_key.objectid, |
705 | inode->i_ino, orig_offset); |
706 | BUG_ON(ret); |
707 | } |
708 | other_start = 0; |
709 | other_end = start; |
710 | if (extent_mergeable(leaf, path->slots[0] - 1, |
711 | inode->i_ino, bytenr, orig_offset, |
712 | &other_start, &other_end)) { |
713 | if (recow) { |
714 | btrfs_release_path(root, path); |
715 | goto again; |
716 | } |
717 | key.offset = other_start; |
718 | del_slot = path->slots[0]; |
719 | del_nr++; |
720 | ret = btrfs_free_extent(trans, root, bytenr, num_bytes, |
721 | 0, root->root_key.objectid, |
722 | inode->i_ino, orig_offset); |
723 | BUG_ON(ret); |
724 | } |
725 | if (del_nr == 0) { |
726 | fi = btrfs_item_ptr(leaf, path->slots[0], |
727 | struct btrfs_file_extent_item); |
728 | btrfs_set_file_extent_type(leaf, fi, |
729 | BTRFS_FILE_EXTENT_REG); |
730 | btrfs_mark_buffer_dirty(leaf); |
731 | } else { |
732 | fi = btrfs_item_ptr(leaf, del_slot - 1, |
733 | struct btrfs_file_extent_item); |
734 | btrfs_set_file_extent_type(leaf, fi, |
735 | BTRFS_FILE_EXTENT_REG); |
736 | btrfs_set_file_extent_num_bytes(leaf, fi, |
737 | extent_end - key.offset); |
738 | btrfs_mark_buffer_dirty(leaf); |
739 | |
740 | ret = btrfs_del_items(trans, root, path, del_slot, del_nr); |
741 | BUG_ON(ret); |
742 | } |
743 | out: |
744 | btrfs_free_path(path); |
745 | return 0; |
746 | } |
747 | |
748 | /* |
749 | * this gets pages into the page cache and locks them down, it also properly |
750 | * waits for data=ordered extents to finish before allowing the pages to be |
751 | * modified. |
752 | */ |
753 | static noinline int prepare_pages(struct btrfs_root *root, struct file *file, |
754 | struct page **pages, size_t num_pages, |
755 | loff_t pos, unsigned long first_index, |
756 | unsigned long last_index, size_t write_bytes) |
757 | { |
758 | struct extent_state *cached_state = NULL; |
759 | int i; |
760 | unsigned long index = pos >> PAGE_CACHE_SHIFT; |
761 | struct inode *inode = fdentry(file)->d_inode; |
762 | int err = 0; |
763 | u64 start_pos; |
764 | u64 last_pos; |
765 | |
766 | start_pos = pos & ~((u64)root->sectorsize - 1); |
767 | last_pos = ((u64)index + num_pages) << PAGE_CACHE_SHIFT; |
768 | |
769 | if (start_pos > inode->i_size) { |
770 | err = btrfs_cont_expand(inode, start_pos); |
771 | if (err) |
772 | return err; |
773 | } |
774 | |
775 | memset(pages, 0, num_pages * sizeof(struct page *)); |
776 | again: |
777 | for (i = 0; i < num_pages; i++) { |
778 | pages[i] = grab_cache_page(inode->i_mapping, index + i); |
779 | if (!pages[i]) { |
780 | err = -ENOMEM; |
781 | BUG_ON(1); |
782 | } |
783 | wait_on_page_writeback(pages[i]); |
784 | } |
785 | if (start_pos < inode->i_size) { |
786 | struct btrfs_ordered_extent *ordered; |
787 | lock_extent_bits(&BTRFS_I(inode)->io_tree, |
788 | start_pos, last_pos - 1, 0, &cached_state, |
789 | GFP_NOFS); |
790 | ordered = btrfs_lookup_first_ordered_extent(inode, |
791 | last_pos - 1); |
792 | if (ordered && |
793 | ordered->file_offset + ordered->len > start_pos && |
794 | ordered->file_offset < last_pos) { |
795 | btrfs_put_ordered_extent(ordered); |
796 | unlock_extent_cached(&BTRFS_I(inode)->io_tree, |
797 | start_pos, last_pos - 1, |
798 | &cached_state, GFP_NOFS); |
799 | for (i = 0; i < num_pages; i++) { |
800 | unlock_page(pages[i]); |
801 | page_cache_release(pages[i]); |
802 | } |
803 | btrfs_wait_ordered_range(inode, start_pos, |
804 | last_pos - start_pos); |
805 | goto again; |
806 | } |
807 | if (ordered) |
808 | btrfs_put_ordered_extent(ordered); |
809 | |
810 | clear_extent_bit(&BTRFS_I(inode)->io_tree, start_pos, |
811 | last_pos - 1, EXTENT_DIRTY | EXTENT_DELALLOC | |
812 | EXTENT_DO_ACCOUNTING, 0, 0, &cached_state, |
813 | GFP_NOFS); |
814 | unlock_extent_cached(&BTRFS_I(inode)->io_tree, |
815 | start_pos, last_pos - 1, &cached_state, |
816 | GFP_NOFS); |
817 | } |
818 | for (i = 0; i < num_pages; i++) { |
819 | clear_page_dirty_for_io(pages[i]); |
820 | set_page_extent_mapped(pages[i]); |
821 | WARN_ON(!PageLocked(pages[i])); |
822 | } |
823 | return 0; |
824 | } |
825 | |
826 | static ssize_t btrfs_file_write(struct file *file, const char __user *buf, |
827 | size_t count, loff_t *ppos) |
828 | { |
829 | loff_t pos; |
830 | loff_t start_pos; |
831 | ssize_t num_written = 0; |
832 | ssize_t err = 0; |
833 | int ret = 0; |
834 | struct inode *inode = fdentry(file)->d_inode; |
835 | struct btrfs_root *root = BTRFS_I(inode)->root; |
836 | struct page **pages = NULL; |
837 | int nrptrs; |
838 | struct page *pinned[2]; |
839 | unsigned long first_index; |
840 | unsigned long last_index; |
841 | int will_write; |
842 | |
843 | will_write = ((file->f_flags & O_DSYNC) || IS_SYNC(inode) || |
844 | (file->f_flags & O_DIRECT)); |
845 | |
846 | nrptrs = min((count + PAGE_CACHE_SIZE - 1) / PAGE_CACHE_SIZE, |
847 | PAGE_CACHE_SIZE / (sizeof(struct page *))); |
848 | pinned[0] = NULL; |
849 | pinned[1] = NULL; |
850 | |
851 | pos = *ppos; |
852 | start_pos = pos; |
853 | |
854 | vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE); |
855 | |
856 | /* do the reserve before the mutex lock in case we have to do some |
857 | * flushing. We wouldn't deadlock, but this is more polite. |
858 | */ |
859 | err = btrfs_reserve_metadata_for_delalloc(root, inode, 1); |
860 | if (err) |
861 | goto out_nolock; |
862 | |
863 | mutex_lock(&inode->i_mutex); |
864 | |
865 | current->backing_dev_info = inode->i_mapping->backing_dev_info; |
866 | err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode)); |
867 | if (err) |
868 | goto out; |
869 | |
870 | if (count == 0) |
871 | goto out; |
872 | |
873 | err = file_remove_suid(file); |
874 | if (err) |
875 | goto out; |
876 | |
877 | file_update_time(file); |
878 | |
879 | pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL); |
880 | |
881 | /* generic_write_checks can change our pos */ |
882 | start_pos = pos; |
883 | |
884 | BTRFS_I(inode)->sequence++; |
885 | first_index = pos >> PAGE_CACHE_SHIFT; |
886 | last_index = (pos + count) >> PAGE_CACHE_SHIFT; |
887 | |
888 | /* |
889 | * there are lots of better ways to do this, but this code |
890 | * makes sure the first and last page in the file range are |
891 | * up to date and ready for cow |
892 | */ |
893 | if ((pos & (PAGE_CACHE_SIZE - 1))) { |
894 | pinned[0] = grab_cache_page(inode->i_mapping, first_index); |
895 | if (!PageUptodate(pinned[0])) { |
896 | ret = btrfs_readpage(NULL, pinned[0]); |
897 | BUG_ON(ret); |
898 | wait_on_page_locked(pinned[0]); |
899 | } else { |
900 | unlock_page(pinned[0]); |
901 | } |
902 | } |
903 | if ((pos + count) & (PAGE_CACHE_SIZE - 1)) { |
904 | pinned[1] = grab_cache_page(inode->i_mapping, last_index); |
905 | if (!PageUptodate(pinned[1])) { |
906 | ret = btrfs_readpage(NULL, pinned[1]); |
907 | BUG_ON(ret); |
908 | wait_on_page_locked(pinned[1]); |
909 | } else { |
910 | unlock_page(pinned[1]); |
911 | } |
912 | } |
913 | |
914 | while (count > 0) { |
915 | size_t offset = pos & (PAGE_CACHE_SIZE - 1); |
916 | size_t write_bytes = min(count, nrptrs * |
917 | (size_t)PAGE_CACHE_SIZE - |
918 | offset); |
919 | size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >> |
920 | PAGE_CACHE_SHIFT; |
921 | |
922 | WARN_ON(num_pages > nrptrs); |
923 | memset(pages, 0, sizeof(struct page *) * nrptrs); |
924 | |
925 | ret = btrfs_check_data_free_space(root, inode, write_bytes); |
926 | if (ret) |
927 | goto out; |
928 | |
929 | ret = prepare_pages(root, file, pages, num_pages, |
930 | pos, first_index, last_index, |
931 | write_bytes); |
932 | if (ret) { |
933 | btrfs_free_reserved_data_space(root, inode, |
934 | write_bytes); |
935 | goto out; |
936 | } |
937 | |
938 | ret = btrfs_copy_from_user(pos, num_pages, |
939 | write_bytes, pages, buf); |
940 | if (ret) { |
941 | btrfs_free_reserved_data_space(root, inode, |
942 | write_bytes); |
943 | btrfs_drop_pages(pages, num_pages); |
944 | goto out; |
945 | } |
946 | |
947 | ret = dirty_and_release_pages(NULL, root, file, pages, |
948 | num_pages, pos, write_bytes); |
949 | btrfs_drop_pages(pages, num_pages); |
950 | if (ret) { |
951 | btrfs_free_reserved_data_space(root, inode, |
952 | write_bytes); |
953 | goto out; |
954 | } |
955 | |
956 | if (will_write) { |
957 | filemap_fdatawrite_range(inode->i_mapping, pos, |
958 | pos + write_bytes - 1); |
959 | } else { |
960 | balance_dirty_pages_ratelimited_nr(inode->i_mapping, |
961 | num_pages); |
962 | if (num_pages < |
963 | (root->leafsize >> PAGE_CACHE_SHIFT) + 1) |
964 | btrfs_btree_balance_dirty(root, 1); |
965 | btrfs_throttle(root); |
966 | } |
967 | |
968 | buf += write_bytes; |
969 | count -= write_bytes; |
970 | pos += write_bytes; |
971 | num_written += write_bytes; |
972 | |
973 | cond_resched(); |
974 | } |
975 | out: |
976 | mutex_unlock(&inode->i_mutex); |
977 | if (ret) |
978 | err = ret; |
979 | btrfs_unreserve_metadata_for_delalloc(root, inode, 1); |
980 | |
981 | out_nolock: |
982 | kfree(pages); |
983 | if (pinned[0]) |
984 | page_cache_release(pinned[0]); |
985 | if (pinned[1]) |
986 | page_cache_release(pinned[1]); |
987 | *ppos = pos; |
988 | |
989 | /* |
990 | * we want to make sure fsync finds this change |
991 | * but we haven't joined a transaction running right now. |
992 | * |
993 | * Later on, someone is sure to update the inode and get the |
994 | * real transid recorded. |
995 | * |
996 | * We set last_trans now to the fs_info generation + 1, |
997 | * this will either be one more than the running transaction |
998 | * or the generation used for the next transaction if there isn't |
999 | * one running right now. |
1000 | */ |
1001 | BTRFS_I(inode)->last_trans = root->fs_info->generation + 1; |
1002 | |
1003 | if (num_written > 0 && will_write) { |
1004 | struct btrfs_trans_handle *trans; |
1005 | |
1006 | err = btrfs_wait_ordered_range(inode, start_pos, num_written); |
1007 | if (err) |
1008 | num_written = err; |
1009 | |
1010 | if ((file->f_flags & O_DSYNC) || IS_SYNC(inode)) { |
1011 | trans = btrfs_start_transaction(root, 1); |
1012 | ret = btrfs_log_dentry_safe(trans, root, |
1013 | file->f_dentry); |
1014 | if (ret == 0) { |
1015 | ret = btrfs_sync_log(trans, root); |
1016 | if (ret == 0) |
1017 | btrfs_end_transaction(trans, root); |
1018 | else |
1019 | btrfs_commit_transaction(trans, root); |
1020 | } else if (ret != BTRFS_NO_LOG_SYNC) { |
1021 | btrfs_commit_transaction(trans, root); |
1022 | } else { |
1023 | btrfs_end_transaction(trans, root); |
1024 | } |
1025 | } |
1026 | if (file->f_flags & O_DIRECT) { |
1027 | invalidate_mapping_pages(inode->i_mapping, |
1028 | start_pos >> PAGE_CACHE_SHIFT, |
1029 | (start_pos + num_written - 1) >> PAGE_CACHE_SHIFT); |
1030 | } |
1031 | } |
1032 | current->backing_dev_info = NULL; |
1033 | return num_written ? num_written : err; |
1034 | } |
1035 | |
1036 | int btrfs_release_file(struct inode *inode, struct file *filp) |
1037 | { |
1038 | /* |
1039 | * ordered_data_close is set by settattr when we are about to truncate |
1040 | * a file from a non-zero size to a zero size. This tries to |
1041 | * flush down new bytes that may have been written if the |
1042 | * application were using truncate to replace a file in place. |
1043 | */ |
1044 | if (BTRFS_I(inode)->ordered_data_close) { |
1045 | BTRFS_I(inode)->ordered_data_close = 0; |
1046 | btrfs_add_ordered_operation(NULL, BTRFS_I(inode)->root, inode); |
1047 | if (inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT) |
1048 | filemap_flush(inode->i_mapping); |
1049 | } |
1050 | if (filp->private_data) |
1051 | btrfs_ioctl_trans_end(filp); |
1052 | return 0; |
1053 | } |
1054 | |
1055 | /* |
1056 | * fsync call for both files and directories. This logs the inode into |
1057 | * the tree log instead of forcing full commits whenever possible. |
1058 | * |
1059 | * It needs to call filemap_fdatawait so that all ordered extent updates are |
1060 | * in the metadata btree are up to date for copying to the log. |
1061 | * |
1062 | * It drops the inode mutex before doing the tree log commit. This is an |
1063 | * important optimization for directories because holding the mutex prevents |
1064 | * new operations on the dir while we write to disk. |
1065 | */ |
1066 | int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync) |
1067 | { |
1068 | struct inode *inode = dentry->d_inode; |
1069 | struct btrfs_root *root = BTRFS_I(inode)->root; |
1070 | int ret = 0; |
1071 | struct btrfs_trans_handle *trans; |
1072 | |
1073 | |
1074 | /* we wait first, since the writeback may change the inode */ |
1075 | root->log_batch++; |
1076 | /* the VFS called filemap_fdatawrite for us */ |
1077 | btrfs_wait_ordered_range(inode, 0, (u64)-1); |
1078 | root->log_batch++; |
1079 | |
1080 | /* |
1081 | * check the transaction that last modified this inode |
1082 | * and see if its already been committed |
1083 | */ |
1084 | if (!BTRFS_I(inode)->last_trans) |
1085 | goto out; |
1086 | |
1087 | /* |
1088 | * if the last transaction that changed this file was before |
1089 | * the current transaction, we can bail out now without any |
1090 | * syncing |
1091 | */ |
1092 | mutex_lock(&root->fs_info->trans_mutex); |
1093 | if (BTRFS_I(inode)->last_trans <= |
1094 | root->fs_info->last_trans_committed) { |
1095 | BTRFS_I(inode)->last_trans = 0; |
1096 | mutex_unlock(&root->fs_info->trans_mutex); |
1097 | goto out; |
1098 | } |
1099 | mutex_unlock(&root->fs_info->trans_mutex); |
1100 | |
1101 | /* |
1102 | * ok we haven't committed the transaction yet, lets do a commit |
1103 | */ |
1104 | if (file && file->private_data) |
1105 | btrfs_ioctl_trans_end(file); |
1106 | |
1107 | trans = btrfs_start_transaction(root, 1); |
1108 | if (!trans) { |
1109 | ret = -ENOMEM; |
1110 | goto out; |
1111 | } |
1112 | |
1113 | ret = btrfs_log_dentry_safe(trans, root, dentry); |
1114 | if (ret < 0) |
1115 | goto out; |
1116 | |
1117 | /* we've logged all the items and now have a consistent |
1118 | * version of the file in the log. It is possible that |
1119 | * someone will come in and modify the file, but that's |
1120 | * fine because the log is consistent on disk, and we |
1121 | * have references to all of the file's extents |
1122 | * |
1123 | * It is possible that someone will come in and log the |
1124 | * file again, but that will end up using the synchronization |
1125 | * inside btrfs_sync_log to keep things safe. |
1126 | */ |
1127 | mutex_unlock(&dentry->d_inode->i_mutex); |
1128 | |
1129 | if (ret != BTRFS_NO_LOG_SYNC) { |
1130 | if (ret > 0) { |
1131 | ret = btrfs_commit_transaction(trans, root); |
1132 | } else { |
1133 | ret = btrfs_sync_log(trans, root); |
1134 | if (ret == 0) |
1135 | ret = btrfs_end_transaction(trans, root); |
1136 | else |
1137 | ret = btrfs_commit_transaction(trans, root); |
1138 | } |
1139 | } else { |
1140 | ret = btrfs_end_transaction(trans, root); |
1141 | } |
1142 | mutex_lock(&dentry->d_inode->i_mutex); |
1143 | out: |
1144 | return ret > 0 ? -EIO : ret; |
1145 | } |
1146 | |
1147 | static const struct vm_operations_struct btrfs_file_vm_ops = { |
1148 | .fault = filemap_fault, |
1149 | .page_mkwrite = btrfs_page_mkwrite, |
1150 | }; |
1151 | |
1152 | static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma) |
1153 | { |
1154 | vma->vm_ops = &btrfs_file_vm_ops; |
1155 | file_accessed(filp); |
1156 | return 0; |
1157 | } |
1158 | |
1159 | const struct file_operations btrfs_file_operations = { |
1160 | .llseek = generic_file_llseek, |
1161 | .read = do_sync_read, |
1162 | .aio_read = generic_file_aio_read, |
1163 | .splice_read = generic_file_splice_read, |
1164 | .write = btrfs_file_write, |
1165 | .mmap = btrfs_file_mmap, |
1166 | .open = generic_file_open, |
1167 | .release = btrfs_release_file, |
1168 | .fsync = btrfs_sync_file, |
1169 | .unlocked_ioctl = btrfs_ioctl, |
1170 | #ifdef CONFIG_COMPAT |
1171 | .compat_ioctl = btrfs_ioctl, |
1172 | #endif |
1173 | }; |
1174 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
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