projects / deliverable / linux.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Btrfs: New data=ordered implementation
[deliverable/linux.git] / fs / btrfs / file.c
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/smp_lock.h>
26 #include <linux/backing-dev.h>
27 #include <linux/mpage.h>
28 #include <linux/swap.h>
29 #include <linux/writeback.h>
30 #include <linux/statfs.h>
31 #include <linux/compat.h>
32 #include <linux/version.h>
33 #include "ctree.h"
34 #include "disk-io.h"
35 #include "transaction.h"
36 #include "btrfs_inode.h"
37 #include "ioctl.h"
38 #include "print-tree.h"
39 #include "compat.h"
40
41
42 static int btrfs_copy_from_user(loff_t pos, int num_pages, int write_bytes,
43 struct page **prepared_pages,
44 const char __user * buf)
45 {
46 long page_fault = 0;
47 int i;
48 int offset = pos & (PAGE_CACHE_SIZE - 1);
49
50 for (i = 0; i < num_pages && write_bytes > 0; i++, offset = 0) {
51 size_t count = min_t(size_t,
52 PAGE_CACHE_SIZE - offset, write_bytes);
53 struct page *page = prepared_pages[i];
54 fault_in_pages_readable(buf, count);
55
56 /* Copy data from userspace to the current page */
57 kmap(page);
58 page_fault = __copy_from_user(page_address(page) + offset,
59 buf, count);
60 /* Flush processor's dcache for this page */
61 flush_dcache_page(page);
62 kunmap(page);
63 buf += count;
64 write_bytes -= count;
65
66 if (page_fault)
67 break;
68 }
69 return page_fault ? -EFAULT : 0;
70 }
71
72 static void btrfs_drop_pages(struct page **pages, size_t num_pages)
73 {
74 size_t i;
75 for (i = 0; i < num_pages; i++) {
76 if (!pages[i])
77 break;
78 unlock_page(pages[i]);
79 mark_page_accessed(pages[i]);
80 page_cache_release(pages[i]);
81 }
82 }
83
84 static int noinline insert_inline_extent(struct btrfs_trans_handle *trans,
85 struct btrfs_root *root, struct inode *inode,
86 u64 offset, size_t size,
87 struct page **pages, size_t page_offset,
88 int num_pages)
89 {
90 struct btrfs_key key;
91 struct btrfs_path *path;
92 struct extent_buffer *leaf;
93 char *kaddr;
94 unsigned long ptr;
95 struct btrfs_file_extent_item *ei;
96 struct page *page;
97 u32 datasize;
98 int err = 0;
99 int ret;
100 int i;
101 ssize_t cur_size;
102
103 path = btrfs_alloc_path();
104 if (!path)
105 return -ENOMEM;
106
107 btrfs_set_trans_block_group(trans, inode);
108
109 key.objectid = inode->i_ino;
110 key.offset = offset;
111 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
112
113 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
114 if (ret < 0) {
115 err = ret;
116 goto fail;
117 }
118 if (ret == 1) {
119 struct btrfs_key found_key;
120
121 if (path->slots[0] == 0)
122 goto insert;
123
124 path->slots[0]--;
125 leaf = path->nodes[0];
126 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
127
128 if (found_key.objectid != inode->i_ino)
129 goto insert;
130
131 if (found_key.type != BTRFS_EXTENT_DATA_KEY)
132 goto insert;
133 ei = btrfs_item_ptr(leaf, path->slots[0],
134 struct btrfs_file_extent_item);
135
136 if (btrfs_file_extent_type(leaf, ei) !=
137 BTRFS_FILE_EXTENT_INLINE) {
138 goto insert;
139 }
140 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
141 ret = 0;
142 }
143 if (ret == 0) {
144 u32 found_size;
145 u64 found_end;
146
147 leaf = path->nodes[0];
148 ei = btrfs_item_ptr(leaf, path->slots[0],
149 struct btrfs_file_extent_item);
150
151 if (btrfs_file_extent_type(leaf, ei) !=
152 BTRFS_FILE_EXTENT_INLINE) {
153 err = ret;
154 btrfs_print_leaf(root, leaf);
155 printk("found wasn't inline offset %Lu inode %lu\n",
156 offset, inode->i_ino);
157 goto fail;
158 }
159 found_size = btrfs_file_extent_inline_len(leaf,
160 btrfs_item_nr(leaf, path->slots[0]));
161 found_end = key.offset + found_size;
162
163 if (found_end < offset + size) {
164 btrfs_release_path(root, path);
165 ret = btrfs_search_slot(trans, root, &key, path,
166 offset + size - found_end, 1);
167 BUG_ON(ret != 0);
168
169 ret = btrfs_extend_item(trans, root, path,
170 offset + size - found_end);
171 if (ret) {
172 err = ret;
173 goto fail;
174 }
175 leaf = path->nodes[0];
176 ei = btrfs_item_ptr(leaf, path->slots[0],
177 struct btrfs_file_extent_item);
178 inode->i_blocks += (offset + size - found_end) >> 9;
179 }
180 if (found_end < offset) {
181 ptr = btrfs_file_extent_inline_start(ei) + found_size;
182 memset_extent_buffer(leaf, 0, ptr, offset - found_end);
183 }
184 } else {
185 insert:
186 btrfs_release_path(root, path);
187 datasize = offset + size - key.offset;
188 inode->i_blocks += datasize >> 9;
189 datasize = btrfs_file_extent_calc_inline_size(datasize);
190 ret = btrfs_insert_empty_item(trans, root, path, &key,
191 datasize);
192 if (ret) {
193 err = ret;
194 printk("got bad ret %d\n", ret);
195 goto fail;
196 }
197 leaf = path->nodes[0];
198 ei = btrfs_item_ptr(leaf, path->slots[0],
199 struct btrfs_file_extent_item);
200 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
201 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
202 }
203 ptr = btrfs_file_extent_inline_start(ei) + offset - key.offset;
204
205 cur_size = size;
206 i = 0;
207 while (size > 0) {
208 page = pages[i];
209 kaddr = kmap_atomic(page, KM_USER0);
210 cur_size = min_t(size_t, PAGE_CACHE_SIZE - page_offset, size);
211 write_extent_buffer(leaf, kaddr + page_offset, ptr, cur_size);
212 kunmap_atomic(kaddr, KM_USER0);
213 page_offset = 0;
214 ptr += cur_size;
215 size -= cur_size;
216 if (i >= num_pages) {
217 printk("i %d num_pages %d\n", i, num_pages);
218 }
219 i++;
220 }
221 btrfs_mark_buffer_dirty(leaf);
222 fail:
223 btrfs_free_path(path);
224 return err;
225 }
226
227 static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
228 struct btrfs_root *root,
229 struct file *file,
230 struct page **pages,
231 size_t num_pages,
232 loff_t pos,
233 size_t write_bytes)
234 {
235 int err = 0;
236 int i;
237 struct inode *inode = fdentry(file)->d_inode;
238 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
239 u64 hint_byte;
240 u64 num_bytes;
241 u64 start_pos;
242 u64 end_of_last_block;
243 u64 end_pos = pos + write_bytes;
244 u64 inline_size;
245 loff_t isize = i_size_read(inode);
246
247 start_pos = pos & ~((u64)root->sectorsize - 1);
248 num_bytes = (write_bytes + pos - start_pos +
249 root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
250
251 end_of_last_block = start_pos + num_bytes - 1;
252
253 lock_extent(io_tree, start_pos, end_of_last_block, GFP_NOFS);
254 trans = btrfs_start_transaction(root, 1);
255 if (!trans) {
256 err = -ENOMEM;
257 goto out_unlock;
258 }
259 btrfs_set_trans_block_group(trans, inode);
260 hint_byte = 0;
261
262 if ((end_of_last_block & 4095) == 0) {
263 printk("strange end of last %Lu %zu %Lu\n", start_pos, write_bytes, end_of_last_block);
264 }
265 set_extent_uptodate(io_tree, start_pos, end_of_last_block, GFP_NOFS);
266
267 /* FIXME...EIEIO, ENOSPC and more */
268 /* insert any holes we need to create */
269 if (isize < start_pos) {
270 u64 last_pos_in_file;
271 u64 hole_size;
272 u64 mask = root->sectorsize - 1;
273 last_pos_in_file = (isize + mask) & ~mask;
274 hole_size = (start_pos - last_pos_in_file + mask) & ~mask;
275 if (hole_size > 0) {
276 btrfs_wait_ordered_range(inode, last_pos_in_file,
277 last_pos_in_file + hole_size);
278 err = btrfs_drop_extents(trans, root, inode,
279 last_pos_in_file,
280 last_pos_in_file + hole_size,
281 last_pos_in_file,
282 &hint_byte);
283 if (err)
284 goto failed;
285
286 err = btrfs_insert_file_extent(trans, root,
287 inode->i_ino,
288 last_pos_in_file,
289 0, 0, hole_size, 0);
290 btrfs_drop_extent_cache(inode, last_pos_in_file,
291 last_pos_in_file + hole_size -1);
292 btrfs_check_file(root, inode);
293 }
294 if (err)
295 goto failed;
296 }
297
298 /*
299 * either allocate an extent for the new bytes or setup the key
300 * to show we are doing inline data in the extent
301 */
302 inline_size = end_pos;
303 if (isize >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
304 inline_size > root->fs_info->max_inline ||
305 (inline_size & (root->sectorsize -1)) == 0 ||
306 inline_size >= BTRFS_MAX_INLINE_DATA_SIZE(root)) {
307 /* check for reserved extents on each page, we don't want
308 * to reset the delalloc bit on things that already have
309 * extents reserved.
310 */
311 set_extent_delalloc(io_tree, start_pos,
312 end_of_last_block, GFP_NOFS);
313 for (i = 0; i < num_pages; i++) {
314 struct page *p = pages[i];
315 SetPageUptodate(p);
316 set_page_dirty(p);
317 }
318 } else {
319 u64 aligned_end;
320 /* step one, delete the existing extents in this range */
321 aligned_end = (pos + write_bytes + root->sectorsize - 1) &
322 ~((u64)root->sectorsize - 1);
323 err = btrfs_drop_extents(trans, root, inode, start_pos,
324 aligned_end, aligned_end, &hint_byte);
325 if (err)
326 goto failed;
327 if (isize > inline_size)
328 inline_size = min_t(u64, isize, aligned_end);
329 inline_size -= start_pos;
330 err = insert_inline_extent(trans, root, inode, start_pos,
331 inline_size, pages, 0, num_pages);
332 btrfs_drop_extent_cache(inode, start_pos, aligned_end - 1);
333 BUG_ON(err);
334 }
335 if (end_pos > isize) {
336 i_size_write(inode, end_pos);
337 btrfs_update_inode(trans, root, inode);
338 }
339 failed:
340 err = btrfs_end_transaction(trans, root);
341 out_unlock:
342 unlock_extent(io_tree, start_pos, end_of_last_block, GFP_NOFS);
343 return err;
344 }
345
346 int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end)
347 {
348 struct extent_map *em;
349 struct extent_map *split = NULL;
350 struct extent_map *split2 = NULL;
351 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
352 struct extent_map *tmp;
353 u64 len = end - start + 1;
354 u64 next_start;
355 int ret;
356 int testend = 1;
357
358 WARN_ON(end < start);
359 if (end == (u64)-1) {
360 len = (u64)-1;
361 testend = 0;
362 }
363 while(1) {
364 if (!split)
365 split = alloc_extent_map(GFP_NOFS);
366 if (!split2)
367 split2 = alloc_extent_map(GFP_NOFS);
368
369 spin_lock(&em_tree->lock);
370 em = lookup_extent_mapping(em_tree, start, len);
371 if (!em) {
372 spin_unlock(&em_tree->lock);
373 break;
374 }
375 tmp = rb_entry(&em->rb_node, struct extent_map, rb_node);
376 next_start = tmp->start;
377 remove_extent_mapping(em_tree, em);
378
379 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
380 em->start < start) {
381 split->start = em->start;
382 split->len = start - em->start;
383 split->block_start = em->block_start;
384 split->bdev = em->bdev;
385 split->flags = em->flags;
386 ret = add_extent_mapping(em_tree, split);
387 BUG_ON(ret);
388 free_extent_map(split);
389 split = split2;
390 split2 = NULL;
391 }
392 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
393 testend && em->start + em->len > start + len) {
394 u64 diff = start + len - em->start;
395
396 split->start = start + len;
397 split->len = em->start + em->len - (start + len);
398 split->bdev = em->bdev;
399 split->flags = em->flags;
400
401 split->block_start = em->block_start + diff;
402
403 ret = add_extent_mapping(em_tree, split);
404 BUG_ON(ret);
405 free_extent_map(split);
406 split = NULL;
407 }
408 spin_unlock(&em_tree->lock);
409
410 /* once for us */
411 free_extent_map(em);
412 /* once for the tree*/
413 free_extent_map(em);
414 }
415 if (split)
416 free_extent_map(split);
417 if (split2)
418 free_extent_map(split2);
419 return 0;
420 }
421
422 int btrfs_check_file(struct btrfs_root *root, struct inode *inode)
423 {
424 return 0;
425 #if 0
426 struct btrfs_path *path;
427 struct btrfs_key found_key;
428 struct extent_buffer *leaf;
429 struct btrfs_file_extent_item *extent;
430 u64 last_offset = 0;
431 int nritems;
432 int slot;
433 int found_type;
434 int ret;
435 int err = 0;
436 u64 extent_end = 0;
437
438 path = btrfs_alloc_path();
439 ret = btrfs_lookup_file_extent(NULL, root, path, inode->i_ino,
440 last_offset, 0);
441 while(1) {
442 nritems = btrfs_header_nritems(path->nodes[0]);
443 if (path->slots[0] >= nritems) {
444 ret = btrfs_next_leaf(root, path);
445 if (ret)
446 goto out;
447 nritems = btrfs_header_nritems(path->nodes[0]);
448 }
449 slot = path->slots[0];
450 leaf = path->nodes[0];
451 btrfs_item_key_to_cpu(leaf, &found_key, slot);
452 if (found_key.objectid != inode->i_ino)
453 break;
454 if (found_key.type != BTRFS_EXTENT_DATA_KEY)
455 goto out;
456
457 if (found_key.offset < last_offset) {
458 WARN_ON(1);
459 btrfs_print_leaf(root, leaf);
460 printk("inode %lu found offset %Lu expected %Lu\n",
461 inode->i_ino, found_key.offset, last_offset);
462 err = 1;
463 goto out;
464 }
465 extent = btrfs_item_ptr(leaf, slot,
466 struct btrfs_file_extent_item);
467 found_type = btrfs_file_extent_type(leaf, extent);
468 if (found_type == BTRFS_FILE_EXTENT_REG) {
469 extent_end = found_key.offset +
470 btrfs_file_extent_num_bytes(leaf, extent);
471 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
472 struct btrfs_item *item;
473 item = btrfs_item_nr(leaf, slot);
474 extent_end = found_key.offset +
475 btrfs_file_extent_inline_len(leaf, item);
476 extent_end = (extent_end + root->sectorsize - 1) &
477 ~((u64)root->sectorsize -1 );
478 }
479 last_offset = extent_end;
480 path->slots[0]++;
481 }
482 if (0 && last_offset < inode->i_size) {
483 WARN_ON(1);
484 btrfs_print_leaf(root, leaf);
485 printk("inode %lu found offset %Lu size %Lu\n", inode->i_ino,
486 last_offset, inode->i_size);
487 err = 1;
488
489 }
490 out:
491 btrfs_free_path(path);
492 return err;
493 #endif
494 }
495
496 /*
497 * this is very complex, but the basic idea is to drop all extents
498 * in the range start - end. hint_block is filled in with a block number
499 * that would be a good hint to the block allocator for this file.
500 *
501 * If an extent intersects the range but is not entirely inside the range
502 * it is either truncated or split. Anything entirely inside the range
503 * is deleted from the tree.
504 */
505 int btrfs_drop_extents(struct btrfs_trans_handle *trans,
506 struct btrfs_root *root, struct inode *inode,
507 u64 start, u64 end, u64 inline_limit, u64 *hint_byte)
508 {
509 u64 extent_end = 0;
510 u64 search_start = start;
511 struct extent_buffer *leaf;
512 struct btrfs_file_extent_item *extent;
513 struct btrfs_path *path;
514 struct btrfs_key key;
515 struct btrfs_file_extent_item old;
516 int keep;
517 int slot;
518 int bookend;
519 int found_type;
520 int found_extent;
521 int found_inline;
522 int recow;
523 int ret;
524
525 btrfs_drop_extent_cache(inode, start, end - 1);
526
527 path = btrfs_alloc_path();
528 if (!path)
529 return -ENOMEM;
530 while(1) {
531 recow = 0;
532 btrfs_release_path(root, path);
533 ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
534 search_start, -1);
535 if (ret < 0)
536 goto out;
537 if (ret > 0) {
538 if (path->slots[0] == 0) {
539 ret = 0;
540 goto out;
541 }
542 path->slots[0]--;
543 }
544 next_slot:
545 keep = 0;
546 bookend = 0;
547 found_extent = 0;
548 found_inline = 0;
549 extent = NULL;
550 leaf = path->nodes[0];
551 slot = path->slots[0];
552 ret = 0;
553 btrfs_item_key_to_cpu(leaf, &key, slot);
554 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY &&
555 key.offset >= end) {
556 goto out;
557 }
558 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
559 key.objectid != inode->i_ino) {
560 goto out;
561 }
562 if (recow) {
563 search_start = key.offset;
564 continue;
565 }
566 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
567 extent = btrfs_item_ptr(leaf, slot,
568 struct btrfs_file_extent_item);
569 found_type = btrfs_file_extent_type(leaf, extent);
570 if (found_type == BTRFS_FILE_EXTENT_REG) {
571 extent_end =
572 btrfs_file_extent_disk_bytenr(leaf,
573 extent);
574 if (extent_end)
575 *hint_byte = extent_end;
576
577 extent_end = key.offset +
578 btrfs_file_extent_num_bytes(leaf, extent);
579 found_extent = 1;
580 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
581 struct btrfs_item *item;
582 item = btrfs_item_nr(leaf, slot);
583 found_inline = 1;
584 extent_end = key.offset +
585 btrfs_file_extent_inline_len(leaf, item);
586 }
587 } else {
588 extent_end = search_start;
589 }
590
591 /* we found nothing we can drop */
592 if ((!found_extent && !found_inline) ||
593 search_start >= extent_end) {
594 int nextret;
595 u32 nritems;
596 nritems = btrfs_header_nritems(leaf);
597 if (slot >= nritems - 1) {
598 nextret = btrfs_next_leaf(root, path);
599 if (nextret)
600 goto out;
601 recow = 1;
602 } else {
603 path->slots[0]++;
604 }
605 goto next_slot;
606 }
607
608 if (found_inline) {
609 u64 mask = root->sectorsize - 1;
610 search_start = (extent_end + mask) & ~mask;
611 } else
612 search_start = extent_end;
613 if (end <= extent_end && start >= key.offset && found_inline) {
614 *hint_byte = EXTENT_MAP_INLINE;
615 continue;
616 }
617 if (end < extent_end && end >= key.offset) {
618 if (found_extent) {
619 u64 disk_bytenr =
620 btrfs_file_extent_disk_bytenr(leaf, extent);
621 u64 disk_num_bytes =
622 btrfs_file_extent_disk_num_bytes(leaf,
623 extent);
624 read_extent_buffer(leaf, &old,
625 (unsigned long)extent,
626 sizeof(old));
627 if (disk_bytenr != 0) {
628 ret = btrfs_inc_extent_ref(trans, root,
629 disk_bytenr, disk_num_bytes,
630 root->root_key.objectid,
631 trans->transid,
632 key.objectid, end);
633 BUG_ON(ret);
634 }
635 }
636 bookend = 1;
637 if (found_inline && start <= key.offset)
638 keep = 1;
639 }
640 /* truncate existing extent */
641 if (start > key.offset) {
642 u64 new_num;
643 u64 old_num;
644 keep = 1;
645 WARN_ON(start & (root->sectorsize - 1));
646 if (found_extent) {
647 new_num = start - key.offset;
648 old_num = btrfs_file_extent_num_bytes(leaf,
649 extent);
650 *hint_byte =
651 btrfs_file_extent_disk_bytenr(leaf,
652 extent);
653 if (btrfs_file_extent_disk_bytenr(leaf,
654 extent)) {
655 dec_i_blocks(inode, old_num - new_num);
656 }
657 btrfs_set_file_extent_num_bytes(leaf, extent,
658 new_num);
659 btrfs_mark_buffer_dirty(leaf);
660 } else if (key.offset < inline_limit &&
661 (end > extent_end) &&
662 (inline_limit < extent_end)) {
663 u32 new_size;
664 new_size = btrfs_file_extent_calc_inline_size(
665 inline_limit - key.offset);
666 dec_i_blocks(inode, (extent_end - key.offset) -
667 (inline_limit - key.offset));
668 btrfs_truncate_item(trans, root, path,
669 new_size, 1);
670 }
671 }
672 /* delete the entire extent */
673 if (!keep) {
674 u64 disk_bytenr = 0;
675 u64 disk_num_bytes = 0;
676 u64 extent_num_bytes = 0;
677 u64 root_gen;
678 u64 root_owner;
679
680 root_gen = btrfs_header_generation(leaf);
681 root_owner = btrfs_header_owner(leaf);
682 if (found_extent) {
683 disk_bytenr =
684 btrfs_file_extent_disk_bytenr(leaf,
685 extent);
686 disk_num_bytes =
687 btrfs_file_extent_disk_num_bytes(leaf,
688 extent);
689 extent_num_bytes =
690 btrfs_file_extent_num_bytes(leaf, extent);
691 *hint_byte =
692 btrfs_file_extent_disk_bytenr(leaf,
693 extent);
694 }
695 ret = btrfs_del_item(trans, root, path);
696 /* TODO update progress marker and return */
697 BUG_ON(ret);
698 btrfs_release_path(root, path);
699 extent = NULL;
700 if (found_extent && disk_bytenr != 0) {
701 dec_i_blocks(inode, extent_num_bytes);
702 ret = btrfs_free_extent(trans, root,
703 disk_bytenr,
704 disk_num_bytes,
705 root_owner,
706 root_gen, inode->i_ino,
707 key.offset, 0);
708 }
709
710 BUG_ON(ret);
711 if (!bookend && search_start >= end) {
712 ret = 0;
713 goto out;
714 }
715 if (!bookend)
716 continue;
717 }
718 if (bookend && found_inline && start <= key.offset) {
719 u32 new_size;
720 new_size = btrfs_file_extent_calc_inline_size(
721 extent_end - end);
722 dec_i_blocks(inode, (extent_end - key.offset) -
723 (extent_end - end));
724 btrfs_truncate_item(trans, root, path, new_size, 0);
725 }
726 /* create bookend, splitting the extent in two */
727 if (bookend && found_extent) {
728 struct btrfs_key ins;
729 ins.objectid = inode->i_ino;
730 ins.offset = end;
731 btrfs_set_key_type(&ins, BTRFS_EXTENT_DATA_KEY);
732 btrfs_release_path(root, path);
733 ret = btrfs_insert_empty_item(trans, root, path, &ins,
734 sizeof(*extent));
735
736 leaf = path->nodes[0];
737 if (ret) {
738 btrfs_print_leaf(root, leaf);
739 printk("got %d on inserting %Lu %u %Lu start %Lu end %Lu found %Lu %Lu keep was %d\n", ret , ins.objectid, ins.type, ins.offset, start, end, key.offset, extent_end, keep);
740 }
741 BUG_ON(ret);
742 extent = btrfs_item_ptr(leaf, path->slots[0],
743 struct btrfs_file_extent_item);
744 write_extent_buffer(leaf, &old,
745 (unsigned long)extent, sizeof(old));
746
747 btrfs_set_file_extent_offset(leaf, extent,
748 le64_to_cpu(old.offset) + end - key.offset);
749 WARN_ON(le64_to_cpu(old.num_bytes) <
750 (extent_end - end));
751 btrfs_set_file_extent_num_bytes(leaf, extent,
752 extent_end - end);
753 btrfs_set_file_extent_type(leaf, extent,
754 BTRFS_FILE_EXTENT_REG);
755
756 btrfs_mark_buffer_dirty(path->nodes[0]);
757 if (le64_to_cpu(old.disk_bytenr) != 0) {
758 inode->i_blocks +=
759 btrfs_file_extent_num_bytes(leaf,
760 extent) >> 9;
761 }
762 ret = 0;
763 goto out;
764 }
765 }
766 out:
767 btrfs_free_path(path);
768 btrfs_check_file(root, inode);
769 return ret;
770 }
771
772 /*
773 * this gets pages into the page cache and locks them down
774 */
775 static int prepare_pages(struct btrfs_root *root, struct file *file,
776 struct page **pages, size_t num_pages,
777 loff_t pos, unsigned long first_index,
778 unsigned long last_index, size_t write_bytes)
779 {
780 int i;
781 unsigned long index = pos >> PAGE_CACHE_SHIFT;
782 struct inode *inode = fdentry(file)->d_inode;
783 int err = 0;
784 u64 start_pos;
785 u64 last_pos;
786
787 start_pos = pos & ~((u64)root->sectorsize - 1);
788 last_pos = ((u64)index + num_pages) << PAGE_CACHE_SHIFT;
789
790 memset(pages, 0, num_pages * sizeof(struct page *));
791 again:
792 for (i = 0; i < num_pages; i++) {
793 pages[i] = grab_cache_page(inode->i_mapping, index + i);
794 if (!pages[i]) {
795 err = -ENOMEM;
796 BUG_ON(1);
797 }
798 wait_on_page_writeback(pages[i]);
799 }
800 if (start_pos < inode->i_size) {
801 struct btrfs_ordered_extent *ordered;
802 lock_extent(&BTRFS_I(inode)->io_tree,
803 start_pos, last_pos - 1, GFP_NOFS);
804 ordered = btrfs_lookup_first_ordered_extent(inode, last_pos -1);
805 if (ordered &&
806 ordered->file_offset + ordered->len > start_pos &&
807 ordered->file_offset < last_pos) {
808 btrfs_put_ordered_extent(ordered);
809 unlock_extent(&BTRFS_I(inode)->io_tree,
810 start_pos, last_pos - 1, GFP_NOFS);
811 for (i = 0; i < num_pages; i++) {
812 unlock_page(pages[i]);
813 page_cache_release(pages[i]);
814 }
815 btrfs_wait_ordered_range(inode, start_pos,
816 last_pos - start_pos);
817 goto again;
818 }
819 if (ordered)
820 btrfs_put_ordered_extent(ordered);
821
822 clear_extent_bits(&BTRFS_I(inode)->io_tree, start_pos,
823 last_pos - 1, EXTENT_DIRTY | EXTENT_DELALLOC,
824 GFP_NOFS);
825 unlock_extent(&BTRFS_I(inode)->io_tree,
826 start_pos, last_pos - 1, GFP_NOFS);
827 }
828 for (i = 0; i < num_pages; i++) {
829 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
830 ClearPageDirty(pages[i]);
831 #else
832 cancel_dirty_page(pages[i], PAGE_CACHE_SIZE);
833 #endif
834 set_page_extent_mapped(pages[i]);
835 WARN_ON(!PageLocked(pages[i]));
836 }
837 return 0;
838 }
839
840 static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
841 size_t count, loff_t *ppos)
842 {
843 loff_t pos;
844 loff_t start_pos;
845 ssize_t num_written = 0;
846 ssize_t err = 0;
847 int ret = 0;
848 struct inode *inode = fdentry(file)->d_inode;
849 struct btrfs_root *root = BTRFS_I(inode)->root;
850 struct page **pages = NULL;
851 int nrptrs;
852 struct page *pinned[2];
853 unsigned long first_index;
854 unsigned long last_index;
855
856 nrptrs = min((count + PAGE_CACHE_SIZE - 1) / PAGE_CACHE_SIZE,
857 PAGE_CACHE_SIZE / (sizeof(struct page *)));
858 pinned[0] = NULL;
859 pinned[1] = NULL;
860
861 pos = *ppos;
862 start_pos = pos;
863
864 vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
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_nolock;
869 if (count == 0)
870 goto out_nolock;
871 #ifdef REMOVE_SUID_PATH
872 err = remove_suid(&file->f_path);
873 #else
874 err = remove_suid(fdentry(file));
875 #endif
876 if (err)
877 goto out_nolock;
878 file_update_time(file);
879
880 pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
881
882 mutex_lock(&inode->i_mutex);
883 first_index = pos >> PAGE_CACHE_SHIFT;
884 last_index = (pos + count) >> PAGE_CACHE_SHIFT;
885
886 /*
887 * if this is a nodatasum mount, force summing off for the inode
888 * all the time. That way a later mount with summing on won't
889 * get confused
890 */
891 if (btrfs_test_opt(root, NODATASUM))
892 btrfs_set_flag(inode, NODATASUM);
893
894 /*
895 * there are lots of better ways to do this, but this code
896 * makes sure the first and last page in the file range are
897 * up to date and ready for cow
898 */
899 if ((pos & (PAGE_CACHE_SIZE - 1))) {
900 pinned[0] = grab_cache_page(inode->i_mapping, first_index);
901 if (!PageUptodate(pinned[0])) {
902 ret = btrfs_readpage(NULL, pinned[0]);
903 BUG_ON(ret);
904 wait_on_page_locked(pinned[0]);
905 } else {
906 unlock_page(pinned[0]);
907 }
908 }
909 if ((pos + count) & (PAGE_CACHE_SIZE - 1)) {
910 pinned[1] = grab_cache_page(inode->i_mapping, last_index);
911 if (!PageUptodate(pinned[1])) {
912 ret = btrfs_readpage(NULL, pinned[1]);
913 BUG_ON(ret);
914 wait_on_page_locked(pinned[1]);
915 } else {
916 unlock_page(pinned[1]);
917 }
918 }
919
920 while(count > 0) {
921 size_t offset = pos & (PAGE_CACHE_SIZE - 1);
922 size_t write_bytes = min(count, nrptrs *
923 (size_t)PAGE_CACHE_SIZE -
924 offset);
925 size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >>
926 PAGE_CACHE_SHIFT;
927
928 WARN_ON(num_pages > nrptrs);
929 memset(pages, 0, sizeof(pages));
930
931 ret = btrfs_check_free_space(root, write_bytes, 0);
932 if (ret)
933 goto out;
934
935 ret = prepare_pages(root, file, pages, num_pages,
936 pos, first_index, last_index,
937 write_bytes);
938 if (ret)
939 goto out;
940
941 ret = btrfs_copy_from_user(pos, num_pages,
942 write_bytes, pages, buf);
943 if (ret) {
944 btrfs_drop_pages(pages, num_pages);
945 goto out;
946 }
947
948 ret = dirty_and_release_pages(NULL, root, file, pages,
949 num_pages, pos, write_bytes);
950 btrfs_drop_pages(pages, num_pages);
951 if (ret)
952 goto out;
953
954 buf += write_bytes;
955 count -= write_bytes;
956 pos += write_bytes;
957 num_written += write_bytes;
958
959 balance_dirty_pages_ratelimited_nr(inode->i_mapping, num_pages);
960 if (num_pages < (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
961 btrfs_btree_balance_dirty(root, 1);
962 cond_resched();
963 }
964 out:
965 mutex_unlock(&inode->i_mutex);
966
967 out_nolock:
968 kfree(pages);
969 if (pinned[0])
970 page_cache_release(pinned[0]);
971 if (pinned[1])
972 page_cache_release(pinned[1]);
973 *ppos = pos;
974
975 if (num_written > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
976 err = sync_page_range(inode, inode->i_mapping,
977 start_pos, num_written);
978 if (err < 0)
979 num_written = err;
980 } else if (num_written > 0 && (file->f_flags & O_DIRECT)) {
981 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
982 do_sync_file_range(file, start_pos,
983 start_pos + num_written - 1,
984 SYNC_FILE_RANGE_WRITE |
985 SYNC_FILE_RANGE_WAIT_AFTER);
986 #else
987 do_sync_mapping_range(inode->i_mapping, start_pos,
988 start_pos + num_written - 1,
989 SYNC_FILE_RANGE_WRITE |
990 SYNC_FILE_RANGE_WAIT_AFTER);
991 #endif
992 invalidate_mapping_pages(inode->i_mapping,
993 start_pos >> PAGE_CACHE_SHIFT,
994 (start_pos + num_written - 1) >> PAGE_CACHE_SHIFT);
995 }
996 current->backing_dev_info = NULL;
997 return num_written ? num_written : err;
998 }
999
1000 int btrfs_release_file(struct inode * inode, struct file * filp)
1001 {
1002 if (filp->private_data)
1003 btrfs_ioctl_trans_end(filp);
1004 return 0;
1005 }
1006
1007 static int btrfs_sync_file(struct file *file,
1008 struct dentry *dentry, int datasync)
1009 {
1010 struct inode *inode = dentry->d_inode;
1011 struct btrfs_root *root = BTRFS_I(inode)->root;
1012 int ret = 0;
1013 struct btrfs_trans_handle *trans;
1014
1015 /*
1016 * check the transaction that last modified this inode
1017 * and see if its already been committed
1018 */
1019 if (!BTRFS_I(inode)->last_trans)
1020 goto out;
1021
1022 mutex_lock(&root->fs_info->trans_mutex);
1023 if (BTRFS_I(inode)->last_trans <=
1024 root->fs_info->last_trans_committed) {
1025 BTRFS_I(inode)->last_trans = 0;
1026 mutex_unlock(&root->fs_info->trans_mutex);
1027 goto out;
1028 }
1029 mutex_unlock(&root->fs_info->trans_mutex);
1030
1031 /*
1032 * ok we haven't committed the transaction yet, lets do a commit
1033 */
1034 if (file->private_data)
1035 btrfs_ioctl_trans_end(file);
1036
1037 trans = btrfs_start_transaction(root, 1);
1038 if (!trans) {
1039 ret = -ENOMEM;
1040 goto out;
1041 }
1042 ret = btrfs_commit_transaction(trans, root);
1043 out:
1044 return ret > 0 ? EIO : ret;
1045 }
1046
1047 static struct vm_operations_struct btrfs_file_vm_ops = {
1048 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
1049 .nopage = filemap_nopage,
1050 .populate = filemap_populate,
1051 #else
1052 .fault = filemap_fault,
1053 #endif
1054 .page_mkwrite = btrfs_page_mkwrite,
1055 };
1056
1057 static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
1058 {
1059 vma->vm_ops = &btrfs_file_vm_ops;
1060 file_accessed(filp);
1061 return 0;
1062 }
1063
1064 struct file_operations btrfs_file_operations = {
1065 .llseek = generic_file_llseek,
1066 .read = do_sync_read,
1067 .aio_read = generic_file_aio_read,
1068 .splice_read = generic_file_splice_read,
1069 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
1070 .sendfile = generic_file_sendfile,
1071 #endif
1072 .write = btrfs_file_write,
1073 .mmap = btrfs_file_mmap,
1074 .open = generic_file_open,
1075 .release = btrfs_release_file,
1076 .fsync = btrfs_sync_file,
1077 .unlocked_ioctl = btrfs_ioctl,
1078 #ifdef CONFIG_COMPAT
1079 .compat_ioctl = btrfs_ioctl,
1080 #endif
1081 };
1082
Linux kernel - Deliverables
This page took 0.053621 seconds and 5 git commands to generate.