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Btrfs: Drop some debugging around the extent_map pinned flag
[linux-2.6/btrfs-unstable.git] / fs / btrfs / file.c
blobc78f184ee5cc5a22f4c227c4a2e8f4ff67dba222
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 ClearPageChecked(pages[i]);
79 unlock_page(pages[i]);
80 mark_page_accessed(pages[i]);
81 page_cache_release(pages[i]);
82 }
83 }
84
85 static int noinline insert_inline_extent(struct btrfs_trans_handle *trans,
86 struct btrfs_root *root, struct inode *inode,
87 u64 offset, size_t size,
88 struct page **pages, size_t page_offset,
89 int num_pages)
90 {
91 struct btrfs_key key;
92 struct btrfs_path *path;
93 struct extent_buffer *leaf;
94 char *kaddr;
95 unsigned long ptr;
96 struct btrfs_file_extent_item *ei;
97 struct page *page;
98 u32 datasize;
99 int err = 0;
100 int ret;
101 int i;
102 ssize_t cur_size;
103
104 path = btrfs_alloc_path();
105 if (!path)
106 return -ENOMEM;
107
108 btrfs_set_trans_block_group(trans, inode);
109
110 key.objectid = inode->i_ino;
111 key.offset = offset;
112 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
113
114 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
115 if (ret < 0) {
116 err = ret;
117 goto fail;
118 }
119 if (ret == 1) {
120 struct btrfs_key found_key;
121
122 if (path->slots[0] == 0)
123 goto insert;
124
125 path->slots[0]--;
126 leaf = path->nodes[0];
127 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
128
129 if (found_key.objectid != inode->i_ino)
130 goto insert;
131
132 if (found_key.type != BTRFS_EXTENT_DATA_KEY)
133 goto insert;
134 ei = btrfs_item_ptr(leaf, path->slots[0],
135 struct btrfs_file_extent_item);
136
137 if (btrfs_file_extent_type(leaf, ei) !=
138 BTRFS_FILE_EXTENT_INLINE) {
139 goto insert;
140 }
141 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
142 ret = 0;
143 }
144 if (ret == 0) {
145 u32 found_size;
146 u64 found_end;
147
148 leaf = path->nodes[0];
149 ei = btrfs_item_ptr(leaf, path->slots[0],
150 struct btrfs_file_extent_item);
151
152 if (btrfs_file_extent_type(leaf, ei) !=
153 BTRFS_FILE_EXTENT_INLINE) {
154 err = ret;
155 btrfs_print_leaf(root, leaf);
156 printk("found wasn't inline offset %Lu inode %lu\n",
157 offset, inode->i_ino);
158 goto fail;
159 }
160 found_size = btrfs_file_extent_inline_len(leaf,
161 btrfs_item_nr(leaf, path->slots[0]));
162 found_end = key.offset + found_size;
163
164 if (found_end < offset + size) {
165 btrfs_release_path(root, path);
166 ret = btrfs_search_slot(trans, root, &key, path,
167 offset + size - found_end, 1);
168 BUG_ON(ret != 0);
169
170 ret = btrfs_extend_item(trans, root, path,
171 offset + size - found_end);
172 if (ret) {
173 err = ret;
174 goto fail;
175 }
176 leaf = path->nodes[0];
177 ei = btrfs_item_ptr(leaf, path->slots[0],
178 struct btrfs_file_extent_item);
179 inode->i_blocks += (offset + size - found_end) >> 9;
180 }
181 if (found_end < offset) {
182 ptr = btrfs_file_extent_inline_start(ei) + found_size;
183 memset_extent_buffer(leaf, 0, ptr, offset - found_end);
184 }
185 } else {
186 insert:
187 btrfs_release_path(root, path);
188 datasize = offset + size - key.offset;
189 inode->i_blocks += datasize >> 9;
190 datasize = btrfs_file_extent_calc_inline_size(datasize);
191 ret = btrfs_insert_empty_item(trans, root, path, &key,
192 datasize);
193 if (ret) {
194 err = ret;
195 printk("got bad ret %d\n", ret);
196 goto fail;
197 }
198 leaf = path->nodes[0];
199 ei = btrfs_item_ptr(leaf, path->slots[0],
200 struct btrfs_file_extent_item);
201 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
202 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
203 }
204 ptr = btrfs_file_extent_inline_start(ei) + offset - key.offset;
205
206 cur_size = size;
207 i = 0;
208 while (size > 0) {
209 page = pages[i];
210 kaddr = kmap_atomic(page, KM_USER0);
211 cur_size = min_t(size_t, PAGE_CACHE_SIZE - page_offset, size);
212 write_extent_buffer(leaf, kaddr + page_offset, ptr, cur_size);
213 kunmap_atomic(kaddr, KM_USER0);
214 page_offset = 0;
215 ptr += cur_size;
216 size -= cur_size;
217 if (i >= num_pages) {
218 printk("i %d num_pages %d\n", i, num_pages);
219 }
220 i++;
221 }
222 btrfs_mark_buffer_dirty(leaf);
223 fail:
224 btrfs_free_path(path);
225 return err;
226 }
227
228 static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
229 struct btrfs_root *root,
230 struct file *file,
231 struct page **pages,
232 size_t num_pages,
233 loff_t pos,
234 size_t write_bytes)
235 {
236 int err = 0;
237 int i;
238 struct inode *inode = fdentry(file)->d_inode;
239 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
240 u64 hint_byte;
241 u64 num_bytes;
242 u64 start_pos;
243 u64 end_of_last_block;
244 u64 end_pos = pos + write_bytes;
245 u64 inline_size;
246 int did_inline = 0;
247 loff_t isize = i_size_read(inode);
248
249 start_pos = pos & ~((u64)root->sectorsize - 1);
250 num_bytes = (write_bytes + pos - start_pos +
251 root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
252
253 end_of_last_block = start_pos + num_bytes - 1;
254
255 lock_extent(io_tree, start_pos, end_of_last_block, GFP_NOFS);
256 trans = btrfs_join_transaction(root, 1);
257 if (!trans) {
258 err = -ENOMEM;
259 goto out_unlock;
260 }
261 btrfs_set_trans_block_group(trans, inode);
262 hint_byte = 0;
263
264 if ((end_of_last_block & 4095) == 0) {
265 printk("strange end of last %Lu %zu %Lu\n", start_pos, write_bytes, end_of_last_block);
266 }
267 set_extent_uptodate(io_tree, start_pos, end_of_last_block, GFP_NOFS);
268
269 /* FIXME...EIEIO, ENOSPC and more */
270 /* insert any holes we need to create */
271 if (isize < start_pos) {
272 u64 last_pos_in_file;
273 u64 hole_size;
274 u64 mask = root->sectorsize - 1;
275 last_pos_in_file = (isize + mask) & ~mask;
276 hole_size = (start_pos - last_pos_in_file + mask) & ~mask;
277 if (hole_size > 0) {
278 btrfs_wait_ordered_range(inode, last_pos_in_file,
279 last_pos_in_file + hole_size);
280 mutex_lock(&BTRFS_I(inode)->extent_mutex);
281 err = btrfs_drop_extents(trans, root, inode,
282 last_pos_in_file,
283 last_pos_in_file + hole_size,
284 last_pos_in_file,
285 &hint_byte);
286 if (err)
287 goto failed;
288
289 err = btrfs_insert_file_extent(trans, root,
290 inode->i_ino,
291 last_pos_in_file,
292 0, 0, hole_size, 0);
293 btrfs_drop_extent_cache(inode, last_pos_in_file,
294 last_pos_in_file + hole_size -1);
295 mutex_unlock(&BTRFS_I(inode)->extent_mutex);
296 btrfs_check_file(root, inode);
297 }
298 if (err)
299 goto failed;
300 }
301
302 /*
303 * either allocate an extent for the new bytes or setup the key
304 * to show we are doing inline data in the extent
305 */
306 inline_size = end_pos;
307 if (isize >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
308 inline_size > root->fs_info->max_inline ||
309 (inline_size & (root->sectorsize -1)) == 0 ||
310 inline_size >= BTRFS_MAX_INLINE_DATA_SIZE(root)) {
311 /* check for reserved extents on each page, we don't want
312 * to reset the delalloc bit on things that already have
313 * extents reserved.
314 */
315 set_extent_delalloc(io_tree, start_pos,
316 end_of_last_block, GFP_NOFS);
317 for (i = 0; i < num_pages; i++) {
318 struct page *p = pages[i];
319 SetPageUptodate(p);
320 ClearPageChecked(p);
321 set_page_dirty(p);
322 }
323 } else {
324 u64 aligned_end;
325 /* step one, delete the existing extents in this range */
326 aligned_end = (pos + write_bytes + root->sectorsize - 1) &
327 ~((u64)root->sectorsize - 1);
328 mutex_lock(&BTRFS_I(inode)->extent_mutex);
329 err = btrfs_drop_extents(trans, root, inode, start_pos,
330 aligned_end, aligned_end, &hint_byte);
331 if (err)
332 goto failed;
333 if (isize > inline_size)
334 inline_size = min_t(u64, isize, aligned_end);
335 inline_size -= start_pos;
336 err = insert_inline_extent(trans, root, inode, start_pos,
337 inline_size, pages, 0, num_pages);
338 btrfs_drop_extent_cache(inode, start_pos, aligned_end - 1);
339 BUG_ON(err);
340 mutex_unlock(&BTRFS_I(inode)->extent_mutex);
341 did_inline = 1;
342 }
343 if (end_pos > isize) {
344 i_size_write(inode, end_pos);
345 if (did_inline)
346 BTRFS_I(inode)->disk_i_size = end_pos;
347 btrfs_update_inode(trans, root, inode);
348 }
349 failed:
350 err = btrfs_end_transaction(trans, root);
351 out_unlock:
352 unlock_extent(io_tree, start_pos, end_of_last_block, GFP_NOFS);
353 return err;
354 }
355
356 int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end)
357 {
358 struct extent_map *em;
359 struct extent_map *split = NULL;
360 struct extent_map *split2 = NULL;
361 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
362 u64 len = end - start + 1;
363 int ret;
364 int testend = 1;
365
366 WARN_ON(end < start);
367 if (end == (u64)-1) {
368 len = (u64)-1;
369 testend = 0;
370 }
371 while(1) {
372 if (!split)
373 split = alloc_extent_map(GFP_NOFS);
374 if (!split2)
375 split2 = alloc_extent_map(GFP_NOFS);
376
377 spin_lock(&em_tree->lock);
378 em = lookup_extent_mapping(em_tree, start, len);
379 if (!em) {
380 spin_unlock(&em_tree->lock);
381 break;
382 }
383 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
384 remove_extent_mapping(em_tree, em);
385
386 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
387 em->start < start) {
388 split->start = em->start;
389 split->len = start - em->start;
390 split->block_start = em->block_start;
391 split->bdev = em->bdev;
392 split->flags = em->flags;
393 ret = add_extent_mapping(em_tree, split);
394 BUG_ON(ret);
395 free_extent_map(split);
396 split = split2;
397 split2 = NULL;
398 }
399 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
400 testend && em->start + em->len > start + len) {
401 u64 diff = start + len - em->start;
402
403 split->start = start + len;
404 split->len = em->start + em->len - (start + len);
405 split->bdev = em->bdev;
406 split->flags = em->flags;
407
408 split->block_start = em->block_start + diff;
409
410 ret = add_extent_mapping(em_tree, split);
411 BUG_ON(ret);
412 free_extent_map(split);
413 split = NULL;
414 }
415 spin_unlock(&em_tree->lock);
416
417 /* once for us */
418 free_extent_map(em);
419 /* once for the tree*/
420 free_extent_map(em);
421 }
422 if (split)
423 free_extent_map(split);
424 if (split2)
425 free_extent_map(split2);
426 return 0;
427 }
428
429 int btrfs_check_file(struct btrfs_root *root, struct inode *inode)
430 {
431 return 0;
432 #if 0
433 struct btrfs_path *path;
434 struct btrfs_key found_key;
435 struct extent_buffer *leaf;
436 struct btrfs_file_extent_item *extent;
437 u64 last_offset = 0;
438 int nritems;
439 int slot;
440 int found_type;
441 int ret;
442 int err = 0;
443 u64 extent_end = 0;
444
445 path = btrfs_alloc_path();
446 ret = btrfs_lookup_file_extent(NULL, root, path, inode->i_ino,
447 last_offset, 0);
448 while(1) {
449 nritems = btrfs_header_nritems(path->nodes[0]);
450 if (path->slots[0] >= nritems) {
451 ret = btrfs_next_leaf(root, path);
452 if (ret)
453 goto out;
454 nritems = btrfs_header_nritems(path->nodes[0]);
455 }
456 slot = path->slots[0];
457 leaf = path->nodes[0];
458 btrfs_item_key_to_cpu(leaf, &found_key, slot);
459 if (found_key.objectid != inode->i_ino)
460 break;
461 if (found_key.type != BTRFS_EXTENT_DATA_KEY)
462 goto out;
463
464 if (found_key.offset < last_offset) {
465 WARN_ON(1);
466 btrfs_print_leaf(root, leaf);
467 printk("inode %lu found offset %Lu expected %Lu\n",
468 inode->i_ino, found_key.offset, last_offset);
469 err = 1;
470 goto out;
471 }
472 extent = btrfs_item_ptr(leaf, slot,
473 struct btrfs_file_extent_item);
474 found_type = btrfs_file_extent_type(leaf, extent);
475 if (found_type == BTRFS_FILE_EXTENT_REG) {
476 extent_end = found_key.offset +
477 btrfs_file_extent_num_bytes(leaf, extent);
478 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
479 struct btrfs_item *item;
480 item = btrfs_item_nr(leaf, slot);
481 extent_end = found_key.offset +
482 btrfs_file_extent_inline_len(leaf, item);
483 extent_end = (extent_end + root->sectorsize - 1) &
484 ~((u64)root->sectorsize -1 );
485 }
486 last_offset = extent_end;
487 path->slots[0]++;
488 }
489 if (0 && last_offset < inode->i_size) {
490 WARN_ON(1);
491 btrfs_print_leaf(root, leaf);
492 printk("inode %lu found offset %Lu size %Lu\n", inode->i_ino,
493 last_offset, inode->i_size);
494 err = 1;
495
496 }
497 out:
498 btrfs_free_path(path);
499 return err;
500 #endif
501 }
502
503 /*
504 * this is very complex, but the basic idea is to drop all extents
505 * in the range start - end. hint_block is filled in with a block number
506 * that would be a good hint to the block allocator for this file.
507 *
508 * If an extent intersects the range but is not entirely inside the range
509 * it is either truncated or split. Anything entirely inside the range
510 * is deleted from the tree.
511 */
512 int btrfs_drop_extents(struct btrfs_trans_handle *trans,
513 struct btrfs_root *root, struct inode *inode,
514 u64 start, u64 end, u64 inline_limit, u64 *hint_byte)
515 {
516 u64 extent_end = 0;
517 u64 search_start = start;
518 struct extent_buffer *leaf;
519 struct btrfs_file_extent_item *extent;
520 struct btrfs_path *path;
521 struct btrfs_key key;
522 struct btrfs_file_extent_item old;
523 int keep;
524 int slot;
525 int bookend;
526 int found_type;
527 int found_extent;
528 int found_inline;
529 int recow;
530 int ret;
531
532 btrfs_drop_extent_cache(inode, start, end - 1);
533
534 path = btrfs_alloc_path();
535 if (!path)
536 return -ENOMEM;
537 while(1) {
538 recow = 0;
539 btrfs_release_path(root, path);
540 ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
541 search_start, -1);
542 if (ret < 0)
543 goto out;
544 if (ret > 0) {
545 if (path->slots[0] == 0) {
546 ret = 0;
547 goto out;
548 }
549 path->slots[0]--;
550 }
551 next_slot:
552 keep = 0;
553 bookend = 0;
554 found_extent = 0;
555 found_inline = 0;
556 extent = NULL;
557 leaf = path->nodes[0];
558 slot = path->slots[0];
559 ret = 0;
560 btrfs_item_key_to_cpu(leaf, &key, slot);
561 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY &&
562 key.offset >= end) {
563 goto out;
564 }
565 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
566 key.objectid != inode->i_ino) {
567 goto out;
568 }
569 if (recow) {
570 search_start = key.offset;
571 continue;
572 }
573 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
574 extent = btrfs_item_ptr(leaf, slot,
575 struct btrfs_file_extent_item);
576 found_type = btrfs_file_extent_type(leaf, extent);
577 if (found_type == BTRFS_FILE_EXTENT_REG) {
578 extent_end =
579 btrfs_file_extent_disk_bytenr(leaf,
580 extent);
581 if (extent_end)
582 *hint_byte = extent_end;
583
584 extent_end = key.offset +
585 btrfs_file_extent_num_bytes(leaf, extent);
586 found_extent = 1;
587 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
588 struct btrfs_item *item;
589 item = btrfs_item_nr(leaf, slot);
590 found_inline = 1;
591 extent_end = key.offset +
592 btrfs_file_extent_inline_len(leaf, item);
593 }
594 } else {
595 extent_end = search_start;
596 }
597
598 /* we found nothing we can drop */
599 if ((!found_extent && !found_inline) ||
600 search_start >= extent_end) {
601 int nextret;
602 u32 nritems;
603 nritems = btrfs_header_nritems(leaf);
604 if (slot >= nritems - 1) {
605 nextret = btrfs_next_leaf(root, path);
606 if (nextret)
607 goto out;
608 recow = 1;
609 } else {
610 path->slots[0]++;
611 }
612 goto next_slot;
613 }
614
615 if (found_inline) {
616 u64 mask = root->sectorsize - 1;
617 search_start = (extent_end + mask) & ~mask;
618 } else
619 search_start = extent_end;
620 if (end <= extent_end && start >= key.offset && found_inline) {
621 *hint_byte = EXTENT_MAP_INLINE;
622 continue;
623 }
624 if (end < extent_end && end >= key.offset) {
625 if (found_extent) {
626 u64 disk_bytenr =
627 btrfs_file_extent_disk_bytenr(leaf, extent);
628 u64 disk_num_bytes =
629 btrfs_file_extent_disk_num_bytes(leaf,
630 extent);
631 read_extent_buffer(leaf, &old,
632 (unsigned long)extent,
633 sizeof(old));
634 if (disk_bytenr != 0) {
635 ret = btrfs_inc_extent_ref(trans, root,
636 disk_bytenr, disk_num_bytes,
637 root->root_key.objectid,
638 trans->transid,
639 key.objectid, end);
640 BUG_ON(ret);
641 }
642 }
643 bookend = 1;
644 if (found_inline && start <= key.offset)
645 keep = 1;
646 }
647 /* truncate existing extent */
648 if (start > key.offset) {
649 u64 new_num;
650 u64 old_num;
651 keep = 1;
652 WARN_ON(start & (root->sectorsize - 1));
653 if (found_extent) {
654 new_num = start - key.offset;
655 old_num = btrfs_file_extent_num_bytes(leaf,
656 extent);
657 *hint_byte =
658 btrfs_file_extent_disk_bytenr(leaf,
659 extent);
660 if (btrfs_file_extent_disk_bytenr(leaf,
661 extent)) {
662 dec_i_blocks(inode, old_num - new_num);
663 }
664 btrfs_set_file_extent_num_bytes(leaf, extent,
665 new_num);
666 btrfs_mark_buffer_dirty(leaf);
667 } else if (key.offset < inline_limit &&
668 (end > extent_end) &&
669 (inline_limit < extent_end)) {
670 u32 new_size;
671 new_size = btrfs_file_extent_calc_inline_size(
672 inline_limit - key.offset);
673 dec_i_blocks(inode, (extent_end - key.offset) -
674 (inline_limit - key.offset));
675 btrfs_truncate_item(trans, root, path,
676 new_size, 1);
677 }
678 }
679 /* delete the entire extent */
680 if (!keep) {
681 u64 disk_bytenr = 0;
682 u64 disk_num_bytes = 0;
683 u64 extent_num_bytes = 0;
684 u64 root_gen;
685 u64 root_owner;
686
687 root_gen = btrfs_header_generation(leaf);
688 root_owner = btrfs_header_owner(leaf);
689 if (found_extent) {
690 disk_bytenr =
691 btrfs_file_extent_disk_bytenr(leaf,
692 extent);
693 disk_num_bytes =
694 btrfs_file_extent_disk_num_bytes(leaf,
695 extent);
696 extent_num_bytes =
697 btrfs_file_extent_num_bytes(leaf, extent);
698 *hint_byte =
699 btrfs_file_extent_disk_bytenr(leaf,
700 extent);
701 }
702 ret = btrfs_del_item(trans, root, path);
703 /* TODO update progress marker and return */
704 BUG_ON(ret);
705 btrfs_release_path(root, path);
706 extent = NULL;
707 if (found_extent && disk_bytenr != 0) {
708 dec_i_blocks(inode, extent_num_bytes);
709 ret = btrfs_free_extent(trans, root,
710 disk_bytenr,
711 disk_num_bytes,
712 root_owner,
713 root_gen, inode->i_ino,
714 key.offset, 0);
715 }
716
717 BUG_ON(ret);
718 if (!bookend && search_start >= end) {
719 ret = 0;
720 goto out;
721 }
722 if (!bookend)
723 continue;
724 }
725 if (bookend && found_inline && start <= key.offset) {
726 u32 new_size;
727 new_size = btrfs_file_extent_calc_inline_size(
728 extent_end - end);
729 dec_i_blocks(inode, (extent_end - key.offset) -
730 (extent_end - end));
731 btrfs_truncate_item(trans, root, path, new_size, 0);
732 }
733 /* create bookend, splitting the extent in two */
734 if (bookend && found_extent) {
735 struct btrfs_key ins;
736 ins.objectid = inode->i_ino;
737 ins.offset = end;
738 btrfs_set_key_type(&ins, BTRFS_EXTENT_DATA_KEY);
739 btrfs_release_path(root, path);
740 ret = btrfs_insert_empty_item(trans, root, path, &ins,
741 sizeof(*extent));
742
743 leaf = path->nodes[0];
744 if (ret) {
745 btrfs_print_leaf(root, leaf);
746 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);
747 }
748 BUG_ON(ret);
749 extent = btrfs_item_ptr(leaf, path->slots[0],
750 struct btrfs_file_extent_item);
751 write_extent_buffer(leaf, &old,
752 (unsigned long)extent, sizeof(old));
753
754 btrfs_set_file_extent_offset(leaf, extent,
755 le64_to_cpu(old.offset) + end - key.offset);
756 WARN_ON(le64_to_cpu(old.num_bytes) <
757 (extent_end - end));
758 btrfs_set_file_extent_num_bytes(leaf, extent,
759 extent_end - end);
760 btrfs_set_file_extent_type(leaf, extent,
761 BTRFS_FILE_EXTENT_REG);
762
763 btrfs_mark_buffer_dirty(path->nodes[0]);
764 if (le64_to_cpu(old.disk_bytenr) != 0) {
765 inode->i_blocks +=
766 btrfs_file_extent_num_bytes(leaf,
767 extent) >> 9;
768 }
769 ret = 0;
770 goto out;
771 }
772 }
773 out:
774 btrfs_free_path(path);
775 btrfs_check_file(root, inode);
776 return ret;
777 }
778
779 /*
780 * this gets pages into the page cache and locks them down
781 */
782 static int prepare_pages(struct btrfs_root *root, struct file *file,
783 struct page **pages, size_t num_pages,
784 loff_t pos, unsigned long first_index,
785 unsigned long last_index, size_t write_bytes)
786 {
787 int i;
788 unsigned long index = pos >> PAGE_CACHE_SHIFT;
789 struct inode *inode = fdentry(file)->d_inode;
790 int err = 0;
791 u64 start_pos;
792 u64 last_pos;
793
794 start_pos = pos & ~((u64)root->sectorsize - 1);
795 last_pos = ((u64)index + num_pages) << PAGE_CACHE_SHIFT;
796
797 memset(pages, 0, num_pages * sizeof(struct page *));
798 again:
799 for (i = 0; i < num_pages; i++) {
800 pages[i] = grab_cache_page(inode->i_mapping, index + i);
801 if (!pages[i]) {
802 err = -ENOMEM;
803 BUG_ON(1);
804 }
805 wait_on_page_writeback(pages[i]);
806 }
807 if (start_pos < inode->i_size) {
808 struct btrfs_ordered_extent *ordered;
809 lock_extent(&BTRFS_I(inode)->io_tree,
810 start_pos, last_pos - 1, GFP_NOFS);
811 ordered = btrfs_lookup_first_ordered_extent(inode, last_pos -1);
812 if (ordered &&
813 ordered->file_offset + ordered->len > start_pos &&
814 ordered->file_offset < last_pos) {
815 btrfs_put_ordered_extent(ordered);
816 unlock_extent(&BTRFS_I(inode)->io_tree,
817 start_pos, last_pos - 1, GFP_NOFS);
818 for (i = 0; i < num_pages; i++) {
819 unlock_page(pages[i]);
820 page_cache_release(pages[i]);
821 }
822 btrfs_wait_ordered_range(inode, start_pos,
823 last_pos - start_pos);
824 goto again;
825 }
826 if (ordered)
827 btrfs_put_ordered_extent(ordered);
828
829 clear_extent_bits(&BTRFS_I(inode)->io_tree, start_pos,
830 last_pos - 1, EXTENT_DIRTY | EXTENT_DELALLOC,
831 GFP_NOFS);
832 unlock_extent(&BTRFS_I(inode)->io_tree,
833 start_pos, last_pos - 1, GFP_NOFS);
834 }
835 for (i = 0; i < num_pages; i++) {
836 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
837 ClearPageDirty(pages[i]);
838 #else
839 cancel_dirty_page(pages[i], PAGE_CACHE_SIZE);
840 #endif
841 set_page_extent_mapped(pages[i]);
842 WARN_ON(!PageLocked(pages[i]));
843 }
844 return 0;
845 }
846
847 static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
848 size_t count, loff_t *ppos)
849 {
850 loff_t pos;
851 loff_t start_pos;
852 ssize_t num_written = 0;
853 ssize_t err = 0;
854 int ret = 0;
855 struct inode *inode = fdentry(file)->d_inode;
856 struct btrfs_root *root = BTRFS_I(inode)->root;
857 struct page **pages = NULL;
858 int nrptrs;
859 struct page *pinned[2];
860 unsigned long first_index;
861 unsigned long last_index;
862
863 nrptrs = min((count + PAGE_CACHE_SIZE - 1) / PAGE_CACHE_SIZE,
864 PAGE_CACHE_SIZE / (sizeof(struct page *)));
865 pinned[0] = NULL;
866 pinned[1] = NULL;
867
868 pos = *ppos;
869 start_pos = pos;
870
871 vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
872 current->backing_dev_info = inode->i_mapping->backing_dev_info;
873 err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
874 if (err)
875 goto out_nolock;
876 if (count == 0)
877 goto out_nolock;
878 #ifdef REMOVE_SUID_PATH
879 err = remove_suid(&file->f_path);
880 #else
881 # if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,26)
882 err = file_remove_suid(file);
883 # else
884 err = remove_suid(fdentry(file));
885 # endif
886 #endif
887 if (err)
888 goto out_nolock;
889 file_update_time(file);
890
891 pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
892
893 mutex_lock(&inode->i_mutex);
894 first_index = pos >> PAGE_CACHE_SHIFT;
895 last_index = (pos + count) >> PAGE_CACHE_SHIFT;
896
897 /*
898 * if this is a nodatasum mount, force summing off for the inode
899 * all the time. That way a later mount with summing on won't
900 * get confused
901 */
902 if (btrfs_test_opt(root, NODATASUM))
903 btrfs_set_flag(inode, NODATASUM);
904
905 /*
906 * there are lots of better ways to do this, but this code
907 * makes sure the first and last page in the file range are
908 * up to date and ready for cow
909 */
910 if ((pos & (PAGE_CACHE_SIZE - 1))) {
911 pinned[0] = grab_cache_page(inode->i_mapping, first_index);
912 if (!PageUptodate(pinned[0])) {
913 ret = btrfs_readpage(NULL, pinned[0]);
914 BUG_ON(ret);
915 wait_on_page_locked(pinned[0]);
916 } else {
917 unlock_page(pinned[0]);
918 }
919 }
920 if ((pos + count) & (PAGE_CACHE_SIZE - 1)) {
921 pinned[1] = grab_cache_page(inode->i_mapping, last_index);
922 if (!PageUptodate(pinned[1])) {
923 ret = btrfs_readpage(NULL, pinned[1]);
924 BUG_ON(ret);
925 wait_on_page_locked(pinned[1]);
926 } else {
927 unlock_page(pinned[1]);
928 }
929 }
930
931 while(count > 0) {
932 size_t offset = pos & (PAGE_CACHE_SIZE - 1);
933 size_t write_bytes = min(count, nrptrs *
934 (size_t)PAGE_CACHE_SIZE -
935 offset);
936 size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >>
937 PAGE_CACHE_SHIFT;
938
939 WARN_ON(num_pages > nrptrs);
940 memset(pages, 0, sizeof(pages));
941
942 ret = btrfs_check_free_space(root, write_bytes, 0);
943 if (ret)
944 goto out;
945
946 ret = prepare_pages(root, file, pages, num_pages,
947 pos, first_index, last_index,
948 write_bytes);
949 if (ret)
950 goto out;
951
952 ret = btrfs_copy_from_user(pos, num_pages,
953 write_bytes, pages, buf);
954 if (ret) {
955 btrfs_drop_pages(pages, num_pages);
956 goto out;
957 }
958
959 ret = dirty_and_release_pages(NULL, root, file, pages,
960 num_pages, pos, write_bytes);
961 btrfs_drop_pages(pages, num_pages);
962 if (ret)
963 goto out;
964
965 buf += write_bytes;
966 count -= write_bytes;
967 pos += write_bytes;
968 num_written += write_bytes;
969
970 balance_dirty_pages_ratelimited_nr(inode->i_mapping, num_pages);
971 if (num_pages < (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
972 btrfs_btree_balance_dirty(root, 1);
973 btrfs_throttle(root);
974 cond_resched();
975 }
976 out:
977 mutex_unlock(&inode->i_mutex);
978
979 out_nolock:
980 kfree(pages);
981 if (pinned[0])
982 page_cache_release(pinned[0]);
983 if (pinned[1])
984 page_cache_release(pinned[1]);
985 *ppos = pos;
986
987 if (num_written > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
988 err = sync_page_range(inode, inode->i_mapping,
989 start_pos, num_written);
990 if (err < 0)
991 num_written = err;
992 } else if (num_written > 0 && (file->f_flags & O_DIRECT)) {
993 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
994 do_sync_file_range(file, start_pos,
995 start_pos + num_written - 1,
996 SYNC_FILE_RANGE_WRITE |
997 SYNC_FILE_RANGE_WAIT_AFTER);
998 #else
999 do_sync_mapping_range(inode->i_mapping, start_pos,
1000 start_pos + num_written - 1,
1001 SYNC_FILE_RANGE_WRITE |
1002 SYNC_FILE_RANGE_WAIT_AFTER);
1003 #endif
1004 invalidate_mapping_pages(inode->i_mapping,
1005 start_pos >> PAGE_CACHE_SHIFT,
1006 (start_pos + num_written - 1) >> PAGE_CACHE_SHIFT);
1007 }
1008 current->backing_dev_info = NULL;
1009 return num_written ? num_written : err;
1010 }
1011
1012 int btrfs_release_file(struct inode * inode, struct file * filp)
1013 {
1014 if (filp->private_data)
1015 btrfs_ioctl_trans_end(filp);
1016 return 0;
1017 }
1018
1019 static int btrfs_sync_file(struct file *file,
1020 struct dentry *dentry, int datasync)
1021 {
1022 struct inode *inode = dentry->d_inode;
1023 struct btrfs_root *root = BTRFS_I(inode)->root;
1024 int ret = 0;
1025 struct btrfs_trans_handle *trans;
1026
1027 /*
1028 * check the transaction that last modified this inode
1029 * and see if its already been committed
1030 */
1031 if (!BTRFS_I(inode)->last_trans)
1032 goto out;
1033
1034 mutex_lock(&root->fs_info->trans_mutex);
1035 if (BTRFS_I(inode)->last_trans <=
1036 root->fs_info->last_trans_committed) {
1037 BTRFS_I(inode)->last_trans = 0;
1038 mutex_unlock(&root->fs_info->trans_mutex);
1039 goto out;
1040 }
1041 mutex_unlock(&root->fs_info->trans_mutex);
1042
1043 /*
1044 * ok we haven't committed the transaction yet, lets do a commit
1045 */
1046 if (file->private_data)
1047 btrfs_ioctl_trans_end(file);
1048
1049 trans = btrfs_start_transaction(root, 1);
1050 if (!trans) {
1051 ret = -ENOMEM;
1052 goto out;
1053 }
1054 ret = btrfs_commit_transaction(trans, root);
1055 out:
1056 return ret > 0 ? EIO : ret;
1057 }
1058
1059 static struct vm_operations_struct btrfs_file_vm_ops = {
1060 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
1061 .nopage = filemap_nopage,
1062 .populate = filemap_populate,
1063 #else
1064 .fault = filemap_fault,
1065 #endif
1066 .page_mkwrite = btrfs_page_mkwrite,
1067 };
1068
1069 static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
1070 {
1071 vma->vm_ops = &btrfs_file_vm_ops;
1072 file_accessed(filp);
1073 return 0;
1074 }
1075
1076 struct file_operations btrfs_file_operations = {
1077 .llseek = generic_file_llseek,
1078 .read = do_sync_read,
1079 .aio_read = generic_file_aio_read,
1080 .splice_read = generic_file_splice_read,
1081 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
1082 .sendfile = generic_file_sendfile,
1083 #endif
1084 .write = btrfs_file_write,
1085 .mmap = btrfs_file_mmap,
1086 .open = generic_file_open,
1087 .release = btrfs_release_file,
1088 .fsync = btrfs_sync_file,
1089 .unlocked_ioctl = btrfs_ioctl,
1090 #ifdef CONFIG_COMPAT
1091 .compat_ioctl = btrfs_ioctl,
1092 #endif
1093 };
(deprecated) Btrfs devel tree