2 * Copyright (C) 2007 Oracle. All rights reserved.
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.
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.
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.
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>
35 #include "transaction.h"
36 #include "btrfs_inode.h"
38 #include "print-tree.h"
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)
48 int offset = pos & (PAGE_CACHE_SIZE - 1);
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);
56 /* Copy data from userspace to the current page */
58 page_fault = __copy_from_user(page_address(page) + offset,
60 /* Flush processor's dcache for this page */
61 flush_dcache_page(page);
69 return page_fault ? -EFAULT : 0;
72 static void btrfs_drop_pages(struct page **pages, size_t num_pages)
75 for (i = 0; i < num_pages; i++) {
78 unlock_page(pages[i]);
79 mark_page_accessed(pages[i]);
80 page_cache_release(pages[i]);
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,
91 struct btrfs_path *path;
92 struct extent_buffer *leaf;
95 struct btrfs_file_extent_item *ei;
103 path = btrfs_alloc_path();
107 btrfs_set_trans_block_group(trans, inode);
109 key.objectid = inode->i_ino;
111 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
113 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
119 struct btrfs_key found_key;
121 if (path->slots[0] == 0)
125 leaf = path->nodes[0];
126 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
128 if (found_key.objectid != inode->i_ino)
131 if (found_key.type != BTRFS_EXTENT_DATA_KEY)
133 ei = btrfs_item_ptr(leaf, path->slots[0],
134 struct btrfs_file_extent_item);
136 if (btrfs_file_extent_type(leaf, ei) !=
137 BTRFS_FILE_EXTENT_INLINE) {
140 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
147 leaf = path->nodes[0];
148 ei = btrfs_item_ptr(leaf, path->slots[0],
149 struct btrfs_file_extent_item);
151 if (btrfs_file_extent_type(leaf, ei) !=
152 BTRFS_FILE_EXTENT_INLINE) {
154 btrfs_print_leaf(root, leaf);
155 printk("found wasn't inline offset %Lu inode %lu\n",
156 offset, inode->i_ino);
159 found_size = btrfs_file_extent_inline_len(leaf,
160 btrfs_item_nr(leaf, path->slots[0]));
161 found_end = key.offset + found_size;
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);
169 ret = btrfs_extend_item(trans, root, path,
170 offset + size - found_end);
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;
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);
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,
194 printk("got bad ret %d\n", ret);
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);
203 ptr = btrfs_file_extent_inline_start(ei) + offset - key.offset;
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);
216 if (i >= num_pages) {
217 printk("i %d num_pages %d\n", i, num_pages);
221 btrfs_mark_buffer_dirty(leaf);
223 btrfs_free_path(path);
227 static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
228 struct btrfs_root *root,
237 struct inode *inode = fdentry(file)->d_inode;
238 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
242 u64 end_of_last_block;
243 u64 end_pos = pos + write_bytes;
245 loff_t isize = i_size_read(inode);
247 start_pos = pos & ~((u64)root->sectorsize - 1);
248 num_bytes = (write_bytes + pos - start_pos +
249 root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
251 end_of_last_block = start_pos + num_bytes - 1;
253 lock_extent(io_tree, start_pos, end_of_last_block, GFP_NOFS);
254 trans = btrfs_start_transaction(root, 1);
259 btrfs_set_trans_block_group(trans, inode);
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);
265 set_extent_uptodate(io_tree, start_pos, end_of_last_block, GFP_NOFS);
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;
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;
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,
280 last_pos_in_file + hole_size,
286 err = btrfs_insert_file_extent(trans, root,
290 btrfs_drop_extent_cache(inode, last_pos_in_file,
291 last_pos_in_file + hole_size -1);
292 btrfs_check_file(root, inode);
299 * either allocate an extent for the new bytes or setup the key
300 * to show we are doing inline data in the extent
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
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];
321 /* step one, delete the existing extents in this range */
322 aligned_end = (pos + write_bytes + root->sectorsize - 1) &
323 ~((u64)root->sectorsize - 1);
324 err = btrfs_drop_extents(trans, root, inode, start_pos,
325 aligned_end, aligned_end, &hint_byte);
328 if (isize > inline_size)
329 inline_size = min_t(u64, isize, aligned_end);
330 inline_size -= start_pos;
331 err = insert_inline_extent(trans, root, inode, start_pos,
332 inline_size, pages, 0, num_pages);
333 btrfs_drop_extent_cache(inode, start_pos, aligned_end - 1);
336 if (end_pos > isize) {
337 i_size_write(inode, end_pos);
338 btrfs_update_inode(trans, root, inode);
341 err = btrfs_end_transaction(trans, root);
343 unlock_extent(io_tree, start_pos, end_of_last_block, GFP_NOFS);
347 int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end)
349 struct extent_map *em;
350 struct extent_map *split = NULL;
351 struct extent_map *split2 = NULL;
352 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
353 struct extent_map *tmp;
354 u64 len = end - start + 1;
359 WARN_ON(end < start);
360 if (end == (u64)-1) {
366 split = alloc_extent_map(GFP_NOFS);
368 split2 = alloc_extent_map(GFP_NOFS);
370 spin_lock(&em_tree->lock);
371 em = lookup_extent_mapping(em_tree, start, len);
373 spin_unlock(&em_tree->lock);
376 tmp = rb_entry(&em->rb_node, struct extent_map, rb_node);
377 next_start = tmp->start;
378 remove_extent_mapping(em_tree, em);
380 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
382 split->start = em->start;
383 split->len = start - em->start;
384 split->block_start = em->block_start;
385 split->bdev = em->bdev;
386 split->flags = em->flags;
387 ret = add_extent_mapping(em_tree, split);
389 free_extent_map(split);
393 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
394 testend && em->start + em->len > start + len) {
395 u64 diff = start + len - em->start;
397 split->start = start + len;
398 split->len = em->start + em->len - (start + len);
399 split->bdev = em->bdev;
400 split->flags = em->flags;
402 split->block_start = em->block_start + diff;
404 ret = add_extent_mapping(em_tree, split);
406 free_extent_map(split);
409 spin_unlock(&em_tree->lock);
413 /* once for the tree*/
417 free_extent_map(split);
419 free_extent_map(split2);
423 int btrfs_check_file(struct btrfs_root *root, struct inode *inode)
427 struct btrfs_path *path;
428 struct btrfs_key found_key;
429 struct extent_buffer *leaf;
430 struct btrfs_file_extent_item *extent;
439 path = btrfs_alloc_path();
440 ret = btrfs_lookup_file_extent(NULL, root, path, inode->i_ino,
443 nritems = btrfs_header_nritems(path->nodes[0]);
444 if (path->slots[0] >= nritems) {
445 ret = btrfs_next_leaf(root, path);
448 nritems = btrfs_header_nritems(path->nodes[0]);
450 slot = path->slots[0];
451 leaf = path->nodes[0];
452 btrfs_item_key_to_cpu(leaf, &found_key, slot);
453 if (found_key.objectid != inode->i_ino)
455 if (found_key.type != BTRFS_EXTENT_DATA_KEY)
458 if (found_key.offset < last_offset) {
460 btrfs_print_leaf(root, leaf);
461 printk("inode %lu found offset %Lu expected %Lu\n",
462 inode->i_ino, found_key.offset, last_offset);
466 extent = btrfs_item_ptr(leaf, slot,
467 struct btrfs_file_extent_item);
468 found_type = btrfs_file_extent_type(leaf, extent);
469 if (found_type == BTRFS_FILE_EXTENT_REG) {
470 extent_end = found_key.offset +
471 btrfs_file_extent_num_bytes(leaf, extent);
472 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
473 struct btrfs_item *item;
474 item = btrfs_item_nr(leaf, slot);
475 extent_end = found_key.offset +
476 btrfs_file_extent_inline_len(leaf, item);
477 extent_end = (extent_end + root->sectorsize - 1) &
478 ~((u64)root->sectorsize -1 );
480 last_offset = extent_end;
483 if (0 && last_offset < inode->i_size) {
485 btrfs_print_leaf(root, leaf);
486 printk("inode %lu found offset %Lu size %Lu\n", inode->i_ino,
487 last_offset, inode->i_size);
492 btrfs_free_path(path);
498 * this is very complex, but the basic idea is to drop all extents
499 * in the range start - end. hint_block is filled in with a block number
500 * that would be a good hint to the block allocator for this file.
502 * If an extent intersects the range but is not entirely inside the range
503 * it is either truncated or split. Anything entirely inside the range
504 * is deleted from the tree.
506 int btrfs_drop_extents(struct btrfs_trans_handle *trans,
507 struct btrfs_root *root, struct inode *inode,
508 u64 start, u64 end, u64 inline_limit, u64 *hint_byte)
511 u64 search_start = start;
512 struct extent_buffer *leaf;
513 struct btrfs_file_extent_item *extent;
514 struct btrfs_path *path;
515 struct btrfs_key key;
516 struct btrfs_file_extent_item old;
526 btrfs_drop_extent_cache(inode, start, end - 1);
528 path = btrfs_alloc_path();
533 btrfs_release_path(root, path);
534 ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
539 if (path->slots[0] == 0) {
551 leaf = path->nodes[0];
552 slot = path->slots[0];
554 btrfs_item_key_to_cpu(leaf, &key, slot);
555 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY &&
559 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
560 key.objectid != inode->i_ino) {
564 search_start = key.offset;
567 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
568 extent = btrfs_item_ptr(leaf, slot,
569 struct btrfs_file_extent_item);
570 found_type = btrfs_file_extent_type(leaf, extent);
571 if (found_type == BTRFS_FILE_EXTENT_REG) {
573 btrfs_file_extent_disk_bytenr(leaf,
576 *hint_byte = extent_end;
578 extent_end = key.offset +
579 btrfs_file_extent_num_bytes(leaf, extent);
581 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
582 struct btrfs_item *item;
583 item = btrfs_item_nr(leaf, slot);
585 extent_end = key.offset +
586 btrfs_file_extent_inline_len(leaf, item);
589 extent_end = search_start;
592 /* we found nothing we can drop */
593 if ((!found_extent && !found_inline) ||
594 search_start >= extent_end) {
597 nritems = btrfs_header_nritems(leaf);
598 if (slot >= nritems - 1) {
599 nextret = btrfs_next_leaf(root, path);
610 u64 mask = root->sectorsize - 1;
611 search_start = (extent_end + mask) & ~mask;
613 search_start = extent_end;
614 if (end <= extent_end && start >= key.offset && found_inline) {
615 *hint_byte = EXTENT_MAP_INLINE;
618 if (end < extent_end && end >= key.offset) {
621 btrfs_file_extent_disk_bytenr(leaf, extent);
623 btrfs_file_extent_disk_num_bytes(leaf,
625 read_extent_buffer(leaf, &old,
626 (unsigned long)extent,
628 if (disk_bytenr != 0) {
629 ret = btrfs_inc_extent_ref(trans, root,
630 disk_bytenr, disk_num_bytes,
631 root->root_key.objectid,
638 if (found_inline && start <= key.offset)
641 /* truncate existing extent */
642 if (start > key.offset) {
646 WARN_ON(start & (root->sectorsize - 1));
648 new_num = start - key.offset;
649 old_num = btrfs_file_extent_num_bytes(leaf,
652 btrfs_file_extent_disk_bytenr(leaf,
654 if (btrfs_file_extent_disk_bytenr(leaf,
656 dec_i_blocks(inode, old_num - new_num);
658 btrfs_set_file_extent_num_bytes(leaf, extent,
660 btrfs_mark_buffer_dirty(leaf);
661 } else if (key.offset < inline_limit &&
662 (end > extent_end) &&
663 (inline_limit < extent_end)) {
665 new_size = btrfs_file_extent_calc_inline_size(
666 inline_limit - key.offset);
667 dec_i_blocks(inode, (extent_end - key.offset) -
668 (inline_limit - key.offset));
669 btrfs_truncate_item(trans, root, path,
673 /* delete the entire extent */
676 u64 disk_num_bytes = 0;
677 u64 extent_num_bytes = 0;
681 root_gen = btrfs_header_generation(leaf);
682 root_owner = btrfs_header_owner(leaf);
685 btrfs_file_extent_disk_bytenr(leaf,
688 btrfs_file_extent_disk_num_bytes(leaf,
691 btrfs_file_extent_num_bytes(leaf, extent);
693 btrfs_file_extent_disk_bytenr(leaf,
696 ret = btrfs_del_item(trans, root, path);
697 /* TODO update progress marker and return */
699 btrfs_release_path(root, path);
701 if (found_extent && disk_bytenr != 0) {
702 dec_i_blocks(inode, extent_num_bytes);
703 ret = btrfs_free_extent(trans, root,
707 root_gen, inode->i_ino,
712 if (!bookend && search_start >= end) {
719 if (bookend && found_inline && start <= key.offset) {
721 new_size = btrfs_file_extent_calc_inline_size(
723 dec_i_blocks(inode, (extent_end - key.offset) -
725 btrfs_truncate_item(trans, root, path, new_size, 0);
727 /* create bookend, splitting the extent in two */
728 if (bookend && found_extent) {
729 struct btrfs_key ins;
730 ins.objectid = inode->i_ino;
732 btrfs_set_key_type(&ins, BTRFS_EXTENT_DATA_KEY);
733 btrfs_release_path(root, path);
734 ret = btrfs_insert_empty_item(trans, root, path, &ins,
737 leaf = path->nodes[0];
739 btrfs_print_leaf(root, leaf);
740 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);
743 extent = btrfs_item_ptr(leaf, path->slots[0],
744 struct btrfs_file_extent_item);
745 write_extent_buffer(leaf, &old,
746 (unsigned long)extent, sizeof(old));
748 btrfs_set_file_extent_offset(leaf, extent,
749 le64_to_cpu(old.offset) + end - key.offset);
750 WARN_ON(le64_to_cpu(old.num_bytes) <
752 btrfs_set_file_extent_num_bytes(leaf, extent,
754 btrfs_set_file_extent_type(leaf, extent,
755 BTRFS_FILE_EXTENT_REG);
757 btrfs_mark_buffer_dirty(path->nodes[0]);
758 if (le64_to_cpu(old.disk_bytenr) != 0) {
760 btrfs_file_extent_num_bytes(leaf,
768 btrfs_free_path(path);
769 btrfs_check_file(root, inode);
774 * this gets pages into the page cache and locks them down
776 static int prepare_pages(struct btrfs_root *root, struct file *file,
777 struct page **pages, size_t num_pages,
778 loff_t pos, unsigned long first_index,
779 unsigned long last_index, size_t write_bytes)
782 unsigned long index = pos >> PAGE_CACHE_SHIFT;
783 struct inode *inode = fdentry(file)->d_inode;
788 start_pos = pos & ~((u64)root->sectorsize - 1);
789 last_pos = ((u64)index + num_pages) << PAGE_CACHE_SHIFT;
791 memset(pages, 0, num_pages * sizeof(struct page *));
793 for (i = 0; i < num_pages; i++) {
794 pages[i] = grab_cache_page(inode->i_mapping, index + i);
799 wait_on_page_writeback(pages[i]);
801 if (start_pos < inode->i_size) {
802 struct btrfs_ordered_extent *ordered;
803 lock_extent(&BTRFS_I(inode)->io_tree,
804 start_pos, last_pos - 1, GFP_NOFS);
805 ordered = btrfs_lookup_first_ordered_extent(inode, last_pos -1);
807 ordered->file_offset + ordered->len > start_pos &&
808 ordered->file_offset < last_pos) {
809 btrfs_put_ordered_extent(ordered);
810 unlock_extent(&BTRFS_I(inode)->io_tree,
811 start_pos, last_pos - 1, GFP_NOFS);
812 for (i = 0; i < num_pages; i++) {
813 unlock_page(pages[i]);
814 page_cache_release(pages[i]);
816 btrfs_wait_ordered_range(inode, start_pos,
817 last_pos - start_pos);
821 btrfs_put_ordered_extent(ordered);
823 clear_extent_bits(&BTRFS_I(inode)->io_tree, start_pos,
824 last_pos - 1, EXTENT_DIRTY | EXTENT_DELALLOC,
826 unlock_extent(&BTRFS_I(inode)->io_tree,
827 start_pos, last_pos - 1, GFP_NOFS);
829 for (i = 0; i < num_pages; i++) {
830 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
831 ClearPageDirty(pages[i]);
833 cancel_dirty_page(pages[i], PAGE_CACHE_SIZE);
835 set_page_extent_mapped(pages[i]);
836 WARN_ON(!PageLocked(pages[i]));
841 static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
842 size_t count, loff_t *ppos)
846 ssize_t num_written = 0;
849 struct inode *inode = fdentry(file)->d_inode;
850 struct btrfs_root *root = BTRFS_I(inode)->root;
851 struct page **pages = NULL;
853 struct page *pinned[2];
854 unsigned long first_index;
855 unsigned long last_index;
857 nrptrs = min((count + PAGE_CACHE_SIZE - 1) / PAGE_CACHE_SIZE,
858 PAGE_CACHE_SIZE / (sizeof(struct page *)));
865 vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
866 current->backing_dev_info = inode->i_mapping->backing_dev_info;
867 err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
872 #ifdef REMOVE_SUID_PATH
873 err = remove_suid(&file->f_path);
875 err = remove_suid(fdentry(file));
879 file_update_time(file);
881 pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
883 mutex_lock(&inode->i_mutex);
884 first_index = pos >> PAGE_CACHE_SHIFT;
885 last_index = (pos + count) >> PAGE_CACHE_SHIFT;
888 * if this is a nodatasum mount, force summing off for the inode
889 * all the time. That way a later mount with summing on won't
892 if (btrfs_test_opt(root, NODATASUM))
893 btrfs_set_flag(inode, NODATASUM);
896 * there are lots of better ways to do this, but this code
897 * makes sure the first and last page in the file range are
898 * up to date and ready for cow
900 if ((pos & (PAGE_CACHE_SIZE - 1))) {
901 pinned[0] = grab_cache_page(inode->i_mapping, first_index);
902 if (!PageUptodate(pinned[0])) {
903 ret = btrfs_readpage(NULL, pinned[0]);
905 wait_on_page_locked(pinned[0]);
907 unlock_page(pinned[0]);
910 if ((pos + count) & (PAGE_CACHE_SIZE - 1)) {
911 pinned[1] = grab_cache_page(inode->i_mapping, last_index);
912 if (!PageUptodate(pinned[1])) {
913 ret = btrfs_readpage(NULL, pinned[1]);
915 wait_on_page_locked(pinned[1]);
917 unlock_page(pinned[1]);
922 size_t offset = pos & (PAGE_CACHE_SIZE - 1);
923 size_t write_bytes = min(count, nrptrs *
924 (size_t)PAGE_CACHE_SIZE -
926 size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >>
929 WARN_ON(num_pages > nrptrs);
930 memset(pages, 0, sizeof(pages));
932 ret = btrfs_check_free_space(root, write_bytes, 0);
936 ret = prepare_pages(root, file, pages, num_pages,
937 pos, first_index, last_index,
942 ret = btrfs_copy_from_user(pos, num_pages,
943 write_bytes, pages, buf);
945 btrfs_drop_pages(pages, num_pages);
949 ret = dirty_and_release_pages(NULL, root, file, pages,
950 num_pages, pos, write_bytes);
951 btrfs_drop_pages(pages, num_pages);
956 count -= write_bytes;
958 num_written += write_bytes;
960 balance_dirty_pages_ratelimited_nr(inode->i_mapping, num_pages);
961 if (num_pages < (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
962 btrfs_btree_balance_dirty(root, 1);
966 mutex_unlock(&inode->i_mutex);
971 page_cache_release(pinned[0]);
973 page_cache_release(pinned[1]);
976 if (num_written > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
977 err = sync_page_range(inode, inode->i_mapping,
978 start_pos, num_written);
981 } else if (num_written > 0 && (file->f_flags & O_DIRECT)) {
982 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
983 do_sync_file_range(file, start_pos,
984 start_pos + num_written - 1,
985 SYNC_FILE_RANGE_WRITE |
986 SYNC_FILE_RANGE_WAIT_AFTER);
988 do_sync_mapping_range(inode->i_mapping, start_pos,
989 start_pos + num_written - 1,
990 SYNC_FILE_RANGE_WRITE |
991 SYNC_FILE_RANGE_WAIT_AFTER);
993 invalidate_mapping_pages(inode->i_mapping,
994 start_pos >> PAGE_CACHE_SHIFT,
995 (start_pos + num_written - 1) >> PAGE_CACHE_SHIFT);
997 current->backing_dev_info = NULL;
998 return num_written ? num_written : err;
1001 int btrfs_release_file(struct inode * inode, struct file * filp)
1003 if (filp->private_data)
1004 btrfs_ioctl_trans_end(filp);
1008 static int btrfs_sync_file(struct file *file,
1009 struct dentry *dentry, int datasync)
1011 struct inode *inode = dentry->d_inode;
1012 struct btrfs_root *root = BTRFS_I(inode)->root;
1014 struct btrfs_trans_handle *trans;
1017 * check the transaction that last modified this inode
1018 * and see if its already been committed
1020 if (!BTRFS_I(inode)->last_trans)
1023 mutex_lock(&root->fs_info->trans_mutex);
1024 if (BTRFS_I(inode)->last_trans <=
1025 root->fs_info->last_trans_committed) {
1026 BTRFS_I(inode)->last_trans = 0;
1027 mutex_unlock(&root->fs_info->trans_mutex);
1030 mutex_unlock(&root->fs_info->trans_mutex);
1033 * ok we haven't committed the transaction yet, lets do a commit
1035 if (file->private_data)
1036 btrfs_ioctl_trans_end(file);
1038 trans = btrfs_start_transaction(root, 1);
1043 ret = btrfs_commit_transaction(trans, root);
1045 return ret > 0 ? EIO : ret;
1048 static struct vm_operations_struct btrfs_file_vm_ops = {
1049 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
1050 .nopage = filemap_nopage,
1051 .populate = filemap_populate,
1053 .fault = filemap_fault,
1055 .page_mkwrite = btrfs_page_mkwrite,
1058 static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
1060 vma->vm_ops = &btrfs_file_vm_ops;
1061 file_accessed(filp);
1065 struct file_operations btrfs_file_operations = {
1066 .llseek = generic_file_llseek,
1067 .read = do_sync_read,
1068 .aio_read = generic_file_aio_read,
1069 .splice_read = generic_file_splice_read,
1070 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
1071 .sendfile = generic_file_sendfile,
1073 .write = btrfs_file_write,
1074 .mmap = btrfs_file_mmap,
1075 .open = generic_file_open,
1076 .release = btrfs_release_file,
1077 .fsync = btrfs_sync_file,
1078 .unlocked_ioctl = btrfs_ioctl,
1079 #ifdef CONFIG_COMPAT
1080 .compat_ioctl = btrfs_ioctl,