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"
41 static int btrfs_copy_from_user(loff_t pos, int num_pages, int write_bytes,
42 struct page **prepared_pages,
43 const char __user * buf)
47 int offset = pos & (PAGE_CACHE_SIZE - 1);
49 for (i = 0; i < num_pages && write_bytes > 0; i++, offset = 0) {
50 size_t count = min_t(size_t,
51 PAGE_CACHE_SIZE - offset, write_bytes);
52 struct page *page = prepared_pages[i];
53 fault_in_pages_readable(buf, count);
55 /* Copy data from userspace to the current page */
57 page_fault = __copy_from_user(page_address(page) + offset,
59 /* Flush processor's dcache for this page */
60 flush_dcache_page(page);
68 return page_fault ? -EFAULT : 0;
71 static void btrfs_drop_pages(struct page **pages, size_t num_pages)
74 for (i = 0; i < num_pages; i++) {
77 unlock_page(pages[i]);
78 mark_page_accessed(pages[i]);
79 page_cache_release(pages[i]);
83 static int insert_inline_extent(struct btrfs_trans_handle *trans,
84 struct btrfs_root *root, struct inode *inode,
85 u64 offset, size_t size,
86 struct page **pages, size_t page_offset,
90 struct btrfs_path *path;
91 struct extent_buffer *leaf;
94 struct btrfs_file_extent_item *ei;
102 path = btrfs_alloc_path();
106 btrfs_set_trans_block_group(trans, inode);
108 key.objectid = inode->i_ino;
110 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
111 datasize = btrfs_file_extent_calc_inline_size(offset + size);
113 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
120 leaf = path->nodes[0];
121 ei = btrfs_item_ptr(leaf, path->slots[0],
122 struct btrfs_file_extent_item);
124 if (btrfs_file_extent_type(leaf, ei) !=
125 BTRFS_FILE_EXTENT_INLINE) {
128 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
135 leaf = path->nodes[0];
136 ei = btrfs_item_ptr(leaf, path->slots[0],
137 struct btrfs_file_extent_item);
139 if (btrfs_file_extent_type(leaf, ei) !=
140 BTRFS_FILE_EXTENT_INLINE) {
142 btrfs_print_leaf(root, leaf);
143 printk("found wasn't inline offset %Lu inode %lu\n",
144 offset, inode->i_ino);
147 found_start = key.offset;
148 found_size = btrfs_file_extent_inline_len(leaf,
149 btrfs_item_nr(leaf, path->slots[0]));
151 if (found_size < offset + size) {
152 btrfs_release_path(root, path);
153 ret = btrfs_search_slot(trans, root, &key, path,
154 offset + size - found_size -
157 ret = btrfs_extend_item(trans, root, path,
158 offset + size - found_size -
164 leaf = path->nodes[0];
165 ei = btrfs_item_ptr(leaf, path->slots[0],
166 struct btrfs_file_extent_item);
170 btrfs_release_path(root, path);
171 ret = btrfs_insert_empty_item(trans, root, path, &key,
175 printk("got bad ret %d\n", ret);
178 leaf = path->nodes[0];
179 ei = btrfs_item_ptr(leaf, path->slots[0],
180 struct btrfs_file_extent_item);
181 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
182 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
184 ptr = btrfs_file_extent_inline_start(ei) + offset;
190 kaddr = kmap_atomic(page, KM_USER0);
191 cur_size = min(PAGE_CACHE_SIZE - page_offset, size);
192 write_extent_buffer(leaf, kaddr + page_offset, ptr, cur_size);
193 kunmap_atomic(kaddr, KM_USER0);
197 if (i >= num_pages) {
198 printk("i %d num_pages %d\n", i, num_pages);
202 btrfs_mark_buffer_dirty(leaf);
204 btrfs_free_path(path);
208 static int dirty_and_release_pages(struct btrfs_trans_handle *trans,
209 struct btrfs_root *root,
218 struct inode *inode = file->f_path.dentry->d_inode;
219 struct extent_map *em;
220 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
224 u64 end_of_last_block;
225 u64 end_pos = pos + write_bytes;
227 loff_t isize = i_size_read(inode);
229 em = alloc_extent_map(GFP_NOFS);
233 em->bdev = inode->i_sb->s_bdev;
235 start_pos = pos & ~((u64)root->sectorsize - 1);
236 num_bytes = (write_bytes + pos - start_pos +
237 root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
239 down_read(&BTRFS_I(inode)->root->snap_sem);
240 end_of_last_block = start_pos + num_bytes - 1;
242 lock_extent(em_tree, start_pos, end_of_last_block, GFP_NOFS);
243 mutex_lock(&root->fs_info->fs_mutex);
244 trans = btrfs_start_transaction(root, 1);
249 btrfs_set_trans_block_group(trans, inode);
250 inode->i_blocks += num_bytes >> 9;
253 if ((end_of_last_block & 4095) == 0) {
254 printk("strange end of last %Lu %zu %Lu\n", start_pos, write_bytes, end_of_last_block);
256 set_extent_uptodate(em_tree, start_pos, end_of_last_block, GFP_NOFS);
258 /* FIXME...EIEIO, ENOSPC and more */
260 /* insert any holes we need to create */
261 if (inode->i_size < start_pos) {
262 u64 last_pos_in_file;
264 u64 mask = root->sectorsize - 1;
265 last_pos_in_file = (isize + mask) & ~mask;
266 hole_size = (start_pos - last_pos_in_file + mask) & ~mask;
268 if (last_pos_in_file < start_pos) {
269 err = btrfs_drop_extents(trans, root, inode,
271 last_pos_in_file + hole_size,
277 err = btrfs_insert_file_extent(trans, root,
287 * either allocate an extent for the new bytes or setup the key
288 * to show we are doing inline data in the extent
290 inline_size = end_pos;
291 if (isize >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
292 inline_size >= BTRFS_MAX_INLINE_DATA_SIZE(root)) {
295 for (i = 0; i < num_pages; i++) {
296 struct page *p = pages[i];
300 last_end = pages[num_pages -1]->index << PAGE_CACHE_SHIFT;
301 last_end += PAGE_CACHE_SIZE - 1;
302 set_extent_delalloc(em_tree, start_pos, end_of_last_block,
306 /* step one, delete the existing extents in this range */
307 aligned_end = (pos + write_bytes + root->sectorsize - 1) &
308 ~((u64)root->sectorsize - 1);
309 err = btrfs_drop_extents(trans, root, inode, start_pos,
310 aligned_end, end_pos, &hint_byte);
313 err = insert_inline_extent(trans, root, inode, start_pos,
314 end_pos - start_pos, pages, 0,
318 if (end_pos > isize) {
319 i_size_write(inode, end_pos);
320 btrfs_update_inode(trans, root, inode);
323 err = btrfs_end_transaction(trans, root);
325 mutex_unlock(&root->fs_info->fs_mutex);
326 unlock_extent(em_tree, start_pos, end_of_last_block, GFP_NOFS);
328 up_read(&BTRFS_I(inode)->root->snap_sem);
332 int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end)
334 struct extent_map *em;
335 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
338 em = lookup_extent_mapping(em_tree, start, end);
341 remove_extent_mapping(em_tree, em);
344 /* once for the tree*/
351 * this is very complex, but the basic idea is to drop all extents
352 * in the range start - end. hint_block is filled in with a block number
353 * that would be a good hint to the block allocator for this file.
355 * If an extent intersects the range but is not entirely inside the range
356 * it is either truncated or split. Anything entirely inside the range
357 * is deleted from the tree.
359 int btrfs_drop_extents(struct btrfs_trans_handle *trans,
360 struct btrfs_root *root, struct inode *inode,
361 u64 start, u64 end, u64 inline_end, u64 *hint_byte)
364 struct btrfs_key key;
365 struct extent_buffer *leaf;
367 struct btrfs_file_extent_item *extent;
370 struct btrfs_file_extent_item old;
371 struct btrfs_path *path;
372 u64 search_start = start;
379 btrfs_drop_extent_cache(inode, start, end - 1);
381 path = btrfs_alloc_path();
386 btrfs_release_path(root, path);
387 ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
392 if (path->slots[0] == 0) {
404 leaf = path->nodes[0];
405 slot = path->slots[0];
407 btrfs_item_key_to_cpu(leaf, &key, slot);
408 if (key.offset >= end || key.objectid != inode->i_ino) {
411 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY) {
415 search_start = key.offset;
418 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
419 extent = btrfs_item_ptr(leaf, slot,
420 struct btrfs_file_extent_item);
421 found_type = btrfs_file_extent_type(leaf, extent);
422 if (found_type == BTRFS_FILE_EXTENT_REG) {
423 extent_end = key.offset +
424 btrfs_file_extent_num_bytes(leaf, extent);
426 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
427 struct btrfs_item *item;
428 item = btrfs_item_nr(leaf, slot);
430 extent_end = key.offset +
431 btrfs_file_extent_inline_len(leaf, item);
434 extent_end = search_start;
437 /* we found nothing we can drop */
438 if ((!found_extent && !found_inline) ||
439 search_start >= extent_end) {
442 nritems = btrfs_header_nritems(leaf);
443 if (slot >= nritems - 1) {
444 nextret = btrfs_next_leaf(root, path);
454 /* FIXME, there's only one inline extent allowed right now */
456 u64 mask = root->sectorsize - 1;
457 search_start = (extent_end + mask) & ~mask;
459 search_start = extent_end;
461 if (end < extent_end && end >= key.offset) {
464 btrfs_file_extent_disk_bytenr(leaf, extent);
466 btrfs_file_extent_disk_num_bytes(leaf,
468 read_extent_buffer(leaf, &old,
469 (unsigned long)extent,
471 if (disk_bytenr != 0) {
472 ret = btrfs_inc_extent_ref(trans, root,
473 disk_bytenr, disk_num_bytes);
480 /* truncate existing extent */
481 if (start > key.offset) {
485 WARN_ON(start & (root->sectorsize - 1));
487 new_num = start - key.offset;
488 old_num = btrfs_file_extent_num_bytes(leaf,
491 btrfs_file_extent_disk_bytenr(leaf,
493 if (btrfs_file_extent_disk_bytenr(leaf,
496 (old_num - new_num) >> 9;
498 btrfs_set_file_extent_num_bytes(leaf, extent,
500 btrfs_mark_buffer_dirty(leaf);
501 } else if (end > extent_end &&
502 key.offset < inline_end &&
503 inline_end < extent_end) {
505 new_size = btrfs_file_extent_calc_inline_size(
506 inline_end - key.offset);
507 btrfs_truncate_item(trans, root, path,
511 /* delete the entire extent */
514 u64 disk_num_bytes = 0;
515 u64 extent_num_bytes = 0;
518 btrfs_file_extent_disk_bytenr(leaf,
521 btrfs_file_extent_disk_num_bytes(leaf,
524 btrfs_file_extent_num_bytes(leaf, extent);
526 btrfs_file_extent_disk_bytenr(leaf,
529 ret = btrfs_del_item(trans, root, path);
530 /* TODO update progress marker and return */
532 btrfs_release_path(root, path);
534 if (found_extent && disk_bytenr != 0) {
535 inode->i_blocks -= extent_num_bytes >> 9;
536 ret = btrfs_free_extent(trans, root,
542 if (!bookend && search_start >= end) {
549 /* create bookend, splitting the extent in two */
550 if (bookend && found_extent) {
551 struct btrfs_key ins;
552 ins.objectid = inode->i_ino;
554 btrfs_set_key_type(&ins, BTRFS_EXTENT_DATA_KEY);
555 btrfs_release_path(root, path);
556 ret = btrfs_insert_empty_item(trans, root, path, &ins,
559 leaf = path->nodes[0];
561 btrfs_print_leaf(root, leaf);
562 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);
565 extent = btrfs_item_ptr(leaf, path->slots[0],
566 struct btrfs_file_extent_item);
567 write_extent_buffer(leaf, &old,
568 (unsigned long)extent, sizeof(old));
570 btrfs_set_file_extent_offset(leaf, extent,
571 le64_to_cpu(old.offset) + end - key.offset);
572 WARN_ON(le64_to_cpu(old.num_bytes) <
574 btrfs_set_file_extent_num_bytes(leaf, extent,
576 btrfs_set_file_extent_type(leaf, extent,
577 BTRFS_FILE_EXTENT_REG);
579 btrfs_mark_buffer_dirty(path->nodes[0]);
580 if (le64_to_cpu(old.disk_bytenr) != 0) {
582 btrfs_file_extent_num_bytes(leaf,
590 btrfs_free_path(path);
595 * this gets pages into the page cache and locks them down
597 static int prepare_pages(struct btrfs_root *root,
602 unsigned long first_index,
603 unsigned long last_index,
607 unsigned long index = pos >> PAGE_CACHE_SHIFT;
608 struct inode *inode = file->f_path.dentry->d_inode;
612 start_pos = pos & ~((u64)root->sectorsize - 1);
614 memset(pages, 0, num_pages * sizeof(struct page *));
616 for (i = 0; i < num_pages; i++) {
617 pages[i] = grab_cache_page(inode->i_mapping, index + i);
622 cancel_dirty_page(pages[i], PAGE_CACHE_SIZE);
623 wait_on_page_writeback(pages[i]);
624 set_page_extent_mapped(pages[i]);
625 WARN_ON(!PageLocked(pages[i]));
630 static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
631 size_t count, loff_t *ppos)
634 size_t num_written = 0;
637 struct inode *inode = file->f_path.dentry->d_inode;
638 struct btrfs_root *root = BTRFS_I(inode)->root;
639 struct page **pages = NULL;
641 struct page *pinned[2];
642 unsigned long first_index;
643 unsigned long last_index;
645 nrptrs = min((count + PAGE_CACHE_SIZE - 1) / PAGE_CACHE_SIZE,
646 PAGE_CACHE_SIZE / (sizeof(struct page *)));
649 if (file->f_flags & O_DIRECT)
652 vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
653 current->backing_dev_info = inode->i_mapping->backing_dev_info;
654 err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
659 err = remove_suid(file->f_path.dentry);
662 file_update_time(file);
664 pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
666 mutex_lock(&inode->i_mutex);
667 first_index = pos >> PAGE_CACHE_SHIFT;
668 last_index = (pos + count) >> PAGE_CACHE_SHIFT;
671 * there are lots of better ways to do this, but this code
672 * makes sure the first and last page in the file range are
673 * up to date and ready for cow
675 if ((pos & (PAGE_CACHE_SIZE - 1))) {
676 pinned[0] = grab_cache_page(inode->i_mapping, first_index);
677 if (!PageUptodate(pinned[0])) {
678 ret = btrfs_readpage(NULL, pinned[0]);
680 wait_on_page_locked(pinned[0]);
682 unlock_page(pinned[0]);
685 if ((pos + count) & (PAGE_CACHE_SIZE - 1)) {
686 pinned[1] = grab_cache_page(inode->i_mapping, last_index);
687 if (!PageUptodate(pinned[1])) {
688 ret = btrfs_readpage(NULL, pinned[1]);
690 wait_on_page_locked(pinned[1]);
692 unlock_page(pinned[1]);
697 size_t offset = pos & (PAGE_CACHE_SIZE - 1);
698 size_t write_bytes = min(count, nrptrs *
699 (size_t)PAGE_CACHE_SIZE -
701 size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >>
704 WARN_ON(num_pages > nrptrs);
705 memset(pages, 0, sizeof(pages));
706 ret = prepare_pages(root, file, pages, num_pages,
707 pos, first_index, last_index,
712 ret = btrfs_copy_from_user(pos, num_pages,
713 write_bytes, pages, buf);
715 btrfs_drop_pages(pages, num_pages);
719 ret = dirty_and_release_pages(NULL, root, file, pages,
720 num_pages, pos, write_bytes);
721 btrfs_drop_pages(pages, num_pages);
726 count -= write_bytes;
728 num_written += write_bytes;
730 balance_dirty_pages_ratelimited_nr(inode->i_mapping, num_pages);
731 btrfs_btree_balance_dirty(root, 1);
734 mutex_unlock(&inode->i_mutex);
738 page_cache_release(pinned[0]);
740 page_cache_release(pinned[1]);
742 current->backing_dev_info = NULL;
743 return num_written ? num_written : err;
746 static int btrfs_sync_file(struct file *file,
747 struct dentry *dentry, int datasync)
749 struct inode *inode = dentry->d_inode;
750 struct btrfs_root *root = BTRFS_I(inode)->root;
752 struct btrfs_trans_handle *trans;
755 * check the transaction that last modified this inode
756 * and see if its already been committed
758 mutex_lock(&root->fs_info->fs_mutex);
759 if (!BTRFS_I(inode)->last_trans)
761 mutex_lock(&root->fs_info->trans_mutex);
762 if (BTRFS_I(inode)->last_trans <=
763 root->fs_info->last_trans_committed) {
764 BTRFS_I(inode)->last_trans = 0;
765 mutex_unlock(&root->fs_info->trans_mutex);
768 mutex_unlock(&root->fs_info->trans_mutex);
771 * ok we haven't committed the transaction yet, lets do a commit
773 trans = btrfs_start_transaction(root, 1);
778 ret = btrfs_commit_transaction(trans, root);
780 mutex_unlock(&root->fs_info->fs_mutex);
781 return ret > 0 ? EIO : ret;
784 static struct vm_operations_struct btrfs_file_vm_ops = {
785 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
786 .nopage = filemap_nopage,
787 .populate = filemap_populate,
789 .fault = filemap_fault,
791 .page_mkwrite = btrfs_page_mkwrite,
794 static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
796 vma->vm_ops = &btrfs_file_vm_ops;
801 struct file_operations btrfs_file_operations = {
802 .llseek = generic_file_llseek,
803 .read = do_sync_read,
804 .aio_read = generic_file_aio_read,
805 .write = btrfs_file_write,
806 .mmap = btrfs_file_mmap,
807 .open = generic_file_open,
808 .fsync = btrfs_sync_file,
809 .unlocked_ioctl = btrfs_ioctl,
811 .compat_ioctl = btrfs_ioctl,