Btrfs: Fix add_extent_mapping to check for duplicates across the whole range

add_extent_mapping was allowing the insertion of overlapping extents.
This never used to happen because it only inserted the extents from disk
and those were never overlapping.

But, with the data=ordered code, the disk and memory representations of the
file are not the same.  add_extent_mapping needs to ensure a new extent
does not overlap before it inserts.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason 2008-08-20 08:51:50 -04:00
parent 902b22f341
commit 7c2fe32a23
2 changed files with 24 additions and 4 deletions

View file

@ -207,7 +207,14 @@ int add_extent_mapping(struct extent_map_tree *tree,
int ret = 0;
struct extent_map *merge = NULL;
struct rb_node *rb;
struct extent_map *exist;
exist = lookup_extent_mapping(tree, em->start, em->len);
if (exist) {
free_extent_map(exist);
ret = -EEXIST;
goto out;
}
assert_spin_locked(&tree->lock);
rb = tree_insert(&tree->map, em->start, &em->rb_node);
if (rb) {

View file

@ -641,8 +641,9 @@ int btrfs_readpage_io_hook(struct page *page, u64 start, u64 end)
if (ret == -ENOENT || ret == -EFBIG)
ret = 0;
csum = 0;
printk("no csum found for inode %lu start %Lu\n", inode->i_ino,
start);
if (printk_ratelimit())
printk("no csum found for inode %lu start %Lu\n", inode->i_ino,
start);
goto out;
}
read_extent_buffer(path->nodes[0], &csum, (unsigned long)item,
@ -1653,8 +1654,20 @@ static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
btrfs_truncate_page(inode->i_mapping, inode->i_size);
hole_size = block_end - hole_start;
btrfs_wait_ordered_range(inode, hole_start, hole_size);
lock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
while(1) {
struct btrfs_ordered_extent *ordered;
btrfs_wait_ordered_range(inode, hole_start, hole_size);
lock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
ordered = btrfs_lookup_ordered_extent(inode, hole_start);
if (ordered) {
unlock_extent(io_tree, hole_start,
block_end - 1, GFP_NOFS);
btrfs_put_ordered_extent(ordered);
} else {
break;
}
}
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, inode);