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>
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 954b047..78ced11 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -207,7 +207,14 @@
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) {
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 6510789..6c77804 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -641,8 +641,9 @@
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 @@
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);