Btrfs: fix all callers of read_tree_block
We kept leaking extent buffers when mounting a broken file system and it turns
out it's because not everybody uses read_tree_block properly. You need to check
and make sure the extent_buffer is uptodate before you use it. This patch fixes
everybody who calls read_tree_block directly to make sure they check that it is
uptodate and free it and return an error if it is not. With this we no longer
leak EB's when things go horribly wrong. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 566d99b..2bc3440 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -1281,7 +1281,8 @@
free_extent_buffer(eb_root);
blocksize = btrfs_level_size(root, old_root->level);
old = read_tree_block(root, logical, blocksize, 0);
- if (!old) {
+ if (!old || !extent_buffer_uptodate(old)) {
+ free_extent_buffer(old);
pr_warn("btrfs: failed to read tree block %llu from get_old_root\n",
logical);
WARN_ON(1);
@@ -1526,8 +1527,10 @@
if (!cur) {
cur = read_tree_block(root, blocknr,
blocksize, gen);
- if (!cur)
+ if (!cur || !extent_buffer_uptodate(cur)) {
+ free_extent_buffer(cur);
return -EIO;
+ }
} else if (!uptodate) {
err = btrfs_read_buffer(cur, gen);
if (err) {
@@ -1692,6 +1695,8 @@
struct extent_buffer *parent, int slot)
{
int level = btrfs_header_level(parent);
+ struct extent_buffer *eb;
+
if (slot < 0)
return NULL;
if (slot >= btrfs_header_nritems(parent))
@@ -1699,9 +1704,15 @@
BUG_ON(level == 0);
- return read_tree_block(root, btrfs_node_blockptr(parent, slot),
- btrfs_level_size(root, level - 1),
- btrfs_node_ptr_generation(parent, slot));
+ eb = read_tree_block(root, btrfs_node_blockptr(parent, slot),
+ btrfs_level_size(root, level - 1),
+ btrfs_node_ptr_generation(parent, slot));
+ if (eb && !extent_buffer_uptodate(eb)) {
+ free_extent_buffer(eb);
+ eb = NULL;
+ }
+
+ return eb;
}
/*