Btrfs: fix an oops of log replay
When btrfs recovers from a crash, it may hit the oops below:
------------[ cut here ]------------
kernel BUG at fs/btrfs/inode.c:4580!
[...]
RIP: 0010:[<ffffffffa03df251>] [<ffffffffa03df251>] btrfs_add_link+0x161/0x1c0 [btrfs]
[...]
Call Trace:
[<ffffffffa03e7b31>] ? btrfs_inode_ref_index+0x31/0x80 [btrfs]
[<ffffffffa04054e9>] add_inode_ref+0x319/0x3f0 [btrfs]
[<ffffffffa0407087>] replay_one_buffer+0x2c7/0x390 [btrfs]
[<ffffffffa040444a>] walk_down_log_tree+0x32a/0x480 [btrfs]
[<ffffffffa0404695>] walk_log_tree+0xf5/0x240 [btrfs]
[<ffffffffa0406cc0>] btrfs_recover_log_trees+0x250/0x350 [btrfs]
[<ffffffffa0406dc0>] ? btrfs_recover_log_trees+0x350/0x350 [btrfs]
[<ffffffffa03d18b2>] open_ctree+0x1442/0x17d0 [btrfs]
[...]
This comes from that while replaying an inode ref item, we forget to
check those old conflicting DIR_ITEM and DIR_INDEX items in fs/file tree,
then we will come to conflict corners which lead to BUG_ON().
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Tested-by: Andy Lutomirski <luto@mit.edu>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index babee65..786639f 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -799,14 +799,15 @@
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
- struct inode *dir;
- int ret;
struct btrfs_inode_ref *ref;
+ struct btrfs_dir_item *di;
+ struct inode *dir;
struct inode *inode;
- char *name;
- int namelen;
unsigned long ref_ptr;
unsigned long ref_end;
+ char *name;
+ int namelen;
+ int ret;
int search_done = 0;
/*
@@ -909,6 +910,25 @@
}
btrfs_release_path(path);
+ /* look for a conflicting sequence number */
+ di = btrfs_lookup_dir_index_item(trans, root, path, btrfs_ino(dir),
+ btrfs_inode_ref_index(eb, ref),
+ name, namelen, 0);
+ if (di && !IS_ERR(di)) {
+ ret = drop_one_dir_item(trans, root, path, dir, di);
+ BUG_ON(ret);
+ }
+ btrfs_release_path(path);
+
+ /* look for a conflicing name */
+ di = btrfs_lookup_dir_item(trans, root, path, btrfs_ino(dir),
+ name, namelen, 0);
+ if (di && !IS_ERR(di)) {
+ ret = drop_one_dir_item(trans, root, path, dir, di);
+ BUG_ON(ret);
+ }
+ btrfs_release_path(path);
+
insert:
/* insert our name */
ret = btrfs_add_link(trans, dir, inode, name, namelen, 0,