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authorLiu Bo <bo.li.liu@oracle.com>2016-07-12 18:24:21 (GMT)
committerDavid Sterba <dsterba@suse.com>2016-07-26 11:52:25 (GMT)
commit5a488b9d2c25d98cdd11d09de311bfc83ba09fbd (patch)
tree3058eb9d14b1e7268b54f1d2f754e598d3c3e22a
parent0fd8c3dae14fb64947842472940b807ca0781da9 (diff)
downloadlinux-5a488b9d2c25d98cdd11d09de311bfc83ba09fbd.tar.xz
Btrfs: fix unexpected balance crash due to BUG_ON
Mounting a btrfs can resume previous balance operations asynchronously. An user got a crash when one drive has some corrupt sectors. Since balance can cancel itself in case of any error, we can gracefully return errors to upper layers and let balance do the cancel job. Reported-by: sash <master.b.at.raven@chefmail.de> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
-rw-r--r--fs/btrfs/volumes.c28
1 files changed, 24 insertions, 4 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 51bd3ee..05aec96 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3460,7 +3460,7 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info)
u64 size_to_free;
u64 chunk_type;
struct btrfs_chunk *chunk;
- struct btrfs_path *path;
+ struct btrfs_path *path = NULL;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_trans_handle *trans;
@@ -3494,13 +3494,33 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info)
ret = btrfs_shrink_device(device, old_size - size_to_free);
if (ret == -ENOSPC)
break;
- BUG_ON(ret);
+ if (ret) {
+ /* btrfs_shrink_device never returns ret > 0 */
+ WARN_ON(ret > 0);
+ goto error;
+ }
trans = btrfs_start_transaction(dev_root, 0);
- BUG_ON(IS_ERR(trans));
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ btrfs_info_in_rcu(fs_info,
+ "resize: unable to start transaction after shrinking device %s (error %d), old size %llu, new size %llu",
+ rcu_str_deref(device->name), ret,
+ old_size, old_size - size_to_free);
+ goto error;
+ }
ret = btrfs_grow_device(trans, device, old_size);
- BUG_ON(ret);
+ if (ret) {
+ btrfs_end_transaction(trans, dev_root);
+ /* btrfs_grow_device never returns ret > 0 */
+ WARN_ON(ret > 0);
+ btrfs_info_in_rcu(fs_info,
+ "resize: unable to grow device after shrinking device %s (error %d), old size %llu, new size %llu",
+ rcu_str_deref(device->name), ret,
+ old_size, old_size - size_to_free);
+ goto error;
+ }
btrfs_end_transaction(trans, dev_root);
}