path: root/fs
diff options
authorMiao Xie <miaox@cn.fujitsu.com>2013-09-25 21:47:44 +0800
committerChris Mason <chris.mason@fusionio.com>2013-10-10 21:31:02 -0400
commitc00869f1ae6a8fa49802d5e60d843b7051a112ec (patch)
treede5f151d7415a8653b5fa40dd265fd2db678aef8 /fs
parent14927d95464956ffe8af4278331a6bfea94ab780 (diff)
Btrfs: fix oops caused by the space balance and dead roots
When doing space balance and subvolume destroy at the same time, we met the following oops: kernel BUG at fs/btrfs/relocation.c:2247! RIP: 0010: [<ffffffffa04cec16>] prepare_to_merge+0x154/0x1f0 [btrfs] Call Trace: [<ffffffffa04b5ab7>] relocate_block_group+0x466/0x4e6 [btrfs] [<ffffffffa04b5c7a>] btrfs_relocate_block_group+0x143/0x275 [btrfs] [<ffffffffa0495c56>] btrfs_relocate_chunk.isra.27+0x5c/0x5a2 [btrfs] [<ffffffffa0459871>] ? btrfs_item_key_to_cpu+0x15/0x31 [btrfs] [<ffffffffa048b46a>] ? btrfs_get_token_64+0x7e/0xcd [btrfs] [<ffffffffa04a3467>] ? btrfs_tree_read_unlock_blocking+0xb2/0xb7 [btrfs] [<ffffffffa049907d>] btrfs_balance+0x9c7/0xb6f [btrfs] [<ffffffffa049ef84>] btrfs_ioctl_balance+0x234/0x2ac [btrfs] [<ffffffffa04a1e8e>] btrfs_ioctl+0xd87/0x1ef9 [btrfs] [<ffffffff81122f53>] ? path_openat+0x234/0x4db [<ffffffff813c3b78>] ? __do_page_fault+0x31d/0x391 [<ffffffff810f8ab6>] ? vma_link+0x74/0x94 [<ffffffff811250f5>] vfs_ioctl+0x1d/0x39 [<ffffffff811258c8>] do_vfs_ioctl+0x32d/0x3e2 [<ffffffff811259d4>] SyS_ioctl+0x57/0x83 [<ffffffff813c3bfa>] ? do_page_fault+0xe/0x10 [<ffffffff813c73c2>] system_call_fastpath+0x16/0x1b It is because we returned the error number if the reference of the root was 0 when doing space relocation. It was not right here, because though the root was dead(refs == 0), but the space it held still need be relocated, or we could not remove the block group. So in this case, we should return the root no matter it is dead or not. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Diffstat (limited to 'fs')
3 files changed, 17 insertions, 7 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 4ae17ed13b3..62176ad8984 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1561,8 +1561,9 @@ int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
return ret;
-struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
- struct btrfs_key *location)
+struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
+ struct btrfs_key *location,
+ bool check_ref)
struct btrfs_root *root;
int ret;
@@ -1586,7 +1587,7 @@ struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
root = btrfs_lookup_fs_root(fs_info, location->objectid);
if (root) {
- if (btrfs_root_refs(&root->root_item) == 0)
+ if (check_ref && btrfs_root_refs(&root->root_item) == 0)
return ERR_PTR(-ENOENT);
return root;
@@ -1595,7 +1596,7 @@ again:
if (IS_ERR(root))
return root;
- if (btrfs_root_refs(&root->root_item) == 0) {
+ if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
ret = -ENOENT;
goto fail;
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index b71acd6e1e5..5ce2a7da8b1 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -68,8 +68,17 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
int btrfs_init_fs_root(struct btrfs_root *root);
int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
struct btrfs_root *root);
-struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
- struct btrfs_key *location);
+struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
+ struct btrfs_key *key,
+ bool check_ref);
+static inline struct btrfs_root *
+btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
+ struct btrfs_key *location)
+ return btrfs_get_fs_root(fs_info, location, true);
int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info);
void btrfs_btree_balance_dirty(struct btrfs_root *root);
void btrfs_btree_balance_dirty_nodelay(struct btrfs_root *root);
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index a5a26320503..4a355726151 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -588,7 +588,7 @@ static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info,
key.offset = (u64)-1;
- return btrfs_read_fs_root_no_name(fs_info, &key);
+ return btrfs_get_fs_root(fs_info, &key, false);