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| author | Jeff Mahoney <jeffm@suse.com> | 2016-08-17 21:58:33 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-09-07 08:34:53 +0200 |
| commit | ff3235105fc7e4ecf04eb308940821d4a098c08d (patch) | |
| tree | 69d06ff0c927b0f239cf722b168cf98641eb06b4 | |
| parent | 64563a38fde57a26f4d68d488d0d4918f843547c (diff) | |
| download | lwn-ff3235105fc7e4ecf04eb308940821d4a098c08d.tar.gz lwn-ff3235105fc7e4ecf04eb308940821d4a098c08d.zip | |
btrfs: don't create or leak aliased root while cleaning up orphans
commit 35bbb97fc898aeb874cb7c8b746f091caa359994 upstream.
commit 909c3a22da3 (Btrfs: fix loading of orphan roots leading to BUG_ON)
avoids the BUG_ON but can add an aliased root to the dead_roots list or
leak the root.
Since we've already been loading roots into the radix tree, we should
use it before looking the root up on disk.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/btrfs/disk-io.c | 4 | ||||
| -rw-r--r-- | fs/btrfs/disk-io.h | 2 | ||||
| -rw-r--r-- | fs/btrfs/root-tree.c | 27 |
3 files changed, 22 insertions, 11 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 7cfa2bd75b0d..864cf3be0251 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1626,8 +1626,8 @@ fail: return ret; } -static struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info, - u64 root_id) +struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info, + u64 root_id) { struct btrfs_root *root; diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h index acba821499a9..355e31f90106 100644 --- a/fs/btrfs/disk-io.h +++ b/fs/btrfs/disk-io.h @@ -68,6 +68,8 @@ struct extent_buffer *btrfs_find_tree_block(struct btrfs_fs_info *fs_info, struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root, struct btrfs_key *location); int btrfs_init_fs_root(struct btrfs_root *root); +struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info, + u64 root_id); int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root); void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info); diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c index f1c30861d062..3454aa4faecb 100644 --- a/fs/btrfs/root-tree.c +++ b/fs/btrfs/root-tree.c @@ -272,6 +272,23 @@ int btrfs_find_orphan_roots(struct btrfs_root *tree_root) root_key.objectid = key.offset; key.offset++; + /* + * The root might have been inserted already, as before we look + * for orphan roots, log replay might have happened, which + * triggers a transaction commit and qgroup accounting, which + * in turn reads and inserts fs roots while doing backref + * walking. + */ + root = btrfs_lookup_fs_root(tree_root->fs_info, + root_key.objectid); + if (root) { + WARN_ON(!test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, + &root->state)); + if (btrfs_root_refs(&root->root_item) == 0) + btrfs_add_dead_root(root); + continue; + } + root = btrfs_read_fs_root(tree_root, &root_key); err = PTR_ERR_OR_ZERO(root); if (err && err != -ENOENT) { @@ -310,16 +327,8 @@ int btrfs_find_orphan_roots(struct btrfs_root *tree_root) set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state); err = btrfs_insert_fs_root(root->fs_info, root); - /* - * The root might have been inserted already, as before we look - * for orphan roots, log replay might have happened, which - * triggers a transaction commit and qgroup accounting, which - * in turn reads and inserts fs roots while doing backref - * walking. - */ - if (err == -EEXIST) - err = 0; if (err) { + BUG_ON(err == -EEXIST); btrfs_free_fs_root(root); break; } |