From: Josef Bacik <josef@xxxxxxxxxxxxxx> [ Upstream commit 4cdfd93002cb84471ed85b4999cd38077a317873 ] We want to use this for dropping all roots, and in some error cases we may not have a root, so handle this to make the cleanup code easier. Make btrfs_grab_fs_root the same so we can use it in cases where the root may not exist (like the quota root). Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx> Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx> Reviewed-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- fs/btrfs/disk-io.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h index 8c2d6cf1ce596..424c9c97b1ce8 100644 --- a/fs/btrfs/disk-io.h +++ b/fs/btrfs/disk-io.h @@ -97,6 +97,8 @@ struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info); */ static inline struct btrfs_root *btrfs_grab_fs_root(struct btrfs_root *root) { + if (!root) + return NULL; if (refcount_inc_not_zero(&root->refs)) return root; return NULL; @@ -104,6 +106,8 @@ static inline struct btrfs_root *btrfs_grab_fs_root(struct btrfs_root *root) static inline void btrfs_put_fs_root(struct btrfs_root *root) { + if (!root) + return; if (refcount_dec_and_test(&root->refs)) kfree(root); } -- 2.20.1