4.9-stable review patch. If anyone has any objections, please let me know.
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From: Chengguang Xu cgxu519@icloud.com
[ Upstream commit 18106734b512664a8541026519ce4b862498b6c3 ]
When failing from ceph_fs_debugfs_init() in ceph_real_mount(), there is lack of dput of root_dentry and it causes slab errors, so change the calling order of ceph_fs_debugfs_init() and open_root_dentry() and do some cleanups to avoid this issue.
Signed-off-by: Chengguang Xu cgxu519@icloud.com Reviewed-by: "Yan, Zheng" zyan@redhat.com Signed-off-by: Ilya Dryomov idryomov@gmail.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ceph/super.c | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-)
--- a/fs/ceph/super.c +++ b/fs/ceph/super.c @@ -816,7 +816,6 @@ static struct dentry *ceph_real_mount(st int err; unsigned long started = jiffies; /* note the start time */ struct dentry *root; - int first = 0; /* first vfsmount for this super_block */
dout("mount start %p\n", fsc); mutex_lock(&fsc->client->mount_mutex); @@ -834,17 +833,17 @@ static struct dentry *ceph_real_mount(st path = fsc->mount_options->server_path + 1; dout("mount opening path %s\n", path); } + + err = ceph_fs_debugfs_init(fsc); + if (err < 0) + goto out; + root = open_root_dentry(fsc, path, started); if (IS_ERR(root)) { err = PTR_ERR(root); goto out; } fsc->sb->s_root = dget(root); - first = 1; - - err = ceph_fs_debugfs_init(fsc); - if (err < 0) - goto fail; } else { root = dget(fsc->sb->s_root); } @@ -854,11 +853,6 @@ static struct dentry *ceph_real_mount(st mutex_unlock(&fsc->client->mount_mutex); return root;
-fail: - if (first) { - dput(fsc->sb->s_root); - fsc->sb->s_root = NULL; - } out: mutex_unlock(&fsc->client->mount_mutex); return ERR_PTR(err);