ceph: must hold snap_rwsem when filling inode for async create
...and add a lockdep assertion for it to ceph_fill_inode().
Cc: stable@vger.kernel.org # v5.7+
Fixes: 9a8d03ca2e2c3 ("ceph: attempt to do async create when possible")
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 77fc037..4dc9688 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -578,6 +578,7 @@ static int ceph_finish_async_create(struct inode *dir, struct dentry *dentry,
struct ceph_inode_info *ci = ceph_inode(dir);
struct inode *inode;
struct timespec64 now;
+ struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
struct ceph_vino vino = { .ino = req->r_deleg_ino,
.snap = CEPH_NOSNAP };
@@ -615,8 +616,10 @@ static int ceph_finish_async_create(struct inode *dir, struct dentry *dentry,
ceph_file_layout_to_legacy(lo, &in.layout);
+ down_read(&mdsc->snap_rwsem);
ret = ceph_fill_inode(inode, NULL, &iinfo, NULL, req->r_session,
req->r_fmode, NULL);
+ up_read(&mdsc->snap_rwsem);
if (ret) {
dout("%s failed to fill inode: %d\n", __func__, ret);
ceph_dir_clear_complete(dir);