From: Jeff Layton <jlayton@kernel.org>

Date: Tue, 1 Jun 2021 09:40:25 -0400

Subject: ceph: must hold snap_rwsem when filling inode for async create

Git-commit: 27171ae6a0fdc75571e5bf3d0961631a1e4fb765

Patch-mainline: v5.13

References: bsc#1187927

...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>

[luis: inlined ceph_sb_to_mdsc() helper, as we don't have commit

 2678da88f4b4 ]

Acked-by: Luis Henriques <lhenriques@suse.com>

---

 fs/ceph/file.c  |    3 +++

 fs/ceph/inode.c |    2 ++

 2 files changed, 5 insertions(+)

--- a/fs/ceph/file.c

+++ b/fs/ceph/file.c

@@ -579,6 +579,7 @@ static int ceph_finish_async_create(stru

 	struct ceph_inode_info *ci = ceph_inode(dir);

 	struct inode *inode;

 	struct timespec64 now;

+	struct ceph_mds_client *mdsc = ceph_sb_to_client(dir->i_sb)->mdsc;

 	struct ceph_vino vino = { .ino = req->r_deleg_ino,

 				  .snap = CEPH_NOSNAP };

@@ -616,8 +617,10 @@ static int ceph_finish_async_create(stru

 	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);

--- a/fs/ceph/inode.c

+++ b/fs/ceph/inode.c

@@ -768,6 +768,8 @@ int ceph_fill_inode(struct inode *inode,

 	bool new_version = false;

 	bool fill_inline = false;

+	lockdep_assert_held(&mdsc->snap_rwsem);

+

 	dout("%s %p ino %llx.%llx v %llu had %llu\n", __func__,

 	     inode, ceph_vinop(inode), le64_to_cpu(info->version),

 	     ci->i_version);