From df2c0cb7f8e8c83e495260ad86df8c5da947f2a7 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Tue, 1 Jun 2021 09:24:38 -0400 Subject: [PATCH] ceph: clean up locking annotation for ceph_get_snap_realm and __lookup_snap_realm They both say that the snap_rwsem must be held for write, but I don't see any real reason for it, and it's not currently always called that way. The lookup is just walking the rbtree, so holding it for read should be fine there. The "get" is bumping the refcount and (possibly) removing it from the empty list. I see no need to hold the snap_rwsem for write for that. Signed-off-by: Jeff Layton Reviewed-by: Ilya Dryomov Signed-off-by: Ilya Dryomov --- fs/ceph/snap.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c index bc6c33d485e6..f8cac2abab3f 100644 --- a/fs/ceph/snap.c +++ b/fs/ceph/snap.c @@ -60,12 +60,12 @@ /* * increase ref count for the realm * - * caller must hold snap_rwsem for write. + * caller must hold snap_rwsem. */ void ceph_get_snap_realm(struct ceph_mds_client *mdsc, struct ceph_snap_realm *realm) { - lockdep_assert_held_write(&mdsc->snap_rwsem); + lockdep_assert_held(&mdsc->snap_rwsem); dout("get_realm %p %d -> %d\n", realm, atomic_read(&realm->nref), atomic_read(&realm->nref)+1); @@ -139,7 +139,7 @@ static struct ceph_snap_realm *ceph_create_snap_realm( /* * lookup the realm rooted at @ino. * - * caller must hold snap_rwsem for write. + * caller must hold snap_rwsem. */ static struct ceph_snap_realm *__lookup_snap_realm(struct ceph_mds_client *mdsc, u64 ino) @@ -147,7 +147,7 @@ static struct ceph_snap_realm *__lookup_snap_realm(struct ceph_mds_client *mdsc, struct rb_node *n = mdsc->snap_realms.rb_node; struct ceph_snap_realm *r; - lockdep_assert_held_write(&mdsc->snap_rwsem); + lockdep_assert_held(&mdsc->snap_rwsem); while (n) { r = rb_entry(n, struct ceph_snap_realm, node); -- 2.20.1