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authorJeff Layton <jlayton@kernel.org>2021-06-01 09:24:38 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-08-18 09:07:08 +0200
commitdcd02a1248cc4a6a889a1ea00734c201d14f5f1a (patch)
tree8215112bdc5d57f3df5cc1c79dbcee17ee1402d0
parent36b361cb1966dea56408c2f9214def2199d13c29 (diff)
ceph: clean up locking annotation for ceph_get_snap_realm and __lookup_snap_realm
commit df2c0cb7f8e8c83e495260ad86df8c5da947f2a7 upstream. 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 <jlayton@kernel.org> Reviewed-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/ceph/snap.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c
index 08cd1751ba63..43ebfc9e6fae 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);