These locks appear to be completely unnecessary. Almost all of this
function is done under the inode->i_ceph_lock, aside from the actual
sending of the message. Don't take either lock in this function.
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/ceph/caps.c | 61 ++++++--------------------------------------------
1 file changed, 7 insertions(+), 54 deletions(-)
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 919eada97a1f..825b1e463ad3 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -1912,7 +1912,6 @@ void ceph_check_caps(struct ceph_inode_info *ci, int flags,
struct ceph_cap *cap;
u64 flush_tid, oldest_flush_tid;
int file_wanted, used, cap_used;
- int took_snap_rwsem = 0; /* true if mdsc->snap_rwsem held */
int issued, implemented, want, retain, revoking, flushing = 0;
int mds = -1; /* keep track of how far we've gone through i_caps list
to avoid an infinite loop on retry */
@@ -1920,6 +1919,9 @@ void ceph_check_caps(struct ceph_inode_info *ci, int flags,
bool queue_invalidate = false;
bool tried_invalidate = false;
+ if (session)
+ ceph_get_mds_session(session);
+
spin_lock(&ci->i_ceph_lock);
if (ci->i_ceph_flags & CEPH_I_FLUSH)
flags |= CHECK_CAPS_FLUSH;
@@ -2021,8 +2023,6 @@ void ceph_check_caps(struct ceph_inode_info *ci, int flags,
((flags & CHECK_CAPS_AUTHONLY) && cap != ci->i_auth_cap))
continue;
- /* NOTE: no side-effects allowed, until we take s_mutex */
-
/*
* If we have an auth cap, we don't need to consider any
* overlapping caps as used.
@@ -2085,37 +2085,8 @@ void ceph_check_caps(struct ceph_inode_info *ci, int flags,
continue; /* nope, all good */
ack:
- if (session && session != cap->session) {
- dout("oops, wrong session %p mutex\n", session);
- mutex_unlock(&session->s_mutex);
- session = NULL;
- }
- if (!session) {
- session = cap->session;
- if (mutex_trylock(&session->s_mutex) == 0) {
- dout("inverting session/ino locks on %p\n",
- session);
- session = ceph_get_mds_session(session);
- spin_unlock(&ci->i_ceph_lock);
- if (took_snap_rwsem) {
- up_read(&mdsc->snap_rwsem);
- took_snap_rwsem = 0;
- }
- if (session) {
- mutex_lock(&session->s_mutex);
- ceph_put_mds_session(session);
- } else {
- /*
- * Because we take the reference while
- * holding the i_ceph_lock, it should
- * never be NULL. Throw a warning if it
- * ever is.
- */
- WARN_ON_ONCE(true);
- }
- goto retry;
- }
- }
+ ceph_put_mds_session(session);
+ session = ceph_get_mds_session(cap->session);
/* kick flushing and flush snaps before sending normal
* cap message */
@@ -2130,19 +2101,6 @@ void ceph_check_caps(struct ceph_inode_info *ci, int flags,
goto retry_locked;
}
- /* take snap_rwsem after session mutex */
- if (!took_snap_rwsem) {
- if (down_read_trylock(&mdsc->snap_rwsem) == 0) {
- dout("inverting snap/in locks on %p\n",
- inode);
- spin_unlock(&ci->i_ceph_lock);
- down_read(&mdsc->snap_rwsem);
- took_snap_rwsem = 1;
- goto retry;
- }
- took_snap_rwsem = 1;
- }
-
if (cap == ci->i_auth_cap && ci->i_dirty_caps) {
flushing = ci->i_dirty_caps;
flush_tid = __mark_caps_flushing(inode, session, false,
@@ -2179,13 +2137,9 @@ void ceph_check_caps(struct ceph_inode_info *ci, int flags,
spin_unlock(&ci->i_ceph_lock);
+ ceph_put_mds_session(session);
if (queue_invalidate)
ceph_queue_invalidate(inode);
-
- if (session)
- mutex_unlock(&session->s_mutex);
- if (took_snap_rwsem)
- up_read(&mdsc->snap_rwsem);
}
/*
@@ -3550,13 +3504,12 @@ static void handle_cap_grant(struct inode *inode,
if (wake)
wake_up_all(&ci->i_cap_wq);
+ mutex_unlock(&session->s_mutex);
if (check_caps == 1)
ceph_check_caps(ci, CHECK_CAPS_AUTHONLY | CHECK_CAPS_NOINVAL,
session);
else if (check_caps == 2)
ceph_check_caps(ci, CHECK_CAPS_NOINVAL, session);
- else
- mutex_unlock(&session->s_mutex);
}
/*
--
2.31.1
