diff options
| author | Sage Weil <sage@newdream.net> | 2010-03-16 13:39:28 -0700 |
|---|---|---|
| committer | Sage Weil <sage@newdream.net> | 2010-03-23 07:46:53 -0700 |
| commit | cdc2ce056a3620139056b60ad7f6d355ad13f445 (patch) | |
| tree | 1aed7f66612d13beeeec6e2c191f19eff44d1054 /fs/ceph | |
| parent | 4ea0043a29c82ca52ca54728d837314563bec574 (diff) | |
ceph: fix session locking in handle_caps, ceph_check_caps
Passing a session pointer to ceph_check_caps() used to mean it would leave
the session mutex locked. That wasn't always possible if it wasn't passed
CHECK_CAPS_AUTHONLY. If could unlock the passed session and lock a
differet session mutex, which was clearly wrong, and also emitted a
warning when it a racing CPU retook it and we did an unlock from the wrong
context.
This was only a problem when there was more than one MDS.
First, make ceph_check_caps unconditionally drop the session mutex, so that
it is free to lock other sessions as needed. Then adjust the one caller
that passes in a session (handle_cap_grant) accordingly.
Signed-off-by: Sage Weil <sage@newdream.net>
Diffstat (limited to 'fs/ceph')
| -rw-r--r-- | fs/ceph/caps.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index 726c8d445995..782848632e81 100644 --- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -1407,6 +1407,7 @@ static int try_nonblocking_invalidate(struct inode *inode) */ void ceph_check_caps(struct ceph_inode_info *ci, int flags, struct ceph_mds_session *session) + __releases(session->s_mutex) { struct ceph_client *client = ceph_inode_to_client(&ci->vfs_inode); struct ceph_mds_client *mdsc = &client->mdsc; @@ -1414,7 +1415,6 @@ void ceph_check_caps(struct ceph_inode_info *ci, int flags, struct ceph_cap *cap; int file_wanted, used; int took_snap_rwsem = 0; /* true if mdsc->snap_rwsem held */ - int drop_session_lock = session ? 0 : 1; 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 */ @@ -1639,7 +1639,7 @@ ack: if (queue_invalidate) ceph_queue_invalidate(inode); - if (session && drop_session_lock) + if (session) mutex_unlock(&session->s_mutex); if (took_snap_rwsem) up_read(&mdsc->snap_rwsem); @@ -2688,14 +2688,17 @@ void ceph_handle_caps(struct ceph_mds_session *session, case CEPH_CAP_OP_REVOKE: case CEPH_CAP_OP_GRANT: r = handle_cap_grant(inode, h, session, cap, msg->middle); - if (r == 1) + if (r == 1) { ceph_check_caps(ceph_inode(inode), CHECK_CAPS_NODELAY|CHECK_CAPS_AUTHONLY, session); - else if (r == 2) + session = NULL; + } else if (r == 2) { ceph_check_caps(ceph_inode(inode), CHECK_CAPS_NODELAY, session); + session = NULL; + } break; case CEPH_CAP_OP_FLUSH_ACK: @@ -2713,7 +2716,8 @@ void ceph_handle_caps(struct ceph_mds_session *session, } done: - mutex_unlock(&session->s_mutex); + if (session) + mutex_unlock(&session->s_mutex); if (check_caps) ceph_check_caps(ceph_inode(inode), CHECK_CAPS_NODELAY, NULL); |