ceph: clean up handle_cap_grant, handle_caps wrt session mutex

Drop session mutex unconditionally in handle_cap_grant, and do the
check_caps from the handle_cap_grant helper.  This avoids using a magic
return value.

Also avoid using a flag variable in the IMPORT case and call
check_caps at the appropriate point.

Signed-off-by: Sage Weil <sage@newdream.net>

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 7828486..d9e860f 100644 (file)
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -2195,18 +2195,19 @@ void ceph_put_wrbuffer_cap_refs(struct ceph_inode_info *ci, int nr,
  * Handle a cap GRANT message from the MDS.  (Note that a GRANT may
  * actually be a revocation if it specifies a smaller cap set.)
  *
- * caller holds s_mutex.
+ * caller holds s_mutex and i_lock, we drop both.
+ *
  * return value:
  *  0 - ok
  *  1 - check_caps on auth cap only (writeback)
  *  2 - check_caps (ack revoke)
  */
-static int handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
-                           struct ceph_mds_session *session,
-                           struct ceph_cap *cap,
-                           struct ceph_buffer *xattr_buf)
+static void handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
+                            struct ceph_mds_session *session,
+                            struct ceph_cap *cap,
+                            struct ceph_buffer *xattr_buf)
        __releases(inode->i_lock)
-
+       __releases(session->s_mutex)
 {
        struct ceph_inode_info *ci = ceph_inode(inode);
        int mds = session->s_mds;
@@ -2216,7 +2217,7 @@ static int handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
        u64 size = le64_to_cpu(grant->size);
        u64 max_size = le64_to_cpu(grant->max_size);
        struct timespec mtime, atime, ctime;
-       int reply = 0;
+       int check_caps = 0;
        int wake = 0;
        int writeback = 0;
        int revoked_rdcache = 0;
@@ -2329,10 +2330,10 @@ static int handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
                if ((used & ~newcaps) & CEPH_CAP_FILE_BUFFER)
                        writeback = 1; /* will delay ack */
                else if (dirty & ~newcaps)
-                       reply = 1;     /* initiate writeback in check_caps */
+                       check_caps = 1;  /* initiate writeback in check_caps */
                else if (((used & ~newcaps) & CEPH_CAP_FILE_CACHE) == 0 ||
                           revoked_rdcache)
-                       reply = 2;     /* send revoke ack in check_caps */
+                       check_caps = 2;     /* send revoke ack in check_caps */
                cap->issued = newcaps;
                cap->implemented |= newcaps;
        } else if (cap->issued == newcaps) {
@@ -2361,7 +2362,14 @@ static int handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
                ceph_queue_invalidate(inode);
        if (wake)
                wake_up(&ci->i_cap_wq);
-       return reply;
+
+       if (check_caps == 1)
+               ceph_check_caps(ci, CHECK_CAPS_NODELAY|CHECK_CAPS_AUTHONLY,
+                               session);
+       else if (check_caps == 2)
+               ceph_check_caps(ci, CHECK_CAPS_NODELAY, session);
+       else
+               mutex_unlock(&session->s_mutex);
 }
 
 /*
@@ -2622,9 +2630,7 @@ void ceph_handle_caps(struct ceph_mds_session *session,
        u64 cap_id;
        u64 size, max_size;
        u64 tid;
-       int check_caps = 0;
        void *snaptrace;
-       int r;
 
        dout("handle_caps from mds%d\n", mds);
 
@@ -2669,8 +2675,9 @@ void ceph_handle_caps(struct ceph_mds_session *session,
        case CEPH_CAP_OP_IMPORT:
                handle_cap_import(mdsc, inode, h, session,
                                  snaptrace, le32_to_cpu(h->snap_trace_len));
-               check_caps = 1; /* we may have sent a RELEASE to the old auth */
-               goto done;
+               ceph_check_caps(ceph_inode(inode), CHECK_CAPS_NODELAY,
+                               session);
+               goto done_unlocked;
        }
 
        /* the rest require a cap */
@@ -2687,19 +2694,8 @@ void ceph_handle_caps(struct ceph_mds_session *session,
        switch (op) {
        case CEPH_CAP_OP_REVOKE:
        case CEPH_CAP_OP_GRANT:
-               r = handle_cap_grant(inode, h, session, cap, msg->middle);
-               if (r == 1) {
-                       ceph_check_caps(ceph_inode(inode),
-                                       CHECK_CAPS_NODELAY|CHECK_CAPS_AUTHONLY,
-                                       session);
-                       session = NULL;
-               } else if (r == 2) {
-                       ceph_check_caps(ceph_inode(inode),
-                                       CHECK_CAPS_NODELAY,
-                                       session);
-                       session = NULL;
-               }
-               break;
+               handle_cap_grant(inode, h, session, cap, msg->middle);
+               goto done_unlocked;
 
        case CEPH_CAP_OP_FLUSH_ACK:
                handle_cap_flush_ack(inode, tid, h, session, cap);
@@ -2716,11 +2712,8 @@ void ceph_handle_caps(struct ceph_mds_session *session,
        }
 
 done:
-       if (session)
-               mutex_unlock(&session->s_mutex);
-
-       if (check_caps)
-               ceph_check_caps(ceph_inode(inode), CHECK_CAPS_NODELAY, NULL);
+       mutex_unlock(&session->s_mutex);
+done_unlocked:
        if (inode)
                iput(inode);
        return;