kclient: try to release RDCACHE if _no_ caps are wanted

As Yehuda pointed out, we aren't really concerned about invalidating pages and
releasing RDCACHE if we are still open for write.  So only bother releasing
RDCACHE when we have _no_ more interest in the file.  If there is a conflict,
the MDS will just revoke.

diff --git a/src/kernel/caps.c b/src/kernel/caps.c
index 9110f12ad3828323f73f745f7aeb7c9979286a2f..3c98922b1b6b88027f5978aa186bd0d95398cb6e 100644 (file)
--- a/src/kernel/caps.c
+++ b/src/kernel/caps.c
@@ -273,7 +273,7 @@ void ceph_remove_cap(struct ceph_cap *cap)
  *    -> we take mdsc->cap_delay_lock
  */
 static void __cap_delay_requeue(struct ceph_mds_client *mdsc,
-                             struct ceph_inode_info *ci)
+                               struct ceph_inode_info *ci)
 {
        ci->i_hold_caps_until = round_jiffies(jiffies + HZ * 5);
        dout(10, "__cap_delay_requeue %p at %lu\n", &ci->vfs_inode,
@@ -568,7 +568,7 @@ retry_locked:
 
        /*
         * Reschedule delayed caps release, unless we are called from
-        * the delayed work handler.
+        * the delayed work handler (i.e. this _is_ the delayed release)
         */
        if (!is_delayed)
                __cap_delay_requeue(mdsc, ci);
@@ -581,7 +581,7 @@ retry_locked:
        if (!time_before(jiffies, ci->i_hold_caps_until) &&
            ci->i_wrbuffer_ref == 0 &&               /* no dirty pages... */
            ci->i_rdcache_gen &&                     /* may have cached pages */
-           (file_wanted & CEPH_CAP_RDCACHE) == 0 && /* but don't need them */
+           file_wanted == 0 &&                      /* no open files */
            !tried_invalidate) {
                u32 invalidating_gen = ci->i_rdcache_gen;
                int ret;
@@ -917,7 +917,7 @@ static int handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
        int wake = 0;
        int writeback = 0;
        int revoked_rdcache = 0;
-       int invalidate = 0;
+       int invalidate_async = 0;
        int tried_invalidate = 0;
        int ret;
 
@@ -956,8 +956,8 @@ start:
         * try to invalidate (once).  (If there are dirty buffers, we
         * will invalidate _after_ writeback.)
         */
-       if (((cap->issued & ~newcaps) & CEPH_CAP_RDCACHE)
-           && !ci->i_wrbuffer_ref && !tried_invalidate) {
+       if (((cap->issued & ~newcaps) & CEPH_CAP_RDCACHE) &&
+           !ci->i_wrbuffer_ref && !tried_invalidate) {
                dout(10, "RDCACHE invalidation\n");
                spin_unlock(&inode->i_lock);
                tried_invalidate = 1;
@@ -968,7 +968,7 @@ start:
                        /* there were locked pages.. invalidate later
                           in a separate thread. */
                        if (ci->i_rdcache_revoking != ci->i_rdcache_gen) {
-                               invalidate = 1;
+                               invalidate_async = 1;
                                ci->i_rdcache_revoking = ci->i_rdcache_gen;
                        }
                } else {
@@ -1067,7 +1067,7 @@ out:
                dout(10, "queueing %p for writeback\n", inode);
                ceph_queue_writeback(inode);
        }
-       if (invalidate) {
+       if (invalidate_async) {
                dout(10, "queueing %p for page invalidation\n", inode);
                ceph_queue_page_invalidation(inode);
        }