GFS2: Eliminate redundant calls to may_grant

Function add_to_queue was checking may_grant for the passed-in
holder for every iteration of its gh2 loop. Now it only checks it
once at the beginning to see if a try lock is futile.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index fca6a87..e6c2fd5 100644 (file)
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -954,7 +954,7 @@ __acquires(&gl->gl_spin)
        struct gfs2_sbd *sdp = gl->gl_sbd;
        struct list_head *insert_pt = NULL;
        struct gfs2_holder *gh2;
-       int try_lock = 0;
+       int try_futile = 0;
 
        BUG_ON(gh->gh_owner_pid == NULL);
        if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
@@ -962,7 +962,7 @@ __acquires(&gl->gl_spin)
 
        if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
                if (test_bit(GLF_LOCK, &gl->gl_flags))
-                       try_lock = 1;
+                       try_futile = !may_grant(gl, gh);
                if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
                        goto fail;
        }
@@ -971,9 +971,8 @@ __acquires(&gl->gl_spin)
                if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid &&
                    (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK)))
                        goto trap_recursive;
-               if (try_lock &&
-                   !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) &&
-                   !may_grant(gl, gh)) {
+               if (try_futile &&
+                   !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
 fail:
                        gh->gh_error = GLR_TRYFAILED;
                        gfs2_holder_wake(gh);