[GFS2] Remove local exclusive glock mode

Here is a patch for GFS2 to remove the local exclusive flag. In
the places it was used, mutex's are always held earlier in the
call path, so it appears redundant in the LM_ST_SHARED case.

Also, the GFS2 holders were setting local exclusive in any case where
the requested lock was LM_ST_EXCLUSIVE. So the other places in the glock
code where the flag was tested have been replaced with tests for the
lock state being LM_ST_EXCLUSIVE in order to ensure the logic is the
same as before (i.e. LM_ST_EXCLUSIVE is always locally exclusive as well
as globally exclusive).

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

1 files changed, 3 insertions, 13 deletions

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 8e4b55a2bd7..1345c3d44ed 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -391,10 +391,6 @@ void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
         gh->gh_flags = flags;
         gh->gh_error = 0;
         gh->gh_iflags = 0;
-
-        if (gh->gh_state == LM_ST_EXCLUSIVE)
-                gh->gh_flags |= GL_LOCAL_EXCL;
-
         gfs2_glock_hold(gl);
 }
 
@@ -412,9 +408,6 @@ void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *
 {
         gh->gh_state = state;
         gh->gh_flags = flags;
-        if (gh->gh_state == LM_ST_EXCLUSIVE)
-                gh->gh_flags |= GL_LOCAL_EXCL;
-
         gh->gh_iflags &= 1 << HIF_ALLOCED;
         gh->gh_ip = (unsigned long)__builtin_return_address(0);
 }
@@ -557,11 +550,11 @@ static int rq_promote(struct gfs2_holder *gh)
                 set_bit(GLF_LOCK, &gl->gl_flags);
         } else {
                 struct gfs2_holder *next_gh;
-                if (gh->gh_flags & GL_LOCAL_EXCL)
+                if (gh->gh_state == LM_ST_EXCLUSIVE)
                         return 1;
                 next_gh = list_entry(gl->gl_holders.next, struct gfs2_holder,
                                      gh_list);
-                if (next_gh->gh_flags & GL_LOCAL_EXCL)
+                if (next_gh->gh_state == LM_ST_EXCLUSIVE)
                          return 1;
         }
 
@@ -1363,10 +1356,7 @@ static int glock_compare(const void *arg_a, const void *arg_b)
                 return 1;
         if (a->ln_number < b->ln_number)
                 return -1;
-        if (gh_a->gh_state == LM_ST_SHARED && gh_b->gh_state == LM_ST_EXCLUSIVE)
-                return 1;
-        if (!(gh_a->gh_flags & GL_LOCAL_EXCL) && (gh_b->gh_flags & GL_LOCAL_EXCL))
-                return 1;
+        BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type);
         return 0;
 }