[GFS2] Clean up the glock core

This patch implements a number of cleanups to the core of the
GFS2 glock code. As a result a lot of code is removed. It looks
like a really big change, but actually a large part of this patch
is either removing or moving existing code.

There are some new bits too though, such as the new run_queue()
function which is considerably streamlined. Highlights of this
patch include:

 o Fixes a cluster coherency bug during SH -> EX lock conversions
 o Removes the "glmutex" code in favour of a single bit lock
 o Removes the ->go_xmote_bh() for inodes since it was duplicating
   ->go_lock()
 o We now only use the ->lm_lock() function for both locks and
   unlocks (i.e. unlock is a lock with target mode LM_ST_UNLOCKED)
 o The fast path is considerably shortly, giving performance gains
   especially with lock_nolock
 o The glock_workqueue is now used for all the callbacks from the DLM
   which allows us to simplify the lock_dlm module (see following patch)
 o The way is now open to make further changes such as eliminating the two
   threads (gfs2_glockd and gfs2_scand) in favour of a more efficient
   scheme.

This patch has undergone extensive testing with various test suites
so it should be pretty stable by now.

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

1 files changed, 7 insertions, 7 deletions

diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
index 78d75f892f82..09853620c951 100644
--- a/fs/gfs2/meta_io.c
+++ b/fs/gfs2/meta_io.c
@@ -129,7 +129,7 @@ void gfs2_meta_sync(struct gfs2_glock *gl)
 }
 
 /**
- * getbuf - Get a buffer with a given address space
+ * gfs2_getbuf - Get a buffer with a given address space
  * @gl: the glock
  * @blkno: the block number (filesystem scope)
  * @create: 1 if the buffer should be created
@@ -137,7 +137,7 @@ void gfs2_meta_sync(struct gfs2_glock *gl)
  * Returns: the buffer
  */
 
-static struct buffer_head *getbuf(struct gfs2_glock *gl, u64 blkno, int create)
+struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno, int create)
 {
         struct address_space *mapping = gl->gl_aspace->i_mapping;
         struct gfs2_sbd *sdp = gl->gl_sbd;
@@ -205,7 +205,7 @@ static void meta_prep_new(struct buffer_head *bh)
 struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
 {
         struct buffer_head *bh;
-        bh = getbuf(gl, blkno, CREATE);
+        bh = gfs2_getbuf(gl, blkno, CREATE);
         meta_prep_new(bh);
         return bh;
 }
@@ -223,7 +223,7 @@ struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
 int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
                    struct buffer_head **bhp)
 {
-        *bhp = getbuf(gl, blkno, CREATE);
+        *bhp = gfs2_getbuf(gl, blkno, CREATE);
         if (!buffer_uptodate(*bhp)) {
                 ll_rw_block(READ_META, 1, bhp);
                 if (flags & DIO_WAIT) {
@@ -346,7 +346,7 @@ void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
         struct buffer_head *bh;
 
         while (blen) {
-                bh = getbuf(ip->i_gl, bstart, NO_CREATE);
+                bh = gfs2_getbuf(ip->i_gl, bstart, NO_CREATE);
                 if (bh) {
                         lock_buffer(bh);
                         gfs2_log_lock(sdp);
@@ -421,7 +421,7 @@ struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
         if (extlen > max_ra)
                 extlen = max_ra;
 
-        first_bh = getbuf(gl, dblock, CREATE);
+        first_bh = gfs2_getbuf(gl, dblock, CREATE);
 
         if (buffer_uptodate(first_bh))
                 goto out;
@@ -432,7 +432,7 @@ struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
         extlen--;
 
         while (extlen) {
-                bh = getbuf(gl, dblock, CREATE);
+                bh = gfs2_getbuf(gl, dblock, CREATE);
 
                 if (!buffer_uptodate(bh) && !buffer_locked(bh))
                         ll_rw_block(READA, 1, &bh);