[GFS2] Clean up gfs2_trans_add_revoke()

The following alters gfs2_trans_add_revoke() to take a struct
gfs2_bufdata as an argument. This eliminates the memory allocation which
was previously required by making use of the already existing struct
gfs2_bufdata. It makes some sanity checks to ensure that the
gfs2_bufdata has been removed from all the lists before its recycled as
a revoke structure. This saves one memory allocation and one free per
revoke structure.

Also as a result, and to simplify the locking, since there is no longer
any blocking code in gfs2_trans_add_revoke() we must hold the log lock
whenever this function is called. This reduces the amount of times we
take and unlock the log lock.

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

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index 20fa528d457d..4d04e6f19706 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -71,8 +71,8 @@ unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct,
 void gfs2_remove_from_ail(struct address_space *mapping, struct gfs2_bufdata *bd)
 {
         bd->bd_ail = NULL;
-        list_del(&bd->bd_ail_st_list);
-        list_del(&bd->bd_ail_gl_list);
+        list_del_init(&bd->bd_ail_st_list);
+        list_del_init(&bd->bd_ail_gl_list);
         atomic_dec(&bd->bd_gl->gl_ail_count);
         if (mapping)
                 gfs2_meta_cache_flush(GFS2_I(mapping->host));