[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, 12 insertions, 23 deletions

diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
index d762e4f7044e..19097bc7c81d 100644
--- a/fs/gfs2/meta_io.c
+++ b/fs/gfs2/meta_io.c
@@ -313,42 +313,31 @@ void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
         while (blen) {
                 bh = getbuf(ip->i_gl, bstart, NO_CREATE);
                 if (bh) {
-                        struct gfs2_bufdata *bd = bh->b_private;
+                        struct gfs2_bufdata *bd;
 
+                        lock_buffer(bh);
+                        gfs2_log_lock(sdp);
+                        bd = bh->b_private;
                         if (test_clear_buffer_pinned(bh)) {
                                 struct gfs2_trans *tr = current->journal_info;
-                                struct gfs2_inode *bh_ip =
-                                        GFS2_I(bh->b_page->mapping->host);
-
-                                gfs2_log_lock(sdp);
                                 list_del_init(&bd->bd_le.le_list);
                                 gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
                                 sdp->sd_log_num_buf--;
-                                gfs2_log_unlock(sdp);
-                                if (bh_ip->i_inode.i_private != NULL)
-                                        tr->tr_num_databuf_rm++;
-                                else
-                                        tr->tr_num_buf_rm++;
+                                tr->tr_num_buf_rm++;
                                 brelse(bh);
                         }
                         if (bd) {
-                                gfs2_log_lock(sdp);
                                 if (bd->bd_ail) {
-                                        u64 blkno = bh->b_blocknr;
-                                        bd->bd_ail = NULL;
-                                        list_del(&bd->bd_ail_st_list);
-                                        list_del(&bd->bd_ail_gl_list);
-                                        atomic_dec(&bd->bd_gl->gl_ail_count);
-                                        brelse(bh);
-                                        gfs2_log_unlock(sdp);
-                                        gfs2_trans_add_revoke(sdp, blkno);
-                                } else
-                                        gfs2_log_unlock(sdp);
+                                        gfs2_remove_from_ail(NULL, bd);
+                                        bh->b_private = NULL;
+                                        bd->bd_bh = NULL;
+                                        bd->bd_blkno = bh->b_blocknr;
+                                        gfs2_trans_add_revoke(sdp, bd);
+                                }
                         }
-
-                        lock_buffer(bh);
                         clear_buffer_dirty(bh);
                         clear_buffer_uptodate(bh);
+                        gfs2_log_unlock(sdp);
                         unlock_buffer(bh);
 
                         brelse(bh);