GFS2: Move log buffer lists into transaction

Over time, we hope to be able to improve the concurrency available
in the log code. This is one small step towards that, by moving
the buffer lists from the super block, and into the transaction
structure, so that each transaction builds its own buffer lists.

At transaction commit time, the buffer lists are merged into
the currently accumulating transaction. That transaction then
is passed into the before and after commit functions at journal
flush time. Thus there should be no change in overall behaviour
yet.

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

1 files changed, 15 insertions, 17 deletions

diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
index 76693793cedd..ee9ec7fa3011 100644
--- a/fs/gfs2/lops.c
+++ b/fs/gfs2/lops.c
@@ -491,24 +491,23 @@ static void gfs2_before_commit(struct gfs2_sbd *sdp, unsigned int limit,
 	gfs2_log_unlock(sdp);
 }
 
-static void buf_lo_before_commit(struct gfs2_sbd *sdp)
+static void buf_lo_before_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 {
 	unsigned int limit = buf_limit(sdp); /* 503 for 4k blocks */
-
-	gfs2_before_commit(sdp, limit, sdp->sd_log_num_buf,
-			   &sdp->sd_log_le_buf, 0);
+	if (tr == NULL)
+		return;
+	gfs2_before_commit(sdp, limit, sdp->sd_log_num_buf, &tr->tr_buf, 0);
 }
 
 static void buf_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 {
-	struct list_head *head = &sdp->sd_log_le_buf;
+	struct list_head *head;
 	struct gfs2_bufdata *bd;
 
-	if (tr == NULL) {
-		gfs2_assert(sdp, list_empty(head));
+	if (tr == NULL)
 		return;
-	}
 
+	head = &tr->tr_buf;
 	while (!list_empty(head)) {
 		bd = list_entry(head->next, struct gfs2_bufdata, bd_list);
 		list_del_init(&bd->bd_list);
@@ -620,7 +619,7 @@ static void buf_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
 	        jd->jd_jid, sdp->sd_replayed_blocks, sdp->sd_found_blocks);
 }
 
-static void revoke_lo_before_commit(struct gfs2_sbd *sdp)
+static void revoke_lo_before_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 {
 	struct gfs2_meta_header *mh;
 	unsigned int offset;
@@ -760,12 +759,12 @@ static void revoke_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
  *
  */
 
-static void databuf_lo_before_commit(struct gfs2_sbd *sdp)
+static void databuf_lo_before_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 {
 	unsigned int limit = buf_limit(sdp) / 2;
-
-	gfs2_before_commit(sdp, limit, sdp->sd_log_num_databuf,
-			   &sdp->sd_log_le_databuf, 1);
+	if (tr == NULL)
+		return;
+	gfs2_before_commit(sdp, limit, sdp->sd_log_num_databuf, &tr->tr_databuf, 1);
 }
 
 static int databuf_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
@@ -840,14 +839,13 @@ static void databuf_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
 
 static void databuf_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 {
-	struct list_head *head = &sdp->sd_log_le_databuf;
+	struct list_head *head;
 	struct gfs2_bufdata *bd;
 
-	if (tr == NULL) {
-		gfs2_assert(sdp, list_empty(head));
+	if (tr == NULL)
 		return;
-	}
 
+	head = &tr->tr_databuf;
 	while (!list_empty(head)) {
 		bd = list_entry(head->next, struct gfs2_bufdata, bd_list);
 		list_del_init(&bd->bd_list);