[GFS2] Move some code inside the log lock

This is the first of five patches for bug #248176:

There were still some critical variables being manipulated outside
the log_lock spinlock.  That usually resulted in a hang.

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

1 files changed, 14 insertions, 3 deletions

diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
index 3b395c41b2f3..a0371f835cfb 100644
--- a/fs/gfs2/lops.c
+++ b/fs/gfs2/lops.c
@@ -117,7 +117,7 @@ static void buf_lo_before_commit(struct gfs2_sbd *sdp)
         struct buffer_head *bh;
         struct gfs2_log_descriptor *ld;
         struct gfs2_bufdata *bd1 = NULL, *bd2;
-        unsigned int total = sdp->sd_log_num_buf;
+        unsigned int total;
         unsigned int offset = BUF_OFFSET;
         unsigned int limit;
         unsigned int num;
@@ -127,12 +127,16 @@ static void buf_lo_before_commit(struct gfs2_sbd *sdp)
         limit = buf_limit(sdp);
         /* for 4k blocks, limit = 503 */
 
+        gfs2_log_lock(sdp);
+        total = sdp->sd_log_num_buf;
         bd1 = bd2 = list_prepare_entry(bd1, &sdp->sd_log_le_buf, bd_le.le_list);
         while(total) {
                 num = total;
                 if (total > limit)
                         num = limit;
+                gfs2_log_unlock(sdp);
                 bh = gfs2_log_get_buf(sdp);
+                gfs2_log_lock(sdp);
                 ld = (struct gfs2_log_descriptor *)bh->b_data;
                 ptr = (__be64 *)(bh->b_data + offset);
                 ld->ld_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
@@ -152,21 +156,27 @@ static void buf_lo_before_commit(struct gfs2_sbd *sdp)
                                 break;
                 }
 
+                gfs2_log_unlock(sdp);
                 set_buffer_dirty(bh);
                 ll_rw_block(WRITE, 1, &bh);
+                gfs2_log_lock(sdp);
 
                 n = 0;
                 list_for_each_entry_continue(bd2, &sdp->sd_log_le_buf,
                                              bd_le.le_list) {
+                        gfs2_log_unlock(sdp);
                         bh = gfs2_log_fake_buf(sdp, bd2->bd_bh);
                         set_buffer_dirty(bh);
                         ll_rw_block(WRITE, 1, &bh);
+                        gfs2_log_lock(sdp);
                         if (++n >= num)
                                 break;
                 }
 
+                BUG_ON(total < num);
                 total -= num;
         }
+        gfs2_log_unlock(sdp);
 }
 
 static void buf_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
@@ -524,7 +534,7 @@ static void databuf_lo_before_commit(struct gfs2_sbd *sdp)
         struct gfs2_log_descriptor *ld;
         unsigned int limit;
         unsigned int total_dbuf;
-        unsigned int total_jdata = sdp->sd_log_num_jdata;
+        unsigned int total_jdata;
         unsigned int num, n;
         __be64 *ptr = NULL;
 
@@ -536,6 +546,7 @@ static void databuf_lo_before_commit(struct gfs2_sbd *sdp)
          */
         gfs2_log_lock(sdp);
         total_dbuf = sdp->sd_log_num_databuf;
+        total_jdata = sdp->sd_log_num_jdata;
         bd2 = bd1 = list_prepare_entry(bd1, &sdp->sd_log_le_databuf,
                                        bd_le.le_list);
         while(total_dbuf) {
@@ -621,10 +632,10 @@ static void databuf_lo_before_commit(struct gfs2_sbd *sdp)
                 }
                 gfs2_log_unlock(sdp);
                 if (bh) {
-                        set_buffer_mapped(bh);
                         set_buffer_dirty(bh);
                         ll_rw_block(WRITE, 1, &bh);
                         bh = NULL;
+                        ptr = NULL;
                 }
                 n = 0;
                 gfs2_log_lock(sdp);