[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>

diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
index 3b395c41b2f3f9acefc623e6e008949231b1e8d3..a0371f835cfb314dcfdd42a809294cfc9ebf2b9b 100644 (file)
--- 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);