2 files changed, 19 insertions, 3 deletions

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index f1ed3a1bf8aa..f566ec1b4e8e 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -432,6 +432,7 @@ enum {
         SDF_JOURNAL_CHECKED     = 0,
         SDF_JOURNAL_LIVE        = 1,
         SDF_SHUTDOWN            = 2,
+        SDF_NOBARRIERS          = 3,
 };
 
 #define GFS2_FSNAME_LEN         256
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index 6c6af9f5e3ab..ad305854bdc6 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -18,6 +18,7 @@
 #include <linux/delay.h>
 #include <linux/kthread.h>
 #include <linux/freezer.h>
+#include <linux/bio.h>
 
 #include "gfs2.h"
 #include "incore.h"
@@ -584,7 +585,6 @@ static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
         memset(bh->b_data, 0, bh->b_size);
         set_buffer_uptodate(bh);
         clear_buffer_dirty(bh);
-        unlock_buffer(bh);
 
         gfs2_ail1_empty(sdp, 0);
         tail = current_tail(sdp);
@@ -601,8 +601,23 @@ static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
         hash = gfs2_disk_hash(bh->b_data, sizeof(struct gfs2_log_header));
         lh->lh_hash = cpu_to_be32(hash);
 
-        set_buffer_dirty(bh);
-        if (sync_dirty_buffer(bh))
+        bh->b_end_io = end_buffer_write_sync;
+        if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
+                goto skip_barrier;
+        get_bh(bh);
+        submit_bh(WRITE_BARRIER | (1 << BIO_RW_META), bh);
+        wait_on_buffer(bh);
+        if (buffer_eopnotsupp(bh)) {
+                clear_buffer_eopnotsupp(bh);
+                set_buffer_uptodate(bh);
+                set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
+                lock_buffer(bh);
+skip_barrier:
+                get_bh(bh);
+                submit_bh(WRITE_SYNC | (1 << BIO_RW_META), bh);
+                wait_on_buffer(bh);
+        }
+        if (!buffer_uptodate(bh))
                 gfs2_io_error_bh(sdp, bh);
         brelse(bh);