GFS2: Support for I/O barriers

[pandora-kernel.git] / fs / gfs2 / log.c

diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index 6c6af9f..ad30585 100644 (file)
--- 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);