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 161ab6f..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"
@@ -87,6 +88,8 @@ void gfs2_remove_from_ail(struct gfs2_bufdata *bd)
  */
 
 static void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
+__releases(&sdp->sd_log_lock)
+__acquires(&sdp->sd_log_lock)
 {
        struct gfs2_bufdata *bd, *s;
        struct buffer_head *bh;
@@ -582,7 +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);
@@ -599,8 +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);
 
@@ -769,8 +786,8 @@ static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
        sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
        gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_revoke) >= 0);
        reserved = calc_reserved(sdp);
+       gfs2_assert_withdraw(sdp, sdp->sd_log_blks_reserved + tr->tr_reserved >= reserved);
        unused = sdp->sd_log_blks_reserved - reserved + tr->tr_reserved;
-       gfs2_assert_withdraw(sdp, unused >= 0);
        atomic_add(unused, &sdp->sd_log_blks_free);
        gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
                             sdp->sd_jdesc->jd_blocks);
@@ -779,6 +796,21 @@ static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
        gfs2_log_unlock(sdp);
 }
 
+static void buf_lo_incore_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
+{
+       struct list_head *head = &tr->tr_list_buf;
+       struct gfs2_bufdata *bd;
+
+       gfs2_log_lock(sdp);
+       while (!list_empty(head)) {
+               bd = list_entry(head->next, struct gfs2_bufdata, bd_list_tr);
+               list_del_init(&bd->bd_list_tr);
+               tr->tr_num_buf--;
+       }
+       gfs2_log_unlock(sdp);
+       gfs2_assert_warn(sdp, !tr->tr_num_buf);
+}
+
 /**
  * gfs2_log_commit - Commit a transaction to the log
  * @sdp: the filesystem
@@ -790,7 +822,7 @@ static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 {
        log_refund(sdp, tr);
-       lops_incore_commit(sdp, tr);
+       buf_lo_incore_commit(sdp, tr);
 
        sdp->sd_vfs->s_dirt = 1;
        up_read(&sdp->sd_log_flush_lock);