xfs: remove periodic superblock writeback
All modifications to the superblock are done transactional through
xfs_trans_log_buf, so there is no reason to initiate periodic
asynchronous writeback. This only removes the superblock from the
delwri list and will lead to sub-optimal I/O scheduling.
Cut down xfs_sync_fsdata now that it's only used for synchronous
superblock writes and move the log coverage checks into the two
callers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
diff --git a/fs/xfs/linux-2.6/xfs_sync.c b/fs/xfs/linux-2.6/xfs_sync.c
index a7ba355..728db01 100644
--- a/fs/xfs/linux-2.6/xfs_sync.c
+++ b/fs/xfs/linux-2.6/xfs_sync.c
@@ -356,68 +356,24 @@
STATIC int
xfs_sync_fsdata(
- struct xfs_mount *mp,
- int flags)
+ struct xfs_mount *mp)
{
struct xfs_buf *bp;
- struct xfs_buf_log_item *bip;
- int error = 0;
/*
- * If this is xfssyncd() then only sync the superblock if we can
- * lock it without sleeping and it is not pinned.
+ * If the buffer is pinned then push on the log so we won't get stuck
+ * waiting in the write for someone, maybe ourselves, to flush the log.
+ *
+ * Even though we just pushed the log above, we did not have the
+ * superblock buffer locked at that point so it can become pinned in
+ * between there and here.
*/
- if (flags & SYNC_TRYLOCK) {
- ASSERT(!(flags & SYNC_WAIT));
+ bp = xfs_getsb(mp, 0);
+ if (XFS_BUF_ISPINNED(bp))
+ xfs_log_force(mp, 0);
- bp = xfs_getsb(mp, XBF_TRYLOCK);
- if (!bp)
- goto out;
-
- bip = XFS_BUF_FSPRIVATE(bp, struct xfs_buf_log_item *);
- if (!bip || !xfs_buf_item_dirty(bip) || XFS_BUF_ISPINNED(bp))
- goto out_brelse;
- } else {
- bp = xfs_getsb(mp, 0);
-
- /*
- * If the buffer is pinned then push on the log so we won't
- * get stuck waiting in the write for someone, maybe
- * ourselves, to flush the log.
- *
- * Even though we just pushed the log above, we did not have
- * the superblock buffer locked at that point so it can
- * become pinned in between there and here.
- */
- if (XFS_BUF_ISPINNED(bp))
- xfs_log_force(mp, 0);
- }
-
-
- if (flags & SYNC_WAIT)
- XFS_BUF_UNASYNC(bp);
- else
- XFS_BUF_ASYNC(bp);
-
- error = xfs_bwrite(mp, bp);
- if (error)
- return error;
-
- /*
- * If this is a data integrity sync make sure all pending buffers
- * are flushed out for the log coverage check below.
- */
- if (flags & SYNC_WAIT)
- xfs_flush_buftarg(mp->m_ddev_targp, 1);
-
- if (xfs_log_need_covered(mp))
- error = xfs_commit_dummy_trans(mp, flags);
- return error;
-
- out_brelse:
- xfs_buf_relse(bp);
- out:
- return error;
+ XFS_BUF_UNASYNC(bp);
+ return xfs_bwrite(mp, bp);
}
/*
@@ -441,7 +397,7 @@
xfs_quiesce_data(
struct xfs_mount *mp)
{
- int error;
+ int error, error2 = 0;
/* push non-blocking */
xfs_sync_data(mp, 0);
@@ -452,13 +408,20 @@
xfs_qm_sync(mp, SYNC_WAIT);
/* write superblock and hoover up shutdown errors */
- error = xfs_sync_fsdata(mp, SYNC_WAIT);
+ error = xfs_sync_fsdata(mp);
+
+ /* make sure all delwri buffers are written out */
+ xfs_flush_buftarg(mp->m_ddev_targp, 1);
+
+ /* mark the log as covered if needed */
+ if (xfs_log_need_covered(mp))
+ error2 = xfs_commit_dummy_trans(mp, SYNC_WAIT);
/* flush data-only devices */
if (mp->m_rtdev_targp)
XFS_bflush(mp->m_rtdev_targp);
- return error;
+ return error ? error : error2;
}
STATIC void
@@ -581,9 +544,9 @@
}
/*
- * Every sync period we need to unpin all items, reclaim inodes, sync
- * quota and write out the superblock. We might need to cover the log
- * to indicate it is idle.
+ * Every sync period we need to unpin all items, reclaim inodes and sync
+ * disk quotas. We might need to cover the log to indicate that the
+ * filesystem is idle.
*/
STATIC void
xfs_sync_worker(
@@ -597,7 +560,8 @@
xfs_reclaim_inodes(mp, 0);
/* dgc: errors ignored here */
error = xfs_qm_sync(mp, SYNC_TRYLOCK);
- error = xfs_sync_fsdata(mp, SYNC_TRYLOCK);
+ if (xfs_log_need_covered(mp))
+ error = xfs_commit_dummy_trans(mp, 0);
}
mp->m_sync_seq++;
wake_up(&mp->m_wait_single_sync_task);