From df308bcfec27e0c6bc83715dfd417caff5c33f19 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 12 Mar 2010 10:59:16 +0000 Subject: [PATCH] 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 Signed-off-by: Alex Elder --- fs/xfs/linux-2.6/xfs_sync.c | 90 ++++++++++++++------------------------------- 1 file changed, 27 insertions(+), 63 deletions(-) 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 @@ xfs_commit_dummy_trans( 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, 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; + bp = xfs_getsb(mp, 0); + if (XFS_BUF_ISPINNED(bp)) + xfs_log_force(mp, 0); - out_brelse: - xfs_buf_relse(bp); - out: - return error; + XFS_BUF_UNASYNC(bp); + return xfs_bwrite(mp, bp); } /* @@ -441,7 +397,7 @@ int 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_quiesce_data( 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 @@ xfs_flush_inodes( } /* - * 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_sync_worker( 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); -- 2.7.4