From 0bfefc46dc028df60120acdb92062169c9328769 Mon Sep 17 00:00:00 2001 From: David Chinner Date: Mon, 14 May 2007 18:24:23 +1000 Subject: [PATCH] [XFS] Barriers need to be dynamically checked and switched off If the underlying block device suddenly stops supporting barriers, we need to handle the -EOPNOTSUPP error in a sane manner rather than shutting down the filesystem. If we get this error, clear the barrier flag, reissue the I/O, and tell the world bad things are occurring. SGI-PV: 964544 SGI-Modid: xfs-linux-melb:xfs-kern:28568a Signed-off-by: David Chinner Signed-off-by: Christoph Hellwig Signed-off-by: Tim Shimmin --- fs/xfs/linux-2.6/xfs_buf.c | 13 ++++++++++++- fs/xfs/linux-2.6/xfs_super.c | 8 -------- fs/xfs/xfs_log.c | 13 +++++++++++++ 3 files changed, 25 insertions(+), 9 deletions(-) diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c index b0f0e58866de..8d9298c99763 100644 --- a/fs/xfs/linux-2.6/xfs_buf.c +++ b/fs/xfs/linux-2.6/xfs_buf.c @@ -997,7 +997,18 @@ xfs_buf_iodone_work( xfs_buf_t *bp = container_of(work, xfs_buf_t, b_iodone_work); - if (bp->b_iodone) + /* + * We can get an EOPNOTSUPP to ordered writes. Here we clear the + * ordered flag and reissue them. Because we can't tell the higher + * layers directly that they should not issue ordered I/O anymore, they + * need to check if the ordered flag was cleared during I/O completion. + */ + if ((bp->b_error == EOPNOTSUPP) && + (bp->b_flags & (XBF_ORDERED|XBF_ASYNC)) == (XBF_ORDERED|XBF_ASYNC)) { + XB_TRACE(bp, "ordered_retry", bp->b_iodone); + bp->b_flags &= ~XBF_ORDERED; + xfs_buf_iorequest(bp); + } else if (bp->b_iodone) (*(bp->b_iodone))(bp); else if (bp->b_flags & XBF_ASYNC) xfs_buf_relse(bp); diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c index 491d1f4f202d..17ad5e463710 100644 --- a/fs/xfs/linux-2.6/xfs_super.c +++ b/fs/xfs/linux-2.6/xfs_super.c @@ -304,14 +304,6 @@ xfs_mountfs_check_barriers(xfs_mount_t *mp) return; } - if (mp->m_ddev_targp->bt_bdev->bd_disk->queue->ordered == - QUEUE_ORDERED_NONE) { - xfs_fs_cmn_err(CE_NOTE, mp, - "Disabling barriers, not supported by the underlying device"); - mp->m_flags &= ~XFS_MOUNT_BARRIER; - return; - } - if (xfs_readonly_buftarg(mp->m_ddev_targp)) { xfs_fs_cmn_err(CE_NOTE, mp, "Disabling barriers, underlying device is readonly"); diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index 9bfb69e1e885..db09e1ea5cf3 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -948,6 +948,19 @@ xlog_iodone(xfs_buf_t *bp) */ l = iclog->ic_log; + /* + * If the ordered flag has been removed by a lower + * layer, it means the underlyin device no longer supports + * barrier I/O. Warn loudly and turn off barriers. + */ + if ((l->l_mp->m_flags & XFS_MOUNT_BARRIER) && !XFS_BUF_ORDERED(bp)) { + l->l_mp->m_flags &= ~XFS_MOUNT_BARRIER; + xfs_fs_cmn_err(CE_WARN, l->l_mp, + "xlog_iodone: Barriers are no longer supported" + " by device. Disabling barriers\n"); + xfs_buftrace("XLOG_IODONE BARRIERS OFF", bp); + } + /* * Race to shutdown the filesystem if we see an error. */ -- 2.34.1