[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 <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
This commit is contained in:
David Chinner 2007-05-14 18:24:23 +10:00 committed by Tim Shimmin
parent c1561cf463
commit 0bfefc46dc
3 changed files with 25 additions and 9 deletions

View File

@ -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);

View File

@ -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");

View File

@ -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.
*/