From 73f6aa4d44ab6157badc456ddfa05b31e58de5f0 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 10 Oct 2008 17:28:29 +1100 Subject: [PATCH] Fix barrier fail detection in XFS Currently we disable barriers as soon as we get a buffer in xlog_iodone that has the XBF_ORDERED flag cleared. But this can be the case not only for buffers where the barrier failed, but also the first buffer of a split log write in case of a log wraparound. Due to the disabled barriers we can easily get directory corruption on unclean shutdowns. So instead of using this check add a new buffer flag for failed barrier writes. This is a regression vs 2.6.26 caused by patch to use the right macro to check for the ORDERED flag, as we previously got true returned for every buffer. Thanks to Toei Rei for reporting the bug. Signed-off-by: Christoph Hellwig Reviewed-by: Eric Sandeen Reviewed-by: David Chinner Signed-off-by: Tim Shimmin Signed-off-by: Linus Torvalds --- fs/xfs/linux-2.6/xfs_buf.c | 3 ++- fs/xfs/linux-2.6/xfs_buf.h | 8 ++++++++ fs/xfs/xfs_log.c | 7 ++++--- 3 files changed, 14 insertions(+), 4 deletions(-) diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c index 986061ae1b9b..36d5fcd3f593 100644 --- a/fs/xfs/linux-2.6/xfs_buf.c +++ b/fs/xfs/linux-2.6/xfs_buf.c @@ -1001,12 +1001,13 @@ xfs_buf_iodone_work( * 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. + * need to check if the _XFS_BARRIER_FAILED flag was set 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; + bp->b_flags |= _XFS_BARRIER_FAILED; xfs_buf_iorequest(bp); } else if (bp->b_iodone) (*(bp->b_iodone))(bp); diff --git a/fs/xfs/linux-2.6/xfs_buf.h b/fs/xfs/linux-2.6/xfs_buf.h index fe0109956656..456519a088c7 100644 --- a/fs/xfs/linux-2.6/xfs_buf.h +++ b/fs/xfs/linux-2.6/xfs_buf.h @@ -85,6 +85,14 @@ typedef enum { * modifications being lost. */ _XBF_PAGE_LOCKED = (1 << 22), + + /* + * If we try a barrier write, but it fails we have to communicate + * this to the upper layers. Unfortunately b_error gets overwritten + * when the buffer is re-issued so we have to add another flag to + * keep this information. + */ + _XFS_BARRIER_FAILED = (1 << 23), } xfs_buf_flags_t; typedef enum { diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index 503ea89e8b9a..0b02c6443551 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -1033,11 +1033,12 @@ 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 + * If the _XFS_BARRIER_FAILED flag was set by a lower + * layer, it means the underlying device no longer supports * barrier I/O. Warn loudly and turn off barriers. */ - if ((l->l_mp->m_flags & XFS_MOUNT_BARRIER) && !XFS_BUF_ISORDERED(bp)) { + if (bp->b_flags & _XFS_BARRIER_FAILED) { + bp->b_flags &= ~_XFS_BARRIER_FAILED; l->l_mp->m_flags &= ~XFS_MOUNT_BARRIER; xfs_fs_cmn_err(CE_WARN, l->l_mp, "xlog_iodone: Barriers are no longer supported" -- 2.20.1