xfs: check for buffer errors before waiting

If we call xfs_buf_iowait() on a buffer that failed dispatch due to
an IO error, it will wait forever for an Io that does not exist.
This is hndled in xfs_buf_read, but there is other code that calls
xfs_buf_iowait directly that doesn't.

Rather than make the call sites have to handle checking for dispatch
errors and then checking for completion errors, make
xfs_buf_iowait() check for dispatch errors on the buffer before
waiting. This means we handle both dispatch and completion errors
with one set of error handling at the caller sites.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 5540e79da6f5..e1577e763fdf 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -179,6 +179,7 @@ xlog_bread_noalign(
         XFS_BUF_SET_ADDR(bp, log->l_logBBstart + blk_no);
         XFS_BUF_READ(bp);
         XFS_BUF_SET_COUNT(bp, BBTOB(nbblks));
+        bp->b_error = 0;
 
         xfsbdstrat(log->l_mp, bp);
         error = xfs_buf_iowait(bp);
@@ -266,6 +267,7 @@ xlog_bwrite(
         xfs_buf_hold(bp);
         xfs_buf_lock(bp);
         XFS_BUF_SET_COUNT(bp, BBTOB(nbblks));
+        bp->b_error = 0;
 
         error = xfs_bwrite(bp);
         if (error)