From 0e95f19ad983e72a9cb93a67b3290b58f0467b36 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Mon, 23 Apr 2012 15:58:46 +1000 Subject: [PATCH] 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 Reviewed-by: Christoph Hellwig Reviewed-by: Mark Tinguely Signed-off-by: Ben Myers --- fs/xfs/xfs_buf.c | 22 ++++++++++------------ fs/xfs/xfs_buf.h | 2 +- fs/xfs/xfs_log_recover.c | 2 ++ 3 files changed, 13 insertions(+), 13 deletions(-) diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index da2541e5ff81..86d9af70ab3b 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -600,17 +600,15 @@ _xfs_buf_read( xfs_buf_t *bp, xfs_buf_flags_t flags) { - int status; - ASSERT(!(flags & XBF_WRITE)); ASSERT(bp->b_bn != XFS_BUF_DADDR_NULL); bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_READ_AHEAD); bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | XBF_READ_AHEAD); - status = xfs_buf_iorequest(bp); - if (status || bp->b_error || (flags & XBF_ASYNC)) - return status; + xfs_buf_iorequest(bp); + if (flags & XBF_ASYNC) + return 0; return xfs_buf_iowait(bp); } @@ -695,7 +693,7 @@ xfs_buf_read_uncached( xfsbdstrat(mp, bp); error = xfs_buf_iowait(bp); - if (error || bp->b_error) { + if (error) { xfs_buf_relse(bp); return NULL; } @@ -1252,7 +1250,7 @@ next_chunk: } } -int +void xfs_buf_iorequest( xfs_buf_t *bp) { @@ -1273,13 +1271,12 @@ xfs_buf_iorequest( _xfs_buf_ioend(bp, 0); xfs_buf_rele(bp); - return 0; } /* - * Waits for I/O to complete on the buffer supplied. - * It returns immediately if no I/O is pending. - * It returns the I/O error code, if any, or 0 if there was no error. + * Waits for I/O to complete on the buffer supplied. It returns immediately if + * no I/O is pending or there is already a pending error on the buffer. It + * returns the I/O error code, if any, or 0 if there was no error. */ int xfs_buf_iowait( @@ -1287,7 +1284,8 @@ xfs_buf_iowait( { trace_xfs_buf_iowait(bp, _RET_IP_); - wait_for_completion(&bp->b_iowait); + if (!bp->b_error) + wait_for_completion(&bp->b_iowait); trace_xfs_buf_iowait_done(bp, _RET_IP_); return bp->b_error; diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h index 7083cf44d95f..87a474853f8a 100644 --- a/fs/xfs/xfs_buf.h +++ b/fs/xfs/xfs_buf.h @@ -191,7 +191,7 @@ extern int xfs_bdstrat_cb(struct xfs_buf *); extern void xfs_buf_ioend(xfs_buf_t *, int); extern void xfs_buf_ioerror(xfs_buf_t *, int); extern void xfs_buf_ioerror_alert(struct xfs_buf *, const char *func); -extern int xfs_buf_iorequest(xfs_buf_t *); +extern void xfs_buf_iorequest(xfs_buf_t *); extern int xfs_buf_iowait(xfs_buf_t *); extern void xfs_buf_iomove(xfs_buf_t *, size_t, size_t, void *, xfs_buf_rw_t); 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) -- 2.20.1