From 0e95f19ad983e72a9cb93a67b3290b58f0467b36 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Mon, 23 Apr 2012 15:58:46 +1000 Subject: 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 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) (limited to 'fs/xfs/xfs_buf.c') diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index da2541e5ff8..86d9af70ab3 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; -- cgit v1.2.3