Commit 0e95f19a authored by Dave Chinner's avatar Dave Chinner Committed by Ben Myers
Browse files

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: default avatarDave Chinner <dchinner@redhat.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarMark Tinguely <tinguely@sgi.com>
Signed-off-by: default avatarBen Myers <bpm@sgi.com>
parent fe2429b0

fs/xfs/xfs_buf.c

+10 −12
Original line number Diff line number Diff line
@@ -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(
@@ -1287,6 +1284,7 @@ xfs_buf_iowait( 
{

	trace_xfs_buf_iowait(bp, _RET_IP_);



	if (!bp->b_error)

		wait_for_completion(&bp->b_iowait);



	trace_xfs_buf_iowait_done(bp, _RET_IP_);

fs/xfs/xfs_buf.h

+1 −1
Original line number Diff line number Diff line
@@ -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);

fs/xfs/xfs_log_recover.c

+2 −0
Original line number Diff line number Diff line
@@ -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)

CRA Git | Maintained and supported by SUSTech CRA and CCSE