[XFS] Ensure errors from xfs_bdstrat() are correctly checked.

xfsbdstrat() is declared to return an error. That is never checked because
the error is propagated by the xfs_buf_t that is passed through the
function.

Mark xfsbdstrat() as returning void and comment the prototype on the
methods needed for error checking.

SGI-PV: 980084
SGI-Modid: xfs-linux-melb:xfs-kern:30823a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Niv Sardi <xaiki@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

fs/xfs/linux-2.6/xfs_lrw.c

@@ -875,28 +875,21 @@ xfs_bdstrat_cb(struct xfs_buf *bp)
 }
 
 /*
- * Wrapper around bdstrat so that we can stop data
+ * Wrapper around bdstrat so that we can stop data from going to disk in case
- * from going to disk in case we are shutting down the filesystem.
+ * we are shutting down the filesystem.  Typically user data goes thru this
- * Typically user data goes thru this path; one of the exceptions
+ * path; one of the exceptions is the superblock.
- * is the superblock.
  */
-int
+void
 xfsbdstrat(
 	struct xfs_mount	*mp,
 	struct xfs_buf		*bp)
 {
 	ASSERT(mp);
-	if (!XFS_FORCED_SHUTDOWN(mp)) {
+	if (!XFS_FORCED_SHUTDOWN(mp))
-		/* Grio redirection would go here
-		 * if (XFS_BUF_IS_GRIO(bp)) {
-		 */
-
 		xfs_buf_iorequest(bp);
-		return 0;
-	}
 
 	xfs_buftrace("XFSBDSTRAT IOERROR", bp);
-	return (xfs_bioerror_relse(bp));
+	xfs_bioerror_relse(bp);
 }
 
 /*

fs/xfs/linux-2.6/xfs_lrw.h

@@ -68,7 +68,8 @@ extern void xfs_inval_cached_trace(struct xfs_inode *,
 #define xfs_inval_cached_trace(ip, offset, len, first, last)
 #endif
 
-extern int xfsbdstrat(struct xfs_mount *, struct xfs_buf *);
+/* errors from xfsbdstrat() must be extracted from the buffer */
+extern void xfsbdstrat(struct xfs_mount *, struct xfs_buf *);
 extern int xfs_bdstrat_cb(struct xfs_buf *);
 extern int xfs_dev_is_read_only(struct xfs_mount *, char *);
 

fs/xfs/xfs_log_recover.c

@@ -121,7 +121,8 @@ xlog_bread(
 	XFS_BUF_SET_TARGET(bp, log->l_mp->m_logdev_targp);
 
 	xfsbdstrat(log->l_mp, bp);
-	if ((error = xfs_iowait(bp)))
+	error = xfs_iowait(bp);
+	if (error)
 		xfs_ioerror_alert("xlog_bread", log->l_mp,
 				  bp, XFS_BUF_ADDR(bp));
 	return error;
@@ -3849,7 +3850,8 @@ xlog_do_recover(
 	XFS_BUF_READ(bp);
 	XFS_BUF_UNASYNC(bp);
 	xfsbdstrat(log->l_mp, bp);
-	if ((error = xfs_iowait(bp))) {
+	error = xfs_iowait(bp);
+	if (error) {
 		xfs_ioerror_alert("xlog_do_recover",
 				  log->l_mp, bp, XFS_BUF_ADDR(bp));
 		ASSERT(0);

fs/xfs/xfs_mount.c

@@ -1470,7 +1470,6 @@ xfs_unmountfs_writesb(xfs_mount_t *mp)
 		XFS_BUF_UNASYNC(sbp);
 		ASSERT(XFS_BUF_TARGET(sbp) == mp->m_ddev_targp);
 		xfsbdstrat(mp, sbp);
-		/* Nevermind errors we might get here. */
 		error = xfs_iowait(sbp);
 		if (error)
 			xfs_ioerror_alert("xfs_unmountfs_writesb",

fs/xfs/xfs_trans_buf.c

@@ -354,17 +354,15 @@ xfs_trans_read_buf(
 			ASSERT(!XFS_BUF_ISASYNC(bp));
 			XFS_BUF_READ(bp);
 			xfsbdstrat(tp->t_mountp, bp);
-			xfs_iowait(bp);
+			error = xfs_iowait(bp);
-			if (XFS_BUF_GETERROR(bp) != 0) {
+			if (error) {
 				xfs_ioerror_alert("xfs_trans_read_buf", mp,
 						  bp, blkno);
-				error = XFS_BUF_GETERROR(bp);
 				xfs_buf_relse(bp);
 				/*
-				 * We can gracefully recover from most
+				 * We can gracefully recover from most read
-				 * read errors. Ones we can't are those
+				 * errors. Ones we can't are those that happen
-				 * that happen after the transaction's
+				 * after the transaction's already dirty.
-				 * already dirty.
 				 */
 				if (tp->t_flags & XFS_TRANS_DIRTY)
 					xfs_force_shutdown(tp->t_mountp,

fs/xfs/xfs_vnodeops.c

@@ -3825,7 +3825,8 @@ xfs_zero_remaining_bytes(
 		XFS_BUF_READ(bp);
 		XFS_BUF_SET_ADDR(bp, XFS_FSB_TO_DB(ip, imap.br_startblock));
 		xfsbdstrat(mp, bp);
-		if ((error = xfs_iowait(bp))) {
+		error = xfs_iowait(bp);
+		if (error) {
 			xfs_ioerror_alert("xfs_zero_remaining_bytes(read)",
 					  mp, bp, XFS_BUF_ADDR(bp));
 			break;
@@ -3837,7 +3838,8 @@ xfs_zero_remaining_bytes(
 		XFS_BUF_UNREAD(bp);
 		XFS_BUF_WRITE(bp);
 		xfsbdstrat(mp, bp);
-		if ((error = xfs_iowait(bp))) {
+		error = xfs_iowait(bp);
+		if (error) {
 			xfs_ioerror_alert("xfs_zero_remaining_bytes(write)",
 					  mp, bp, XFS_BUF_ADDR(bp));
 			break;