xfs: fix xfs_buf_ioerror_alert location reporting

Instead of passing __func__ to the error reporting function, let's use
the return address builtins so that the messages actually tell you which
higher level function called the buffer functions.  This was previously
true for the xfs_buf_read callers, but not for the xfs_trans_read_buf
callers.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index b420e86..217e4f8 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -803,7 +803,8 @@
 	int			nmaps,
 	xfs_buf_flags_t		flags,
 	struct xfs_buf		**bpp,
-	const struct xfs_buf_ops *ops)
+	const struct xfs_buf_ops *ops,
+	xfs_failaddr_t		fa)
 {
 	struct xfs_buf		*bp;
 	int			error;
@@ -852,7 +853,7 @@
 	 */
 	if (error) {
 		if (!XFS_FORCED_SHUTDOWN(target->bt_mount))
-			xfs_buf_ioerror_alert(bp, __func__);
+			xfs_buf_ioerror_alert(bp, fa);
 
 		bp->b_flags &= ~XBF_DONE;
 		xfs_buf_stale(bp);
@@ -885,7 +886,8 @@
 		return;
 
 	xfs_buf_read_map(target, map, nmaps,
-		     XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD, &bp, ops);
+		     XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD, &bp, ops,
+		     __this_address);
 }
 
 /*
@@ -1234,10 +1236,10 @@
 void
 xfs_buf_ioerror_alert(
 	struct xfs_buf		*bp,
-	const char		*func)
+	xfs_failaddr_t		func)
 {
 	xfs_alert(bp->b_mount,
-"metadata I/O error in \"%s\" at daddr 0x%llx len %d error %d",
+"metadata I/O error in \"%pS\" at daddr 0x%llx len %d error %d",
 			func, (uint64_t)XFS_BUF_ADDR(bp), bp->b_length,
 			-bp->b_error);
 }
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
index aa145ad..d79a1fe 100644
--- a/fs/xfs/xfs_buf.h
+++ b/fs/xfs/xfs_buf.h
@@ -196,7 +196,7 @@
 		int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp);
 int xfs_buf_read_map(struct xfs_buftarg *target, struct xfs_buf_map *map,
 		int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp,
-		const struct xfs_buf_ops *ops);
+		const struct xfs_buf_ops *ops, xfs_failaddr_t fa);
 void xfs_buf_readahead_map(struct xfs_buftarg *target,
 			       struct xfs_buf_map *map, int nmaps,
 			       const struct xfs_buf_ops *ops);
@@ -224,7 +224,8 @@
 {
 	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
 
-	return xfs_buf_read_map(target, &map, 1, flags, bpp, ops);
+	return xfs_buf_read_map(target, &map, 1, flags, bpp, ops,
+			__builtin_return_address(0));
 }
 
 static inline void
@@ -261,7 +262,7 @@
 extern void __xfs_buf_ioerror(struct xfs_buf *bp, int error,
 		xfs_failaddr_t failaddr);
 #define xfs_buf_ioerror(bp, err) __xfs_buf_ioerror((bp), (err), __this_address)
-extern void xfs_buf_ioerror_alert(struct xfs_buf *, const char *func);
+extern void xfs_buf_ioerror_alert(struct xfs_buf *bp, xfs_failaddr_t fa);
 
 extern int __xfs_buf_submit(struct xfs_buf *bp, bool);
 static inline int xfs_buf_submit(struct xfs_buf *bp)
diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index 5be8973..663810e 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c
@@ -1113,7 +1113,7 @@
 	if (bp->b_target != lasttarg ||
 	    time_after(jiffies, (lasttime + 5*HZ))) {
 		lasttime = jiffies;
-		xfs_buf_ioerror_alert(bp, __func__);
+		xfs_buf_ioerror_alert(bp, __this_address);
 	}
 	lasttarg = bp->b_target;
 
diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index ac79537..25cfc85 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -294,7 +294,7 @@
 		 * this during recovery. One strike!
 		 */
 		if (!XFS_FORCED_SHUTDOWN(bp->b_mount)) {
-			xfs_buf_ioerror_alert(bp, __func__);
+			xfs_buf_ioerror_alert(bp, __this_address);
 			xfs_force_shutdown(bp->b_mount, SHUTDOWN_META_IO_ERROR);
 		}
 	}
@@ -5627,7 +5627,7 @@
 	error = xfs_buf_submit(bp);
 	if (error) {
 		if (!XFS_FORCED_SHUTDOWN(mp)) {
-			xfs_buf_ioerror_alert(bp, __func__);
+			xfs_buf_ioerror_alert(bp, __this_address);
 			ASSERT(0);
 		}
 		xfs_buf_relse(bp);
diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c
index 8347099..08174ff 100644
--- a/fs/xfs/xfs_trans_buf.c
+++ b/fs/xfs/xfs_trans_buf.c
@@ -280,7 +280,7 @@
 		ASSERT(bp->b_ops != NULL);
 		error = xfs_buf_reverify(bp, ops);
 		if (error) {
-			xfs_buf_ioerror_alert(bp, __func__);
+			xfs_buf_ioerror_alert(bp, __return_address);
 
 			if (tp->t_flags & XFS_TRANS_DIRTY)
 				xfs_force_shutdown(tp->t_mountp,
@@ -302,7 +302,8 @@
 		return 0;
 	}
 
-	error = xfs_buf_read_map(target, map, nmaps, flags, &bp, ops);
+	error = xfs_buf_read_map(target, map, nmaps, flags, &bp, ops,
+			__return_address);
 	switch (error) {
 	case 0:
 		break;