xfs: report corruption only as a regular error

Redefine XFS_IS_CORRUPT so that it reports corruptions only via
xfs_corruption_report.  Since these are on-disk contents (and not checks
of internal state), we don't ever want to panic the kernel.  This also
amends the corruption report to recommend unmounting and running
xfs_repair.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

fs/xfs/xfs_error.c

@@ -335,7 +335,7 @@ xfs_corruption_error(
 	int			linenum,
 	xfs_failaddr_t		failaddr)
 {
-	if (level <= xfs_error_level)
+	if (buf && level <= xfs_error_level)
 		xfs_hex_dump(buf, bufsize);
 	xfs_error_report(tag, level, mp, filename, linenum, failaddr);
 	xfs_alert(mp, "Corruption detected. Unmount and run xfs_repair");

fs/xfs/xfs_linux.h

@@ -229,10 +229,6 @@ int xfs_rw_bdev(struct block_device *bdev, sector_t sector, unsigned int count,
 #define ASSERT(expr)	\
 	(likely(expr) ? (void)0 : assfail(NULL, #expr, __FILE__, __LINE__))
 
-#define XFS_IS_CORRUPT(mp, expr)	\
-	(unlikely(expr) ? assfail((mp), #expr, __FILE__, __LINE__), \
-			  true : false)
-
 #else	/* !DEBUG */
 
 #ifdef XFS_WARN
@@ -240,20 +236,19 @@ int xfs_rw_bdev(struct block_device *bdev, sector_t sector, unsigned int count,
 #define ASSERT(expr)	\
 	(likely(expr) ? (void)0 : asswarn(NULL, #expr, __FILE__, __LINE__))
 
-#define XFS_IS_CORRUPT(mp, expr)	\
-	(unlikely(expr) ? asswarn((mp), #expr, __FILE__, __LINE__), \
-			  true : false)
-
 #else	/* !DEBUG && !XFS_WARN */
 
 #define ASSERT(expr)		((void)0)
-#define XFS_IS_CORRUPT(mp, expr)	\
-	(unlikely(expr) ? XFS_ERROR_REPORT(#expr, XFS_ERRLEVEL_LOW, (mp)), \
-			  true : false)
 
 #endif /* XFS_WARN */
 #endif /* DEBUG */
 
+#define XFS_IS_CORRUPT(mp, expr)	\
+	(unlikely(expr) ? xfs_corruption_error(#expr, XFS_ERRLEVEL_LOW, (mp), \
+					       NULL, 0, __FILE__, __LINE__, \
+					       __this_address), \
+			  true : false)
+
 #define STATIC static noinline
 
 #ifdef CONFIG_XFS_RT