xfs: allow setting full range of panic tags

xfs will not allow combining other panic masks with
XFS_PTAG_VERIFIER_ERROR.

 # sysctl fs.xfs.panic_mask=511
 sysctl: setting key "fs.xfs.panic_mask": Invalid argument
 fs.xfs.panic_mask = 511

Update to the maximum value that can be set to allow the full range of
masks. Do this using a mask of possible values to prevent this happening
again as suggested by Darrick.

Fixes: d519da41 ("xfs: Introduce XFS_PTAG_VERIFIER_ERROR panic mask")
Signed-off-by: Donald Douwsma <ddouwsma@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

Documentation/admin-guide/xfs.rst

@@ -296,7 +296,7 @@ The following sysctls are available for the XFS filesystem:
 		XFS_ERRLEVEL_LOW:       1
 		XFS_ERRLEVEL_HIGH:      5
 
-  fs.xfs.panic_mask		(Min: 0  Default: 0  Max: 256)
+  fs.xfs.panic_mask		(Min: 0  Default: 0  Max: 511)
 	Causes certain error conditions to call BUG(). Value is a bitmask;
 	OR together the tags which represent errors which should cause panics:
 

fs/xfs/xfs_error.h

@@ -75,7 +75,7 @@ extern int xfs_errortag_clearall(struct xfs_mount *mp);
 
 /*
  * XFS panic tags -- allow a call to xfs_alert_tag() be turned into
- *			a panic by setting xfs_panic_mask in a sysctl.
+ *			a panic by setting fs.xfs.panic_mask in a sysctl.
  */
 #define		XFS_NO_PTAG			0u
 #define		XFS_PTAG_IFLUSH			(1u << 0)
@@ -88,6 +88,16 @@ extern int xfs_errortag_clearall(struct xfs_mount *mp);
 #define		XFS_PTAG_FSBLOCK_ZERO		(1u << 7)
 #define		XFS_PTAG_VERIFIER_ERROR		(1u << 8)
 
+#define		XFS_PTAG_MASK	(XFS_PTAG_IFLUSH | \
+				 XFS_PTAG_LOGRES | \
+				 XFS_PTAG_AILDELETE | \
+				 XFS_PTAG_ERROR_REPORT | \
+				 XFS_PTAG_SHUTDOWN_CORRUPT | \
+				 XFS_PTAG_SHUTDOWN_IOERROR | \
+				 XFS_PTAG_SHUTDOWN_LOGERROR | \
+				 XFS_PTAG_FSBLOCK_ZERO | \
+				 XFS_PTAG_VERIFIER_ERROR)
+
 #define XFS_PTAG_STRINGS \
 	{ XFS_NO_PTAG,			"none" }, \
 	{ XFS_PTAG_IFLUSH,		"iflush" }, \

fs/xfs/xfs_globals.c

@@ -4,6 +4,7 @@
  * All Rights Reserved.
  */
 #include "xfs.h"
+#include "xfs_error.h"
 
 /*
  * Tunable XFS parameters.  xfs_params is required even when CONFIG_SYSCTL=n,
@@ -15,7 +16,7 @@ xfs_param_t xfs_params = {
 			  /*	MIN		DFLT		MAX	*/
 	.sgid_inherit	= {	0,		0,		1	},
 	.symlink_mode	= {	0,		0,		1	},
-	.panic_mask	= {	0,		0,		256	},
+	.panic_mask	= {	0,		0,		XFS_PTAG_MASK},
 	.error_level	= {	0,		3,		11	},
 	.syncd_timer	= {	1*100,		30*100,		7200*100},
 	.stats_clear	= {	0,		0,		1	},