GFS2: Add "-o errors=panic|withdraw" mount options

This patch adds "-o errors=panic" and "-o errors=withdraw" to the
gfs2 mount options.  The "errors=withdraw" option is today's
current behaviour, meaning to withdraw from the file system if a
non-serious gfs2 error occurs.  The new "errors=panic" option
tells gfs2 to force a kernel panic if a non-serious gfs2 file
system error occurs.  This may be useful, for example, where
fabric-level fencing is used that has no way to reboot (such as
fence_scsi).

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 36 insertions, 0 deletions

diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index 85bd2bc8c1de..7a5c128e8776 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -68,6 +68,8 @@ enum {
 	Opt_discard,
 	Opt_nodiscard,
 	Opt_commit,
+	Opt_err_withdraw,
+	Opt_err_panic,
 	Opt_error,
 };
 
@@ -97,6 +99,8 @@ static const match_table_t tokens = {
 	{Opt_discard, "discard"},
 	{Opt_nodiscard, "nodiscard"},
 	{Opt_commit, "commit=%d"},
+	{Opt_err_withdraw, "errors=withdraw"},
+	{Opt_err_panic, "errors=panic"},
 	{Opt_error, NULL}
 };
 
@@ -152,6 +156,11 @@ int gfs2_mount_args(struct gfs2_sbd *sdp, struct gfs2_args *args, char *options)
 			args->ar_localcaching = 1;
 			break;
 		case Opt_debug:
+			if (args->ar_errors == GFS2_ERRORS_PANIC) {
+				fs_info(sdp, "-o debug and -o errors=panic "
+				       "are mutually exclusive.\n");
+				return -EINVAL;
+			}
 			args->ar_debug = 1;
 			break;
 		case Opt_nodebug:
@@ -205,6 +214,17 @@ int gfs2_mount_args(struct gfs2_sbd *sdp, struct gfs2_args *args, char *options)
 				return rv ? rv : -EINVAL;
 			}
 			break;
+		case Opt_err_withdraw:
+			args->ar_errors = GFS2_ERRORS_WITHDRAW;
+			break;
+		case Opt_err_panic:
+			if (args->ar_debug) {
+				fs_info(sdp, "-o debug and -o errors=panic "
+					"are mutually exclusive.\n");
+				return -EINVAL;
+			}
+			args->ar_errors = GFS2_ERRORS_PANIC;
+			break;
 		case Opt_error:
 		default:
 			fs_info(sdp, "invalid mount option: %s\n", o);
@@ -1226,6 +1246,22 @@ static int gfs2_show_options(struct seq_file *s, struct vfsmount *mnt)
 	lfsecs = sdp->sd_tune.gt_log_flush_secs;
 	if (lfsecs != 60)
 		seq_printf(s, ",commit=%d", lfsecs);
+	if (args->ar_errors != GFS2_ERRORS_DEFAULT) {
+		const char *state;
+
+		switch (args->ar_errors) {
+		case GFS2_ERRORS_WITHDRAW:
+			state = "withdraw";
+			break;
+		case GFS2_ERRORS_PANIC:
+			state = "panic";
+			break;
+		default:
+			state = "unknown";
+			break;
+		}
+		seq_printf(s, ",errors=%s", state);
+	}
 	return 0;
 }