[Cluster-devel] Re: [GFS2 patch] Add "-o errors=panic|withdraw" mount options

[Steven Whitehouse <swhiteho@redhat.com>]

Hi,

Now in the -nmw git tree. Thanks,

Steve.

On Thu, 2009-08-20 at 10:29 -0400, Bob Peterson wrote:
> Hi,
> 
> 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).
> 
> Regards,
> 
> Bob Peterson
> Red Hat GFS
> 
> Signed-off-by: Bob Peterson <rpeterso@redhat.com> 
> --
>  fs/gfs2/incore.h     |    7 +++++++
>  fs/gfs2/ops_fstype.c |    1 +
>  fs/gfs2/super.c      |   36 ++++++++++++++++++++++++++++++++++++
>  fs/gfs2/util.c       |   41 +++++++++++++++++++++++++++--------------
>  4 files changed, 71 insertions(+), 14 deletions(-)
> 
> diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
> index 61801ad..1d11e6e 100644
> --- a/fs/gfs2/incore.h
> +++ b/fs/gfs2/incore.h
> @@ -406,6 +406,12 @@ struct gfs2_statfs_change_host {
>  #define GFS2_DATA_WRITEBACK	1
>  #define GFS2_DATA_ORDERED	2
>  
> +#define GFS2_ERRORS_DEFAULT     GFS2_ERRORS_WITHDRAW
> +#define GFS2_ERRORS_WITHDRAW    0
> +#define GFS2_ERRORS_CONTINUE    1 /* place holder for future feature */
> +#define GFS2_ERRORS_RO          2 /* place holder for future feature */
> +#define GFS2_ERRORS_PANIC       3
> +
>  struct gfs2_args {
>  	char ar_lockproto[GFS2_LOCKNAME_LEN];	/* Name of the Lock Protocol */
>  	char ar_locktable[GFS2_LOCKNAME_LEN];	/* Name of the Lock Table */
> @@ -422,6 +428,7 @@ struct gfs2_args {
>  	unsigned int ar_data:2;			/* ordered/writeback */
>  	unsigned int ar_meta:1;			/* mount metafs */
>  	unsigned int ar_discard:1;		/* discard requests */
> +	unsigned int ar_errors:2;               /* errors=withdraw | panic */
>  	int ar_commit;				/* Commit interval */
>  };
>  
> diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
> index 39021c0..165518a 100644
> --- a/fs/gfs2/ops_fstype.c
> +++ b/fs/gfs2/ops_fstype.c
> @@ -1168,6 +1168,7 @@ static int fill_super(struct super_block *sb, void *data, int silent)
>  	sdp->sd_args.ar_quota = GFS2_QUOTA_DEFAULT;
>  	sdp->sd_args.ar_data = GFS2_DATA_DEFAULT;
>  	sdp->sd_args.ar_commit = 60;
> +	sdp->sd_args.ar_errors = GFS2_ERRORS_DEFAULT;
>  
>  	error = gfs2_mount_args(sdp, &sdp->sd_args, data);
>  	if (error) {
> diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
> index 85bd2bc..7a5c128 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;
>  }
>  
> diff --git a/fs/gfs2/util.c b/fs/gfs2/util.c
> index 9d12b11..f6a7efa 100644
> --- a/fs/gfs2/util.c
> +++ b/fs/gfs2/util.c
> @@ -38,24 +38,30 @@ int gfs2_lm_withdraw(struct gfs2_sbd *sdp, char *fmt, ...)
>  	const struct lm_lockops *lm = ls->ls_ops;
>  	va_list args;
>  
> -	if (test_and_set_bit(SDF_SHUTDOWN, &sdp->sd_flags))
> +	if (sdp->sd_args.ar_errors == GFS2_ERRORS_WITHDRAW &&
> +	    test_and_set_bit(SDF_SHUTDOWN, &sdp->sd_flags))
>  		return 0;
>  
>  	va_start(args, fmt);
>  	vprintk(fmt, args);
>  	va_end(args);
>  
> -	fs_err(sdp, "about to withdraw this file system\n");
> -	BUG_ON(sdp->sd_args.ar_debug);
> +	if (sdp->sd_args.ar_errors == GFS2_ERRORS_WITHDRAW) {
> +		fs_err(sdp, "about to withdraw this file system\n");
> +		BUG_ON(sdp->sd_args.ar_debug);
>  
> -	kobject_uevent(&sdp->sd_kobj, KOBJ_OFFLINE);
> +		kobject_uevent(&sdp->sd_kobj, KOBJ_OFFLINE);
>  
> -	if (lm->lm_unmount) {
> -		fs_err(sdp, "telling LM to unmount\n");
> -		lm->lm_unmount(sdp);
> +		if (lm->lm_unmount) {
> +			fs_err(sdp, "telling LM to unmount\n");
> +			lm->lm_unmount(sdp);
> +		}
> +		fs_err(sdp, "withdrawn\n");
> +		dump_stack();
>  	}
> -	fs_err(sdp, "withdrawn\n");
> -	dump_stack();
> +
> +	if (sdp->sd_args.ar_errors == GFS2_ERRORS_PANIC)
> +		panic("GFS2: fsid=%s: panic requested.\n", sdp->sd_fsname);
>  
>  	return -1;
>  }
> @@ -93,17 +99,24 @@ int gfs2_assert_warn_i(struct gfs2_sbd *sdp, char *assertion,
>  			gfs2_tune_get(sdp, gt_complain_secs) * HZ))
>  		return -2;
>  
> -	printk(KERN_WARNING
> -	       "GFS2: fsid=%s: warning: assertion \"%s\" failed\n"
> -	       "GFS2: fsid=%s:   function = %s, file = %s, line = %u\n",
> -	       sdp->sd_fsname, assertion,
> -	       sdp->sd_fsname, function, file, line);
> +	if (sdp->sd_args.ar_errors == GFS2_ERRORS_WITHDRAW)
> +		printk(KERN_WARNING
> +		       "GFS2: fsid=%s: warning: assertion \"%s\" failed\n"
> +		       "GFS2: fsid=%s:   function = %s, file = %s, line = %u\n",
> +		       sdp->sd_fsname, assertion,
> +		       sdp->sd_fsname, function, file, line);
>  
>  	if (sdp->sd_args.ar_debug)
>  		BUG();
>  	else
>  		dump_stack();
>  
> +	if (sdp->sd_args.ar_errors == GFS2_ERRORS_PANIC)
> +		panic("GFS2: fsid=%s: warning: assertion \"%s\" failed\n"
> +		      "GFS2: fsid=%s:   function = %s, file = %s, line = %u\n",
> +		      sdp->sd_fsname, assertion,
> +		      sdp->sd_fsname, function, file, line);
> +
>  	sdp->sd_last_warning = jiffies;
>  
>  	return -1;