Re: [PATCH 1/4] mdadm: bad block support for external metadata - initialization

[keld@keldix.com]

Hi 

Is this safe for 2TB+ arrays?
I think the badblocks program does not handle 2TB+ partitions?

best regards
Keld

Best regards
Keld

On Thu, Oct 20, 2016 at 03:03:46PM +0200, Tomasz Majchrzak wrote:
> If metadata handler provides support for bad blocks, tell md by writing
> 'external_bbl' to rdev state file (both on create and assemble),
> followed by a list of known bad blocks written via sysfs 'bad_blocks'
> file.
> 
> Signed-off-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com>
> Reviewed-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
> ---
>  mdadm.h | 13 +++++++++++++
>  sysfs.c | 29 ++++++++++++++++++++++++++++-
>  2 files changed, 41 insertions(+), 1 deletion(-)
> 
> diff --git a/mdadm.h b/mdadm.h
> index 0516c82..5156ea4 100755
> --- a/mdadm.h
> +++ b/mdadm.h
> @@ -237,6 +237,17 @@ struct dlm_lksb {
>  
>  extern const char Name[];
>  
> +struct md_bb_entry {
> +	unsigned long long sector;
> +	int length;
> +};
> +
> +struct md_bb {
> +	int supported;
> +	int count;
> +	struct md_bb_entry *entries;
> +};
> +
>  /* general information that might be extracted from a superblock */
>  struct mdinfo {
>  	mdu_array_info_t	array;
> @@ -311,6 +322,8 @@ struct mdinfo {
>  
>  	/* info read from sysfs */
>  	char		sysfs_array_state[20];
> +
> +	struct md_bb bb;
>  };
>  
>  struct createinfo {
> diff --git a/sysfs.c b/sysfs.c
> index d28e21a..c7a8e66 100644
> --- a/sysfs.c
> +++ b/sysfs.c
> @@ -50,8 +50,12 @@ void sysfs_free(struct mdinfo *sra)
>  		while (sra->devs) {
>  			struct mdinfo *d = sra->devs;
>  			sra->devs = d->next;
> +			if (d->bb.entries)
> +				free(d->bb.entries);
>  			free(d);
>  		}
> +		if (sra->bb.entries)
> +			free(sra->bb.entries);
>  		free(sra);
>  		sra = sra2;
>  	}
> @@ -259,7 +263,7 @@ struct mdinfo *sysfs_read(int fd, char *devnm, unsigned long options)
>  		dbase = base + strlen(base);
>  		*dbase++ = '/';
>  
> -		dev = xmalloc(sizeof(*dev));
> +		dev = xcalloc(1, sizeof(*dev));
>  
>  		/* Always get slot, major, minor */
>  		strcpy(dbase, "slot");
> @@ -687,6 +691,7 @@ int sysfs_add_disk(struct mdinfo *sra, struct mdinfo *sd, int resume)
>  	char nm[PATH_MAX];
>  	char *dname;
>  	int rv;
> +	int i;
>  
>  	sprintf(dv, "%d:%d", sd->disk.major, sd->disk.minor);
>  	rv = sysfs_set_str(sra, NULL, "new_dev", dv);
> @@ -718,6 +723,28 @@ int sysfs_add_disk(struct mdinfo *sra, struct mdinfo *sd, int resume)
>  		if (resume)
>  			sysfs_set_num(sra, sd, "recovery_start", sd->recovery_start);
>  	}
> +	if (sd->bb.supported) {
> +		if (sysfs_set_str(sra, sd, "state", "external_bbl")) {
> +			/*
> +			 * backward compatibility - if kernel doesn't support
> +			 * bad blocks for external metadata, let it continue
> +			 * as long as there are none known so far
> +			 */
> +			if (sd->bb.count) {
> +				pr_err("The kernel has no support for bad blocks in external metadata\n");
> +				return -1;
> +			}
> +		}
> +
> +		for (i = 0; i < sd->bb.count; i++) {
> +			char s[30];
> +			const struct md_bb_entry *entry = &sd->bb.entries[i];
> +
> +			snprintf(s, sizeof(s) - 1, "%llu %d\n", entry->sector,
> +				 entry->length);
> +			rv |= sysfs_set_str(sra, sd, "bad_blocks", s);
> +		}
> +	}
>  	return rv;
>  }
>  
> -- 
> 1.8.3.1
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html