Re: [PATCH] mdadm: check bitmap first when reshape raid1 to raid0

[Xiao Ni <xni@redhat.com>]

Hi Neil

Could you review this patch? For the bitmap part, I don't remove it in 
Grow_reshape.
I described the reason in the patch.

Regards
Xiao

On 11/03/2015 08:25 AM, Xiao Ni wrote:
> One raid1 with bitmap is composed by 4 disks. It'll fail when rashape
> to raid0 and lose 3 disks. It should check bitmap first when reshape
> raid1 to raid0.
>
> And need to free subarray, close cfd in Grow_reshape.
>
> It can't remove bitmap in Grow_reshape, because it's already frozen. I
> think it should not unfreeze in the process of the function. So I just
> test the bitmap.
>
> Signed-off-by: Xiao Ni <xni@redhat.com>
> ---
>   Grow.c  | 45 ++++++++++++++++++++++++++++-----------------
>   mdadm.c | 16 ++++++++++++----
>   2 files changed, 40 insertions(+), 21 deletions(-)
>
> diff --git a/Grow.c b/Grow.c
> index 80d7b22..c4ea2a5 100644
> --- a/Grow.c
> +++ b/Grow.c
> @@ -1600,15 +1600,14 @@ int Grow_reshape(char *devname, int fd,
>   			cfd = open_dev_excl(st->container_devnm);
>   		} else {
>   			container = st->devnm;
> -			close(fd);
>   			cfd = open_dev_excl(st->devnm);
>   			fd = cfd;
>   		}
>   		if (cfd < 0) {
>   			pr_err("Unable to open container for %s\n",
>   				devname);
> -			free(subarray);
> -			return 1;
> +			rv = 1;
> +			goto release;
>   		}
>   
>   		rv = st->ss->load_container(st, cfd, NULL);
> @@ -1616,8 +1615,8 @@ int Grow_reshape(char *devname, int fd,
>   		if (rv) {
>   			pr_err("Cannot read superblock for %s\n",
>   				devname);
> -			free(subarray);
> -			return 1;
> +			rv = 1;
> +			goto release;
>   		}
>   
>   		/* check if operation is supported for metadata handler */
> @@ -1641,8 +1640,8 @@ int Grow_reshape(char *devname, int fd,
>   					pr_err("cannot reshape arrays in container with unsupported metadata: %s(%s)\n",
>   					       devname, container);
>   					sysfs_free(cc);
> -					free(subarray);
> -					return 1;
> +					rv = 1;
> +					goto release;
>   				}
>   			}
>   			sysfs_free(cc);
> @@ -1662,7 +1661,8 @@ int Grow_reshape(char *devname, int fd,
>   		       s->raiddisks - array.raid_disks,
>   		       s->raiddisks - array.raid_disks == 1 ? "" : "s",
>   		       array.spare_disks + added_disks);
> -		return 1;
> +		rv = 1;
> +		goto release;
>   	}
>   
>   	sra = sysfs_read(fd, NULL, GET_LEVEL | GET_DISKS | GET_DEVS
> @@ -1675,17 +1675,18 @@ int Grow_reshape(char *devname, int fd,
>   	} else {
>   		pr_err("failed to read sysfs parameters for %s\n",
>   			devname);
> -		return 1;
> +		rv = 1;
> +		goto release;
>   	}
>   	frozen = freeze(st);
>   	if (frozen < -1) {
>   		/* freeze() already spewed the reason */
> -		sysfs_free(sra);
> -		return 1;
> +		rv = 1;
> +		goto release;
>   	} else if (frozen < 0) {
>   		pr_err("%s is performing resync/recovery and cannot be reshaped\n", devname);
> -		sysfs_free(sra);
> -		return 1;
> +		rv = 1;
> +		goto release;
>   	}
>   
>   	/* ========= set size =============== */
> @@ -1898,11 +1899,16 @@ size_change_error:
>   	     array.layout == ((1 << 8) + 2) && !(array.raid_disks & 1)) ||
>   	    (s->level == 0 && array.level == 1 && sra)) {
>   		int err;
> +		
> +		if (array.state & (1<<MD_SB_BITMAP_PRESENT)) {
> +		        pr_err("Bitmap must be removed before level can be changed\n");
> +		        rv = 1;
> +		        goto release;
> +		}
> +
>   		err = remove_disks_for_takeover(st, sra, array.layout);
>   		if (err) {
> -			dprintf("Array cannot be reshaped\n");
> -			if (cfd > -1)
> -				close(cfd);
> +			pr_err("Array cannot be reshaped\n");
>   			rv = 1;
>   			goto release;
>   		}
> @@ -2078,9 +2084,14 @@ size_change_error:
>   		frozen = 0;
>   	}
>   release:
> -	sysfs_free(sra);
>   	if (frozen > 0)
>   		unfreeze(st);
> +	if (sra)
> +		sysfs_free(sra);
> +	if (cfd > -1)
> +		close(cfd);
> +	if (subarray)
> +		free(subarray);
>   	return rv;
>   }
>   
> diff --git a/mdadm.c b/mdadm.c
> index f56a8cf..95db2a0 100644
> --- a/mdadm.c
> +++ b/mdadm.c
> @@ -1299,7 +1299,8 @@ int main(int argc, char *argv[])
>   			pr_err("'1' is an unusual number of drives for an array, so it is probably\n"
>   				"     a mistake.  If you really mean it you will need to specify --force before\n"
>   				"     setting the number of drives.\n");
> -			exit(2);
> +			rv = 2;
> +			goto release;
>   		}
>   	}
>   
> @@ -1326,13 +1327,15 @@ int main(int argc, char *argv[])
>   			rv = get_cluster_name(&c.homecluster);
>   		if (rv) {
>   			pr_err("The md can't get cluster name\n");
> -			exit(1);
> +			rv = 1;
> +			goto release;
>   		}
>   	}
>   
>   	if (c.backup_file && data_offset != INVALID_SECTORS) {
>   		pr_err("--backup-file and --data-offset are incompatible\n");
> -		exit(2);
> +		rv = 2;
> +		goto release;
>   	}
>   
>   	if ((mode == MISC && devmode == 'E')
> @@ -1340,7 +1343,8 @@ int main(int argc, char *argv[])
>   		/* Anyone may try this */;
>   	else if (geteuid() != 0) {
>   		pr_err("must be super-user to perform this action\n");
> -		exit(1);
> +		rv = 1;
> +		goto release;
>   	}
>   
>   	ident.autof = c.autof;
> @@ -1640,6 +1644,10 @@ int main(int argc, char *argv[])
>   		autodetect();
>   		break;
>   	}
> +
> +release:
> +	if (mdfd > -1)
> +		close(mdfd);
>   	exit(rv);
>   }
>