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revert-reshape: make sure reshape_position is acceptable. 

We can only revert a reshape if the reshape_position aligns
properly for the old geometry.
If it doesn't we just fail for now.

Also fix a +/- error with updating raid_disks for super1.c

Signed-off-by: NeilBrown <neilb@suse.de>
This commit is contained in:
NeilBrown 2013-06-27 16:38:53 +10:00
parent 240cb5a41a
commit a2836f12c4
2 changed files with 36 additions and 3 deletions
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9
super0.c
View File

@ -654,7 +654,16 @@ static int update_super0(struct supertype *st, struct mdinfo *info,
devname);
else {
int tmp;
int parity = sb->level == 6 ? 2 : 1;
rv = 0;
if (sb->reshape_position % (
sb->new_chunk/512 *
(sb->raid_disks - sb->delta_disks - parity))) {
pr_err("Reshape position is not suitably aligned.\n");
pr_err("Try normal assembly as stop again\n");
return -2;
}
sb->raid_disks -= sb->delta_disks;
sb->delta_disks = -sb->delta_disks;

30
super1.c
View File

@ -57,7 +57,7 @@ struct mdp_superblock_1 {
__u64 reshape_position; /* next address in array-space for reshape */
__u32 delta_disks; /* change in number of raid_disks */
__u32 new_layout; /* new layout */
__u32 new_chunk; /* new chunk size (bytes) */
__u32 new_chunk; /* new chunk size (sectors) */
__u32 new_offset; /* signed number to add to data_offset in new
* layout. 0 == no-change. This can be
* different on each device in the array.
@ -1259,9 +1259,33 @@ static int update_super1(struct supertype *st, struct mdinfo *info,
pr_err("No active reshape to revert on %s\n",
devname);
else {
rv = 0;
__u32 temp;
sb->raid_disks = __cpu_to_le32(__le32_to_cpu(sb->raid_disks) +
unsigned long long reshape_sectors;
long reshape_chunk;
rv = 0;
/* reshape_position is a little messy.
* Its value must be a multiple of the larger
* chunk size, and of the "after" data disks.
* So when reverting we need to change it to
* be a multiple of the new "after" data disks,
* which is the old "before".
* If it isn't already a multiple of 'before',
* the only thing we could do would be
* copy some block around on the disks, which
* is easy to get wrong.
* So we reject a revert-reshape unless the
* alignment is good.
*/
reshape_sectors = __le64_to_cpu(sb->reshape_position);
reshape_chunk = __le32_to_cpu(sb->new_chunk);
reshape_chunk *= __le32_to_cpu(sb->raid_disks) - __le32_to_cpu(sb->delta_disks) -
(__le32_to_cpu(sb->level)==6 ? 2 : 1);
if (reshape_sectors % reshape_chunk) {
pr_err("Reshape position is not suitably aligned.\n");
pr_err("Try normal assembly as stop again\n");
return -2;
}
sb->raid_disks = __cpu_to_le32(__le32_to_cpu(sb->raid_disks) -
__le32_to_cpu(sb->delta_disks));
if (sb->delta_disks == 0)
sb->feature_map ^= __cpu_to_le32(MD_FEATURE_RESHAPE_BACKWARDS);