diff options
| author | NeilBrown | 2015-07-15 17:36:21 +1000 |
|---|---|---|
| committer | NeilBrown | 2015-08-31 19:34:21 +0200 |
| commit | 05256d9884d3276f61537d3d7f5605dc21bd3477 (patch) | |
| tree | 41833f3fb7fc323e30b481eabbe0802e24c40c9c /drivers/md | |
| parent | 3cb5edf45457948347b5ae8cc9650c000cef4391 (diff) | |
md/raid5: strengthen check on reshape_position at run.
When reshaping, we work in units of the largest chunk size.
If changing from a larger to a smaller chunk size, that means we
reshape more than one stripe at a time. So the required alignment
of reshape_position needs to take into account both the old
and new chunk size.
This means that both 'here_new' and 'here_old' are calculated with
respect to the same (maximum) chunk size, so testing if they are the
same when delta_disks is zero becomes pointless.
Signed-off-by: NeilBrown <neilb@suse.com>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/raid5.c | 29 |
1 files changed, 14 insertions, 15 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index a98162f5d97f..e95219bf8859 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -6688,6 +6688,8 @@ static int run(struct mddev *mddev) sector_t here_new, here_old; int old_disks; int max_degraded = (mddev->level == 6 ? 2 : 1); + int chunk_sectors; + int new_data_disks; if (mddev->new_level != mddev->level) { printk(KERN_ERR "md/raid:%s: unsupported reshape " @@ -6699,28 +6701,25 @@ static int run(struct mddev *mddev) /* reshape_position must be on a new-stripe boundary, and one * further up in new geometry must map after here in old * geometry. + * If the chunk sizes are different, then as we perform reshape + * in units of the largest of the two, reshape_position needs + * be a multiple of the largest chunk size times new data disks. */ here_new = mddev->reshape_position; - if (sector_div(here_new, mddev->new_chunk_sectors * - (mddev->raid_disks - max_degraded))) { + chunk_sectors = max(mddev->chunk_sectors, mddev->new_chunk_sectors); + new_data_disks = mddev->raid_disks - max_degraded; + if (sector_div(here_new, chunk_sectors * new_data_disks)) { printk(KERN_ERR "md/raid:%s: reshape_position not " "on a stripe boundary\n", mdname(mddev)); return -EINVAL; } - reshape_offset = here_new * mddev->new_chunk_sectors; + reshape_offset = here_new * chunk_sectors; /* here_new is the stripe we will write to */ here_old = mddev->reshape_position; - sector_div(here_old, mddev->chunk_sectors * - (old_disks-max_degraded)); + sector_div(here_old, chunk_sectors * (old_disks-max_degraded)); /* here_old is the first stripe that we might need to read * from */ if (mddev->delta_disks == 0) { - if ((here_new * mddev->new_chunk_sectors != - here_old * mddev->chunk_sectors)) { - printk(KERN_ERR "md/raid:%s: reshape position is" - " confused - aborting\n", mdname(mddev)); - return -EINVAL; - } /* We cannot be sure it is safe to start an in-place * reshape. It is only safe if user-space is monitoring * and taking constant backups. @@ -6739,10 +6738,10 @@ static int run(struct mddev *mddev) return -EINVAL; } } else if (mddev->reshape_backwards - ? (here_new * mddev->new_chunk_sectors + min_offset_diff <= - here_old * mddev->chunk_sectors) - : (here_new * mddev->new_chunk_sectors >= - here_old * mddev->chunk_sectors + (-min_offset_diff))) { + ? (here_new * chunk_sectors + min_offset_diff <= + here_old * chunk_sectors) + : (here_new * chunk_sectors >= + here_old * chunk_sectors + (-min_offset_diff))) { /* Reading from the same stripe as writing to - bad */ printk(KERN_ERR "md/raid:%s: reshape_position too early for " "auto-recovery - aborting.\n", |