From 3cb5edf45457948347b5ae8cc9650c000cef4391 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Wed, 15 Jul 2015 17:24:17 +1000 Subject: md/raid5: switch to use conf->chunk_sectors in place of mddev->chunk_sectors where possible The chunk_sectors and new_chunk_sectors fields of mddev can be changed any time (via sysfs) that the reconfig mutex can be taken. So raid5 keeps internal copies in 'conf' which are stable except for a short locked moment when reshape stops/starts. So any access that does not hold reconfig_mutex should use the 'conf' values, not the 'mddev' values. Several don't. This could result in corruption if new values were written at awkward times. Also use min() or max() rather than open-coding. Signed-off-by: NeilBrown --- drivers/md/raid5.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) (limited to 'drivers/md') diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index e543bfd7ae66..a98162f5d97f 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -4676,9 +4676,10 @@ static int raid5_mergeable_bvec(struct mddev *mddev, struct bvec_merge_data *bvm, struct bio_vec *biovec) { + struct r5conf *conf = mddev->private; sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev); int max; - unsigned int chunk_sectors = mddev->chunk_sectors; + unsigned int chunk_sectors; unsigned int bio_sectors = bvm->bi_size >> 9; /* @@ -4688,8 +4689,7 @@ static int raid5_mergeable_bvec(struct mddev *mddev, if ((bvm->bi_rw & 1) == WRITE || mddev->degraded) return biovec->bv_len; - if (mddev->new_chunk_sectors < mddev->chunk_sectors) - chunk_sectors = mddev->new_chunk_sectors; + chunk_sectors = min(conf->chunk_sectors, conf->prev_chunk_sectors); max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9; if (max < 0) max = 0; if (max <= biovec->bv_len && bio_sectors == 0) @@ -4700,12 +4700,12 @@ static int raid5_mergeable_bvec(struct mddev *mddev, static int in_chunk_boundary(struct mddev *mddev, struct bio *bio) { + struct r5conf *conf = mddev->private; sector_t sector = bio->bi_iter.bi_sector + get_start_sect(bio->bi_bdev); - unsigned int chunk_sectors = mddev->chunk_sectors; + unsigned int chunk_sectors; unsigned int bio_sectors = bio_sectors(bio); - if (mddev->new_chunk_sectors < mddev->chunk_sectors) - chunk_sectors = mddev->new_chunk_sectors; + chunk_sectors = min(conf->chunk_sectors, conf->prev_chunk_sectors); return chunk_sectors >= ((sector & (chunk_sectors - 1)) + bio_sectors); } @@ -5372,10 +5372,8 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, int *sk * If old and new chunk sizes differ, we need to process the * largest of these */ - if (mddev->new_chunk_sectors > mddev->chunk_sectors) - reshape_sectors = mddev->new_chunk_sectors; - else - reshape_sectors = mddev->chunk_sectors; + + reshape_sectors = max(conf->chunk_sectors, conf->prev_chunk_sectors); /* We update the metadata at least every 10 seconds, or when * the data about to be copied would over-write the source of @@ -6260,8 +6258,8 @@ raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks) /* size is defined by the smallest of previous and new size */ raid_disks = min(conf->raid_disks, conf->previous_raid_disks); - sectors &= ~((sector_t)mddev->chunk_sectors - 1); - sectors &= ~((sector_t)mddev->new_chunk_sectors - 1); + sectors &= ~((sector_t)conf->chunk_sectors - 1); + sectors &= ~((sector_t)conf->prev_chunk_sectors - 1); return sectors * (raid_disks - conf->max_degraded); } @@ -6996,7 +6994,7 @@ static void status(struct seq_file *seq, struct mddev *mddev) int i; seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level, - mddev->chunk_sectors / 2, mddev->layout); + conf->chunk_sectors / 2, mddev->layout); seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded); for (i = 0; i < conf->raid_disks; i++) seq_printf (seq, "%s", @@ -7202,7 +7200,9 @@ static int raid5_resize(struct mddev *mddev, sector_t sectors) * worth it. */ sector_t newsize; - sectors &= ~((sector_t)mddev->chunk_sectors - 1); + struct r5conf *conf = mddev->private; + + sectors &= ~((sector_t)conf->chunk_sectors - 1); newsize = raid5_size(mddev, sectors, mddev->raid_disks); if (mddev->external_size && mddev->array_sectors > newsize) -- cgit v1.2.3-58-ga151