From 01ee22b496c41384eaa6dcae983c86d8bc32fbb8 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 18 Jun 2009 08:47:20 +1000 Subject: [PATCH] md: raid5: check stripe cache is large enough in start_reshape In reshape cases that do not change the number of devices, start_reshape is called without first calling check_reshape. Currently, the check that the stripe_cache is large enough is only done in check_reshape. It should be in start_reshape too. Signed-off-by: NeilBrown --- drivers/md/raid5.c | 44 +++++++++++++++++++++++++++----------------- 1 file changed, 27 insertions(+), 17 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 009344156751..b84766e347c3 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -4845,6 +4845,29 @@ static int raid5_resize(mddev_t *mddev, sector_t sectors) return 0; } +static int check_stripe_cache(mddev_t *mddev) +{ + /* Can only proceed if there are plenty of stripe_heads. + * We need a minimum of one full stripe,, and for sensible progress + * it is best to have about 4 times that. + * If we require 4 times, then the default 256 4K stripe_heads will + * allow for chunk sizes up to 256K, which is probably OK. + * If the chunk size is greater, user-space should request more + * stripe_heads first. + */ + raid5_conf_t *conf = mddev->private; + if (((mddev->chunk_sectors << 9) / STRIPE_SIZE) * 4 + > conf->max_nr_stripes || + ((mddev->new_chunk_sectors << 9) / STRIPE_SIZE) * 4 + > conf->max_nr_stripes) { + printk(KERN_WARNING "raid5: reshape: not enough stripes. Needed %lu\n", + ((max(mddev->chunk_sectors, mddev->new_chunk_sectors) << 9) + / STRIPE_SIZE)*4); + return 0; + } + return 1; +} + static int raid5_check_reshape(mddev_t *mddev) { raid5_conf_t *conf = mddev->private; @@ -4871,24 +4894,8 @@ static int raid5_check_reshape(mddev_t *mddev) return -EINVAL; } - /* Can only proceed if there are plenty of stripe_heads. - * We need a minimum of one full stripe,, and for sensible progress - * it is best to have about 4 times that. - * If we require 4 times, then the default 256 4K stripe_heads will - * allow for chunk sizes up to 256K, which is probably OK. - * If the chunk size is greater, user-space should request more - * stripe_heads first. - */ - if (((mddev->chunk_sectors << 9) / STRIPE_SIZE) * 4 - > conf->max_nr_stripes || - ((mddev->new_chunk_sectors << 9) / STRIPE_SIZE) * 4 - > conf->max_nr_stripes) { - printk(KERN_WARNING "raid5: reshape: not enough stripes. Needed %lu\n", - (max(mddev->chunk_sectors << 9, - mddev->new_chunk_sectors << 9) - / STRIPE_SIZE)*4); + if (!check_stripe_cache(mddev)) return -ENOSPC; - } return resize_stripes(conf, conf->raid_disks + mddev->delta_disks); } @@ -4904,6 +4911,9 @@ static int raid5_start_reshape(mddev_t *mddev) if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) return -EBUSY; + if (!check_stripe_cache(mddev)) + return -ENOSPC; + list_for_each_entry(rdev, &mddev->disks, same_set) if (rdev->raid_disk < 0 && !test_bit(Faulty, &rdev->flags))