Commit 6af10a33 authored Aug 20, 2020 by Yufen Yu Committed by Song Liu Aug 27, 2020

md/raid5: make sure stripe_size as power of two



Commit 3b5408b9 ("md/raid5: support config stripe_size by sysfs
entry") make stripe_size as a configurable value. It just requires
stripe_size as multiple of 4KB.

In fact, we should make sure stripe_size as power of two. Otherwise,
stripe_shift which is the result of ilog2 can not represent the real
stripe_size. Then, stripe_hash() and stripe_hash_locks_hash() may
get unexpected value.

Fixes: 3b5408b9 ("md/raid5: support config stripe_size by sysfs entry")
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Song Liu <songliubraving@fb.com>

parent 79e5dc59

drivers/md/raid5.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -6514,9 +6514,12 @@ raid5_store_stripe_size(struct mddev mddev, const char page, size_t len)

		/*
		* The value should not be bigger than PAGE_SIZE. It requires to
		* be multiple of DEFAULT_STRIPE_SIZE.
		* be multiple of DEFAULT_STRIPE_SIZE and the value should be power
		* of two.
		*/
		if (new % DEFAULT_STRIPE_SIZE != 0 \|\| new > PAGE_SIZE \|\| new == 0)
		if (new % DEFAULT_STRIPE_SIZE != 0 \|\|
		new > PAGE_SIZE \|\| new == 0 \|\|
		new != roundup_pow_of_two(new))
		return -EINVAL;

		err = mddev_lock(mddev);

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