Revision 6af10a33c501b0b5878476501143c2cfbbfd63a2 authored by Yufen Yu on 20 August 2020, 13:22:05 UTC, committed by Song Liu on 28 August 2020, 05:41:03 UTC
Commit 3b5408b98e4d ("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: 3b5408b98e4d ("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>
1 parent 79e5dc5
Raw File
lshrdi3.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * lib/lshrdi3.c
 */

#include <linux/module.h>
#include <linux/libgcc.h>

long long notrace __lshrdi3(long long u, word_type b)
{
	DWunion uu, w;
	word_type bm;

	if (b == 0)
		return u;

	uu.ll = u;
	bm = 32 - b;

	if (bm <= 0) {
		w.s.high = 0;
		w.s.low = (unsigned int) uu.s.high >> -bm;
	} else {
		const unsigned int carries = (unsigned int) uu.s.high << bm;

		w.s.high = (unsigned int) uu.s.high >> b;
		w.s.low = ((unsigned int) uu.s.low >> b) | carries;
	}

	return w.ll;
}
EXPORT_SYMBOL(__lshrdi3);
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