Revision 021ba8e98fe5c6691b3cc3669faafa02403aa211 authored by Darrick J. Wong on 17 April 2018, 06:07:36 UTC, committed by Darrick J. Wong on 02 May 2018, 16:21:33 UTC
Since deduplication potentially has to read in all the pages in both files in order to compare the contents, cap the deduplication request length at MAX_RW_COUNT/2 (roughly 1GB) so that we have /some/ upper bound on the request length and can't just lock up the kernel forever. Found by running generic/304 after commit 1ddae54555b62 ("common/rc: add missing 'local' keywords"). Reported-by: matorola@gmail.com Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
1 parent 7b38460
int_sqrt.c
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2013 Davidlohr Bueso <davidlohr.bueso@hp.com>
*
* Based on the shift-and-subtract algorithm for computing integer
* square root from Guy L. Steele.
*/
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/bitops.h>
/**
* int_sqrt - computes the integer square root
* @x: integer of which to calculate the sqrt
*
* Computes: floor(sqrt(x))
*/
unsigned long int_sqrt(unsigned long x)
{
unsigned long b, m, y = 0;
if (x <= 1)
return x;
m = 1UL << (__fls(x) & ~1UL);
while (m != 0) {
b = y + m;
y >>= 1;
if (x >= b) {
x -= b;
y += m;
}
m >>= 2;
}
return y;
}
EXPORT_SYMBOL(int_sqrt);
#if BITS_PER_LONG < 64
/**
* int_sqrt64 - strongly typed int_sqrt function when minimum 64 bit input
* is expected.
* @x: 64bit integer of which to calculate the sqrt
*/
u32 int_sqrt64(u64 x)
{
u64 b, m, y = 0;
if (x <= ULONG_MAX)
return int_sqrt((unsigned long) x);
m = 1ULL << (fls64(x) & ~1ULL);
while (m != 0) {
b = y + m;
y >>= 1;
if (x >= b) {
x -= b;
y += m;
}
m >>= 2;
}
return y;
}
EXPORT_SYMBOL(int_sqrt64);
#endif
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