Revision 83193e5ebb0164d612aa620ceab7d3746e80e2a4 authored by Darrick J. Wong on 12 July 2021, 19:58:50 UTC, committed by Darrick J. Wong on 15 July 2021, 16:58:42 UTC
While auditing the realtime growfs code, I realized that the GROWFSRT
ioctl (and by extension xfs_growfs) has always allowed sysadmins to
change the realtime extent size when adding a realtime section to the
filesystem. Since we also have always allowed sysadmins to set
RTINHERIT and EXTSZINHERIT on directories even if there is no realtime
device, this invalidates the premise laid out in the comments added in
commit 603f000b15f2.
In other words, this is not a case of inadequate metadata validation.
This is a case of nearly forgotten (and apparently untested) but
supported functionality. Update the comments to reflect what we've
learned, and remove the log message about correcting the misalignment.
Fixes: 603f000b15f2 ("xfs: validate extsz hints against rt extent size when rtinherit is set")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
1 parent 5838d03
muldi3.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
*/
#include <linux/export.h>
#include <linux/libgcc.h>
#define W_TYPE_SIZE 32
#define __ll_B ((unsigned long) 1 << (W_TYPE_SIZE / 2))
#define __ll_lowpart(t) ((unsigned long) (t) & (__ll_B - 1))
#define __ll_highpart(t) ((unsigned long) (t) >> (W_TYPE_SIZE / 2))
/* If we still don't have umul_ppmm, define it using plain C. */
#if !defined(umul_ppmm)
#define umul_ppmm(w1, w0, u, v) \
do { \
unsigned long __x0, __x1, __x2, __x3; \
unsigned short __ul, __vl, __uh, __vh; \
\
__ul = __ll_lowpart(u); \
__uh = __ll_highpart(u); \
__vl = __ll_lowpart(v); \
__vh = __ll_highpart(v); \
\
__x0 = (unsigned long) __ul * __vl; \
__x1 = (unsigned long) __ul * __vh; \
__x2 = (unsigned long) __uh * __vl; \
__x3 = (unsigned long) __uh * __vh; \
\
__x1 += __ll_highpart(__x0); /* this can't give carry */\
__x1 += __x2; /* but this indeed can */ \
if (__x1 < __x2) /* did we get it? */ \
__x3 += __ll_B; /* yes, add it in the proper pos */ \
\
(w1) = __x3 + __ll_highpart(__x1); \
(w0) = __ll_lowpart(__x1) * __ll_B + __ll_lowpart(__x0);\
} while (0)
#endif
#if !defined(__umulsidi3)
#define __umulsidi3(u, v) ({ \
DWunion __w; \
umul_ppmm(__w.s.high, __w.s.low, u, v); \
__w.ll; \
})
#endif
long long notrace __muldi3(long long u, long long v)
{
const DWunion uu = {.ll = u};
const DWunion vv = {.ll = v};
DWunion w = {.ll = __umulsidi3(uu.s.low, vv.s.low)};
w.s.high += ((unsigned long) uu.s.low * (unsigned long) vv.s.high
+ (unsigned long) uu.s.high * (unsigned long) vv.s.low);
return w.ll;
}
EXPORT_SYMBOL(__muldi3);
Computing file changes ...
