Commit bd7c1933 authored by Carlos Maiolino's avatar Carlos Maiolino
Browse files

XFS: fix zoned gc threshold math for 32-bit arches 



xfs_zoned_need_gc makes use of mult_frac() to calculate the threshold
for triggering the zoned garbage collector, but, turns out mult_frac()
doesn't properly work with 64-bit data types and this caused build
failures on some 32-bit architectures.

Fix this by essentially open coding mult_frac() in a 64-bit friendly
way.

Notice we don't need to bother with counters underflow here because
xfs_estimate_freecounter() will always return a positive value, as it
leverages percpu_counter_read_positive to read such counters.

Fixes: 845abeb1 ("xfs: add tunable threshold parameter for triggering zone GC")
Reported-by: default avatarkernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202504181233.F7D9Atra-lkp@intel.com/


Signed-off-by: default avatarCarlos Maiolino <cmaiolino@redhat.com>
Tested-by: default avatarGuenter Roeck <linux@roeck-us.net>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarHans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: default avatarCarlos Maiolino <cem@kernel.org>
parent c7b67ddc

fs/xfs/xfs_zone_gc.c

+8 −2
Original line number Diff line number Diff line
@@ -170,7 +170,8 @@ bool 
xfs_zoned_need_gc(

	struct xfs_mount	*mp)

{

	s64			available, free;

	s64			available, free, threshold;

	s32			remainder;



	if (!xfs_group_marked(mp, XG_TYPE_RTG, XFS_RTG_RECLAIMABLE))

		return false;
@@ -183,7 +184,12 @@ xfs_zoned_need_gc( 
		return true;



	free = xfs_estimate_freecounter(mp, XC_FREE_RTEXTENTS);

	if (available < mult_frac(free, mp->m_zonegc_low_space, 100))



	threshold = div_s64_rem(free, 100, &remainder);

	threshold = threshold * mp->m_zonegc_low_space +

		    remainder * div_s64(mp->m_zonegc_low_space, 100);



	if (available < threshold)

		return true;



	return false;