From bd7c19331913b955a7823e6315ca16bbcc65aeff Mon Sep 17 00:00:00 2001 From: Carlos Maiolino Date: Tue, 22 Apr 2025 14:54:54 +0200 Subject: [PATCH] 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: 845abeb1f06a ("xfs: add tunable threshold parameter for triggering zone GC") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202504181233.F7D9Atra-lkp@intel.com/ Signed-off-by: Carlos Maiolino Tested-by: Guenter Roeck Reviewed-by: Christoph Hellwig Reviewed-by: Hans Holmberg Signed-off-by: Carlos Maiolino --- fs/xfs/xfs_zone_gc.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/fs/xfs/xfs_zone_gc.c b/fs/xfs/xfs_zone_gc.c index 8c541ca71872..81c94dd1d596 100644 --- a/fs/xfs/xfs_zone_gc.c +++ b/fs/xfs/xfs_zone_gc.c @@ -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; -- 2.25.1