From 988c3c186c730590a71df8adc1424c5578ef8bae Mon Sep 17 00:00:00 2001 From: Ojaswin Mujoo Date: Sun, 16 Aug 2026 18:37:09 +0530 Subject: [PATCH] erofs: fix unused pcluster_pools for higher page sizes pcluster_pool[] hardcodes {1,4,16,64,128,Z_EROFS_PCLUSTER_MAX_PAGES+1}, but the assumption of Z_EROFS_PCLUSTER_MAX_PAGES == 256 is only right for 4k page sizes. For higher page sizes like 16k or 64k, This results in us ending up with clusters bigger than what we will ever use, since we only support upto 1MB of compressed data. For example, on 64k page size we will only ever use clusters with nrpages= 1, 4 and 17. This patch fixes the allocation for such higher pages sizes by adding some compile time checks. Below are the clusters created right after boot on a 64KB page size machine $cat /proc/slabinfo | grep pcluster | cut -d" " -f1: Before the patch: erofs_pcluster-1 erofs_pcluster-4 erofs_pcluster-16 erofs_pcluster-17 erofs_pcluster-64 erofs_pcluster-128 After the patch: erofs_pcluster-1 erofs_pcluster-4 erofs_pcluster-17 Fixes: 9f6cc76e6ff0 ("erofs: introduce physical cluster slab pools") Reported-by: Shirisha G Signed-off-by: Ojaswin Mujoo Reviewed-by: Gao Xiang Reviewed-by: Chao Yu Signed-off-by: Gao Xiang --- fs/erofs/zdata.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c index 602ba8b7cc79..5c2c22ed64d0 100644 --- a/fs/erofs/zdata.c +++ b/fs/erofs/zdata.c @@ -128,7 +128,17 @@ struct z_erofs_pcluster_slab { #define _PCLP(n) { .maxpages = n } static struct z_erofs_pcluster_slab pcluster_pool[] __read_mostly = { - _PCLP(1), _PCLP(4), _PCLP(16), _PCLP(64), _PCLP(128), + _PCLP(1), + _PCLP(4), +#if Z_EROFS_PCLUSTER_MAX_PAGES > 16 + _PCLP(16), +#endif +#if Z_EROFS_PCLUSTER_MAX_PAGES > 64 + _PCLP(64), +#endif +#if Z_EROFS_PCLUSTER_MAX_PAGES > 128 + _PCLP(128), +#endif _PCLP(Z_EROFS_PCLUSTER_MAX_PAGES + 1) };