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 <shirisha@linux.ibm.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Gao Xiang <xiang@kernel.org>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <xiang@kernel.org>

0 files changed, 0 insertions, 0 deletions