Commit d7fdc5a6 authored by Sergey Senozhatsky's avatar Sergey Senozhatsky Committed by Andrew Morton
Browse files

zram: limit max recompress prio to num_active_comps 

Use the actual number of algorithms zram was configure with instead of
theoretical limit of ZRAM_MAX_COMPS.

Also make sure that min prio is not above max prio.

Link: https://lkml.kernel.org/r/20250303022425.285971-9-senozhatsky@chromium.org


Signed-off-by: default avatarSergey Senozhatsky <senozhatsky@chromium.org>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Yosry Ahmed <yosry.ahmed@linux.dev>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent f3b0c6c8

drivers/block/zram/zram_drv.c

+12 −3
Original line number Diff line number Diff line
@@ -2027,16 +2027,19 @@ static ssize_t recompress_store(struct device *dev, 
				struct device_attribute *attr,

				const char *buf, size_t len)

{

	u32 prio = ZRAM_SECONDARY_COMP, prio_max = ZRAM_MAX_COMPS;

	struct zram *zram = dev_to_zram(dev);

	char *args, *param, *val, *algo = NULL;

	u64 num_recomp_pages = ULLONG_MAX;

	struct zram_pp_ctl *ctl = NULL;

	struct zram_pp_slot *pps;

	u32 mode = 0, threshold = 0;

	u32 prio, prio_max;

	struct page *page;

	ssize_t ret;



	prio = ZRAM_SECONDARY_COMP;

	prio_max = zram->num_active_comps;



	args = skip_spaces(buf);

	while (*args) {

		args = next_arg(args, &param, &val);
@@ -2089,7 +2092,7 @@ static ssize_t recompress_store(struct device *dev, 
			if (prio == ZRAM_PRIMARY_COMP)

				prio = ZRAM_SECONDARY_COMP;



			prio_max = min(prio + 1, ZRAM_MAX_COMPS);

			prio_max = prio + 1;

			continue;

		}

	}
@@ -2117,7 +2120,7 @@ static ssize_t recompress_store(struct device *dev, 
				continue;



			if (!strcmp(zram->comp_algs[prio], algo)) {

				prio_max = min(prio + 1, ZRAM_MAX_COMPS);

				prio_max = prio + 1;

				found = true;

				break;

			}
@@ -2129,6 +2132,12 @@ static ssize_t recompress_store(struct device *dev, 
		}

	}



	prio_max = min(prio_max, (u32)zram->num_active_comps);

	if (prio >= prio_max) {

		ret = -EINVAL;

		goto release_init_lock;

	}



	page = alloc_page(GFP_KERNEL);

	if (!page) {

		ret = -ENOMEM;