[PATCH v5 07/18] zram: limit max recompress prio to num_active_comps
From: Sergey Senozhatsky
Date: Wed Feb 12 2025 - 01:34:15 EST
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.
Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
---
drivers/block/zram/zram_drv.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 7e2694079760..27148f3e5ae9 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -2026,16 +2026,19 @@ 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, ¶m, &val);
@@ -2088,7 +2091,7 @@ 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;
}
}
@@ -2116,7 +2119,7 @@ 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;
}
@@ -2128,6 +2131,12 @@ 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;
--
2.48.1.502.g6dc24dfdaf-goog