This is the case the "compressed" data is larger than the original data,
it is better to return -ENOSPC which can help zswap record a poor compr
rather than an invalid request. Then we get more friendly counting for
reject_compress_poor in debugfs.
bool zswap_store(struct folio *folio)
{
...
ret = zpool_malloc(zpool, dlen, gfp, &handle);
if (ret == -ENOSPC) {
zswap_reject_compress_poor++;
goto put_dstmem;
}
if (ret) {
zswap_reject_alloc_fail++;
goto put_dstmem;
}
...
}
Also, zbud_alloc() and z3fold_alloc() are returning ENOSPC in the same
case, eg
static int z3fold_alloc(struct z3fold_pool *pool, size_t size, gfp_t gfp,
unsigned long *handle)
{
...
if (!size || (gfp & __GFP_HIGHMEM))
return -EINVAL;
if (size > PAGE_SIZE)
return -ENOSPC;
...
}
Signed-off-by: Barry Song <v-songbaohua@xxxxxxxx>
---
mm/zsmalloc.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index b1c0dad7f4cf..c937635e0ad1 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -1364,9 +1364,12 @@ unsigned long zs_malloc(struct zs_pool *pool, size_t size, gfp_t gfp)
int newfg;
struct zspage *zspage;
- if (unlikely(!size || size > ZS_MAX_ALLOC_SIZE))
+ if (unlikely(!size))
return (unsigned long)ERR_PTR(-EINVAL);
+ if (unlikely(size > ZS_MAX_ALLOC_SIZE))
+ return (unsigned long)ERR_PTR(-ENOSPC);
+
handle = cache_alloc_handle(pool, gfp);
if (!handle)
return (unsigned long)ERR_PTR(-ENOMEM);
--
2.34.1
