On (23/12/28 11:12), Andrew Morton wrote:
> 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;
> ...
> }
>
> Link: https://lkml.kernel.org/r/20231228061802.25280-1-v-songbaohua@xxxxxxxx
> Signed-off-by: Barry Song <v-songbaohua@xxxxxxxx>
> Reviewed-by: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx>
> Cc: Chris Li <chrisl@xxxxxxxxxx>
> Cc: Dan Streetman <ddstreet@xxxxxxxx>
> Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
> Cc: Minchan Kim <minchan@xxxxxxxxxx>
> Cc: Nhat Pham <nphamcs@xxxxxxxxx>
> Cc: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
> Cc: Seth Jennings <sjenning@xxxxxxxxxx>
> Cc: Vitaly Wool <vitaly.wool@xxxxxxxxxxxx>
> Cc: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Acked-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
