mm/zswap: cleanup zswap_writeback_entry()

Also after the common decompress part goes to __zswap_load(), we can
cleanup the zswap_writeback_entry() a little.

Link: https://lkml.kernel.org/r/20231213-zswap-dstmem-v5-4-9382162bbf05@bytedance.com
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Acked-by: Chris Li <chrisl@kernel.org> (Google)
Cc: Barry Song <21cnbao@gmail.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Chengming Zhou 2023-12-28 09:45:45 +00:00 committed by Andrew Morton
parent 66447fd036
commit e947ba0bbf

View file

@ -1434,7 +1434,6 @@ static int zswap_writeback_entry(struct zswap_entry *entry,
struct page *page;
struct mempolicy *mpol;
bool page_was_allocated;
int ret;
struct writeback_control wbc = {
.sync_mode = WB_SYNC_NONE,
};
@ -1443,16 +1442,17 @@ static int zswap_writeback_entry(struct zswap_entry *entry,
mpol = get_task_policy(current);
page = __read_swap_cache_async(swpentry, GFP_KERNEL, mpol,
NO_INTERLEAVE_INDEX, &page_was_allocated, true);
if (!page) {
ret = -ENOMEM;
goto fail;
}
if (!page)
return -ENOMEM;
/* Found an existing page, we raced with load/swapin */
/*
* Found an existing page, we raced with load/swapin. We generally
* writeback cold pages from zswap, and swapin means the page just
* became hot. Skip this page and let the caller find another one.
*/
if (!page_was_allocated) {
put_page(page);
ret = -EEXIST;
goto fail;
return -EEXIST;
}
/*
@ -1466,8 +1466,7 @@ static int zswap_writeback_entry(struct zswap_entry *entry,
if (zswap_rb_search(&tree->rbroot, swp_offset(entry->swpentry)) != entry) {
spin_unlock(&tree->lock);
delete_from_swap_cache(page_folio(page));
ret = -ENOMEM;
goto fail;
return -ENOMEM;
}
spin_unlock(&tree->lock);
@ -1483,15 +1482,7 @@ static int zswap_writeback_entry(struct zswap_entry *entry,
__swap_writepage(page, &wbc);
put_page(page);
return ret;
fail:
/*
* If we get here because the page is already in swapcache, a
* load may be happening concurrently. It is safe and okay to
* not free the entry. It is also okay to return !0.
*/
return ret;
return 0;
}
static int zswap_is_page_same_filled(void *ptr, unsigned long *value)