Commit b8d3ff7b authored by Sergey Senozhatsky's avatar Sergey Senozhatsky Committed by Andrew Morton
Browse files

zram: use zram_read_from_zspool() in writeback 

We only can read pages from zspool in writeback, zram_read_page() is not
really right in that context not only because it's a more generic function
that handles ZRAM_WB pages, but also because it requires us to unlock slot
between slot flag check and actual page read.  Use zram_read_from_zspool()
instead and do slot flags check and page read under the same slot lock.

Link: https://lkml.kernel.org/r/20241218063513.297475-7-senozhatsky@chromium.org


Signed-off-by: default avatarSergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent e355b253

drivers/block/zram/zram_drv.c

+4 −7
Original line number Diff line number Diff line
@@ -55,8 +55,8 @@ static size_t huge_class_size; 
static const struct block_device_operations zram_devops;



static void zram_free_page(struct zram *zram, size_t index);

static int zram_read_page(struct zram *zram, struct page *page, u32 index,

			  struct bio *parent);

static int zram_read_from_zspool(struct zram *zram, struct page *page,

				 u32 index);



static int zram_slot_trylock(struct zram *zram, u32 index)

{
@@ -831,13 +831,10 @@ static ssize_t writeback_store(struct device *dev, 
		 */

		if (!zram_test_flag(zram, index, ZRAM_PP_SLOT))

			goto next;

		if (zram_read_from_zspool(zram, page, index))

			goto next;

		zram_slot_unlock(zram, index);



		if (zram_read_page(zram, page, index, NULL)) {

			release_pp_slot(zram, pps);

			continue;

		}



		bio_init(&bio, zram->bdev, &bio_vec, 1,

			 REQ_OP_WRITE | REQ_SYNC);

		bio.bi_iter.bi_sector = blk_idx * (PAGE_SIZE >> 9);