From 889ae9169b45f0fc3fc05f93c3c6fa8a851eab67 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Tue, 11 Apr 2023 19:14:53 +0200
Subject: [PATCH] zram: refactor zram_bdev_read
Split the partial read into a separate helper.
Link: https://lkml.kernel.org/r/20230411171459.567614-12-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
drivers/block/zram/zram_drv.c | 40 +++++++++++++++++------------------
1 file changed, 20 insertions(+), 20 deletions(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 40ef0a7ce348a..2e985531d8cba 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1416,33 +1416,33 @@ static int zram_read_page(struct zram *zram, struct page *page, u32 index,
return ret;
}
-static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
- u32 index, int offset, struct bio *bio)
+/*
+ * Use a temporary buffer to decompress the page, as the decompressor
+ * always expects a full page for the output.
+ */
+static int zram_bvec_read_partial(struct zram *zram, struct bio_vec *bvec,
+ u32 index, int offset, struct bio *bio)
{
+ struct page *page = alloc_page(GFP_NOIO);
int ret;
- struct page *page;
-
- page = bvec->bv_page;
- if (is_partial_io(bvec)) {
- /* Use a temporary buffer to decompress the page */
- page = alloc_page(GFP_NOIO);
- if (!page)
- return -ENOMEM;
- }
-
- ret = zram_read_page(zram, page, index, bio, is_partial_io(bvec));
- if (unlikely(ret))
- goto out;
- if (is_partial_io(bvec))
+ if (!page)
+ return -ENOMEM;
+ ret = zram_read_page(zram, page, index, bio, true);
+ if (likely(!ret))
memcpy_to_bvec(bvec, page_address(page) + offset);
-out:
- if (is_partial_io(bvec))
- __free_page(page);
-
+ __free_page(page);
return ret;
}
+static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
+ u32 index, int offset, struct bio *bio)
+{
+ if (is_partial_io(bvec))
+ return zram_bvec_read_partial(zram, bvec, index, offset, bio);
+ return zram_read_page(zram, bvec->bv_page, index, bio, false);
+}
+
static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec,
u32 index, struct bio *bio)
{
--
2.30.2