The patch titled
Subject: zram: refactor zram_bdev_write
has been added to the -mm mm-unstable branch. Its filename is
zram-refactor-zram_bdev_write.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/zram-refactor-zram_bdev_write.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Christoph Hellwig <hch@xxxxxx>
Subject: zram: refactor zram_bdev_write
Date: Thu, 6 Apr 2023 16:40:58 +0200
Split the read/modify/write case into a separate helper.
Link: https://lkml.kernel.org/r/20230406144102.149231-13-hch@xxxxxx
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Acked-by: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/block/zram/zram_drv.c | 38 ++++++++++++++++----------------
1 file changed, 19 insertions(+), 19 deletions(-)
--- a/drivers/block/zram/zram_drv.c~zram-refactor-zram_bdev_write
+++ a/drivers/block/zram/zram_drv.c
@@ -1574,33 +1574,33 @@ out:
return ret;
}
-static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec,
- u32 index, int offset, struct bio *bio)
+/*
+ * This is a partial IO. Read the full page before writing the changes.
+ */
+static int zram_bvec_write_partial(struct zram *zram, struct bio_vec *bvec,
+ u32 index, int offset, struct bio *bio)
{
- struct page *page = bvec->bv_page;
+ struct page *page = alloc_page(GFP_NOIO);
int ret;
- if (is_partial_io(bvec)) {
- /*
- * This is a partial IO. We need to read the full page
- * before to write the changes.
- */
- page = alloc_page(GFP_NOIO);
- if (!page)
- return -ENOMEM;
-
- ret = zram_read_page(zram, page, index, bio, true);
- if (ret)
- goto out;
+ if (!page)
+ return -ENOMEM;
+ ret = zram_read_page(zram, page, index, bio, true);
+ if (!ret) {
memcpy_from_bvec(page_address(page) + offset, bvec);
+ ret = zram_write_page(zram, page, index);
}
+ __free_page(page);
+ return ret;
+}
- ret = zram_write_page(zram, page, index);
-out:
+static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec,
+ u32 index, int offset, struct bio *bio)
+{
if (is_partial_io(bvec))
- __free_page(page);
- return ret;
+ return zram_bvec_write_partial(zram, bvec, index, offset, bio);
+ return zram_write_page(zram, bvec->bv_page, index);
}
#ifdef CONFIG_ZRAM_MULTI_COMP
_
Patches currently in -mm which might be from hch@xxxxxx are
zram-remove-valid_io_request.patch
zram-make-zram_bio_discard-more-self-contained.patch
zram-simplify-bvec-iteration-in-__zram_make_request.patch
zram-move-discard-handling-to-zram_submit_bio.patch
zram-return-early-on-error-in-zram_bvec_rw.patch
zram-refactor-highlevel-read-and-write-handling.patch
zram-dont-use-highmem-for-the-bounce-buffer-in-zram_bvec_readwrite.patch
zram-rename-__zram_bvec_read-to-zram_read_page.patch
zram-directly-call-zram_read_page-in-writeback_store.patch
zram-refactor-zram_bdev_read.patch
zram-dont-pass-a-bvec-to-__zram_bvec_write.patch
zram-refactor-zram_bdev_write.patch
zram-pass-a-page-to-read_from_bdev.patch
zram-dont-return-errors-from-read_from_bdev_async.patch
zram-fix-synchronous-reads.patch
zram-return-errors-from-read_from_bdev_sync.patch
