The patch titled
Subject: zram: pass a page to read_from_bdev
has been added to the -mm mm-unstable branch. Its filename is
zram-pass-a-page-to-read_from_bdev.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/zram-pass-a-page-to-read_from_bdev.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: pass a page to read_from_bdev
Date: Thu, 6 Apr 2023 16:40:59 +0200
read_from_bdev always reads a whole page, so pass a page to it instead of
the bvec and remove the now pointless zram_bvec_read_from_bdev wrapper.
Link: https://lkml.kernel.org/r/20230406144102.149231-14-hch@xxxxxx
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Acked-by: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/block/zram/zram_drv.c | 46 +++++++++++---------------------
1 file changed, 17 insertions(+), 29 deletions(-)
--- a/drivers/block/zram/zram_drv.c~zram-pass-a-page-to-read_from_bdev
+++ a/drivers/block/zram/zram_drv.c
@@ -587,7 +587,7 @@ static void zram_page_end_io(struct bio
/*
* Returns 1 if the submission is successful.
*/
-static int read_from_bdev_async(struct zram *zram, struct bio_vec *bvec,
+static int read_from_bdev_async(struct zram *zram, struct page *page,
unsigned long entry, struct bio *parent)
{
struct bio *bio;
@@ -598,7 +598,7 @@ static int read_from_bdev_async(struct z
return -ENOMEM;
bio->bi_iter.bi_sector = entry * (PAGE_SIZE >> 9);
- if (!bio_add_page(bio, bvec->bv_page, bvec->bv_len, bvec->bv_offset)) {
+ if (!bio_add_page(bio, page, PAGE_SIZE, 0)) {
bio_put(bio);
return -EIO;
}
@@ -794,7 +794,7 @@ struct zram_work {
struct zram *zram;
unsigned long entry;
struct bio *bio;
- struct bio_vec bvec;
+ struct page *page;
};
#if PAGE_SIZE != 4096
@@ -805,7 +805,7 @@ static void zram_sync_read(struct work_s
unsigned long entry = zw->entry;
struct bio *bio = zw->bio;
- read_from_bdev_async(zram, &zw->bvec, entry, bio);
+ read_from_bdev_async(zram, zw->page, entry, bio);
}
/*
@@ -813,12 +813,12 @@ static void zram_sync_read(struct work_s
* chained IO with parent IO in same context, it's a deadlock. To avoid that,
* use a worker thread context.
*/
-static int read_from_bdev_sync(struct zram *zram, struct bio_vec *bvec,
+static int read_from_bdev_sync(struct zram *zram, struct page *page,
unsigned long entry, struct bio *bio)
{
struct zram_work work;
- work.bvec = *bvec;
+ work.page = page;
work.zram = zram;
work.entry = entry;
work.bio = bio;
@@ -831,7 +831,7 @@ static int read_from_bdev_sync(struct zr
return 1;
}
#else
-static int read_from_bdev_sync(struct zram *zram, struct bio_vec *bvec,
+static int read_from_bdev_sync(struct zram *zram, struct page *page,
unsigned long entry, struct bio *bio)
{
WARN_ON(1);
@@ -839,18 +839,17 @@ static int read_from_bdev_sync(struct zr
}
#endif
-static int read_from_bdev(struct zram *zram, struct bio_vec *bvec,
+static int read_from_bdev(struct zram *zram, struct page *page,
unsigned long entry, struct bio *parent, bool sync)
{
atomic64_inc(&zram->stats.bd_reads);
if (sync)
- return read_from_bdev_sync(zram, bvec, entry, parent);
- else
- return read_from_bdev_async(zram, bvec, entry, parent);
+ return read_from_bdev_sync(zram, page, entry, parent);
+ return read_from_bdev_async(zram, page, entry, parent);
}
#else
static inline void reset_bdev(struct zram *zram) {};
-static int read_from_bdev(struct zram *zram, struct bio_vec *bvec,
+static int read_from_bdev(struct zram *zram, struct page *page,
unsigned long entry, struct bio *parent, bool sync)
{
return -EIO;
@@ -1335,20 +1334,6 @@ out:
}
/*
- * Reads a page from the writeback devices. Corresponding ZRAM slot
- * should be unlocked.
- */
-static int zram_bvec_read_from_bdev(struct zram *zram, struct page *page,
- u32 index, struct bio *bio, bool partial_io)
-{
- struct bio_vec bvec;
-
- bvec_set_page(&bvec, page, PAGE_SIZE, 0);
- return read_from_bdev(zram, &bvec, zram_get_element(zram, index), bio,
- partial_io);
-}
-
-/*
* Reads (decompresses if needed) a page from zspool (zsmalloc).
* Corresponding ZRAM slot should be locked.
*/
@@ -1408,11 +1393,14 @@ static int zram_read_page(struct zram *z
ret = zram_read_from_zspool(zram, page, index);
zram_slot_unlock(zram, index);
} else {
- /* Slot should be unlocked before the function call */
+ /*
+ * The slot should be unlocked before reading from the backing
+ * device.
+ */
zram_slot_unlock(zram, index);
- ret = zram_bvec_read_from_bdev(zram, page, index, bio,
- partial_io);
+ ret = read_from_bdev(zram, page, zram_get_element(zram, index),
+ bio, partial_io);
}
/* Should NEVER happen. Return bio error if it does. */
_
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
