The patch titled
Subject: zram: refactor highlevel read and write handling
has been added to the -mm mm-unstable branch. Its filename is
zram-refactor-highlevel-read-and-write-handling.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/zram-refactor-highlevel-read-and-write-handling.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 highlevel read and write handling
Date: Thu, 6 Apr 2023 16:40:52 +0200
Instead of having an outer loop in __zram_make_request and then branch out
for reads vs writes for each loop iteration in zram_bvec_rw, split the
main handler into separat zram_bio_read and zram_bio_write handlers that
also include the functionality formerly in zram_bvec_rw.
Link: https://lkml.kernel.org/r/20230406144102.149231-7-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 | 58 ++++++++++++++++----------------
1 file changed, 30 insertions(+), 28 deletions(-)
--- a/drivers/block/zram/zram_drv.c~zram-refactor-highlevel-read-and-write-handling
+++ a/drivers/block/zram/zram_drv.c
@@ -1927,38 +1927,34 @@ static void zram_bio_discard(struct zram
bio_endio(bio);
}
-/*
- * Returns errno if it has some problem. Otherwise return 0 or 1.
- * Returns 0 if IO request was done synchronously
- * Returns 1 if IO request was successfully submitted.
- */
-static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index,
- int offset, enum req_op op, struct bio *bio)
+static void zram_bio_read(struct zram *zram, struct bio *bio)
{
- int ret;
+ struct bvec_iter iter;
+ struct bio_vec bv;
+ unsigned long start_time;
+
+ start_time = bio_start_io_acct(bio);
+ bio_for_each_segment(bv, bio, iter) {
+ u32 index = iter.bi_sector >> SECTORS_PER_PAGE_SHIFT;
+ u32 offset = (iter.bi_sector & (SECTORS_PER_PAGE - 1)) <<
+ SECTOR_SHIFT;
- if (!op_is_write(op)) {
- ret = zram_bvec_read(zram, bvec, index, offset, bio);
- if (unlikely(ret < 0)) {
+ if (zram_bvec_read(zram, &bv, index, offset, bio) < 0) {
atomic64_inc(&zram->stats.failed_reads);
- return ret;
- }
- flush_dcache_page(bvec->bv_page);
- } else {
- ret = zram_bvec_write(zram, bvec, index, offset, bio);
- if (unlikely(ret < 0)) {
- atomic64_inc(&zram->stats.failed_writes);
- return ret;
+ bio->bi_status = BLK_STS_IOERR;
+ break;
}
- }
+ flush_dcache_page(bv.bv_page);
- zram_slot_lock(zram, index);
- zram_accessed(zram, index);
- zram_slot_unlock(zram, index);
- return 0;
+ zram_slot_lock(zram, index);
+ zram_accessed(zram, index);
+ zram_slot_unlock(zram, index);
+ }
+ bio_end_io_acct(bio, start_time);
+ bio_endio(bio);
}
-static void __zram_make_request(struct zram *zram, struct bio *bio)
+static void zram_bio_write(struct zram *zram, struct bio *bio)
{
struct bvec_iter iter;
struct bio_vec bv;
@@ -1970,11 +1966,15 @@ static void __zram_make_request(struct z
u32 offset = (iter.bi_sector & (SECTORS_PER_PAGE - 1)) <<
SECTOR_SHIFT;
- if (zram_bvec_rw(zram, &bv, index, offset, bio_op(bio),
- bio) < 0) {
+ if (zram_bvec_write(zram, &bv, index, offset, bio) < 0) {
+ atomic64_inc(&zram->stats.failed_writes);
bio->bi_status = BLK_STS_IOERR;
break;
}
+
+ zram_slot_lock(zram, index);
+ zram_accessed(zram, index);
+ zram_slot_unlock(zram, index);
}
bio_end_io_acct(bio, start_time);
bio_endio(bio);
@@ -1989,8 +1989,10 @@ static void zram_submit_bio(struct bio *
switch (bio_op(bio)) {
case REQ_OP_READ:
+ zram_bio_read(zram, bio);
+ break;
case REQ_OP_WRITE:
- __zram_make_request(zram, bio);
+ zram_bio_write(zram, bio);
break;
case REQ_OP_DISCARD:
case REQ_OP_WRITE_ZEROES:
_
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
