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zram: factor out WB and non-WB zram read functions

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We will use non-WB variant in ZRAM page recompression path.

Link: https://lkml.kernel.org/r/20221109115047.2921851-4-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Alexey Romanov <avromanov@sberdevices.ru>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Suleiman Souhlal <suleiman@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Sergey Senozhatsky 2022-11-09 20:50:37 +09:00 committed by Andrew Morton
parent 001d927357
commit 5561347aa5
1 changed files with 49 additions and 23 deletions
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72
drivers/block/zram/zram_drv.c
View file

@ -1336,8 +1336,29 @@ static void zram_free_page(struct zram *zram, size_t index)
~(1UL << ZRAM_LOCK | 1UL << ZRAM_UNDER_WB));
}
static int __zram_bvec_read(struct zram *zram, struct page *page, u32 index,
struct bio *bio, bool partial_io)
/*
* 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 = {
.bv_page = page,
.bv_len = PAGE_SIZE,
.bv_offset = 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.
*/
static int zram_read_from_zspool(struct zram *zram, struct page *page,
u32 index)
{
struct zcomp_strm *zstrm;
unsigned long handle;
@ -1345,23 +1366,6 @@ static int __zram_bvec_read(struct zram *zram, struct page *page, u32 index,
void *src, *dst;
int ret;
zram_slot_lock(zram, index);
if (zram_test_flag(zram, index, ZRAM_WB)) {
struct bio_vec bvec;
zram_slot_unlock(zram, index);
/* A null bio means rw_page was used, we must fallback to bio */
if (!bio)
return -EOPNOTSUPP;
bvec.bv_page = page;
bvec.bv_len = PAGE_SIZE;
bvec.bv_offset = 0;
return read_from_bdev(zram, &bvec,
zram_get_element(zram, index),
bio, partial_io);
}
handle = zram_get_handle(zram, index);
if (!handle || zram_test_flag(zram, index, ZRAM_SAME)) {
unsigned long value;
@ -1371,7 +1375,6 @@ static int __zram_bvec_read(struct zram *zram, struct page *page, u32 index,
mem = kmap_atomic(page);
zram_fill_page(mem, PAGE_SIZE, value);
kunmap_atomic(mem);
zram_slot_unlock(zram, index);
return 0;
}
@ -1393,17 +1396,40 @@ static int __zram_bvec_read(struct zram *zram, struct page *page, u32 index,
zcomp_stream_put(zram->comps[ZRAM_PRIMARY_COMP]);
}
zs_unmap_object(zram->mem_pool, handle);
zram_slot_unlock(zram, index);
return ret;
}
static int __zram_bvec_read(struct zram *zram, struct page *page, u32 index,
struct bio *bio, bool partial_io)
{
int ret;
zram_slot_lock(zram, index);
if (!zram_test_flag(zram, index, ZRAM_WB)) {
/* Slot should be locked through out the function call */
ret = zram_read_from_zspool(zram, page, index);
zram_slot_unlock(zram, index);
} else {
/* Slot should be unlocked before the function call */
zram_slot_unlock(zram, index);
/* A null bio means rw_page was used, we must fallback to bio */
if (!bio)
return -EOPNOTSUPP;
ret = zram_bvec_read_from_bdev(zram, page, index, bio,
partial_io);
}
/* Should NEVER happen. Return bio error if it does. */
if (WARN_ON(ret))
if (WARN_ON(ret < 0))
pr_err("Decompression failed! err=%d, page=%u\n", ret, index);
return ret;
}
static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
u32 index, int offset, struct bio *bio)
u32 index, int offset, struct bio *bio)
{
int ret;
struct page *page;