From: Huang Ying <ying.huang@xxxxxxxxx>
The .rw_page in struct block_device_operations is used by the swap
subsystem to read/write the page contents from/into the corresponding
swap slot in the swap device. To support the THP (Transparent Huge
Page) swap optimization, the .rw_page is enhanced to support to
read/write THP if possible.
Signed-off-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Reviewed-by: Ross Zwisler <ross.zwisler@xxxxxxxxx> [for brd.c, zram_drv.c, pmem.c]
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Vishal L Verma <vishal.l.verma@xxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: linux-nvdimm@xxxxxxxxxxxx
---
drivers/block/brd.c | 6 +++++-
drivers/block/zram/zram_drv.c | 2 ++
drivers/nvdimm/btt.c | 4 +++-
drivers/nvdimm/pmem.c | 41 ++++++++++++++++++++++++++++++-----------
4 files changed, 40 insertions(+), 13 deletions(-)
diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index 57b574f2f66a..4240d2a9dcf9 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -324,7 +324,11 @@ static int brd_rw_page(struct block_device *bdev, sector_t sector,
struct page *page, bool is_write)
{
struct brd_device *brd = bdev->bd_disk->private_data;
- int err = brd_do_bvec(brd, page, PAGE_SIZE, 0, is_write, sector);
+ int err;
+
+ if (PageTransHuge(page))
+ return -ENOTSUPP;
+ err = brd_do_bvec(brd, page, PAGE_SIZE, 0, is_write, sector);
page_endio(page, is_write, err);
return err;
}
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index d3e3af22a088..9f4973f6ba56 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -927,6 +927,8 @@ static int zram_rw_page(struct block_device *bdev, sector_t sector,
struct zram *zram;
struct bio_vec bv;
+ if (PageTransHuge(page))
+ return -ENOTSUPP;
zram = bdev->bd_disk->private_data;
if (!valid_io_request(zram, sector, PAGE_SIZE)) {
diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c
index 31b2d14e210d..6ec2250b5276 100644
--- a/drivers/nvdimm/btt.c
+++ b/drivers/nvdimm/btt.c
@@ -1248,8 +1248,10 @@ static int btt_rw_page(struct block_device *bdev, sector_t sector,
struct page *page, bool is_write)
{
struct btt *btt = bdev->bd_disk->private_data;
+ unsigned int len;
- btt_do_bvec(btt, NULL, page, PAGE_SIZE, 0, is_write, sector);
+ len = hpage_nr_pages(page) * PAGE_SIZE;
+ btt_do_bvec(btt, NULL, page, len, 0, is_write, sector);
page_endio(page, is_write, 0);
return 0;
}
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 7bd383aeea14..72e3fbaefee9 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -78,22 +78,40 @@ static blk_status_t pmem_clear_poison(struct pmem_device *pmem,
static void write_pmem(void *pmem_addr, struct page *page,
unsigned int off, unsigned int len)
{
- void *mem = kmap_atomic(page);
-
- memcpy_to_pmem(pmem_addr, mem + off, len);
- kunmap_atomic(mem);
+ unsigned int chunk;
+ void *mem;
+
+ while (len) {
+ mem = kmap_atomic(page);
+ chunk = min_t(unsigned int, len, PAGE_SIZE);
+ memcpy_to_pmem(pmem_addr, mem + off, chunk);
+ kunmap_atomic(mem);
+ len -= chunk;
+ off = 0;
+ page++;
+ pmem_addr += PAGE_SIZE;
+ }
}
static blk_status_t read_pmem(struct page *page, unsigned int off,
void *pmem_addr, unsigned int len)
{
+ unsigned int chunk;
int rc;
- void *mem = kmap_atomic(page);
-
- rc = memcpy_mcsafe(mem + off, pmem_addr, len);
- kunmap_atomic(mem);
- if (rc)
- return BLK_STS_IOERR;
+ void *mem;
+
+ while (len) {
+ mem = kmap_atomic(page);
+ chunk = min_t(unsigned int, len, PAGE_SIZE);
+ rc = memcpy_mcsafe(mem + off, pmem_addr, chunk);
+ kunmap_atomic(mem);
+ if (rc)
+ return BLK_STS_IOERR;
+ len -= chunk;
+ off = 0;
+ page++;
+ pmem_addr += PAGE_SIZE;
+ }
return BLK_STS_OK;
}
@@ -186,7 +204,8 @@ static int pmem_rw_page(struct block_device *bdev, sector_t sector,
struct pmem_device *pmem = bdev->bd_queue->queuedata;
blk_status_t rc;
- rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, is_write, sector);
+ rc = pmem_do_bvec(pmem, page, hpage_nr_pages(page) * PAGE_SIZE,
+ 0, is_write, sector);
/*
* The ->rw_page interface is subtle and tricky. The core
--
2.11.0
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