[PATCH 09/29] dm-linear: add a linear_dax_pgoff helper
From: Christoph Hellwig <hch@lst.de>
Date: 2021-11-09 08:33:45
Also in:
dm-devel, linux-fsdevel, linux-s390, linux-xfs, nvdimm, virtualization
Subsystem:
device-mapper (lvm), the rest · Maintainers:
Alasdair Kergon, Mike Snitzer, Mikulas Patocka, Benjamin Marzinski, Linus Torvalds
Add a helper to perform the entire remapping for DAX accesses. This helper open codes bdev_dax_pgoff given that the alignment checks have already been done by the submitting file system and don't need to be repeated. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Mike Snitzer <redacted> --- drivers/md/dm-linear.c | 49 +++++++++++++----------------------------- 1 file changed, 15 insertions(+), 34 deletions(-)
diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 0a260c35aeeed..90de42f6743ac 100644
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c@@ -163,63 +163,44 @@ static int linear_iterate_devices(struct dm_target *ti, } #if IS_ENABLED(CONFIG_FS_DAX) +static struct dax_device *linear_dax_pgoff(struct dm_target *ti, pgoff_t *pgoff) +{ + struct linear_c *lc = ti->private; + sector_t sector = linear_map_sector(ti, *pgoff << PAGE_SECTORS_SHIFT); + + *pgoff = (get_start_sect(lc->dev->bdev) + sector) >> PAGE_SECTORS_SHIFT; + return lc->dev->dax_dev; +} + static long linear_dax_direct_access(struct dm_target *ti, pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn) { - long ret; - struct linear_c *lc = ti->private; - struct block_device *bdev = lc->dev->bdev; - struct dax_device *dax_dev = lc->dev->dax_dev; - sector_t dev_sector, sector = pgoff * PAGE_SECTORS; - - dev_sector = linear_map_sector(ti, sector); - ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages * PAGE_SIZE, &pgoff); - if (ret) - return ret; + struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff); + return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn); } static size_t linear_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i) { - struct linear_c *lc = ti->private; - struct block_device *bdev = lc->dev->bdev; - struct dax_device *dax_dev = lc->dev->dax_dev; - sector_t dev_sector, sector = pgoff * PAGE_SECTORS; + struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff); - dev_sector = linear_map_sector(ti, sector); - if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff)) - return 0; return dax_copy_from_iter(dax_dev, pgoff, addr, bytes, i); } static size_t linear_dax_copy_to_iter(struct dm_target *ti, pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i) { - struct linear_c *lc = ti->private; - struct block_device *bdev = lc->dev->bdev; - struct dax_device *dax_dev = lc->dev->dax_dev; - sector_t dev_sector, sector = pgoff * PAGE_SECTORS; + struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff); - dev_sector = linear_map_sector(ti, sector); - if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff)) - return 0; return dax_copy_to_iter(dax_dev, pgoff, addr, bytes, i); } static int linear_dax_zero_page_range(struct dm_target *ti, pgoff_t pgoff, size_t nr_pages) { - int ret; - struct linear_c *lc = ti->private; - struct block_device *bdev = lc->dev->bdev; - struct dax_device *dax_dev = lc->dev->dax_dev; - sector_t dev_sector, sector = pgoff * PAGE_SECTORS; - - dev_sector = linear_map_sector(ti, sector); - ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages << PAGE_SHIFT, &pgoff); - if (ret) - return ret; + struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff); + return dax_zero_page_range(dax_dev, pgoff, nr_pages); }
--
2.30.2