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| author | Dan Williams <dan.j.williams@intel.com> | 2018-05-02 16:46:33 +0300 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2018-05-23 09:18:31 +0300 |
| commit | b3a9a0c36e1f7b9e2e6cf965c2bb973624f2b3b9 (patch) | |
| tree | 54f43a8720a29159310b112cf21e7d3a3b5dce85 /drivers/md/dm-linear.c | |
| parent | 522239b445a2de988edb81672963708a6aaf9046 (diff) | |
| download | linux-b3a9a0c36e1f7b9e2e6cf965c2bb973624f2b3b9.tar.xz | |
dax: Introduce a ->copy_to_iter dax operation
Similar to the ->copy_from_iter() operation, a platform may want to
deploy an architecture or device specific routine for handling reads
from a dax_device like /dev/pmemX. On x86 this routine will point to a
machine check safe version of copy_to_iter(). For now, add the plumbing
to device-mapper and the dax core.
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/md/dm-linear.c')
| -rw-r--r-- | drivers/md/dm-linear.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c index 775c06d953b7..d10964d41fd7 100644 --- a/drivers/md/dm-linear.c +++ b/drivers/md/dm-linear.c @@ -185,9 +185,24 @@ static size_t linear_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff, 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; + + 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); +} + #else #define linear_dax_direct_access NULL #define linear_dax_copy_from_iter NULL +#define linear_dax_copy_to_iter NULL #endif static struct target_type linear_target = { @@ -204,6 +219,7 @@ static struct target_type linear_target = { .iterate_devices = linear_iterate_devices, .direct_access = linear_dax_direct_access, .dax_copy_from_iter = linear_dax_copy_from_iter, + .dax_copy_to_iter = linear_dax_copy_to_iter, }; int __init dm_linear_init(void) |