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| author |   Dan Williams <dan.j.williams@intel.com> | 2018-05-02 06:46:33 -0700 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2018-05-22 23:18:31 -0700 |
| commit | b3a9a0c36e1f7b9e2e6cf965c2bb973624f2b3b9 (patch) | |
| tree | 54f43a8720a29159310b112cf21e7d3a3b5dce85 /drivers/md/dm.c | |
| parent | uio, lib: Fix CONFIG_ARCH_HAS_UACCESS_MCSAFE compilation (diff) | |
| download | wireguard-linux-b3a9a0c36e1f7b9e2e6cf965c2bb973624f2b3b9.tar.xz wireguard-linux-b3a9a0c36e1f7b9e2e6cf965c2bb973624f2b3b9.zip | |
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.c')
| -rw-r--r-- | drivers/md/dm.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 0a7b0107ca78..6752f1c25258 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1089,6 +1089,30 @@ static size_t dm_dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, return ret; } +static size_t dm_dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, + void *addr, size_t bytes, struct iov_iter *i) +{ + struct mapped_device *md = dax_get_private(dax_dev); + sector_t sector = pgoff * PAGE_SECTORS; + struct dm_target *ti; + long ret = 0; + int srcu_idx; + + ti = dm_dax_get_live_target(md, sector, &srcu_idx); + + if (!ti) + goto out; + if (!ti->type->dax_copy_to_iter) { + ret = copy_to_iter(addr, bytes, i); + goto out; + } + ret = ti->type->dax_copy_to_iter(ti, pgoff, addr, bytes, i); + out: + dm_put_live_table(md, srcu_idx); + + return ret; +} + /* * A target may call dm_accept_partial_bio only from the map routine. It is * allowed for all bio types except REQ_PREFLUSH and REQ_OP_ZONE_RESET. @@ -3134,6 +3158,7 @@ static const struct block_device_operations dm_blk_dops = { static const struct dax_operations dm_dax_ops = { .direct_access = dm_dax_direct_access, .copy_from_iter = dm_dax_copy_from_iter, + .copy_to_iter = dm_dax_copy_to_iter, }; /* |