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authorDan Williams <dan.j.williams@intel.com>2018-05-02 06:46:33 -0700
committerDan Williams <dan.j.williams@intel.com>2018-05-22 23:18:31 -0700
commitb3a9a0c36e1f7b9e2e6cf965c2bb973624f2b3b9 (patch)
tree54f43a8720a29159310b112cf21e7d3a3b5dce85 /drivers/md/dm-log-writes.c
parent522239b445a2de988edb81672963708a6aaf9046 (diff)
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-log-writes.c')
-rw-r--r--drivers/md/dm-log-writes.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/md/dm-log-writes.c b/drivers/md/dm-log-writes.c
index c90c7c08a77f..9ea2b0291f20 100644
--- a/drivers/md/dm-log-writes.c
+++ b/drivers/md/dm-log-writes.c
@@ -962,9 +962,23 @@ static size_t log_writes_dax_copy_from_iter(struct dm_target *ti,
dax_copy:
return dax_copy_from_iter(lc->dev->dax_dev, pgoff, addr, bytes, i);
}
+
+static size_t log_writes_dax_copy_to_iter(struct dm_target *ti,
+ pgoff_t pgoff, void *addr, size_t bytes,
+ struct iov_iter *i)
+{
+ struct log_writes_c *lc = ti->private;
+ sector_t sector = pgoff * PAGE_SECTORS;
+
+ if (bdev_dax_pgoff(lc->dev->bdev, sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
+ return 0;
+ return dax_copy_to_iter(lc->dev->dax_dev, pgoff, addr, bytes, i);
+}
+
#else
#define log_writes_dax_direct_access NULL
#define log_writes_dax_copy_from_iter NULL
+#define log_writes_dax_copy_to_iter NULL
#endif
static struct target_type log_writes_target = {
@@ -982,6 +996,7 @@ static struct target_type log_writes_target = {
.io_hints = log_writes_io_hints,
.direct_access = log_writes_dax_direct_access,
.dax_copy_from_iter = log_writes_dax_copy_from_iter,
+ .dax_copy_to_iter = log_writes_dax_copy_to_iter,
};
static int __init dm_log_writes_init(void)