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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
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')
-rw-r--r--drivers/md/dm-linear.c16
-rw-r--r--drivers/md/dm-log-writes.c15
-rw-r--r--drivers/md/dm-stripe.c21
-rw-r--r--drivers/md/dm.c25
4 files changed, 77 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)
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)
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index fe7fb9b1aec3..8547d7594338 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -354,9 +354,29 @@ static size_t stripe_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 stripe_dax_copy_to_iter(struct dm_target *ti, pgoff_t pgoff,
+ void *addr, size_t bytes, struct iov_iter *i)
+{
+ sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
+ struct stripe_c *sc = ti->private;
+ struct dax_device *dax_dev;
+ struct block_device *bdev;
+ uint32_t stripe;
+
+ stripe_map_sector(sc, sector, &stripe, &dev_sector);
+ dev_sector += sc->stripe[stripe].physical_start;
+ dax_dev = sc->stripe[stripe].dev->dax_dev;
+ bdev = sc->stripe[stripe].dev->bdev;
+
+ 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 stripe_dax_direct_access NULL
#define stripe_dax_copy_from_iter NULL
+#define stripe_dax_copy_to_iter NULL
#endif
/*
@@ -478,6 +498,7 @@ static struct target_type stripe_target = {
.io_hints = stripe_io_hints,
.direct_access = stripe_dax_direct_access,
.dax_copy_from_iter = stripe_dax_copy_from_iter,
+ .dax_copy_to_iter = stripe_dax_copy_to_iter,
};
int __init dm_stripe_init(void)
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,
};
/*