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Groups > linux.kernel > #1678032
| From | Dan Williams <dan.j.williams@intel.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH v4 02/16] dm: add ->copy_from_iter() dax operation support |
| Date | 2017-06-29 20:10 +0200 |
| Message-ID | <tXM39-2wf-43@gated-at.bofh.it> (permalink) |
| References | <tXLTr-2de-1@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Allow device-mapper to route copy_from_iter operations to the
per-target implementation. In order for the device stacking to work we
need a dax_dev and a pgoff relative to that device. This gives each
layer of the stack the information it needs to look up the operation
pointer for the next level.
This conceptually allows for an array of mixed device drivers with
varying copy_from_iter implementations.
Reviewed-by: Toshi Kani <toshi.kani@hpe.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/dax/super.c | 13 +++++++++++++
drivers/md/dm-linear.c | 15 +++++++++++++++
drivers/md/dm-stripe.c | 20 ++++++++++++++++++++
drivers/md/dm.c | 26 ++++++++++++++++++++++++++
include/linux/dax.h | 2 ++
include/linux/device-mapper.h | 3 +++
6 files changed, 79 insertions(+)
diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index 6ed32aac8bbe..dd299e55f65d 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -18,6 +18,7 @@
#include <linux/cdev.h>
#include <linux/hash.h>
#include <linux/slab.h>
+#include <linux/uio.h>
#include <linux/dax.h>
#include <linux/fs.h>
@@ -172,6 +173,18 @@ long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
}
EXPORT_SYMBOL_GPL(dax_direct_access);
+size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
+ size_t bytes, struct iov_iter *i)
+{
+ if (!dax_alive(dax_dev))
+ return 0;
+
+ if (!dax_dev->ops->copy_from_iter)
+ return copy_from_iter(addr, bytes, i);
+ return dax_dev->ops->copy_from_iter(dax_dev, pgoff, addr, bytes, i);
+}
+EXPORT_SYMBOL_GPL(dax_copy_from_iter);
+
bool dax_alive(struct dax_device *dax_dev)
{
lockdep_assert_held(&dax_srcu);
diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 7d42a9d9f406..0841ec1bfbad 100644
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -159,6 +159,20 @@ static long linear_dax_direct_access(struct dm_target *ti, pgoff_t 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;
+
+ 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 struct target_type linear_target = {
.name = "linear",
.version = {1, 3, 0},
@@ -171,6 +185,7 @@ static struct target_type linear_target = {
.prepare_ioctl = linear_prepare_ioctl,
.iterate_devices = linear_iterate_devices,
.direct_access = linear_dax_direct_access,
+ .dax_copy_from_iter = linear_dax_copy_from_iter,
};
int __init dm_linear_init(void)
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index 75152482f3ad..1ef914f9ca72 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -332,6 +332,25 @@ static long stripe_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);
}
+static size_t stripe_dax_copy_from_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_from_iter(dax_dev, pgoff, addr, bytes, i);
+}
+
/*
* Stripe status:
*
@@ -451,6 +470,7 @@ static struct target_type stripe_target = {
.iterate_devices = stripe_iterate_devices,
.io_hints = stripe_io_hints,
.direct_access = stripe_dax_direct_access,
+ .dax_copy_from_iter = stripe_dax_copy_from_iter,
};
int __init dm_stripe_init(void)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 37ccd73c79ec..7faaceb52819 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -19,6 +19,7 @@
#include <linux/dax.h>
#include <linux/slab.h>
#include <linux/idr.h>
+#include <linux/uio.h>
#include <linux/hdreg.h>
#include <linux/delay.h>
#include <linux/wait.h>
@@ -969,6 +970,30 @@ static long dm_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff,
return ret;
}
+static size_t dm_dax_copy_from_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_from_iter) {
+ ret = copy_from_iter(addr, bytes, i);
+ goto out;
+ }
+ ret = ti->type->dax_copy_from_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.
@@ -2859,6 +2884,7 @@ 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,
};
/*
diff --git a/include/linux/dax.h b/include/linux/dax.h
index bbe79ed90e2b..28e398f8c59e 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -78,6 +78,8 @@ void kill_dax(struct dax_device *dax_dev);
void *dax_get_private(struct dax_device *dax_dev);
long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
void **kaddr, pfn_t *pfn);
+size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
+ size_t bytes, struct iov_iter *i);
/*
* We use lowest available bit in exceptional entry for locking, one bit for
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index f4c639c0c362..11c8a0a92f9c 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -132,6 +132,8 @@ typedef int (*dm_busy_fn) (struct dm_target *ti);
*/
typedef long (*dm_dax_direct_access_fn) (struct dm_target *ti, pgoff_t pgoff,
long nr_pages, void **kaddr, pfn_t *pfn);
+typedef size_t (*dm_dax_copy_from_iter_fn)(struct dm_target *ti, pgoff_t pgoff,
+ void *addr, size_t bytes, struct iov_iter *i);
#define PAGE_SECTORS (PAGE_SIZE / 512)
void dm_error(const char *message);
@@ -181,6 +183,7 @@ struct target_type {
dm_iterate_devices_fn iterate_devices;
dm_io_hints_fn io_hints;
dm_dax_direct_access_fn direct_access;
+ dm_dax_copy_from_iter_fn dax_copy_from_iter;
/* For internal device-mapper use. */
struct list_head list;
Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread
[PATCH v4 00/16] pmem: stop abusing copy_user_nocache(), and other reworks Dan Williams <dan.j.williams@intel.com> - 2017-06-29 20:00 +0200
[PATCH v4 07/16] x86, dax: replace clear_pmem() with open coded memset + dax_ops->flush Dan Williams <dan.j.williams@intel.com> - 2017-06-29 20:10 +0200
[PATCH v4 06/16] filesystem-dax: convert to dax_flush() Dan Williams <dan.j.williams@intel.com> - 2017-06-29 20:10 +0200
[PATCH v4 12/16] libnvdimm, nfit: enable support for volatile ranges Dan Williams <dan.j.williams@intel.com> - 2017-06-29 20:10 +0200
Re: [PATCH v4 12/16] libnvdimm, nfit: enable support for volatile ranges Dan Williams <dan.j.williams@intel.com> - 2017-06-29 22:50 +0200
Re: [PATCH v4 12/16] libnvdimm, nfit: enable support for volatile ranges Dan Williams <dan.j.williams@intel.com> - 2017-06-30 00:00 +0200
Re: [PATCH v4 12/16] libnvdimm, nfit: enable support for volatile ranges Dan Williams <dan.j.williams@intel.com> - 2017-06-30 00:30 +0200
Re: [PATCH v4 12/16] libnvdimm, nfit: enable support for volatile ranges Dan Williams <dan.j.williams@intel.com> - 2017-06-30 00:50 +0200
Re: [PATCH v4 12/16] libnvdimm, nfit: enable support for volatile ranges Dan Williams <dan.j.williams@intel.com> - 2017-06-30 01:00 +0200
Re: [PATCH v4 12/16] libnvdimm, nfit: enable support for volatile ranges Dan Williams <dan.j.williams@intel.com> - 2017-06-30 03:30 +0200
[PATCH v4 04/16] dax, pmem: introduce an optional 'flush' dax_operation Dan Williams <dan.j.williams@intel.com> - 2017-06-29 20:10 +0200
[PATCH v4 08/16] x86, dax, libnvdimm: remove wb_cache_pmem() indirection Dan Williams <dan.j.williams@intel.com> - 2017-06-29 20:10 +0200
[PATCH v4 16/16] libnvdimm, pmem: disable dax flushing when pmem is fronting a volatile region Dan Williams <dan.j.williams@intel.com> - 2017-06-29 20:10 +0200
[PATCH v4 15/16] libnvdimm, pmem, dax: export a cache control attribute Dan Williams <dan.j.williams@intel.com> - 2017-06-29 20:10 +0200
[PATCH v4 05/16] dm: add ->flush() dax operation support Dan Williams <dan.j.williams@intel.com> - 2017-06-29 20:10 +0200
[PATCH v4 11/16] libnvdimm, pmem: fix persistence warning Dan Williams <dan.j.williams@intel.com> - 2017-06-29 20:10 +0200
[PATCH v4 13/16] dax: remove default copy_from_iter fallback Dan Williams <dan.j.williams@intel.com> - 2017-06-29 20:10 +0200
[PATCH v4 03/16] filesystem-dax: convert to dax_copy_from_iter() Dan Williams <dan.j.williams@intel.com> - 2017-06-29 20:10 +0200
[PATCH v4 09/16] x86, libnvdimm, pmem: move arch_invalidate_pmem() to libnvdimm Dan Williams <dan.j.williams@intel.com> - 2017-06-29 20:10 +0200
[PATCH v4 10/16] x86, libnvdimm, pmem: remove global pmem api Dan Williams <dan.j.williams@intel.com> - 2017-06-29 20:10 +0200
[PATCH v4 14/16] dax: convert to bitmask for flags Dan Williams <dan.j.williams@intel.com> - 2017-06-29 20:10 +0200
[PATCH v4 01/16] x86, uaccess: introduce copy_from_iter_flushcache for pmem / cache-bypass operations Dan Williams <dan.j.williams@intel.com> - 2017-06-29 20:10 +0200
[PATCH v4 02/16] dm: add ->copy_from_iter() dax operation support Dan Williams <dan.j.williams@intel.com> - 2017-06-29 20:10 +0200
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