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Commit 817bf402 authored by Dan Williams's avatar Dan Williams
Browse files

dm: teach dm-targets to use a dax_device + dax_operations 



Arrange for dm to lookup the dax services available from member devices.
Update the dax-capable targets, linear and stripe, to route dax
operations to the underlying device. Changes the target-internal
->direct_access() method to more closely align with the dax_operations
->direct_access() calling convention.

Cc: Toshi Kani <toshi.kani@hpe.com>
Reviewed-by: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent f26c5719

drivers/md/dm-linear.c

+13 −14
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include <linux/init.h>

#include <linux/blkdev.h>

#include <linux/bio.h>

#include <linux/dax.h>

#include <linux/slab.h>

#include <linux/device-mapper.h>
@@ -141,22 +142,20 @@ static int linear_iterate_devices(struct dm_target *ti, 
	return fn(ti, lc->dev, lc->start, ti->len, data);

}



static long linear_direct_access(struct dm_target *ti, sector_t sector,

				 void **kaddr, pfn_t *pfn, long size)

static long linear_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,

		long nr_pages, void **kaddr, pfn_t *pfn)

{

	long ret;

	struct linear_c *lc = ti->private;

	struct block_device *bdev = lc->dev->bdev;

	struct blk_dax_ctl dax = {

		.sector = linear_map_sector(ti, sector),

		.size = size,

	};

	long ret;



	ret = bdev_direct_access(bdev, &dax);

	*kaddr = dax.addr;

	*pfn = dax.pfn;

	struct dax_device *dax_dev = lc->dev->dax_dev;

	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;



	dev_sector = linear_map_sector(ti, sector);

	ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages * PAGE_SIZE, &pgoff);

	if (ret)

		return ret;

	return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);

}



static struct target_type linear_target = {
@@ -169,7 +168,7 @@ static struct target_type linear_target = { 
	.status = linear_status,

	.prepare_ioctl = linear_prepare_ioctl,

	.iterate_devices = linear_iterate_devices,

	.direct_access = linear_direct_access,

	.direct_access = linear_dax_direct_access,

};



int __init dm_linear_init(void)

drivers/md/dm-snap.c

+3 −3
Original line number Diff line number Diff line
@@ -2302,8 +2302,8 @@ static int origin_map(struct dm_target *ti, struct bio *bio) 
	return do_origin(o->dev, bio);

}



static long origin_direct_access(struct dm_target *ti, sector_t sector,

		void **kaddr, pfn_t *pfn, long size)

static long origin_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,

		long nr_pages, void **kaddr, pfn_t *pfn)

{

	DMWARN("device does not support dax.");

	return -EIO;
@@ -2368,7 +2368,7 @@ static struct target_type origin_target = { 
	.postsuspend = origin_postsuspend,

	.status  = origin_status,

	.iterate_devices = origin_iterate_devices,

	.direct_access = origin_direct_access,

	.direct_access = origin_dax_direct_access,

};



static struct target_type snapshot_target = {

drivers/md/dm-stripe.c

+14 −15
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include <linux/init.h>

#include <linux/blkdev.h>

#include <linux/bio.h>

#include <linux/dax.h>

#include <linux/slab.h>

#include <linux/log2.h>
@@ -308,27 +309,25 @@ static int stripe_map(struct dm_target *ti, struct bio *bio) 
	return DM_MAPIO_REMAPPED;

}



static long stripe_direct_access(struct dm_target *ti, sector_t sector,

				 void **kaddr, pfn_t *pfn, long size)

static long stripe_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,

		long nr_pages, void **kaddr, pfn_t *pfn)

{

	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;

	struct stripe_c *sc = ti->private;

	uint32_t stripe;

	struct dax_device *dax_dev;

	struct block_device *bdev;

	struct blk_dax_ctl dax = {

		.size = size,

	};

	uint32_t stripe;

	long ret;



	stripe_map_sector(sc, sector, &stripe, &dax.sector);



	dax.sector += sc->stripe[stripe].physical_start;

	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;



	ret = bdev_direct_access(bdev, &dax);

	*kaddr = dax.addr;

	*pfn = dax.pfn;



	ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages * PAGE_SIZE, &pgoff);

	if (ret)

		return ret;

	return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);

}



/*
@@ -448,7 +447,7 @@ static struct target_type stripe_target = { 
	.status = stripe_status,

	.iterate_devices = stripe_iterate_devices,

	.io_hints = stripe_io_hints,

	.direct_access = stripe_direct_access,

	.direct_access = stripe_dax_direct_access,

};



int __init dm_stripe_init(void)

drivers/md/dm-target.c

+3 −3
Original line number Diff line number Diff line
@@ -142,8 +142,8 @@ static void io_err_release_clone_rq(struct request *clone) 
{

}



static long io_err_direct_access(struct dm_target *ti, sector_t sector,

				 void **kaddr, pfn_t *pfn, long size)

static long io_err_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,

		long nr_pages, void **kaddr, pfn_t *pfn)

{

	return -EIO;

}
@@ -157,7 +157,7 @@ static struct target_type error_target = { 
	.map  = io_err_map,

	.clone_and_map_rq = io_err_clone_and_map_rq,

	.release_clone_rq = io_err_release_clone_rq,

	.direct_access = io_err_direct_access,

	.direct_access = io_err_dax_direct_access,

};



int __init dm_target_init(void)

drivers/md/dm.c

+6 −10
Original line number Diff line number Diff line
@@ -630,6 +630,7 @@ static int open_table_device(struct table_device *td, dev_t dev, 
	}



	td->dm_dev.bdev = bdev;

	td->dm_dev.dax_dev = dax_get_by_host(bdev->bd_disk->disk_name);

	return 0;

}
@@ -643,7 +644,9 @@ static void close_table_device(struct table_device *td, struct mapped_device *md 


	bd_unlink_disk_holder(td->dm_dev.bdev, dm_disk(md));

	blkdev_put(td->dm_dev.bdev, td->dm_dev.mode | FMODE_EXCL);

	put_dax(td->dm_dev.dax_dev);

	td->dm_dev.bdev = NULL;

	td->dm_dev.dax_dev = NULL;

}



static struct table_device *find_table_device(struct list_head *l, dev_t dev,
@@ -945,16 +948,9 @@ static long dm_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, 
	if (len < 1)

		goto out;

	nr_pages = min(len, nr_pages);

	if (ti->type->direct_access) {

		ret = ti->type->direct_access(ti, sector, kaddr, pfn,

				nr_pages * PAGE_SIZE);

		/*

		 * FIXME: convert ti->type->direct_access to return

		 * nr_pages directly.

		 */

		if (ret >= 0)

			ret /= PAGE_SIZE;

	}

	if (ti->type->direct_access)

		ret = ti->type->direct_access(ti, pgoff, nr_pages, kaddr, pfn);



 out:

	dm_put_live_table(md, srcu_idx);