[resend PATCH v2 12/33] dm: teach dm-targets to use a dax_device + dax_operations
From: Dan Williams <hidden>
Date: 2017-04-17 19:15:39
Also in:
dm-devel, linux-fsdevel, lkml, nvdimm
Subsystem:
device-mapper (lvm), the rest · Maintainers:
Alasdair Kergon, Mike Snitzer, Mikulas Patocka, Benjamin Marzinski, Linus Torvalds
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 <redacted> Cc: Mike Snitzer <redacted> Signed-off-by: Dan Williams <redacted> --- drivers/md/dm-linear.c | 27 +++++++++++++-------------- drivers/md/dm-snap.c | 6 +++--- drivers/md/dm-stripe.c | 29 ++++++++++++++--------------- drivers/md/dm-target.c | 6 +++--- drivers/md/dm.c | 16 ++++++---------- include/linux/device-mapper.h | 7 ++++--- 6 files changed, 43 insertions(+), 48 deletions(-)
diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 4788b0b989a9..c5a52f4dae81 100644
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c@@ -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; - - return ret; + 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)
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index c65feeada864..e152d9817c81 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c@@ -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 = {
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index 28193a57bf47..cb4b1e9e16ab 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c@@ -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; - - return ret; + 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)
diff --git a/drivers/md/dm-target.c b/drivers/md/dm-target.c
index 43d3445b121d..6a7968f93f3c 100644
--- a/drivers/md/dm-target.c
+++ b/drivers/md/dm-target.c@@ -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)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index bd56dfe43a99..ef4c6f8cad47 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c@@ -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);
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index bcba4d89089c..df830d167892 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h@@ -128,14 +128,15 @@ typedef int (*dm_busy_fn) (struct dm_target *ti); * < 0 : error * >= 0 : the number of bytes accessible at the address */ -typedef long (*dm_direct_access_fn) (struct dm_target *ti, sector_t sector, - void **kaddr, pfn_t *pfn, long size); +typedef long (*dm_dax_direct_access_fn) (struct dm_target *ti, pgoff_t pgoff, + long nr_pages, void **kaddr, pfn_t *pfn); #define PAGE_SECTORS (PAGE_SIZE / 512) void dm_error(const char *message); struct dm_dev { struct block_device *bdev; + struct dax_device *dax_dev; fmode_t mode; char name[16]; };
@@ -177,7 +178,7 @@ struct target_type { dm_busy_fn busy; dm_iterate_devices_fn iterate_devices; dm_io_hints_fn io_hints; - dm_direct_access_fn direct_access; + dm_dax_direct_access_fn direct_access; /* For internal device-mapper use. */ struct list_head list;