From b3a9a0c36e1f7b9e2e6cf965c2bb973624f2b3b9 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 2 May 2018 06:46:33 -0700 Subject: 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 Cc: Mike Snitzer Cc: Christoph Hellwig Signed-off-by: Dan Williams --- drivers/md/dm-linear.c | 16 ++++++++++++++++ drivers/md/dm-log-writes.c | 15 +++++++++++++++ drivers/md/dm-stripe.c | 21 +++++++++++++++++++++ drivers/md/dm.c | 25 +++++++++++++++++++++++++ 4 files changed, 77 insertions(+) (limited to 'drivers/md') 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, }; /* -- cgit v1.2.3