From e2460f2a4bc740fae9e23f14d653cf53e90b3f9a Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Tue, 18 Apr 2017 16:51:48 -0400 Subject: [PATCH] dm: mark targets that pass integrity data A dm-crypt on dm-integrity device incorrectly advertises an integrity profile on the DM crypt device. It can be seen in the files "/sys/block/dm-*/integrity/*" that both dm-integrity and dm-crypt target advertise the integrity profile. That is incorrect, only the dm-integrity target should advertise the integrity profile. A general problem in DM is that if we have a DM device that depends on another device with an integrity profile, the upper device will always advertise the integrity profile, even when the target driver doesn't support handling integrity data. Most targets don't support integrity data, so we provide a whitelist of targets that support it (linear, delay and striped). The targets that support passing integrity data to the lower device are marked with the flag DM_TARGET_PASSES_INTEGRITY. The DM core will now advertise integrity data on a DM device only if all the targets support the integrity data. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer --- drivers/md/dm-delay.c | 1 + drivers/md/dm-linear.c | 1 + drivers/md/dm-stripe.c | 1 + drivers/md/dm-table.c | 7 +++++++ drivers/md/dm.c | 16 +++++++++++++--- include/linux/device-mapper.h | 6 ++++++ 6 files changed, 29 insertions(+), 3 deletions(-) diff --git a/drivers/md/dm-delay.c b/drivers/md/dm-delay.c index cc70871a6d298a..ae3158795d26bd 100644 --- a/drivers/md/dm-delay.c +++ b/drivers/md/dm-delay.c @@ -340,6 +340,7 @@ static int delay_iterate_devices(struct dm_target *ti, static struct target_type delay_target = { .name = "delay", .version = {1, 2, 1}, + .features = DM_TARGET_PASSES_INTEGRITY, .module = THIS_MODULE, .ctr = delay_ctr, .dtr = delay_dtr, diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c index 4788b0b989a9ba..ffa0c9c5968a38 100644 --- a/drivers/md/dm-linear.c +++ b/drivers/md/dm-linear.c @@ -162,6 +162,7 @@ static long linear_direct_access(struct dm_target *ti, sector_t sector, static struct target_type linear_target = { .name = "linear", .version = {1, 3, 0}, + .features = DM_TARGET_PASSES_INTEGRITY, .module = THIS_MODULE, .ctr = linear_ctr, .dtr = linear_dtr, diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c index 28193a57bf471e..d7e1b86e7570b1 100644 --- a/drivers/md/dm-stripe.c +++ b/drivers/md/dm-stripe.c @@ -440,6 +440,7 @@ static void stripe_io_hints(struct dm_target *ti, static struct target_type stripe_target = { .name = "striped", .version = {1, 6, 0}, + .features = DM_TARGET_PASSES_INTEGRITY, .module = THIS_MODULE, .ctr = stripe_ctr, .dtr = stripe_dtr, diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 7fb29db478cdc7..c68757f94e164a 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1135,6 +1135,13 @@ static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t) struct list_head *devices = dm_table_get_devices(t); struct dm_dev_internal *dd = NULL; struct gendisk *prev_disk = NULL, *template_disk = NULL; + unsigned i; + + for (i = 0; i < dm_table_get_num_targets(t); i++) { + struct dm_target *ti = dm_table_get_target(t, i); + if (!dm_target_passes_integrity(ti->type)) + goto no_integrity; + } list_for_each_entry(dd, devices, list) { template_disk = dd->dm_dev->bdev->bd_disk; diff --git a/drivers/md/dm.c b/drivers/md/dm.c index f4ffd1eb8f44c3..e602ae0d5d755d 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1089,8 +1089,18 @@ static int clone_bio(struct dm_target_io *tio, struct bio *bio, __bio_clone_fast(clone, bio); - if (bio_integrity(bio)) { - int r = bio_integrity_clone(clone, bio, GFP_NOIO); + if (unlikely(bio_integrity(bio) != NULL)) { + int r; + + if (unlikely(!dm_target_has_integrity(tio->ti->type) && + !dm_target_passes_integrity(tio->ti->type))) { + DMWARN("%s: the target %s doesn't support integrity data.", + dm_device_name(tio->io->md), + tio->ti->type->name); + return -EIO; + } + + r = bio_integrity_clone(clone, bio, GFP_NOIO); if (r < 0) return r; } @@ -1098,7 +1108,7 @@ static int clone_bio(struct dm_target_io *tio, struct bio *bio, bio_advance(clone, to_bytes(sector - clone->bi_iter.bi_sector)); clone->bi_iter.bi_size = to_bytes(len); - if (bio_integrity(bio)) + if (unlikely(bio_integrity(bio) != NULL)) bio_integrity_trim(clone, 0, len); return 0; diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 874462153f143e..98f981026e4e0c 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -227,6 +227,12 @@ typedef unsigned (*dm_num_write_bios_fn) (struct dm_target *ti, struct bio *bio) #define DM_TARGET_INTEGRITY 0x00000010 #define dm_target_has_integrity(type) ((type)->features & DM_TARGET_INTEGRITY) +/* + * A target passes integrity data to the lower device. + */ +#define DM_TARGET_PASSES_INTEGRITY 0x00000020 +#define dm_target_passes_integrity(type) ((type)->features & DM_TARGET_PASSES_INTEGRITY) + struct dm_target { struct dm_table *table; struct target_type *type;