diff options
| author | John Garry <john.g.garry@oracle.com> | 2025-01-16 17:02:56 +0000 |
|---|---|---|
| committer | Mikulas Patocka <mpatocka@redhat.com> | 2025-01-17 22:23:47 +0100 |
| commit | 3194e36488e2dae05f9a822c73eaa367e47b2e3d (patch) | |
| tree | eb2c2089c158123926c2fdfd067903421435a663 | |
| parent | a38425935f7886cef5fe04c796f36715e9d0ef3f (diff) | |
dm-table: atomic writes support
Support stacking atomic write limits for DM devices.
All the pre-existing code in blk_stack_atomic_writes_limits() already takes
care of finding the aggregrate limits from the bottom devices.
Feature flag DM_TARGET_ATOMIC_WRITES is introduced so that atomic writes
can be enabled on personalities selectively. This is to ensure that atomic
writes are only enabled when verified to be working properly (for a
specific personality). In addition, it just may not make sense to enable
atomic writes on some personalities (so this flag also helps there).
Signed-off-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
| -rw-r--r-- | drivers/md/dm-table.c | 29 | ||||
| -rw-r--r-- | include/linux/device-mapper.h | 3 | ||||
| -rw-r--r-- | include/uapi/linux/dm-ioctl.h | 4 |
3 files changed, 34 insertions, 2 deletions
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index bd8b796ae683..0ef5203387b2 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1806,6 +1806,32 @@ static bool dm_table_supports_secure_erase(struct dm_table *t) return true; } +static int device_not_atomic_write_capable(struct dm_target *ti, + struct dm_dev *dev, sector_t start, + sector_t len, void *data) +{ + return !bdev_can_atomic_write(dev->bdev); +} + +static bool dm_table_supports_atomic_writes(struct dm_table *t) +{ + for (unsigned int i = 0; i < t->num_targets; i++) { + struct dm_target *ti = dm_table_get_target(t, i); + + if (!dm_target_supports_atomic_writes(ti->type)) + return false; + + if (!ti->type->iterate_devices) + return false; + + if (ti->type->iterate_devices(ti, + device_not_atomic_write_capable, NULL)) { + return false; + } + } + return true; +} + int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, struct queue_limits *limits) { @@ -1854,6 +1880,9 @@ int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, return r; } + if (dm_table_supports_atomic_writes(t)) + limits->features |= BLK_FEAT_ATOMIC_WRITES; + r = queue_limits_set(q, limits); if (r) return r; diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 8321f65897f3..bcc6d7b69470 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -299,6 +299,9 @@ struct target_type { #define dm_target_supports_mixed_zoned_model(type) (false) #endif +#define DM_TARGET_ATOMIC_WRITES 0x00000400 +#define dm_target_supports_atomic_writes(type) ((type)->features & DM_TARGET_ATOMIC_WRITES) + struct dm_target { struct dm_table *table; struct target_type *type; diff --git a/include/uapi/linux/dm-ioctl.h b/include/uapi/linux/dm-ioctl.h index 1990b5700f69..b08c7378164d 100644 --- a/include/uapi/linux/dm-ioctl.h +++ b/include/uapi/linux/dm-ioctl.h @@ -286,9 +286,9 @@ enum { #define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl) #define DM_VERSION_MAJOR 4 -#define DM_VERSION_MINOR 48 +#define DM_VERSION_MINOR 49 #define DM_VERSION_PATCHLEVEL 0 -#define DM_VERSION_EXTRA "-ioctl (2023-03-01)" +#define DM_VERSION_EXTRA "-ioctl (2025-01-17)" /* Status bits */ #define DM_READONLY_FLAG (1 << 0) /* In/Out */ |