diff options
| author | Mikulas Patocka <mpatocka@redhat.com> | 2013-07-10 23:41:18 +0100 |
|---|---|---|
| committer | Alasdair G Kergon <agk@redhat.com> | 2013-07-10 23:41:18 +0100 |
| commit | 83d5e5b0af907d46d241a86d9e44003b3f0accbd (patch) | |
| tree | 46349d07c2090da15c250af3bac40833eb96e9f0 /include | |
| parent | 2480945cd44b50ba8b1646544eec2db21f064f12 (diff) | |
dm: optimize use SRCU and RCU
This patch removes "io_lock" and "map_lock" in struct mapped_device and
"holders" in struct dm_table and replaces these mechanisms with
sleepable-rcu.
Previously, the code would call "dm_get_live_table" and "dm_table_put" to
get and release table. Now, the code is changed to call "dm_get_live_table"
and "dm_put_live_table". dm_get_live_table locks sleepable-rcu and
dm_put_live_table unlocks it.
dm_get_live_table_fast/dm_put_live_table_fast can be used instead of
dm_get_live_table/dm_put_live_table. These *_fast functions use
non-sleepable RCU, so the caller must not block between them.
If the code changes active or inactive dm table, it must call
dm_sync_table before destroying the old table.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/device-mapper.h | 6 | ||||
| -rw-r--r-- | include/uapi/linux/dm-ioctl.h | 4 |
2 files changed, 5 insertions, 5 deletions
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 3cd32478f2f..e151d4c9298 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -446,9 +446,9 @@ int __must_check dm_set_target_max_io_len(struct dm_target *ti, sector_t len); /* * Table reference counting. */ -struct dm_table *dm_get_live_table(struct mapped_device *md); -void dm_table_get(struct dm_table *t); -void dm_table_put(struct dm_table *t); +struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx); +void dm_put_live_table(struct mapped_device *md, int srcu_idx); +void dm_sync_table(struct mapped_device *md); /* * Queries diff --git a/include/uapi/linux/dm-ioctl.h b/include/uapi/linux/dm-ioctl.h index 7e75b6fd8d4..afd0cbd52ed 100644 --- a/include/uapi/linux/dm-ioctl.h +++ b/include/uapi/linux/dm-ioctl.h @@ -267,9 +267,9 @@ 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 24 +#define DM_VERSION_MINOR 25 #define DM_VERSION_PATCHLEVEL 0 -#define DM_VERSION_EXTRA "-ioctl (2013-01-15)" +#define DM_VERSION_EXTRA "-ioctl (2013-06-26)" /* Status bits */ #define DM_READONLY_FLAG (1 << 0) /* In/Out */ |