Cleaning policy callbacks are typically called with hash buckets or
cache lines locked. However cleaning policies maintain structures
which are shared across multiple cache lines (e.g. ALRU list).
Additional synchronization is required for theese structures to
maintain integrity.
ACP already implements hash bucket locks. This patch is adding
ALRU list mutex.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Adding locks to assure partition list consistency. Partition
lists is typically modified under cacheline or hash bucket lock.
This is not sufficient synchronization as adding/removing cacheline
from partition list affects neighbouring cachelines state as well.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Since ocf requires loading cache with the same name as it was stopped, it should
also allow to read name from metadata.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
This change allows to check if specified cache name name is unique. To prevent
adding cache instance with the same name, context lock is acquired until name
isn't set.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
Adding synchronization around metadata collision segment pages.
This part of metadata is modified when cacheline is mapped/unmapped
and when dirty status changes.
Synchronization on page level is required on top of cacheline
and hash bucket locks to assure metadata flush always reads
consistent state when copying entire collision table memory
page.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Modifying _ocf_mngt_io_class_configure and _ocf_mngt_io_class_remove
to never return -OCF_ERR_IO_CLASS_NOT_EXIST error code. This
return code was ignored by the caller anyway. In _ocf_mngt_io_class_remove
-OCF_ERR_IO_CLASS_NOT_EXIST indicated the IO class is already
removed, which is not an error. In _ocf_mngt_io_class_configure
-OCF_ERR_IO_CLASS_NOT_EXIST indicated empty IO class name, which
is actualy invalid input. This change made it possible to remove
erroneous error handling for -OCF_ERR_IO_CLASS_NOT_EXIST case in
ocf_mngt_cache_io_classes_configure.
This change fixes IO class configuration.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
When loading cache metadata, it should be started with exactly the same name as
it was running previously. Otherwise load should fail and return newly added
error code.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
The ocf_async_lock may be used in atomic context, thus we need
to replace synchronization primitives to non-sleeping variants.
Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>
Hash bucket read/write lock is sufficient to safely attempt
cacheline trylock/lock. This change removes cacheline lock
global RW semaprhore and moves cacheline trylock/lock under
hash bucket read/write lock respectively.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
This temporarily increases amount of boiler-plate code, but
this is going to be mitigated in the following commits.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
There is one RW lock per hash bucket. Write lock is required
to map cacheline, read lock is sufficient for traversing.
Hash bucket locks are always acquired under global metadata
read lock. This assures mutual exclusion with eviction and
management paths, where global metadata write lock is held.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
