Before async metadata we used to return 0 on flushing volatile
containers, this way we didn't have to special-case them.
This change brings back this behavior.
Signed-off-by: Jan Musial <jan.musial@intel.com>
Core volume I/O must not be queued on management queue - this would
break I/O accounting code, resulting in use-after-free type of errors
after cache detach, core remove etc.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
There is a risk that without uuid.data pointer denitialization it will
be freed during original volume deinit, zeroing uuid.data pointer
prevents that.
Signed-off-by: Michal Rakowski <michal.rakowski@intel.com>
This pointer is used to provide optional volume specific data
from the user down to bottom volume open callback. volume_params
is provided to OCF in ocf_mngt_cache_device_config.volume_params.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
In order to synchronize management operations with I/O OCF
maintains in-flight request counters. For example such ref
counters are used during ocf_mngt_detach to drain requests
accessing cache metadata (cache requests counter) and in
ocf_mngt_flush where we wait for outstanding requests sent
in write back mode (dirty requests counter).
Typically I/O threads increment cache/dirty counter when
creating request and decrement counter on request completion.
Management thread sets atomic variable to signal the start of
management operation. I/O threads react to this by changing
I/O requests mode so that the cache/dirty reference counter
is not incremented. As a result reference counter keeps getting
decremented. Management thread waits for the counter to drop to 0
and proceeds with management operation with assumption that no
cache/dirty requests are in progress.
This patch introduces a handy utility for requests reference
counting logic. ocf_refcnt_inc / dec are used to increment/
decrement counter. ocf_refcnt_freeze() makes subsequent
ocf_refcnt_inc() calls to return false, indicating that counter
cannot be incremented at this moment. ocf_refcnt_register_zero_cb
can be used to asynchronously wait for counter to drop to 0.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Cache is used during pipeline_destroy which means that
doing put_cache before destroying pipeline may result in
accessing memory that was freed.
Signed-off-by: Vitaliy Mysak <vitaliy.mysak@intel.com>
For flush/purge entry points to be fully asynchronous we still
need to rework flush mutex and waiting for outstanding dirty
requests.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
