Flush I/O should be forwarded to core and cache device. In case of core
this is simple - just mirror the I/O from the top volume. Since
cache data is owned by OCF it makes sense to send a simple flush I/O
with 0 address and size.
Current implementation attempts to use cache data I/O interface
(ocf_submit_cache_reqs function) instead of submitting empty flush to
the underlying cache device. This function is designed to read/write
from mapped cachelines while there is no traversation/mapping
performed on flush I/O.
If request map allocation succeeds, this results in sending I/O to
addres 0 with size and flags inherited from the top adapter I/O.
This doesn't make any sense, and can even result in invalid I/O if the
size is greater than cache device size.
Even worse, if flush request map allocation fails (which happens
always in case of large flush requests) then the erroneous call to
ocf_submit_cache_reqs results in NULL pointer dereference.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Right now alock assumes that number of locks taken will equal number of
core lines. This is not the case in pio, where only parts of metadata
are under locks. If pio request overlaps locked and not-locked metadata
section it will have different core lines number and awaited locks
number. To remedy this discrepancy additional method which gets count of
locks that will be taken/waited on is added to alock API.
Signed-off-by: Jan Musial <jan.musial@intel.com>
Configuration parameters are available in standby mode, while
stats are not. Need to separate the two.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Make ErrorDevice a wraper over any type of volume rather than
inheriting from RamVolume. This way error injection layer can be added
over any type of volume.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
It's required, because environments other than Linux kernel may not define
their own DIV_ROUND_UP. Moving it to env would just generate boilerplate,
because its implementation is trivial and portable.
Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>
This allows to avoid allocating cleaner metadata section and effectively
save up to 20% of metadata memory footprint.
Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>
... since a started cache is required to construct a queue object.
Instead add params to control whether to construct and register
management and default I/O queue in start().
Additionally introducing Cache method to register additional I/O
queues.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Since the threshold for the first bucket is always zero and the condition to
exit from the loop is never met in the first iteration it is save to start
iterating from `1`
This change is meant to avoid confusing static code analyzers
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
