Because of metadata flapping it is much more complicated to capture those
sections in flight in standby mode, so we read them directly from the cache
volume during the activate.
Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>
This feature provides double buffering of config sections to prevent
situation when power failure during metadata flush leads to partially
updated metadata. Flapping mechanism makes it always possible to perform
graceful rollback to previous config metadata content in such situation.
Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>
Request submitted in fast path may be freed before the sequential cutoff stats
are updated. Increment request reference counter to prevent it.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
Move error print to where it belongs, preventing this message to
pop up when same error code is reported elsewhere for other reason.
Signed-off-by: Rafal Stefanowski <rafal.stefanowski@intel.com>
This patch fixes the issue 988 (and 997) causing a kernel stack
overflow.
Signed-off-by: Krzysztof Majzerowicz-Jaszcz <krzysztof.majzerowicz-jaszcz@intel.com>
To allow the fastest switching from the passive-standby to active mode, the
runtime metadata must be kept 100% synced with the metadata on the drive and in
the RAM thus recovery is required after each collision section update.
To avoid long-lasting recovering of all the cachelines each time the collision
section is being updated, the passive update procedure recovers only those
which have its MD entries on the updated pages.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
Starting cache in a standby mode requires access to a valid cleaning policy
type. If the policy is stored only in the superblock, it may be overridden by
one of the metadata passive updates.
To prevent losing the information it should be stored in cache's runtime
metadata.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
Initializing cleaning policy is very time consuming. To reduce the time required
for activating cache instance the initialization sholud be done during passitve
start
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
Since part of the recovery is done during `standby init`, the correct shutdown
status has to be set
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
The unsafe mode is useful if the metadata of added cores is incomplete.
Such scenario is possible when starting cache to standby mode from partially
vaild metadata.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
Make sure all the invalid cachelines have reset status bits. This allows to
recognize invalid cachelines easily during populate.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
Recovery during passive start is based on the assuption that metadata collision
section stored on disk might be partially valid. Reseting this data would make
rebuilding metadata impossible.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
Decide whether to promote sequential cutoff stream
to global structures when threshold is reached
Signed-off-by: Rafal Stefanowski <rafal.stefanowski@intel.com>
GCC 11 static check finds an array size mismatch and prevents OCF from
compiling correctly. This fixes OpenCAS Linux issue #968
Signed-off-by: Krzysztof Majzerowicz-Jaszcz <krzysztof.majzerowicz-jaszcz@intel.com>
Error for an invalid cache operation while in passive mode added
Signed-off-by: Krzysztof Majzerowicz-Jaszcz <krzysztof.majzerowicz-jaszcz@intel.com>
Error name correction
Signed-off-by: Krzysztof Majzerowicz-Jaszcz <krzysztof.majzerowicz-jaszcz@intel.com>
API changes for passive cache mode
Moved the passive cache error return source to the api for flush and
set_param
Signed-off-by: Krzysztof Majzerowicz-Jaszcz <krzysztof.majzerowicz-jaszcz@intel.com>
Further API changes for passive cache mode
Signed-off-by: Krzysztof Majzerowicz-Jaszcz <krzysztof.majzerowicz-jaszcz@intel.com>
Passive api - review changes
Signed-off-by: Krzysztof Majzerowicz-Jaszcz <krzysztof.majzerowicz-jaszcz@intel.com>
Management pipelines tend to consist of multiple asynchronous steps.
Allowing synchronous queue kick results in massive call stacks (e.g.
almost 500 functions deep in case of cache stop). Since async kick
is required anyway, it seems reasonable to switch to async kick
in pipeline implementation.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Cache name is needed for logging in passive mode, when config metadata
is still not accessible.
Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>
To prevent deinitializing cleaner context (i.e. during switching policy) during
processing requests, access to cleaner should be protected with reference
counter
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
Making the operation asynchronous will allow to use refcnt utility as an
synchronization mechanism between processing cachelines and deinitializing
cleaning policy.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
The change should unify access to cleaning policy resources and facilitate
synchronization when switching cleaning policies
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
All remapped cachelines are write locked. If the operation fails cachelines has
to be unlocked during rollback
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
ocf_lru_get_list() now returs clean list for freelist partition to
provide common interface regardless of partition type.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Flushing metadata in WT is required only if at least of the request's cacheline
changed its state to clean.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
There's a possibility that WT write is performed to dirty cache line (i.e. after
switching WB->WT without flush) and status bits change from dirty to clean. If
power failure occurs it might happen that recovery would ignore recent data from
cache and would assume that data is clean while backend storage data is out of
date.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
In WB mode metadata should be updated only if the actuall data had been saved
on disk. Otherwise metadata might be flushed too early and consequently data
corruption might occur.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
src/eviction/lru.c -> src/ocf_lru.c
src/eviction/lru.h -> src/ocf_lru.h
src/eviction/lru_structs.h -> src/ocf_lru_structs.h
src/eviction/eviction.c -> src/ocf_space.c
src/eviction/eviction.h -> src/ocf_space.h
.. as well as corresponding UT files.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
... in UT as well
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
New structure ocf_part is added to contain all the data common for both
user partitions and freelist partition: part_runtime and part_id.
ocf_user_part now contains ocf_part structure as well as pointer to
cleaning partition runtime metadata (moved out from part_runtime) and
user partition config (no change here).
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Lookup is repeated after request is identified as miss and hash bucket
lock is upgraded (in order to map missing cachelines). At this point
cachelines status might change and the request might turn out to be
a hit after all. Adding check for this condition removes unnecessary
calls to remap logic.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
