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path: root/drivers/md/raid5.h
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* MD: raid5 trim supportShaohua Li2012-10-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Discard for raid4/5/6 has limitation. If discard request size is small, we do discard for one disk, but we need calculate parity and write parity disk. To correctly calculate parity, zero_after_discard must be guaranteed. Even it's true, we need do discard for one disk but write another disks, which makes the parity disks wear out fast. This doesn't make sense. So an efficient discard for raid4/5/6 should discard all data disks and parity disks, which requires the write pattern to be (A, A+chunk_size, A+chunk_size*2...). If A's size is smaller than chunk_size, such pattern is almost impossible in practice. So in this patch, I only handle the case that A's size equals to chunk_size. That is discard request should be aligned to stripe size and its size is multiple of stripe size. Since we can only handle request with specific alignment and size (or part of the request fitting stripes), we can't guarantee zero_after_discard even zero_after_discard is true in low level drives. The block layer doesn't send down correctly aligned requests even correct discard alignment is set, so I must filter out. For raid4/5/6 parity calculation, if data is 0, parity is 0. So if zero_after_discard is true for all disks, data is consistent after discard. Otherwise, data might be lost. Let's consider a scenario: discard a stripe, write data to one disk and write parity disk. The stripe could be still inconsistent till then depending on using data from other data disks or parity disks to calculate new parity. If the disk is broken, we can't restore it. So in this patch, we only enable discard support if all disks have zero_after_discard. If discard fails in one disk, we face the similar inconsistent issue above. The patch will make discard follow the same path as normal write request. If discard fails, a resync will be scheduled to make the data consistent. This isn't good to have extra writes, but data consistency is important. If a subsequent read/write request hits raid5 cache of a discarded stripe, the discarded dev page should have zero filled, so the data is consistent. This patch will always zero dev page for discarded request stripe. This isn't optimal because discard request doesn't need such payload. Next patch will avoid it. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
* Merge tag 'md-3.6' of git://neil.brown.name/mdLinus Torvalds2012-08-02
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | Pull additional md update from NeilBrown: "This contains a few patches that depend on plugging changes in the block layer so needed to wait for those. It also contains a Kconfig fix for the new RAID10 support in dm-raid." * tag 'md-3.6' of git://neil.brown.name/md: md/dm-raid: DM_RAID should select MD_RAID10 md/raid1: submit IO from originating thread instead of md thread. raid5: raid5d handle stripe in batch way raid5: make_request use batch stripe release
| * raid5: make_request use batch stripe releaseShaohua Li2012-08-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | make_request() does stripe release for every stripe and the stripe usually has count 1, which makes previous release_stripe() optimization not work. In my test, this release_stripe() becomes the heaviest pleace to take conf->device_lock after previous patches applied. Below patch makes stripe release batch. All the stripes will be released in unplug. The STRIPE_ON_UNPLUG_LIST bit is to protect concurrent access stripe lru. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
* | raid5: Add R5_ReadNoMerge flag which prevent bio from merging at block layermajianpeng2012-07-30
| | | | | | | | | | | | | | | | | | | | | | | | | | Because bios will merge at block-layer,so bios-error may caused by other bio which be merged into to the same request. Using this flag,it will find exactly error-sector and not do redundant operation like re-write and re-read. V0->V1:Using REQ_FLUSH instead REQ_NOMERGE avoid bio merging at block layer. Signed-off-by: Jianpeng Ma <majianpeng@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
* | raid5: add a per-stripe lockShaohua Li2012-07-19
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a per-stripe lock to protect stripe specific data. The purpose is to reduce lock contention of conf->device_lock. stripe ->toread, ->towrite are protected by per-stripe lock. Accessing bio list of the stripe is always serialized by this lock, so adding bio to the lists (add_stripe_bio()) and removing bio from the lists (like ops_run_biofill()) not race. If bio in ->read, ->written ... list are not shared by multiple stripes, we don't need any lock to protect ->read, ->written, because STRIPE_ACTIVE will protect them. If the bio are shared, there are two protections: 1. bi_phys_segments acts as a reference count 2. traverse the list uses r5_next_bio, which makes traverse never access bio not belonging to the stripe Let's have an example: | stripe1 | stripe2 | stripe3 | ...bio1......|bio2|bio3|....bio4..... stripe2 has 4 bios, when it's finished, it will decrement bi_phys_segments for all bios, but only end_bio for bio2 and bio3. bio1->bi_next still points to bio2, but this doesn't matter. When stripe1 is finished, it will not touch bio2 because of r5_next_bio check. Next time stripe1 will end_bio for bio1 and stripe3 will end_bio bio4. before add_stripe_bio() addes a bio to a stripe, we already increament the bio bi_phys_segments, so don't worry other stripes release the bio. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
* raid5: support sync requestShaohua Li2012-05-21
| | | | | | | | | REQ_SYNC is ignored in current raid5 code. Block layer does use it to do policy, for example ioscheduler. This patch adds it. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: allow for change in data_offset while managing a reshape.NeilBrown2012-05-20
| | | | | | | | | | | The important issue here is incorporating the different in data_offset into calculations concerning when we might need to over-write data that is still thought to be valid. To this end we find the minimum offset difference across all devices and add that where appropriate. Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: detect and handle replacements during recovery.NeilBrown2011-12-22
| | | | | | | | | | | | | | | | | | | During recovery we want to write to the replacement but not the original. So we have two new flags - R5_NeedReplace if this stripe has a replacement that needs to be written at some stage - R5_WantReplace if NeedReplace, and the data is available, and a 'sync' has been requested on this stripe. We also distinguish between 'sync and replace' which need to read all other devices, and 'replace' which only needs to read the devices being replaced. Note that during resync we always write to any replacement device. It might not need to be written to, but as we don't read to compare, we have to write to be sure. Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: writes should get directed to replacement as well as original.NeilBrown2011-12-22
| | | | | | | | | | | | | | | When writing, we need to submit two writes, one to the original, and one to the replacement - if there is a replacement. If the write to the replacement results in a write error, we just fail the device. We only try to record write errors to the original. When writing for recovery, we shouldn't write to the original. This will be addressed in a subsequent patch that generally addresses recovery. Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: raid5.h cleanupNeilBrown2011-12-22
| | | | | | | | | Remove some #defines that are no longer used, and replace some others with an enum. And remove an unused field. Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: allow each slot to have an extra replacement deviceNeilBrown2011-12-22
| | | | | | | | | | | | | | | | | | | Just enhance data structures to record a second device per slot to be used as a 'replacement' device, replacing the original. We also have a second bio in each slot in each stripe_head. This will only be used when writing to the array - we need to write to both the original and the replacement at the same time, so will need two bios. For now, only try using the replacement drive for aligned-reads. In this case, we prefer the replacement if it has been recovered far enough, otherwise use the original. This includes a small enhancement. Previously we would only do aligned reads if the target device was fully recovered. Now we also do them if it has recovered far enough. Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: typedef removal: raid5_conf_t -> struct r5confNeilBrown2011-10-11
| | | | Signed-off-by: NeilBrown <neilb@suse.de>
* md: remove typedefs: mdk_thread_t -> struct md_threadNeilBrown2011-10-11
| | | | Signed-off-by: NeilBrown <neilb@suse.de>
* md: remove typedefs: mddev_t -> struct mddevNeilBrown2011-10-11
| | | | | | Having mddev_t and 'struct mddev_s' is ugly and not preferred Signed-off-by: NeilBrown <neilb@suse.de>
* md: removing typedefs: mdk_rdev_t -> struct md_rdevNeilBrown2011-10-11
| | | | | | | The typedefs are just annoying. 'mdk' probably refers to 'md_k.h' which used to be an include file that defined this thing. Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: Clear bad blocks on successful write.NeilBrown2011-07-27
| | | | | | | On a successful write to a known bad block, flag the sh so that raid5d can remove the known bad block from the list. Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: write errors should be recorded as bad blocks if possible.NeilBrown2011-07-27
| | | | | | | | | | When a write error is detected, don't mark the device as failed immediately but rather record the fact for handle_stripe to deal with. Handle_stripe then attempts to record a bad block. Only if that fails does the device get marked as faulty. Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: use bad-block log to improve handling of uncorrectable read errors.NeilBrown2011-07-27
| | | | | | | | | | | | | If we get an uncorrectable read error - record a bad block rather than failing the device. And if these errors (which may be due to known bad blocks) cause recovery to be impossible, record a bad block on the recovering devices, or abort the recovery. As we might abort a recovery without failing a device we need to teach RAID5 about recovery_disabled handling. Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: add some more fields to stripe_head_stateNeilBrown2011-07-25
| | | | | | | | | | Adding these three fields will allow more common code to be moved to handle_stripe() struct field rearrangement by Namhyung Kim. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
* md/raid5: unify stripe_head_state and r6_stateNeilBrown2011-07-25
| | | | | | | | | | | | | | | 'struct stripe_head_state' stores state about the 'current' stripe that is passed around while handling the stripe. For RAID6 there is an extension structure: r6_state, which is also passed around. There is no value in keeping these separate, so move the fields from the latter into the former. This means that all code now needs to treat s->failed_num as an small array, but this is a small cost. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
* md/raid5: replace sh->lock with an 'active' flag.NeilBrown2011-07-25
| | | | | | | | | | | | | | | | | | | | | | | sh->lock is now mainly used to ensure that two threads aren't running in the locked part of handle_stripe[56] at the same time. That can more neatly be achieved with an 'active' flag which we set while running handle_stripe. If we find the flag is set, we simply requeue the stripe for later by setting STRIPE_HANDLE. For safety we take ->device_lock while examining the state of the stripe and creating a summary in 'stripe_head_state / r6_state'. This possibly isn't needed but as shared fields like ->toread, ->towrite are checked it is safer for now at least. We leave the label after the old 'unlock' called "unlock" because it will disappear in a few patches, so renaming seems pointless. This leaves the stripe 'locked' for longer as we clear STRIPE_ACTIVE later, but that is not a problem. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
* md/raid5: Remove use of sh->lock in sync_requestNeilBrown2011-07-25
| | | | | | | | | | | | | | This is the start of a series of patches to remove sh->lock. sync_request takes sh->lock before setting STRIPE_SYNCING to ensure there is no race with testing it in handle_stripe[56]. Instead, use a new flag STRIPE_SYNC_REQUESTED and test it early in handle_stripe[56] (after getting the same lock) and perform the same set/clear operations if it was set. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com>
* md - remove old plugging code.NeilBrown2011-04-18
| | | | | | | | | | | | | md has some plugging infrastructure for RAID5 to use because the normal plugging infrastructure required a 'request_queue', and when called from dm, RAID5 doesn't have one of those available. This relied on the ->unplug_fn callback which doesn't exist any more. So remove all of that code, both in md and raid5. Subsequent patches with restore the plugging functionality. Signed-off-by: NeilBrown <neilb@suse.de>
* block: remove per-queue pluggingJens Axboe2011-03-10
| | | | | | | | Code has been converted over to the new explicit on-stack plugging, and delay users have been converted to use the new API for that. So lets kill off the old plugging along with aops->sync_page(). Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* md: implment REQ_FLUSH/FUA supportTejun Heo2010-09-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch converts md to support REQ_FLUSH/FUA instead of now deprecated REQ_HARDBARRIER. In the core part (md.c), the following changes are notable. * Unlike REQ_HARDBARRIER, REQ_FLUSH/FUA don't interfere with processing of other requests and thus there is no reason to mark the queue congested while FLUSH/FUA is in progress. * REQ_FLUSH/FUA failures are final and its users don't need retry logic. Retry logic is removed. * Preflush needs to be issued to all member devices but FUA writes can be handled the same way as other writes - their processing can be deferred to request_queue of member devices. md_barrier_request() is renamed to md_flush_request() and simplified accordingly. For linear, raid0 and multipath, the core changes are enough. raid1, 5 and 10 need the following conversions. * raid1: Handling of FLUSH/FUA bio's can simply be deferred to request_queues of member devices. Barrier related logic removed. * raid5: Queue draining logic dropped. FUA bit is propagated through biodrain and stripe resconstruction such that all the updated parts of the stripe are written out with FUA writes if any of the dirtying writes was FUA. preread_active_stripes handling in make_request() is updated as suggested by Neil Brown. * raid10: FUA bit needs to be propagated to write clones. linear, raid0, 1, 5 and 10 tested. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Neil Brown <neilb@suse.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* md/raid5: export raid5 unplugging interface.NeilBrown2010-07-25
| | | | | | | Also remove remaining accesses to ->queue and ->gendisk when ->queue is NULL (As it is in a DM target). Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: add simple plugging infrastructure.NeilBrown2010-07-25
| | | | | | | | | | | md/raid5 uses the plugging infrastructure provided by the block layer and 'struct request_queue'. However when we plug raid5 under dm there is no request queue so we cannot use that. So create a similar infrastructure that is much lighter weight and use it for raid5. Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: export is_congested testNeilBrown2010-07-25
| | | | | | | | | the dm module will need this for dm-raid45. Also only access ->queue->backing_dev_info->congested_fn if ->queue actually exists. It won't in a dm target. Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: ensure we create a unique name for kmem_cache when mddev has no ↵NeilBrown2010-07-25
| | | | | | | | | | | | | gendisk We will shortly allow md devices with no gendisk (they are attached to a dm-target instead). That will cause mdname() to return 'mdX'. There is one place where mdname really needs to be unique: when creating the name for a slab cache. So in that case, if there is no gendisk, you the address of the mddev formatted in HEX to provide a unique name. Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: factor out code for changing size of stripe cache.NeilBrown2010-07-20
| | | | | | | Separate the actual 'change' code from the sysfs interface so that it can eventually be called internally. Signed-off-by: NeilBrown <neilb@suse.de>
* percpu: add __percpu sparse annotations to what's leftTejun Heo2010-02-16
| | | | | | | | | | | | | | | | Add __percpu sparse annotations to places which didn't make it in one of the previous patches. All converions are trivial. These annotations are to make sparse consider percpu variables to be in a different address space and warn if accessed without going through percpu accessors. This patch doesn't affect normal builds. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Borislav Petkov <borislav.petkov@amd.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Len Brown <lenb@kernel.org> Cc: Neil Brown <neilb@suse.de>
* md: fix problems with RAID6 calculations for DDF.NeilBrown2009-10-16
| | | | Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid456: downlevel multicore operations to raid_run_opsDan Williams2009-10-16
| | | | | | | | | | | | | | | | | | | | | | | | | The percpu conversion allowed a straightforward handoff of stripe processing to the async subsytem that initially showed some modest gains (+4%). However, this model is too simplistic and leads to stripes bouncing between raid5d and the async thread pool for every invocation of handle_stripe(). As reported by Holger this can fall into a pathological situation severely impacting throughput (6x performance loss). By downleveling the parallelism to raid_run_ops the pathological stripe_head bouncing is eliminated. This version still exhibits an average 11% throughput loss for: mdadm --create /dev/md0 /dev/sd[b-q] -n 16 -l 6 echo 1024 > /sys/block/md0/md/stripe_cache_size dd if=/dev/zero of=/dev/md0 bs=1024k count=2048 ...but the results are at least stable and can be used as a base for further multicore experimentation. Reported-by: Holger Kiehl <Holger.Kiehl@dwd.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
* Merge branch 'dmaengine' into async-tx-nextDan Williams2009-09-08
|\ | | | | | | | | | | | | | | Conflicts: crypto/async_tx/async_xor.c drivers/dma/ioat/dma_v2.h drivers/dma/ioat/pci.c drivers/md/raid5.c
| * md: convert conf->chunk_size and conf->prev_chunk to sectors.Andre Noll2009-06-17
| | | | | | | | | | | | | | This kills some more shifts. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
| * md: remove mddev_to_conf "helper" macroNeilBrown2009-06-16
| | | | | | | | | | | | | | | | | | | | Having a macro just to cast a void* isn't really helpful. I would must rather see that we are simply de-referencing ->private, than have to know what the macro does. So open code the macro everywhere and remove the pointless cast. Signed-off-by: NeilBrown <neilb@suse.de>
* | md/raid6: asynchronous raid6 operationsDan Williams2009-08-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Based on an original patch by Yuri Tikhonov ] The raid_run_ops routine uses the asynchronous offload api and the stripe_operations member of a stripe_head to carry out xor+pq+copy operations asynchronously, outside the lock. The operations performed by RAID-6 are the same as in the RAID-5 case except for no support of STRIPE_OP_PREXOR operations. All the others are supported: STRIPE_OP_BIOFILL - copy data into request buffers to satisfy a read request STRIPE_OP_COMPUTE_BLK - generate missing blocks (1 or 2) in the cache from the other blocks STRIPE_OP_BIODRAIN - copy data out of request buffers to satisfy a write request STRIPE_OP_RECONSTRUCT - recalculate parity for new data that has entered the cache STRIPE_OP_CHECK - verify that the parity is correct The flow is the same as in the RAID-5 case, and reuses some routines, namely: 1/ ops_complete_postxor (renamed to ops_complete_reconstruct) 2/ ops_complete_compute (updated to set up to 2 targets uptodate) 3/ ops_run_check (renamed to ops_run_check_p for xor parity checks) [neilb@suse.de: fixes to get it to pass mdadm regression suite] Reviewed-by: Andre Noll <maan@systemlinux.org> Signed-off-by: Yuri Tikhonov <yur@emcraft.com> Signed-off-by: Ilya Yanok <yanok@emcraft.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | async_tx: add sum check flagsDan Williams2009-08-29
| | | | | | | | | | | | | | | | | | | | | | | | | | Replace the flat zero_sum_result with a collection of flags to contain the P (xor) zero-sum result, and the soon to be utilized Q (raid6 reed solomon syndrome) zero-sum result. Use the SUM_CHECK_ namespace instead of DMA_ since these flags will be used on non-dma-zero-sum enabled platforms. Reviewed-by: Andre Noll <maan@systemlinux.org> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | md/raid5,6: add percpu scribble region for buffer listsDan Williams2009-08-29
| | | | | | | | | | | | | | | | | | | | | | | | | | Use percpu memory rather than stack for storing the buffer lists used in parity calculations. Include space for dma address conversions and pass that to async_tx via the async_submit_ctl.scribble pointer. [ Impact: move memory pressure from stack to heap ] Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | md/raid6: move the spare page to a percpu allocationDan Williams2009-08-29
|/ | | | | | | | | | | | | | In preparation for asynchronous handling of raid6 operations move the spare page to a percpu allocation to allow multiple simultaneous synchronous raid6 recovery operations. Make this allocation cpu hotplug aware to maximize allocation efficiency. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* md/raid5 revise rules for when to update metadata during reshapeNeilBrown2009-03-31
| | | | | | | | | | | | | | | | | | | | | | | | We currently update the metadata : 1/ every 3Megabytes 2/ When the place we will write new-layout data to is recorded in the metadata as still containing old-layout data. Rule one exists to avoid having to re-do too much reshaping in the face of a crash/restart. So it should really be time based rather than size based. So change it to "every 10 seconds". Rule two turns out to be too harsh when restriping an array 'in-place', as in that case the metadata much be updates for every stripe. For the in-place update, it can only possibly be safe from a crash if some user-space program data a backup of every e.g. few hundred stripes before allowing them to be reshaped. In that case, the constant metadata update is pointless. So only update the metadata if the new metadata will report that the end of the 'old-layout' data is beyond where we are currently writing 'new-layout' data. Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: prepare for allowing reshape to change layoutNeilBrown2009-03-31
| | | | | | | Add prev_algo to raid5_conf_t along the same lines as prev_chunk and previous_raid_disks. Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: prepare for allowing reshape to change chunksize.NeilBrown2009-03-31
| | | | | | | | | | | | | | | | | | | Add "prev_chunk" to raid5_conf_t, similar to "previous_raid_disks", to remember what the chunk size was before the reshape that is currently underway. This seems like duplication with "chunk_size" and "new_chunk" in mddev_t, and to some extent it is, but there are differences. The values in mddev_t are always defined and often the same. The prev* values are only defined if a reshape is underway. Also (and more significantly) the raid5_conf_t values will be changed at the same time (inside an appropriate lock) that the reshape is started by setting reshape_position. In contrast, the new_chunk value is set when the sysfs file is written which could be well before the reshape starts. Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: clearly differentiate 'before' and 'after' stripes during reshape.NeilBrown2009-03-31
| | | | | | | | | | | | | | During a raid5 reshape, we have some stripes in the cache that are 'before' the reshape (and are still to be processed) and some that are 'after'. They are currently differentiated by having different ->disks values as the only reshape current supported involves changing the number of disks. However we will soon support reshapes that do not change the number of disks (chunk parity or chunk size). So make the difference more explicit with a 'generation' number. Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: change reshape-progress measurement to cope with reshaping backwards.NeilBrown2009-03-31
| | | | | | | | | | | | | | When reducing the number of devices in a raid4/5/6, the reshape process has to start at the end of the array and work down to the beginning. So we need to handle expand_progress and expand_lo differently. This patch renames "expand_progress" and "expand_lo" to avoid the implication that anything is getting bigger (expand->reshape) and every place they are used, we make sure that they are used the right way depending on whether delta_disks is positive or negative. Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: drop qd_idx from r6_stateNeilBrown2009-03-31
| | | | | | | We now have this value in stripe_head so we don't need to duplicate it. Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid6: move raid6 data processing to raid6_pq.koDan Williams2009-03-31
| | | | | | | | | | | | | | | | | Move the raid6 data processing routines into a standalone module (raid6_pq) to prepare them to be called from async_tx wrappers and other non-md drivers/modules. This precludes a circular dependency of raid456 needing the async modules for data processing while those modules in turn depend on raid456 for the base level synchronous raid6 routines. To support this move: 1/ The exportable definitions in raid6.h move to include/linux/raid/pq.h 2/ The raid6_call, recovery calls, and table symbols are exported 3/ Extra #ifdef __KERNEL__ statements to enable the userspace raid6test to compile Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: refactor raid5 "run"NeilBrown2009-03-30
| | | | | | | | .. so that the code to create the private data structures is separate. This will help with future code to change the level of an active array. Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: finish support for DDF/raid6NeilBrown2009-03-30
| | | | | | | | | | | | | DDF requires RAID6 calculations over different devices in a different order. For md/raid6, we calculate over just the data devices, starting immediately after the 'Q' block. For ddf/raid6 we calculate over all devices, using zeros in place of the P and Q blocks. This requires unfortunately complex loops... Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: Add support for new layouts for raid5 and raid6.NeilBrown2009-03-30
| | | | | | | | | | | | | | | | | DDF uses different layouts for P and Q blocks than current md/raid6 so add those that are missing. Also add support for RAID6 layouts that are identical to various raid5 layouts with the simple addition of one device to hold all of the 'Q' blocks. Finally add 'raid5' layouts to match raid4. These last to will allow online level conversion. Note that this does not provide correct support for DDF/raid6 yet as the order in which data blocks are summed to produce the Q block is significant and different between current md code and DDF requirements. Signed-off-by: NeilBrown <neilb@suse.de>
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-22 18:26:54 -0500