- 09 9月, 2009 1 次提交
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由 Dan Williams 提交于
Some engines optimize operation by reading ahead in the descriptor chain such that descriptor2 may start execution before descriptor1 completes. If descriptor2 depends on the result from descriptor1 then a fence is required (on descriptor2) to disable this optimization. The async_tx api could implicitly identify dependencies via the 'depend_tx' parameter, but that would constrain cases where the dependency chain only specifies a completion order rather than a data dependency. So, provide an ASYNC_TX_FENCE to explicitly identify data dependencies. Signed-off-by: NDan Williams <dan.j.williams@intel.com>
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- 30 8月, 2009 12 次提交
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由 Dan Williams 提交于
Now that the resources to handle stripe_head operations are allocated percpu it is possible for raid5d to distribute stripe handling over multiple cores. This conversion also adds a call to cond_resched() in the non-multicore case to prevent one core from getting monopolized for raid operations. Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: NDan Williams <dan.j.williams@intel.com>
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由 Yuri Tikhonov 提交于
These routines have been replaced by there asynchronous counterparts. Signed-off-by: NYuri Tikhonov <yur@emcraft.com> Signed-off-by: NIlya Yanok <yanok@emcraft.com> Signed-off-by: NDan Williams <dan.j.williams@intel.com>
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由 Yuri Tikhonov 提交于
1/ Use STRIPE_OP_BIOFILL to offload completion of read requests to raid_run_ops 2/ Implement a handler for sh->reconstruct_state similar to the raid5 case (adds handling of Q parity) 3/ Prevent handle_parity_checks6 from running concurrently with 'compute' operations 4/ Hook up raid_run_ops Signed-off-by: NYuri Tikhonov <yur@emcraft.com> Signed-off-by: NIlya Yanok <yanok@emcraft.com> Signed-off-by: NDan Williams <dan.j.williams@intel.com>
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由 Dan Williams 提交于
[ Based on an original patch by Yuri Tikhonov ] Implement the state machine for handling the RAID-6 parities check and repair functionality. Note that the raid6 case does not need to check for new failures, like raid5, as it will always writeback the correct disks. The raid5 case can be updated to check zero_sum_result to avoid getting confused by new failures rather than retrying the entire check operation. Signed-off-by: NYuri Tikhonov <yur@emcraft.com> Signed-off-by: NIlya Yanok <yanok@emcraft.com> Signed-off-by: NDan Williams <dan.j.williams@intel.com>
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由 Yuri Tikhonov 提交于
In the synchronous implementation of stripe dirtying we processed a degraded stripe with one call to handle_stripe_dirtying6(). I.e. compute the missing blocks from the other drives, then copy in the new data and reconstruct the parities. In the asynchronous case we do not perform stripe operations directly. Instead, operations are scheduled with flags to be later serviced by raid_run_ops. So, for the degraded case the final reconstruction step can only be carried out after all blocks have been brought up to date by being read, or computed. Like the raid5 case schedule_reconstruction() sets STRIPE_OP_RECONSTRUCT to request a parity generation pass and through operation chaining can handle compute and reconstruct in a single raid_run_ops pass. [dan.j.williams@intel.com: fixup handle_stripe_dirtying6 gating] Signed-off-by: NYuri Tikhonov <yur@emcraft.com> Signed-off-by: NIlya Yanok <yanok@emcraft.com> Signed-off-by: NDan Williams <dan.j.williams@intel.com>
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由 Yuri Tikhonov 提交于
Modify handle_stripe_fill6 to work asynchronously by introducing fetch_block6 as the raid6 analog of fetch_block5 (schedule compute operations for missing/out-of-sync disks). [dan.j.williams@intel.com: compute D+Q in one pass] Signed-off-by: NYuri Tikhonov <yur@emcraft.com> Signed-off-by: NIlya Yanok <yanok@emcraft.com> Signed-off-by: NDan Williams <dan.j.williams@intel.com>
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由 Yuri Tikhonov 提交于
Extend schedule_reconstruction5 for reuse by the raid6 path. Add support for generating Q and BUG() if a request is made to perform 'prexor'. Signed-off-by: NYuri Tikhonov <yur@emcraft.com> Signed-off-by: NIlya Yanok <yanok@emcraft.com> Signed-off-by: NDan Williams <dan.j.williams@intel.com>
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由 Dan Williams 提交于
[ 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: NAndre Noll <maan@systemlinux.org> Signed-off-by: NYuri Tikhonov <yur@emcraft.com> Signed-off-by: NIlya Yanok <yanok@emcraft.com> Signed-off-by: NDan Williams <dan.j.williams@intel.com>
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由 Dan Williams 提交于
ops_complete_compute5 can be reused in the raid6 path if it is updated to generically handle a second target. Signed-off-by: NDan Williams <dan.j.williams@intel.com>
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由 Dan Williams 提交于
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: NAndre Noll <maan@systemlinux.org> Acked-by: NMaciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: NDan Williams <dan.j.williams@intel.com>
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由 Dan Williams 提交于
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: NDan Williams <dan.j.williams@intel.com>
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由 Dan Williams 提交于
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: NDan Williams <dan.j.williams@intel.com>
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- 15 7月, 2009 1 次提交
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由 Dan Williams 提交于
Add missing call to safe_put_page from stop() by unifying open coded raid5_conf_t de-allocation under free_conf(). Signed-off-by: NDan Williams <dan.j.williams@intel.com>
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- 09 6月, 2009 3 次提交
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由 NeilBrown 提交于
Now that we support changing the chunksize, we calculate "reshape_sectors" to be the max of number of sectors in old and new chunk size. However there is one please where we still use 'chunksize' rather than 'reshape_sectors'. This causes a reshape that reduces the size of chunks to freeze. Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
md has functionality to 'quiesce' and array so that all pending IO completed and no new IO starts. This is used to achieve a stable state before making internal changes. Currently this quiescing applies equally to normal IO, resync IO, and reshape IO. However there is a problem with applying it to reshape IO. Reshape can have multiple 'stripe_heads' that must be active together. If the quiesce come between allocating the first and the last of such a collection, then we deadlock, as the last will not be allocated until the quiesce is lifted, the quiesce will not be lifted until the first (which has been allocated) gets used, and that first cannot be used until the last is allocated. It is not necessary to inhibit reshape IO when a quiesce is requested. Those places in the code that require a full quiesce will ensure the reshape thread is not running at all. So allow reshape requests to get access to new stripe_heads without being blocked by a 'quiesce'. This only affects in-place reshapes (i.e. where the array does not grow or shrink) and these are only newly supported. So this patch is not needed in earlier kernels. Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
mddev->raid_disks can be changed and any time by a request from user-space. It is a suggestion as to what number of raid_disks is desired. conf->raid_disks can only be changed by the raid5 module with suitable locks in place. It is a statement as to the current number of raid_disks. There are two places where the latter should be used, but the former is used. This can lead to a crash when reshaping an array. This patch changes to mddev-> to conf-> Signed-off-by: NNeilBrown <neilb@suse.de>
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- 04 6月, 2009 2 次提交
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由 Dan Williams 提交于
Prepare the api for the arrival of a new parameter, 'scribble'. This will allow callers to identify scratchpad memory for dma address or page address conversions. As this adds yet another parameter, take this opportunity to convert the common submission parameters (flags, dependency, callback, and callback argument) into an object that is passed by reference. Also, take this opportunity to fix up the kerneldoc and add notes about the relevant ASYNC_TX_* flags for each routine. [ Impact: moves api pass-by-value parameters to a pass-by-reference struct ] Signed-off-by: NAndre Noll <maan@systemlinux.org> Acked-by: NMaciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: NDan Williams <dan.j.williams@intel.com>
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由 Dan Williams 提交于
In support of inter-channel chaining async_tx utilizes an ack flag to gate whether a dependent operation can be chained to another. While the flag is not set the chain can be considered open for appending. Setting the ack flag closes the chain and flags the descriptor for garbage collection. The ASYNC_TX_DEP_ACK flag essentially means "close the chain after adding this dependency". Since each operation can only have one child the api now implicitly sets the ack flag at dependency submission time. This removes an unnecessary management burden from clients of the api. [ Impact: clean up and enforce one dependency per operation ] Reviewed-by: NAndre Noll <maan@systemlinux.org> Acked-by: NMaciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: NDan Williams <dan.j.williams@intel.com>
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- 27 5月, 2009 1 次提交
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由 NeilBrown 提交于
A recent patch to raid5.c use min on an int and a sector_t. This isn't allowed. So change it to min_t(sector_t,x,y). Signed-off-by: NNeilBrown <neilb@suse.de>
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- 26 5月, 2009 1 次提交
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由 NeilBrown 提交于
As sector_t in unsigned, we cannot afford to let 'safepos' etc go negative. So replace a -= b; by a -= min(b,a); Signed-off-by: NNeilBrown <neilb@suse.de>
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- 17 4月, 2009 1 次提交
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由 NeilBrown 提交于
There are circumstances when a user-space process might need to "oversee" a resync/reshape process. For example when doing an in-place reshape of a raid5, it is prudent to take a backup of each section before reshaping it as this is the only way to provide safety against an unplanned shutdown (i.e. crash/power failure). The sync_max sysfs value can be used to stop the resync from advancing beyond a particular point. So user-space can: suspend IO to the first section and back it up set 'sync_max' to the end of the section wait for 'sync_completed' to reach that point resume IO on the first section and move on to the next section. However this process requires the kernel and user-space to run in lock-step which could introduce unnecessary delays. It would be better if a 'double buffered' approach could be used with userspace and kernel space working on different sections with the 'next' section always ready when the 'current' section is finished. One problem with implementing this is that sync_completed is only guaranteed to be updated when the sync process reaches sync_max. (it is updated on a time basis at other times, but it is hard to rely on that). This defeats some of the double buffering. With this patch, sync_completed (and reshape_position) get updated as the current position approaches sync_max, so there is room for userspace to advance sync_max early without losing updates. To be precise, sync_completed is updated when the current sync position reaches half way between the current value of sync_completed and the value of sync_max. This will usually be a good time for user space to update sync_max. If sync_max does not get updated, the updates to sync_completed (together with associated metadata updates) will occur at an exponentially increasing frequency which will get unreasonably fast (one update every page) immediately before the process hits sync_max and stops. So the update rate will be unreasonably fast only for an insignificant period of time. Signed-off-by: NNeilBrown <neilb@suse.de>
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- 14 4月, 2009 1 次提交
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由 NeilBrown 提交于
The sync_completed file reports how much of a resync (or recovery or reshape) has been completed. However due to the possibility of out-of-order completion of writes, it is not certain to be accurate. We have an internal value - mddev->curr_resync_completed - which is an accurate value (though it might not always be quite so uptodate). So: - make curr_resync_completed be uptodate a little more often, particularly when raid5 reshape updates status in the metadata - report curr_resync_completed in the sysfs file - allow poll/select to report all updates to md/sync_completed. This makes sync_completed completed usable by any external metadata handler that wants to record this status information in its metadata. Signed-off-by: NNeilBrown <neilb@suse.de>
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- 09 4月, 2009 1 次提交
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由 Dan Williams 提交于
'zero_sum' does not properly describe the operation of generating parity and checking that it validates against an existing buffer. Change the name of the operation to 'val' (for 'validate'). This is in anticipation of the p+q case where it is a requirement to identify the target parity buffers separately from the source buffers, because the target parity buffers will not have corresponding pq coefficients. Reviewed-by: NAndre Noll <maan@systemlinux.org> Acked-by: NMaciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: NDan Williams <dan.j.williams@intel.com>
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- 31 3月, 2009 16 次提交
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由 NeilBrown 提交于
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: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
... and to be certain the that make_request doesn't wait forever, add a 'wake_up' when ->reshape_progress has been set to MaxSector Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
This was only needed when the code was experimental. Most of it is well tested now, so the option is no longer useful. Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
When we are reshaping an array, it is very important that we read the data from a particular sector offset before writing new data at that offset. In most cases when growing or shrinking an array we read long before we even consider writing. But when restriping an array without changing it size, there is a small possibility that we might have some data to available write before the read has happened at the same location. This would require some stripes to be in cache already. To guard against this small possibility, we check, before writing, that the 'old' stripe at the same location is not in the process of being read. And we ensure that we mark all 'source' stripes as such before allowing new 'destination' stripes to proceed. Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
If an array has 3 or more devices, we allow the chunksize or layout to be changed and when a reshape starts, we use these as the 'new' values. Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
This ensures that even when old and new stripes are overlapping, we will try to read all of the old before having to write any of the new. Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
Add prev_algo to raid5_conf_t along the same lines as prev_chunk and previous_raid_disks. Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
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: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
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: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
When reshaping a raid5 to have fewer devices, we work from the end of the array to the beginning. md_do_sync gives addresses to sync_request that go from the beginning to the end. So largely ignore them use the internal state variable "reshape_progress" to keep track of what to do next. Never allow the size to be reduced below the minimum (4 for raid6, 3 otherwise). We require that the size of the array has already been reduced before the array is reshaped to a smaller size. This is because simply reducing the size is an easily reversible operation, while the reshape is immediately destructive and so is not reversible for the blocks at the ends of the devices. Thus to reshape an array to have fewer devices, you must first write an appropriately small size to md/array_size. When reshape finished, we remove any drives that are no longer needed and fix up ->degraded. Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
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: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
Currently raid5 (the only module that supports restriping) notices that the reshape has finished be sync_request being given a large value, and handles any cleanup them. This patch changes it so md_check_recovery calls into an explicit finish_reshape method as well. The clean-up from sync_request can do things that need to be done promptly, typically things local to the raid5_conf_t structure. The "finish_reshape" method is called under the mddev_lock so it can do things involving reconfiguring the device. This allows us to get rid of md_set_array_sectors_locked, which would have caused a deadlock if you tried to stop and array while a reshape was happening. Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
This is the first of four patches which combine to allow md/raid5 to reduce the number of devices in the array by restriping the data over a subset of the devices. If the number of disks in a raid4/5/6 is being reduced, then the default size must be based on the new number, not the old number of devices. In general, it should be based on the smaller of new and old. Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
We now have this value in stripe_head so we don't need to duplicate it. Signed-off-by: NNeilBrown <neilb@suse.de>
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由 Dan Williams 提交于
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: NDan Williams <dan.j.williams@intel.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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由 Andre Noll 提交于
raid4 allows only one failed disk. Signed-off-by: NAndre Noll <maan@systemlinux.org> Signed-off-by: NNeilBrown <neilb@suse.de>
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