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2009-04-08async_tx: rename zero_sum to valDan Williams
'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: Andre Noll <maan@systemlinux.org> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-04-08Merge branch 'dmaengine' into async-tx-raid6Dan Williams
2009-04-02dma: Add SoF and EoF debugging to ipu_idmac.c, minor cleanupGuennadi Liakhovetski
Add Start-of-Frame and End-of-Frame debugging to ipu_idmac.c, in the future it might also be needed for the actual video processing in mx3-camera, at which point, the ISRs will have to be transferred to mx3_camera.c, for which ipu_irq_map() and ipu_irq_unmap() functions will have to be exported. Also simplify a couple of pointer-dereferences. Signed-off-by: Guennadi Liakhovetski <lg@denx.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-04-01dw_dmac: add cyclic API to DW DMA driverHans-Christian Egtvedt
This patch adds a cyclic DMA interface to the DW DMA driver. This is very useful if you want to use the DMA controller in combination with a sound device which uses cyclic buffers. Using a DMA channel for cyclic DMA will disable the possibility to use it as a normal DMA engine until the user calls the cyclic free function on the DMA channel. Also a cyclic DMA list can not be prepared if the channel is already active. Signed-off-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com> Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-03-31md/raid5 revise rules for when to update metadata during reshapeNeilBrown
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>
2009-03-31md/raid5: minor code cleanups in make_request.NeilBrown
... 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: NeilBrown <neilb@suse.de>
2009-03-31md: remove CONFIG_MD_RAID_RESHAPE config option.NeilBrown
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: NeilBrown <neilb@suse.de>
2009-03-31md/raid5: be more careful about write ordering when reshaping.NeilBrown
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: NeilBrown <neilb@suse.de>
2009-03-31md: don't display meaningless values in sysfs files resync_start and sync_speedNeilBrown
When no resync if happening, both of these files currently have meaningless values (is slightly different ways). Change them to "none" in that case. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md/raid5: allow layout and chunksize to be changed on active array.NeilBrown
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: NeilBrown <neilb@suse.de>
2009-03-31md/raid5: reshape using largest of old and new chunk sizeNeilBrown
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: NeilBrown <neilb@suse.de>
2009-03-31md/raid5: prepare for allowing reshape to change layoutNeilBrown
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>
2009-03-31md/raid5: prepare for allowing reshape to change chunksize.NeilBrown
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>
2009-03-31md/raid5: clearly differentiate 'before' and 'after' stripes during reshape.NeilBrown
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>
2009-03-31Documentation/md.txt updateNeilBrown
Update md.txt to reflect recent changes in a number of sysfs attributes. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: allow number of drives in raid5 to be reducedNeilBrown
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: NeilBrown <neilb@suse.de>
2009-03-31md/raid5: change reshape-progress measurement to cope with reshaping backwards.NeilBrown
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>
2009-03-31md: add explicit method to signal the end of a reshape.NeilBrown
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: NeilBrown <neilb@suse.de>
2009-03-31md/raid5: enhance raid5_size to work correctly with negative delta_disksNeilBrown
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: NeilBrown <neilb@suse.de>
2009-03-31md/raid5: drop qd_idx from r6_stateNeilBrown
We now have this value in stripe_head so we don't need to duplicate it. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md/raid6: move raid6 data processing to raid6_pq.koDan Williams
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>
2009-03-31md: raid5 run(): Fix max_degraded for raid level 4.Andre Noll
raid4 allows only one failed disk. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: 'array_size' sysfs attributeDan Williams
Allow userspace to set the size of the array according to the following semantics: 1/ size must be <= to the size returned by mddev->pers->size(mddev, 0, 0) a) If size is set before the array is running, do_md_run will fail if size is greater than the default size b) A reshape attempt that reduces the default size to less than the set array size should be blocked 2/ once userspace sets the size the kernel will not change it 3/ writing 'default' to this attribute returns control of the size to the kernel and reverts to the size reported by the personality Also, convert locations that need to know the default size from directly reading ->array_sectors to <pers>_size. Resync/reshape operations always follow the default size. Finally, fixup other locations that read a number of 1k-blocks from userspace to use strict_blocks_to_sectors() which checks for unsigned long long to sector_t overflow and blocks to sectors overflow. Reviewed-by: Andre Noll <maan@systemlinux.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-03-31md: centralize ->array_sectors modificationsDan Williams
Get personalities out of the business of directly modifying ->array_sectors. Lays groundwork to introduce policy on when ->array_sectors can be modified. Reviewed-by: Andre Noll <maan@systemlinux.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-03-31md: add 'size' as a personality methodDan Williams
In preparation for giving userspace control over ->array_sectors we need to be able to retrieve the 'default' size, and the 'anticipated' size when a reshape is requested. For personalities that do not reshape emit a warning if anything but the default size is requested. In the raid5 case we need to update ->previous_raid_disks to make the new 'default' size available. Reviewed-by: Andre Noll <maan@systemlinux.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-03-31md: fix typo in FSF addressAtsushi SAKAI
Hello, I found a typo Bosto"m" in FSF address. And I am checking around linux source code. Here is the only place which uses Bosto"m" (not Boston). Signed-off-by: Atsushi SAKAI <sakaia@jp.fujitsu.com> Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: add takeover support for converting raid6 back into raid5NeilBrown
If a raid6 is still in the layout that comes from converting raid5 into a raid6. this will allow us to convert it back again. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: add takeover support for raid4 -> raid5 conversion.NeilBrown
Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md/raid5: allow layout/chunksize to be changed on an active 2-drive raid5.NeilBrown
2-drive raid5's aren't very interesting. But if you are converting a raid1 into a raid5, you will at least temporarily have one. And that it a good time to set the layout/chunksize for the new RAID5 if you aren't happy with the defaults. layout and chunksize don't actually affect the placement of data on a 2-drive raid5, so we just do some internal book-keeping. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: add ->takeover method for raid5 to be able to take over raid1NeilBrown
The RAID1 must have two drives and be a suitable size to be a multiple of a chunksize that isn't too small. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: add ->takeover method to support changing the personality managing an arrayNeilBrown
Implement this for RAID6 to be able to 'takeover' a RAID5 array. The new RAID6 will use a layout which places Q on the last device, and that device will be missing. If there are any available spares, one will immediately have Q recovered onto it. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: enable suspend/resume of md devices.NeilBrown
To be able to change the 'level' of an md/raid array, we need to suspend the device so that no requests are active - then move some pointers around etc. The code already keeps counts of active requests and the ->quiesce function can be used to wait until those counts hit zero. However the quiesce function blocks new requests once they are all ready 'inside' the personality module, and that is too late if we want to replace the personality modules. So make all md requests come in through a common md_make_request function that keeps track of how many requests have entered the modules but may not yet be on the internal reference counts. Allow md_make_request to be blocked when we want to suspend the device, and make it possible to wait for all those in-transit requests to be added to internal lists so that ->quiesce can wait for them. There is still a problem that when a request completes, we drop the ref count inside the personality code so there is a short time between when the refcount hits zero, and when the personality code is no longer being used. The personality code never blocks (schedule or spinlock) between dropping the refcount and exiting the routine, so this should be safe (as put_module calls synchronize_sched() before unmapping the module code). Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: md_unregister_thread should cope with being passed NULLNeilBrown
Mostly md_unregister_thread is only called when we know that the thread is NULL, but sometimes we need to check first. It is safer to put the check inside md_unregister_thread itself. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md/raid5: refactor raid5 "run"NeilBrown
.. 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>
2009-03-31md: make sure new_level, new_chunksize, new_layout always have sensible values.NeilBrown
When an md array is undergoing a change, we have new_* fields that show the new values. When no change is happening, it is least confusing if these have the same value as the normal fields. This is true in most cases, but not when the values are set via sysfs. So fix this up. A subsequent patch will BUG_ON if these things aren't consistent. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md/raid5: finish support for DDF/raid6NeilBrown
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>
2009-03-31md/raid5: Add support for new layouts for raid5 and raid6.NeilBrown
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>
2009-03-31md/raid5: simplify raid5_compute_sector interfaceNeilBrown
Rather than passing 'pd_idx' and 'qd_idx' to be filled in, pass a 'struct stripe_head *' and fill in the relevant fields. This is more extensible. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md/raid6: remove expectation that Q device is immediately after P device.NeilBrown
Code currently assumes that the devices in a raid6 stripe are 0 1 ... N-1 P Q in some rotated order. We will shortly add new layouts in which this strict pattern is broken. So remove this expectation. We still assume that the data disks are roughly in-order. However P and Q can be inserted anywhere within that order. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md/raid5: change raid5_compute_sector and stripe_to_pdidx to take a ↵NeilBrown
'previous' argument This similar to the recent change to get_active_stripe. There is no functional change, just come rearrangement to make future patches cleaner. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md/raid5: simplify interface for init_stripe and get_active_stripeNeilBrown
Rather than passing 'pd_idx' and 'disks' to these functions, just pass 'previous' which tells whether to use the 'previous' or 'current' geometry during a reshape, and let init_stripe calculate disks and pd_idx and anything else it might need. This is not a substantial simplification and even adds a division. However we will shortly be adding more complexity to init_stripe to handle more interesting 'reshape' activities, and without this change, the interface to these functions would get very complex. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: Represent raid device size in sectors.Andre Noll
This patch renames the "size" field of struct mdk_rdev_s to "sectors" and changes this field to store sectors instead of blocks. All users of this field, linear.c, raid0.c and md.c, are fixed up accordingly which gets rid of many multiplications and divisions. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: Make mddev->size sector-based.Andre Noll
This patch renames the "size" field of struct mddev_s to "dev_sectors" and stores the number of 512-byte sectors instead of the number of 1K-blocks in it. All users of that field, including raid levels 1,4-6,10, are adjusted accordingly. This simplifies the code a bit because it allows to get rid of a couple of divisions/multiplications by two. In order to make checkpatch happy, some minor coding style issues have also been addressed. In particular, size_store() now uses strict_strtoull() instead of simple_strtoull(). Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: be more consistent about setting WriteMostly flag when adding a drive to ↵NeilBrown
an array When a drive is added to an array using ADD_NEW_DISK, there are two places we can get certain flags from: the metadata on the disk or the flags passed through the IOCTL. For the WriteMostly flag (aka MD_DISK_WRITEMOSTLY) we take the value from either of those sources depending on if it is set (i.e. we effectively 'or' the two sources together). This makes it awkward to clear, and is at best inconsistent. As documented code (in mdadm) requires that setting MD_DISK_WRITEMOSTLY in the ioctl will be effective, we resolve the inconsistency by always using the value for this flag from the ioctl, and ignoring the value on disk. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: occasionally checkpoint drive recovery to reduce duplicate effort after ↵NeilBrown
a crash Version 1.x metadata has the ability to record the status of a partially completed drive recovery. However we only update that record on a clean shutdown. It would be nice to update it on unclean shutdowns too, particularly when using a bitmap that removes much to the 'sync' effort after an unclean shutdown. One complication with checkpointing recovery is that we only know where we are up to in terms of IO requests started, not which ones have completed. And we need to know what has completed to record how much is recovered. So occasionally pause the recovery until all submitted requests are completed, then update the record of where we are up to. When we have a bitmap, we already do that pause occasionally to keep the bitmap up-to-date. So enhance that code to record the recovery offset and schedule a superblock update. And when there is no bitmap, just pause 16 times during the resync to do a checkpoint. '16' is a fairly arbitrary number. But we don't really have any good way to judge how often is acceptable, and it seems like a reasonable number for now. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: move md_k.h from include/linux/raid/ to drivers/md/NeilBrown
It really is nicer to keep related code together.. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: move lots of #include lines out of .h files and into .cNeilBrown
This makes the includes more explicit, and is preparation for moving md_k.h to drivers/md/md.h Remove include/raid/md.h as its only remaining use was to #include other files. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: move most content from md.h to md_k.hNeilBrown
The extern function definitions are kernel-internal definitions, so they belong in md_k.h The MD_*_VERSION values could reasonably go in a number of places, but md_u.h seems most reasonable. This leaves almost nothing in md.h. It will go soon. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: move LEVEL_* definition from md_k.h to md_u.hNeilBrown
.. as they are part of the user-space interface. Also move MdpMinorShift into there so we can remove duplication. Lastly move mdp_major in. It is less obviously part of the user-space interface, but do_mounts_md.c uses it, and it is acting a bit like user-space. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: move headers out of include/linux/raid/Christoph Hellwig
Move the headers with the local structures for the disciplines and bitmap.h into drivers/md/ so that they are more easily grepable for hacking and not far away. md.h is left where it is for now as there are some uses from the outside. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: NeilBrown <neilb@suse.de>