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path: root/drivers/md/raid5.c
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2011-05-23Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits) b43: fix comment typo reqest -> request Haavard Skinnemoen has left Atmel cris: typo in mach-fs Makefile Kconfig: fix copy/paste-ism for dell-wmi-aio driver doc: timers-howto: fix a typo ("unsgined") perf: Only include annotate.h once in tools/perf/util/ui/browsers/annotate.c md, raid5: Fix spelling error in comment ('Ofcourse' --> 'Of course'). treewide: fix a few typos in comments regulator: change debug statement be consistent with the style of the rest Revert "arm: mach-u300/gpio: Fix mem_region resource size miscalculations" audit: acquire creds selectively to reduce atomic op overhead rtlwifi: don't touch with treewide double semicolon removal treewide: cleanup continuations and remove logging message whitespace ath9k_hw: don't touch with treewide double semicolon removal include/linux/leds-regulator.h: fix syntax in example code tty: fix typo in descripton of tty_termios_encode_baud_rate xtensa: remove obsolete BKL kernel option from defconfig m68k: fix comment typo 'occcured' arch:Kconfig.locks Remove unused config option. treewide: remove extra semicolons ...
2011-05-11md: allow resync_start to be set while an array is active.NeilBrown
The sysfs attribute 'resync_start' (known internally as recovery_cp), records where a resync is up to. A value of 0 means the array is not known to be in-sync at all. A value of MaxSector means the array is believed to be fully in-sync. When the size of member devices of an array (RAID1,RAID4/5/6) is increased, the array can be increased to match. This process sets resync_start to the old end-of-device offset so that the new part of the array gets resynced. However with RAID1 (and RAID6) a resync is not technically necessary and may be undesirable. So it would be good if the implied resync after the array is resized could be avoided. So: change 'resync_start' so the value can be changed while the array is active, and as a precaution only allow it to be changed while resync/recovery is 'frozen'. Changing it once resync has started is not going to be useful anyway. This allows the array to be resized without a resync by: write 'frozen' to 'sync_action' write new size to 'component_size' (this will set resync_start) write 'none' to 'resync_start' write 'idle' to 'sync_action'. Also slightly improve some tests on recovery_cp when resizing raid1/raid5. Now that an arbitrary value could be set we should be more careful in our tests. Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11md: make error_handler functions more uniform and correct.NeilBrown
- there is no need to test_bit Faulty, as that was already done in md_error which is the only caller of these functions. - MD_CHANGE_DEVS should be set *after* faulty is set to ensure metadata is updated correctly. - spinlock should be held while updating ->degraded. Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-10md, raid5: Fix spelling error in comment ('Ofcourse' --> 'Of course').Jesper Juhl
There's a small typo in a comment in drivers/md/raid5.c - 'Of course' is misspelled as 'Ofcourse'. This patch fixes the spelling error. Signed-off-by: Jesper Juhl <jj@chaosbits.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-04-21raid5: fix build error, sector_t usageRandy Dunlap
Change <sectors> from unsigned long long to sector_t. This matches its source field. ERROR: "__udivdi3" [drivers/md/raid456.ko] undefined! Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-20md: Fix dev_sectors on takeover from raid0 to raid4/5NeilBrown
A raid0 array doesn't set 'dev_sectors' as each device might contribute a different number of sectors. So when converting to a RAID4 or RAID5 we need to set dev_sectors as they need the number. We have already verified that in fact all devices do contribute the same number of sectors, so use that number. Signed-off-by: NeilBrown <neilb@suse.de>
2011-04-20md/raid5: remove setting of ->queue_lockNeilBrown
We previously needed to set ->queue_lock to match the raid5 device_lock so we could safely use queue_flag_* operations (e.g. for plugging). which test the ->queue_lock is in fact locked. However that need has completely gone away and is unlikely to come back to remove this now-pointless setting. Signed-off-by: NeilBrown <neilb@suse.de>
2011-04-18md: incorporate new plugging into raid5.NeilBrown
In raid5 plugging is used for 2 things: 1/ collecting writes that require a bitmap update 2/ collecting writes in the hope that we can create full stripes - or at least more-full. We now release these different sets of stripes when plug_cnt is zero. Also in make_request, we call mddev_check_plug to hopefully increase plug_cnt, and wake up the thread at the end if plugging wasn't achieved for some reason. Signed-off-by: NeilBrown <neilb@suse.de>
2011-04-18md - remove old plugging code.NeilBrown
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>
2011-04-18md: use new plugging interface for RAID IO.NeilBrown
md/raid submits a lot of IO from the various raid threads. So adding start/finish plug calls to those so that some plugging happens. Signed-off-by: NeilBrown <neilb@suse.de>
2011-03-10block: remove per-queue pluggingJens Axboe
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>
2011-01-31md: don't abort checking spares as soon as one cannot be added.NeilBrown
As spares can be added manually before a reshape starts, we need to find them all to mark some of them as in_sync. Previously we would abort looking for spares when we found an unallocated spare what could not be added to the array (implying there was no room for new spares). However already-added spares could be later in the list, so we need to keep searching. Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-31md: fix the test for finding spares in raid5_start_reshape.NeilBrown
As spares can be added to the array before the reshape is started, we need to find and count them when checking there are enough. The array could have been degraded, so we need to check all devices, no just those out side of the range of devices in the array before the reshape. So instead of checking the index, check the In_sync flag as that reliably tells if the device is a spare or this purpose. Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-31md: simplify some 'if' conditionals in raid5_start_reshape.NeilBrown
There are two consecutive 'if' statements. if (mddev->delta_disks >= 0) .... if (mddev->delta_disks > 0) The code in the second is equally valid if delta_disks == 0, and these two statements are the only place that 'added_devices' is used. So make them a single if statement, make added_devices a local variable, and re-indent it all. No functional change. Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-13md/raid5: handle manually-added spares in start_reshape.NeilBrown
It is possible to manually add spares to specific slots before starting a reshape. raid5_start_reshape should recognised this possibility and include it in the accounting. Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-13md: Don't let implementation detail of curr_resync leak out through sysfs.NeilBrown
mddev->curr_resync has artificial values of '1' and '2' which are used by the code which ensures only one resync is happening at a time on any given device. These values are internal and should never be exposed to user-space (except when translated appropriately as in the 'pending' status in /proc/mdstat). Unfortunately they are as ->curr_resync is assigned to ->curr_resync_completed and that value is directly visible through sysfs. So change the assignments to ->curr_resync_completed to get the same valued from elsewhere in a form that doesn't have the magic '1' or '2' values. Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-13md/raid5: use sysfs_notify_dirent_safe to avoid NULL pointerJonathan Brassow
With the module parameter 'start_dirty_degraded' set, raid5_spare_active() previously called sysfs_notify_dirent() with a NULL argument (rdev->sysfs_state) when a rebuild finished. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2011-01-13md: Fix single printks with multiple KERN_<level>sJoe Perches
Noticed-by: Russell King <linux@arm.linux.org.uk> Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28md: use separate bio pool for each md device.NeilBrown
bio_clone and bio_alloc allocate from a common bio pool. If an md device is stacked with other devices that use this pool, or under something like swap which uses the pool, then the multiple calls on the pool can cause deadlocks. So allocate a local bio pool for each md array and use that rather than the common pool. This pool is used both for regular IO and metadata updates. Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28md: use sector_t in bitmap_get_counterNeilBrown
bitmap_get_counter returns the number of sectors covered by the counter in a pass-by-reference variable. In some cases this can be very large, so make it a sector_t for safety. Signed-off-by: NeilBrown <neilb@suse.de>
2010-09-10md: implment REQ_FLUSH/FUA supportTejun Heo
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>
2010-08-18md: provide appropriate return value for spare_active functions.NeilBrown
md_check_recovery expects ->spare_active to return 'true' if any spares were activated, but none of them do, so the consequent change in 'degraded' is not notified through sysfs. So count the number of spares activated, subtract it from 'degraded' just once, and return it. Reported-by: Adrian Drzewiecki <adriand@vmware.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-18md: Notify sysfs when RAID1/5/10 disk is In_sync.Adrian Drzewiecki
When RAID1 is done syncing disks, it'll update the state of synced rdevs to In_sync. But it neglected to notify sysfs that the attribute changed. So any programs that are waiting for an rdev's state to change will not be woken. (raid5/raid10 added by neilb) Signed-off-by: Adrian Drzewiecki <adriand@vmware.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-10Merge branch 'for-linus' of git://neil.brown.name/mdLinus Torvalds
* 'for-linus' of git://neil.brown.name/md: (24 commits) md: clean up do_md_stop md: fix another deadlock with removing sysfs attributes. md: move revalidate_disk() back outside open_mutex md/raid10: fix deadlock with unaligned read during resync md/bitmap: separate out loading a bitmap from initialising the structures. md/bitmap: prepare for storing write-intent-bitmap via dm-dirty-log. md/bitmap: optimise scanning of empty bitmaps. md/bitmap: clean up plugging calls. md/bitmap: reduce dependence on sysfs. md/bitmap: white space clean up and similar. md/raid5: export raid5 unplugging interface. md/plug: optionally use plugger to unplug an array during resync/recovery. md/raid5: add simple plugging infrastructure. md/raid5: export is_congested test raid5: Don't set read-ahead when there is no queue md: add support for raising dm events. md: export various start/stop interfaces md: split out md_rdev_init md: be more careful setting MD_CHANGE_CLEAN md/raid5: ensure we create a unique name for kmem_cache when mddev has no gendisk ...
2010-08-07block: unify flags for struct bio and struct requestChristoph Hellwig
Remove the current bio flags and reuse the request flags for the bio, too. This allows to more easily trace the type of I/O from the filesystem down to the block driver. There were two flags in the bio that were missing in the requests: BIO_RW_UNPLUG and BIO_RW_AHEAD. Also I've renamed two request flags that had a superflous RW in them. Note that the flags are in bio.h despite having the REQ_ name - as blkdev.h includes bio.h that is the only way to go for now. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-07-26md/raid5: export raid5 unplugging interface.NeilBrown
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>
2010-07-26md/plug: optionally use plugger to unplug an array during resync/recovery.NeilBrown
If an array doesn't have a 'queue' then md_do_sync cannot unplug it. In that case it will have a 'plugger', so make that available to the mddev, and use it to unplug the array if needed. Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26md/raid5: add simple plugging infrastructure.NeilBrown
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>
2010-07-26md/raid5: export is_congested testNeilBrown
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>
2010-07-26raid5: Don't set read-ahead when there is no queueNeilBrown
dm-raid456 does not provide a 'queue' for raid5 to use, so we must make raid5 stop depending on the queue. First: read_ahead dm handles read-ahead adjustment fully in userspace, so simply don't do any readahead adjustments if there is no queue. Also re-arrange code slightly so all the accesses to ->queue are together. Finally, move the blk_queue_merge_bvec function into the 'if' as the ->split_io setting in dm-raid456 has the same effect. Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26md/raid5: ensure we create a unique name for kmem_cache when mddev has no ↵NeilBrown
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>
2010-07-21md/raid5: factor out code for changing size of stripe cache.NeilBrown
Separate the actual 'change' code from the sysfs interface so that it can eventually be called internally. Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-21md: reduce dependence on sysfs.NeilBrown
We will want md devices to live as dm targets where sysfs is not visible. So allow md to not connect to sysfs. Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24md/raid5: don't include 'spare' drives when reshaping to fewer devices.NeilBrown
There are few situations where it would make any sense to add a spare when reducing the number of devices in an array, but it is conceivable: A 6 drive RAID6 with two missing devices could be reshaped to a 5 drive RAID6, and a spare could become available just in time for the reshape, but not early enough to have been recovered first. 'freezing' recovery can make this easy to do without any races. However doing such a thing is a bad idea. md will not record the partially-recovered state of the 'spare' and when the reshape finished it will think that the spare is still spare. Easiest way to avoid this confusion is to simply disallow it. Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24md/raid5: add a missing 'continue' in a loop.NeilBrown
As the comment says, the tail of this loop only applies to devices that are not fully in sync, so if In_sync was set, we should avoid the rest of the loop. This bug will hardly ever cause an actual problem. The worst it can do is allow an array to be assembled that is dirty and degraded, which is not generally a good idea (without warning the sysadmin first). This will only happen if the array is RAID4 or a RAID5/6 in an intermediate state during a reshape and so has one drive that is all 'parity' - no data - while some other device has failed. This is certainly possible, but not at all common. Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24md/raid5: Allow recovered part of partially recovered devices to be in-syncNeilBrown
During a recovery of reshape the early part of some devices might be in-sync while the later parts are not. We we know we are looking at an early part it is good to treat that part as in-sync for stripe calculations. This is particularly important for a reshape which suffers device failure. Treating the data as in-sync can mean the difference between data-safety and data-loss. Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24md/raid5: More careful check for "has array failed".NeilBrown
When we are reshaping an array, the device failure combinations that cause us to decide that the array as failed are more subtle. In particular, any 'spare' will be fully in-sync in the section of the array that has already been reshaped, thus failures that affect only that section are less critical. So encode this subtlety in a new function and call it as appropriate. The case that showed this problem was a 4 drive RAID5 to 8 drive RAID6 conversion where the last two devices failed. This resulted in: good good good good incomplete good good failed failed while converting a 5-drive RAID6 to 8 drive RAID5 The incomplete device causes the whole array to look bad, bad as it was actually good for the section that had been converted to 8-drives, all the data was actually safe. Reported-by: Terry Morris <tbmorris@tbmorris.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24md: Don't update ->recovery_offset when reshaping an array to fewer devices.NeilBrown
When an array is reshaped to have fewer devices, the reshape proceeds from the end of the devices to the beginning. If a device happens to be non-In_sync (which is possible but rare) we would normally update the ->recovery_offset as the reshape progresses. However that would be wrong as the recover_offset records that the early part of the device is in_sync, while in fact it would only be the later part that is in_sync, and in any case the offset number would be measured from the wrong end of the device. Relatedly, if after a reshape a spare is discovered to not be recoverred all the way to the end, not allow spare_active to incorporate it in the array. This becomes relevant in the following sample scenario: A 4 drive RAID5 is converted to a 6 drive RAID6 in a combined operation. The RAID5->RAID6 conversion will cause a 5 drive to be included as a spare, then the 5drive -> 6drive reshape will effectively rebuild that spare as it progresses. The 6th drive is treated as in_sync the whole time as there is never any case that we might consider reading from it, but must not because there is no valid data. If we interrupt this reshape part-way through and reverse it to return to a 5-drive RAID6 (or event a 4-drive RAID5), we don't want to update the recovery_offset - as that would be wrong - and we don't want to include that spare as active in the 5-drive RAID6 when the reversed reshape completed and it will be mostly out-of-sync still. Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24md/raid5: avoid oops when number of devices is reduced then increased.NeilBrown
The entries in the stripe_cache maintained by raid5 are enlarged when we increased the number of devices in the array, but not shrunk when we reduce the number of devices. So if entries are added after reducing the number of devices, we much ensure to initialise the whole entry, not just the part that is currently relevant. Otherwise if we enlarge the array again, we will reference uninitialised values. As grow_buffers/shrink_buffer now want to use a count that is stored explicity in the raid_conf, they should get it from there rather than being passed it as a parameter. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-27md: convert cpu notifier to return encapsulate errno valueAkinobu Mita
By the previous modification, the cpu notifier can return encapsulate errno value. This converts the cpu notifiers for raid5. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-21Merge commit '3ff195b011d7decf501a4d55aeed312731094796' into for-linusNeilBrown
Conflicts: drivers/md/md.c - Resolved conflict in md_update_sb - Added extra 'NULL' arg to new instance of sysfs_get_dirent. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md/raid6: Fix raid-6 read-error correction in degraded stateGabriele A. Trombetti
Fix: Raid-6 was not trying to correct a read-error when in singly-degraded state and was instead dropping one more device, going to doubly-degraded state. This patch fixes this behaviour. Tested-by: Janos Haar <janos.haar@netcenter.hu> Signed-off-by: Gabriele A. Trombetti <g.trombetti.lkrnl1213@logicschema.com> Reported-by: Janos Haar <janos.haar@netcenter.hu> Signed-off-by: NeilBrown <neilb@suse.de> Cc: stable@kernel.org
2010-05-18md/raid5: improve consistency of error messages.NeilBrown
Many 'printk' messages from the raid456 module mention 'raid5' even though it may be a 'raid6' or even 'raid4' array. This can cause confusion. Also the actual array name is not always reported and when it is it is not reported consistently. So change all the messages to start: md/raid:%s: where '%s' becomes e.g. md3 to identify the particular array. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md/raid4: permit raid0 takeoverDan Williams
For consistency allow raid4 to takeover raid0 in addition to raid5 (with a raid4 layout). Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-05-18md: pass mddev to make_request functions rather than request_queueNeilBrown
We used to pass the personality make_request function direct to the block layer so the first argument had to be a queue. But now we have the intermediary md_make_request so it makes at lot more sense to pass a struct mddev_s. It makes it possible to have an mddev without its own queue too. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: remove ->changed and related code.NeilBrown
We set ->changed to 1 and call check_disk_change at the end of md_open so that bd_invalidated would be set and thus partition rescan would happen appropriately. Now that we call revalidate_disk directly, which sets bd_invalidates, that indirection is no longer needed and can be removed. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: move io accounting out of personalities into md_make_requestNeilBrown
While I generally prefer letting personalities do as much as possible, given that we have a central md_make_request anyway we may as well use it to simplify code. Also this centralises knowledge of ->gendisk which will help later. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md/raid5: small tidyup in raid5_align_endioNeilBrown
Diving through ->queue to find mddev is unnecessarily complex - there is an easier path to finding mddev, so use that. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: add support for raid5 to raid4 conversionNeilBrown
This is unlikely to be wanted, but we may as well provide it for completeness. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md:Add support for Raid0->Raid5 takeoverTrela Maciej
Signed-off-by: Maciej Trela <maciej.trela@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>