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* MD: ignore discard request for hard disks of hybid raid1/raid10 arrayShaohua Li2013-04-302-2/+12
| | | | | | | | | | | | In SSD/hard disk hybid storage, discard request should be ignored for hard disk. We used to be doing this way, but the unplug path forgets it. This is suitable for stable tree since v3.6. Cc: stable@vger.kernel.org Reported-and-tested-by: Markus <M4rkusXXL@web.de> Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
* md: bad block list should default to disabled.NeilBrown2013-04-301-6/+3Star
| | | | | | | | | | | | | | | | | | Maintenance of a bad-block-list currently defaults to 'enabled' and is then disabled when it cannot be supported. This is backwards and causes problem for dm-raid which didn't know to disable it. So fix the defaults, and only enabled for v1.x metadata which explicitly has bad blocks enabled. The problem with dm-raid has been present since badblock support was added in v3.1, so this patch is suitable for any -stable from 3.1 onwards. Cc: stable@vger.kernel.org (3.1+) Reported-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* md: raid1/raid10 md devices leak memory when stoppingHirokazu Takahashi2013-04-302-0/+2
| | | | | | | | | | | | | Hi. Raid1 and raid10 devices leak memory every time they stop. This is a patch for linux-3.9.0-rc7 to fix this problem. Thanks, Hirokazu Takahashi. Signed-off-by: Hirokazu Takahashi <taka@valinux.co.jp> Signed-off-by: NeilBrown <neilb@suse.de>
* DM RAID: Add message/status support for changing sync actionJonathan Brassow2013-04-241-2/+109
| | | | | | | | | | | | | | | | | DM RAID: Add message/status support for changing sync action This patch adds a message interface to dm-raid to allow the user to more finely control the sync actions being performed by the MD driver. This gives the user the ability to initiate "check" and "repair" (i.e. scrubbing). Two additional fields have been appended to the status output to provide more information about the type of sync action occurring and the results of those actions, specifically: <sync_action> and <mismatch_cnt>. These new fields will always be populated. This is essentially the device-mapper way of doing what MD controls through the 'sync_action' sysfs file and shows through the 'mismatch_cnt' sysfs file. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* MD: Export 'md_reap_sync_thread' functionJonathan Brassow2013-04-242-50/+50
| | | | | | | | | | | | MD: Export 'md_reap_sync_thread' function Make 'md_reap_sync_thread' available to other files, specifically dm-raid.c. - rename reap_sync_thread to md_reap_sync_thread - move the fn after md_check_recovery to match md.h declaration placement - export md_reap_sync_thread Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* md: don't update metadata when stopping a read-only array.NeilBrown2013-04-241-1/+2
| | | | | | | | read-only arrays should stay that way as much as possible. Updating the metadata - which could be triggered by a re-add while assembling the array metadata - should be avoided. Signed-off-by: NeilBrown <neilb@suse.de>
* md: Allow devices to be re-added to a read-only array.NeilBrown2013-04-241-26/+57
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When assembling an array incrementally we might want to make it device available when "enough" devices are present, but maybe not "all" devices are present. If the remaining devices appear before the array is actually used, they should be added transparently. We do this by using the "read-auto" mode where the array acts like it is read-only until a write request arrives. Current an add-device request switches a read-auto array to active. This means that only one device can be added after the array is first made read-auto. This isn't a problem for RAID5, but is not ideal for RAID6 or RAID10. Also we don't really want to switch the array to read-auto at all when re-adding a device as this doesn't really imply any change. So: - remove the "md_update_sb()" call from add_new_disk(). This isn't really needed as just adding a disk doesn't require a metadata update. Instead, just set MD_CHANGE_DEVS. This will effect a metadata update soon enough, once the array is not read-only. - Allow the ADD_NEW_DISK ioctl to succeed without activating a read-auto array, providing the MD_DISK_SYNC flag is set. In this case, the device will be rejected if it cannot be added with the correct device number, or has an incorrect event count. - Teach remove_and_add_spares() to be careful about adding spares when the array is read-only (or read-mostly) - only add devices that are thought to be in-sync, and only do it if the array is in-sync itself. - In md_check_recovery, use remove_and_add_spares in the read-only case, rather than open coding just the 'remove' part of it. Reported-by: Martin Wilck <mwilck@arcor.de> Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid10: Allow skipping recovery when clean arrays are assembledMartin Wilck2013-04-241-0/+16
| | | | | | | | | | | | When an array is assembled incrementally with mdadm -I -R and the array switches to "active" mode, md starts a recovery. If the array was clean, the "fullsync" flag will be 0. Skip the full recovery in this case, as RAID1 does (the code was actually copied from the sync_request() method of RAID1). Signed-off-by: Martin Wilck <mwilck@arcor.de> Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: avoid an extra write when writing to a known-bad-block.NeilBrown2013-04-241-1/+8
| | | | | | | | | | | | | | If we write to a known-bad-block it will be flags as having a ReadError by analyse_stripe, but the write will proceed anyway (as it should). Then the read-error handling will kick in an write again, then re-read. We don't need that 'write-again', so set R5_ReWrite so it looks like it has already been done. Then we will just get the re-read, which we want. Reported-by: majianpeng <majianpeng@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid5: Change or of some order to improve efficiency.majianpeng2013-04-241-3/+4
| | | | | | | | As the function call is the most expensive of these tests it should be done later in the chain so that it can be avoided in some cases. Signed-off-by: Jianpeng Ma <majianpeng@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
* md: use set_bit_le and clear_bit_leAkinobu Mita2013-04-241-2/+2
| | | | | | | | | | The value returned by test_and_set_bit_le() drivers/md/bitmap.c is not used. So just use set_bit_le(). The same goes for test_and_clear_bit_le(). Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Neil Brown <neilb@suse.de> Cc: linux-raid@vger.kernel.org Signed-off-by: NeilBrown <neilb@suse.de>
* md: HOT_DISK_REMOVE shouldn't make a read-auto device active.NeilBrown2013-04-241-4/+7
| | | | | | | | | | | | | | | | If a fail device or a spare is removed from an array, there is not need to make the array 'active'. If/when the array does become active for some other reason the metadata will be update to reflect the removal. If that never happens and the array is stopped while still read-auto, then there is no loss in forgetting the that the device had 'failed'. A read-only array will leave failed devices attached to the array personality, so we need to explicitly call remove_and_add_spares() to free it (clearing Blocked just like we do in store_slot()). Signed-off-by: NeilBrown <neilb@suse.de>
* md: use common code for all calls to ->hot_remove_disk()NeilBrown2013-04-241-9/+16
| | | | | | | | | | | | | | | | | | | | slot_store and remove_and_add_spares both call ->hot_remove_disk(), but with slightly different tests and consequences, which is at least untidy and might be buggy. So modify remove_and_add_spaces() so that it can be asked to remove a specific device, and call it from slot_store(). We also clear the Blocked flag to ensure that doesn't prevent removal. The purpose of Blocked is to prevent automatic removal by the kernel before an error is acknowledged. If the array is read/write then user-space would have not reason to remove a device unless it was known to be 'spare' or 'faulty' in which it would have already cleared the Blocked flag. If the array is read-only, the flag might still be blocked, but there is no harm in clearing the flag for read-only arrays. Signed-off-by: NeilBrown <neilb@suse.de>
* md: never update metadata when array is read-only.NeilBrown2013-04-241-0/+5
| | | | | | | | | | | | | | | | | | Normally we don't even try to update the metadata if the array is read-only. However future patches will increase the number of things that can happen on a read-only array, so it is safest to explicitly disable this. Every time that mddev->ro is set to 0, either - md_update_sb will be called again (at least if MD_CHANGE_DEVS is set) or - the mddev->thread is scheduled, which will also run md_update_sb if needed. So this is safe: if the array ever become read-write the metadata will be updated. Signed-off-by: NeilBrown <neilb@suse.de>
* Revert "block: add missing block_bio_complete() tracepoint"Linus Torvalds2013-04-182-1/+11
| | | | | | | | | | | | | | | | | | | | This reverts commit 3a366e614d0837d9fc23f78cdb1a1186ebc3387f. Wanlong Gao reports that it causes a kernel panic on his machine several minutes after boot. Reverting it removes the panic. Jens says: "It's not quite clear why that is yet, so I think we should just revert the commit for 3.9 final (which I'm assuming is pretty close). The wifi is crap at the LSF hotel, so sending this email instead of queueing up a revert and pull request." Reported-by: Wanlong Gao <gaowanlong@cn.fujitsu.com> Requested-by: Jens Axboe <axboe@kernel.dk> Cc: Tejun Heo <tj@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dm cache: reduce bio front_pad size in writeback modeMike Snitzer2013-04-051-13/+34
| | | | | | | | | | | | | | | | A recent patch to fix the dm cache target's writethrough mode extended the bio's front_pad to include a 1056-byte struct dm_bio_details. Writeback mode doesn't need this, so this patch reduces the per_bio_data_size to 16 bytes in this case instead of 1096. The dm_bio_details structure was added in "dm cache: fix writes to cache device in writethrough mode" which fixed commit e2e74d617e ("dm cache: fix race in writethrough implementation"). In writeback mode we avoid allocating the writethrough-specific members of the per_bio_data structure (the dm_bio_details structure included). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm cache: fix writes to cache device in writethrough modeDarrick J. Wong2013-04-051-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The dm-cache writethrough strategy introduced by commit e2e74d617eadc15 ("dm cache: fix race in writethrough implementation") issues a bio to the origin device, remaps and then issues the bio to the cache device. This more conservative in-series approach was selected to favor correctness over performance (of the previous parallel writethrough). However, this in-series implementation that reuses the same bio to write both the origin and cache device didn't take into account that the block layer's req_bio_endio() modifies a completing bio's bi_sector and bi_size. So the new writethrough strategy needs to preserve these bio fields, and restore them before submission to the cache device, otherwise nothing gets written to the cache (because bi_size is 0). This patch adds a struct dm_bio_details field to struct per_bio_data, and uses dm_bio_record() and dm_bio_restore() to ensure the bio is restored before reissuing to the cache device. Adding such a large structure to the per_bio_data is not ideal but we can improve this later, for now correctness is the important thing. This problem initially went unnoticed because the dm-cache test-suite uses a linear DM device for the dm-cache device's origin device. Writethrough worked as expected because DM submits a *clone* of the original bio, so the original bio which was reused for the cache was never touched. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* Merge tag 'md-3.9-fixes' of git://neil.brown.name/mdLinus Torvalds2013-03-234-45/+86
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull md fixes from NeilBrown: "A few bugfixes for md - recent regressions in raid5 - recent regressions in dmraid - a few instances of CONFIG_MULTICORE_RAID456 linger Several tagged for -stable" * tag 'md-3.9-fixes' of git://neil.brown.name/md: md: remove CONFIG_MULTICORE_RAID456 entirely md/raid5: ensure sync and DISCARD don't happen at the same time. MD: Prevent sysfs operations on uninitialized kobjects MD RAID5: Avoid accessing gendisk or queue structs when not available md/raid5: schedule_construction should abort if nothing to do.
| * md: remove CONFIG_MULTICORE_RAID456 entirelyPaul Bolle2013-03-201-4/+0Star
| | | | | | | | | | | | | | | | | | | | Once instance of this Kconfig macro remained after commit 51acbcec6c42b24482bac18e42befc822524535d ("md: remove CONFIG_MULTICORE_RAID456"). Remove that one too. And, while we're at it, also remove it from the defconfig files that carry it. Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: NeilBrown <neilb@suse.de>
| * md/raid5: ensure sync and DISCARD don't happen at the same time.NeilBrown2013-03-202-6/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A number of problems can occur due to races between resync/recovery and discard. - if sync_request calls handle_stripe() while a discard is happening on the stripe, it might call handle_stripe_clean_event before all of the individual discard requests have completed (so some devices are still locked, but not all). Since commit ca64cae96037de16e4af92678814f5d4bf0c1c65 md/raid5: Make sure we clear R5_Discard when discard is finished. this will cause R5_Discard to be cleared for the parity device, so handle_stripe_clean_event() will not be called when the other devices do become unlocked, so their ->written will not be cleared. This ultimately leads to a WARN_ON in init_stripe and a lock-up. - If handle_stripe_clean_event() does clear R5_UPTODATE at an awkward time for resync, it can lead to s->uptodate being less than disks in handle_parity_checks5(), which triggers a BUG (because it is one). So: - keep R5_Discard on the parity device until all other devices have completed their discard request - make sure we don't try to have a 'discard' and a 'sync' action at the same time. This involves a new stripe flag to we know when a 'discard' is happening, and the use of R5_Overlap on the parity disk so when a discard is wanted while a sync is active, so we know to wake up the discard at the appropriate time. Discard support for RAID5 was added in 3.7, so this is suitable for any -stable kernel since 3.7. Cc: stable@vger.kernel.org (v3.7+) Reported-by: Jes Sorensen <Jes.Sorensen@redhat.com> Tested-by: Jes Sorensen <Jes.Sorensen@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * MD: Prevent sysfs operations on uninitialized kobjectsJonathan Brassow2013-03-202-6/+4Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MD: Prevent sysfs operations on uninitialized kobjects Device-mapper does not use sysfs; but when device-mapper is leveraging MD's RAID personalities, MD sometimes attempts to update sysfs. This patch adds checks for 'mddev-kobj.sd' in sysfs_[un]link_rdev to ensure it is about to operate on something valid. This patch also checks for 'mddev->kobj.sd' before calling 'sysfs_notify' in 'remove_and_add_spares'. Although 'sysfs_notify' already makes this check, doing so in 'remove_and_add_spares' prevents an additional mutex operation. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * MD RAID5: Avoid accessing gendisk or queue structs when not availableJonathan Brassow2013-03-201-13/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MD RAID5: Fix kernel oops when RAID4/5/6 is used via device-mapper Commit a9add5d (v3.8-rc1) added blktrace calls to the RAID4/5/6 driver. However, when device-mapper is used to create RAID4/5/6 arrays, the mddev->gendisk and mddev->queue fields are not setup. Therefore, calling things like trace_block_bio_remap will cause a kernel oops. This patch conditionalizes those calls on whether the proper fields exist to make the calls. (Device-mapper will call trace_block_bio_remap on its own.) This patch is suitable for the 3.8.y stable kernel. Cc: stable@vger.kernel.org (v3.8+) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * md/raid5: schedule_construction should abort if nothing to do.NeilBrown2013-03-201-16/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 1ed850f356a0a422013846b5291acff08815008b md/raid5: make sure to_read and to_write never go negative. It has been possible for handle_stripe_dirtying to be called when there isn't actually any work to do. It then calls schedule_reconstruction() which will set R5_LOCKED on the parity block(s) even when nothing else is happening. This then causes problems in do_release_stripe(). So add checks to schedule_reconstruction() so that if it doesn't find anything to do, it just aborts. This bug was introduced in v3.7, so the patch is suitable for -stable kernels since then. Cc: stable@vger.kernel.org (v3.7+) Reported-by: majianpeng <majianpeng@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
* | dm cache: policy ignore hints if generated by different versionMike Snitzer2013-03-203-13/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When reading the dm cache metadata from disk, ignore the policy hints unless they were generated by the same major version number of the same policy module. The hints are considered to be private data belonging to the specific module that generated them and there is no requirement for them to make sense to different versions of the policy that generated them. Policy modules are all required to work fine if no previous hints are supplied (or if existing hints are lost). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* | dm cache: policy change version from string to integer setMike Snitzer2013-03-206-6/+36
| | | | | | | | | | | | | | | | | | | | Separate dm cache policy version string into 3 unsigned numbers corresponding to major, minor and patchlevel and store them at the end of the on-disk metadata so we know which version of the policy generated the hints in case a future version wants to use them differently. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* | dm cache: fix race in writethrough implementationJoe Thornber2013-03-201-50/+88
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have found a race in the optimisation used in the dm cache writethrough implementation. Currently, dm core sends the cache target two bios, one for the origin device and one for the cache device and these are processed in parallel. This patch avoids the race by changing the code back to a simpler (slower) implementation which processes the two writes in series, one after the other, until we can develop a complete fix for the problem. When the cache is in writethrough mode it needs to send WRITE bios to both the origin and cache devices. Previously we've been implementing this by having dm core query the cache target on every write to find out how many copies of the bio it wants. The cache will ask for two bios if the block is in the cache, and one otherwise. Then main problem with this is it's racey. At the time this check is made the bio hasn't yet been submitted and so isn't being taken into account when quiescing a block for migration (promotion or demotion). This means a single bio may be submitted when two were needed because the block has since been promoted to the cache (catastrophic), or two bios where only one is needed (harmless). I really don't want to start entering bios into the quiescing system (deferred_set) in the get_num_write_bios callback. Instead this patch simplifies things; only one bio is submitted by the core, this is first written to the origin and then the cache device in series. Obviously this will have a latency impact. deferred_writethrough_bios is introduced to record bios that must be later issued to the cache device from the worker thread. This deferred submission, after the origin bio completes, is required given that we're in interrupt context (writethrough_endio). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* | dm cache: metadata clear dirty bits on clean shutdownJoe Thornber2013-03-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | When writing the dirty bitset to the metadata device on a clean shutdown, clear the dirty bits. Previously they were left indicating the cache was dirty. This led to confusion about whether there really was dirty data in the cache or not. (This was a harmless bug.) Reported-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* | dm cache: avoid calling policy destructor twice on errorHeinz Mauelshagen2013-03-201-1/+4
| | | | | | | | | | | | | | | | | | | | If the cache policy's config values are not able to be set we must set the policy to NULL after destroying it in create_cache_policy() so we don't attempt to destroy it a second time later. Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* | dm cache: detect cache_create failureHeinz Mauelshagen2013-03-201-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | Return error if cache_create() fails. A missing return check made cache_ctr continue even after an error in cache_create() resulting in the cache object being destroyed. So a simple failure like an odd number of cache policy config value arguments would result in an oops. Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* | dm cache: avoid 64 bit division on 32 bitJoe Thornber2013-03-201-7/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | Squash various 32bit link errors. >> on i386: >> drivers/built-in.o: In function `is_discarded_oblock': >> dm-cache-target.c:(.text+0x1ea28e): undefined reference to `__udivdi3' ... Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* | dm verity: avoid deadlockMikulas Patocka2013-03-202-5/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A deadlock was found in the prefetch code in the dm verity map function. This patch fixes this by transferring the prefetch to a worker thread and skipping it completely if kmalloc fails. If generic_make_request is called recursively, it queues the I/O request on the current->bio_list without making the I/O request and returns. The routine making the recursive call cannot wait for the I/O to complete. The deadlock occurs when one thread grabs the bufio_client mutex and waits for an I/O to complete but the I/O is queued on another thread's current->bio_list and is waiting to get the mutex held by the first thread. The fix recognises that prefetching is not essential. If memory can be allocated, it queues the prefetch request to the worker thread, but if not, it does nothing. Signed-off-by: Paul Taysom <taysom@chromium.org> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: stable@kernel.org
* | dm thin: fix non power of two discard granularity calcJoe Thornber2013-03-201-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix a discard granularity calculation to work for non power of 2 block sizes. In order for thinp to passdown discard bios to the underlying data device, the data device must have a discard granularity that is a factor of the thinp block size. Originally this check was done by using bitops since the block_size was known to be a power of two. Introduced by commit f13945d75730081830b6f3360266950e2b7c9067 ("dm thin: support a non power of 2 discard_granularity"). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* | dm thin: fix discard corruptionJoe Thornber2013-03-202-24/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix a bug in dm_btree_remove that could leave leaf values with incorrect reference counts. The effect of this was that removal of a shared block could result in the space maps thinking the block was no longer used. More concretely, if you have a thin device and a snapshot of it, sending a discard to a shared region of the thin could corrupt the snapshot. Thinp uses a 2-level nested btree to store it's mappings. This first level is indexed by thin device, and the second level by logical block. Often when we're removing an entry in this mapping tree we need to rebalance nodes, which can involve shadowing them, possibly creating a copy if the block is shared. If we do create a copy then children of that node need to have their reference counts incremented. In this way reference counts percolate down the tree as shared trees diverge. The rebalance functions were incrementing the children at the appropriate time, but they were always assuming the children were internal nodes. This meant the leaf values (in our case packed block/flags entries) were not being incremented. Cc: stable@vger.kernel.org Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* | Merge tag 'md-3.9' of git://neil.brown.name/mdLinus Torvalds2013-03-068-95/+219
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull md updates from NeilBrown: "Mostly little bugfixes. Only "feature" is a new RAID10 layout which slightly improves the number of sets of devices that can concurrently fail, without data loss." * tag 'md-3.9' of git://neil.brown.name/md: md: expedite metadata update when switching read-auto -> active md: remove CONFIG_MULTICORE_RAID456 md/raid1,raid10: fix deadlock with freeze_array() md/raid0: improve error message when converting RAID4-with-spares to RAID0 md: raid0: fix error return from create_stripe_zones. md: fix two bugs when attempting to resize RAID0 array. DM RAID: Add support for MD's RAID10 "far" and "offset" algorithms MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 2) MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 1) MD RAID10: Minor non-functional code changes md: raid1,10: Handle REQ_WRITE_SAME flag in write bios md: protect against crash upon fsync on ro array
| * md: expedite metadata update when switching read-auto -> activeNeilBrown2013-02-281-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | If something has failed while the array was read-auto, then when we switch to 'active' we need to update the metadata. This will happen anyway but it is good to expedite it, and also to ensure any failed device has been released by the underlying device before we try to action the ioctl which caused us to switch to 'active' mode. Reported-by: Joe Lawrence <Joe.Lawrence@stratus.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * md: remove CONFIG_MULTICORE_RAID456NeilBrown2013-02-272-48/+1Star
| | | | | | | | | | | | | | | | | | | | | | | | This doesn't seem to actually help and we have an alternate multi-threading approach waiting in the wings, so just get rid of this config option and associated code. As a bonus, we remove one use of CONFIG_EXPERIMENTAL Cc: Dan Williams <djbw@fb.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: NeilBrown <neilb@suse.de>
| * md/raid1,raid10: fix deadlock with freeze_array()NeilBrown2013-02-262-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When raid1/raid10 needs to fix a read error, it first drains all pending requests by calling freeze_array(). This calls flush_pending_writes() if it needs to sleep, but some writes may be pending in a per-process plug rather than in the per-array request queue. When raid1{,0}_unplug() moves the request from the per-process plug to the per-array request queue (from which flush_pending_writes() can flush them), it needs to wake up freeze_array(), or freeze_array() will never flush them and so it will block forever. So add the requires wake_up() calls. This bug was introduced by commit f54a9d0e59c4bea3db733921ca9147612a6f292c for raid1 and a similar commit for RAID10, and so has been present since linux-3.6. As the bug causes a deadlock I believe this fix is suitable for -stable. Cc: stable@vger.kernel.org (3.6.y 3.7.y 3.8.y) Reported-by: Tregaron Bayly <tbayly@bluehost.com> Tested-by: Tregaron Bayly <tbayly@bluehost.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * md/raid0: improve error message when converting RAID4-with-spares to RAID0NeilBrown2013-02-261-1/+7
| | | | | | | | | | | | | | Mentioning "bad disk number -1" exposes irrelevant internal detail. Just say they are inactive and must be removed. Signed-off-by: NeilBrown <neilb@suse.de>
| * md: raid0: fix error return from create_stripe_zones.NeilBrown2013-02-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Create_stripe_zones returns an error slightly differently to raid0_run and to raid0_takeover_*. The error returned used by the second was wrong and an error would result in mddev->private being set to NULL and sooner or later a crash. So never return NULL, return ERR_PTR(err), not NULL from create_stripe_zones. This bug has been present since 2.6.35 so the fix is suitable for any kernel since then. Cc: stable@vger.kernel.org Signed-off-by: NeilBrown <neilb@suse.de>
| * md: fix two bugs when attempting to resize RAID0 array.NeilBrown2013-02-262-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | You cannot resize a RAID0 array (in terms of making the devices bigger), but the code doesn't entirely stop you. So: disable setting of the available size on each device for RAID0 and Linear devices. This must not change as doing so can change the effective layout of data. Make sure that the size that raid0_size() reports is accurate, but rounding devices sizes to chunk sizes. As the device sizes cannot change now, this isn't so important, but it is best to be safe. Without this change: mdadm --grow /dev/md0 -z max mdadm --grow /dev/md0 -Z max then read to the end of the array can cause a BUG in a RAID0 array. These bugs have been present ever since it became possible to resize any device, which is a long time. So the fix is suitable for any -stable kerenl. Cc: stable@vger.kernel.org Signed-off-by: NeilBrown <neilb@suse.de>
| * DM RAID: Add support for MD's RAID10 "far" and "offset" algorithmsJonathan Brassow2013-02-261-20/+103
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | DM RAID: Add support for MD's RAID10 "far" and "offset" algorithms Until now, dm-raid.c only supported the "near" algorthm of MD's RAID10 implementation. This patch adds support for the "far" and "offset" algorithms, but only with the improved redundancy that is brought with the introduction of the 'use_far_sets' bit, which shifts copied stripes according to smaller sets vs the entire array. That is, the 17th bit of the 'layout' variable that defines the RAID10 implementation will always be set. (More information on how the 'layout' variable selects the RAID10 algorithm can be found in the opening comments of drivers/md/raid10.c.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 2)Jonathan Brassow2013-02-261-2/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 2) This patch addresses raid arrays that have a number of devices that cannot be evenly divided by 'far_copies'. (E.g. 5 devices, far_copies = 2) This case must be handled differently because it causes that last set to be of a different size than the rest of the sets. We must compute a new modulo for this last set so that copied chunks are properly wrapped around. Example use_far_sets=1, far_copies=2, near_copies=1, devices=5: "far" algorithm dev1 dev2 dev3 dev4 dev5 ==== ==== ==== ==== ==== [ A B ] [ C D E ] [ G H ] [ I J K ] ... [ B A ] [ E C D ] --> nominal set of 2 and last set of 3 [ H G ] [ K I J ] []'s show far/offset sets Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 1)Jonathan Brassow2013-02-262-18/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The MD RAID10 'far' and 'offset' algorithms make copies of entire stripe widths - copying them to a different location on the same devices after shifting the stripe. An example layout of each follows below: "far" algorithm dev1 dev2 dev3 dev4 dev5 dev6 ==== ==== ==== ==== ==== ==== A B C D E F G H I J K L ... F A B C D E --> Copy of stripe0, but shifted by 1 L G H I J K ... "offset" algorithm dev1 dev2 dev3 dev4 dev5 dev6 ==== ==== ==== ==== ==== ==== A B C D E F F A B C D E --> Copy of stripe0, but shifted by 1 G H I J K L L G H I J K ... Redundancy for these algorithms is gained by shifting the copied stripes one device to the right. This patch proposes that array be divided into sets of adjacent devices and when the stripe copies are shifted, they wrap on set boundaries rather than the array size boundary. That is, for the purposes of shifting, the copies are confined to their sets within the array. The sets are 'near_copies * far_copies' in size. The above "far" algorithm example would change to: "far" algorithm dev1 dev2 dev3 dev4 dev5 dev6 ==== ==== ==== ==== ==== ==== A B C D E F G H I J K L ... B A D C F E --> Copy of stripe0, shifted 1, 2-dev sets H G J I L K Dev sets are 1-2, 3-4, 5-6 ... This has the affect of improving the redundancy of the array. We can always sustain at least one failure, but sometimes more than one can be handled. In the first examples, the pairs of devices that CANNOT fail together are: (1,2) (2,3) (3,4) (4,5) (5,6) (1, 6) [40% of possible pairs] In the example where the copies are confined to sets, the pairs of devices that cannot fail together are: (1,2) (3,4) (5,6) [20% of possible pairs] We cannot simply replace the old algorithms, so the 17th bit of the 'layout' variable is used to indicate whether we use the old or new method of computing the shift. (This is similar to the way the 16th bit indicates whether the "far" algorithm or the "offset" algorithm is being used.) This patch only handles the cases where the number of total raid disks is a multiple of 'far_copies'. A follow-on patch addresses the condition where this is not true. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * MD RAID10: Minor non-functional code changesJonathan Brassow2013-02-261-3/+2Star
| | | | | | | | | | | | | | | | | | Changes include assigning 'addr' from 's' instead of 'sector' to be consistent with the way the code does it just a few lines later and using '%=' vs a conditional and subtraction. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * md: raid1,10: Handle REQ_WRITE_SAME flag in write biosJoe Lawrence2013-02-262-3/+13
| | | | | | | | | | | | | | | | | | | | | | | | Set mddev queue's max_write_same_sectors to its chunk_sector value (before disk_stack_limits merges the underlying disk limits.) With that in place, be sure to handle writes coming down from the block layer that have the REQ_WRITE_SAME flag set. That flag needs to be copied into any newly cloned write bio. Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com> Acked-by: "Martin K. Petersen" <martin.petersen@oracle.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * md: protect against crash upon fsync on ro arraySebastian Riemer2013-02-211-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If an fsync occurs on a read-only array, we need to send a completion for the IO and may not increment the active IO count. Otherwise, we hit a bug trace and can't stop the MD array anymore. By advice of Christoph Hellwig we return success upon a flush request but we return -EROFS for other writes. We detect flush requests by checking if the bio has zero sectors. This patch is suitable to any -stable kernel to which it applies. Cc: Christoph Hellwig <hch@infradead.org> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: NeilBrown <neilb@suse.de> Cc: stable@vger.kernel.org Signed-off-by: Sebastian Riemer <sebastian.riemer@profitbricks.com> Reported-by: Ben Hutchings <ben@decadent.org.uk> Acked-by: Paul Menzel <paulepanter@users.sourceforge.net> Signed-off-by: NeilBrown <neilb@suse.de>
* | dm cache: add cleaner policyHeinz Mauelshagen2013-03-013-0/+474
| | | | | | | | | | | | | | | | | | | | A simple cache policy that writes back all data to the origin. This is used to decommission a dm cache by emptying it. Signed-off-by: Heinz Mauelshagen <mauelshagen@redhat.com> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* | dm cache: add mq policyJoe Thornber2013-03-013-0/+1207
| | | | | | | | | | | | | | | | | | | | A cache policy that uses a multiqueue ordered by recent hit count to select which blocks should be promoted and demoted. This is meant to be a general purpose policy. It prioritises reads over writes. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* | dm: add cache targetJoe Thornber2013-03-0112-0/+4475
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a target that allows a fast device such as an SSD to be used as a cache for a slower device such as a disk. A plug-in architecture was chosen so that the decisions about which data to migrate and when are delegated to interchangeable tunable policy modules. The first general purpose module we have developed, called "mq" (multiqueue), follows in the next patch. Other modules are under development. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Heinz Mauelshagen <mauelshagen@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* | dm persistent data: add bitsetJoe Thornber2013-03-013-0/+329
| | | | | | | | | | | | | | Add a persistent bitset as a wrapper around dm-array. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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