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* md/raid10: fix bug when raid10 recovery fails to recover a block.NeilBrown2014-01-141-4/+4
| | | | | | | | | | | | | | | | | | | commit e875ecea266a543e643b19e44cf472f1412708f9 md/raid10 record bad blocks as needed during recovery. added code to the "cannot recover this block" path to record a bad block rather than fail the whole recovery. Unfortunately this new case was placed *after* r10bio was freed rather than *before*, yet it still uses r10bio. This is will crash with a null dereference. So move the freeing of r10bio down where it is safe. Cc: stable@vger.kernel.org (v3.1+) Fixes: e875ecea266a543e643b19e44cf472f1412708f9 Reported-by: Damian Nowak <spam@nowaker.net> URL: https://bugzilla.kernel.org/show_bug.cgi?id=68181 Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid10: fix two bugs in handling of known-bad-blocks.NeilBrown2014-01-141-2/+2
| | | | | | | | | | | | | | | | | | | If we discover a bad block when reading we split the request and potentially read some of it from a different device. The code path of this has two bugs in RAID10. 1/ we get a spin_lock with _irq, but unlock without _irq!! 2/ The calculation of 'sectors_handled' is wrong, as can be clearly seen by comparison with raid1.c This leads to at least 2 warnings and a probable crash is a RAID10 ever had known bad blocks. Cc: stable@vger.kernel.org (v3.1+) Fixes: 856e08e23762dfb92ffc68fd0a8d228f9e152160 Reported-by: Damian Nowak <spam@nowaker.net> URL: https://bugzilla.kernel.org/show_bug.cgi?id=68181 Signed-off-by: NeilBrown <neilb@suse.de>
* Merge tag 'md/3.13' of git://neil.brown.name/mdLinus Torvalds2013-11-201-1/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull md update from Neil Brown: "Mostly optimisations and obscure bug fixes. - raid5 gets less lock contention - raid1 gets less contention between normal-io and resync-io during resync" * tag 'md/3.13' of git://neil.brown.name/md: md/raid5: Use conf->device_lock protect changing of multi-thread resources. md/raid5: Before freeing old multi-thread worker, it should flush them. md/raid5: For stripe with R5_ReadNoMerge, we replace REQ_FLUSH with REQ_NOMERGE. UAPI: include <asm/byteorder.h> in linux/raid/md_p.h raid1: Rewrite the implementation of iobarrier. raid1: Add some macros to make code clearly. raid1: Replace raise_barrier/lower_barrier with freeze_array/unfreeze_array when reconfiguring the array. raid1: Add a field array_frozen to indicate whether raid in freeze state. md: Convert use of typedef ctl_table to struct ctl_table md/raid5: avoid deadlock when raid5 array has unack badblocks during md_stop_writes. md: use MD_RECOVERY_INTR instead of kthread_should_stop in resync thread. md: fix some places where mddev_lock return value is not checked. raid5: Retry R5_ReadNoMerge flag when hit a read error. raid5: relieve lock contention in get_active_stripe() raid5: relieve lock contention in get_active_stripe() wait: add wait_event_cmd() md/raid5.c: add proper locking to error path of raid5_start_reshape. md: fix calculation of stacking limits on level change. raid5: Use slow_path to release stripe when mddev->thread is null
| * md: use MD_RECOVERY_INTR instead of kthread_should_stop in resync thread.NeilBrown2013-11-191-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We currently use kthread_should_stop() in various places in the sync/reshape code to abort early. However some places set MD_RECOVERY_INTR but don't immediately call md_reap_sync_thread() (and we will shortly get another one). When this happens we are relying on md_check_recovery() to reap the thread and that only happen when it finishes normally. So MD_RECOVERY_INTR must lead to a normal finish without the kthread_should_stop() test. So replace all relevant tests, and be more careful when the thread is interrupted not to acknowledge that latest step in a reshape as it may not be fully committed yet. Also add a test on MD_RECOVERY_INTR in the 'is_mddev_idle' loop so we don't wait have to wait for the speed to drop before we can abort. Signed-off-by: NeilBrown <neilb@suse.de>
* | block: Consolidate duplicated bio_trim() implementationsKent Overstreet2013-11-081-10/+8
|/ | | | | | | | | | | | Someone cut and pasted md's md_trim_bio() into xen-blkfront.c. Come on, we should know better than this. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Neil Brown <neilb@suse.de> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* md: Fix skipping recovery for read-only arrays.Lukasz Dorau2013-10-241-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | Since: commit 7ceb17e87bde79d285a8b988cfed9eaeebe60b86 md: Allow devices to be re-added to a read-only array. spares are activated on a read-only array. In case of raid1 and raid10 personalities it causes that not-in-sync devices are marked in-sync without checking if recovery has been finished. If a read-only array is degraded and one of its devices is not in-sync (because the array has been only partially recovered) recovery will be skipped. This patch adds checking if recovery has been finished before marking a device in-sync for raid1 and raid10 personalities. In case of raid5 personality such condition is already present (at raid5.c:6029). Bug was introduced in 3.10 and causes data corruption. Cc: stable@vger.kernel.org Signed-off-by: Pawel Baldysiak <pawel.baldysiak@intel.com> Signed-off-by: Lukasz Dorau <lukasz.dorau@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid10: remove use-after-free bug.NeilBrown2013-07-251-1/+7
| | | | | | | | | | | | | | | | We always need to be careful when calling generic_make_request, as it can start a chain of events which might free something that we are using. Here is one place I wasn't careful enough. If the wbio2 is not in use, then it might get freed at the first generic_make_request call. So perform all necessary tests first. This bug was introduced in 3.3-rc3 (24afd80d99) and can cause an oops, so fix is suitable for any -stable since then. Cc: stable@vger.kernel.org (3.3+) Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid10: fix two problems with RAID10 resync.NeilBrown2013-07-181-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | 1/ When an different between blocks is found, data is copied from one bio to the other. However bv_len is used as the length to copy and this could be zero. So use r10_bio->sectors to calculate length instead. Using bv_len was probably always a bit dubious, but the introduction of bio_advance made it much more likely to be a problem. 2/ When preparing some blocks for sync, we don't set BIO_UPTODATE except on bios that we schedule for a read. This ensures that missing/failed devices don't confuse the loop at the top of sync_request write. Commit 8be185f2c9d54d6 "raid10: Use bio_reset()" removed a loop which set BIO_UPTDATE on all appropriate bios. So we need to re-add that flag. These bugs were introduced in 3.10, so this patch is suitable for 3.10-stable, and can remove a potential for data corruption. Cc: stable@vger.kernel.org (3.10) Reported-by: Brassow Jonathan <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid10: fix bug which causes all RAID10 reshapes to move no data.NeilBrown2013-07-041-5/+4
| | | | | | | | | | | | | | | | | | | | The recent comment: commit 7e83ccbecd608b971f340e951c9e84cd0343002f md/raid10: Allow skipping recovery when clean arrays are assembled Causes raid10 to skip a recovery in certain cases where it is safe to do so. Unfortunately it also causes a reshape to be skipped which is never safe. The result is that an attempt to reshape a RAID10 will appear to complete instantly, but no data will have been moves so the array will now contain garbage. (If nothing is written, you can recovery by simple performing the reverse reshape which will also complete instantly). Bug was introduced in 3.10, so this is suitable for 3.10-stable. Cc: stable@vger.kernel.org (3.10) Cc: Martin Wilck <mwilck@arcor.de> Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid10: fix two bugs affecting RAID10 reshape.NeilBrown2013-07-031-2/+2
| | | | | | | | | | | | | | | | 1/ If a RAID10 is being reshaped to a fewer number of devices and is stopped while this is ongoing, then when the array is reassembled the 'mirrors' array will be allocated too small. This will lead to an access error or memory corruption. 2/ A sanity test for a reshaping RAID10 array is restarted is slightly incorrect. Due to the first bug, this is suitable for any -stable kernel since 3.5 where this code was introduced. Cc: stable@vger.kernel.org (v3.5+) Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid10: check In_sync flag in 'enough()'.NeilBrown2013-06-141-4/+11
| | | | | | | | | | | It isn't really enough to check that the rdev is present, we need to also be sure that the device is still In_sync. Doing this requires using rcu_dereference to access the rdev, and holding the rcu_read_lock() to ensure the rdev doesn't disappear while we look at it. Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid10: locking changes for 'enough()'.NeilBrown2013-06-141-16/+29
| | | | | | | | | | | | | | | | | | | | | As 'enough' accesses conf->prev and conf->geo, which can change spontanously, it should guard against changes. This can be done with device_lock as start_reshape holds device_lock while updating 'geo' and end_reshape holds it while updating 'prev'. So 'error' needs to hold 'device_lock'. On the other hand, raid10_end_read_request knows which of the two it really wants to access, and as it is an active request on that one, the value cannot change underneath it. So change _enough to take flag rather than a pointer, pass the appropriate flag from raid10_end_read_request(), and remove the locking. All other calls to 'enough' are made with reconfig_mutex held, so neither 'prev' nor 'geo' can change. Signed-off-by: NeilBrown <neilb@suse.de>
* DM RAID: Add ability to restore transiently failed devices on resumeJonathan Brassow2013-06-141-4/+6
| | | | | | | | | | | | | | | DM RAID: Add ability to restore transiently failed devices on resume This patch adds code to the resume function to check over the devices in the RAID array. If any are found to be marked as failed and their superblocks can be read, an attempt is made to reintegrate them into the array. This allows the user to refresh the array with a simple suspend and resume of the array - rather than having to load a completely new table, allocate and initialize all the structures and throw away the old instantiation. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* Merge tag 'md-3.10-fixes' of git://neil.brown.name/mdLinus Torvalds2013-06-131-10/+19
|\ | | | | | | | | | | | | | | | | | | | | | | | | Pull md bugfixes from Neil Brown: "A few bugfixes for md Some tagged for -stable" * tag 'md-3.10-fixes' of git://neil.brown.name/md: md/raid1,5,10: Disable WRITE SAME until a recovery strategy is in place md/raid1,raid10: use freeze_array in place of raise_barrier in various places. md/raid1: consider WRITE as successful only if at least one non-Faulty and non-rebuilding drive completed it. md: md_stop_writes() should always freeze recovery.
| * md/raid1,5,10: Disable WRITE SAME until a recovery strategy is in placeH. Peter Anvin2013-06-131-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are cases where the kernel will believe that the WRITE SAME command is supported by a block device which does not, in fact, support WRITE SAME. This currently happens for SATA drivers behind a SAS controller, but there are probably a hundred other ways that can happen, including drive firmware bugs. After receiving an error for WRITE SAME the block layer will retry the request as a plain write of zeroes, but mdraid will consider the failure as fatal and consider the drive failed. This has the effect that all the mirrors containing a specific set of data are each offlined in very rapid succession resulting in data loss. However, just bouncing the request back up to the block layer isn't ideal either, because the whole initial request-retry sequence should be inside the write bitmap fence, which probably means that md needs to do its own conversion of WRITE SAME to write zero. Until the failure scenario has been sorted out, disable WRITE SAME for raid1, raid5, and raid10. [neilb: added raid5] This patch is appropriate for any -stable since 3.7 when write_same support was added. Cc: stable@vger.kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * md/raid1,raid10: use freeze_array in place of raise_barrier in various places.NeilBrown2013-06-131-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Various places in raid1 and raid10 are calling raise_barrier when they really should call freeze_array. The former is only intended to be called from "make_request". The later has extra checks for 'nr_queued' and makes a call to flush_pending_writes(), so it is safe to call it from within the management thread. Using raise_barrier will sometimes deadlock. Using freeze_array should not. As 'freeze_array' currently expects one request to be pending (in handle_read_error - the only previous caller), we need to pass it the number of pending requests (extra) to ignore. The deadlock was made particularly noticeable by commits 050b66152f87c7 (raid10) and 6b740b8d79252f13 (raid1) which appeared in 3.4, so the fix is appropriate for any -stable kernel since then. This patch probably won't apply directly to some early kernels and will need to be applied by hand. Cc: stable@vger.kernel.org Reported-by: Alexander Lyakas <alex.bolshoy@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * md/raid1: consider WRITE as successful only if at least one non-Faulty and ↵Alex Lyakas2013-06-131-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | non-rebuilding drive completed it. Without that fix, the following scenario could happen: - RAID1 with drives A and B; drive B was freshly-added and is rebuilding - Drive A fails - WRITE request arrives to the array. It is failed by drive A, so r1_bio is marked as R1BIO_WriteError, but the rebuilding drive B succeeds in writing it, so the same r1_bio is marked as R1BIO_Uptodate. - r1_bio arrives to handle_write_finished, badblocks are disabled, md_error()->error() does nothing because we don't fail the last drive of raid1 - raid_end_bio_io() calls call_bio_endio() - As a result, in call_bio_endio(): if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) clear_bit(BIO_UPTODATE, &bio->bi_flags); this code doesn't clear the BIO_UPTODATE flag, and the whole master WRITE succeeds, back to the upper layer. So we returned success to the upper layer, even though we had written the data onto the rebuilding drive only. But when we want to read the data back, we would not read from the rebuilding drive, so this data is lost. [neilb - applied identical change to raid10 as well] This bug can result in lost data, so it is suitable for any -stable kernel. Cc: stable@vger.kernel.org Signed-off-by: Alex Lyakas <alex@zadarastorage.com> Signed-off-by: NeilBrown <neilb@suse.de>
* | Merge branch 'for-3.10/core' of git://git.kernel.dk/linux-blockLinus Torvalds2013-05-081-57/+21
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block core updates from Jens Axboe: - Major bit is Kents prep work for immutable bio vecs. - Stable candidate fix for a scheduling-while-atomic in the queue bypass operation. - Fix for the hang on exceeded rq->datalen 32-bit unsigned when merging discard bios. - Tejuns changes to convert the writeback thread pool to the generic workqueue mechanism. - Runtime PM framework, SCSI patches exists on top of these in James' tree. - A few random fixes. * 'for-3.10/core' of git://git.kernel.dk/linux-block: (40 commits) relay: move remove_buf_file inside relay_close_buf partitions/efi.c: replace useless kzalloc's by kmalloc's fs/block_dev.c: fix iov_shorten() criteria in blkdev_aio_read() block: fix max discard sectors limit blkcg: fix "scheduling while atomic" in blk_queue_bypass_start Documentation: cfq-iosched: update documentation help for cfq tunables writeback: expose the bdi_wq workqueue writeback: replace custom worker pool implementation with unbound workqueue writeback: remove unused bdi_pending_list aoe: Fix unitialized var usage bio-integrity: Add explicit field for owner of bip_buf block: Add an explicit bio flag for bios that own their bvec block: Add bio_alloc_pages() block: Convert some code to bio_for_each_segment_all() block: Add bio_for_each_segment_all() bounce: Refactor __blk_queue_bounce to not use bi_io_vec raid1: use bio_copy_data() pktcdvd: Use bio_reset() in disabled code to kill bi_idx usage pktcdvd: use bio_copy_data() block: Add bio_copy_data() ...
| * raid10: Use bio_reset()Kent Overstreet2013-03-231-22/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | More prep work for immutable bio vecs, mainly getting rid of references to bi_idx. bio_reset was being open coded in a few places. The one in sync_request was a bit nontrivial to convert, so could use some extra eyeballs. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: NeilBrown <neilb@suse.de> Acked-by: NeilBrown <neilb@suse.de>
| * block: Add submit_bio_wait(), remove from mdKent Overstreet2013-03-231-19/+0
| | | | | | | | | | | | | | | | | | | | | | | | Random cleanup - this code was duplicated and it's not really specific to md. Also added the ability to return the actual error code. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: NeilBrown <neilb@suse.de> Acked-by: Tejun Heo <tj@kernel.org>
| * block: Remove bi_idx referencesKent Overstreet2013-03-231-1/+0
| | | | | | | | | | | | | | | | | | | | | | For immutable bvecs, all bi_idx usage needs to be audited - so here we're removing all the unnecessary uses. Most of these are places where it was being initialized on a bio that was just allocated, a few others are conversions to standard macros. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk>
| * block: Change bio_split() to respect the current value of bi_idxKent Overstreet2013-03-231-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the current code bio_split() won't be seeing partially completed bios so this doesn't change any behaviour, but this makes the code a bit clearer as to what bio_split() actually requires. The immediate purpose of the patch is removing unnecessary bi_idx references, but the end goal is to allow partial completed bios to be submitted, which along with immutable biovecs enables effecient bio splitting. Some of the callers were (double) checking that bios could be split, so update their checks too. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: Lars Ellenberg <drbd-dev@lists.linbit.com> CC: Neil Brown <neilb@suse.de> CC: Martin K. Petersen <martin.petersen@oracle.com>
| * block: Use bio_sectors() more consistentlyKent Overstreet2013-03-231-13/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Bunch of places in the code weren't using it where they could be - this'll reduce the size of the patch that puts bi_sector/bi_size/bi_idx into a struct bvec_iter. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: "Ed L. Cashin" <ecashin@coraid.com> CC: Nick Piggin <npiggin@kernel.dk> CC: Jiri Kosina <jkosina@suse.cz> CC: Jim Paris <jim@jtan.com> CC: Geoff Levand <geoff@infradead.org> CC: Alasdair Kergon <agk@redhat.com> CC: dm-devel@redhat.com CC: Neil Brown <neilb@suse.de> CC: Steven Rostedt <rostedt@goodmis.org> Acked-by: Ed Cashin <ecashin@coraid.com>
* | MD: ignore discard request for hard disks of hybid raid1/raid10 arrayShaohua Li2013-04-301-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | 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: raid1/raid10 md devices leak memory when stoppingHirokazu Takahashi2013-04-301-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | 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/raid1,raid10: fix deadlock with freeze_array()NeilBrown2013-02-261-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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 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 Brassow2013-02-261-18/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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/+2
| | | | | | | | | 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 Lawrence2013-02-261-2/+7
| | | | | | | | | | | | 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>
* Merge branch 'for-3.8/drivers' of git://git.kernel.dk/linux-blockLinus Torvalds2012-12-171-8/+7
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block driver update from Jens Axboe: "Now that the core bits are in, here are the driver bits for 3.8. The branch contains: - A huge pile of drbd bits that were dumped from the 3.7 merge window. Following that, it was both made perfectly clear that there is going to be no more over-the-wall pulls and how the situation on individual pulls can be improved. - A few cleanups from Akinobu Mita for drbd and cciss. - Queue improvement for loop from Lukas. This grew into adding a generic interface for waiting/checking an even with a specific lock, allowing this to be pulled out of md and now loop and drbd is also using it. - A few fixes for xen back/front block driver from Roger Pau Monne. - Partition improvements from Stephen Warren, allowing partiion UUID to be used as an identifier." * 'for-3.8/drivers' of git://git.kernel.dk/linux-block: (609 commits) drbd: update Kconfig to match current dependencies drbd: Fix drbdsetup wait-connect, wait-sync etc... commands drbd: close race between drbd_set_role and drbd_connect drbd: respect no-md-barriers setting also when changed online via disk-options drbd: Remove obsolete check drbd: fixup after wait_even_lock_irq() addition to generic code loop: Limit the number of requests in the bio list wait: add wait_event_lock_irq() interface xen-blkfront: free allocated page xen-blkback: move free persistent grants code block: partition: msdos: provide UUIDs for partitions init: reduce PARTUUID min length to 1 from 36 block: store partition_meta_info.uuid as a string cciss: use check_signature() cciss: cleanup bitops usage drbd: use copy_highpage drbd: if the replication link breaks during handshake, keep retrying drbd: check return of kmalloc in receive_uuids drbd: Broadcast sync progress no more often than once per second drbd: don't try to clear bits once the disk has failed ...
| * wait: add wait_event_lock_irq() interfaceLukas Czerner2012-11-301-8/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | New wait_event{_interruptible}_lock_irq{_cmd} macros added. This commit moves the private wait_event_lock_irq() macro from MD to regular wait includes, introduces new macro wait_event_lock_irq_cmd() instead of using the old method with omitting cmd parameter which is ugly and makes a use of new macros in the MD. It also introduces the _interruptible_ variant. The use of new interface is when one have a special lock to protect data structures used in the condition, or one also needs to invoke "cmd" before putting it to sleep. All new macros are expected to be called with the lock taken. The lock is released before sleep and is reacquired afterwards. We will leave the macro with the lock held. Note to DM: IMO this should also fix theoretical race on waitqueue while using simultaneously wait_event_lock_irq() and wait_event() because of lack of locking around current state setting and wait queue removal. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Cc: Neil Brown <neilb@suse.de> Cc: David Howells <dhowells@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | md/raid1{,0}: fix deadlock in bitmap_unplug.NeilBrown2012-11-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the raid1 or raid10 unplug function gets called from a make_request function (which is very possible) when there are bios on the current->bio_list list, then it will not be able to successfully call bitmap_unplug() and it could need to submit more bios and wait for them to complete. But they won't complete while current->bio_list is non-empty. So detect that case and handle the unplugging off to another thread just like we already do when called from within the scheduler. RAID1 version of bug was introduced in 3.6, so that part of fix is suitable for 3.6.y. RAID10 part won't apply. Cc: stable@vger.kernel.org Reported-by: Torsten Kaiser <just.for.lkml@googlemail.com> Reported-by: Peter Maloney <peter.maloney@brockmann-consult.de> Signed-off-by: NeilBrown <neilb@suse.de>
* | md/raid10: decrement correct pending counter when writing to replacement.NeilBrown2012-11-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a write to a replacement device completes, we carefully and correctly found the rdev that the write actually went to and the blithely called rdev_dec_pending on the primary rdev, even if this write was to the replacement. This means that any writes to an array while a replacement was ongoing would cause the nr_pending count for the primary device to go negative, so it could never be removed. This bug has been present since replacement was introduced in 3.3, so it is suitable for any -stable kernel since then. Reported-by: "George Spelvin" <linux@horizon.com> Cc: stable@vger.kernel.org Signed-off-by: NeilBrown <neilb@suse.de>
* | md/raid10: close race that lose writes lost when replacement completes.NeilBrown2012-11-221-61/+68
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a replacement operation completes there is a small window when the original device is marked 'faulty' and the replacement still looks like a replacement. The faulty should be removed and the replacement moved in place very quickly, bit it isn't instant. So the code write out to the array must handle the possibility that the only working device for some slot in the replacement - but it doesn't. If the primary device is faulty it just gives up. This can lead to corruption. So make the code more robust: if either the primary or the replacement is present and working, write to them. Only when neither are present do we give up. This bug has been present since replacement was introduced in 3.3, so it is suitable for any -stable kernel since then. Reported-by: "George Spelvin" <linux@horizon.com> Cc: stable@vger.kernel.org Signed-off-by: NeilBrown <neilb@suse.de>
* | MD RAID10: Fix oops when creating RAID10 arrays via dm-raid.cJonathan Brassow2012-10-311-6/+9
|/ | | | | | | | | | | | Commit 2863b9eb didn't take into account the changes to add TRIM support to RAID10 (commit 532a2a3fb). That is, when using dm-raid.c to create the RAID10 arrays, there is no mddev->gendisk or mddev->queue. The code added to support TRIM simply assumes that mddev->queue is available without checking. The result is an oops any time dm-raid.c attempts to create a RAID10 device. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* Merge tag 'md-3.7' of git://neil.brown.name/mdLinus Torvalds2012-10-131-11/+84
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull md updates from NeilBrown: - "discard" support, some dm-raid improvements and other assorted bits and pieces. * tag 'md-3.7' of git://neil.brown.name/md: (29 commits) md: refine reporting of resync/reshape delays. md/raid5: be careful not to resize_stripes too big. md: make sure manual changes to recovery checkpoint are saved. md/raid10: use correct limit variable md: writing to sync_action should clear the read-auto state. Subject: [PATCH] md:change resync_mismatches to atomic64_t to avoid races md/raid5: make sure to_read and to_write never go negative. md: When RAID5 is dirty, force reconstruct-write instead of read-modify-write. md/raid5: protect debug message against NULL derefernce. md/raid5: add some missing locking in handle_failed_stripe. MD: raid5 avoid unnecessary zero page for trim MD: raid5 trim support md/bitmap:Don't use IS_ERR to judge alloc_page(). md/raid1: Don't release reference to device while handling read error. raid: replace list_for_each_continue_rcu with new interface add further __init annotations to crypto/xor.c DM RAID: Fix for "sync" directive ineffectiveness DM RAID: Fix comparison of index and quantity for "rebuild" parameter DM RAID: Add rebuild capability for RAID10 DM RAID: Move 'rebuild' checking code to its own function ...
| * md/raid10: use correct limit variableDan Carpenter2012-10-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Clang complains that we are assigning a variable to itself. This should be using bad_sectors like the similar earlier check does. Bug has been present since 3.1-rc1. It is minor but could conceivably cause corruption or other bad behaviour. Cc: stable@vger.kernel.org Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * Subject: [PATCH] md:change resync_mismatches to atomic64_t to avoid racesJianpeng Ma2012-10-111-1/+1
| | | | | | | | | | | | | | | | Now that multiple threads can handle stripes, it is safer to use an atomic64_t for resync_mismatches, to avoid update races. Signed-off-by: Jianpeng Ma <majianpeng@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * MD RAID10: Prep for DM RAID10 device replacement capabilityJonathan Brassow2012-10-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | MD RAID10: Fix a couple potential kernel panics if RAID10 is used by dm-raid When device-mapper uses the RAID10 personality through dm-raid.c, there is no 'gendisk' structure in mddev and some sysfs information is also not populated. This patch avoids touching those non-existent structures. Signed-off-by: Jonathan Brassow <jbrassow@rehdat.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * MD: change the parameter of md threadShaohua Li2012-10-111-1/+2
| | | | | | | | | | | | | | | | Change the thread parameter, so the thread can carry extra info. Next patch will use it. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * md/raid10: submit IO from originating thread instead of md thread.NeilBrown2012-10-111-3/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | queuing writes to the md thread means that all requests go through the one processor which may not be able to keep up with very high request rates. So use the plugging infrastructure to submit all requests on unplug. If a 'schedule' is needed, we fall back on the old approach of handing the requests to the thread for it to handle. This is nearly identical to a recent patch which provided similar functionality to RAID1. Signed-off-by: NeilBrown <neilb@suse.de>
| * md: raid 10 supports TRIMShaohua Li2012-10-111-4/+25
| | | | | | | | | | | | | | | | | | | | | | | | This makes md raid 10 support TRIM. If one disk supports discard and another not, or one has discard_zero_data and another not, there could be inconsistent between data from such disks. But this should not matter, discarded data is useless. This will add extra copy in rebuild though. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
* | md/raid10: fix "enough" function for detecting if array is failed.NeilBrown2012-09-271-3/+5
|/ | | | | | | | | | | | | | | | | | The 'enough' function is written to work with 'near' arrays only in that is implicitly assumes that the offset from one 'group' of devices to the next is the same as the number of copies. In reality it is the number of 'near' copies. So change it to make this number explicit. This bug makes it possible to run arrays without enough drives present, which is dangerous. It is appropriate for an -stable kernel, but will almost certainly need to be modified for some of them. Cc: stable@vger.kernel.org Reported-by: Jakub Husák <jakub@gooseman.cz> Signed-off-by: NeilBrown <neilb@suse.de>
* md/raid10: fix problem with on-stack allocation of r10bio structure.NeilBrown2012-08-181-11/+19
| | | | | | | | | | | | | | | | | | | | | | A 'struct r10bio' has an array of per-copy information at the end. This array is declared with size [0] and r10bio_pool_alloc allocates enough extra space to store the per-copy information depending on the number of copies needed. So declaring a 'struct r10bio on the stack isn't going to work. It won't allocate enough space, and memory corruption will ensue. So in the two places where this is done, declare a sufficiently large structure and use that instead. The two call-sites of this bug were introduced in 3.4 and 3.5 so this is suitable for both those kernels. The patch will have to be modified for 3.4 as it only has one bug. Cc: stable@vger.kernel.org Reported-by: Ivan Vasilyev <ivan.vasilyev@gmail.com> Tested-by: Ivan Vasilyev <ivan.vasilyev@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
* Merge branch 'for-3.6/drivers' of git://git.kernel.dk/linux-blockLinus Torvalds2012-08-011-2/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block driver changes from Jens Axboe: - Making the plugging support for drivers a bit more sane from Neil. This supersedes the plugging change from Shaohua as well. - The usual round of drbd updates. - Using a tail add instead of a head add in the request completion for ndb, making us find the most completed request more quickly. - A few floppy changes, getting rid of a duplicated flag and also running the floppy init async (since it takes forever in boot terms) from Andi. * 'for-3.6/drivers' of git://git.kernel.dk/linux-block: floppy: remove duplicated flag FD_RAW_NEED_DISK blk: pass from_schedule to non-request unplug functions. block: stack unplug blk: centralize non-request unplug handling. md: remove plug_cnt feature of plugging. block/nbd: micro-optimization in nbd request completion drbd: announce FLUSH/FUA capability to upper layers drbd: fix max_bio_size to be unsigned drbd: flush drbd work queue before invalidate/invalidate remote drbd: fix potential access after free drbd: call local-io-error handler early drbd: do not reset rs_pending_cnt too early drbd: reset congestion information before reporting it in /proc/drbd drbd: report congestion if we are waiting for some userland callback drbd: differentiate between normal and forced detach drbd: cleanup, remove two unused global flags floppy: Run floppy initialization asynchronous
| * md: remove plug_cnt feature of plugging.NeilBrown2012-07-311-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This seemed like a good idea at the time, but after further thought I cannot see it making a difference other than very occasionally and testing to try to exercise the case it is most likely to help did not show any performance difference by removing it. So remove the counting of active plugs and allow 'pending writes' to be activated at any time, not just when no plugs are active. This is only relevant when there is a write-intent bitmap, and the updating of the bitmap will likely introduce enough delay that the single-threading of bitmap updates will be enough to collect large numbers of updates together. Removing this will make it easier to centralise the unplug code, and will clear the other for other unplug enhancements which have a measurable effect. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | MD RAID10: Export md_raid10_congestedJonathan Brassow2012-07-311-22/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | md/raid10: Export is_congested test. In similar fashion to commits 11d8a6e3719519fbc0e2c9d61b6fa931b84bf813 1ed7242e591af7e233234d483f12d33818b189d9 we export the RAID10 congestion checking function so that dm-raid.c can make use of it and make use of the personality. The 'queue' and 'gendisk' structures will not be available to the MD code when device-mapper sets up the device, so we conditionalize access to these fields also. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* | MD: Move macros from raid1*.h to raid1*.cJonathan Brassow2012-07-311-1/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MD RAID1/RAID10: Move some macros from .h file to .c file There are three macros (IO_BLOCKED,IO_MADE_GOOD,BIO_SPECIAL) which are defined in both raid1.h and raid10.h. They are only used in there respective .c files. However, if we wish to make RAID10 accessible to the device-mapper RAID target (dm-raid.c), then we need to move these macros into the .c files where they are used so that they do not conflict with each other. The macros from the two files are identical and could be moved into md.h, but I chose to leave the duplication and have them remain in the personality files. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
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