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* Merge tag 'dm-4.1-fixes-3' of ↵Linus Torvalds2015-05-293-24/+36
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device-mapper fixes from Mike Snitzer: "Quite a few fixes for DM's blk-mq support thanks to extra DM multipath testing from Junichi Nomura and Bart Van Assche. Also fix a casting bug in dm_merge_bvec() that could cause only a single page to be added to a bio (Joe identified this while testing dm-cache writeback)" * tag 'dm-4.1-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm: fix casting bug in dm_merge_bvec() dm: fix reload failure of 0 path multipath mapping on blk-mq devices dm: fix false warning in free_rq_clone() for unmapped requests dm: requeue from blk-mq dm_mq_queue_rq() using BLK_MQ_RQ_QUEUE_BUSY dm mpath: fix leak of dm_mpath_io structure in blk-mq .queue_rq error path dm: fix NULL pointer when clone_and_map_rq returns !DM_MAPIO_REMAPPED dm: run queue on re-queue
| * dm: fix casting bug in dm_merge_bvec()Joe Thornber2015-05-291-5/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | dm_merge_bvec() was originally added in f6fccb ("dm: introduce merge_bvec_fn"). In that commit a value in sectors is converted to bytes using << 9, and then assigned to an int. This code made assumptions about the value of BIO_MAX_SECTORS. A later commit 148e51 ("dm: improve documentation and code clarity in dm_merge_bvec") was meant to have no functional change but it removed the use of BIO_MAX_SECTORS in favor of using queue_max_sectors(). At this point the cast from sector_t to int resulted in a zero value. The fallout being dm_merge_bvec() would only allow a single page to be added to a bio. This interim fix is minimal for the benefit of stable@ because the more comprehensive cleanup of passing a sector_t to all DM targets' merge function will impact quite a few DM targets. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 3.19+
| * dm: fix reload failure of 0 path multipath mapping on blk-mq devicesJunichi Nomura2015-05-291-7/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | dm-multipath accepts 0 path mapping. # echo '0 2097152 multipath 0 0 0 0' | dmsetup create newdev Such a mapping can be used to release underlying devices while still holding requests in its queue until working paths come back. However, once the multipath device is created over blk-mq devices, it rejects reloading of 0 path mapping: # echo '0 2097152 multipath 0 0 1 1 queue-length 0 1 1 /dev/sda 1' \ | dmsetup create mpath1 # echo '0 2097152 multipath 0 0 0 0' | dmsetup load mpath1 device-mapper: reload ioctl on mpath1 failed: Invalid argument Command failed With following kernel message: device-mapper: ioctl: can't change device type after initial table load. DM tries to inherit the current table type using dm_table_set_type() but it doesn't work as expected because of unnecessary check about whether the target type is hybrid or not. Hybrid type is for targets that work as either request-based or bio-based and not required for blk-mq or non blk-mq checking. Fixes: 65803c205983 ("dm table: train hybrid target type detection to select blk-mq if appropriate") Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm: fix false warning in free_rq_clone() for unmapped requestsMike Snitzer2015-05-291-5/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When stacking request-based dm device on non blk-mq device and device-mapper target could not map the request (error target is used, multipath target with all paths down, etc), the WARN_ON_ONCE() in free_rq_clone() will trigger when it shouldn't. The warning was added by commit aa6df8d ("dm: fix free_rq_clone() NULL pointer when requeueing unmapped request"). But free_rq_clone() with clone->q == NULL is valid usage for the case where dm_kill_unmapped_request() initiates request cleanup. Fix this false warning by just removing the WARN_ON -- it only generated false positives and was never useful in catching the intended case (completing clone request not being mapped e.g. clone->q being NULL). Fixes: aa6df8d ("dm: fix free_rq_clone() NULL pointer when requeueing unmapped request") Reported-by: Bart Van Assche <bart.vanassche@sandisk.com> Reported-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm: requeue from blk-mq dm_mq_queue_rq() using BLK_MQ_RQ_QUEUE_BUSYMike Snitzer2015-05-271-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use BLK_MQ_RQ_QUEUE_BUSY to requeue a blk-mq request directly from the DM blk-mq device's .queue_rq. This cleans up the previous convoluted handling of request requeueing that would return BLK_MQ_RQ_QUEUE_OK (even though it wasn't) and then run blk_mq_requeue_request() followed by blk_mq_kick_requeue_list(). Also, document that DM blk-mq ontop of old request_fn devices cannot fail in clone_rq() since the clone request is preallocated as part of the pdu. Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm mpath: fix leak of dm_mpath_io structure in blk-mq .queue_rq error pathMike Snitzer2015-05-271-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Otherwise kmemleak reported: unreferenced object 0xffff88009b14e2b0 (size 16): comm "fio", pid 4274, jiffies 4294978034 (age 1253.210s) hex dump (first 16 bytes): 40 12 f3 99 01 88 ff ff 00 10 00 00 00 00 00 00 @............... backtrace: [<ffffffff81600029>] kmemleak_alloc+0x49/0xb0 [<ffffffff811679a8>] kmem_cache_alloc+0xf8/0x160 [<ffffffff8111c950>] mempool_alloc_slab+0x10/0x20 [<ffffffff8111cb37>] mempool_alloc+0x57/0x150 [<ffffffffa04d2b61>] __multipath_map.isra.17+0xe1/0x220 [dm_multipath] [<ffffffffa04d2cb5>] multipath_clone_and_map+0x15/0x20 [dm_multipath] [<ffffffffa02889b5>] map_request.isra.39+0xd5/0x220 [dm_mod] [<ffffffffa028b0e4>] dm_mq_queue_rq+0x134/0x240 [dm_mod] [<ffffffff812cccb5>] __blk_mq_run_hw_queue+0x1d5/0x380 [<ffffffff812ccaa5>] blk_mq_run_hw_queue+0xc5/0x100 [<ffffffff812ce350>] blk_sq_make_request+0x240/0x300 [<ffffffff812c0f30>] generic_make_request+0xc0/0x110 [<ffffffff812c0ff2>] submit_bio+0x72/0x150 [<ffffffff811c07cb>] do_blockdev_direct_IO+0x1f3b/0x2da0 [<ffffffff811c166e>] __blockdev_direct_IO+0x3e/0x40 [<ffffffff8120aa1a>] ext4_direct_IO+0x1aa/0x390 Fixes: e5863d9ad ("dm: allocate requests in target when stacking on blk-mq devices") Reported-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 4.0+
| * dm: fix NULL pointer when clone_and_map_rq returns !DM_MAPIO_REMAPPEDJunichi Nomura2015-05-271-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When stacking request-based DM on blk_mq device, request cloning and remapping are done in a single call to target's clone_and_map_rq(). The clone is allocated and valid only if clone_and_map_rq() returns DM_MAPIO_REMAPPED. The "IS_ERR(clone)" check in map_request() does not cover all the !DM_MAPIO_REMAPPED cases that are possible (E.g. if underlying devices are not ready or unavailable, clone_and_map_rq() may return DM_MAPIO_REQUEUE without ever having established an ERR_PTR). Fix this by explicitly checking for a return that is not DM_MAPIO_REMAPPED in map_request(). Without this fix, DM core may call setup_clone() for a NULL clone and oops like this: BUG: unable to handle kernel NULL pointer dereference at 0000000000000068 IP: [<ffffffff81227525>] blk_rq_prep_clone+0x7d/0x137 ... CPU: 2 PID: 5793 Comm: kdmwork-253:3 Not tainted 4.0.0-nm #1 ... Call Trace: [<ffffffffa01d1c09>] map_tio_request+0xa9/0x258 [dm_mod] [<ffffffff81071de9>] kthread_worker_fn+0xfd/0x150 [<ffffffff81071cec>] ? kthread_parkme+0x24/0x24 [<ffffffff81071cec>] ? kthread_parkme+0x24/0x24 [<ffffffff81071fdd>] kthread+0xe6/0xee [<ffffffff81093a59>] ? put_lock_stats+0xe/0x20 [<ffffffff81071ef7>] ? __init_kthread_worker+0x5b/0x5b [<ffffffff814c2d98>] ret_from_fork+0x58/0x90 [<ffffffff81071ef7>] ? __init_kthread_worker+0x5b/0x5b Fixes: e5863d9ad ("dm: allocate requests in target when stacking on blk-mq devices") Reported-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 4.0+
| * dm: run queue on re-queueJunichi Nomura2015-05-261-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Without kicking queue, requeued request may stay forever in the queue if there are no other I/O activities to the device. The original error had been in v2.6.39 with commit 7eaceaccab5f ("block: remove per-queue plugging"), which replaced conditional plugging by periodic runqueue. Commit 9d1deb83d489 in v4.1-rc1 removed the periodic runqueue and the problem started to manifest. Fixes: 9d1deb83d489 ("dm: don't schedule delayed run of the queue if nothing to do") Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* | Merge tag 'md/4.1-rc5-fixes' of git://neil.brown.name/mdLinus Torvalds2015-05-293-67/+98
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull m,ore md bugfixes gfrom Neil Brown: "Assorted fixes for new RAID5 stripe-batching functionality. Unfortunately this functionality was merged a little prematurely. The necessary testing and code review is now complete (or as complete as it can be) and to code passes a variety of tests and looks quite sensible. Also a fix for some recent locking changes - a race was introduced which causes a reshape request to sometimes fail. No data safety issues" * tag 'md/4.1-rc5-fixes' of git://neil.brown.name/md: md: fix race when unfreezing sync_action md/raid5: break stripe-batches when the array has failed. md/raid5: call break_stripe_batch_list from handle_stripe_clean_event md/raid5: be more selective about distributing flags across batch. md/raid5: add handle_flags arg to break_stripe_batch_list. md/raid5: duplicate some more handle_stripe_clean_event code in break_stripe_batch_list md/raid5: remove condition test from check_break_stripe_batch_list. md/raid5: Ensure a batch member is not handled prematurely. md/raid5: close race between STRIPE_BIT_DELAY and batching. md/raid5: ensure whole batch is delayed for all required bitmap updates.
| * md: fix race when unfreezing sync_actionNeilBrown2015-05-281-6/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A recent change removed the need for locking around writing to "sync_action" (and various other places), but introduced a subtle race. When e.g. setting 'reshape' on a 'frozen' array, the 'frozen' flag is cleared before 'reshape' is set, so the md thread can get in and start trying recovery - which isn't wanted. So instead of clearing MD_RECOVERY_FROZEN for any command except 'frozen', only clear it when each specific command is parsed. This allows the handling of 'reshape' to clear the bit while a lock is held. Also remove some places where we set MD_RECOVERY_NEEDED, as it is always set on non-error exit of the function. Signed-off-by: NeilBrown <neilb@suse.de> Fixes: 6791875e2e53 ("md: make reconfig_mutex optional for writes to md sysfs files.")
| * md/raid5: break stripe-batches when the array has failed.NeilBrown2015-05-281-0/+1
| | | | | | | | | | | | | | Once the array has too much failure, we need to break stripe-batches up so they can all be dealt with. Signed-off-by: NeilBrown <neilb@suse.de>
| * md/raid5: call break_stripe_batch_list from handle_stripe_clean_eventNeilBrown2015-05-281-57/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that the code in break_stripe_batch_list() is nearly identical to the end of handle_stripe_clean_event, replace the later with a function call. The only remaining difference of any interest is the masking that is applieds to dev[i].flags copied from head_sh. R5_WriteError certainly isn't wanted as it is set per-stripe, not per-patch. R5_Overlap isn't wanted as it is explicitly handled. Signed-off-by: NeilBrown <neilb@suse.de>
| * md/raid5: be more selective about distributing flags across batch.NeilBrown2015-05-282-12/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a batch of stripes is broken up, we keep some of the flags that were per-stripe, and copy other flags from the head to all others. This only happens while a stripe is being handled, so many of the flags are irrelevant. The "SYNC_FLAGS" (which I've renamed to make it clear there are several) and STRIPE_DEGRADED are set per-stripe and so need to be preserved. STRIPE_INSYNC is the only flag that is set on the head that needs to be propagated to all others. For safety, add a WARN_ON if others are set, except: STRIPE_HANDLE - this is safe and per-stripe and we are going to set in several cases anyway STRIPE_INSYNC STRIPE_IO_STARTED - this is just a hint and doesn't hurt. STRIPE_ON_PLUG_LIST STRIPE_ON_RELEASE_LIST - It is a point pointless for a batched stripe to be on one of these lists, but it can happen as can be safely ignored. Signed-off-by: NeilBrown <neilb@suse.de>
| * md/raid5: add handle_flags arg to break_stripe_batch_list.NeilBrown2015-05-281-4/+8
| | | | | | | | | | | | | | | | | | | | | | When we break a stripe_batch_list we sometimes want to set STRIPE_HANDLE on the individual stripes, and sometimes not. So pass a 'handle_flags' arg. If it is zero, always set STRIPE_HANDLE (on non-head stripes). If not zero, only set it if any of the given flags are present. Signed-off-by: NeilBrown <neilb@suse.de>
| * md/raid5: duplicate some more handle_stripe_clean_event code in ↵NeilBrown2015-05-281-3/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | break_stripe_batch_list break_stripe_batch list didn't clear head_sh->batch_head. This was probably a bug. Also clear all R5_Overlap flags and if any were cleared, wake up 'wait_for_overlap'. This isn't always necessary but the worst effect is a little extra checking for code that is waiting on wait_for_overlap. Also, don't use wake_up_nr() because that does the wrong thing if 'nr' is zero, and it number of flags cleared doesn't strongly correlate with the number of threads to wake. Signed-off-by: NeilBrown <neilb@suse.de>
| * md/raid5: remove condition test from check_break_stripe_batch_list.NeilBrown2015-05-281-8/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | handle_stripe_clean_event() contains a chunk of code very similar to check_break_stripe_batch_list(). If we make the latter more like the former, we can end up with just one copy of this code. This first step removed the condition (and the 'check_') part of the name. This has the added advantage of making it clear what check is being performed at the point where the function is called. Signed-off-by: NeilBrown <neilb@suse.de>
| * md/raid5: Ensure a batch member is not handled prematurely.NeilBrown2015-05-281-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | If a stripe is a member of a batch, but not the head, it must not be handled separately from the rest of the batch. 'clear_batch_ready()' handles this requirement to some extent but not completely. If a member is passed to handle_stripe() a second time it returns '0' indicating the stripe can be handled, which is wrong. So add an extra test. Signed-off-by: NeilBrown <neilb@suse.de>
| * md/raid5: close race between STRIPE_BIT_DELAY and batching.NeilBrown2015-05-282-3/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we add a write to a stripe we need to make sure the bitmap bit is set. While doing that the stripe is not locked so it could be added to a batch after which further changes to STRIPE_BIT_DELAY and ->bm_seq are ineffective. So we need to hold off adding to a stripe until bitmap_startwrite has completed at least once, and we need to avoid further changes to STRIPE_BIT_DELAY once the stripe has been added to a batch. If a bitmap_startwrite() completes after the stripe was added to a batch, it will not have set the bit, only incremented a counter, so no extra delay of the stripe is needed. Reported-by: Shaohua Li <shli@kernel.org> Signed-off-by: NeilBrown <neilb@suse.de>
| * md/raid5: ensure whole batch is delayed for all required bitmap updates.NeilBrown2015-05-281-0/+9
| | | | | | | | | | | | | | | | When we add a stripe to a batch, we need to be sure that head stripe will wait for the bitmap update required for the new stripe. Signed-off-by: NeilBrown <neilb@suse.de>
* | Merge tag 'md/4.1-rc4-fixes' of git://neil.brown.name/mdLinus Torvalds2015-05-223-3/+10
|\ \ | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull md bugfixes from Neil Brown: "I have a few more raid5 bugfixes pending, but I want them to get a bit more review first. In the meantime: - one serious RAID0 data corruption - caused by recent bugfix that wasn't reviewed properly. - one raid5 fix in new code (a couple more of those to come). - one little fix to stop static analysis complaining about silly rcu annotation" * tag 'md/4.1-rc4-fixes' of git://neil.brown.name/md: md/bitmap: remove rcu annotation from pointer arithmetic. md/raid0: fix restore to sector variable in raid0_make_request raid5: fix broken async operation chain
| * md/bitmap: remove rcu annotation from pointer arithmetic.NeilBrown2015-05-211-1/+6
| | | | | | | | | | | | | | | | | | | | | | Evaluating "&mddev->disks" is simple pointer arithmetic, so it does not need 'rcu' annotations - no dereferencing is happening. Also enhance the comment to explain that 'rdev' in that case is not actually a pointer to an rdev. Reported-by: Patrick Marlier <patrick.marlier@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * md/raid0: fix restore to sector variable in raid0_make_requestEric Work2015-05-211-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The variable "sector" in "raid0_make_request()" was improperly updated by a call to "sector_div()" which modifies its first argument in place. Commit 47d68979cc968535cb87f3e5f2e6a3533ea48fbd restored this variable after the call for later re-use. Unfortunetly the restore was done after the referenced variable "bio" was advanced. This lead to the original value and the restored value being different. Here we move this line to the proper place. One observed side effect of this bug was discarding a file though unlinking would cause an unrelated file's contents to be discarded. Signed-off-by: NeilBrown <neilb@suse.de> Fixes: 47d68979cc96 ("md/raid0: fix bug with chunksize not a power of 2.") Cc: stable@vger.kernel.org (any that received above backport) URL: https://bugzilla.kernel.org/show_bug.cgi?id=98501
| * raid5: fix broken async operation chainShaohua Li2015-05-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | ops_run_reconstruct6() doesn't correctly chain asyn operations. The tx returned by async_gen_syndrome should be added as the dependent tx of next stripe. The issue is introduced by commit 59fc630b8b5f9f21c8ce3ba153341c107dce1b0c RAID5: batch adjacent full stripe write Reported-and-tested-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.de>
* | Merge tag 'md/4.1-rc3-fixes' of git://neil.brown.name/mdLinus Torvalds2015-05-112-55/+73
|\ \ | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull md bugfixes from Neil Brown: "A few fixes for md. Most of these are related to the new "batched stripe writeout", but there are a few others" * tag 'md/4.1-rc3-fixes' of git://neil.brown.name/md: md/raid5: fix handling of degraded stripes in batches. md/raid5: fix allocation of 'scribble' array. md/raid5: don't record new size if resize_stripes fails. md/raid5: avoid reading parity blocks for full-stripe write to degraded array md/raid5: more incorrect BUG_ON in handle_stripe_fill. md/raid5: new alloc_stripe() to allocate an initialize a stripe. md-raid0: conditional mddev->queue access to suit dm-raid
| * md/raid5: fix handling of degraded stripes in batches.NeilBrown2015-05-081-14/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no need for special handling of stripe-batches when the array is degraded. There may be if there is a failure in the batch, but STRIPE_DEGRADED does not imply an error. So don't set STRIPE_BATCH_ERR in ops_run_io just because the array is degraded. This actually causes a bug: the STRIPE_DEGRADED flag gets cleared in check_break_stripe_batch_list() and so the bitmap bit gets cleared when it shouldn't. So in check_break_stripe_batch_list(), split the batch up completely - again STRIPE_DEGRADED isn't meaningful. Also don't set STRIPE_BATCH_ERR when there is a write error to a replacement device. This simply removes the replacement device and requires no extra handling. Signed-off-by: NeilBrown <neilb@suse.de>
| * md/raid5: fix allocation of 'scribble' array.NeilBrown2015-05-081-22/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As the new 'scribble' array is sized based on chunk size, we need to make sure the size matches the largest of 'old' and 'new' chunk sizes when the array is undergoing reshape. We also potentially need to resize it even when not resizing the stripe cache, as chunk size can change without changing number of devices. So move the 'resize' code into a separate function, and consider old and new sizes when allocating. Signed-off-by: NeilBrown <neilb@suse.de> Fixes: 46d5b785621a ("raid5: use flex_array for scribble data")
| * md/raid5: don't record new size if resize_stripes fails.NeilBrown2015-05-081-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If any memory allocation in resize_stripes fails we will return -ENOMEM, but in some cases we update conf->pool_size anyway. This means that if we try again, the allocations will be assumed to be larger than they are, and badness results. So only update pool_size if there is no error. This bug was introduced in 2.6.17 and the patch is suitable for -stable. Fixes: ad01c9e3752f ("[PATCH] md: Allow stripes to be expanded in preparation for expanding an array") Cc: stable@vger.kernel.org (v2.6.17+) Signed-off-by: NeilBrown <neilb@suse.de>
| * md/raid5: avoid reading parity blocks for full-stripe write to degraded arrayNeilBrown2015-05-081-1/+3
| | | | | | | | | | | | | | | | | | | | | | When performing a reconstruct write, we need to read all blocks that are not being over-written .. except the parity (P and Q) blocks. The code currently reads these (as they are not being over-written!) unnecessarily. Signed-off-by: NeilBrown <neilb@suse.de> Fixes: ea664c8245f3 ("md/raid5: need_this_block: tidy/fix last condition.")
| * md/raid5: more incorrect BUG_ON in handle_stripe_fill.NeilBrown2015-05-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | It is not incorrect to call handle_stripe_fill() when a batch of full-stripe writes is active. It is, however, a BUG if fetch_block() then decides it needs to actually fetch anything. So move the 'BUG_ON' to where it belongs. Signed-off-by: NeilBrown <neilb@suse.de> Fixes: 59fc630b8b5f ("RAID5: batch adjacent full stripe write")
| * md/raid5: new alloc_stripe() to allocate an initialize a stripe.NeilBrown2015-05-081-14/+18
| | | | | | | | | | | | | | | | | | | | | | | | The new batch_lock and batch_list fields are being initialized in grow_one_stripe() but not in resize_stripes(). This causes a crash on resize. So separate the core initialization into a new function and call it from both allocation sites. Signed-off-by: NeilBrown <neilb@suse.de> Fixes: 59fc630b8b5f ("RAID5: batch adjacent full stripe write")
| * md-raid0: conditional mddev->queue access to suit dm-raidHeinz Mauelshagen2015-05-081-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is a prerequisite for dm-raid "raid0" support to allow dm-raid to access the MD RAID0 personality doing unconditional accesses to mddev->queue, which is NULL in case of dm-raid stacked on top of MD. Most of the conditional mddev->queue accesses made it to upstream but this missing one, which prohibits md raid0 to set disk stack limits (being done in dm core in case of md underneath dm). Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Tested-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
* | Merge tag 'dm-4.1-fixes-2' of ↵Linus Torvalds2015-05-081-6/+6
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper fixes from Mike Snitzer: "Two additional fixes for changes introduced via DM during the 4.1 merge window. The first reverts a dm-crypt change that wasn't correct. The second fixes a device format regression that impacted userspace" * tag 'dm-4.1-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: init: fix regression by supporting devices with major:minor:offset format Revert "dm crypt: fix deadlock when async crypto algorithm returns -EBUSY"
| * | Revert "dm crypt: fix deadlock when async crypto algorithm returns -EBUSY"Rabin Vincent2015-05-051-6/+6
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts Linux 4.1-rc1 commit 0618764cb25f6fa9fb31152995de42a8a0496475. The problem which that commit attempts to fix actually lies in the Freescale CAAM crypto driver not dm-crypt. dm-crypt uses CRYPTO_TFM_REQ_MAY_BACKLOG. This means the the crypto driver should internally backlog requests which arrive when the queue is full and process them later. Until the crypto hw's queue becomes full, the driver returns -EINPROGRESS. When the crypto hw's queue if full, the driver returns -EBUSY, and if CRYPTO_TFM_REQ_MAY_BACKLOG is set, is expected to backlog the request and process it when the hardware has queue space. At the point when the driver takes the request from the backlog and starts processing it, it calls the completion function with a status of -EINPROGRESS. The completion function is called (for a second time, in the case of backlogged requests) with a status/err of 0 when a request is done. Crypto drivers for hardware without hardware queueing use the helpers, crypto_init_queue(), crypto_enqueue_request(), crypto_dequeue_request() and crypto_get_backlog() helpers to implement this behaviour correctly, while others implement this behaviour without these helpers (ccp, for example). dm-crypt (before the patch that needs reverting) uses this API correctly. It queues up as many requests as the hw queues will allow (i.e. as long as it gets back -EINPROGRESS from the request function). Then, when it sees at least one backlogged request (gets -EBUSY), it waits till that backlogged request is handled (completion gets called with -EINPROGRESS), and then continues. The references to af_alg_wait_for_completion() and af_alg_complete() in that commit's commit message are irrelevant because those functions only handle one request at a time, unlink dm-crypt. The problem is that the Freescale CAAM driver, which that commit describes as having being tested with, fails to implement the backlogging behaviour correctly. In cam_jr_enqueue(), if the hardware queue is full, it simply returns -EBUSY without backlogging the request. What the observed deadlock was is not described in the commit message but it is obviously the wait_for_completion() in crypto_convert() where dm-crypto would wait for the completion being called with -EINPROGRESS in the case of backlogged requests. This completion will never be completed due to the bug in the CAAM driver. Commit 0618764cb25 incorrectly made dm-crypt wait for every request, even when the driver/hardware queues are not full, which means that dm-crypt will never see -EBUSY. This means that that commit will cause a performance regression on all crypto drivers which implement the API correctly. Revert it. Correct backlog handling should be implemented in the CAAM driver instead. Cc'ing stable purely because commit 0618764cb25 did. If for some reason a stable@ kernel did pick up commit 0618764cb25 it should get reverted. Signed-off-by: Rabin Vincent <rabin.vincent@axis.com> Reviewed-by: Horia Geanta <horia.geanta@freescale.com> Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* | Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds2015-05-081-2/+2
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block fixes from Jens Axboe: "A collection of fixes since the merge window; - fix for a double elevator module release, from Chao Yu. Ancient bug. - the splice() MORE flag fix from Christophe Leroy. - a fix for NVMe, fixing a patch that went in in the merge window. From Keith. - two fixes for blk-mq CPU hotplug handling, from Ming Lei. - bdi vs blockdev lifetime fix from Neil Brown, fixing and oops in md. - two blk-mq fixes from Shaohua, fixing a race on queue stop and a bad merge issue with FUA writes. - division-by-zero fix for writeback from Tejun. - a block bounce page accounting fix, making sure we inc/dec after bouncing so that pre/post IO pages match up. From Wang YanQing" * 'for-linus' of git://git.kernel.dk/linux-block: splice: sendfile() at once fails for big files blk-mq: don't lose requests if a stopped queue restarts blk-mq: fix FUA request hang block: destroy bdi before blockdev is unregistered. block:bounce: fix call inc_|dec_zone_page_state on different pages confuse value of NR_BOUNCE elevator: fix double release of elevator module writeback: use |1 instead of +1 to protect against div by zero blk-mq: fix CPU hotplug handling blk-mq: fix race between timeout and CPU hotplug NVMe: Fix VPD B0 max sectors translation
| * block: destroy bdi before blockdev is unregistered.NeilBrown2015-04-271-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Because of the peculiar way that md devices are created (automatically when the device node is opened), a new device can be created and registered immediately after the blk_unregister_region(disk_devt(disk), disk->minors); call in del_gendisk(). Therefore it is important that all visible artifacts of the previous device are removed before this call. In particular, the 'bdi'. Since: commit c4db59d31e39ea067c32163ac961e9c80198fd37 Author: Christoph Hellwig <hch@lst.de> fs: don't reassign dirty inodes to default_backing_dev_info moved the device_unregister(bdi->dev); call from bdi_unregister() to bdi_destroy() it has been quite easy to lose a race and have a new (e.g.) "md127" be created after the blk_unregister_region() call and before bdi_destroy() is ultimately called by the final 'put_disk', which must come after del_gendisk(). The new device finds that the bdi name is already registered in sysfs and complains > [ 9627.630029] WARNING: CPU: 18 PID: 3330 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x5a/0x70() > [ 9627.630032] sysfs: cannot create duplicate filename '/devices/virtual/bdi/9:127' We can fix this by moving the bdi_destroy() call out of blk_release_queue() (which can happen very late when a refcount reaches zero) and into blk_cleanup_queue() - which happens exactly when the md device driver calls it. Then it is only necessary for md to call blk_cleanup_queue() before del_gendisk(). As loop.c devices are also created on demand by opening the device node, we make the same change there. Fixes: c4db59d31e39ea067c32163ac961e9c80198fd37 Reported-by: Azat Khuzhin <a3at.mail@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Cc: stable@vger.kernel.org (v4.0) Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
* | dm: fix free_rq_clone() NULL pointer when requeueing unmapped requestMike Snitzer2015-04-301-4/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 022333427a ("dm: optimize dm_mq_queue_rq to _not_ use kthread if using pure blk-mq") mistakenly removed free_rq_clone()'s clone->q check before testing clone->q->mq_ops. It was an oversight to discontinue that check for 1 of the 2 use-cases for free_rq_clone(): 1) free_rq_clone() called when an unmapped original request is requeued 2) free_rq_clone() called in the request-based IO completion path The clone->q check made sense for case #1 but not for #2. However, we cannot just reinstate the check as it'd mask a serious bug in the IO completion case #2 -- no in-flight request should have an uninitialized request_queue (basic block layer refcounting _should_ ensure this). The NULL pointer seen for case #1 is detailed here: https://www.redhat.com/archives/dm-devel/2015-April/msg00160.html Fix this free_rq_clone() NULL pointer by simply checking if the mapped_device's type is DM_TYPE_MQ_REQUEST_BASED (clone's queue is blk-mq) rather than checking clone->q->mq_ops. This avoids the need to dereference clone->q, but a WARN_ON_ONCE is added to let us know if an uninitialized clone request is being completed. Reported-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* | dm: only initialize the request_queue onceChristoph Hellwig2015-04-302-11/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit bfebd1cdb4 ("dm: add full blk-mq support to request-based DM") didn't properly account for the need to short-circuit re-initializing DM's blk-mq request_queue if it was already initialized. Otherwise, reloading a blk-mq request-based DM table (either manually or via multipathd) resulted in errors, see: https://www.redhat.com/archives/dm-devel/2015-April/msg00132.html Fix is to only initialize the request_queue on the initial table load (when the mapped_device type is assigned). This is better than having dm_init_request_based_blk_mq_queue() return early if the queue was already initialized because it elevates the constraint to a more meaningful location in DM core. As such the pre-existing early return in dm_init_request_based_queue() can now be removed. Fixes: bfebd1cdb4 ("dm: add full blk-mq support to request-based DM") Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* | Merge tag 'md/4.1' of git://neil.brown.name/mdLinus Torvalds2015-04-2413-279/+2309
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull md updates from Neil Brown: "More updates that usual this time. A few have performance impacts which hould mostly be positive, but RAID5 (in particular) can be very work-load ensitive... We'll have to wait and see. Highlights: - "experimental" code for managing md/raid1 across a cluster using DLM. Code is not ready for general use and triggers a WARNING if used. However it is looking good and mostly done and having in mainline will help co-ordinate development. - RAID5/6 can now batch multiple (4K wide) stripe_heads so as to handle a full (chunk wide) stripe as a single unit. - RAID6 can now perform read-modify-write cycles which should help performance on larger arrays: 6 or more devices. - RAID5/6 stripe cache now grows and shrinks dynamically. The value set is used as a minimum. - Resync is now allowed to go a little faster than the 'mininum' when there is competing IO. How much faster depends on the speed of the devices, so the effective minimum should scale with device speed to some extent" * tag 'md/4.1' of git://neil.brown.name/md: (58 commits) md/raid5: don't do chunk aligned read on degraded array. md/raid5: allow the stripe_cache to grow and shrink. md/raid5: change ->inactive_blocked to a bit-flag. md/raid5: move max_nr_stripes management into grow_one_stripe and drop_one_stripe md/raid5: pass gfp_t arg to grow_one_stripe() md/raid5: introduce configuration option rmw_level md/raid5: activate raid6 rmw feature md/raid6 algorithms: xor_syndrome() for SSE2 md/raid6 algorithms: xor_syndrome() for generic int md/raid6 algorithms: improve test program md/raid6 algorithms: delta syndrome functions raid5: handle expansion/resync case with stripe batching raid5: handle io error of batch list RAID5: batch adjacent full stripe write raid5: track overwrite disk count raid5: add a new flag to track if a stripe can be batched raid5: use flex_array for scribble data md raid0: access mddev->queue (request queue member) conditionally because it is not set when accessed from dm-raid md: allow resync to go faster when there is competing IO. md: remove 'go_faster' option from ->sync_request() ...
| * | md/raid5: don't do chunk aligned read on degraded array.Eric Mei2015-04-221-3/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When array is degraded, read data landed on failed drives will result in reading rest of data in a stripe. So a single sequential read would result in same data being read twice. This patch is to avoid chunk aligned read for degraded array. The downside is to involve stripe cache which means associated CPU overhead and extra memory copy. Test Results: Following test are done on a enterprise storage node with Seagate 6T SAS drives and Xeon E5-2648L CPU (10 cores, 1.9Ghz), 10 disks MD RAID6 8+2, chunk size 128 KiB. I use FIO, using direct-io with various bs size, enough queue depth, tested sequential and 100% random read against 3 array config: 1) optimal, as baseline; 2) degraded; 3) degraded with this patch. Kernel version is 4.0-rc3. Each individual test I only did once so there might be some variations, but we just focus on big trend. Sequential Read: bs=(KiB) optimal(MiB/s) degraded(MiB/s) degraded-with-patch (MiB/s) 1024 1608 656 995 512 1624 710 956 256 1635 728 980 128 1636 771 983 64 1612 1119 1000 32 1580 1420 1004 16 1368 688 986 8 768 647 953 4 411 413 850 Random Read: bs=(KiB) optimal(IOPS) degraded(IOPS) degraded-with-patch (IOPS) 1024 163 160 156 512 274 273 272 256 426 428 424 128 576 592 591 64 726 724 726 32 849 848 837 16 900 970 971 8 927 940 929 4 948 940 955 Some notes: * In sequential + optimal, as bs size getting smaller, the FIO thread become CPU bound. * In sequential + degraded, there's big increase when bs is 64K and 32K, I don't have explanation. * In sequential + degraded-with-patch, the MD thread mostly become CPU bound. If you want to we can discuss specific data point in those data. But in general it seems with this patch, we have more predictable and in most cases significant better sequential read performance when array is degraded, and almost no noticeable impact on random read. Performance is a complicated thing, the patch works well for this particular configuration, but may not be universal. For example I imagine testing on all SSD array may have very different result. But I personally think in most cases IO bandwidth is more scarce resource than CPU. Signed-off-by: Eric Mei <eric.mei@seagate.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * | md/raid5: allow the stripe_cache to grow and shrink.NeilBrown2015-04-222-8/+71
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The default setting of 256 stripe_heads is probably much too small for many configurations. So it is best to make it auto-configure. Shrinking the cache under memory pressure is easy. The only interesting part here is that we put a fairly high cost ('seeks') on shrinking the cache as the cost is greater than just having to read more data, it reduces parallelism. Growing the cache on demand needs to be done carefully. If we allow fast growth, that can upset memory balance as lots of dirty memory can quickly turn into lots of memory queued in the stripe_cache. It is important for the raid5 block device to appear congested to allow write-throttling to work. So we only add stripes slowly. We set a flag when an allocation fails because all stripes are in use, allocate at a convenient time when that flag is set, and don't allow it to be set again until at least one stripe_head has been released for re-use. This means that a spurt of requests will only cause one stripe_head to be allocated, but a steady stream of requests will slowly increase the cache size - until memory pressure puts it back again. It could take hours to reach a steady state. The value written to, and displayed in, stripe_cache_size is used as a minimum. The cache can grow above this and shrink back down to it. The actual size is not directly visible, though it can be deduced to some extent by watching stripe_cache_active. Signed-off-by: NeilBrown <neilb@suse.de>
| * | md/raid5: change ->inactive_blocked to a bit-flag.NeilBrown2015-04-222-8/+14
| | | | | | | | | | | | | | | | | | This allows us to easily add more (atomic) flags. Signed-off-by: NeilBrown <neilb@suse.de>
| * | md/raid5: move max_nr_stripes management into grow_one_stripe and ↵NeilBrown2015-04-221-33/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | drop_one_stripe Rather than adjusting max_nr_stripes whenever {grow,drop}_one_stripe() succeeds, do it inside the functions. Also choose the correct hash to handle next inside the functions. This removes duplication and will help with future new uses of {grow,drop}_one_stripe. This also fixes a minor bug where the "md/raid:%md: allocate XXkB" message always said "0kB". Signed-off-by: NeilBrown <neilb@suse.de>
| * | md/raid5: pass gfp_t arg to grow_one_stripe()NeilBrown2015-04-221-7/+7
| | | | | | | | | | | | | | | | | | This is needed for future improvement to stripe cache management. Signed-off-by: NeilBrown <neilb@suse.de>
| * | md/raid5: introduce configuration option rmw_levelMarkus Stockhausen2015-04-222-0/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Depending on the available coding we allow optimized rmw logic for write operations. To support easier testing this patch allows manual control of the rmw/rcw descision through the interface /sys/block/mdX/md/rmw_level. The configuration can handle three levels of control. rmw_level=0: Disable rmw for all RAID types. Hardware assisted P/Q calculation has no implementation path yet to factor in/out chunks of a syndrome. Enforcing this level can be benefical for slow CPUs with hardware syndrome support and fast SSDs. rmw_level=1: Estimate rmw IOs and rcw IOs. Execute rmw only if we will save IOs. This equals the "old" unpatched behaviour and will be the default. rmw_level=2: Execute rmw even if calculated IOs for rmw and rcw are equal. We might have higher CPU consumption because of calculating the parity twice but it can be benefical otherwise. E.g. RAID4 with fast dedicated parity disk/SSD. The option is implemented just to be forward-looking and will ONLY work with this patch! Signed-off-by: Markus Stockhausen <stockhausen@collogia.de> Signed-off-by: NeilBrown <neilb@suse.de>
| * | md/raid5: activate raid6 rmw featureMarkus Stockhausen2015-04-222-27/+96
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Glue it altogehter. The raid6 rmw path should work the same as the already existing raid5 logic. So emulate the prexor handling/flags and split functions as needed. 1) Enable xor_syndrome() in the async layer. 2) Split ops_run_prexor() into RAID4/5 and RAID6 logic. Xor the syndrome at the start of a rmw run as we did it before for the single parity. 3) Take care of rmw run in ops_run_reconstruct6(). Again process only the changed pages to get syndrome back into sync. 4) Enhance set_syndrome_sources() to fill NULL pages if we are in a rmw run. The lower layers will calculate start & end pages from that and call the xor_syndrome() correspondingly. 5) Adapt the several places where we ignored Q handling up to now. Performance numbers for a single E5630 system with a mix of 10 7200k desktop/server disks. 300 seconds random write with 8 threads onto a 3,2TB (10*400GB) RAID6 64K chunk without spare (group_thread_cnt=4) bsize rmw_level=1 rmw_level=0 rmw_level=1 rmw_level=0 skip_copy=1 skip_copy=1 skip_copy=0 skip_copy=0 4K 115 KB/s 141 KB/s 165 KB/s 140 KB/s 8K 225 KB/s 275 KB/s 324 KB/s 274 KB/s 16K 434 KB/s 536 KB/s 640 KB/s 534 KB/s 32K 751 KB/s 1,051 KB/s 1,234 KB/s 1,045 KB/s 64K 1,339 KB/s 1,958 KB/s 2,282 KB/s 1,962 KB/s 128K 2,673 KB/s 3,862 KB/s 4,113 KB/s 3,898 KB/s 256K 7,685 KB/s 7,539 KB/s 7,557 KB/s 7,638 KB/s 512K 19,556 KB/s 19,558 KB/s 19,652 KB/s 19,688 Kb/s Signed-off-by: Markus Stockhausen <stockhausen@collogia.de> Signed-off-by: NeilBrown <neilb@suse.de>
| * | raid5: handle expansion/resync case with stripe batchingshli@kernel.org2015-04-222-8/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | expansion/resync can grab a stripe when the stripe is in batch list. Since all stripes in batch list must be in the same state, we can't allow some stripes run into expansion/resync. So we delay expansion/resync for stripe in batch list. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * | raid5: handle io error of batch listshli@kernel.org2015-04-222-0/+49
| | | | | | | | | | | | | | | | | | | | | | | | If io error happens in any stripe of a batch list, the batch list will be split, then normal process will run for the stripes in the list. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * | RAID5: batch adjacent full stripe writeshli@kernel.org2015-04-222-25/+336
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | stripe cache is 4k size. Even adjacent full stripe writes are handled in 4k unit. Idealy we should use big size for adjacent full stripe writes. Bigger stripe cache size means less stripes runing in the state machine so can reduce cpu overhead. And also bigger size can cause bigger IO size dispatched to under layer disks. With below patch, we will automatically batch adjacent full stripe write together. Such stripes will be added to the batch list. Only the first stripe of the list will be put to handle_list and so run handle_stripe(). Some steps of handle_stripe() are extended to cover all stripes of the list, including ops_run_io, ops_run_biodrain and so on. With this patch, we have less stripes running in handle_stripe() and we send IO of whole stripe list together to increase IO size. Stripes added to a batch list have some limitations. A batch list can only include full stripe write and can't cross chunk boundary to make sure stripes have the same parity disks. Stripes in a batch list must be in the same state (no written, toread and so on). If a stripe is in a batch list, all new read/write to add_stripe_bio will be blocked to overlap conflict till the batch list is handled. The limitations will make sure stripes in a batch list be in exactly the same state in the life circly. I did test running 160k randwrite in a RAID5 array with 32k chunk size and 6 PCIe SSD. This patch improves around 30% performance and IO size to under layer disk is exactly 32k. I also run a 4k randwrite test in the same array to make sure the performance isn't changed with the patch. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * | raid5: track overwrite disk countshli@kernel.org2015-04-222-1/+17
| | | | | | | | | | | | | | | | | | | | | Track overwrite disk count, so we can know if a stripe is a full stripe write. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * | raid5: add a new flag to track if a stripe can be batchedshli@kernel.org2015-04-222-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | A freshly new stripe with write request can be batched. Any time the stripe is handled or new read is queued, the flag will be cleared. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
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