- 02 9月, 2013 1 次提交
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由 Shaohua Li 提交于
If there are not enough stripes to handle, we'd better not always queue all available work_structs. If one worker can only handle small or even none stripes, it will impact request merge and create lock contention. With this patch, the number of work_struct running will depend on pending stripes number. Note: some statistics info used in the patch are accessed without locking protection. This should doesn't matter, we just try best to avoid queue unnecessary work_struct. Signed-off-by: NShaohua Li <shli@fusionio.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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- 28 8月, 2013 6 次提交
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由 NeilBrown 提交于
Some requests - particularly 'discard' and 'read' are handled differently depending on whether a reshape is active or not. It is harmless to assume reshape is active if it isn't but wrong to act as though reshape is not active when it is. So when we start reshape - after making clear to all requests that reshape has started - use mddev_suspend/mddev_resume to flush out all requests. This will ensure that no requests will be assuming the absence of reshape once it really starts. Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
make_request() access various shape parameters (raid_disks, chunk_size etc) which might be changed by raid5_start_reshape(). If the later is called at and awkward time during the form, the wrong stripe_head might be used. So introduce a 'seqcount' and after finding a stripe_head make sure there is no reason to expect that we got the wrong one. Signed-off-by: NNeilBrown <neilb@suse.de>
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由 Shaohua Li 提交于
Add a sysfs entry to control running workqueue thread number. If group_thread_cnt is set to 0, we will disable workqueue offload handling of stripes. Signed-off-by: NShaohua Li <shli@fusionio.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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由 Shaohua Li 提交于
This is another attempt to create multiple threads to handle raid5 stripes. This time I use workqueue. raid5 handles request (especially write) in stripe unit. A stripe is page size aligned/long and acrosses all disks. Writing to any disk sector, raid5 runs a state machine for the corresponding stripe, which includes reading some disks of the stripe, calculating parity, and writing some disks of the stripe. The state machine is running in raid5d thread currently. Since there is only one thread, it doesn't scale well for high speed storage. An obvious solution is multi-threading. To get better performance, we have some requirements: a. locality. stripe corresponding to request submitted from one cpu is better handled in thread in local cpu or local node. local cpu is preferred but some times could be a bottleneck, for example, parity calculation is too heavy. local node running has wide adaptability. b. configurablity. Different setup of raid5 array might need diffent configuration. Especially the thread number. More threads don't always mean better performance because of lock contentions. My original implementation is creating some kernel threads. There are interfaces to control which cpu's stripe each thread should handle. And userspace can set affinity of the threads. This provides biggest flexibility and configurability. But it's hard to use and apparently a new thread pool implementation is disfavor. Recent workqueue improvement is quite promising. unbound workqueue will be bound to numa node. If WQ_SYSFS is set in workqueue, there are sysfs option to do affinity setting. For example, we can only include one HT sibling in affinity. Since work is non-reentrant by default, and we can control running thread number by limiting dispatched work_struct number. In this patch, I created several stripe worker group. A group is a numa node. stripes from cpus of one node will be added to a group list. Workqueue thread of one node will only handle stripes of worker group of the node. In this way, stripe handling has numa node locality. And as I said, we can control thread number by limiting dispatched work_struct number. The work_struct callback function handles several stripes in one run. A typical work queue usage is to run one unit in each work_struct. In raid5 case, the unit is a stripe. But we can't do that: a. Though handling a stripe doesn't need lock because of reference accounting and stripe isn't in any list, queuing a work_struct for each stripe will make workqueue lock contended very heavily. b. blk_start_plug()/blk_finish_plug() should surround stripe handle, as we might dispatch request. If each work_struct only handles one stripe, such block plug is meaningless. This implementation can't do very fine grained configuration. But the numa binding is most popular usage model, should be enough for most workloads. Note: since we have only one stripe queue, switching to multi-thread might decrease request size dispatching down to low level layer. The impact depends on thread number, raid configuration and workload. So multi-thread raid5 might not be proper for all setups. Changes V1 -> V2: 1. remove WQ_NON_REENTRANT 2. disabling multi-threading by default 3. Add more descriptions in changelog Signed-off-by: NShaohua Li <shli@fusionio.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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由 Shaohua Li 提交于
patch "make release_stripe lockless" changes the order stripes are released. Originally I thought block layer can take care of request merge, but it appears there are still some requests not merged. It's easy to fix the order. Signed-off-by: NShaohua Li <shli@fusionio.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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由 Shaohua Li 提交于
release_stripe still has big lock contention. We just add the stripe to a llist without taking device_lock. We let the raid5d thread to do the real stripe release, which must hold device_lock anyway. In this way, release_stripe doesn't hold any locks. The side effect is the released stripes order is changed. But sounds not a big deal, stripes are never handled in order. And I thought block layer can already do nice request merge, which means order isn't that important. I kept the unplug release batch, which is unnecessary with this patch from lock contention avoid point of view, and actually if we delete it, the stripe_head release_list and lru can share storage. But the unplug release batch is also helpful for request merge. We probably can delay wakeup raid5d till unplug, but I'm still afraid of the case which raid5d is running. Signed-off-by: NShaohua Li <shli@fusionio.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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- 25 7月, 2013 1 次提交
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由 NeilBrown 提交于
If a device in a RAID4/5/6 is being replaced while another is being recovered, then the writes to the replacement device currently don't happen, resulting in corruption when the replacement completes and the new drive takes over. This is because the replacement writes are only triggered when 's.replacing' is set and not when the similar 's.sync' is set (which is the case during resync and recovery - it means all devices need to be read). So schedule those writes when s.replacing is set as well. In this case we cannot use "STRIPE_INSYNC" to record that the replacement has happened as that is needed for recording that any parity calculation is complete. So introduce STRIPE_REPLACED to record if the replacement has happened. For safety we should also check that STRIPE_COMPUTE_RUN is not set. This has a similar effect to the "s.locked == 0" test. The latter ensure that now IO has been flagged but not started. The former checks if any parity calculation has been flagged by not started. We must wait for both of these to complete before triggering the 'replace'. Add a similar test to the subsequent check for "are we finished yet". This possibly isn't needed (is subsumed in the STRIPE_INSYNC test), but it makes it more obvious that the REPLACE will happen before we think we are finished. Finally if a NeedReplace device is not UPTODATE then that is an error. We really must trigger a warning. This bug was introduced in commit 9a3e1101 (md/raid5: detect and handle replacements during recovery.) which introduced replacement for raid5. That was in 3.3-rc3, so any stable kernel since then would benefit from this fix. Cc: stable@vger.kernel.org (3.3+) Reported-by: Nqindehua <13691222965@163.com> Tested-by: Nqindehua <qindehua@163.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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- 04 7月, 2013 1 次提交
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由 NeilBrown 提交于
There is a bug in 'check_reshape' for raid5.c To checks that the new minimum number of devices is large enough (which is good), but it does so also after the reshape has started (bad). This is bad because - the calculation is now wrong as mddev->raid_disks has changed already, and - it is pointless because it is now too late to stop. So only perform that test when reshape has not been committed to. Signed-off-by: NNeilBrown <neilb@suse.de>
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- 14 6月, 2013 1 次提交
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由 Jingoo Han 提交于
The usage of strict_strtoul() is not preferred, because strict_strtoul() is obsolete. Thus, kstrtoul() should be used. Signed-off-by: NJingoo Han <jg1.han@samsung.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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- 13 6月, 2013 1 次提交
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由 H. Peter Anvin 提交于
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: NH. Peter Anvin <hpa@linux.intel.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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- 30 5月, 2013 1 次提交
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由 Kent Overstreet 提交于
The patch that converted raid5 to use bio_reset() forgot to initialize bi_vcnt. Signed-off-by: NKent Overstreet <koverstreet@google.com> Cc: NeilBrown <neilb@suse.de> Cc: linux-raid@vger.kernel.org Tested-by: NIlia Mirkin <imirkin@alum.mit.edu> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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- 24 4月, 2013 2 次提交
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由 NeilBrown 提交于
If we write to a known-bad-block it will be flags as having a ReadError by analyse_stripe, but the write will proceed anyway (as it should). Then the read-error handling will kick in an write again, then re-read. We don't need that 'write-again', so set R5_ReWrite so it looks like it has already been done. Then we will just get the re-read, which we want. Reported-by: Nmajianpeng <majianpeng@gmail.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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由 majianpeng 提交于
As the function call is the most expensive of these tests it should be done later in the chain so that it can be avoided in some cases. Signed-off-by: NJianpeng Ma <majianpeng@gmail.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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- 19 4月, 2013 1 次提交
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由 Linus Torvalds 提交于
This reverts commit 3a366e61. Wanlong Gao reports that it causes a kernel panic on his machine several minutes after boot. Reverting it removes the panic. Jens says: "It's not quite clear why that is yet, so I think we should just revert the commit for 3.9 final (which I'm assuming is pretty close). The wifi is crap at the LSF hotel, so sending this email instead of queueing up a revert and pull request." Reported-by: NWanlong Gao <gaowanlong@cn.fujitsu.com> Requested-by: NJens Axboe <axboe@kernel.dk> Cc: Tejun Heo <tj@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 24 3月, 2013 3 次提交
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由 Kent Overstreet 提交于
Had to shuffle the code around a bit (where bi_rw and bi_end_io were set), but shouldn't really be anything tricky here Signed-off-by: NKent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: NeilBrown <neilb@suse.de>
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由 Kent Overstreet 提交于
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: NKent 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: NEd Cashin <ecashin@coraid.com>
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由 Kent Overstreet 提交于
Just a little convenience macro - main reason to add it now is preparing for immutable bio vecs, it'll reduce the size of the patch that puts bi_sector/bi_size/bi_idx into a struct bvec_iter. Signed-off-by: NKent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: Lars Ellenberg <drbd-dev@lists.linbit.com> CC: Jiri Kosina <jkosina@suse.cz> CC: Alasdair Kergon <agk@redhat.com> CC: dm-devel@redhat.com CC: Neil Brown <neilb@suse.de> CC: Martin Schwidefsky <schwidefsky@de.ibm.com> CC: Heiko Carstens <heiko.carstens@de.ibm.com> CC: linux-s390@vger.kernel.org CC: Chris Mason <chris.mason@fusionio.com> CC: Steven Whitehouse <swhiteho@redhat.com> Acked-by: NSteven Whitehouse <swhiteho@redhat.com>
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- 20 3月, 2013 3 次提交
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由 NeilBrown 提交于
A number of problems can occur due to races between resync/recovery and discard. - if sync_request calls handle_stripe() while a discard is happening on the stripe, it might call handle_stripe_clean_event before all of the individual discard requests have completed (so some devices are still locked, but not all). Since commit ca64cae9 md/raid5: Make sure we clear R5_Discard when discard is finished. this will cause R5_Discard to be cleared for the parity device, so handle_stripe_clean_event() will not be called when the other devices do become unlocked, so their ->written will not be cleared. This ultimately leads to a WARN_ON in init_stripe and a lock-up. - If handle_stripe_clean_event() does clear R5_UPTODATE at an awkward time for resync, it can lead to s->uptodate being less than disks in handle_parity_checks5(), which triggers a BUG (because it is one). So: - keep R5_Discard on the parity device until all other devices have completed their discard request - make sure we don't try to have a 'discard' and a 'sync' action at the same time. This involves a new stripe flag to we know when a 'discard' is happening, and the use of R5_Overlap on the parity disk so when a discard is wanted while a sync is active, so we know to wake up the discard at the appropriate time. Discard support for RAID5 was added in 3.7, so this is suitable for any -stable kernel since 3.7. Cc: stable@vger.kernel.org (v3.7+) Reported-by: NJes Sorensen <Jes.Sorensen@redhat.com> Tested-by: NJes Sorensen <Jes.Sorensen@redhat.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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由 Jonathan Brassow 提交于
MD RAID5: Fix kernel oops when RAID4/5/6 is used via device-mapper Commit a9add5d9 (v3.8-rc1) added blktrace calls to the RAID4/5/6 driver. However, when device-mapper is used to create RAID4/5/6 arrays, the mddev->gendisk and mddev->queue fields are not setup. Therefore, calling things like trace_block_bio_remap will cause a kernel oops. This patch conditionalizes those calls on whether the proper fields exist to make the calls. (Device-mapper will call trace_block_bio_remap on its own.) This patch is suitable for the 3.8.y stable kernel. Cc: stable@vger.kernel.org (v3.8+) Signed-off-by: NJonathan Brassow <jbrassow@redhat.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
Since commit 1ed850f3 md/raid5: make sure to_read and to_write never go negative. It has been possible for handle_stripe_dirtying to be called when there isn't actually any work to do. It then calls schedule_reconstruction() which will set R5_LOCKED on the parity block(s) even when nothing else is happening. This then causes problems in do_release_stripe(). So add checks to schedule_reconstruction() so that if it doesn't find anything to do, it just aborts. This bug was introduced in v3.7, so the patch is suitable for -stable kernels since then. Cc: stable@vger.kernel.org (v3.7+) Reported-by: Nmajianpeng <majianpeng@gmail.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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- 28 2月, 2013 2 次提交
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由 Sasha Levin 提交于
I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: NPeter Senna Tschudin <peter.senna@gmail.com> Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: NSasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 NeilBrown 提交于
This doesn't seem to actually help and we have an alternate multi-threading approach waiting in the wings, so just get rid of this config option and associated code. As a bonus, we remove one use of CONFIG_EXPERIMENTAL Cc: Dan Williams <djbw@fb.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: NNeilBrown <neilb@suse.de>
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- 14 1月, 2013 1 次提交
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由 Tejun Heo 提交于
bio completion didn't kick block_bio_complete TP. Only dm was explicitly triggering the TP on IO completion. This makes block_bio_complete TP useless for tracers which want to know about bios, and all other bio based drivers skip generating blktrace completion events. This patch makes all bio completions via bio_endio() generate block_bio_complete TP. * Explicit trace_block_bio_complete() invocation removed from dm and the trace point is unexported. * @rq dropped from trace_block_bio_complete(). bios may fly around w/o queue associated. Verifying and accessing the assocaited queue belongs to TP probes. * blktrace now gets both request and bio completions. Make it ignore bio completions if request completion path is happening. This makes all bio based drivers generate blktrace completion events properly and makes the block_bio_complete TP actually useful. v2: With this change, block_bio_complete TP could be invoked on sg commands which have bio's with %NULL bi_bdev. Update TP assignment code to check whether bio->bi_bdev is %NULL before dereferencing. Signed-off-by: NTejun Heo <tj@kernel.org> Original-patch-by: NNamhyung Kim <namhyung@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Alasdair Kergon <agk@redhat.com> Cc: dm-devel@redhat.com Cc: Neil Brown <neilb@suse.de> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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- 18 12月, 2012 1 次提交
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由 NeilBrown 提交于
This makes it easier to trace what raid5 is doing. Signed-off-by: NNeilBrown <neilb@suse.de>
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- 13 12月, 2012 1 次提交
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由 NeilBrown 提交于
handle_stripe_expansion contains: if (tx) { async_tx_ack(tx); dma_wait_for_async_tx(tx); } which is very similar to the body of async_tx_quiesce(), except that the later handles an error from dma_wait_for_async_tx() (admittedly by panicing, but that decision belongs in the dma code, not the md code). So just us async_tx_quiesce(). Acked-by: NDan Williams <djbw@fb.com> Reported-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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- 30 11月, 2012 1 次提交
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由 Lukas Czerner 提交于
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: NLukas 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: NJens Axboe <axboe@kernel.dk>
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- 22 11月, 2012 2 次提交
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由 NeilBrown 提交于
commit 9e444768 MD: raid5 avoid unnecessary zero page for trim change raid5 to clear R5_Discard when the complete request is handled rather than when submitting the per-device discard request. However it did not clear R5_Discard for the parity device. This means that if the stripe_head was reused before it expired from the cache, the setting would be wrong and a hang would result. Also if the R5_Uptodate bit happens to be set, R5_Discard again won't be cleared. But R5_Uptodate really should be clear at this point. So make sure R5_Discard is cleared in all cases, and clear R5_Uptodate when a 'discard' completes. Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
stripe_handle. The chunk of code in stripe_handle which responds to a *_result value in reconstruct_state is really the completion of some processing that happened outside of handle_stripe (possibly asynchronously) and so should be one of the first things done in handle_stripe(). After the next patch it will be important that it happens before handle_stripe_clean_event(), as that will clear some dev->flags bit that this code tests. Signed-off-by: NNeilBrown <neilb@suse.de>
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- 20 11月, 2012 1 次提交
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由 NeilBrown 提交于
blkdev_issue_discard currently assumes that the granularity is a power of 2. So in raid5, round the chosen number up to avoid embarrassment. Cc: Shaohua Li <shli@kernel.org> Signed-off-by: NNeilBrown <neilb@suse.de>
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- 30 10月, 2012 1 次提交
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由 Masanari Iida 提交于
Correct spelling typo in drivers/md. Signed-off-by: NMasanari Iida <standby24x7@gmail.com> Signed-off-by: NJiri Kosina <jkosina@suse.cz>
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- 11 10月, 2012 9 次提交
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由 NeilBrown 提交于
When a RAID5 is reshaping, conf->raid_disks is increased before mddev->delta_disks becomes zero. This can result in check_reshape calling resize_stripes with a number that is too large. This particularly happens when md_check_recovery calls ->check_reshape(). If we use ->previous_raid_disks, we don't risk this. Signed-off-by: NNeilBrown <neilb@suse.de>
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由 Jianpeng Ma 提交于
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: NJianpeng Ma <majianpeng@gmail.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
to_read and to_write are part of the result of analysing a stripe before handling it. Their use is to avoid some loops and tests if the values are known to be zero. Thus it is not a problem if they are a little bit larger than they should be. So decrementing them in handle_failed_stripe serves little value, and due to races it could cause some loops to be skipped incorrectly. So remove those decrements. Reported-by: N"Jianpeng Ma" <majianpeng@gmail.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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由 Alexander Lyakas 提交于
Signed-off-by: NAlex Lyakas <alex@zadarastorage.com> Suggested-by: NYair Hershko <yair@zadarastorage.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
The pr_debug in add_stripe_bio could race with something changing *bip, so it is best to hold the lock until after the pr_debug. Reported-by: N"Jianpeng Ma" <majianpeng@gmail.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
We really should hold the stripe_lock while accessing 'toread' else we could race with add_stripe_bio and corrupt a list. Reported-by: N"Jianpeng Ma" <majianpeng@gmail.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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由 Shaohua Li 提交于
We want to avoid zero discarded dev page, because it's useless for discard. But if we don't zero it, another read/write hit such page in the cache and will get inconsistent data. To avoid zero the page, we don't set R5_UPTODATE flag after construction is done. In this way, discard write request is still issued and finished, but read will not hit the page. If the stripe gets accessed soon, we need reread the stripe, but since the chance is low, the reread isn't a big deal. Signed-off-by: NShaohua Li <shli@fusionio.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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由 Shaohua Li 提交于
Discard for raid4/5/6 has limitation. If discard request size is small, we do discard for one disk, but we need calculate parity and write parity disk. To correctly calculate parity, zero_after_discard must be guaranteed. Even it's true, we need do discard for one disk but write another disks, which makes the parity disks wear out fast. This doesn't make sense. So an efficient discard for raid4/5/6 should discard all data disks and parity disks, which requires the write pattern to be (A, A+chunk_size, A+chunk_size*2...). If A's size is smaller than chunk_size, such pattern is almost impossible in practice. So in this patch, I only handle the case that A's size equals to chunk_size. That is discard request should be aligned to stripe size and its size is multiple of stripe size. Since we can only handle request with specific alignment and size (or part of the request fitting stripes), we can't guarantee zero_after_discard even zero_after_discard is true in low level drives. The block layer doesn't send down correctly aligned requests even correct discard alignment is set, so I must filter out. For raid4/5/6 parity calculation, if data is 0, parity is 0. So if zero_after_discard is true for all disks, data is consistent after discard. Otherwise, data might be lost. Let's consider a scenario: discard a stripe, write data to one disk and write parity disk. The stripe could be still inconsistent till then depending on using data from other data disks or parity disks to calculate new parity. If the disk is broken, we can't restore it. So in this patch, we only enable discard support if all disks have zero_after_discard. If discard fails in one disk, we face the similar inconsistent issue above. The patch will make discard follow the same path as normal write request. If discard fails, a resync will be scheduled to make the data consistent. This isn't good to have extra writes, but data consistency is important. If a subsequent read/write request hits raid5 cache of a discarded stripe, the discarded dev page should have zero filled, so the data is consistent. This patch will always zero dev page for discarded request stripe. This isn't optimal because discard request doesn't need such payload. Next patch will avoid it. Signed-off-by: NShaohua Li <shli@fusionio.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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由 Shaohua Li 提交于
Change the thread parameter, so the thread can carry extra info. Next patch will use it. Signed-off-by: NShaohua Li <shli@fusionio.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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