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| * | md/raid5: use seqcount to protect access to shape in make_request.NeilBrown2013-08-282-1/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: NeilBrown <neilb@suse.de>
| * | raid5: sysfs entry to control worker thread numberShaohua Li2013-08-281-0/+60
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * | raid5: offload stripe handle to workqueueShaohua Li2013-08-282-15/+186
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * | raid5: fix stripe release orderShaohua Li2013-08-281-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * | raid5: make release_stripe locklessShaohua Li2013-08-282-3/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Shaohua Li <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * | md: avoid deadlock when dirty buffers during md_stop.NeilBrown2013-08-272-9/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the last process closes /dev/mdX sync_blockdev will be called so that all buffers get flushed. So if it is then opened for the STOP_ARRAY ioctl to be sent there will be nothing to flush. However if we open /dev/mdX in order to send the STOP_ARRAY ioctl just moments before some other process which was writing closes their file descriptor, then there won't be a 'last close' and the buffers might not get flushed. So do_md_stop() calls sync_blockdev(). However at this point it is holding ->reconfig_mutex. So if the array is currently 'clean' then the writes from sync_blockdev() will not complete until the array can be marked dirty and that won't happen until some other thread can get ->reconfig_mutex. So we deadlock. We need to move the sync_blockdev() call to before we take ->reconfig_mutex. However then some other thread could open /dev/mdX and write to it after we call sync_blockdev() and before we actually stop the array. This can leave dirty data in the page cache which is awkward. So introduce new flag MD_STILL_CLOSED. Set it before calling sync_blockdev(), clear it if anyone does open the file, and abort the STOP_ARRAY attempt if it gets set before we lock against further opens. It is still possible to get problems if you open /dev/mdX, write to it, then issue the STOP_ARRAY ioctl. Just don't do that. Signed-off-by: NeilBrown <neilb@suse.de>
| * | md: Don't test all of mddev->flags at once.NeilBrown2013-08-272-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mddev->flags is mostly used to record if an update of the metadata is needed. Sometimes the whole field is tested instead of just the important bits. This makes it difficult to introduce more state bits. So replace all bare tests of mddev->flags with tests for the bits that actually need testing. Signed-off-by: NeilBrown <neilb@suse.de>
| * | md: Fix apparent cut-and-paste error in super_90_validateDave Jones2013-08-271-1/+1
| | | | | | | | | | | | | | | | | | | | | Setting a variable to itself probably wasn't the intention here. Signed-off-by: Dave Jones <davej@fedoraproject.org> Signed-off-by: NeilBrown <neilb@suse.de>
| * | md: fix safe_mode buglet.NeilBrown2013-08-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Whe we set the safe_mode_timeout to a smaller value we trigger a timeout immediately - otherwise the small value might not be honoured. However if the previous timeout was 0 meaning "no timeout", we didn't. This would mean that no timeout happens until the next write completes, which could be a long time. Signed-off-by: NeilBrown <neilb@suse.de>
| * | md: don't call md_allow_write in get_bitmap_file.NeilBrown2013-08-271-4/+1
| |/ | | | | | | | | | | | | | | | | | | | | There is no really need as GFP_NOIO is very likely sufficient, and failure is not catastrophic. Calling md_allow_write here will convert a read-auto array to read/write which could be confusing when you are just performing a read operation. Signed-off-by: NeilBrown <neilb@suse.de>
* | Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds2013-09-031-1/+15
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull first round of SCSI updates from James Bottomley: "This patch set is a set of driver updates (ufs, zfcp, lpfc, mpt2/3sas, qla4xxx, qla2xxx [adding support for ISP8044 + other things]). We also have a new driver: esas2r which has a number of static checker problems, but which I expect to resolve over the -rc course of 3.12 under the new driver exception. We also have the error return that were discussed at LSF" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (118 commits) [SCSI] sg: push file descriptor list locking down to per-device locking [SCSI] sg: checking sdp->detached isn't protected when open [SCSI] sg: no need sg_open_exclusive_lock [SCSI] sg: use rwsem to solve race during exclusive open [SCSI] scsi_debug: fix logical block provisioning support when unmap_alignment != 0 [SCSI] scsi_debug: fix endianness bug in sdebug_build_parts() [SCSI] qla2xxx: Update the driver version to 8.06.00.08-k. [SCSI] qla2xxx: print MAC via %pMR. [SCSI] qla2xxx: Correction to message ids. [SCSI] qla2xxx: Correctly print out/in mailbox registers. [SCSI] qla2xxx: Add a new interface to update versions. [SCSI] qla2xxx: Move queue depth ramp down message to i/o debug level. [SCSI] qla2xxx: Select link initialization option bits from current operating mode. [SCSI] qla2xxx: Add loopback IDC-TIME-EXTEND aen handling support. [SCSI] qla2xxx: Set default critical temperature value in cases when ISPFX00 firmware doesn't provide it [SCSI] qla2xxx: QLAFX00 make over temperature AEN handling informational, add log for normal temperature AEN [SCSI] qla2xxx: Correct Interrupt Register offset for ISPFX00 [SCSI] qla2xxx: Remove handling of Shutdown Requested AEN from qlafx00_process_aen(). [SCSI] qla2xxx: Send all AENs for ISPFx00 to above layers. [SCSI] qla2xxx: Add changes in initialization for ISPFX00 cards with BIOS ...
| * [SCSI] Return ENODATA on medium errorHannes Reinecke2013-08-231-1/+15
| | | | | | | | | | | | | | | | | | When a medium error is detected the SCSI stack should return ENODATA to the upper layers. [jejb: fix whitespace error] Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
* | dm cache: avoid conflicting remove_mapping() in mq policyGeert Uytterhoeven2013-08-161-9/+7
|/ | | | | | | | | | | | | | | On sparc32, which includes <linux/swap.h> from <asm/pgtable_32.h>: drivers/md/dm-cache-policy-mq.c:962:13: error: conflicting types for 'remove_mapping' include/linux/swap.h:285:12: note: previous declaration of 'remove_mapping' was here As mq_remove_mapping() already exists, and the local remove_mapping() is used only once, inline it manually to avoid the conflict. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair Kergon <agk@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
* Merge tag 'md/3.11-fixes' of git://neil.brown.name/mdLinus Torvalds2013-07-263-6/+18
|\ | | | | | | | | | | | | | | | | | | | | | | Pull md fixes from Neil Brown: "Two more bugfixes for md in 3.11 Both marked for -stable, both since 3.3. I guess I should spend more time testing..." * tag 'md/3.11-fixes' of git://neil.brown.name/md: md/raid5: fix interaction of 'replace' and 'recovery'. md/raid10: remove use-after-free bug.
| * md/raid5: fix interaction of 'replace' and 'recovery'.NeilBrown2013-07-252-5/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 9a3e1101b827a59ac9036a672f5fa8d5279d0fe2 (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: qindehua <13691222965@163.com> Tested-by: qindehua <qindehua@163.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>
* | Merge branch 'for-3.11/drivers' of git://git.kernel.dk/linux-blockLinus Torvalds2013-07-2221-801/+869
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block IO driver bits from Jens Axboe: "As I mentioned in the core block pull request, due to real life circumstances the driver pull request would be late. Now it looks like -rc2 late... On the plus side, apart form the rsxx update, these are all things that I could argue could go in later in the cycle as they are fixes and not features. So even though things are late, it's not ALL bad. The pull request contains: - Updates to bcache, all bug fixes, from Kent. - A pile of drbd bug fixes (no big features this time!). - xen blk front/back fixes. - rsxx driver updates, some of them deferred form 3.10. So should be well cooked by now" * 'for-3.11/drivers' of git://git.kernel.dk/linux-block: (63 commits) bcache: Allocation kthread fixes bcache: Fix GC_SECTORS_USED() calculation bcache: Journal replay fix bcache: Shutdown fix bcache: Fix a sysfs splat on shutdown bcache: Advertise that flushes are supported bcache: check for allocation failures bcache: Fix a dumb race bcache: Use standard utility code bcache: Update email address bcache: Delete fuzz tester bcache: Document shrinker reserve better bcache: FUA fixes drbd: Allow online change of al-stripes and al-stripe-size drbd: Constants should be UPPERCASE drbd: Ignore the exit code of a fence-peer handler if it returns too late drbd: Fix rcu_read_lock balance on error path drbd: fix error return code in drbd_init() drbd: Do not sleep inside rcu bcache: Refresh usage docs ...
| * bcache: Allocation kthread fixesKent Overstreet2013-07-123-18/+15
| | | | | | | | | | | | | | | | The alloc kthread should've been using try_to_freeze() - and also there was the potential for the alloc kthread to get woken up after it had shut down, which would have been bad. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
| * bcache: Fix GC_SECTORS_USED() calculationKent Overstreet2013-07-121-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | Part of the job of garbage collection is to add up however many sectors of live data it finds in each bucket, but that doesn't work very well if it doesn't reset GC_SECTORS_USED() when it starts. Whoops. This wouldn't have broken anything horribly, but allocation tries to preferentially reclaim buckets that are mostly empty and that's not gonna work with an incorrect GC_SECTORS_USED() value. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
| * bcache: Journal replay fixKent Overstreet2013-07-121-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The journal replay code starts by finding something that looks like a valid journal entry, then it does a binary search over the unchecked region of the journal for the journal entries with the highest sequence numbers. Trouble is, the logic was wrong - journal_read_bucket() returns true if it found journal entries we need, but if the range of journal entries we're looking for loops around the end of the journal - in that case journal_read_bucket() could return true when it hadn't found the highest sequence number we'd seen yet, and in that case the binary search did the wrong thing. Whoops. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
| * bcache: Shutdown fixKent Overstreet2013-07-121-7/+11
| | | | | | | | | | | | | | | | | | Stopping a cache set is supposed to make it stop attached backing devices, but somewhere along the way that code got lost. Fixing this mainly has the effect of fixing our reboot notifier. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
| * bcache: Fix a sysfs splat on shutdownKent Overstreet2013-07-122-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | If we stopped a bcache device when we were already detaching (or something like that), bcache_device_unlink() would try to remove a symlink from sysfs that was already gone because the bcache dev kobject had already been removed from sysfs. So keep track of whether we've removed stuff from sysfs. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
| * bcache: Advertise that flushes are supportedKent Overstreet2013-07-122-1/+9
| | | | | | | | | | | | | | | | Whoops - bcache's flush/FUA was mostly correct, but flushes get filtered out unless we say we support them... Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
| * bcache: check for allocation failuresDan Carpenter2013-07-121-0/+2
| | | | | | | | | | | | There is a missing NULL check after the kzalloc(). Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
| * bcache: Fix a dumb raceKent Overstreet2013-07-121-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the far-too-complicated closure code - closures can have destructors, for probably dubious reasons; they get run after the closure is no longer waiting on anything but before dropping the parent ref, intended just for freeing whatever memory the closure is embedded in. Trouble is, when remaining goes to 0 and we've got nothing more to run - we also have to unlock the closure, setting remaining to -1. If there's a destructor, that unlock isn't doing anything - nobody could be trying to lock it if we're about to free it - but if the unlock _is needed... that check for a destructor was racy. Argh. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
| * bcache: Use standard utility codeKent Overstreet2013-07-018-144/+51
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some of bcache's utility code has made it into the rest of the kernel, so drop the bcache versions. Bcache used to have a workaround for allocating from a bio set under generic_make_request() (if you allocated more than once, the bios you already allocated would get stuck on current->bio_list when you submitted, and you'd risk deadlock) - bcache would mask out __GFP_WAIT when allocating bios under generic_make_request() so that allocation could fail and it could retry from workqueue. But bio_alloc_bioset() has a workaround now, so we can drop this hack and the associated error handling. Signed-off-by: Kent Overstreet <koverstreet@google.com>
| * bcache: Delete fuzz testerKent Overstreet2013-07-013-152/+2
| | | | | | | | | | | | This code has rotted and it hasn't been used in ages anyways. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
| * bcache: Document shrinker reserve betterKent Overstreet2013-07-011-0/+7
| | | | | | | | Signed-off-by: Kent Overstreet <kmo@daterainc.com>
| * bcache: FUA fixesKent Overstreet2013-07-013-5/+35
| | | | | | | | | | | | | | Journal writes need to be marked FUA, not just REQ_FLUSH. And btree node writes have... weird ordering requirements. Signed-off-by: Kent Overstreet <koverstreet@google.com>
| * bcache: Send label ueventsGabriel de Perthuis2013-06-262-1/+17
| | | | | | | | | | Signed-off-by: Gabriel de Perthuis <g2p.code@gmail.com> Signed-off-by: Kent Overstreet <koverstreet@google.com>
| * bcache: Send a uevent with a cached device's UUIDGabriel de Perthuis2013-06-261-3/+9
| | | | | | | | Signed-off-by: Gabriel de Perthuis <g2p.code@gmail.com>
| * bcache: Write out full stripesKent Overstreet2013-06-269-37/+121
| | | | | | | | | | | | | | | | | | | | | | | | | | Now that we're tracking dirty data per stripe, we can add two optimizations for raid5/6: * If a stripe is already dirty, force writes to that stripe to writeback mode - to help build up full stripes of dirty data * When flushing dirty data, preferentially write out full stripes first if there are any. Signed-off-by: Kent Overstreet <koverstreet@google.com>
| * bcache: Track dirty data by stripeKent Overstreet2013-06-267-26/+105
| | | | | | | | | | | | | | | | To make background writeback aware of raid5/6 stripes, we first need to track the amount of dirty data within each stripe - we do this by breaking up the existing sectors_dirty into per stripe atomic_ts Signed-off-by: Kent Overstreet <koverstreet@google.com>
| * bcache: Initialize sectors_dirty when attachingKent Overstreet2013-06-264-29/+39
| | | | | | | | | | | | | | | | | | | | | | Previously, dirty_data wouldn't get initialized until the first garbage collection... which was a bit of a problem for background writeback (as the PD controller keys off of it) and also confusing for users. This is also prep work for making background writeback aware of raid5/6 stripes. Signed-off-by: Kent Overstreet <koverstreet@google.com>
| * bcache: Improve lazy sortingKent Overstreet2013-06-263-17/+26
| | | | | | | | | | | | | | | | | | The old lazy sorting code was kind of hacky - rewrite in a way that mathematically makes more sense; the idea is that the size of the sets of keys in a btree node should increase by a more or less fixed ratio from smallest to biggest. Signed-off-by: Kent Overstreet <koverstreet@google.com>
| * bcache: Rip out pkey()/pbtree()Kent Overstreet2013-06-267-45/+57
| | | | | | | | | | | | | | | | Old gcc doesnt like the struct hack, and it is kind of ugly. So finish off the work to convert pr_debug() statements to tracepoints, and delete pkey()/pbtree(). Signed-off-by: Kent Overstreet <koverstreet@google.com>
| * bcache: Fix/revamp tracepointsKent Overstreet2013-06-2614-110/+126
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The tracepoints were reworked to be more sensible, and fixed a null pointer deref in one of the tracepoints. Converted some of the pr_debug()s to tracepoints - this is partly a performance optimization; it used to be that with DEBUG or CONFIG_DYNAMIC_DEBUG pr_debug() was an empty macro; but at some point it was changed to an empty inline function. Some of the pr_debug() statements had rather expensive function calls as part of the arguments, so this code was getting run unnecessarily even on non debug kernels - in some fast paths, too. Signed-off-by: Kent Overstreet <koverstreet@google.com>
| * bcache: Refactor btree ioKent Overstreet2013-06-266-176/+140
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The most significant change is that btree reads are now done synchronously, instead of asynchronously and doing the post read stuff from a workqueue. This was originally done because we can't block on IO under generic_make_request(). But - we already have a mechanism to punt cache lookups to workqueue if needed, so if we just use that we don't have to deal with the complexity of doing things asynchronously. The main benefit is this makes the locking situation saner; we can hold our write lock on the btree node until we're finished reading it, and we don't need that btree_node_read_done() flag anymore. Also, for writes, btree_write() was broken out into btree_node_write() and btree_leaf_dirty() - the old code with the boolean argument was dumb and confusing. The prio_blocked mechanism was improved a bit too, now the only counter is in struct btree_write, we don't mess with transfering a count from struct btree anymore. This required changing garbage collection to block prios at the start and unblock when it finishes, which is cleaner than what it was doing anyways (the old code had mostly the same effect, but was doing it in a convoluted way) And the btree iter btree_node_read_done() uses was converted to a real mempool. Signed-off-by: Kent Overstreet <koverstreet@google.com>
| * bcache: Convert allocator thread to kthreadKent Overstreet2013-06-264-33/+43
| | | | | | | | | | | | Using a workqueue when we just want a single thread is a bit silly. Signed-off-by: Kent Overstreet <koverstreet@google.com>
| * bcache: Warn when a device is already registered.Gabriel de Perthuis2013-06-261-2/+37
| | | | | | | | | | Signed-off-by: Gabriel de Perthuis <g2p.code+bcache@gmail.com> Signed-off-by: Kent Overstreet <koverstreet@google.com>
| * bcache: fix a spurious gcc complaint, use scnprintfKent Overstreet2013-06-261-21/+22
| | | | | | | | | | | | | | | | | | | | An old version of gcc was complaining about using a const int as the size of a stack allocated array. Which should be fine - but using ARRAY_SIZE() is better, anyways. Also, refactor the code to use scnprintf(). Signed-off-by: Kent Overstreet <koverstreet@google.com>
| * md: bcache: io.c: fix a potential NULL pointer dereferenceKumar Amit Mehta2013-06-261-0/+2
| | | | | | | | | | | | | | | | bio_alloc_bioset returns NULL on failure. This fix adds a missing check for potential NULL pointer dereferencing. Signed-off-by: Kumar Amit Mehta <gmate.amit@gmail.com> Signed-off-by: Kent Overstreet <koverstreet@google.com>
* | md/raid1: fix bio handling problems in process_checks()NeilBrown2013-07-181-23/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Recent change to use bio_copy_data() in raid1 when repairing an array is faulty. The underlying may have changed the bio in various ways using bio_advance and these need to be undone not just for the 'sbio' which is being copied to, but also the 'pbio' (primary) which is being copied from. So perform the reset on all bios that were read from and do it early. This also ensure that the sbio->bi_io_vec[j].bv_len passed to memcmp is correct. This fixes a crash during a 'check' of a RAID1 array. The crash was introduced in 3.10 so this is suitable for 3.10-stable. Cc: stable@vger.kernel.org (3.10) Reported-by: Joe Lawrence <joe.lawrence@stratus.com> Signed-off-by: NeilBrown <neilb@suse.de>
* | md: Remove recent change which allows devices to skip recovery.NeilBrown2013-07-181-14/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 7ceb17e87bde79d285a8b988cfed9eaeebe60b86 md: Allow devices to be re-added to a read-only array. allowed a bit more than just that. It also allows devices to be added to a read-write array and to end up skipping recovery. This patch removes the offending piece of code pending a rewrite for a subsequent release. More specifically: If the array has a bitmap, then the device will still need a bitmap based resync ('saved_raid_disk' is set under different conditions is a bitmap is present). If the array doesn't have a bitmap, then this is correct as long as nothing has been written to the array since the metadata was checked by ->validate_super. However there is no locking to ensure that there was no write. Bug was introduced in 3.10 and causes data corruption so patch is suitable for 3.10-stable. Cc: stable@vger.kernel.org (3.10) Reported-by: Joe Lawrence <joe.lawrence@stratus.com> 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>
* | Merge tag 'dm-3.11-changes' of ↵Linus Torvalds2013-07-1111-180/+818
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm Pull device-mapper changes from Alasdair G Kergon: "Add a device-mapper target called dm-switch to provide a multipath framework for storage arrays that dynamically reconfigure their preferred paths for different device regions. Fix a bug in the verity target that prevented its use with some specific sizes of devices. Improve some locking mechanisms in the device-mapper core and bufio. Add Mike Snitzer as a device-mapper maintainer. A few more clean-ups and fixes" * tag 'dm-3.11-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm: dm: add switch target dm: update maintainers dm: optimize reorder structure dm: optimize use SRCU and RCU dm bufio: submit writes outside lock dm cache: fix arm link errors with inline dm verity: use __ffs and __fls dm flakey: correct ctr alloc failure mesg dm verity: remove pointless comparison dm: use __GFP_HIGHMEM in __vmalloc dm verity: fix inability to use a few specific devices sizes dm ioctl: set noio flag to avoid __vmalloc deadlock dm mpath: fix ioctl deadlock when no paths
| * | dm: add switch targetJim Ramsay2013-07-103-0/+553
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | dm-switch is a new target that maps IO to underlying block devices efficiently when there is a large number of fixed-sized address regions but there is no simple pattern to allow for a compact mapping representation such as dm-stripe. Though we have developed this target for a specific storage device, Dell EqualLogic, we have made an effort to keep it as general purpose as possible in the hope that others may benefit. Originally developed by Jim Ramsay. Simplified by Mikulas Patocka. Signed-off-by: Jim Ramsay <jim_ramsay@dell.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * | dm: optimize reorder structureMikulas Patocka2013-07-101-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reorder actually improves performance by 20% (from 39.1s to 32.8s) on x86-64 quad core Opteron. I have no explanation for this, possibly it makes some other entries are better cache-aligned. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * | dm: optimize use SRCU and RCUMikulas Patocka2013-07-103-142/+175
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch removes "io_lock" and "map_lock" in struct mapped_device and "holders" in struct dm_table and replaces these mechanisms with sleepable-rcu. Previously, the code would call "dm_get_live_table" and "dm_table_put" to get and release table. Now, the code is changed to call "dm_get_live_table" and "dm_put_live_table". dm_get_live_table locks sleepable-rcu and dm_put_live_table unlocks it. dm_get_live_table_fast/dm_put_live_table_fast can be used instead of dm_get_live_table/dm_put_live_table. These *_fast functions use non-sleepable RCU, so the caller must not block between them. If the code changes active or inactive dm table, it must call dm_sync_table before destroying the old table. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * | dm bufio: submit writes outside lockMikulas Patocka2013-07-101-15/+58
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch changes dm-bufio so that it submits write I/Os outside of the lock. If the number of submitted buffers is greater than the number of requests on the target queue, submit_bio blocks. We want to block outside of the lock to improve latency of other threads that may need the lock. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>