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* dm thin: add timeout to stop out-of-data-space mode holding IO foreverJoe Thornber2014-05-141-0/+21
| | | | | | | | | | | | | | | | If the pool runs out of data space, dm-thin can be configured to either error IOs that would trigger provisioning, or hold those IOs until the pool is resized. Unfortunately, holding IOs until the pool is resized can result in a cascade of tasks hitting the hung_task_timeout, which may render the system unavailable. Add a fixed timeout so IOs can only be held for a maximum of 60 seconds. If LVM is going to resize a thin-pool that is out of data space it needs to be prompt about it. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 3.14+
* dm thin: allow metadata commit if pool is in PM_OUT_OF_DATA_SPACE modeJoe Thornber2014-05-141-1/+1
| | | | | | | | | | | | | | | Commit 3e1a0699 ("dm thin: fix out of data space handling") introduced a regression in the metadata commit() method by returning an error if the pool is in PM_OUT_OF_DATA_SPACE mode. This oversight caused a thin device to return errors even if the default queue_if_no_space ENOSPC handling mode is used. Fix commit() to only fail if pool is in PM_READ_ONLY or PM_FAIL mode. Reported-by: qindehua@163.com Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 3.14+
* dm thin: use INIT_WORK_ONSTACK in noflush_work to avoid ODEBUG warningMike Snitzer2014-04-291-1/+1
| | | | | | | | | Use INIT_WORK_ONSTACK to silence "ODEBUG: object is on stack, but not annotated". Reported-by: Zdeněk Kabeláč <zkabelac@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
* dm thin: fix rcu_read_lock being held in code that can sleepJoe Thornber2014-04-081-3/+67
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit c140e1c4e23 ("dm thin: use per thin device deferred bio lists") introduced the use of an rculist for all active thin devices. The use of rcu_read_lock() in process_deferred_bios() can result in a BUG if a dm_bio_prison_cell must be allocated as a side-effect of bio_detain(): BUG: sleeping function called from invalid context at mm/mempool.c:203 in_atomic(): 1, irqs_disabled(): 0, pid: 6, name: kworker/u8:0 3 locks held by kworker/u8:0/6: #0: ("dm-" "thin"){.+.+..}, at: [<ffffffff8106be42>] process_one_work+0x192/0x550 #1: ((&pool->worker)){+.+...}, at: [<ffffffff8106be42>] process_one_work+0x192/0x550 #2: (rcu_read_lock){.+.+..}, at: [<ffffffff816360b5>] do_worker+0x5/0x4d0 We can't process deferred bios with the rcu lock held, since dm_bio_prison_cell allocation may block if the bio-prison's cell mempool is exhausted. To fix: - Introduce a refcount and completion field to each thin_c - Add thin_get/put methods for adjusting the refcount. If the refcount hits zero then the completion is triggered. - Initialise refcount to 1 when creating thin_c - When iterating the active_thins list we thin_get() whilst the rcu lock is held. - After the rcu lock is dropped we process the deferred bios for that thin. - When destroying a thin_c we thin_put() and then wait for the completion -- to avoid a race between the worker thread iterating from that thin_c and destroying the thin_c. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm thin: irqsave must always be used with the pool->lock spinlockJoe Thornber2014-04-081-2/+3
| | | | | | | | | | | | Commit c140e1c4e23 ("dm thin: use per thin device deferred bio lists") incorrectly stopped disabling irqs when taking the pool's spinlock. Irqs must be disabled when taking the pool's spinlock otherwise a thread could spin_lock(), then get interrupted to service thin_endio() in interrupt context, which would then deadlock in spin_lock_irqsave(). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm thin: sort the per thin deferred bios using an rb_treeMike Snitzer2014-04-041-2/+82
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A thin-pool will allocate blocks using FIFO order for all thin devices which share the thin-pool. Because of this simplistic allocation the thin-pool's space can become fragmented quite easily; especially when multiple threads are requesting blocks in parallel. Sort each thin device's deferred_bio_list based on logical sector to help reduce fragmentation of the thin-pool's ondisk layout. The following tables illustrate the realized gains/potential offered by sorting each thin device's deferred_bio_list. An "io size"-sized random read of the device would result in "seeks/io" fragments being read, with an average "distance/seek" between each fragment. Data was written to a single thin device using multiple threads via iozone (8 threads, 64K for both the block_size and io_size). unsorted: io size seeks/io distance/seek -------------------------------------- 4k 0.000 0b 16k 0.013 11m 64k 0.065 11m 256k 0.274 10m 1m 1.109 10m 4m 4.411 10m 16m 17.097 11m 64m 60.055 13m 256m 148.798 25m 1g 809.929 21m sorted: io size seeks/io distance/seek -------------------------------------- 4k 0.000 0b 16k 0.000 1g 64k 0.001 1g 256k 0.003 1g 1m 0.011 1g 4m 0.045 1g 16m 0.181 1g 64m 0.747 1011m 256m 3.299 1g 1g 14.373 1g Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
* dm thin: use per thin device deferred bio listsMike Snitzer2014-03-311-61/+104
| | | | | | | | | | | | | The thin-pool previously only had a single deferred_bios list that would collect bios for all thin devices in the pool. Split this per-pool deferred_bios list out to per-thin deferred_bios_list -- doing so enables increased parallelism when processing deferred bios. And now that each thin device has it's own deferred_bios_list we can sort all bios in the list using logical sector. The requeue code in error handling path is also cleaner as a side-effect. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
* dm thin: simplify pool_is_congestedMike Snitzer2014-03-311-11/+5
| | | | | | | | | The pool is congested if the pool is in PM_OUT_OF_DATA_SPACE mode. This is more explicit/clear/efficient than inferring whether or not the pool is congested by checking if retry_on_resume_list is empty. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
* dm thin: fix dangling bio in process_deferred_bios error pathMike Snitzer2014-03-281-1/+1
| | | | | | | | | | If unable to ensure_next_mapping() we must add the current bio, which was removed from the @bios list via bio_list_pop, back to the deferred_bios list before all the remaining @bios. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Cc: stable@vger.kernel.org
* dm thin: fix noflush suspend IO queueingJoe Thornber2014-03-051-2/+72
| | | | | | | | | | | | | | | | | i) by the time DM core calls the postsuspend hook the dm_noflush flag has been cleared. So the old thin_postsuspend did nothing. We need to use the presuspend hook instead. ii) There was a race between bios leaving DM core and arriving in the deferred queue. thin_presuspend now sets a 'requeue' flag causing all bios destined for that thin to be requeued back to DM core. Then it requeues all held IO, and all IO on the deferred queue (destined for that thin). Finally postsuspend clears the 'requeue' flag. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm thin: fix deadlock in __requeue_bio_listJoe Thornber2014-03-051-6/+7
| | | | | | | | | | | The spin lock in requeue_io() was held for too long, allowing deadlock. Don't worry, due to other issues addressed in the following "dm thin: fix noflush suspend IO queueing" commit, this code was never called. Fix this by taking the spin lock for a much shorter period of time. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm thin: fix out of data space handlingJoe Thornber2014-03-051-45/+102
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Ideally a thin pool would never run out of data space; the low water mark would trigger userland to extend the pool before we completely run out of space. However, many small random IOs to unprovisioned space can consume data space at an alarming rate. Adjust your low water mark if you're frequently seeing "out-of-data-space" mode. Before this fix, if data space ran out the pool would be put in PM_READ_ONLY mode which also aborted the pool's current metadata transaction (data loss for any changes in the transaction). This had a side-effect of needlessly compromising data consistency. And retry of queued unserviceable bios, once the data pool was resized, could initiate changes to potentially inconsistent pool metadata. Now when the pool's data space is exhausted transition to a new pool mode (PM_OUT_OF_DATA_SPACE) that allows metadata to be changed but data may not be allocated. This allows users to remove thin volumes or discard data to recover data space. The pool is no longer put in PM_READ_ONLY mode in response to the pool running out of data space. And PM_READ_ONLY mode no longer aborts the pool's current metadata transaction. Also, set_pool_mode() will now notify userspace when the pool mode is changed. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm thin: ensure user takes action to validate data and metadata consistencyMike Snitzer2014-03-051-22/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a thin metadata operation fails the current transaction will abort, whereby causing potential for IO layers up the stack (e.g. filesystems) to have data loss. As such, set THIN_METADATA_NEEDS_CHECK_FLAG in the thin metadata's superblock which: 1) requires the user verify the thin metadata is consistent (e.g. use thin_check, etc) 2) suggests the user verify the thin data is consistent (e.g. use fsck) The only way to clear the superblock's THIN_METADATA_NEEDS_CHECK_FLAG is to run thin_repair. On metadata operation failure: abort current metadata transaction, set pool in read-only mode, and now set the needs_check flag. As part of this change, constraints are introduced or relaxed: * don't allow a pool to transition to write mode if needs_check is set * don't allow data or metadata space to be resized if needs_check is set * if a thin pool's metadata space is exhausted: the kernel will now force the user to take the pool offline for repair before the kernel will allow the metadata space to be extended. Also, update Documentation to include information about when the thin provisioning target commits metadata, how it handles metadata failures and running out of space. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Joe Thornber <ejt@redhat.com>
* dm thin: synchronize the pool mode during suspendMike Snitzer2014-03-041-0/+6
| | | | | | | | | | | | | | | | | | Commit b5330655 ("dm thin: handle metadata failures more consistently") increased potential for the pool's mode to be changed in response to metadata operation failures. When the pool mode is changed it isn't synchronized with the mode in pool_features stored in the target's context (ti->private) that is used as the basis for (re)establishing the pool mode during resume via bind_control_target. It is important that we synchronize the pool mode when it is changed otherwise the pool may experience and unexpected mode transition on the next resume (especially if there was no new table load). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
* dm thin: allow metadata space larger than supported to go unusedMike Snitzer2014-02-271-12/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It was always intended that a user could provide a thin metadata device that is larger than the max supported by the on-disk format. The extra space would just go unused. Unfortunately that never worked. If the user attempted to use a larger metadata device on creation they would get an error like the following: device-mapper: space map common: space map too large device-mapper: transaction manager: couldn't create metadata space map device-mapper: thin metadata: tm_create_with_sm failed device-mapper: table: 252:17: thin-pool: Error creating metadata object device-mapper: ioctl: error adding target to table Fix this by allowing the initial metadata space map creation to cap its size at the max number of blocks supported (DM_SM_METADATA_MAX_BLOCKS). get_metadata_dev_size() must also impose DM_SM_METADATA_MAX_BLOCKS (via THIN_METADATA_MAX_SECTORS), otherwise extending metadata would cap at THIN_METADATA_MAX_SECTORS_WARNING (which is larger than supported). Also, the calculation for THIN_METADATA_MAX_SECTORS didn't account for the sizeof the disk_bitmap_header. So the supported maximum metadata size is a bit smaller (reduced from 33423360 to 33292800 sectors). Lastly, remove the "excess space will not be used" warning message from get_metadata_dev_size(); it resulted in printing the warning multiple times. Factor out warn_if_metadata_device_too_big(), call it from pool_ctr() and maybe_resize_metadata_dev(). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
* dm thin: fix the error path for the thin device constructorMike Snitzer2014-02-241-1/+4
| | | | | | | | | | | | | | | | dm_pool_close_thin_device() must be called if dm_set_target_max_io_len() fails in thin_ctr(). Otherwise __pool_destroy() will fail because the pool will still have an open thin device: device-mapper: thin metadata: attempt to close pmd when 1 device(s) are still open device-mapper: thin: __pool_destroy: dm_pool_metadata_close() failed. Also, must establish error code if failing thin_ctr() because the pool is in fail_io mode. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Cc: stable@vger.kernel.org
* dm thin: avoid metadata commit if a pool's thin devices haven't changedMike Snitzer2014-02-171-1/+2
| | | | | | | | | | | | | | Commit 905e51b ("dm thin: commit outstanding data every second") introduced a periodic commit. This commit occurs regardless of whether any thin devices have made changes. Fix the periodic commit to check if any of a pool's thin devices have changed using dm_pool_changed_this_transaction(). Reported-by: Alexander Larsson <alexl@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Cc: stable@vger.kernel.org
* Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-blockLinus Torvalds2014-01-301-12/+18
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull core block IO changes from Jens Axboe: "The major piece in here is the immutable bio_ve series from Kent, the rest is fairly minor. It was supposed to go in last round, but various issues pushed it to this release instead. The pull request contains: - Various smaller blk-mq fixes from different folks. Nothing major here, just minor fixes and cleanups. - Fix for a memory leak in the error path in the block ioctl code from Christian Engelmayer. - Header export fix from CaiZhiyong. - Finally the immutable biovec changes from Kent Overstreet. This enables some nice future work on making arbitrarily sized bios possible, and splitting more efficient. Related fixes to immutable bio_vecs: - dm-cache immutable fixup from Mike Snitzer. - btrfs immutable fixup from Muthu Kumar. - bio-integrity fix from Nic Bellinger, which is also going to stable" * 'for-3.14/core' of git://git.kernel.dk/linux-block: (44 commits) xtensa: fixup simdisk driver to work with immutable bio_vecs block/blk-mq-cpu.c: use hotcpu_notifier() blk-mq: for_each_* macro correctness block: Fix memory leak in rw_copy_check_uvector() handling bio-integrity: Fix bio_integrity_verify segment start bug block: remove unrelated header files and export symbol blk-mq: uses page->list incorrectly blk-mq: use __smp_call_function_single directly btrfs: fix missing increment of bi_remaining Revert "block: Warn and free bio if bi_end_io is not set" block: Warn and free bio if bi_end_io is not set blk-mq: fix initializing request's start time block: blk-mq: don't export blk_mq_free_queue() block: blk-mq: make blk_sync_queue support mq block: blk-mq: support draining mq queue dm cache: increment bi_remaining when bi_end_io is restored block: fixup for generic bio chaining block: Really silence spurious compiler warnings block: Silence spurious compiler warnings block: Kill bio_pair_split() ...
| * Merge tag 'v3.13-rc6' into for-3.14/coreJens Axboe2013-12-311-27/+39
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Needed to bring blk-mq uptodate, since changes have been going in since for-3.14/core was established. Fixup merge issues related to the immutable biovec changes. Signed-off-by: Jens Axboe <axboe@kernel.dk> Conflicts: block/blk-flush.c fs/btrfs/check-integrity.c fs/btrfs/extent_io.c fs/btrfs/scrub.c fs/logfs/dev_bdev.c
| * | block: Generic bio chainingKent Overstreet2013-11-231-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds a generic mechanism for chaining bio completions. This is going to be used for a bio_split() replacement, and it turns out to be very useful in a fair amount of driver code - a fair number of drivers were implementing this in their own roundabout ways, often painfully. Note that this means it's no longer to call bio_endio() more than once on the same bio! This can cause problems for drivers that save/restore bi_end_io. Arguably they shouldn't be saving/restoring bi_end_io at all - in all but the simplest cases they'd be better off just cloning the bio, and immutable biovecs is making bio cloning cheaper. But for now, we add a bio_endio_nodec() for these cases. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk>
| * | block: Abstract out bvec iteratorKent Overstreet2013-11-231-10/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Immutable biovecs are going to require an explicit iterator. To implement immutable bvecs, a later patch is going to add a bi_bvec_done member to this struct; for now, this patch effectively just renames things. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "Ed L. Cashin" <ecashin@coraid.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Yehuda Sadeh <yehuda@inktank.com> Cc: Sage Weil <sage@inktank.com> Cc: Alex Elder <elder@inktank.com> Cc: ceph-devel@vger.kernel.org Cc: Joshua Morris <josh.h.morris@us.ibm.com> Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Neil Brown <neilb@suse.de> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: Boaz Harrosh <bharrosh@panasas.com> Cc: Benny Halevy <bhalevy@tonian.com> Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Chris Mason <chris.mason@fusionio.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jaegeuk Kim <jaegeuk.kim@samsung.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: Joern Engel <joern@logfs.org> Cc: Prasad Joshi <prasadjoshi.linux@gmail.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Ben Myers <bpm@sgi.com> Cc: xfs@oss.sgi.com Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Guo Chao <yan@linux.vnet.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: "Roger Pau Monné" <roger.pau@citrix.com> Cc: Jan Beulich <jbeulich@suse.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Ian Campbell <Ian.Campbell@citrix.com> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Jerome Marchand <jmarchand@redhat.com> Cc: Joe Perches <joe@perches.com> Cc: Peng Tao <tao.peng@emc.com> Cc: Andy Adamson <andros@netapp.com> Cc: fanchaoting <fanchaoting@cn.fujitsu.com> Cc: Jie Liu <jeff.liu@oracle.com> Cc: Sunil Mushran <sunil.mushran@gmail.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Pankaj Kumar <pankaj.km@samsung.com> Cc: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: Mel Gorman <mgorman@suse.de>6
* | | dm thin: fix pool feature parsingMike Snitzer2014-01-151-1/+1
| | | | | | | | | | | | | | | | | | | | | Commit 787a996cb251e20 ("dm thin: add error_if_no_space feature") mistakenly forgot to increase the number of feature args supported. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* | | dm thin: fix set_pool_mode exposed pool operation racesMike Snitzer2014-01-071-13/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The pool mode must not be switched until after the corresponding pool process_* methods have been established. Otherwise, because set_pool_mode() isn't interlocked with the IO path for performance reasons, the IO path can end up executing process_* operations that don't match the mode. This patch eliminates problems like the following (as seen on really fast PCIe SSD storage when transitioning the pool's mode from PM_READ_ONLY to PM_WRITE): kernel: device-mapper: thin: 253:2: reached low water mark for data device: sending event. kernel: device-mapper: thin: 253:2: no free data space available. kernel: device-mapper: thin: 253:2: switching pool to read-only mode kernel: device-mapper: thin: 253:2: switching pool to write mode kernel: ------------[ cut here ]------------ kernel: WARNING: CPU: 11 PID: 7564 at drivers/md/dm-thin.c:995 handle_unserviceable_bio+0x146/0x160 [dm_thin_pool]() ... kernel: Workqueue: dm-thin do_worker [dm_thin_pool] kernel: 00000000000003e3 ffff880308831cc8 ffffffff8152ebcb 00000000000003e3 kernel: 0000000000000000 ffff880308831d08 ffffffff8104c46c ffff88032502a800 kernel: ffff880036409000 ffff88030ec7ce00 0000000000000001 00000000ffffffc3 kernel: Call Trace: kernel: [<ffffffff8152ebcb>] dump_stack+0x49/0x5e kernel: [<ffffffff8104c46c>] warn_slowpath_common+0x8c/0xc0 kernel: [<ffffffff8104c4ba>] warn_slowpath_null+0x1a/0x20 kernel: [<ffffffffa001e2c6>] handle_unserviceable_bio+0x146/0x160 [dm_thin_pool] kernel: [<ffffffffa001f276>] process_bio_read_only+0x136/0x180 [dm_thin_pool] kernel: [<ffffffffa0020b75>] process_deferred_bios+0xc5/0x230 [dm_thin_pool] kernel: [<ffffffffa0020d31>] do_worker+0x51/0x60 [dm_thin_pool] kernel: [<ffffffff81067823>] process_one_work+0x183/0x490 kernel: [<ffffffff81068c70>] worker_thread+0x120/0x3a0 kernel: [<ffffffff81068b50>] ? manage_workers+0x160/0x160 kernel: [<ffffffff8106e86e>] kthread+0xce/0xf0 kernel: [<ffffffff8106e7a0>] ? kthread_freezable_should_stop+0x70/0x70 kernel: [<ffffffff8153b3ec>] ret_from_fork+0x7c/0xb0 kernel: [<ffffffff8106e7a0>] ? kthread_freezable_should_stop+0x70/0x70 kernel: ---[ end trace 3f00528e08ffa55c ]--- kernel: device-mapper: thin: pool mode is PM_WRITE not PM_READ_ONLY like expected!? dm-thin.c:995 was the WARN_ON_ONCE(get_pool_mode(pool) != PM_READ_ONLY); at the top of handle_unserviceable_bio(). And as the additional debugging I had conveys: the pool mode was _not_ PM_READ_ONLY like expected, it was already PM_WRITE, yet pool->process_bio was still set to process_bio_read_only(). Also, while fixing this up, reduce logging of redundant pool mode transitions by checking new_mode is different from old_mode. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
* | | dm thin: eliminate the no_free_space flagMike Snitzer2014-01-071-22/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The pool's error_if_no_space flag can easily serve the same purpose that no_free_space did, namely: control whether handle_unserviceable_bio() will error a bio or requeue it. This is cleaner since error_if_no_space is established when the pool's features are processed during table load. So it avoids managing the no_free_space flag by taking the pool's spinlock. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* | | dm thin: add error_if_no_space featureMike Snitzer2014-01-071-6/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the pool runs out of data or metadata space, the pool can either queue or error the IO destined to the data device. The default is to queue the IO until more space is added. An admin may now configure the pool to error IO when no space is available by setting the 'error_if_no_space' feature when loading the thin-pool table. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
* | | dm thin: requeue bios to DM core if no_free_space and in read-only modeMike Snitzer2014-01-071-6/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we switch the pool to read-only mode when the data device runs out of space it causes active writers to get IO errors once we resume after resizing the data device. If no_free_space is set, save bios to the 'retry_on_resume_list' and requeue them on resume (once the data or metadata device may have been resized). With this patch the resize_io test passes again (on slower storage): dmtest run --suite thin-provisioning -n /resize_io/ Later patches fix some subtle races associated with the pool mode transitions done as part of the pool's -ENOSPC handling. These races are exposed on fast storage (e.g. PCIe SSD). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
* | | dm thin: cleanup and improve no space handlingMike Snitzer2014-01-071-29/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Factor out_of_data_space() out of alloc_data_block(). Eliminate the use of 'no_free_space' as a latch in alloc_data_block() -- this is no longer needed now that we switch to read-only mode when we run out of data or metadata space. In a later patch, the 'no_free_space' flag will be eliminated entirely (in favor of checking metadata rather than relying on a transient flag). Move no metdata space handling into metdata_operation_failed(). Set no_free_space when metadata space is exhausted too. This is useful, because it offers consistency, for the following patch that will requeue data IOs if no_free_space. Also, rename no_space() to retry_bios_on_resume(). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
* | | dm thin: log info when growing the data or metadata deviceMike Snitzer2014-01-071-0/+7
| | | | | | | | | | | | | | | Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
* | | dm thin: handle metadata failures more consistentlyJoe Thornber2014-01-071-21/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce metadata_operation_failed() wrappers, around set_pool_mode(), to assist with improving the consistency of how metadata failures are handled. Logging is improved and metadata operation failures trigger read-only mode immediately. Also, eliminate redundant set_pool_mode() calls in the two alloc_data_block() caller's error paths. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* | | dm thin: factor out check_low_water_mark and use boolsJoe Thornber2014-01-071-15/+22
| | | | | | | | | | | | | | | | | | | | | | | | Factor check_low_water_mark() out of alloc_data_block(). Change a couple unsigned flags in the pool structure to bool. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* | | dm thin: add mappings to end of prepared_* listsMike Snitzer2014-01-071-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mappings could be processed in descending logical block order, particularly if buffered IO is used. This could adversely affect the latency of IO processing. Fix this by adding mappings to the end of the 'prepared_mappings' and 'prepared_discards' lists. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
* | | dm thin: return error from alloc_data_block if pool is not in write modeJoe Thornber2014-01-071-0/+3
| | | | | | | | | | | | | | | Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* | | dm thin: use bool rather than unsigned for flags in structuresMike Snitzer2014-01-071-11/+11
| | | | | | | | | | | | | | | | | | | | | | | | Also, move 'err' member in dm_thin_new_mapping structure to eliminate 4 byte hole (reduces size from 88 bytes to 80). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
* | | dm thin: fix discard support to a previously shared blockJoe Thornber2014-01-071-2/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a snapshot is created and later deleted the origin dm_thin_device's snapshotted_time will have been updated to reflect the snapshot's creation time. The 'shared' flag in the dm_thin_lookup_result struct returned from dm_thin_find_block() is an approximation based on snapshotted_time -- this is done to avoid 0(n), or worse, time complexity. In this case, the shared flag would be true. But because the 'shared' flag reflects an approximation a block can be incorrectly assumed to be shared (e.g. false positive for 'shared' because the snapshot no longer exists). This could result in discards issued to a thin device not being passed down to the pool's underlying data device. To fix this we double check that a thin block is really still in-use after a mapping is removed using dm_pool_block_is_used(). If the reference count for a block is now zero the discard is allowed to be passed down. Also add a 'definitely_not_shared' member to the dm_thin_new_mapping structure -- reflects that the 'shared' flag in the response from dm_thin_find_block() can only be held as definitive if false is returned. Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1043527 Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
* | | dm thin: initialize dm_thin_new_mapping returned by get_next_mappingMike Snitzer2014-01-071-11/+6
| |/ |/| | | | | | | | | | | | | | | As additional members are added to the dm_thin_new_mapping structure care should be taken to make sure they get initialized before use. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Cc: stable@vger.kernel.org
* | dm thin: allow pool in read-only mode to transition to read-write modeJoe Thornber2013-12-101-2/+10
| | | | | | | | | | | | | | | | | | | | | | | | A thin-pool may be in read-only mode because the pool's data or metadata space was exhausted. To allow for recovery, by adding more space to the pool, we must allow a pool to transition from PM_READ_ONLY to PM_WRITE mode. Otherwise, running out of space will render the pool permanently read-only. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
* | dm thin: re-establish read-only state when switching to fail modeJoe Thornber2013-12-101-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the thin-pool transitioned to fail mode and the thin-pool's table were reloaded for some reason: the new table's default pool mode would be read-write, though it will transition to fail mode during resume. When the pool mode transitions directly from PM_WRITE to PM_FAIL we need to re-establish the intermediate read-only state in both the metadata and persistent-data block manager (as is usually done with the normal pool mode transition sequence: PM_WRITE -> PM_READ_ONLY -> PM_FAIL). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
* | dm thin: always fallback the pool mode if commit failsJoe Thornber2013-12-101-22/+15
| | | | | | | | | | | | | | | | | | | | | | Rename commit_or_fallback() to commit(). Now all previous calls to commit() will trigger the pool mode to fallback if the commit fails. Also, check the error returned from commit() in alloc_data_block(). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
* | dm thin: switch to read-only mode if metadata space is exhaustedMike Snitzer2013-12-101-2/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Switch the thin pool to read-only mode in alloc_data_block() if dm_pool_alloc_data_block() fails because the pool's metadata space is exhausted. Differentiate between data and metadata space in messages about no free space available. This issue was noticed with the device-mapper-test-suite using: dmtest run --suite thin-provisioning -n /exhausting_metadata_space_causes_fail_mode/ The quantity of errors logged in this case must be reduced. before patch: device-mapper: thin: 253:4: reached low water mark for metadata device: sending event. device-mapper: space map metadata: unable to allocate new metadata block device-mapper: space map common: dm_tm_shadow_block() failed device-mapper: space map metadata: unable to allocate new metadata block device-mapper: space map common: dm_tm_shadow_block() failed device-mapper: space map metadata: unable to allocate new metadata block device-mapper: space map common: dm_tm_shadow_block() failed device-mapper: space map metadata: unable to allocate new metadata block device-mapper: space map common: dm_tm_shadow_block() failed device-mapper: space map metadata: unable to allocate new metadata block device-mapper: space map common: dm_tm_shadow_block() failed <snip ... these repeat for a _very_ long while ... > device-mapper: space map metadata: unable to allocate new metadata block device-mapper: thin: 253:4: commit failed: error = -28 device-mapper: thin: 253:4: switching pool to read-only mode after patch: device-mapper: thin: 253:4: reached low water mark for metadata device: sending event. device-mapper: space map metadata: unable to allocate new metadata block device-mapper: thin: 253:4: no free metadata space available. device-mapper: thin: 253:4: switching pool to read-only mode Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Cc: stable@vger.kernel.org
* | dm thin: switch to read only mode if a mapping insert failsJoe Thornber2013-12-101-1/+3
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Switch the thin pool to read-only mode when dm_thin_insert_block() fails since there is little reason to expect the cause of the failure to be resolved without further action by user space. This issue was noticed with the device-mapper-test-suite using: dmtest run --suite thin-provisioning -n /exhausting_metadata_space_causes_fail_mode/ The quantity of errors logged in this case must be reduced. before patch: device-mapper: thin: dm_thin_insert_block() failed device-mapper: space map metadata: unable to allocate new metadata block device-mapper: thin: dm_thin_insert_block() failed device-mapper: space map metadata: unable to allocate new metadata block device-mapper: thin: dm_thin_insert_block() failed device-mapper: space map metadata: unable to allocate new metadata block device-mapper: thin: dm_thin_insert_block() failed device-mapper: space map metadata: unable to allocate new metadata block device-mapper: thin: dm_thin_insert_block() failed device-mapper: space map metadata: unable to allocate new metadata block device-mapper: thin: dm_thin_insert_block() failed device-mapper: space map metadata: unable to allocate new metadata block device-mapper: thin: dm_thin_insert_block() failed device-mapper: space map metadata: unable to allocate new metadata block device-mapper: thin: dm_thin_insert_block() failed device-mapper: space map metadata: unable to allocate new metadata block device-mapper: thin: dm_thin_insert_block() failed device-mapper: space map metadata: unable to allocate new metadata block device-mapper: thin: dm_thin_insert_block() failed device-mapper: space map metadata: unable to allocate new metadata block device-mapper: space map metadata: unable to allocate new metadata block device-mapper: space map metadata: unable to allocate new metadata block device-mapper: space map metadata: unable to allocate new metadata block device-mapper: space map metadata: unable to allocate new metadata block device-mapper: space map metadata: unable to allocate new metadata block <snip ... these repeat for a long while ... > device-mapper: space map metadata: unable to allocate new metadata block device-mapper: space map common: dm_tm_shadow_block() failed device-mapper: thin: 253:4: no free metadata space available. device-mapper: thin: 253:4: switching pool to read-only mode after patch: device-mapper: space map metadata: unable to allocate new metadata block device-mapper: thin: 253:4: dm_thin_insert_block() failed: error = -28 device-mapper: thin: 253:4: switching pool to read-only mode Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
* dm thin: do not expose non-zero discard limits if discards disabledMike Snitzer2013-09-231-3/+11
| | | | | | | | | | | | | | | | | | Fix issue where the block layer would stack the discard limits of the pool's data device even if the "ignore_discard" pool feature was specified. The pool and thin device(s) still had discards disabled because the QUEUE_FLAG_DISCARD request_queue flag wasn't set. But to avoid user confusion when "ignore_discard" is used: both the pool device and the thin device(s) have zeroes for all discard limits. Also, always set discard_zeroes_data_unsupported in targets because they should never advertise the 'discard_zeroes_data' capability (even if the pool's data device supports it). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
* dm thin: always return -ENOSPC if no_free_space is setMike Snitzer2013-09-051-25/+31
| | | | | | | | | | | | | | | | | | If pool has 'no_free_space' set it means a previous allocation already determined the pool has no free space (and failed that allocation with -ENOSPC). By always returning -ENOSPC if 'no_free_space' is set, we do not allow the pool to oscillate between allocating blocks and then not. But a side-effect of this determinism is that if a user wants to be able to allocate new blocks they'll need to reload the pool's table (to clear the 'no_free_space' flag). This reload will happen automatically if the pool's data volume is resized. But if the user takes action to free a lot of space by deleting snapshot volumes, etc the pool will no longer allow data allocations to continue without an intervening table reload. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm thin: set pool read-only if breaking_sharing fails block allocationMike Snitzer2013-09-051-2/+4
| | | | | | | | | | break_sharing() now handles an arbitrary alloc_data_block() error the same way as provision_block(): marks pool read-only and errors the cell. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm thin: prefix pool error messages with pool device nameMike Snitzer2013-09-051-16/+32
| | | | | | | | Useful to know which pool is experiencing the error. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm thin: fix stacking of geometry limitsMike Snitzer2013-08-231-2/+10
| | | | | | | | | | | | | | Do not blindly override the queue limits (specifically io_min and io_opt). Allow traditional stacking of these limits if io_opt is a factor of the thin-pool's data block size. Without this patch mkfs.xfs does not recognize the thin device's provided limits as a useful geometry (e.g. raid) so these hints are ignored. This was due to setting io_min to a useless value. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
* dm thin: fix metadata dev resize detectionAlasdair G Kergon2013-05-191-2/+2
| | | | | | | | | | | | | | | Fix detection of the need to resize the dm thin metadata device. The code incorrectly tried to extend the metadata device when it didn't need to due to a merging error with patch 24347e9 ("dm thin: detect metadata device resizing"). device-mapper: transaction manager: couldn't open metadata space map device-mapper: thin metadata: tm_open_with_sm failed device-mapper: thin: aborting transaction failed device-mapper: thin: switching pool to failure mode Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm thin: generate event when metadata threshold passedJoe Thornber2013-05-101-0/+38
| | | | | | | | | | | Generate a dm event when the amount of remaining thin pool metadata space falls below a certain level. The threshold is taken to be a quarter of the size of the metadata device with a minimum threshold of 4MB. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm thin: detect metadata device resizingJoe Thornber2013-05-101-3/+51
| | | | | | | | | | | Allow the dm thin pool metadata device to be extended. Whenever a pool is resumed, detect whether the size of the metadata device has increased, and if so, extend the metadata to use the new space. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm thin: open dev read only when possibleJoe Thornber2013-05-101-11/+14
| | | | | | | | | | | | | | | If a thin pool is created in read-only-metadata mode then only open the metadata device read-only. Previously it was always opened with FMODE_READ | FMODE_WRITE. (Note that dm_get_device() still allows read-only dm devices to be used read-write at the moment: If I create a read-only linear device for the metadata, via dmsetup load --readonly, then I can still create a rw pool out of it.) Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm thin: refactor data dev resizeJoe Thornber2013-05-101-28/+59
| | | | | | | | Refactor device size functions in preparation for similar metadata device resizing functions. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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