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2015-11-23dm thin: fix regression in advertised discard limitsMike Snitzer
When establishing a thin device's discard limits we cannot rely on the underlying thin-pool device's discard capabilities (which are inherited from the thin-pool's underlying data device) given that DM thin devices must provide discard support even when the thin-pool's underlying data device doesn't support discards. Users were exposed to this thin device discard limits regression if their thin-pool's underlying data device does _not_ support discards. This regression caused all upper-layers that called the blkdev_issue_discard() interface to not be able to issue discards to thin devices (because discard_granularity was 0). This regression wasn't caught earlier because the device-mapper-test-suite's extensive 'thin-provisioning' discard tests are only ever performed against thin-pool's with data devices that support discards. Fix is to have thin_io_hints() test the pool's 'discard_enabled' feature rather than inferring whether or not a thin device's discard support should be enabled by looking at the thin-pool's discard_granularity. Fixes: 216076705 ("dm thin: disable discard support for thin devices if pool's is disabled") Reported-by: Mike Gerber <mike@sprachgewalt.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 4.1+
2015-11-19dm crypt: fix a possible hang due to race condition on exitMikulas Patocka
A kernel thread executes __set_current_state(TASK_INTERRUPTIBLE), __add_wait_queue, spin_unlock_irq and then tests kthread_should_stop(). It is possible that the processor reorders memory accesses so that kthread_should_stop() is executed before __set_current_state(). If such reordering happens, there is a possible race on thread termination: CPU 0: calls kthread_should_stop() it tests KTHREAD_SHOULD_STOP bit, returns false CPU 1: calls kthread_stop(cc->write_thread) sets the KTHREAD_SHOULD_STOP bit calls wake_up_process on the kernel thread, that sets the thread state to TASK_RUNNING CPU 0: sets __set_current_state(TASK_INTERRUPTIBLE) spin_unlock_irq(&cc->write_thread_wait.lock) schedule() - and the process is stuck and never terminates, because the state is TASK_INTERRUPTIBLE and wake_up_process on CPU 1 already terminated Fix this race condition by using a new flag DM_CRYPT_EXIT_THREAD to signal that the kernel thread should exit. The flag is set and tested while holding cc->write_thread_wait.lock, so there is no possibility of racy access to the flag. Also, remove the unnecessary set_task_state(current, TASK_RUNNING) following the schedule() call. When the process was woken up, its state was already set to TASK_RUNNING. Other kernel code also doesn't set the state to TASK_RUNNING following schedule() (for example, do_wait_for_common in completion.c doesn't do it). Fixes: dc2676210c42 ("dm crypt: offload writes to thread") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org # v4.0+ Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-11-17dm mpath: fix infinite recursion in ioctl when no paths and !queue_if_no_pathJunichi Nomura
In multipath_prepare_ioctl(), - pgpath is a path selected from available paths - m->queue_io is true if we cannot send a request immediately to paths, either because: * there is no available path * the path group needs activation (pg_init) - pg_init is not started - pg_init is still running - m->queue_if_no_path is true if the device is configured to queue I/O if there are no available paths If !pgpath && !m->queue_if_no_path, the handler should return -EIO. However in the course of refactoring the condition check has broken and returns success in that case. Since bdev points to the dm device itself, dm_blk_ioctl() calls __blk_dev_driver_ioctl() for itself and recurses until crash. You could reproduce the problem like this: # dmsetup create mp --table '0 1024 multipath 0 0 0 0' # sg_inq /dev/mapper/mp <crash> [ 172.648615] BUG: unable to handle kernel paging request at fffffffc81b10268 [ 172.662843] PGD 19dd067 PUD 0 [ 172.666269] Thread overran stack, or stack corrupted [ 172.671808] Oops: 0000 [#1] SMP ... Fix the condition check with some clarifications. Fixes: e56f81e0b01e ("dm: refactor ioctl handling") Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-11-17dm: do not reuse dm_blk_ioctl block_device input as local variableMike Snitzer
(Ab)using the @bdev passed to dm_blk_ioctl() opens the potential for targets' .prepare_ioctl to fail if they go on to check the bdev for !NULL. Fixes: e56f81e0b01e ("dm: refactor ioctl handling") Reported-by: Junichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-11-17dm: fix ioctl retry termination with signalJunichi Nomura
dm-mpath retries ioctl, when no path is readily available and the device is configured to queue I/O in such a case. If you want to stop the retry before multipathd decides to turn off queueing mode, you could send signal for the process to exit from the loop. However the check of fatal signal has not carried along when commit 6c182cd88d17 ("dm mpath: fix ioctl deadlock when no paths") moved the loop from dm-mpath to dm core. As a result, we can't terminate such a process in the retry loop. Easy reproducer of the situation is: # dmsetup create mp --table '0 1024 multipath 0 0 0 0' # dmsetup message mp 0 'queue_if_no_path' # sg_inq /dev/mapper/mp then you should be able to terminate sg_inq by pressing Ctrl+C. Fixes: 6c182cd88d17 ("dm mpath: fix ioctl deadlock when no paths") Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
2015-11-16dm thin: restore requested 'error_if_no_space' setting on OODS to WRITE ↵Mike Snitzer
transition A thin-pool that is in out-of-data-space (OODS) mode may transition back to write mode -- without the admin adding more space to the thin-pool -- if/when blocks are released (either by deleting thin devices or discarding provisioned blocks). But as part of the thin-pool's earlier transition to out-of-data-space mode the thin-pool may have set the 'error_if_no_space' flag to true if the no_space_timeout expires without more space having been made available. That implementation detail, of changing the pool's error_if_no_space setting, needs to be reset back to the default that the user specified when the thin-pool's table was loaded. Otherwise we'll drop the user requested behaviour on the floor when this out-of-data-space to write mode transition occurs. Reported-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Fixes: 2c43fd26e4 ("dm thin: fix missing out-of-data-space to write mode transition if blocks are released") Cc: stable@vger.kernel.org
2015-11-10Merge branch 'for-4.4/io-poll' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block IO poll support from Jens Axboe: "Various groups have been doing experimentation around IO polling for (really) fast devices. The code has been reviewed and has been sitting on the side for a few releases, but this is now good enough for coordinated benchmarking and further experimentation. Currently O_DIRECT sync read/write are supported. A framework is in the works that allows scalable stats tracking so we can auto-tune this. And we'll add libaio support as well soon. Fow now, it's an opt-in feature for test purposes" * 'for-4.4/io-poll' of git://git.kernel.dk/linux-block: direct-io: be sure to assign dio->bio_bdev for both paths directio: add block polling support NVMe: add blk polling support block: add block polling support blk-mq: return tag/queue combo in the make_request_fn handlers block: change ->make_request_fn() and users to return a queue cookie
2015-11-10Merge tag 'md/4.4-rc0-fix' of git://neil.brown.name/mdLinus Torvalds
Pull config fix for md from Neil Brown: "New config dependency needed as md/raid5 now uses crc32c" * tag 'md/4.4-rc0-fix' of git://neil.brown.name/md: raid5-cache: add crc32c Kconfig dependency
2015-11-09raid5-cache: add crc32c Kconfig dependencyArnd Bergmann
The recent change of the raid5-cache code to use crc32c instead of crc32 causes link errors when CONFIG_LIBCRC32C is disabled: drivers/built-in.o: In function crc32c' core.c:(.text+0x1c6060): undefined reference to `crc32c' This adds an explicit 'select' statement like all other users of this function do. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 5cb2fbd6ea0d ("raid5-cache: use crc32c checksum") Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-07Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge second patch-bomb from Andrew Morton: - most of the rest of MM - procfs - lib/ updates - printk updates - bitops infrastructure tweaks - checkpatch updates - nilfs2 update - signals - various other misc bits: coredump, seqfile, kexec, pidns, zlib, ipc, dma-debug, dma-mapping, ... * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (102 commits) ipc,msg: drop dst nil validation in copy_msg include/linux/zutil.h: fix usage example of zlib_adler32() panic: release stale console lock to always get the logbuf printed out dma-debug: check nents in dma_sync_sg* dma-mapping: tidy up dma_parms default handling pidns: fix set/getpriority and ioprio_set/get in PRIO_USER mode kexec: use file name as the output message prefix fs, seqfile: always allow oom killer seq_file: reuse string_escape_str() fs/seq_file: use seq_* helpers in seq_hex_dump() coredump: change zap_threads() and zap_process() to use for_each_thread() coredump: ensure all coredumping tasks have SIGNAL_GROUP_COREDUMP signal: remove jffs2_garbage_collect_thread()->allow_signal(SIGCONT) signal: introduce kernel_signal_stop() to fix jffs2_garbage_collect_thread() signal: turn dequeue_signal_lock() into kernel_dequeue_signal() signals: kill block_all_signals() and unblock_all_signals() nilfs2: fix gcc uninitialized-variable warnings in powerpc build nilfs2: fix gcc unused-but-set-variable warnings MAINTAINERS: nilfs2: add header file for tracing nilfs2: add tracepoints for analyzing reading and writing metadata files ...
2015-11-07Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial updates from Jiri Kosina: "Trivial stuff from trivial tree that can be trivially summed up as: - treewide drop of spurious unlikely() before IS_ERR() from Viresh Kumar - cosmetic fixes (that don't really affect basic functionality of the driver) for pktcdvd and bcache, from Julia Lawall and Petr Mladek - various comment / printk fixes and updates all over the place" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: bcache: Really show state of work pending bit hwmon: applesmc: fix comment typos Kconfig: remove comment about scsi_wait_scan module class_find_device: fix reference to argument "match" debugfs: document that debugfs_remove*() accepts NULL and error values net: Drop unlikely before IS_ERR(_OR_NULL) mm: Drop unlikely before IS_ERR(_OR_NULL) fs: Drop unlikely before IS_ERR(_OR_NULL) drivers: net: Drop unlikely before IS_ERR(_OR_NULL) drivers: misc: Drop unlikely before IS_ERR(_OR_NULL) UBI: Update comments to reflect UBI_METAONLY flag pktcdvd: drop null test before destroy functions
2015-11-07block: change ->make_request_fn() and users to return a queue cookieJens Axboe
No functional changes in this patch, but it prepares us for returning a more useful cookie related to the IO that was queued up. Signed-off-by: Jens Axboe <axboe@fb.com> Acked-by: Christoph Hellwig <hch@lst.de> Acked-by: Keith Busch <keith.busch@intel.com>
2015-11-06mm, page_alloc: distinguish between being unable to sleep, unwilling to ↵Mel Gorman
sleep and avoiding waking kswapd __GFP_WAIT has been used to identify atomic context in callers that hold spinlocks or are in interrupts. They are expected to be high priority and have access one of two watermarks lower than "min" which can be referred to as the "atomic reserve". __GFP_HIGH users get access to the first lower watermark and can be called the "high priority reserve". Over time, callers had a requirement to not block when fallback options were available. Some have abused __GFP_WAIT leading to a situation where an optimisitic allocation with a fallback option can access atomic reserves. This patch uses __GFP_ATOMIC to identify callers that are truely atomic, cannot sleep and have no alternative. High priority users continue to use __GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify callers that want to wake kswapd for background reclaim. __GFP_WAIT is redefined as a caller that is willing to enter direct reclaim and wake kswapd for background reclaim. This patch then converts a number of sites o __GFP_ATOMIC is used by callers that are high priority and have memory pools for those requests. GFP_ATOMIC uses this flag. o Callers that have a limited mempool to guarantee forward progress clear __GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall into this category where kswapd will still be woken but atomic reserves are not used as there is a one-entry mempool to guarantee progress. o Callers that are checking if they are non-blocking should use the helper gfpflags_allow_blocking() where possible. This is because checking for __GFP_WAIT as was done historically now can trigger false positives. Some exceptions like dm-crypt.c exist where the code intent is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to flag manipulations. o Callers that built their own GFP flags instead of starting with GFP_KERNEL and friends now also need to specify __GFP_KSWAPD_RECLAIM. The first key hazard to watch out for is callers that removed __GFP_WAIT and was depending on access to atomic reserves for inconspicuous reasons. In some cases it may be appropriate for them to use __GFP_HIGH. The second key hazard is callers that assembled their own combination of GFP flags instead of starting with something like GFP_KERNEL. They may now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless if it's missed in most cases as other activity will wake kswapd. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Vitaly Wool <vitalywool@gmail.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-06bcache: Really show state of work pending bitPetr Mladek
WORK_STRUCT_PENDING is a mask for testing the pending bit. test_bit() expects the number of the bit and we need to use WORK_STRUCT_PENDING_BIT there. Also work_data_bits() is defined in workqueues.h now. I have noticed this just by chance when looking how WORK_STRUCT_PENDING_BIT is used. The change is compile tested. Signed-off-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-11-04Merge tag 'dm-4.4-changes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: "Smaller set of DM changes for this merge. I've based these changes on Jens' for-4.4/reservations branch because the associated DM changes required it. - Revert a dm-multipath change that caused a regression for unprivledged users (e.g. kvm guests) that issued ioctls when a multipath device had no available paths. - Include Christoph's refactoring of DM's ioctl handling and add support for passing through persistent reservations with DM multipath. - All other changes are very simple cleanups" * tag 'dm-4.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm switch: simplify conditional in alloc_region_table() dm delay: document that offsets are specified in sectors dm delay: capitalize the start of an delay_ctr() error message dm delay: Use DM_MAPIO macros instead of open-coded equivalents dm linear: remove redundant target name from error messages dm persistent data: eliminate unnecessary return values dm: eliminate unused "bioset" process for each bio-based DM device dm: convert ffs to __ffs dm: drop NULL test before kmem_cache_destroy() and mempool_destroy() dm: add support for passing through persistent reservations dm: refactor ioctl handling Revert "dm mpath: fix stalls when handling invalid ioctls" dm: initialize non-blk-mq queue data before queue is used
2015-11-04Merge tag 'md/4.4' of git://neil.brown.name/mdLinus Torvalds
Pull md updates from Neil Brown: "Two major components to this update. 1) The clustered-raid1 support from SUSE is nearly complete. There are a few outstanding issues being worked on. Maybe half a dozen patches will bring this to a usable state. 2) The first stage of journalled-raid5 support from Facebook makes an appearance. With a journal device configured (typically NVRAM or SSD), the "RAID5 write hole" should be closed - a crash during degraded operations cannot result in data corruption. The next stage will be to use the journal as a write-behind cache so that latency can be reduced and in some cases throughput increased by performing more full-stripe writes. * tag 'md/4.4' of git://neil.brown.name/md: (66 commits) MD: when RAID journal is missing/faulty, block RESTART_ARRAY_RW MD: set journal disk ->raid_disk MD: kick out journal disk if it's not fresh raid5-cache: start raid5 readonly if journal is missing MD: add new bit to indicate raid array with journal raid5-cache: IO error handling raid5: journal disk can't be removed raid5-cache: add trim support for log MD: fix info output for journal disk raid5-cache: use bio chaining raid5-cache: small log->seq cleanup raid5-cache: new helper: r5_reserve_log_entry raid5-cache: inline r5l_alloc_io_unit into r5l_new_meta raid5-cache: take rdev->data_offset into account early on raid5-cache: refactor bio allocation raid5-cache: clean up r5l_get_meta raid5-cache: simplify state machine when caches flushes are not needed raid5-cache: factor out a helper to run all stripes for an I/O unit raid5-cache: rename flushed_ios to finished_ios raid5-cache: free I/O units earlier ...
2015-11-04Merge branch 'for-4.4/integrity' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block integrity updates from Jens Axboe: ""This is the joint work of Dan and Martin, cleaning up and improving the support for block data integrity" * 'for-4.4/integrity' of git://git.kernel.dk/linux-block: block, libnvdimm, nvme: provide a built-in blk_integrity nop profile block: blk_flush_integrity() for bio-based drivers block: move blk_integrity to request_queue block: generic request_queue reference counting nvme: suspend i/o during runtime blk_integrity_unregister md: suspend i/o during runtime blk_integrity_unregister md, dm, scsi, nvme, libnvdimm: drop blk_integrity_unregister() at shutdown block: Inline blk_integrity in struct gendisk block: Export integrity data interval size in sysfs block: Reduce the size of struct blk_integrity block: Consolidate static integrity profile properties block: Move integrity kobject to struct gendisk
2015-10-31Merge tag 'md/4.3-rc7-fixes' of git://neil.brown.name/mdLinus Torvalds
Pull md bug fixes from Neil Brown: "Two more bug fixes for md. One bugfix for a list corruption in raid5 because of incorrect locking. Other for possible data corruption when a recovering device is failed, removed, and re-added. Both tagged for -stable" * tag 'md/4.3-rc7-fixes' of git://neil.brown.name/md: Revert "md: allow a partially recovered device to be hot-added to an array." md/raid5: fix locking in handle_stripe_clean_event()
2015-11-01MD: when RAID journal is missing/faulty, block RESTART_ARRAY_RWSong Liu
When RAID-4/5/6 array suffers from missing journal device, we put the array in read only state. We should not allow trasition to read-write states (clean and active) before replacing journal device. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01MD: set journal disk ->raid_diskShaohua Li
Set journal disk ->raid_disk to >=0, I choose raid_disks + 1 instead of 0, because we already have a disk with ->raid_disk 0 and this causes sysfs entry creation conflict. A lot of places assumes disk with ->raid_disk >=0 is normal raid disk, so we add check for journal disk. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01MD: kick out journal disk if it's not freshSong Liu
When journal disk is faulty and we are reassemabling the raid array, the journal disk is old. We don't allow the journal disk added to the raid array. Since journal disk is missing in the array, the raid5 will mark the array readonly. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5-cache: start raid5 readonly if journal is missingShaohua Li
If raid array is expected to have journal (eg, journal is set in MD superblock feature map) and the array is started without journal disk, start the array readonly. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01MD: add new bit to indicate raid array with journalSong Liu
If a raid array has journal feature bit set, add a new bit to indicate this. If the array is started without journal disk existing, we know there is something wrong. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5-cache: IO error handlingShaohua Li
There are 3 places the raid5-cache dispatches IO. The discard IO error doesn't matter, so we ignore it. The superblock write IO error can be handled in MD core. The remaining are log write and flush. When the IO error happens, we mark log disk faulty and fail all write IO. Read IO is still allowed to run. Userspace will get a notification too and corresponding daemon can choose setting raid array readonly for example. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5: journal disk can't be removedShaohua Li
raid5-cache uses journal disk rdev->bdev, rdev->mddev in several places. Don't allow journal disk disappear magically. On the other hand, we do need to update superblock for other disks to bump up ->events, so next time journal disk will be identified as stale. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5-cache: add trim support for logShaohua Li
Since superblock is updated infrequently, we do a simple trim of log disk (a synchronous trim) Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01MD: fix info output for journal diskShaohua Li
journal disk can be faulty. The Journal and Faulty aren't exclusive with each other. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5-cache: use bio chainingChristoph Hellwig
Simplify the bio completion handler by using bio chaining and submitting bios as soon as they are full. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5-cache: small log->seq cleanupChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5-cache: new helper: r5_reserve_log_entryChristoph Hellwig
Factor out code to reserve log space. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5-cache: inline r5l_alloc_io_unit into r5l_new_metaChristoph Hellwig
This is the only user, and keeping all code initializing the io_unit structure together improves readbility. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5-cache: take rdev->data_offset into account early onChristoph Hellwig
Set up bi_sector properly when we allocate an bio instead of updating it at submission time. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5-cache: refactor bio allocationChristoph Hellwig
Split out a helper to allocate a bio for log writes. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5-cache: clean up r5l_get_metaChristoph Hellwig
Remove the only partially used local 'io' variable to simplify the code flow. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5-cache: simplify state machine when caches flushes are not neededChristoph Hellwig
For devices without a volatile write cache we don't need to send a FLUSH command to ensure writes are stable on disk, and thus can avoid the whole step of batching up bios for processing by the MD thread. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5-cache: factor out a helper to run all stripes for an I/O unitChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5-cache: rename flushed_ios to finished_iosChristoph Hellwig
After this series we won't nessecarily have flushed the cache for these I/Os, so give the list a more neutral name. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5-cache: free I/O units earlierChristoph Hellwig
There is no good reason to keep the I/O unit structures around after the stripe has been written back to the RAID array. The only information we need is the log sequence number, and the checkpoint offset of the highest successfull writeback. Store those in the log structure, and free the IO units from __r5l_stripe_write_finished. Besides simplifying the code this also avoid having to keep the allocation for the I/O unit around for a potentially long time as superblock updates that checkpoint the log do not happen very often. This also fixes the previously incorrect calculation of 'free' in r5l_do_reclaim as a side effect: previous if took the last unit which isn't checkpointed into account. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5-cache: move reclaim stop to quiesceShaohua Li
Move reclaim stop to quiesce handling, where is safer for this stuff. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01md: show journal for journal disk in disk state sysfsShaohua Li
Journal disk state sysfs entry should indicate it's journal Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01skip match_mddev_units check for special rolesSong Liu
match_mddev_units is used to check whether 2 RAID arrays share same disk(s). Arrays that share disk(s) will not do resync at the same time for better performance (fewer HDD seek). However, this check should not apply to Spare, Faulty, and Journal disks, as they do not paticipate in resync. In this patch, match_mddev_units skips check for disks with flag "Faulty" or "Journal" or raid_disk < 0. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5-cache: don't delay stripe captured in logShaohua Li
There is a case a stripe gets delayed forever. 1. a stripe finishes construction 2. a new bio hits the stripe 3. handle_stripe runs for the stripe. The stripe gets DELAYED bit set since construction can't run for new bio (the stripe is locked since step 1) Without log, handle_stripe will call ops_run_io. After IO finishes, the stripe gets unlocked and the stripe will restart and run construction for the new bio. With log, ops_run_io need to run two times. If the DELAYED bit set, the stripe can't enter into the handle_list, so the second ops_run_io doesn't run, which leaves the stripe stalled. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5-cache: check stripe finish out of orderShaohua Li
stripes could finish out of order. Hence r5l_move_io_unit_list() of __r5l_stripe_write_finished might not move any entry and leave stripe_end_ios list empty. This applies on top of http://marc.info/?l=linux-raid&m=144122700510667 Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01md: skip resync for raid array with journalShaohua Li
If a raid array has journal, the journal can guarantee the consistency, we can skip resync after a unclean shutdown. The exception is raid creation or user initiated resync, which we still do a raid resync. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5-cache: optimize FLUSH IO with log enabledShaohua Li
With log enabled, bio is written to raid disks after the bio is settled down in log disk. The recovery guarantees we can recovery the bio data from log disk, so we we skip FLUSH IO. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5-cache: move functionality out of __r5l_set_io_unit_stateChristoph Hellwig
Just keep __r5l_set_io_unit_state as a small set the state wrapper, and remove r5l_set_io_unit_state entirely after moving the real functionality to the two callers that need it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5-cache: fix a user-after-free bugShaohua Li
r5l_compress_stripe_end_list() can free an io_unit. This breaks the assumption only reclaimer can free io_unit. We can add a reference count based io_unit free, but since only reclaim can wait io_unit becoming to STRIPE_END state, we use a simple global wait queue here. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5-cache: switching to state machine for log disk cache flushShaohua Li
Before we write stripe data to raid disks, we must guarantee stripe data is settled down in log disk. To do this, we flush log disk cache and wait the flush finish. That wait introduces sleep time in raid5d thread and impact performance. This patch moves the log disk cache flush process to the stripe handling state machine, which can remove the wait in raid5d. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5: enable log for raid array with cache diskShaohua Li
Now log is safe to enable for raid array with cache disk Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01raid5: don't allow resize/reshape with cache(log) supportShaohua Li
If cache(log) support is enabled, don't allow resize/reshape in current stage. In the future, we can flush all data from cache(log) to raid before resize/reshape and then allow resize/reshape. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>