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2017-11-24bcache: check return value of register_shrinkerMichael Lyle
register_shrinker is now __must_check, so check it to kill a warning. Caller of bch_btree_cache_alloc in super.c appropriately checks return value so this is fully plumbed through. This V2 fixes checkpatch warnings and improves the commit description, as I was too hasty getting the previous version out. Signed-off-by: Michael Lyle <mlyle@lyle.org> Reviewed-by: Vojtech Pavlik <vojtech@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-24bcache: recover data from backing when data is cleanRui Hua
When we send a read request and hit the clean data in cache device, there is a situation called cache read race in bcache(see the commit in the tail of cache_look_up(), the following explaination just copy from there): The bucket we're reading from might be reused while our bio is in flight, and we could then end up reading the wrong data. We guard against this by checking (in bch_cache_read_endio()) if the pointer is stale again; if so, we treat it as an error (s->iop.error = -EINTR) and reread from the backing device (but we don't pass that error up anywhere) It should be noted that cache read race happened under normal circumstances, not the circumstance when SSD failed, it was counted and shown in /sys/fs/bcache/XXX/internal/cache_read_races. Without this patch, when we use writeback mode, we will never reread from the backing device when cache read race happened, until the whole cache device is clean, because the condition (s->recoverable && (dc && !atomic_read(&dc->has_dirty))) is false in cached_dev_read_error(). In this situation, the s->iop.error(= -EINTR) will be passed up, at last, user will receive -EINTR when it's bio end, this is not suitable, and wield to up-application. In this patch, we use s->read_dirty_data to judge whether the read request hit dirty data in cache device, it is safe to reread data from the backing device when the read request hit clean data. This can not only handle cache read race, but also recover data when failed read request from cache device. [edited by mlyle to fix up whitespace, commit log title, comment spelling] Fixes: d59b23795933 ("bcache: only permit to recovery read error when cache device is clean") Cc: <stable@vger.kernel.org> # 4.14 Signed-off-by: Hua Rui <huarui.dev@gmail.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-24bcache: Fix building error on MIPSHuacai Chen
This patch try to fix the building error on MIPS. The reason is MIPS has already defined the PTR macro, which conflicts with the PTR macro in include/uapi/linux/bcache.h. [fixed by mlyle: corrected a line-length issue] Cc: stable@vger.kernel.org Signed-off-by: Huacai Chen <chenhc@lemote.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-24bcache: add a comment in journal bucket readingTang Junhui
Journal bucket is a circular buffer, the bucket can be like YYYNNNYY, which means the first valid journal in the 7th bucket, and the latest valid journal in third bucket, in this case, if we do not try we the zero index first, We may get a valid journal in the 7th bucket, then we call find_next_bit(bitmap,ca->sb.njournal_buckets, l + 1) to get the first invalid bucket after the 7th bucket, because all these buckets is valid, so no bit 1 in bitmap, thus find_next_bit() function would return with ca->sb.njournal_buckets (8). So, after that, bcache only read journal in 7th and 8the bucket, the first to the third buckets are lost. So, it is important to let developer know that, we need to try the zero index at first in the hash-search, and avoid any breaks in future's code modification. [ML: Fixed whitespace & formatting & file permissions] Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn> Signed-off-by: Michael Lyle <mlyle@lyle.org> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-17Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull more block layer updates from Jens Axboe: "A followup pull request, with some parts that either needed a bit more testing before going in, merge sync, or just later arriving fixes. This contains: - Timer related updates from Kees. These were purposefully delayed since I didn't want to pull in a later v4.14-rc tag to my block tree. - ide-cd prep sense buffer fix from Bart. Also delayed, as not to clash with the late fix we put into 4.14-rc. - Small BFQ updates series from Luca and Paolo. - Single nvmet fix from James, fixing a non-functional case there. - Bio fast clone fix from Michael, which made bcache return the wrong data for some cases. - Legacy IO path regression hang fix from Ming" * 'for-linus' of git://git.kernel.dk/linux-block: bio: ensure __bio_clone_fast copies bi_partno nvmet_fc: fix better length checking block: wake up all tasks blocked in get_request() block, bfq: move debug blkio stats behind CONFIG_DEBUG_BLK_CGROUP block, bfq: update blkio stats outside the scheduler lock block, bfq: add missing invocations of bfqg_stats_update_io_add/remove doc, block, bfq: update max IOPS sustainable with BFQ ide: Make ide_cdrom_prep_fs() initialize the sense buffer pointer md: Convert timers to use timer_setup() block: swim3: Convert timers to use timer_setup() block/aoe: Convert timers to use timer_setup() amifloppy: Convert timers to use timer_setup() block/floppy: Convert callback to pass timer_list
2017-11-17Merge tag 'for-4.15/dm-changes-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull more device mapper updates from Mike Snitzer: "Given your expected travel I figured I'd get these fixes to you sooner rather than later. - a DM multipath stable@ fix to silence an annoying error message that isn't _really_ an error - a DM core @stable fix for discard support that was enabled for an entire DM device despite only having partial support for discards due to a mix of discard capabilities across the underlying devices. - a couple other DM core discard fixes. - a DM bufio @stable fix that resolves a 32-bit overflow" * tag 'for-4.15/dm-changes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm bufio: fix integer overflow when limiting maximum cache size dm: clear all discard attributes in queue_limits when discards are disabled dm: do not set 'discards_supported' in targets that do not need it dm: discard support requires all targets in a table support discards dm mpath: remove annoying message of 'blk_get_request() returned -11'
2017-11-16dm bufio: fix integer overflow when limiting maximum cache sizeEric Biggers
The default max_cache_size_bytes for dm-bufio is meant to be the lesser of 25% of the size of the vmalloc area and 2% of the size of lowmem. However, on 32-bit systems the intermediate result in the expression (VMALLOC_END - VMALLOC_START) * DM_BUFIO_VMALLOC_PERCENT / 100 overflows, causing the wrong result to be computed. For example, on a 32-bit system where the vmalloc area is 520093696 bytes, the result is 1174405 rather than the expected 130023424, which makes the maximum cache size much too small (far less than 2% of lowmem). This causes severe performance problems for dm-verity users on affected systems. Fix this by using mult_frac() to correctly multiply by a percentage. Do this for all places in dm-bufio that multiply by a percentage. Also replace (VMALLOC_END - VMALLOC_START) with VMALLOC_TOTAL, which contrary to the comment is now defined in include/linux/vmalloc.h. Depends-on: 9993bc635 ("sched/x86: Fix overflow in cyc2ns_offset") Fixes: 95d402f057f2 ("dm: add bufio") Cc: <stable@vger.kernel.org> # v3.2+ Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-16dm: clear all discard attributes in queue_limits when discards are disabledMike Snitzer
Otherwise, it can happen that the QUEUE_FLAG_DISCARD isn't set but the various discard attributes (which get exposed via sysfs) may be set. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-16dm: do not set 'discards_supported' in targets that do not need itMike Snitzer
The DM target's 'discards_supported' flag is intended to act as an override. Meaning, even if the underlying storage doesn't support discards the DM target will. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-16dm: discard support requires all targets in a table support discardsMike Snitzer
A DM device with a mix of discard capabilities (due to some underlying devices not having discard support) _should_ just return -EOPNOTSUPP for the region of the device that doesn't support discards (even if only by way of the underlying driver formally not supporting discards). BUT, that does ask the underlying driver to handle something that it never advertised support for. In doing so we're exposing users to the potential for a underlying disk driver hanging if/when a discard is issued a the device that is incapable and never claimed to support discards. Fix this by requiring that each DM target in a DM table provide discard support as a prereq for a DM device to advertise support for discards. This may cause some configurations that were happily supporting discards (even in the face of a mix of discard support) to stop supporting discards -- but the risk of users hitting driver hangs, and forced reboots, outweighs supporting those fringe mixed discard configurations. Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-16dm mpath: remove annoying message of 'blk_get_request() returned -11'Ming Lei
It is very normal to see allocation failure, especially with blk-mq request_queues, so it's unnecessary to report this error and annoy people. In practice this 'blk_get_request() returned -11' error gets logged quite frequently when a blk-mq DM multipath device sees heavy IO. This change is marked for stable@ because the annoying message in question was included in stable@ commit 7083abbbf. Fixes: 7083abbbf ("dm mpath: avoid that path removal can trigger an infinite loop") Cc: stable@vger.kernel.org Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-15Merge tag 'modules-for-v4.15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux Pull module updates from Jessica Yu: "Summary of modules changes for the 4.15 merge window: - treewide module_param_call() cleanup, fix up set/get function prototype mismatches, from Kees Cook - minor code cleanups" * tag 'modules-for-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux: module: Do not paper over type mismatches in module_param_call() treewide: Fix function prototypes for module_param_call() module: Prepare to convert all module_param_call() prototypes kernel/module: Delete an error message for a failed memory allocation in add_module_usage()
2017-11-14md: Convert timers to use timer_setup()Kees Cook
In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Shaohua Li <shli@kernel.org> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: linux-bcache@vger.kernel.org Cc: linux-raid@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Michael Lyle <mlyle@lyle.org> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-14Merge tag 'gpio-v4.15-1' of ↵Linus Torvalds
ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio Pull GPIO updates from Linus Walleij: "This is the bulk of GPIO changes for the v4.15 kernel cycle: Core: - Fix the semantics of raw GPIO to actually be raw. No inversion semantics as before, but also no open draining, and allow the raw operations to affect lines used for interrupts as the caller supposedly knows what they are doing if they are getting the big hammer. - Rewrote the __inner_function() notation calls to names that make more sense. I just find this kind of code disturbing. - Drop the .irq_base() field from the gpiochip since now all IRQs are mapped dynamically. This is nice. - Support for .get_multiple() in the core driver API. This allows us to read several GPIO lines with a single register read. This has high value for some usecases: it can be used to create oscilloscopes and signal analyzers and other things that rely on reading several lines at exactly the same instant. Also a generally nice optimization. This uses the new assign_bit() macro from the bitops lib that was ACKed by Andrew Morton and is implemented for two drivers, one of them being the generic MMIO driver so everyone using that will be able to benefit from this. - Do not allow requests of Open Drain and Open Source setting of a GPIO line simultaneously. If the hardware actually supports enabling both at the same time the electrical result would be disastrous. - A new interrupt chip core helper. This will be helpful to deal with "banked" GPIOs, which means GPIO controllers with several logical blocks of GPIO inside them. This is several gpiochips per device in the device model, in contrast to the case when there is a 1-to-1 relationship between a device and a gpiochip. New drivers: - Maxim MAX3191x industrial serializer, a very interesting piece of professional I/O hardware. - Uniphier GPIO driver. This is the GPIO block from the recent Socionext (ex Fujitsu and Panasonic) platform. - Tegra 186 driver. This is based on the new banked GPIO infrastructure. Other improvements: - Some documentation improvements. - Wakeup support for the DesignWare DWAPB GPIO controller. - Reset line support on the DesignWare DWAPB GPIO controller. - Several non-critical bug fixes and improvements for the Broadcom BRCMSTB driver. - Misc non-critical bug fixes like exotic errorpaths, removal of dead code etc. - Explicit comments on fall-through switch() statements" * tag 'gpio-v4.15-1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (65 commits) gpio: tegra186: Remove tegra186_gpio_lock_class gpio: rcar: Add r8a77995 (R-Car D3) support pinctrl: bcm2835: Fix some merge fallout gpio: Fix undefined lock_dep_class gpio: Automatically add lockdep keys gpio: Introduce struct gpio_irq_chip.first gpio: Disambiguate struct gpio_irq_chip.nested gpio: Add Tegra186 support gpio: Export gpiochip_irq_{map,unmap}() gpio: Implement tighter IRQ chip integration gpio: Move lock_key into struct gpio_irq_chip gpio: Move irq_valid_mask into struct gpio_irq_chip gpio: Move irq_nested into struct gpio_irq_chip gpio: Move irq_chained_parent to struct gpio_irq_chip gpio: Move irq_default_type to struct gpio_irq_chip gpio: Move irq_handler to struct gpio_irq_chip gpio: Move irqdomain into struct gpio_irq_chip gpio: Move irqchip into struct gpio_irq_chip gpio: Introduce struct gpio_irq_chip pinctrl: armada-37xx: remove unused variable ...
2017-11-14Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/mdLinus Torvalds
Pull MD update from Shaohua Li: "This update mostly includes bug fixes: - md-cluster now supports raid10 from Guoqing - raid5 PPL fixes from Artur - badblock regression fix from Bo - suspend hang related fixes from Neil - raid5 reshape fixes from Neil - raid1 freeze deadlock fix from Nate - memleak fixes from Zdenek - bitmap related fixes from Me and Tao - other fixes and cleanups" * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md: (33 commits) md: free unused memory after bitmap resize md: release allocated bitset sync_set md/bitmap: clear BITMAP_WRITE_ERROR bit before writing it to sb md: be cautious about using ->curr_resync_completed for ->recovery_offset badblocks: fix wrong return value in badblocks_set if badblocks are disabled md: don't check MD_SB_CHANGE_CLEAN in md_allow_write md-cluster: update document for raid10 md: remove redundant variable q raid1: remove obsolete code in raid1_write_request md-cluster: Use a small window for raid10 resync md-cluster: Suspend writes in RAID10 if within range md-cluster/raid10: set "do_balance = 0" if area is resyncing md: use lockdep_assert_held raid1: prevent freeze_array/wait_all_barriers deadlock md: use TASK_IDLE instead of blocking signals md: remove special meaning of ->quiesce(.., 2) md: allow metadata update while suspending. md: use mddev_suspend/resume instead of ->quiesce() md: move suspend_hi/lo handling into core md code md: don't call bitmap_create() while array is quiesced. ...
2017-11-14Merge tag 'for-4.15/dm' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - a few conversions from atomic_t to ref_count_t - a DM core fix for a race during device destruction that could result in a BUG_ON - a stable@ fix for a DM cache race condition that could lead to data corruption when operating in writeback mode (writethrough is default) - various DM cache cleanups and improvements - add DAX support to the DM log-writes target - a fix for the DM zoned target's ability to deal with the last zone of the drive being smaller than all others - a stable@ DM crypt and DM integrity fix for a negative check that was to restrictive (prevented slab debug with XFS ontop of DM crypt from working) - a DM raid target fix for a panic that can occur when forcing a raid to sync * tag 'for-4.15/dm' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (25 commits) dm cache: lift common migration preparation code to alloc_migration() dm cache: remove usused deferred_cells member from struct cache dm cache policy smq: allocate cache blocks in order dm cache policy smq: change max background work from 10240 to 4096 blocks dm cache background tracker: limit amount of background work that may be issued at once dm cache policy smq: take origin idle status into account when queuing writebacks dm cache policy smq: handle races with queuing background_work dm raid: fix panic when attempting to force a raid to sync dm integrity: allow unaligned bv_offset dm crypt: allow unaligned bv_offset dm: small cleanup in dm_get_md() dm: fix race between dm_get_from_kobject() and __dm_destroy() dm: allocate struct mapped_device with kvzalloc dm zoned: ignore last smaller runt zone dm space map metadata: use ARRAY_SIZE dm log writes: add support for DAX dm log writes: add support for inline data buffers dm cache: simplify get_per_bio_data() by removing data_size argument dm cache: remove all obsolete writethrough-specific code dm cache: submit writethrough writes in parallel to origin and cache ...
2017-11-14Merge branch 'for-4.15/block' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull core block layer updates from Jens Axboe: "This is the main pull request for block storage for 4.15-rc1. Nothing out of the ordinary in here, and no API changes or anything like that. Just various new features for drivers, core changes, etc. In particular, this pull request contains: - A patch series from Bart, closing the whole on blk/scsi-mq queue quescing. - A series from Christoph, building towards hidden gendisks (for multipath) and ability to move bio chains around. - NVMe - Support for native multipath for NVMe (Christoph). - Userspace notifications for AENs (Keith). - Command side-effects support (Keith). - SGL support (Chaitanya Kulkarni) - FC fixes and improvements (James Smart) - Lots of fixes and tweaks (Various) - bcache - New maintainer (Michael Lyle) - Writeback control improvements (Michael) - Various fixes (Coly, Elena, Eric, Liang, et al) - lightnvm updates, mostly centered around the pblk interface (Javier, Hans, and Rakesh). - Removal of unused bio/bvec kmap atomic interfaces (me, Christoph) - Writeback series that fix the much discussed hundreds of millions of sync-all units. This goes all the way, as discussed previously (me). - Fix for missing wakeup on writeback timer adjustments (Yafang Shao). - Fix laptop mode on blk-mq (me). - {mq,name} tupple lookup for IO schedulers, allowing us to have alias names. This means you can use 'deadline' on both !mq and on mq (where it's called mq-deadline). (me). - blktrace race fix, oopsing on sg load (me). - blk-mq optimizations (me). - Obscure waitqueue race fix for kyber (Omar). - NBD fixes (Josef). - Disable writeback throttling by default on bfq, like we do on cfq (Luca Miccio). - Series from Ming that enable us to treat flush requests on blk-mq like any other request. This is a really nice cleanup. - Series from Ming that improves merging on blk-mq with schedulers, getting us closer to flipping the switch on scsi-mq again. - BFQ updates (Paolo). - blk-mq atomic flags memory ordering fixes (Peter Z). - Loop cgroup support (Shaohua). - Lots of minor fixes from lots of different folks, both for core and driver code" * 'for-4.15/block' of git://git.kernel.dk/linux-block: (294 commits) nvme: fix visibility of "uuid" ns attribute blk-mq: fixup some comment typos and lengths ide: ide-atapi: fix compile error with defining macro DEBUG blk-mq: improve tag waiting setup for non-shared tags brd: remove unused brd_mutex blk-mq: only run the hardware queue if IO is pending block: avoid null pointer dereference on null disk fs: guard_bio_eod() needs to consider partitions xtensa/simdisk: fix compile error nvme: expose subsys attribute to sysfs nvme: create 'slaves' and 'holders' entries for hidden controllers block: create 'slaves' and 'holders' entries for hidden gendisks nvme: also expose the namespace identification sysfs files for mpath nodes nvme: implement multipath access to nvme subsystems nvme: track shared namespaces nvme: introduce a nvme_ns_ids structure nvme: track subsystems block, nvme: Introduce blk_mq_req_flags_t block, scsi: Make SCSI quiesce and resume work reliably block: Add the QUEUE_FLAG_PREEMPT_ONLY request queue flag ...
2017-11-14Merge branch 'linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 Pull crypto updates from Herbert Xu: "Here is the crypto update for 4.15: API: - Disambiguate EBUSY when queueing crypto request by adding ENOSPC. This change touches code outside the crypto API. - Reset settings when empty string is written to rng_current. Algorithms: - Add OSCCA SM3 secure hash. Drivers: - Remove old mv_cesa driver (replaced by marvell/cesa). - Enable rfc3686/ecb/cfb/ofb AES in crypto4xx. - Add ccm/gcm AES in crypto4xx. - Add support for BCM7278 in iproc-rng200. - Add hash support on Exynos in s5p-sss. - Fix fallback-induced error in vmx. - Fix output IV in atmel-aes. - Fix empty GCM hash in mediatek. Others: - Fix DoS potential in lib/mpi. - Fix potential out-of-order issues with padata" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (162 commits) lib/mpi: call cond_resched() from mpi_powm() loop crypto: stm32/hash - Fix return issue on update crypto: dh - Remove pointless checks for NULL 'p' and 'g' crypto: qat - Clean up error handling in qat_dh_set_secret() crypto: dh - Don't permit 'key' or 'g' size longer than 'p' crypto: dh - Don't permit 'p' to be 0 crypto: dh - Fix double free of ctx->p hwrng: iproc-rng200 - Add support for BCM7278 dt-bindings: rng: Document BCM7278 RNG200 compatible crypto: chcr - Replace _manual_ swap with swap macro crypto: marvell - Add a NULL entry at the end of mv_cesa_plat_id_table[] hwrng: virtio - Virtio RNG devices need to be re-registered after suspend/resume crypto: atmel - remove empty functions crypto: ecdh - remove empty exit() MAINTAINERS: update maintainer for qat crypto: caam - remove unused param of ctx_map_to_sec4_sg() crypto: caam - remove unneeded edesc zeroization crypto: atmel-aes - Reset the controller before each use crypto: atmel-aes - properly set IV after {en,de}crypt hwrng: core - Reset user selected rng by writing "" to rng_current ...
2017-11-10dm cache: lift common migration preparation code to alloc_migration()Mike Snitzer
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm cache: remove usused deferred_cells member from struct cacheJoe Thornber
Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm cache policy smq: allocate cache blocks in orderJoe Thornber
Previously, cache blocks were being allocated in reverse order. Fix this by pulling the block off the head of the free list. Shouldn't have any impact on performance or latency but it is more correct to have the cache blocks allocated/mapped in ascending order. This fix will slightly increase the chances of two adjacent oblocks being in adjacent cblocks. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm cache policy smq: change max background work from 10240 to 4096 blocksJoe Thornber
10240 blocks was too much, lowering this reduces the latency of copying and consumes less memory. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm cache background tracker: limit amount of background work that may be ↵Joe Thornber
issued at once On large systems the cache policy can be over enthusiastic and queue far too much dirty data to be written back. This consumes memory. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm cache policy smq: take origin idle status into account when queuing ↵Joe Thornber
writebacks If the origin device is idle try and writeback more data. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm cache policy smq: handle races with queuing background_workJoe Thornber
The background_tracker holds a set of promotions/demotions that the cache policy wishes the core target to implement. When adding a new operation to the tracker it's possible that an operation on the same block is already present (but in practise this doesn't appear to be happening). Catch these situations and do the appropriate cleanup. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm raid: fix panic when attempting to force a raid to syncHeinz Mauelshagen
Requesting a sync on an active raid device via a table reload (see 'sync' parameter in Documentation/device-mapper/dm-raid.txt) skips the super_load() call that defines the superblock size (rdev->sb_size) -- resulting in an oops if/when super_sync()->memset() is called. Fix by moving the initialization of the superblock start and size out of super_load() to the caller (analyse_superblocks). Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm integrity: allow unaligned bv_offsetMikulas Patocka
When slub_debug is enabled kmalloc returns unaligned memory. XFS uses this unaligned memory for its buffers (if an unaligned buffer crosses a page, XFS frees it and allocates a full page instead - see the function xfs_buf_allocate_memory). dm-integrity checks if bv_offset is aligned on page size and this check fail with slub_debug and XFS. Fix this bug by removing the bv_offset check, leaving only the check for bv_len. Fixes: 7eada909bfd7 ("dm: add integrity target") Cc: stable@vger.kernel.org # v4.12+ Reported-by: Bruno Prémont <bonbons@sysophe.eu> Reviewed-by: Milan Broz <gmazyland@gmail.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm crypt: allow unaligned bv_offsetMikulas Patocka
When slub_debug is enabled kmalloc returns unaligned memory. XFS uses this unaligned memory for its buffers (if an unaligned buffer crosses a page, XFS frees it and allocates a full page instead - see the function xfs_buf_allocate_memory). dm-crypt checks if bv_offset is aligned on page size and these checks fail with slub_debug and XFS. Fix this bug by removing the bv_offset checks. Switch to checking if bv_len is aligned instead of bv_offset (this check should be sufficient to prevent overruns if a bio with too small bv_len is received). Fixes: 8f0009a22517 ("dm crypt: optionally support larger encryption sector size") Cc: stable@vger.kernel.org # v4.12+ Reported-by: Bruno Prémont <bonbons@sysophe.eu> Tested-by: Bruno Prémont <bonbons@sysophe.eu> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Milan Broz <gmazyland@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm: small cleanup in dm_get_md()Mike Snitzer
Makes dm_get_md() and dm_get_from_kobject() have similar code. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm: fix race between dm_get_from_kobject() and __dm_destroy()Hou Tao
The following BUG_ON was hit when testing repeat creation and removal of DM devices: kernel BUG at drivers/md/dm.c:2919! CPU: 7 PID: 750 Comm: systemd-udevd Not tainted 4.1.44 Call Trace: [<ffffffff81649e8b>] dm_get_from_kobject+0x34/0x3a [<ffffffff81650ef1>] dm_attr_show+0x2b/0x5e [<ffffffff817b46d1>] ? mutex_lock+0x26/0x44 [<ffffffff811df7f5>] sysfs_kf_seq_show+0x83/0xcf [<ffffffff811de257>] kernfs_seq_show+0x23/0x25 [<ffffffff81199118>] seq_read+0x16f/0x325 [<ffffffff811de994>] kernfs_fop_read+0x3a/0x13f [<ffffffff8117b625>] __vfs_read+0x26/0x9d [<ffffffff8130eb59>] ? security_file_permission+0x3c/0x44 [<ffffffff8117bdb8>] ? rw_verify_area+0x83/0xd9 [<ffffffff8117be9d>] vfs_read+0x8f/0xcf [<ffffffff81193e34>] ? __fdget_pos+0x12/0x41 [<ffffffff8117c686>] SyS_read+0x4b/0x76 [<ffffffff817b606e>] system_call_fastpath+0x12/0x71 The bug can be easily triggered, if an extra delay (e.g. 10ms) is added between the test of DMF_FREEING & DMF_DELETING and dm_get() in dm_get_from_kobject(). To fix it, we need to ensure the test of DMF_FREEING & DMF_DELETING and dm_get() are done in an atomic way, so _minor_lock is used. The other callers of dm_get() have also been checked to be OK: some callers invoke dm_get() under _minor_lock, some callers invoke it under _hash_lock, and dm_start_request() invoke it after increasing md->open_count. Cc: stable@vger.kernel.org Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm: allocate struct mapped_device with kvzallocMikulas Patocka
The structure srcu_struct can be very big, its size is proportional to the value CONFIG_NR_CPUS. The Fedora kernel has CONFIG_NR_CPUS 8192, the field io_barrier in the struct mapped_device has 84kB in the debugging kernel and 50kB in the non-debugging kernel. The large size may result in failure of the function kzalloc_node. In order to avoid the allocation failure, we use the function kvzalloc_node, this function falls back to vmalloc if a large contiguous chunk of memory is not available. This patch also moves the field io_barrier to the last position of struct mapped_device - the reason is that on many processor architectures, short memory offsets result in smaller code than long memory offsets - on x86-64 it reduces code size by 320 bytes. Note to stable kernel maintainers - the kernels 4.11 and older don't have the function kvzalloc_node, you can use the function vzalloc_node instead. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm zoned: ignore last smaller runt zoneDamien Le Moal
The SCSI layer allows ZBC drives to have a smaller last runt zone. For such a device, specifying the entire capacity for a dm-zoned target table entry fails because the specified capacity is not aligned on a device zone size indicated in the request queue structure of the device. Fix this problem by ignoring the last runt zone in the entry length when seting up the dm-zoned target (ctr method) and when iterating table entries of the target (iterate_devices method). This allows dm-zoned users to still easily setup a target using the entire device capacity (as mandated by dm-zoned) or the aligned capacity excluding the last runt zone. While at it, replace direct references to the device queue chunk_sectors limit with calls to the accessor blk_queue_zone_sectors(). Reported-by: Peter Desnoyers <pjd@ccs.neu.edu> Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm space map metadata: use ARRAY_SIZEJérémy Lefaure
Using the ARRAY_SIZE macro improves the readability of the code. Found with Coccinelle with the following semantic patch: @r depends on (org || report)@ type T; T[] E; position p; @@ ( (sizeof(E)@p /sizeof(*E)) | (sizeof(E)@p /sizeof(E[...])) | (sizeof(E)@p /sizeof(T)) ) Signed-off-by: Jérémy Lefaure <jeremy.lefaure@lse.epita.fr> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm log writes: add support for DAXRoss Zwisler
Now that we have the ability log filesystem writes using a flat buffer, add support for DAX. The motivation for this support is the need for an xfstest that can test the new MAP_SYNC DAX flag. By logging the filesystem activity with dm-log-writes we can show that the MAP_SYNC page faults are writing out their metadata as they happen, instead of requiring an explicit msync/fsync. Unfortunately we can't easily track data that has been written via mmap() now that the dax_flush() abstraction was removed by commit c3ca015fab6d ("dax: remove the pmem_dax_ops->flush abstraction"). Otherwise we could just treat each flush as a big write, and store the data that is being synced to media. It may be worthwhile to add the dax_flush() entry point back, just as a notifier so we can do this logging. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm log writes: add support for inline data buffersRoss Zwisler
Currently dm-log-writes supports writing filesystem data via BIOs, and writing internal metadata from a flat buffer via write_metadata(). For DAX writes, though, we won't have a BIO, but will instead have an iterator that we'll want to use to fill a flat data buffer. So, create write_inline_data() which allows us to write filesystem data using a flat buffer as a source, and wire it up in log_one_block(). Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm cache: simplify get_per_bio_data() by removing data_size argumentMike Snitzer
There is only one per_bio_data size now that writethrough-specific data was removed from the per_bio_data structure. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm cache: remove all obsolete writethrough-specific codeMike Snitzer
Now that the writethrough code is much simpler there is no need to track so much state or cascade bio submission (as was done, via writethrough_endio(), to issue origin then cache IO in series). As such the obsolete writethrough list and workqueue is also removed. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm cache: submit writethrough writes in parallel to origin and cacheMike Snitzer
Discontinue issuing writethrough write IO in series to the origin and then cache. Use bio_clone_fast() to create a new origin clone bio that will be mapped to the origin device and then bio_chain() it to the bio that gets remapped to the cache device. The origin clone bio does _not_ have a copy of the per_bio_data -- as such check_if_tick_bio_needed() will not be called. The cache bio (parent bio) will not complete until the origin bio has completed -- this fulfills bio_clone_fast()'s requirements as well as the requirement to not complete the original IO until the write IO has completed to both the origin and cache device. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm cache: pass cache structure to mode functionsMike Snitzer
No functional changes, just a bit cleaner than passing cache_features structure. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm cache: fix race condition in the writeback mode overwrite_bio optimisationJoe Thornber
When a DM cache in writeback mode moves data between the slow and fast device it can often avoid a copy if the triggering bio either: i) covers the whole block (no point copying if we're about to overwrite it) ii) the migration is a promotion and the origin block is currently discarded Prior to this fix there was a race with case (ii). The discard status was checked with a shared lock held (rather than exclusive). This meant another bio could run in parallel and write data to the origin, removing the discard state. After the promotion the parallel write would have been lost. With this fix the discard status is re-checked once the exclusive lock has been aquired. If the block is no longer discarded it falls back to the slower full copy path. Fixes: b29d4986d ("dm cache: significant rework to leverage dm-bio-prison-v2") Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10md: free unused memory after bitmap resizeZdenek Kabelac
When bitmap is resized, the old kalloced chunks just are not released once the resized bitmap starts to use new space. This fixes in particular kmemleak reports like this one: unreferenced object 0xffff8f4311e9c000 (size 4096): comm "lvm", pid 19333, jiffies 4295263268 (age 528.265s) hex dump (first 32 bytes): 02 80 02 80 02 80 02 80 02 80 02 80 02 80 02 80 ................ 02 80 02 80 02 80 02 80 02 80 02 80 02 80 02 80 ................ backtrace: [<ffffffffa69471ca>] kmemleak_alloc+0x4a/0xa0 [<ffffffffa628c10e>] kmem_cache_alloc_trace+0x14e/0x2e0 [<ffffffffa676cfec>] bitmap_checkpage+0x7c/0x110 [<ffffffffa676d0c5>] bitmap_get_counter+0x45/0xd0 [<ffffffffa676d6b3>] bitmap_set_memory_bits+0x43/0xe0 [<ffffffffa676e41c>] bitmap_init_from_disk+0x23c/0x530 [<ffffffffa676f1ae>] bitmap_load+0xbe/0x160 [<ffffffffc04c47d3>] raid_preresume+0x203/0x2f0 [dm_raid] [<ffffffffa677762f>] dm_table_resume_targets+0x4f/0xe0 [<ffffffffa6774b52>] dm_resume+0x122/0x140 [<ffffffffa6779b9f>] dev_suspend+0x18f/0x290 [<ffffffffa677a3a7>] ctl_ioctl+0x287/0x560 [<ffffffffa677a693>] dm_ctl_ioctl+0x13/0x20 [<ffffffffa62d6b46>] do_vfs_ioctl+0xa6/0x750 [<ffffffffa62d7269>] SyS_ioctl+0x79/0x90 [<ffffffffa6956d41>] entry_SYSCALL_64_fastpath+0x1f/0xc2 Signed-off-by: Zdenek Kabelac <zkabelac@redhat.com> Signed-off-by: Shaohua Li <shli@fb.com>
2017-11-10md: release allocated bitset sync_setZdenek Kabelac
Patch fixes kmemleak on md_stop() path used likely only by dm-raid wrapper. Code of md is using mddev_put() where both bitsets are released however this freeing is not shared. Also set NULL to bio_set and sync_set pointers just like mddev_put is doing. Signed-off-by: Zdenek Kabelac <zkabelac@redhat.com> Signed-off-by: Shaohua Li <shli@fb.com>
2017-11-09md/bitmap: clear BITMAP_WRITE_ERROR bit before writing it to sbHou Tao
For a RAID1 device using a file-based bitmap, if a bitmap write error occurs but the later writes succeed, it's possible both BITMAP_STALE and BITMAP_WRITE_ERROR bits will be written to the bitmap super block, the BITMAP_STALE bit will be handled properly and be cleared, but the BITMAP_WRITE_ERROR bit in sb->flags will make bitmap_create() to fail. So clear it to protect against the write failure-and-then-recovery case. Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Shaohua Li <shli@fb.com>
2017-11-09md: be cautious about using ->curr_resync_completed for ->recovery_offsetNeilBrown
The ->recovery_offset shows how much of a non-InSync device is actually in sync - how much has been recoveryed. When performing a recovery, ->curr_resync and ->curr_resync_completed follow the device address being recovered and so can be used to update ->recovery_offset. When performing a reshape, ->curr_resync* might follow the device addresses (raid5) or might follow array addresses (raid10), so cannot in general be used to set ->recovery_offset. When reshaping backwards, ->curre_resync* measures from the *end* of the array-or-device, so is particularly unhelpful. So change the common code in md.c to only use ->curr_resync_complete for the simple recovery case, and add code to raid5.c to update ->recovery_offset during a forwards reshape. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Shaohua Li <shli@fb.com>
2017-11-07Merge branch 'linus' into locking/core, to resolve conflictsIngo Molnar
Conflicts: include/linux/compiler-clang.h include/linux/compiler-gcc.h include/linux/compiler-intel.h include/uapi/linux/stddef.h Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-03dm: move dm-verity to generic async completionGilad Ben-Yossef
dm-verity is starting async. crypto ops and waiting for them to complete. Move it over to generic code doing the same. This also avoids a future potential data coruption bug created by the use of wait_for_completion_interruptible() without dealing correctly with an interrupt aborting the wait prior to the async op finishing, should this code ever move to a context where signals are not masked. Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com> CC: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01md: don't check MD_SB_CHANGE_CLEAN in md_allow_writeArtur Paszkiewicz
Only MD_SB_CHANGE_PENDING should be used to wait for transition from clean to dirty. Checking also MD_SB_CHANGE_CLEAN is unnecessary and can race with e.g. md_do_sync(). This sporadically causes a hang when changing consistency policy during resync: INFO: task mdadm:6183 blocked for more than 30 seconds. Not tainted 4.14.0-rc3+ #391 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. mdadm D12752 6183 6022 0x00000000 Call Trace: __schedule+0x93f/0x990 schedule+0x6b/0x90 md_allow_write+0x100/0x130 [md_mod] ? do_wait_intr_irq+0x90/0x90 resize_stripes+0x3a/0x5b0 [raid456] ? kernfs_fop_write+0xbe/0x180 raid5_change_consistency_policy+0xa6/0x200 [raid456] consistency_policy_store+0x2e/0x70 [md_mod] md_attr_store+0x90/0xc0 [md_mod] sysfs_kf_write+0x42/0x50 kernfs_fop_write+0x119/0x180 __vfs_write+0x28/0x110 ? rcu_sync_lockdep_assert+0x12/0x60 ? __sb_start_write+0x15a/0x1c0 ? vfs_write+0xa3/0x1a0 vfs_write+0xb4/0x1a0 SyS_write+0x49/0xa0 entry_SYSCALL_64_fastpath+0x18/0xad Fixes: 2214c260c72b ("md: don't return -EAGAIN in md_allow_write for external metadata arrays") Cc: <stable@vger.kernel.org> Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com> Signed-off-by: Shaohua Li <shli@fb.com>
2017-11-01md-cluster: update document for raid10Guoqing Jiang
Signed-off-by: Guoqing Jiang <gqjiang@suse.com> Signed-off-by: Shaohua Li <shli@fb.com>
2017-11-01md: remove redundant variable qColin Ian King
The pointer q is assigned but never read; it is redundant and can be removed. Cleans up clang warning: drivers/md/md-multipath.c:260:4: warning: Value stored to 'q' is never read Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Shaohua Li <shli@fb.com>