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* Merge branch 'for-4.8/drivers' of git://git.kernel.dk/linux-blockLinus Torvalds2016-07-2710-137/+168
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block driver updates from Jens Axboe: "This branch also contains core changes. I've come to the conclusion that from 4.9 and forward, I'll be doing just a single branch. We often have dependencies between core and drivers, and it's hard to always split them up appropriately without pulling core into drivers when that happens. That said, this contains: - separate secure erase type for the core block layer, from Christoph. - set of discard fixes, from Christoph. - bio shrinking fixes from Christoph, as a followup up to the op/flags change in the core branch. - map and append request fixes from Christoph. - NVMeF (NVMe over Fabrics) code from Christoph. This is pretty exciting! - nvme-loop fixes from Arnd. - removal of ->driverfs_dev from Dan, after providing a device_add_disk() helper. - bcache fixes from Bhaktipriya and Yijing. - cdrom subchannel read fix from Vchannaiah. - set of lightnvm updates from Wenwei, Matias, Johannes, and Javier. - set of drbd updates and fixes from Fabian, Lars, and Philipp. - mg_disk error path fix from Bart. - user notification for failed device add for loop, from Minfei. - NVMe in general: + NVMe delay quirk from Guilherme. + SR-IOV support and command retry limits from Keith. + fix for memory-less NUMA node from Masayoshi. + use UINT_MAX for discard sectors, from Minfei. + cancel IO fixes from Ming. + don't allocate unused major, from Neil. + error code fixup from Dan. + use constants for PSDT/FUSE from James. + variable init fix from Jay. + fabrics fixes from Ming, Sagi, and Wei. + various fixes" * 'for-4.8/drivers' of git://git.kernel.dk/linux-block: (115 commits) nvme/pci: Provide SR-IOV support nvme: initialize variable before logical OR'ing it block: unexport various bio mapping helpers scsi/osd: open code blk_make_request target: stop using blk_make_request block: simplify and export blk_rq_append_bio block: ensure bios return from blk_get_request are properly initialized virtio_blk: use blk_rq_map_kern memstick: don't allow REQ_TYPE_BLOCK_PC requests block: shrink bio size again block: simplify and cleanup bvec pool handling block: get rid of bio_rw and READA block: don't ignore -EOPNOTSUPP blkdev_issue_write_same block: introduce BLKDEV_DISCARD_ZERO to fix zeroout NVMe: don't allocate unused nvme_major nvme: avoid crashes when node 0 is memoryless node. nvme: Limit command retries loop: Make user notify for adding loop device failed nvme-loop: fix nvme-loop Kconfig dependencies nvmet: fix return value check in nvmet_subsys_alloc() ...
| * block: unexport various bio mapping helpersChristoph Hellwig2016-07-211-3/+0
| | | | | | | | | | | | | | | | They are unused and potential new users really should use the blk_rq_map* versions. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * scsi/osd: open code blk_make_requestChristoph Hellwig2016-07-211-57/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I wish the OSD code could simply use blk_rq_map_* helpers like everyone else, but the complex nature of deciding if we have DATA IN and/or DATA OUT buffers might make this impossible (at least for a mere human like me). But using blk_rq_append_bio at least allows sharing the setup code between request with or without dat a buffers, and given that this is the last user of blk_make_request it allows getting rid of that somewhat awkward interface. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Boaz Harrosh <ooo@electrozaur.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: simplify and export blk_rq_append_bioChristoph Hellwig2016-07-213-13/+16
| | | | | | | | | | | | | | | | | | | | | | The target SCSI passthrough backend is much better served with the low-level blk_rq_append_bio construct then the helpers built on top of it, so export it. Also use the opportunity to remove the pointless request_queue argument and make the code flow a little more readable. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: ensure bios return from blk_get_request are properly initializedChristoph Hellwig2016-07-212-5/+11
| | | | | | | | | | | | | | | | | | | | | | | | blk_get_request is used for BLOCK_PC and similar passthrough requests. Currently we always need to call blk_rq_set_block_pc or an open coded version of it to allow appending bios using the request mapping helpers later on, which is a somewhat awkward API. Instead move the initialization part of blk_rq_set_block_pc into blk_get_request, so that we always have a safe to use request. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: simplify and cleanup bvec pool handlingChristoph Hellwig2016-07-212-19/+22
| | | | | | | | | | | | | | | | | | | | | | | | Instead of a flag and an index just make sure an index of 0 means no need to free the bvec array. Also move the constants related to the bvec pools together and use a consistent naming scheme for them. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: don't ignore -EOPNOTSUPP blkdev_issue_write_sameChristoph Hellwig2016-07-211-1/+1
| | | | | | | | | | | | | | | | | | WRITE SAME is a data integrity operation and we can't simply ignore errors. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: introduce BLKDEV_DISCARD_ZERO to fix zerooutChristoph Hellwig2016-07-211-6/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently blkdev_issue_zeroout cascades down from discards (if the driver guarantees that discards zero data), to WRITE SAME and then to a loop writing zeroes. Unfortunately we ignore run-time EOPNOTSUPP errors in the block layer blkdev_issue_discard helper to work around DM volumes that may have mixed discard support underneath. This patch intoroduces a new BLKDEV_DISCARD_ZERO flag to blkdev_issue_discard that indicates we are called for zeroing operation. This allows both to ignore the EOPNOTSUPP hack and actually consolidating the discard_zeroes_data check into the function. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * Merge branch 'for-4.8/block' of ↵Jens Axboe2016-07-091-9/+9
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm into for-4.8/drivers Dan writes: "The removal of ->driverfs_dev in favor of just passing the parent device in as a parameter to add_disk(). See below, it has received a "Reviewed-by" from Christoph, Bart, and Johannes. It is also a pre-requisite for Fam Zheng's work to cleanup gendisk uevents vs attribute visibility [1]. We would extend device_add_disk() to take an attribute_group list. This is based off a branch of block.git/for-4.8/drivers and has received a positive build success notification from the kbuild robot across several configs. [1]: "gendisk: Generate uevent after attribute available" http://marc.info/?l=linux-virtualization&m=146725201522201&w=2"
| | * block: remove ->driverfs_devDan Williams2016-06-271-7/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that all drivers that specify a ->driverfs_dev have been converted to device_add_disk(), the pointer can be removed from struct gendisk. Cc: Jens Axboe <axboe@fb.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| | * block: introduce device_add_disk()Dan Williams2016-06-161-6/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation for removing the ->driverfs_dev member of a gendisk, add an api that takes the parent device as a parameter to add_disk(). For now this maintains the status quo of WARN()ing on failure, but not return a error code. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * | blk-mq: Introduce blk_mq_reinit_tagsetSagi Grimberg2016-07-081-0/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The new nvme-rdma driver will need to reinitialize all the tags as part of the error recovery procedure (realloc the tag memory region). Add a helper in blk-mq for it that can iterate over all requests in a tagset to make this easier. Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Tested-by: Ming Lin <ming.l@ssi.samsung.com> Reviewed-by: Stephen Bates <Stephen.Bates@pmcs.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Steve Wise <swise@opengridcomputing.com> Tested-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | block: Export blk_pollSagi Grimberg2016-07-051-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The new NVMe over fabrics target will make use of this outside from a module. Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blk-mq: add blk_mq_alloc_request_hctxMing Lin2016-07-051-0/+39
| |/ | | | | | | | | | | | | | | | | | | | | | | | | For some protocols like NVMe over Fabrics we need to be able to send initialization commands to a specific queue. Based on an earlier patch from Christoph Hellwig <hch@lst.de>. Signed-off-by: Ming Lin <ming.l@ssi.samsung.com> [hch: disallow sleeping allocation, req_op fixes] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: add a separate operation type for secure eraseChristoph Hellwig2016-06-093-25/+33
| | | | | | | | | | | | | | | | | | | | Instead of overloading the discard support with the REQ_SECURE flag. Use the opportunity to rename the queue flag as well, and remove the dead checks for this flag in the RAID 1 and RAID 10 drivers that don't claim support for secure erase. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
* | Merge branch 'for-4.8/core' of git://git.kernel.dk/linux-blockLinus Torvalds2016-07-2716-312/+434
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull core block updates from Jens Axboe: - the big change is the cleanup from Mike Christie, cleaning up our uses of command types and modified flags. This is what will throw some merge conflicts - regression fix for the above for btrfs, from Vincent - following up to the above, better packing of struct request from Christoph - a 2038 fix for blktrace from Arnd - a few trivial/spelling fixes from Bart Van Assche - a front merge check fix from Damien, which could cause issues on SMR drives - Atari partition fix from Gabriel - convert cfq to highres timers, since jiffies isn't granular enough for some devices these days. From Jan and Jeff - CFQ priority boost fix idle classes, from me - cleanup series from Ming, improving our bio/bvec iteration - a direct issue fix for blk-mq from Omar - fix for plug merging not involving the IO scheduler, like we do for other types of merges. From Tahsin - expose DAX type internally and through sysfs. From Toshi and Yigal * 'for-4.8/core' of git://git.kernel.dk/linux-block: (76 commits) block: Fix front merge check block: do not merge requests without consulting with io scheduler block: Fix spelling in a source code comment block: expose QUEUE_FLAG_DAX in sysfs block: add QUEUE_FLAG_DAX for devices to advertise their DAX support Btrfs: fix comparison in __btrfs_map_block() block: atari: Return early for unsupported sector size Doc: block: Fix a typo in queue-sysfs.txt cfq-iosched: Charge at least 1 jiffie instead of 1 ns cfq-iosched: Fix regression in bonnie++ rewrite performance cfq-iosched: Convert slice_resid from u64 to s64 block: Convert fifo_time from ulong to u64 blktrace: avoid using timespec block/blk-cgroup.c: Declare local symbols static block/bio-integrity.c: Add #include "blk.h" block/partition-generic.c: Remove a set-but-not-used variable block: bio: kill BIO_MAX_SIZE cfq-iosched: temporarily boost queue priority for idle classes block: drbd: avoid to use BIO_MAX_SIZE block: bio: remove BIO_MAX_SECTORS ...
| * | block: Fix front merge checkDamien Le Moal2016-07-211-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For a front merge, the maximum number of sectors of the request must be checked against the front merge BIO sector, not the current sector of the request. Signed-off-by: Damien Le Moal <damien.lemoal@hgst.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | block: do not merge requests without consulting with io schedulerTahsin Erdogan2016-07-214-16/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before merging a bio into an existing request, io scheduler is called to get its approval first. However, the requests that come from a plug flush may get merged by block layer without consulting with io scheduler. In case of CFQ, this can cause fairness problems. For instance, if a request gets merged into a low weight cgroup's request, high weight cgroup now will depend on low weight cgroup to get scheduled. If high weigt cgroup needs that io request to complete before submitting more requests, then it will also lose its timeslice. Following script demonstrates the problem. Group g1 has a low weight, g2 and g3 have equal high weights but g2's requests are adjacent to g1's requests so they are subject to merging. Due to these merges, g2 gets poor disk time allocation. cat > cfq-merge-repro.sh << "EOF" #!/bin/bash set -e IO_ROOT=/mnt-cgroup/io mkdir -p $IO_ROOT if ! mount | grep -qw $IO_ROOT; then mount -t cgroup none -oblkio $IO_ROOT fi cd $IO_ROOT for i in g1 g2 g3; do if [ -d $i ]; then rmdir $i fi done mkdir g1 && echo 10 > g1/blkio.weight mkdir g2 && echo 495 > g2/blkio.weight mkdir g3 && echo 495 > g3/blkio.weight RUNTIME=10 (echo $BASHPID > g1/cgroup.procs && fio --readonly --name name1 --filename /dev/sdb \ --rw read --size 64k --bs 64k --time_based \ --runtime=$RUNTIME --offset=0k &> /dev/null)& (echo $BASHPID > g2/cgroup.procs && fio --readonly --name name1 --filename /dev/sdb \ --rw read --size 64k --bs 64k --time_based \ --runtime=$RUNTIME --offset=64k &> /dev/null)& (echo $BASHPID > g3/cgroup.procs && fio --readonly --name name1 --filename /dev/sdb \ --rw read --size 64k --bs 64k --time_based \ --runtime=$RUNTIME --offset=256k &> /dev/null)& sleep $((RUNTIME+1)) for i in g1 g2 g3; do echo ---- $i ---- cat $i/blkio.time done EOF # ./cfq-merge-repro.sh ---- g1 ---- 8:16 162 ---- g2 ---- 8:16 165 ---- g3 ---- 8:16 686 After applying the patch: # ./cfq-merge-repro.sh ---- g1 ---- 8:16 90 ---- g2 ---- 8:16 445 ---- g3 ---- 8:16 471 Signed-off-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | block: Fix spelling in a source code commentBart Van Assche2016-07-211-1/+1
| | | | | | | | | | | | | | | | | | Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | block: expose QUEUE_FLAG_DAX in sysfsYigal Korman2016-07-211-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provides the ability to identify DAX enabled devices in userspace. Signed-off-by: Yigal Korman <yigal@plexistor.com> Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | block: atari: Return early for unsupported sector sizeGabriel Krisman Bertazi2016-07-131-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For 4K LBA or very large disks, atari_partition can easily get tricked into thinking it has found an Atari partition table. Depending on the data in the disk, it ends up creating partitions with awkward lengths. We saw logs like this while playing with fio. [5.625867] nvme2n1: AHDI p2 [5.625872] nvme2n1: p2 size 2910030523 extends beyond EOD, truncated People has had issues with misinterpreted AHDI partition tables for a long time, see this BSD thread from 1995, for example. https://mail-index.netbsd.org/port-atari/1995/11/19/0001.html Since the atari partition, according to the spec, doesn't even support sector sizes with more than 512, a quick sanity check is reasonable to just bail out early, before even attempting to read sector 0. Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | cfq-iosched: Charge at least 1 jiffie instead of 1 nsJan Kara2016-06-281-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 9a7f38c42c2b (cfq-iosched: Convert from jiffies to nanoseconds) could result in charging just 1 ns to a cgroup submitting IO instead of 1 jiffie we always charged before. It is arguable what is the right amount to change but for now lets retain the old behavior of always charging at least one jiffie. Fixes: 9a7f38c42c2b92391d9dabaf9f51df7cfe5608e4 Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | cfq-iosched: Fix regression in bonnie++ rewrite performanceJan Kara2016-06-281-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 9a7f38c42c2 (cfq-iosched: Convert from jiffies to nanoseconds) broke the condition for detecting starved sync IO in cfq_completed_request() because rq->start_time remained in jiffies but we compared it with nanosecond values. This manifested as a regression in bonnie++ rewrite performance because we always ended up considering sync IO starved and thus never increased async IO queue depth. Since rq->start_time is used in a lot of places, converting it to ns values would be non-trivial. So just revert the condition in CFQ to use comparison with jiffies. This will lead to suboptimal results if cfq_fifo_expire[1] will ever come close to 1 jiffie but so far we are relatively far from that with the storage used with CFQ (the default value is 128 ms). Fixes: 9a7f38c42c2b92391d9dabaf9f51df7cfe5608e4 Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | cfq-iosched: Convert slice_resid from u64 to s64Jan Kara2016-06-281-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | slice_resid can be both positive and negative. Commit 9a7f38c42c2b (cfq-iosched: Convert from jiffies to nanoseconds) converted it from long to u64. Although this did not introduce any functional regression (the operations just overflow and the result was fine), it is certainly wrong and could cause issues in future. So convert the type to more appropriate s64. Fixes: 9a7f38c42c2b92391d9dabaf9f51df7cfe5608e4 Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | block: Convert fifo_time from ulong to u64Jan Kara2016-06-281-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently rq->fifo_time is unsigned long but CFQ stores nanosecond timestamp in it which would overflow on 32-bit archs. Convert it to u64 to avoid the overflow. Since the rq->fifo_time is unioned with struct call_single_data(), this does not change the size of struct request in any way. We have to slightly fixup block/deadline-iosched.c so that comparison happens in the right types. Fixes: 9a7f38c42c2b92391d9dabaf9f51df7cfe5608e4 Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | block/blk-cgroup.c: Declare local symbols staticBart Van Assche2016-06-141-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | Detected by sparse. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | block/bio-integrity.c: Add #include "blk.h"Bart Van Assche2016-06-141-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch avoids that building with W=1 C=2 triggers the following warning: block/bio-integrity.c:35:6: warning: symbol 'blk_flush_integrity' was not declared. Should it be static? Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | block/partition-generic.c: Remove a set-but-not-used variableBart Van Assche2016-06-141-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | A value is assigned to the variable 'info' but that value is never used. Hence remove the variable 'info'. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | cfq-iosched: temporarily boost queue priority for idle classesJens Axboe2016-06-102-1/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we're queuing REQ_PRIO IO and the task is running at an idle IO class, then temporarily boost the priority. This prevents livelocks due to priority inversion, when a low priority task is holding file system resources while attempting to do IO. An example of that is shown below. An ioniced idle task is holding the directory mutex, while a normal priority task is trying to do a directory lookup. [478381.198925] ------------[ cut here ]------------ [478381.200315] INFO: task ionice:1168369 blocked for more than 120 seconds. [478381.201324] Not tainted 4.0.9-38_fbk5_hotfix1_2936_g85409c6 #1 [478381.202278] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [478381.203462] ionice D ffff8803692736a8 0 1168369 1 0x00000080 [478381.203466] ffff8803692736a8 ffff880399c21300 ffff880276adcc00 ffff880369273698 [478381.204589] ffff880369273fd8 0000000000000000 7fffffffffffffff 0000000000000002 [478381.205752] ffffffff8177d5e0 ffff8803692736c8 ffffffff8177cea7 0000000000000000 [478381.206874] Call Trace: [478381.207253] [<ffffffff8177d5e0>] ? bit_wait_io_timeout+0x80/0x80 [478381.208175] [<ffffffff8177cea7>] schedule+0x37/0x90 [478381.208932] [<ffffffff8177f5fc>] schedule_timeout+0x1dc/0x250 [478381.209805] [<ffffffff81421c17>] ? __blk_run_queue+0x37/0x50 [478381.210706] [<ffffffff810ca1c5>] ? ktime_get+0x45/0xb0 [478381.211489] [<ffffffff8177c407>] io_schedule_timeout+0xa7/0x110 [478381.212402] [<ffffffff810a8c2b>] ? prepare_to_wait+0x5b/0x90 [478381.213280] [<ffffffff8177d616>] bit_wait_io+0x36/0x50 [478381.214063] [<ffffffff8177d325>] __wait_on_bit+0x65/0x90 [478381.214961] [<ffffffff8177d5e0>] ? bit_wait_io_timeout+0x80/0x80 [478381.215872] [<ffffffff8177d47c>] out_of_line_wait_on_bit+0x7c/0x90 [478381.216806] [<ffffffff810a89f0>] ? wake_atomic_t_function+0x40/0x40 [478381.217773] [<ffffffff811f03aa>] __wait_on_buffer+0x2a/0x30 [478381.218641] [<ffffffff8123c557>] ext4_bread+0x57/0x70 [478381.219425] [<ffffffff8124498c>] __ext4_read_dirblock+0x3c/0x380 [478381.220467] [<ffffffff8124665d>] ext4_dx_find_entry+0x7d/0x170 [478381.221357] [<ffffffff8114c49e>] ? find_get_entry+0x1e/0xa0 [478381.222208] [<ffffffff81246bd4>] ext4_find_entry+0x484/0x510 [478381.223090] [<ffffffff812471a2>] ext4_lookup+0x52/0x160 [478381.223882] [<ffffffff811c401d>] lookup_real+0x1d/0x60 [478381.224675] [<ffffffff811c4698>] __lookup_hash+0x38/0x50 [478381.225697] [<ffffffff817745bd>] lookup_slow+0x45/0xab [478381.226941] [<ffffffff811c690e>] link_path_walk+0x7ae/0x820 [478381.227880] [<ffffffff811c6a42>] path_init+0xc2/0x430 [478381.228677] [<ffffffff813e6e26>] ? security_file_alloc+0x16/0x20 [478381.229776] [<ffffffff811c8c57>] path_openat+0x77/0x620 [478381.230767] [<ffffffff81185c6e>] ? page_add_file_rmap+0x2e/0x70 [478381.232019] [<ffffffff811cb253>] do_filp_open+0x43/0xa0 [478381.233016] [<ffffffff8108c4a9>] ? creds_are_invalid+0x29/0x70 [478381.234072] [<ffffffff811c0cb0>] do_open_execat+0x70/0x170 [478381.235039] [<ffffffff811c1bf8>] do_execveat_common.isra.36+0x1b8/0x6e0 [478381.236051] [<ffffffff811c214c>] do_execve+0x2c/0x30 [478381.236809] [<ffffffff811ca392>] ? getname+0x12/0x20 [478381.237564] [<ffffffff811c23be>] SyS_execve+0x2e/0x40 [478381.238338] [<ffffffff81780a1d>] stub_execve+0x6d/0xa0 [478381.239126] ------------[ cut here ]------------ [478381.239915] ------------[ cut here ]------------ [478381.240606] INFO: task python2.7:1168375 blocked for more than 120 seconds. [478381.242673] Not tainted 4.0.9-38_fbk5_hotfix1_2936_g85409c6 #1 [478381.243653] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [478381.244902] python2.7 D ffff88005cf8fb98 0 1168375 1168248 0x00000080 [478381.244904] ffff88005cf8fb98 ffff88016c1f0980 ffffffff81c134c0 ffff88016c1f11a0 [478381.246023] ffff88005cf8ffd8 ffff880466cd0cbc ffff88016c1f0980 00000000ffffffff [478381.247138] ffff880466cd0cc0 ffff88005cf8fbb8 ffffffff8177cea7 ffff88005cf8fcc8 [478381.248252] Call Trace: [478381.248630] [<ffffffff8177cea7>] schedule+0x37/0x90 [478381.249382] [<ffffffff8177d08e>] schedule_preempt_disabled+0xe/0x10 [478381.250465] [<ffffffff8177e892>] __mutex_lock_slowpath+0x92/0x100 [478381.251409] [<ffffffff8177e91b>] mutex_lock+0x1b/0x2f [478381.252199] [<ffffffff817745ae>] lookup_slow+0x36/0xab [478381.253023] [<ffffffff811c690e>] link_path_walk+0x7ae/0x820 [478381.253877] [<ffffffff811aeb41>] ? try_charge+0xc1/0x700 [478381.254690] [<ffffffff811c6a42>] path_init+0xc2/0x430 [478381.255525] [<ffffffff813e6e26>] ? security_file_alloc+0x16/0x20 [478381.256450] [<ffffffff811c8c57>] path_openat+0x77/0x620 [478381.257256] [<ffffffff8115b2fb>] ? lru_cache_add_active_or_unevictable+0x2b/0xa0 [478381.258390] [<ffffffff8117b623>] ? handle_mm_fault+0x13f3/0x1720 [478381.259309] [<ffffffff811cb253>] do_filp_open+0x43/0xa0 [478381.260139] [<ffffffff811d7ae2>] ? __alloc_fd+0x42/0x120 [478381.260962] [<ffffffff811b95ac>] do_sys_open+0x13c/0x230 [478381.261779] [<ffffffff81011393>] ? syscall_trace_enter_phase1+0x113/0x170 [478381.262851] [<ffffffff811b96c2>] SyS_open+0x22/0x30 [478381.263598] [<ffffffff81780532>] system_call_fastpath+0x12/0x17 [478381.264551] ------------[ cut here ]------------ [478381.265377] ------------[ cut here ]------------ Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
| * | blk-mq: actually hook up defer list when running requestsOmar Sandoval2016-06-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If ->queue_rq() returns BLK_MQ_RQ_QUEUE_OK, we use continue and skip over the rest of the loop body. However, dptr is assigned later in the loop body, and the BLK_MQ_RQ_QUEUE_OK case is exactly the case that we'd want it for. NVMe isn't actually using BLK_MQ_F_DEFER_ISSUE yet, nor is any other in-tree driver, but if the code's going to be there, it might as well work. Fixes: 74c450521dd8 ("blk-mq: add a 'list' parameter to ->queue_rq()") Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | cfq-iosched: Convert to use highres timersJan Kara2016-06-081-9/+12
| | | | | | | | | | | | | | | | | | Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jan Kara <jack@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | cfq-iosched: Expose microsecond interfacesJeff Moyer2016-06-081-0/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | Expose interfaces to tune time slices of CFQ IO scheduler in microseconds. Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | cfq-iosched: Convert from jiffies to nanosecondsJeff Moyer2016-06-081-137/+136
| |/ | | | | | | | | | | | | | | | | | | | | | | Convert all time-keeping in CFQ IO scheduler from jiffies to nanoseconds so that we can later make the intervals more fine-grained than jiffies. One jiffie is several miliseconds and even for today's rotating disks that is a noticeable amount of time and thus we leave disk unnecessarily idle. Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block, drivers, fs: rename REQ_FLUSH to REQ_PREFLUSHMike Christie2016-06-073-16/+16
| | | | | | | | | | | | | | | | | | | | | | | | To avoid confusion between REQ_OP_FLUSH, which is handled by request_fn drivers, and upper layers requesting the block layer perform a flush sequence along with possibly a WRITE, this patch renames REQ_FLUSH to REQ_PREFLUSH. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block, drivers: add REQ_OP_FLUSH operationMike Christie2016-06-071-2/+2
| | | | | | | | | | | | | | | | | | | | | | This adds a REQ_OP_FLUSH operation that is sent to request_fn based drivers by the block layer's flush code, instead of sending requests with the request->cmd_flags REQ_FLUSH bit set. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block, drivers, fs: shrink bi_rw from long to intMike Christie2016-06-071-1/+1
| | | | | | | | | | | | | | | | | | We don't need bi_rw to be so large on 64 bit archs, so reduce it to unsigned int. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: convert is_sync helpers to use REQ_OPs.Mike Christie2016-06-073-8/+8
| | | | | | | | | | | | | | | | | | | | This patch converts the is_sync helpers to use separate variables for the operation and flags. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: convert merge/insert code to check for REQ_OPs.Mike Christie2016-06-072-5/+7
| | | | | | | | | | | | | | | | | | | | This patch converts the block layer merging code to use separate variables for the operation and flags, and to check req_op for the REQ_OP. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * blkg_rwstat: separate op from flagsMike Christie2016-06-071-20/+29
| | | | | | | | | | | | | | | | | | | | | | | | The bio and request operation and flags are going to be separate definitions, so we cannot pass them in as a bitmap. This patch converts the blkg_rwstat code and its caller, cfq, to pass in the values separately. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: prepare elevator to use REQ_OPs.Mike Christie2016-06-073-7/+6
| | | | | | | | | | | | | | | | | | | | This patch converts the elevator code to use separate variables for the operation and flags, and to check req_op for the REQ_OP. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: prepare mq request creation to use REQ_OPsMike Christie2016-06-071-14/+16
| | | | | | | | | | | | | | | | | | | | | | | | This patch modifies the blk mq request creation code to use separate variables for the operation and flags, because in the the next patches the struct request users will be converted like was done for bios. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: prepare request creation/destruction code to use REQ_OPsMike Christie2016-06-071-25/+29
| | | | | | | | | | | | | | | | | | | | | | | | This patch prepares *_get_request/*_put_request and freed_request, to use separate variables for the operation and flags. In the next patches the struct request users will be converted like was done for bios where the op and flags are set separately. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: copy bio op to request opMike Christie2016-06-071-3/+3
| | | | | | | | | | | | | | | | The bio users should now always be setting up the bio op. This patch has the block layer copy that to the request. Signed-off-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block discard: use bio set op accessorMike Christie2016-06-071-6/+7
| | | | | | | | | | | | | | | | | | | | This converts the block issue discard helper and users to use the bio_set_op_attrs accessor and only pass in the operation flags like REQ_SEQURE. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block, fs, mm, drivers: use bio set/get op accessorsMike Christie2016-06-076-20/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch converts the simple bi_rw use cases in the block, drivers, mm and fs code to set/get the bio operation using bio_set_op_attrs/bio_op These should be simple one or two liner cases, so I just did them in one patch. The next patches handle the more complicated cases in a module per patch. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block, drivers, cgroup: use op_is_write helper instead of checking for REQ_WRITEMike Christie2016-06-072-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We currently set REQ_WRITE/WRITE for all non READ IOs like discard, flush, writesame, etc. In the next patches where we no longer set up the op as a bitmap, we will not be able to detect a operation direction like writesame by testing if REQ_WRITE is set. This patch converts the drivers and cgroup to use the op_is_write helper. This should just cover the simple cases. I did dm, md and bcache in their own patches because they were more involved. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block/fs/drivers: remove rw argument from submit_bioMike Christie2016-06-074-21/+20
| | | | | | | | | | | | | | | | | | | | | | | | This has callers of submit_bio/submit_bio_wait set the bio->bi_rw instead of passing it in. This makes that use the same as generic_make_request and how we set the other bio fields. Signed-off-by: Mike Christie <mchristi@redhat.com> Fixed up fs/ext4/crypto.c Signed-off-by: Jens Axboe <axboe@fb.com>
* | Merge branch 'timers-core-for-linus' of ↵Linus Torvalds2016-07-261-5/+0
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "This update provides the following changes: - The rework of the timer wheel which addresses the shortcomings of the current wheel (cascading, slow search for next expiring timer, etc). That's the first major change of the wheel in almost 20 years since Finn implemted it. - A large overhaul of the clocksource drivers init functions to consolidate the Device Tree initialization - Some more Y2038 updates - A capability fix for timerfd - Yet another clock chip driver - The usual pile of updates, comment improvements all over the place" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (130 commits) tick/nohz: Optimize nohz idle enter clockevents: Make clockevents_subsys static clocksource/drivers/time-armada-370-xp: Fix return value check timers: Implement optimization for same expiry time in mod_timer() timers: Split out index calculation timers: Only wake softirq if necessary timers: Forward the wheel clock whenever possible timers/nohz: Remove pointless tick_nohz_kick_tick() function timers: Optimize collect_expired_timers() for NOHZ timers: Move __run_timers() function timers: Remove set_timer_slack() leftovers timers: Switch to a non-cascading wheel timers: Reduce the CPU index space to 256k timers: Give a few structs and members proper names hlist: Add hlist_is_singular_node() helper signals: Use hrtimer for sigtimedwait() timers: Remove the deprecated mod_timer_pinned() API timers, net/ipv4/inet: Initialize connection request timers as pinned timers, drivers/tty/mips_ejtag: Initialize the poll timer as pinned timers, drivers/tty/metag_da: Initialize the poll timer as pinned ...
| * | timers: Remove set_timer_slack() leftoversThomas Gleixner2016-07-071-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We now have implicit batching in the timer wheel. The slack API is no longer used, so remove it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Andrew F. Davis <afd@ti.com> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Chris Mason <clm@fb.com> Cc: David S. Miller <davem@davemloft.net> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: George Spelvin <linux@sciencehorizons.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jaehoon Chung <jh80.chung@samsung.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: John Stultz <john.stultz@linaro.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathias Nyman <mathias.nyman@intel.com> Cc: Pali Rohár <pali.rohar@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Sebastian Reichel <sre@kernel.org> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: linux-block@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mmc@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: linux-usb@vger.kernel.org Cc: netdev@vger.kernel.org Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160704094342.189813118@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | block: fix use-after-free in sys_ioprio_get()Omar Sandoval2016-07-011-0/+2
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | get_task_ioprio() accesses the task->io_context without holding the task lock and thus can race with exit_io_context(), leading to a use-after-free. The reproducer below hits this within a few seconds on my 4-core QEMU VM: #define _GNU_SOURCE #include <assert.h> #include <unistd.h> #include <sys/syscall.h> #include <sys/wait.h> int main(int argc, char **argv) { pid_t pid, child; long nproc, i; /* ioprio_set(IOPRIO_WHO_PROCESS, 0, IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0)); */ syscall(SYS_ioprio_set, 1, 0, 0x6000); nproc = sysconf(_SC_NPROCESSORS_ONLN); for (i = 0; i < nproc; i++) { pid = fork(); assert(pid != -1); if (pid == 0) { for (;;) { pid = fork(); assert(pid != -1); if (pid == 0) { _exit(0); } else { child = wait(NULL); assert(child == pid); } } } pid = fork(); assert(pid != -1); if (pid == 0) { for (;;) { /* ioprio_get(IOPRIO_WHO_PGRP, 0); */ syscall(SYS_ioprio_get, 2, 0); } } } for (;;) { /* ioprio_get(IOPRIO_WHO_PGRP, 0); */ syscall(SYS_ioprio_get, 2, 0); } return 0; } This gets us KASAN dumps like this: [ 35.526914] ================================================================== [ 35.530009] BUG: KASAN: out-of-bounds in get_task_ioprio+0x7b/0x90 at addr ffff880066f34e6c [ 35.530009] Read of size 2 by task ioprio-gpf/363 [ 35.530009] ============================================================================= [ 35.530009] BUG blkdev_ioc (Not tainted): kasan: bad access detected [ 35.530009] ----------------------------------------------------------------------------- [ 35.530009] Disabling lock debugging due to kernel taint [ 35.530009] INFO: Allocated in create_task_io_context+0x2b/0x370 age=0 cpu=0 pid=360 [ 35.530009] ___slab_alloc+0x55d/0x5a0 [ 35.530009] __slab_alloc.isra.20+0x2b/0x40 [ 35.530009] kmem_cache_alloc_node+0x84/0x200 [ 35.530009] create_task_io_context+0x2b/0x370 [ 35.530009] get_task_io_context+0x92/0xb0 [ 35.530009] copy_process.part.8+0x5029/0x5660 [ 35.530009] _do_fork+0x155/0x7e0 [ 35.530009] SyS_clone+0x19/0x20 [ 35.530009] do_syscall_64+0x195/0x3a0 [ 35.530009] return_from_SYSCALL_64+0x0/0x6a [ 35.530009] INFO: Freed in put_io_context+0xe7/0x120 age=0 cpu=0 pid=1060 [ 35.530009] __slab_free+0x27b/0x3d0 [ 35.530009] kmem_cache_free+0x1fb/0x220 [ 35.530009] put_io_context+0xe7/0x120 [ 35.530009] put_io_context_active+0x238/0x380 [ 35.530009] exit_io_context+0x66/0x80 [ 35.530009] do_exit+0x158e/0x2b90 [ 35.530009] do_group_exit+0xe5/0x2b0 [ 35.530009] SyS_exit_group+0x1d/0x20 [ 35.530009] entry_SYSCALL_64_fastpath+0x1a/0xa4 [ 35.530009] INFO: Slab 0xffffea00019bcd00 objects=20 used=4 fp=0xffff880066f34ff0 flags=0x1fffe0000004080 [ 35.530009] INFO: Object 0xffff880066f34e58 @offset=3672 fp=0x0000000000000001 [ 35.530009] ================================================================== Fix it by grabbing the task lock while we poke at the io_context. Cc: stable@vger.kernel.org Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>