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path: root/include/linux/genhd.h
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2020-07-17blk-cgroup: show global disk stats in root cgroup io.statBoris Burkov
In order to improve consistency and usability in cgroup stat accounting, we would like to support the root cgroup's io.stat. Since the root cgroup has processes doing io even if the system has no explicitly created cgroups, we need to be careful to avoid overhead in that case. For that reason, the rstat algorithms don't handle the root cgroup, so just turning the file on wouldn't give correct statistics. To get around this, we simulate flushing the iostat struct by filling it out directly from global disk stats. The result is a root cgroup io.stat file consistent with both /proc/diskstats and io.stat. Note that in order to collect the disk stats, we needed to iterate over devices. To facilitate that, we had to change the linkage of a disk_type to external so that it can be used from blk-cgroup.c to iterate over disks. Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Boris Burkov <boris@bur.io> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24block: reduce ifdef CONFIG_BLOCK madness in headersChristoph Hellwig
Large part of bio.h, blkdev.h and genhd.h are under ifdef CONFIG_BLOCK for no good reason. Only stub out function that are called from code that is not dependent on CONFIG_BLOCK and leave the harmless other declarations around. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24block: move block-related definitions out of fs.hChristoph Hellwig
Move most of the block related definition out of fs.h into more suitable headers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-02Merge tag 'for-5.8/drivers-2020-06-01' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block driver updates from Jens Axboe: "On top of the core changes, here are the block driver changes for this merge window: - NVMe changes: - NVMe over Fibre Channel protocol updates, which also reach over to drivers/scsi/lpfc (James Smart) - namespace revalidation support on the target (Anthony Iliopoulos) - gcc zero length array fix (Arnd Bergmann) - nvmet cleanups (Chaitanya Kulkarni) - misc cleanups and fixes (me, Keith Busch, Sagi Grimberg) - use a SRQ per completion vector (Max Gurtovoy) - fix handling of runtime changes to the queue count (Weiping Zhang) - t10 protection information support for nvme-rdma and nvmet-rdma (Israel Rukshin and Max Gurtovoy) - target side AEN improvements (Chaitanya Kulkarni) - various fixes and minor improvements all over, icluding the nvme part of the lpfc driver" - Floppy code cleanup series (Willy, Denis) - Floppy contention fix (Jiri) - Loop CONFIGURE support (Martijn) - bcache fixes/improvements (Coly, Joe, Colin) - q->queuedata cleanups (Christoph) - Get rid of ioctl_by_bdev (Christoph, Stefan) - md/raid5 allocation fixes (Coly) - zero length array fixes (Gustavo) - swim3 task state fix (Xu)" * tag 'for-5.8/drivers-2020-06-01' of git://git.kernel.dk/linux-block: (166 commits) bcache: configure the asynchronous registertion to be experimental bcache: asynchronous devices registration bcache: fix refcount underflow in bcache_device_free() bcache: Convert pr_<level> uses to a more typical style bcache: remove redundant variables i and n lpfc: Fix return value in __lpfc_nvme_ls_abort lpfc: fix axchg pointer reference after free and double frees lpfc: Fix pointer checks and comments in LS receive refactoring nvme: set dma alignment to qword nvmet: cleanups the loop in nvmet_async_events_process nvmet: fix memory leak when removing namespaces and controllers concurrently nvmet-rdma: add metadata/T10-PI support nvmet: add metadata support for block devices nvmet: add metadata/T10-PI support nvme: add Metadata Capabilities enumerations nvmet: rename nvmet_check_data_len to nvmet_check_transfer_len nvmet: rename nvmet_rw_len to nvmet_rw_data_len nvmet: add metadata characteristics for a namespace nvme-rdma: add metadata/T10-PI support nvme-rdma: introduce nvme_rdma_sgl structure ...
2020-05-27block: always use a percpu variable for disk statsChristoph Hellwig
percpu variables have a perfectly fine working stub implementation for UP kernels, so use that. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27block: always define struct blk_integrity in genhd.hMax Gurtovoy
This will reduce the amount of ifdefs inside the source code for various drivers and also will reduce the amount of stub functions that were created for the !CONFIG_BLK_DEV_INTEGRITY case. Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Israel Rukshin <israelr@mellanox.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-05-12block: re-organize fields of 'struct hd_part'Ming Lei
Put all fields accessed in IO path together at the beginning of the struct, so that all can be fetched in single cacheline. Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@infradead.org> Cc: Yufen Yu <yuyufen@huawei.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Hou Tao <houtao1@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12block: only define 'nr_sects_seq' in hd_part for 32bit SMPMing Lei
The seqcount of 'nr_sects_seq' is only needed in case of 32bit SMP, so define it just for 32bit SMP. Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@infradead.org> Cc: Yufen Yu <yuyufen@huawei.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Hou Tao <houtao1@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-04block: add a cdrom_device_info pointer to struct gendiskChristoph Hellwig
Add a pointer to the CDROM information structure to struct gendisk. This will allow various removable media file systems to call directly into the CDROM layer instead of abusing ioctls with kernel pointers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-20block: remove the disk argument from blk_drop_partitionsChristoph Hellwig
The gendisk can be trivially deducted from the block_device. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-30Merge tag 'for-5.7/block-2020-03-29' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block updates from Jens Axboe: - Online capacity resizing (Balbir) - Number of hardware queue change fixes (Bart) - null_blk fault injection addition (Bart) - Cleanup of queue allocation, unifying the node/no-node API (Christoph) - Cleanup of genhd, moving code to where it makes sense (Christoph) - Cleanup of the partition handling code (Christoph) - disk stat fixes/improvements (Konstantin) - BFQ improvements (Paolo) - Various fixes and improvements * tag 'for-5.7/block-2020-03-29' of git://git.kernel.dk/linux-block: (72 commits) block: return NULL in blk_alloc_queue() on error block: move bio_map_* to blk-map.c Revert "blkdev: check for valid request queue before issuing flush" block: simplify queue allocation bcache: pass the make_request methods to blk_queue_make_request null_blk: use blk_mq_init_queue_data block: add a blk_mq_init_queue_data helper block: move the ->devnode callback to struct block_device_operations block: move the part_stat* helpers from genhd.h to a new header block: move block layer internals out of include/linux/genhd.h block: move guard_bio_eod to bio.c block: unexport get_gendisk block: unexport disk_map_sector_rcu block: unexport disk_get_part block: mark part_in_flight and part_in_flight_rw static block: mark block_depr static block: factor out requeue handling from dispatch code block/diskstats: replace time_in_queue with sum of request times block/diskstats: accumulate all per-cpu counters in one pass block/diskstats: more accurate approximation of io_ticks for slow disks ...
2020-03-27block: move the ->devnode callback to struct block_device_operationsChristoph Hellwig
There really isn't any good reason to stash a method directly into struct gendisk. Move it together with the other block device operations. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25block: move the part_stat* helpers from genhd.h to a new headerChristoph Hellwig
These macros are just used by a few files. Move them out of genhd.h, which is included everywhere into a new standalone header. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25block: move block layer internals out of include/linux/genhd.hChristoph Hellwig
None of this needs to be exposed to drivers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25block: mark part_in_flight and part_in_flight_rw staticChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25block: mark block_depr staticChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25block/diskstats: replace time_in_queue with sum of request timesKonstantin Khlebnikov
Column "time_in_queue" in diskstats is supposed to show total waiting time of all requests. I.e. value should be equal to the sum of times from other columns. But this is not true, because column "time_in_queue" is counted separately in jiffies rather than in nanoseconds as other times. This patch removes redundant counter for "time_in_queue" and shows total time of read, write, discard and flush requests. Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25block/diskstats: accumulate all per-cpu counters in one passKonstantin Khlebnikov
Reading /proc/diskstats iterates over all cpus for summing each field. It's faster to sum all fields in one pass. Hammering /proc/diskstats with fio shows 2x performance improvement: fio --name=test --numjobs=$JOBS --filename=/proc/diskstats \ --size=1k --bs=1k --fallocate=none --create_on_open=1 \ --time_based=1 --runtime=10 --invalidate=0 --group_report JOBS=1 JOBS=10 Before: 7k iops 64k iops After: 18k iops 120k iops Also this way code is more compact: add/remove: 1/0 grow/shrink: 0/2 up/down: 194/-1540 (-1346) Function old new delta part_stat_read_all - 194 +194 diskstats_show 1344 631 -713 part_stat_show 1219 392 -827 Total: Before=14966947, After=14965601, chg -0.01% Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25block/diskstats: more accurate approximation of io_ticks for slow disksKonstantin Khlebnikov
Currently io_ticks is approximated by adding one at each start and end of requests if jiffies counter has changed. This works perfectly for requests shorter than a jiffy or if one of requests starts/ends at each jiffy. If disk executes just one request at a time and they are longer than two jiffies then only first and last jiffies will be accounted. Fix is simple: at the end of request add up into io_ticks jiffies passed since last update rather than just one jiffy. Example: common HDD executes random read 4k requests around 12ms. fio --name=test --filename=/dev/sdb --rw=randread --direct=1 --runtime=30 & iostat -x 10 sdb Note changes of iostat's "%util" 8,43% -> 99,99% before/after patch: Before: Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util sdb 0,00 0,00 82,60 0,00 330,40 0,00 8,00 0,96 12,09 12,09 0,00 1,02 8,43 After: Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util sdb 0,00 0,00 82,50 0,00 330,00 0,00 8,00 1,00 12,10 12,10 0,00 12,12 99,99 Now io_ticks does not loose time between start and end of requests, but for queue-depth > 1 some I/O time between adjacent starts might be lost. For load estimation "%util" is not as useful as average queue length, but it clearly shows how often disk queue is completely empty. Fixes: 5b18b5a73760 ("block: delete part_round_stats and switch to less precise counting") Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24block: move the various x86 Unix label formats out of genhd.hChristoph Hellwig
All these are just used in block/partitions/msdos.c, so move them out of the genhd.h driver included by every driver. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24block: move the *_PARTITION enum out of genhd.hChristoph Hellwig
The enum containing the *_PARTITION symbolic names is only relevant for the partition parser. More specifically most values are MSDOS partition table system indicators and thus should go straight into msdos.c. One value is only used by the sun partition parser, and the sun and sgi partition parsers use the same value as the x86 Linux RAID indicator to also indicate RAID autodetection. Duplicate them in sun.c and sgi.c given that the different partition types use entirely different values otherwise. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24block: move struct partition out of genhd.hChristoph Hellwig
struct partition is the on-disk format of a MSDOS partition table entry. Move it out of genhd.h into a new msdos_partition.h header and give it a msdos_ prefix to avoid confusion. Also move the magic number from block/partitions/msdos.h to the new header so that it can be used by the SCSI drivers looking at the DOS partition tables. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24block: remove alloc_part_info and free_part_infoChristoph Hellwig
There isn't any good reason not to simply open code the allocation and freeing of the partition_meta_info structure. Especially as one of the branches in alloc_part_info is entirely dead code. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24block: move sysfs methods shared by disks and partitions to genhd.cChristoph Hellwig
Move the sysfs _show methods that are used both on the full disk and partition nodes to genhd.c instead of hiding them in the partitioning code. Also move the declaration for these methods to block/blk.h so that we don't expose them to drivers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-18block/genhd: Notify udev about capacity changeBalbir Singh
Allow block/genhd to notify user space (via udev) about disk size changes using a new helper set_capacity_revalidate_and_notify(), which is a wrapper on top of set_capacity(). set_capacity_revalidate_and_notify() will only notify via udev if the current capacity or the target capacity is not zero and iff the capacity changes. Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Someswarudu Sangaraju <ssomesh@amazon.com> Signed-off-by: Balbir Singh <sblbir@amazon.com> Reviewed-by: Bob Liu <bob.liu@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-12block: Fix partition support for host aware zoned block devicesShin'ichiro Kawasaki
Commit b72053072c0b ("block: allow partitions on host aware zone devices") introduced the helper function disk_has_partitions() to check if a given disk has valid partitions. However, since this function result directly depends on the disk partition table length rather than the actual existence of valid partitions in the table, it returns true even after all partitions are removed from the disk. For host aware zoned block devices, this results in zone management support to be kept disabled even after removing all partitions. Fix this by changing disk_has_partitions() to walk through the partition table entries and return true if and only if a valid non-zero size partition is found. Fixes: b72053072c0b ("block: allow partitions on host aware zone devices") Cc: stable@vger.kernel.org # 5.5 Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-12block: Document genhd capability flagsStephen Kitt
The kernel documentation includes a brief section about genhd capabilities, but it turns out that the only documented capability (GENHD_FL_MEDIA_CHANGE_NOTIFY) isn't used any more. This patch removes that flag, and documents the rest, based on my understanding of the current uses of these flags in the kernel. The documentation is kept in the header file, alongside the declarations, in the hope that it will be kept up-to-date in future; the kernel documentation is changed to include the documentation generated from the header file. Because the ultimate goal is to provide some end-user documentation (or end-administrator documentation), the comments are perhaps more user-oriented than might be expected. Since the values are shown to users in hexadecimal, the documentation lists them in hexadecimal, and the constant declarations are adjusted to match. Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Stephen Kitt <steve@sk2.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-01-28Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "These were the main changes in this cycle: - More -rt motivated separation of CONFIG_PREEMPT and CONFIG_PREEMPTION. - Add more low level scheduling topology sanity checks and warnings to filter out nonsensical topologies that break scheduling. - Extend uclamp constraints to influence wakeup CPU placement - Make the RT scheduler more aware of asymmetric topologies and CPU capacities, via uclamp metrics, if CONFIG_UCLAMP_TASK=y - Make idle CPU selection more consistent - Various fixes, smaller cleanups, updates and enhancements - please see the git log for details" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (58 commits) sched/fair: Define sched_idle_cpu() only for SMP configurations sched/topology: Assert non-NUMA topology masks don't (partially) overlap idle: fix spelling mistake "iterrupts" -> "interrupts" sched/fair: Remove redundant call to cpufreq_update_util() sched/psi: create /proc/pressure and /proc/pressure/{io|memory|cpu} only when psi enabled sched/fair: Fix sgc->{min,max}_capacity calculation for SD_OVERLAP sched/fair: calculate delta runnable load only when it's needed sched/cputime: move rq parameter in irqtime_account_process_tick stop_machine: Make stop_cpus() static sched/debug: Reset watchdog on all CPUs while processing sysrq-t sched/core: Fix size of rq::uclamp initialization sched/uclamp: Fix a bug in propagating uclamp value in new cgroups sched/fair: Load balance aggressively for SCHED_IDLE CPUs sched/fair : Improve update_sd_pick_busiest for spare capacity case watchdog: Remove soft_lockup_hrtimer_cnt and related code sched/rt: Make RT capacity-aware sched/fair: Make EAS wakeup placement consider uclamp restrictions sched/fair: Make task_fits_capacity() consider uclamp restrictions sched/uclamp: Rename uclamp_util_with() into uclamp_rq_util_with() sched/uclamp: Make uclamp util helpers use and return UL values ...
2020-01-26block: allow partitions on host aware zone devicesChristoph Hellwig
Host-aware SMR drives can be used with the commands to explicitly manage zone state, but they can also be used as normal disks. In the former case it makes perfect sense to allow partitions on them, in the latter it does not, just like for host managed devices. Add a check to add_partition to allow partitions on host aware devices, but give up any zone management capabilities in that case, which also catches the previously missed case of adding a partition vs just scanning it. Because sd can rescan the attribute at runtime it needs to check if a disk has partitions, for which a new helper is added to genhd.h. Fixes: 5eac3eb30c9a ("block: Remove partition support for zoned block devices") Reported-by: Borislav Petkov <bp@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-12-08sched/rt, fs: Use CONFIG_PREEMPTIONThomas Gleixner
CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT. Both PREEMPT and PREEMPT_RT require the same functionality which today depends on CONFIG_PREEMPT. Switch the i_size() and part_nr_sects_…() code over to use CONFIG_PREEMPTION. Update the comment for fsstack_copy_inode_size() also to refer to CONFIG_PREEMPTION. [bigeasy: +PREEMPT comments] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/20191015191821.11479-24-bigeasy@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-14block: fix bdev_disk_changed for non-partitioned devicesChristoph Hellwig
We still have to set the capacity to 0 if invalidating or call revalidate_disk if not even if the disk has no partitions. Fix that by merging rescan_partitions into bdev_disk_changed and just stubbing out blk_add_partitions and blk_drop_partitions for non-partitioned devices. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-14block: move rescan_partitions to fs/block_dev.cChristoph Hellwig
Large parts of rescan_partitions aren't about partitions, and moving it to block_dev.c will allow for some further cleanups by merging it into its only caller. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-14block: merge invalidate_partitions into rescan_partitionsChristoph Hellwig
A lot of the logic in invalidate_partitions and rescan_partitions is shared. Merge the two functions to simplify things. There is a small behavior change in that we now send the kevent change notice also if we were not invalidating but no partitions were found, which seems like the right thing to do. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-22block: fix use-after-free on gendiskYufen Yu
commit 2da78092dda "block: Fix dev_t minor allocation lifetime" specifically moved blk_free_devt(dev->devt) call to part_release() to avoid reallocating device number before the device is fully shutdown. However, it can cause use-after-free on gendisk in get_gendisk(). We use md device as example to show the race scenes: Process1 Worker Process2 md_free blkdev_open del_gendisk add delete_partition_work_fn() to wq __blkdev_get get_gendisk put_disk disk_release kfree(disk) find part from ext_devt_idr get_disk_and_module(disk) cause use after free delete_partition_work_fn put_device(part) part_release remove part from ext_devt_idr Before <devt, hd_struct pointer> is removed from ext_devt_idr by delete_partition_work_fn(), we can find the devt and then access gendisk by hd_struct pointer. But, if we access the gendisk after it have been freed, it can cause in use-after-freeon gendisk in get_gendisk(). We fix this by adding a new helper blk_invalidate_devt() in delete_partition() and del_gendisk(). It replaces hd_struct pointer in idr with value 'NULL', and deletes the entry from idr in part_release() as we do now. Thanks to Jan Kara for providing the solution and more clear comments for the code. Fixes: 2da78092dda1 ("block: Fix dev_t minor allocation lifetime") Cc: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Yufen Yu <yuyufen@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-12block: disk_events: introduce event flagsMartin Wilck
Currently, an empty disk->events field tells the block layer not to forward media change events to user space. This was done in commit 7c88a168da80 ("block: don't propagate unlisted DISK_EVENTs to userland") in order to avoid events from "fringe" drivers to be forwarded to user space. By doing so, the block layer lost the information which events were supported by a particular block device, and most importantly, whether or not a given device supports media change events at all. Prepare for not interpreting the "events" field this way in the future any more. This is done by adding an additional field "event_flags" to struct gendisk, and two flag bits that can be set to have the device treated like one that had the "events" field set to a non-zero value before. This applies only to the sd and sr drivers, which are changed to set the new flags. The new flags are DISK_EVENT_FLAG_POLL to enforce polling of the device for synchronous events, and DISK_EVENT_FLAG_UEVENT to tell the blocklayer to generate udev events from kernel events. In order to add the event_flags field to struct gendisk, the events field is converted to an "unsigned short"; it doesn't need to hold values bigger than 2 anyway. This patch doesn't change behavior. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martin Wilck <mwilck@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-12block: genhd: remove async_events fieldMartin Wilck
The async_events field, intended to be used for drivers that support asynchronous notifications about disk events (aka media change events), isn't currently used by any driver, and apparently that has been that way for a long time (if not forever). Remove it. Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martin Wilck <mwilck@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-06block: remove CONFIG_LBDAFChristoph Hellwig
Currently support for 64-bit sector_t and blkcnt_t is optional on 32-bit architectures. These types are required to support block device and/or file sizes larger than 2 TiB, and have generally defaulted to on for a long time. Enabling the option only increases the i386 tinyconfig size by 145 bytes, and many data structures already always use 64-bit values for their in-core and on-disk data structures anyway, so there should not be a large change in dynamic memory usage either. Dropping this option removes a somewhat weird non-default config that has cause various bugs or compiler warnings when actually used. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-10block: return just one value from part_in_flightMikulas Patocka
The previous patches deleted all the code that needed the second value returned from part_in_flight - now the kernel only uses the first value. Consequently, part_in_flight (and blk_mq_in_flight) may be changed so that it only returns one value. This patch just refactors the code, there's no functional change. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-10block: switch to per-cpu in-flight countersMikulas Patocka
Now when part_round_stats is gone, we can switch to per-cpu in-flight counters. We use the local-atomic type local_t, so that if part_inc_in_flight or part_dec_in_flight is reentrantly called from an interrupt, the value will be correct. The other counters could be corrupted due to reentrant interrupt, but the corruption only results in slight counter skew - the in_flight counter must be exact, so it needs local_t. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-10block: delete part_round_stats and switch to less precise countingMikulas Patocka
We want to convert to per-cpu in_flight counters. The function part_round_stats needs the in_flight counter every jiffy, it would be too costly to sum all the percpu variables every jiffy, so it must be deleted. part_round_stats is used to calculate two counters - time_in_queue and io_ticks. time_in_queue can be calculated without part_round_stats, by adding the duration of the I/O when the I/O ends (the value is almost as exact as the previously calculated value, except that time for in-progress I/Os is not counted). io_ticks can be approximated by increasing the value when I/O is started or ended and the jiffies value has changed. If the I/Os take less than a jiffy, the value is as exact as the previously calculated value. If the I/Os take more than a jiffy, io_ticks can drift behind the previously calculated value. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-10block: stop passing 'cpu' to all percpu stats methodsMike Snitzer
All of part_stat_* and related methods are used with preempt disabled, so there is no need to pass cpu around to allow of them. Just call smp_processor_id() as needed. Suggested-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-28block: use rcu_work instead of call_rcu to avoid sleep in softirqYufen Yu
We recently got a stack by syzkaller like this: BUG: sleeping function called from invalid context at mm/slab.h:361 in_atomic(): 1, irqs_disabled(): 0, pid: 6644, name: blkid INFO: lockdep is turned off. CPU: 1 PID: 6644 Comm: blkid Not tainted 4.4.163-514.55.6.9.x86_64+ #76 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 0000000000000000 5ba6a6b879e50c00 ffff8801f6b07b10 ffffffff81cb2194 0000000041b58ab3 ffffffff833c7745 ffffffff81cb2080 5ba6a6b879e50c00 0000000000000000 0000000000000001 0000000000000004 0000000000000000 Call Trace: <IRQ> [<ffffffff81cb2194>] __dump_stack lib/dump_stack.c:15 [inline] <IRQ> [<ffffffff81cb2194>] dump_stack+0x114/0x1a0 lib/dump_stack.c:51 [<ffffffff8129a981>] ___might_sleep+0x291/0x490 kernel/sched/core.c:7675 [<ffffffff8129ac33>] __might_sleep+0xb3/0x270 kernel/sched/core.c:7637 [<ffffffff81794c13>] slab_pre_alloc_hook mm/slab.h:361 [inline] [<ffffffff81794c13>] slab_alloc_node mm/slub.c:2610 [inline] [<ffffffff81794c13>] slab_alloc mm/slub.c:2692 [inline] [<ffffffff81794c13>] kmem_cache_alloc_trace+0x2c3/0x5c0 mm/slub.c:2709 [<ffffffff81cbe9a7>] kmalloc include/linux/slab.h:479 [inline] [<ffffffff81cbe9a7>] kzalloc include/linux/slab.h:623 [inline] [<ffffffff81cbe9a7>] kobject_uevent_env+0x2c7/0x1150 lib/kobject_uevent.c:227 [<ffffffff81cbf84f>] kobject_uevent+0x1f/0x30 lib/kobject_uevent.c:374 [<ffffffff81cbb5b9>] kobject_cleanup lib/kobject.c:633 [inline] [<ffffffff81cbb5b9>] kobject_release+0x229/0x440 lib/kobject.c:675 [<ffffffff81cbb0a2>] kref_sub include/linux/kref.h:73 [inline] [<ffffffff81cbb0a2>] kref_put include/linux/kref.h:98 [inline] [<ffffffff81cbb0a2>] kobject_put+0x72/0xd0 lib/kobject.c:692 [<ffffffff8216f095>] put_device+0x25/0x30 drivers/base/core.c:1237 [<ffffffff81c4cc34>] delete_partition_rcu_cb+0x1d4/0x2f0 block/partition-generic.c:232 [<ffffffff813c08bc>] __rcu_reclaim kernel/rcu/rcu.h:118 [inline] [<ffffffff813c08bc>] rcu_do_batch kernel/rcu/tree.c:2705 [inline] [<ffffffff813c08bc>] invoke_rcu_callbacks kernel/rcu/tree.c:2973 [inline] [<ffffffff813c08bc>] __rcu_process_callbacks kernel/rcu/tree.c:2940 [inline] [<ffffffff813c08bc>] rcu_process_callbacks+0x59c/0x1c70 kernel/rcu/tree.c:2957 [<ffffffff8120f509>] __do_softirq+0x299/0xe20 kernel/softirq.c:273 [<ffffffff81210496>] invoke_softirq kernel/softirq.c:350 [inline] [<ffffffff81210496>] irq_exit+0x216/0x2c0 kernel/softirq.c:391 [<ffffffff82c2cd7b>] exiting_irq arch/x86/include/asm/apic.h:652 [inline] [<ffffffff82c2cd7b>] smp_apic_timer_interrupt+0x8b/0xc0 arch/x86/kernel/apic/apic.c:926 [<ffffffff82c2bc25>] apic_timer_interrupt+0xa5/0xb0 arch/x86/entry/entry_64.S:746 <EOI> [<ffffffff814cbf40>] ? audit_kill_trees+0x180/0x180 [<ffffffff8187d2f7>] fd_install+0x57/0x80 fs/file.c:626 [<ffffffff8180989e>] do_sys_open+0x45e/0x550 fs/open.c:1043 [<ffffffff818099c2>] SYSC_open fs/open.c:1055 [inline] [<ffffffff818099c2>] SyS_open+0x32/0x40 fs/open.c:1050 [<ffffffff82c299e1>] entry_SYSCALL_64_fastpath+0x1e/0x9a In softirq context, we call rcu callback function delete_partition_rcu_cb(), which may allocate memory by kzalloc with GFP_KERNEL flag. If the allocation cannot be satisfied, it may sleep. However, That is not allowed in softirq contex. Although we found this problem on linux 4.4, the latest kernel version seems to have this problem as well. And it is very similar to the previous one: https://lkml.org/lkml/2018/7/9/391 Fix it by using RCU workqueue, which allows sleep. Reviewed-by: Paul E. McKenney <paulmck@linux.ibm.com> Signed-off-by: Yufen Yu <yuyufen@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-01Merge tag 'v4.19-rc6' into for-4.20/blockJens Axboe
Merge -rc6 in, for two reasons: 1) Resolve a trivial conflict in the blk-mq-tag.c documentation 2) A few important regression fixes went into upstream directly, so they aren't in the 4.20 branch. Signed-off-by: Jens Axboe <axboe@kernel.dk> * tag 'v4.19-rc6': (780 commits) Linux 4.19-rc6 MAINTAINERS: fix reference to moved drivers/{misc => auxdisplay}/panel.c cpufreq: qcom-kryo: Fix section annotations perf/core: Add sanity check to deal with pinned event failure xen/blkfront: correct purging of persistent grants Revert "xen/blkfront: When purging persistent grants, keep them in the buffer" selftests/powerpc: Fix Makefiles for headers_install change blk-mq: I/O and timer unplugs are inverted in blktrace dax: Fix deadlock in dax_lock_mapping_entry() x86/boot: Fix kexec booting failure in the SEV bit detection code bcache: add separate workqueue for journal_write to avoid deadlock drm/amd/display: Fix Edid emulation for linux drm/amd/display: Fix Vega10 lightup on S3 resume drm/amdgpu: Fix vce work queue was not cancelled when suspend Revert "drm/panel: Add device_link from panel device to DRM device" xen/blkfront: When purging persistent grants, keep them in the buffer clocksource/drivers/timer-atmel-pit: Properly handle error cases block: fix deadline elevator drain for zoned block devices ACPI / hotplug / PCI: Don't scan for non-hotplug bridges if slot is not bridge drm/syncobj: Don't leak fences when WAIT_FOR_SUBMIT is set ... Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-28block: genhd: add 'groups' argument to device_add_diskHannes Reinecke
Update device_add_disk() to take an 'groups' argument so that individual drivers can register a device with additional sysfs attributes. This avoids race condition the driver would otherwise have if these groups were to be created with sysfs_add_groups(). Signed-off-by: Martin Wilck <martin.wilck@suse.com> Signed-off-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-21block: use nanosecond resolution for iostatOmar Sandoval
Klaus Kusche reported that the I/O busy time in /proc/diskstats was not updating properly on 4.18. This is because we started using ktime to track elapsed time, and we convert nanoseconds to jiffies when we update the partition counter. However, this gets rounded down, so any I/Os that take less than a jiffy are not accounted for. Previously in this case, the value of jiffies would sometimes increment while we were doing I/O, so at least some I/Os were accounted for. Let's convert the stats to use nanoseconds internally. We still report milliseconds as before, now more accurately than ever. The value is still truncated to 32 bits for backwards compatibility. Fixes: 522a777566f5 ("block: consolidate struct request timestamp fields") Cc: stable@vger.kernel.org Reported-by: Klaus Kusche <klaus.kusche@computerix.info> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-18block: Track DISCARD statistics and output them in stat and diskstatMichael Callahan
Add tracking of REQ_OP_DISCARD ios to the partition statistics and append them to the various stat files in /sys as well as /proc/diskstats. These are tracked with the same four stats as reads and writes: Number of discard ios completed. Number of discard ios merged Number of discard sectors completed Milliseconds spent on discard requests This is done via adding a new STAT_DISCARD define to genhd.h and then using it to index that stat field for discard requests. tj: Refreshed on top of v4.17 and other previous updates. Signed-off-by: Michael Callahan <michaelcallahan@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Andy Newell <newella@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-18block: Define and use STAT_READ and STAT_WRITEMichael Callahan
Add defines for STAT_READ and STAT_WRITE for indexing the partition stat entries. This clarifies some fs/ code which has hardcoded 1 for STAT_WRITE and will make it easier to extend the stats with additional fields. tj: Refreshed on top of v4.17. Signed-off-by: Michael Callahan <michaelcallahan@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-18block: Add part_stat_read_accum to read across field entries.Michael Callahan
Add a part_stat_read_accum macro to genhd.h to read and sum across field entries. For example to sum up the number read and write sectors completed. In addition to being ar reasonable cleanup by itself this will make it easier to add new stat fields in the future. tj: Refreshed on top of v4.17. Signed-off-by: Michael Callahan <michaelcallahan@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-04-26blk-mq: fix sysfs inflight counterOmar Sandoval
When the blk-mq inflight implementation was added, /proc/diskstats was converted to use it, but /sys/block/$dev/inflight was not. Fix it by adding another helper to count in-flight requests by data direction. Fixes: f299b7c7a9de ("blk-mq: provide internal in-flight variant") Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-02-26genhd: Fix BUG in blkdev_open()Jan Kara
When two blkdev_open() calls for a partition race with device removal and recreation, we can hit BUG_ON(!bd_may_claim(bdev, whole, holder)) in blkdev_open(). The race can happen as follows: CPU0 CPU1 CPU2 del_gendisk() bdev_unhash_inode(part1); blkdev_open(part1, O_EXCL) blkdev_open(part1, O_EXCL) bdev = bd_acquire() bdev = bd_acquire() blkdev_get(bdev) bd_start_claiming(bdev) - finds old inode 'whole' bd_prepare_to_claim() -> 0 bdev_unhash_inode(whole); <device removed> <new device under same number created> blkdev_get(bdev); bd_start_claiming(bdev) - finds new inode 'whole' bd_prepare_to_claim() - this also succeeds as we have different 'whole' here... - bad things happen now as we have two exclusive openers of the same bdev The problem here is that block device opens can see various intermediate states while gendisk is shutting down and then being recreated. We fix the problem by introducing new lookup_sem in gendisk that synchronizes gendisk deletion with get_gendisk() and furthermore by making sure that get_gendisk() does not return gendisk that is being (or has been) deleted. This makes sure that once we ever manage to look up newly created bdev inode, we are also guaranteed that following get_gendisk() will either return failure (and we fail open) or it returns gendisk for the new device and following bdget_disk() will return new bdev inode (i.e., blkdev_open() follows the path as if it is completely run after new device is created). Reported-and-analyzed-by: Hou Tao <houtao1@huawei.com> Tested-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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