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2021-08-16dm-integrity: use bvec_virtChristoph Hellwig
Use bvec_virt instead of open coding it. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210804095634.460779-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-16dm-ebs: use bvec_virtChristoph Hellwig
Use bvec_virt instead of open coding it. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210804095634.460779-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-16dm: make EBS depend on !HIGHMEMChristoph Hellwig
__ebs_rw_bvec use page_address on the submitted bios data, and thus can't deal with highmem. Disable the target on highmem configs. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210804095634.460779-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-16block: use bvec_virt in bio_integrity_{process,free}Christoph Hellwig
Use the bvec_virt helper to clean up the bio integrity processing a little bit. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@kernel.org> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20210804095634.460779-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-16bvec: add a bvec_virt helperChristoph Hellwig
Add a helper to get the virtual address for a bvec. This avoids that all callers need to know about the page + offset representation. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@kernel.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20210804095634.460779-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-16block: ensure the bdi is freed after inode_detach_wbChristoph Hellwig
inode_detach_wb references the "main" bdi of the inode. With the recent change to move the bdi from the request_queue to the gendisk this causes a guaranteed use after free when using certain cgroup configurations. The big itself is older through as any non-default inode reference (e.g. an open file descriptor) could have injected this use after free even before that. Fixes: 52ebea749aae ("writeback: make backing_dev_info host cgroup-specific bdi_writebacks") Reported-by: Qian Cai <quic_qiancai@quicinc.com> Reported-by: syzbot <syzbot+1fb38bb7d3ce0fa3e1c4@syzkaller.appspotmail.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210816122614.601358-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-16block: free the extended dev_t minor laterChristoph Hellwig
The dev_t is used as the inode hash, so we should only released it once then block device inode is gone from the inode cache. Move it to bdev_free_inode to ensure that. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210816122614.601358-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-14blk-throtl: optimize IOPS throttle for large IO scenariosChunguang Xu
After patch 54efd50 (block: make generic_make_request handle arbitrarily sized bios), the IO through io-throttle may be larger, and these IOs may be further split into more small IOs. However, IOPS throttle does not seem to be aware of this change, which makes the calculation of IOPS of large IOs incomplete, resulting in disk-side IOPS that does not meet expectations. Maybe we should fix this problem. We can reproduce it by set max_sectors_kb of disk to 128, set blkio.write_iops_throttle to 100, run a dd instance inside blkio and use iostat to watch IOPS: dd if=/dev/zero of=/dev/sdb bs=1M count=1000 oflag=direct As a result, without this change the average IOPS is 1995, with this change the IOPS is 98. Signed-off-by: Chunguang Xu <brookxu@tencent.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/65869aaad05475797d63b4c3fed4f529febe3c26.1627876014.git.brookxu@tencent.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12block: pass a gendisk to bdev_resize_partitionChristoph Hellwig
bdev_resize_partition can only operate on the whole device. Make that clear by passing a gendisk instead of a block_device. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210810154512.1809898-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12block: pass a gendisk to bdev_del_partitionChristoph Hellwig
bdev_del_partition can only operate on the whole device. Make that clear by passing a gendisk instead of a block_device. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210810154512.1809898-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12block: pass a gendisk to bdev_add_partitionChristoph Hellwig
bdev_add_partition can only operate on the whole device. Make that clear by passing a gendisk instead of a block_device. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210810154512.1809898-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12block: store a gendisk in struct parsed_partitionsChristoph Hellwig
Partition scanning only happens on the whole device, so pass a struct gendisk instead of the whole device block_device to the scanners. This allows to simplify printing the device name in various places as the disk name is available in disk->name. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Stefan Haberland <sth@linux.ibm.com> Link: https://lore.kernel.org/r/20210810154512.1809898-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12block: remove GENHD_FL_UPChristoph Hellwig
Just check inode_unhashed on the whole device bdev inode instead, and provide a helper to check for that information. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210809064028.1198327-9-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12bcache: move the del_gendisk call out of bcache_device_freeChristoph Hellwig
Let the callers call del_gendisk so that we can check if add_disk has been called properly for the cached device case instead of relying on the block layer internal GENHD_FL_UP flag. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Coly Li <colyli@suse.de> Link: https://lore.kernel.org/r/20210809064028.1198327-8-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12bcache: add proper error unwinding in bcache_device_initChristoph Hellwig
Except for the IDA none of the allocations in bcache_device_init is unwound on error, fix that. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Coly Li <colyli@suse.de> Link: https://lore.kernel.org/r/20210809064028.1198327-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12sx8: use the internal state machine to check if del_gendisk needs to be calledChristoph Hellwig
Remove usage of the block layer internal GENHD_FL_UP by just looking at the host state. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210809064028.1198327-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12nvme: replace the GENHD_FL_UP check in nvme_mpath_shutdown_diskChristoph Hellwig
Use the nvme-internal NVME_NSHEAD_DISK_LIVE flag instead of abusing the block layer state. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210809064028.1198327-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12nvme: remove the GENHD_FL_UP check in nvme_ns_removeChristoph Hellwig
Early probe failure never reaches nvme_ns_remove, so GENHD_FL_UP must be set at this point. Remove the check. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210809064028.1198327-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12mmc: block: cleanup gendisk creationChristoph Hellwig
Restructure mmc_blk_probe to avoid a failure path with a half created disk. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> Link: https://lore.kernel.org/r/20210809064028.1198327-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12mmc: block: let device_add_disk create disk attributesChristoph Hellwig
Pass the attribute group for the attributes on the gendisk to device_add_disk so that they are created atomically with the disk creation. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> Link: https://lore.kernel.org/r/20210809064028.1198327-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-11block: move some macros to blkdev.hGuoqing Jiang
Move them (PAGE_SECTORS_SHIFT, PAGE_SECTORS and SECTOR_MASK) to the generic header file to remove redundancy. Signed-off-by: Guoqing Jiang <jiangguoqing@kylinos.cn> Link: https://lore.kernel.org/r/20210721025315.1729118-1-guoqing.jiang@linux.dev Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-10writeback: make the laptop_mode prototypes available unconditionallyChristoph Hellwig
Fix the !CONFIG_BLOCK build after the recent cleanup. Fixes: 5ed964f8e54e ("mm: hide laptop_mode_wb_timer entirely behind the BDI API") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09block: return ELEVATOR_DISCARD_MERGE if possibleMing Lei
When merging one bio to request, if they are discard IO and the queue supports multi-range discard, we need to return ELEVATOR_DISCARD_MERGE because both block core and related drivers(nvme, virtio-blk) doesn't handle mixed discard io merge(traditional IO merge together with discard merge) well. Fix the issue by returning ELEVATOR_DISCARD_MERGE in this situation, so both blk-mq and drivers just need to handle multi-range discard. Reported-by: Oleksandr Natalenko <oleksandr@natalenko.name> Signed-off-by: Ming Lei <ming.lei@redhat.com> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Fixes: 2705dfb20947 ("block: fix discard request merge") Link: https://lore.kernel.org/r/20210729034226.1591070-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09block: remove the bd_bdi in struct block_deviceChristoph Hellwig
Just retrieve the bdi from the disk. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20210809141744.1203023-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09block: move the bdi from the request_queue to the gendiskChristoph Hellwig
The backing device information only makes sense for file system I/O, and thus belongs into the gendisk and not the lower level request_queue structure. Move it there. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20210809141744.1203023-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09block: add a queue_has_disk helperChristoph Hellwig
Add a helper to check if a gendisk is associated with a request_queue. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20210809141744.1203023-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09block: pass a gendisk to blk_queue_update_readaheadChristoph Hellwig
.. and rename the function to disk_update_readahead. This is in preparation for moving the BDI from the request_queue to the gendisk. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20210809141744.1203023-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09mm: hide laptop_mode_wb_timer entirely behind the BDI APIChristoph Hellwig
Don't leak the detaŃ–ls of the timer into the block layer, instead initialize the timer in bdi_alloc and delete it in bdi_unregister. Note that this means the timer is initialized (but not armed) for non-block queues as well now. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20210809141744.1203023-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09block: remove support for delayed queue registrationsChristoph Hellwig
Now that device mapper has been changed to register the disk once it is fully ready all this code is unused. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Link: https://lore.kernel.org/r/20210804094147.459763-9-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09dm: delay registering the gendiskChristoph Hellwig
device mapper is currently the only outlier that tries to call register_disk after add_disk, leading to fairly inconsistent state of these block layer data structures. Instead change device-mapper to just register the gendisk later now that the holder mechanism can cope with that. Note that this introduces a user visible change: the dm kobject is now only visible after the initial table has been loaded. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Link: https://lore.kernel.org/r/20210804094147.459763-8-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09dm: move setting md->type into dm_setup_md_queueChristoph Hellwig
Move setting md->type from both callers into dm_setup_md_queue. This ensures that md->type is only set to a valid value after the queue has been fully setup, something we'll rely on future changes. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Link: https://lore.kernel.org/r/20210804094147.459763-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09dm: cleanup cleanup_mapped_deviceChristoph Hellwig
md->queue is now always set when md->disk is set, so simplify the conditionals a bit. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Link: https://lore.kernel.org/r/20210804094147.459763-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09block: support delayed holder registrationChristoph Hellwig
device mapper needs to register holders before it is ready to do I/O. Currently it does so by registering the disk early, which can leave the disk and queue in a weird half state where the queue is registered with the disk, except for sysfs and the elevator. And this state has been a bit promlematic before, and will get more so when sorting out the responsibilities between the queue and the disk. Support registering holders on an initialized but not registered disk instead by delaying the sysfs registration until the disk is registered. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Link: https://lore.kernel.org/r/20210804094147.459763-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09block: look up holders by bdevChristoph Hellwig
Invert they way the holder relations are tracked. This very slightly reduces the memory overhead for partitioned devices. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210804094147.459763-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09block: remove the extra kobject reference in bd_link_disk_holderChristoph Hellwig
Since commit 0d02129e76ed ("block: merge struct block_device and struct hd_struct") there is no way for the bdev to go away as long as there is a holder, so remove the extra references. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Link: https://lore.kernel.org/r/20210804094147.459763-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09block: make the block holder code optionalChristoph Hellwig
Move the block holder code into a separate file as it is not in any way related to the other block_dev.c code, and add a new selectable config option for it so that we don't have to build it without any remapped drivers selected. The Kconfig symbol contains a _DEPRECATED suffix to match the comments added in commit 49731baa41df ("block: restore multiple bd_link_disk_holder() support"). Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Link: https://lore.kernel.org/r/20210804094147.459763-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-05loop: Select I/O scheduler 'none' from inside add_disk()Bart Van Assche
We noticed that the user interface of Android devices becomes very slow under memory pressure. This is because Android uses the zram driver on top of the loop driver for swapping, because under memory pressure the swap code alternates reads and writes quickly, because mq-deadline is the default scheduler for loop devices and because mq-deadline delays writes by five seconds for such a workload with default settings. Fix this by making the kernel select I/O scheduler 'none' from inside add_disk() for loop devices. This default can be overridden at any time from user space, e.g. via a udev rule. This approach has an advantage compared to changing the I/O scheduler from userspace from 'mq-deadline' into 'none', namely that synchronize_rcu() does not get called. This patch changes the default I/O scheduler for loop devices from 'mq-deadline' into 'none'. Additionally, this patch reduces the Android boot time on my test setup with 0.5 seconds compared to configuring the loop I/O scheduler from user space. Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Martijn Coenen <maco@android.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20210805174200.3250718-3-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-05blk-mq: Introduce the BLK_MQ_F_NO_SCHED_BY_DEFAULT flagBart Van Assche
elevator_get_default() uses the following algorithm to select an I/O scheduler from inside add_disk(): - In case of a single hardware queue or if sharing hardware queues across multiple request queues (BLK_MQ_F_TAG_HCTX_SHARED), use mq-deadline. - Otherwise, use 'none'. This is a good choice for most but not for all block drivers. Make it possible to override the selection of mq-deadline with a new flag, namely BLK_MQ_F_NO_SCHED_BY_DEFAULT. Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Martijn Coenen <maco@android.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20210805174200.3250718-2-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02block: remove blk-mq-sysfs dead codeDamien Le Moal
In block/blk-mq-sysfs.c, struct blk_mq_ctx_sysfs_entry is not used to define any attribute since the "mq" sysfs directory contains only sub-directories (no attribute files). As a result, blk_mq_sysfs_show(), blk_mq_sysfs_store(), and struct sysfs_ops blk_mq_sysfs_ops are all unused and unnecessary. Remove all this unused code. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Link: https://lore.kernel.org/r/20210713081837.524422-1-damien.lemoal@wdc.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02loop: raise media_change eventMatteo Croce
Make the loop device raise a DISK_MEDIA_CHANGE event on attach or detach. # udevadm monitor -up |grep -e DISK_MEDIA_CHANGE -e DEVNAME & # losetup -f zero [ 7.454235] loop0: detected capacity change from 0 to 16384 DISK_MEDIA_CHANGE=1 DEVNAME=/dev/loop0 DEVNAME=/dev/loop0 DEVNAME=/dev/loop0 # losetup -f zero [ 10.205245] loop1: detected capacity change from 0 to 16384 DISK_MEDIA_CHANGE=1 DEVNAME=/dev/loop1 DEVNAME=/dev/loop1 DEVNAME=/dev/loop1 # losetup -f zero2 [ 13.532368] loop2: detected capacity change from 0 to 40960 DISK_MEDIA_CHANGE=1 DEVNAME=/dev/loop2 DEVNAME=/dev/loop2 # losetup -D DEVNAME=/dev/loop1 DISK_MEDIA_CHANGE=1 DEVNAME=/dev/loop1 DEVNAME=/dev/loop2 DISK_MEDIA_CHANGE=1 DEVNAME=/dev/loop2 DEVNAME=/dev/loop0 DISK_MEDIA_CHANGE=1 DEVNAME=/dev/loop0 Signed-off-by: Matteo Croce <mcroce@microsoft.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Luca Boccassi <bluca@debian.org> Link: https://lore.kernel.org/r/20210712230530.29323-7-mcroce@linux.microsoft.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02block: add a helper to raise a media changed eventMatteo Croce
Refactor disk_check_events() and move some code into disk_event_uevent(). Then add disk_force_media_change(), a helper which will be used by devices to force issuing a DISK_EVENT_MEDIA_CHANGE event. Co-developed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Matteo Croce <mcroce@microsoft.com> Tested-by: Luca Boccassi <bluca@debian.org> Link: https://lore.kernel.org/r/20210712230530.29323-6-mcroce@linux.microsoft.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02block: export diskseq in sysfsMatteo Croce
Add a new sysfs handle to export the new diskseq value. Place it in <sysfs>/block/<disk>/diskseq and document it. $ grep . /sys/class/block/*/diskseq /sys/class/block/loop0/diskseq:13 /sys/class/block/loop1/diskseq:14 /sys/class/block/loop2/diskseq:5 /sys/class/block/loop3/diskseq:6 /sys/class/block/ram0/diskseq:1 /sys/class/block/ram1/diskseq:2 /sys/class/block/vda/diskseq:7 Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Matteo Croce <mcroce@microsoft.com> Tested-by: Luca Boccassi <bluca@debian.org> Link: https://lore.kernel.org/r/20210712230530.29323-5-mcroce@linux.microsoft.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02block: add ioctl to read the disk sequence numberMatteo Croce
Add a new BLKGETDISKSEQ ioctl which retrieves the disk sequence number from the genhd structure. # ./getdiskseq /dev/loop* /dev/loop0: 13 /dev/loop0p1: 13 /dev/loop0p2: 13 /dev/loop0p3: 13 /dev/loop1: 14 /dev/loop1p1: 14 /dev/loop1p2: 14 /dev/loop2: 5 /dev/loop3: 6 Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Matteo Croce <mcroce@microsoft.com> Tested-by: Luca Boccassi <bluca@debian.org> Link: https://lore.kernel.org/r/20210712230530.29323-4-mcroce@linux.microsoft.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02block: export the diskseq in ueventsMatteo Croce
Export the newly introduced diskseq in uevents: $ udevadm info /sys/class/block/* |grep -e DEVNAME -e DISKSEQ E: DEVNAME=/dev/loop0 E: DISKSEQ=1 E: DEVNAME=/dev/loop1 E: DISKSEQ=2 E: DEVNAME=/dev/loop2 E: DISKSEQ=3 E: DEVNAME=/dev/loop3 E: DISKSEQ=4 E: DEVNAME=/dev/loop4 E: DISKSEQ=5 E: DEVNAME=/dev/loop5 E: DISKSEQ=6 E: DEVNAME=/dev/loop6 E: DISKSEQ=7 E: DEVNAME=/dev/loop7 E: DISKSEQ=8 E: DEVNAME=/dev/nvme0n1 E: DISKSEQ=9 E: DEVNAME=/dev/nvme0n1p1 E: DISKSEQ=9 E: DEVNAME=/dev/nvme0n1p2 E: DISKSEQ=9 E: DEVNAME=/dev/nvme0n1p3 E: DISKSEQ=9 E: DEVNAME=/dev/nvme0n1p4 E: DISKSEQ=9 E: DEVNAME=/dev/nvme0n1p5 E: DISKSEQ=9 E: DEVNAME=/dev/sda E: DISKSEQ=10 E: DEVNAME=/dev/sda1 E: DISKSEQ=10 E: DEVNAME=/dev/sda2 E: DISKSEQ=10 Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Matteo Croce <mcroce@microsoft.com> Tested-by: Luca Boccassi <bluca@debian.org> Link: https://lore.kernel.org/r/20210712230530.29323-3-mcroce@linux.microsoft.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02block: add disk sequence numberMatteo Croce
Associating uevents with block devices in userspace is difficult and racy: the uevent netlink socket is lossy, and on slow and overloaded systems has a very high latency. Block devices do not have exclusive owners in userspace, any process can set one up (e.g. loop devices). Moreover, device names can be reused (e.g. loop0 can be reused again and again). A userspace process setting up a block device and watching for its events cannot thus reliably tell whether an event relates to the device it just set up or another earlier instance with the same name. Being able to set a UUID on a loop device would solve the race conditions. But it does not allow to derive orderings from uevents: if you see a uevent with a UUID that does not match the device you are waiting for, you cannot tell whether it's because the right uevent has not arrived yet, or it was already sent and you missed it. So you cannot tell whether you should wait for it or not. Associating a unique, monotonically increasing sequential number to the lifetime of each block device, which can be retrieved with an ioctl immediately upon setting it up, allows to solve the race conditions with uevents, and also allows userspace processes to know whether they should wait for the uevent they need or if it was dropped and thus they should move on. Additionally, increment the disk sequence number when the media change, i.e. on DISK_EVENT_MEDIA_CHANGE event. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Matteo Croce <mcroce@microsoft.com> Tested-by: Luca Boccassi <bluca@debian.org> Link: https://lore.kernel.org/r/20210712230530.29323-2-mcroce@linux.microsoft.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02block: remove cmdline-parser.cChristoph Hellwig
cmdline-parser.c is only used by the cmdline faux partition format, so merge the code into that and avoid an indirect call. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210728053756.409654-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02block: remove disk_name()Christoph Hellwig
Remove the disk_name function now that all users are gone. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20210727062518.122108-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02block: simplify disk name formatting in check_partitionChristoph Hellwig
disk_name for partition 0 just copies out the disk_name field. Replace the call to disk_name with a %s format specifier. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20210727062518.122108-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02block: simplify printing the device names disk_stack_limitsChristoph Hellwig
Printk ->disk_name directly for the disk and use the %pg format specifier for the block device, which is equivalent to a bdevname call. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20210727062518.122108-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02block: use the %pg format specifier in show_partitionChristoph Hellwig
Simplify printing the partition name by using the %pg format specifier that is equivalent to a bdevname call. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20210727062518.122108-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>