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2020-11-12loop: Fix occasional uevent dropPetr Vorel
Commit 716ad0986cbd ("loop: Switch to set_capacity_revalidate_and_notify") causes an occasional drop of loop device uevent, which are no longer triggered in loop_set_size() but in a different part of code. Bug is reproducible with LTP test uevent01 [1]: i=0; while true; do i=$((i+1)); echo "== $i ==" lsmod |grep -q loop && rmmod -f loop ./uevent01 || break done Put back triggering through code called in loop_set_size(). Fix required to add yet another parameter to set_capacity_revalidate_and_notify(). [1] https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/uevents/uevent01.c [hch: rebased on a different change to the prototype of set_capacity_revalidate_and_notify] Cc: stable@vger.kernel.org # v5.9 Fixes: 716ad0986cbd ("loop: Switch to set_capacity_revalidate_and_notify") Reported-by: <ltp@lists.linux.it> Signed-off-by: Petr Vorel <pvorel@suse.cz> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01block: replace bd_set_size with bd_set_nr_sectorsChristoph Hellwig
Replace bd_set_size with a version that takes the number of sectors instead, as that fits most of the current and future callers much better. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-28Merge tag 'block-5.9-2020-08-28' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: - nbd timeout fix (Hou) - device size fix for loop LOOP_CONFIGURE (Martijn) - MD pull from Song with raid5 stripe size fix (Yufen) * tag 'block-5.9-2020-08-28' of git://git.kernel.dk/linux-block: md/raid5: make sure stripe_size as power of two loop: Set correct device size when using LOOP_CONFIGURE nbd: restore default timeout when setting it to zero
2020-08-26loop: Set correct device size when using LOOP_CONFIGUREMartijn Coenen
The device size calculation was done before processing the loop configuration, which meant that the we set the size on the underlying block device incorrectly in case lo_offset/lo_sizelimit were set in the configuration. Delay computing the size until we've setup the device parameters correctly. Fixes: 3448914e8cc5("loop: Add LOOP_CONFIGURE ioctl") Reported-by: Lennart Poettering <mzxreary@0pointer.de> Tested-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com> Signed-off-by: Martijn Coenen <maco@android.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-24Merge tag 'io_uring-5.9-2020-08-23' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: - NVMe pull request from Sagi: - nvme completion rework from Christoph and Chao that mostly came from a bit of divergence of how we classify errors related to pathing/retry etc. - nvmet passthru fixes from Chaitanya - minor nvmet fixes from Amit and I - mpath round-robin path selection fix from Martin - ignore noiob for zoned devices from Keith - minor nvme-fc fix from Tianjia" - BFQ cgroup leak fix (Dmitry) - block layer MAINTAINERS addition (Geert) - fix null_blk FUA checking (Hou) - get_max_io_size() size fix (Keith) - fix block page_is_mergeable() for compound pages (Matthew) - discard granularity fixes (Ming) - IO scheduler ordering fix (Ming) - misc fixes * tag 'io_uring-5.9-2020-08-23' of git://git.kernel.dk/linux-block: (31 commits) null_blk: fix passing of REQ_FUA flag in null_handle_rq nvmet: Disable keep-alive timer when kato is cleared to 0h nvme: redirect commands on dying queue nvme: just check the status code type in nvme_is_path_error nvme: refactor command completion nvme: rename and document nvme_end_request nvme: skip noiob for zoned devices nvme-pci: fix PRP pool size nvme-pci: Use u32 for nvme_dev.q_depth and nvme_queue.q_depth nvme: Use spin_lock_irq() when taking the ctrl->lock nvmet: call blk_mq_free_request() directly nvmet: fix oops in pt cmd execution nvmet: add ns tear down label for pt-cmd handling nvme: multipath: round-robin: eliminate "fallback" variable nvme: multipath: round-robin: fix single non-optimized path case nvme-fc: Fix wrong return value in __nvme_fc_init_request() nvmet-passthru: Reject commands with non-sgl flags set nvmet: fix a memory leak blkcg: fix memleak for iolatency MAINTAINERS: Add missing header files to BLOCK LAYER section ...
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-17block: loop: set discard granularity and alignment for block device backed loopMing Lei
In case of block device backend, if the backend supports write zeros, the loop device will set queue flag of QUEUE_FLAG_DISCARD. However, limits.discard_granularity isn't setup, and this way is wrong, see the following description in Documentation/ABI/testing/sysfs-block: A discard_granularity of 0 means that the device does not support discard functionality. Especially 9b15d109a6b2 ("block: improve discard bio alignment in __blkdev_issue_discard()") starts to take q->limits.discard_granularity for computing max discard sectors. And zero discard granularity may cause kernel oops, or fail discard request even though the loop queue claims discard support via QUEUE_FLAG_DISCARD. Fix the issue by setup discard granularity and alignment. Fixes: c52abf563049 ("loop: Better discard support for block devices") Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Coly Li <colyli@suse.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Xiao Ni <xni@redhat.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Evan Green <evgreen@chromium.org> Cc: Gwendal Grignou <gwendal@chromium.org> Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Cc: Andrzej Pietrasiewicz <andrzej.p@collabora.com> Cc: Christoph Hellwig <hch@lst.de> Cc: <stable@vger.kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-11loop: unset GENHD_FL_NO_PART_SCAN on LOOP_CONFIGURELennart Poettering
When LOOP_CONFIGURE is used with LO_FLAGS_PARTSCAN we need to propagate this into the GENHD_FL_NO_PART_SCAN. LOOP_SETSTATUS does this, LOOP_CONFIGURE doesn't so far. Effect is that setting up a loopback device with partition scanning doesn't actually work when LOOP_CONFIGURE is issued, though it works fine with LOOP_SETSTATUS. Let's correct that and propagate the flag in LOOP_CONFIGURE too. Fixes: 3448914e8cc5("loop: Add LOOP_CONFIGURE ioctl") Signed-off-by: Lennart Poettering <lennart@poettering.net> Acked-by: Martijn Coenen <maco@android.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-16block: use bd_prepare_to_claim directly in the loop driverChristoph Hellwig
The arcane magic in bd_start_claiming is only needed to be able to claim a block_device that hasn't been fully set up. Switch the loop driver that claims from the ioctl path with a fully set up struct block_device to just use the much simpler bd_prepare_to_claim directly. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24loop: be paranoid on exit and prevent new additions / removalsLuis Chamberlain
Be pedantic on removal as well and hold the mutex. This should prevent uses of addition while we exit. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24blk-mq: move failure injection out of blk_mq_complete_requestChristoph Hellwig
Move the call to blk_should_fake_timeout out of blk_mq_complete_request and into the drivers, skipping call sites that are obvious error handlers, and remove the now superflous blk_mq_force_complete_rq helper. This ensures we don't keep injecting errors into completions that just terminate the Linux request after the hardware has been reset or the command has been aborted. Reviewed-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-18loop: replace kill_bdev with invalidate_bdevZheng Bin
When a filesystem is mounted on a loop device and on a loop ioctl LOOP_SET_STATUS64, because of kill_bdev, buffer_head mappings are getting destroyed. kill_bdev truncate_inode_pages truncate_inode_pages_range do_invalidatepage block_invalidatepage discard_buffer -->clear BH_Mapped flag sb_bread __bread_gfp bh = __getblk_gfp -->discard_buffer clear BH_Mapped flag __bread_slow submit_bh submit_bh_wbc BUG_ON(!buffer_mapped(bh)) --> hit this BUG_ON Fixes: 5db470e229e2 ("loop: drop caches if offset or block_size are changed") Signed-off-by: Zheng Bin <zhengbin13@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-11Merge tag 'block-5.8-2020-06-11' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: "Some followup fixes for this merge window. In particular: - Seqcount write missing preemption disable for stats (Ahmed) - blktrace fixes (Chaitanya) - Redundant initializations (Colin) - Various small NVMe fixes (Chaitanya, Christoph, Daniel, Max, Niklas, Rikard) - loop flag bug regression fix (Martijn) - blk-mq tagging fixes (Christoph, Ming)" * tag 'block-5.8-2020-06-11' of git://git.kernel.dk/linux-block: umem: remove redundant initialization of variable ret pktcdvd: remove redundant initialization of variable ret nvmet: fail outstanding host posted AEN req nvme-pci: use simple suspend when a HMB is enabled nvme-fc: don't call nvme_cleanup_cmd() for AENs nvmet-tcp: constify nvmet_tcp_ops nvme-tcp: constify nvme_tcp_mq_ops and nvme_tcp_admin_mq_ops nvme: do not call del_gendisk() on a disk that was never added blk-mq: fix blk_mq_all_tag_iter blk-mq: split out a __blk_mq_get_driver_tag helper blktrace: fix endianness for blk_log_remap() blktrace: fix endianness in get_pdu_int() blktrace: use errno instead of bi_status block: nr_sects_write(): Disable preemption on seqcount write block: remove the error argument to the block_bio_complete tracepoint loop: Fix wrong masking of status flags block/bio-integrity: don't free 'buf' if bio_integrity_add_page() failed
2020-06-04loop: Fix wrong masking of status flagsMartijn Coenen
In faf1d25440d6, loop_set_status() now assigns lo_status directly from the passed in lo_flags, but then fixes it up by masking out flags that can't be set by LOOP_SET_STATUS; unfortunately the mask was negated. Re-ran all ltp ioctl_loop tests, and they all passed. Pass run of the previously failing one: tst_test.c:1247: INFO: Timeout per run is 0h 05m 00s tst_device.c:88: INFO: Found free device 0 '/dev/loop0' ioctl_loop01.c:49: PASS: /sys/block/loop0/loop/partscan = 0 ioctl_loop01.c:50: PASS: /sys/block/loop0/loop/autoclear = 0 ioctl_loop01.c:51: PASS: /sys/block/loop0/loop/backing_file = '/tmp/ZRJ6H4/test.img' ioctl_loop01.c:65: PASS: get expected lo_flag 12 ioctl_loop01.c:67: PASS: /sys/block/loop0/loop/partscan = 1 ioctl_loop01.c:68: PASS: /sys/block/loop0/loop/autoclear = 1 ioctl_loop01.c:77: PASS: access /dev/loop0p1 succeeds ioctl_loop01.c:83: PASS: access /sys/block/loop0/loop0p1 succeeds Summary: passed 8 failed 0 skipped 0 warnings 0 Fixes: faf1d25440d6 ("loop: Clean up LOOP_SET_STATUS lo_flags handling") Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Martijn Coenen <maco@android.com> Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-02Merge tag 'vfs-5.8-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds
Pull DAX updates part one from Darrick Wong: "After many years of LKML-wrangling about how to enable programs to query and influence the file data access mode (DAX) when a filesystem resides on storage devices such as persistent memory, Ira Weiny has emerged with a proposed set of standard behaviors that has not been shot down by anyone! We're more or less standardizing on the current XFS behavior and adapting ext4 to do the same. This is the first of a handful pull requests that will make ext4 and XFS present a consistent interface for user programs that care about DAX. We add a statx attribute that programs can check to see if DAX is enabled on a particular file. Then, we update the DAX documentation to spell out the user-visible behaviors that filesystems will guarantee (until the next storage industry shakeup). The on-disk inode flag has been in XFS for a few years now. Summary: - Clean up io_is_direct. - Add a new statx flag to indicate when file data access is being done via DAX (as opposed to the page cache). - Update the documentation for how system administrators and application programmers can take advantage of the (still experimental DAX) feature" Link: https://lore.kernel.org/lkml/20200505002016.1085071-1-ira.weiny@intel.com/ * tag 'vfs-5.8-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: Documentation/dax: Update Usage section fs/stat: Define DAX statx attribute fs: Remove unneeded IS_DAX() check in io_is_direct()
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 ...
2020-06-02Merge tag 'for-5.8/block-2020-06-01' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block updates from Jens Axboe: "Core block changes that have been queued up for this release: - Remove dead blk-throttle and blk-wbt code (Guoqing) - Include pid in blktrace note traces (Jan) - Don't spew I/O errors on wouldblock termination (me) - Zone append addition (Johannes, Keith, Damien) - IO accounting improvements (Konstantin, Christoph) - blk-mq hardware map update improvements (Ming) - Scheduler dispatch improvement (Salman) - Inline block encryption support (Satya) - Request map fixes and improvements (Weiping) - blk-iocost tweaks (Tejun) - Fix for timeout failing with error injection (Keith) - Queue re-run fixes (Douglas) - CPU hotplug improvements (Christoph) - Queue entry/exit improvements (Christoph) - Move DMA drain handling to the few drivers that use it (Christoph) - Partition handling cleanups (Christoph)" * tag 'for-5.8/block-2020-06-01' of git://git.kernel.dk/linux-block: (127 commits) block: mark bio_wouldblock_error() bio with BIO_QUIET blk-wbt: rename __wbt_update_limits to wbt_update_limits blk-wbt: remove wbt_update_limits blk-throttle: remove tg_drain_bios blk-throttle: remove blk_throtl_drain null_blk: force complete for timeout request blk-mq: drain I/O when all CPUs in a hctx are offline blk-mq: add blk_mq_all_tag_iter blk-mq: open code __blk_mq_alloc_request in blk_mq_alloc_request_hctx blk-mq: use BLK_MQ_NO_TAG in more places blk-mq: rename BLK_MQ_TAG_FAIL to BLK_MQ_NO_TAG blk-mq: move more request initialization to blk_mq_rq_ctx_init blk-mq: simplify the blk_mq_get_request calling convention blk-mq: remove the bio argument to ->prepare_request nvme: force complete cancelled requests blk-mq: blk-mq: provide forced completion method block: fix a warning when blkdev.h is included for !CONFIG_BLOCK builds block: blk-crypto-fallback: remove redundant initialization of variable err block: reduce part_stat_lock() scope block: use __this_cpu_add() instead of access by smp_processor_id() ...
2020-06-02mm/writeback: replace PF_LESS_THROTTLE with PF_LOCAL_THROTTLENeilBrown
PF_LESS_THROTTLE exists for loop-back nfsd (and a similar need in the loop block driver and callers of prctl(PR_SET_IO_FLUSHER)), where a daemon needs to write to one bdi (the final bdi) in order to free up writes queued to another bdi (the client bdi). The daemon sets PF_LESS_THROTTLE and gets a larger allowance of dirty pages, so that it can still dirty pages after other processses have been throttled. The purpose of this is to avoid deadlock that happen when the PF_LESS_THROTTLE process must write for any dirty pages to be freed, but it is being thottled and cannot write. This approach was designed when all threads were blocked equally, independently on which device they were writing to, or how fast it was. Since that time the writeback algorithm has changed substantially with different threads getting different allowances based on non-trivial heuristics. This means the simple "add 25%" heuristic is no longer reliable. The important issue is not that the daemon needs a *larger* dirty page allowance, but that it needs a *private* dirty page allowance, so that dirty pages for the "client" bdi that it is helping to clear (the bdi for an NFS filesystem or loop block device etc) do not affect the throttling of the daemon writing to the "final" bdi. This patch changes the heuristic so that the task is not throttled when the bdi it is writing to has a dirty page count below below (or equal to) the free-run threshold for that bdi. This ensures it will always be able to have some pages in flight, and so will not deadlock. In a steady-state, it is expected that PF_LOCAL_THROTTLE tasks might still be throttled by global threshold, but that is acceptable as it is only the deadlock state that is interesting for this flag. This approach of "only throttle when target bdi is busy" is consistent with the other use of PF_LESS_THROTTLE in current_may_throttle(), were it causes attention to be focussed only on the target bdi. So this patch - renames PF_LESS_THROTTLE to PF_LOCAL_THROTTLE, - removes the 25% bonus that that flag gives, and - If PF_LOCAL_THROTTLE is set, don't delay at all unless the global and the local free-run thresholds are exceeded. Note that previously realtime threads were treated the same as PF_LESS_THROTTLE threads. This patch does *not* change the behvaiour for real-time threads, so it is now different from the behaviour of nfsd and loop tasks. I don't know what is wanted for realtime. [akpm@linux-foundation.org: coding style fixes] Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Chuck Lever <chuck.lever@oracle.com> [nfsd] Cc: Christoph Hellwig <hch@lst.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Link: http://lkml.kernel.org/r/87ftbf7gs3.fsf@notabene.neil.brown.name Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-05-29blk-mq: drain I/O when all CPUs in a hctx are offlineMing Lei
Most of blk-mq drivers depend on managed IRQ's auto-affinity to setup up queue mapping. Thomas mentioned the following point[1]: "That was the constraint of managed interrupts from the very beginning: The driver/subsystem has to quiesce the interrupt line and the associated queue _before_ it gets shutdown in CPU unplug and not fiddle with it until it's restarted by the core when the CPU is plugged in again." However, current blk-mq implementation doesn't quiesce hw queue before the last CPU in the hctx is shutdown. Even worse, CPUHP_BLK_MQ_DEAD is a cpuhp state handled after the CPU is down, so there isn't any chance to quiesce the hctx before shutting down the CPU. Add new CPUHP_AP_BLK_MQ_ONLINE state to stop allocating from blk-mq hctxs where the last CPU goes away, and wait for completion of in-flight requests. This guarantees that there is no inflight I/O before shutting down the managed IRQ. Add a BLK_MQ_F_STACKING and set it for dm-rq and loop, so we don't need to wait for completion of in-flight requests from these drivers to avoid a potential dead-lock. It is safe to do this for stacking drivers as those do not use interrupts at all and their I/O completions are triggered by underlying devices I/O completion. [1] https://lore.kernel.org/linux-block/alpine.DEB.2.21.1904051331270.1802@nanos.tec.linutronix.de/ [hch: different retry mechanism, merged two patches, minor cleanups] Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-24loop: remove redundant assignment to variable errorColin Ian King
The variable error is being assigned a value that is never read so the assignment is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-21loop: Add LOOP_CONFIGURE ioctlMartijn Coenen
This allows userspace to completely setup a loop device with a single ioctl, removing the in-between state where the device can be partially configured - eg the loop device has a backing file associated with it, but is reading from the wrong offset. Besides removing the intermediate state, another big benefit of this ioctl is that LOOP_SET_STATUS can be slow; the main reason for this slowness is that LOOP_SET_STATUS(64) calls blk_mq_freeze_queue() to freeze the associated queue; this requires waiting for RCU synchronization, which I've measured can take about 15-20ms on this device on average. In addition to doing what LOOP_SET_STATUS can do, LOOP_CONFIGURE can also be used to: - Set the correct block size immediately by setting loop_config.block_size (avoids LOOP_SET_BLOCK_SIZE) - Explicitly request direct I/O mode by setting LO_FLAGS_DIRECT_IO in loop_config.info.lo_flags (avoids LOOP_SET_DIRECT_IO) - Explicitly request read-only mode by setting LO_FLAGS_READ_ONLY in loop_config.info.lo_flags Here's setting up ~70 regular loop devices with an offset on an x86 Android device, using LOOP_SET_FD and LOOP_SET_STATUS: vsoc_x86:/system/apex # time for i in `seq 30 100`; do losetup -r -o 4096 /dev/block/loop$i com.android.adbd.apex; done 0m03.40s real 0m00.02s user 0m00.03s system Here's configuring ~70 devices in the same way, but using a modified losetup that uses the new LOOP_CONFIGURE ioctl: vsoc_x86:/system/apex # time for i in `seq 30 100`; do losetup -r -o 4096 /dev/block/loop$i com.android.adbd.apex; done 0m01.94s real 0m00.01s user 0m00.01s system Signed-off-by: Martijn Coenen <maco@android.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-21loop: Clean up LOOP_SET_STATUS lo_flags handlingMartijn Coenen
LOOP_SET_STATUS(64) will actually allow some lo_flags to be modified; in particular, LO_FLAGS_AUTOCLEAR can be set and cleared, whereas LO_FLAGS_PARTSCAN can be set to request a partition scan. Make this explicit by updating the UAPI to include the flags that can be set/cleared using this ioctl. The implementation can then blindly take over the passed in flags, and use the previous flags for those flags that can't be set / cleared using LOOP_SET_STATUS. Signed-off-by: Martijn Coenen <maco@android.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-21loop: Rework lo_ioctl() __user argument castingMartijn Coenen
In preparation for a new ioctl that needs to copy_from_user(); makes the code easier to read as well. Signed-off-by: Martijn Coenen <maco@android.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-21loop: Move loop_set_status_from_info() and friends upMartijn Coenen
So we can use it without forward declaration. This is a separate commit to make it easier to verify that this is just a move, without functional modifications. Signed-off-by: Martijn Coenen <maco@android.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-21loop: Factor out configuring loop from statusMartijn Coenen
Factor out this code into a separate function, so it can be reused by other code more easily. Signed-off-by: Martijn Coenen <maco@android.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-21loop: Remove figure_loop_size()Martijn Coenen
This function was now only used by loop_set_capacity(). Just open code the remaining code in the caller instead. Signed-off-by: Martijn Coenen <maco@android.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-21loop: Refactor loop_set_status() size calculationMartijn Coenen
figure_loop_size() calculates the loop size based on the passed in parameters, but at the same time it updates the offset and sizelimit parameters in the loop device configuration. That is a somewhat unexpected side effect of a function with this name, and it is only only needed by one of the two callers of this function - loop_set_status(). Move the lo_offset and lo_sizelimit assignment back into loop_set_status(), and use the newly factored out functions to validate and apply the newly calculated size. This allows us to get rid of figure_loop_size() in a follow-up commit. Signed-off-by: Martijn Coenen <maco@android.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-21loop: Switch to set_capacity_revalidate_and_notify()Martijn Coenen
This was recently added to block/genhd.c, and takes care of both updating the capacity and notifying userspace of the new size. Signed-off-by: Martijn Coenen <maco@android.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-21loop: Factor out setting loop device sizeMartijn Coenen
This code is used repeatedly. Signed-off-by: Martijn Coenen <maco@android.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-21loop: Remove sector_t truncation checksMartijn Coenen
sector_t is now always u64, so we don't need to check for truncation. Signed-off-by: Martijn Coenen <maco@android.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-21loop: Call loop_config_discard() only after new config is appliedMartijn Coenen
loop_set_status() calls loop_config_discard() to configure discard for the loop device; however, the discard configuration depends on whether the loop device uses encryption, and when we call it the encryption configuration has not been updated yet. Move the call down so we apply the correct discard configuration based on the new configuration. Signed-off-by: Martijn Coenen <maco@android.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bob Liu <bob.liu@oracle.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-04fs: Remove unneeded IS_DAX() check in io_is_direct()Ira Weiny
Remove the check because DAX now has it's own read/write methods and file systems which support DAX check IS_DAX() prior to IOCB_DIRECT on their own. Therefore, it does not matter if the file state is DAX when the iocb flags are created. Also remove io_is_direct() as it is just a simple flag check. Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-04-03loop: Better discard support for block devicesEvan Green
If the backing device for a loop device is itself a block device, then mirror the "write zeroes" capabilities of the underlying block device into the loop device. Copy this capability into both max_write_zeroes_sectors and max_discard_sectors of the loop device. The reason for this is that REQ_OP_DISCARD on a loop device translates into blkdev_issue_zeroout(), rather than blkdev_issue_discard(). This presents a consistent interface for loop devices (that discarded data is zeroed), regardless of the backing device type of the loop device. There should be no behavior change for loop devices backed by regular files. This change fixes blktest block/003, and removes an extraneous error print in block/013 when testing on a loop device backed by a block device that does not support discard. Signed-off-by: Evan Green <evgreen@chromium.org> Reviewed-by: Gwendal Grignou <gwendal@chromium.org> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> [used updated version of Evan's comment in loop_config_discard()] [moved backingq to local scope, removed redundant braces] Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-03loop: Report EOPNOTSUPP properlyEvan Green
Properly plumb out EOPNOTSUPP from loop driver operations, which may get returned when for instance a discard operation is attempted but not supported by the underlying block device. Before this change, everything was reported in the log as an I/O error, which is scary and not helpful in debugging. Signed-off-by: Evan Green <evgreen@chromium.org> Reviewed-by: Gwendal Grignou <gwendal@chromium.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-10loop: Only freeze block queue when needed.Martijn Coenen
__loop_update_dio() can be called as a part of loop_set_fd(), when the block queue is not yet up and running; avoid freezing the block queue in that case, since that is an expensive operation. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Martijn Coenen <maco@android.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-10loop: Only change blocksize when needed.Martijn Coenen
Return early in loop_set_block_size() if the requested block size is identical to the one we already have; this avoids expensive calls to freeze the block queue. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martijn Coenen <maco@android.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-14block: remove (__)blkdev_reread_part as an exported APIChristoph Hellwig
In general drivers should never mess with partition tables directly. Unfortunately s390 and loop do for somewhat historic reasons, but they can use bdev_disk_changed directly instead when we export it as they satisfy the sanity checks we have in __blkdev_reread_part. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Stefan Haberland <sth@linux.ibm.com> [dasd] Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-01loop: fix no-unmap write-zeroes request behaviorDarrick J. Wong
Currently, if the loop device receives a WRITE_ZEROES request, it asks the underlying filesystem to punch out the range. This behavior is correct if unmapping is allowed. However, a NOUNMAP request means that the caller doesn't want us to free the storage backing the range, so punching out the range is incorrect behavior. To satisfy a NOUNMAP | WRITE_ZEROES request, loop should ask the underlying filesystem to FALLOC_FL_ZERO_RANGE, which is (according to the fallocate documentation) required to ensure that the entire range is backed by real storage, which suffices for our purposes. Fixes: 19372e2769179dd ("loop: implement REQ_OP_WRITE_ZEROES") Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-01loop: change queue block size to match when using DIOMartijn Coenen
The loop driver assumes that if the passed in fd is opened with O_DIRECT, the caller wants to use direct I/O on the loop device. However, if the underlying block device has a different block size than the loop block queue, direct I/O can't be enabled. Instead of requiring userspace to manually change the blocksize and re-enable direct I/O, just change the queue block sizes to match, as well as the io_min size. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martijn Coenen <maco@android.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-17Merge tag 'for-5.4/block-2019-09-16' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block updates from Jens Axboe: - Two NVMe pull requests: - ana log parse fix from Anton - nvme quirks support for Apple devices from Ben - fix missing bio completion tracing for multipath stack devices from Hannes and Mikhail - IP TOS settings for nvme rdma and tcp transports from Israel - rq_dma_dir cleanups from Israel - tracing for Get LBA Status command from Minwoo - Some nvme-tcp cleanups from Minwoo, Potnuri and Myself - Some consolidation between the fabrics transports for handling the CAP register - reset race with ns scanning fix for fabrics (move fabrics commands to a dedicated request queue with a different lifetime from the admin request queue)." - controller reset and namespace scan races fixes - nvme discovery log change uevent support - naming improvements from Keith - multiple discovery controllers reject fix from James - some regular cleanups from various people - Series fixing (and re-fixing) null_blk debug printing and nr_devices checks (André) - A few pull requests from Song, with fixes from Andy, Guoqing, Guilherme, Neil, Nigel, and Yufen. - REQ_OP_ZONE_RESET_ALL support (Chaitanya) - Bio merge handling unification (Christoph) - Pick default elevator correctly for devices with special needs (Damien) - Block stats fixes (Hou) - Timeout and support devices nbd fixes (Mike) - Series fixing races around elevator switching and device add/remove (Ming) - sed-opal cleanups (Revanth) - Per device weight support for BFQ (Fam) - Support for blk-iocost, a new model that can properly account cost of IO workloads. (Tejun) - blk-cgroup writeback fixes (Tejun) - paride queue init fixes (zhengbin) - blk_set_runtime_active() cleanup (Stanley) - Block segment mapping optimizations (Bart) - lightnvm fixes (Hans/Minwoo/YueHaibing) - Various little fixes and cleanups * tag 'for-5.4/block-2019-09-16' of git://git.kernel.dk/linux-block: (186 commits) null_blk: format pr_* logs with pr_fmt null_blk: match the type of parameter nr_devices null_blk: do not fail the module load with zero devices block: also check RQF_STATS in blk_mq_need_time_stamp() block: make rq sector size accessible for block stats bfq: Fix bfq linkage error raid5: use bio_end_sector in r5_next_bio raid5: remove STRIPE_OPS_REQ_PENDING md: add feature flag MD_FEATURE_RAID0_LAYOUT md/raid0: avoid RAID0 data corruption due to layout confusion. raid5: don't set STRIPE_HANDLE to stripe which is in batch list raid5: don't increment read_errors on EILSEQ return nvmet: fix a wrong error status returned in error log page nvme: send discovery log page change events to userspace nvme: add uevent variables for controller devices nvme: enable aen regardless of the presence of I/O queues nvme-fabrics: allow discovery subsystems accept a kato nvmet: Use PTR_ERR_OR_ZERO() in nvmet_init_discovery() nvme: Remove redundant assignment of cq vector nvme: Assign subsys instance from first ctrl ...
2019-08-08loop: Add LOOP_SET_DIRECT_IO to compat ioctlAlessio Balsini
Enabling Direct I/O with loop devices helps reducing memory usage by avoiding double caching. 32 bit applications running on 64 bits systems are currently not able to request direct I/O because is missing from the lo_compat_ioctl. This patch fixes the compatibility issue mentioned above by exporting LOOP_SET_DIRECT_IO as additional lo_compat_ioctl() entry. The input argument for this ioctl is a single long converted to a 1-bit boolean, so compatibility is preserved. Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Alessio Balsini <balsini@android.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-08loop: set PF_MEMALLOC_NOIO for the worker threadMikulas Patocka
A deadlock with this stacktrace was observed. The loop thread does a GFP_KERNEL allocation, it calls into dm-bufio shrinker and the shrinker depends on I/O completion in the dm-bufio subsystem. In order to fix the deadlock (and other similar ones), we set the flag PF_MEMALLOC_NOIO at loop thread entry. PID: 474 TASK: ffff8813e11f4600 CPU: 10 COMMAND: "kswapd0" #0 [ffff8813dedfb938] __schedule at ffffffff8173f405 #1 [ffff8813dedfb990] schedule at ffffffff8173fa27 #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186 #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8 #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81 #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio] #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio] #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio] #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778 #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f #13 [ffff8813dedfbec0] kthread at ffffffff810a8428 #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242 PID: 14127 TASK: ffff881455749c00 CPU: 11 COMMAND: "loop1" #0 [ffff88272f5af228] __schedule at ffffffff8173f405 #1 [ffff88272f5af280] schedule at ffffffff8173fa27 #2 [ffff88272f5af2a0] schedule_preempt_disabled at ffffffff8173fd5e #3 [ffff88272f5af2b0] __mutex_lock_slowpath at ffffffff81741fb5 #4 [ffff88272f5af330] mutex_lock at ffffffff81742133 #5 [ffff88272f5af350] dm_bufio_shrink_count at ffffffffa03865f9 [dm_bufio] #6 [ffff88272f5af380] shrink_slab at ffffffff811a86bd #7 [ffff88272f5af470] shrink_zone at ffffffff811ad778 #8 [ffff88272f5af500] do_try_to_free_pages at ffffffff811adb34 #9 [ffff88272f5af590] try_to_free_pages at ffffffff811adef8 #10 [ffff88272f5af610] __alloc_pages_nodemask at ffffffff811a09c3 #11 [ffff88272f5af710] alloc_pages_current at ffffffff811e8b71 #12 [ffff88272f5af760] new_slab at ffffffff811f4523 #13 [ffff88272f5af7b0] __slab_alloc at ffffffff8173a1b5 #14 [ffff88272f5af880] kmem_cache_alloc at ffffffff811f484b #15 [ffff88272f5af8d0] do_blockdev_direct_IO at ffffffff812535b3 #16 [ffff88272f5afb00] __blockdev_direct_IO at ffffffff81255dc3 #17 [ffff88272f5afb30] xfs_vm_direct_IO at ffffffffa01fe3fc [xfs] #18 [ffff88272f5afb90] generic_file_read_iter at ffffffff81198994 #19 [ffff88272f5afc50] __dta_xfs_file_read_iter_2398 at ffffffffa020c970 [xfs] #20 [ffff88272f5afcc0] lo_rw_aio at ffffffffa0377042 [loop] #21 [ffff88272f5afd70] loop_queue_work at ffffffffa0377c3b [loop] #22 [ffff88272f5afe60] kthread_worker_fn at ffffffff810a8a0c #23 [ffff88272f5afec0] kthread at ffffffff810a8428 #24 [ffff88272f5aff50] ret_from_fork at ffffffff81745242 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-07-30loop: Fix mount(2) failure due to race with LOOP_SET_FDJan Kara
Commit 33ec3e53e7b1 ("loop: Don't change loop device under exclusive opener") made LOOP_SET_FD ioctl acquire exclusive block device reference while it updates loop device binding. However this can make perfectly valid mount(2) fail with EBUSY due to racing LOOP_SET_FD holding temporarily the exclusive bdev reference in cases like this: for i in {a..z}{a..z}; do dd if=/dev/zero of=$i.image bs=1k count=0 seek=1024 mkfs.ext2 $i.image mkdir mnt$i done echo "Run" for i in {a..z}{a..z}; do mount -o loop -t ext2 $i.image mnt$i & done Fix the problem by not getting full exclusive bdev reference in LOOP_SET_FD but instead just mark the bdev as being claimed while we update the binding information. This just blocks new exclusive openers instead of failing them with EBUSY thus fixing the problem. Fixes: 33ec3e53e7b1 ("loop: Don't change loop device under exclusive opener") Cc: stable@vger.kernel.org Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-29block: never take page references for ITER_BVECChristoph Hellwig
If we pass pages through an iov_iter we always already have a reference in the caller. Thus remove the ITER_BVEC_FLAG_NO_REF and don't take reference to pages by default for bvec backed iov_iters. Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-27loop: Don't change loop device under exclusive openerJan Kara
Loop module allows calling LOOP_SET_FD while there are other openers of the loop device. Even exclusive ones. This can lead to weird consequences such as kernel deadlocks like: mount_bdev() lo_ioctl() udf_fill_super() udf_load_vrs() sb_set_blocksize() - sets desired block size B udf_tread() sb_bread() __bread_gfp(bdev, block, B) loop_set_fd() set_blocksize() - now __getblk_slow() indefinitely loops because B != bdev block size Fix the problem by disallowing LOOP_SET_FD ioctl when there are exclusive openers of a loop device. [Deliberately chosen not to CC stable as a user with priviledges to trigger this race has other means of taking the system down and this has a potential of breaking some weird userspace setup] Reported-and-tested-by: syzbot+10007d66ca02b08f0e60@syzkaller.appspotmail.com Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01block: loop: mark bvec as ITER_BVEC_FLAG_NO_REFMing Lei
loop is one block device, for any bio submitted to this device, the upper layer does guarantee that pages added to loop's bio won't go away when the bio is in-flight. So mark loop's bvec as ITER_BVEC_FLAG_NO_REF then get_page/put_page can be saved for serving loop's IO. Cc: linux-fsdevel@vger.kernel.org Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01loop: properly observe rotational flag of underlying deviceHolger Hoffstätte
The loop driver always declares the rotational flag of its device as rotational, even when the device of the mapped file is nonrotational, as is the case with SSDs or on tmpfs. This can confuse filesystem tools which are SSD-aware; in my case I frequently forget to tell mkfs.btrfs that my loop device on tmpfs is nonrotational, and that I really don't need any automatic metadata redundancy. The attached patch fixes this by introspecting the rotational flag of the mapped file's underlying block device, if it exists. If the mapped file's filesystem has no associated block device - as is the case on e.g. tmpfs - we assume nonrotational storage. If there is a better way to identify such non-devices I'd love to hear them. Cc: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Cc: holger@applied-asynchrony.com Signed-off-by: Holger Hoffstätte <holger.hoffstaette@googlemail.com> Signed-off-by: Gwendal Grignou <gwendal@chromium.org> Signed-off-by: Benjamin Gordon <bmgordon@chromium.org> Reviewed-by: Guenter Roeck <groeck@chromium.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-03-18loop: access lo_backing_file only when the loop device is Lo_boundDongli Zhang
Commit 758a58d0bc67 ("loop: set GENHD_FL_NO_PART_SCAN after blkdev_reread_part()") separates "lo->lo_backing_file = NULL" and "lo->lo_state = Lo_unbound" into different critical regions protected by loop_ctl_mutex. However, there is below race that the NULL lo->lo_backing_file would be accessed when the backend of a loop is another loop device, e.g., loop0's backend is a file, while loop1's backend is loop0. loop0's backend is file loop1's backend is loop0 __loop_clr_fd() mutex_lock(&loop_ctl_mutex); lo->lo_backing_file = NULL; --> set to NULL mutex_unlock(&loop_ctl_mutex); loop_set_fd() mutex_lock_killable(&loop_ctl_mutex); loop_validate_file() f = l->lo_backing_file; --> NULL access if loop0 is not Lo_unbound mutex_lock(&loop_ctl_mutex); lo->lo_state = Lo_unbound; mutex_unlock(&loop_ctl_mutex); lo->lo_backing_file should be accessed only when the loop device is Lo_bound. In fact, the problem has been introduced already in commit 7ccd0791d985 ("loop: Push loop_ctl_mutex down into loop_clr_fd()") after which loop_validate_file() could see devices in Lo_rundown state with which it did not count. It was harmless at that point but still. Fixes: 7ccd0791d985 ("loop: Push loop_ctl_mutex down into loop_clr_fd()") Reported-by: syzbot+9bdc1adc1c55e7fe765b@syzkaller.appspotmail.com Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-22loop: set GENHD_FL_NO_PART_SCAN after blkdev_reread_part()Dongli Zhang
Commit 0da03cab87e6 ("loop: Fix deadlock when calling blkdev_reread_part()") moves blkdev_reread_part() out of the loop_ctl_mutex. However, GENHD_FL_NO_PART_SCAN is set before __blkdev_reread_part(). As a result, __blkdev_reread_part() will fail the check of GENHD_FL_NO_PART_SCAN and will not rescan the loop device to delete all partitions. Below are steps to reproduce the issue: step1 # dd if=/dev/zero of=tmp.raw bs=1M count=100 step2 # losetup -P /dev/loop0 tmp.raw step3 # parted /dev/loop0 mklabel gpt step4 # parted -a none -s /dev/loop0 mkpart primary 64s 1 step5 # losetup -d /dev/loop0 Step5 will not be able to delete /dev/loop0p1 (introduced by step4) and there is below kernel warning message: [ 464.414043] __loop_clr_fd: partition scan of loop0 failed (rc=-22) This patch sets GENHD_FL_NO_PART_SCAN after blkdev_reread_part(). Fixes: 0da03cab87e6 ("loop: Fix deadlock when calling blkdev_reread_part()") Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-22loop: do not print warn message if partition scan is successfulDongli Zhang
Do not print warn message when the partition scan returns 0. Fixes: d57f3374ba48 ("loop: Move special partition reread handling in loop_clr_fd()") Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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