- 28 Feb, 2019 9 commits
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Jens Axboe authored
If we have fixed user buffers, we can map them into the kernel when we setup the io_uring. That avoids the need to do get_user_pages() for each and every IO. To utilize this feature, the application must call io_uring_register() after having setup an io_uring instance, passing in IORING_REGISTER_BUFFERS as the opcode. The argument must be a pointer to an iovec array, and the nr_args should contain how many iovecs the application wishes to map. If successful, these buffers are now mapped into the kernel, eligible for IO. To use these fixed buffers, the application must use the IORING_OP_READ_FIXED and IORING_OP_WRITE_FIXED opcodes, and then set sqe->index to the desired buffer index. sqe->addr..sqe->addr+seq->len must point to somewhere inside the indexed buffer. The application may register buffers throughout the lifetime of the io_uring instance. It can call io_uring_register() with IORING_UNREGISTER_BUFFERS as the opcode to unregister the current set of buffers, and then register a new set. The application need not unregister buffers explicitly before shutting down the io_uring instance. It's perfectly valid to setup a larger buffer, and then sometimes only use parts of it for an IO. As long as the range is within the originally mapped region, it will work just fine. For now, buffers must not be file backed. If file backed buffers are passed in, the registration will fail with -1/EOPNOTSUPP. This restriction may be relaxed in the future. RLIMIT_MEMLOCK is used to check how much memory we can pin. A somewhat arbitrary 1G per buffer size is also imposed. Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Jens Axboe authored
For an ITER_BVEC, we can just iterate the iov and add the pages to the bio directly. For now, we grab a reference to those pages, and release them normally on IO completion. This isn't really needed for the normal case of O_DIRECT from/to a file, but some of the more esoteric use cases (like splice(2)) will unconditionally put the pipe buffer pages when the buffers are released. Until we can manage that case properly, ITER_BVEC pages are treated like normal pages in terms of reference counting. Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Jens Axboe authored
Similarly to how we use the state->ios_left to know how many references to get to a file, we can use it to allocate the io_kiocb's we need in bulk. Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Jens Axboe authored
Add a separate io_submit_state structure, to cache some of the things we need for IO submission. One such example is file reference batching. io_submit_state. We get as many references as the number of sqes we are submitting, and drop unused ones if we end up switching files. The assumption here is that we're usually only dealing with one fd, and if there are multiple, hopefuly they are at least somewhat ordered. Could trivially be extended to cover multiple fds, if needed. On the completion side we do the same thing, except this is trivially done just locally in io_iopoll_reap(). Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Jens Axboe authored
Some uses cases repeatedly get and put references to the same file, but the only exposed interface is doing these one at the time. As each of these entail an atomic inc or dec on a shared structure, that cost can add up. Add fget_many(), which works just like fget(), except it takes an argument for how many references to get on the file. Ditto fput_many(), which can drop an arbitrary number of references to a file. Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Jens Axboe authored
Add support for a polled io_uring instance. When a read or write is submitted to a polled io_uring, the application must poll for completions on the CQ ring through io_uring_enter(2). Polled IO may not generate IRQ completions, hence they need to be actively found by the application itself. To use polling, io_uring_setup() must be used with the IORING_SETUP_IOPOLL flag being set. It is illegal to mix and match polled and non-polled IO on an io_uring. Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Christoph Hellwig authored
Add a new fsync opcode, which either syncs a range if one is passed, or the whole file if the offset and length fields are both cleared to zero. A flag is provided to use fdatasync semantics, that is only force out metadata which is required to retrieve the file data, but not others like metadata. Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Jens Axboe authored
The submission queue (SQ) and completion queue (CQ) rings are shared between the application and the kernel. This eliminates the need to copy data back and forth to submit and complete IO. IO submissions use the io_uring_sqe data structure, and completions are generated in the form of io_uring_cqe data structures. The SQ ring is an index into the io_uring_sqe array, which makes it possible to submit a batch of IOs without them being contiguous in the ring. The CQ ring is always contiguous, as completion events are inherently unordered, and hence any io_uring_cqe entry can point back to an arbitrary submission. Two new system calls are added for this: io_uring_setup(entries, params) Sets up an io_uring instance for doing async IO. On success, returns a file descriptor that the application can mmap to gain access to the SQ ring, CQ ring, and io_uring_sqes. io_uring_enter(fd, to_submit, min_complete, flags, sigset, sigsetsize) Initiates IO against the rings mapped to this fd, or waits for them to complete, or both. The behavior is controlled by the parameters passed in. If 'to_submit' is non-zero, then we'll try and submit new IO. If IORING_ENTER_GETEVENTS is set, the kernel will wait for 'min_complete' events, if they aren't already available. It's valid to set IORING_ENTER_GETEVENTS and 'min_complete' == 0 at the same time, this allows the kernel to return already completed events without waiting for them. This is useful only for polling, as for IRQ driven IO, the application can just check the CQ ring without entering the kernel. With this setup, it's possible to do async IO with a single system call. Future developments will enable polled IO with this interface, and polled submission as well. The latter will enable an application to do IO without doing ANY system calls at all. For IRQ driven IO, an application only needs to enter the kernel for completions if it wants to wait for them to occur. Each io_uring is backed by a workqueue, to support buffered async IO as well. We will only punt to an async context if the command would need to wait for IO on the device side. Any data that can be accessed directly in the page cache is done inline. This avoids the slowness issue of usual threadpools, since cached data is accessed as quickly as a sync interface. Sample application: http://git.kernel.dk/cgit/fio/plain/t/io_uring.cReviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Ming Lei authored
mp_bvec_for_each_segment() is a bit big for the iteration, so introduce a light-weight helper for iterating over pages, then 32bytes stack space can be saved. Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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- 27 Feb, 2019 3 commits
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Ming Lei authored
Introduce a fast path for single-page bvec IO, then we can avoid to call bvec_split_segs() unnecessarily. Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Ming Lei authored
Introduce a fast path for single-page bvec IO, then blk_bvec_map_sg() can be avoided. Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Ming Lei authored
Single-page bvec can often be seen in small BS workloads, so introduce bvec_nth_page() for avoiding to call nth_page() unnecessarily, which looks not cheap. Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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- 24 Feb, 2019 4 commits
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Christoph Hellwig authored
Store the request queue the last bio was submitted to in the iocb private data in addition to the cookie so that we find the right block device. Also refactor the common direct I/O bio submission code into a nice little helper. Signed-off-by: Christoph Hellwig <hch@lst.de> Modified to use bio_set_polled(). Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Jens Axboe authored
For the upcoming async polled IO, we can't sleep allocating requests. If we do, then we introduce a deadlock where the submitter already has async polled IO in-flight, but can't wait for them to complete since polled requests must be active found and reaped. Utilize the helper in the blockdev DIRECT_IO code. Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Christoph Hellwig authored
Just call blk_poll on the iocb cookie, we can derive the block device from the inode trivially. Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Christoph Hellwig authored
This new methods is used to explicitly poll for I/O completion for an iocb. It must be called for any iocb submitted asynchronously (that is with a non-null ki_complete) which has the IOCB_HIPRI flag set. The method is assisted by a new ki_cookie field in struct iocb to store the polling cookie. Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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- 22 Feb, 2019 2 commits
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Dongli Zhang authored
Commit 0da03cab ("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: 0da03cab ("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>
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Dongli Zhang authored
Do not print warn message when the partition scan returns 0. Fixes: d57f3374 ("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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- 21 Feb, 2019 3 commits
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Ming Lei authored
Block bounce needs to allocate new page for doing IO, and the new page has to be updated to bvec table. Commit 6dc4f100 switches __blk_queue_bounce() to use the new bio_for_each_segment_all() interface. Unfortunately the new bio_for_each_segment_all() can't be used to update bvec table. This patch fixes this issue by retrieving bvec from the table directly, then the new allocated page can be updated to the bio. This way is safe because the cloned bio is single page bvec. Fixes: 6dc4f100 ("block: allow bio_for_each_segment_all() to iterate over multi-page bvec") Cc: Christoph Hellwig <hch@lst.de> Cc: Omar Sandoval <osandov@fb.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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git://git.infradead.org/nvmeJens Axboe authored
Pull NVMe changes for 5.1 from Christoph * 'nvme-5.1' of git://git.infradead.org/nvme: (22 commits) nvme-rdma: use nr_phys_segments when map rq to sgl nvmet: convert to SPDX identifiers nvmet-rdma: convert to SPDX identifiers nvme-loop: convert to SPDX identifiers nvmet-fcloop: convert to SPDX identifiers nvmet-fc: convert to SPDX identifiers nvme: convert to SPDX identifiers nvme-pci: convert to SPDX identifiers nvme-lightnvm: convert to SPDX identifiers nvme-rdma: convert to SPDX identifiers nvme-fc: convert to SPDX identifiers nvme-fabrics: convert to SPDX identifiers nvme-tcp.h: fix SPDX header nvme_ioctl.h: remove duplicate GPL boilerplate nvme: return error from nvme_alloc_ns() nvme: avoid that deleting a controller triggers a circular locking complaint nvme: introduce a helper function for controller deletion nvme: unexport nvme_delete_ctrl_sync() nvme-pci: check kstrtoint() return value in queue_count_set() nvme-fabrics: document the poll function argument ...
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Chaitanya Kulkarni authored
Use blk_rq_nr_phys_segments() instead of blk_rq_payload_bytes() to check if a command contains data to be mapped. This fixes the case where a struct request contains LBAs, but it has no payload, such as Write Zeroes support. Fixes: 6e02318e ("nvme: add support for the Write Zeroes command") Reported-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Tested-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
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- 20 Feb, 2019 19 commits
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Christoph Hellwig authored
Update license to use SPDX-License-Identifier instead of verbose license text. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
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Christoph Hellwig authored
Update license to use SPDX-License-Identifier instead of verbose license text. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
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Christoph Hellwig authored
Update license to use SPDX-License-Identifier instead of verbose license text. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
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Christoph Hellwig authored
Update license to use SPDX-License-Identifier instead of verbose license text. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
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Christoph Hellwig authored
Update license to use SPDX-License-Identifier instead of verbose license text. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
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Christoph Hellwig authored
Update license to use SPDX-License-Identifier instead of verbose license text. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
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Christoph Hellwig authored
Update license to use SPDX-License-Identifier instead of verbose license text. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
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Christoph Hellwig authored
Update license to use SPDX-License-Identifier instead of verbose license text. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
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Christoph Hellwig authored
Update license to use SPDX-License-Identifier instead of verbose license text. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
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Christoph Hellwig authored
Update license to use SPDX-License-Identifier instead of verbose license text. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
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Christoph Hellwig authored
Update license to use SPDX-License-Identifier instead of verbose license text. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
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Christoph Hellwig authored
For .h files we need to use /* */ style comments. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
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Christoph Hellwig authored
We already have a ЅPDX header, so no need to duplicate the information. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
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Hannes Reinecke authored
nvme_alloc_ns() might fail, so we should be returning an error code. Signed-off-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de>
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Bart Van Assche authored
Rework nvme_delete_ctrl_sync() such that it does not have to wait for queued work. This patch avoids that test nvme/008 triggers the following complaint: WARNING: possible circular locking dependency detected 5.0.0-rc6-dbg+ #10 Not tainted ------------------------------------------------------ nvme/7918 is trying to acquire lock: 000000009a1a7b69 ((work_completion)(&ctrl->delete_work)){+.+.}, at: __flush_work+0x379/0x410 but task is already holding lock: 00000000ef5a45b4 (kn->count#389){++++}, at: kernfs_remove_self+0x196/0x210 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (kn->count#389){++++}: lock_acquire+0xc5/0x1e0 __kernfs_remove+0x42a/0x4a0 kernfs_remove_by_name_ns+0x45/0x90 remove_files.isra.1+0x3a/0x90 sysfs_remove_group+0x5c/0xc0 sysfs_remove_groups+0x39/0x60 device_remove_attrs+0x68/0xb0 device_del+0x24d/0x570 cdev_device_del+0x1a/0x50 nvme_delete_ctrl_work+0xbd/0xe0 process_one_work+0x4f1/0xa40 worker_thread+0x67/0x5b0 kthread+0x1cf/0x1f0 ret_from_fork+0x24/0x30 -> #0 ((work_completion)(&ctrl->delete_work)){+.+.}: __lock_acquire+0x1323/0x17b0 lock_acquire+0xc5/0x1e0 __flush_work+0x399/0x410 flush_work+0x10/0x20 nvme_delete_ctrl_sync+0x65/0x70 nvme_sysfs_delete+0x4f/0x60 dev_attr_store+0x3e/0x50 sysfs_kf_write+0x87/0xa0 kernfs_fop_write+0x186/0x240 __vfs_write+0xd7/0x430 vfs_write+0xfa/0x260 ksys_write+0xab/0x130 __x64_sys_write+0x43/0x50 do_syscall_64+0x71/0x210 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(kn->count#389); lock((work_completion)(&ctrl->delete_work)); lock(kn->count#389); lock((work_completion)(&ctrl->delete_work)); *** DEADLOCK *** 3 locks held by nvme/7918: #0: 00000000e2223b44 (sb_writers#6){.+.+}, at: vfs_write+0x1eb/0x260 #1: 000000003404976f (&of->mutex){+.+.}, at: kernfs_fop_write+0x128/0x240 #2: 00000000ef5a45b4 (kn->count#389){++++}, at: kernfs_remove_self+0x196/0x210 stack backtrace: CPU: 4 PID: 7918 Comm: nvme Not tainted 5.0.0-rc6-dbg+ #10 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 Call Trace: dump_stack+0x86/0xca print_circular_bug.isra.36.cold.54+0x173/0x1d5 check_prev_add.constprop.45+0x996/0x1110 __lock_acquire+0x1323/0x17b0 lock_acquire+0xc5/0x1e0 __flush_work+0x399/0x410 flush_work+0x10/0x20 nvme_delete_ctrl_sync+0x65/0x70 nvme_sysfs_delete+0x4f/0x60 dev_attr_store+0x3e/0x50 sysfs_kf_write+0x87/0xa0 kernfs_fop_write+0x186/0x240 __vfs_write+0xd7/0x430 vfs_write+0xfa/0x260 ksys_write+0xab/0x130 __x64_sys_write+0x43/0x50 do_syscall_64+0x71/0x210 entry_SYSCALL_64_after_hwframe+0x49/0xbe Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
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Bart Van Assche authored
This patch does not change any functionality but makes the next patch in this series easier to read. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de>
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Bart Van Assche authored
Since nvme_delete_ctrl_sync() is not called from any other kernel module, unexport it. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
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Bart Van Assche authored
This patch avoids that the compiler complains about 'ret' being set but not being used when building with W=1. Fixes: 3b6592f7 ("nvme: utilize two queue maps, one for reads and one for writes") # v5.0-rc1 Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
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Bart Van Assche authored
This patch avoids that the kernel-doc tool reports a warning when building with W=1. Fixes: 26c68227 ("nvme-fabrics: allow nvmf_connect_io_queue to poll") # v5.0-rc1 Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
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