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2023-06-07blk-ioc: fix recursive spin_lock/unlock_irq() in ioc_clear_queue()Yu Kuai1-2/+2
Recursive spin_lock/unlock_irq() is not safe, because spin_unlock_irq() will enable irq unconditionally: spin_lock_irq queue_lock -> disable irq spin_lock_irq ioc->lock spin_unlock_irq ioc->lock -> enable irq /* * AA dead lock will be triggered if current context is preempted by irq, * and irq try to hold queue_lock again. */ spin_unlock_irq queue_lock Fix this problem by using spin_lock/unlock() directly for 'ioc->lock'. Fixes: 5a0ac57c48aa ("blk-ioc: protect ioc_destroy_icq() by 'queue_lock'") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20230606011438.3743440-1-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-01blk-ioc: protect ioc_destroy_icq() by 'queue_lock'Yu Kuai1-17/+13
Currently, icq is tracked by both request_queue(icq->q_node) and task(icq->ioc_node), and ioc_clear_queue() from elevator exit is not safe because it can access the list without protection: ioc_clear_queue ioc_release_fn lock queue_lock list_splice /* move queue list to a local list */ unlock queue_lock /* * lock is released, the local list * can be accessed through task exit. */ lock ioc->lock while (!hlist_empty) icq = hlist_entry lock queue_lock ioc_destroy_icq delete icq->ioc_node while (!list_empty) icq = list_entry() list_del icq->q_node /* * This is not protected by any lock, * list_entry concurrent with list_del * is not safe. */ unlock queue_lock unlock ioc->lock Fix this problem by protecting list 'icq->q_node' by queue_lock from ioc_clear_queue(). Reported-and-tested-by: Pradeep Pragallapati <quic_pragalla@quicinc.com> Link: https://lore.kernel.org/lkml/20230517084434.18932-1-quic_pragalla@quicinc.com/ Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20230531073435.2923422-1-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-27block: fix default IO priority handling againJan Kara1-0/+2
Commit e70344c05995 ("block: fix default IO priority handling") introduced an inconsistency in get_current_ioprio() that tasks without IO context return IOPRIO_DEFAULT priority while tasks with freshly allocated IO context will return 0 (IOPRIO_CLASS_NONE/0) IO priority. Tasks without IO context used to be rare before 5a9d041ba2f6 ("block: move io_context creation into where it's needed") but after this commit they became common because now only BFQ IO scheduler setups task's IO context. Similar inconsistency is there for get_task_ioprio() so this inconsistency is now exposed to userspace and userspace will see different IO priority for tasks operating on devices with BFQ compared to devices without BFQ. Furthemore the changes done by commit e70344c05995 change the behavior when no IO priority is set for BFQ IO scheduler which is also documented in ioprio_set(2) manpage: "If no I/O scheduler has been set for a thread, then by default the I/O priority will follow the CPU nice value (setpriority(2)). In Linux kernels before version 2.6.24, once an I/O priority had been set using ioprio_set(), there was no way to reset the I/O scheduling behavior to the default. Since Linux 2.6.24, specifying ioprio as 0 can be used to reset to the default I/O scheduling behavior." So make sure we default to IOPRIO_CLASS_NONE as used to be the case before commit e70344c05995. Also cleanup alloc_io_context() to explicitely set this IO priority for the allocated IO context to avoid future surprises. Note that we tweak ioprio_best() to maintain ioprio_get(2) behavior and make this commit easily backportable. CC: stable@vger.kernel.org Fixes: e70344c05995 ("block: fix default IO priority handling") Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220623074840.5960-1-jack@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-03-28block: restore the old set_task_ioprio() behaviour wrt PF_EXITINGJiri Slaby1-2/+1
PF_EXITING tasks were silently ignored before the below commits. Continue doing so. Otherwise python-psutil tests fail: ERROR: psutil.tests.test_process.TestProcess.test_zombie_process ---------------------------------------------------------------------- Traceback (most recent call last): File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/build/lib.linux-x86_64-3.9/psutil/_pslinux.py", line 1661, in wrapper return fun(self, *args, **kwargs) File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/build/lib.linux-x86_64-3.9/psutil/_pslinux.py", line 2133, in ionice_set return cext.proc_ioprio_set(self.pid, ioclass, value) ProcessLookupError: [Errno 3] No such process During handling of the above exception, another exception occurred: Traceback (most recent call last): File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/psutil/tests/test_process.py", line 1313, in test_zombie_process succeed_or_zombie_p_exc(fun) File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/psutil/tests/test_process.py", line 1288, in succeed_or_zombie_p_exc return fun() File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/build/lib.linux-x86_64-3.9/psutil/__init__.py", line 792, in ionice return self._proc.ionice_set(ioclass, value) File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/build/lib.linux-x86_64-3.9/psutil/_pslinux.py", line 1665, in wrapper raise NoSuchProcess(self.pid, self._name) psutil.NoSuchProcess: process no longer exists (pid=2057) Cc: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Fixes: 5fc11eebb4 (block: open code create_task_io_context in set_task_ioprio) Fixes: a957b61254 (block: fix error in handling dead task for ioprio setting) Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20220328085928.7899-1-jslaby@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-23block: drop needless assignment in set_task_ioprio()Lukas Bulwahn1-4/+2
Commit 5fc11eebb4a9 ("block: open code create_task_io_context in set_task_ioprio") introduces a needless assignment 'ioc = task->io_context', as the local variable ioc is not further used before returning. Even after the further fix, commit a957b61254a7 ("block: fix error in handling dead task for ioprio setting"), the assignment still remains needless. Drop this needless assignment in set_task_ioprio(). This code smell was identified with 'make clang-analyzer'. Fixes: 5fc11eebb4a9 ("block: open code create_task_io_context in set_task_ioprio") Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211223125300.20691-1-lukas.bulwahn@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-21block: fix error in handling dead task for ioprio settingJens Axboe1-2/+8
Don't combine the task exiting and "already have io_context" case, we need to just abort if the task is marked as dead. Return -ESRCH, which is the documented value for ioprio_set() if the specified task could not be found. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Reported-by: syzbot+8836466a79f4175961b0@syzkaller.appspotmail.com Fixes: 5fc11eebb4a9 ("block: open code create_task_io_context in set_task_ioprio") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-16block: only build the icq tracking code when neededChristoph Hellwig1-27/+41
Only bfq needs to code to track icq, so make it conditional. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20211209063131.18537-12-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-16block: fold create_task_io_context into ioc_find_get_icqChristoph Hellwig1-31/+12
Fold create_task_io_context into the only remaining caller. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20211209063131.18537-11-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-16block: open code create_task_io_context in set_task_ioprioChristoph Hellwig1-5/+11
The flow in set_task_ioprio can be simplified by simply open coding create_task_io_context, which removes a refcount roundtrip on the I/O context. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20211209063131.18537-10-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-16block: fold get_task_io_context into set_task_ioprioChristoph Hellwig1-38/+14
Fold get_task_io_context into its only caller, and simplify the code as no reference to the I/O context is required to just set the ioprio field. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20211209063131.18537-9-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-16block: move set_task_ioprio to blk-ioc.cChristoph Hellwig1-2/+32
Keep set_task_ioprio with the other low-level code that accesses the io_context structure. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20211209063131.18537-8-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-16block: cleanup ioc_clear_queueChristoph Hellwig1-22/+11
Fold __ioc_clear_queue into ioc_clear_queue and switch to always use plain _irq locking instead of the more expensive _irqsave that is not needed here. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20211209063131.18537-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-16block: refactor put_io_contextChristoph Hellwig1-19/+19
Move the code to delay freeing the icqs into a separate helper. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20211209063131.18537-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-16block: remove the NULL ioc check in put_io_contextChristoph Hellwig1-3/+0
No caller passes in a NULL pointer, so remove the check. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20211209063131.18537-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-16block: refactor put_iocontext_activeChristoph Hellwig1-27/+14
Factor out a ioc_exit_icqs helper to tear down the icqs and the fold the rest of put_iocontext_active into exit_io_context. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20211209063131.18537-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-16block: simplify struct io_context refcountingChristoph Hellwig1-4/+1
Don't hold a reference to ->refcount for each active reference, but just one for all active references. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20211209063131.18537-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-16block: remove the nr_task field from struct io_contextChristoph Hellwig1-3/+0
Nothing ever looks at ->nr_tasks, so remove it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20211209063131.18537-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: simplify ioc_lookup_icqChristoph Hellwig1-4/+4
Remove the ioc argument as it always points to current->io_context. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211126115817.2087431-15-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: simplify ioc_create_icqChristoph Hellwig1-7/+5
Remove the ioc and gfp_mask argument, which are hard coded by the caller. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211126115817.2087431-14-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: return the io_context from create_task_io_contextChristoph Hellwig1-36/+30
Grab a reference to the newly allocated or existing io_context in create_task_io_context and return it. This simplifies the callers and removes the need for double lookups. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211126115817.2087431-13-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: use alloc_io_context in __copy_ioChristoph Hellwig1-6/+3
In __copy_io we know that the newly allocate task_struct does not have an I/O context yet and is not exiting. So just allocate the I/O context struct and install it directly. There is no need to lock the task either as it is just being created. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211126115817.2087431-12-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: factor out a alloc_io_context helperChristoph Hellwig1-5/+14
Factor out a helper that just allocate an I/O context. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211126115817.2087431-11-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: remove get_io_context_activeChristoph Hellwig1-5/+3
Fold it into it's only caller, and remove a lof of the debug checks that are not needed. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211126115817.2087431-10-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: move the remaining elv.icq handling to the I/O schedulerChristoph Hellwig1-0/+1
After the prepare side has been moved to the only I/O scheduler that cares, do the same for the cleanup and the NULL initialization. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211126115817.2087431-9-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: move blk_mq_sched_assign_ioc to blk-ioc.cChristoph Hellwig1-4/+35
Move blk_mq_sched_assign_ioc so that many interfaces from the file can be marked static. Rename the function to ioc_find_get_icq as well and return the icq to simplify the interface. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211126115817.2087431-8-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: mark put_io_context_active staticChristoph Hellwig1-1/+1
Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211126115817.2087431-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29fork: move copy_io to block/blk-ioc.cChristoph Hellwig1-0/+27
Move the copying of the I/O context to the block layer as that is where we can use the proper low-level interfaces. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211126115817.2087431-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: don't include blk-mq-sched.h in blk.hChristoph Hellwig1-0/+1
No needed, shift it into the source files that need it instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211123185312.1432157-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-16block: remove retry loop in ioc_release_fn()John Ogness1-3/+17
The reverse-order double lock dance in ioc_release_fn() is using a retry loop. This is a problem on PREEMPT_RT because it could preempt the task that would release q->queue_lock and thus live lock in the retry loop. RCU is already managing the freeing of the request queue and icq. If the trylock fails, use RCU to guarantee that the request queue and icq are not freed and re-acquire the locks in the correct order, allowing forward progress. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-16block: remove unnecessary ioc nested lockingJohn Ogness1-20/+6
The legacy CFQ IO scheduler could call put_io_context() in its exit_icq() elevator callback. This led to a lockdep warning, which was fixed in commit d8c66c5d5924 ("block: fix lockdep warning on io_context release put_io_context()") by using a nested subclass for the ioc spinlock. However, with commit f382fb0bcef4 ("block: remove legacy IO schedulers") the CFQ IO scheduler no longer exists. The BFQ IO scheduler also implements the exit_icq() elevator callback but does not call put_io_context(). The nested subclass for the ioc spinlock is no longer needed. Since it existed as an exception and no longer applies, remove the nested subclass usage. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-12block: Fix use-after-free issue accessing struct io_cqSahitya Tummala1-0/+7
There is a potential race between ioc_release_fn() and ioc_clear_queue() as shown below, due to which below kernel crash is observed. It also can result into use-after-free issue. context#1: context#2: ioc_release_fn() __ioc_clear_queue() gets the same icq ->spin_lock(&ioc->lock); ->spin_lock(&ioc->lock); ->ioc_destroy_icq(icq); ->list_del_init(&icq->q_node); ->call_rcu(&icq->__rcu_head, icq_free_icq_rcu); ->spin_unlock(&ioc->lock); ->ioc_destroy_icq(icq); ->hlist_del_init(&icq->ioc_node); This results into below crash as this memory is now used by icq->__rcu_head in context#1. There is a chance that icq could be free'd as well. 22150.386550: <6> Unable to handle kernel write to read-only memory at virtual address ffffffaa8d31ca50 ... Call trace: 22150.607350: <2> ioc_destroy_icq+0x44/0x110 22150.611202: <2> ioc_clear_queue+0xac/0x148 22150.615056: <2> blk_cleanup_queue+0x11c/0x1a0 22150.619174: <2> __scsi_remove_device+0xdc/0x128 22150.623465: <2> scsi_forget_host+0x2c/0x78 22150.627315: <2> scsi_remove_host+0x7c/0x2a0 22150.631257: <2> usb_stor_disconnect+0x74/0xc8 22150.635371: <2> usb_unbind_interface+0xc8/0x278 22150.639665: <2> device_release_driver_internal+0x198/0x250 22150.644897: <2> device_release_driver+0x24/0x30 22150.649176: <2> bus_remove_device+0xec/0x140 22150.653204: <2> device_del+0x270/0x460 22150.656712: <2> usb_disable_device+0x120/0x390 22150.660918: <2> usb_disconnect+0xf4/0x2e0 22150.664684: <2> hub_event+0xd70/0x17e8 22150.668197: <2> process_one_work+0x210/0x480 22150.672222: <2> worker_thread+0x32c/0x4c8 Fix this by adding a new ICQ_DESTROYED flag in ioc_destroy_icq() to indicate this icq is once marked as destroyed. Also, ensure __ioc_clear_queue() is accessing icq within rcu_read_lock/unlock so that icq doesn't get free'd up while it is still using it. Signed-off-by: Sahitya Tummala <stummala@codeaurora.org> Co-developed-by: Pradeep P V K <ppvk@codeaurora.org> Signed-off-by: Pradeep P V K <ppvk@codeaurora.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-15block: remove the queue_lock indirectionChristoph Hellwig1-7/+7
With the legacy request path gone there is no good reason to keep queue_lock as a pointer, we can always use the embedded lock now. Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Fixed floppy and blk-cgroup missing conversions and half done edits. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-15block: remove a few unused exportsChristoph Hellwig1-3/+0
Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-10block: remove set but not used variable 'et'YueHaibing1-2/+0
Fixes gcc '-Wunused-but-set-variable' warning: block/blk-ioc.c: In function 'put_io_context_active': block/blk-ioc.c:174:24: warning: variable 'et' set but not used [-Wunused-but-set-variable] It not used any more after commit a1ce35fa4985 ("block: remove dead elevator code") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-07block: get rid of MQ scheduler ops unionJens Axboe1-4/+4
This is a remnant of when we had ops for both SQ and MQ schedulers. Now it's just MQ, so get rid of the union. Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-07block: remove dead elevator codeJens Axboe1-27/+6
This removes a bunch of core and elevator related code. On the core front, we remove anything related to queue running, draining, initialization, plugging, and congestions. We also kill anything related to request allocation, merging, retrieval, and completion. Remove any checking for single queue IO schedulers, as they no longer exist. This means we can also delete a bunch of code related to request issue, adding, completion, etc - and all the SQ related ops and helpers. Also kill the load_default_modules(), as all that did was provide for a way to load the default single queue elevator. Tested-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-09block, mm: remove unnecessary __GFP_HIGH flagShakeel Butt1-1/+1
The flag GFP_ATOMIC already contains __GFP_HIGH. There is no need to explicitly or __GFP_HIGH again. So, just remove unnecessary __GFP_HIGH. Signed-off-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-03Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds1-13/+31
Pull block layer fixes from Jens Axboe: "A collection of fixes for this merge window, either fixes for existing issues, or parts that were waiting for acks to come in. This pull request contains: - Allocation of nvme queues on the right node from Shaohua. This was ready long before the merge window, but waiting on an ack from Bjorn on the PCI bit. Now that we have that, the three patches can go in. - Two fixes for blk-mq-sched with nvmeof, which uses hctx specific request allocations. This caused an oops. One part from Sagi, one part from Omar. - A loop partition scan deadlock fix from Omar, fixing a regression in this merge window. - A three-patch series from Keith, closing up a hole on clearing out requests on shutdown/resume. - A stable fix for nbd from Josef, fixing a leak of sockets. - Two fixes for a regression in this window from Jan, fixing a problem with one of his earlier patches dealing with queue vs bdi life times. - A fix for a regression with virtio-blk, causing an IO stall if scheduling is used. From me. - A fix for an io context lock ordering problem. From me" * 'for-linus' of git://git.kernel.dk/linux-block: block: Move bdi_unregister() to del_gendisk() blk-mq: ensure that bd->last is always set correctly block: don't call ioc_exit_icq() with the queue lock held for blk-mq block: Initialize bd_bdi on inode initialization loop: fix LO_FLAGS_PARTSCAN hang nvme: Complete all stuck requests blk-mq: Provide freeze queue timeout blk-mq: Export blk_mq_freeze_queue_wait nbd: stop leaking sockets blk-mq: move update of tags->rqs to __blk_mq_alloc_request() blk-mq: kill blk_mq_set_alloc_data() blk-mq: make blk_mq_alloc_request_hctx() allocate a scheduler request blk-mq-sched: Allocate sched reserved tags as specified in the original queue tagset nvme: allocate nvme_queue in correct node PCI: add an API to get node from vector blk-mq: allocate blk_mq_tags and requests in correct node
2017-03-02block: don't call ioc_exit_icq() with the queue lock held for blk-mqJens Axboe1-13/+31
For legacy scheduling, we always call ioc_exit_icq() with both the ioc and queue lock held. This poses a problem for blk-mq with scheduling, since the queue lock isn't what we use in the scheduler. And since we don't need the queue lock held for ioc exit there, don't grab it and leave any extra locking up to the blk-mq scheduler. Reported-by: Paolo Valente <paolo.valente@linaro.org> Tested-by: Paolo Valente <paolo.valente@linaro.org> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-02sched/headers: Prepare to move the task_lock()/unlock() APIs to ↵Ingo Molnar1-0/+1
<linux/sched/task.h> But first update the code that uses these facilities with the new header. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-10blk-mq-sched: don't hold queue_lock when calling exit_icqOmar Sandoval1-6/+16
None of the other blk-mq elevator hooks are called with this lock held. Additionally, it can lead to circular locking dependencies between queue_lock and the private scheduler lock. Reported-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-17blk-mq-sched: add framework for MQ capable IO schedulersJens Axboe1-2/+6
This adds a set of hooks that intercepts the blk-mq path of allocating/inserting/issuing/completing requests, allowing us to develop a scheduler within that framework. We reuse the existing elevator scheduler API on the registration side, but augment that with the scheduler flagging support for the blk-mq interfce, and with a separate set of ops hooks for MQ devices. We split driver and scheduler tags, so we can run the scheduling independently of device queue depth. Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Omar Sandoval <osandov@fb.com>
2017-01-17block: move existing elevator ops to unionJens Axboe1-4/+4
Prep patch for adding MQ ops as well, since doing anon unions with named initializers doesn't work on older compilers. Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Omar Sandoval <osandov@fb.com>
2015-11-07mm, page_alloc: distinguish between being unable to sleep, unwilling to ↵Mel Gorman1-1/+1
sleep and avoiding waking kswapd __GFP_WAIT has been used to identify atomic context in callers that hold spinlocks or are in interrupts. They are expected to be high priority and have access one of two watermarks lower than "min" which can be referred to as the "atomic reserve". __GFP_HIGH users get access to the first lower watermark and can be called the "high priority reserve". Over time, callers had a requirement to not block when fallback options were available. Some have abused __GFP_WAIT leading to a situation where an optimisitic allocation with a fallback option can access atomic reserves. This patch uses __GFP_ATOMIC to identify callers that are truely atomic, cannot sleep and have no alternative. High priority users continue to use __GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify callers that want to wake kswapd for background reclaim. __GFP_WAIT is redefined as a caller that is willing to enter direct reclaim and wake kswapd for background reclaim. This patch then converts a number of sites o __GFP_ATOMIC is used by callers that are high priority and have memory pools for those requests. GFP_ATOMIC uses this flag. o Callers that have a limited mempool to guarantee forward progress clear __GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall into this category where kswapd will still be woken but atomic reserves are not used as there is a one-entry mempool to guarantee progress. o Callers that are checking if they are non-blocking should use the helper gfpflags_allow_blocking() where possible. This is because checking for __GFP_WAIT as was done historically now can trigger false positives. Some exceptions like dm-crypt.c exist where the code intent is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to flag manipulations. o Callers that built their own GFP flags instead of starting with GFP_KERNEL and friends now also need to specify __GFP_KSWAPD_RECLAIM. The first key hazard to watch out for is callers that removed __GFP_WAIT and was depending on access to atomic reserves for inconspicuous reasons. In some cases it may be appropriate for them to use __GFP_HIGH. The second key hazard is callers that assembled their own combination of GFP flags instead of starting with something like GFP_KERNEL. They may now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless if it's missed in most cases as other activity will wake kswapd. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Vitaly Wool <vitalywool@gmail.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-02-19block: Substitute rcu_access_pointer() for rcu_dereference_raw()Paul E. McKenney1-1/+1
(Trivial patch.) If the code is looking at the RCU-protected pointer itself, but not dereferencing it, the rcu_dereference() functions can be downgraded to rcu_access_pointer(). This commit makes this downgrade in blkg_destroy() and ioc_destroy_icq(), both of which simply compare the RCU-protected pointer against another pointer with no dereferencing. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jens Axboe <axboe@fb.com>
2013-11-09block: cleanup removing dependency on bootmem headersGrygorii Strashko1-1/+0
Cc: Yinghai Lu <yinghai@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-09-12lib/radix-tree.c: make radix_tree_node_alloc() work correctly within interruptJan Kara1-1/+1
With users of radix_tree_preload() run from interrupt (block/blk-ioc.c is one such possible user), the following race can happen: radix_tree_preload() ... radix_tree_insert() radix_tree_node_alloc() if (rtp->nr) { ret = rtp->nodes[rtp->nr - 1]; <interrupt> ... radix_tree_preload() ... radix_tree_insert() radix_tree_node_alloc() if (rtp->nr) { ret = rtp->nodes[rtp->nr - 1]; And we give out one radix tree node twice. That clearly results in radix tree corruption with different results (usually OOPS) depending on which two users of radix tree race. We fix the problem by making radix_tree_node_alloc() always allocate fresh radix tree nodes when in interrupt. Using preloading when in interrupt doesn't make sense since all the allocations have to be atomic anyway and we cannot steal nodes from process-context users because some users rely on radix_tree_insert() succeeding after radix_tree_preload(). in_interrupt() check is somewhat ugly but we cannot simply key off passed gfp_mask as that is acquired from root_gfp_mask() and thus the same for all preload users. Another part of the fix is to avoid node preallocation in radix_tree_preload() when passed gfp_mask doesn't allow waiting. Again, preallocation in such case doesn't make sense and when preallocation would happen in interrupt we could possibly leak some allocated nodes. However, some users of radix_tree_preload() require following radix_tree_insert() to succeed. To avoid unexpected effects for these users, radix_tree_preload() only warns if passed gfp mask doesn't allow waiting and we provide a new function radix_tree_maybe_preload() for those users which get different gfp mask from different call sites and which are prepared to handle radix_tree_insert() failure. Signed-off-by: Jan Kara <jack@suse.cz> Cc: Jens Axboe <jaxboe@fusionio.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-14block: queue work on power efficient wqViresh Kumar1-1/+2
Block layer uses workqueues for multiple purposes. There is no real dependency of scheduling these on the cpu which scheduled them. On a idle system, it is observed that and idle cpu wakes up many times just to service this work. It would be better if we can schedule it on a cpu which the scheduler believes to be the most appropriate one. This patch replaces normal workqueues with power efficient versions. Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2013-02-28hlist: drop the node parameter from iteratorsSasha Levin1-2/+1
I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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