- 08 12月, 2018 5 次提交
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由 Dennis Zhou 提交于
bio_issue_init among other things initializes the timestamp for an IO. Rather than have this logic handled by policies, this consolidates it to be on the init paths (normal, clone, bounce clone). Signed-off-by: NDennis Zhou <dennis@kernel.org> Acked-by: NTejun Heo <tj@kernel.org> Reviewed-by: NLiu Bo <bo.liu@linux.alibaba.com> Reviewed-by: NJosef Bacik <josef@toxicpanda.com> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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由 Dennis Zhou 提交于
Previously, blkg association was handled by controller specific code in blk-throttle and blk-iolatency. However, because a blkg represents a relationship between a blkcg and a request_queue, it makes sense to keep the blkg->q and bio->bi_disk->queue consistent. This patch moves association into the bio_set_dev macro(). This should cover the majority of cases where the device is set/changed keeping the two pointers consistent. Fallback code is added to blkcg_bio_issue_check() to catch any missing paths. Signed-off-by: NDennis Zhou <dennis@kernel.org> Reviewed-by: NJosef Bacik <josef@toxicpanda.com> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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由 Dennis Zhou 提交于
There are several scenarios where blkg_lookup_create() can fail such as the blkcg dying, request_queue is dying, or simply being OOM. Most handle this by simply falling back to the q->root_blkg and calling it a day. This patch implements the notion of closest blkg. During blkg_lookup_create(), if it fails to create, return the closest blkg found or the q->root_blkg. blkg_try_get_closest() is introduced and used during association so a bio is always attached to a blkg. Signed-off-by: NDennis Zhou <dennis@kernel.org> Acked-by: NTejun Heo <tj@kernel.org> Reviewed-by: NJosef Bacik <josef@toxicpanda.com> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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由 Dennis Zhou 提交于
To know when to create a blkg, the general pattern is to do a blkg_lookup() and if that fails, lock and do the lookup again, and if that fails finally create. It doesn't make much sense for everyone who wants to do creation to write this themselves. This changes blkg_lookup_create() to do locking and implement this pattern. The old blkg_lookup_create() is renamed to __blkg_lookup_create(). If a call site wants to do its own error handling or already owns the queue lock, they can use __blkg_lookup_create(). This will be used in upcoming patches. Signed-off-by: NDennis Zhou <dennis@kernel.org> Reviewed-by: NJosef Bacik <josef@toxicpanda.com> Acked-by: NTejun Heo <tj@kernel.org> Reviewed-by: NLiu Bo <bo.liu@linux.alibaba.com> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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由 Dennis Zhou 提交于
The bio_blkcg() function turns out to be inconsistent and consequently dangerous to use. The first part returns a blkcg where a reference is owned by the bio meaning it does not need to be rcu protected. However, the third case, the last line, is problematic: return css_to_blkcg(task_css(current, io_cgrp_id)); This can race against task migration and the cgroup dying. It is also semantically different as it must be called rcu protected and is susceptible to failure when trying to get a reference to it. This patch adds association ahead of calling bio_blkcg() rather than after. This makes association a required and explicit step along the code paths for calling bio_blkcg(). In blk-iolatency, association is moved above the bio_blkcg() call to ensure it will not return %NULL. BFQ uses the old bio_blkcg() function, but I do not want to address it in this series due to the complexity. I have created a private version documenting the inconsistency and noting not to use it. Signed-off-by: NDennis Zhou <dennis@kernel.org> Acked-by: NTejun Heo <tj@kernel.org> Reviewed-by: NJosef Bacik <josef@toxicpanda.com> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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- 16 11月, 2018 2 次提交
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由 Christoph Hellwig 提交于
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: NHannes Reinecke <hare@suse.com> Signed-off-by: NChristoph Hellwig <hch@lst.de> Fixed floppy and blk-cgroup missing conversions and half done edits. Signed-off-by: NJens Axboe <axboe@kernel.dk>
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由 Christoph Hellwig 提交于
Unused since the removal of the legacy request code. Reviewed-by: NHannes Reinecke <hare@suse.com> Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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- 08 11月, 2018 1 次提交
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由 Jens Axboe 提交于
It's now dead code, nobody uses it. Reviewed-by: NHannes Reinecke <hare@suse.com> Tested-by: NMing Lei <ming.lei@redhat.com> Reviewed-by: NOmar Sandoval <osandov@fb.com> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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- 02 11月, 2018 1 次提交
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由 Dennis Zhou 提交于
This reverts a series committed earlier due to null pointer exception bug report in [1]. It seems there are edge case interactions that I did not consider and will need some time to understand what causes the adverse interactions. The original series can be found in [2] with a follow up series in [3]. [1] https://www.spinics.net/lists/cgroups/msg20719.html [2] https://lore.kernel.org/lkml/20180911184137.35897-1-dennisszhou@gmail.com/ [3] https://lore.kernel.org/lkml/20181020185612.51587-1-dennis@kernel.org/ This reverts the following commits: d459d853, b2c3fa54, 101246ec, b3b9f24f, e2b09899, f0fcb3ec, c839e7a0, bdc24917, 74b7c02a, 5bf9a1f3, a7b39b4e, 07b05bcc, 49f4c2dc, 27e6fa99Signed-off-by: NDennis Zhou <dennis@kernel.org> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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- 21 10月, 2018 1 次提交
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由 Dennis Zhou 提交于
It is possible for blkg creation to fail when in blk_get_rl(). In this situation, the fallback logic returns the nearest created blkg. There is however special handling for the request_list for the root blkcg. This fixes the missing edge case from the earlier series changing blk_get_rl(). Fixes: e2b09899 ("blkcg: cleanup and make blk_get_rl use blkg_lookup_create") Signed-off-by: NDennis Zhou <dennis@kernel.org> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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- 22 9月, 2018 10 次提交
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由 Dennis Zhou (Facebook) 提交于
blkg reference counting now uses percpu_ref rather than atomic_t. Let's make this consistent with css_tryget. This renames blkg_try_get to blkg_tryget and now returns a bool rather than the blkg or NULL. Signed-off-by: NDennis Zhou <dennisszhou@gmail.com> Reviewed-by: NJosef Bacik <josef@toxicpanda.com> Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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由 Dennis Zhou (Facebook) 提交于
Now that every bio is associated with a blkg, this puts the use of blkg_get, blkg_try_get, and blkg_put on the hot path. This switches over the refcnt in blkg to use percpu_ref. Signed-off-by: NDennis Zhou <dennisszhou@gmail.com> Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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由 Dennis Zhou (Facebook) 提交于
blk_get_rl is responsible for identifying which request_list a request should be allocated to. Try get logic was added earlier, but semantically the logic was not changed. This patch makes better use of the bio already having a reference to the blkg in the hot path. The cold path uses a better fallback of blkg_lookup_create rather than just blkg_lookup and then falling back to the q->root_rl. If lookup_create fails with anything but -ENODEV, it falls back to q->root_rl. A clarifying comment is added to explain why q->root_rl is used rather than the root blkg's rl. Signed-off-by: NDennis Zhou <dennisszhou@gmail.com> Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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由 Dennis Zhou (Facebook) 提交于
The previous patch in this series removed carrying around a pointer to the css in blkg. However, the blkg association logic still relied on taking a reference on the css to ensure we wouldn't fail in getting a reference for the blkg. Here the implicit dependency on the css is removed. The association continues to rely on the tryget logic walking up the blkg tree. This streamlines the three ways that association can happen: normal, swap, and writeback. Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NDennis Zhou <dennisszhou@gmail.com> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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由 Dennis Zhou (Facebook) 提交于
Prior patches ensured that all bios are now associated with some blkg. This now makes bio->bi_css unnecessary as blkg maintains a reference to the blkcg already. This patch removes the field bi_css and transfers corresponding uses to access via bi_blkg. Signed-off-by: NDennis Zhou <dennisszhou@gmail.com> Reviewed-by: NJosef Bacik <josef@toxicpanda.com> Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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由 Dennis Zhou (Facebook) 提交于
bio_issue_init among other things initializes the timestamp for an IO. Rather than have this logic handled by policies, this consolidates it to be on the init paths (normal, clone, bounce clone). Signed-off-by: NDennis Zhou <dennisszhou@gmail.com> Acked-by: NTejun Heo <tj@kernel.org> Reviewed-by: NLiu Bo <bo.liu@linux.alibaba.com> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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由 Dennis Zhou (Facebook) 提交于
Previously, blkg's were only assigned as needed by blk-iolatency and blk-throttle. bio->css was also always being associated while blkg was being looked up and then thrown away in blkcg_bio_issue_check. This patch begins the cleanup of bio->css and bio->bi_blkg by always associating a blkg in blkcg_bio_issue_check. This tries to create the blkg, but if it is not possible, falls back to using the root_blkg of the request_queue. Therefore, a bio will always be associated with a blkg. The duplicate association logic is removed from blk-throttle and blk-iolatency. Signed-off-by: NDennis Zhou <dennisszhou@gmail.com> Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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由 Dennis Zhou (Facebook) 提交于
There are several scenarios where blkg_lookup_create can fail. Examples include the blkcg dying, request_queue is dying, or simply being OOM. At the end of the day, most handle this by simply falling back to the q->root_blkg and calling it a day. This patch implements the notion of closest blkg. During blkg_lookup_create, if it fails to create, return the closest blkg found or the q->root_blkg. blkg_try_get_closest is introduced and used during association so a bio is always attached to a blkg. Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NDennis Zhou <dennisszhou@gmail.com> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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由 Dennis Zhou (Facebook) 提交于
To know when to create a blkg, the general pattern is to do a blkg_lookup and if that fails, lock and then do a lookup again and if that fails finally create. It doesn't make much sense for everyone who wants to do creation to write this themselves. This changes blkg_lookup_create to do locking and implement this pattern. The old blkg_lookup_create is renamed to __blkg_lookup_create. If a call site wants to do its own error handling or already owns the queue lock, they can use __blkg_lookup_create. This will be used in upcoming patches. Signed-off-by: NDennis Zhou <dennisszhou@gmail.com> Reviewed-by: NJosef Bacik <josef@toxicpanda.com> Acked-by: NTejun Heo <tj@kernel.org> Reviewed-by: NLiu Bo <bo.liu@linux.alibaba.com> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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由 Dennis Zhou (Facebook) 提交于
The accessor function bio_blkcg either returns the blkcg associated with the bio or finds one in the current context. This can cause an issue when trying to associate a bio with a blkcg. Particularly, it's the third case that is problematic: return css_to_blkcg(task_css(current, io_cgrp_id)); As the above may race against task migration and the cgroup exiting, it is not always ok to take a reference on the blkcg returned from bio_blkcg. This patch adds association ahead of calling bio_blkcg rather than after. This makes association a required and explicit step along the code paths for calling bio_blkcg. blk_get_rl is modified as well to get a reference to the blkcg it may use and blk_put_rl will always put the reference back. Association is also moved above the bio_blkcg call to ensure it will not return NULL in blk-iolatency. BFQ and CFQ utilize this flaw, but due to the complexity, I do not want to address this in this series. I've created a private version of the function with notes not to use it describing the flaw. Hopefully soon, that code can be cleaned up. Signed-off-by: NDennis Zhou <dennisszhou@gmail.com> Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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- 01 9月, 2018 2 次提交
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由 Dennis Zhou (Facebook) 提交于
Currently, blkcg destruction relies on a sequence of events: 1. Destruction starts. blkcg_css_offline() is called and blkgs release their reference to the blkcg. This immediately destroys the cgwbs (writeback). 2. With blkgs giving up their reference, the blkcg ref count should become zero and eventually call blkcg_css_free() which finally frees the blkcg. Jiufei Xue reported that there is a race between blkcg_bio_issue_check() and cgroup_rmdir(). To remedy this, blkg destruction becomes contingent on the completion of all writeback associated with the blkcg. A count of the number of cgwbs is maintained and once that goes to zero, blkg destruction can follow. This should prevent premature blkg destruction related to writeback. The new process for blkcg cleanup is as follows: 1. Destruction starts. blkcg_css_offline() is called which offlines writeback. Blkg destruction is delayed on the cgwb_refcnt count to avoid punting potentially large amounts of outstanding writeback to root while maintaining any ongoing policies. Here, the base cgwb_refcnt is put back. 2. When the cgwb_refcnt becomes zero, blkcg_destroy_blkgs() is called and handles destruction of blkgs. This is where the css reference held by each blkg is released. 3. Once the blkcg ref count goes to zero, blkcg_css_free() is called. This finally frees the blkg. It seems in the past blk-throttle didn't do the most understandable things with taking data from a blkg while associating with current. So, the simplification and unification of what blk-throttle is doing caused this. Fixes: 08e18eab ("block: add bi_blkg to the bio for cgroups") Reviewed-by: NJosef Bacik <josef@toxicpanda.com> Signed-off-by: NDennis Zhou <dennisszhou@gmail.com> Cc: Jiufei Xue <jiufei.xue@linux.alibaba.com> Cc: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Tejun Heo <tj@kernel.org> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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由 Dennis Zhou (Facebook) 提交于
This reverts commit 4c699480. Destroying blkgs is tricky because of the nature of the relationship. A blkg should go away when either a blkcg or a request_queue goes away. However, blkg's pin the blkcg to ensure they remain valid. To break this cycle, when a blkcg is offlined, blkgs put back their css ref. This eventually lets css_free() get called which frees the blkcg. The above commit (4c699480) breaks this order of events by trying to destroy blkgs in css_free(). As the blkgs still hold references to the blkcg, css_free() is never called. The race between blkcg_bio_issue_check() and cgroup_rmdir() will be addressed in the following patch by delaying destruction of a blkg until all writeback associated with the blkcg has been finished. Fixes: 4c699480 ("blk-throttle: fix race between blkcg_bio_issue_check() and cgroup_rmdir()") Reviewed-by: NJosef Bacik <josef@toxicpanda.com> Signed-off-by: NDennis Zhou <dennisszhou@gmail.com> Cc: Jiufei Xue <jiufei.xue@linux.alibaba.com> Cc: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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- 12 8月, 2018 1 次提交
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由 Bart Van Assche 提交于
For legacy queues the only call of blkg_root_lookup() happens after bypass mode has been enabled. Since blkg_lookup() returns NULL for queues in bypass mode, modify the blkg_root_lookup() such that it no longer depends on bypass mode. Rename the function into blk_queue_root_blkg() as suggested by Tejun. Suggested-by: NTejun Heo <tj@kernel.org> Fixes: 6bad9b21 ("blkcg: Introduce blkg_root_lookup()") Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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- 09 8月, 2018 1 次提交
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由 Bart Van Assche 提交于
This new function will be used in a later patch to verify whether a queue has been dissociated from the cgroup controller before being released. Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: Alexandru Moise <00moses.alexander00@gmail.com> Cc: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: <stable@vger.kernel.org> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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- 30 7月, 2018 1 次提交
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由 Josef Bacik 提交于
We need to check in blkcg_bio_issue_check if the bio is flagged as QUEUE_ENTERED, because if it is then we've already accounted for the size of the IO in the cgroup stats. We can still however account for the extra IO since it'll be another request. Reported-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJosef Bacik <josef@toxicpanda.com> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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- 18 7月, 2018 1 次提交
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由 Tejun Heo 提交于
Add tracking of REQ_OP_DISCARD ios to the per-cgroup io.stat. Two fields, dbytes and dios, to respectively count the total bytes and number of discards are added. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Andy Newell <newella@fb.com> Cc: Michael Callahan <michaelcallahan@fb.com> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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- 09 7月, 2018 4 次提交
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由 Josef Bacik 提交于
Since IO can be issued from literally anywhere it's almost impossible to do throttling without having some sort of adverse effect somewhere else in the system because of locking or other dependencies. The best way to solve this is to do the throttling when we know we aren't holding any other kernel resources. Do this by tracking throttling in a per-blkg basis, and if we require throttling flag the task that it needs to check before it returns to user space and possibly sleep there. This is to address the case where a process is doing work that is generating IO that can't be throttled, whether that is directly with a lot of REQ_META IO, or indirectly by allocating so much memory that it is swamping the disk with REQ_SWAP. We can't use task_add_work as we don't want to induce a memory allocation in the IO path, so simply saving the request queue in the task and flagging it to do the notify_resume thing achieves the same result without the overhead of a memory allocation. Signed-off-by: NJosef Bacik <jbacik@fb.com> Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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由 Josef Bacik 提交于
Just like REQ_META, it's important to know the IO coming down is swap in order to guard against potential IO priority inversion issues with cgroups. Add REQ_SWAP and use it for all swap IO, and add it to our bio_issue_as_root_blkg helper. Signed-off-by: NJosef Bacik <jbacik@fb.com> Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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由 Josef Bacik 提交于
blk-iolatency has a few stats that it would like to print out, and instead of adding a bunch of crap to the generic code just provide a helper so that controllers can add stuff to the stat line if they want to. Hide it behind a boot option since it changes the output of io.stat from normal, and these stats are only interesting to developers. Signed-off-by: NJosef Bacik <jbacik@fb.com> Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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由 Josef Bacik 提交于
Instead of forcing all file systems to get the right context on their bio's, simply check for REQ_META to see if we need to issue as the root blkg. We don't want to force all bio's to have the root blkg associated with them if REQ_META is set, as some controllers (blk-iolatency) need to know who the originating cgroup is so it can backcharge them for the work they are doing. This helper will make sure that the controllers do the proper thing wrt the IO priority and backcharging. Signed-off-by: NJosef Bacik <jbacik@fb.com> Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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- 17 3月, 2018 1 次提交
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由 Joseph Qi 提交于
We've triggered a WARNING in blk_throtl_bio() when throttling writeback io, which complains blkg->refcnt is already 0 when calling blkg_get(), and then kernel crashes with invalid page request. After investigating this issue, we've found it is caused by a race between blkcg_bio_issue_check() and cgroup_rmdir(), which is described below: writeback kworker cgroup_rmdir cgroup_destroy_locked kill_css css_killed_ref_fn css_killed_work_fn offline_css blkcg_css_offline blkcg_bio_issue_check rcu_read_lock blkg_lookup spin_trylock(q->queue_lock) blkg_destroy spin_unlock(q->queue_lock) blk_throtl_bio spin_lock_irq(q->queue_lock) ... spin_unlock_irq(q->queue_lock) rcu_read_unlock Since rcu can only prevent blkg from releasing when it is being used, the blkg->refcnt can be decreased to 0 during blkg_destroy() and schedule blkg release. Then trying to blkg_get() in blk_throtl_bio() will complains the WARNING. And then the corresponding blkg_put() will schedule blkg release again, which result in double free. This race is introduced by commit ae118896 ("blkcg: consolidate blkg creation in blkcg_bio_issue_check()"). Before this commit, it will lookup first and then try to lookup/create again with queue_lock. Since revive this logic is a bit drastic, so fix it by only offlining pd during blkcg_css_offline(), and move the rest destruction (especially blkg_put()) into blkcg_css_free(), which should be the right way as discussed. Fixes: ae118896 ("blkcg: consolidate blkg creation in blkcg_bio_issue_check()") Reported-by: NJiufei Xue <jiufei.xue@linux.alibaba.com> Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com> Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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- 16 1月, 2018 1 次提交
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由 Arnd Bergmann 提交于
Some older compilers (gcc-4.4 through 4.6 in particular) struggle with the way that blkg_rwstat_read() returns a structure, leading to excessive stack usage and rather inefficient code: block/blk-cgroup.c: In function 'blkg_destroy': block/blk-cgroup.c:354:1: error: the frame size of 1296 bytes is larger than 1024 bytes [-Werror=frame-larger-than=] block/cfq-iosched.c: In function 'cfqg_stats_add_aux': block/cfq-iosched.c:753:1: error: the frame size of 1928 bytes is larger than 1024 bytes [-Werror=frame-larger-than=] block/bfq-cgroup.c: In function 'bfqg_stats_add_aux': block/bfq-cgroup.c:299:1: error: the frame size of 1928 bytes is larger than 1024 bytes [-Werror=frame-larger-than=] I also notice that there is no point in using atomic accesses for the local variables, so storing the temporaries in simple 'u64' variables not only avoids the stack usage on older compilers but also improves the object code on modern versions. Fixes: e6269c44 ("blkcg: add blkg_[rw]stat->aux_cnt and replace cfq_group->dead_stats with it") Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NArnd Bergmann <arnd@arndb.de> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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- 02 11月, 2017 1 次提交
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由 Greg Kroah-Hartman 提交于
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: NKate Stewart <kstewart@linuxfoundation.org> Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com> Reviewed-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 26 9月, 2017 2 次提交
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由 Shaohua Li 提交于
bio_blkcg is the only API to get cgroup info for a bio right now. If bio_blkcg finds current task is a kthread and has original blkcg associated, it will use the css instead of associating the bio to current task. This makes it possible that kthread dispatches bios on behalf of other threads. Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NShaohua Li <shli@fb.com> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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由 Shaohua Li 提交于
Nobody uses the APIs right now. Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NShaohua Li <shli@fb.com> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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- 29 7月, 2017 1 次提交
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由 Shaohua Li 提交于
blkcg_bio_issue_check() already gets blkcg for a BIO. bio_associate_blkcg() uses a percpu refcounter, so it's a very cheap operation. There is no point we don't attach the cgroup info into bio at blkcg_bio_issue_check. This also makes blktrace outputs correct cgroup info. Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NShaohua Li <shli@fb.com> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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- 21 6月, 2017 1 次提交
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由 Nikolay Borisov 提交于
Currently, percpu_counter_add is a wrapper around __percpu_counter_add which is preempt safe due to explicit calls to preempt_disable. Given how __ prefix is used in percpu related interfaces, the naming unfortunately creates the false sense that __percpu_counter_add is less safe than percpu_counter_add. In terms of context-safety, they're equivalent. The only difference is that the __ version takes a batch parameter. Make this a bit more explicit by just renaming __percpu_counter_add to percpu_counter_add_batch. This patch doesn't cause any functional changes. tj: Minor updates to patch description for clarity. Cosmetic indentation updates. Signed-off-by: NNikolay Borisov <nborisov@suse.com> Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <jbacik@fb.com> Cc: David Sterba <dsterba@suse.com> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Jan Kara <jack@suse.com> Cc: Jens Axboe <axboe@fb.com> Cc: linux-mm@kvack.org Cc: "David S. Miller" <davem@davemloft.net>
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- 30 3月, 2017 1 次提交
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由 Jens Axboe 提交于
I inadvertently applied the v5 version of this patch, whereas the agreed upon version was v5. Revert this one so we can apply the right one. This reverts commit 7fc6b87a.
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- 29 3月, 2017 1 次提交
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由 Tahsin Erdogan 提交于
blkg_conf_prep() currently calls blkg_lookup_create() while holding request queue spinlock. This means allocating memory for struct blkcg_gq has to be made non-blocking. This causes occasional -ENOMEM failures in call paths like below: pcpu_alloc+0x68f/0x710 __alloc_percpu_gfp+0xd/0x10 __percpu_counter_init+0x55/0xc0 cfq_pd_alloc+0x3b2/0x4e0 blkg_alloc+0x187/0x230 blkg_create+0x489/0x670 blkg_lookup_create+0x9a/0x230 blkg_conf_prep+0x1fb/0x240 __cfqg_set_weight_device.isra.105+0x5c/0x180 cfq_set_weight_on_dfl+0x69/0xc0 cgroup_file_write+0x39/0x1c0 kernfs_fop_write+0x13f/0x1d0 __vfs_write+0x23/0x120 vfs_write+0xc2/0x1f0 SyS_write+0x44/0xb0 entry_SYSCALL_64_fastpath+0x18/0xad In the code path above, percpu allocator cannot call vmalloc() due to queue spinlock. A failure in this call path gives grief to tools which are trying to configure io weights. We see occasional failures happen shortly after reboots even when system is not under any memory pressure. Machines with a lot of cpus are more vulnerable to this condition. Update blkg_create() function to temporarily drop the rcu and queue locks when it is allowed by gfp mask. Suggested-by: NTejun Heo <tj@kernel.org> Signed-off-by: NTahsin Erdogan <tahsin@google.com> Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <axboe@fb.com>
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- 01 11月, 2016 1 次提交
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJens Axboe <axboe@fb.com>
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