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* blk-mq, percpu_ref: implement a kludge for SCSI blk-mq stall during probeTejun Heo2014-09-241-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blk-mq uses percpu_ref for its usage counter which tracks the number of in-flight commands and used to synchronously drain the queue on freeze. percpu_ref shutdown takes measureable wallclock time as it involves a sched RCU grace period. This means that draining a blk-mq takes measureable wallclock time. One would think that this shouldn't matter as queue shutdown should be a rare event which takes place asynchronously w.r.t. userland. Unfortunately, SCSI probing involves synchronously setting up and then tearing down a lot of request_queues back-to-back for non-existent LUNs. This means that SCSI probing may take more than ten seconds when scsi-mq is used. This will be properly fixed by implementing a mechanism to keep q->mq_usage_counter in atomic mode till genhd registration; however, that involves rather big updates to percpu_ref which is difficult to apply late in the devel cycle (v3.17-rc6 at the moment). As a stop-gap measure till the proper fix can be implemented in the next cycle, this patch introduces __percpu_ref_kill_expedited() and makes blk_mq_freeze_queue() use it. This is heavy-handed but should work for testing the experimental SCSI blk-mq implementation. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Christoph Hellwig <hch@infradead.org> Link: http://lkml.kernel.org/g/20140919113815.GA10791@lst.de Fixes: add703fda981 ("blk-mq: use percpu_ref for mq usage count") Cc: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Tested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
* genhd: fix leftover might_sleep() in blk_free_devt()Jens Axboe2014-09-221-2/+0
| | | | | | | | | | Commit 2da78092 changed the locking from a mutex to a spinlock, so we now longer sleep in this context. But there was a leftover might_sleep() in there, which now triggers since we do the final free from an RCU callback. Get rid of it. Reported-by: Pontus Fuchs <pontus.fuchs@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-mq: use blk_mq_start_hw_queues() when running requeue workJens Axboe2014-09-221-1/+5
| | | | | | | | | When requests are retried due to hw or sw resource shortages, we often stop the associated hardware queue. So ensure that we restart the queues when running the requeue work, otherwise the queue run will be a no-op. Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-mq: fix potential oops on out-of-memory in __blk_mq_alloc_rq_maps()Jens Axboe2014-09-221-1/+0
| | | | | | | | | | __blk_mq_alloc_rq_maps() can be invoked multiple times, if we scale back the queue depth if we are low on memory. So don't clear set->tags when we fail, this is handled directly in the parent function, blk_mq_alloc_tag_set(). Reported-by: Robert Elliott <Elliott@hp.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-mq: avoid infinite recursion with the FUA flagChristoph Hellwig2014-09-222-8/+4
| | | | | | | | | | | | | | We should not insert requests into the flush state machine from blk_mq_insert_request. All incoming flush requests come through blk_{m,s}q_make_request and are handled there, while blk_execute_rq_nowait should only be called for BLOCK_PC requests. All other callers deal with requests that already went through the flush statemchine and shouldn't be reinserted into it. Reported-by: Robert Elliott <Elliott@hp.com> Debugged-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-mq: Avoid race condition with uninitialized requestsDavid Hildenbrand2014-09-221-1/+3
| | | | | | | | | | | | | | | | | | | | | | | This patch should fix the bug reported in https://lkml.org/lkml/2014/9/11/249. We have to initialize at least the atomic_flags and the cmd_flags when allocating storage for the requests. Otherwise blk_mq_timeout_check() might dereference uninitialized pointers when racing with the creation of a request. Also move the reset of cmd_flags for the initializing code to the point where a request is freed. So we will never end up with pending flush request indicators that might trigger dereferences of invalid pointers in blk_mq_timeout_check(). Cc: stable@vger.kernel.org Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reported-by: Paulo De Rezende Pinatti <ppinatti@linux.vnet.ibm.com> Tested-by: Paulo De Rezende Pinatti <ppinatti@linux.vnet.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-mq: request deadline must be visible before marking rq as startedJens Axboe2014-09-221-0/+6
| | | | | | | | | | | | When we start the request, we set the deadline and flip the bits marking the request as started and non-complete. However, it's important that the deadline store is ordered before flipping the bits, otherwise we could have a small window where the request is marked started but with an invalid deadline. This can confuse the timeout handling. Suggested-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-mq: scale depth and rq map appropriate if low on memoryJens Axboe2014-09-101-19/+69
| | | | | | | | | | | | | | If we are running in a kdump environment, resources are scarce. For some SCSI setups with a huge set of shared tags, we run out of memory allocating what the drivers is asking for. So implement a scale back logic to reduce the tag depth for those cases, allowing the driver to successfully load. We should extend this to detect low memory situations, and implement a sane fallback for those (1 queue, 64 tags, or something like that). Tested-by: Robert Elliott <elliott@hp.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* Block: fix unbalanced bypass-disable in blk_register_queueAlan Stern2014-09-091-2/+4
| | | | | | | | | | | | | | | | | When a queue is registered, the block layer turns off the bypass setting (because bypass is enabled when the queue is created). This doesn't work well for queues that are unregistered and then registered again; we get a WARNING because of the unbalanced calls to blk_queue_bypass_end(). This patch fixes the problem by making blk_register_queue() call blk_queue_bypass_end() only the first time the queue is registered. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Tejun Heo <tj@kernel.org> CC: James Bottomley <James.Bottomley@HansenPartnership.com> CC: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: Fix dev_t minor allocation lifetimeKeith Busch2014-09-032-11/+15
| | | | | | | | | | | | | Releases the dev_t minor when all references are closed to prevent another device from acquiring the same major/minor. Since the partition's release may be invoked from call_rcu's soft-irq context, the ext_dev_idr's mutex had to be replaced with a spinlock so as not so sleep. Signed-off-by: Keith Busch <keith.busch@intel.com> Cc: stable@kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-mq: cleanup after blk_mq_init_rq_map failuresRobert Elliott2014-09-031-0/+3
| | | | | | | | | | | | | | | | | | | | | | In blk-mq.c blk_mq_alloc_tag_set, if: set->tags = kmalloc_node() succeeds, but one of the blk_mq_init_rq_map() calls fails, goto out_unwind; needs to free set->tags so the caller is not obligated to do so. None of the current callers (null_blk, virtio_blk, virtio_blk, or the forthcoming scsi-mq) do so. set->tags needs to be set to NULL after doing so, so other tag cleanup logic doesn't try to free a stale pointer later. Also set it to NULL in blk_mq_free_tag_set. Tested with error injection on the forthcoming scsi-mq + hpsa combination. Signed-off-by: Robert Elliott <elliott@hp.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-merge: fix blk_recount_segmentsMing Lei2014-09-021-6/+11
| | | | | | | | | | | | | | | | | | | | QUEUE_FLAG_NO_SG_MERGE is set at default for blk-mq devices, so bio->bi_phys_segment computed may be bigger than queue_max_segments(q) for blk-mq devices, then drivers will fail to handle the case, for example, BUG_ON() in virtio_queue_rq() can be triggerd for virtio-blk: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1359146 This patch fixes the issue by ignoring the QUEUE_FLAG_NO_SG_MERGE flag if the computed bio->bi_phys_segment is bigger than queue_max_segments(q), and the regression is caused by commit 05f1dd53152173(block: add queue flag for disabling SG merging). Reported-by: Kick In <pierre-andre.morey@canonical.com> Tested-by: Chris J Arges <chris.j.arges@canonical.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* cfq-iosched: Add comments on update timing of weightToshiaki Makita2014-08-281-0/+8
| | | | | | | | | Explain that weight has to be updated on activation. This complements previous fix e15693ef18e1 ("cfq-iosched: Fix wrong children_weight calculation"). Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Signed-off-by: Jens Axboe <axboe@fb.com>
* cfq-iosched: Fix wrong children_weight calculationToshiaki Makita2014-08-261-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cfq_group_service_tree_add() is applying new_weight at the beginning of the function via cfq_update_group_weight(). This actually allows weight to change between adding it to and subtracting it from children_weight, and triggers WARN_ON_ONCE() in cfq_group_service_tree_del(), or even causes oops by divide error during vfr calculation in cfq_group_service_tree_add(). The detailed scenario is as follows: 1. Create blkio cgroups X and Y as a child of X. Set X's weight to 500 and perform some I/O to apply new_weight. This X's I/O completes before starting Y's I/O. 2. Y starts I/O and cfq_group_service_tree_add() is called with Y. 3. cfq_group_service_tree_add() walks up the tree during children_weight calculation and adds parent X's weight (500) to children_weight of root. children_weight becomes 500. 4. Set X's weight to 1000. 5. X starts I/O and cfq_group_service_tree_add() is called with X. 6. cfq_group_service_tree_add() applies its new_weight (1000). 7. I/O of Y completes and cfq_group_service_tree_del() is called with Y. 8. I/O of X completes and cfq_group_service_tree_del() is called with X. 9. cfq_group_service_tree_del() subtracts X's weight (1000) from children_weight of root. children_weight becomes -500. This triggers WARN_ON_ONCE(). 10. Set X's weight to 500. 11. X starts I/O and cfq_group_service_tree_add() is called with X. 12. cfq_group_service_tree_add() applies its new_weight (500) and adds it to children_weight of root. children_weight becomes 0. Calcularion of vfr triggers oops by divide error. weight should be updated right before adding it to children_weight. Reported-by: Ruki Sekiya <sekiya.ruki@lab.ntt.co.jp> Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Acked-by: Tejun Heo <tj@kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
* block: fix error handling in sg_ioSabrina Dubroca2014-08-261-0/+1
| | | | | | | | | | | | | | | | | Before commit 2cada584b200 ("block: cleanup error handling in sg_io"), we had ret = 0 before entering the last big if block of sg_io. Since 2cada584b200, ret = -EFAULT, which breaks hdparm: /dev/sda: setting Advanced Power Management level to 0xc8 (200) HDIO_DRIVE_CMD failed: Bad address APM_level = 128 Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Fixes: 2cada584b200 ("block: cleanup error handling in sg_io") Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
* fix regression in SCSI_IOCTL_SEND_COMMANDTony Battersby2014-08-221-2/+7
| | | | | | | | | | | blk_rq_set_block_pc() memsets rq->cmd to 0, so it should come immediately after blk_get_request() to avoid overwriting the user-supplied CDB. Also check for failure to allocate rq. Fixes: f27b087b81b7 ("block: add blk_rq_set_block_pc()") Cc: <stable@vger.kernel.org> # 3.16.x Signed-off-by: Tony Battersby <tonyb@cybernetics.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* scsi-mq: fix requests that use a separate CDB bufferTony Battersby2014-08-222-1/+2
| | | | | | | | | | | | | | | | | | This patch fixes code such as the following with scsi-mq enabled: rq = blk_get_request(...); blk_rq_set_block_pc(rq); rq->cmd = my_cmd_buffer; /* separate CDB buffer */ blk_execute_rq_nowait(...); Code like this appears in e.g. sg_start_req() in drivers/scsi/sg.c (for large CDBs only). Without this patch, scsi_mq_prep_fn() will set rq->cmd back to rq->__cmd, causing the wrong CDB to be sent to the device. Signed-off-by: Tony Battersby <tonyb@cybernetics.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: support > 16 byte CDBs for SG_IOChristoph Hellwig2014-08-211-7/+17
| | | | | | Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Boaz Harrosh <boaz@plexistor.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: cleanup error handling in sg_ioChristoph Hellwig2014-08-211-6/+4
| | | | | | | | Make sure we always clean up through the out label and just have a single place to put the request. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-mq: blk_mq_freeze_queue() should allow nestingTejun Heo2014-08-211-4/+8
| | | | | | | | | | | | | | | | | | While converting to percpu_ref for freezing, add703fda981 ("blk-mq: use percpu_ref for mq usage count") incorrectly made blk_mq_freeze_queue() misbehave when freezing is nested due to percpu_ref_kill() being invoked on an already killed ref. Fix it by making blk_mq_freeze_queue() kill and kick the queue only for the outermost freeze attempt. All the nested ones can simply wait for the ref to reach zero. While at it, remove unnecessary @wake initialization from blk_mq_unfreeze_queue(). Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-mq: correct a few wrong/bad commentsJens Axboe2014-08-211-3/+3
| | | | | | Just grammar or spelling errors, nothing major. Signed-off-by: Jens Axboe <axboe@fb.com>
* block: Fix BUG_ON when pi errors occurSagi Grimberg2014-08-211-1/+1
| | | | | | | | | | | When getting a pi error we get to bio_integrity_end_io with bi_remaining already decremented to 0 where we will eventually need to call bio_endio with restored original bio completion handler. Calling bio_endio invokes a BUG_ON(). We should call bio_endio_nodec instead, like what is done in bio_integrity_verify_fn. Signed-off-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-mq: don't allow merges if turned off for the queueJens Axboe2014-08-211-3/+9
| | | | | | | | | | | | blk-mq uses BLK_MQ_F_SHOULD_MERGE, as set by the driver at init time, to determine whether it should merge IO or not. However, this could also be disabled by the admin, if merging is switched off through sysfs. So check the general queue state as well before attempting to merge IO. Reported-by: Rob Elliott <Elliott@hp.com> Tested-by: Rob Elliott <Elliott@hp.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-mq: fix WARNING "percpu_ref_kill() called more than once!"Ming Lei2014-08-151-4/+0
| | | | | | | | | | | | | Before doing queue release, the queue has been freezed already by blk_cleanup_queue(), so needn't to freeze queue for deleting tag set. This patch fixes the WARNING of "percpu_ref_kill() called more than once!" which is triggered during unloading block driver. Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* Merge tag 'dm-3.17-changes' of ↵Linus Torvalds2014-08-141-1/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper changes from Mike Snitzer: - Allow the thin target to paired with any size external origin; also allow thin snapshots to be larger than the external origin. - Add support for quickly loading a repetitive pattern into the dm-switch target. - Use per-bio data in the dm-crypt target instead of always using a mempool for each allocation. Required switching to kmalloc alignment for the bio slab. - Fix DM core to properly stack the QUEUE_FLAG_NO_SG_MERGE flag - Fix the dm-cache and dm-thin targets' export of the minimum_io_size to match the data block size -- this fixes an issue where mkfs.xfs would improperly infer raid striping was in place on the underlying storage. - Small cleanups in dm-io, dm-mpath and dm-cache * tag 'dm-3.17-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm table: propagate QUEUE_FLAG_NO_SG_MERGE dm switch: efficiently support repetitive patterns dm switch: factor out switch_region_table_read dm cache: set minimum_io_size to cache's data block size dm thin: set minimum_io_size to pool's data block size dm crypt: use per-bio data block: use kmalloc alignment for bio slab dm table: make dm_table_supports_discards static dm cache metadata: use dm-space-map-metadata.h defined size limits dm cache: fail migrations in the do_worker error path dm cache: simplify deferred set reference count increments dm thin: relax external origin size constraints dm thin: switch to an atomic_t for tracking pending new block preparations dm mpath: eliminate pg_ready() wrapper dm io: simplify dec_count and sync_io
| * block: use kmalloc alignment for bio slabMikulas Patocka2014-08-011-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Various subsystems can ask the bio subsystem to create a bio slab cache with some free space before the bio. This free space can be used for any purpose. Device mapper uses this per-bio-data feature to place some target-specific and device-mapper specific data before the bio, so that the target-specific data doesn't have to be allocated separately. This per-bio-data mechanism is used in place of kmalloc, so we need the allocated slab to have the same memory alignment as memory allocated with kmalloc. Change bio_find_or_create_slab() so that it uses ARCH_KMALLOC_MINALIGN alignment when creating the slab cache. This is needed so that dm-crypt can use per-bio-data for encryption - the crypto subsystem assumes this data will have the same alignment as kmalloc'ed memory. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Jens Axboe <axboe@fb.com>
* | Merge branch 'for-3.17/drivers' of git://git.kernel.dk/linux-blockLinus Torvalds2014-08-141-1/+4
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block driver changes from Jens Axboe: "Nothing out of the ordinary here, this pull request contains: - A big round of fixes for bcache from Kent Overstreet, Slava Pestov, and Surbhi Palande. No new features, just a lot of fixes. - The usual round of drbd updates from Andreas Gruenbacher, Lars Ellenberg, and Philipp Reisner. - virtio_blk was converted to blk-mq back in 3.13, but now Ming Lei has taken it one step further and added support for actually using more than one queue. - Addition of an explicit SG_FLAG_Q_AT_HEAD for block/bsg, to compliment the the default behavior of adding to the tail of the queue. From Douglas Gilbert" * 'for-3.17/drivers' of git://git.kernel.dk/linux-block: (86 commits) bcache: Drop unneeded blk_sync_queue() calls bcache: add mutex lock for bch_is_open bcache: Correct printing of btree_gc_max_duration_ms bcache: try to set b->parent properly bcache: fix memory corruption in init error path bcache: fix crash with incomplete cache set bcache: Fix more early shutdown bugs bcache: fix use-after-free in btree_gc_coalesce() bcache: Fix an infinite loop in journal replay bcache: fix crash in bcache_btree_node_alloc_fail tracepoint bcache: bcache_write tracepoint was crashing bcache: fix typo in bch_bkey_equal_header bcache: Allocate bounce buffers with GFP_NOWAIT bcache: Make sure to pass GFP_WAIT to mempool_alloc() bcache: fix uninterruptible sleep in writeback thread bcache: wait for buckets when allocating new btree root bcache: fix crash on shutdown in passthrough mode bcache: fix lockdep warnings on shutdown bcache allocator: send discards with correct size bcache: Fix to remove the rcu_sched stalls. ...
| * | block SG_IO: add SG_FLAG_Q_AT_HEAD flagDouglas Gilbert2014-07-011-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After the SG_IO ioctl was copied into the block layer and later into the bsg driver, subtle differences emerged. One difference is the way injected commands are queued through the block layer (i.e. this is not SCSI device queueing nor SATA NCQ). Summarizing: - SG_IO on block layer device: blk_exec*(at_head=false) - sg device SG_IO: at_head=true - bsg device SG_IO: at_head=true Some time ago Boaz Harrosh introduced a sg v4 flag called BSG_FLAG_Q_AT_TAIL to override the bsg driver default. A recent patch titled: "sg: add SG_FLAG_Q_AT_TAIL flag" allowed the sg driver default to be overridden. This patch allows a SG_IO ioctl sent to a block layer device to have its default overridden. ChangeLog: - introduce SG_FLAG_Q_AT_HEAD flag in sg.h to cause commands that are injected via a block layer device SG_IO ioctl to set at_head=true - make comments clearer about queueing in sg.h since the header is used both by the sg device and block layer device implementations of the SG_IO ioctl. - introduce BSG_FLAG_Q_AT_HEAD in bsg.h for compatibility (it does nothing) and update comments. Signed-off-by: Douglas Gilbert <dgilbert@interlog.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: Jens Axboe <axboe@fb.com>
* | | Merge branch 'for-3.17/core' of git://git.kernel.dk/linux-blockLinus Torvalds2014-08-1412-109/+102
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block core bits from Jens Axboe: "Small round this time, after the massive blk-mq dump for 3.16. This pull request contains: - Fixes for max_sectors overflow in ioctls from Akinoby Mita. - Partition off-by-one bug fix in aix partitions from Dan Carpenter. - Various small partition cleanups from Fabian Frederick. - Fix for the block integrity code sometimes returning the wrong vector count from Gu Zheng. - Cleanup an re-org of the blk-mq queue enter/exit percpu counters from Tejun. Dependent on the percpu pull for 3.17 (which was in the block tree too), that you have already pulled in. - A blkcg oops fix, also from Tejun" * 'for-3.17/core' of git://git.kernel.dk/linux-block: partitions: aix.c: off by one bug blkcg: don't call into policy draining if root_blkg is already gone Revert "bio: modify __bio_add_page() to accept pages that don't start a new segment" bio: modify __bio_add_page() to accept pages that don't start a new segment block: fix SG_[GS]ET_RESERVED_SIZE ioctl when max_sectors is huge block: fix BLKSECTGET ioctl when max_sectors is greater than USHRT_MAX block/partitions/efi.c: kerneldoc fixing block/partitions/msdos.c: code clean-up block/partitions/amiga.c: replace nolevel printk by pr_err block/partitions/aix.c: replace count*size kzalloc by kcalloc bio-integrity: add "bip_max_vcnt" into struct bio_integrity_payload blk-mq: use percpu_ref for mq usage count blk-mq: collapse __blk_mq_drain_queue() into blk_mq_freeze_queue() blk-mq: decouble blk-mq freezing from generic bypassing block, blk-mq: draining can't be skipped even if bypass_depth was non-zero blk-mq: fix a memory ordering bug in blk_mq_queue_enter()
| * | | partitions: aix.c: off by one bugDan Carpenter2014-08-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The lvip[] array has "state->limit" elements so the condition here should be >= instead of >. Fixes: 6ceea22bbbc8 ('partitions: add aix lvm partition support files') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Philippe De Muyter <phdm@macqel.be> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | blkcg: don't call into policy draining if root_blkg is already goneTejun Heo2014-07-161-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While a queue is being destroyed, all the blkgs are destroyed and its ->root_blkg pointer is set to NULL. If someone else starts to drain while the queue is in this state, the following oops happens. NULL pointer dereference at 0000000000000028 IP: [<ffffffff8144e944>] blk_throtl_drain+0x84/0x230 PGD e4a1067 PUD b773067 PMD 0 Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC Modules linked in: cfq_iosched(-) [last unloaded: cfq_iosched] CPU: 1 PID: 537 Comm: bash Not tainted 3.16.0-rc3-work+ #2 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 task: ffff88000e222250 ti: ffff88000efd4000 task.ti: ffff88000efd4000 RIP: 0010:[<ffffffff8144e944>] [<ffffffff8144e944>] blk_throtl_drain+0x84/0x230 RSP: 0018:ffff88000efd7bf0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffff880015091450 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88000efd7c10 R08: 0000000000000000 R09: 0000000000000001 R10: ffff88000e222250 R11: 0000000000000000 R12: ffff880015091450 R13: ffff880015092e00 R14: ffff880015091d70 R15: ffff88001508fc28 FS: 00007f1332650740(0000) GS:ffff88001fa80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000028 CR3: 0000000009446000 CR4: 00000000000006e0 Stack: ffffffff8144e8f6 ffff880015091450 0000000000000000 ffff880015091d80 ffff88000efd7c28 ffffffff8144ae2f ffff880015091450 ffff88000efd7c58 ffffffff81427641 ffff880015091450 ffffffff82401f00 ffff880015091450 Call Trace: [<ffffffff8144ae2f>] blkcg_drain_queue+0x1f/0x60 [<ffffffff81427641>] __blk_drain_queue+0x71/0x180 [<ffffffff81429b3e>] blk_queue_bypass_start+0x6e/0xb0 [<ffffffff814498b8>] blkcg_deactivate_policy+0x38/0x120 [<ffffffff8144ec44>] blk_throtl_exit+0x34/0x50 [<ffffffff8144aea5>] blkcg_exit_queue+0x35/0x40 [<ffffffff8142d476>] blk_release_queue+0x26/0xd0 [<ffffffff81454968>] kobject_cleanup+0x38/0x70 [<ffffffff81454848>] kobject_put+0x28/0x60 [<ffffffff81427505>] blk_put_queue+0x15/0x20 [<ffffffff817d07bb>] scsi_device_dev_release_usercontext+0x16b/0x1c0 [<ffffffff810bc339>] execute_in_process_context+0x89/0xa0 [<ffffffff817d064c>] scsi_device_dev_release+0x1c/0x20 [<ffffffff817930e2>] device_release+0x32/0xa0 [<ffffffff81454968>] kobject_cleanup+0x38/0x70 [<ffffffff81454848>] kobject_put+0x28/0x60 [<ffffffff817934d7>] put_device+0x17/0x20 [<ffffffff817d11b9>] __scsi_remove_device+0xa9/0xe0 [<ffffffff817d121b>] scsi_remove_device+0x2b/0x40 [<ffffffff817d1257>] sdev_store_delete+0x27/0x30 [<ffffffff81792ca8>] dev_attr_store+0x18/0x30 [<ffffffff8126f75e>] sysfs_kf_write+0x3e/0x50 [<ffffffff8126ea87>] kernfs_fop_write+0xe7/0x170 [<ffffffff811f5e9f>] vfs_write+0xaf/0x1d0 [<ffffffff811f69bd>] SyS_write+0x4d/0xc0 [<ffffffff81d24692>] system_call_fastpath+0x16/0x1b 776687bce42b ("block, blk-mq: draining can't be skipped even if bypass_depth was non-zero") made it easier to trigger this bug by making blk_queue_bypass_start() drain even when it loses the first bypass test to blk_cleanup_queue(); however, the bug has always been there even before the commit as blk_queue_bypass_start() could race against queue destruction, win the initial bypass test but perform the actual draining after blk_cleanup_queue() already destroyed all blkgs. Fix it by skippping calling into policy draining if all the blkgs are already gone. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Shirish Pargaonkar <spargaonkar@suse.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Reported-by: Jet Chen <jet.chen@intel.com> Cc: stable@vger.kernel.org Tested-by: Shirish Pargaonkar <spargaonkar@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | Revert "bio: modify __bio_add_page() to accept pages that don't start a new ↵Jens Axboe2014-07-141-29/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | segment" This reverts commit 254c4407cb84a6dec90336054615b0f0e996bb7c. It causes crashes with cryptsetup, even after a few iterations and updates. Drop it for now.
| * | | bio: modify __bio_add_page() to accept pages that don't start a new segmentMaurizio Lombardi2014-07-011-23/+29
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The original behaviour is to refuse to add a new page if the maximum number of segments has been reached, regardless of the fact the page we are going to add can be merged into the last segment or not. Unfortunately, when the system runs under heavy memory fragmentation conditions, a driver may try to add multiple pages to the last segment. The original code won't accept them and EBUSY will be reported to userspace. This patch modifies the function so it refuses to add a page only in case the latter starts a new segment and the maximum number of segments has already been reached. The bug can be easily reproduced with the st driver: 1) set CONFIG_SCSI_MPT2SAS_MAX_SGE or CONFIG_SCSI_MPT3SAS_MAX_SGE to 16 2) modprobe st buffer_kbs=1024 3) #dd if=/dev/zero of=/dev/st0 bs=1M count=10 dd: error writing `/dev/st0': Device or resource busy [ming.lei@canonical.com: update bi_iter.bi_size before recounting segments] Signed-off-by: Maurizio Lombardi <mlombard@redhat.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Tested-by: Dongsu Park <dongsu.park@profitbricks.com> Tested-by: Jet Chen <jet.chen@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Cc: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | block: fix SG_[GS]ET_RESERVED_SIZE ioctl when max_sectors is hugeAkinobu Mita2014-07-011-4/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SG_GET_RESERVED_SIZE and SG_SET_RESERVED_SIZE ioctls access a reserved buffer in bytes as int type. The value needs to be capped at the request queue's max_sectors. But integer overflow is not correctly handled in the calculation when converting max_sectors from sectors to bytes. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Douglas Gilbert <dgilbert@interlog.com> Cc: linux-scsi@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | block: fix BLKSECTGET ioctl when max_sectors is greater than USHRT_MAXAkinobu Mita2014-07-012-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BLKSECTGET ioctl loads the request queue's max_sectors as unsigned short value to the argument pointer. So if the max_sector is greater than USHRT_MAX, the upper 16 bits of that is just discarded. In such case, USHRT_MAX is more preferable than the lower 16 bits of max_sectors. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Douglas Gilbert <dgilbert@interlog.com> Cc: linux-scsi@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | block/partitions/efi.c: kerneldoc fixingFabian Frederick2014-07-011-22/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adding function documentation and fixing kerneldoc warnings ('field: description' uniformization). Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | block/partitions/msdos.c: code clean-upFabian Frederick2014-07-011-5/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | checkpatch fixing: WARNING: Missing a blank line after declarations WARNING: space prohibited between function name and open parenthesis '(' ERROR: spaces required around that '<' (ctx:VxV) Cc: Jens Axboe <axboe@kernel.dk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | block/partitions/amiga.c: replace nolevel printk by pr_errFabian Frederick2014-07-011-5/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | Also add no prefix pr_fmt to avoid any future default format update Cc: Jens Axboe <axboe@kernel.dk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | block/partitions/aix.c: replace count*size kzalloc by kcallocFabian Frederick2014-07-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | kcalloc manages count*sizeof overflow. Cc: Jens Axboe <axboe@kernel.dk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | bio-integrity: add "bip_max_vcnt" into struct bio_integrity_payloadGu Zheng2014-07-011-9/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 08778795 ("block: Fix nr_vecs for inline integrity vectors") from Martin introduces the function bip_integrity_vecs(get the useful vectors) to fix the issue about nr_vecs for inline integrity vectors that reported by David Milburn. But it seems that bip_integrity_vecs() will return the wrong number if the bio is not based on any bio_set for some reason(bio->bi_pool == NULL), because in that case, the bip_inline_vecs[0] is malloced directly. So here we add the bip_max_vcnt to record the count of vector slots, and cleanup the function bip_integrity_vecs(). Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Kent Overstreet <kmo@daterainc.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blk-mq: use percpu_ref for mq usage countTejun Heo2014-07-011-39/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, blk-mq uses a percpu_counter to keep track of how many usages are in flight. The percpu_counter is drained while freezing to ensure that no usage is left in-flight after freezing is complete. blk_mq_queue_enter/exit() and blk_mq_[un]freeze_queue() implement this per-cpu gating mechanism. This type of code has relatively high chance of subtle bugs which are extremely difficult to trigger and it's way too hairy to be open coded in blk-mq. percpu_ref can serve the same purpose after the recent changes. This patch replaces the open-coded per-cpu usage counting and draining mechanism with percpu_ref. blk_mq_queue_enter() performs tryget_live on the ref and exit() performs put. blk_mq_freeze_queue() kills the ref and waits until the reference count reaches zero. blk_mq_unfreeze_queue() revives the ref and wakes up the waiters. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Nicholas A. Bellinger <nab@linux-iscsi.org> Cc: Kent Overstreet <kmo@daterainc.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blk-mq: collapse __blk_mq_drain_queue() into blk_mq_freeze_queue()Tejun Heo2014-07-011-14/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Keeping __blk_mq_drain_queue() as a separate function doesn't buy us anything and it's gonna be further simplified. Let's flatten it into its caller. This patch doesn't make any functional change. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Nicholas A. Bellinger <nab@linux-iscsi.org> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blk-mq: decouble blk-mq freezing from generic bypassingTejun Heo2014-07-013-13/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blk_mq freezing is entangled with generic bypassing which bypasses blkcg and io scheduler and lets IO requests fall through the block layer to the drivers in FIFO order. This allows forward progress on IOs with the advanced features disabled so that those features can be configured or altered without worrying about stalling IO which may lead to deadlock through memory allocation. However, generic bypassing doesn't quite fit blk-mq. blk-mq currently doesn't make use of blkcg or ioscheds and it maps bypssing to freezing, which blocks request processing and drains all the in-flight ones. This causes problems as bypassing assumes that request processing is online. blk-mq works around this by conditionally allowing request processing for the problem case - during queue initialization. Another weirdity is that except for during queue cleanup, bypassing started on the generic side prevents blk-mq from processing new requests but doesn't drain the in-flight ones. This shouldn't break anything but again highlights that something isn't quite right here. The root cause is conflating blk-mq freezing and generic bypassing which are two different mechanisms. The only intersecting purpose that they serve is during queue cleanup. Let's properly separate blk-mq freezing from generic bypassing and simply use it where necessary. * request_queue->mq_freeze_depth is added and blk_mq_[un]freeze_queue() now operate on this counter instead of ->bypass_depth. The replacement for QUEUE_FLAG_BYPASS isn't added but the counter is tested directly. This will be further updated by later changes. * blk_mq_drain_queue() is dropped and "__" prefix is dropped from blk_mq_freeze_queue(). Queue cleanup path now calls blk_mq_freeze_queue() directly. * blk_queue_enter()'s fast path condition is simplified to simply check @q->mq_freeze_depth. Previously, the condition was !blk_queue_dying(q) && (!blk_queue_bypass(q) || !blk_queue_init_done(q)) mq_freeze_depth is incremented right after dying is set and blk_queue_init_done() exception isn't necessary as blk-mq doesn't start frozen, which only leaves the blk_queue_bypass() test which can be replaced by @q->mq_freeze_depth test. This change simplifies the code and reduces confusion in the area. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Nicholas A. Bellinger <nab@linux-iscsi.org> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | block, blk-mq: draining can't be skipped even if bypass_depth was non-zeroTejun Heo2014-07-013-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, both blk_queue_bypass_start() and blk_mq_freeze_queue() skip queue draining if bypass_depth was already above zero. The assumption is that the one which bumped the bypass_depth should have performed draining already; however, there's nothing which prevents a new instance of bypassing/freezing from starting before the previous one finishes draining. The current code may allow the later bypassing/freezing instances to complete while there still are in-flight requests which haven't finished draining. Fix it by draining regardless of bypass_depth. We still skip draining from blk_queue_bypass_start() while the queue is initializing to avoid introducing excessive delays during boot. INIT_DONE setting is moved above the initial blk_queue_bypass_end() so that bypassing attempts can't slip inbetween. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Nicholas A. Bellinger <nab@linux-iscsi.org> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blk-mq: fix a memory ordering bug in blk_mq_queue_enter()Tejun Heo2014-07-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blk-mq uses a percpu_counter to keep track of how many usages are in flight. The percpu_counter is drained while freezing to ensure that no usage is left in-flight after freezing is complete. blk_mq_queue_enter/exit() and blk_mq_[un]freeze_queue() implement this per-cpu gating mechanism; unfortunately, it contains a subtle bug - smp_wmb() in blk_mq_queue_enter() doesn't prevent prevent the cpu from fetching @q->bypass_depth before incrementing @q->mq_usage_counter and if freezing happens inbetween the caller can slip through and freezing can be complete while there are active users. Use smp_mb() instead so that bypass_depth and mq_usage_counter modifications and tests are properly interlocked. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Nicholas A. Bellinger <nab@linux-iscsi.org> Signed-off-by: Jens Axboe <axboe@fb.com>
* | | Merge branch 'for-3.17' of ↵Linus Torvalds2014-08-042-5/+14
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup changes from Tejun Heo: "Mostly changes to get the v2 interface ready. The core features are mostly ready now and I think it's reasonable to expect to drop the devel mask in one or two devel cycles at least for a subset of controllers. - cgroup added a controller dependency mechanism so that block cgroup can depend on memory cgroup. This will be used to finally support IO provisioning on the writeback traffic, which is currently being implemented. - The v2 interface now uses a separate table so that the interface files for the new interface are explicitly declared in one place. Each controller will explicitly review and add the files for the new interface. - cpuset is getting ready for the hierarchical behavior which is in the similar style with other controllers so that an ancestor's configuration change doesn't change the descendants' configurations irreversibly and processes aren't silently migrated when a CPU or node goes down. All the changes are to the new interface and no behavior changed for the multiple hierarchies" * 'for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (29 commits) cpuset: fix the WARN_ON() in update_nodemasks_hier() cgroup: initialize cgrp_dfl_root_inhibit_ss_mask from !->dfl_files test cgroup: make CFTYPE_ONLY_ON_DFL and CFTYPE_NO_ internal to cgroup core cgroup: distinguish the default and legacy hierarchies when handling cftypes cgroup: replace cgroup_add_cftypes() with cgroup_add_legacy_cftypes() cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes cgroup: split cgroup_base_files[] into cgroup_{dfl|legacy}_base_files[] cpuset: export effective masks to userspace cpuset: allow writing offlined masks to cpuset.cpus/mems cpuset: enable onlined cpu/node in effective masks cpuset: refactor cpuset_hotplug_update_tasks() cpuset: make cs->{cpus, mems}_allowed as user-configured masks cpuset: apply cs->effective_{cpus,mems} cpuset: initialize top_cpuset's configured masks at mount cpuset: use effective cpumask to build sched domains cpuset: inherit ancestor's masks if effective_{cpus, mems} becomes empty cpuset: update cs->effective_{cpus, mems} when config changes cpuset: update cpuset->effective_{cpus,mems} at hotplug cpuset: add cs->effective_cpus and cs->effective_mems cgroup: clean up sane_behavior handling ...
| * | cgroup: replace cgroup_add_cftypes() with cgroup_add_legacy_cftypes()Tejun Heo2014-07-151-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, cftypes added by cgroup_add_cftypes() are used for both the unified default hierarchy and legacy ones and subsystems can mark each file with either CFTYPE_ONLY_ON_DFL or CFTYPE_INSANE if it has to appear only on one of them. This is quite hairy and error-prone. Also, we may end up exposing interface files to the default hierarchy without thinking it through. cgroup_subsys will grow two separate cftype addition functions and apply each only on the hierarchies of the matching type. This will allow organizing cftypes in a lot clearer way and encourage subsystems to scrutinize the interface which is being exposed in the new default hierarchy. In preparation, this patch adds cgroup_add_legacy_cftypes() which currently is a simple wrapper around cgroup_add_cftypes() and replaces all cgroup_add_cftypes() usages with it. While at it, this patch drops a completely spurious return from __hugetlb_cgroup_file_init(). This patch doesn't introduce any functional differences. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
| * | cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypesTejun Heo2014-07-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, cgroup_subsys->base_cftypes is used for both the unified default hierarchy and legacy ones and subsystems can mark each file with either CFTYPE_ONLY_ON_DFL or CFTYPE_INSANE if it has to appear only on one of them. This is quite hairy and error-prone. Also, we may end up exposing interface files to the default hierarchy without thinking it through. cgroup_subsys will grow two separate cftype arrays and apply each only on the hierarchies of the matching type. This will allow organizing cftypes in a lot clearer way and encourage subsystems to scrutinize the interface which is being exposed in the new default hierarchy. In preparation, this patch renames cgroup_subsys->base_cftypes to cgroup_subsys->legacy_cftypes. This patch is pure rename. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Aristeu Rozanski <aris@redhat.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
| * | cgroup: remove sane_behavior support on non-default hierarchiesTejun Heo2014-07-091-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sane_behavior has been used as a development vehicle for the default unified hierarchy. Now that the default hierarchy is in place, the flag became redundant and confusing as its usage is allowed on all hierarchies. There are gonna be either the default hierarchy or legacy ones. Let's make that clear by removing sane_behavior support on non-default hierarchies. This patch replaces cgroup_sane_behavior() with cgroup_on_dfl(). The comment on top of CGRP_ROOT_SANE_BEHAVIOR is moved to on top of cgroup_on_dfl() with sane_behavior specific part dropped. On the default and legacy hierarchies w/o sane_behavior, this shouldn't cause any behavior differences. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz>
| * | blkcg, memcg: make blkcg depend on memcg on the default hierarchyTejun Heo2014-07-081-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the blkio subsystem attributes all of writeback IOs to the root. One of the issues is that there's no way to tell who originated a writeback IO from block layer. Those IOs are usually issued asynchronously from a task which didn't have anything to do with actually generating the dirty pages. The memory subsystem, when enabled, already keeps track of the ownership of each dirty page and it's desirable for blkio to piggyback instead of adding its own per-page tag. cgroup now has a mechanism to express such dependency - cgroup_subsys->depends_on. This patch declares that blkcg depends on memcg so that memcg is enabled automatically on the default hierarchy when available. Future changes will make blkcg map the memcg tag to find out the cgroup to blame for writeback IOs. As this means that a memcg may be made invisible, this patch also implements css_reset() for memcg which resets its basic configurations. This implementation will probably need to be expanded to cover other states which are used in the default hierarchy. v2: blkcg's dependency on memcg is wrapped with CONFIG_MEMCG to avoid build failure. Reported by kbuild test robot. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Jens Axboe <axboe@kernel.dk>