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2017-10-25block: cope with WRITE ZEROES failing in blkdev_issue_zeroout()Ilya Dryomov1-10/+35
sd_config_write_same() ignores ->max_ws_blocks == 0 and resets it to permit trying WRITE SAME on older SCSI devices, unless ->no_write_same is set. Because REQ_OP_WRITE_ZEROES is implemented in terms of WRITE SAME, blkdev_issue_zeroout() may fail with -EREMOTEIO: $ fallocate -zn -l 1k /dev/sdg fallocate: fallocate failed: Remote I/O error $ fallocate -zn -l 1k /dev/sdg # OK $ fallocate -zn -l 1k /dev/sdg # OK The following calls succeed because sd_done() sets ->no_write_same in response to a sense that would become BLK_STS_TARGET/-EREMOTEIO, causing __blkdev_issue_zeroout() to fall back to generating ZERO_PAGE bios. This means blkdev_issue_zeroout() must cope with WRITE ZEROES failing and fall back to manually zeroing, unless BLKDEV_ZERO_NOFALLBACK is specified. For BLKDEV_ZERO_NOFALLBACK case, return -EOPNOTSUPP if sd_done() has just set ->no_write_same thus indicating lack of offload support. Fixes: c20cfc27a473 ("block: stop using blkdev_issue_write_same for zeroing") Cc: Hannes Reinecke <hare@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-25block: factor out __blkdev_issue_zero_pages()Ilya Dryomov1-26/+37
blkdev_issue_zeroout() will use this in !BLKDEV_ZERO_NOFALLBACK case. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-25block: move CAP_SYS_ADMIN check in blkdev_roset()Ilya Dryomov1-2/+3
Check for CAP_SYS_ADMIN before calling into the driver, similar to blkdev_flushbuf(). This is safer and can spare a check in the driver. (Currently BLKROSET is overridden by md and rbd, rbd is missing the check. md has the check, but it covers a lot more than BLKROSET.) Acked-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-25block: Invalidate cache on discard v2Dmitry Monakhov1-4/+10
It is reasonable drop page cache on discard, otherwise that pages may be written by writeback second later, so thin provision devices will not be happy. This seems to be a security leak in case of secure discard case. Also add check for queue_discard flag on early stage. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-24lightnvm: pblk: remove leftover testing functionJavier González1-5/+0
A previous patch inadvertently left an unused test function in the header, kill it. Fixes: 8bd400204bd5 ("lightnvm: pblk: cleanup unused and static functions") Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-23nvme-rdma: Add debug message when reaches timeoutNitzan Carmi1-0/+4
Signed-off-by: Nitzan Carmi <nitzanc@mellanox.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-23nvme-rdma: align nvme_rdma_device structureMax Gurtovoy1-2/+2
Signed-off-by: Max Gurtovoy <maxg@mellanox.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-20nvme-fc: correct io timeout behaviorJames Smart1-4/+10
The transport io timeout behavior wasn't quite correct. It ignored that the io error handler is supposed to be synchronous so it possibly allowed the blk request to be restarted while the io associated was still aborting. Timeouts on reserved commands, those used for association create, were never timing out thus they hung out forever. To correct: If an io is times out while a remoteport is not connected, just restart the io timer. The lack of connectivity will simultaneously be resetting the controller, so the reset path will abort and terminate the io. If an io is times out while it was marked for transport abort, just reset the io timer. The abort process is underway and will complete the io. Otherwise, if an io times out, abort the io. If the abort was unsuccessful (unlikely) give up and return not handled. If the abort was successful, as the abort process is underway it will terminate the io, so rather than synchronously waiting, just restart the io timer. Signed-off-by: James Smart <james.smart@broadcom.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-20nvme-fc: correct io termination handlingJames Smart1-13/+18
The io completion handling for i/o's that are failing due to to a transport error or association termination had issues, causing io failures (DNR set so retries didn't kick in) or long stalls. Change the io completion handler for the following items: When an io has been completed due to a transport abort (based on an exchange error) or when marked as aborted as part of an association termination (FCOP_FLAGS_TERMIO), set the NVME completion status to NVME_SC_ABORTED. By default, do not set DNR on the status so that a retry can be attempted after association recreate. In cases where an io is failed (non-successful nvme status including aborted), if the controller is being deleted (blk_queue_dying) or the io was part of the ios used for association creation (ctrl state is NEW or RECONNECTING), then additionally set the DNR bit so the io will not be retried. If the failed io was part of association creation, the failure will tear down the partially completioned association and typically restart a new reconnect attempt (another create association later). Rearranged code flow to remove a largely unneeded local variable. Signed-off-by: James Smart <james.smart@broadcom.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-20nvme-pci: add SGL supportChaitanya Kulkarni1-27/+187
This adds SGL support for NVMe PCIe driver, based on an earlier patch from Rajiv Shanmugam Madeswaran <smrajiv15 at gmail.com>. This patch refactors the original code and adds new module parameter sgl_threshold to determine whether to use SGL or PRP for IOs. The usage of SGLs is controlled by the sgl_threshold module parameter, which allows to conditionally use SGLs if average request segment size (avg_seg_size) is greater than sgl_threshold. In the original patch, the decision of using SGLs was dependent only on the IO size, with the new approach we consider not only IO size but also the number of physical segments present in the IO. We calculate avg_seg_size based on request payload bytes and number of physical segments present in the request. For e.g.:- 1. blk_rq_nr_phys_segments = 2 blk_rq_payload_bytes = 8k avg_seg_size = 4K use sgl if avg_seg_size >= sgl_threshold. 2. blk_rq_nr_phys_segments = 2 blk_rq_payload_bytes = 64k avg_seg_size = 32K use sgl if avg_seg_size >= sgl_threshold. 3. blk_rq_nr_phys_segments = 16 blk_rq_payload_bytes = 64k avg_seg_size = 4K use sgl if avg_seg_size >= sgl_threshold. Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-20nvme: use ida_simple_{get,remove} for the controller instanceChristoph Hellwig1-33/+7
Switch to the ida_simple_* helpers instead of opencoding them. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2017-10-20nvmet: Change max_nsid in subsystem due to ns_disable if neededRoy Shterman1-0/+13
In case we disable namespaces which has the nsid like subsystem max_nsid we need to search for the next largest nsid in this subsystem. If the subsystem don't has more namespaces we set it to 0, else we take nsid from the last namespace in namespaces list because the list is sorted while inserting. Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Roy Shterman <roys@lightbitslabs.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> [hch: slight refactor] Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-19nvme-loop: Add BLK_MQ_F_NO_SCHED flag to admin tag setIsrael Rukshin1-0/+1
This flag is useful for admin queues that aren't used for normal IO. Signed-off-by: Israel Rukshin <israelr@mellanox.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-19nvme-fc: Add BLK_MQ_F_NO_SCHED flag to admin tag setIsrael Rukshin1-0/+1
Since commit b86dd81 "block: get rid of blk-mq default scheduler choice Kconfig entries", when setting nr_hw_queues to 1 the admin tag set uses mq-deadline scheduler. This flag is useful for admin queues that aren't used for normal IO. Signed-off-by: Israel Rukshin <israelr@mellanox.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: James Smart <james.smart@broadcom.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-19nvme-rdma: Add BLK_MQ_F_NO_SCHED flag to admin tag setIsrael Rukshin1-0/+1
Since commit b86dd81 "block: get rid of blk-mq default scheduler choice Kconfig entries", when setting nr_hw_queues to 1 the admin tag set uses mq-deadline scheduler. This flag is useful for admin queues that aren't used for normal IO. Signed-off-by: Israel Rukshin <israelr@mellanox.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-19nvme-pci: fix typos in commentsMinwoo Im1-2/+2
fixed comment typos in adapter_alloc_cq() and adapter_alloc_sq(). 'the the' duplications are replaced with 'that the'. Signed-off-by: Minwoo Im <dn3108@gmail.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-18nvme-rdma: stop controller reset if the controller is deletingSagi Grimberg1-1/+5
If the controller is deleting (in case the user decided to delete it), we have no point to continue reset sequence. Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-18nvme-rdma: change queue flag semantics DELETING -> ALLOCATEDSagi Grimberg1-4/+4
Instead of marking we are deleting, mark we are allocated and check that instead. This makes the logic symmetrical to connected mark check. Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-18nvme-rdma: Don't local invalidate if the queue is not liveSagi Grimberg1-1/+1
No chance for the local invalidate to succeed if the queue-pair is in error state. Most likely the target will do a remote invalidation of our mr so not a big loss on the test_bit. Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-18nvme-rdma: teardown admin/io queues once on error recoverySagi Grimberg1-15/+12
Relying on the queue state while tearing down on every reconnect attempt is not a good design. We should do it once in err_work and simply try to establish the queues for each reconnect attempt. Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-18nvme-rdma: Check that reinit_request got a proper mrSagi Grimberg1-0/+3
Warn if req->mr is NULL as it should never happen. Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-18nvme-rdma: move assignment to declarationSagi Grimberg1-4/+2
No need for the extra line for trivial assignments. Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-18nvme-rdma: fix wrong logging messageSagi Grimberg1-1/+1
Not necessarily address resolution failed. Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-18nvme-rdma: pass tagset to directly nvme_rdma_free_tagsetSagi Grimberg1-7/+6
Instead of flagging admin/io. Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-18block: remove blk_mq_reinit_tagsetSagi Grimberg2-9/+0
No callers left. Reviewed-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-18nvme: introduce nvme_reinit_tagsetSagi Grimberg4-5/+17
Move blk_mq_reinit_tagset from blk-mq to nvme core as the only user of it. Current transports that use it (rdma, fc) simply implement .reinit_request op. This patch does not change any functionality. Reviewed-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-18block: introduce blk_mq_tagset_iterSagi Grimberg2-5/+13
Iterator helper to apply a function on all the tags in a given tagset. export it as it will be used outside the block layer later on. Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-18kyber: fix hang on domain token wait queueOmar Sandoval1-1/+9
When we're getting a domain token, if we fail to get a token on our first attempt, we put the current hardware queue on a wait queue and then try again just in case a token was freed after our initial attempt but before we got on the wait queue. If this second attempt succeeds, we currently leave the hardware queue on the wait queue. Usually this is okay; we'll just run the hardware queue one extra time when another token is freed. However, if the hardware queue doesn't have any other requests waiting, then when it it gets the extra wakeup, it won't have anything to free and therefore won't wake up any other hardware queues. If tokens are limited, then we won't make forward progress and the device will hang. Reported-by: Bin Zha <zhabin.zb@alibaba-inc.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-17nullb: fix error return code in null_init()Wei Yongjun1-1/+3
Fix to return error code -ENOMEM from the null_alloc_dev() error handling case instead of 0, as done elsewhere in this function. Fixes: 2984c8684f96 ("nullb: factor disk parameters") Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-16block: fix Sphinx kernel-doc warningRandy Dunlap1-1/+1
Sphinx treats symbols that end with '_' as a kind of special documentation indicator, so fix that by adding an ending '*' to it. ../block/bio.c:404: ERROR: Unknown target name: "gfp". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-16bcache: writeback rate clamping: make 32 bit safeMichael Lyle1-2/+2
Sorry this got through to linux-block, was detected by the kbuilds test robot. NSEC_PER_SEC is a long constant; 2.5 * 10^9 doesn't fit in a signed long constant. Fixes: e41166c5c44e ("bcache: writeback rate shouldn't artifically clamp") Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-16bcache: MAINTAINERS: set bcache to MAINTAINEDMichael Lyle1-1/+2
Also add URL for IRC channel. Signed-off-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-16bcache: Add Michael Lyle to MAINTAINERSKent Overstreet1-0/+1
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-16bcache: safeguard a dangerous addressing in closure_queueLiang Chen1-0/+6
The use of the union reduces the size of closure struct by taking advantage of the current size of its members. The offset of func in work_struct equals the size of the first three members, so that work.work_func will just reference the forth member - fn. This is smart but dangerous. It can be broken if work_struct or the other structs get changed, and can be a bit difficult to debug. Signed-off-by: Liang Chen <liangchen.linux@gmail.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-16bcache: rearrange writeback main thread ratelimitMichael Lyle1-1/+4
The time spent searching for things to write back "counts" for the actual rate achieved, so don't flush the accumulated rate with each chunk. This will maintain better fidelity to user-commanded rates, but it may slightly increase the burstiness of writeback. The writeback lock needs improvement to help mitigate this. Signed-off-by: Michael Lyle <mlyle@lyle.org> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-16bcache: writeback rate shouldn't artifically clampMichael Lyle3-6/+7
The previous code artificially limited writeback rate to 1000000 blocks/second (NSEC_PER_MSEC), which is a rate that can be met on fast hardware. The rate limiting code works fine (though with decreased precision) up to 3 orders of magnitude faster, so use NSEC_PER_SEC. Additionally, ensure that uint32_t is used as a type for rate throughout the rate management so that type checking/clamp_t can work properly. bch_next_delay should be rewritten for increased precision and better handling of high rates and long sleep periods, but this is adequate for now. Signed-off-by: Michael Lyle <mlyle@lyle.org> Reported-by: Coly Li <colyli@suse.de> Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-16bcache: smooth writeback rate controlMichael Lyle2-3/+9
This works in conjunction with the new PI controller. Currently, in real-world workloads, the rate controller attempts to write back 1 sector per second. In practice, these minimum-rate writebacks are between 4k and 60k in test scenarios, since bcache aggregates and attempts to do contiguous writes and because filesystems on top of bcachefs typically write 4k or more. Previously, bcache used to guarantee to write at least once per second. This means that the actual writeback rate would exceed the configured amount by a factor of 8-120 or more. This patch adjusts to be willing to sleep up to 2.5 seconds, and to target writing 4k/second. On the smallest writes, it will sleep 1 second like before, but many times it will sleep longer and load the backing device less. This keeps the loading on the cache and backing device related to writeback more consistent when writing back at low rates. Signed-off-by: Michael Lyle <mlyle@lyle.org> Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-16bcache: implement PI controller for writeback rateMichael Lyle3-52/+66
bcache uses a control system to attempt to keep the amount of dirty data in cache at a user-configured level, while not responding excessively to transients and variations in write rate. Previously, the system was a PD controller; but the output from it was integrated, turning the Proportional term into an Integral term, and turning the Derivative term into a crude Proportional term. Performance of the controller has been uneven in production, and it has tended to respond slowly, oscillate, and overshoot. This patch set replaces the current control system with an explicit PI controller and tuning that should be correct for most hardware. By default, it attempts to write at a rate that would retire 1/40th of the current excess blocks per second. An integral term in turn works to remove steady state errors. IMO, this yields benefits in simplicity (removing weighted average filtering, etc) and system performance. Another small change is a tunable parameter is introduced to allow the user to specify a minimum rate at which dirty blocks are retired. There is a slight difference from earlier versions of the patch in integral handling to prevent excessive negative integral windup. Signed-off-by: Michael Lyle <mlyle@lyle.org> Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-16bcache: don't write back data if reading it failedMichael Lyle1-6/+14
If an IO operation fails, and we didn't successfully read data from the cache, don't writeback invalid/partial data to the backing disk. Signed-off-by: Michael Lyle <mlyle@lyle.org> Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-16bcache: remove unused parameterYijing Wang1-6/+6
Parameter bio is no longer used, clean it. Signed-off-by: Yijing Wang <wangyijing@huawei.com> Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-16bcache: update bio->bi_opf bypass/writeback REQ_ flag hintsEric Wheeler2-1/+11
Flag for bypass if the IO is for read-ahead or background, unless the read-ahead request is for metadata (eg, from gfs2). Bypass if: bio->bi_opf & (REQ_RAHEAD|REQ_BACKGROUND) && !(bio->bi_opf & REQ_META)) Writeback if: op_is_sync(bio->bi_opf) || bio->bi_opf & (REQ_META|REQ_PRIO) Signed-off-by: Eric Wheeler <bcache@linux.ewheeler.net> Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-16bcache: Remove redundant set_capacityYijing Wang1-3/+0
set_capacity() has been called in bcache_device_init(), remove the redundant one. Signed-off-by: Yijing Wang <wangyijing@huawei.com> Reviewed-by: Eric Wheeler <bcache@linux.ewheeler.net> Acked-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-16bcache: rewrite multiple partitions supportColy Li1-12/+25
Current partition support of bcache is confusing and buggy. It tries to trace non-continuous device minor numbers by an ida bit string, and mistakenly mixed bcache device index with minor numbers. This design generates several negative results, - Index of bcache device name is not consecutive under /dev/. If there are 3 bcache devices, they name will be, /dev/bcache0, /dev/bcache16, /dev/bcache32 Only bcache code indexes bcache device name is such an interesting way. - First minor number of each bcache device is traced by ida bit string. One bcache device will occupy 16 bits, this is not a good idea. Indeed only one bit is enough. - Because minor number and bcache device index are mixed, a device index is allocated by ida_simple_get(), but an first minor number is sent into ida_simple_remove() to release the device. It confused original author too. Root cause of the above errors is, bcache code should not handle device minor numbers at all! A standard process to support multiple partitions in Linux kernel is, - Device driver provides major device number, and indexes multiple device instances. - Device driver does not allocat nor trace device minor number, only provides a first minor number of a given device instance, and sets how many minor numbers (paritions) the device instance may have. All rested stuffs are handled by block layer code, most of the details can be found from block/{genhd, partition-generic}.c files. This patch re-writes multiple partitions support for bcache. It makes whole things to be more clear, and uses ida bit string in a more efficeint way. - Ida bit string only traces bcache device index, not minor number. For a bcache device with 128 partitions, only one bit in ida bit string is enough. - Device minor number and device index are separated in concept. Device index is used for /dev node naming, and ida bit string trace. Minor number is calculated from device index and only used to initialize first_minor of a bcache device. - It does not follow any standard for 16 partitions on a bcache device. This patch sets 128 partitions on single bcache device at max, this is the limitation from GPT (GUID Partition Table) and supported by fdisk. Considering a typical device minor number is 20 bits width, each bcache device may have 128 partitions (7 bits), there can be 8192 bcache devices existing on system. For most common deployment for a single server in now days, it should be enough. [minor spelling fixes in commit message by Michael Lyle] Signed-off-by: Coly Li <colyli@suse.de> Cc: Eric Wheeler <bcache@lists.ewheeler.net> Cc: Junhui Tang <tang.junhui@zte.com.cn> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-16bcache: fix a comments typo in bch_alloc_sectors()Coly Li1-1/+1
Code comments in alloc.c:bch_alloc_sectors() mentions a function name find_data_bucket(), the correct function name should be pick_data_bucket() indeed. bch_alloc_sectors() is a quite important function in bcache allocation code, fixing the typo may help other people to have less confusion. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Tang Junhui <tang.junhui@zte.com.cn> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-16bcache: check ca->alloc_thread initialized before wake up itColy Li1-1/+2
In bcache code, sysfs entries are created before all resources get allocated, e.g. allocation thread of a cache set. There is posibility for NULL pointer deference if a resource is accessed but which is not initialized yet. Indeed Jorg Bornschein catches one on cache set allocation thread and gets a kernel oops. The reason for this bug is, when bch_bucket_alloc() is called during cache set registration and attaching, ca->alloc_thread is not properly allocated and initialized yet, call wake_up_process() on ca->alloc_thread triggers NULL pointer deference failure. A simple and fast fix is, before waking up ca->alloc_thread, checking whether it is allocated, and only wake up ca->alloc_thread when it is not NULL. Signed-off-by: Coly Li <colyli@suse.de> Reported-by: Jorg Bornschein <jb@capsec.org> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: stable@vger.kernel.org Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-16bcache: Avoid nested function definitionPeter Foley1-4/+6
Fixes below error with clang: ../drivers/md/bcache/sysfs.c:759:3: error: function definition is not allowed here { return *((uint16_t *) r) - *((uint16_t *) l); } ^ ../drivers/md/bcache/sysfs.c:789:32: error: use of undeclared identifier 'cmp' sort(p, n, sizeof(uint16_t), cmp, NULL); ^ 2 errors generated. v2: rename function to __bch_cache_cmp Signed-off-by: Peter Foley <pefoley2@pefoley.com> Reviewed-by: Coly Li <colyli@suse.de> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-16nvme: simplify compat_ioctl handlingChristoph Hellwig1-11/+1
We can just use our normal ioctl handler for the compat case and remove the boilerplate code for it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
2017-10-14mm/page-writeback.c: make changes of dirty_writeback_centisecs take effect ↵Yafang Shao1-1/+10
immediately This patch is the followup of the prvious patch: [writeback: schedule periodic writeback with sysctl]. There's another issue to fix. For example, - When the tunable was set to one hour and is reset to one second, the new setting will not take effect for up to one hour. Kicking the flusher threads immediately fixes it. Cc: Jens Axboe <axboe@kernel.dk> Cc: Jan Kara <jack@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-13null_blk: add usage hints for no_schedweiping zhang1-0/+4
This parameter provide an option to disable io scheduler when nullb* in multi-queue mode. Signed-off-by: weiping zhang <zhangweiping@didichuxing.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-13null_blk: update usage hints for submit_queuesweiping zhang1-3/+3
update the range of submits_queues, and correct usage hints. Signed-off-by: weiping zhang <zhangweiping@didichuxing.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>