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path: root/drivers/md/bcache/request.c
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2021-01-25block: use ->bi_bdev for bio based I/O accountingChristoph Hellwig1-13/+21
Rework the I/O accounting for bio based drivers to use ->bi_bdev. This means all drivers can now simply use bio_start_io_acct to start accounting, and it will take partitions into account automatically. To end I/O account either bio_end_io_acct can be used if the driver never remaps I/O to a different device, or bio_end_io_acct_remapped if the driver did remap the I/O. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-01-25block: store a block_device pointer in struct bioChristoph Hellwig1-3/+4
Replace the gendisk pointer in struct bio with a pointer to the newly improved struct block device. From that the gendisk can be trivially accessed with an extra indirection, but it also allows to directly look up all information related to partition remapping. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-02block: switch partition lookup to use struct block_deviceChristoph Hellwig1-2/+2
Use struct block_device to lookup partitions on a disk. This removes all usage of struct hd_struct from the I/O path. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Hannes Reinecke <hare@suse.de> Acked-by: Coly Li <colyli@suse.de> [bcache] Acked-by: Chao Yu <yuchao0@huawei.com> [f2fs] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-16block: remove __blkdev_driver_ioctlChristoph Hellwig1-2/+3
Just open code it in the few callers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-02bcache: remove embedded struct cache_sb from struct cache_setColy Li1-2/+2
Since bcache code was merged into mainline kerrnel, each cache set only as one single cache in it. The multiple caches framework is here but the code is far from completed. Considering the multiple copies of cached data can also be stored on e.g. md raid1 devices, it is unnecessary to support multiple caches in one cache set indeed. The previous preparation patches fix the dependencies of explicitly making a cache set only have single cache. Now we don't have to maintain an embedded partial super block in struct cache_set, the in-memory super block can be directly referenced from struct cache. This patch removes the embedded struct cache_sb from struct cache_set, and fixes all locations where the superb lock was referenced from this removed super block by referencing the in-memory super block of struct cache. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-02bcache: only use block_bytes() on struct cacheColy Li1-1/+1
Because struct cache_set and struct cache both have struct cache_sb, therefore macro block_bytes() can be used on both of them. When removing the embedded struct cache_sb from struct cache_set, this macro won't be used on struct cache_set anymore. This patch unifies all block_bytes() usage only on struct cache, this is one of the preparation to remove the embedded struct cache_sb from struct cache_set. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-12bcache: use part_[begin|end]_io_acct instead of disk_[begin|end]_io_acctSong Liu1-4/+6
This enables proper statistics in /proc/diskstats for bcache partitions. Signed-off-by: Song Liu <songliubraving@fb.com> Reviewed-by: Coly Li <colyli@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-05Merge tag 'for-5.9/drivers-20200803' of git://git.kernel.dk/linux-blockLinus Torvalds1-5/+9
Pull block driver updates from Jens Axboe: - NVMe: - ZNS support (Aravind, Keith, Matias, Niklas) - Misc cleanups, optimizations, fixes (Baolin, Chaitanya, David, Dongli, Max, Sagi) - null_blk zone capacity support (Aravind) - MD: - raid5/6 fixes (ChangSyun) - Warning fixes (Damien) - raid5 stripe fixes (Guoqing, Song, Yufen) - sysfs deadlock fix (Junxiao) - raid10 deadlock fix (Vitaly) - struct_size conversions (Gustavo) - Set of bcache updates/fixes (Coly) * tag 'for-5.9/drivers-20200803' of git://git.kernel.dk/linux-block: (117 commits) md/raid5: Allow degraded raid6 to do rmw md/raid5: Fix Force reconstruct-write io stuck in degraded raid5 raid5: don't duplicate code for different paths in handle_stripe raid5-cache: hold spinlock instead of mutex in r5c_journal_mode_show md: print errno in super_written md/raid5: remove the redundant setting of STRIPE_HANDLE md: register new md sysfs file 'uuid' read-only md: fix max sectors calculation for super 1.0 nvme-loop: remove extra variable in create ctrl nvme-loop: set ctrl state connecting after init nvme-multipath: do not fall back to __nvme_find_path() for non-optimized paths nvme-multipath: fix logic for non-optimized paths nvme-rdma: fix controller reset hang during traffic nvme-tcp: fix controller reset hang during traffic nvmet: introduce the passthru Kconfig option nvmet: introduce the passthru configfs interface nvmet: Add passthru enable/disable helpers nvmet: add passthru code to process commands nvme: export nvme_find_get_ns() and nvme_put_ns() nvme: introduce nvme_ctrl_get_by_path() ...
2020-07-28bcache: use disk_{start,end}_io_acct() to count I/O for bcache deviceColy Li1-28/+9
This patch is a fix to patch "bcache: fix bio_{start,end}_io_acct with proper device". The previous patch uses a hack to temporarily set bi_disk to bcache device, which is mistaken too. As Christoph suggests, this patch uses disk_{start,end}_io_acct() to count I/O for bcache device in the correct way. Fixes: 85750aeb748f ("bcache: use bio_{start,end}_io_acct") Signed-off-by: Coly Li <colyli@suse.de> Cc: Christoph Hellwig <hch@lst.de> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-25bcache: fix bio_{start,end}_io_acct with proper deviceColy Li1-4/+27
Commit 85750aeb748f ("bcache: use bio_{start,end}_io_acct") moves the io account code to the location after bio_set_dev(bio, dc->bdev) in cached_dev_make_request(). Then the account is performed incorrectly on backing device, indeed the I/O should be counted to bcache device like /dev/bcache0. With the mistaken I/O account, iostat does not display I/O counts for bcache device and all the numbers go to backing device. In writeback mode, the hard drive may have 340K+ IOPS which is impossible and wrong for spinning disk. This patch introduces bch_bio_start_io_acct() and bch_bio_end_io_acct(), which switches bio->bi_disk to bcache device before calling bio_start_io_acct() or bio_end_io_acct(). Now the I/Os are counted to bcache device, and bcache device, cache device and backing device have their correct I/O count information back. Fixes: 85750aeb748f ("bcache: use bio_{start,end}_io_acct") Signed-off-by: Coly Li <colyli@suse.de> Cc: Christoph Hellwig <hch@lst.de> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-09writeback: remove bdi->congested_fnChristoph Hellwig1-47/+0
Except for pktdvd, the only places setting congested bits are file systems that allocate their own backing_dev_info structures. And pktdvd is a deprecated driver that isn't useful in stack setup either. So remove the dead congested_fn stacking infrastructure. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Song Liu <song@kernel.org> Acked-by: David Sterba <dsterba@suse.com> [axboe: fixup unused variables in bcache/request.c] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-01block: rename generic_make_request to submit_bio_noacctChristoph Hellwig1-4/+3
generic_make_request has always been very confusingly misnamed, so rename it to submit_bio_noacct to make it clear that it is submit_bio minus accounting and a few checks. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-01block: move ->make_request_fn to struct block_device_operationsChristoph Hellwig1-2/+2
The make_request_fn is a little weird in that it sits directly in struct request_queue instead of an operation vector. Replace it with a block_device_operations method called submit_bio (which describes much better what it does). Also remove the request_queue argument to it, as the queue can be derived pretty trivially from the bio. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-03Merge tag 'for-5.8/drivers-2020-06-01' of git://git.kernel.dk/linux-blockLinus Torvalds1-3/+3
Pull block driver updates from Jens Axboe: "On top of the core changes, here are the block driver changes for this merge window: - NVMe changes: - NVMe over Fibre Channel protocol updates, which also reach over to drivers/scsi/lpfc (James Smart) - namespace revalidation support on the target (Anthony Iliopoulos) - gcc zero length array fix (Arnd Bergmann) - nvmet cleanups (Chaitanya Kulkarni) - misc cleanups and fixes (me, Keith Busch, Sagi Grimberg) - use a SRQ per completion vector (Max Gurtovoy) - fix handling of runtime changes to the queue count (Weiping Zhang) - t10 protection information support for nvme-rdma and nvmet-rdma (Israel Rukshin and Max Gurtovoy) - target side AEN improvements (Chaitanya Kulkarni) - various fixes and minor improvements all over, icluding the nvme part of the lpfc driver" - Floppy code cleanup series (Willy, Denis) - Floppy contention fix (Jiri) - Loop CONFIGURE support (Martijn) - bcache fixes/improvements (Coly, Joe, Colin) - q->queuedata cleanups (Christoph) - Get rid of ioctl_by_bdev (Christoph, Stefan) - md/raid5 allocation fixes (Coly) - zero length array fixes (Gustavo) - swim3 task state fix (Xu)" * tag 'for-5.8/drivers-2020-06-01' of git://git.kernel.dk/linux-block: (166 commits) bcache: configure the asynchronous registertion to be experimental bcache: asynchronous devices registration bcache: fix refcount underflow in bcache_device_free() bcache: Convert pr_<level> uses to a more typical style bcache: remove redundant variables i and n lpfc: Fix return value in __lpfc_nvme_ls_abort lpfc: fix axchg pointer reference after free and double frees lpfc: Fix pointer checks and comments in LS receive refactoring nvme: set dma alignment to qword nvmet: cleanups the loop in nvmet_async_events_process nvmet: fix memory leak when removing namespaces and controllers concurrently nvmet-rdma: add metadata/T10-PI support nvmet: add metadata support for block devices nvmet: add metadata/T10-PI support nvme: add Metadata Capabilities enumerations nvmet: rename nvmet_check_data_len to nvmet_check_transfer_len nvmet: rename nvmet_rw_len to nvmet_rw_data_len nvmet: add metadata characteristics for a namespace nvme-rdma: add metadata/T10-PI support nvme-rdma: introduce nvme_rdma_sgl structure ...
2020-05-27bcache: use bio_{start,end}_io_acctChristoph Hellwig1-14/+4
Switch bcache to use the nicer bio accounting helpers, and call the routines where we also sample the start time to give coherent accounting results. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27bcache: Convert pr_<level> uses to a more typical styleJoe Perches1-3/+3
Remove the trailing newline from the define of pr_fmt and add newlines to the uses. Miscellanea: o Convert bch_bkey_dump from multiple uses of pr_err to pr_cont as the earlier conversion was inappropriate done causing multiple lines to be emitted where only a single output line was desired o Use vsprintf extension %pV in bch_cache_set_error to avoid multiple line output where only a single line output was desired o Coalesce formats Fixes: 6ae63e3501c4 ("bcache: replace printk() by pr_*() routines") Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-25bcache: remove a duplicate ->make_request_fn assignmentChristoph Hellwig1-1/+0
The make_request_fn pointer should only be assigned by blk_alloc_queue. Fix a left over manual initialization. Fixes: ff27668ce809 ("bcache: pass the make_request methods to blk_queue_make_request") Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-27bcache: pass the make_request methods to blk_queue_make_requestChristoph Hellwig1-5/+2
bcache is the only driver not actually passing its make_request methods to blk_queue_make_request, but instead just sets them up manually a little later. Make bcache follow the common way of setting up make_request based queues. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-02-01bcache: add readahead cache policy options via sysfs interfaceColy Li1-5/+12
In year 2007 high performance SSD was still expensive, in order to save more space for real workload or meta data, the readahead I/Os for non-meta data was bypassed and not cached on SSD. In now days, SSD price drops a lot and people can find larger size SSD with more comfortable price. It is unncessary to alway bypass normal readahead I/Os to save SSD space for now. This patch adds options for readahead data cache policies via sysfs file /sys/block/bcache<N>/readahead_cache_policy, the options are, - "all": cache all readahead data I/Os. - "meta-only": only cache meta data, and bypass other regular I/Os. If users want to make bcache continue to only cache readahead request for metadata and bypass regular data readahead, please set "meta-only" to this sysfs file. By default, bcache will back to cache all read- ahead requests now. Cc: stable@vger.kernel.org Signed-off-by: Coly Li <colyli@suse.de> Acked-by: Eric Wheeler <bcache@linux.ewheeler.net> Cc: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-14bcache: deleted code comments for dead code in bch_data_insert_keys()Coly Li1-12/+0
In request.c:bch_data_insert_keys(), there is code comment for a piece of dead code. This patch deletes the dead code and its code comment since they are useless in practice. Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-24bcache: Clean up bch_get_congested()George Spelvin1-7/+8
There are a few nits in this function. They could in theory all be separate patches, but that's probably taking small commits too far. 1) I added a brief comment saying what it does. 2) I like to declare pointer parameters "const" where possible for documentation reasons. 3) It uses bitmap_weight(&rand, BITS_PER_LONG) to compute the Hamming weight of a 32-bit random number (giving a random integer with mean 16 and variance 8). Passing by reference in a 64-bit variable is silly; just use hweight32(). 4) Its helper function fract_exp_two is unnecessarily tangled. Gcc can optimize the multiply by (1 << x) to a shift, but it can be written in a much more straightforward way at the cost of one more bit of internal precision. Some analysis reveals that this bit is always available. This shrinks the object code for fract_exp_two(x, 6) from 23 bytes: 0000000000000000 <foo1>: 0: 89 f9 mov %edi,%ecx 2: c1 e9 06 shr $0x6,%ecx 5: b8 01 00 00 00 mov $0x1,%eax a: d3 e0 shl %cl,%eax c: 83 e7 3f and $0x3f,%edi f: d3 e7 shl %cl,%edi 11: c1 ef 06 shr $0x6,%edi 14: 01 f8 add %edi,%eax 16: c3 retq To 19: 0000000000000017 <foo2>: 17: 89 f8 mov %edi,%eax 19: 83 e0 3f and $0x3f,%eax 1c: 83 c0 40 add $0x40,%eax 1f: 89 f9 mov %edi,%ecx 21: c1 e9 06 shr $0x6,%ecx 24: d3 e0 shl %cl,%eax 26: c1 e8 06 shr $0x6,%eax 29: c3 retq (Verified with 0 <= frac_bits <= 8, 0 <= x < 16<<frac_bits; both versions produce the same output.) 5) And finally, the call to bch_get_congested() in check_should_bypass() is separated from the use of the value by multiple tests which could moot the need to compute it. Move the computation down to where it's needed. This also saves a local register to hold the computed value. Signed-off-by: George Spelvin <lkml@sdf.org> Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-24bcache: fix crashes stopping bcache device before read miss doneGuoju Fang1-5/+21
The bio from upper layer is considered completed when bio_complete() returns. In most scenarios bio_complete() is called in search_free(), but when read miss happens, the bio_compete() is called when backing device reading completed, while the struct search is still in use until cache inserting finished. If someone stops the bcache device just then, the device may be closed and released, but after cache inserting finished the struct search will access a freed struct cached_dev. This patch add the reference of bcache device before bio_complete() when read miss happens, and put it after the search is not used. Signed-off-by: Guoju Fang <fangguoju@gmail.com> Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-09bcache: use (REQ_META|REQ_PRIO) to indicate bio for metadataColy Li1-3/+4
In 'commit 752f66a75aba ("bcache: use REQ_PRIO to indicate bio for metadata")' REQ_META is replaced by REQ_PRIO to indicate metadata bio. This assumption is not always correct, e.g. XFS uses REQ_META to mark metadata bio other than REQ_PRIO. This is why Nix noticed that bcache does not cache metadata for XFS after the above commit. Thanks to Dave Chinner, he explains the difference between REQ_META and REQ_PRIO from view of file system developer. Here I quote part of his explanation from mailing list, REQ_META is used for metadata. REQ_PRIO is used to communicate to the lower layers that the submitter considers this IO to be more important that non REQ_PRIO IO and so dispatch should be expedited. IOWs, if the filesystem considers metadata IO to be more important that user data IO, then it will use REQ_PRIO | REQ_META rather than just REQ_META. Then it seems bios with REQ_META or REQ_PRIO should both be cached for performance optimation, because they are all probably low I/O latency demand by upper layer (e.g. file system). So in this patch, when we want to decide whether to bypass the cache, REQ_META and REQ_PRIO are both checked. Then both metadata and high priority I/O requests will be handled properly. Reported-by: Nix <nix@esperi.org.uk> Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Andre Noll <maan@tuebingen.mpg.de> Tested-by: Nix <nix@esperi.org.uk> Cc: stable@vger.kernel.org Cc: Dave Chinner <david@fromorbit.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-13bcache: update comment for bch_data_insertShenghui Wang1-3/+3
commit 220bb38c21b8 ("bcache: Break up struct search") introduced changes to struct search and s->iop. bypass/bio are fields of struct data_insert_op now. Update the comment. Signed-off-by: Shenghui Wang <shhuiw@foxmail.com> Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-08bcache: fix ioctl in flash deviceTang Junhui1-0/+3
When doing ioctl in flash device, it will call ioctl_dev() in super.c, then we should not to get cached device since flash only device has no backend device. This patch just move the jugement dc->io_disable to cached_dev_ioctl() to make ioctl in flash device correctly. Fixes: 0f0709e6bfc3c ("bcache: stop bcache device when backing device is offline") Signed-off-by: Tang Junhui <tang.junhui.linux@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-08bcache: use REQ_PRIO to indicate bio for metadataColy Li1-2/+2
In cached_dev_cache_miss() and check_should_bypass(), REQ_META is used to check whether a bio is for metadata request. REQ_META is used for blktrace, the correct REQ_ flag should be REQ_PRIO. This flag means the bio should be prior to other bio, and frequently be used to indicate metadata io in file system code. This patch replaces REQ_META with correct flag REQ_PRIO. CC Adam Manzanares because he explains to me what REQ_PRIO is for. Signed-off-by: Coly Li <colyli@suse.de> Cc: Adam Manzanares <adam.manzanares@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-08bcache: trace missed reading by cache_missedTang Junhui1-1/+1
Missed reading IOs are identified by s->cache_missed, not the s->cache_miss, so in trace_bcache_read() using trace_bcache_read to identify whether the IO is missed or not. Signed-off-by: Tang Junhui <tang.junhui.linux@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-08-12bcache: do not check NULL pointer before calling kmem_cache_destroyColy Li1-2/+1
kmem_cache_destroy() is safe for NULL pointer as input, the NULL pointer checking is unncessary. This patch just removes the NULL pointer checking to make code simpler. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Shenghui Wang <shhuiw@foxmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-08-12bcache: fix typo 'succesfully' to 'successfully'Coly Li1-1/+1
This patch fixes typo 'succesfully' to correct 'successfully', which is suggested by checkpatch.pl. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Shenghui Wang <shhuiw@foxmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-08-12bcache: style fixes for lines over 80 charactersColy Li1-2/+5
This patch fixes the lines over 80 characters into more lines, to minimize warnings by checkpatch.pl. There are still some lines exceed 80 characters, but it is better to be a single line and I don't change them. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Shenghui Wang <shhuiw@foxmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-08-12bcache: add identifier names to arguments of function definitionsColy Li1-1/+1
There are many function definitions do not have identifier argument names, scripts/checkpatch.pl complains warnings like this, WARNING: function definition argument 'struct bcache_device *' should also have an identifier name #16735: FILE: writeback.h:120: +void bch_sectors_dirty_init(struct bcache_device *); This patch adds identifier argument names to all bcache function definitions to fix such warnings. Signed-off-by: Coly Li <colyli@suse.de> Reviewed: Shenghui Wang <shhuiw@foxmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-08-12bcache: style fix to add a blank line after declarationsColy Li1-1/+4
Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Shenghui Wang <shhuiw@foxmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-08-12bcache: style fix to replace 'unsigned' by 'unsigned int'Coly Li1-21/+21
This patch fixes warning reported by checkpatch.pl by replacing 'unsigned' with 'unsigned int'. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Shenghui Wang <shhuiw@foxmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-08-09bcache: set max writeback rate when I/O request is idleColy Li1-2/+57
Commit b1092c9af9ed ("bcache: allow quick writeback when backing idle") allows the writeback rate to be faster if there is no I/O request on a bcache device. It works well if there is only one bcache device attached to the cache set. If there are many bcache devices attached to a cache set, it may introduce performance regression because multiple faster writeback threads of the idle bcache devices will compete the btree level locks with the bcache device who have I/O requests coming. This patch fixes the above issue by only permitting fast writebac when all bcache devices attached on the cache set are idle. And if one of the bcache devices has new I/O request coming, minimized all writeback throughput immediately and let PI controller __update_writeback_rate() to decide the upcoming writeback rate for each bcache device. Also when all bcache devices are idle, limited wrieback rate to a small number is wast of thoughput, especially when backing devices are slower non-rotation devices (e.g. SATA SSD). This patch sets a max writeback rate for each backing device if the whole cache set is idle. A faster writeback rate in idle time means new I/Os may have more available space for dirty data, and people may observe a better write performance then. Please note bcache may change its cache mode in run time, and this patch still works if the cache mode is switched from writeback mode and there is still dirty data on cache. Fixes: Commit b1092c9af9ed ("bcache: allow quick writeback when backing idle") Cc: stable@vger.kernel.org #4.16+ Signed-off-by: Coly Li <colyli@suse.de> Tested-by: Kai Krakow <kai@kaishome.de> Tested-by: Stefan Priebe <s.priebe@profihost.ag> Cc: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-08-09bcache: fix mistaken comments in request.cColy Li1-1/+1
This patch updates code comment in bch_keylist_realloc() by fixing incorrected function names, to make the code to be more comprehennsible. Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-27bcache: finish incremental GCTang Junhui1-0/+3
In GC thread, we record the latest GC key in gc_done, which is expected to be used for incremental GC, but in currently code, we didn't realize it. When GC runs, front side IO would be blocked until the GC over, it would be a long time if there is a lot of btree nodes. This patch realizes incremental GC, the main ideal is that, when there are front side I/Os, after GC some nodes (100), we stop GC, release locker of the btree node, and go to process the front side I/Os for some times (100 ms), then go back to GC again. By this patch, when we doing GC, I/Os are not blocked all the time, and there is no obvious I/Os zero jump problem any more. Patch v2: Rename some variables and macros name as Coly suggested. Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn> Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-18block: Add and use op_stat_group() for indexing disk_stat fields.Michael Callahan1-8/+5
Add and use a new op_stat_group() function for indexing partition stat fields rather than indexing them by rq_data_dir() or bio_data_dir(). This function works similarly to op_is_sync() in that it takes the request::cmd_flags or bio::bi_opf flags and determines which stats should et updated. In addition, the second parameter to generic_start_io_acct() and generic_end_io_acct() is now a REQ_OP rather than simply a read or write bit and it uses op_stat_group() on the parameter to determine the stat group. Note that the partition in_flight counts are not part of the per-cpu statistics and as such are not indexed via this function. It's now indexed by op_is_write(). tj: Refreshed on top of v4.17. Updated to pass around REQ_OP. Signed-off-by: Michael Callahan <michaelcallahan@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Joshua Morris <josh.h.morris@us.ibm.com> Cc: Philipp Reisner <philipp.reisner@linbit.com> Cc: Matias Bjorling <mb@lightnvm.io> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Alasdair Kergon <agk@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-05-31bcache: convert to bioset_init()/mempool_init()Kent Overstreet1-9/+9
Convert bcache to embedded bio sets. Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-05-03bcache: store disk name in struct cache and struct cached_devColy Li1-4/+1
Current code uses bdevname() or bio_devname() to reference gendisk disk name when bcache needs to display the disk names in kernel message. It was safe before bcache device failure handling patch set merged in, because when devices are failed, there was deadlock to prevent bcache printing error messages with gendisk disk name. But after the failure handling patch set merged, the deadlock is fixed, so it is possible that the gendisk structure bdev->hd_disk is released when bdevname() is called to reference bdev->bd_disk->disk_name[]. This is why I receive bug report of NULL pointers deference panic. This patch stores gendisk disk name in a buffer inside struct cache and struct cached_dev, then print out the offline device name won't reference bdev->hd_disk anymore. And this patch also avoids extra function calls of bdevname() and bio_devnmae(). Changelog: v3, add Reviewed-by from Hannes. v2, call bdevname() earlier in register_bdev() v1, first version with segguestion from Junhui Tang. Fixes: c7b7bd07404c5 ("bcache: add io_disable to struct cached_dev") Fixes: 5138ac6748e38 ("bcache: fix misleading error message in bch_count_io_errors()") Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-03-19bcache: Fix kernel-doc warningsBart Van Assche1-0/+1
Avoid that building with W=1 triggers warnings about the kernel-doc headers. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-03-19bcache: add io_disable to struct cached_devColy Li1-2/+12
If a bcache device is configured to writeback mode, current code does not handle write I/O errors on backing devices properly. In writeback mode, write request is written to cache device, and latter being flushed to backing device. If I/O failed when writing from cache device to the backing device, bcache code just ignores the error and upper layer code is NOT noticed that the backing device is broken. This patch tries to handle backing device failure like how the cache device failure is handled, - Add a error counter 'io_errors' and error limit 'error_limit' in struct cached_dev. Add another io_disable to struct cached_dev to disable I/Os on the problematic backing device. - When I/O error happens on backing device, increase io_errors counter. And if io_errors reaches error_limit, set cache_dev->io_disable to true, and stop the bcache device. The result is, if backing device is broken of disconnected, and I/O errors reach its error limit, backing device will be disabled and the associated bcache device will be removed from system. Changelog: v2: remove "bcache: " prefix in pr_error(), and use correct name string to print out bcache device gendisk name. v1: indeed this is new added in v2 patch set. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Cc: Michael Lyle <mlyle@lyle.org> Cc: Junhui Tang <tang.junhui@zte.com.cn> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-03-19bcache: add backing_request_endio() for bi_end_ioColy Li1-16/+77
In order to catch I/O error of backing device, a separate bi_end_io call back is required. Then a per backing device counter can record I/O errors number and retire the backing device if the counter reaches a per backing device I/O error limit. This patch adds backing_request_endio() to bcache backing device I/O code path, this is a preparation for further complicated backing device failure handling. So far there is no real code logic change, I make this change a separate patch to make sure it is stable and reliable for further work. Changelog: v2: Fix code comments typo, remove a redundant bch_writeback_add() line added in v4 patch set. v1: indeed this is new added in this patch set. [mlyle: truncated commit subject] Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Cc: Junhui Tang <tang.junhui@zte.com.cn> Cc: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-03-19bcache: fix inaccurate io state for detached bcache devicesTang Junhui1-7/+51
When we run IO in a detached device, and run iostat to shows IO status, normally it will show like bellow (Omitted some fields): Device: ... avgrq-sz avgqu-sz await r_await w_await svctm %util sdd ... 15.89 0.53 1.82 0.20 2.23 1.81 52.30 bcache0 ... 15.89 115.42 0.00 0.00 0.00 2.40 69.60 but after IO stopped, there are still very big avgqu-sz and %util values as bellow: Device: ... avgrq-sz avgqu-sz await r_await w_await svctm %util bcache0 ... 0 5326.32 0.00 0.00 0.00 0.00 100.10 The reason for this issue is that, only generic_start_io_acct() called and no generic_end_io_acct() called for detached device in cached_dev_make_request(). See the code: //start generic_start_io_acct() generic_start_io_acct(q, rw, bio_sectors(bio), &d->disk->part0); if (cached_dev_get(dc)) { //will callback generic_end_io_acct() } else { //will not call generic_end_io_acct() } This patch calls generic_end_io_acct() in the end of IO for detached devices, so we can show IO state correctly. (Modified to use GFP_NOIO in kzalloc() by Coly Li) Changelog: v2: fix typo. v1: the initial version. Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn> Reviewed-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-03-19bcache: add CACHE_SET_IO_DISABLE to struct cache_set flagsColy Li1-7/+19
When too many I/Os failed on cache device, bch_cache_set_error() is called in the error handling code path to retire whole problematic cache set. If new I/O requests continue to come and take refcount dc->count, the cache set won't be retired immediately, this is a problem. Further more, there are several kernel thread and self-armed kernel work may still running after bch_cache_set_error() is called. It needs to wait quite a while for them to stop, or they won't stop at all. They also prevent the cache set from being retired. The solution in this patch is, to add per cache set flag to disable I/O request on this cache and all attached backing devices. Then new coming I/O requests can be rejected in *_make_request() before taking refcount, kernel threads and self-armed kernel worker can stop very fast when flags bit CACHE_SET_IO_DISABLE is set. Because bcache also do internal I/Os for writeback, garbage collection, bucket allocation, journaling, this kind of I/O should be disabled after bch_cache_set_error() is called. So closure_bio_submit() is modified to check whether CACHE_SET_IO_DISABLE is set on cache_set->flags. If set, closure_bio_submit() will set bio->bi_status to BLK_STS_IOERR and return, generic_make_request() won't be called. A sysfs interface is also added to set or clear CACHE_SET_IO_DISABLE bit from cache_set->flags, to disable or enable cache set I/O for debugging. It is helpful to trigger more corner case issues for failed cache device. Changelog v4, add wait_for_kthread_stop(), and call it before exits writeback and gc kernel threads. v3, change CACHE_SET_IO_DISABLE from 4 to 3, since it is bit index. remove "bcache: " prefix when printing out kernel message. v2, more changes by previous review, - Use CACHE_SET_IO_DISABLE of cache_set->flags, suggested by Junhui. - Check CACHE_SET_IO_DISABLE in bch_btree_gc() to stop a while-loop, this is reported and inspired from origal patch of Pavel Vazharov. v1, initial version. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Cc: Junhui Tang <tang.junhui@zte.com.cn> Cc: Michael Lyle <mlyle@lyle.org> Cc: Pavel Vazharov <freakpv@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-02-27bcache: fix kcrashes with fio in RAID5 backend devTang Junhui1-1/+1
Kernel crashed when run fio in a RAID5 backend bcache device, the call trace is bellow: [ 440.012034] kernel BUG at block/blk-ioc.c:146! [ 440.012696] invalid opcode: 0000 [#1] SMP NOPTI [ 440.026537] CPU: 2 PID: 2205 Comm: md127_raid5 Not tainted 4.15.0 #8 [ 440.027441] Hardware name: HP ProLiant MicroServer Gen8, BIOS J06 07/16 /2015 [ 440.028615] RIP: 0010:put_io_context+0x8b/0x90 [ 440.029246] RSP: 0018:ffffa8c882b43af8 EFLAGS: 00010246 [ 440.029990] RAX: 0000000000000000 RBX: ffffa8c88294fca0 RCX: 0000000000 0f4240 [ 440.031006] RDX: 0000000000000004 RSI: 0000000000000286 RDI: ffffa8c882 94fca0 [ 440.032030] RBP: ffffa8c882b43b10 R08: 0000000000000003 R09: ffff949cb8 0c1700 [ 440.033206] R10: 0000000000000104 R11: 000000000000b71c R12: 00000000000 01000 [ 440.034222] R13: 0000000000000000 R14: ffff949cad84db70 R15: ffff949cb11 bd1e0 [ 440.035239] FS: 0000000000000000(0000) GS:ffff949cba280000(0000) knlGS: 0000000000000000 [ 440.060190] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 440.084967] CR2: 00007ff0493ef000 CR3: 00000002f1e0a002 CR4: 00000000001 606e0 [ 440.110498] Call Trace: [ 440.135443] bio_disassociate_task+0x1b/0x60 [ 440.160355] bio_free+0x1b/0x60 [ 440.184666] bio_put+0x23/0x30 [ 440.208272] search_free+0x23/0x40 [bcache] [ 440.231448] cached_dev_write_complete+0x31/0x70 [bcache] [ 440.254468] closure_put+0xb6/0xd0 [bcache] [ 440.277087] request_endio+0x30/0x40 [bcache] [ 440.298703] bio_endio+0xa1/0x120 [ 440.319644] handle_stripe+0x418/0x2270 [raid456] [ 440.340614] ? load_balance+0x17b/0x9c0 [ 440.360506] handle_active_stripes.isra.58+0x387/0x5a0 [raid456] [ 440.380675] ? __release_stripe+0x15/0x20 [raid456] [ 440.400132] raid5d+0x3ed/0x5d0 [raid456] [ 440.419193] ? schedule+0x36/0x80 [ 440.437932] ? schedule_timeout+0x1d2/0x2f0 [ 440.456136] md_thread+0x122/0x150 [ 440.473687] ? wait_woken+0x80/0x80 [ 440.491411] kthread+0x102/0x140 [ 440.508636] ? find_pers+0x70/0x70 [ 440.524927] ? kthread_associate_blkcg+0xa0/0xa0 [ 440.541791] ret_from_fork+0x35/0x40 [ 440.558020] Code: c2 48 00 5b 41 5c 41 5d 5d c3 48 89 c6 4c 89 e7 e8 bb c2 48 00 48 8b 3d bc 36 4b 01 48 89 de e8 7c f7 e0 ff 5b 41 5c 41 5d 5d c3 <0f> 0b 0f 1f 00 0f 1f 44 00 00 55 48 8d 47 b8 48 89 e5 41 57 41 [ 440.610020] RIP: put_io_context+0x8b/0x90 RSP: ffffa8c882b43af8 [ 440.628575] ---[ end trace a1fd79d85643a73e ]-- All the crash issue happened when a bypass IO coming, in such scenario s->iop.bio is pointed to the s->orig_bio. In search_free(), it finishes the s->orig_bio by calling bio_complete(), and after that, s->iop.bio became invalid, then kernel would crash when calling bio_put(). Maybe its upper layer's faulty, since bio should not be freed before we calling bio_put(), but we'd better calling bio_put() first before calling bio_complete() to notify upper layer ending this bio. This patch moves bio_complete() under bio_put() to avoid kernel crash. [mlyle: fixed commit subject for character limits] Reported-by: Matthias Ferdinand <bcache@mfedv.net> Tested-by: Matthias Ferdinand <bcache@mfedv.net> Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-08bcache: fix unmatched generic_end_io_acct() & generic_start_io_acct()Zhai Zhaoxuan1-2/+2
The function cached_dev_make_request() and flash_dev_make_request() call generic_start_io_acct() with (struct bcache_device)->disk when they start a closure. Then the function bio_complete() calls generic_end_io_acct() with (struct search)->orig_bio->bi_disk when the closure has done. Since the `bi_disk` is not the bcache device, the generic_end_io_acct() is called with a wrong device queue. It causes the "inflight" (in struct hd_struct) counter keep increasing without decreasing. This patch fix the problem by calling generic_end_io_acct() with (struct bcache_device)->disk. Signed-off-by: Zhai Zhaoxuan <kxuanobj@gmail.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Reviewed-by: Coly Li <colyli@suse.de> Reviewed-by: Tang Junhui <tang.junhui@zte.com.cn> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-08bcache: allow quick writeback when backing idleMichael Lyle1-0/+1
If the control system would wait for at least half a second, and there's been no reqs hitting the backing disk for awhile: use an alternate mode where we have at most one contiguous set of writebacks in flight at a time. (But don't otherwise delay). If front-end IO appears, it will still be quick, as it will only have to contend with one real operation in flight. But otherwise, we'll be sending data to the backing disk as quickly as it can accept it (with one op at a time). Signed-off-by: Michael Lyle <mlyle@lyle.org> Reviewed-by: Tang Junhui <tang.junhui@zte.com.cn> Acked-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-08bcache: ret IOERR when read meets metadata errorRui Hua1-0/+22
The read request might meet error when searching the btree, but the error was not handled in cache_lookup(), and this kind of metadata failure will not go into cached_dev_read_error(), finally, the upper layer will receive bi_status=0. In this patch we judge the metadata error by the return value of bch_btree_map_keys(), there are two potential paths give rise to the error: 1. Because the btree is not totally cached in memery, we maybe get error when read btree node from cache device (see bch_btree_node_get()), the likely errno is -EIO, -ENOMEM 2. When read miss happens, bch_btree_insert_check_key() will be called to insert a "replace_key" to btree(see cached_dev_cache_miss(), just for doing preparatory work before insert the missed data to cache device), a failure can also happen in this situation, the likely errno is -ENOMEM bch_btree_map_keys() will return MAP_DONE in normal scenario, but we will get either -EIO or -ENOMEM in above two cases. if this happened, we should NOT recover data from backing device (when cache device is dirty) because we don't know whether bkeys the read request covered are all clean. And after that happened, s->iop.status is still its initially value(0) before we submit s->bio.bio, we set it to BLK_STS_IOERR, so it can go into cached_dev_read_error(), and finally it can be passed to upper layer, or recovered by reread from backing device. [edit by mlyle: patch formatting, word-wrap, comment spelling, commit log format] Signed-off-by: Hua Rui <huarui.dev@gmail.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-06block: move bio_alloc_pages() to bcacheMing Lei1-1/+1
bcache is the only user of bio_alloc_pages(), so move this function into bcache, and avoid it being misused in the future. Also rename it to bch_bio_allo_pages() since it is bcache only. Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-25bcache: recover data from backing when data is cleanRui Hua1-7/+6
When we send a read request and hit the clean data in cache device, there is a situation called cache read race in bcache(see the commit in the tail of cache_look_up(), the following explaination just copy from there): The bucket we're reading from might be reused while our bio is in flight, and we could then end up reading the wrong data. We guard against this by checking (in bch_cache_read_endio()) if the pointer is stale again; if so, we treat it as an error (s->iop.error = -EINTR) and reread from the backing device (but we don't pass that error up anywhere) It should be noted that cache read race happened under normal circumstances, not the circumstance when SSD failed, it was counted and shown in /sys/fs/bcache/XXX/internal/cache_read_races. Without this patch, when we use writeback mode, we will never reread from the backing device when cache read race happened, until the whole cache device is clean, because the condition (s->recoverable && (dc && !atomic_read(&dc->has_dirty))) is false in cached_dev_read_error(). In this situation, the s->iop.error(= -EINTR) will be passed up, at last, user will receive -EINTR when it's bio end, this is not suitable, and wield to up-application. In this patch, we use s->read_dirty_data to judge whether the read request hit dirty data in cache device, it is safe to reread data from the backing device when the read request hit clean data. This can not only handle cache read race, but also recover data when failed read request from cache device. [edited by mlyle to fix up whitespace, commit log title, comment spelling] Fixes: d59b23795933 ("bcache: only permit to recovery read error when cache device is clean") Cc: <stable@vger.kernel.org> # 4.14 Signed-off-by: Hua Rui <huarui.dev@gmail.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>