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2017-09-27bcache: fix bch_hprint crash and improve outputMichael Lyle
commit 9276717b9e297a62d1151a43d1cd286213f68eb7 upstream. Most importantly, solve a crash where %llu was used to format signed numbers. This would cause a buffer overflow when reading sysfs writeback_rate_debug, as only 20 bytes were allocated for this and %llu writes 20 characters plus a null. Always use the units mechanism rather than having different output paths for simplicity. Also, correct problems with display output where 1.10 was a larger number than 1.09, by multiplying by 10 and then dividing by 1024 instead of dividing by 100. (Remainders of >= 1000 would print as .10). Minor changes: Always display the decimal point instead of trying to omit it based on number of digits shown. Decide what units to use based on 1000 as a threshold, not 1024 (in other words, always print at most 3 digits before the decimal point). Signed-off-by: Michael Lyle <mlyle@lyle.org> Reported-by: Dmitry Yu Okunev <dyokunev@ut.mephi.ru> Acked-by: Kent Overstreet <kent.overstreet@gmail.com> Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27bcache: fix for gc and write-back raceTang Junhui
commit 9baf30972b5568d8b5bc8b3c46a6ec5b58100463 upstream. gc and write-back get raced (see the email "bcache get stucked" I sended before): gc thread write-back thread | |bch_writeback_thread() |bch_gc_thread() | | |==>read_dirty() |==>bch_btree_gc() | |==>btree_root() //get btree root | | //node write locker | |==>bch_btree_gc_root() | | |==>read_dirty_submit() | |==>write_dirty() | |==>continue_at(cl, | | write_dirty_finish, | | system_wq); | |==>write_dirty_finish()//excute | | //in system_wq | |==>bch_btree_insert() | |==>bch_btree_map_leaf_nodes() | |==>__bch_btree_map_nodes() | |==>btree_root //try to get btree | | //root node read | | //lock | |-----stuck here |==>bch_btree_set_root() |==>bch_journal_meta() |==>bch_journal() |==>journal_try_write() |==>journal_write_unlocked() //journal_full(&c->journal) | //condition satisfied |==>continue_at(cl, journal_write, system_wq); //try to excute | //journal_write in system_wq | //but work queue is excuting | //write_dirty_finish() |==>closure_sync(); //wait journal_write execute | //over and wake up gc, |-------------stuck here |==>release root node write locker This patch alloc a separate work-queue for write-back thread to avoid such race. (Commit log re-organized by Coly Li to pass checkpatch.pl checking) Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn> Acked-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27bcache: Correct return value for sysfs attach errorsTony Asleson
commit 77fa100f27475d08a569b9d51c17722130f089e7 upstream. If you encounter any errors in bch_cached_dev_attach it will return a negative error code. The variable 'v' which stores the result is unsigned, thus user space sees a very large value returned for bytes written which can cause incorrect user space behavior. Utilize 1 signed variable to use throughout the function to preserve error return capability. Signed-off-by: Tony Asleson <tasleson@redhat.com> Acked-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27bcache: correct cache_dirty_target in __update_writeback_rate()Tang Junhui
commit a8394090a9129b40f9d90dcb7f4a49d60c727ca6 upstream. __update_write_rate() uses a Proportion-Differentiation Controller algorithm to control writeback rate. A dirty target number is used in this PD controller to control writeback rate. A larger target number will make the writeback rate smaller, on the versus, a smaller target number will make the writeback rate larger. bcache uses the following steps to calculate the target number, 1) cache_sectors = all-buckets-of-cache-set * buckets-size 2) cache_dirty_target = cache_sectors * cached-device-writeback_percent 3) target = cache_dirty_target * (sectors-of-cached-device/sectors-of-all-cached-devices-of-this-cache-set) The calculation at step 1) for cache_sectors is incorrect, which does not consider dirty blocks occupied by flash only volume. A flash only volume can be took as a bcache device without cached device. All data sectors allocated for it are persistent on cache device and marked dirty, they are not touched by bcache writeback and garbage collection code. So data blocks of flash only volume should be ignore when calculating cache_sectors of cache set. Current code does not subtract dirty sectors of flash only volume, which results a larger target number from the above 3 steps. And in sequence the cache device's writeback rate is smaller then a correct value, writeback speed is slower on all cached devices. This patch fixes the incorrect slower writeback rate by subtracting dirty sectors of flash only volumes in __update_writeback_rate(). (Commit log composed by Coly Li to pass checkpatch.pl checking) Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn> Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27bcache: do not subtract sectors_to_gc for bypassed IOTang Junhui
commit 69daf03adef5f7bc13e0ac86b4b8007df1767aab upstream. Since bypassed IOs use no bucket, so do not subtract sectors_to_gc to trigger gc thread. Signed-off-by: tang.junhui <tang.junhui@zte.com.cn> Acked-by: Coly Li <colyli@suse.de> Reviewed-by: Eric Wheeler <bcache@linux.ewheeler.net> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27bcache: Fix leak of bdev referenceJan Kara
commit 4b758df21ee7081ab41448d21d60367efaa625b3 upstream. If blkdev_get_by_path() in register_bcache() fails, we try to lookup the block device using lookup_bdev() to detect which situation we are in to properly report error. However we never drop the reference returned to us from lookup_bdev(). Fix that. Signed-off-by: Jan Kara <jack@suse.cz> Acked-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27bcache: initialize dirty stripes in flash_dev_run()Tang Junhui
commit 175206cf9ab63161dec74d9cd7f9992e062491f5 upstream. bcache uses a Proportion-Differentiation Controller algorithm to control writeback rate to cached devices. In the PD controller algorithm, dirty stripes of thin flash device should not be counted in, because flash only volumes never write back dirty data. Currently dirty stripe counter for thin flash device is not initialized when the thin flash device starts. Which means the following calculation in PD controller will reference an undefined dirty stripes number, and all cached devices attached to the same cache set where the thin flash device lies on may have an inaccurate writeback rate. This patch calles bch_sectors_dirty_init() in flash_dev_run(), to correctly initialize dirty stripe counter when the thin flash device starts to run. This patch also does following parameter data type change, -void bch_sectors_dirty_init(struct cached_dev *dc); +void bch_sectors_dirty_init(struct bcache_device *); to call this function conveniently in flash_dev_run(). (Commit log is composed by Coly Li) Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn> Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-23bcache: Make gc wakeup sane, remove set_task_state()Kent Overstreet
commit be628be09563f8f6e81929efbd7cf3f45c344416 upstream. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Cc: Coly Li <colyli@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-22block: export bio_free_pages to other modulesGuoqing Jiang
bio_free_pages is introduced in commit 1dfa0f68c040 ("block: add a helper to free bio bounce buffer pages"), we can reuse the func in other modules after it was imported. Cc: Christoph Hellwig <hch@infradead.org> Cc: Jens Axboe <axboe@fb.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Shaohua Li <shli@fb.com> Signed-off-by: Guoqing Jiang <gqjiang@suse.com> Acked-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-19bcache: pr_err: more meaningful error message when nr_stripes is invalidEric Wheeler
The original error was thought to be corruption, but was actually caused by: make-bcache --data-offset N where N was in bytes and should have been in sectors. While userspace tools should be updated to check --data-offset beyond end of volume, hopefully this will help others that might not have noticed the units. Signed-off-by: Eric Wheeler <bcache@linux.ewheeler.net> Cc: Kent Overstreet <kent.overstreet@gmail.com>
2016-08-19bcache: RESERVE_PRIO is too small by one when prio_buckets() is a power of two.Kent Overstreet
This patch fixes a cachedev registration-time allocation deadlock. This can deadlock on boot if your initrd auto-registeres bcache devices: Allocator thread: [ 720.727614] INFO: task bcache_allocato:3833 blocked for more than 120 seconds. [ 720.732361] [<ffffffff816eeac7>] schedule+0x37/0x90 [ 720.732963] [<ffffffffa05192b8>] bch_bucket_alloc+0x188/0x360 [bcache] [ 720.733538] [<ffffffff810e6950>] ? prepare_to_wait_event+0xf0/0xf0 [ 720.734137] [<ffffffffa05302bd>] bch_prio_write+0x19d/0x340 [bcache] [ 720.734715] [<ffffffffa05190bf>] bch_allocator_thread+0x3ff/0x470 [bcache] [ 720.735311] [<ffffffff816ee41c>] ? __schedule+0x2dc/0x950 [ 720.735884] [<ffffffffa0518cc0>] ? invalidate_buckets+0x980/0x980 [bcache] Registration thread: [ 720.710403] INFO: task bash:3531 blocked for more than 120 seconds. [ 720.715226] [<ffffffff816eeac7>] schedule+0x37/0x90 [ 720.715805] [<ffffffffa05235cd>] __bch_btree_map_nodes+0x12d/0x150 [bcache] [ 720.716409] [<ffffffffa0522d30>] ? bch_btree_insert_check_key+0x1c0/0x1c0 [bcache] [ 720.717008] [<ffffffffa05236e4>] bch_btree_insert+0xf4/0x170 [bcache] [ 720.717586] [<ffffffff810e6950>] ? prepare_to_wait_event+0xf0/0xf0 [ 720.718191] [<ffffffffa0527d9a>] bch_journal_replay+0x14a/0x290 [bcache] [ 720.718766] [<ffffffff810cc90d>] ? ttwu_do_activate.constprop.94+0x5d/0x70 [ 720.719369] [<ffffffff810cf684>] ? try_to_wake_up+0x1d4/0x350 [ 720.719968] [<ffffffffa05317d0>] run_cache_set+0x580/0x8e0 [bcache] [ 720.720553] [<ffffffffa053302e>] register_bcache+0xe2e/0x13b0 [bcache] [ 720.721153] [<ffffffff81354cef>] kobj_attr_store+0xf/0x20 [ 720.721730] [<ffffffff812a2dad>] sysfs_kf_write+0x3d/0x50 [ 720.722327] [<ffffffff812a225a>] kernfs_fop_write+0x12a/0x180 [ 720.722904] [<ffffffff81225177>] __vfs_write+0x37/0x110 [ 720.723503] [<ffffffff81228048>] ? __sb_start_write+0x58/0x110 [ 720.724100] [<ffffffff812cedb3>] ? security_file_permission+0x23/0xa0 [ 720.724675] [<ffffffff812258a9>] vfs_write+0xa9/0x1b0 [ 720.725275] [<ffffffff8102479c>] ? do_audit_syscall_entry+0x6c/0x70 [ 720.725849] [<ffffffff81226755>] SyS_write+0x55/0xd0 [ 720.726451] [<ffffffff8106a390>] ? do_page_fault+0x30/0x80 [ 720.727045] [<ffffffff816f2cae>] system_call_fastpath+0x12/0x71 The fifo code in upstream bcache can't use the last element in the buffer, which was the cause of the bug: if you asked for a power of two size, it'd give you a fifo that could hold one less than what you asked for rather than allocating a buffer twice as big. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Tested-by: Eric Wheeler <bcache@linux.ewheeler.net> Cc: stable@vger.kernel.org
2016-08-19bcache: register_bcache(): call blkdev_put() when cache_alloc() failsEric Wheeler
register_cache() is supposed to return an error string on error so that register_bcache() will will blkdev_put and cleanup other user counters, but it does not set 'char *err' when cache_alloc() fails (eg, due to memory pressure) and thus register_bcache() performs no cleanup. register_bcache() <----------\ <- no jump to err_close, no blkdev_put() | | +->register_cache() | <- fails to set char *err | | +->cache_alloc() ---/ <- returns error This patch sets `char *err` for this failure case so that register_cache() will cause register_bcache() to correctly jump to err_close and do cleanup. This was tested under OOM conditions that triggered the bug. Signed-off-by: Eric Wheeler <bcache@linux.ewheeler.net> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: stable@vger.kernel.org
2016-08-07block: rename bio bi_rw to bi_opfJens Axboe
Since commit 63a4cc24867d, bio->bi_rw contains flags in the lower portion and the op code in the higher portions. This means that old code that relies on manually setting bi_rw is most likely going to be broken. Instead of letting that brokeness linger, rename the member, to force old and out-of-tree code to break at compile time instead of at runtime. No intended functional changes in this commit. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-20block: simplify and cleanup bvec pool handlingChristoph Hellwig
Instead of a flag and an index just make sure an index of 0 means no need to free the bvec array. Also move the constants related to the bvec pools together and use a consistent naming scheme for them. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-05bcache: Remove redundant block_size assignmentYijing Wang
We have assigned sb->block_size before the switch, so remove the redundant one. Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Acked-by: Eric Wheeler <bcache@lists.ewheeler.net> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-05bcache: update document infoYijing Wang
There is no return in continue_at(), update the documentation. Signed-off-by: Yijing Wang <wangyijing@huawei.com> Acked-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-05bcache: Remove redundant parameter for cache_alloc()Yijing Wang
Cache_sb is not used in cache_alloc, and we have copied sb info to cache->sb already, remove it. Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-12bcache: Remove deprecated create_workqueueBhaktipriya Shridhar
alloc_workqueue replaces deprecated create_workqueue(). Dedicated workqueues have been used since bcache_wq and moving_gc_wq are workqueues for writes and are being used on a memory reclaim path. WQ_MEM_RECLAIM has been set to ensure forward progress under memory pressure. Since there are only a fixed number of work items, explicit concurrency limit is unnecessary here. Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07block, drivers, fs: rename REQ_FLUSH to REQ_PREFLUSHMike Christie
To avoid confusion between REQ_OP_FLUSH, which is handled by request_fn drivers, and upper layers requesting the block layer perform a flush sequence along with possibly a WRITE, this patch renames REQ_FLUSH to REQ_PREFLUSH. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07bcache: use bio op accessorsMike Christie
Separate the op from the rq_flag_bits and have bcache set/get the bio using bio_set_op_attrs/bio_op. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07bcache: use op_is_write instead of checking for REQ_WRITEMike Christie
We currently set REQ_WRITE/WRITE for all non READ IOs like discard, flush, writesame, etc. In the next patches where we no longer set up the op as a bitmap, we will not be able to detect a operation direction like writesame by testing if REQ_WRITE is set. This has bcache use the op_is_write helper which will do the right thing. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07block/fs/drivers: remove rw argument from submit_bioMike Christie
This has callers of submit_bio/submit_bio_wait set the bio->bi_rw instead of passing it in. This makes that use the same as generic_make_request and how we set the other bio fields. Signed-off-by: Mike Christie <mchristi@redhat.com> Fixed up fs/ext4/crypto.c Signed-off-by: Jens Axboe <axboe@fb.com>
2016-05-24bcache: bch_gc_thread() is not freezableJiri Kosina
bch_gc_thread() doesn't mark itself freezable, so calling try_to_freeze() in its context is just an expensive no-op. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-05-24bcache: bch_allocator_thread() is not freezableJiri Kosina
bch_allocator_thread() is calling try_to_freeze(), but that's just an expensive no-op given the fact that the thread is not marked freezable. Bucket allocator has to be up and running to the very last stages of the suspend, as the bcache I/O that's in flight (think of writing an hibernation image to a swap device served by bcache). Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-05-24bcache: bch_writeback_thread() is not freezableJiri Kosina
bch_writeback_thread() is calling try_to_freeze(), but that's just an expensive no-op given the fact that the thread is not marked freezable. I/O helper kthreads, exactly such as the bcache writeback thread, actually shouldn't be freezable, because they are potentially necessary for finalizing the image write-out. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-04-12bcache: switch to using blk_queue_write_cache()Jens Axboe
Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-03-08bcache: fix cache_set_flush() NULL pointer dereference on OOMEric Wheeler
When bch_cache_set_alloc() fails to kzalloc the cache_set, the asyncronous closure handling tries to dereference a cache_set that hadn't yet been allocated inside of cache_set_flush() which is called by __cache_set_unregister() during cleanup. This appears to happen only during an OOM condition on bcache_register. Signed-off-by: Eric Wheeler <bcache@linux.ewheeler.net> Cc: stable@vger.kernel.org
2016-03-08bcache: cleaned up error handling around register_cache()Eric Wheeler
Fix null pointer dereference by changing register_cache() to return an int instead of being void. This allows it to return -ENOMEM or -ENODEV and enables upper layers to handle the OOM case without NULL pointer issues. See this thread: http://thread.gmane.org/gmane.linux.kernel.bcache.devel/3521 Fixes this error: gargamel:/sys/block/md5/bcache# echo /dev/sdh2 > /sys/fs/bcache/register bcache: register_cache() error opening sdh2: cannot allocate memory BUG: unable to handle kernel NULL pointer dereference at 00000000000009b8 IP: [<ffffffffc05a7e8d>] cache_set_flush+0x102/0x15c [bcache] PGD 120dff067 PUD 1119a3067 PMD 0 Oops: 0000 [#1] SMP Modules linked in: veth ip6table_filter ip6_tables (...) CPU: 4 PID: 3371 Comm: kworker/4:3 Not tainted 4.4.2-amd64-i915-volpreempt-20160213bc1 #3 Hardware name: System manufacturer System Product Name/P8H67-M PRO, BIOS 3904 04/27/2013 Workqueue: events cache_set_flush [bcache] task: ffff88020d5dc280 ti: ffff88020b6f8000 task.ti: ffff88020b6f8000 RIP: 0010:[<ffffffffc05a7e8d>] [<ffffffffc05a7e8d>] cache_set_flush+0x102/0x15c [bcache] Signed-off-by: Eric Wheeler <bcache@linux.ewheeler.net> Tested-by: Marc MERLIN <marc@merlins.org> Cc: <stable@vger.kernel.org>
2016-03-08bcache: fix race of writeback thread starting before complete initializationEric Wheeler
The bch_writeback_thread might BUG_ON in read_dirty() if dc->sb==BDEV_STATE_DIRTY and bch_sectors_dirty_init has not yet completed its related initialization. This patch downs the dc->writeback_lock until after initialization is complete, thus preventing bch_writeback_thread from proceeding prematurely. See this thread: http://thread.gmane.org/gmane.linux.kernel.bcache.devel/3453 Signed-off-by: Eric Wheeler <bcache@linux.ewheeler.net> Tested-by: Marc MERLIN <marc@merlins.org> Cc: <stable@vger.kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-01-22Merge branch 'for-4.5/drivers' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block driver updates from Jens Axboe: "This is the block driver pull request for 4.5, with the exception of NVMe, which is in a separate branch and will be posted after this one. This pull request contains: - A set of bcache stability fixes, which have been acked by Kent. These have been used and tested for more than a year by the community, so it's about time that they got in. - A set of drbd updates from the drbd team (Andreas, Lars, Philipp) and Markus Elfring, Oleg Drokin. - A set of fixes for xen blkback/front from the usual suspects, (Bob, Konrad) as well as community based fixes from Kiri, Julien, and Peng. - A 2038 time fix for sx8 from Shraddha, with a fix from me. - A small mtip32xx cleanup from Zhu Yanjun. - A null_blk division fix from Arnd" * 'for-4.5/drivers' of git://git.kernel.dk/linux-block: (71 commits) null_blk: use sector_div instead of do_div mtip32xx: restrict variables visible in current code module xen/blkfront: Fix crash if backend doesn't follow the right states. xen/blkback: Fix two memory leaks. xen/blkback: make st_ statistics per ring xen/blkfront: Handle non-indirect grant with 64KB pages xen-blkfront: Introduce blkif_ring_get_request xen-blkback: clear PF_NOFREEZE for xen_blkif_schedule() xen/blkback: Free resources if connect_ring failed. xen/blocks: Return -EXX instead of -1 xen/blkback: make pool of persistent grants and free pages per-queue xen/blkback: get the number of hardware queues/rings from blkfront xen/blkback: pseudo support for multi hardware queues/rings xen/blkback: separate ring information out of struct xen_blkif xen/blkfront: correct setting for xen_blkif_max_ring_order xen/blkfront: make persistent grants pool per-queue xen/blkfront: Remove duplicate setting of ->xbdev. xen/blkfront: Cleanup of comments, fix unaligned variables, and syntax errors. xen/blkfront: negotiate number of queues/rings to be used with backend xen/blkfront: split per device io_lock ...
2016-01-04md: more open-coded offset_in_page()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-31bcache: Change refill_dirty() to always scan entire disk if necessaryKent Overstreet
Previously, it would only scan the entire disk if it was starting from the very start of the disk - i.e. if the previous scan got to the end. This was broken by refill_full_stripes(), which updates last_scanned so that refill_dirty was never triggering the searched_from_start path. But if we change refill_dirty() to always scan the entire disk if necessary, regardless of what last_scanned was, the code gets cleaner and we fix that bug too. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-31bcache: prevent crash on changing writeback_runningStefan Bader
Added a safeguard in the shutdown case. At least while not being attached it is also possible to trigger a kernel bug by writing into writeback_running. This change adds the same check before trying to wake up the thread for that case. Signed-off-by: Stefan Bader <stefan.bader@canonical.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-31bcache: allows use of register in udev to avoid "device_busy" error.Gabriel de Perthuis
Allows to use register, not register_quiet in udev to avoid "device_busy" error. The initial patch proposed at https://lkml.org/lkml/2013/8/26/549 by Gabriel de Perthuis <g2p.code@gmail.com> does not unlock the mutex and hangs the kernel. See http://thread.gmane.org/gmane.linux.kernel.bcache.devel/2594 for the discussion. Cc: Denis Bychkov <manover@gmail.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Eric Wheeler <bcache@linux.ewheeler.net> Cc: Gabriel de Perthuis <g2p.code@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-31bcache: unregister reboot notifier if bcache fails to unregister deviceZheng Liu
In bcache_init() function it forgot to unregister reboot notifier if bcache fails to unregister a block device. This commit fixes this. Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Tested-by: Joshua Schmid <jschmid@suse.com> Tested-by: Eric Wheeler <bcache@linux.ewheeler.net> Cc: Kent Overstreet <kmo@daterainc.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-31bcache: fix a leak in bch_cached_dev_run()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Joshua Schmid <jschmid@suse.com> Tested-by: Eric Wheeler <bcache@linux.ewheeler.net> Cc: Kent Overstreet <kmo@daterainc.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-31bcache: clear BCACHE_DEV_UNLINK_DONE flag when attaching a backing deviceZheng Liu
This bug can be reproduced by the following script: #!/bin/bash bcache_sysfs="/sys/fs/bcache" function clear_cache() { if [ ! -e $bcache_sysfs ]; then echo "no bcache sysfs" exit fi cset_uuid=$(ls -l $bcache_sysfs|head -n 2|tail -n 1|awk '{print $9}') sudo sh -c "echo $cset_uuid > /sys/block/sdb/sdb1/bcache/detach" sleep 5 sudo sh -c "echo $cset_uuid > /sys/block/sdb/sdb1/bcache/attach" } for ((i=0;i<10;i++)); do clear_cache done The warning messages look like below: [ 275.948611] ------------[ cut here ]------------ [ 275.963840] WARNING: at fs/sysfs/dir.c:512 sysfs_add_one+0xb8/0xd0() (Tainted: P W --------------- ) [ 275.979253] Hardware name: Tecal RH2285 [ 275.994106] sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:09.0/0000:08:00.0/host4/target4:2:1/4:2:1:0/block/sdb/sdb1/bcache/cache' [ 276.024105] Modules linked in: bcache tcp_diag inet_diag ipmi_devintf ipmi_si ipmi_msghandler bonding 8021q garp stp llc ipv6 ext3 jbd loop sg iomemory_vsl(P) bnx2 microcode serio_raw i2c_i801 i2c_core iTCO_wdt iTCO_vendor_support i7core_edac edac_core shpchp ext4 jbd2 mbcache megaraid_sas pata_acpi ata_generic ata_piix dm_mod [last unloaded: scsi_wait_scan] [ 276.072643] Pid: 2765, comm: sh Tainted: P W --------------- 2.6.32 #1 [ 276.089315] Call Trace: [ 276.105801] [<ffffffff81070fe7>] ? warn_slowpath_common+0x87/0xc0 [ 276.122650] [<ffffffff810710d6>] ? warn_slowpath_fmt+0x46/0x50 [ 276.139361] [<ffffffff81205c08>] ? sysfs_add_one+0xb8/0xd0 [ 276.156012] [<ffffffff8120609b>] ? sysfs_do_create_link+0x12b/0x170 [ 276.172682] [<ffffffff81206113>] ? sysfs_create_link+0x13/0x20 [ 276.189282] [<ffffffffa03bda21>] ? bcache_device_link+0xc1/0x110 [bcache] [ 276.205993] [<ffffffffa03bfa08>] ? bch_cached_dev_attach+0x478/0x4f0 [bcache] [ 276.222794] [<ffffffffa03c4a17>] ? bch_cached_dev_store+0x627/0x780 [bcache] [ 276.239680] [<ffffffff8116783a>] ? alloc_pages_current+0xaa/0x110 [ 276.256594] [<ffffffff81203b15>] ? sysfs_write_file+0xe5/0x170 [ 276.273364] [<ffffffff811887b8>] ? vfs_write+0xb8/0x1a0 [ 276.290133] [<ffffffff811890b1>] ? sys_write+0x51/0x90 [ 276.306368] [<ffffffff8100c072>] ? system_call_fastpath+0x16/0x1b [ 276.322301] ---[ end trace 9f5d4fcdd0c3edfb ]--- [ 276.338241] ------------[ cut here ]------------ [ 276.354109] WARNING: at /home/wenqing.lz/bcache/bcache/super.c:720 bcache_device_link+0xdf/0x110 [bcache]() (Tainted: P W --------------- ) [ 276.386017] Hardware name: Tecal RH2285 [ 276.401430] Couldn't create device <-> cache set symlinks [ 276.401759] Modules linked in: bcache tcp_diag inet_diag ipmi_devintf ipmi_si ipmi_msghandler bonding 8021q garp stp llc ipv6 ext3 jbd loop sg iomemory_vsl(P) bnx2 microcode serio_raw i2c_i801 i2c_core iTCO_wdt iTCO_vendor_support i7core_edac edac_core shpchp ext4 jbd2 mbcache megaraid_sas pata_acpi ata_generic ata_piix dm_mod [last unloaded: scsi_wait_scan] [ 276.465477] Pid: 2765, comm: sh Tainted: P W --------------- 2.6.32 #1 [ 276.482169] Call Trace: [ 276.498610] [<ffffffff81070fe7>] ? warn_slowpath_common+0x87/0xc0 [ 276.515405] [<ffffffff810710d6>] ? warn_slowpath_fmt+0x46/0x50 [ 276.532059] [<ffffffffa03bda3f>] ? bcache_device_link+0xdf/0x110 [bcache] [ 276.548808] [<ffffffffa03bfa08>] ? bch_cached_dev_attach+0x478/0x4f0 [bcache] [ 276.565569] [<ffffffffa03c4a17>] ? bch_cached_dev_store+0x627/0x780 [bcache] [ 276.582418] [<ffffffff8116783a>] ? alloc_pages_current+0xaa/0x110 [ 276.599341] [<ffffffff81203b15>] ? sysfs_write_file+0xe5/0x170 [ 276.616142] [<ffffffff811887b8>] ? vfs_write+0xb8/0x1a0 [ 276.632607] [<ffffffff811890b1>] ? sys_write+0x51/0x90 [ 276.648671] [<ffffffff8100c072>] ? system_call_fastpath+0x16/0x1b [ 276.664756] ---[ end trace 9f5d4fcdd0c3edfc ]--- We forget to clear BCACHE_DEV_UNLINK_DONE flag in bcache_device_attach() function when we attach a backing device first time. After detaching this backing device, this flag will be true and sysfs_remove_link() isn't called in bcache_device_unlink(). Then when we attach this backing device again, sysfs_create_link() will return EEXIST error in bcache_device_link(). So the fix is trival and we clear this flag in bcache_device_link(). Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Tested-by: Joshua Schmid <jschmid@suse.com> Tested-by: Eric Wheeler <bcache@linux.ewheeler.net> Cc: Kent Overstreet <kmo@daterainc.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-31bcache: Add a cond_resched() call to gcKent Overstreet
Signed-off-by: Takashi Iwai <tiwai@suse.de> Tested-by: Eric Wheeler <bcache@linux.ewheeler.net> Cc: Kent Overstreet <kmo@daterainc.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-31bcache: fix a livelock when we cause a huge number of cache missesZheng Liu
Subject : [PATCH v2] bcache: fix a livelock in btree lock Date : Wed, 25 Feb 2015 20:32:09 +0800 (02/25/2015 04:32:09 AM) This commit tries to fix a livelock in bcache. This livelock might happen when we causes a huge number of cache misses simultaneously. When we get a cache miss, bcache will execute the following path. ->cached_dev_make_request() ->cached_dev_read() ->cached_lookup() ->bch->btree_map_keys() ->btree_root() <------------------------ ->bch_btree_map_keys_recurse() | ->cache_lookup_fn() | ->cached_dev_cache_miss() | ->bch_btree_insert_check_key() -| [If btree->seq is not equal to seq + 1, we should return EINTR and traverse btree again.] In bch_btree_insert_check_key() function we first need to check upgrade flag (op->lock == -1), and when this flag is true we need to release read btree->lock and try to take write btree->lock. During taking and releasing this write lock, btree->seq will be monotone increased in order to prevent other threads modify this in cache miss (see btree.h:74). But if there are some cache misses caused by some requested, we could meet a livelock because btree->seq is always changed by others. Thus no one can make progress. This commit will try to take write btree->lock if it encounters a race when we traverse btree. Although it sacrifice the scalability but we can ensure that only one can modify the btree. Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Tested-by: Joshua Schmid <jschmid@suse.com> Tested-by: Eric Wheeler <bcache@linux.ewheeler.net> Cc: Joshua Schmid <jschmid@suse.com> Cc: Zhu Yanhai <zhu.yanhai@gmail.com> Cc: Kent Overstreet <kmo@daterainc.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-11Merge branch 'for-4.4/io-poll' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block IO poll support from Jens Axboe: "Various groups have been doing experimentation around IO polling for (really) fast devices. The code has been reviewed and has been sitting on the side for a few releases, but this is now good enough for coordinated benchmarking and further experimentation. Currently O_DIRECT sync read/write are supported. A framework is in the works that allows scalable stats tracking so we can auto-tune this. And we'll add libaio support as well soon. Fow now, it's an opt-in feature for test purposes" * 'for-4.4/io-poll' of git://git.kernel.dk/linux-block: direct-io: be sure to assign dio->bio_bdev for both paths directio: add block polling support NVMe: add blk polling support block: add block polling support blk-mq: return tag/queue combo in the make_request_fn handlers block: change ->make_request_fn() and users to return a queue cookie
2015-11-07Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial updates from Jiri Kosina: "Trivial stuff from trivial tree that can be trivially summed up as: - treewide drop of spurious unlikely() before IS_ERR() from Viresh Kumar - cosmetic fixes (that don't really affect basic functionality of the driver) for pktcdvd and bcache, from Julia Lawall and Petr Mladek - various comment / printk fixes and updates all over the place" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: bcache: Really show state of work pending bit hwmon: applesmc: fix comment typos Kconfig: remove comment about scsi_wait_scan module class_find_device: fix reference to argument "match" debugfs: document that debugfs_remove*() accepts NULL and error values net: Drop unlikely before IS_ERR(_OR_NULL) mm: Drop unlikely before IS_ERR(_OR_NULL) fs: Drop unlikely before IS_ERR(_OR_NULL) drivers: net: Drop unlikely before IS_ERR(_OR_NULL) drivers: misc: Drop unlikely before IS_ERR(_OR_NULL) UBI: Update comments to reflect UBI_METAONLY flag pktcdvd: drop null test before destroy functions
2015-11-07block: change ->make_request_fn() and users to return a queue cookieJens Axboe
No functional changes in this patch, but it prepares us for returning a more useful cookie related to the IO that was queued up. Signed-off-by: Jens Axboe <axboe@fb.com> Acked-by: Christoph Hellwig <hch@lst.de> Acked-by: Keith Busch <keith.busch@intel.com>
2015-11-06bcache: Really show state of work pending bitPetr Mladek
WORK_STRUCT_PENDING is a mask for testing the pending bit. test_bit() expects the number of the bit and we need to use WORK_STRUCT_PENDING_BIT there. Also work_data_bits() is defined in workqueues.h now. I have noticed this just by chance when looking how WORK_STRUCT_PENDING_BIT is used. The change is compile tested. Signed-off-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-08-13bcache: remove driver private bio splitting codeKent Overstreet
The bcache driver has always accepted arbitrarily large bios and split them internally. Now that every driver must accept arbitrarily large bios this code isn't nessecary anymore. Cc: linux-bcache@vger.kernel.org Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> [dpark: add more description in commit message] Signed-off-by: Dongsu Park <dpark@posteo.net> Signed-off-by: Ming Lin <ming.l@ssi.samsung.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-29block: add a bi_error field to struct bioChristoph Hellwig
Currently we have two different ways to signal an I/O error on a BIO: (1) by clearing the BIO_UPTODATE flag (2) by returning a Linux errno value to the bi_end_io callback The first one has the drawback of only communicating a single possible error (-EIO), and the second one has the drawback of not beeing persistent when bios are queued up, and are not passed along from child to parent bio in the ever more popular chaining scenario. Having both mechanisms available has the additional drawback of utterly confusing driver authors and introducing bugs where various I/O submitters only deal with one of them, and the others have to add boilerplate code to deal with both kinds of error returns. So add a new bi_error field to store an errno value directly in struct bio and remove the existing mechanisms to clean all this up. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-17block: have drivers use blk_queue_max_discard_sectors()Jens Axboe
Some drivers use it now, others just set the limits field manually. But in preparation for splitting this into a hard and soft limit, ensure that they all call the proper function for setting the hw limit for discards. Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-11bcache: don't embed 'return' statements in closure macrosJens Axboe
This is horribly confusing, it breaks the flow of the code without it being apparent in the caller. Signed-off-by: Jens Axboe <axboe@fb.com> Acked-by: Christoph Hellwig <hch@lst.de>
2015-07-01MAINTAINERS: BCACHE: Kent Overstreet has changed email addressJoe Perches
Kent's email address in MAINTAINERS seems to be invalid. This was his last sign-off address, so use that if appropriate. Fix the S: status entry while there. Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-07-01bcache: use kvfree() in various placesPekka Enberg
Use kvfree() instead of open-coding it. Signed-off-by: Pekka Enberg <penberg@kernel.org> Cc: Kent Overstreet <kmo@daterainc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-02writeback: separate out include/linux/backing-dev-defs.hTejun Heo
With the planned cgroup writeback support, backing-dev related declarations will be more widely used across block and cgroup; unfortunately, including backing-dev.h from include/linux/blkdev.h makes cyclic include dependency quite likely. This patch separates out backing-dev-defs.h which only has the essential definitions and updates blkdev.h to include it. c files which need access to more backing-dev details now include backing-dev.h directly. This takes backing-dev.h off the common include dependency chain making it a lot easier to use it across block and cgroup. v2: fs/fat build failure fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jens Axboe <axboe@fb.com>