kernel/linux.git/drivers/md/bcache/request.c, branch v3.18.100

bcache: fix wrong cache_misses statistics

2017-12-20T09:01:33+00:00

[ Upstream commit c157313791a999646901b3e3c6888514ebc36d62 ] Currently, Cache missed IOs are identified by s->cache_miss, but actually, there are many situations that missed IOs are not assigned a value for s->cache_miss in cached_dev_cache_miss(), for example, a bypassed IO (s->iop.bypass = 1), or the cache_bio allocate failed. In these situations, it will go to out_put or out_submit, and s->cache_miss is null, which leads bch_mark_cache_accounting() to treat this IO as a hit IO. [ML: applied by 3-way merge] Signed-off-by: tang.junhui Reviewed-by: Michael Lyle Reviewed-by: Coly Li Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

bcache: recover data from backing when data is clean

2017-12-09T17:29:46+00:00

commit e393aa2446150536929140739f09c6ecbcbea7f0 upstream. 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") Signed-off-by: Hua Rui Reviewed-by: Michael Lyle Reviewed-by: Coly Li Signed-off-by: Michael Lyle Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

bcache: only permit to recovery read error when cache device is clean

2017-12-09T17:29:46+00:00

commit d59b23795933678c9638fd20c942d2b4f3cd6185 upstream. When bcache does read I/Os, for example in writeback or writethrough mode, if a read request on cache device is failed, bcache will try to recovery the request by reading from cached device. If the data on cached device is not synced with cache device, then requester will get a stale data. For critical storage system like database, providing stale data from recovery may result an application level data corruption, which is unacceptible. With this patch, for a failed read request in writeback or writethrough mode, recovery a recoverable read request only happens when cache device is clean. That is to say, all data on cached device is up to update. For other cache modes in bcache, read request will never hit cached_dev_read_error(), they don't need this patch. Please note, because cache mode can be switched arbitrarily in run time, a writethrough mode might be switched from a writeback mode. Therefore checking dc->has_data in writethrough mode still makes sense. Changelog: V4: Fix parens error pointed by Michael Lyle. v3: By response from Kent Oversteet, he thinks recovering stale data is a bug to fix, and option to permit it is unnecessary. So this version the sysfs file is removed. v2: rename sysfs entry from allow_stale_data_on_failure to allow_stale_data_on_failure, and fix the confusing commit log. v1: initial patch posted. [small change to patch comment spelling by mlyle] Signed-off-by: Coly Li Signed-off-by: Michael Lyle Reported-by: Arne Wolf Reviewed-by: Michael Lyle Cc: Kent Overstreet Cc: Nix Cc: Kai Krakow Cc: Eric Wheeler Cc: Junhui Tang Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

bcache: bcache_write tracepoint was crashing

2014-08-04T22:23:03+00:00

Signed-off-by: Kent Overstreet

bcache: Kill dead cgroup code

2014-03-18T19:22:35+00:00

This hasn't been used or even enabled in ages. Signed-off-by: Kent Overstreet

bcache: Fix moving_gc deadlocking with a foreground write

2014-03-18T19:22:33+00:00

Deadlock happened because a foreground write slept, waiting for a bucket to be allocated. Normally the gc would mark buckets available for invalidation. But the moving_gc was stuck waiting for outstanding writes to complete. These writes used the bcache_wq, the same queue foreground writes used. This fix gives moving_gc its own work queue, so it was still finish moving even if foreground writes are stuck waiting for allocation. It also makes work queue a parameter to the data_insert path, so moving_gc can use its workqueue for writes. Signed-off-by: Nicholas Swenson Signed-off-by: Kent Overstreet

bcache: Fix flash_dev_cache_miss() for real this time

2014-02-26T02:41:11+00:00

The code was using sectors to count the number of sectors it was zeroing... but then it passed it to bio_advance()... after it had been set to 0. Amusing... Signed-off-by: Kent Overstreet

Merge branch 'bcache-for-3.14' of git://evilpiepirate.org/~kent/linux-bcache into for-linus

2014-01-30T19:57:55+00:00

Merge branch 'for-3.14/drivers' of git://git.kernel.dk/linux-block

2014-01-30T19:40:10+00:00

Pull block IO driver changes from Jens Axboe: - bcache update from Kent Overstreet. - two bcache fixes from Nicholas Swenson. - cciss pci init error fix from Andrew. - underflow fix in the parallel IDE pg_write code from Dan Carpenter. I'm sure the 1 (or 0) users of that are now happy. - two PCI related fixes for sx8 from Jingoo Han. - floppy init fix for first block read from Jiri Kosina. - pktcdvd error return miss fix from Julia Lawall. - removal of IRQF_SHARED from the SEGA Dreamcast CD-ROM code from Michael Opdenacker. - comment typo fix for the loop driver from Olaf Hering. - potential oops fix for null_blk from Raghavendra K T. - two fixes from Sam Bradshaw (Micron) for the mtip32xx driver, fixing an OOM problem and a problem with handling security locked conditions * 'for-3.14/drivers' of git://git.kernel.dk/linux-block: (47 commits) mg_disk: Spelling s/finised/finished/ null_blk: Null pointer deference problem in alloc_page_buffers mtip32xx: Correctly handle security locked condition mtip32xx: Make SGL container per-command to eliminate high order dma allocation drivers/block/loop.c: fix comment typo in loop_config_discard drivers/block/cciss.c:cciss_init_one(): use proper errnos drivers/block/paride/pg.c: underflow bug in pg_write() drivers/block/sx8.c: remove unnecessary pci_set_drvdata() drivers/block/sx8.c: use module_pci_driver() floppy: bail out in open() if drive is not responding to block0 read bcache: Fix auxiliary search trees for key size > cacheline size bcache: Don't return -EINTR when insert finished bcache: Improve bucket_prio() calculation bcache: Add bch_bkey_equal_header() bcache: update bch_bkey_try_merge bcache: Move insert_fixup() to btree_keys_ops bcache: Convert sorting to btree_keys bcache: Convert debug code to btree_keys bcache: Convert btree_iter to struct btree_keys bcache: Refactor bset_tree sysfs stats ...

Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block

2014-01-30T19:19:05+00:00

Pull core block IO changes from Jens Axboe: "The major piece in here is the immutable bio_ve series from Kent, the rest is fairly minor. It was supposed to go in last round, but various issues pushed it to this release instead. The pull request contains: - Various smaller blk-mq fixes from different folks. Nothing major here, just minor fixes and cleanups. - Fix for a memory leak in the error path in the block ioctl code from Christian Engelmayer. - Header export fix from CaiZhiyong. - Finally the immutable biovec changes from Kent Overstreet. This enables some nice future work on making arbitrarily sized bios possible, and splitting more efficient. Related fixes to immutable bio_vecs: - dm-cache immutable fixup from Mike Snitzer. - btrfs immutable fixup from Muthu Kumar. - bio-integrity fix from Nic Bellinger, which is also going to stable" * 'for-3.14/core' of git://git.kernel.dk/linux-block: (44 commits) xtensa: fixup simdisk driver to work with immutable bio_vecs block/blk-mq-cpu.c: use hotcpu_notifier() blk-mq: for_each_* macro correctness block: Fix memory leak in rw_copy_check_uvector() handling bio-integrity: Fix bio_integrity_verify segment start bug block: remove unrelated header files and export symbol blk-mq: uses page->list incorrectly blk-mq: use __smp_call_function_single directly btrfs: fix missing increment of bi_remaining Revert "block: Warn and free bio if bi_end_io is not set" block: Warn and free bio if bi_end_io is not set blk-mq: fix initializing request's start time block: blk-mq: don't export blk_mq_free_queue() block: blk-mq: make blk_sync_queue support mq block: blk-mq: support draining mq queue dm cache: increment bi_remaining when bi_end_io is restored block: fixup for generic bio chaining block: Really silence spurious compiler warnings block: Silence spurious compiler warnings block: Kill bio_pair_split() ...