kernel/linux.git/drivers/md/bcache/request.c, branch linux-4.20.y

bcache: fix ioctl in flash device

2018-10-08T14:19:42+00:00

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 Cc: stable@vger.kernel.org Signed-off-by: Coly Li Signed-off-by: Jens Axboe

bcache: use REQ_PRIO to indicate bio for metadata

2018-10-08T14:19:40+00:00

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 Cc: Adam Manzanares Signed-off-by: Jens Axboe

bcache: trace missed reading by cache_missed

2018-10-08T14:19:39+00:00

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 Cc: stable@vger.kernel.org Signed-off-by: Coly Li Signed-off-by: Jens Axboe

bcache: do not check NULL pointer before calling kmem_cache_destroy

2018-08-11T21:46:42+00:00

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 Reviewed-by: Shenghui Wang Signed-off-by: Jens Axboe

bcache: fix typo 'succesfully' to 'successfully'

2018-08-11T21:46:42+00:00

This patch fixes typo 'succesfully' to correct 'successfully', which is suggested by checkpatch.pl. Signed-off-by: Coly Li Reviewed-by: Shenghui Wang Signed-off-by: Jens Axboe

bcache: style fixes for lines over 80 characters

2018-08-11T21:46:41+00:00

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 Reviewed-by: Shenghui Wang Signed-off-by: Jens Axboe

bcache: add identifier names to arguments of function definitions

2018-08-11T21:46:41+00:00

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 Reviewed: Shenghui Wang Signed-off-by: Jens Axboe

bcache: style fix to add a blank line after declarations

2018-08-11T21:46:41+00:00

Signed-off-by: Coly Li Reviewed-by: Shenghui Wang Signed-off-by: Jens Axboe

bcache: style fix to replace 'unsigned' by 'unsigned int'

2018-08-11T21:46:41+00:00

This patch fixes warning reported by checkpatch.pl by replacing 'unsigned' with 'unsigned int'. Signed-off-by: Coly Li Reviewed-by: Shenghui Wang Signed-off-by: Jens Axboe

bcache: set max writeback rate when I/O request is idle

2018-08-09T14:21:15+00:00

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 Tested-by: Kai Krakow Tested-by: Stefan Priebe Cc: Michael Lyle Signed-off-by: Jens Axboe