linux/drivers/md/bcache/writeback.c, branch v4.9

block: export bio_free_pages to other modules

2016-09-22T13:48:03Z

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 Cc: Jens Axboe Cc: Mike Snitzer Cc: Shaohua Li Signed-off-by: Guoqing Jiang Acked-by: Kent Overstreet Signed-off-by: Jens Axboe

bcache: use bio op accessors

2016-06-07T19:41:38Z

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 Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe

bcache: bch_writeback_thread() is not freezable

2016-05-24T15:00:40Z

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 Signed-off-by: Jens Axboe

bcache: Change refill_dirty() to always scan entire disk if necessary

2015-12-31T03:23:16Z

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

bcache: remove driver private bio splitting code

2015-08-13T18:31:40Z

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 [dpark: add more description in commit message] Signed-off-by: Dongsu Park Signed-off-by: Ming Lin Signed-off-by: Jens Axboe

block: add a bi_error field to struct bio

2015-07-29T14:55:15Z

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 Reviewed-by: Hannes Reinecke Reviewed-by: NeilBrown Signed-off-by: Jens Axboe

bcache: fix uninterruptible sleep in writeback thread

2014-08-04T22:23:03Z

There were two issues here: - writeback thread did not start until the device first became dirty - writeback thread used uninterruptible sleep once running Without this patch I see kernel warnings printed and a load average of 1.52 after booting my test VM. With this patch the warnings are gone and the load average is near 0.00 as expected. Signed-off-by: Kent Overstreet

Merge tag 'v3.13-rc6' into for-3.14/core

2013-12-31T16:51:02Z

Needed to bring blk-mq uptodate, since changes have been going in since for-3.14/core was established. Fixup merge issues related to the immutable biovec changes. Signed-off-by: Jens Axboe Conflicts: block/blk-flush.c fs/btrfs/check-integrity.c fs/btrfs/extent_io.c fs/btrfs/scrub.c fs/logfs/dev_bdev.c

bcache: New writeback PD controller

2013-12-16T22:22:59Z

The old writeback PD controller could get into states where it had throttled all the way down and take way too long to recover - it was too complicated to really understand what it was doing. This rewrites a good chunk of it to hopefully be simpler and make more sense, and it also pays more attention to units which should make the behaviour a bit easier to understand. Signed-off-by: Kent Overstreet

bcache: Use uninterruptible sleep in writeback

2013-12-16T22:04:57Z

We're just waiting on kthread_should_stop(), nothing else, so interruptible sleep was wrong here. Signed-off-by: Kent Overstreet