user/sven/linux.git/include/linux/bio.h, branch stable/4.2.y

blkcg: implement bio_associate_blkcg()

2015-06-02T14:33:34Z

Currently, a bio can only be associated with the io_context and blkcg of %current using bio_associate_current(). This is too restrictive for cgroup writeback support. Implement bio_associate_blkcg() which associates a bio with the specified blkcg. bio_associate_blkcg() leaves the io_context unassociated. bio_associate_current() is updated so that it considers a bio as already associated if it has a blkcg_css, instead of an io_context, associated with it. Signed-off-by: Tejun Heo Cc: Jens Axboe Cc: Vivek Goyal Signed-off-by: Jens Axboe

block: remove management of bi_remaining when restoring original bi_end_io

2015-05-22T14:58:55Z

Commit c4cf5261 ("bio: skip atomic inc/dec of ->bi_remaining for non-chains") regressed all existing callers that followed this pattern: 1) saving a bio's original bi_end_io 2) wiring up an intermediate bi_end_io 3) restoring the original bi_end_io from intermediate bi_end_io 4) calling bio_endio() to execute the restored original bi_end_io The regression was due to BIO_CHAIN only ever getting set if bio_inc_remaining() is called. For the above pattern it isn't set until step 3 above (step 2 would've needed to establish BIO_CHAIN). As such the first bio_endio(), in step 2 above, never decremented __bi_remaining before calling the intermediate bi_end_io -- leaving __bi_remaining with the value 1 instead of 0. When bio_inc_remaining() occurred during step 3 it brought it to a value of 2. When the second bio_endio() was called, in step 4 above, it should've called the original bi_end_io but it didn't because there was an extra reference that wasn't dropped (due to atomic operations being optimized away since BIO_CHAIN wasn't set upfront). Fix this issue by removing the __bi_remaining management complexity for all callers that use the above pattern -- bio_chain() is the only interface that _needs_ to be concerned with __bi_remaining. For the above pattern callers just expect the bi_end_io they set to get called! Remove bio_endio_nodec() and also remove all bio_inc_remaining() calls that aren't associated with the bio_chain() interface. Also, the bio_inc_remaining() interface has been moved local to bio.c. Fixes: c4cf5261 ("bio: skip atomic inc/dec of ->bi_remaining for non-chains") Reviewed-by: Christoph Hellwig Reviewed-by: Jan Kara Signed-off-by: Mike Snitzer Signed-off-by: Jens Axboe

bio: skip atomic inc/dec of ->bi_cnt for most use cases

2015-05-05T19:32:49Z

Struct bio has a reference count that controls when it can be freed. Most uses cases is allocating the bio, which then returns with a single reference to it, doing IO, and then dropping that single reference. We can remove this atomic_dec_and_test() in the completion path, if nobody else is holding a reference to the bio. If someone does call bio_get() on the bio, then we flag the bio as now having valid count and that we must properly honor the reference count when it's being put. Tested-by: Robert Elliott Signed-off-by: Jens Axboe

bio: skip atomic inc/dec of ->bi_remaining for non-chains

2015-05-05T19:32:47Z

Struct bio has an atomic ref count for chained bio's, and we use this to know when to end IO on the bio. However, most bio's are not chained, so we don't need to always introduce this atomic operation as part of ending IO. Add a helper to elevate the bi_remaining count, and flag the bio as now actually needing the decrement at end_io time. Rename the field to __bi_remaining to catch any current users of this doing the incrementing manually. For high IOPS workloads, this reduces the overhead of bio_endio() substantially. Tested-by: Robert Elliott Acked-by: Kent Overstreet Reviewed-by: Jan Kara Signed-off-by: Jens Axboe

block: merge __bio_map_user_iov into bio_map_user_iov

2015-02-05T16:30:43Z

And also remove the unused bdev argument. Signed-off-by: Christoph Hellwig Reviewed-by: Ming Lei Signed-off-by: Jens Axboe

block: pass iov_iter to the BLOCK_PC mapping functions

2015-02-05T16:30:40Z

Make use of a new interface provided by iov_iter, backed by scatter-gather list of iovec, instead of the old interface based on sg_iovec. Also use iov_iter_advance() instead of manual iteration. This commit should contain only literal replacements, without functional changes. Cc: Christoph Hellwig Cc: Jens Axboe Cc: Doug Gilbert Cc: "James E.J. Bottomley" Signed-off-by: Kent Overstreet [dpark: add more description in commit message] Signed-off-by: Dongsu Park [hch: fixed to do a deep clone of the iov_iter, and to properly use the iov_iter direction] Signed-off-by: Christoph Hellwig Reviewed-by: Ming Lei Signed-off-by: Jens Axboe

block: use blk_rq_map_user_iov to implement blk_rq_map_user

2015-02-05T16:30:37Z

Signed-off-by: Christoph Hellwig Reviewed-by: Ming Lei Signed-off-by: Jens Axboe

blk: introduce generic io stat accounting help function

2014-11-24T15:04:44Z

Many block drivers accounting io stat based on bio (e.g. NVMe...), the blk_account_io_start/end() which is based on request does not make sense to them, so here we introduce the similar help function named generic_start/end_io_acct base on raw sectors, and it can simplify some driver's open io accounting code. Signed-off-by: Gu Zheng Signed-off-by: Jens Axboe

block: add bioset_create_nobvec()

2014-10-03T21:28:18Z

Users of bio_clone_fast() do not want bios with their own bvecs. Allocating a bvec mempool as part of the bioset intended for such users is a waste of memory. bioset_create_nobvec() creates a bioset that doesn't have the bvec mempool. Signed-off-by: Jun'ichi Nomura Signed-off-by: Mike Snitzer Signed-off-by: Jens Axboe

sd: Honor block layer integrity handling flags

2014-09-30T21:17:35Z

A set of flags introduced in the block layer enable better control over how protection information is handled. These flags are useful for both error injection and data recovery purposes. Checking can be enabled and disabled for controller and disk, and the guard tag format is now a per-I/O property. Update sd_protect_op to communicate the relevant information to the low-level device driver via a set of flags in scsi_cmnd. Signed-off-by: Martin K. Petersen Reviewed-by: Sagi Grimberg Acked-by: Christoph Hellwig Signed-off-by: Jens Axboe