kernel/linux.git/block/bio.c, branch v4.0.8

block: rewrite and split __bio_copy_iov()

2015-02-05T16:30:44+00:00

Rewrite __bio_copy_iov using the copy_page_{from,to}_iter helpers, and split it into two simpler functions. This commit should contain only literal replacements, without functional changes. Cc: Kent Overstreet Cc: Jens Axboe Cc: Al Viro Signed-off-by: Dongsu Park [hch: removed the __bio_copy_iov wrapper] Signed-off-by: Christoph Hellwig Reviewed-by: Ming Lei Signed-off-by: Jens Axboe

block: merge __bio_map_user_iov into bio_map_user_iov

2015-02-05T16:30:43+00:00

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

block: merge __bio_map_kern into bio_map_kern

2015-02-05T16:30:42+00:00

This saves a little code, and allow to simplify the error handling. Signed-off-by: Christoph Hellwig Reviewed-by: Ming Lei Signed-off-by: Jens Axboe

block: pass iov_iter to the BLOCK_PC mapping functions

2015-02-05T16:30:40+00:00

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: add a helper to free bio bounce buffer pages

2015-02-05T16:30:39+00:00

The code sniplet to walk all bio_vecs and free their pages is opencoded in way to many places, so factor it into a helper. Also convert the slightly more complex cases in bio_kern_endio and __bio_copy_iov where we break the freeing from an existing loop into a separate one. 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

2015-02-05T16:30:37+00:00

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

block: simplify bio_map_kern

2015-02-05T16:30:35+00:00

Just open code the trivial mapping from a kernel virtual address to a bio instead of going through the complex user address mapping machinery. Signed-off-by: Christoph Hellwig Reviewed-by: Ming Lei Signed-off-by: Jens Axboe

bio: modify __bio_add_page() to accept pages that don't start a new segment

2014-12-11T16:11:52+00:00

The original behaviour is to refuse to add a new page if the maximum number of segments has been reached, regardless of the fact the page we are going to add can be merged into the last segment or not. Unfortunately, when the system runs under heavy memory fragmentation conditions, a driver may try to add multiple pages to the last segment. The original code won't accept them and EBUSY will be reported to userspace. This patch modifies the function so it refuses to add a page only in case the latter starts a new segment and the maximum number of segments has already been reached. The bug can be easily reproduced with the st driver: 1) set CONFIG_SCSI_MPT2SAS_MAX_SGE or CONFIG_SCSI_MPT3SAS_MAX_SGE to 16 2) modprobe st buffer_kbs=1024 3) #dd if=/dev/zero of=/dev/st0 bs=1M count=10 dd: error writing `/dev/st0': Device or resource busy Signed-off-by: Maurizio Lombardi Signed-off-by: Ming Lei Cc: Jet Chen Cc: Tomas Henzl Cc: Jens Axboe Signed-off-by: Andrew Morton Signed-off-by: Jens Axboe

blk: introduce generic io stat accounting help function

2014-11-24T15:04:44+00:00

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()

2014-10-03T21:28:18+00:00

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