linux-toradex.git/include/linux/bio.h, branch v4.11-rc3

block: introduce bio_clone_bioset_partial()

2017-02-15T19:22:05+00:00

md still need bio clone(not the fast version) for behind write,
and it is more efficient to use bio_clone_bioset_partial().

The idea is simple and just copy the bvecs range specified from
parameters.

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

block: improve handling of the magic discard payload

2016-12-09T15:30:51+00:00

Instead of allocating a single unused biovec for discard requests, send
them down without any payload.  Instead we allow the driver to add a
"special" payload using a biovec embedded into struct request (unioned
over other fields never used while in the driver), and overloading
the number of segments for this case.

This has a couple of advantages:

 - we don't have to allocate the bio_vec
 - the amount of special casing for discard requests in the block
   layer is significantly reduced
 - using this same scheme for other request types is trivial,
   which will be important for implementing the new WRITE_ZEROES
   op on devices where it actually requires a payload (e.g. SCSI)
 - we can get rid of playing games with the request length, as
   we'll never touch it and completions will work just fine
 - it will allow us to support ranged discard operations in the
   future by merging non-contiguous discard bios into a single
   request
 - last but not least it removes a lot of code

This patch is the common base for my WIP series for ranges discards and to
remove discard_zeroes_data in favor of always using REQ_OP_WRITE_ZEROES,
so it would be good to get it in quickly.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: add support for REQ_OP_WRITE_ZEROES

2016-12-01T14:58:40+00:00

This adds a new block layer operation to zero out a range of
LBAs. This allows to implement zeroing for devices that don't use
either discard with a predictable zero pattern or WRITE SAME of zeroes.
The prominent example of that is NVMe with the Write Zeroes command,
but in the future, this should also help with improving the way
zeroing discards work. For this operation, suitable entry is exported in
sysfs which indicate the number of maximum bytes allowed in one
write zeroes operation by the device.

Signed-off-by: Chaitanya Kulkarni 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: bio: pass bvec table to bio_init()

2016-11-22T15:57:21+00:00

Some drivers often use external bvec table, so introduce
this helper for this case. It is always safe to access the
bio->bi_io_vec in this way for this case.

After converting to this usage, it will becomes a bit easier
to evaluate the remaining direct access to bio->bi_io_vec,
so it can help to prepare for the following multipage bvec
support.

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

Fixed up the new O_DIRECT cases.

Signed-off-by: Jens Axboe

block: add bio_iov_iter_get_pages()

2016-11-02T16:50:18+00:00

This is a helper that pins down a range from an iov_iter and adds it to
a bio without requiring a separate memory allocation for the page array.
It will be used for upcoming direct I/O implementations for block devices
and iomap based file systems.

Signed-off-by: Kent Overstreet 
[hch: ported to the iov_iter interface, renamed and added comments.
      All blame should be directed to me and all fame should go to Kent
      after this!]
Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block, fs: move submit_bio to bio.h

2016-11-01T15:43:26+00:00

This is where all the other bio operations live, so users must include
bio.h anyway.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

fs: decouple READ and WRITE from the block layer ops

2016-11-01T15:43:26+00:00

Move READ and WRITE to kernel.h and don't define them in terms of block
layer ops; they are our generic data direction indicators these days
and have no more resemblance with the block layer ops.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: remove bio_is_rw

2016-10-28T14:45:17+00:00

With the addition of the zoned operations the tests in this function
became incorrect.  But I think it's much better to just open code the
allow operations in the only caller anyway.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Shaun Tancheff 
Signed-off-by: Jens Axboe

block: export bio_free_pages to other modules

2016-09-22T13:48:03+00:00

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

bio.h: remove a very outdated comment

2016-09-14T15:18:08+00:00

Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe