linux-toradex.git/include/linux/bio.h, branch v2.6.27.13

block: fix nr_phys_segments miscalculation bug

2008-11-20T22:54:47+00:00

commit 8677142710516d986d932d6f1fba7be8382c1fec upstream
backported by Nikanth Karthikesan  to the 2.6.27.y tree.

block: fix nr_phys_segments miscalculation bug

This fixes the bug reported by Nikanth Karthikesan :

http://lkml.org/lkml/2008/10/2/203

The root cause of the bug is that blk_phys_contig_segment
miscalculates q->max_segment_size.

blk_phys_contig_segment checks:

req->biotail->bi_size + next_req->bio->bi_size > q->max_segment_size

But blk_recalc_rq_segments might expect that req->biotail and the
previous bio in the req are supposed be merged into one
segment. blk_recalc_rq_segments might also expect that next_req->bio
and the next bio in the next_req are supposed be merged into one
segment. In such case, we merge two requests that can't be merged
here. Later, blk_rq_map_sg gives more segments than it should.

We need to keep track of segment size in blk_recalc_rq_segments and
use it to see if two requests can be merged. This patch implements it
in the similar way that we used to do for hw merging (virtual
merging).

Signed-off-by: FUJITA Tomonori 
Signed-off-by: Jens Axboe 
Cc: Nikanth Karthikesan 
Signed-off-by: Greg Kroah-Hartman

block: integrity cleanups

2008-07-03T11:21:14+00:00

- No need to check for NULL bio, we'll get an immediate oops anyway.
- Make bio_integrity() a proper function.

Signed-off-by: Jens Axboe

block: Block layer data integrity support

2008-07-03T11:21:13+00:00

Some block devices support verifying the integrity of requests by way
of checksums or other protection information that is submitted along
with the I/O.

This patch implements support for generating and verifying integrity
metadata, as well as correctly merging, splitting and cloning bios and
requests that have this extra information attached.

See Documentation/block/data-integrity.txt for more information.

Signed-off-by: Martin K. Petersen 
Signed-off-by: Jens Axboe

block: Globalize bio_set and bio_vec_slab

2008-07-03T11:21:13+00:00

Move struct bio_set and biovec_slab definitions to bio.h so they can
be used outside of bio.c.

Signed-off-by: Martin K. Petersen 
Reviewed-by: Jeff Moyer 
Signed-off-by: Jens Axboe

block: add dma alignment and padding support to blk_rq_map_kern

2008-04-29T07:50:34+00:00

This patch adds bio_copy_kern similar to
bio_copy_user. blk_rq_map_kern uses bio_copy_kern instead of
bio_map_kern if necessary.

bio_copy_kern uses temporary pages and the bi_end_io callback frees
these pages. bio_copy_kern saves the original kernel buffer at
bio->bi_private it doesn't use something like struct bio_map_data to
store the information about the caller.

Signed-off-by: FUJITA Tomonori 
Cc: Tejun Heo 
Signed-off-by: Jens Axboe

block: convert bio_copy_user to bio_copy_user_iov

2008-04-21T07:50:08+00:00

This patch enables bio_copy_user to take struct sg_iovec (renamed
bio_copy_user_iov). bio_copy_user uses bio_copy_user_iov internally as
bio_map_user uses bio_map_user_iov.

The major changes are:

- adds sg_iovec array to struct bio_map_data

- adds __bio_copy_iov that copy data between bio and
sg_iovec. bio_copy_user_iov and bio_uncopy_user use it.

Signed-off-by: FUJITA Tomonori 
Cc: Tejun Heo 
Cc: Mike Christie 
Cc: James Bottomley 
Signed-off-by: Jens Axboe

fs/block_dev.c: remove #if 0'ed code

2008-02-19T09:04:00+00:00

Commit b2e895dbd80c420bfc0937c3729b4afe073b3848 #if 0'ed this code stating:

<--  snip  -->

    [PATCH] revert blockdev direct io back to 2.6.19 version

    Andrew Vasquez is reporting as-iosched oopses and a 65% throughput
    slowdown due to the recent special-casing of direct-io against
    blockdevs.  We don't know why either of these things are occurring.

    The patch minimally reverts us back to the 2.6.19 code for a 2.6.20
    release.

<--  snip  -->

It has since been dead code, and unless someone wants to revive it now
it's time to remove it.

This patch also makes bio_release_pages() static again and removes the
ki_bio_count member from struct kiocb, reverting changes that had been
done for this dead code.

Signed-off-by: Adrian Bunk 
Signed-off-by: Jens Axboe

block: Initial support for data-less (or empty) barrier support

2007-10-16T09:03:56+00:00

This implements functionality to pass down or insert a barrier
in a queue, without having data attached to it. The ->prepare_flush_fn()
infrastructure from data barriers are reused to provide this
functionality.

Signed-off-by: Jens Axboe

Drop 'size' argument from bio_endio and bi_end_io

2007-10-10T07:25:57+00:00

As bi_end_io is only called once when the reqeust is complete,
the 'size' argument is now redundant.  Remove it.

Now there is no need for bio_endio to subtract the size completed
from bi_size.  So don't do that either.

While we are at it, change bi_end_io to return void.

Signed-off-by: Neil Brown 
Signed-off-by: Jens Axboe

BLOCK: Hide the contents of linux/bio.h if CONFIG_BLOCK=n

2007-08-11T20:34:49+00:00

Hide the contents of linux/bio.h if CONFIG_BLOCK=n as there shouldn't be
compiled code that uses it.

Signed-off-by: David Howells 
Cc: James Bottomley 
Signed-off-by: Andrew Morton 
Signed-off-by: Jens Axboe