Instead of having a global bio slab cache, add a reference to one
in each bio_set that is created. This allows for personalized slabs
in each bio_set, so that they can have bios of different sizes.

This means we can personalize the bios we return. File systems may
want to embed the bio inside another structure, to avoid allocation
more items (and stuffing them in ->bi_private) after the get a bio.
Or we may want to embed a number of bio_vecs directly at the end
of a bio, to avoid doing two allocations to return a bio. This is now
possible.
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

A filesystem might supply its own integrity metadata.  Introduce a
flag that indicates whether the filesystem or the block layer owns the
integrity buffer.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

We need bdev_get_integrity() to support the pending md/dm patches.
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Don't put functions that are only used in fs/bio-integrity.c in
blkdev.h, it's much cleaner to just keep it in there. Also kill
completely unused bdev_get_tag_size()
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

I got section mismatch message about bio_integrity_init_slab().

WARNING: fs/built-in.o(__ksymtab+0xb60): Section mismatch in reference from the variable __ksymtab_bio_integrity_init_slab to the function .init.text:bio_integrity_init_slab()

The symbol bio_integrity_init_slab is exported and annotated __init Fix
this by removing the __init annotation of bio_integrity_init_slab or drop
the export.

It only call from init_bio().  The EXPORT_SYMBOL() can be removed.
Signed-off-by: NYoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

> 80 char lines and that sort of thing.
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

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: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>