linux-toradex.git/include/linux/bvec.h, branch v6.0-rc1

block: define 'struct bvec_iter' as packed

2021-10-18T12:17:36+00:00

'struct bvec_iter' is embedded into 'struct bio', define it as packed
so that we can get one extra 4bytes for other uses without expanding
bio.

'struct bvec_iter' is often allocated on stack, so making it packed
doesn't affect performance. Also I have run io_uring on both
nvme/null_blk, and not observe performance effect in this way.

Suggested-by: Christoph Hellwig 
Signed-off-by: Ming Lei 
Reviewed-by: Sagi Grimberg 
Reviewed-by: Hannes Reinecke 
Signed-off-by: Christoph Hellwig 
Tested-by: Mark Wunderlich 
Link: https://lore.kernel.org/r/20211012111226.760968-14-hch@lst.de
Signed-off-by: Jens Axboe

bvec: add a bvec_virt helper

2021-08-16T16:50:32+00:00

Add a helper to get the virtual address for a bvec.  This avoids that
all callers need to know about the page + offset representation.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Chaitanya Kulkarni 
Reviewed-by: Martin K. Petersen 
Link: https://lore.kernel.org/r/20210804095634.460779-2-hch@lst.de
Signed-off-by: Jens Axboe

bvec: add memcpy_{from,to}_bvec and memzero_bvec helper

2021-08-02T19:37:27+00:00

Add helpers to perform common memory operation on a bvec.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Chaitanya Kulkarni 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Ira Weiny 
Link: https://lore.kernel.org/r/20210727055646.118787-5-hch@lst.de
Signed-off-by: Jens Axboe

bvec: add a bvec_kmap_local helper

2021-08-02T19:37:27+00:00

Add a helper to call kmap_local_page on a bvec.  There is no need for
an unmap helper given that kunmap_local accept any address in the mapped
page.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Chaitanya Kulkarni 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Ira Weiny 
Link: https://lore.kernel.org/r/20210727055646.118787-4-hch@lst.de
Signed-off-by: Jens Axboe

bvec: fix the include guards for bvec.h

2021-08-02T19:37:27+00:00

Fix the include guards to match the file naming.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Bart Van Assche 
Reviewed-by: Chaitanya Kulkarni 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Ira Weiny 
Link: https://lore.kernel.org/r/20210727055646.118787-3-hch@lst.de
Signed-off-by: Jens Axboe

block: optimise for_each_bvec() advance

2020-12-02T16:46:55+00:00

Because of how for_each_bvec() works it never advances across multiple
entries at a time, so bvec_iter_advance() is an overkill. Add
specialised bvec_iter_advance_single() that is faster. It also handles
zero-len bvecs, so can kill bvec_iter_skip_zero_bvec().

   text    data     bss     dec     hex filename
before:
  23977     805       0   24782    60ce lib/iov_iter.o
before, bvec_iter_advance() w/o WARN_ONCE()
  22886     600       0   23486    5bbe ./lib/iov_iter.o
after:
  21862     600       0   22462    57be lib/iov_iter.o

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

kernel.h: split out min()/max() et al. helpers

2020-10-16T18:11:19+00:00

kernel.h is being used as a dump for all kinds of stuff for a long time.
Here is the attempt to start cleaning it up by splitting out min()/max()
et al.  helpers.

At the same time convert users in header and lib folder to use new header.
Though for time being include new header back to kernel.h to avoid
twisted indirected includes for other existing users.

Signed-off-by: Andy Shevchenko 
Signed-off-by: Andrew Morton 
Cc: "Rafael J. Wysocki" 
Cc: Steven Rostedt 
Cc: Rasmus Villemoes 
Cc: Joe Perches 
Cc: Linus Torvalds 
Link: https://lkml.kernel.org/r/20200910164152.GA1891694@smile.fi.intel.com
Signed-off-by: Linus Torvalds

block: allow for_each_bvec to support zero len bvec

2020-09-03T02:59:40+00:00

Block layer usually doesn't support or allow zero-length bvec. Since
commit 1bdc76aea115 ("iov_iter: use bvec iterator to implement
iterate_bvec()"), iterate_bvec() switches to bvec iterator. However,
Al mentioned that 'Zero-length segments are not disallowed' in iov_iter.

Fixes for_each_bvec() so that it can move on after seeing one zero
length bvec.

Fixes: 1bdc76aea115 ("iov_iter: use bvec iterator to implement iterate_bvec()")
Reported-by: syzbot 
Signed-off-by: Ming Lei 
Tested-by: Tetsuo Handa 
Cc: Al Viro 
Cc: Matthew Wilcox 
Cc: 
Link: https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg2262077.html
Signed-off-by: Jens Axboe

block: Document the bio_vec properties

2020-05-19T15:40:29+00:00

Since it is nontrivial that nth_page() does not have to be used for a
bio_vec, document this.

Signed-off-by: Bart Van Assche 
Reviewed-by: Christoph Hellwig 
CC: Christoph Hellwig 
Cc: Ming Lei 
Signed-off-by: Jens Axboe

block: remove unused mp_bvec_last_segment

2020-01-05T03:23:39+00:00

After commit 85a8ce62c2ea ("block: add bio_truncate to fix guard_bio_eod")
this function is unused, remove it.

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