2008-06-30 18:04:41 +00:00
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/*
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* blk-integrity.c - Block layer data integrity extensions
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*
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* Copyright (C) 2007, 2008 Oracle Corporation
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* Written by: Martin K. Petersen <martin.petersen@oracle.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License version
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* 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; see the file COPYING. If not, write to
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* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
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* USA.
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*
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*/
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#include <linux/blkdev.h>
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#include <linux/mempool.h>
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#include <linux/bio.h>
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#include <linux/scatterlist.h>
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2011-05-26 20:00:52 +00:00
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#include <linux/export.h>
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include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
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#include <linux/slab.h>
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2008-06-30 18:04:41 +00:00
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#include "blk.h"
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static struct kmem_cache *integrity_cachep;
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2011-04-01 19:02:31 +00:00
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static const char *bi_unsupported_name = "unsupported";
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2008-06-30 18:04:41 +00:00
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/**
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* blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
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2010-09-10 18:50:10 +00:00
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* @q: request queue
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* @bio: bio with integrity metadata attached
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2008-06-30 18:04:41 +00:00
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*
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* Description: Returns the number of elements required in a
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2010-09-10 18:50:10 +00:00
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* scatterlist corresponding to the integrity metadata in a bio.
|
2008-06-30 18:04:41 +00:00
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*/
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2010-09-10 18:50:10 +00:00
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int blk_rq_count_integrity_sg(struct request_queue *q, struct bio *bio)
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2008-06-30 18:04:41 +00:00
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{
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2013-11-24 01:20:16 +00:00
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struct bio_vec iv, ivprv = { NULL };
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2010-09-10 18:50:10 +00:00
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unsigned int segments = 0;
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unsigned int seg_size = 0;
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2013-11-24 01:20:16 +00:00
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struct bvec_iter iter;
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int prev = 0;
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2008-06-30 18:04:41 +00:00
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2013-11-24 01:20:16 +00:00
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bio_for_each_integrity_vec(iv, bio, iter) {
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2008-06-30 18:04:41 +00:00
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2013-11-24 01:20:16 +00:00
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if (prev) {
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if (!BIOVEC_PHYS_MERGEABLE(&ivprv, &iv))
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2010-09-10 18:50:10 +00:00
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goto new_segment;
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2013-11-24 01:20:16 +00:00
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if (!BIOVEC_SEG_BOUNDARY(q, &ivprv, &iv))
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2010-09-10 18:50:10 +00:00
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goto new_segment;
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2013-11-24 01:20:16 +00:00
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if (seg_size + iv.bv_len > queue_max_segment_size(q))
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2010-09-10 18:50:10 +00:00
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goto new_segment;
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2008-06-30 18:04:41 +00:00
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2013-11-24 01:20:16 +00:00
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seg_size += iv.bv_len;
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2010-09-10 18:50:10 +00:00
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} else {
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new_segment:
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2008-06-30 18:04:41 +00:00
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segments++;
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2013-11-24 01:20:16 +00:00
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seg_size = iv.bv_len;
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2010-09-10 18:50:10 +00:00
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}
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2008-06-30 18:04:41 +00:00
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2013-11-24 01:20:16 +00:00
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prev = 1;
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2008-06-30 18:04:41 +00:00
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ivprv = iv;
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}
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return segments;
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}
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EXPORT_SYMBOL(blk_rq_count_integrity_sg);
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/**
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* blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
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2010-09-10 18:50:10 +00:00
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* @q: request queue
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* @bio: bio with integrity metadata attached
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2008-06-30 18:04:41 +00:00
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* @sglist: target scatterlist
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*
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* Description: Map the integrity vectors in request into a
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* scatterlist. The scatterlist must be big enough to hold all
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* elements. I.e. sized using blk_rq_count_integrity_sg().
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*/
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2010-09-10 18:50:10 +00:00
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int blk_rq_map_integrity_sg(struct request_queue *q, struct bio *bio,
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struct scatterlist *sglist)
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2008-06-30 18:04:41 +00:00
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{
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2013-11-24 01:20:16 +00:00
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struct bio_vec iv, ivprv = { NULL };
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2010-09-10 18:50:10 +00:00
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struct scatterlist *sg = NULL;
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unsigned int segments = 0;
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2013-11-24 01:20:16 +00:00
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struct bvec_iter iter;
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int prev = 0;
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2008-06-30 18:04:41 +00:00
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2013-11-24 01:20:16 +00:00
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bio_for_each_integrity_vec(iv, bio, iter) {
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2008-06-30 18:04:41 +00:00
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2013-11-24 01:20:16 +00:00
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if (prev) {
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if (!BIOVEC_PHYS_MERGEABLE(&ivprv, &iv))
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2008-06-30 18:04:41 +00:00
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goto new_segment;
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2013-11-24 01:20:16 +00:00
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if (!BIOVEC_SEG_BOUNDARY(q, &ivprv, &iv))
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2010-09-10 18:50:10 +00:00
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goto new_segment;
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2013-11-24 01:20:16 +00:00
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if (sg->length + iv.bv_len > queue_max_segment_size(q))
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2010-09-10 18:50:10 +00:00
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goto new_segment;
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2013-11-24 01:20:16 +00:00
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sg->length += iv.bv_len;
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2008-06-30 18:04:41 +00:00
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} else {
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new_segment:
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if (!sg)
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sg = sglist;
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else {
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2013-03-20 05:07:08 +00:00
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sg_unmark_end(sg);
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2008-06-30 18:04:41 +00:00
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sg = sg_next(sg);
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}
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2013-11-24 01:20:16 +00:00
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sg_set_page(sg, iv.bv_page, iv.bv_len, iv.bv_offset);
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2008-06-30 18:04:41 +00:00
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segments++;
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}
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2013-11-24 01:20:16 +00:00
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prev = 1;
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2008-06-30 18:04:41 +00:00
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ivprv = iv;
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}
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if (sg)
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sg_mark_end(sg);
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return segments;
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}
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EXPORT_SYMBOL(blk_rq_map_integrity_sg);
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/**
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2008-10-01 07:38:39 +00:00
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* blk_integrity_compare - Compare integrity profile of two disks
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* @gd1: Disk to compare
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* @gd2: Disk to compare
|
2008-06-30 18:04:41 +00:00
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*
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* Description: Meta-devices like DM and MD need to verify that all
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* sub-devices use the same integrity format before advertising to
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* upper layers that they can send/receive integrity metadata. This
|
2008-10-01 07:38:39 +00:00
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* function can be used to check whether two gendisk devices have
|
2008-06-30 18:04:41 +00:00
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* compatible integrity formats.
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*/
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2008-10-01 07:38:39 +00:00
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int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2)
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2008-06-30 18:04:41 +00:00
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{
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2008-10-01 07:38:39 +00:00
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struct blk_integrity *b1 = gd1->integrity;
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struct blk_integrity *b2 = gd2->integrity;
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2008-06-30 18:04:41 +00:00
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2008-10-01 07:38:39 +00:00
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if (!b1 && !b2)
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return 0;
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2008-06-30 18:04:41 +00:00
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if (!b1 || !b2)
|
2008-10-01 07:38:39 +00:00
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return -1;
|
2008-06-30 18:04:41 +00:00
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2014-09-26 23:19:59 +00:00
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if (b1->interval != b2->interval) {
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pr_err("%s: %s/%s protection interval %u != %u\n",
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__func__, gd1->disk_name, gd2->disk_name,
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b1->interval, b2->interval);
|
2008-06-30 18:04:41 +00:00
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return -1;
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}
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if (b1->tuple_size != b2->tuple_size) {
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printk(KERN_ERR "%s: %s/%s tuple sz %u != %u\n", __func__,
|
2008-10-01 07:38:39 +00:00
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gd1->disk_name, gd2->disk_name,
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2008-06-30 18:04:41 +00:00
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b1->tuple_size, b2->tuple_size);
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return -1;
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}
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if (b1->tag_size && b2->tag_size && (b1->tag_size != b2->tag_size)) {
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printk(KERN_ERR "%s: %s/%s tag sz %u != %u\n", __func__,
|
2008-10-01 07:38:39 +00:00
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gd1->disk_name, gd2->disk_name,
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2008-06-30 18:04:41 +00:00
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b1->tag_size, b2->tag_size);
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return -1;
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}
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if (strcmp(b1->name, b2->name)) {
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printk(KERN_ERR "%s: %s/%s type %s != %s\n", __func__,
|
2008-10-01 07:38:39 +00:00
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gd1->disk_name, gd2->disk_name,
|
2008-06-30 18:04:41 +00:00
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b1->name, b2->name);
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return -1;
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}
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return 0;
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}
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EXPORT_SYMBOL(blk_integrity_compare);
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|
2010-09-10 18:50:10 +00:00
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int blk_integrity_merge_rq(struct request_queue *q, struct request *req,
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struct request *next)
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{
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if (blk_integrity_rq(req) != blk_integrity_rq(next))
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return -1;
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if (req->nr_integrity_segments + next->nr_integrity_segments >
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q->limits.max_integrity_segments)
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return -1;
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return 0;
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|
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}
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EXPORT_SYMBOL(blk_integrity_merge_rq);
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|
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|
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int blk_integrity_merge_bio(struct request_queue *q, struct request *req,
|
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|
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struct bio *bio)
|
|
|
|
{
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|
|
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int nr_integrity_segs;
|
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|
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struct bio *next = bio->bi_next;
|
|
|
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|
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bio->bi_next = NULL;
|
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|
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nr_integrity_segs = blk_rq_count_integrity_sg(q, bio);
|
|
|
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bio->bi_next = next;
|
|
|
|
|
|
|
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if (req->nr_integrity_segments + nr_integrity_segs >
|
|
|
|
q->limits.max_integrity_segments)
|
|
|
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return -1;
|
|
|
|
|
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|
|
req->nr_integrity_segments += nr_integrity_segs;
|
|
|
|
|
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|
|
return 0;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(blk_integrity_merge_bio);
|
|
|
|
|
2008-06-30 18:04:41 +00:00
|
|
|
struct integrity_sysfs_entry {
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|
|
|
struct attribute attr;
|
|
|
|
ssize_t (*show)(struct blk_integrity *, char *);
|
|
|
|
ssize_t (*store)(struct blk_integrity *, const char *, size_t);
|
|
|
|
};
|
|
|
|
|
|
|
|
static ssize_t integrity_attr_show(struct kobject *kobj, struct attribute *attr,
|
|
|
|
char *page)
|
|
|
|
{
|
|
|
|
struct blk_integrity *bi =
|
|
|
|
container_of(kobj, struct blk_integrity, kobj);
|
|
|
|
struct integrity_sysfs_entry *entry =
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|
|
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container_of(attr, struct integrity_sysfs_entry, attr);
|
|
|
|
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|
|
return entry->show(bi, page);
|
|
|
|
}
|
|
|
|
|
2008-06-17 17:05:48 +00:00
|
|
|
static ssize_t integrity_attr_store(struct kobject *kobj,
|
|
|
|
struct attribute *attr, const char *page,
|
|
|
|
size_t count)
|
2008-06-30 18:04:41 +00:00
|
|
|
{
|
|
|
|
struct blk_integrity *bi =
|
|
|
|
container_of(kobj, struct blk_integrity, kobj);
|
|
|
|
struct integrity_sysfs_entry *entry =
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|
|
|
container_of(attr, struct integrity_sysfs_entry, attr);
|
|
|
|
ssize_t ret = 0;
|
|
|
|
|
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|
|
if (entry->store)
|
|
|
|
ret = entry->store(bi, page, count);
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t integrity_format_show(struct blk_integrity *bi, char *page)
|
|
|
|
{
|
|
|
|
if (bi != NULL && bi->name != NULL)
|
|
|
|
return sprintf(page, "%s\n", bi->name);
|
|
|
|
else
|
|
|
|
return sprintf(page, "none\n");
|
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t integrity_tag_size_show(struct blk_integrity *bi, char *page)
|
|
|
|
{
|
|
|
|
if (bi != NULL)
|
|
|
|
return sprintf(page, "%u\n", bi->tag_size);
|
|
|
|
else
|
|
|
|
return sprintf(page, "0\n");
|
|
|
|
}
|
|
|
|
|
2014-09-26 23:20:02 +00:00
|
|
|
static ssize_t integrity_verify_store(struct blk_integrity *bi,
|
|
|
|
const char *page, size_t count)
|
2008-06-30 18:04:41 +00:00
|
|
|
{
|
|
|
|
char *p = (char *) page;
|
|
|
|
unsigned long val = simple_strtoul(p, &p, 10);
|
|
|
|
|
|
|
|
if (val)
|
2014-09-26 23:20:02 +00:00
|
|
|
bi->flags |= BLK_INTEGRITY_VERIFY;
|
2008-06-30 18:04:41 +00:00
|
|
|
else
|
2014-09-26 23:20:02 +00:00
|
|
|
bi->flags &= ~BLK_INTEGRITY_VERIFY;
|
2008-06-30 18:04:41 +00:00
|
|
|
|
|
|
|
return count;
|
|
|
|
}
|
|
|
|
|
2014-09-26 23:20:02 +00:00
|
|
|
static ssize_t integrity_verify_show(struct blk_integrity *bi, char *page)
|
2008-06-30 18:04:41 +00:00
|
|
|
{
|
2014-09-26 23:20:02 +00:00
|
|
|
return sprintf(page, "%d\n", (bi->flags & BLK_INTEGRITY_VERIFY) != 0);
|
2008-06-30 18:04:41 +00:00
|
|
|
}
|
|
|
|
|
2014-09-26 23:20:02 +00:00
|
|
|
static ssize_t integrity_generate_store(struct blk_integrity *bi,
|
|
|
|
const char *page, size_t count)
|
2008-06-30 18:04:41 +00:00
|
|
|
{
|
|
|
|
char *p = (char *) page;
|
|
|
|
unsigned long val = simple_strtoul(p, &p, 10);
|
|
|
|
|
|
|
|
if (val)
|
2014-09-26 23:20:02 +00:00
|
|
|
bi->flags |= BLK_INTEGRITY_GENERATE;
|
2008-06-30 18:04:41 +00:00
|
|
|
else
|
2014-09-26 23:20:02 +00:00
|
|
|
bi->flags &= ~BLK_INTEGRITY_GENERATE;
|
2008-06-30 18:04:41 +00:00
|
|
|
|
|
|
|
return count;
|
|
|
|
}
|
|
|
|
|
2014-09-26 23:20:02 +00:00
|
|
|
static ssize_t integrity_generate_show(struct blk_integrity *bi, char *page)
|
2008-06-30 18:04:41 +00:00
|
|
|
{
|
2014-09-26 23:20:02 +00:00
|
|
|
return sprintf(page, "%d\n", (bi->flags & BLK_INTEGRITY_GENERATE) != 0);
|
2008-06-30 18:04:41 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
static struct integrity_sysfs_entry integrity_format_entry = {
|
|
|
|
.attr = { .name = "format", .mode = S_IRUGO },
|
|
|
|
.show = integrity_format_show,
|
|
|
|
};
|
|
|
|
|
|
|
|
static struct integrity_sysfs_entry integrity_tag_size_entry = {
|
|
|
|
.attr = { .name = "tag_size", .mode = S_IRUGO },
|
|
|
|
.show = integrity_tag_size_show,
|
|
|
|
};
|
|
|
|
|
2014-09-26 23:20:02 +00:00
|
|
|
static struct integrity_sysfs_entry integrity_verify_entry = {
|
2008-06-30 18:04:41 +00:00
|
|
|
.attr = { .name = "read_verify", .mode = S_IRUGO | S_IWUSR },
|
2014-09-26 23:20:02 +00:00
|
|
|
.show = integrity_verify_show,
|
|
|
|
.store = integrity_verify_store,
|
2008-06-30 18:04:41 +00:00
|
|
|
};
|
|
|
|
|
2014-09-26 23:20:02 +00:00
|
|
|
static struct integrity_sysfs_entry integrity_generate_entry = {
|
2008-06-30 18:04:41 +00:00
|
|
|
.attr = { .name = "write_generate", .mode = S_IRUGO | S_IWUSR },
|
2014-09-26 23:20:02 +00:00
|
|
|
.show = integrity_generate_show,
|
|
|
|
.store = integrity_generate_store,
|
2008-06-30 18:04:41 +00:00
|
|
|
};
|
|
|
|
|
|
|
|
static struct attribute *integrity_attrs[] = {
|
|
|
|
&integrity_format_entry.attr,
|
|
|
|
&integrity_tag_size_entry.attr,
|
2014-09-26 23:20:02 +00:00
|
|
|
&integrity_verify_entry.attr,
|
|
|
|
&integrity_generate_entry.attr,
|
2008-06-30 18:04:41 +00:00
|
|
|
NULL,
|
|
|
|
};
|
|
|
|
|
2010-01-19 01:58:23 +00:00
|
|
|
static const struct sysfs_ops integrity_ops = {
|
2008-06-30 18:04:41 +00:00
|
|
|
.show = &integrity_attr_show,
|
|
|
|
.store = &integrity_attr_store,
|
|
|
|
};
|
|
|
|
|
|
|
|
static int __init blk_dev_integrity_init(void)
|
|
|
|
{
|
|
|
|
integrity_cachep = kmem_cache_create("blkdev_integrity",
|
|
|
|
sizeof(struct blk_integrity),
|
|
|
|
0, SLAB_PANIC, NULL);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
subsys_initcall(blk_dev_integrity_init);
|
|
|
|
|
|
|
|
static void blk_integrity_release(struct kobject *kobj)
|
|
|
|
{
|
|
|
|
struct blk_integrity *bi =
|
|
|
|
container_of(kobj, struct blk_integrity, kobj);
|
|
|
|
|
|
|
|
kmem_cache_free(integrity_cachep, bi);
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct kobj_type integrity_ktype = {
|
|
|
|
.default_attrs = integrity_attrs,
|
|
|
|
.sysfs_ops = &integrity_ops,
|
|
|
|
.release = blk_integrity_release,
|
|
|
|
};
|
|
|
|
|
2011-04-01 19:02:31 +00:00
|
|
|
bool blk_integrity_is_initialized(struct gendisk *disk)
|
|
|
|
{
|
|
|
|
struct blk_integrity *bi = blk_get_integrity(disk);
|
|
|
|
|
|
|
|
return (bi && bi->name && strcmp(bi->name, bi_unsupported_name) != 0);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(blk_integrity_is_initialized);
|
|
|
|
|
2008-06-30 18:04:41 +00:00
|
|
|
/**
|
|
|
|
* blk_integrity_register - Register a gendisk as being integrity-capable
|
|
|
|
* @disk: struct gendisk pointer to make integrity-aware
|
2009-01-04 07:43:40 +00:00
|
|
|
* @template: optional integrity profile to register
|
2008-06-30 18:04:41 +00:00
|
|
|
*
|
|
|
|
* Description: When a device needs to advertise itself as being able
|
|
|
|
* to send/receive integrity metadata it must use this function to
|
|
|
|
* register the capability with the block layer. The template is a
|
|
|
|
* blk_integrity struct with values appropriate for the underlying
|
2009-01-04 07:43:40 +00:00
|
|
|
* hardware. If template is NULL the new profile is allocated but
|
|
|
|
* not filled out. See Documentation/block/data-integrity.txt.
|
2008-06-30 18:04:41 +00:00
|
|
|
*/
|
|
|
|
int blk_integrity_register(struct gendisk *disk, struct blk_integrity *template)
|
|
|
|
{
|
|
|
|
struct blk_integrity *bi;
|
|
|
|
|
|
|
|
BUG_ON(disk == NULL);
|
|
|
|
|
|
|
|
if (disk->integrity == NULL) {
|
2008-06-17 17:05:48 +00:00
|
|
|
bi = kmem_cache_alloc(integrity_cachep,
|
2009-01-04 07:43:40 +00:00
|
|
|
GFP_KERNEL | __GFP_ZERO);
|
2008-06-30 18:04:41 +00:00
|
|
|
if (!bi)
|
|
|
|
return -1;
|
|
|
|
|
|
|
|
if (kobject_init_and_add(&bi->kobj, &integrity_ktype,
|
2008-08-25 10:56:05 +00:00
|
|
|
&disk_to_dev(disk)->kobj,
|
|
|
|
"%s", "integrity")) {
|
2008-06-30 18:04:41 +00:00
|
|
|
kmem_cache_free(integrity_cachep, bi);
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
|
|
|
|
kobject_uevent(&bi->kobj, KOBJ_ADD);
|
|
|
|
|
2014-09-26 23:20:02 +00:00
|
|
|
bi->flags |= BLK_INTEGRITY_VERIFY | BLK_INTEGRITY_GENERATE;
|
2014-09-26 23:19:59 +00:00
|
|
|
bi->interval = queue_logical_block_size(disk->queue);
|
2008-06-30 18:04:41 +00:00
|
|
|
disk->integrity = bi;
|
|
|
|
} else
|
|
|
|
bi = disk->integrity;
|
|
|
|
|
|
|
|
/* Use the provided profile as template */
|
2009-01-04 07:43:40 +00:00
|
|
|
if (template != NULL) {
|
|
|
|
bi->name = template->name;
|
|
|
|
bi->generate_fn = template->generate_fn;
|
|
|
|
bi->verify_fn = template->verify_fn;
|
|
|
|
bi->tuple_size = template->tuple_size;
|
|
|
|
bi->tag_size = template->tag_size;
|
2014-09-26 23:20:02 +00:00
|
|
|
bi->flags |= template->flags;
|
2009-01-04 07:43:40 +00:00
|
|
|
} else
|
2011-04-01 19:02:31 +00:00
|
|
|
bi->name = bi_unsupported_name;
|
2008-06-30 18:04:41 +00:00
|
|
|
|
bdi: allow block devices to say that they require stable page writes
This patchset ("stable page writes, part 2") makes some key
modifications to the original 'stable page writes' patchset. First, it
provides creators (devices and filesystems) of a backing_dev_info a flag
that declares whether or not it is necessary to ensure that page
contents cannot change during writeout. It is no longer assumed that
this is true of all devices (which was never true anyway). Second, the
flag is used to relaxed the wait_on_page_writeback calls so that wait
only occurs if the device needs it. Third, it fixes up the remaining
disk-backed filesystems to use this improved conditional-wait logic to
provide stable page writes on those filesystems.
It is hoped that (for people not using checksumming devices, anyway)
this patchset will give back unnecessary performance decreases since the
original stable page write patchset went into 3.0. Sorry about not
fixing it sooner.
Complaints were registered by several people about the long write
latencies introduced by the original stable page write patchset.
Generally speaking, the kernel ought to allocate as little extra memory
as possible to facilitate writeout, but for people who simply cannot
wait, a second page stability strategy is (re)introduced: snapshotting
page contents. The waiting behavior is still the default strategy; to
enable page snapshotting, a superblock flag (MS_SNAP_STABLE) must be
set. This flag is used to bandaid^Henable stable page writeback on
ext3[1], and is not used anywhere else.
Given that there are already a few storage devices and network FSes that
have rolled their own page stability wait/page snapshot code, it would
be nice to move towards consolidating all of these. It seems possible
that iscsi and raid5 may wish to use the new stable page write support
to enable zero-copy writeout.
Thank you to Jan Kara for helping fix a couple more filesystems.
Per Andrew Morton's request, here are the result of using dbench to measure
latencies on ext2:
3.8.0-rc3:
Operation Count AvgLat MaxLat
----------------------------------------
WriteX 109347 0.028 59.817
ReadX 347180 0.004 3.391
Flush 15514 29.828 287.283
Throughput 57.429 MB/sec 4 clients 4 procs max_latency=287.290 ms
3.8.0-rc3 + patches:
WriteX 105556 0.029 4.273
ReadX 335004 0.005 4.112
Flush 14982 30.540 298.634
Throughput 55.4496 MB/sec 4 clients 4 procs max_latency=298.650 ms
As you can see, for ext2 the maximum write latency decreases from ~60ms
on a laptop hard disk to ~4ms. I'm not sure why the flush latencies
increase, though I suspect that being able to dirty pages faster gives
the flusher more work to do.
On ext4, the average write latency decreases as well as all the maximum
latencies:
3.8.0-rc3:
WriteX 85624 0.152 33.078
ReadX 272090 0.010 61.210
Flush 12129 36.219 168.260
Throughput 44.8618 MB/sec 4 clients 4 procs max_latency=168.276 ms
3.8.0-rc3 + patches:
WriteX 86082 0.141 30.928
ReadX 273358 0.010 36.124
Flush 12214 34.800 165.689
Throughput 44.9941 MB/sec 4 clients 4 procs max_latency=165.722 ms
XFS seems to exhibit similar latency improvements as ext2:
3.8.0-rc3:
WriteX 125739 0.028 104.343
ReadX 399070 0.005 4.115
Flush 17851 25.004 131.390
Throughput 66.0024 MB/sec 4 clients 4 procs max_latency=131.406 ms
3.8.0-rc3 + patches:
WriteX 123529 0.028 6.299
ReadX 392434 0.005 4.287
Flush 17549 25.120 188.687
Throughput 64.9113 MB/sec 4 clients 4 procs max_latency=188.704 ms
...and btrfs, just to round things out, also shows some latency
decreases:
3.8.0-rc3:
WriteX 67122 0.083 82.355
ReadX 212719 0.005 2.828
Flush 9547 47.561 147.418
Throughput 35.3391 MB/sec 4 clients 4 procs max_latency=147.433 ms
3.8.0-rc3 + patches:
WriteX 64898 0.101 71.631
ReadX 206673 0.005 7.123
Flush 9190 47.963 219.034
Throughput 34.0795 MB/sec 4 clients 4 procs max_latency=219.044 ms
Before this patchset, all filesystems would block, regardless of whether
or not it was necessary. ext3 would wait, but still generate occasional
checksum errors. The network filesystems were left to do their own
thing, so they'd wait too.
After this patchset, all the disk filesystems except ext3 and btrfs will
wait only if the hardware requires it. ext3 (if necessary) snapshots
pages instead of blocking, and btrfs provides its own bdi so the mm will
never wait. Network filesystems haven't been touched, so either they
provide their own wait code, or they don't block at all. The blocking
behavior is back to what it was before 3.0 if you don't have a disk
requiring stable page writes.
This patchset has been tested on 3.8.0-rc3 on x64 with ext3, ext4, and
xfs. I've spot-checked 3.8.0-rc4 and seem to be getting the same
results as -rc3.
[1] The alternative fixes to ext3 include fixing the locking order and
page bit handling like we did for ext4 (but then why not just use
ext4?), or setting PG_writeback so early that ext3 becomes extremely
slow. I tried that, but the number of write()s I could initiate dropped
by nearly an order of magnitude. That was a bit much even for the
author of the stable page series! :)
This patch:
Creates a per-backing-device flag that tracks whether or not pages must
be held immutable during writeout. Eventually it will be used to waive
wait_for_page_writeback() if nothing requires stable pages.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-22 00:42:48 +00:00
|
|
|
disk->queue->backing_dev_info.capabilities |= BDI_CAP_STABLE_WRITES;
|
|
|
|
|
2008-06-30 18:04:41 +00:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(blk_integrity_register);
|
|
|
|
|
|
|
|
/**
|
|
|
|
* blk_integrity_unregister - Remove block integrity profile
|
|
|
|
* @disk: disk whose integrity profile to deallocate
|
|
|
|
*
|
|
|
|
* Description: This function frees all memory used by the block
|
|
|
|
* integrity profile. To be called at device teardown.
|
|
|
|
*/
|
|
|
|
void blk_integrity_unregister(struct gendisk *disk)
|
|
|
|
{
|
|
|
|
struct blk_integrity *bi;
|
|
|
|
|
|
|
|
if (!disk || !disk->integrity)
|
|
|
|
return;
|
|
|
|
|
bdi: allow block devices to say that they require stable page writes
This patchset ("stable page writes, part 2") makes some key
modifications to the original 'stable page writes' patchset. First, it
provides creators (devices and filesystems) of a backing_dev_info a flag
that declares whether or not it is necessary to ensure that page
contents cannot change during writeout. It is no longer assumed that
this is true of all devices (which was never true anyway). Second, the
flag is used to relaxed the wait_on_page_writeback calls so that wait
only occurs if the device needs it. Third, it fixes up the remaining
disk-backed filesystems to use this improved conditional-wait logic to
provide stable page writes on those filesystems.
It is hoped that (for people not using checksumming devices, anyway)
this patchset will give back unnecessary performance decreases since the
original stable page write patchset went into 3.0. Sorry about not
fixing it sooner.
Complaints were registered by several people about the long write
latencies introduced by the original stable page write patchset.
Generally speaking, the kernel ought to allocate as little extra memory
as possible to facilitate writeout, but for people who simply cannot
wait, a second page stability strategy is (re)introduced: snapshotting
page contents. The waiting behavior is still the default strategy; to
enable page snapshotting, a superblock flag (MS_SNAP_STABLE) must be
set. This flag is used to bandaid^Henable stable page writeback on
ext3[1], and is not used anywhere else.
Given that there are already a few storage devices and network FSes that
have rolled their own page stability wait/page snapshot code, it would
be nice to move towards consolidating all of these. It seems possible
that iscsi and raid5 may wish to use the new stable page write support
to enable zero-copy writeout.
Thank you to Jan Kara for helping fix a couple more filesystems.
Per Andrew Morton's request, here are the result of using dbench to measure
latencies on ext2:
3.8.0-rc3:
Operation Count AvgLat MaxLat
----------------------------------------
WriteX 109347 0.028 59.817
ReadX 347180 0.004 3.391
Flush 15514 29.828 287.283
Throughput 57.429 MB/sec 4 clients 4 procs max_latency=287.290 ms
3.8.0-rc3 + patches:
WriteX 105556 0.029 4.273
ReadX 335004 0.005 4.112
Flush 14982 30.540 298.634
Throughput 55.4496 MB/sec 4 clients 4 procs max_latency=298.650 ms
As you can see, for ext2 the maximum write latency decreases from ~60ms
on a laptop hard disk to ~4ms. I'm not sure why the flush latencies
increase, though I suspect that being able to dirty pages faster gives
the flusher more work to do.
On ext4, the average write latency decreases as well as all the maximum
latencies:
3.8.0-rc3:
WriteX 85624 0.152 33.078
ReadX 272090 0.010 61.210
Flush 12129 36.219 168.260
Throughput 44.8618 MB/sec 4 clients 4 procs max_latency=168.276 ms
3.8.0-rc3 + patches:
WriteX 86082 0.141 30.928
ReadX 273358 0.010 36.124
Flush 12214 34.800 165.689
Throughput 44.9941 MB/sec 4 clients 4 procs max_latency=165.722 ms
XFS seems to exhibit similar latency improvements as ext2:
3.8.0-rc3:
WriteX 125739 0.028 104.343
ReadX 399070 0.005 4.115
Flush 17851 25.004 131.390
Throughput 66.0024 MB/sec 4 clients 4 procs max_latency=131.406 ms
3.8.0-rc3 + patches:
WriteX 123529 0.028 6.299
ReadX 392434 0.005 4.287
Flush 17549 25.120 188.687
Throughput 64.9113 MB/sec 4 clients 4 procs max_latency=188.704 ms
...and btrfs, just to round things out, also shows some latency
decreases:
3.8.0-rc3:
WriteX 67122 0.083 82.355
ReadX 212719 0.005 2.828
Flush 9547 47.561 147.418
Throughput 35.3391 MB/sec 4 clients 4 procs max_latency=147.433 ms
3.8.0-rc3 + patches:
WriteX 64898 0.101 71.631
ReadX 206673 0.005 7.123
Flush 9190 47.963 219.034
Throughput 34.0795 MB/sec 4 clients 4 procs max_latency=219.044 ms
Before this patchset, all filesystems would block, regardless of whether
or not it was necessary. ext3 would wait, but still generate occasional
checksum errors. The network filesystems were left to do their own
thing, so they'd wait too.
After this patchset, all the disk filesystems except ext3 and btrfs will
wait only if the hardware requires it. ext3 (if necessary) snapshots
pages instead of blocking, and btrfs provides its own bdi so the mm will
never wait. Network filesystems haven't been touched, so either they
provide their own wait code, or they don't block at all. The blocking
behavior is back to what it was before 3.0 if you don't have a disk
requiring stable page writes.
This patchset has been tested on 3.8.0-rc3 on x64 with ext3, ext4, and
xfs. I've spot-checked 3.8.0-rc4 and seem to be getting the same
results as -rc3.
[1] The alternative fixes to ext3 include fixing the locking order and
page bit handling like we did for ext4 (but then why not just use
ext4?), or setting PG_writeback so early that ext3 becomes extremely
slow. I tried that, but the number of write()s I could initiate dropped
by nearly an order of magnitude. That was a bit much even for the
author of the stable page series! :)
This patch:
Creates a per-backing-device flag that tracks whether or not pages must
be held immutable during writeout. Eventually it will be used to waive
wait_for_page_writeback() if nothing requires stable pages.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-22 00:42:48 +00:00
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disk->queue->backing_dev_info.capabilities &= ~BDI_CAP_STABLE_WRITES;
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2008-06-30 18:04:41 +00:00
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bi = disk->integrity;
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kobject_uevent(&bi->kobj, KOBJ_REMOVE);
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kobject_del(&bi->kobj);
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2009-07-28 07:11:14 +00:00
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kobject_put(&bi->kobj);
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2008-10-01 07:38:38 +00:00
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disk->integrity = NULL;
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2008-06-30 18:04:41 +00:00
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}
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EXPORT_SYMBOL(blk_integrity_unregister);
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