2005-04-16 16:20:36 -06:00
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/*
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* faulty.c : Multiple Devices driver for Linux
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*
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* Copyright (C) 2004 Neil Brown
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*
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* fautly-device-simulator personality for md
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*
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*
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* You should have received a copy of the GNU General Public License
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* (for example /usr/src/linux/COPYING); if not, write to the Free
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* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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/*
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* The "faulty" personality causes some requests to fail.
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*
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* Possible failure modes are:
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* reads fail "randomly" but succeed on retry
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* writes fail "randomly" but succeed on retry
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* reads for some address fail and then persist until a write
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* reads for some address fail and then persist irrespective of write
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* writes for some address fail and persist
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* all writes fail
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*
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* Different modes can be active at a time, but only
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* one can be set at array creation. Others can be added later.
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2011-03-30 19:57:33 -06:00
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* A mode can be one-shot or recurrent with the recurrence being
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2005-04-16 16:20:36 -06:00
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* once in every N requests.
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* The bottom 5 bits of the "layout" indicate the mode. The
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* remainder indicate a period, or 0 for one-shot.
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*
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* There is an implementation limit on the number of concurrently
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* persisting-faulty blocks. When a new fault is requested that would
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* exceed the limit, it is ignored.
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* All current faults can be clear using a layout of "0".
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*
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* Requests are always sent to the device. If they are to fail,
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* we clone the bio and insert a new b_end_io into the chain.
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*/
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#define WriteTransient 0
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#define ReadTransient 1
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#define WritePersistent 2
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#define ReadPersistent 3
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#define WriteAll 4 /* doesn't go to device */
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#define ReadFixable 5
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#define Modes 6
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#define ClearErrors 31
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#define ClearFaults 30
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#define AllPersist 100 /* internal use only */
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#define NoPersist 101
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#define ModeMask 0x1f
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#define ModeShift 5
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#define MaxFault 50
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2009-03-30 21:33:13 -06:00
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#include <linux/blkdev.h>
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2011-07-03 11:58:33 -06:00
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#include <linux/module.h>
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2009-03-30 21:33:13 -06:00
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#include <linux/raid/md_u.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 02:04:11 -06:00
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#include <linux/slab.h>
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2009-03-30 21:33:13 -06:00
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#include "md.h"
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2009-03-30 21:33:13 -06:00
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#include <linux/seq_file.h>
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2005-04-16 16:20:36 -06:00
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2007-09-27 04:47:43 -06:00
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static void faulty_fail(struct bio *bio, int error)
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2005-04-16 16:20:36 -06:00
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{
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struct bio *b = bio->bi_private;
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b->bi_size = bio->bi_size;
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b->bi_sector = bio->bi_sector;
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2007-09-27 04:47:43 -06:00
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bio_put(bio);
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2005-04-16 16:20:36 -06:00
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2007-09-27 04:47:43 -06:00
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bio_io_error(b);
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2005-04-16 16:20:36 -06:00
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}
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2011-10-10 23:48:52 -06:00
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struct faulty_conf {
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2005-04-16 16:20:36 -06:00
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int period[Modes];
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atomic_t counters[Modes];
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sector_t faults[MaxFault];
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int modes[MaxFault];
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int nfaults;
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2011-10-10 23:45:26 -06:00
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struct md_rdev *rdev;
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2011-10-10 23:48:52 -06:00
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};
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2005-04-16 16:20:36 -06:00
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2011-10-10 23:48:52 -06:00
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static int check_mode(struct faulty_conf *conf, int mode)
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2005-04-16 16:20:36 -06:00
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{
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if (conf->period[mode] == 0 &&
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atomic_read(&conf->counters[mode]) <= 0)
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return 0; /* no failure, no decrement */
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if (atomic_dec_and_test(&conf->counters[mode])) {
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if (conf->period[mode])
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atomic_set(&conf->counters[mode], conf->period[mode]);
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return 1;
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}
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return 0;
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}
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2011-10-10 23:48:52 -06:00
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static int check_sector(struct faulty_conf *conf, sector_t start, sector_t end, int dir)
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2005-04-16 16:20:36 -06:00
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{
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/* If we find a ReadFixable sector, we fix it ... */
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int i;
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for (i=0; i<conf->nfaults; i++)
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if (conf->faults[i] >= start &&
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conf->faults[i] < end) {
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/* found it ... */
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switch (conf->modes[i] * 2 + dir) {
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case WritePersistent*2+WRITE: return 1;
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case ReadPersistent*2+READ: return 1;
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case ReadFixable*2+READ: return 1;
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case ReadFixable*2+WRITE:
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conf->modes[i] = NoPersist;
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return 0;
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case AllPersist*2+READ:
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case AllPersist*2+WRITE: return 1;
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default:
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return 0;
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}
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}
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return 0;
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}
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2011-10-10 23:48:52 -06:00
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static void add_sector(struct faulty_conf *conf, sector_t start, int mode)
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2005-04-16 16:20:36 -06:00
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{
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int i;
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int n = conf->nfaults;
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for (i=0; i<conf->nfaults; i++)
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if (conf->faults[i] == start) {
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switch(mode) {
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case NoPersist: conf->modes[i] = mode; return;
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case WritePersistent:
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if (conf->modes[i] == ReadPersistent ||
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conf->modes[i] == ReadFixable)
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conf->modes[i] = AllPersist;
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else
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conf->modes[i] = WritePersistent;
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return;
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case ReadPersistent:
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if (conf->modes[i] == WritePersistent)
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conf->modes[i] = AllPersist;
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else
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conf->modes[i] = ReadPersistent;
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return;
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case ReadFixable:
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if (conf->modes[i] == WritePersistent ||
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conf->modes[i] == ReadPersistent)
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conf->modes[i] = AllPersist;
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else
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conf->modes[i] = ReadFixable;
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return;
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}
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} else if (conf->modes[i] == NoPersist)
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n = i;
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if (n >= MaxFault)
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return;
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conf->faults[n] = start;
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conf->modes[n] = mode;
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if (conf->nfaults == n)
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conf->nfaults = n+1;
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}
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2011-11-04 18:06:58 -06:00
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static void make_request(struct mddev *mddev, struct bio *bio)
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2005-04-16 16:20:36 -06:00
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{
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2011-10-10 23:48:52 -06:00
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struct faulty_conf *conf = mddev->private;
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2005-04-16 16:20:36 -06:00
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int failit = 0;
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2006-12-13 01:34:13 -07:00
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if (bio_data_dir(bio) == WRITE) {
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2005-04-16 16:20:36 -06:00
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/* write request */
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if (atomic_read(&conf->counters[WriteAll])) {
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/* special case - don't decrement, don't generic_make_request,
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* just fail immediately
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*/
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2007-09-27 04:47:43 -06:00
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bio_endio(bio, -EIO);
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2011-09-12 04:12:01 -06:00
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return;
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2005-04-16 16:20:36 -06:00
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}
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if (check_sector(conf, bio->bi_sector, bio->bi_sector+(bio->bi_size>>9),
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WRITE))
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failit = 1;
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if (check_mode(conf, WritePersistent)) {
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add_sector(conf, bio->bi_sector, WritePersistent);
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failit = 1;
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}
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if (check_mode(conf, WriteTransient))
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failit = 1;
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} else {
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/* read request */
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if (check_sector(conf, bio->bi_sector, bio->bi_sector + (bio->bi_size>>9),
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READ))
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failit = 1;
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if (check_mode(conf, ReadTransient))
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failit = 1;
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if (check_mode(conf, ReadPersistent)) {
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add_sector(conf, bio->bi_sector, ReadPersistent);
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failit = 1;
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}
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if (check_mode(conf, ReadFixable)) {
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add_sector(conf, bio->bi_sector, ReadFixable);
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failit = 1;
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}
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}
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if (failit) {
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2010-10-26 01:31:13 -06:00
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struct bio *b = bio_clone_mddev(bio, GFP_NOIO, mddev);
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2011-09-12 04:12:01 -06:00
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2005-04-16 16:20:36 -06:00
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b->bi_bdev = conf->rdev->bdev;
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b->bi_private = bio;
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b->bi_end_io = faulty_fail;
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2011-09-12 04:12:01 -06:00
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bio = b;
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} else
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2005-04-16 16:20:36 -06:00
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bio->bi_bdev = conf->rdev->bdev;
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2011-09-12 04:12:01 -06:00
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generic_make_request(bio);
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2005-04-16 16:20:36 -06:00
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}
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2011-10-10 23:47:53 -06:00
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static void status(struct seq_file *seq, struct mddev *mddev)
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2005-04-16 16:20:36 -06:00
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{
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2011-10-10 23:48:52 -06:00
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struct faulty_conf *conf = mddev->private;
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2005-04-16 16:20:36 -06:00
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int n;
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if ((n=atomic_read(&conf->counters[WriteTransient])) != 0)
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seq_printf(seq, " WriteTransient=%d(%d)",
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n, conf->period[WriteTransient]);
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if ((n=atomic_read(&conf->counters[ReadTransient])) != 0)
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seq_printf(seq, " ReadTransient=%d(%d)",
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n, conf->period[ReadTransient]);
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if ((n=atomic_read(&conf->counters[WritePersistent])) != 0)
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seq_printf(seq, " WritePersistent=%d(%d)",
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n, conf->period[WritePersistent]);
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if ((n=atomic_read(&conf->counters[ReadPersistent])) != 0)
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seq_printf(seq, " ReadPersistent=%d(%d)",
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n, conf->period[ReadPersistent]);
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if ((n=atomic_read(&conf->counters[ReadFixable])) != 0)
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seq_printf(seq, " ReadFixable=%d(%d)",
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n, conf->period[ReadFixable]);
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if ((n=atomic_read(&conf->counters[WriteAll])) != 0)
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seq_printf(seq, " WriteAll");
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seq_printf(seq, " nfaults=%d", conf->nfaults);
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}
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2011-10-10 23:47:53 -06:00
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static int reshape(struct mddev *mddev)
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2005-04-16 16:20:36 -06:00
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{
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2009-06-17 16:47:42 -06:00
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int mode = mddev->new_layout & ModeMask;
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int count = mddev->new_layout >> ModeShift;
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2011-10-10 23:48:52 -06:00
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struct faulty_conf *conf = mddev->private;
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2005-04-16 16:20:36 -06:00
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2009-06-17 16:47:42 -06:00
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if (mddev->new_layout < 0)
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return 0;
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2005-04-16 16:20:36 -06:00
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/* new layout */
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if (mode == ClearFaults)
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conf->nfaults = 0;
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else if (mode == ClearErrors) {
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int i;
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for (i=0 ; i < Modes ; i++) {
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conf->period[i] = 0;
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atomic_set(&conf->counters[i], 0);
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}
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} else if (mode < Modes) {
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conf->period[mode] = count;
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if (!count) count++;
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atomic_set(&conf->counters[mode], count);
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} else
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return -EINVAL;
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2009-06-17 16:47:42 -06:00
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mddev->new_layout = -1;
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2005-04-16 16:20:36 -06:00
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mddev->layout = -1; /* makes sure further changes come through */
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return 0;
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}
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2011-10-10 23:47:53 -06:00
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static sector_t faulty_size(struct mddev *mddev, sector_t sectors, int raid_disks)
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2009-03-17 19:10:40 -06:00
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{
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WARN_ONCE(raid_disks,
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"%s does not support generic reshape\n", __func__);
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if (sectors == 0)
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return mddev->dev_sectors;
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return sectors;
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}
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2011-10-10 23:47:53 -06:00
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static int run(struct mddev *mddev)
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2005-04-16 16:20:36 -06:00
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{
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2011-10-10 23:45:26 -06:00
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struct md_rdev *rdev;
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2005-04-16 16:20:36 -06:00
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int i;
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2011-10-10 23:48:52 -06:00
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struct faulty_conf *conf;
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2005-04-16 16:20:36 -06:00
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2009-06-17 16:49:23 -06:00
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if (md_check_no_bitmap(mddev))
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return -EINVAL;
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conf = kmalloc(sizeof(*conf), GFP_KERNEL);
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2008-10-15 21:16:53 -06:00
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if (!conf)
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return -ENOMEM;
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2005-04-16 16:20:36 -06:00
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for (i=0; i<Modes; i++) {
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atomic_set(&conf->counters[i], 0);
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conf->period[i] = 0;
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}
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conf->nfaults = 0;
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2012-10-21 17:44:55 -06:00
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rdev_for_each(rdev, mddev) {
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2005-04-16 16:20:36 -06:00
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conf->rdev = rdev;
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2012-10-21 17:44:55 -06:00
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disk_stack_limits(mddev->gendisk, rdev->bdev,
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rdev->data_offset << 9);
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}
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2005-04-16 16:20:36 -06:00
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2009-03-30 21:59:03 -06:00
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md_set_array_sectors(mddev, faulty_size(mddev, 0, 0));
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2005-04-16 16:20:36 -06:00
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mddev->private = conf;
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2009-06-17 16:47:55 -06:00
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reshape(mddev);
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2005-04-16 16:20:36 -06:00
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return 0;
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}
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2011-10-10 23:47:53 -06:00
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static int stop(struct mddev *mddev)
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2005-04-16 16:20:36 -06:00
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{
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2011-10-10 23:48:52 -06:00
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struct faulty_conf *conf = mddev->private;
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2005-04-16 16:20:36 -06:00
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kfree(conf);
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mddev->private = NULL;
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return 0;
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}
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2011-10-10 23:49:58 -06:00
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static struct md_personality faulty_personality =
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2005-04-16 16:20:36 -06:00
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{
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.name = "faulty",
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2006-01-06 01:20:36 -07:00
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.level = LEVEL_FAULTY,
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2005-04-16 16:20:36 -06:00
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.owner = THIS_MODULE,
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.make_request = make_request,
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.run = run,
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.stop = stop,
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.status = status,
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2009-06-17 16:47:55 -06:00
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.check_reshape = reshape,
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2009-03-17 19:10:40 -06:00
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.size = faulty_size,
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2005-04-16 16:20:36 -06:00
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};
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static int __init raid_init(void)
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{
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2006-01-06 01:20:36 -07:00
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return register_md_personality(&faulty_personality);
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2005-04-16 16:20:36 -06:00
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}
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static void raid_exit(void)
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{
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2006-01-06 01:20:36 -07:00
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unregister_md_personality(&faulty_personality);
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2005-04-16 16:20:36 -06:00
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}
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module_init(raid_init);
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module_exit(raid_exit);
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MODULE_LICENSE("GPL");
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2009-12-13 18:49:58 -07:00
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MODULE_DESCRIPTION("Fault injection personality for MD");
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2005-04-16 16:20:36 -06:00
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MODULE_ALIAS("md-personality-10"); /* faulty */
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2006-01-06 01:20:51 -07:00
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MODULE_ALIAS("md-faulty");
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2006-01-06 01:20:36 -07:00
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MODULE_ALIAS("md-level--5");
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