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![Kent Overstreet](/assets/img/avatar_default.png)
Immutable biovecs are going to require an explicit iterator. To implement immutable bvecs, a later patch is going to add a bi_bvec_done member to this struct; for now, this patch effectively just renames things. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "Ed L. Cashin" <ecashin@coraid.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Yehuda Sadeh <yehuda@inktank.com> Cc: Sage Weil <sage@inktank.com> Cc: Alex Elder <elder@inktank.com> Cc: ceph-devel@vger.kernel.org Cc: Joshua Morris <josh.h.morris@us.ibm.com> Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Neil Brown <neilb@suse.de> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: Boaz Harrosh <bharrosh@panasas.com> Cc: Benny Halevy <bhalevy@tonian.com> Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Chris Mason <chris.mason@fusionio.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jaegeuk Kim <jaegeuk.kim@samsung.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: Joern Engel <joern@logfs.org> Cc: Prasad Joshi <prasadjoshi.linux@gmail.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Ben Myers <bpm@sgi.com> Cc: xfs@oss.sgi.com Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Guo Chao <yan@linux.vnet.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: "Roger Pau Monné" <roger.pau@citrix.com> Cc: Jan Beulich <jbeulich@suse.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Ian Campbell <Ian.Campbell@citrix.com> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Jerome Marchand <jmarchand@redhat.com> Cc: Joe Perches <joe@perches.com> Cc: Peng Tao <tao.peng@emc.com> Cc: Andy Adamson <andros@netapp.com> Cc: fanchaoting <fanchaoting@cn.fujitsu.com> Cc: Jie Liu <jeff.liu@oracle.com> Cc: Sunil Mushran <sunil.mushran@gmail.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Pankaj Kumar <pankaj.km@samsung.com> Cc: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: Mel Gorman <mgorman@suse.de>6
373 lines
8.9 KiB
C
373 lines
8.9 KiB
C
/*
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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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* A mode can be one-shot or recurrent with the recurrence being
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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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#include <linux/blkdev.h>
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#include <linux/module.h>
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#include <linux/raid/md_u.h>
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#include <linux/slab.h>
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#include "md.h"
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#include <linux/seq_file.h>
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static void faulty_fail(struct bio *bio, int error)
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{
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struct bio *b = bio->bi_private;
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b->bi_iter.bi_size = bio->bi_iter.bi_size;
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b->bi_iter.bi_sector = bio->bi_iter.bi_sector;
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bio_put(bio);
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bio_io_error(b);
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}
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struct faulty_conf {
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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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struct md_rdev *rdev;
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};
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static int check_mode(struct faulty_conf *conf, int mode)
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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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static int check_sector(struct faulty_conf *conf, sector_t start, sector_t end, int dir)
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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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static void add_sector(struct faulty_conf *conf, sector_t start, int mode)
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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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static void make_request(struct mddev *mddev, struct bio *bio)
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{
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struct faulty_conf *conf = mddev->private;
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int failit = 0;
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if (bio_data_dir(bio) == WRITE) {
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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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bio_endio(bio, -EIO);
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return;
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}
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if (check_sector(conf, bio->bi_iter.bi_sector,
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bio_end_sector(bio), 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_iter.bi_sector,
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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_iter.bi_sector,
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bio_end_sector(bio), 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_iter.bi_sector,
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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_iter.bi_sector,
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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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struct bio *b = bio_clone_mddev(bio, GFP_NOIO, mddev);
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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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bio = b;
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} else
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bio->bi_bdev = conf->rdev->bdev;
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generic_make_request(bio);
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}
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static void status(struct seq_file *seq, struct mddev *mddev)
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{
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struct faulty_conf *conf = mddev->private;
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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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static int reshape(struct mddev *mddev)
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{
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int mode = mddev->new_layout & ModeMask;
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int count = mddev->new_layout >> ModeShift;
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struct faulty_conf *conf = mddev->private;
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if (mddev->new_layout < 0)
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return 0;
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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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mddev->new_layout = -1;
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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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static sector_t faulty_size(struct mddev *mddev, sector_t sectors, int raid_disks)
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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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static int run(struct mddev *mddev)
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{
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struct md_rdev *rdev;
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int i;
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struct faulty_conf *conf;
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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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if (!conf)
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return -ENOMEM;
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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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rdev_for_each(rdev, mddev) {
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conf->rdev = rdev;
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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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md_set_array_sectors(mddev, faulty_size(mddev, 0, 0));
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mddev->private = conf;
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reshape(mddev);
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return 0;
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}
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static int stop(struct mddev *mddev)
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{
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struct faulty_conf *conf = mddev->private;
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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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static struct md_personality faulty_personality =
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{
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.name = "faulty",
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.level = LEVEL_FAULTY,
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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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.check_reshape = reshape,
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.size = faulty_size,
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};
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static int __init raid_init(void)
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{
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return register_md_personality(&faulty_personality);
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}
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static void raid_exit(void)
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{
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unregister_md_personality(&faulty_personality);
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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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MODULE_DESCRIPTION("Fault injection personality for MD");
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MODULE_ALIAS("md-personality-10"); /* faulty */
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MODULE_ALIAS("md-faulty");
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MODULE_ALIAS("md-level--5");
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