![NeilBrown](/assets/img/avatar_default.png)
1/ I really should be using the __ATTR macros for defining attributes, so that the .owner field get set properly, otherwise modules can be removed while sysfs files are open. This also involves some name changes of _show routines. 2/ Always lock the mddev (against reconfiguration) for all sysfs attribute access. This easily avoid certain races and is completely consistant with other interfaces (ioctl and /proc/mdstat both always lock against reconfiguration). 3/ raid5 attributes must check that the 'conf' structure actually exists (the array could have been stopped while an attribute file was open). 4/ A missing 'kfree' from when the raid5_conf_t was converted to have a kobject embedded, and then converted back again. Signed-off-by: Neil Brown <neilb@suse.de> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2231 lines
60 KiB
C
2231 lines
60 KiB
C
/*
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* raid5.c : Multiple Devices driver for Linux
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* Copyright (C) 1996, 1997 Ingo Molnar, Miguel de Icaza, Gadi Oxman
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* Copyright (C) 1999, 2000 Ingo Molnar
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*
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* RAID-5 management functions.
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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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#include <linux/config.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/raid/raid5.h>
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#include <linux/highmem.h>
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#include <linux/bitops.h>
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#include <asm/atomic.h>
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#include <linux/raid/bitmap.h>
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/*
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* Stripe cache
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*/
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#define NR_STRIPES 256
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#define STRIPE_SIZE PAGE_SIZE
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#define STRIPE_SHIFT (PAGE_SHIFT - 9)
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#define STRIPE_SECTORS (STRIPE_SIZE>>9)
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#define IO_THRESHOLD 1
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#define HASH_PAGES 1
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#define HASH_PAGES_ORDER 0
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#define NR_HASH (HASH_PAGES * PAGE_SIZE / sizeof(struct stripe_head *))
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#define HASH_MASK (NR_HASH - 1)
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#define stripe_hash(conf, sect) ((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK])
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/* bio's attached to a stripe+device for I/O are linked together in bi_sector
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* order without overlap. There may be several bio's per stripe+device, and
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* a bio could span several devices.
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* When walking this list for a particular stripe+device, we must never proceed
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* beyond a bio that extends past this device, as the next bio might no longer
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* be valid.
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* This macro is used to determine the 'next' bio in the list, given the sector
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* of the current stripe+device
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*/
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#define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL)
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/*
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* The following can be used to debug the driver
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*/
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#define RAID5_DEBUG 0
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#define RAID5_PARANOIA 1
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#if RAID5_PARANOIA && defined(CONFIG_SMP)
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# define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock)
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#else
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# define CHECK_DEVLOCK()
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#endif
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#define PRINTK(x...) ((void)(RAID5_DEBUG && printk(x)))
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#if RAID5_DEBUG
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#define inline
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#define __inline__
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#endif
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static void print_raid5_conf (raid5_conf_t *conf);
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static inline void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh)
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{
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if (atomic_dec_and_test(&sh->count)) {
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if (!list_empty(&sh->lru))
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BUG();
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if (atomic_read(&conf->active_stripes)==0)
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BUG();
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if (test_bit(STRIPE_HANDLE, &sh->state)) {
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if (test_bit(STRIPE_DELAYED, &sh->state))
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list_add_tail(&sh->lru, &conf->delayed_list);
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else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
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conf->seq_write == sh->bm_seq)
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list_add_tail(&sh->lru, &conf->bitmap_list);
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else {
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clear_bit(STRIPE_BIT_DELAY, &sh->state);
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list_add_tail(&sh->lru, &conf->handle_list);
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}
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md_wakeup_thread(conf->mddev->thread);
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} else {
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if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
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atomic_dec(&conf->preread_active_stripes);
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if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD)
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md_wakeup_thread(conf->mddev->thread);
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}
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list_add_tail(&sh->lru, &conf->inactive_list);
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atomic_dec(&conf->active_stripes);
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if (!conf->inactive_blocked ||
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atomic_read(&conf->active_stripes) < (NR_STRIPES*3/4))
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wake_up(&conf->wait_for_stripe);
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}
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}
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}
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static void release_stripe(struct stripe_head *sh)
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{
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raid5_conf_t *conf = sh->raid_conf;
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unsigned long flags;
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spin_lock_irqsave(&conf->device_lock, flags);
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__release_stripe(conf, sh);
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spin_unlock_irqrestore(&conf->device_lock, flags);
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}
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static void remove_hash(struct stripe_head *sh)
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{
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PRINTK("remove_hash(), stripe %llu\n", (unsigned long long)sh->sector);
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if (sh->hash_pprev) {
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if (sh->hash_next)
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sh->hash_next->hash_pprev = sh->hash_pprev;
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*sh->hash_pprev = sh->hash_next;
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sh->hash_pprev = NULL;
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}
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}
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static __inline__ void insert_hash(raid5_conf_t *conf, struct stripe_head *sh)
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{
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struct stripe_head **shp = &stripe_hash(conf, sh->sector);
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PRINTK("insert_hash(), stripe %llu\n", (unsigned long long)sh->sector);
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CHECK_DEVLOCK();
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if ((sh->hash_next = *shp) != NULL)
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(*shp)->hash_pprev = &sh->hash_next;
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*shp = sh;
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sh->hash_pprev = shp;
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}
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/* find an idle stripe, make sure it is unhashed, and return it. */
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static struct stripe_head *get_free_stripe(raid5_conf_t *conf)
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{
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struct stripe_head *sh = NULL;
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struct list_head *first;
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CHECK_DEVLOCK();
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if (list_empty(&conf->inactive_list))
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goto out;
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first = conf->inactive_list.next;
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sh = list_entry(first, struct stripe_head, lru);
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list_del_init(first);
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remove_hash(sh);
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atomic_inc(&conf->active_stripes);
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out:
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return sh;
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}
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static void shrink_buffers(struct stripe_head *sh, int num)
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{
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struct page *p;
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int i;
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for (i=0; i<num ; i++) {
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p = sh->dev[i].page;
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if (!p)
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continue;
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sh->dev[i].page = NULL;
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page_cache_release(p);
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}
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}
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static int grow_buffers(struct stripe_head *sh, int num)
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{
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int i;
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for (i=0; i<num; i++) {
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struct page *page;
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if (!(page = alloc_page(GFP_KERNEL))) {
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return 1;
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}
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sh->dev[i].page = page;
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}
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return 0;
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}
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static void raid5_build_block (struct stripe_head *sh, int i);
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static inline void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx)
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{
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raid5_conf_t *conf = sh->raid_conf;
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int disks = conf->raid_disks, i;
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if (atomic_read(&sh->count) != 0)
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BUG();
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if (test_bit(STRIPE_HANDLE, &sh->state))
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BUG();
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CHECK_DEVLOCK();
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PRINTK("init_stripe called, stripe %llu\n",
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(unsigned long long)sh->sector);
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remove_hash(sh);
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sh->sector = sector;
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sh->pd_idx = pd_idx;
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sh->state = 0;
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for (i=disks; i--; ) {
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struct r5dev *dev = &sh->dev[i];
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if (dev->toread || dev->towrite || dev->written ||
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test_bit(R5_LOCKED, &dev->flags)) {
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printk("sector=%llx i=%d %p %p %p %d\n",
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(unsigned long long)sh->sector, i, dev->toread,
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dev->towrite, dev->written,
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test_bit(R5_LOCKED, &dev->flags));
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BUG();
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}
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dev->flags = 0;
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raid5_build_block(sh, i);
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}
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insert_hash(conf, sh);
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}
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static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector)
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{
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struct stripe_head *sh;
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CHECK_DEVLOCK();
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PRINTK("__find_stripe, sector %llu\n", (unsigned long long)sector);
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for (sh = stripe_hash(conf, sector); sh; sh = sh->hash_next)
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if (sh->sector == sector)
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return sh;
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PRINTK("__stripe %llu not in cache\n", (unsigned long long)sector);
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return NULL;
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}
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static void unplug_slaves(mddev_t *mddev);
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static void raid5_unplug_device(request_queue_t *q);
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static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector,
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int pd_idx, int noblock)
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{
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struct stripe_head *sh;
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PRINTK("get_stripe, sector %llu\n", (unsigned long long)sector);
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spin_lock_irq(&conf->device_lock);
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do {
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wait_event_lock_irq(conf->wait_for_stripe,
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conf->quiesce == 0,
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conf->device_lock, /* nothing */);
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sh = __find_stripe(conf, sector);
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if (!sh) {
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if (!conf->inactive_blocked)
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sh = get_free_stripe(conf);
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if (noblock && sh == NULL)
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break;
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if (!sh) {
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conf->inactive_blocked = 1;
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wait_event_lock_irq(conf->wait_for_stripe,
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!list_empty(&conf->inactive_list) &&
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(atomic_read(&conf->active_stripes) < (NR_STRIPES *3/4)
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|| !conf->inactive_blocked),
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conf->device_lock,
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unplug_slaves(conf->mddev);
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);
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conf->inactive_blocked = 0;
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} else
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init_stripe(sh, sector, pd_idx);
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} else {
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if (atomic_read(&sh->count)) {
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if (!list_empty(&sh->lru))
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BUG();
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} else {
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if (!test_bit(STRIPE_HANDLE, &sh->state))
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atomic_inc(&conf->active_stripes);
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if (list_empty(&sh->lru))
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BUG();
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list_del_init(&sh->lru);
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}
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}
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} while (sh == NULL);
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if (sh)
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atomic_inc(&sh->count);
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spin_unlock_irq(&conf->device_lock);
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return sh;
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}
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static int grow_one_stripe(raid5_conf_t *conf)
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{
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struct stripe_head *sh;
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sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL);
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if (!sh)
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return 0;
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memset(sh, 0, sizeof(*sh) + (conf->raid_disks-1)*sizeof(struct r5dev));
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sh->raid_conf = conf;
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spin_lock_init(&sh->lock);
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if (grow_buffers(sh, conf->raid_disks)) {
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shrink_buffers(sh, conf->raid_disks);
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kmem_cache_free(conf->slab_cache, sh);
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return 0;
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}
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/* we just created an active stripe so... */
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atomic_set(&sh->count, 1);
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atomic_inc(&conf->active_stripes);
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INIT_LIST_HEAD(&sh->lru);
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release_stripe(sh);
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return 1;
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}
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static int grow_stripes(raid5_conf_t *conf, int num)
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{
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kmem_cache_t *sc;
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int devs = conf->raid_disks;
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sprintf(conf->cache_name, "raid5/%s", mdname(conf->mddev));
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sc = kmem_cache_create(conf->cache_name,
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sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),
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0, 0, NULL, NULL);
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if (!sc)
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return 1;
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conf->slab_cache = sc;
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while (num--) {
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if (!grow_one_stripe(conf))
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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 drop_one_stripe(raid5_conf_t *conf)
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{
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struct stripe_head *sh;
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spin_lock_irq(&conf->device_lock);
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sh = get_free_stripe(conf);
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spin_unlock_irq(&conf->device_lock);
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if (!sh)
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return 0;
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if (atomic_read(&sh->count))
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BUG();
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shrink_buffers(sh, conf->raid_disks);
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kmem_cache_free(conf->slab_cache, sh);
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atomic_dec(&conf->active_stripes);
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return 1;
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}
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static void shrink_stripes(raid5_conf_t *conf)
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{
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while (drop_one_stripe(conf))
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;
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kmem_cache_destroy(conf->slab_cache);
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conf->slab_cache = NULL;
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}
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static int raid5_end_read_request(struct bio * bi, unsigned int bytes_done,
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int error)
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{
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struct stripe_head *sh = bi->bi_private;
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raid5_conf_t *conf = sh->raid_conf;
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int disks = conf->raid_disks, i;
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int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
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if (bi->bi_size)
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return 1;
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for (i=0 ; i<disks; i++)
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if (bi == &sh->dev[i].req)
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break;
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PRINTK("end_read_request %llu/%d, count: %d, uptodate %d.\n",
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(unsigned long long)sh->sector, i, atomic_read(&sh->count),
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uptodate);
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if (i == disks) {
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BUG();
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return 0;
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}
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if (uptodate) {
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#if 0
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struct bio *bio;
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unsigned long flags;
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spin_lock_irqsave(&conf->device_lock, flags);
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/* we can return a buffer if we bypassed the cache or
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* if the top buffer is not in highmem. If there are
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* multiple buffers, leave the extra work to
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* handle_stripe
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*/
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buffer = sh->bh_read[i];
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if (buffer &&
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(!PageHighMem(buffer->b_page)
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|| buffer->b_page == bh->b_page )
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) {
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sh->bh_read[i] = buffer->b_reqnext;
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buffer->b_reqnext = NULL;
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} else
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buffer = NULL;
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spin_unlock_irqrestore(&conf->device_lock, flags);
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if (sh->bh_page[i]==bh->b_page)
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set_buffer_uptodate(bh);
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if (buffer) {
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if (buffer->b_page != bh->b_page)
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memcpy(buffer->b_data, bh->b_data, bh->b_size);
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buffer->b_end_io(buffer, 1);
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}
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#else
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set_bit(R5_UPTODATE, &sh->dev[i].flags);
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#endif
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if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
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printk("R5: read error corrected!!\n");
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clear_bit(R5_ReadError, &sh->dev[i].flags);
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clear_bit(R5_ReWrite, &sh->dev[i].flags);
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}
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if (atomic_read(&conf->disks[i].rdev->read_errors))
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atomic_set(&conf->disks[i].rdev->read_errors, 0);
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} else {
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int retry = 0;
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clear_bit(R5_UPTODATE, &sh->dev[i].flags);
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atomic_inc(&conf->disks[i].rdev->read_errors);
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if (conf->mddev->degraded)
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printk("R5: read error not correctable.\n");
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else if (test_bit(R5_ReWrite, &sh->dev[i].flags))
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/* Oh, no!!! */
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printk("R5: read error NOT corrected!!\n");
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else if (atomic_read(&conf->disks[i].rdev->read_errors)
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> conf->max_nr_stripes)
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printk("raid5: Too many read errors, failing device.\n");
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else
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retry = 1;
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if (retry)
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set_bit(R5_ReadError, &sh->dev[i].flags);
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else {
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clear_bit(R5_ReadError, &sh->dev[i].flags);
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clear_bit(R5_ReWrite, &sh->dev[i].flags);
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md_error(conf->mddev, conf->disks[i].rdev);
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}
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}
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rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
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#if 0
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/* must restore b_page before unlocking buffer... */
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if (sh->bh_page[i] != bh->b_page) {
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bh->b_page = sh->bh_page[i];
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bh->b_data = page_address(bh->b_page);
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clear_buffer_uptodate(bh);
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}
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#endif
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clear_bit(R5_LOCKED, &sh->dev[i].flags);
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set_bit(STRIPE_HANDLE, &sh->state);
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release_stripe(sh);
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return 0;
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}
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static int raid5_end_write_request (struct bio *bi, unsigned int bytes_done,
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int error)
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{
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struct stripe_head *sh = bi->bi_private;
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raid5_conf_t *conf = sh->raid_conf;
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int disks = conf->raid_disks, i;
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unsigned long flags;
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int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
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if (bi->bi_size)
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return 1;
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for (i=0 ; i<disks; i++)
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if (bi == &sh->dev[i].req)
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break;
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PRINTK("end_write_request %llu/%d, count %d, uptodate: %d.\n",
|
|
(unsigned long long)sh->sector, i, atomic_read(&sh->count),
|
|
uptodate);
|
|
if (i == disks) {
|
|
BUG();
|
|
return 0;
|
|
}
|
|
|
|
spin_lock_irqsave(&conf->device_lock, flags);
|
|
if (!uptodate)
|
|
md_error(conf->mddev, conf->disks[i].rdev);
|
|
|
|
rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
|
|
|
|
clear_bit(R5_LOCKED, &sh->dev[i].flags);
|
|
set_bit(STRIPE_HANDLE, &sh->state);
|
|
__release_stripe(conf, sh);
|
|
spin_unlock_irqrestore(&conf->device_lock, flags);
|
|
return 0;
|
|
}
|
|
|
|
|
|
static sector_t compute_blocknr(struct stripe_head *sh, int i);
|
|
|
|
static void raid5_build_block (struct stripe_head *sh, int i)
|
|
{
|
|
struct r5dev *dev = &sh->dev[i];
|
|
|
|
bio_init(&dev->req);
|
|
dev->req.bi_io_vec = &dev->vec;
|
|
dev->req.bi_vcnt++;
|
|
dev->req.bi_max_vecs++;
|
|
dev->vec.bv_page = dev->page;
|
|
dev->vec.bv_len = STRIPE_SIZE;
|
|
dev->vec.bv_offset = 0;
|
|
|
|
dev->req.bi_sector = sh->sector;
|
|
dev->req.bi_private = sh;
|
|
|
|
dev->flags = 0;
|
|
if (i != sh->pd_idx)
|
|
dev->sector = compute_blocknr(sh, i);
|
|
}
|
|
|
|
static void error(mddev_t *mddev, mdk_rdev_t *rdev)
|
|
{
|
|
char b[BDEVNAME_SIZE];
|
|
raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
|
|
PRINTK("raid5: error called\n");
|
|
|
|
if (!test_bit(Faulty, &rdev->flags)) {
|
|
mddev->sb_dirty = 1;
|
|
if (test_bit(In_sync, &rdev->flags)) {
|
|
conf->working_disks--;
|
|
mddev->degraded++;
|
|
conf->failed_disks++;
|
|
clear_bit(In_sync, &rdev->flags);
|
|
/*
|
|
* if recovery was running, make sure it aborts.
|
|
*/
|
|
set_bit(MD_RECOVERY_ERR, &mddev->recovery);
|
|
}
|
|
set_bit(Faulty, &rdev->flags);
|
|
printk (KERN_ALERT
|
|
"raid5: Disk failure on %s, disabling device."
|
|
" Operation continuing on %d devices\n",
|
|
bdevname(rdev->bdev,b), conf->working_disks);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Input: a 'big' sector number,
|
|
* Output: index of the data and parity disk, and the sector # in them.
|
|
*/
|
|
static sector_t raid5_compute_sector(sector_t r_sector, unsigned int raid_disks,
|
|
unsigned int data_disks, unsigned int * dd_idx,
|
|
unsigned int * pd_idx, raid5_conf_t *conf)
|
|
{
|
|
long stripe;
|
|
unsigned long chunk_number;
|
|
unsigned int chunk_offset;
|
|
sector_t new_sector;
|
|
int sectors_per_chunk = conf->chunk_size >> 9;
|
|
|
|
/* First compute the information on this sector */
|
|
|
|
/*
|
|
* Compute the chunk number and the sector offset inside the chunk
|
|
*/
|
|
chunk_offset = sector_div(r_sector, sectors_per_chunk);
|
|
chunk_number = r_sector;
|
|
BUG_ON(r_sector != chunk_number);
|
|
|
|
/*
|
|
* Compute the stripe number
|
|
*/
|
|
stripe = chunk_number / data_disks;
|
|
|
|
/*
|
|
* Compute the data disk and parity disk indexes inside the stripe
|
|
*/
|
|
*dd_idx = chunk_number % data_disks;
|
|
|
|
/*
|
|
* Select the parity disk based on the user selected algorithm.
|
|
*/
|
|
if (conf->level == 4)
|
|
*pd_idx = data_disks;
|
|
else switch (conf->algorithm) {
|
|
case ALGORITHM_LEFT_ASYMMETRIC:
|
|
*pd_idx = data_disks - stripe % raid_disks;
|
|
if (*dd_idx >= *pd_idx)
|
|
(*dd_idx)++;
|
|
break;
|
|
case ALGORITHM_RIGHT_ASYMMETRIC:
|
|
*pd_idx = stripe % raid_disks;
|
|
if (*dd_idx >= *pd_idx)
|
|
(*dd_idx)++;
|
|
break;
|
|
case ALGORITHM_LEFT_SYMMETRIC:
|
|
*pd_idx = data_disks - stripe % raid_disks;
|
|
*dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks;
|
|
break;
|
|
case ALGORITHM_RIGHT_SYMMETRIC:
|
|
*pd_idx = stripe % raid_disks;
|
|
*dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks;
|
|
break;
|
|
default:
|
|
printk("raid5: unsupported algorithm %d\n",
|
|
conf->algorithm);
|
|
}
|
|
|
|
/*
|
|
* Finally, compute the new sector number
|
|
*/
|
|
new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset;
|
|
return new_sector;
|
|
}
|
|
|
|
|
|
static sector_t compute_blocknr(struct stripe_head *sh, int i)
|
|
{
|
|
raid5_conf_t *conf = sh->raid_conf;
|
|
int raid_disks = conf->raid_disks, data_disks = raid_disks - 1;
|
|
sector_t new_sector = sh->sector, check;
|
|
int sectors_per_chunk = conf->chunk_size >> 9;
|
|
sector_t stripe;
|
|
int chunk_offset;
|
|
int chunk_number, dummy1, dummy2, dd_idx = i;
|
|
sector_t r_sector;
|
|
|
|
chunk_offset = sector_div(new_sector, sectors_per_chunk);
|
|
stripe = new_sector;
|
|
BUG_ON(new_sector != stripe);
|
|
|
|
|
|
switch (conf->algorithm) {
|
|
case ALGORITHM_LEFT_ASYMMETRIC:
|
|
case ALGORITHM_RIGHT_ASYMMETRIC:
|
|
if (i > sh->pd_idx)
|
|
i--;
|
|
break;
|
|
case ALGORITHM_LEFT_SYMMETRIC:
|
|
case ALGORITHM_RIGHT_SYMMETRIC:
|
|
if (i < sh->pd_idx)
|
|
i += raid_disks;
|
|
i -= (sh->pd_idx + 1);
|
|
break;
|
|
default:
|
|
printk("raid5: unsupported algorithm %d\n",
|
|
conf->algorithm);
|
|
}
|
|
|
|
chunk_number = stripe * data_disks + i;
|
|
r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset;
|
|
|
|
check = raid5_compute_sector (r_sector, raid_disks, data_disks, &dummy1, &dummy2, conf);
|
|
if (check != sh->sector || dummy1 != dd_idx || dummy2 != sh->pd_idx) {
|
|
printk("compute_blocknr: map not correct\n");
|
|
return 0;
|
|
}
|
|
return r_sector;
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* Copy data between a page in the stripe cache, and a bio.
|
|
* There are no alignment or size guarantees between the page or the
|
|
* bio except that there is some overlap.
|
|
* All iovecs in the bio must be considered.
|
|
*/
|
|
static void copy_data(int frombio, struct bio *bio,
|
|
struct page *page,
|
|
sector_t sector)
|
|
{
|
|
char *pa = page_address(page);
|
|
struct bio_vec *bvl;
|
|
int i;
|
|
int page_offset;
|
|
|
|
if (bio->bi_sector >= sector)
|
|
page_offset = (signed)(bio->bi_sector - sector) * 512;
|
|
else
|
|
page_offset = (signed)(sector - bio->bi_sector) * -512;
|
|
bio_for_each_segment(bvl, bio, i) {
|
|
int len = bio_iovec_idx(bio,i)->bv_len;
|
|
int clen;
|
|
int b_offset = 0;
|
|
|
|
if (page_offset < 0) {
|
|
b_offset = -page_offset;
|
|
page_offset += b_offset;
|
|
len -= b_offset;
|
|
}
|
|
|
|
if (len > 0 && page_offset + len > STRIPE_SIZE)
|
|
clen = STRIPE_SIZE - page_offset;
|
|
else clen = len;
|
|
|
|
if (clen > 0) {
|
|
char *ba = __bio_kmap_atomic(bio, i, KM_USER0);
|
|
if (frombio)
|
|
memcpy(pa+page_offset, ba+b_offset, clen);
|
|
else
|
|
memcpy(ba+b_offset, pa+page_offset, clen);
|
|
__bio_kunmap_atomic(ba, KM_USER0);
|
|
}
|
|
if (clen < len) /* hit end of page */
|
|
break;
|
|
page_offset += len;
|
|
}
|
|
}
|
|
|
|
#define check_xor() do { \
|
|
if (count == MAX_XOR_BLOCKS) { \
|
|
xor_block(count, STRIPE_SIZE, ptr); \
|
|
count = 1; \
|
|
} \
|
|
} while(0)
|
|
|
|
|
|
static void compute_block(struct stripe_head *sh, int dd_idx)
|
|
{
|
|
raid5_conf_t *conf = sh->raid_conf;
|
|
int i, count, disks = conf->raid_disks;
|
|
void *ptr[MAX_XOR_BLOCKS], *p;
|
|
|
|
PRINTK("compute_block, stripe %llu, idx %d\n",
|
|
(unsigned long long)sh->sector, dd_idx);
|
|
|
|
ptr[0] = page_address(sh->dev[dd_idx].page);
|
|
memset(ptr[0], 0, STRIPE_SIZE);
|
|
count = 1;
|
|
for (i = disks ; i--; ) {
|
|
if (i == dd_idx)
|
|
continue;
|
|
p = page_address(sh->dev[i].page);
|
|
if (test_bit(R5_UPTODATE, &sh->dev[i].flags))
|
|
ptr[count++] = p;
|
|
else
|
|
printk("compute_block() %d, stripe %llu, %d"
|
|
" not present\n", dd_idx,
|
|
(unsigned long long)sh->sector, i);
|
|
|
|
check_xor();
|
|
}
|
|
if (count != 1)
|
|
xor_block(count, STRIPE_SIZE, ptr);
|
|
set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
|
|
}
|
|
|
|
static void compute_parity(struct stripe_head *sh, int method)
|
|
{
|
|
raid5_conf_t *conf = sh->raid_conf;
|
|
int i, pd_idx = sh->pd_idx, disks = conf->raid_disks, count;
|
|
void *ptr[MAX_XOR_BLOCKS];
|
|
struct bio *chosen;
|
|
|
|
PRINTK("compute_parity, stripe %llu, method %d\n",
|
|
(unsigned long long)sh->sector, method);
|
|
|
|
count = 1;
|
|
ptr[0] = page_address(sh->dev[pd_idx].page);
|
|
switch(method) {
|
|
case READ_MODIFY_WRITE:
|
|
if (!test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags))
|
|
BUG();
|
|
for (i=disks ; i-- ;) {
|
|
if (i==pd_idx)
|
|
continue;
|
|
if (sh->dev[i].towrite &&
|
|
test_bit(R5_UPTODATE, &sh->dev[i].flags)) {
|
|
ptr[count++] = page_address(sh->dev[i].page);
|
|
chosen = sh->dev[i].towrite;
|
|
sh->dev[i].towrite = NULL;
|
|
|
|
if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
|
|
wake_up(&conf->wait_for_overlap);
|
|
|
|
if (sh->dev[i].written) BUG();
|
|
sh->dev[i].written = chosen;
|
|
check_xor();
|
|
}
|
|
}
|
|
break;
|
|
case RECONSTRUCT_WRITE:
|
|
memset(ptr[0], 0, STRIPE_SIZE);
|
|
for (i= disks; i-- ;)
|
|
if (i!=pd_idx && sh->dev[i].towrite) {
|
|
chosen = sh->dev[i].towrite;
|
|
sh->dev[i].towrite = NULL;
|
|
|
|
if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
|
|
wake_up(&conf->wait_for_overlap);
|
|
|
|
if (sh->dev[i].written) BUG();
|
|
sh->dev[i].written = chosen;
|
|
}
|
|
break;
|
|
case CHECK_PARITY:
|
|
break;
|
|
}
|
|
if (count>1) {
|
|
xor_block(count, STRIPE_SIZE, ptr);
|
|
count = 1;
|
|
}
|
|
|
|
for (i = disks; i--;)
|
|
if (sh->dev[i].written) {
|
|
sector_t sector = sh->dev[i].sector;
|
|
struct bio *wbi = sh->dev[i].written;
|
|
while (wbi && wbi->bi_sector < sector + STRIPE_SECTORS) {
|
|
copy_data(1, wbi, sh->dev[i].page, sector);
|
|
wbi = r5_next_bio(wbi, sector);
|
|
}
|
|
|
|
set_bit(R5_LOCKED, &sh->dev[i].flags);
|
|
set_bit(R5_UPTODATE, &sh->dev[i].flags);
|
|
}
|
|
|
|
switch(method) {
|
|
case RECONSTRUCT_WRITE:
|
|
case CHECK_PARITY:
|
|
for (i=disks; i--;)
|
|
if (i != pd_idx) {
|
|
ptr[count++] = page_address(sh->dev[i].page);
|
|
check_xor();
|
|
}
|
|
break;
|
|
case READ_MODIFY_WRITE:
|
|
for (i = disks; i--;)
|
|
if (sh->dev[i].written) {
|
|
ptr[count++] = page_address(sh->dev[i].page);
|
|
check_xor();
|
|
}
|
|
}
|
|
if (count != 1)
|
|
xor_block(count, STRIPE_SIZE, ptr);
|
|
|
|
if (method != CHECK_PARITY) {
|
|
set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
|
|
set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
|
|
} else
|
|
clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
|
|
}
|
|
|
|
/*
|
|
* Each stripe/dev can have one or more bion attached.
|
|
* toread/towrite point to the first in a chain.
|
|
* The bi_next chain must be in order.
|
|
*/
|
|
static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, int forwrite)
|
|
{
|
|
struct bio **bip;
|
|
raid5_conf_t *conf = sh->raid_conf;
|
|
int firstwrite=0;
|
|
|
|
PRINTK("adding bh b#%llu to stripe s#%llu\n",
|
|
(unsigned long long)bi->bi_sector,
|
|
(unsigned long long)sh->sector);
|
|
|
|
|
|
spin_lock(&sh->lock);
|
|
spin_lock_irq(&conf->device_lock);
|
|
if (forwrite) {
|
|
bip = &sh->dev[dd_idx].towrite;
|
|
if (*bip == NULL && sh->dev[dd_idx].written == NULL)
|
|
firstwrite = 1;
|
|
} else
|
|
bip = &sh->dev[dd_idx].toread;
|
|
while (*bip && (*bip)->bi_sector < bi->bi_sector) {
|
|
if ((*bip)->bi_sector + ((*bip)->bi_size >> 9) > bi->bi_sector)
|
|
goto overlap;
|
|
bip = & (*bip)->bi_next;
|
|
}
|
|
if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9))
|
|
goto overlap;
|
|
|
|
if (*bip && bi->bi_next && (*bip) != bi->bi_next)
|
|
BUG();
|
|
if (*bip)
|
|
bi->bi_next = *bip;
|
|
*bip = bi;
|
|
bi->bi_phys_segments ++;
|
|
spin_unlock_irq(&conf->device_lock);
|
|
spin_unlock(&sh->lock);
|
|
|
|
PRINTK("added bi b#%llu to stripe s#%llu, disk %d.\n",
|
|
(unsigned long long)bi->bi_sector,
|
|
(unsigned long long)sh->sector, dd_idx);
|
|
|
|
if (conf->mddev->bitmap && firstwrite) {
|
|
sh->bm_seq = conf->seq_write;
|
|
bitmap_startwrite(conf->mddev->bitmap, sh->sector,
|
|
STRIPE_SECTORS, 0);
|
|
set_bit(STRIPE_BIT_DELAY, &sh->state);
|
|
}
|
|
|
|
if (forwrite) {
|
|
/* check if page is covered */
|
|
sector_t sector = sh->dev[dd_idx].sector;
|
|
for (bi=sh->dev[dd_idx].towrite;
|
|
sector < sh->dev[dd_idx].sector + STRIPE_SECTORS &&
|
|
bi && bi->bi_sector <= sector;
|
|
bi = r5_next_bio(bi, sh->dev[dd_idx].sector)) {
|
|
if (bi->bi_sector + (bi->bi_size>>9) >= sector)
|
|
sector = bi->bi_sector + (bi->bi_size>>9);
|
|
}
|
|
if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS)
|
|
set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags);
|
|
}
|
|
return 1;
|
|
|
|
overlap:
|
|
set_bit(R5_Overlap, &sh->dev[dd_idx].flags);
|
|
spin_unlock_irq(&conf->device_lock);
|
|
spin_unlock(&sh->lock);
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*
|
|
* handle_stripe - do things to a stripe.
|
|
*
|
|
* We lock the stripe and then examine the state of various bits
|
|
* to see what needs to be done.
|
|
* Possible results:
|
|
* return some read request which now have data
|
|
* return some write requests which are safely on disc
|
|
* schedule a read on some buffers
|
|
* schedule a write of some buffers
|
|
* return confirmation of parity correctness
|
|
*
|
|
* Parity calculations are done inside the stripe lock
|
|
* buffers are taken off read_list or write_list, and bh_cache buffers
|
|
* get BH_Lock set before the stripe lock is released.
|
|
*
|
|
*/
|
|
|
|
static void handle_stripe(struct stripe_head *sh)
|
|
{
|
|
raid5_conf_t *conf = sh->raid_conf;
|
|
int disks = conf->raid_disks;
|
|
struct bio *return_bi= NULL;
|
|
struct bio *bi;
|
|
int i;
|
|
int syncing;
|
|
int locked=0, uptodate=0, to_read=0, to_write=0, failed=0, written=0;
|
|
int non_overwrite = 0;
|
|
int failed_num=0;
|
|
struct r5dev *dev;
|
|
|
|
PRINTK("handling stripe %llu, cnt=%d, pd_idx=%d\n",
|
|
(unsigned long long)sh->sector, atomic_read(&sh->count),
|
|
sh->pd_idx);
|
|
|
|
spin_lock(&sh->lock);
|
|
clear_bit(STRIPE_HANDLE, &sh->state);
|
|
clear_bit(STRIPE_DELAYED, &sh->state);
|
|
|
|
syncing = test_bit(STRIPE_SYNCING, &sh->state);
|
|
/* Now to look around and see what can be done */
|
|
|
|
for (i=disks; i--; ) {
|
|
mdk_rdev_t *rdev;
|
|
dev = &sh->dev[i];
|
|
clear_bit(R5_Insync, &dev->flags);
|
|
clear_bit(R5_Syncio, &dev->flags);
|
|
|
|
PRINTK("check %d: state 0x%lx read %p write %p written %p\n",
|
|
i, dev->flags, dev->toread, dev->towrite, dev->written);
|
|
/* maybe we can reply to a read */
|
|
if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) {
|
|
struct bio *rbi, *rbi2;
|
|
PRINTK("Return read for disc %d\n", i);
|
|
spin_lock_irq(&conf->device_lock);
|
|
rbi = dev->toread;
|
|
dev->toread = NULL;
|
|
if (test_and_clear_bit(R5_Overlap, &dev->flags))
|
|
wake_up(&conf->wait_for_overlap);
|
|
spin_unlock_irq(&conf->device_lock);
|
|
while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) {
|
|
copy_data(0, rbi, dev->page, dev->sector);
|
|
rbi2 = r5_next_bio(rbi, dev->sector);
|
|
spin_lock_irq(&conf->device_lock);
|
|
if (--rbi->bi_phys_segments == 0) {
|
|
rbi->bi_next = return_bi;
|
|
return_bi = rbi;
|
|
}
|
|
spin_unlock_irq(&conf->device_lock);
|
|
rbi = rbi2;
|
|
}
|
|
}
|
|
|
|
/* now count some things */
|
|
if (test_bit(R5_LOCKED, &dev->flags)) locked++;
|
|
if (test_bit(R5_UPTODATE, &dev->flags)) uptodate++;
|
|
|
|
|
|
if (dev->toread) to_read++;
|
|
if (dev->towrite) {
|
|
to_write++;
|
|
if (!test_bit(R5_OVERWRITE, &dev->flags))
|
|
non_overwrite++;
|
|
}
|
|
if (dev->written) written++;
|
|
rdev = conf->disks[i].rdev; /* FIXME, should I be looking rdev */
|
|
if (!rdev || !test_bit(In_sync, &rdev->flags)) {
|
|
/* The ReadError flag wil just be confusing now */
|
|
clear_bit(R5_ReadError, &dev->flags);
|
|
clear_bit(R5_ReWrite, &dev->flags);
|
|
}
|
|
if (!rdev || !test_bit(In_sync, &rdev->flags)
|
|
|| test_bit(R5_ReadError, &dev->flags)) {
|
|
failed++;
|
|
failed_num = i;
|
|
} else
|
|
set_bit(R5_Insync, &dev->flags);
|
|
}
|
|
PRINTK("locked=%d uptodate=%d to_read=%d"
|
|
" to_write=%d failed=%d failed_num=%d\n",
|
|
locked, uptodate, to_read, to_write, failed, failed_num);
|
|
/* check if the array has lost two devices and, if so, some requests might
|
|
* need to be failed
|
|
*/
|
|
if (failed > 1 && to_read+to_write+written) {
|
|
for (i=disks; i--; ) {
|
|
int bitmap_end = 0;
|
|
|
|
if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
|
|
mdk_rdev_t *rdev = conf->disks[i].rdev;
|
|
if (rdev && test_bit(In_sync, &rdev->flags))
|
|
/* multiple read failures in one stripe */
|
|
md_error(conf->mddev, rdev);
|
|
}
|
|
|
|
spin_lock_irq(&conf->device_lock);
|
|
/* fail all writes first */
|
|
bi = sh->dev[i].towrite;
|
|
sh->dev[i].towrite = NULL;
|
|
if (bi) { to_write--; bitmap_end = 1; }
|
|
|
|
if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
|
|
wake_up(&conf->wait_for_overlap);
|
|
|
|
while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){
|
|
struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
|
|
clear_bit(BIO_UPTODATE, &bi->bi_flags);
|
|
if (--bi->bi_phys_segments == 0) {
|
|
md_write_end(conf->mddev);
|
|
bi->bi_next = return_bi;
|
|
return_bi = bi;
|
|
}
|
|
bi = nextbi;
|
|
}
|
|
/* and fail all 'written' */
|
|
bi = sh->dev[i].written;
|
|
sh->dev[i].written = NULL;
|
|
if (bi) bitmap_end = 1;
|
|
while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS) {
|
|
struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
|
|
clear_bit(BIO_UPTODATE, &bi->bi_flags);
|
|
if (--bi->bi_phys_segments == 0) {
|
|
md_write_end(conf->mddev);
|
|
bi->bi_next = return_bi;
|
|
return_bi = bi;
|
|
}
|
|
bi = bi2;
|
|
}
|
|
|
|
/* fail any reads if this device is non-operational */
|
|
if (!test_bit(R5_Insync, &sh->dev[i].flags) ||
|
|
test_bit(R5_ReadError, &sh->dev[i].flags)) {
|
|
bi = sh->dev[i].toread;
|
|
sh->dev[i].toread = NULL;
|
|
if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
|
|
wake_up(&conf->wait_for_overlap);
|
|
if (bi) to_read--;
|
|
while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){
|
|
struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
|
|
clear_bit(BIO_UPTODATE, &bi->bi_flags);
|
|
if (--bi->bi_phys_segments == 0) {
|
|
bi->bi_next = return_bi;
|
|
return_bi = bi;
|
|
}
|
|
bi = nextbi;
|
|
}
|
|
}
|
|
spin_unlock_irq(&conf->device_lock);
|
|
if (bitmap_end)
|
|
bitmap_endwrite(conf->mddev->bitmap, sh->sector,
|
|
STRIPE_SECTORS, 0, 0);
|
|
}
|
|
}
|
|
if (failed > 1 && syncing) {
|
|
md_done_sync(conf->mddev, STRIPE_SECTORS,0);
|
|
clear_bit(STRIPE_SYNCING, &sh->state);
|
|
syncing = 0;
|
|
}
|
|
|
|
/* might be able to return some write requests if the parity block
|
|
* is safe, or on a failed drive
|
|
*/
|
|
dev = &sh->dev[sh->pd_idx];
|
|
if ( written &&
|
|
( (test_bit(R5_Insync, &dev->flags) && !test_bit(R5_LOCKED, &dev->flags) &&
|
|
test_bit(R5_UPTODATE, &dev->flags))
|
|
|| (failed == 1 && failed_num == sh->pd_idx))
|
|
) {
|
|
/* any written block on an uptodate or failed drive can be returned.
|
|
* Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
|
|
* never LOCKED, so we don't need to test 'failed' directly.
|
|
*/
|
|
for (i=disks; i--; )
|
|
if (sh->dev[i].written) {
|
|
dev = &sh->dev[i];
|
|
if (!test_bit(R5_LOCKED, &dev->flags) &&
|
|
test_bit(R5_UPTODATE, &dev->flags) ) {
|
|
/* We can return any write requests */
|
|
struct bio *wbi, *wbi2;
|
|
int bitmap_end = 0;
|
|
PRINTK("Return write for disc %d\n", i);
|
|
spin_lock_irq(&conf->device_lock);
|
|
wbi = dev->written;
|
|
dev->written = NULL;
|
|
while (wbi && wbi->bi_sector < dev->sector + STRIPE_SECTORS) {
|
|
wbi2 = r5_next_bio(wbi, dev->sector);
|
|
if (--wbi->bi_phys_segments == 0) {
|
|
md_write_end(conf->mddev);
|
|
wbi->bi_next = return_bi;
|
|
return_bi = wbi;
|
|
}
|
|
wbi = wbi2;
|
|
}
|
|
if (dev->towrite == NULL)
|
|
bitmap_end = 1;
|
|
spin_unlock_irq(&conf->device_lock);
|
|
if (bitmap_end)
|
|
bitmap_endwrite(conf->mddev->bitmap, sh->sector,
|
|
STRIPE_SECTORS,
|
|
!test_bit(STRIPE_DEGRADED, &sh->state), 0);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Now we might consider reading some blocks, either to check/generate
|
|
* parity, or to satisfy requests
|
|
* or to load a block that is being partially written.
|
|
*/
|
|
if (to_read || non_overwrite || (syncing && (uptodate < disks))) {
|
|
for (i=disks; i--;) {
|
|
dev = &sh->dev[i];
|
|
if (!test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) &&
|
|
(dev->toread ||
|
|
(dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
|
|
syncing ||
|
|
(failed && (sh->dev[failed_num].toread ||
|
|
(sh->dev[failed_num].towrite && !test_bit(R5_OVERWRITE, &sh->dev[failed_num].flags))))
|
|
)
|
|
) {
|
|
/* we would like to get this block, possibly
|
|
* by computing it, but we might not be able to
|
|
*/
|
|
if (uptodate == disks-1) {
|
|
PRINTK("Computing block %d\n", i);
|
|
compute_block(sh, i);
|
|
uptodate++;
|
|
} else if (test_bit(R5_Insync, &dev->flags)) {
|
|
set_bit(R5_LOCKED, &dev->flags);
|
|
set_bit(R5_Wantread, &dev->flags);
|
|
#if 0
|
|
/* if I am just reading this block and we don't have
|
|
a failed drive, or any pending writes then sidestep the cache */
|
|
if (sh->bh_read[i] && !sh->bh_read[i]->b_reqnext &&
|
|
! syncing && !failed && !to_write) {
|
|
sh->bh_cache[i]->b_page = sh->bh_read[i]->b_page;
|
|
sh->bh_cache[i]->b_data = sh->bh_read[i]->b_data;
|
|
}
|
|
#endif
|
|
locked++;
|
|
PRINTK("Reading block %d (sync=%d)\n",
|
|
i, syncing);
|
|
if (syncing)
|
|
md_sync_acct(conf->disks[i].rdev->bdev,
|
|
STRIPE_SECTORS);
|
|
}
|
|
}
|
|
}
|
|
set_bit(STRIPE_HANDLE, &sh->state);
|
|
}
|
|
|
|
/* now to consider writing and what else, if anything should be read */
|
|
if (to_write) {
|
|
int rmw=0, rcw=0;
|
|
for (i=disks ; i--;) {
|
|
/* would I have to read this buffer for read_modify_write */
|
|
dev = &sh->dev[i];
|
|
if ((dev->towrite || i == sh->pd_idx) &&
|
|
(!test_bit(R5_LOCKED, &dev->flags)
|
|
#if 0
|
|
|| sh->bh_page[i]!=bh->b_page
|
|
#endif
|
|
) &&
|
|
!test_bit(R5_UPTODATE, &dev->flags)) {
|
|
if (test_bit(R5_Insync, &dev->flags)
|
|
/* && !(!mddev->insync && i == sh->pd_idx) */
|
|
)
|
|
rmw++;
|
|
else rmw += 2*disks; /* cannot read it */
|
|
}
|
|
/* Would I have to read this buffer for reconstruct_write */
|
|
if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx &&
|
|
(!test_bit(R5_LOCKED, &dev->flags)
|
|
#if 0
|
|
|| sh->bh_page[i] != bh->b_page
|
|
#endif
|
|
) &&
|
|
!test_bit(R5_UPTODATE, &dev->flags)) {
|
|
if (test_bit(R5_Insync, &dev->flags)) rcw++;
|
|
else rcw += 2*disks;
|
|
}
|
|
}
|
|
PRINTK("for sector %llu, rmw=%d rcw=%d\n",
|
|
(unsigned long long)sh->sector, rmw, rcw);
|
|
set_bit(STRIPE_HANDLE, &sh->state);
|
|
if (rmw < rcw && rmw > 0)
|
|
/* prefer read-modify-write, but need to get some data */
|
|
for (i=disks; i--;) {
|
|
dev = &sh->dev[i];
|
|
if ((dev->towrite || i == sh->pd_idx) &&
|
|
!test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) &&
|
|
test_bit(R5_Insync, &dev->flags)) {
|
|
if (test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
|
|
{
|
|
PRINTK("Read_old block %d for r-m-w\n", i);
|
|
set_bit(R5_LOCKED, &dev->flags);
|
|
set_bit(R5_Wantread, &dev->flags);
|
|
locked++;
|
|
} else {
|
|
set_bit(STRIPE_DELAYED, &sh->state);
|
|
set_bit(STRIPE_HANDLE, &sh->state);
|
|
}
|
|
}
|
|
}
|
|
if (rcw <= rmw && rcw > 0)
|
|
/* want reconstruct write, but need to get some data */
|
|
for (i=disks; i--;) {
|
|
dev = &sh->dev[i];
|
|
if (!test_bit(R5_OVERWRITE, &dev->flags) && i != sh->pd_idx &&
|
|
!test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) &&
|
|
test_bit(R5_Insync, &dev->flags)) {
|
|
if (test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
|
|
{
|
|
PRINTK("Read_old block %d for Reconstruct\n", i);
|
|
set_bit(R5_LOCKED, &dev->flags);
|
|
set_bit(R5_Wantread, &dev->flags);
|
|
locked++;
|
|
} else {
|
|
set_bit(STRIPE_DELAYED, &sh->state);
|
|
set_bit(STRIPE_HANDLE, &sh->state);
|
|
}
|
|
}
|
|
}
|
|
/* now if nothing is locked, and if we have enough data, we can start a write request */
|
|
if (locked == 0 && (rcw == 0 ||rmw == 0) &&
|
|
!test_bit(STRIPE_BIT_DELAY, &sh->state)) {
|
|
PRINTK("Computing parity...\n");
|
|
compute_parity(sh, rcw==0 ? RECONSTRUCT_WRITE : READ_MODIFY_WRITE);
|
|
/* now every locked buffer is ready to be written */
|
|
for (i=disks; i--;)
|
|
if (test_bit(R5_LOCKED, &sh->dev[i].flags)) {
|
|
PRINTK("Writing block %d\n", i);
|
|
locked++;
|
|
set_bit(R5_Wantwrite, &sh->dev[i].flags);
|
|
if (!test_bit(R5_Insync, &sh->dev[i].flags)
|
|
|| (i==sh->pd_idx && failed == 0))
|
|
set_bit(STRIPE_INSYNC, &sh->state);
|
|
}
|
|
if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
|
|
atomic_dec(&conf->preread_active_stripes);
|
|
if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD)
|
|
md_wakeup_thread(conf->mddev->thread);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* maybe we need to check and possibly fix the parity for this stripe
|
|
* Any reads will already have been scheduled, so we just see if enough data
|
|
* is available
|
|
*/
|
|
if (syncing && locked == 0 &&
|
|
!test_bit(STRIPE_INSYNC, &sh->state) && failed <= 1) {
|
|
set_bit(STRIPE_HANDLE, &sh->state);
|
|
if (failed == 0) {
|
|
char *pagea;
|
|
if (uptodate != disks)
|
|
BUG();
|
|
compute_parity(sh, CHECK_PARITY);
|
|
uptodate--;
|
|
pagea = page_address(sh->dev[sh->pd_idx].page);
|
|
if ((*(u32*)pagea) == 0 &&
|
|
!memcmp(pagea, pagea+4, STRIPE_SIZE-4)) {
|
|
/* parity is correct (on disc, not in buffer any more) */
|
|
set_bit(STRIPE_INSYNC, &sh->state);
|
|
} else {
|
|
conf->mddev->resync_mismatches += STRIPE_SECTORS;
|
|
if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
|
|
/* don't try to repair!! */
|
|
set_bit(STRIPE_INSYNC, &sh->state);
|
|
}
|
|
}
|
|
if (!test_bit(STRIPE_INSYNC, &sh->state)) {
|
|
if (failed==0)
|
|
failed_num = sh->pd_idx;
|
|
/* should be able to compute the missing block and write it to spare */
|
|
if (!test_bit(R5_UPTODATE, &sh->dev[failed_num].flags)) {
|
|
if (uptodate+1 != disks)
|
|
BUG();
|
|
compute_block(sh, failed_num);
|
|
uptodate++;
|
|
}
|
|
if (uptodate != disks)
|
|
BUG();
|
|
dev = &sh->dev[failed_num];
|
|
set_bit(R5_LOCKED, &dev->flags);
|
|
set_bit(R5_Wantwrite, &dev->flags);
|
|
clear_bit(STRIPE_DEGRADED, &sh->state);
|
|
locked++;
|
|
set_bit(STRIPE_INSYNC, &sh->state);
|
|
set_bit(R5_Syncio, &dev->flags);
|
|
}
|
|
}
|
|
if (syncing && locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
|
|
md_done_sync(conf->mddev, STRIPE_SECTORS,1);
|
|
clear_bit(STRIPE_SYNCING, &sh->state);
|
|
}
|
|
|
|
/* If the failed drive is just a ReadError, then we might need to progress
|
|
* the repair/check process
|
|
*/
|
|
if (failed == 1 && ! conf->mddev->ro &&
|
|
test_bit(R5_ReadError, &sh->dev[failed_num].flags)
|
|
&& !test_bit(R5_LOCKED, &sh->dev[failed_num].flags)
|
|
&& test_bit(R5_UPTODATE, &sh->dev[failed_num].flags)
|
|
) {
|
|
dev = &sh->dev[failed_num];
|
|
if (!test_bit(R5_ReWrite, &dev->flags)) {
|
|
set_bit(R5_Wantwrite, &dev->flags);
|
|
set_bit(R5_ReWrite, &dev->flags);
|
|
set_bit(R5_LOCKED, &dev->flags);
|
|
} else {
|
|
/* let's read it back */
|
|
set_bit(R5_Wantread, &dev->flags);
|
|
set_bit(R5_LOCKED, &dev->flags);
|
|
}
|
|
}
|
|
|
|
spin_unlock(&sh->lock);
|
|
|
|
while ((bi=return_bi)) {
|
|
int bytes = bi->bi_size;
|
|
|
|
return_bi = bi->bi_next;
|
|
bi->bi_next = NULL;
|
|
bi->bi_size = 0;
|
|
bi->bi_end_io(bi, bytes, 0);
|
|
}
|
|
for (i=disks; i-- ;) {
|
|
int rw;
|
|
struct bio *bi;
|
|
mdk_rdev_t *rdev;
|
|
if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
|
|
rw = 1;
|
|
else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
|
|
rw = 0;
|
|
else
|
|
continue;
|
|
|
|
bi = &sh->dev[i].req;
|
|
|
|
bi->bi_rw = rw;
|
|
if (rw)
|
|
bi->bi_end_io = raid5_end_write_request;
|
|
else
|
|
bi->bi_end_io = raid5_end_read_request;
|
|
|
|
rcu_read_lock();
|
|
rdev = rcu_dereference(conf->disks[i].rdev);
|
|
if (rdev && test_bit(Faulty, &rdev->flags))
|
|
rdev = NULL;
|
|
if (rdev)
|
|
atomic_inc(&rdev->nr_pending);
|
|
rcu_read_unlock();
|
|
|
|
if (rdev) {
|
|
if (test_bit(R5_Syncio, &sh->dev[i].flags))
|
|
md_sync_acct(rdev->bdev, STRIPE_SECTORS);
|
|
|
|
bi->bi_bdev = rdev->bdev;
|
|
PRINTK("for %llu schedule op %ld on disc %d\n",
|
|
(unsigned long long)sh->sector, bi->bi_rw, i);
|
|
atomic_inc(&sh->count);
|
|
bi->bi_sector = sh->sector + rdev->data_offset;
|
|
bi->bi_flags = 1 << BIO_UPTODATE;
|
|
bi->bi_vcnt = 1;
|
|
bi->bi_max_vecs = 1;
|
|
bi->bi_idx = 0;
|
|
bi->bi_io_vec = &sh->dev[i].vec;
|
|
bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
|
|
bi->bi_io_vec[0].bv_offset = 0;
|
|
bi->bi_size = STRIPE_SIZE;
|
|
bi->bi_next = NULL;
|
|
generic_make_request(bi);
|
|
} else {
|
|
if (rw == 1)
|
|
set_bit(STRIPE_DEGRADED, &sh->state);
|
|
PRINTK("skip op %ld on disc %d for sector %llu\n",
|
|
bi->bi_rw, i, (unsigned long long)sh->sector);
|
|
clear_bit(R5_LOCKED, &sh->dev[i].flags);
|
|
set_bit(STRIPE_HANDLE, &sh->state);
|
|
}
|
|
}
|
|
}
|
|
|
|
static inline void raid5_activate_delayed(raid5_conf_t *conf)
|
|
{
|
|
if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) {
|
|
while (!list_empty(&conf->delayed_list)) {
|
|
struct list_head *l = conf->delayed_list.next;
|
|
struct stripe_head *sh;
|
|
sh = list_entry(l, struct stripe_head, lru);
|
|
list_del_init(l);
|
|
clear_bit(STRIPE_DELAYED, &sh->state);
|
|
if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
|
|
atomic_inc(&conf->preread_active_stripes);
|
|
list_add_tail(&sh->lru, &conf->handle_list);
|
|
}
|
|
}
|
|
}
|
|
|
|
static inline void activate_bit_delay(raid5_conf_t *conf)
|
|
{
|
|
/* device_lock is held */
|
|
struct list_head head;
|
|
list_add(&head, &conf->bitmap_list);
|
|
list_del_init(&conf->bitmap_list);
|
|
while (!list_empty(&head)) {
|
|
struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
|
|
list_del_init(&sh->lru);
|
|
atomic_inc(&sh->count);
|
|
__release_stripe(conf, sh);
|
|
}
|
|
}
|
|
|
|
static void unplug_slaves(mddev_t *mddev)
|
|
{
|
|
raid5_conf_t *conf = mddev_to_conf(mddev);
|
|
int i;
|
|
|
|
rcu_read_lock();
|
|
for (i=0; i<mddev->raid_disks; i++) {
|
|
mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
|
|
if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
|
|
request_queue_t *r_queue = bdev_get_queue(rdev->bdev);
|
|
|
|
atomic_inc(&rdev->nr_pending);
|
|
rcu_read_unlock();
|
|
|
|
if (r_queue->unplug_fn)
|
|
r_queue->unplug_fn(r_queue);
|
|
|
|
rdev_dec_pending(rdev, mddev);
|
|
rcu_read_lock();
|
|
}
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static void raid5_unplug_device(request_queue_t *q)
|
|
{
|
|
mddev_t *mddev = q->queuedata;
|
|
raid5_conf_t *conf = mddev_to_conf(mddev);
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&conf->device_lock, flags);
|
|
|
|
if (blk_remove_plug(q)) {
|
|
conf->seq_flush++;
|
|
raid5_activate_delayed(conf);
|
|
}
|
|
md_wakeup_thread(mddev->thread);
|
|
|
|
spin_unlock_irqrestore(&conf->device_lock, flags);
|
|
|
|
unplug_slaves(mddev);
|
|
}
|
|
|
|
static int raid5_issue_flush(request_queue_t *q, struct gendisk *disk,
|
|
sector_t *error_sector)
|
|
{
|
|
mddev_t *mddev = q->queuedata;
|
|
raid5_conf_t *conf = mddev_to_conf(mddev);
|
|
int i, ret = 0;
|
|
|
|
rcu_read_lock();
|
|
for (i=0; i<mddev->raid_disks && ret == 0; i++) {
|
|
mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
|
|
if (rdev && !test_bit(Faulty, &rdev->flags)) {
|
|
struct block_device *bdev = rdev->bdev;
|
|
request_queue_t *r_queue = bdev_get_queue(bdev);
|
|
|
|
if (!r_queue->issue_flush_fn)
|
|
ret = -EOPNOTSUPP;
|
|
else {
|
|
atomic_inc(&rdev->nr_pending);
|
|
rcu_read_unlock();
|
|
ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk,
|
|
error_sector);
|
|
rdev_dec_pending(rdev, mddev);
|
|
rcu_read_lock();
|
|
}
|
|
}
|
|
}
|
|
rcu_read_unlock();
|
|
return ret;
|
|
}
|
|
|
|
static inline void raid5_plug_device(raid5_conf_t *conf)
|
|
{
|
|
spin_lock_irq(&conf->device_lock);
|
|
blk_plug_device(conf->mddev->queue);
|
|
spin_unlock_irq(&conf->device_lock);
|
|
}
|
|
|
|
static int make_request (request_queue_t *q, struct bio * bi)
|
|
{
|
|
mddev_t *mddev = q->queuedata;
|
|
raid5_conf_t *conf = mddev_to_conf(mddev);
|
|
const unsigned int raid_disks = conf->raid_disks;
|
|
const unsigned int data_disks = raid_disks - 1;
|
|
unsigned int dd_idx, pd_idx;
|
|
sector_t new_sector;
|
|
sector_t logical_sector, last_sector;
|
|
struct stripe_head *sh;
|
|
const int rw = bio_data_dir(bi);
|
|
|
|
if (unlikely(bio_barrier(bi))) {
|
|
bio_endio(bi, bi->bi_size, -EOPNOTSUPP);
|
|
return 0;
|
|
}
|
|
|
|
md_write_start(mddev, bi);
|
|
|
|
disk_stat_inc(mddev->gendisk, ios[rw]);
|
|
disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bi));
|
|
|
|
logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
|
|
last_sector = bi->bi_sector + (bi->bi_size>>9);
|
|
bi->bi_next = NULL;
|
|
bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
|
|
|
|
for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
|
|
DEFINE_WAIT(w);
|
|
|
|
new_sector = raid5_compute_sector(logical_sector,
|
|
raid_disks, data_disks, &dd_idx, &pd_idx, conf);
|
|
|
|
PRINTK("raid5: make_request, sector %llu logical %llu\n",
|
|
(unsigned long long)new_sector,
|
|
(unsigned long long)logical_sector);
|
|
|
|
retry:
|
|
prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
|
|
sh = get_active_stripe(conf, new_sector, pd_idx, (bi->bi_rw&RWA_MASK));
|
|
if (sh) {
|
|
if (!add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) {
|
|
/* Add failed due to overlap. Flush everything
|
|
* and wait a while
|
|
*/
|
|
raid5_unplug_device(mddev->queue);
|
|
release_stripe(sh);
|
|
schedule();
|
|
goto retry;
|
|
}
|
|
finish_wait(&conf->wait_for_overlap, &w);
|
|
raid5_plug_device(conf);
|
|
handle_stripe(sh);
|
|
release_stripe(sh);
|
|
|
|
} else {
|
|
/* cannot get stripe for read-ahead, just give-up */
|
|
clear_bit(BIO_UPTODATE, &bi->bi_flags);
|
|
finish_wait(&conf->wait_for_overlap, &w);
|
|
break;
|
|
}
|
|
|
|
}
|
|
spin_lock_irq(&conf->device_lock);
|
|
if (--bi->bi_phys_segments == 0) {
|
|
int bytes = bi->bi_size;
|
|
|
|
if ( bio_data_dir(bi) == WRITE )
|
|
md_write_end(mddev);
|
|
bi->bi_size = 0;
|
|
bi->bi_end_io(bi, bytes, 0);
|
|
}
|
|
spin_unlock_irq(&conf->device_lock);
|
|
return 0;
|
|
}
|
|
|
|
/* FIXME go_faster isn't used */
|
|
static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
|
|
{
|
|
raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
|
|
struct stripe_head *sh;
|
|
int sectors_per_chunk = conf->chunk_size >> 9;
|
|
sector_t x;
|
|
unsigned long stripe;
|
|
int chunk_offset;
|
|
int dd_idx, pd_idx;
|
|
sector_t first_sector;
|
|
int raid_disks = conf->raid_disks;
|
|
int data_disks = raid_disks-1;
|
|
sector_t max_sector = mddev->size << 1;
|
|
int sync_blocks;
|
|
|
|
if (sector_nr >= max_sector) {
|
|
/* just being told to finish up .. nothing much to do */
|
|
unplug_slaves(mddev);
|
|
|
|
if (mddev->curr_resync < max_sector) /* aborted */
|
|
bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
|
|
&sync_blocks, 1);
|
|
else /* compelted sync */
|
|
conf->fullsync = 0;
|
|
bitmap_close_sync(mddev->bitmap);
|
|
|
|
return 0;
|
|
}
|
|
/* if there is 1 or more failed drives and we are trying
|
|
* to resync, then assert that we are finished, because there is
|
|
* nothing we can do.
|
|
*/
|
|
if (mddev->degraded >= 1 && test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
|
|
sector_t rv = (mddev->size << 1) - sector_nr;
|
|
*skipped = 1;
|
|
return rv;
|
|
}
|
|
if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
|
|
!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
|
|
!conf->fullsync && sync_blocks >= STRIPE_SECTORS) {
|
|
/* we can skip this block, and probably more */
|
|
sync_blocks /= STRIPE_SECTORS;
|
|
*skipped = 1;
|
|
return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */
|
|
}
|
|
|
|
x = sector_nr;
|
|
chunk_offset = sector_div(x, sectors_per_chunk);
|
|
stripe = x;
|
|
BUG_ON(x != stripe);
|
|
|
|
first_sector = raid5_compute_sector((sector_t)stripe*data_disks*sectors_per_chunk
|
|
+ chunk_offset, raid_disks, data_disks, &dd_idx, &pd_idx, conf);
|
|
sh = get_active_stripe(conf, sector_nr, pd_idx, 1);
|
|
if (sh == NULL) {
|
|
sh = get_active_stripe(conf, sector_nr, pd_idx, 0);
|
|
/* make sure we don't swamp the stripe cache if someone else
|
|
* is trying to get access
|
|
*/
|
|
schedule_timeout_uninterruptible(1);
|
|
}
|
|
bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 0);
|
|
spin_lock(&sh->lock);
|
|
set_bit(STRIPE_SYNCING, &sh->state);
|
|
clear_bit(STRIPE_INSYNC, &sh->state);
|
|
spin_unlock(&sh->lock);
|
|
|
|
handle_stripe(sh);
|
|
release_stripe(sh);
|
|
|
|
return STRIPE_SECTORS;
|
|
}
|
|
|
|
/*
|
|
* This is our raid5 kernel thread.
|
|
*
|
|
* We scan the hash table for stripes which can be handled now.
|
|
* During the scan, completed stripes are saved for us by the interrupt
|
|
* handler, so that they will not have to wait for our next wakeup.
|
|
*/
|
|
static void raid5d (mddev_t *mddev)
|
|
{
|
|
struct stripe_head *sh;
|
|
raid5_conf_t *conf = mddev_to_conf(mddev);
|
|
int handled;
|
|
|
|
PRINTK("+++ raid5d active\n");
|
|
|
|
md_check_recovery(mddev);
|
|
|
|
handled = 0;
|
|
spin_lock_irq(&conf->device_lock);
|
|
while (1) {
|
|
struct list_head *first;
|
|
|
|
if (conf->seq_flush - conf->seq_write > 0) {
|
|
int seq = conf->seq_flush;
|
|
bitmap_unplug(mddev->bitmap);
|
|
conf->seq_write = seq;
|
|
activate_bit_delay(conf);
|
|
}
|
|
|
|
if (list_empty(&conf->handle_list) &&
|
|
atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD &&
|
|
!blk_queue_plugged(mddev->queue) &&
|
|
!list_empty(&conf->delayed_list))
|
|
raid5_activate_delayed(conf);
|
|
|
|
if (list_empty(&conf->handle_list))
|
|
break;
|
|
|
|
first = conf->handle_list.next;
|
|
sh = list_entry(first, struct stripe_head, lru);
|
|
|
|
list_del_init(first);
|
|
atomic_inc(&sh->count);
|
|
if (atomic_read(&sh->count)!= 1)
|
|
BUG();
|
|
spin_unlock_irq(&conf->device_lock);
|
|
|
|
handled++;
|
|
handle_stripe(sh);
|
|
release_stripe(sh);
|
|
|
|
spin_lock_irq(&conf->device_lock);
|
|
}
|
|
PRINTK("%d stripes handled\n", handled);
|
|
|
|
spin_unlock_irq(&conf->device_lock);
|
|
|
|
unplug_slaves(mddev);
|
|
|
|
PRINTK("--- raid5d inactive\n");
|
|
}
|
|
|
|
static ssize_t
|
|
raid5_show_stripe_cache_size(mddev_t *mddev, char *page)
|
|
{
|
|
raid5_conf_t *conf = mddev_to_conf(mddev);
|
|
if (conf)
|
|
return sprintf(page, "%d\n", conf->max_nr_stripes);
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t
|
|
raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len)
|
|
{
|
|
raid5_conf_t *conf = mddev_to_conf(mddev);
|
|
char *end;
|
|
int new;
|
|
if (len >= PAGE_SIZE)
|
|
return -EINVAL;
|
|
if (!conf)
|
|
return -ENODEV;
|
|
|
|
new = simple_strtoul(page, &end, 10);
|
|
if (!*page || (*end && *end != '\n') )
|
|
return -EINVAL;
|
|
if (new <= 16 || new > 32768)
|
|
return -EINVAL;
|
|
while (new < conf->max_nr_stripes) {
|
|
if (drop_one_stripe(conf))
|
|
conf->max_nr_stripes--;
|
|
else
|
|
break;
|
|
}
|
|
while (new > conf->max_nr_stripes) {
|
|
if (grow_one_stripe(conf))
|
|
conf->max_nr_stripes++;
|
|
else break;
|
|
}
|
|
return len;
|
|
}
|
|
|
|
static struct md_sysfs_entry
|
|
raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,
|
|
raid5_show_stripe_cache_size,
|
|
raid5_store_stripe_cache_size);
|
|
|
|
static ssize_t
|
|
stripe_cache_active_show(mddev_t *mddev, char *page)
|
|
{
|
|
raid5_conf_t *conf = mddev_to_conf(mddev);
|
|
if (conf)
|
|
return sprintf(page, "%d\n", atomic_read(&conf->active_stripes));
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
static struct md_sysfs_entry
|
|
raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
|
|
|
|
static struct attribute *raid5_attrs[] = {
|
|
&raid5_stripecache_size.attr,
|
|
&raid5_stripecache_active.attr,
|
|
NULL,
|
|
};
|
|
static struct attribute_group raid5_attrs_group = {
|
|
.name = NULL,
|
|
.attrs = raid5_attrs,
|
|
};
|
|
|
|
static int run(mddev_t *mddev)
|
|
{
|
|
raid5_conf_t *conf;
|
|
int raid_disk, memory;
|
|
mdk_rdev_t *rdev;
|
|
struct disk_info *disk;
|
|
struct list_head *tmp;
|
|
|
|
if (mddev->level != 5 && mddev->level != 4) {
|
|
printk("raid5: %s: raid level not set to 4/5 (%d)\n", mdname(mddev), mddev->level);
|
|
return -EIO;
|
|
}
|
|
|
|
mddev->private = kmalloc (sizeof (raid5_conf_t)
|
|
+ mddev->raid_disks * sizeof(struct disk_info),
|
|
GFP_KERNEL);
|
|
if ((conf = mddev->private) == NULL)
|
|
goto abort;
|
|
memset (conf, 0, sizeof (*conf) + mddev->raid_disks * sizeof(struct disk_info) );
|
|
conf->mddev = mddev;
|
|
|
|
if ((conf->stripe_hashtbl = (struct stripe_head **) __get_free_pages(GFP_ATOMIC, HASH_PAGES_ORDER)) == NULL)
|
|
goto abort;
|
|
memset(conf->stripe_hashtbl, 0, HASH_PAGES * PAGE_SIZE);
|
|
|
|
spin_lock_init(&conf->device_lock);
|
|
init_waitqueue_head(&conf->wait_for_stripe);
|
|
init_waitqueue_head(&conf->wait_for_overlap);
|
|
INIT_LIST_HEAD(&conf->handle_list);
|
|
INIT_LIST_HEAD(&conf->delayed_list);
|
|
INIT_LIST_HEAD(&conf->bitmap_list);
|
|
INIT_LIST_HEAD(&conf->inactive_list);
|
|
atomic_set(&conf->active_stripes, 0);
|
|
atomic_set(&conf->preread_active_stripes, 0);
|
|
|
|
PRINTK("raid5: run(%s) called.\n", mdname(mddev));
|
|
|
|
ITERATE_RDEV(mddev,rdev,tmp) {
|
|
raid_disk = rdev->raid_disk;
|
|
if (raid_disk >= mddev->raid_disks
|
|
|| raid_disk < 0)
|
|
continue;
|
|
disk = conf->disks + raid_disk;
|
|
|
|
disk->rdev = rdev;
|
|
|
|
if (test_bit(In_sync, &rdev->flags)) {
|
|
char b[BDEVNAME_SIZE];
|
|
printk(KERN_INFO "raid5: device %s operational as raid"
|
|
" disk %d\n", bdevname(rdev->bdev,b),
|
|
raid_disk);
|
|
conf->working_disks++;
|
|
}
|
|
}
|
|
|
|
conf->raid_disks = mddev->raid_disks;
|
|
/*
|
|
* 0 for a fully functional array, 1 for a degraded array.
|
|
*/
|
|
mddev->degraded = conf->failed_disks = conf->raid_disks - conf->working_disks;
|
|
conf->mddev = mddev;
|
|
conf->chunk_size = mddev->chunk_size;
|
|
conf->level = mddev->level;
|
|
conf->algorithm = mddev->layout;
|
|
conf->max_nr_stripes = NR_STRIPES;
|
|
|
|
/* device size must be a multiple of chunk size */
|
|
mddev->size &= ~(mddev->chunk_size/1024 -1);
|
|
mddev->resync_max_sectors = mddev->size << 1;
|
|
|
|
if (!conf->chunk_size || conf->chunk_size % 4) {
|
|
printk(KERN_ERR "raid5: invalid chunk size %d for %s\n",
|
|
conf->chunk_size, mdname(mddev));
|
|
goto abort;
|
|
}
|
|
if (conf->algorithm > ALGORITHM_RIGHT_SYMMETRIC) {
|
|
printk(KERN_ERR
|
|
"raid5: unsupported parity algorithm %d for %s\n",
|
|
conf->algorithm, mdname(mddev));
|
|
goto abort;
|
|
}
|
|
if (mddev->degraded > 1) {
|
|
printk(KERN_ERR "raid5: not enough operational devices for %s"
|
|
" (%d/%d failed)\n",
|
|
mdname(mddev), conf->failed_disks, conf->raid_disks);
|
|
goto abort;
|
|
}
|
|
|
|
if (mddev->degraded == 1 &&
|
|
mddev->recovery_cp != MaxSector) {
|
|
printk(KERN_ERR
|
|
"raid5: cannot start dirty degraded array for %s\n",
|
|
mdname(mddev));
|
|
goto abort;
|
|
}
|
|
|
|
{
|
|
mddev->thread = md_register_thread(raid5d, mddev, "%s_raid5");
|
|
if (!mddev->thread) {
|
|
printk(KERN_ERR
|
|
"raid5: couldn't allocate thread for %s\n",
|
|
mdname(mddev));
|
|
goto abort;
|
|
}
|
|
}
|
|
memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
|
|
conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
|
|
if (grow_stripes(conf, conf->max_nr_stripes)) {
|
|
printk(KERN_ERR
|
|
"raid5: couldn't allocate %dkB for buffers\n", memory);
|
|
shrink_stripes(conf);
|
|
md_unregister_thread(mddev->thread);
|
|
goto abort;
|
|
} else
|
|
printk(KERN_INFO "raid5: allocated %dkB for %s\n",
|
|
memory, mdname(mddev));
|
|
|
|
if (mddev->degraded == 0)
|
|
printk("raid5: raid level %d set %s active with %d out of %d"
|
|
" devices, algorithm %d\n", conf->level, mdname(mddev),
|
|
mddev->raid_disks-mddev->degraded, mddev->raid_disks,
|
|
conf->algorithm);
|
|
else
|
|
printk(KERN_ALERT "raid5: raid level %d set %s active with %d"
|
|
" out of %d devices, algorithm %d\n", conf->level,
|
|
mdname(mddev), mddev->raid_disks - mddev->degraded,
|
|
mddev->raid_disks, conf->algorithm);
|
|
|
|
print_raid5_conf(conf);
|
|
|
|
/* read-ahead size must cover two whole stripes, which is
|
|
* 2 * (n-1) * chunksize where 'n' is the number of raid devices
|
|
*/
|
|
{
|
|
int stripe = (mddev->raid_disks-1) * mddev->chunk_size
|
|
/ PAGE_CACHE_SIZE;
|
|
if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
|
|
mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
|
|
}
|
|
|
|
/* Ok, everything is just fine now */
|
|
sysfs_create_group(&mddev->kobj, &raid5_attrs_group);
|
|
|
|
if (mddev->bitmap)
|
|
mddev->thread->timeout = mddev->bitmap->daemon_sleep * HZ;
|
|
|
|
mddev->queue->unplug_fn = raid5_unplug_device;
|
|
mddev->queue->issue_flush_fn = raid5_issue_flush;
|
|
|
|
mddev->array_size = mddev->size * (mddev->raid_disks - 1);
|
|
return 0;
|
|
abort:
|
|
if (conf) {
|
|
print_raid5_conf(conf);
|
|
if (conf->stripe_hashtbl)
|
|
free_pages((unsigned long) conf->stripe_hashtbl,
|
|
HASH_PAGES_ORDER);
|
|
kfree(conf);
|
|
}
|
|
mddev->private = NULL;
|
|
printk(KERN_ALERT "raid5: failed to run raid set %s\n", mdname(mddev));
|
|
return -EIO;
|
|
}
|
|
|
|
|
|
|
|
static int stop(mddev_t *mddev)
|
|
{
|
|
raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
|
|
|
|
md_unregister_thread(mddev->thread);
|
|
mddev->thread = NULL;
|
|
shrink_stripes(conf);
|
|
free_pages((unsigned long) conf->stripe_hashtbl, HASH_PAGES_ORDER);
|
|
blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
|
|
sysfs_remove_group(&mddev->kobj, &raid5_attrs_group);
|
|
kfree(conf);
|
|
mddev->private = NULL;
|
|
return 0;
|
|
}
|
|
|
|
#if RAID5_DEBUG
|
|
static void print_sh (struct stripe_head *sh)
|
|
{
|
|
int i;
|
|
|
|
printk("sh %llu, pd_idx %d, state %ld.\n",
|
|
(unsigned long long)sh->sector, sh->pd_idx, sh->state);
|
|
printk("sh %llu, count %d.\n",
|
|
(unsigned long long)sh->sector, atomic_read(&sh->count));
|
|
printk("sh %llu, ", (unsigned long long)sh->sector);
|
|
for (i = 0; i < sh->raid_conf->raid_disks; i++) {
|
|
printk("(cache%d: %p %ld) ",
|
|
i, sh->dev[i].page, sh->dev[i].flags);
|
|
}
|
|
printk("\n");
|
|
}
|
|
|
|
static void printall (raid5_conf_t *conf)
|
|
{
|
|
struct stripe_head *sh;
|
|
int i;
|
|
|
|
spin_lock_irq(&conf->device_lock);
|
|
for (i = 0; i < NR_HASH; i++) {
|
|
sh = conf->stripe_hashtbl[i];
|
|
for (; sh; sh = sh->hash_next) {
|
|
if (sh->raid_conf != conf)
|
|
continue;
|
|
print_sh(sh);
|
|
}
|
|
}
|
|
spin_unlock_irq(&conf->device_lock);
|
|
}
|
|
#endif
|
|
|
|
static void status (struct seq_file *seq, mddev_t *mddev)
|
|
{
|
|
raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
|
|
int i;
|
|
|
|
seq_printf (seq, " level %d, %dk chunk, algorithm %d", mddev->level, mddev->chunk_size >> 10, mddev->layout);
|
|
seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->working_disks);
|
|
for (i = 0; i < conf->raid_disks; i++)
|
|
seq_printf (seq, "%s",
|
|
conf->disks[i].rdev &&
|
|
test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
|
|
seq_printf (seq, "]");
|
|
#if RAID5_DEBUG
|
|
#define D(x) \
|
|
seq_printf (seq, "<"#x":%d>", atomic_read(&conf->x))
|
|
printall(conf);
|
|
#endif
|
|
}
|
|
|
|
static void print_raid5_conf (raid5_conf_t *conf)
|
|
{
|
|
int i;
|
|
struct disk_info *tmp;
|
|
|
|
printk("RAID5 conf printout:\n");
|
|
if (!conf) {
|
|
printk("(conf==NULL)\n");
|
|
return;
|
|
}
|
|
printk(" --- rd:%d wd:%d fd:%d\n", conf->raid_disks,
|
|
conf->working_disks, conf->failed_disks);
|
|
|
|
for (i = 0; i < conf->raid_disks; i++) {
|
|
char b[BDEVNAME_SIZE];
|
|
tmp = conf->disks + i;
|
|
if (tmp->rdev)
|
|
printk(" disk %d, o:%d, dev:%s\n",
|
|
i, !test_bit(Faulty, &tmp->rdev->flags),
|
|
bdevname(tmp->rdev->bdev,b));
|
|
}
|
|
}
|
|
|
|
static int raid5_spare_active(mddev_t *mddev)
|
|
{
|
|
int i;
|
|
raid5_conf_t *conf = mddev->private;
|
|
struct disk_info *tmp;
|
|
|
|
for (i = 0; i < conf->raid_disks; i++) {
|
|
tmp = conf->disks + i;
|
|
if (tmp->rdev
|
|
&& !test_bit(Faulty, &tmp->rdev->flags)
|
|
&& !test_bit(In_sync, &tmp->rdev->flags)) {
|
|
mddev->degraded--;
|
|
conf->failed_disks--;
|
|
conf->working_disks++;
|
|
set_bit(In_sync, &tmp->rdev->flags);
|
|
}
|
|
}
|
|
print_raid5_conf(conf);
|
|
return 0;
|
|
}
|
|
|
|
static int raid5_remove_disk(mddev_t *mddev, int number)
|
|
{
|
|
raid5_conf_t *conf = mddev->private;
|
|
int err = 0;
|
|
mdk_rdev_t *rdev;
|
|
struct disk_info *p = conf->disks + number;
|
|
|
|
print_raid5_conf(conf);
|
|
rdev = p->rdev;
|
|
if (rdev) {
|
|
if (test_bit(In_sync, &rdev->flags) ||
|
|
atomic_read(&rdev->nr_pending)) {
|
|
err = -EBUSY;
|
|
goto abort;
|
|
}
|
|
p->rdev = NULL;
|
|
synchronize_rcu();
|
|
if (atomic_read(&rdev->nr_pending)) {
|
|
/* lost the race, try later */
|
|
err = -EBUSY;
|
|
p->rdev = rdev;
|
|
}
|
|
}
|
|
abort:
|
|
|
|
print_raid5_conf(conf);
|
|
return err;
|
|
}
|
|
|
|
static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
|
|
{
|
|
raid5_conf_t *conf = mddev->private;
|
|
int found = 0;
|
|
int disk;
|
|
struct disk_info *p;
|
|
|
|
if (mddev->degraded > 1)
|
|
/* no point adding a device */
|
|
return 0;
|
|
|
|
/*
|
|
* find the disk ...
|
|
*/
|
|
for (disk=0; disk < mddev->raid_disks; disk++)
|
|
if ((p=conf->disks + disk)->rdev == NULL) {
|
|
clear_bit(In_sync, &rdev->flags);
|
|
rdev->raid_disk = disk;
|
|
found = 1;
|
|
if (rdev->saved_raid_disk != disk)
|
|
conf->fullsync = 1;
|
|
rcu_assign_pointer(p->rdev, rdev);
|
|
break;
|
|
}
|
|
print_raid5_conf(conf);
|
|
return found;
|
|
}
|
|
|
|
static int raid5_resize(mddev_t *mddev, sector_t sectors)
|
|
{
|
|
/* no resync is happening, and there is enough space
|
|
* on all devices, so we can resize.
|
|
* We need to make sure resync covers any new space.
|
|
* If the array is shrinking we should possibly wait until
|
|
* any io in the removed space completes, but it hardly seems
|
|
* worth it.
|
|
*/
|
|
sectors &= ~((sector_t)mddev->chunk_size/512 - 1);
|
|
mddev->array_size = (sectors * (mddev->raid_disks-1))>>1;
|
|
set_capacity(mddev->gendisk, mddev->array_size << 1);
|
|
mddev->changed = 1;
|
|
if (sectors/2 > mddev->size && mddev->recovery_cp == MaxSector) {
|
|
mddev->recovery_cp = mddev->size << 1;
|
|
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
|
|
}
|
|
mddev->size = sectors /2;
|
|
mddev->resync_max_sectors = sectors;
|
|
return 0;
|
|
}
|
|
|
|
static void raid5_quiesce(mddev_t *mddev, int state)
|
|
{
|
|
raid5_conf_t *conf = mddev_to_conf(mddev);
|
|
|
|
switch(state) {
|
|
case 1: /* stop all writes */
|
|
spin_lock_irq(&conf->device_lock);
|
|
conf->quiesce = 1;
|
|
wait_event_lock_irq(conf->wait_for_stripe,
|
|
atomic_read(&conf->active_stripes) == 0,
|
|
conf->device_lock, /* nothing */);
|
|
spin_unlock_irq(&conf->device_lock);
|
|
break;
|
|
|
|
case 0: /* re-enable writes */
|
|
spin_lock_irq(&conf->device_lock);
|
|
conf->quiesce = 0;
|
|
wake_up(&conf->wait_for_stripe);
|
|
spin_unlock_irq(&conf->device_lock);
|
|
break;
|
|
}
|
|
if (mddev->thread) {
|
|
if (mddev->bitmap)
|
|
mddev->thread->timeout = mddev->bitmap->daemon_sleep * HZ;
|
|
else
|
|
mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
|
|
md_wakeup_thread(mddev->thread);
|
|
}
|
|
}
|
|
static mdk_personality_t raid5_personality=
|
|
{
|
|
.name = "raid5",
|
|
.owner = THIS_MODULE,
|
|
.make_request = make_request,
|
|
.run = run,
|
|
.stop = stop,
|
|
.status = status,
|
|
.error_handler = error,
|
|
.hot_add_disk = raid5_add_disk,
|
|
.hot_remove_disk= raid5_remove_disk,
|
|
.spare_active = raid5_spare_active,
|
|
.sync_request = sync_request,
|
|
.resize = raid5_resize,
|
|
.quiesce = raid5_quiesce,
|
|
};
|
|
|
|
static int __init raid5_init (void)
|
|
{
|
|
return register_md_personality (RAID5, &raid5_personality);
|
|
}
|
|
|
|
static void raid5_exit (void)
|
|
{
|
|
unregister_md_personality (RAID5);
|
|
}
|
|
|
|
module_init(raid5_init);
|
|
module_exit(raid5_exit);
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("md-personality-4"); /* RAID5 */
|