b158156618
The default resync_max_sector is set to "mddev->size << 1". If the raid-personality-module updates mddev->size, it must update resync_max_sectors too. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2139 lines
58 KiB
C
2139 lines
58 KiB
C
/*
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* raid6main.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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* Copyright (C) 2002, 2003 H. Peter Anvin
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*
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* RAID-6 management functions. This code is derived from raid5.c.
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* Last merge from raid5.c bkcvs version 1.79 (kernel 2.6.1).
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*
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* Thanks to Penguin Computing for making the RAID-6 development possible
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* by donating a test server!
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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/highmem.h>
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#include <linux/bitops.h>
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#include <asm/atomic.h>
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#include "raid6.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 RAID6_DEBUG 0 /* Extremely verbose printk */
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#define RAID6_PARANOIA 1 /* Check spinlocks */
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#define RAID6_DUMPSTATE 0 /* Include stripe cache state in /proc/mdstat */
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#if RAID6_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)(RAID6_DEBUG && printk(KERN_DEBUG x)))
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#if RAID6_DEBUG
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#undef inline
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#undef __inline__
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#define inline
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#define __inline__
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#endif
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#if !RAID6_USE_EMPTY_ZERO_PAGE
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/* In .bss so it's zeroed */
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const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
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#endif
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static inline int raid6_next_disk(int disk, int raid_disks)
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{
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disk++;
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return (disk < raid_disks) ? disk : 0;
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}
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static void print_raid6_conf (raid6_conf_t *conf);
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static inline void __release_stripe(raid6_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
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list_add_tail(&sh->lru, &conf->handle_list);
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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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raid6_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(raid6_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(raid6_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 raid6_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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raid6_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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raid6_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(raid6_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 struct stripe_head *get_active_stripe(raid6_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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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_stripes(raid6_conf_t *conf, int num)
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{
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struct stripe_head *sh;
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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, "raid6/%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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sh = kmem_cache_alloc(sc, GFP_KERNEL);
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if (!sh)
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return 1;
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memset(sh, 0, sizeof(*sh) + (devs-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(sc, sh);
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return 1;
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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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}
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return 0;
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}
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static void shrink_stripes(raid6_conf_t *conf)
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{
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struct stripe_head *sh;
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while (1) {
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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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break;
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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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}
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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 raid6_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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raid6_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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} else {
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md_error(conf->mddev, conf->disks[i].rdev);
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clear_bit(R5_UPTODATE, &sh->dev[i].flags);
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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 raid6_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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raid6_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",
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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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|
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spin_lock_irqsave(&conf->device_lock, flags);
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if (!uptodate)
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md_error(conf->mddev, conf->disks[i].rdev);
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rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
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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(conf, sh);
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spin_unlock_irqrestore(&conf->device_lock, flags);
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return 0;
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}
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|
|
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static sector_t compute_blocknr(struct stripe_head *sh, int i);
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static void raid6_build_block (struct stripe_head *sh, int i)
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{
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struct r5dev *dev = &sh->dev[i];
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int pd_idx = sh->pd_idx;
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int qd_idx = raid6_next_disk(pd_idx, sh->raid_conf->raid_disks);
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bio_init(&dev->req);
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dev->req.bi_io_vec = &dev->vec;
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dev->req.bi_vcnt++;
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dev->req.bi_max_vecs++;
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dev->vec.bv_page = dev->page;
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dev->vec.bv_len = STRIPE_SIZE;
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dev->vec.bv_offset = 0;
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dev->req.bi_sector = sh->sector;
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dev->req.bi_private = sh;
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dev->flags = 0;
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if (i != pd_idx && i != qd_idx)
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dev->sector = compute_blocknr(sh, i);
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}
|
|
|
|
static void error(mddev_t *mddev, mdk_rdev_t *rdev)
|
|
{
|
|
char b[BDEVNAME_SIZE];
|
|
raid6_conf_t *conf = (raid6_conf_t *) mddev->private;
|
|
PRINTK("raid6: error called\n");
|
|
|
|
if (!rdev->faulty) {
|
|
mddev->sb_dirty = 1;
|
|
if (rdev->in_sync) {
|
|
conf->working_disks--;
|
|
mddev->degraded++;
|
|
conf->failed_disks++;
|
|
rdev->in_sync = 0;
|
|
/*
|
|
* if recovery was running, make sure it aborts.
|
|
*/
|
|
set_bit(MD_RECOVERY_ERR, &mddev->recovery);
|
|
}
|
|
rdev->faulty = 1;
|
|
printk (KERN_ALERT
|
|
"raid6: 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 raid6_compute_sector(sector_t r_sector, unsigned int raid_disks,
|
|
unsigned int data_disks, unsigned int * dd_idx,
|
|
unsigned int * pd_idx, raid6_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;
|
|
if ( r_sector != chunk_number ) {
|
|
printk(KERN_CRIT "raid6: ERROR: r_sector = %llu, chunk_number = %lu\n",
|
|
(unsigned long long)r_sector, (unsigned long)chunk_number);
|
|
BUG();
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
|
|
/**** FIX THIS ****/
|
|
switch (conf->algorithm) {
|
|
case ALGORITHM_LEFT_ASYMMETRIC:
|
|
*pd_idx = raid_disks - 1 - (stripe % raid_disks);
|
|
if (*pd_idx == raid_disks-1)
|
|
(*dd_idx)++; /* Q D D D P */
|
|
else if (*dd_idx >= *pd_idx)
|
|
(*dd_idx) += 2; /* D D P Q D */
|
|
break;
|
|
case ALGORITHM_RIGHT_ASYMMETRIC:
|
|
*pd_idx = stripe % raid_disks;
|
|
if (*pd_idx == raid_disks-1)
|
|
(*dd_idx)++; /* Q D D D P */
|
|
else if (*dd_idx >= *pd_idx)
|
|
(*dd_idx) += 2; /* D D P Q D */
|
|
break;
|
|
case ALGORITHM_LEFT_SYMMETRIC:
|
|
*pd_idx = raid_disks - 1 - (stripe % raid_disks);
|
|
*dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks;
|
|
break;
|
|
case ALGORITHM_RIGHT_SYMMETRIC:
|
|
*pd_idx = stripe % raid_disks;
|
|
*dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks;
|
|
break;
|
|
default:
|
|
printk (KERN_CRIT "raid6: unsupported algorithm %d\n",
|
|
conf->algorithm);
|
|
}
|
|
|
|
PRINTK("raid6: chunk_number = %lu, pd_idx = %u, dd_idx = %u\n",
|
|
chunk_number, *pd_idx, *dd_idx);
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
raid6_conf_t *conf = sh->raid_conf;
|
|
int raid_disks = conf->raid_disks, data_disks = raid_disks - 2;
|
|
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;
|
|
int i0 = i;
|
|
|
|
chunk_offset = sector_div(new_sector, sectors_per_chunk);
|
|
stripe = new_sector;
|
|
if ( new_sector != stripe ) {
|
|
printk(KERN_CRIT "raid6: ERROR: new_sector = %llu, stripe = %lu\n",
|
|
(unsigned long long)new_sector, (unsigned long)stripe);
|
|
BUG();
|
|
}
|
|
|
|
switch (conf->algorithm) {
|
|
case ALGORITHM_LEFT_ASYMMETRIC:
|
|
case ALGORITHM_RIGHT_ASYMMETRIC:
|
|
if (sh->pd_idx == raid_disks-1)
|
|
i--; /* Q D D D P */
|
|
else if (i > sh->pd_idx)
|
|
i -= 2; /* D D P Q D */
|
|
break;
|
|
case ALGORITHM_LEFT_SYMMETRIC:
|
|
case ALGORITHM_RIGHT_SYMMETRIC:
|
|
if (sh->pd_idx == raid_disks-1)
|
|
i--; /* Q D D D P */
|
|
else {
|
|
/* D D P Q D */
|
|
if (i < sh->pd_idx)
|
|
i += raid_disks;
|
|
i -= (sh->pd_idx + 2);
|
|
}
|
|
break;
|
|
default:
|
|
printk (KERN_CRIT "raid6: unsupported algorithm %d\n",
|
|
conf->algorithm);
|
|
}
|
|
|
|
PRINTK("raid6: compute_blocknr: pd_idx = %u, i0 = %u, i = %u\n", sh->pd_idx, i0, i);
|
|
|
|
chunk_number = stripe * data_disks + i;
|
|
r_sector = (sector_t)chunk_number * sectors_per_chunk + chunk_offset;
|
|
|
|
check = raid6_compute_sector (r_sector, raid_disks, data_disks, &dummy1, &dummy2, conf);
|
|
if (check != sh->sector || dummy1 != dd_idx || dummy2 != sh->pd_idx) {
|
|
printk(KERN_CRIT "raid6: compute_blocknr: map not correct\n");
|
|
return 0;
|
|
}
|
|
return r_sector;
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* Copy data between a page in the stripe cache, and one or more bion
|
|
* The page could align with the middle of the bio, or there could be
|
|
* several bion, each with several bio_vecs, which cover part of the page
|
|
* Multiple bion are linked together on bi_next. There may be extras
|
|
* at the end of this list. We ignore them.
|
|
*/
|
|
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)
|
|
|
|
/* Compute P and Q syndromes */
|
|
static void compute_parity(struct stripe_head *sh, int method)
|
|
{
|
|
raid6_conf_t *conf = sh->raid_conf;
|
|
int i, pd_idx = sh->pd_idx, qd_idx, d0_idx, disks = conf->raid_disks, count;
|
|
struct bio *chosen;
|
|
/**** FIX THIS: This could be very bad if disks is close to 256 ****/
|
|
void *ptrs[disks];
|
|
|
|
qd_idx = raid6_next_disk(pd_idx, disks);
|
|
d0_idx = raid6_next_disk(qd_idx, disks);
|
|
|
|
PRINTK("compute_parity, stripe %llu, method %d\n",
|
|
(unsigned long long)sh->sector, method);
|
|
|
|
switch(method) {
|
|
case READ_MODIFY_WRITE:
|
|
BUG(); /* READ_MODIFY_WRITE N/A for RAID-6 */
|
|
case RECONSTRUCT_WRITE:
|
|
for (i= disks; i-- ;)
|
|
if ( i != pd_idx && i != qd_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:
|
|
BUG(); /* Not implemented yet */
|
|
}
|
|
|
|
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:
|
|
// case UPDATE_PARITY:
|
|
/* Note that unlike RAID-5, the ordering of the disks matters greatly. */
|
|
/* FIX: Is this ordering of drives even remotely optimal? */
|
|
count = 0;
|
|
i = d0_idx;
|
|
do {
|
|
ptrs[count++] = page_address(sh->dev[i].page);
|
|
if (count <= disks-2 && !test_bit(R5_UPTODATE, &sh->dev[i].flags))
|
|
printk("block %d/%d not uptodate on parity calc\n", i,count);
|
|
i = raid6_next_disk(i, disks);
|
|
} while ( i != d0_idx );
|
|
// break;
|
|
// }
|
|
|
|
raid6_call.gen_syndrome(disks, STRIPE_SIZE, ptrs);
|
|
|
|
switch(method) {
|
|
case RECONSTRUCT_WRITE:
|
|
set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
|
|
set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags);
|
|
set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
|
|
set_bit(R5_LOCKED, &sh->dev[qd_idx].flags);
|
|
break;
|
|
case UPDATE_PARITY:
|
|
set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
|
|
set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Compute one missing block */
|
|
static void compute_block_1(struct stripe_head *sh, int dd_idx)
|
|
{
|
|
raid6_conf_t *conf = sh->raid_conf;
|
|
int i, count, disks = conf->raid_disks;
|
|
void *ptr[MAX_XOR_BLOCKS], *p;
|
|
int pd_idx = sh->pd_idx;
|
|
int qd_idx = raid6_next_disk(pd_idx, disks);
|
|
|
|
PRINTK("compute_block_1, stripe %llu, idx %d\n",
|
|
(unsigned long long)sh->sector, dd_idx);
|
|
|
|
if ( dd_idx == qd_idx ) {
|
|
/* We're actually computing the Q drive */
|
|
compute_parity(sh, UPDATE_PARITY);
|
|
} else {
|
|
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 || i == qd_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);
|
|
}
|
|
}
|
|
|
|
/* Compute two missing blocks */
|
|
static void compute_block_2(struct stripe_head *sh, int dd_idx1, int dd_idx2)
|
|
{
|
|
raid6_conf_t *conf = sh->raid_conf;
|
|
int i, count, disks = conf->raid_disks;
|
|
int pd_idx = sh->pd_idx;
|
|
int qd_idx = raid6_next_disk(pd_idx, disks);
|
|
int d0_idx = raid6_next_disk(qd_idx, disks);
|
|
int faila, failb;
|
|
|
|
/* faila and failb are disk numbers relative to d0_idx */
|
|
/* pd_idx become disks-2 and qd_idx become disks-1 */
|
|
faila = (dd_idx1 < d0_idx) ? dd_idx1+(disks-d0_idx) : dd_idx1-d0_idx;
|
|
failb = (dd_idx2 < d0_idx) ? dd_idx2+(disks-d0_idx) : dd_idx2-d0_idx;
|
|
|
|
BUG_ON(faila == failb);
|
|
if ( failb < faila ) { int tmp = faila; faila = failb; failb = tmp; }
|
|
|
|
PRINTK("compute_block_2, stripe %llu, idx %d,%d (%d,%d)\n",
|
|
(unsigned long long)sh->sector, dd_idx1, dd_idx2, faila, failb);
|
|
|
|
if ( failb == disks-1 ) {
|
|
/* Q disk is one of the missing disks */
|
|
if ( faila == disks-2 ) {
|
|
/* Missing P+Q, just recompute */
|
|
compute_parity(sh, UPDATE_PARITY);
|
|
return;
|
|
} else {
|
|
/* We're missing D+Q; recompute D from P */
|
|
compute_block_1(sh, (dd_idx1 == qd_idx) ? dd_idx2 : dd_idx1);
|
|
compute_parity(sh, UPDATE_PARITY); /* Is this necessary? */
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* We're missing D+P or D+D; build pointer table */
|
|
{
|
|
/**** FIX THIS: This could be very bad if disks is close to 256 ****/
|
|
void *ptrs[disks];
|
|
|
|
count = 0;
|
|
i = d0_idx;
|
|
do {
|
|
ptrs[count++] = page_address(sh->dev[i].page);
|
|
i = raid6_next_disk(i, disks);
|
|
if (i != dd_idx1 && i != dd_idx2 &&
|
|
!test_bit(R5_UPTODATE, &sh->dev[i].flags))
|
|
printk("compute_2 with missing block %d/%d\n", count, i);
|
|
} while ( i != d0_idx );
|
|
|
|
if ( failb == disks-2 ) {
|
|
/* We're missing D+P. */
|
|
raid6_datap_recov(disks, STRIPE_SIZE, faila, ptrs);
|
|
} else {
|
|
/* We're missing D+D. */
|
|
raid6_2data_recov(disks, STRIPE_SIZE, faila, failb, ptrs);
|
|
}
|
|
|
|
/* Both the above update both missing blocks */
|
|
set_bit(R5_UPTODATE, &sh->dev[dd_idx1].flags);
|
|
set_bit(R5_UPTODATE, &sh->dev[dd_idx2].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;
|
|
raid6_conf_t *conf = sh->raid_conf;
|
|
|
|
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;
|
|
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 (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)
|
|
{
|
|
raid6_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[2] = {0, 0};
|
|
struct r5dev *dev, *pdev, *qdev;
|
|
int pd_idx = sh->pd_idx;
|
|
int qd_idx = raid6_next_disk(pd_idx, disks);
|
|
int p_failed, q_failed;
|
|
|
|
PRINTK("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d, qd_idx=%d\n",
|
|
(unsigned long long)sh->sector, sh->state, atomic_read(&sh->count),
|
|
pd_idx, qd_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 || !rdev->in_sync) {
|
|
if ( failed < 2 )
|
|
failed_num[failed] = i;
|
|
failed++;
|
|
} else
|
|
set_bit(R5_Insync, &dev->flags);
|
|
}
|
|
PRINTK("locked=%d uptodate=%d to_read=%d"
|
|
" to_write=%d failed=%d failed_num=%d,%d\n",
|
|
locked, uptodate, to_read, to_write, failed,
|
|
failed_num[0], failed_num[1]);
|
|
/* check if the array has lost >2 devices and, if so, some requests might
|
|
* need to be failed
|
|
*/
|
|
if (failed > 2 && to_read+to_write+written) {
|
|
spin_lock_irq(&conf->device_lock);
|
|
for (i=disks; i--; ) {
|
|
/* fail all writes first */
|
|
bi = sh->dev[i].towrite;
|
|
sh->dev[i].towrite = NULL;
|
|
if (bi) to_write--;
|
|
|
|
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;
|
|
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)) {
|
|
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 (failed > 2 && 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 blocks
|
|
* are safe, or on a failed drive
|
|
*/
|
|
pdev = &sh->dev[pd_idx];
|
|
p_failed = (failed >= 1 && failed_num[0] == pd_idx)
|
|
|| (failed >= 2 && failed_num[1] == pd_idx);
|
|
qdev = &sh->dev[qd_idx];
|
|
q_failed = (failed >= 1 && failed_num[0] == qd_idx)
|
|
|| (failed >= 2 && failed_num[1] == qd_idx);
|
|
|
|
if ( written &&
|
|
( p_failed || ((test_bit(R5_Insync, &pdev->flags)
|
|
&& !test_bit(R5_LOCKED, &pdev->flags)
|
|
&& test_bit(R5_UPTODATE, &pdev->flags))) ) &&
|
|
( q_failed || ((test_bit(R5_Insync, &qdev->flags)
|
|
&& !test_bit(R5_LOCKED, &qdev->flags)
|
|
&& test_bit(R5_UPTODATE, &qdev->flags))) ) ) {
|
|
/* 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;
|
|
PRINTK("Return write for stripe %llu disc %d\n",
|
|
(unsigned long long)sh->sector, 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;
|
|
}
|
|
spin_unlock_irq(&conf->device_lock);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* 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 || (to_write && failed) || (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 >= 1 && (sh->dev[failed_num[0]].toread || to_write)) ||
|
|
(failed >= 2 && (sh->dev[failed_num[1]].toread || to_write))
|
|
)
|
|
) {
|
|
/* we would like to get this block, possibly
|
|
* by computing it, but we might not be able to
|
|
*/
|
|
if (uptodate == disks-1) {
|
|
PRINTK("Computing stripe %llu block %d\n",
|
|
(unsigned long long)sh->sector, i);
|
|
compute_block_1(sh, i);
|
|
uptodate++;
|
|
} else if ( uptodate == disks-2 && failed >= 2 ) {
|
|
/* Computing 2-failure is *very* expensive; only do it if failed >= 2 */
|
|
int other;
|
|
for (other=disks; other--;) {
|
|
if ( other == i )
|
|
continue;
|
|
if ( !test_bit(R5_UPTODATE, &sh->dev[other].flags) )
|
|
break;
|
|
}
|
|
BUG_ON(other < 0);
|
|
PRINTK("Computing stripe %llu blocks %d,%d\n",
|
|
(unsigned long long)sh->sector, i, other);
|
|
compute_block_2(sh, i, other);
|
|
uptodate += 2;
|
|
} 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 rcw=0, must_compute=0;
|
|
for (i=disks ; i--;) {
|
|
dev = &sh->dev[i];
|
|
/* Would I have to read this buffer for reconstruct_write */
|
|
if (!test_bit(R5_OVERWRITE, &dev->flags)
|
|
&& i != pd_idx && i != qd_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 {
|
|
PRINTK("raid6: must_compute: disk %d flags=%#lx\n", i, dev->flags);
|
|
must_compute++;
|
|
}
|
|
}
|
|
}
|
|
PRINTK("for sector %llu, rcw=%d, must_compute=%d\n",
|
|
(unsigned long long)sh->sector, rcw, must_compute);
|
|
set_bit(STRIPE_HANDLE, &sh->state);
|
|
|
|
if (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)
|
|
&& !(failed == 0 && (i == pd_idx || i == qd_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 stripe %llu block %d for Reconstruct\n",
|
|
(unsigned long long)sh->sector, i);
|
|
set_bit(R5_LOCKED, &dev->flags);
|
|
set_bit(R5_Wantread, &dev->flags);
|
|
locked++;
|
|
} else {
|
|
PRINTK("Request delayed stripe %llu block %d for Reconstruct\n",
|
|
(unsigned long long)sh->sector, i);
|
|
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) {
|
|
if ( must_compute > 0 ) {
|
|
/* We have failed blocks and need to compute them */
|
|
switch ( failed ) {
|
|
case 0: BUG();
|
|
case 1: compute_block_1(sh, failed_num[0]); break;
|
|
case 2: compute_block_2(sh, failed_num[0], failed_num[1]); break;
|
|
default: BUG(); /* This request should have been failed? */
|
|
}
|
|
}
|
|
|
|
PRINTK("Computing parity for stripe %llu\n", (unsigned long long)sh->sector);
|
|
compute_parity(sh, RECONSTRUCT_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 stripe %llu block %d\n",
|
|
(unsigned long long)sh->sector, i);
|
|
locked++;
|
|
set_bit(R5_Wantwrite, &sh->dev[i].flags);
|
|
#if 0 /**** FIX: I don't understand the logic here... ****/
|
|
if (!test_bit(R5_Insync, &sh->dev[i].flags)
|
|
|| ((i==pd_idx || i==qd_idx) && failed == 0)) /* FIX? */
|
|
set_bit(STRIPE_INSYNC, &sh->state);
|
|
#endif
|
|
}
|
|
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 <= 2) {
|
|
set_bit(STRIPE_HANDLE, &sh->state);
|
|
#if 0 /* RAID-6: Don't support CHECK PARITY yet */
|
|
if (failed == 0) {
|
|
char *pagea;
|
|
if (uptodate != disks)
|
|
BUG();
|
|
compute_parity(sh, CHECK_PARITY);
|
|
uptodate--;
|
|
pagea = page_address(sh->dev[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);
|
|
}
|
|
}
|
|
#endif
|
|
if (!test_bit(STRIPE_INSYNC, &sh->state)) {
|
|
int failed_needupdate[2];
|
|
struct r5dev *adev, *bdev;
|
|
|
|
if ( failed < 1 )
|
|
failed_num[0] = pd_idx;
|
|
if ( failed < 2 )
|
|
failed_num[1] = (failed_num[0] == qd_idx) ? pd_idx : qd_idx;
|
|
|
|
failed_needupdate[0] = !test_bit(R5_UPTODATE, &sh->dev[failed_num[0]].flags);
|
|
failed_needupdate[1] = !test_bit(R5_UPTODATE, &sh->dev[failed_num[1]].flags);
|
|
|
|
PRINTK("sync: failed=%d num=%d,%d fnu=%u%u\n",
|
|
failed, failed_num[0], failed_num[1], failed_needupdate[0], failed_needupdate[1]);
|
|
|
|
#if 0 /* RAID-6: This code seems to require that CHECK_PARITY destroys the uptodateness of the parity */
|
|
/* should be able to compute the missing block(s) and write to spare */
|
|
if ( failed_needupdate[0] ^ failed_needupdate[1] ) {
|
|
if (uptodate+1 != disks)
|
|
BUG();
|
|
compute_block_1(sh, failed_needupdate[0] ? failed_num[0] : failed_num[1]);
|
|
uptodate++;
|
|
} else if ( failed_needupdate[0] & failed_needupdate[1] ) {
|
|
if (uptodate+2 != disks)
|
|
BUG();
|
|
compute_block_2(sh, failed_num[0], failed_num[1]);
|
|
uptodate += 2;
|
|
}
|
|
#else
|
|
compute_block_2(sh, failed_num[0], failed_num[1]);
|
|
uptodate += failed_needupdate[0] + failed_needupdate[1];
|
|
#endif
|
|
|
|
if (uptodate != disks)
|
|
BUG();
|
|
|
|
PRINTK("Marking for sync stripe %llu blocks %d,%d\n",
|
|
(unsigned long long)sh->sector, failed_num[0], failed_num[1]);
|
|
|
|
/**** FIX: Should we really do both of these unconditionally? ****/
|
|
adev = &sh->dev[failed_num[0]];
|
|
locked += !test_bit(R5_LOCKED, &adev->flags);
|
|
set_bit(R5_LOCKED, &adev->flags);
|
|
set_bit(R5_Wantwrite, &adev->flags);
|
|
bdev = &sh->dev[failed_num[1]];
|
|
locked += !test_bit(R5_LOCKED, &bdev->flags);
|
|
set_bit(R5_LOCKED, &bdev->flags);
|
|
set_bit(R5_Wantwrite, &bdev->flags);
|
|
|
|
set_bit(STRIPE_INSYNC, &sh->state);
|
|
set_bit(R5_Syncio, &adev->flags);
|
|
set_bit(R5_Syncio, &bdev->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);
|
|
}
|
|
|
|
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 = raid6_end_write_request;
|
|
else
|
|
bi->bi_end_io = raid6_end_read_request;
|
|
|
|
rcu_read_lock();
|
|
rdev = conf->disks[i].rdev;
|
|
if (rdev && rdev->faulty)
|
|
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 {
|
|
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 raid6_activate_delayed(raid6_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 void unplug_slaves(mddev_t *mddev)
|
|
{
|
|
raid6_conf_t *conf = mddev_to_conf(mddev);
|
|
int i;
|
|
|
|
rcu_read_lock();
|
|
for (i=0; i<mddev->raid_disks; i++) {
|
|
mdk_rdev_t *rdev = conf->disks[i].rdev;
|
|
if (rdev && !rdev->faulty && 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 raid6_unplug_device(request_queue_t *q)
|
|
{
|
|
mddev_t *mddev = q->queuedata;
|
|
raid6_conf_t *conf = mddev_to_conf(mddev);
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&conf->device_lock, flags);
|
|
|
|
if (blk_remove_plug(q))
|
|
raid6_activate_delayed(conf);
|
|
md_wakeup_thread(mddev->thread);
|
|
|
|
spin_unlock_irqrestore(&conf->device_lock, flags);
|
|
|
|
unplug_slaves(mddev);
|
|
}
|
|
|
|
static int raid6_issue_flush(request_queue_t *q, struct gendisk *disk,
|
|
sector_t *error_sector)
|
|
{
|
|
mddev_t *mddev = q->queuedata;
|
|
raid6_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 = conf->disks[i].rdev;
|
|
if (rdev && !rdev->faulty) {
|
|
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 raid6_plug_device(raid6_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;
|
|
raid6_conf_t *conf = mddev_to_conf(mddev);
|
|
const unsigned int raid_disks = conf->raid_disks;
|
|
const unsigned int data_disks = raid_disks - 2;
|
|
unsigned int dd_idx, pd_idx;
|
|
sector_t new_sector;
|
|
sector_t logical_sector, last_sector;
|
|
struct stripe_head *sh;
|
|
|
|
md_write_start(mddev, bi);
|
|
|
|
if (bio_data_dir(bi)==WRITE) {
|
|
disk_stat_inc(mddev->gendisk, writes);
|
|
disk_stat_add(mddev->gendisk, write_sectors, bio_sectors(bi));
|
|
} else {
|
|
disk_stat_inc(mddev->gendisk, reads);
|
|
disk_stat_add(mddev->gendisk, read_sectors, 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 = raid6_compute_sector(logical_sector,
|
|
raid_disks, data_disks, &dd_idx, &pd_idx, conf);
|
|
|
|
PRINTK("raid6: 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
|
|
*/
|
|
raid6_unplug_device(mddev->queue);
|
|
release_stripe(sh);
|
|
schedule();
|
|
goto retry;
|
|
}
|
|
finish_wait(&conf->wait_for_overlap, &w);
|
|
raid6_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)
|
|
{
|
|
raid6_conf_t *conf = (raid6_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 - 2;
|
|
|
|
if (sector_nr >= mddev->size <<1) {
|
|
/* just being told to finish up .. nothing much to do */
|
|
unplug_slaves(mddev);
|
|
return 0;
|
|
}
|
|
/* if there are 2 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 >= 2 && test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
|
|
sector_t rv = (mddev->size << 1) - sector_nr;
|
|
*skipped = 1;
|
|
return rv;
|
|
}
|
|
|
|
x = sector_nr;
|
|
chunk_offset = sector_div(x, sectors_per_chunk);
|
|
stripe = x;
|
|
BUG_ON(x != stripe);
|
|
|
|
first_sector = raid6_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
|
|
*/
|
|
set_current_state(TASK_UNINTERRUPTIBLE);
|
|
schedule_timeout(1);
|
|
}
|
|
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 raid6 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 raid6d (mddev_t *mddev)
|
|
{
|
|
struct stripe_head *sh;
|
|
raid6_conf_t *conf = mddev_to_conf(mddev);
|
|
int handled;
|
|
|
|
PRINTK("+++ raid6d active\n");
|
|
|
|
md_check_recovery(mddev);
|
|
|
|
handled = 0;
|
|
spin_lock_irq(&conf->device_lock);
|
|
while (1) {
|
|
struct list_head *first;
|
|
|
|
if (list_empty(&conf->handle_list) &&
|
|
atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD &&
|
|
!blk_queue_plugged(mddev->queue) &&
|
|
!list_empty(&conf->delayed_list))
|
|
raid6_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("--- raid6d inactive\n");
|
|
}
|
|
|
|
static int run (mddev_t *mddev)
|
|
{
|
|
raid6_conf_t *conf;
|
|
int raid_disk, memory;
|
|
mdk_rdev_t *rdev;
|
|
struct disk_info *disk;
|
|
struct list_head *tmp;
|
|
|
|
if (mddev->level != 6) {
|
|
PRINTK("raid6: %s: raid level not set to 6 (%d)\n", mdname(mddev), mddev->level);
|
|
return -EIO;
|
|
}
|
|
|
|
mddev->private = kmalloc (sizeof (raid6_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->inactive_list);
|
|
atomic_set(&conf->active_stripes, 0);
|
|
atomic_set(&conf->preread_active_stripes, 0);
|
|
|
|
PRINTK("raid6: 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 (rdev->in_sync) {
|
|
char b[BDEVNAME_SIZE];
|
|
printk(KERN_INFO "raid6: 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 or 2 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->raid_disks < 4) {
|
|
printk(KERN_ERR "raid6: not enough configured devices for %s (%d, minimum 4)\n",
|
|
mdname(mddev), conf->raid_disks);
|
|
goto abort;
|
|
}
|
|
if (!conf->chunk_size || conf->chunk_size % 4) {
|
|
printk(KERN_ERR "raid6: invalid chunk size %d for %s\n",
|
|
conf->chunk_size, mdname(mddev));
|
|
goto abort;
|
|
}
|
|
if (conf->algorithm > ALGORITHM_RIGHT_SYMMETRIC) {
|
|
printk(KERN_ERR
|
|
"raid6: unsupported parity algorithm %d for %s\n",
|
|
conf->algorithm, mdname(mddev));
|
|
goto abort;
|
|
}
|
|
if (mddev->degraded > 2) {
|
|
printk(KERN_ERR "raid6: not enough operational devices for %s"
|
|
" (%d/%d failed)\n",
|
|
mdname(mddev), conf->failed_disks, conf->raid_disks);
|
|
goto abort;
|
|
}
|
|
|
|
#if 0 /* FIX: For now */
|
|
if (mddev->degraded > 0 &&
|
|
mddev->recovery_cp != MaxSector) {
|
|
printk(KERN_ERR "raid6: cannot start dirty degraded array for %s\n", mdname(mddev));
|
|
goto abort;
|
|
}
|
|
#endif
|
|
|
|
{
|
|
mddev->thread = md_register_thread(raid6d, mddev, "%s_raid6");
|
|
if (!mddev->thread) {
|
|
printk(KERN_ERR
|
|
"raid6: 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
|
|
"raid6: couldn't allocate %dkB for buffers\n", memory);
|
|
shrink_stripes(conf);
|
|
md_unregister_thread(mddev->thread);
|
|
goto abort;
|
|
} else
|
|
printk(KERN_INFO "raid6: allocated %dkB for %s\n",
|
|
memory, mdname(mddev));
|
|
|
|
if (mddev->degraded == 0)
|
|
printk(KERN_INFO "raid6: 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 "raid6: 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_raid6_conf(conf);
|
|
|
|
/* read-ahead size must cover two whole stripes, which is
|
|
* 2 * (n-2) * chunksize where 'n' is the number of raid devices
|
|
*/
|
|
{
|
|
int stripe = (mddev->raid_disks-2) * 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 */
|
|
mddev->array_size = mddev->size * (mddev->raid_disks - 2);
|
|
|
|
mddev->queue->unplug_fn = raid6_unplug_device;
|
|
mddev->queue->issue_flush_fn = raid6_issue_flush;
|
|
return 0;
|
|
abort:
|
|
if (conf) {
|
|
print_raid6_conf(conf);
|
|
if (conf->stripe_hashtbl)
|
|
free_pages((unsigned long) conf->stripe_hashtbl,
|
|
HASH_PAGES_ORDER);
|
|
kfree(conf);
|
|
}
|
|
mddev->private = NULL;
|
|
printk(KERN_ALERT "raid6: failed to run raid set %s\n", mdname(mddev));
|
|
return -EIO;
|
|
}
|
|
|
|
|
|
|
|
static int stop (mddev_t *mddev)
|
|
{
|
|
raid6_conf_t *conf = (raid6_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'*/
|
|
kfree(conf);
|
|
mddev->private = NULL;
|
|
return 0;
|
|
}
|
|
|
|
#if RAID6_DUMPSTATE
|
|
static void print_sh (struct seq_file *seq, struct stripe_head *sh)
|
|
{
|
|
int i;
|
|
|
|
seq_printf(seq, "sh %llu, pd_idx %d, state %ld.\n",
|
|
(unsigned long long)sh->sector, sh->pd_idx, sh->state);
|
|
seq_printf(seq, "sh %llu, count %d.\n",
|
|
(unsigned long long)sh->sector, atomic_read(&sh->count));
|
|
seq_printf(seq, "sh %llu, ", (unsigned long long)sh->sector);
|
|
for (i = 0; i < sh->raid_conf->raid_disks; i++) {
|
|
seq_printf(seq, "(cache%d: %p %ld) ",
|
|
i, sh->dev[i].page, sh->dev[i].flags);
|
|
}
|
|
seq_printf(seq, "\n");
|
|
}
|
|
|
|
static void printall (struct seq_file *seq, raid6_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(seq, sh);
|
|
}
|
|
}
|
|
spin_unlock_irq(&conf->device_lock);
|
|
}
|
|
#endif
|
|
|
|
static void status (struct seq_file *seq, mddev_t *mddev)
|
|
{
|
|
raid6_conf_t *conf = (raid6_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 &&
|
|
conf->disks[i].rdev->in_sync ? "U" : "_");
|
|
seq_printf (seq, "]");
|
|
#if RAID6_DUMPSTATE
|
|
seq_printf (seq, "\n");
|
|
printall(seq, conf);
|
|
#endif
|
|
}
|
|
|
|
static void print_raid6_conf (raid6_conf_t *conf)
|
|
{
|
|
int i;
|
|
struct disk_info *tmp;
|
|
|
|
printk("RAID6 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, !tmp->rdev->faulty,
|
|
bdevname(tmp->rdev->bdev,b));
|
|
}
|
|
}
|
|
|
|
static int raid6_spare_active(mddev_t *mddev)
|
|
{
|
|
int i;
|
|
raid6_conf_t *conf = mddev->private;
|
|
struct disk_info *tmp;
|
|
|
|
for (i = 0; i < conf->raid_disks; i++) {
|
|
tmp = conf->disks + i;
|
|
if (tmp->rdev
|
|
&& !tmp->rdev->faulty
|
|
&& !tmp->rdev->in_sync) {
|
|
mddev->degraded--;
|
|
conf->failed_disks--;
|
|
conf->working_disks++;
|
|
tmp->rdev->in_sync = 1;
|
|
}
|
|
}
|
|
print_raid6_conf(conf);
|
|
return 0;
|
|
}
|
|
|
|
static int raid6_remove_disk(mddev_t *mddev, int number)
|
|
{
|
|
raid6_conf_t *conf = mddev->private;
|
|
int err = 0;
|
|
mdk_rdev_t *rdev;
|
|
struct disk_info *p = conf->disks + number;
|
|
|
|
print_raid6_conf(conf);
|
|
rdev = p->rdev;
|
|
if (rdev) {
|
|
if (rdev->in_sync ||
|
|
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_raid6_conf(conf);
|
|
return err;
|
|
}
|
|
|
|
static int raid6_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
|
|
{
|
|
raid6_conf_t *conf = mddev->private;
|
|
int found = 0;
|
|
int disk;
|
|
struct disk_info *p;
|
|
|
|
if (mddev->degraded > 2)
|
|
/* 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) {
|
|
rdev->in_sync = 0;
|
|
rdev->raid_disk = disk;
|
|
found = 1;
|
|
p->rdev = rdev;
|
|
break;
|
|
}
|
|
print_raid6_conf(conf);
|
|
return found;
|
|
}
|
|
|
|
static int raid6_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-2))>>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 mdk_personality_t raid6_personality=
|
|
{
|
|
.name = "raid6",
|
|
.owner = THIS_MODULE,
|
|
.make_request = make_request,
|
|
.run = run,
|
|
.stop = stop,
|
|
.status = status,
|
|
.error_handler = error,
|
|
.hot_add_disk = raid6_add_disk,
|
|
.hot_remove_disk= raid6_remove_disk,
|
|
.spare_active = raid6_spare_active,
|
|
.sync_request = sync_request,
|
|
.resize = raid6_resize,
|
|
};
|
|
|
|
static int __init raid6_init (void)
|
|
{
|
|
int e;
|
|
|
|
e = raid6_select_algo();
|
|
if ( e )
|
|
return e;
|
|
|
|
return register_md_personality (RAID6, &raid6_personality);
|
|
}
|
|
|
|
static void raid6_exit (void)
|
|
{
|
|
unregister_md_personality (RAID6);
|
|
}
|
|
|
|
module_init(raid6_init);
|
|
module_exit(raid6_exit);
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("md-personality-8"); /* RAID6 */
|