--- /dev/null
+/*
+ * raid5.c : Multiple Devices driver for Linux
+ * Copyright (C) 1996, 1997 Ingo Molnar, Miguel de Icaza, Gadi Oxman
+ * Copyright (C) 1999, 2000 Ingo Molnar
+ *
+ * RAID-5 management functions.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * You should have received a copy of the GNU General Public License
+ * (for example /usr/src/linux/COPYING); if not, write to the Free
+ * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/locks.h>
+#include <linux/slab.h>
+#include <linux/raid/raid5.h>
+#include <asm/bitops.h>
+#include <asm/atomic.h>
+
+/*
+ * Stripe cache
+ */
+
+#define NR_STRIPES 256
+#define STRIPE_SIZE PAGE_SIZE
+#define STRIPE_SECTORS (STRIPE_SIZE>>9)
+#define IO_THRESHOLD 1
+#define HASH_PAGES 1
+#define HASH_PAGES_ORDER 0
+#define NR_HASH (HASH_PAGES * PAGE_SIZE / sizeof(struct stripe_head *))
+#define HASH_MASK (NR_HASH - 1)
+#define stripe_hash(conf, sect) ((conf)->stripe_hashtbl[((sect) / STRIPE_SECTORS) & HASH_MASK])
+
+/*
+ * The following can be used to debug the driver
+ */
+#define RAID5_DEBUG 0
+#define RAID5_PARANOIA 1
+#if RAID5_PARANOIA && CONFIG_SMP
+# define CHECK_DEVLOCK() if (!spin_is_locked(&conf->device_lock)) BUG()
+#else
+# define CHECK_DEVLOCK()
+#endif
+
+#if RAID5_DEBUG
+#define PRINTK(x...) printk(x)
+#define inline
+#define __inline__
+#else
+#define PRINTK(x...) do { } while (0)
+#endif
+
+static void print_raid5_conf (raid5_conf_t *conf);
+
+static inline void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh)
+{
+ if (atomic_dec_and_test(&sh->count)) {
+ if (!list_empty(&sh->lru))
+ BUG();
+ if (atomic_read(&conf->active_stripes)==0)
+ BUG();
+ if (test_bit(STRIPE_HANDLE, &sh->state)) {
+ if (test_bit(STRIPE_DELAYED, &sh->state))
+ list_add_tail(&sh->lru, &conf->delayed_list);
+ else
+ list_add_tail(&sh->lru, &conf->handle_list);
+ md_wakeup_thread(conf->thread);
+ } else {
+ 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->thread);
+ }
+ list_add_tail(&sh->lru, &conf->inactive_list);
+ atomic_dec(&conf->active_stripes);
+ if (!conf->inactive_blocked ||
+ atomic_read(&conf->active_stripes) < (NR_STRIPES*3/4))
+ wake_up(&conf->wait_for_stripe);
+ }
+ }
+}
+static void release_stripe(struct stripe_head *sh)
+{
+ raid5_conf_t *conf = sh->raid_conf;
+ unsigned long flags;
+
+ spin_lock_irqsave(&conf->device_lock, flags);
+ __release_stripe(conf, sh);
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+}
+
+static void remove_hash(struct stripe_head *sh)
+{
+ PRINTK("remove_hash(), stripe %lu\n", sh->sector);
+
+ if (sh->hash_pprev) {
+ if (sh->hash_next)
+ sh->hash_next->hash_pprev = sh->hash_pprev;
+ *sh->hash_pprev = sh->hash_next;
+ sh->hash_pprev = NULL;
+ }
+}
+
+static __inline__ void insert_hash(raid5_conf_t *conf, struct stripe_head *sh)
+{
+ struct stripe_head **shp = &stripe_hash(conf, sh->sector);
+
+ PRINTK("insert_hash(), stripe %lu\n",sh->sector);
+
+ CHECK_DEVLOCK();
+ if ((sh->hash_next = *shp) != NULL)
+ (*shp)->hash_pprev = &sh->hash_next;
+ *shp = sh;
+ sh->hash_pprev = shp;
+}
+
+
+/* find an idle stripe, make sure it is unhashed, and return it. */
+static struct stripe_head *get_free_stripe(raid5_conf_t *conf)
+{
+ struct stripe_head *sh = NULL;
+ struct list_head *first;
+
+ CHECK_DEVLOCK();
+ if (list_empty(&conf->inactive_list))
+ goto out;
+ first = conf->inactive_list.next;
+ sh = list_entry(first, struct stripe_head, lru);
+ list_del_init(first);
+ remove_hash(sh);
+ atomic_inc(&conf->active_stripes);
+out:
+ return sh;
+}
+
+static void shrink_buffers(struct stripe_head *sh, int num)
+{
+ struct page *p;
+ int i;
+
+ for (i=0; i<num ; i++) {
+ p = sh->dev[i].page;
+ if (!p)
+ continue;
+ sh->dev[i].page = NULL;
+ page_cache_release(p);
+ }
+}
+
+static int grow_buffers(struct stripe_head *sh, int num)
+{
+ int i;
+
+ for (i=0; i<num; i++) {
+ struct page *page;
+
+<<<<<<<
+ if (!bh)
+ return 1;
+ memset(bh, 0, sizeof (struct buffer_head));
+ init_waitqueue_head(&bh->b_wait);
+ if ((page = alloc_page(priority)))
+ bh->b_data = page_address(page);
+ else {
+|||||||
+ if (!bh)
+ return 1;
+ memset(bh, 0, sizeof (struct buffer_head));
+ if ((page = alloc_page(priority)))
+ bh->b_data = page_address(page);
+ else {
+=======
+ if (!(page = alloc_page(GFP_KERNEL))) {
+>>>>>>>
+ return 1;
+ }
+ sh->dev[i].page = page;
+ }
+ return 0;
+}
+
+static void raid5_build_block (struct stripe_head *sh, int i);
+
+static inline void init_stripe(struct stripe_head *sh, unsigned long sector, int pd_idx)
+{
+ raid5_conf_t *conf = sh->raid_conf;
+ int disks = conf->raid_disks, i;
+
+ if (atomic_read(&sh->count) != 0)
+ BUG();
+ if (test_bit(STRIPE_HANDLE, &sh->state))
+ BUG();
+
+ CHECK_DEVLOCK();
+ PRINTK("init_stripe called, stripe %lu\n", sh->sector);
+
+ remove_hash(sh);
+
+ sh->sector = sector;
+ sh->pd_idx = pd_idx;
+ sh->state = 0;
+
+ for (i=disks; i--; ) {
+ struct r5dev *dev = &sh->dev[i];
+
+ if (dev->toread || dev->towrite || dev->written ||
+ test_bit(R5_LOCKED, &dev->flags)) {
+ printk("sector=%lx i=%d %p %p %p %d\n",
+ sh->sector, i, dev->toread,
+ dev->towrite, dev->written,
+ test_bit(R5_LOCKED, &dev->flags));
+ BUG();
+ }
+<<<<<<<
+ clear_bit(BH_Uptodate, &sh->bh_cache[i]->b_state);
+|||||||
+ clear_buffer_uptodate(sh->bh_cache[i]);
+=======
+ dev->flags = 0;
+>>>>>>>
+ raid5_build_block(sh, i);
+ }
+ insert_hash(conf, sh);
+}
+
+static struct stripe_head *__find_stripe(raid5_conf_t *conf, unsigned long sector)
+{
+ struct stripe_head *sh;
+
+ CHECK_DEVLOCK();
+ PRINTK("__find_stripe, sector %lu\n", sector);
+ for (sh = stripe_hash(conf, sector); sh; sh = sh->hash_next)
+ if (sh->sector == sector)
+ return sh;
+ PRINTK("__stripe %lu not in cache\n", sector);
+ return NULL;
+}
+
+static struct stripe_head *get_active_stripe(raid5_conf_t *conf, unsigned long sector,
+ int pd_idx, int noblock)
+{
+ struct stripe_head *sh;
+
+ PRINTK("get_stripe, sector %lu\n", sector);
+
+ spin_lock_irq(&conf->device_lock);
+
+ do {
+ sh = __find_stripe(conf, sector);
+ if (!sh) {
+ if (!conf->inactive_blocked)
+ sh = get_free_stripe(conf);
+ if (noblock && sh == NULL)
+ break;
+ if (!sh) {
+ conf->inactive_blocked = 1;
+ wait_event_lock_irq(conf->wait_for_stripe,
+ !list_empty(&conf->inactive_list) &&
+ (atomic_read(&conf->active_stripes) < (NR_STRIPES *3/4)
+ || !conf->inactive_blocked),
+ conf->device_lock);
+ conf->inactive_blocked = 0;
+ } else
+ init_stripe(sh, sector, pd_idx);
+ } else {
+ if (atomic_read(&sh->count)) {
+ if (!list_empty(&sh->lru))
+ BUG();
+ } else {
+ if (!test_bit(STRIPE_HANDLE, &sh->state))
+ atomic_inc(&conf->active_stripes);
+ if (list_empty(&sh->lru))
+ BUG();
+ list_del_init(&sh->lru);
+ }
+ }
+ } while (sh == NULL);
+
+ if (sh)
+ atomic_inc(&sh->count);
+
+ spin_unlock_irq(&conf->device_lock);
+ return sh;
+}
+
+static int grow_stripes(raid5_conf_t *conf, int num)
+{
+ struct stripe_head *sh;
+ kmem_cache_t *sc;
+ int devs = conf->raid_disks;
+
+ sprintf(conf->cache_name, "md/raid5-%d", conf->mddev->__minor);
+
+ sc = kmem_cache_create(conf->cache_name,
+ sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),
+ 0, 0, NULL, NULL);
+ if (!sc)
+ return 1;
+ conf->slab_cache = sc;
+ while (num--) {
+ sh = kmem_cache_alloc(sc, GFP_KERNEL);
+ if (!sh)
+ return 1;
+ memset(sh, 0, sizeof(*sh) + (devs-1)*sizeof(struct r5dev));
+ sh->raid_conf = conf;
+ sh->lock = SPIN_LOCK_UNLOCKED;
+
+ if (grow_buffers(sh, conf->raid_disks)) {
+ shrink_buffers(sh, conf->raid_disks);
+ kmem_cache_free(sc, sh);
+ return 1;
+ }
+ /* we just created an active stripe so... */
+ atomic_set(&sh->count, 1);
+ atomic_inc(&conf->active_stripes);
+ INIT_LIST_HEAD(&sh->lru);
+ release_stripe(sh);
+ }
+ return 0;
+}
+
+static void shrink_stripes(raid5_conf_t *conf)
+{
+ struct stripe_head *sh;
+
+ while (1) {
+ spin_lock_irq(&conf->device_lock);
+ sh = get_free_stripe(conf);
+ spin_unlock_irq(&conf->device_lock);
+ if (!sh)
+ break;
+ if (atomic_read(&sh->count))
+ BUG();
+ shrink_buffers(sh, conf->raid_disks);
+ kmem_cache_free(conf->slab_cache, sh);
+ atomic_dec(&conf->active_stripes);
+ }
+ kmem_cache_destroy(conf->slab_cache);
+ conf->slab_cache = NULL;
+}
+
+static void raid5_end_read_request (struct bio * bi)
+{
+ struct stripe_head *sh = bi->bi_private;
+ raid5_conf_t *conf = sh->raid_conf;
+ int disks = conf->raid_disks, i;
+ int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
+
+ for (i=0 ; i<disks; i++)
+ if (bi == &sh->dev[i].req)
+ break;
+
+ PRINTK("end_read_request %lu/%d, count: %d, uptodate %d.\n", sh->sector, i, atomic_read(&sh->count), uptodate);
+ if (i == disks) {
+ BUG();
+ return;
+ }
+
+ if (uptodate) {
+#if 0
+ struct bio *bio;
+ unsigned long flags;
+ spin_lock_irqsave(&conf->device_lock, flags);
+ /* we can return a buffer if we bypassed the cache or
+ * if the top buffer is not in highmem. If there are
+ * multiple buffers, leave the extra work to
+ * handle_stripe
+ */
+ buffer = sh->bh_read[i];
+ if (buffer &&
+ (!PageHighMem(buffer->b_page)
+ || buffer->b_page == bh->b_page )
+ ) {
+ sh->bh_read[i] = buffer->b_reqnext;
+ buffer->b_reqnext = NULL;
+ } else
+ buffer = NULL;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ if (sh->bh_page[i]==bh->b_page)
+ set_bit(BH_Uptodate, &bh->b_state);
+ if (buffer) {
+ if (buffer->b_page != bh->b_page)
+ memcpy(buffer->b_data, bh->b_data, bh->b_size);
+ buffer->b_end_io(buffer, 1);
+ }
+#else
+ set_bit(R5_UPTODATE, &sh->dev[i].flags);
+#endif
+<<<<<<<
+ } else {
+ md_error(conf->mddev, bh->b_dev);
+ clear_bit(BH_Uptodate, &bh->b_state);
+|||||||
+ } else {
+ md_error(conf->mddev, bh->b_bdev);
+ clear_buffer_uptodate(bh);
+=======
+ } else {
+ md_error(conf->mddev, bi->bi_bdev);
+ clear_bit(R5_UPTODATE, &sh->dev[i].flags);
+>>>>>>>
+ }
+#if 0
+ /* must restore b_page before unlocking buffer... */
+ if (sh->bh_page[i] != bh->b_page) {
+ bh->b_page = sh->bh_page[i];
+ bh->b_data = page_address(bh->b_page);
+ clear_bit(BH_Uptodate, &bh->b_state);
+ }
+#endif
+<<<<<<<
+ clear_bit(BH_Lock, &bh->b_state);
+|||||||
+ clear_buffer_locked(bh);
+=======
+ clear_bit(R5_LOCKED, &sh->dev[i].flags);
+>>>>>>>
+ set_bit(STRIPE_HANDLE, &sh->state);
+ release_stripe(sh);
+}
+
+static void raid5_end_write_request (struct bio *bi)
+{
+ struct stripe_head *sh = bi->bi_private;
+ raid5_conf_t *conf = sh->raid_conf;
+ int disks = conf->raid_disks, i;
+ unsigned long flags;
+ int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
+
+ for (i=0 ; i<disks; i++)
+ if (bi == &sh->dev[i].req)
+ break;
+
+ PRINTK("end_write_request %lu/%d, count %d, uptodate: %d.\n", sh->sector, i, atomic_read(&sh->count), uptodate);
+ if (i == disks) {
+ BUG();
+ return;
+ }
+
+ spin_lock_irqsave(&conf->device_lock, flags);
+ if (!uptodate)
+<<<<<<<
+ md_error(conf->mddev, bh->b_dev);
+ clear_bit(BH_Lock, &bh->b_state);
+|||||||
+ md_error(conf->mddev, bh->b_bdev);
+ clear_buffer_locked(bh);
+=======
+ md_error(conf->mddev, bi->bi_bdev);
+
+ 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);
+}
+
+
+static unsigned long compute_blocknr(struct stripe_head *sh, int i);
+
+static void raid5_build_block (struct stripe_head *sh, int i)
+{
+ raid5_conf_t *conf = sh->raid_conf;
+ struct r5dev *dev = &sh->dev[i];
+
+ bio_init(&dev->req);
+ dev->req.bi_io_vec = &dev->vec;
+ dev->req.bi_vcnt++;
+ dev->vec.bv_page = dev->page;
+ dev->vec.bv_len = STRIPE_SIZE;
+ dev->vec.bv_offset = 0;
+
+<<<<<<<
+ bh->b_dev = conf->disks[i].dev;
+|||||||
+ bh->b_dev = conf->disks[i].dev;
+ /* FIXME - later we will need bdev here */
+=======
+ dev->req.bi_bdev = conf->disks[i].bdev;
+ dev->req.bi_sector = sh->sector;
+>>>>>>>
+ dev->req.bi_private = sh;
+
+ dev->flags = 0;
+ if (i != sh->pd_idx)
+<<<<<<<
+ bh->b_size = sh->size;
+ bh->b_list = BUF_LOCKED;
+ return bh;
+|||||||
+ bh->b_size = sh->size;
+ return bh;
+=======
+ dev->sector = compute_blocknr(sh, i);
+>>>>>>>
+}
+
+static int error (mddev_t *mddev, kdev_t dev)
+{
+ raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
+ mdp_super_t *sb = mddev->sb;
+ struct disk_info *disk;
+ int i;
+
+ PRINTK("raid5: error called\n");
+
+ for (i = 0, disk = conf->disks; i < conf->raid_disks; i++, disk++) {
+ if (disk->dev == dev) {
+ if (disk->operational) {
+ disk->operational = 0;
+ mark_disk_faulty(sb->disks+disk->number);
+ mark_disk_nonsync(sb->disks+disk->number);
+ mark_disk_inactive(sb->disks+disk->number);
+ sb->active_disks--;
+ sb->working_disks--;
+ sb->failed_disks++;
+ mddev->sb_dirty = 1;
+ conf->working_disks--;
+ conf->failed_disks++;
+ md_wakeup_thread(conf->thread);
+ printk (KERN_ALERT
+ "raid5: Disk failure on %s, disabling device."
+ " Operation continuing on %d devices\n",
+ partition_name (dev), conf->working_disks);
+ }
+ return 0;
+ }
+ }
+ /*
+ * handle errors in spares (during reconstruction)
+ */
+ if (conf->spare) {
+ disk = conf->spare;
+ if (disk->dev == dev) {
+ printk (KERN_ALERT
+ "raid5: Disk failure on spare %s\n",
+ partition_name (dev));
+ if (!conf->spare->operational) {
+ /* probably a SET_DISK_FAULTY ioctl */
+ return -EIO;
+ }
+ disk->operational = 0;
+ disk->write_only = 0;
+ conf->spare = NULL;
+ mark_disk_faulty(sb->disks+disk->number);
+ mark_disk_nonsync(sb->disks+disk->number);
+ mark_disk_inactive(sb->disks+disk->number);
+ sb->spare_disks--;
+ sb->working_disks--;
+ sb->failed_disks++;
+
+ mddev->sb_dirty = 1;
+ md_wakeup_thread(conf->thread);
+
+ return 0;
+ }
+ }
+ MD_BUG();
+ return -EIO;
+}
+
+/*
+ * Input: a 'big' sector number,
+ * Output: index of the data and parity disk, and the sector # in them.
+ */
+static unsigned long 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)
+{
+ sector_t 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_number = r_sector / sectors_per_chunk;
+ chunk_offset = r_sector % sectors_per_chunk;
+
+ /*
+ * 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 = 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 = new_sector / sectors_per_chunk;
+ int chunk_offset = new_sector % sectors_per_chunk;
+ int chunk_number, dummy1, dummy2, dd_idx = i;
+ sector_t r_sector;
+
+ 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 = 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 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;
+
+ for (;bio && bio->bi_sector < sector+STRIPE_SECTORS;
+ bio = bio->bi_next) {
+ 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) {
+ char *ba = __bio_kmap(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 (len > 0) {
+ if (frombio)
+ memcpy(pa+page_offset, ba+b_offset, clen);
+ else
+ memcpy(ba+b_offset, pa+page_offset, clen);
+ }
+ __bio_kunmap(bio, i);
+ 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 %lu, idx %d\n", 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 %lu, %d not present\n", dd_idx, sh->sector, i);
+
+ check_xor();
+ }
+ if (count != 1)
+<<<<<<<
+ xor_block(count, bh_ptr);
+ set_bit(BH_Uptodate, &sh->bh_cache[dd_idx]->b_state);
+|||||||
+ xor_block(count, bh_ptr);
+ set_buffer_uptodate(sh->bh_cache[dd_idx]);
+=======
+ xor_block(count, STRIPE_SIZE, ptr);
+ set_bit(R5_UPTODATE, &sh->dev[i].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[MD_SB_DISKS];
+
+ PRINTK("compute_parity, stripe %lu, method %d\n", sh->sector, method);
+ memset(chosen, 0, sizeof(chosen));
+
+ 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[i] = sh->dev[i].towrite;
+ sh->dev[i].towrite = NULL;
+ if (sh->dev[i].written) BUG();
+ sh->dev[i].written = chosen[i];
+ 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[i] = sh->dev[i].towrite;
+ sh->dev[i].towrite = NULL;
+ if (sh->dev[i].written) BUG();
+ sh->dev[i].written = chosen[i];
+ }
+ break;
+ case CHECK_PARITY:
+ break;
+ }
+ if (count>1) {
+ xor_block(count, STRIPE_SIZE, ptr);
+ count = 1;
+ }
+
+ for (i = disks; i--;)
+ if (chosen[i]) {
+ sector_t sector = sh->dev[i].sector;
+ copy_data(1, chosen[i], sh->dev[i].page, sector);
+
+<<<<<<<
+ memcpy(bh->b_data,
+ bdata,sh->size);
+ bh_kunmap(chosen[i]);
+ set_bit(BH_Lock, &bh->b_state);
+ mark_buffer_uptodate(bh, 1);
+|||||||
+ memcpy(bh->b_data,
+ bdata,sh->size);
+ bh_kunmap(chosen[i]);
+ set_buffer_locked(bh);
+ set_buffer_uptodate(bh);
+=======
+ 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 (chosen[i]) {
+ ptr[count++] = page_address(sh->dev[i].page);
+ check_xor();
+ }
+ }
+ if (count != 1)
+ xor_block(count, STRIPE_SIZE, ptr);
+
+ if (method != CHECK_PARITY) {
+<<<<<<<
+ mark_buffer_uptodate(sh->bh_cache[pd_idx], 1);
+ set_bit(BH_Lock, &sh->bh_cache[pd_idx]->b_state);
+ } else
+ mark_buffer_uptodate(sh->bh_cache[pd_idx], 0);
+|||||||
+ set_buffer_uptodate(sh->bh_cache[pd_idx]);
+ set_buffer_locked(sh->bh_cache[pd_idx]);
+ } else
+ clear_buffer_uptodate(sh->bh_cache[pd_idx]);
+=======
+ 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 void 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;
+
+ PRINTK("adding bh b#%lu to stripe s#%lu\n", bi->bi_sector, 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)
+ bip = & (*bip)->bi_next;
+/* FIXME do I need to worry about overlapping bion */
+ 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);
+
+ if (forwrite) {
+ /* check if page is coverred */
+ 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 = bi->bi_next) {
+ 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);
+ }
+
+ PRINTK("added bi b#%lu to stripe s#%lu, disk %d.\n", bi->bi_sector, sh->sector, dd_idx);
+}
+
+
+/*
+ * 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 action[MD_SB_DISKS];
+ int i;
+ int syncing;
+ int locked=0, uptodate=0, to_read=0, to_write=0, failed=0, written=0;
+ int failed_num=0;
+ struct r5dev *dev;
+
+ PRINTK("handling stripe %ld, cnt=%d, pd_idx=%d\n", sh->sector, atomic_read(&sh->count), sh->pd_idx);
+ memset(action, 0, sizeof(action));
+
+ 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--; ) {
+ dev = &sh->dev[i];
+ 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;
+ spin_unlock_irq(&conf->device_lock);
+ while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) {
+ copy_data(0, rbi, dev->page, dev->sector);
+ rbi2 = rbi->bi_next;
+ 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 (dev->written) written++;
+ if (!conf->disks[i].operational) {
+ failed++;
+ failed_num = i;
+ }
+ }
+ 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) {
+ 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--;
+
+ while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){
+ struct bio *nextbi = bi->bi_next;
+ clear_bit(BIO_UPTODATE, &bi->bi_flags);
+ if (--bi->bi_phys_segments == 0) {
+ bi->bi_next = return_bi;
+ return_bi = bi;
+ }
+ bi = nextbi;
+ }
+ /* fail any reads if this device is non-operational */
+ if (!conf->disks[i].operational) {
+ bi = sh->dev[i].toread;
+ sh->dev[i].toread = NULL;
+ if (bi) to_read--;
+ while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){
+ struct bio *nextbi = bi->bi_next;
+ 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 > 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 &&
+ ( (conf->disks[sh->pd_idx].operational && !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 */
+ for (i=disks; i--; )
+ if (sh->dev[i].written) {
+ dev = &sh->dev[i];
+ if (!conf->disks[sh->pd_idx].operational ||
+ (!test_bit(R5_LOCKED, &dev->flags) && test_bit(R5_UPTODATE, &dev->flags)) ) {
+ /* maybe we can return some write requests */
+ struct bio *wbi, *wbi2;
+ PRINTK("Return write for disc %d\n", i);
+ wbi = dev->written;
+ dev->written = NULL;
+ while (wbi && wbi->bi_sector < dev->sector + STRIPE_SECTORS) {
+ wbi2 = wbi->bi_next;
+ if (--wbi->bi_phys_segments == 0) {
+ wbi->bi_next = return_bi;
+ return_bi = wbi;
+ }
+ wbi = wbi2;
+ }
+ }
+ }
+ }
+
+ /* Now we might consider reading some blocks, either to check/generate
+ * parity, or to satisfy requests
+ */
+ if (to_read || (syncing && (uptodate+failed < disks))) {
+ for (i=disks; i--;) {
+ dev = &sh->dev[i];
+ if (!test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) &&
+ (dev->toread || syncing || (failed && sh->dev[failed_num].toread))) {
+ /* 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 (conf->disks[i].operational) {
+<<<<<<<
+ set_bit(BH_Lock, &bh->b_state);
+ action[i] = READ+1;
+|||||||
+ set_buffer_locked(bh);
+ action[i] = READ+1;
+=======
+ set_bit(R5_LOCKED, &dev->flags);
+ action[i] = READ+1;
+#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].dev, 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 (conf->disks[i].operational
+/* && !(conf->resync_parity && 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 (conf->disks[i].operational) rcw++;
+ else rcw += 2*disks;
+ }
+ }
+ PRINTK("for sector %ld, rmw=%d rcw=%d\n", 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) &&
+ conf->disks[i].operational) {
+ if (test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
+ {
+ PRINTK("Read_old block %d for r-m-w\n", i);
+<<<<<<<
+ set_bit(BH_Lock, &bh->b_state);
+|||||||
+ set_buffer_locked(bh);
+=======
+ set_bit(R5_LOCKED, &dev->flags);
+>>>>>>>
+ action[i] = READ+1;
+ 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) &&
+ conf->disks[i].operational) {
+ if (test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
+ {
+ PRINTK("Read_old block %d for Reconstruct\n", i);
+<<<<<<<
+ set_bit(BH_Lock, &bh->b_state);
+|||||||
+ set_buffer_locked(bh);
+=======
+ set_bit(R5_LOCKED, &dev->flags);
+>>>>>>>
+ action[i] = READ+1;
+ 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)) {
+ 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++;
+ action[i] = WRITE+1;
+ if (!conf->disks[i].operational
+ || (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->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);
+ }
+ }
+ if (!test_bit(STRIPE_INSYNC, &sh->state)) {
+ struct disk_info *spare;
+ 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();
+<<<<<<<
+ bh = sh->bh_cache[failed_num];
+ set_bit(BH_Lock, &bh->b_state);
+|||||||
+ bh = sh->bh_cache[failed_num];
+ set_buffer_locked(bh);
+=======
+ dev = &sh->dev[failed_num];
+ set_bit(R5_LOCKED, &dev->flags);
+>>>>>>>
+ action[failed_num] = WRITE+1;
+ locked++;
+ set_bit(STRIPE_INSYNC, &sh->state);
+ if (conf->disks[failed_num].operational)
+ md_sync_acct(conf->disks[failed_num].dev, STRIPE_SECTORS);
+ else if ((spare=conf->spare))
+ md_sync_acct(spare->dev, STRIPE_SECTORS);
+
+ }
+ }
+ 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)) {
+ return_bi = bi->bi_next;
+ bi->bi_next = NULL;
+ bi->bi_end_io(bi);
+ }
+ for (i=disks; i-- ;)
+ if (action[i]) {
+ struct bio *bi = &sh->dev[i].req;
+ struct disk_info *spare = conf->spare;
+ int skip = 0;
+ if (action[i] == READ+1)
+ bi->bi_end_io = raid5_end_read_request;
+ else
+ bi->bi_end_io = raid5_end_write_request;
+ if (conf->disks[i].operational)
+ bi->bi_bdev = conf->disks[i].bdev;
+ else if (spare && action[i] == WRITE+1)
+ bi->bi_bdev = spare->bdev;
+ else skip=1;
+ if (!skip) {
+ PRINTK("for %ld schedule op %d on disc %d\n", sh->sector, action[i]-1, i);
+ atomic_inc(&sh->count);
+ bi->bi_sector = sh->sector;
+ if (action[i] == READ+1)
+ bi->bi_rw = 0;
+ else
+ bi->bi_rw = 1;
+ bi->bi_flags = 0;
+ bi->bi_vcnt = 1;
+ bi->bi_idx = 0;
+ bi->bi_io_vec = &sh->dev[i].vec;
+ bi->bi_size = STRIPE_SIZE;
+ bi->bi_next = NULL;
+ generic_make_request(bi);
+ } else {
+ PRINTK("skip op %d on disc %d for sector %ld\n", action[i]-1, i, sh->sector);
+<<<<<<<
+ clear_bit(BH_Lock, &bh->b_state);
+|||||||
+ clear_buffer_locked(bh);
+=======
+ clear_bit(R5_LOCKED, &dev->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 void raid5_unplug_device(void *data)
+{
+ raid5_conf_t *conf = (raid5_conf_t *)data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&conf->device_lock, flags);
+
+ raid5_activate_delayed(conf);
+
+ conf->plugged = 0;
+ md_wakeup_thread(conf->thread);
+
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+}
+
+static inline void raid5_plug_device(raid5_conf_t *conf)
+{
+ spin_lock_irq(&conf->device_lock);
+ if (list_empty(&conf->delayed_list))
+ if (!conf->plugged) {
+ conf->plugged = 1;
+ queue_task(&conf->plug_tq, &tq_disk);
+ }
+ spin_unlock_irq(&conf->device_lock);
+}
+
+static int make_request (mddev_t *mddev, int rw, struct bio * bi)
+{
+ raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
+ 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;
+ int read_ahead = 0;
+
+ struct stripe_head *sh;
+
+ if (rw == READA) {
+ rw = READ;
+ read_ahead=1;
+ }
+
+ logical_sector = bi->bi_sector & ~(STRIPE_SECTORS-1);
+ last_sector = bi->bi_sector + (bi->bi_size>>9);
+
+ bi->bi_next = NULL;
+ set_bit(BIO_UPTODATE, &bi->bi_flags); /* will be cleared if error detected */
+ bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
+ for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
+
+ new_sector = raid5_compute_sector(logical_sector,
+ raid_disks, data_disks, &dd_idx, &pd_idx, conf);
+
+ PRINTK("raid5: make_request, sector %ul logical %ul\n",
+ new_sector, logical_sector);
+
+ sh = get_active_stripe(conf, new_sector, pd_idx, read_ahead);
+ if (sh) {
+
+ add_stripe_bio(sh, bi, dd_idx, rw);
+
+ raid5_plug_device(conf);
+ handle_stripe(sh);
+ release_stripe(sh);
+ }
+<<<<<<<
+ } else
+ bh->b_end_io(bh, test_bit(BH_Uptodate, &bh->b_state));
+|||||||
+ } else
+ bh->b_end_io(bh, buffer_uptodate(bh));
+=======
+ }
+ spin_lock_irq(&conf->device_lock);
+ if (--bi->bi_phys_segments == 0)
+ bi->bi_end_io(bi);
+ spin_unlock_irq(&conf->device_lock);
+>>>>>>>
+ return 0;
+}
+
+<<<<<<<
+/*
+ * Determine correct block size for this device.
+ */
+unsigned int device_bsize (kdev_t dev)
+{
+ unsigned int i, correct_size;
+
+ correct_size = BLOCK_SIZE;
+ if (blksize_size[MAJOR(dev)]) {
+ i = blksize_size[MAJOR(dev)][MINOR(dev)];
+ if (i)
+ correct_size = i;
+ }
+
+ return correct_size;
+}
+
+|||||||
+=======
+/* FIXME go_faster isn't used */
+>>>>>>>
+static int sync_request (mddev_t *mddev, sector_t sector_nr, int go_faster)
+{
+ raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
+ struct stripe_head *sh;
+ int sectors_per_chunk = conf->chunk_size >> 9;
+ unsigned long stripe = sector_nr/sectors_per_chunk;
+ int chunk_offset = sector_nr % sectors_per_chunk;
+ int dd_idx, pd_idx;
+ unsigned long first_sector;
+ int raid_disks = conf->raid_disks;
+ int data_disks = raid_disks-1;
+
+ first_sector = raid5_compute_sector(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, 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 (void *data)
+{
+ struct stripe_head *sh;
+ raid5_conf_t *conf = data;
+ mddev_t *mddev = conf->mddev;
+ int handled;
+
+ PRINTK("+++ raid5d active\n");
+
+ handled = 0;
+
+ if (mddev->sb_dirty)
+ md_update_sb(mddev);
+ 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 &&
+ !conf->plugged &&
+ !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);
+
+ PRINTK("--- raid5d inactive\n");
+}
+
+/*
+ * Private kernel thread for parity reconstruction after an unclean
+ * shutdown. Reconstruction on spare drives in case of a failed drive
+ * is done by the generic mdsyncd.
+ */
+static void raid5syncd (void *data)
+{
+ raid5_conf_t *conf = data;
+ mddev_t *mddev = conf->mddev;
+
+ if (!conf->resync_parity)
+ return;
+ if (conf->resync_parity == 2)
+ return;
+ down(&mddev->recovery_sem);
+ if (md_do_sync(mddev,NULL)) {
+ up(&mddev->recovery_sem);
+ printk("raid5: resync aborted!\n");
+ return;
+ }
+ conf->resync_parity = 0;
+ up(&mddev->recovery_sem);
+ printk("raid5: resync finished.\n");
+}
+
+static int run (mddev_t *mddev)
+{
+ raid5_conf_t *conf;
+ int i, j, raid_disk, memory;
+ mdp_super_t *sb = mddev->sb;
+ mdp_disk_t *desc;
+ mdk_rdev_t *rdev;
+ struct disk_info *disk;
+ struct list_head *tmp;
+ int start_recovery = 0;
+
+ MOD_INC_USE_COUNT;
+
+ if (sb->level != 5 && sb->level != 4) {
+ printk("raid5: md%d: raid level not set to 4/5 (%d)\n", mdidx(mddev), sb->level);
+ MOD_DEC_USE_COUNT;
+ return -EIO;
+ }
+
+ mddev->private = kmalloc (sizeof (raid5_conf_t), GFP_KERNEL);
+ if ((conf = mddev->private) == NULL)
+ goto abort;
+ memset (conf, 0, sizeof (*conf));
+ 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);
+
+ conf->device_lock = SPIN_LOCK_UNLOCKED;
+ init_waitqueue_head(&conf->wait_for_stripe);
+ 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);
+
+ conf->plugged = 0;
+ conf->plug_tq.sync = 0;
+ conf->plug_tq.routine = &raid5_unplug_device;
+ conf->plug_tq.data = conf;
+
+ PRINTK("raid5: run(md%d) called.\n", mdidx(mddev));
+
+ ITERATE_RDEV(mddev,rdev,tmp) {
+ /*
+ * This is important -- we are using the descriptor on
+ * the disk only to get a pointer to the descriptor on
+ * the main superblock, which might be more recent.
+ */
+ desc = sb->disks + rdev->desc_nr;
+ raid_disk = desc->raid_disk;
+ disk = conf->disks + raid_disk;
+
+ if (disk_faulty(desc)) {
+ printk(KERN_ERR "raid5: disabled device %s (errors detected)\n", partition_name(rdev->dev));
+ if (!rdev->faulty) {
+ MD_BUG();
+ goto abort;
+ }
+ disk->number = desc->number;
+ disk->raid_disk = raid_disk;
+ disk->dev = rdev->dev;
+ disk->bdev = rdev->bdev;
+
+ disk->operational = 0;
+ disk->write_only = 0;
+ disk->spare = 0;
+ disk->used_slot = 1;
+ continue;
+ }
+ if (disk_active(desc)) {
+ if (!disk_sync(desc)) {
+ printk(KERN_ERR "raid5: disabled device %s (not in sync)\n", partition_name(rdev->dev));
+ MD_BUG();
+ goto abort;
+ }
+ if (raid_disk > sb->raid_disks) {
+ printk(KERN_ERR "raid5: disabled device %s (inconsistent descriptor)\n", partition_name(rdev->dev));
+ continue;
+ }
+ if (disk->operational) {
+ printk(KERN_ERR "raid5: disabled device %s (device %d already operational)\n", partition_name(rdev->dev), raid_disk);
+ continue;
+ }
+ printk(KERN_INFO "raid5: device %s operational as raid disk %d\n", partition_name(rdev->dev), raid_disk);
+
+ disk->number = desc->number;
+ disk->raid_disk = raid_disk;
+ disk->dev = rdev->dev;
+ disk->bdev = rdev->bdev;
+ disk->operational = 1;
+ disk->used_slot = 1;
+
+ conf->working_disks++;
+ } else {
+ /*
+ * Must be a spare disk ..
+ */
+ printk(KERN_INFO "raid5: spare disk %s\n", partition_name(rdev->dev));
+ disk->number = desc->number;
+ disk->raid_disk = raid_disk;
+ disk->dev = rdev->dev;
+ disk->bdev = rdev->bdev;
+
+ disk->operational = 0;
+ disk->write_only = 0;
+ disk->spare = 1;
+ disk->used_slot = 1;
+ }
+ }
+
+ for (i = 0; i < MD_SB_DISKS; i++) {
+ desc = sb->disks + i;
+ raid_disk = desc->raid_disk;
+ disk = conf->disks + raid_disk;
+
+ if (disk_faulty(desc) && (raid_disk < sb->raid_disks) &&
+ !conf->disks[raid_disk].used_slot) {
+
+ disk->number = desc->number;
+ disk->raid_disk = raid_disk;
+ disk->dev = MKDEV(0,0);
+ disk->bdev = NULL;
+
+ disk->operational = 0;
+ disk->write_only = 0;
+ disk->spare = 0;
+ disk->used_slot = 1;
+ }
+ }
+
+ conf->raid_disks = sb->raid_disks;
+ /*
+ * 0 for a fully functional array, 1 for a degraded array.
+ */
+ conf->failed_disks = conf->raid_disks - conf->working_disks;
+ conf->mddev = mddev;
+ conf->chunk_size = sb->chunk_size;
+ conf->level = sb->level;
+ conf->algorithm = sb->layout;
+ conf->max_nr_stripes = NR_STRIPES;
+
+#if 0
+ for (i = 0; i < conf->raid_disks; i++) {
+ if (!conf->disks[i].used_slot) {
+ MD_BUG();
+ goto abort;
+ }
+ }
+#endif
+ if (!conf->chunk_size || conf->chunk_size % 4) {
+ printk(KERN_ERR "raid5: invalid chunk size %d for md%d\n", conf->chunk_size, mdidx(mddev));
+ goto abort;
+ }
+ if (conf->algorithm > ALGORITHM_RIGHT_SYMMETRIC) {
+ printk(KERN_ERR "raid5: unsupported parity algorithm %d for md%d\n", conf->algorithm, mdidx(mddev));
+ goto abort;
+ }
+ if (conf->failed_disks > 1) {
+ printk(KERN_ERR "raid5: not enough operational devices for md%d (%d/%d failed)\n", mdidx(mddev), conf->failed_disks, conf->raid_disks);
+ goto abort;
+ }
+
+ if (conf->working_disks != sb->raid_disks) {
+ printk(KERN_ALERT "raid5: md%d, not all disks are operational -- trying to recover array\n", mdidx(mddev));
+ start_recovery = 1;
+ }
+
+ {
+ const char * name = "raid5d";
+
+ conf->thread = md_register_thread(raid5d, conf, name);
+ if (!conf->thread) {
+ printk(KERN_ERR "raid5: couldn't allocate thread for md%d\n", mdidx(mddev));
+ goto abort;
+ }
+ }
+
+ memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
+ conf->raid_disks * ((sizeof(struct buffer_head) + 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);
+ goto abort;
+ } else
+ printk(KERN_INFO "raid5: allocated %dkB for md%d\n", memory, mdidx(mddev));
+
+ /*
+ * Regenerate the "device is in sync with the raid set" bit for
+ * each device.
+ */
+ for (i = 0; i < MD_SB_DISKS ; i++) {
+ mark_disk_nonsync(sb->disks + i);
+ for (j = 0; j < sb->raid_disks; j++) {
+ if (!conf->disks[j].operational)
+ continue;
+ if (sb->disks[i].number == conf->disks[j].number)
+ mark_disk_sync(sb->disks + i);
+ }
+ }
+ sb->active_disks = conf->working_disks;
+
+ if (sb->active_disks == sb->raid_disks)
+ printk("raid5: raid level %d set md%d active with %d out of %d devices, algorithm %d\n", conf->level, mdidx(mddev), sb->active_disks, sb->raid_disks, conf->algorithm);
+ else
+ printk(KERN_ALERT "raid5: raid level %d set md%d active with %d out of %d devices, algorithm %d\n", conf->level, mdidx(mddev), sb->active_disks, sb->raid_disks, conf->algorithm);
+
+ if (!start_recovery && !(sb->state & (1 << MD_SB_CLEAN))) {
+ const char * name = "raid5syncd";
+
+ conf->resync_thread = md_register_thread(raid5syncd, conf,name);
+ if (!conf->resync_thread) {
+ printk(KERN_ERR "raid5: couldn't allocate thread for md%d\n", mdidx(mddev));
+ goto abort;
+ }
+
+ printk("raid5: raid set md%d not clean; reconstructing parity\n", mdidx(mddev));
+ conf->resync_parity = 1;
+ md_wakeup_thread(conf->resync_thread);
+ }
+
+ print_raid5_conf(conf);
+ if (start_recovery)
+ md_recover_arrays();
+ print_raid5_conf(conf);
+
+ /* Ok, everything is just fine now */
+ 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 md%d\n", mdidx(mddev));
+ MOD_DEC_USE_COUNT;
+ return -EIO;
+}
+
+static int stop_resync (mddev_t *mddev)
+{
+ raid5_conf_t *conf = mddev_to_conf(mddev);
+ mdk_thread_t *thread = conf->resync_thread;
+
+ if (thread) {
+ if (conf->resync_parity) {
+ conf->resync_parity = 2;
+ md_interrupt_thread(thread);
+ printk(KERN_INFO "raid5: parity resync was not fully finished, restarting next time.\n");
+ return 1;
+ }
+ return 0;
+ }
+ return 0;
+}
+
+static int restart_resync (mddev_t *mddev)
+{
+ raid5_conf_t *conf = mddev_to_conf(mddev);
+
+ if (conf->resync_parity) {
+ if (!conf->resync_thread) {
+ MD_BUG();
+ return 0;
+ }
+ printk("raid5: waking up raid5resync.\n");
+ conf->resync_parity = 1;
+ md_wakeup_thread(conf->resync_thread);
+ return 1;
+ } else
+ printk("raid5: no restart-resync needed.\n");
+ return 0;
+}
+
+
+static int stop (mddev_t *mddev)
+{
+ raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
+
+ if (conf->resync_thread)
+ md_unregister_thread(conf->resync_thread);
+ md_unregister_thread(conf->thread);
+ shrink_stripes(conf);
+ free_pages((unsigned long) conf->stripe_hashtbl, HASH_PAGES_ORDER);
+ kfree(conf);
+ mddev->private = NULL;
+ MOD_DEC_USE_COUNT;
+ return 0;
+}
+
+#if RAID5_DEBUG
+static void print_sh (struct stripe_head *sh)
+{
+ int i;
+
+ printk("sh %lu, pd_idx %d, state %ld.\n", sh->sector, sh->pd_idx, sh->state);
+ printk("sh %lu, count %d.\n", sh->sector, atomic_read(&sh->count));
+ printk("sh %lu, ", 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);
+
+ PRINTK("--- raid5d inactive\n");
+}
+#endif
+
+static void status (struct seq_file *seq, mddev_t *mddev)
+{
+ raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
+ mdp_super_t *sb = mddev->sb;
+ int i;
+
+ seq_printf (seq, " level %d, %dk chunk, algorithm %d", sb->level, sb->chunk_size >> 10, sb->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].operational ? "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);
+
+#if RAID5_DEBUG
+ for (i = 0; i < MD_SB_DISKS; i++) {
+#else
+ for (i = 0; i < conf->working_disks+conf->failed_disks; i++) {
+#endif
+ tmp = conf->disks + i;
+ printk(" disk %d, s:%d, o:%d, n:%d rd:%d us:%d dev:%s\n",
+ i, tmp->spare,tmp->operational,
+ tmp->number,tmp->raid_disk,tmp->used_slot,
+ partition_name(tmp->dev));
+ }
+}
+
+static int diskop(mddev_t *mddev, mdp_disk_t **d, int state)
+{
+ int err = 0;
+ int i, failed_disk=-1, spare_disk=-1, removed_disk=-1, added_disk=-1;
+ raid5_conf_t *conf = mddev->private;
+ struct disk_info *tmp, *sdisk, *fdisk, *rdisk, *adisk;
+ mdp_super_t *sb = mddev->sb;
+ mdp_disk_t *failed_desc, *spare_desc, *added_desc;
+ mdk_rdev_t *spare_rdev, *failed_rdev;
+
+ print_raid5_conf(conf);
+ spin_lock_irq(&conf->device_lock);
+ /*
+ * find the disk ...
+ */
+ switch (state) {
+
+ case DISKOP_SPARE_ACTIVE:
+
+ /*
+ * Find the failed disk within the RAID5 configuration ...
+ * (this can only be in the first conf->raid_disks part)
+ */
+ for (i = 0; i < conf->raid_disks; i++) {
+ tmp = conf->disks + i;
+ if ((!tmp->operational && !tmp->spare) ||
+ !tmp->used_slot) {
+ failed_disk = i;
+ break;
+ }
+ }
+ /*
+ * When we activate a spare disk we _must_ have a disk in
+ * the lower (active) part of the array to replace.
+ */
+ if ((failed_disk == -1) || (failed_disk >= conf->raid_disks)) {
+ MD_BUG();
+ err = 1;
+ goto abort;
+ }
+ /* fall through */
+
+ case DISKOP_SPARE_WRITE:
+ case DISKOP_SPARE_INACTIVE:
+
+ /*
+ * Find the spare disk ... (can only be in the 'high'
+ * area of the array)
+ */
+ for (i = conf->raid_disks; i < MD_SB_DISKS; i++) {
+ tmp = conf->disks + i;
+ if (tmp->spare && tmp->number == (*d)->number) {
+ spare_disk = i;
+ break;
+ }
+ }
+ if (spare_disk == -1) {
+ MD_BUG();
+ err = 1;
+ goto abort;
+ }
+ break;
+
+ case DISKOP_HOT_REMOVE_DISK:
+
+ for (i = 0; i < MD_SB_DISKS; i++) {
+ tmp = conf->disks + i;
+ if (tmp->used_slot && (tmp->number == (*d)->number)) {
+ if (tmp->operational) {
+ err = -EBUSY;
+ goto abort;
+ }
+ removed_disk = i;
+ break;
+ }
+ }
+ if (removed_disk == -1) {
+ MD_BUG();
+ err = 1;
+ goto abort;
+ }
+ break;
+
+ case DISKOP_HOT_ADD_DISK:
+
+ for (i = conf->raid_disks; i < MD_SB_DISKS; i++) {
+ tmp = conf->disks + i;
+ if (!tmp->used_slot) {
+ added_disk = i;
+ break;
+ }
+ }
+ if (added_disk == -1) {
+ MD_BUG();
+ err = 1;
+ goto abort;
+ }
+ break;
+ }
+
+ switch (state) {
+ /*
+ * Switch the spare disk to write-only mode:
+ */
+ case DISKOP_SPARE_WRITE:
+ if (conf->spare) {
+ MD_BUG();
+ err = 1;
+ goto abort;
+ }
+ sdisk = conf->disks + spare_disk;
+ sdisk->operational = 1;
+ sdisk->write_only = 1;
+ conf->spare = sdisk;
+ break;
+ /*
+ * Deactivate a spare disk:
+ */
+ case DISKOP_SPARE_INACTIVE:
+ sdisk = conf->disks + spare_disk;
+ sdisk->operational = 0;
+ sdisk->write_only = 0;
+ /*
+ * Was the spare being resynced?
+ */
+ if (conf->spare == sdisk)
+ conf->spare = NULL;
+ break;
+ /*
+ * Activate (mark read-write) the (now sync) spare disk,
+ * which means we switch it's 'raid position' (->raid_disk)
+ * with the failed disk. (only the first 'conf->raid_disks'
+ * slots are used for 'real' disks and we must preserve this
+ * property)
+ */
+ case DISKOP_SPARE_ACTIVE:
+ if (!conf->spare) {
+ MD_BUG();
+ err = 1;
+ goto abort;
+ }
+ sdisk = conf->disks + spare_disk;
+ fdisk = conf->disks + failed_disk;
+
+ spare_desc = &sb->disks[sdisk->number];
+ failed_desc = &sb->disks[fdisk->number];
+
+ if (spare_desc != *d) {
+ MD_BUG();
+ err = 1;
+ goto abort;
+ }
+
+ if (spare_desc->raid_disk != sdisk->raid_disk) {
+ MD_BUG();
+ err = 1;
+ goto abort;
+ }
+
+ if (sdisk->raid_disk != spare_disk) {
+ MD_BUG();
+ err = 1;
+ goto abort;
+ }
+
+ if (failed_desc->raid_disk != fdisk->raid_disk) {
+ MD_BUG();
+ err = 1;
+ goto abort;
+ }
+
+ if (fdisk->raid_disk != failed_disk) {
+ MD_BUG();
+ err = 1;
+ goto abort;
+ }
+
+ /*
+ * do the switch finally
+ */
+ spare_rdev = find_rdev_nr(mddev, spare_desc->number);
+ failed_rdev = find_rdev_nr(mddev, failed_desc->number);
+
+ /* There must be a spare_rdev, but there may not be a
+ * failed_rdev. That slot might be empty...
+ */
+ spare_rdev->desc_nr = failed_desc->number;
+ if (failed_rdev)
+ failed_rdev->desc_nr = spare_desc->number;
+
+ xchg_values(*spare_desc, *failed_desc);
+ xchg_values(*fdisk, *sdisk);
+
+ /*
+ * (careful, 'failed' and 'spare' are switched from now on)
+ *
+ * we want to preserve linear numbering and we want to
+ * give the proper raid_disk number to the now activated
+ * disk. (this means we switch back these values)
+ */
+
+ xchg_values(spare_desc->raid_disk, failed_desc->raid_disk);
+ xchg_values(sdisk->raid_disk, fdisk->raid_disk);
+ xchg_values(spare_desc->number, failed_desc->number);
+ xchg_values(sdisk->number, fdisk->number);
+
+ *d = failed_desc;
+
+ if (sdisk->dev == MKDEV(0,0))
+ sdisk->used_slot = 0;
+
+ /*
+ * this really activates the spare.
+ */
+ fdisk->spare = 0;
+ fdisk->write_only = 0;
+
+ /*
+ * if we activate a spare, we definitely replace a
+ * non-operational disk slot in the 'low' area of
+ * the disk array.
+ */
+ conf->failed_disks--;
+ conf->working_disks++;
+ conf->spare = NULL;
+
+ break;
+
+ case DISKOP_HOT_REMOVE_DISK:
+ rdisk = conf->disks + removed_disk;
+
+ if (rdisk->spare && (removed_disk < conf->raid_disks)) {
+ MD_BUG();
+ err = 1;
+ goto abort;
+ }
+ rdisk->dev = MKDEV(0,0);
+ rdisk->bdev = NULL;
+ rdisk->used_slot = 0;
+
+ break;
+
+ case DISKOP_HOT_ADD_DISK:
+ adisk = conf->disks + added_disk;
+ added_desc = *d;
+
+ if (added_disk != added_desc->number) {
+ MD_BUG();
+ err = 1;
+ goto abort;
+ }
+
+ adisk->number = added_desc->number;
+ adisk->raid_disk = added_desc->raid_disk;
+ adisk->dev = MKDEV(added_desc->major,added_desc->minor);
+ /* it will be held open by rdev */
+ adisk->bdev = bdget(kdev_t_to_nr(adisk->dev));
+
+ adisk->operational = 0;
+ adisk->write_only = 0;
+ adisk->spare = 1;
+ adisk->used_slot = 1;
+
+
+ break;
+
+ default:
+ MD_BUG();
+ err = 1;
+ goto abort;
+ }
+abort:
+ spin_unlock_irq(&conf->device_lock);
+ print_raid5_conf(conf);
+ return err;
+}
+
+static mdk_personality_t raid5_personality=
+{
+ name: "raid5",
+ make_request: make_request,
+ run: run,
+ stop: stop,
+ status: status,
+ error_handler: error,
+ diskop: diskop,
+ stop_resync: stop_resync,
+ restart_resync: restart_resync,
+ sync_request: sync_request
+};
+
+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");
git / wiggle.git / commitdiff