* raid5.c : Multiple Devices driver for Linux
* Copyright (C) 1996, 1997 Ingo Molnar, Miguel de Icaza, Gadi Oxman
* Copyright (C) 1999, 2000 Ingo Molnar
- * Copyright (C) 2002, 2003 H. Peter Anvin
*
- * RAID-4/5/6 management functions.
- * Thanks to Penguin Computing for making the RAID-6 development possible
- * by donating a test server!
+ * 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
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
-/*
- * BITMAP UNPLUGGING:
- *
- * The sequencing for updating the bitmap reliably is a little
- * subtle (and I got it wrong the first time) so it deserves some
- * explanation.
- *
- * We group bitmap updates into batches. Each batch has a number.
- * We may write out several batches at once, but that isn't very important.
- * conf->bm_write is the number of the last batch successfully written.
- * conf->bm_flush is the number of the last batch that was closed to
- * new additions.
- * When we discover that we will need to write to any block in a stripe
- * (in add_stripe_bio) we update the in-memory bitmap and record in sh->bm_seq
- * the number of the batch it will be in. This is bm_flush+1.
- * When we are ready to do a write, if that batch hasn't been written yet,
- * we plug the array and queue the stripe for later.
- * When an unplug happens, we increment bm_flush, thus closing the current
- * batch.
- * When we notice that bm_flush > bm_write, we write out all pending updates
- * to the bitmap, and advance bm_write to where bm_flush was.
- * This may occasionally write a bit out twice, but is sure never to
- * miss any bits.
- */
+#include <linux/config.h>
#include <linux/module.h>
#include <linux/slab.h>
+#include <linux/raid/raid5.h>
#include <linux/highmem.h>
#include <linux/bitops.h>
-#include <linux/kthread.h>
#include <asm/atomic.h>
-#include "raid6.h"
#include <linux/raid/bitmap.h>
#define __inline__
#endif
-#if !RAID6_USE_EMPTY_ZERO_PAGE
-/* In .bss so it's zeroed */
-const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
-#endif
-
-static inline int raid6_next_disk(int disk, int raid_disks)
-{
- disk++;
- return (disk < raid_disks) ? disk : 0;
-}
static void print_raid5_conf (raid5_conf_t *conf);
static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh)
{
if (atomic_dec_and_test(&sh->count)) {
- BUG_ON(!list_empty(&sh->lru));
- BUG_ON(atomic_read(&conf->active_stripes)==0);
+ 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)) {
+ if (test_bit(STRIPE_DELAYED, &sh->state))
list_add_tail(&sh->lru, &conf->delayed_list);
- blk_plug_device(conf->mddev->queue);
- } else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
- sh->bm_seq - conf->seq_write > 0) {
+ else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
+ conf->seq_write == sh->bm_seq)
list_add_tail(&sh->lru, &conf->bitmap_list);
- blk_plug_device(conf->mddev->queue);
- } else {
+ else {
clear_bit(STRIPE_BIT_DELAY, &sh->state);
list_add_tail(&sh->lru, &conf->handle_list);
}
if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD)
md_wakeup_thread(conf->mddev->thread);
}
+ list_add_tail(&sh->lru, &conf->inactive_list);
atomic_dec(&conf->active_stripes);
- if (!test_bit(STRIPE_EXPANDING, &sh->state)) {
- list_add_tail(&sh->lru, &conf->inactive_list);
+ if (!conf->inactive_blocked ||
+ atomic_read(&conf->active_stripes) < (conf->max_nr_stripes*3/4))
wake_up(&conf->wait_for_stripe);
- }
}
}
}
{
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);
hlist_del_init(&sh->hash);
}
-static inline void insert_hash(raid5_conf_t *conf, struct stripe_head *sh)
+static void insert_hash(raid5_conf_t *conf, struct stripe_head *sh)
{
struct hlist_head *hp = stripe_hash(conf, sh->sector);
static void raid5_build_block (struct stripe_head *sh, int i);
-static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx, int disks)
+static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx)
{
raid5_conf_t *conf = sh->raid_conf;
- int i;
+ int disks = conf->raid_disks, i;
- BUG_ON(atomic_read(&sh->count) != 0);
- BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
+ if (atomic_read(&sh->count) != 0)
+ BUG();
+ if (test_bit(STRIPE_HANDLE, &sh->state))
+ BUG();
CHECK_DEVLOCK();
PRINTK("init_stripe called, stripe %llu\n",
(unsigned long long)sh->sector);
remove_hash(sh);
-
+
sh->sector = sector;
sh->pd_idx = pd_idx;
sh->state = 0;
- sh->disks = disks;
-
- for (i = sh->disks; i--; ) {
+ for (i=disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
if (dev->toread || dev->towrite || dev->written ||
insert_hash(conf, sh);
}
-static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector, int disks)
+static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector)
{
struct stripe_head *sh;
struct hlist_node *hn;
CHECK_DEVLOCK();
PRINTK("__find_stripe, sector %llu\n", (unsigned long long)sector);
hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash)
- if (sh->sector == sector && sh->disks == disks)
+ if (sh->sector == sector)
return sh;
PRINTK("__stripe %llu not in cache\n", (unsigned long long)sector);
return NULL;
static void unplug_slaves(mddev_t *mddev);
static void raid5_unplug_device(request_queue_t *q);
-static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector, int disks,
- int pd_idx, int noblock)
+static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector,
+ int pd_idx, int noblock)
{
struct stripe_head *sh;
wait_event_lock_irq(conf->wait_for_stripe,
conf->quiesce == 0,
conf->device_lock, /* nothing */);
- sh = __find_stripe(conf, sector, disks);
+ sh = __find_stripe(conf, sector);
if (!sh) {
if (!conf->inactive_blocked)
sh = get_free_stripe(conf);
< (conf->max_nr_stripes *3/4)
|| !conf->inactive_blocked),
conf->device_lock,
- raid5_unplug_device(conf->mddev->queue)
+ unplug_slaves(conf->mddev);
);
conf->inactive_blocked = 0;
} else
- init_stripe(sh, sector, pd_idx, disks);
+ init_stripe(sh, sector, pd_idx);
} else {
if (atomic_read(&sh->count)) {
- BUG_ON(!list_empty(&sh->lru));
+ if (!list_empty(&sh->lru))
+ BUG();
} else {
if (!test_bit(STRIPE_HANDLE, &sh->state))
atomic_inc(&conf->active_stripes);
- if (list_empty(&sh->lru) &&
- !test_bit(STRIPE_EXPANDING, &sh->state))
+ if (list_empty(&sh->lru))
BUG();
list_del_init(&sh->lru);
}
kmem_cache_free(conf->slab_cache, sh);
return 0;
}
- sh->disks = conf->raid_disks;
/* we just created an active stripe so... */
atomic_set(&sh->count, 1);
atomic_inc(&conf->active_stripes);
kmem_cache_t *sc;
int devs = conf->raid_disks;
- sprintf(conf->cache_name[0], "raid5/%s", mdname(conf->mddev));
- sprintf(conf->cache_name[1], "raid5/%s-alt", mdname(conf->mddev));
- conf->active_name = 0;
- sc = kmem_cache_create(conf->cache_name[conf->active_name],
+ sprintf(conf->cache_name, "raid5/%s", mdname(conf->mddev));
+
+ 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;
- conf->pool_size = devs;
- while (num--)
+ while (num--) {
if (!grow_one_stripe(conf))
return 1;
- return 0;
-}
-
-#ifdef CONFIG_MD_RAID5_RESHAPE
-static int resize_stripes(raid5_conf_t *conf, int newsize)
-{
- /* Make all the stripes able to hold 'newsize' devices.
- * New slots in each stripe get 'page' set to a new page.
- *
- * This happens in stages:
- * 1/ create a new kmem_cache and allocate the required number of
- * stripe_heads.
- * 2/ gather all the old stripe_heads and tranfer the pages across
- * to the new stripe_heads. This will have the side effect of
- * freezing the array as once all stripe_heads have been collected,
- * no IO will be possible. Old stripe heads are freed once their
- * pages have been transferred over, and the old kmem_cache is
- * freed when all stripes are done.
- * 3/ reallocate conf->disks to be suitable bigger. If this fails,
- * we simple return a failre status - no need to clean anything up.
- * 4/ allocate new pages for the new slots in the new stripe_heads.
- * If this fails, we don't bother trying the shrink the
- * stripe_heads down again, we just leave them as they are.
- * As each stripe_head is processed the new one is released into
- * active service.
- *
- * Once step2 is started, we cannot afford to wait for a write,
- * so we use GFP_NOIO allocations.
- */
- struct stripe_head *osh, *nsh;
- LIST_HEAD(newstripes);
- struct disk_info *ndisks;
- int err = 0;
- kmem_cache_t *sc;
- int i;
-
- if (newsize <= conf->pool_size)
- return 0; /* never bother to shrink */
-
- /* Step 1 */
- sc = kmem_cache_create(conf->cache_name[1-conf->active_name],
- sizeof(struct stripe_head)+(newsize-1)*sizeof(struct r5dev),
- 0, 0, NULL, NULL);
- if (!sc)
- return -ENOMEM;
-
- for (i = conf->max_nr_stripes; i; i--) {
- nsh = kmem_cache_alloc(sc, GFP_KERNEL);
- if (!nsh)
- break;
-
- memset(nsh, 0, sizeof(*nsh) + (newsize-1)*sizeof(struct r5dev));
-
- nsh->raid_conf = conf;
- spin_lock_init(&nsh->lock);
-
- list_add(&nsh->lru, &newstripes);
- }
- if (i) {
- /* didn't get enough, give up */
- while (!list_empty(&newstripes)) {
- nsh = list_entry(newstripes.next, struct stripe_head, lru);
- list_del(&nsh->lru);
- kmem_cache_free(sc, nsh);
- }
- kmem_cache_destroy(sc);
- return -ENOMEM;
- }
- /* Step 2 - Must use GFP_NOIO now.
- * OK, we have enough stripes, start collecting inactive
- * stripes and copying them over
- */
- list_for_each_entry(nsh, &newstripes, lru) {
- spin_lock_irq(&conf->device_lock);
- wait_event_lock_irq(conf->wait_for_stripe,
- !list_empty(&conf->inactive_list),
- conf->device_lock,
- unplug_slaves(conf->mddev)
- );
- osh = get_free_stripe(conf);
- spin_unlock_irq(&conf->device_lock);
- atomic_set(&nsh->count, 1);
- for(i=0; i<conf->pool_size; i++)
- nsh->dev[i].page = osh->dev[i].page;
- for( ; i<newsize; i++)
- nsh->dev[i].page = NULL;
- kmem_cache_free(conf->slab_cache, osh);
- }
- kmem_cache_destroy(conf->slab_cache);
-
- /* Step 3.
- * At this point, we are holding all the stripes so the array
- * is completely stalled, so now is a good time to resize
- * conf->disks.
- */
- ndisks = kzalloc(newsize * sizeof(struct disk_info), GFP_NOIO);
- if (ndisks) {
- for (i=0; i<conf->raid_disks; i++)
- ndisks[i] = conf->disks[i];
- kfree(conf->disks);
- conf->disks = ndisks;
- } else
- err = -ENOMEM;
-
- /* Step 4, return new stripes to service */
- while(!list_empty(&newstripes)) {
- nsh = list_entry(newstripes.next, struct stripe_head, lru);
- list_del_init(&nsh->lru);
- for (i=conf->raid_disks; i < newsize; i++)
- if (nsh->dev[i].page == NULL) {
- struct page *p = alloc_page(GFP_NOIO);
- nsh->dev[i].page = p;
- if (!p)
- err = -ENOMEM;
- }
- release_stripe(nsh);
}
- /* critical section pass, GFP_NOIO no longer needed */
-
- conf->slab_cache = sc;
- conf->active_name = 1-conf->active_name;
- conf->pool_size = newsize;
- return err;
+ return 0;
}
-#endif
static int drop_one_stripe(raid5_conf_t *conf)
{
spin_unlock_irq(&conf->device_lock);
if (!sh)
return 0;
- BUG_ON(atomic_read(&sh->count));
- shrink_buffers(sh, conf->pool_size);
+ if (atomic_read(&sh->count))
+ BUG();
+ shrink_buffers(sh, conf->raid_disks);
kmem_cache_free(conf->slab_cache, sh);
atomic_dec(&conf->active_stripes);
return 1;
{
struct stripe_head *sh = bi->bi_private;
raid5_conf_t *conf = sh->raid_conf;
- int disks = sh->disks, i;
+ int disks = conf->raid_disks, i;
int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
- char b[BDEVNAME_SIZE];
- mdk_rdev_t *rdev;
if (bi->bi_size)
return 1;
set_bit(R5_UPTODATE, &sh->dev[i].flags);
#endif
if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
- rdev = conf->disks[i].rdev;
- printk(KERN_INFO "raid5:%s: read error corrected (%lu sectors at %llu on %s)\n",
- mdname(conf->mddev), STRIPE_SECTORS,
- (unsigned long long)sh->sector + rdev->data_offset,
- bdevname(rdev->bdev, b));
+ printk(KERN_INFO "raid5: read error corrected!!\n");
clear_bit(R5_ReadError, &sh->dev[i].flags);
clear_bit(R5_ReWrite, &sh->dev[i].flags);
}
if (atomic_read(&conf->disks[i].rdev->read_errors))
atomic_set(&conf->disks[i].rdev->read_errors, 0);
} else {
- const char *bdn = bdevname(conf->disks[i].rdev->bdev, b);
int retry = 0;
- rdev = conf->disks[i].rdev;
-
clear_bit(R5_UPTODATE, &sh->dev[i].flags);
- atomic_inc(&rdev->read_errors);
+ atomic_inc(&conf->disks[i].rdev->read_errors);
if (conf->mddev->degraded)
- printk(KERN_WARNING "raid5:%s: read error not correctable (sector %llu on %s).\n",
- mdname(conf->mddev),
- (unsigned long long)sh->sector + rdev->data_offset,
- bdn);
+ printk(KERN_WARNING "raid5: read error not correctable.\n");
else if (test_bit(R5_ReWrite, &sh->dev[i].flags))
/* Oh, no!!! */
- printk(KERN_WARNING "raid5:%s: read error NOT corrected!! (sector %llu on %s).\n",
- mdname(conf->mddev),
- (unsigned long long)sh->sector + rdev->data_offset,
- bdn);
- else if (atomic_read(&rdev->read_errors)
+ printk(KERN_WARNING "raid5: read error NOT corrected!!\n");
+ else if (atomic_read(&conf->disks[i].rdev->read_errors)
> conf->max_nr_stripes)
printk(KERN_WARNING
- "raid5:%s: Too many read errors, failing device %s.\n",
- mdname(conf->mddev), bdn);
+ "raid5: Too many read errors, failing device.\n");
else
retry = 1;
if (retry)
else {
clear_bit(R5_ReadError, &sh->dev[i].flags);
clear_bit(R5_ReWrite, &sh->dev[i].flags);
- md_error(conf->mddev, rdev);
+ md_error(conf->mddev, conf->disks[i].rdev);
}
}
rdev_dec_pending(conf->disks[i].rdev, conf->mddev);
{
struct stripe_head *sh = bi->bi_private;
raid5_conf_t *conf = sh->raid_conf;
- int disks = sh->disks, i;
+ int disks = conf->raid_disks, i;
unsigned long flags;
int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
dev->req.bi_private = sh;
dev->flags = 0;
- dev->sector = compute_blocknr(sh, i);
+ if (i != sh->pd_idx)
+ dev->sector = compute_blocknr(sh, i);
}
static void error(mddev_t *mddev, mdk_rdev_t *rdev)
" Operation continuing on %d devices\n",
bdevname(rdev->bdev,b), conf->working_disks);
}
-}
+}
/*
* Input: a 'big' sector number,
/*
* Select the parity disk based on the user selected algorithm.
*/
- switch(conf->level) {
- case 4:
+ if (conf->level == 4)
*pd_idx = data_disks;
- break;
- case 5:
- switch (conf->algorithm) {
+ else switch (conf->algorithm) {
case ALGORITHM_LEFT_ASYMMETRIC:
*pd_idx = data_disks - stripe % raid_disks;
if (*dd_idx >= *pd_idx)
default:
printk(KERN_ERR "raid5: unsupported algorithm %d\n",
conf->algorithm);
- }
- break;
- case 6:
-
- /**** 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);
- }
- break;
}
/*
static sector_t compute_blocknr(struct stripe_head *sh, int i)
{
raid5_conf_t *conf = sh->raid_conf;
- int raid_disks = sh->disks, data_disks = raid_disks - 1;
+ int raid_disks = conf->raid_disks, data_disks = raid_disks - 1;
sector_t new_sector = sh->sector, check;
int sectors_per_chunk = conf->chunk_size >> 9;
sector_t stripe;
int chunk_number, dummy1, dummy2, dd_idx = i;
sector_t r_sector;
-
chunk_offset = sector_div(new_sector, sectors_per_chunk);
stripe = new_sector;
BUG_ON(new_sector != stripe);
- if (i == sh->pd_idx)
- return 0;
- switch(conf->level) {
- case 4: break;
- case 5:
- switch (conf->algorithm) {
+
+ switch (conf->algorithm) {
case ALGORITHM_LEFT_ASYMMETRIC:
case ALGORITHM_RIGHT_ASYMMETRIC:
if (i > sh->pd_idx)
break;
default:
printk(KERN_ERR "raid5: unsupported algorithm %d\n",
- conf->algorithm);
- }
- break;
- case 6:
- data_disks = raid_disks - 2;
- if (i == raid6_next_disk(sh->pd_idx, raid_disks))
- return 0; /* It is the Q disk */
- 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);
- }
- break;
}
chunk_number = stripe * data_disks + i;
/*
- * 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.
+ * Copy data between a page in the stripe cache, and a bio.
+ * There are no alignment or size guarantees between the page or the
+ * bio except that there is some overlap.
+ * All iovecs in the bio must be considered.
*/
static void copy_data(int frombio, struct bio *bio,
struct page *page,
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)
static void compute_block(struct stripe_head *sh, int dd_idx)
{
- int i, count, disks = sh->disks;
+ raid5_conf_t *conf = sh->raid_conf;
+ int i, count, disks = conf->raid_disks;
void *ptr[MAX_XOR_BLOCKS], *p;
PRINTK("compute_block, stripe %llu, idx %d\n",
set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
}
-static void compute_parity5(struct stripe_head *sh, int method)
+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 = sh->disks, count;
+ int i, pd_idx = sh->pd_idx, disks = conf->raid_disks, count;
void *ptr[MAX_XOR_BLOCKS];
struct bio *chosen;
- PRINTK("compute_parity5, stripe %llu, method %d\n",
+ PRINTK("compute_parity, stripe %llu, method %d\n",
(unsigned long long)sh->sector, method);
count = 1;
ptr[0] = page_address(sh->dev[pd_idx].page);
switch(method) {
case READ_MODIFY_WRITE:
- BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags));
+ if (!test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags))
+ BUG();
for (i=disks ; i-- ;) {
if (i==pd_idx)
continue;
if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
wake_up(&conf->wait_for_overlap);
- BUG_ON(sh->dev[i].written);
+ if (sh->dev[i].written) BUG();
sh->dev[i].written = chosen;
check_xor();
}
if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
wake_up(&conf->wait_for_overlap);
- BUG_ON(sh->dev[i].written);
+ if (sh->dev[i].written) BUG();
sh->dev[i].written = chosen;
}
break;
clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
}
-static void compute_parity6(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, int nozero)
-{
- 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_parity6(sh, UPDATE_PARITY);
- } else {
- ptr[0] = page_address(sh->dev[dd_idx].page);
- if (!nozero) 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);
- if (!nozero) set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
- else clear_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_parity6(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, 0);
- compute_parity6(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.
+ * 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)
if (*bip && (*bip)->bi_sector < bi->bi_sector + ((bi->bi_size)>>9))
goto overlap;
- BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next);
+ if (*bip && bi->bi_next && (*bip) != bi->bi_next)
+ BUG();
if (*bip)
bi->bi_next = *bip;
*bip = bi;
(unsigned long long)sh->sector, dd_idx);
if (conf->mddev->bitmap && firstwrite) {
+ sh->bm_seq = conf->seq_write;
bitmap_startwrite(conf->mddev->bitmap, sh->sector,
STRIPE_SECTORS, 0);
- sh->bm_seq = conf->seq_flush+1;
set_bit(STRIPE_BIT_DELAY, &sh->state);
}
return 0;
}
-static void end_reshape(raid5_conf_t *conf);
-
-static int page_is_zero(struct page *p)
-{
- char *a = page_address(p);
- return ((*(u32*)a) == 0 &&
- memcmp(a, a+4, STRIPE_SIZE-4)==0);
-}
-
-static int stripe_to_pdidx(sector_t stripe, raid5_conf_t *conf, int disks)
-{
- int sectors_per_chunk = conf->chunk_size >> 9;
- sector_t x = stripe;
- int pd_idx, dd_idx;
- int chunk_offset = sector_div(x, sectors_per_chunk);
- stripe = x;
- raid5_compute_sector(stripe*(disks-1)*sectors_per_chunk
- + chunk_offset, disks, disks-1, &dd_idx, &pd_idx, conf);
- return pd_idx;
-}
-
/*
* handle_stripe - do things to a stripe.
*
*/
-static void handle_stripe5(struct stripe_head *sh)
+static void handle_stripe(struct stripe_head *sh)
{
raid5_conf_t *conf = sh->raid_conf;
- int disks = sh->disks;
+ int disks = conf->raid_disks;
struct bio *return_bi= NULL;
struct bio *bi;
int i;
- int syncing, expanding, expanded;
+ int syncing;
int locked=0, uptodate=0, to_read=0, to_write=0, failed=0, written=0;
int non_overwrite = 0;
int failed_num=0;
clear_bit(STRIPE_DELAYED, &sh->state);
syncing = test_bit(STRIPE_SYNCING, &sh->state);
- expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
- expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
/* Now to look around and see what can be done */
rcu_read_lock();
* parity, or to satisfy requests
* or to load a block that is being partially written.
*/
- if (to_read || non_overwrite || (syncing && (uptodate < disks)) || expanding) {
+ if (to_read || non_overwrite || (syncing && (uptodate < disks))) {
for (i=disks; i--;) {
dev = &sh->dev[i];
if (!test_bit(R5_LOCKED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags) &&
(dev->toread ||
(dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
syncing ||
- expanding ||
(failed && (sh->dev[failed_num].toread ||
(sh->dev[failed_num].towrite && !test_bit(R5_OVERWRITE, &sh->dev[failed_num].flags))))
)
if (locked == 0 && (rcw == 0 ||rmw == 0) &&
!test_bit(STRIPE_BIT_DELAY, &sh->state)) {
PRINTK("Computing parity...\n");
- compute_parity5(sh, rcw==0 ? RECONSTRUCT_WRITE : READ_MODIFY_WRITE);
+ 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)) {
!test_bit(STRIPE_INSYNC, &sh->state)) {
set_bit(STRIPE_HANDLE, &sh->state);
if (failed == 0) {
- BUG_ON(uptodate != disks);
- compute_parity5(sh, CHECK_PARITY);
+ char *pagea;
+ if (uptodate != disks)
+ BUG();
+ compute_parity(sh, CHECK_PARITY);
uptodate--;
- if (page_is_zero(sh->dev[sh->pd_idx].page)) {
+ pagea = page_address(sh->dev[sh->pd_idx].page);
+ if ((*(u32*)pagea) == 0 &&
+ !memcmp(pagea, pagea+4, STRIPE_SIZE-4)) {
/* parity is correct (on disc, not in buffer any more) */
set_bit(STRIPE_INSYNC, &sh->state);
} else {
set_bit(R5_Wantwrite, &dev->flags);
set_bit(R5_ReWrite, &dev->flags);
set_bit(R5_LOCKED, &dev->flags);
- locked++;
} else {
/* let's read it back */
set_bit(R5_Wantread, &dev->flags);
set_bit(R5_LOCKED, &dev->flags);
- locked++;
- }
- }
-
- if (expanded && test_bit(STRIPE_EXPANDING, &sh->state)) {
- /* Need to write out all blocks after computing parity */
- sh->disks = conf->raid_disks;
- sh->pd_idx = stripe_to_pdidx(sh->sector, conf, conf->raid_disks);
- compute_parity5(sh, RECONSTRUCT_WRITE);
- for (i= conf->raid_disks; i--;) {
- set_bit(R5_LOCKED, &sh->dev[i].flags);
- locked++;
- set_bit(R5_Wantwrite, &sh->dev[i].flags);
}
- clear_bit(STRIPE_EXPANDING, &sh->state);
- } else if (expanded) {
- clear_bit(STRIPE_EXPAND_READY, &sh->state);
- atomic_dec(&conf->reshape_stripes);
- wake_up(&conf->wait_for_overlap);
- md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
- }
-
- if (expanding && locked == 0) {
- /* We have read all the blocks in this stripe and now we need to
- * copy some of them into a target stripe for expand.
- */
- clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
- for (i=0; i< sh->disks; i++)
- if (i != sh->pd_idx) {
- int dd_idx, pd_idx, j;
- struct stripe_head *sh2;
-
- sector_t bn = compute_blocknr(sh, i);
- sector_t s = raid5_compute_sector(bn, conf->raid_disks,
- conf->raid_disks-1,
- &dd_idx, &pd_idx, conf);
- sh2 = get_active_stripe(conf, s, conf->raid_disks, pd_idx, 1);
- if (sh2 == NULL)
- /* so far only the early blocks of this stripe
- * have been requested. When later blocks
- * get requested, we will try again
- */
- continue;
- if(!test_bit(STRIPE_EXPANDING, &sh2->state) ||
- test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) {
- /* must have already done this block */
- release_stripe(sh2);
- continue;
- }
- memcpy(page_address(sh2->dev[dd_idx].page),
- page_address(sh->dev[i].page),
- STRIPE_SIZE);
- set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
- set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
- for (j=0; j<conf->raid_disks; j++)
- if (j != sh2->pd_idx &&
- !test_bit(R5_Expanded, &sh2->dev[j].flags))
- break;
- if (j == conf->raid_disks) {
- set_bit(STRIPE_EXPAND_READY, &sh2->state);
- set_bit(STRIPE_HANDLE, &sh2->state);
- }
- release_stripe(sh2);
- }
}
spin_unlock(&sh->lock);
rcu_read_unlock();
if (rdev) {
- if (syncing || expanding || expanded)
+ if (syncing)
md_sync_acct(rdev->bdev, STRIPE_SECTORS);
bi->bi_bdev = rdev->bdev;
}
}
-static void handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
+static void raid5_activate_delayed(raid5_conf_t *conf)
{
- 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);
+ 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);
+ }
+ }
+}
- spin_lock(&sh->lock);
- clear_bit(STRIPE_HANDLE, &sh->state);
- clear_bit(STRIPE_DELAYED, &sh->state);
+static void activate_bit_delay(raid5_conf_t *conf)
+{
+ /* device_lock is held */
+ struct list_head head;
+ list_add(&head, &conf->bitmap_list);
+ list_del_init(&conf->bitmap_list);
+ while (!list_empty(&head)) {
+ struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
+ list_del_init(&sh->lru);
+ atomic_inc(&sh->count);
+ __release_stripe(conf, sh);
+ }
+}
- syncing = test_bit(STRIPE_SYNCING, &sh->state);
- /* Now to look around and see what can be done */
-
- rcu_read_lock();
- for (i=disks; i--; ) {
- mdk_rdev_t *rdev;
- dev = &sh->dev[i];
- clear_bit(R5_Insync, &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 = rcu_dereference(conf->disks[i].rdev);
- if (!rdev || !test_bit(In_sync, &rdev->flags)) {
- /* The ReadError flag will just be confusing now */
- clear_bit(R5_ReadError, &dev->flags);
- clear_bit(R5_ReWrite, &dev->flags);
- }
- if (!rdev || !test_bit(In_sync, &rdev->flags)
- || test_bit(R5_ReadError, &dev->flags)) {
- if ( failed < 2 )
- failed_num[failed] = i;
- failed++;
- } else
- set_bit(R5_Insync, &dev->flags);
- }
- rcu_read_unlock();
- 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) {
- for (i=disks; i--; ) {
- int bitmap_end = 0;
-
- if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
- mdk_rdev_t *rdev;
- rcu_read_lock();
- rdev = rcu_dereference(conf->disks[i].rdev);
- if (rdev && test_bit(In_sync, &rdev->flags))
- /* multiple read failures in one stripe */
- md_error(conf->mddev, rdev);
- rcu_read_unlock();
- }
-
- spin_lock_irq(&conf->device_lock);
- /* fail all writes first */
- bi = sh->dev[i].towrite;
- sh->dev[i].towrite = NULL;
- if (bi) { to_write--; bitmap_end = 1; }
-
- if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
- wake_up(&conf->wait_for_overlap);
-
- while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){
- struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
- clear_bit(BIO_UPTODATE, &bi->bi_flags);
- if (--bi->bi_phys_segments == 0) {
- md_write_end(conf->mddev);
- bi->bi_next = return_bi;
- return_bi = bi;
- }
- bi = nextbi;
- }
- /* and fail all 'written' */
- bi = sh->dev[i].written;
- sh->dev[i].written = NULL;
- if (bi) bitmap_end = 1;
- while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS) {
- struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
- clear_bit(BIO_UPTODATE, &bi->bi_flags);
- if (--bi->bi_phys_segments == 0) {
- md_write_end(conf->mddev);
- bi->bi_next = return_bi;
- return_bi = bi;
- }
- bi = bi2;
- }
-
- /* fail any reads if this device is non-operational */
- if (!test_bit(R5_Insync, &sh->dev[i].flags) ||
- test_bit(R5_ReadError, &sh->dev[i].flags)) {
- bi = sh->dev[i].toread;
- sh->dev[i].toread = NULL;
- if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
- wake_up(&conf->wait_for_overlap);
- if (bi) to_read--;
- while (bi && bi->bi_sector < sh->dev[i].sector + STRIPE_SECTORS){
- struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
- clear_bit(BIO_UPTODATE, &bi->bi_flags);
- if (--bi->bi_phys_segments == 0) {
- bi->bi_next = return_bi;
- return_bi = bi;
- }
- bi = nextbi;
- }
- }
- spin_unlock_irq(&conf->device_lock);
- if (bitmap_end)
- bitmap_endwrite(conf->mddev->bitmap, sh->sector,
- STRIPE_SECTORS, 0, 0);
- }
- }
- if (failed > 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 */
- int bitmap_end = 0;
- 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;
- }
- if (dev->towrite == NULL)
- bitmap_end = 1;
- spin_unlock_irq(&conf->device_lock);
- if (bitmap_end)
- bitmap_endwrite(conf->mddev->bitmap, sh->sector,
- STRIPE_SECTORS,
- !test_bit(STRIPE_DEGRADED, &sh->state), 0);
- }
- }
- }
-
- /* Now we might consider reading some blocks, either to check/generate
- * parity, or to satisfy requests
- * or to load a block that is being partially written.
- */
- if (to_read || non_overwrite || (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, 0);
- 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);
- }
- }
- }
- 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 &&
- !test_bit(STRIPE_BIT_DELAY, &sh->state)) {
- 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], 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_parity6(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);
- }
- /* after a RECONSTRUCT_WRITE, the stripe MUST be in-sync */
- set_bit(STRIPE_INSYNC, &sh->state);
-
- if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
- atomic_dec(&conf->preread_active_stripes);
- if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD)
- md_wakeup_thread(conf->mddev->thread);
- }
- }
- }
-
- /* maybe we need to check and possibly fix the parity for this stripe
- * Any reads will already have been scheduled, so we just see if enough data
- * is available
- */
- if (syncing && locked == 0 && !test_bit(STRIPE_INSYNC, &sh->state)) {
- int update_p = 0, update_q = 0;
- struct r5dev *dev;
-
- set_bit(STRIPE_HANDLE, &sh->state);
-
- BUG_ON(failed>2);
- BUG_ON(uptodate < disks);
- /* Want to check and possibly repair P and Q.
- * However there could be one 'failed' device, in which
- * case we can only check one of them, possibly using the
- * other to generate missing data
- */
-
- /* If !tmp_page, we cannot do the calculations,
- * but as we have set STRIPE_HANDLE, we will soon be called
- * by stripe_handle with a tmp_page - just wait until then.
- */
- if (tmp_page) {
- if (failed == q_failed) {
- /* The only possible failed device holds 'Q', so it makes
- * sense to check P (If anything else were failed, we would
- * have used P to recreate it).
- */
- compute_block_1(sh, pd_idx, 1);
- if (!page_is_zero(sh->dev[pd_idx].page)) {
- compute_block_1(sh,pd_idx,0);
- update_p = 1;
- }
- }
- if (!q_failed && failed < 2) {
- /* q is not failed, and we didn't use it to generate
- * anything, so it makes sense to check it
- */
- memcpy(page_address(tmp_page),
- page_address(sh->dev[qd_idx].page),
- STRIPE_SIZE);
- compute_parity6(sh, UPDATE_PARITY);
- if (memcmp(page_address(tmp_page),
- page_address(sh->dev[qd_idx].page),
- STRIPE_SIZE)!= 0) {
- clear_bit(STRIPE_INSYNC, &sh->state);
- update_q = 1;
- }
- }
- if (update_p || update_q) {
- conf->mddev->resync_mismatches += STRIPE_SECTORS;
- if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
- /* don't try to repair!! */
- update_p = update_q = 0;
- }
-
- /* now write out any block on a failed drive,
- * or P or Q if they need it
- */
-
- if (failed == 2) {
- dev = &sh->dev[failed_num[1]];
- locked++;
- set_bit(R5_LOCKED, &dev->flags);
- set_bit(R5_Wantwrite, &dev->flags);
- }
- if (failed >= 1) {
- dev = &sh->dev[failed_num[0]];
- locked++;
- set_bit(R5_LOCKED, &dev->flags);
- set_bit(R5_Wantwrite, &dev->flags);
- }
-
- if (update_p) {
- dev = &sh->dev[pd_idx];
- locked ++;
- set_bit(R5_LOCKED, &dev->flags);
- set_bit(R5_Wantwrite, &dev->flags);
- }
- if (update_q) {
- dev = &sh->dev[qd_idx];
- locked++;
- set_bit(R5_LOCKED, &dev->flags);
- set_bit(R5_Wantwrite, &dev->flags);
- }
- clear_bit(STRIPE_DEGRADED, &sh->state);
-
- set_bit(STRIPE_INSYNC, &sh->state);
- }
- }
-
- if (syncing && locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
- md_done_sync(conf->mddev, STRIPE_SECTORS,1);
- clear_bit(STRIPE_SYNCING, &sh->state);
- }
-
- /* If the failed drives are just a ReadError, then we might need
- * to progress the repair/check process
- */
- if (failed <= 2 && ! conf->mddev->ro)
- for (i=0; i<failed;i++) {
- dev = &sh->dev[failed_num[i]];
- if (test_bit(R5_ReadError, &dev->flags)
- && !test_bit(R5_LOCKED, &dev->flags)
- && test_bit(R5_UPTODATE, &dev->flags)
- ) {
- if (!test_bit(R5_ReWrite, &dev->flags)) {
- set_bit(R5_Wantwrite, &dev->flags);
- set_bit(R5_ReWrite, &dev->flags);
- set_bit(R5_LOCKED, &dev->flags);
- } else {
- /* let's read it back */
- set_bit(R5_Wantread, &dev->flags);
- set_bit(R5_LOCKED, &dev->flags);
- }
- }
- }
- spin_unlock(&sh->lock);
-
- while ((bi=return_bi)) {
- int bytes = bi->bi_size;
-
- return_bi = bi->bi_next;
- bi->bi_next = NULL;
- bi->bi_size = 0;
- bi->bi_end_io(bi, bytes, 0);
- }
- for (i=disks; i-- ;) {
- int rw;
- struct bio *bi;
- mdk_rdev_t *rdev;
- if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
- rw = 1;
- else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
- rw = 0;
- else
- continue;
-
- bi = &sh->dev[i].req;
-
- bi->bi_rw = rw;
- if (rw)
- bi->bi_end_io = raid5_end_write_request;
- else
- bi->bi_end_io = raid5_end_read_request;
-
- rcu_read_lock();
- rdev = rcu_dereference(conf->disks[i].rdev);
- if (rdev && test_bit(Faulty, &rdev->flags))
- rdev = NULL;
- if (rdev)
- atomic_inc(&rdev->nr_pending);
- rcu_read_unlock();
-
- if (rdev) {
- if (syncing)
- 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;
- if (rw == WRITE &&
- test_bit(R5_ReWrite, &sh->dev[i].flags))
- atomic_add(STRIPE_SECTORS, &rdev->corrected_errors);
- generic_make_request(bi);
- } else {
- if (rw == 1)
- set_bit(STRIPE_DEGRADED, &sh->state);
- PRINTK("skip op %ld on disc %d for sector %llu\n",
- bi->bi_rw, i, (unsigned long long)sh->sector);
- clear_bit(R5_LOCKED, &sh->dev[i].flags);
- set_bit(STRIPE_HANDLE, &sh->state);
- }
- }
-}
-
-static void handle_stripe(struct stripe_head *sh, struct page *tmp_page)
-{
- if (sh->raid_conf->level == 6)
- handle_stripe6(sh, tmp_page);
- else
- handle_stripe5(sh);
-}
-
-
-
-static 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 activate_bit_delay(raid5_conf_t *conf)
-{
- /* device_lock is held */
- struct list_head head;
- list_add(&head, &conf->bitmap_list);
- list_del_init(&conf->bitmap_list);
- while (!list_empty(&head)) {
- struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
- list_del_init(&sh->lru);
- atomic_inc(&sh->count);
- __release_stripe(conf, sh);
- }
-}
-
-static void unplug_slaves(mddev_t *mddev)
-{
- raid5_conf_t *conf = mddev_to_conf(mddev);
- int i;
+static void unplug_slaves(mddev_t *mddev)
+{
+ raid5_conf_t *conf = mddev_to_conf(mddev);
+ int i;
rcu_read_lock();
for (i=0; i<mddev->raid_disks; i++) {
return ret;
}
-static int make_request(request_queue_t *q, struct bio * bi)
+static inline void raid5_plug_device(raid5_conf_t *conf)
+{
+ spin_lock_irq(&conf->device_lock);
+ blk_plug_device(conf->mddev->queue);
+ spin_unlock_irq(&conf->device_lock);
+}
+
+static int make_request (request_queue_t *q, struct bio * bi)
{
mddev_t *mddev = q->queuedata;
raid5_conf_t *conf = mddev_to_conf(mddev);
+ const unsigned int raid_disks = conf->raid_disks;
+ const unsigned int data_disks = raid_disks - 1;
unsigned int dd_idx, pd_idx;
sector_t new_sector;
sector_t logical_sector, last_sector;
struct stripe_head *sh;
const int rw = bio_data_dir(bi);
- int remaining;
if (unlikely(bio_barrier(bi))) {
bio_endio(bi, bi->bi_size, -EOPNOTSUPP);
for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
DEFINE_WAIT(w);
- int disks, data_disks;
-
- retry:
- prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
- if (likely(conf->expand_progress == MaxSector))
- disks = conf->raid_disks;
- else {
- /* spinlock is needed as expand_progress may be
- * 64bit on a 32bit platform, and so it might be
- * possible to see a half-updated value
- * Ofcourse expand_progress could change after
- * the lock is dropped, so once we get a reference
- * to the stripe that we think it is, we will have
- * to check again.
- */
- spin_lock_irq(&conf->device_lock);
- disks = conf->raid_disks;
- if (logical_sector >= conf->expand_progress)
- disks = conf->previous_raid_disks;
- else {
- if (logical_sector >= conf->expand_lo) {
- spin_unlock_irq(&conf->device_lock);
- schedule();
- goto retry;
- }
- }
- spin_unlock_irq(&conf->device_lock);
- }
- data_disks = disks - conf->max_degraded;
+
+ new_sector = raid5_compute_sector(logical_sector,
+ raid_disks, data_disks, &dd_idx, &pd_idx, conf);
- new_sector = raid5_compute_sector(logical_sector, disks, data_disks,
- &dd_idx, &pd_idx, conf);
PRINTK("raid5: make_request, sector %llu logical %llu\n",
(unsigned long long)new_sector,
(unsigned long long)logical_sector);
- sh = get_active_stripe(conf, new_sector, disks, pd_idx, (bi->bi_rw&RWA_MASK));
+ 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 (unlikely(conf->expand_progress != MaxSector)) {
- /* expansion might have moved on while waiting for a
- * stripe, so we must do the range check again.
- * Expansion could still move past after this
- * test, but as we are holding a reference to
- * 'sh', we know that if that happens,
- * STRIPE_EXPANDING will get set and the expansion
- * won't proceed until we finish with the stripe.
- */
- int must_retry = 0;
- spin_lock_irq(&conf->device_lock);
- if (logical_sector < conf->expand_progress &&
- disks == conf->previous_raid_disks)
- /* mismatch, need to try again */
- must_retry = 1;
- spin_unlock_irq(&conf->device_lock);
- if (must_retry) {
- release_stripe(sh);
- goto retry;
- }
- }
- /* FIXME what if we get a false positive because these
- * are being updated.
- */
- if (logical_sector >= mddev->suspend_lo &&
- logical_sector < mddev->suspend_hi) {
- release_stripe(sh);
- schedule();
- goto retry;
- }
-
- if (test_bit(STRIPE_EXPANDING, &sh->state) ||
- !add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) {
- /* Stripe is busy expanding or
- * add failed due to overlap. Flush everything
+ if (!add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) {
+ /* Add failed due to overlap. Flush everything
* and wait a while
*/
raid5_unplug_device(mddev->queue);
goto retry;
}
finish_wait(&conf->wait_for_overlap, &w);
- handle_stripe(sh, NULL);
+ raid5_plug_device(conf);
+ handle_stripe(sh);
release_stripe(sh);
+
} else {
/* cannot get stripe for read-ahead, just give-up */
clear_bit(BIO_UPTODATE, &bi->bi_flags);
}
spin_lock_irq(&conf->device_lock);
- remaining = --bi->bi_phys_segments;
- spin_unlock_irq(&conf->device_lock);
- if (remaining == 0) {
+ if (--bi->bi_phys_segments == 0) {
int bytes = bi->bi_size;
- if ( rw == WRITE )
+ if ( bio_data_dir(bi) == WRITE )
md_write_end(mddev);
bi->bi_size = 0;
bi->bi_end_io(bi, bytes, 0);
}
- return 0;
-}
-
-static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped)
-{
- /* reshaping is quite different to recovery/resync so it is
- * handled quite separately ... here.
- *
- * On each call to sync_request, we gather one chunk worth of
- * destination stripes and flag them as expanding.
- * Then we find all the source stripes and request reads.
- * As the reads complete, handle_stripe will copy the data
- * into the destination stripe and release that stripe.
- */
- raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
- struct stripe_head *sh;
- int pd_idx;
- sector_t first_sector, last_sector;
- int raid_disks;
- int data_disks;
- int i;
- int dd_idx;
- sector_t writepos, safepos, gap;
-
- if (sector_nr == 0 &&
- conf->expand_progress != 0) {
- /* restarting in the middle, skip the initial sectors */
- sector_nr = conf->expand_progress;
- sector_div(sector_nr, conf->raid_disks-1);
- *skipped = 1;
- return sector_nr;
- }
-
- /* we update the metadata when there is more than 3Meg
- * in the block range (that is rather arbitrary, should
- * probably be time based) or when the data about to be
- * copied would over-write the source of the data at
- * the front of the range.
- * i.e. one new_stripe forward from expand_progress new_maps
- * to after where expand_lo old_maps to
- */
- writepos = conf->expand_progress +
- conf->chunk_size/512*(conf->raid_disks-1);
- sector_div(writepos, conf->raid_disks-1);
- safepos = conf->expand_lo;
- sector_div(safepos, conf->previous_raid_disks-1);
- gap = conf->expand_progress - conf->expand_lo;
-
- if (writepos >= safepos ||
- gap > (conf->raid_disks-1)*3000*2 /*3Meg*/) {
- /* Cannot proceed until we've updated the superblock... */
- wait_event(conf->wait_for_overlap,
- atomic_read(&conf->reshape_stripes)==0);
- mddev->reshape_position = conf->expand_progress;
- mddev->sb_dirty = 1;
- md_wakeup_thread(mddev->thread);
- wait_event(mddev->sb_wait, mddev->sb_dirty == 0 ||
- kthread_should_stop());
- spin_lock_irq(&conf->device_lock);
- conf->expand_lo = mddev->reshape_position;
- spin_unlock_irq(&conf->device_lock);
- wake_up(&conf->wait_for_overlap);
- }
-
- for (i=0; i < conf->chunk_size/512; i+= STRIPE_SECTORS) {
- int j;
- int skipped = 0;
- pd_idx = stripe_to_pdidx(sector_nr+i, conf, conf->raid_disks);
- sh = get_active_stripe(conf, sector_nr+i,
- conf->raid_disks, pd_idx, 0);
- set_bit(STRIPE_EXPANDING, &sh->state);
- atomic_inc(&conf->reshape_stripes);
- /* If any of this stripe is beyond the end of the old
- * array, then we need to zero those blocks
- */
- for (j=sh->disks; j--;) {
- sector_t s;
- if (j == sh->pd_idx)
- continue;
- s = compute_blocknr(sh, j);
- if (s < (mddev->array_size<<1)) {
- skipped = 1;
- continue;
- }
- memset(page_address(sh->dev[j].page), 0, STRIPE_SIZE);
- set_bit(R5_Expanded, &sh->dev[j].flags);
- set_bit(R5_UPTODATE, &sh->dev[j].flags);
- }
- if (!skipped) {
- set_bit(STRIPE_EXPAND_READY, &sh->state);
- set_bit(STRIPE_HANDLE, &sh->state);
- }
- release_stripe(sh);
- }
- spin_lock_irq(&conf->device_lock);
- conf->expand_progress = (sector_nr + i)*(conf->raid_disks-1);
spin_unlock_irq(&conf->device_lock);
- /* Ok, those stripe are ready. We can start scheduling
- * reads on the source stripes.
- * The source stripes are determined by mapping the first and last
- * block on the destination stripes.
- */
- raid_disks = conf->previous_raid_disks;
- data_disks = raid_disks - 1;
- first_sector =
- raid5_compute_sector(sector_nr*(conf->raid_disks-1),
- raid_disks, data_disks,
- &dd_idx, &pd_idx, conf);
- last_sector =
- raid5_compute_sector((sector_nr+conf->chunk_size/512)
- *(conf->raid_disks-1) -1,
- raid_disks, data_disks,
- &dd_idx, &pd_idx, conf);
- if (last_sector >= (mddev->size<<1))
- last_sector = (mddev->size<<1)-1;
- while (first_sector <= last_sector) {
- pd_idx = stripe_to_pdidx(first_sector, conf, conf->previous_raid_disks);
- sh = get_active_stripe(conf, first_sector,
- conf->previous_raid_disks, pd_idx, 0);
- set_bit(STRIPE_EXPAND_SOURCE, &sh->state);
- set_bit(STRIPE_HANDLE, &sh->state);
- release_stripe(sh);
- first_sector += STRIPE_SECTORS;
- }
- return conf->chunk_size>>9;
+ return 0;
}
/* FIXME go_faster isn't used */
-static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
+static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
{
raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
struct stripe_head *sh;
- int pd_idx;
+ int sectors_per_chunk = conf->chunk_size >> 9;
+ sector_t x;
+ unsigned long stripe;
+ int chunk_offset;
+ int dd_idx, pd_idx;
+ sector_t first_sector;
int raid_disks = conf->raid_disks;
+ int data_disks = raid_disks-1;
sector_t max_sector = mddev->size << 1;
int sync_blocks;
- int still_degraded = 0;
- int i;
if (sector_nr >= max_sector) {
/* just being told to finish up .. nothing much to do */
unplug_slaves(mddev);
- if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
- end_reshape(conf);
- return 0;
- }
if (mddev->curr_resync < max_sector) /* aborted */
bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
&sync_blocks, 1);
- else /* completed sync */
+ else /* compelted sync */
conf->fullsync = 0;
bitmap_close_sync(mddev->bitmap);
return 0;
}
-
- if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
- return reshape_request(mddev, sector_nr, skipped);
-
- /* if there is too many failed drives and we are trying
+ /* if there is 1 or more failed drives and we are trying
* to resync, then assert that we are finished, because there is
* nothing we can do.
*/
- if (mddev->degraded >= conf->max_degraded &&
- test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
+ if (mddev->degraded >= 1 && test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
sector_t rv = (mddev->size << 1) - sector_nr;
*skipped = 1;
return rv;
return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */
}
- pd_idx = stripe_to_pdidx(sector_nr, conf, raid_disks);
- sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 1);
+ x = sector_nr;
+ chunk_offset = sector_div(x, sectors_per_chunk);
+ stripe = x;
+ BUG_ON(x != stripe);
+
+ first_sector = raid5_compute_sector((sector_t)stripe*data_disks*sectors_per_chunk
+ + chunk_offset, raid_disks, data_disks, &dd_idx, &pd_idx, conf);
+ sh = get_active_stripe(conf, sector_nr, pd_idx, 1);
if (sh == NULL) {
- sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 0);
+ 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
+ * is trying to get access
*/
schedule_timeout_uninterruptible(1);
}
- /* Need to check if array will still be degraded after recovery/resync
- * We don't need to check the 'failed' flag as when that gets set,
- * recovery aborts.
- */
- for (i=0; i<mddev->raid_disks; i++)
- if (conf->disks[i].rdev == NULL)
- still_degraded = 1;
-
- bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded);
-
- spin_lock(&sh->lock);
+ bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 0);
+ spin_lock(&sh->lock);
set_bit(STRIPE_SYNCING, &sh->state);
clear_bit(STRIPE_INSYNC, &sh->state);
spin_unlock(&sh->lock);
- handle_stripe(sh, NULL);
+ handle_stripe(sh);
release_stripe(sh);
return STRIPE_SECTORS;
while (1) {
struct list_head *first;
- if (conf->seq_flush != conf->seq_write) {
+ if (conf->seq_flush - conf->seq_write > 0) {
int seq = conf->seq_flush;
spin_unlock_irq(&conf->device_lock);
bitmap_unplug(mddev->bitmap);
list_del_init(first);
atomic_inc(&sh->count);
- BUG_ON(atomic_read(&sh->count)!= 1);
+ if (atomic_read(&sh->count)!= 1)
+ BUG();
spin_unlock_irq(&conf->device_lock);
handled++;
- handle_stripe(sh, conf->spare_page);
+ handle_stripe(sh);
release_stripe(sh);
spin_lock_irq(&conf->device_lock);
struct disk_info *disk;
struct list_head *tmp;
- if (mddev->level != 5 && mddev->level != 4 && mddev->level != 6) {
- printk(KERN_ERR "raid5: %s: raid level not set to 4/5/6 (%d)\n",
+ if (mddev->level != 5 && mddev->level != 4) {
+ printk(KERN_ERR "raid5: %s: raid level not set to 4/5 (%d)\n",
mdname(mddev), mddev->level);
return -EIO;
}
- if (mddev->reshape_position != MaxSector) {
- /* Check that we can continue the reshape.
- * Currently only disks can change, it must
- * increase, and we must be past the point where
- * a stripe over-writes itself
- */
- sector_t here_new, here_old;
- int old_disks;
-
- if (mddev->new_level != mddev->level ||
- mddev->new_layout != mddev->layout ||
- mddev->new_chunk != mddev->chunk_size) {
- printk(KERN_ERR "raid5: %s: unsupported reshape required - aborting.\n",
- mdname(mddev));
- return -EINVAL;
- }
- if (mddev->delta_disks <= 0) {
- printk(KERN_ERR "raid5: %s: unsupported reshape (reduce disks) required - aborting.\n",
- mdname(mddev));
- return -EINVAL;
- }
- old_disks = mddev->raid_disks - mddev->delta_disks;
- /* reshape_position must be on a new-stripe boundary, and one
- * further up in new geometry must map after here in old geometry.
- */
- here_new = mddev->reshape_position;
- if (sector_div(here_new, (mddev->chunk_size>>9)*(mddev->raid_disks-1))) {
- printk(KERN_ERR "raid5: reshape_position not on a stripe boundary\n");
- return -EINVAL;
- }
- /* here_new is the stripe we will write to */
- here_old = mddev->reshape_position;
- sector_div(here_old, (mddev->chunk_size>>9)*(old_disks-1));
- /* here_old is the first stripe that we might need to read from */
- if (here_new >= here_old) {
- /* Reading from the same stripe as writing to - bad */
- printk(KERN_ERR "raid5: reshape_position too early for auto-recovery - aborting.\n");
- return -EINVAL;
- }
- printk(KERN_INFO "raid5: reshape will continue\n");
- /* OK, we should be able to continue; */
- }
-
-
- mddev->private = kzalloc(sizeof (raid5_conf_t), GFP_KERNEL);
+ mddev->private = kzalloc(sizeof (raid5_conf_t)
+ + mddev->raid_disks * sizeof(struct disk_info),
+ GFP_KERNEL);
if ((conf = mddev->private) == NULL)
goto abort;
- if (mddev->reshape_position == MaxSector) {
- conf->previous_raid_disks = conf->raid_disks = mddev->raid_disks;
- } else {
- conf->raid_disks = mddev->raid_disks;
- conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
- }
-
- conf->disks = kzalloc(conf->raid_disks * sizeof(struct disk_info),
- GFP_KERNEL);
- if (!conf->disks)
- goto abort;
conf->mddev = mddev;
if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
goto abort;
- if (mddev->level == 6) {
- conf->spare_page = alloc_page(GFP_KERNEL);
- if (!conf->spare_page)
- goto abort;
- }
spin_lock_init(&conf->device_lock);
init_waitqueue_head(&conf->wait_for_stripe);
init_waitqueue_head(&conf->wait_for_overlap);
ITERATE_RDEV(mddev,rdev,tmp) {
raid_disk = rdev->raid_disk;
- if (raid_disk >= conf->raid_disks
+ if (raid_disk >= mddev->raid_disks
|| raid_disk < 0)
continue;
disk = conf->disks + raid_disk;
}
}
+ conf->raid_disks = mddev->raid_disks;
/*
- * 0 for a fully functional array, 1 or 2 for a degraded array.
+ * 0 for a fully functional array, 1 for a degraded array.
*/
mddev->degraded = conf->failed_disks = conf->raid_disks - conf->working_disks;
conf->mddev = mddev;
conf->chunk_size = mddev->chunk_size;
conf->level = mddev->level;
- if (conf->level == 6)
- conf->max_degraded = 2;
- else
- conf->max_degraded = 1;
conf->algorithm = mddev->layout;
conf->max_nr_stripes = NR_STRIPES;
- conf->expand_progress = mddev->reshape_position;
/* 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->level == 6 && 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 "raid5: invalid chunk size %d for %s\n",
conf->chunk_size, mdname(mddev));
conf->algorithm, mdname(mddev));
goto abort;
}
- if (mddev->degraded > conf->max_degraded) {
+ if (mddev->degraded > 1) {
printk(KERN_ERR "raid5: not enough operational devices for %s"
" (%d/%d failed)\n",
mdname(mddev), conf->failed_disks, conf->raid_disks);
goto abort;
}
- if (mddev->degraded > 0 &&
+ if (mddev->degraded == 1 &&
mddev->recovery_cp != MaxSector) {
if (mddev->ok_start_degraded)
printk(KERN_WARNING
print_raid5_conf(conf);
- if (conf->expand_progress != MaxSector) {
- printk("...ok start reshape thread\n");
- conf->expand_lo = conf->expand_progress;
- atomic_set(&conf->reshape_stripes, 0);
- clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
- clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
- set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
- set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
- mddev->sync_thread = md_register_thread(md_do_sync, mddev,
- "%s_reshape");
- }
-
/* read-ahead size must cover two whole stripes, which is
- * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
+ * 2 * (n-1) * chunksize where 'n' is the number of raid devices
*/
{
- int data_disks = conf->previous_raid_disks - conf->max_degraded;
- int stripe = data_disks *
- (mddev->chunk_size / PAGE_SIZE);
+ int stripe = (mddev->raid_disks-1) * mddev->chunk_size
+ / PAGE_SIZE;
if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
}
mddev->queue->unplug_fn = raid5_unplug_device;
mddev->queue->issue_flush_fn = raid5_issue_flush;
- mddev->array_size = mddev->size * (conf->previous_raid_disks -
- conf->max_degraded);
+ mddev->array_size = mddev->size * (mddev->raid_disks - 1);
return 0;
abort:
if (conf) {
print_raid5_conf(conf);
- safe_put_page(conf->spare_page);
- kfree(conf->disks);
kfree(conf->stripe_hashtbl);
kfree(conf);
}
kfree(conf->stripe_hashtbl);
blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
sysfs_remove_group(&mddev->kobj, &raid5_attrs_group);
- kfree(conf->disks);
kfree(conf);
mddev->private = NULL;
return 0;
}
#if RAID5_DEBUG
-static void print_sh (struct seq_file *seq, struct stripe_head *sh)
+static void print_sh (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->disks; i++) {
- seq_printf(seq, "(cache%d: %p %ld) ",
- i, sh->dev[i].page, sh->dev[i].flags);
+ printk("sh %llu, pd_idx %d, state %ld.\n",
+ (unsigned long long)sh->sector, sh->pd_idx, sh->state);
+ printk("sh %llu, count %d.\n",
+ (unsigned long long)sh->sector, atomic_read(&sh->count));
+ printk("sh %llu, ", (unsigned long long)sh->sector);
+ for (i = 0; i < sh->raid_conf->raid_disks; i++) {
+ printk("(cache%d: %p %ld) ",
+ i, sh->dev[i].page, sh->dev[i].flags);
}
- seq_printf(seq, "\n");
+ printk("\n");
}
-static void printall (struct seq_file *seq, raid5_conf_t *conf)
+static void printall (raid5_conf_t *conf)
{
struct stripe_head *sh;
struct hlist_node *hn;
hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) {
if (sh->raid_conf != conf)
continue;
- print_sh(seq, sh);
+ print_sh(sh);
}
}
spin_unlock_irq(&conf->device_lock);
test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_");
seq_printf (seq, "]");
#if RAID5_DEBUG
- seq_printf (seq, "\n");
- printall(seq, conf);
+#define D(x) \
+ seq_printf (seq, "<"#x":%d>", atomic_read(&conf->x))
+ printall(conf);
#endif
}
int disk;
struct disk_info *p;
- if (mddev->degraded > conf->max_degraded)
+ if (mddev->degraded > 1)
/* no point adding a device */
return 0;
/*
- * find the disk ... but prefer rdev->saved_raid_disk
- * if possible.
+ * find the disk ...
*/
- if (rdev->saved_raid_disk >= 0 &&
- conf->disks[rdev->saved_raid_disk].rdev == NULL)
- disk = rdev->saved_raid_disk;
- else
- disk = 0;
- for ( ; disk < conf->raid_disks; disk++)
+ for (disk=0; disk < mddev->raid_disks; disk++)
if ((p=conf->disks + disk)->rdev == NULL) {
clear_bit(In_sync, &rdev->flags);
rdev->raid_disk = disk;
* any io in the removed space completes, but it hardly seems
* worth it.
*/
- raid5_conf_t *conf = mddev_to_conf(mddev);
-
sectors &= ~((sector_t)mddev->chunk_size/512 - 1);
- mddev->array_size = (sectors * (mddev->raid_disks-conf->max_degraded))>>1;
+ mddev->array_size = (sectors * (mddev->raid_disks-1))>>1;
set_capacity(mddev->gendisk, mddev->array_size << 1);
mddev->changed = 1;
if (sectors/2 > mddev->size && mddev->recovery_cp == MaxSector) {
return 0;
}
-#ifdef CONFIG_MD_RAID5_RESHAPE
-static int raid5_check_reshape(mddev_t *mddev)
-{
- raid5_conf_t *conf = mddev_to_conf(mddev);
- int err;
-
- if (mddev->delta_disks < 0 ||
- mddev->new_level != mddev->level)
- return -EINVAL; /* Cannot shrink array or change level yet */
- if (mddev->delta_disks == 0)
- return 0; /* nothing to do */
-
- /* Can only proceed if there are plenty of stripe_heads.
- * We need a minimum of one full stripe,, and for sensible progress
- * it is best to have about 4 times that.
- * If we require 4 times, then the default 256 4K stripe_heads will
- * allow for chunk sizes up to 256K, which is probably OK.
- * If the chunk size is greater, user-space should request more
- * stripe_heads first.
- */
- if ((mddev->chunk_size / STRIPE_SIZE) * 4 > conf->max_nr_stripes ||
- (mddev->new_chunk / STRIPE_SIZE) * 4 > conf->max_nr_stripes) {
- printk(KERN_WARNING "raid5: reshape: not enough stripes. Needed %lu\n",
- (mddev->chunk_size / STRIPE_SIZE)*4);
- return -ENOSPC;
- }
-
- err = resize_stripes(conf, conf->raid_disks + mddev->delta_disks);
- if (err)
- return err;
-
- /* looks like we might be able to manage this */
- return 0;
-}
-
-static int raid5_start_reshape(mddev_t *mddev)
-{
- raid5_conf_t *conf = mddev_to_conf(mddev);
- mdk_rdev_t *rdev;
- struct list_head *rtmp;
- int spares = 0;
- int added_devices = 0;
-
- if (mddev->degraded ||
- test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
- return -EBUSY;
-
- ITERATE_RDEV(mddev, rdev, rtmp)
- if (rdev->raid_disk < 0 &&
- !test_bit(Faulty, &rdev->flags))
- spares++;
-
- if (spares < mddev->delta_disks-1)
- /* Not enough devices even to make a degraded array
- * of that size
- */
- return -EINVAL;
-
- atomic_set(&conf->reshape_stripes, 0);
- spin_lock_irq(&conf->device_lock);
- conf->previous_raid_disks = conf->raid_disks;
- conf->raid_disks += mddev->delta_disks;
- conf->expand_progress = 0;
- conf->expand_lo = 0;
- spin_unlock_irq(&conf->device_lock);
-
- /* Add some new drives, as many as will fit.
- * We know there are enough to make the newly sized array work.
- */
- ITERATE_RDEV(mddev, rdev, rtmp)
- if (rdev->raid_disk < 0 &&
- !test_bit(Faulty, &rdev->flags)) {
- if (raid5_add_disk(mddev, rdev)) {
- char nm[20];
- set_bit(In_sync, &rdev->flags);
- conf->working_disks++;
- added_devices++;
- rdev->recovery_offset = 0;
- sprintf(nm, "rd%d", rdev->raid_disk);
- sysfs_create_link(&mddev->kobj, &rdev->kobj, nm);
- } else
- break;
- }
-
- mddev->degraded = (conf->raid_disks - conf->previous_raid_disks) - added_devices;
- mddev->raid_disks = conf->raid_disks;
- mddev->reshape_position = 0;
- mddev->sb_dirty = 1;
-
- clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
- clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
- set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
- set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
- mddev->sync_thread = md_register_thread(md_do_sync, mddev,
- "%s_reshape");
- if (!mddev->sync_thread) {
- mddev->recovery = 0;
- spin_lock_irq(&conf->device_lock);
- mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
- conf->expand_progress = MaxSector;
- spin_unlock_irq(&conf->device_lock);
- return -EAGAIN;
- }
- md_wakeup_thread(mddev->sync_thread);
- md_new_event(mddev);
- return 0;
-}
-#endif
-
-static void end_reshape(raid5_conf_t *conf)
-{
- struct block_device *bdev;
-
- if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
- conf->mddev->array_size = conf->mddev->size * (conf->raid_disks-1);
- set_capacity(conf->mddev->gendisk, conf->mddev->array_size << 1);
- conf->mddev->changed = 1;
-
- bdev = bdget_disk(conf->mddev->gendisk, 0);
- if (bdev) {
- mutex_lock(&bdev->bd_inode->i_mutex);
- i_size_write(bdev->bd_inode, conf->mddev->array_size << 10);
- mutex_unlock(&bdev->bd_inode->i_mutex);
- bdput(bdev);
- }
- spin_lock_irq(&conf->device_lock);
- conf->expand_progress = MaxSector;
- spin_unlock_irq(&conf->device_lock);
- conf->mddev->reshape_position = MaxSector;
-
- /* read-ahead size must cover two whole stripes, which is
- * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
- */
- {
- int data_disks = conf->previous_raid_disks - conf->max_degraded;
- int stripe = data_disks *
- (conf->mddev->chunk_size / PAGE_SIZE);
- if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
- conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
- }
- }
-}
-
static void raid5_quiesce(mddev_t *mddev, int state)
{
raid5_conf_t *conf = mddev_to_conf(mddev);
switch(state) {
- case 2: /* resume for a suspend */
- wake_up(&conf->wait_for_overlap);
- break;
-
case 1: /* stop all writes */
spin_lock_irq(&conf->device_lock);
conf->quiesce = 1;
spin_lock_irq(&conf->device_lock);
conf->quiesce = 0;
wake_up(&conf->wait_for_stripe);
- wake_up(&conf->wait_for_overlap);
spin_unlock_irq(&conf->device_lock);
break;
}
}
-static struct mdk_personality raid6_personality =
-{
- .name = "raid6",
- .level = 6,
- .owner = THIS_MODULE,
- .make_request = make_request,
- .run = run,
- .stop = stop,
- .status = status,
- .error_handler = error,
- .hot_add_disk = raid5_add_disk,
- .hot_remove_disk= raid5_remove_disk,
- .spare_active = raid5_spare_active,
- .sync_request = sync_request,
- .resize = raid5_resize,
- .quiesce = raid5_quiesce,
-};
static struct mdk_personality raid5_personality =
{
.name = "raid5",
.spare_active = raid5_spare_active,
.sync_request = sync_request,
.resize = raid5_resize,
-#ifdef CONFIG_MD_RAID5_RESHAPE
- .check_reshape = raid5_check_reshape,
- .start_reshape = raid5_start_reshape,
-#endif
.quiesce = raid5_quiesce,
};
static int __init raid5_init(void)
{
- int e;
-
- e = raid6_select_algo();
- if ( e )
- return e;
- register_md_personality(&raid6_personality);
register_md_personality(&raid5_personality);
register_md_personality(&raid4_personality);
return 0;
static void raid5_exit(void)
{
- unregister_md_personality(&raid6_personality);
unregister_md_personality(&raid5_personality);
unregister_md_personality(&raid4_personality);
}
MODULE_ALIAS("md-raid4");
MODULE_ALIAS("md-level-5");
MODULE_ALIAS("md-level-4");
-MODULE_ALIAS("md-personality-8"); /* RAID6 */
-MODULE_ALIAS("md-raid6");
-MODULE_ALIAS("md-level-6");
-
-/* This used to be two separate modules, they were: */
-MODULE_ALIAS("raid5");
-MODULE_ALIAS("raid6");
git://git.onelab.eu / linux-2.6.git / blobdiff