Skip to content

L
linux
Commit 313d90b7 authored by Neil Brown's avatar Neil Brown Committed by Christoph Hellwig
Browse files
Options

[PATCH] Initial md/raid5 support for 2.5 (with bio) 

With this patch raid5 works.  There is still some more
work to though.

- uses bio instead of buffer_head
- stripe cache is now a fixed size.
   If read requests are smaller, we read the whole block anyway
   If write reqeusts are smaller, we pre-read.
- stripe_head is now variable sized with an array of structures at
  the end.  We allocate extra space depending on how many devices
  are in the array.
  stripe_head has it's very own slab cache.
- store and use bdev for each device in array

by-passing the cache for reads is currently disabled.  I need to
think through the implications (and implementation) of allowing
large bion that are larger than the stripe cache to go directly
to the device (if it isn't failed of-course).
parent 7d684b93
Show whitespace changes
Inline Side-by-side
Showing with 440 additions and 361 deletions
drivers/md/raid5.c
View file @ 313d90b7
......@@ -24,19 +24,19 @@
#include <asm/bitops.h>
#include <asm/atomic.h>
static mdk_personality_t raid5_personality;
/*
* 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) / ((conf)->buffer_size >> 9)) & HASH_MASK])
#define stripe_hash(conf, sect) ((conf)->stripe_hashtbl[((sect) / STRIPE_SECTORS) & HASH_MASK])
/*
* The following can be used to debug the driver
......@@ -142,47 +142,36 @@ static struct stripe_head *get_free_stripe(raid5_conf_t *conf)
static void shrink_buffers(struct stripe_head *sh, int num)
{
struct buffer_head *bh;
struct page *p;
int i;
for (i=0; i<num ; i++) {
bh = sh->bh_cache[i];
if (!bh)
return;
sh->bh_cache[i] = NULL;
free_page((unsigned long) bh->b_data);
kfree(bh);
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 b_size, int priority)
static int grow_buffers(struct stripe_head *sh, int num)
{
struct buffer_head *bh;
int i;
for (i=0; i<num; i++) {
struct page *page;
bh = kmalloc(sizeof(struct buffer_head), priority);
if (!bh)
return 1;
memset(bh, 0, sizeof (struct buffer_head));
if ((page = alloc_page(priority)))
bh->b_data = page_address(page);
else {
kfree(bh);
if (!(page = alloc_page(GFP_KERNEL))) {
return 1;
}
atomic_set(&bh->b_count, 0);
bh->b_page = page;
sh->bh_cache[i] = bh;
sh->dev[i].page = page;
}
return 0;
}
static struct buffer_head *raid5_build_block (struct stripe_head *sh, int i);
static void raid5_build_block (struct stripe_head *sh, int i);
static inline void init_stripe(struct stripe_head *sh, unsigned long sector)
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;
......@@ -198,40 +187,26 @@ static inline void init_stripe(struct stripe_head *sh, unsigned long sector)
remove_hash(sh);
sh->sector = sector;
sh->size = conf->buffer_size;
sh->pd_idx = pd_idx;
sh->state = 0;
for (i=disks; i--; ) {
if (sh->bh_read[i] || sh->bh_write[i] || sh->bh_written[i] ||
buffer_locked(sh->bh_cache[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, sh->bh_read[i],
sh->bh_write[i], sh->bh_written[i],
buffer_locked(sh->bh_cache[i]));
sh->sector, i, dev->toread,
dev->towrite, dev->written,
test_bit(R5_LOCKED, &dev->flags));
BUG();
}
clear_buffer_uptodate(sh->bh_cache[i]);
dev->flags = 0;
raid5_build_block(sh, i);
}
insert_hash(conf, sh);
}
/* the buffer size has changed, so unhash all stripes
* as active stripes complete, they will go onto inactive list
*/
static void shrink_stripe_cache(raid5_conf_t *conf)
{
int i;
CHECK_DEVLOCK();
if (atomic_read(&conf->active_stripes))
BUG();
for (i=0; i < NR_HASH; i++) {
struct stripe_head *sh;
while ((sh = conf->stripe_hashtbl[i]))
remove_hash(sh);
}
}
static struct stripe_head *__find_stripe(raid5_conf_t *conf, unsigned long sector)
{
struct stripe_head *sh;
......@@ -245,7 +220,8 @@ static struct stripe_head *__find_stripe(raid5_conf_t *conf, unsigned long secto
return NULL;
}
static struct stripe_head *get_active_stripe(raid5_conf_t *conf, unsigned long sector, int size, int noblock)
static struct stripe_head *get_active_stripe(raid5_conf_t *conf, unsigned long sector,
int pd_idx, int noblock)
{
struct stripe_head *sh;
......@@ -254,44 +230,6 @@ static struct stripe_head *get_active_stripe(raid5_conf_t *conf, unsigned long s
spin_lock_irq(&conf->device_lock);
do {
if (conf->buffer_size == 0 ||
(size && size != conf->buffer_size)) {
/* either the size is being changed (buffer_size==0) or
* we need to change it.
* If size==0, we can proceed as soon as buffer_size gets set.
* If size>0, we can proceed when active_stripes reaches 0, or
* when someone else sets the buffer_size to size.
* If someone sets the buffer size to something else, we will need to
* assert that we want to change it again
*/
int oldsize = conf->buffer_size;
PRINTK("get_stripe %ld/%d buffer_size is %d, %d active\n", sector, size, conf->buffer_size, atomic_read(&conf->active_stripes));
if (size==0)
wait_event_lock_irq(conf->wait_for_stripe,
conf->buffer_size,
conf->device_lock);
else {
while (conf->buffer_size != size && atomic_read(&conf->active_stripes)) {
conf->buffer_size = 0;
wait_event_lock_irq(conf->wait_for_stripe,
atomic_read(&conf->active_stripes)==0 || conf->buffer_size,
conf->device_lock);
PRINTK("waited and now %ld/%d buffer_size is %d - %d active\n", sector, size,
conf->buffer_size, atomic_read(&conf->active_stripes));
}
if (conf->buffer_size != size) {
printk("raid5: switching cache buffer size, %d --> %d\n", oldsize, size);
shrink_stripe_cache(conf);
if (size==0) BUG();
conf->buffer_size = size;
PRINTK("size now %d\n", conf->buffer_size);
}
}
}
if (size == 0)
sector -= sector & ((conf->buffer_size>>9)-1);
sh = __find_stripe(conf, sector);
if (!sh) {
if (!conf->inactive_blocked)
......@@ -307,7 +245,7 @@ static struct stripe_head *get_active_stripe(raid5_conf_t *conf, unsigned long s
conf->device_lock);
conf->inactive_blocked = 0;
} else
init_stripe(sh, sector);
init_stripe(sh, sector, pd_idx);
} else {
if (atomic_read(&sh->count)) {
if (!list_empty(&sh->lru))
......@@ -329,21 +267,31 @@ static struct stripe_head *get_active_stripe(raid5_conf_t *conf, unsigned long s
return sh;
}
static int grow_stripes(raid5_conf_t *conf, int num, int priority)
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 = kmalloc(sizeof(struct stripe_head), priority);
sh = kmem_cache_alloc(sc, GFP_KERNEL);
if (!sh)
return 1;
memset(sh, 0, sizeof(*sh));
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, PAGE_SIZE, priority)) {
if (grow_buffers(sh, conf->raid_disks)) {
shrink_buffers(sh, conf->raid_disks);
kfree(sh);
kmem_cache_free(sc, sh);
return 1;
}
/* we just created an active stripe so... */
......@@ -355,11 +303,11 @@ static int grow_stripes(raid5_conf_t *conf, int num, int priority)
return 0;
}
static void shrink_stripes(raid5_conf_t *conf, int num)
static void shrink_stripes(raid5_conf_t *conf)
{
struct stripe_head *sh;
while (num--) {
while (1) {
spin_lock_irq(&conf->device_lock);
sh = get_free_stripe(conf);
spin_unlock_irq(&conf->device_lock);
......@@ -368,21 +316,22 @@ static void shrink_stripes(raid5_conf_t *conf, int num)
if (atomic_read(&sh->count))
BUG();
shrink_buffers(sh, conf->raid_disks);
kfree(sh);
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 buffer_head * bh, int uptodate)
static void raid5_end_read_request (struct bio * bi)
{
struct stripe_head *sh = bh->b_private;
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 (bh == sh->bh_cache[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);
......@@ -392,7 +341,9 @@ static void raid5_end_read_request (struct buffer_head * bh, int uptodate)
}
if (uptodate) {
struct buffer_head *buffer;
#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
......@@ -409,38 +360,43 @@ static void raid5_end_read_request (struct buffer_head * bh, int uptodate)
} else
buffer = NULL;
spin_unlock_irqrestore(&conf->device_lock, flags);
if (sh->bh_page[i]==NULL)
if (sh->bh_page[i]==bh->b_page)
set_buffer_uptodate(bh);
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_bdev);
clear_buffer_uptodate(bh);
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]) {
if (sh->bh_page[i] != bh->b_page) {
bh->b_page = sh->bh_page[i];
bh->b_data = page_address(bh->b_page);
sh->bh_page[i] = NULL;
clear_buffer_uptodate(bh);
}
clear_buffer_locked(bh);
#endif
clear_bit(R5_LOCKED, &sh->dev[i].flags);
set_bit(STRIPE_HANDLE, &sh->state);
release_stripe(sh);
}
static void raid5_end_write_request (struct buffer_head *bh, int uptodate)
static void raid5_end_write_request (struct bio *bi)
{
struct stripe_head *sh = bh->b_private;
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 (bh == sh->bh_cache[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);
......@@ -451,29 +407,36 @@ static void raid5_end_write_request (struct buffer_head *bh, int uptodate)
spin_lock_irqsave(&conf->device_lock, flags);
if (!uptodate)
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 struct buffer_head *raid5_build_block (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 buffer_head *bh = sh->bh_cache[i];
unsigned long block = sh->sector / (sh->size >> 9);
init_buffer(bh, raid5_end_read_request, sh);
bh->b_dev = conf->disks[i].dev;
/* FIXME - later we will need bdev here */
bh->b_blocknr = block;
bh->b_state = (1 << BH_Req) | (1 << BH_Mapped);
bh->b_size = sh->size;
return bh;
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;
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)
dev->sector = compute_blocknr(sh, i);
}
static int error (mddev_t *mddev, kdev_t dev)
......@@ -544,14 +507,14 @@ static int error (mddev_t *mddev, kdev_t dev)
* Input: a 'big' sector number,
* Output: index of the data and parity disk, and the sector # in them.
*/
static unsigned long raid5_compute_sector(unsigned long r_sector, unsigned int raid_disks,
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)
{
unsigned long stripe;
sector_t stripe;
unsigned long chunk_number;
unsigned int chunk_offset;
unsigned long new_sector;
sector_t new_sector;
int sectors_per_chunk = conf->chunk_size >> 9;
/* First compute the information on this sector */
......@@ -607,17 +570,17 @@ static unsigned long raid5_compute_sector(unsigned long r_sector, unsigned int r
return new_sector;
}
#if 0
static unsigned long compute_blocknr(struct stripe_head *sh, int i)
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;
unsigned long new_sector = sh->sector, check;
sector_t new_sector = sh->sector, check;
int sectors_per_chunk = conf->chunk_size >> 9;
unsigned long stripe = new_sector / sectors_per_chunk;
sector_t stripe = new_sector / sectors_per_chunk;
int chunk_offset = new_sector % sectors_per_chunk;
int chunk_number, dummy1, dummy2, dd_idx = i;
unsigned long r_sector, blocknr;
sector_t r_sector;
switch (conf->algorithm) {
case ALGORITHM_LEFT_ASYMMETRIC:
......@@ -637,20 +600,70 @@ static unsigned long compute_blocknr(struct stripe_head *sh, int i)
chunk_number = stripe * data_disks + i;
r_sector = chunk_number * sectors_per_chunk + chunk_offset;
blocknr = r_sector / (sh->size >> 9);
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 blocknr;
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;
}
}
}
#endif
#define check_xor() do { \
if (count == MAX_XOR_BLOCKS) { \
xor_block(count, bh_ptr); \
xor_block(count, STRIPE_SIZE, ptr); \
count = 1; \
} \
} while(0)
......@@ -660,88 +673,84 @@ 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;
struct buffer_head *bh_ptr[MAX_XOR_BLOCKS], *bh;
void *ptr[MAX_XOR_BLOCKS], *p;
PRINTK("compute_block, stripe %lu, idx %d\n", sh->sector, dd_idx);
memset(sh->bh_cache[dd_idx]->b_data, 0, sh->size);
bh_ptr[0] = sh->bh_cache[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;
bh = sh->bh_cache[i];
if (buffer_uptodate(bh))
bh_ptr[count++] = bh;
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_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;
struct buffer_head *bh_ptr[MAX_XOR_BLOCKS];
struct buffer_head *chosen[MD_SB_DISKS];
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;
bh_ptr[0] = sh->bh_cache[pd_idx];
ptr[0] = page_address(sh->dev[pd_idx].page);
switch(method) {
case READ_MODIFY_WRITE:
if (!buffer_uptodate(sh->bh_cache[pd_idx]))
if (!test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags))
BUG();
for (i=disks ; i-- ;) {
if (i==pd_idx)
continue;
if (sh->bh_write[i] &&
buffer_uptodate(sh->bh_cache[i])) {
bh_ptr[count++] = sh->bh_cache[i];
chosen[i] = sh->bh_write[i];
sh->bh_write[i] = sh->bh_write[i]->b_reqnext;
chosen[i]->b_reqnext = sh->bh_written[i];
sh->bh_written[i] = chosen[i];
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(sh->bh_cache[pd_idx]->b_data, 0, sh->size);
memset(ptr[0], 0, STRIPE_SIZE);
for (i= disks; i-- ;)
if (i!=pd_idx && sh->bh_write[i]) {
chosen[i] = sh->bh_write[i];
sh->bh_write[i] = sh->bh_write[i]->b_reqnext;
chosen[i]->b_reqnext = sh->bh_written[i];
sh->bh_written[i] = chosen[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, bh_ptr);
xor_block(count, STRIPE_SIZE, ptr);
count = 1;
}
for (i = disks; i--;)
if (chosen[i]) {
struct buffer_head *bh = sh->bh_cache[i];
char *bdata;
bdata = bh_kmap(chosen[i]);
memcpy(bh->b_data,
bdata,sh->size);
bh_kunmap(chosen[i]);
set_buffer_locked(bh);
set_buffer_uptodate(bh);
sector_t sector = sh->dev[i].sector;
copy_data(1, chosen[i], sh->dev[i].page, sector);
set_bit(R5_LOCKED, &sh->dev[i].flags);
set_bit(R5_UPTODATE, &sh->dev[i].flags);
}
switch(method) {
......@@ -749,55 +758,74 @@ static void compute_parity(struct stripe_head *sh, int method)
case CHECK_PARITY:
for (i=disks; i--;)
if (i != pd_idx) {
bh_ptr[count++] = sh->bh_cache[i];
ptr[count++] = page_address(sh->dev[i].page);
check_xor();
}
break;
case READ_MODIFY_WRITE:
for (i = disks; i--;)
if (chosen[i]) {
bh_ptr[count++] = sh->bh_cache[i];
ptr[count++] = page_address(sh->dev[i].page);
check_xor();
}
}
if (count != 1)
xor_block(count, bh_ptr);
xor_block(count, STRIPE_SIZE, ptr);
if (method != CHECK_PARITY) {
set_buffer_uptodate(sh->bh_cache[pd_idx]);
set_buffer_locked(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_buffer_uptodate(sh->bh_cache[pd_idx]);
clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
}
static void add_stripe_bh (struct stripe_head *sh, struct buffer_head *bh, int dd_idx, int rw)
/*
* 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 buffer_head **bhp;
struct bio **bip;
raid5_conf_t *conf = sh->raid_conf;
PRINTK("adding bh b#%lu to stripe s#%lu\n", bh->b_blocknr, sh->sector);
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);
bh->b_reqnext = NULL;
if (rw == READ)
bhp = &sh->bh_read[dd_idx];
if (forwrite)
bip = &sh->dev[dd_idx].towrite;
else
bhp = &sh->bh_write[dd_idx];
while (*bhp) {
printk(KERN_NOTICE "raid5: multiple %d requests for sector %ld\n", rw, sh->sector);
bhp = & (*bhp)->b_reqnext;
}
*bhp = bh;
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);
PRINTK("added bh b#%lu to stripe s#%lu, disk %d.\n", bh->b_blocknr, sh->sector, dd_idx);
}
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);
}
/*
......@@ -822,13 +850,14 @@ static void handle_stripe(struct stripe_head *sh)
{
raid5_conf_t *conf = sh->raid_conf;
int disks = conf->raid_disks;
struct buffer_head *return_ok= NULL, *return_fail = NULL;
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 buffer_head *bh;
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));
......@@ -841,36 +870,38 @@ static void handle_stripe(struct stripe_head *sh)
/* Now to look around and see what can be done */
for (i=disks; i--; ) {
bh = sh->bh_cache[i];
PRINTK("check %d: state 0x%lx read %p write %p written %p\n", i, bh->b_state, sh->bh_read[i], sh->bh_write[i], sh->bh_written[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 (buffer_uptodate(bh) && sh->bh_read[i]) {
struct buffer_head *rbh, *rbh2;
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);
rbh = sh->bh_read[i];
sh->bh_read[i] = NULL;
rbi = dev->toread;
dev->toread = NULL;
spin_unlock_irq(&conf->device_lock);
while (rbh) {
char *bdata;
bdata = bh_kmap(rbh);
memcpy(bdata, bh->b_data, bh->b_size);
bh_kunmap(rbh);
rbh2 = rbh->b_reqnext;
rbh->b_reqnext = return_ok;
return_ok = rbh;
rbh = rbh2;
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 (buffer_locked(bh)) locked++;
if (buffer_uptodate(bh)) uptodate++;
if (test_bit(R5_LOCKED, &dev->flags)) locked++;
if (test_bit(R5_UPTODATE, &dev->flags)) uptodate++;
if (sh->bh_read[i]) to_read++;
if (sh->bh_write[i]) to_write++;
if (sh->bh_written[i]) written++;
if (dev->toread) to_read++;
if (dev->towrite) to_write++;
if (dev->written) written++;
if (!conf->disks[i].operational) {
failed++;
failed_num = i;
......@@ -882,29 +913,42 @@ static void handle_stripe(struct stripe_head *sh)
* 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 */
if (sh->bh_write[i]) to_write--;
while ((bh = sh->bh_write[i])) {
sh->bh_write[i] = bh->b_reqnext;
bh->b_reqnext = return_fail;
return_fail = bh;
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) {
spin_lock_irq(&conf->device_lock);
if (sh->bh_read[i]) to_read--;
while ((bh = sh->bh_read[i])) {
sh->bh_read[i] = bh->b_reqnext;
bh->b_reqnext = return_fail;
return_fail = bh;
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;
}
spin_unlock_irq(&conf->device_lock);
bi = nextbi;
}
}
}
spin_unlock_irq(&conf->device_lock);
}
if (failed > 1 && syncing) {
md_done_sync(conf->mddev, (sh->size>>9) - sh->sync_redone,0);
md_done_sync(conf->mddev, STRIPE_SECTORS,0);
clear_bit(STRIPE_SYNCING, &sh->state);
syncing = 0;
}
......@@ -912,27 +956,30 @@ static void handle_stripe(struct stripe_head *sh)
/* might be able to return some write requests if the parity block
* is safe, or on a failed drive
*/
bh = sh->bh_cache[sh->pd_idx];
dev = &sh->dev[sh->pd_idx];
if ( written &&
( (conf->disks[sh->pd_idx].operational && !buffer_locked(bh) && buffer_uptodate(bh))
( (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 a uptodate or failed drive can be returned */
/* any written block on an uptodate or failed drive can be returned */
for (i=disks; i--; )
if (sh->bh_written[i]) {
bh = sh->bh_cache[i];
if (sh->dev[i].written) {
dev = &sh->dev[i];
if (!conf->disks[sh->pd_idx].operational ||
(!buffer_locked(bh) && buffer_uptodate(bh)) ) {
(!test_bit(R5_LOCKED, &dev->flags) && test_bit(R5_UPTODATE, &dev->flags)) ) {
/* maybe we can return some write requests */
struct buffer_head *wbh, *wbh2;
struct bio *wbi, *wbi2;
PRINTK("Return write for disc %d\n", i);
wbh = sh->bh_written[i];
sh->bh_written[i] = NULL;
while (wbh) {
wbh2 = wbh->b_reqnext;
wbh->b_reqnext = return_ok;
return_ok = wbh;
wbh = wbh2;
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;
}
}
}
......@@ -943,9 +990,9 @@ static void handle_stripe(struct stripe_head *sh)
*/
if (to_read || (syncing && (uptodate+failed < disks))) {
for (i=disks; i--;) {
bh = sh->bh_cache[i];
if (!buffer_locked(bh) && !buffer_uptodate(bh) &&
(sh->bh_read[i] || syncing || (failed && sh->bh_read[failed_num]))) {
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
*/
......@@ -954,21 +1001,21 @@ static void handle_stripe(struct stripe_head *sh)
compute_block(sh, i);
uptodate++;
} else if (conf->disks[i].operational) {
set_buffer_locked(bh);
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_page[i]) BUG();
if (sh->bh_read[i] && !sh->bh_read[i]->b_reqnext &&
! syncing && !failed && !to_write) {
sh->bh_page[i] = sh->bh_cache[i]->b_page;
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, bh->b_size>>9);
md_sync_acct(conf->disks[i].dev, STRIPE_SECTORS);
}
}
}
......@@ -980,10 +1027,14 @@ static void handle_stripe(struct stripe_head *sh)
int rmw=0, rcw=0;
for (i=disks ; i--;) {
/* would I have to read this buffer for read_modify_write */
bh = sh->bh_cache[i];
if ((sh->bh_write[i] || i == sh->pd_idx) &&
(!buffer_locked(bh) || sh->bh_page[i]) &&
!buffer_uptodate(bh)) {
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) */
)
......@@ -991,9 +1042,13 @@ static void handle_stripe(struct stripe_head *sh)
else rmw += 2*disks; /* cannot read it */
}
/* Would I have to read this buffer for reconstruct_write */
if (!sh->bh_write[i] && i != sh->pd_idx &&
(!buffer_locked(bh) || sh->bh_page[i]) &&
!buffer_uptodate(bh)) {
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;
}
......@@ -1003,14 +1058,14 @@ static void handle_stripe(struct stripe_head *sh)
if (rmw < rcw && rmw > 0)
/* prefer read-modify-write, but need to get some data */
for (i=disks; i--;) {
bh = sh->bh_cache[i];
if ((sh->bh_write[i] || i == sh->pd_idx) &&
!buffer_locked(bh) && !buffer_uptodate(bh) &&
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_buffer_locked(bh);
set_bit(R5_LOCKED, &dev->flags);
action[i] = READ+1;
locked++;
} else {
......@@ -1022,14 +1077,14 @@ static void handle_stripe(struct stripe_head *sh)
if (rcw <= rmw && rcw > 0)
/* want reconstruct write, but need to get some data */
for (i=disks; i--;) {
bh = sh->bh_cache[i];
if (!sh->bh_write[i] && i != sh->pd_idx &&
!buffer_locked(bh) && !buffer_uptodate(bh) &&
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_buffer_locked(bh);
set_bit(R5_LOCKED, &dev->flags);
action[i] = READ+1;
locked++;
} else {
......@@ -1044,7 +1099,7 @@ static void handle_stripe(struct stripe_head *sh)
compute_parity(sh, rcw==0 ? RECONSTRUCT_WRITE : READ_MODIFY_WRITE);
/* now every locked buffer is ready to be written */
for (i=disks; i--;)
if (buffer_locked(sh->bh_cache[i])) {
if (test_bit(R5_LOCKED, &sh->dev[i].flags)) {
PRINTK("Writing block %d\n", i);
locked++;
action[i] = WRITE+1;
......@@ -1068,13 +1123,14 @@ static void handle_stripe(struct stripe_head *sh)
!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--;
bh = sh->bh_cache[sh->pd_idx];
if ((*(u32*)bh->b_data) == 0 &&
!memcmp(bh->b_data, bh->b_data+4, bh->b_size-4)) {
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);
}
......@@ -1084,7 +1140,7 @@ static void handle_stripe(struct stripe_head *sh)
if (failed==0)
failed_num = sh->pd_idx;
/* should be able to compute the missing block and write it to spare */
if (!buffer_uptodate(sh->bh_cache[failed_num])) {
if (!test_bit(R5_UPTODATE, &sh->dev[failed_num].flags)) {
if (uptodate+1 != disks)
BUG();
compute_block(sh, failed_num);
......@@ -1092,60 +1148,62 @@ static void handle_stripe(struct stripe_head *sh)
}
if (uptodate != disks)
BUG();
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, bh->b_size>>9);
md_sync_acct(conf->disks[failed_num].dev, STRIPE_SECTORS);
else if ((spare=conf->spare))
md_sync_acct(spare->dev, bh->b_size>>9);
md_sync_acct(spare->dev, STRIPE_SECTORS);
}
}
if (syncing && locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
md_done_sync(conf->mddev, (sh->size>>9) - sh->sync_redone,1);
md_done_sync(conf->mddev, STRIPE_SECTORS,1);
clear_bit(STRIPE_SYNCING, &sh->state);
}
spin_unlock(&sh->lock);
while ((bh=return_ok)) {
return_ok = bh->b_reqnext;
bh->b_reqnext = NULL;
bh->b_end_io(bh, 1);
}
while ((bh=return_fail)) {
return_fail = bh->b_reqnext;
bh->b_reqnext = NULL;
bh->b_end_io(bh, 0);
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 buffer_head *bh = sh->bh_cache[i];
struct bio *bi = &sh->dev[i].req;
struct disk_info *spare = conf->spare;
int skip = 0;
if (action[i] == READ+1)
bh->b_end_io = raid5_end_read_request;
bi->bi_end_io = raid5_end_read_request;
else
bh->b_end_io = raid5_end_write_request;
bi->bi_end_io = raid5_end_write_request;
if (conf->disks[i].operational)
bh->b_dev = conf->disks[i].dev;
bi->bi_bdev = conf->disks[i].bdev;
else if (spare && action[i] == WRITE+1)
bh->b_dev = spare->dev;
bi->bi_bdev = spare->bdev;
else skip=1;
/* FIXME - later we will need bdev here */
if (!skip) {
PRINTK("for %ld schedule op %d on disc %d\n", sh->sector, action[i]-1, i);
atomic_inc(&sh->count);
bh->b_rdev = bh->b_dev;
bh->b_rsector = bh->b_blocknr * (bh->b_size>>9);
generic_make_request(action[i]-1, bh);
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_buffer_locked(bh);
clear_bit(R5_LOCKED, &dev->flags);
set_bit(STRIPE_HANDLE, &sh->state);
}
}
......@@ -1192,13 +1250,14 @@ static inline void raid5_plug_device(raid5_conf_t *conf)
spin_unlock_irq(&conf->device_lock);
}
static int make_request (mddev_t *mddev, int rw, struct buffer_head * bh)
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;
unsigned long new_sector;
sector_t new_sector;
sector_t logical_sector, last_sector;
int read_ahead = 0;
struct stripe_head *sh;
......@@ -1208,25 +1267,39 @@ static int make_request (mddev_t *mddev, int rw, struct buffer_head * bh)
read_ahead=1;
}
new_sector = raid5_compute_sector(bh->b_rsector,
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 %lu\n", new_sector);
sh = get_active_stripe(conf, new_sector, bh->b_size, read_ahead);
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) {
sh->pd_idx = pd_idx;
add_stripe_bh(sh, bh, dd_idx, rw);
add_stripe_bio(sh, bi, dd_idx, rw);
raid5_plug_device(conf);
handle_stripe(sh);
release_stripe(sh);
} 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;
}
static int sync_request (mddev_t *mddev, unsigned long sector_nr)
/* 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;
......@@ -1237,25 +1310,19 @@ static int sync_request (mddev_t *mddev, unsigned long sector_nr)
unsigned long first_sector;
int raid_disks = conf->raid_disks;
int data_disks = raid_disks-1;
int redone = 0;
int bufsize;
sh = get_active_stripe(conf, sector_nr, 0, 0);
bufsize = sh->size;
redone = sector_nr - sh->sector;
first_sector = raid5_compute_sector(stripe*data_disks*sectors_per_chunk
+ chunk_offset, raid_disks, data_disks, &dd_idx, &pd_idx, conf);
sh->pd_idx = pd_idx;
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);
sh->sync_redone = redone;
spin_unlock(&sh->lock);
handle_stripe(sh);
release_stripe(sh);
return (bufsize>>9)-redone;
return STRIPE_SECTORS;
}
/*
......@@ -1376,7 +1443,6 @@ static int run (mddev_t *mddev)
INIT_LIST_HEAD(&conf->inactive_list);
atomic_set(&conf->active_stripes, 0);
atomic_set(&conf->preread_active_stripes, 0);
conf->buffer_size = PAGE_SIZE; /* good default for rebuild */
conf->plugged = 0;
conf->plug_tq.sync = 0;
......@@ -1404,6 +1470,7 @@ static int run (mddev_t *mddev)
disk->number = desc->number;
disk->raid_disk = raid_disk;
disk->dev = rdev->dev;
disk->bdev = rdev->bdev;
disk->operational = 0;
disk->write_only = 0;
......@@ -1430,6 +1497,7 @@ static int run (mddev_t *mddev)
disk->number = desc->number;
disk->raid_disk = raid_disk;
disk->dev = rdev->dev;
disk->bdev = rdev->bdev;
disk->operational = 1;
disk->used_slot = 1;
......@@ -1442,6 +1510,7 @@ static int run (mddev_t *mddev)
disk->number = desc->number;
disk->raid_disk = raid_disk;
disk->dev = rdev->dev;
disk->bdev = rdev->bdev;
disk->operational = 0;
disk->write_only = 0;
......@@ -1461,6 +1530,7 @@ static int run (mddev_t *mddev)
disk->number = desc->number;
disk->raid_disk = raid_disk;
disk->dev = NODEV;
disk->bdev = NULL;
disk->operational = 0;
disk->write_only = 0;
......@@ -1518,9 +1588,9 @@ static int run (mddev_t *mddev)
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, GFP_KERNEL)) {
if (grow_stripes(conf, conf->max_nr_stripes)) {
printk(KERN_ERR "raid5: couldn't allocate %dkB for buffers\n", memory);
shrink_stripes(conf, conf->max_nr_stripes);
shrink_stripes(conf);
goto abort;
} else
printk(KERN_INFO "raid5: allocated %dkB for md%d\n", memory, mdidx(mddev));
......@@ -1623,7 +1693,7 @@ static int stop (mddev_t *mddev)
if (conf->resync_thread)
md_unregister_thread(conf->resync_thread);
md_unregister_thread(conf->thread);
shrink_stripes(conf, conf->max_nr_stripes);
shrink_stripes(conf);
free_pages((unsigned long) conf->stripe_hashtbl, HASH_PAGES_ORDER);
kfree(conf);
mddev->private = NULL;
......@@ -1636,12 +1706,11 @@ static void print_sh (struct stripe_head *sh)
{
int i;
printk("sh %lu, size %d, pd_idx %d, state %ld.\n", sh->sector, sh->size, sh->pd_idx, sh->state);
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 < MD_SB_DISKS; i++) {
if (sh->bh_cache[i])
printk("(cache%d: %p %ld) ", i, sh->bh_cache[i], sh->bh_cache[i]->b_state);
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");
}
......@@ -1948,6 +2017,7 @@ static int diskop(mddev_t *mddev, mdp_disk_t **d, int state)
goto abort;
}
rdisk->dev = NODEV;
rdisk->bdev = NULL;
rdisk->used_slot = 0;
break;
......@@ -1965,6 +2035,8 @@ static int diskop(mddev_t *mddev, mdp_disk_t **d, int state)
adisk->number = added_desc->number;
adisk->raid_disk = added_desc->raid_disk;
adisk->dev = mk_kdev(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;
......
drivers/md/xor.c
View file @ 313d90b7
......@@ -26,31 +26,30 @@
static struct xor_block_template *active_template;
void
xor_block(unsigned int count, struct buffer_head **bh_ptr)
xor_block(unsigned int count, unsigned int bytes, void **ptr)
{
unsigned long *p0, *p1, *p2, *p3, *p4;
unsigned long bytes = bh_ptr[0]->b_size;
p0 = (unsigned long *) bh_ptr[0]->b_data;
p1 = (unsigned long *) bh_ptr[1]->b_data;
p0 = (unsigned long *) ptr[0];
p1 = (unsigned long *) ptr[1];
if (count == 2) {
active_template->do_2(bytes, p0, p1);
return;
}
p2 = (unsigned long *) bh_ptr[2]->b_data;
p2 = (unsigned long *) ptr[2];
if (count == 3) {
active_template->do_3(bytes, p0, p1, p2);
return;
}
p3 = (unsigned long *) bh_ptr[3]->b_data;
p3 = (unsigned long *) ptr[3];
if (count == 4) {
active_template->do_4(bytes, p0, p1, p2, p3);
return;
}
p4 = (unsigned long *) bh_ptr[4]->b_data;
p4 = (unsigned long *) ptr[4];
active_template->do_5(bytes, p0, p1, p2, p3, p4);
}
......
include/linux/raid/raid5.h
View file @ 313d90b7
......@@ -7,21 +7,21 @@
/*
*
* Each stripe contains one buffer per disc. Each buffer can be in
* one of a number of states determined by bh_state. Changes between
* one of a number of states stored in "flags". Changes between
* these states happen *almost* exclusively under a per-stripe
* spinlock. Some very specific changes can happen in b_end_io, and
* spinlock. Some very specific changes can happen in bi_end_io, and
* these are not protected by the spin lock.
*
* The bh_state bits that are used to represent these states are:
* BH_Uptodate, BH_Lock
* The flag bits that are used to represent these states are:
* R5_UPTODATE and R5_LOCKED
*
* State Empty == !Uptodate, !Lock
* State Empty == !UPTODATE, !LOCK
* We have no data, and there is no active request
* State Want == !Uptodate, Lock
* State Want == !UPTODATE, LOCK
* A read request is being submitted for this block
* State Dirty == Uptodate, Lock
* State Dirty == UPTODATE, LOCK
* Some new data is in this buffer, and it is being written out
* State Clean == Uptodate, !Lock
* State Clean == UPTODATE, !LOCK
* We have valid data which is the same as on disc
*
* The possible state transitions are:
......@@ -124,24 +124,29 @@
* plus raid5d if it is handling it, plus one for each active request
* on a cached buffer.
*/
struct stripe_head {
struct stripe_head *hash_next, **hash_pprev; /* hash pointers */
struct list_head lru; /* inactive_list or handle_list */
struct raid5_private_data *raid_conf;
struct buffer_head *bh_cache[MD_SB_DISKS]; /* buffered copy */
struct buffer_head *bh_read[MD_SB_DISKS]; /* read request buffers of the MD device */
struct buffer_head *bh_write[MD_SB_DISKS]; /* write request buffers of the MD device */
struct buffer_head *bh_written[MD_SB_DISKS]; /* write request buffers of the MD device that have been scheduled for write */
struct page *bh_page[MD_SB_DISKS]; /* saved bh_cache[n]->b_page when reading around the cache */
unsigned long sector; /* sector of this row */
int size; /* buffers size */
sector_t sector; /* sector of this row */
int pd_idx; /* parity disk index */
unsigned long state; /* state flags */
atomic_t count; /* nr of active thread/requests */
spinlock_t lock;
int sync_redone;
struct r5dev {
struct bio req;
struct bio_vec vec;
struct page *page;
struct bio *toread, *towrite, *written;
sector_t sector; /* sector of this page */
unsigned long flags;
} dev[1]; /* allocated with extra space depending of RAID geometry */
};
/* Flags */
#define R5_UPTODATE 0 /* page contains current data */
#define R5_LOCKED 1 /* IO has been submitted on "req" */
#define R5_OVERWRITE 2 /* towrite covers whole page */
/*
* Write method
......@@ -187,6 +192,7 @@ struct stripe_head {
struct disk_info {
kdev_t dev;
struct block_device *bdev;
int operational;
int number;
int raid_disk;
......@@ -201,7 +207,6 @@ struct raid5_private_data {
mdk_thread_t *thread, *resync_thread;
struct disk_info disks[MD_SB_DISKS];
struct disk_info *spare;
int buffer_size;
int chunk_size, level, algorithm;
int raid_disks, working_disks, failed_disks;
int resync_parity;
......@@ -210,6 +215,9 @@ struct raid5_private_data {
struct list_head handle_list; /* stripes needing handling */
struct list_head delayed_list; /* stripes that have plugged requests */
atomic_t preread_active_stripes; /* stripes with scheduled io */
char cache_name[20];
kmem_cache_t *slab_cache; /* for allocating stripes */
/*
* Free stripes pool
*/
......
include/linux/raid/xor.h
View file @ 313d90b7
......@@ -5,7 +5,7 @@
#define MAX_XOR_BLOCKS 5
extern void xor_block(unsigned int count, struct buffer_head **bh_ptr);
extern void xor_block(unsigned int count, unsigned int bytes, void **ptr);
struct xor_block_template {
struct xor_block_template *next;
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7