lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Btrfs: Add support for mirroring across drives

Browse Source 
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason
2008-04-03 16:29:03 -04:00
parent 0ef8b2428a
commit 8790d502e4
6 changed files with 198 additions and 93 deletions
Download Patch File Download Diff File Expand all files Collapse all files

152
fs/btrfs/volumes.c
View File

@ -31,6 +31,13 @@ struct stripe {
u64 physical;
};
struct multi_bio {
atomic_t stripes;
bio_end_io_t *end_io;
void *private;
int error;
};
struct map_lookup {
u64 type;
int io_align;
@ -632,12 +639,12 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
if (list_empty(dev_list))
return -ENOSPC;
if (type & BTRFS_BLOCK_GROUP_RAID0)
if (type & (BTRFS_BLOCK_GROUP_RAID0))
num_stripes = btrfs_super_num_devices(&info->super_copy);
if (type & BTRFS_BLOCK_GROUP_DATA)
stripe_len = 64 * 1024;
if (type & (BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_SYSTEM))
stripe_len = 32 * 1024;
if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
num_stripes = min_t(u64, 2,
btrfs_super_num_devices(&info->super_copy));
}
again:
INIT_LIST_HEAD(&private_devs);
cur = dev_list->next;
@ -682,7 +689,11 @@ again:
stripes = &chunk->stripe;
*num_bytes = calc_size * num_stripes;
if (type & BTRFS_BLOCK_GROUP_RAID1)
*num_bytes = calc_size;
else
*num_bytes = calc_size * num_stripes;
index = 0;
while(index < num_stripes) {
BUG_ON(list_empty(&private_devs));
@ -694,7 +705,7 @@ again:
key.objectid,
calc_size, &dev_offset);
BUG_ON(ret);
printk("alloc chunk size %Lu from dev %Lu\n", calc_size, device->devid);
printk("alloc chunk start %Lu size %Lu from dev %Lu type %Lu\n", key.objectid, calc_size, device->devid, type);
device->bytes_used += calc_size;
ret = btrfs_update_device(trans, device);
BUG_ON(ret);
@ -774,9 +785,9 @@ void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
}
}
int btrfs_map_block(struct btrfs_mapping_tree *map_tree,
u64 logical, u64 *phys, u64 *length,
struct btrfs_device **dev)
int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
int dev_nr, u64 logical, u64 *phys, u64 *length,
struct btrfs_device **dev, int *total_devs)
{
struct extent_map *em;
struct map_lookup *map;
@ -808,19 +819,39 @@ int btrfs_map_block(struct btrfs_mapping_tree *map_tree,
/* stripe_offset is the offset of this block in its stripe*/
stripe_offset = offset - stripe_offset;
/*
* after this do_div call, stripe_nr is the number of stripes
* on this device we have to walk to find the data, and
* stripe_index is the number of our device in the stripe array
*/
stripe_index = do_div(stripe_nr, map->num_stripes);
if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
stripe_index = dev_nr;
if (rw & (1 << BIO_RW))
*total_devs = map->num_stripes;
else {
int i;
u64 least = (u64)-1;
struct btrfs_device *cur;
for (i = 0; i < map->num_stripes; i++) {
cur = map->stripes[i].dev;
spin_lock(&cur->io_lock);
if (cur->total_ios < least) {
least = cur->total_ios;
stripe_index = i;
}
spin_unlock(&cur->io_lock);
}
*total_devs = 1;
}
} else {
/*
* after this do_div call, stripe_nr is the number of stripes
* on this device we have to walk to find the data, and
* stripe_index is the number of our device in the stripe array
*/
stripe_index = do_div(stripe_nr, map->num_stripes);
}
BUG_ON(stripe_index >= map->num_stripes);
*phys = map->stripes[stripe_index].physical + stripe_offset +
stripe_nr * map->stripe_len;
if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1)) {
/* we limit the length of each bio to what fits in a stripe */
*length = min_t(u64, em->len - offset,
map->stripe_len - stripe_offset);
@ -833,33 +864,98 @@ int btrfs_map_block(struct btrfs_mapping_tree *map_tree,
return 0;
}
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
static void end_bio_multi_stripe(struct bio *bio, int err)
#else
static int end_bio_multi_stripe(struct bio *bio,
unsigned int bytes_done, int err)
#endif
{
struct multi_bio *multi = bio->bi_private;
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
if (bio->bi_size)
return 1;
#endif
if (err)
multi->error = err;
if (atomic_dec_and_test(&multi->stripes)) {
bio->bi_private = multi->private;
bio->bi_end_io = multi->end_io;
if (!err && multi->error)
err = multi->error;
kfree(multi);
bio_endio(bio, err);
} else {
bio_put(bio);
}
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
return 0;
#endif
}
int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio)
{
struct btrfs_mapping_tree *map_tree;
struct btrfs_device *dev;
struct bio *first_bio = bio;
u64 logical = bio->bi_sector << 9;
u64 physical;
u64 length = 0;
u64 map_length;
struct bio_vec *bvec;
struct multi_bio *multi = NULL;
int i;
int ret;
int dev_nr = 0;
int total_devs = 1;
bio_for_each_segment(bvec, bio, i) {
length += bvec->bv_len;
}
map_tree = &root->fs_info->mapping_tree;
map_length = length;
ret = btrfs_map_block(map_tree, logical, &physical, &map_length, &dev);
if (map_length < length) {
printk("mapping failed logical %Lu bio len %Lu physical %Lu "
"len %Lu\n", logical, length, physical, map_length);
BUG();
while(dev_nr < total_devs) {
ret = btrfs_map_block(map_tree, rw, dev_nr, logical,
&physical, &map_length, &dev,
&total_devs);
if (map_length < length) {
printk("mapping failed logical %Lu bio len %Lu physical %Lu "
"len %Lu\n", logical, length, physical, map_length);
BUG();
}
BUG_ON(map_length < length);
if (total_devs > 1) {
if (!multi) {
multi = kmalloc(sizeof(*multi), GFP_NOFS);
atomic_set(&multi->stripes, 1);
multi->end_io = bio->bi_end_io;
multi->private = first_bio->bi_private;
multi->error = 0;
} else {
atomic_inc(&multi->stripes);
}
if (dev_nr < total_devs - 1) {
bio = bio_clone(first_bio, GFP_NOFS);
BUG_ON(!bio);
} else {
bio = first_bio;
}
bio->bi_private = multi;
bio->bi_end_io = end_bio_multi_stripe;
}
bio->bi_sector = physical >> 9;
bio->bi_bdev = dev->bdev;
spin_lock(&dev->io_lock);
dev->total_ios++;
spin_unlock(&dev->io_lock);
submit_bio(rw, bio);
dev_nr++;
}
BUG_ON(map_length < length);
bio->bi_sector = physical >> 9;
bio->bi_bdev = dev->bdev;
submit_bio(rw, bio);
return 0;
}
@ -982,6 +1078,8 @@ static int read_one_dev(struct btrfs_root *root,
return -ENOMEM;
list_add(&device->dev_list,
&root->fs_info->fs_devices->devices);
device->total_ios = 0;
spin_lock_init(&device->io_lock);
}
fill_device_from_item(leaf, dev_item, device);