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btrfs-progs: Introduce new btrfs_map_block function which returns more unified result.

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Introduce a new function, __btrfs_map_block_v2().

Unlike old btrfs_map_block(), which needs different parameter to handle
different RAID profile, this new function uses unified btrfs_map_block
structure to handle all RAID profile in a more meaningful method:

Return physical address along with logical address for each stripe.

For RAID1/Single/DUP (none-stripped):
result would be like:
Map block: Logical 128M, Len 10M, Type RAID1, Stripe len 0, Nr_stripes 2
Stripe 0: Logical 128M, Physical X, Len: 10M Dev dev1
Stripe 1: Logical 128M, Physical Y, Len: 10M Dev dev2

Result will be as long as possible, since it's not stripped at all.

For RAID0/10 (stripped without parity):
Result will be aligned to full stripe size:
Map block: Logical 64K, Len 128K, Type RAID10, Stripe len 64K, Nr_stripes 4
Stripe 0: Logical 64K, Physical X, Len 64K Dev dev1
Stripe 1: Logical 64K, Physical Y, Len 64K Dev dev2
Stripe 2: Logical 128K, Physical Z, Len 64K Dev dev3
Stripe 3: Logical 128K, Physical W, Len 64K Dev dev4

For RAID5/6 (stripped with parity and dev-rotation):
Result will be aligned to full stripe size:
Map block: Logical 64K, Len 128K, Type RAID6, Stripe len 64K, Nr_stripes 4
Stripe 0: Logical 64K, Physical X, Len 64K Dev dev1
Stripe 1: Logical 128K, Physical Y, Len 64K Dev dev2
Stripe 2: Logical RAID5_P, Physical Z, Len 64K Dev dev3
Stripe 3: Logical RAID6_Q, Physical W, Len 64K Dev dev4

The new unified layout should be very flex and can even handle things
like N-way RAID1 (which old mirror_num basic one can't handle well).

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Gu Jinxiang <gujx@cn.fujitsu.com>
This commit is contained in:
Qu Wenruo 2017-07-14 15:31:08 +08:00 committed by David Sterba
parent cb1be701ce
commit 066745d697
2 changed files with 259 additions and 0 deletions
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181
volumes.c
View file

@ -1598,6 +1598,187 @@ out:
return 0;
}
static inline struct btrfs_map_block *alloc_map_block(int num_stripes)
{
struct btrfs_map_block *ret;
int size;
size = sizeof(struct btrfs_map_stripe) * num_stripes +
sizeof(struct btrfs_map_block);
ret = malloc(size);
if (!ret)
return NULL;
memset(ret, 0, size);
return ret;
}
static int fill_full_map_block(struct map_lookup *map, u64 start, u64 length,
struct btrfs_map_block *map_block)
{
u64 profile = map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK;
u64 bg_start = map->ce.start;
u64 bg_end = bg_start + map->ce.size;
u64 bg_offset = start - bg_start; /* offset inside the block group */
u64 fstripe_logical = 0; /* Full stripe start logical bytenr */
u64 fstripe_size = 0; /* Full stripe logical size */
u64 fstripe_phy_off = 0; /* Full stripe offset in each dev */
u32 stripe_len = map->stripe_len;
int sub_stripes = map->sub_stripes;
int data_stripes = nr_data_stripes(map);
int dev_rotation;
int i;
map_block->num_stripes = map->num_stripes;
map_block->type = profile;
/*
* Common full stripe data for stripe based profiles
*/
if (profile & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10 |
BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
fstripe_size = stripe_len * data_stripes;
if (sub_stripes)
fstripe_size /= sub_stripes;
fstripe_logical = bg_offset / fstripe_size * fstripe_size +
bg_start;
fstripe_phy_off = bg_offset / fstripe_size * stripe_len;
}
switch (profile) {
case BTRFS_BLOCK_GROUP_DUP:
case BTRFS_BLOCK_GROUP_RAID1:
case 0: /* SINGLE */
/*
* None-stripe mode, (Single, DUP and RAID1)
* Just use offset to fill map_block
*/
map_block->stripe_len = 0;
map_block->start = start;
map_block->length = min(bg_end, start + length) - start;
for (i = 0; i < map->num_stripes; i++) {
struct btrfs_map_stripe *stripe;
stripe = &map_block->stripes[i];
stripe->dev = map->stripes[i].dev;
stripe->logical = start;
stripe->physical = map->stripes[i].physical + bg_offset;
stripe->length = map_block->length;
}
break;
case BTRFS_BLOCK_GROUP_RAID10:
case BTRFS_BLOCK_GROUP_RAID0:
/*
* Stripe modes without parity (0 and 10)
* Return the whole full stripe
*/
map_block->start = fstripe_logical;
map_block->length = fstripe_size;
map_block->stripe_len = map->stripe_len;
for (i = 0; i < map->num_stripes; i++) {
struct btrfs_map_stripe *stripe;
u64 cur_offset;
/* Handle RAID10 sub stripes */
if (sub_stripes)
cur_offset = i / sub_stripes * stripe_len;
else
cur_offset = stripe_len * i;
stripe = &map_block->stripes[i];
stripe->dev = map->stripes[i].dev;
stripe->logical = fstripe_logical + cur_offset;
stripe->length = stripe_len;
stripe->physical = map->stripes[i].physical +
fstripe_phy_off;
}
break;
case BTRFS_BLOCK_GROUP_RAID5:
case BTRFS_BLOCK_GROUP_RAID6:
/*
* Stripe modes with parity and device rotation (5 and 6)
*
* Return the whole full stripe
*/
dev_rotation = (bg_offset / fstripe_size) % map->num_stripes;
map_block->start = fstripe_logical;
map_block->length = fstripe_size;
map_block->stripe_len = map->stripe_len;
for (i = 0; i < map->num_stripes; i++) {
struct btrfs_map_stripe *stripe;
int dest_index;
u64 cur_offset = stripe_len * i;
stripe = &map_block->stripes[i];
dest_index = (i + dev_rotation) % map->num_stripes;
stripe->dev = map->stripes[dest_index].dev;
stripe->length = stripe_len;
stripe->physical = map->stripes[dest_index].physical +
fstripe_phy_off;
if (i < data_stripes) {
/* data stripe */
stripe->logical = fstripe_logical +
cur_offset;
} else if (i == data_stripes) {
/* P */
stripe->logical = BTRFS_RAID5_P_STRIPE;
} else {
/* Q */
stripe->logical = BTRFS_RAID6_Q_STRIPE;
}
}
break;
default:
return -EINVAL;
}
return 0;
}
int __btrfs_map_block_v2(struct btrfs_fs_info *fs_info, int rw, u64 logical,
u64 length, struct btrfs_map_block **map_ret)
{
struct cache_extent *ce;
struct map_lookup *map;
struct btrfs_map_block *map_block;
int ret;
/* Eearly parameter check */
if (!length || !map_ret) {
error("wrong parameter for %s", __func__);
return -EINVAL;
}
ce = search_cache_extent(&fs_info->mapping_tree.cache_tree, logical);
if (!ce)
return -ENOENT;
if (ce->start > logical)
return -ENOENT;
map = container_of(ce, struct map_lookup, ce);
/*
* Allocate a full map_block anyway
*
* For write, we need the full map_block anyway.
* For read, it will be striped to the needed stripe before returning.
*/
map_block = alloc_map_block(map->num_stripes);
if (!map_block)
return -ENOMEM;
ret = fill_full_map_block(map, logical, length, map_block);
if (ret < 0) {
free(map_block);
return ret;
}
/* TODO: Remove unrelated map_stripes for READ operation */
*map_ret = map_block;
return 0;
}
struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
u8 *uuid, u8 *fsid)
{

78
volumes.h
View file

@ -108,6 +108,51 @@ struct map_lookup {
struct btrfs_bio_stripe stripes[];
};
struct btrfs_map_stripe {
struct btrfs_device *dev;
/*
* Logical address of the stripe start.
* Caller should check if this logical is the desired map start.
* It's possible that the logical is smaller or larger than desired
* map range.
*
* For P/Q stipre, it will be BTRFS_RAID5_P_STRIPE
* and BTRFS_RAID6_Q_STRIPE.
*/
u64 logical;
u64 physical;
/* The length of the stripe */
u64 length;
};
struct btrfs_map_block {
/*
* The logical start of the whole map block.
* For RAID5/6 it will be the bytenr of the full stripe start,
* so it's possible that @start is smaller than desired map range
* start.
*/
u64 start;
/*
* The logical length of the map block.
* For RAID5/6 it will be total data stripe size
*/
u64 length;
/* Block group type */
u64 type;
/* Stripe length, for non-stripped mode, it will be 0 */
u32 stripe_len;
int num_stripes;
struct btrfs_map_stripe stripes[];
};
#define btrfs_multi_bio_size(n) (sizeof(struct btrfs_multi_bio) + \
(sizeof(struct btrfs_bio_stripe) * (n)))
#define btrfs_map_lookup_size(n) (sizeof(struct map_lookup) + \
@ -187,6 +232,39 @@ int btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
u64 logical, u64 *length,
struct btrfs_multi_bio **multi_ret, int mirror_num,
u64 **raid_map_ret);
/*
* TODO: Use this map_block_v2 to replace __btrfs_map_block()
*
* New btrfs_map_block(), unlike old one, each stripe will contain the
* physical offset *AND* logical address.
* So caller won't ever need to care about how the stripe/mirror is organized.
* Which makes csum check quite easy.
*
* Only P/Q based profile needs to care their P/Q stripe.
*
* @map_ret example:
* Raid1:
* Map block: logical=128M len=10M type=RAID1 stripe_len=0 nr_stripes=2
* Stripe 0: logical=128M physical=X len=10M dev=devid1
* Stripe 1: logical=128M physical=Y len=10M dev=devid2
*
* Raid10:
* Map block: logical=64K len=128K type=RAID10 stripe_len=64K nr_stripes=4
* Stripe 0: logical=64K physical=X len=64K dev=devid1
* Stripe 1: logical=64K physical=Y len=64K dev=devid2
* Stripe 2: logical=128K physical=Z len=64K dev=devid3
* Stripe 3: logical=128K physical=W len=64K dev=devid4
*
* Raid6:
* Map block: logical=64K len=128K type=RAID6 stripe_len=64K nr_stripes=4
* Stripe 0: logical=64K physical=X len=64K dev=devid1
* Stripe 1: logical=128K physical=Y len=64K dev=devid2
* Stripe 2: logical=RAID5_P physical=Z len=64K dev=devid3
* Stripe 3: logical=RAID6_Q physical=W len=64K dev=devid4
*/
int __btrfs_map_block_v2(struct btrfs_fs_info *fs_info, int rw, u64 logical,
u64 length, struct btrfs_map_block **map_ret);
int btrfs_next_bg(struct btrfs_fs_info *map_tree, u64 *logical,
u64 *size, u64 type);
static inline int btrfs_next_bg_metadata(struct btrfs_fs_info *fs_info,