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 <quwen...@cn.fujitsu.com>
---
volumes.c | 181 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
volumes.h | 78 +++++++++++++++++++++++++++
2 files changed, 259 insertions(+)
diff --git a/volumes.c b/volumes.c
index 8c2ffd92..985e5661 100644
--- a/volumes.c
+++ b/volumes.c
@@ -1597,6 +1597,187 @@ 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_root *root, u64 devid,
u8 *uuid, u8 *fsid)
{
diff --git a/volumes.h b/volumes.h
index 699b0bae..7454fbbc 100644
--- a/volumes.h
+++ b/volumes.h
@@ -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_mapping_tree *map_tree,
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_mapping_tree *map_tree, u64 *logical,
u64 *size, u64 type);
static inline int btrfs_next_bg_metadata(struct btrfs_mapping_tree *map_tree,
--
2.13.0
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