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authorJosef Bacik <jbacik@fusionio.com>2013-03-07 20:22:04 +0100
committerJosef Bacik <jbacik@fusionio.com>2013-05-06 21:54:18 +0200
commit3173a18f70554fe7880bb2d85c7da566e364eb3c (patch)
tree0a23b42a8d275d3499fac2b90ded76276c64c1c1 /fs/btrfs/relocation.c
parentBtrfs: use helper to cleanup tree roots (diff)
downloadlinux-3173a18f70554fe7880bb2d85c7da566e364eb3c.tar.xz
linux-3173a18f70554fe7880bb2d85c7da566e364eb3c.zip
Btrfs: add a incompatible format change for smaller metadata extent refs
We currently store the first key of the tree block inside the reference for the tree block in the extent tree. This takes up quite a bit of space. Make a new key type for metadata which holds the level as the offset and completely removes storing the btrfs_tree_block_info inside the extent ref. This reduces the size from 51 bytes to 33 bytes per extent reference for each tree block. In practice this results in a 30-35% decrease in the size of our extent tree, which means we COW less and can keep more of the extent tree in memory which makes our heavy metadata operations go much faster. This is not an automatic format change, you must enable it at mkfs time or with btrfstune. This patch deals with having metadata stored as either the old format or the new format so it is easy to convert. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Diffstat (limited to 'fs/btrfs/relocation.c')
-rw-r--r--fs/btrfs/relocation.c73
1 files changed, 58 insertions, 15 deletions
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index b67171e6d688..86f192ffc212 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -619,10 +619,13 @@ static noinline_for_stack
int find_inline_backref(struct extent_buffer *leaf, int slot,
unsigned long *ptr, unsigned long *end)
{
+ struct btrfs_key key;
struct btrfs_extent_item *ei;
struct btrfs_tree_block_info *bi;
u32 item_size;
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+
item_size = btrfs_item_size_nr(leaf, slot);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (item_size < sizeof(*ei)) {
@@ -634,13 +637,18 @@ int find_inline_backref(struct extent_buffer *leaf, int slot,
WARN_ON(!(btrfs_extent_flags(leaf, ei) &
BTRFS_EXTENT_FLAG_TREE_BLOCK));
- if (item_size <= sizeof(*ei) + sizeof(*bi)) {
+ if (key.type == BTRFS_EXTENT_ITEM_KEY &&
+ item_size <= sizeof(*ei) + sizeof(*bi)) {
WARN_ON(item_size < sizeof(*ei) + sizeof(*bi));
return 1;
}
- bi = (struct btrfs_tree_block_info *)(ei + 1);
- *ptr = (unsigned long)(bi + 1);
+ if (key.type == BTRFS_EXTENT_ITEM_KEY) {
+ bi = (struct btrfs_tree_block_info *)(ei + 1);
+ *ptr = (unsigned long)(bi + 1);
+ } else {
+ *ptr = (unsigned long)(ei + 1);
+ }
*end = (unsigned long)ei + item_size;
return 0;
}
@@ -708,7 +716,7 @@ again:
end = 0;
ptr = 0;
key.objectid = cur->bytenr;
- key.type = BTRFS_EXTENT_ITEM_KEY;
+ key.type = BTRFS_METADATA_ITEM_KEY;
key.offset = (u64)-1;
path1->search_commit_root = 1;
@@ -766,7 +774,8 @@ again:
break;
}
- if (key.type == BTRFS_EXTENT_ITEM_KEY) {
+ if (key.type == BTRFS_EXTENT_ITEM_KEY ||
+ key.type == BTRFS_METADATA_ITEM_KEY) {
ret = find_inline_backref(eb, path1->slots[0],
&ptr, &end);
if (ret)
@@ -2768,8 +2777,13 @@ static int reada_tree_block(struct reloc_control *rc,
struct tree_block *block)
{
BUG_ON(block->key_ready);
- readahead_tree_block(rc->extent_root, block->bytenr,
- block->key.objectid, block->key.offset);
+ if (block->key.type == BTRFS_METADATA_ITEM_KEY)
+ readahead_tree_block(rc->extent_root, block->bytenr,
+ block->key.objectid,
+ rc->extent_root->leafsize);
+ else
+ readahead_tree_block(rc->extent_root, block->bytenr,
+ block->key.objectid, block->key.offset);
return 0;
}
@@ -3176,12 +3190,17 @@ static int add_tree_block(struct reloc_control *rc,
eb = path->nodes[0];
item_size = btrfs_item_size_nr(eb, path->slots[0]);
- if (item_size >= sizeof(*ei) + sizeof(*bi)) {
+ if (extent_key->type == BTRFS_METADATA_ITEM_KEY ||
+ item_size >= sizeof(*ei) + sizeof(*bi)) {
ei = btrfs_item_ptr(eb, path->slots[0],
struct btrfs_extent_item);
- bi = (struct btrfs_tree_block_info *)(ei + 1);
+ if (extent_key->type == BTRFS_EXTENT_ITEM_KEY) {
+ bi = (struct btrfs_tree_block_info *)(ei + 1);
+ level = btrfs_tree_block_level(eb, bi);
+ } else {
+ level = (int)extent_key->offset;
+ }
generation = btrfs_extent_generation(eb, ei);
- level = btrfs_tree_block_level(eb, bi);
} else {
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
u64 ref_owner;
@@ -3210,7 +3229,7 @@ static int add_tree_block(struct reloc_control *rc,
return -ENOMEM;
block->bytenr = extent_key->objectid;
- block->key.objectid = extent_key->offset;
+ block->key.objectid = rc->extent_root->leafsize;
block->key.offset = generation;
block->level = level;
block->key_ready = 0;
@@ -3252,9 +3271,15 @@ static int __add_tree_block(struct reloc_control *rc,
ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0);
if (ret < 0)
goto out;
- BUG_ON(ret);
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+ if (ret > 0) {
+ if (key.objectid == bytenr &&
+ key.type == BTRFS_METADATA_ITEM_KEY)
+ ret = 0;
+ }
+ BUG_ON(ret);
+
ret = add_tree_block(rc, &key, path, blocks);
out:
btrfs_free_path(path);
@@ -3275,7 +3300,8 @@ static int block_use_full_backref(struct reloc_control *rc,
return 1;
ret = btrfs_lookup_extent_info(NULL, rc->extent_root,
- eb->start, eb->len, NULL, &flags);
+ eb->start, btrfs_header_level(eb), 1,
+ NULL, &flags);
BUG_ON(ret);
if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
@@ -3644,12 +3670,25 @@ next:
break;
}
- if (key.type != BTRFS_EXTENT_ITEM_KEY ||
+ if (key.type != BTRFS_EXTENT_ITEM_KEY &&
+ key.type != BTRFS_METADATA_ITEM_KEY) {
+ path->slots[0]++;
+ goto next;
+ }
+
+ if (key.type == BTRFS_EXTENT_ITEM_KEY &&
key.objectid + key.offset <= rc->search_start) {
path->slots[0]++;
goto next;
}
+ if (key.type == BTRFS_METADATA_ITEM_KEY &&
+ key.objectid + rc->extent_root->leafsize <=
+ rc->search_start) {
+ path->slots[0]++;
+ goto next;
+ }
+
ret = find_first_extent_bit(&rc->processed_blocks,
key.objectid, &start, &end,
EXTENT_DIRTY, NULL);
@@ -3658,7 +3697,11 @@ next:
btrfs_release_path(path);
rc->search_start = end + 1;
} else {
- rc->search_start = key.objectid + key.offset;
+ if (key.type == BTRFS_EXTENT_ITEM_KEY)
+ rc->search_start = key.objectid + key.offset;
+ else
+ rc->search_start = key.objectid +
+ rc->extent_root->leafsize;
memcpy(extent_key, &key, sizeof(key));
return 0;
}