On 07/18/2011 02:11 PM, Josef Bacik wrote:
> Currently we reserve enough space to COW an entirely full btree for every
> extent
> we have reserved for an inode. This _sucks_, because you only need to COW
> once,
> and then everybody else is ok. Unfortunately we don't know we'll all be able
> to
> get into the same transaction so that's what we have had to do. But the
> global
> reserve holds a reservation large enough to cover a large percentage of all
> the
> metadata currently in the fs. So all we really need to account for is any new
> blocks that we may allocate. So fix this by
>
> 1) Passing to btrfs_alloc_free_block() wether this is a new block or a COW
> block. If it is a COW block we use the global reserve, if not we use the
> trans->block_rsv.
> 2) Reduce the amount of space we reserve. Since we don't need to account for
> cow'ing the tree we can just keep track of new blocks to reserve, which
> greatly
> reduces the reservation amount.
>
> This makes my basic random write test go from 3 mb/s to 75 mb/s. I've tested
> this with my horrible ENOSPC test and it seems to work out fine. Thanks,
>
> Signed-off-by: Josef Bacik <jo...@redhat.com>
> ---
> V1->V2:
> -fix a problem reported by Liubo, we need to make sure that we move bytes
> over for any new extents we may add to the extent tree so we don't get a bunch
> of warnings.
> -fix the global reserve to reserve 50% of the metadata space currently used.
Argh helps if I actually send the updated patch, sorry!
---
fs/btrfs/ctree.c | 10 +++++-----
fs/btrfs/ctree.h | 5 ++---
fs/btrfs/disk-io.c | 3 ++-
fs/btrfs/extent-tree.c | 31 ++++++++++++++++++++++++-------
fs/btrfs/ioctl.c | 2 +-
5 files changed, 34 insertions(+), 17 deletions(-)
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 2e66786..fbd48e9 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -206,7 +206,7 @@ int btrfs_copy_root(struct btrfs_trans_handle *trans,
cow = btrfs_alloc_free_block(trans, root, buf->len, 0,
new_root_objectid, &disk_key, level,
- buf->start, 0);
+ buf->start, 0, 1);
if (IS_ERR(cow))
return PTR_ERR(cow);
@@ -412,7 +412,7 @@ static noinline int __btrfs_cow_block(struct
btrfs_trans_handle *trans,
cow = btrfs_alloc_free_block(trans, root, buf->len, parent_start,
root->root_key.objectid, &disk_key,
- level, search_start, empty_size);
+ level, search_start, empty_size, 0);
if (IS_ERR(cow))
return PTR_ERR(cow);
@@ -1985,7 +1985,7 @@ static noinline int insert_new_root(struct
btrfs_trans_handle *trans,
c = btrfs_alloc_free_block(trans, root, root->nodesize, 0,
root->root_key.objectid, &lower_key,
- level, root->node->start, 0);
+ level, root->node->start, 0, 1);
if (IS_ERR(c))
return PTR_ERR(c);
@@ -2112,7 +2112,7 @@ static noinline int split_node(struct
btrfs_trans_handle *trans,
split = btrfs_alloc_free_block(trans, root, root->nodesize, 0,
root->root_key.objectid,
- &disk_key, level, c->start, 0);
+ &disk_key, level, c->start, 0, 1);
if (IS_ERR(split))
return PTR_ERR(split);
@@ -2937,7 +2937,7 @@ again:
right = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
root->root_key.objectid,
- &disk_key, 0, l->start, 0);
+ &disk_key, 0, l->start, 0, 1);
if (IS_ERR(right))
return PTR_ERR(right);
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 3ba4d5f..1accb56 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2135,8 +2135,7 @@ static inline bool btrfs_mixed_space_info(struct
btrfs_space_info *space_info)
static inline u64 btrfs_calc_trans_metadata_size(struct btrfs_root *root,
unsigned num_items)
{
- return (root->leafsize + root->nodesize * (BTRFS_MAX_LEVEL - 1)) *
- 3 * num_items;
+ return root->leafsize * 3 * num_items;
}
void btrfs_put_block_group(struct btrfs_block_group_cache *cache);
@@ -2161,7 +2160,7 @@ struct extent_buffer
*btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u32 blocksize,
u64 parent, u64 root_objectid,
struct btrfs_disk_key *key, int level,
- u64 hint, u64 empty_size);
+ u64 hint, u64 empty_size, int
new_block);
void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *buf,
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 234a084..0245cad 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1143,7 +1143,8 @@ static struct btrfs_root *alloc_log_tree(struct
btrfs_trans_handle *trans,
root->ref_cows = 0;
leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
- BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0);
+ BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0,
+ 1);
if (IS_ERR(leaf)) {
kfree(root);
return ERR_CAST(leaf);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 2e0f87b..1011bcb 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3779,7 +3779,7 @@ static u64 calc_global_metadata_size(struct
btrfs_fs_info *fs_info)
num_bytes = (data_used >> fs_info->sb->s_blocksize_bits) *
csum_size * 2;
- num_bytes += div64_u64(data_used + meta_used, 50);
+ num_bytes += div_factor(data_used + meta_used, 5);
if (num_bytes * 3 > meta_used)
num_bytes = div64_u64(meta_used, 3);
@@ -5552,10 +5552,17 @@ int btrfs_alloc_reserved_file_extent(struct
btrfs_trans_handle *trans,
u64 root_objectid, u64 owner,
u64 offset, struct btrfs_key *ins)
{
+ struct btrfs_block_rsv *block_rsv = get_block_rsv(trans, root);
+ struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
int ret;
BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
-
+ if (block_rsv != global_rsv) {
+ u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
+ ret = btrfs_block_rsv_migrate(block_rsv, global_rsv,
+ num_bytes);
+ WARN_ON(ret);
+ }
ret = btrfs_add_delayed_data_ref(trans, ins->objectid, ins->offset,
0, root_objectid, owner, offset,
BTRFS_ADD_DELAYED_EXTENT, NULL);
@@ -5661,13 +5668,23 @@ struct extent_buffer
*btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
static struct btrfs_block_rsv *
use_block_rsv(struct btrfs_trans_handle *trans,
- struct btrfs_root *root, u32 blocksize)
+ struct btrfs_root *root, u32 blocksize, int new_block)
{
- struct btrfs_block_rsv *block_rsv;
+ struct btrfs_block_rsv *block_rsv = NULL;
struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
int ret;
- block_rsv = get_block_rsv(trans, root);
+ if (root->ref_cows) {
+ if (new_block)
+ block_rsv = trans->block_rsv;
+ else
+ block_rsv = global_rsv;
+ } else {
+ block_rsv = root->block_rsv;
+ }
+
+ if (!block_rsv)
+ block_rsv = &root->fs_info->empty_block_rsv;
if (block_rsv->size == 0) {
ret = reserve_metadata_bytes(trans, root, block_rsv,
@@ -5726,7 +5743,7 @@ struct extent_buffer
*btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u32 blocksize,
u64 parent, u64 root_objectid,
struct btrfs_disk_key *key, int level,
- u64 hint, u64 empty_size)
+ u64 hint, u64 empty_size, int new_block)
{
struct btrfs_key ins;
struct btrfs_block_rsv *block_rsv;
@@ -5735,7 +5752,7 @@ struct extent_buffer
*btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
int ret;
- block_rsv = use_block_rsv(trans, root, blocksize);
+ block_rsv = use_block_rsv(trans, root, blocksize, new_block);
if (IS_ERR(block_rsv))
return ERR_CAST(block_rsv);
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index fd252ff..39fb634 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -352,7 +352,7 @@ static noinline int create_subvol(struct btrfs_root
*root,
}
leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
- 0, objectid, NULL, 0, 0, 0);
+ 0, objectid, NULL, 0, 0, 0, 1);
if (IS_ERR(leaf)) {
ret = PTR_ERR(leaf);
goto fail;
--
1.7.5.2
--
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