Skip to content

Commit

Permalink
Btrfs: Introduce contexts for metadata reservation
Browse files Browse the repository at this point in the history 
Introducing metadata reseravtion contexts has two major advantages.
First, it makes metadata reseravtion more traceable. Second, it can
reclaim freed space and re-add them to the itself after transaction
committed.

Besides add btrfs_block_rsv structure and related helper functions,
This patch contains following changes:

Move code that decides if freed tree block should be pinned into
btrfs_free_tree_block().

Make space accounting more accurate, mainly for handling read only
block groups.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
  • Loading branch information
Yan, Zheng authored and Chris Mason committed May 25, 2010
1 parent 2ead6ae commit f0486c6
Show file tree
Hide file tree
Showing 7 changed files with 853 additions and 385 deletions.
104 changes: 63 additions & 41 deletions fs/btrfs/ctree.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -280,7 +280,8 @@ int btrfs_block_can_be_shared(struct btrfs_root *root,
static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *buf,
struct extent_buffer *cow)
struct extent_buffer *cow,
int *last_ref)
{
u64 refs;
u64 owner;
Expand Down Expand Up @@ -366,6 +367,7 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
BUG_ON(ret);
}
clean_tree_block(trans, root, buf);
*last_ref = 1;
}
return 0;
}
Expand All @@ -392,6 +394,7 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
struct btrfs_disk_key disk_key;
struct extent_buffer *cow;
int level;
int last_ref = 0;
int unlock_orig = 0;
u64 parent_start;

Expand Down Expand Up @@ -442,7 +445,7 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
(unsigned long)btrfs_header_fsid(cow),
BTRFS_FSID_SIZE);

update_ref_for_cow(trans, root, buf, cow);
update_ref_for_cow(trans, root, buf, cow, &last_ref);

if (buf == root->node) {
WARN_ON(parent && parent != buf);
Expand All @@ -457,8 +460,8 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
extent_buffer_get(cow);
spin_unlock(&root->node_lock);

btrfs_free_tree_block(trans, root, buf->start, buf->len,
parent_start, root->root_key.objectid, level);
btrfs_free_tree_block(trans, root, buf, parent_start,
last_ref);
free_extent_buffer(buf);
add_root_to_dirty_list(root);
} else {
Expand All @@ -473,8 +476,8 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
btrfs_set_node_ptr_generation(parent, parent_slot,
trans->transid);
btrfs_mark_buffer_dirty(parent);
btrfs_free_tree_block(trans, root, buf->start, buf->len,
parent_start, root->root_key.objectid, level);
btrfs_free_tree_block(trans, root, buf, parent_start,
last_ref);
}
if (unlock_orig)
btrfs_tree_unlock(buf);
Expand Down Expand Up @@ -949,6 +952,22 @@ int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key,
return bin_search(eb, key, level, slot);
}

static void root_add_used(struct btrfs_root *root, u32 size)
{
spin_lock(&root->accounting_lock);
btrfs_set_root_used(&root->root_item,
btrfs_root_used(&root->root_item) + size);
spin_unlock(&root->accounting_lock);
}

static void root_sub_used(struct btrfs_root *root, u32 size)
{
spin_lock(&root->accounting_lock);
btrfs_set_root_used(&root->root_item,
btrfs_root_used(&root->root_item) - size);
spin_unlock(&root->accounting_lock);
}

/* given a node and slot number, this reads the blocks it points to. The
* extent buffer is returned with a reference taken (but unlocked).
* NULL is returned on error.
Expand Down Expand Up @@ -1019,7 +1038,11 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
btrfs_tree_lock(child);
btrfs_set_lock_blocking(child);
ret = btrfs_cow_block(trans, root, child, mid, 0, &child);
BUG_ON(ret);
if (ret) {
btrfs_tree_unlock(child);
free_extent_buffer(child);
goto enospc;
}

spin_lock(&root->node_lock);
root->node = child;
Expand All @@ -1034,11 +1057,12 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
btrfs_tree_unlock(mid);
/* once for the path */
free_extent_buffer(mid);
ret = btrfs_free_tree_block(trans, root, mid->start, mid->len,
0, root->root_key.objectid, level);

root_sub_used(root, mid->len);
btrfs_free_tree_block(trans, root, mid, 0, 1);
/* once for the root ptr */
free_extent_buffer(mid);
return ret;
return 0;
}
if (btrfs_header_nritems(mid) >
BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
Expand Down Expand Up @@ -1088,23 +1112,16 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
if (wret < 0 && wret != -ENOSPC)
ret = wret;
if (btrfs_header_nritems(right) == 0) {
u64 bytenr = right->start;
u32 blocksize = right->len;

clean_tree_block(trans, root, right);
btrfs_tree_unlock(right);
free_extent_buffer(right);
right = NULL;
wret = del_ptr(trans, root, path, level + 1, pslot +
1);
if (wret)
ret = wret;
wret = btrfs_free_tree_block(trans, root,
bytenr, blocksize, 0,
root->root_key.objectid,
level);
if (wret)
ret = wret;
root_sub_used(root, right->len);
btrfs_free_tree_block(trans, root, right, 0, 1);
free_extent_buffer(right);
right = NULL;
} else {
struct btrfs_disk_key right_key;
btrfs_node_key(right, &right_key, 0);
Expand Down Expand Up @@ -1136,21 +1153,15 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
BUG_ON(wret == 1);
}
if (btrfs_header_nritems(mid) == 0) {
/* we've managed to empty the middle node, drop it */
u64 bytenr = mid->start;
u32 blocksize = mid->len;

clean_tree_block(trans, root, mid);
btrfs_tree_unlock(mid);
free_extent_buffer(mid);
mid = NULL;
wret = del_ptr(trans, root, path, level + 1, pslot);
if (wret)
ret = wret;
wret = btrfs_free_tree_block(trans, root, bytenr, blocksize,
0, root->root_key.objectid, level);
if (wret)
ret = wret;
root_sub_used(root, mid->len);
btrfs_free_tree_block(trans, root, mid, 0, 1);
free_extent_buffer(mid);
mid = NULL;
} else {
/* update the parent key to reflect our changes */
struct btrfs_disk_key mid_key;
Expand Down Expand Up @@ -1740,7 +1751,6 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
p->nodes[level + 1],
p->slots[level + 1], &b);
if (err) {
free_extent_buffer(b);
ret = err;
goto done;
}
Expand Down Expand Up @@ -2076,6 +2086,8 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans,
if (IS_ERR(c))
return PTR_ERR(c);

root_add_used(root, root->nodesize);

memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header));
btrfs_set_header_nritems(c, 1);
btrfs_set_header_level(c, level);
Expand Down Expand Up @@ -2134,6 +2146,7 @@ static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
int nritems;

BUG_ON(!path->nodes[level]);
btrfs_assert_tree_locked(path->nodes[level]);
lower = path->nodes[level];
nritems = btrfs_header_nritems(lower);
BUG_ON(slot > nritems);
Expand Down Expand Up @@ -2202,6 +2215,8 @@ static noinline int split_node(struct btrfs_trans_handle *trans,
if (IS_ERR(split))
return PTR_ERR(split);

root_add_used(root, root->nodesize);

memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header));
btrfs_set_header_level(split, btrfs_header_level(c));
btrfs_set_header_bytenr(split, split->start);
Expand Down Expand Up @@ -2415,6 +2430,9 @@ static noinline int __push_leaf_right(struct btrfs_trans_handle *trans,

if (left_nritems)
btrfs_mark_buffer_dirty(left);
else
clean_tree_block(trans, root, left);

btrfs_mark_buffer_dirty(right);

btrfs_item_key(right, &disk_key, 0);
Expand Down Expand Up @@ -2660,6 +2678,8 @@ static noinline int __push_leaf_left(struct btrfs_trans_handle *trans,
btrfs_mark_buffer_dirty(left);
if (right_nritems)
btrfs_mark_buffer_dirty(right);
else
clean_tree_block(trans, root, right);

btrfs_item_key(right, &disk_key, 0);
wret = fixup_low_keys(trans, root, path, &disk_key, 1);
Expand All @@ -2669,8 +2689,6 @@ static noinline int __push_leaf_left(struct btrfs_trans_handle *trans,
/* then fixup the leaf pointer in the path */
if (path->slots[0] < push_items) {
path->slots[0] += old_left_nritems;
if (btrfs_header_nritems(path->nodes[0]) == 0)
clean_tree_block(trans, root, path->nodes[0]);
btrfs_tree_unlock(path->nodes[0]);
free_extent_buffer(path->nodes[0]);
path->nodes[0] = left;
Expand Down Expand Up @@ -2932,10 +2950,10 @@ static noinline int split_leaf(struct btrfs_trans_handle *trans,
right = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
root->root_key.objectid,
&disk_key, 0, l->start, 0);
if (IS_ERR(right)) {
BUG_ON(1);
if (IS_ERR(right))
return PTR_ERR(right);
}

root_add_used(root, root->leafsize);

memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
btrfs_set_header_bytenr(right, right->start);
Expand Down Expand Up @@ -3054,7 +3072,8 @@ static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans,

btrfs_set_path_blocking(path);
ret = split_leaf(trans, root, &key, path, ins_len, 1);
BUG_ON(ret);
if (ret)
goto err;

path->keep_locks = 0;
btrfs_unlock_up_safe(path, 1);
Expand Down Expand Up @@ -3796,9 +3815,10 @@ static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans,
*/
btrfs_unlock_up_safe(path, 0);

ret = btrfs_free_tree_block(trans, root, leaf->start, leaf->len,
0, root->root_key.objectid, 0);
return ret;
root_sub_used(root, leaf->len);

btrfs_free_tree_block(trans, root, leaf, 0, 1);
return 0;
}
/*
* delete the item at the leaf level in path. If that empties
Expand Down Expand Up @@ -3865,6 +3885,8 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
if (leaf == root->node) {
btrfs_set_header_level(leaf, 0);
} else {
btrfs_set_path_blocking(path);
clean_tree_block(trans, root, leaf);
ret = btrfs_del_leaf(trans, root, path, leaf);
BUG_ON(ret);
}
Expand Down
69 changes: 62 additions & 7 deletions fs/btrfs/ctree.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -707,6 +707,20 @@ struct btrfs_space_info {
atomic_t caching_threads;
};

struct btrfs_block_rsv {
u64 size;
u64 reserved;
u64 freed[2];
struct btrfs_space_info *space_info;
struct list_head list;
spinlock_t lock;
atomic_t usage;
unsigned int priority:8;
unsigned int durable:1;
unsigned int refill_used:1;
unsigned int full:1;
};

/*
* free clusters are used to claim free space in relatively large chunks,
* allowing us to do less seeky writes. They are used for all metadata
Expand Down Expand Up @@ -757,6 +771,7 @@ struct btrfs_block_group_cache {
spinlock_t lock;
u64 pinned;
u64 reserved;
u64 reserved_pinned;
u64 bytes_super;
u64 flags;
u64 sectorsize;
Expand Down Expand Up @@ -822,6 +837,22 @@ struct btrfs_fs_info {
/* logical->physical extent mapping */
struct btrfs_mapping_tree mapping_tree;

/* block reservation for extent, checksum and root tree */
struct btrfs_block_rsv global_block_rsv;
/* block reservation for delay allocation */
struct btrfs_block_rsv delalloc_block_rsv;
/* block reservation for metadata operations */
struct btrfs_block_rsv trans_block_rsv;
/* block reservation for chunk tree */
struct btrfs_block_rsv chunk_block_rsv;

struct btrfs_block_rsv empty_block_rsv;

/* list of block reservations that cross multiple transactions */
struct list_head durable_block_rsv_list;

struct mutex durable_block_rsv_mutex;

u64 generation;
u64 last_trans_committed;

Expand Down Expand Up @@ -1008,6 +1039,9 @@ struct btrfs_root {
struct completion kobj_unregister;
struct mutex objectid_mutex;

spinlock_t accounting_lock;
struct btrfs_block_rsv *block_rsv;

struct mutex log_mutex;
wait_queue_head_t log_writer_wait;
wait_queue_head_t log_commit_wait[2];
Expand Down Expand Up @@ -1980,10 +2014,10 @@ struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
u64 parent, u64 root_objectid,
struct btrfs_disk_key *key, int level,
u64 hint, u64 empty_size);
int btrfs_free_tree_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u32 blocksize,
u64 parent, u64 root_objectid, int level);
void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *buf,
u64 parent, int last_ref);
struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u32 blocksize,
Expand Down Expand Up @@ -2037,9 +2071,6 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans,
u64 size);
int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 group_start);
int btrfs_prepare_block_group_relocation(struct btrfs_root *root,
struct btrfs_block_group_cache *group);

u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags);
void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *ionde);
void btrfs_clear_space_info_full(struct btrfs_fs_info *info);
Expand All @@ -2058,6 +2089,30 @@ void btrfs_delalloc_reserve_space(struct btrfs_root *root, struct inode *inode,
u64 bytes);
void btrfs_delalloc_free_space(struct btrfs_root *root, struct inode *inode,
u64 bytes);
void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv);
struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root);
void btrfs_free_block_rsv(struct btrfs_root *root,
struct btrfs_block_rsv *rsv);
void btrfs_add_durable_block_rsv(struct btrfs_fs_info *fs_info,
struct btrfs_block_rsv *rsv);
int btrfs_block_rsv_add(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_block_rsv *block_rsv,
u64 num_bytes, int *retries);
int btrfs_block_rsv_check(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_block_rsv *block_rsv,
u64 min_reserved, int min_factor);
int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv,
struct btrfs_block_rsv *dst_rsv,
u64 num_bytes);
void btrfs_block_rsv_release(struct btrfs_root *root,
struct btrfs_block_rsv *block_rsv,
u64 num_bytes);
int btrfs_set_block_group_ro(struct btrfs_root *root,
struct btrfs_block_group_cache *cache);
int btrfs_set_block_group_rw(struct btrfs_root *root,
struct btrfs_block_group_cache *cache);
/* ctree.c */
int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key,
int level, int *slot);
Expand Down
Loading

0 comments on commit f0486c6

Please sign in to comment.