提交 15ee9bc7 编写于 作者: J Josef Bacik 提交者: David Woodhouse

Btrfs: delay commits during fsync to allow more writers

Signed-off-by: NChris Mason <chris.mason@oracle.com>
上级 f2183bde
......@@ -25,6 +25,11 @@ struct btrfs_inode {
struct btrfs_block_group_cache *block_group;
struct btrfs_key location;
struct inode vfs_inode;
/*
* transid of the trans_handle that last modified this inode
*/
u64 last_trans;
};
static inline struct btrfs_inode *BTRFS_I(struct inode *inode)
{
......
......@@ -301,6 +301,7 @@ struct btrfs_fs_info {
struct radix_tree_root extent_map_radix;
struct radix_tree_root extent_ins_radix;
u64 generation;
u64 last_trans_committed;
struct btrfs_transaction *running_transaction;
struct btrfs_super_block *disk_super;
struct btrfs_super_block super_copy;
......
......@@ -435,6 +435,7 @@ struct btrfs_root *open_ctree(struct super_block *sb)
INIT_LIST_HEAD(&fs_info->dead_roots);
sb_set_blocksize(sb, 4096);
fs_info->running_transaction = NULL;
fs_info->last_trans_committed = 0;
fs_info->tree_root = tree_root;
fs_info->extent_root = extent_root;
fs_info->sb = sb;
......
......@@ -694,22 +694,36 @@ static int btrfs_sync_file(struct file *file,
{
struct inode *inode = dentry->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret;
int ret = 0;
struct btrfs_trans_handle *trans;
/*
* FIXME, use inode generation number to check if we can skip the
* commit
* check the transaction that last modified this inode
* and see if its already been committed
*/
mutex_lock(&root->fs_info->fs_mutex);
if (!BTRFS_I(inode)->last_trans)
goto out;
mutex_lock(&root->fs_info->trans_mutex);
if (BTRFS_I(inode)->last_trans <=
root->fs_info->last_trans_committed) {
BTRFS_I(inode)->last_trans = 0;
mutex_unlock(&root->fs_info->trans_mutex);
goto out;
}
mutex_unlock(&root->fs_info->trans_mutex);
/*
* ok we haven't committed the transaction yet, lets do a commit
*/
trans = btrfs_start_transaction(root, 1);
if (!trans) {
ret = -ENOMEM;
goto out;
}
ret = btrfs_commit_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
out:
mutex_unlock(&root->fs_info->fs_mutex);
return ret > 0 ? EIO : ret;
}
......
......@@ -193,6 +193,7 @@ static int btrfs_update_inode(struct btrfs_trans_handle *trans,
fill_inode_item(inode_item, inode);
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_set_inode_last_trans(trans, inode);
ret = 0;
failed:
btrfs_release_path(root, path);
......@@ -2234,6 +2235,7 @@ struct inode *btrfs_alloc_inode(struct super_block *sb)
ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
if (!ei)
return NULL;
ei->last_trans = 0;
return &ei->vfs_inode;
}
......
......@@ -55,7 +55,8 @@ static int join_transaction(struct btrfs_root *root)
BUG_ON(!cur_trans);
root->fs_info->generation++;
root->fs_info->running_transaction = cur_trans;
cur_trans->num_writers = 0;
cur_trans->num_writers = 1;
cur_trans->num_joined = 0;
cur_trans->transid = root->fs_info->generation;
init_waitqueue_head(&cur_trans->writer_wait);
init_waitqueue_head(&cur_trans->commit_wait);
......@@ -65,8 +66,11 @@ static int join_transaction(struct btrfs_root *root)
cur_trans->start_time = get_seconds();
list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
init_bit_radix(&cur_trans->dirty_pages);
} else {
cur_trans->num_writers++;
cur_trans->num_joined++;
}
cur_trans->num_writers++;
return 0;
}
......@@ -428,12 +432,14 @@ static int drop_dirty_roots(struct btrfs_root *tree_root,
int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
int ret = 0;
unsigned long joined = 0;
unsigned long timeout = 1;
struct btrfs_transaction *cur_trans;
struct btrfs_transaction *prev_trans = NULL;
struct list_head dirty_fs_roots;
struct radix_tree_root pinned_copy;
DEFINE_WAIT(wait);
int ret;
init_bit_radix(&pinned_copy);
INIT_LIST_HEAD(&dirty_fs_roots);
......@@ -448,7 +454,11 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
mutex_unlock(&root->fs_info->fs_mutex);
ret = wait_for_commit(root, cur_trans);
BUG_ON(ret);
mutex_lock(&root->fs_info->trans_mutex);
put_transaction(cur_trans);
mutex_unlock(&root->fs_info->trans_mutex);
mutex_lock(&root->fs_info->fs_mutex);
return 0;
}
......@@ -463,26 +473,35 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
mutex_unlock(&root->fs_info->trans_mutex);
wait_for_commit(root, prev_trans);
put_transaction(prev_trans);
mutex_lock(&root->fs_info->fs_mutex);
mutex_lock(&root->fs_info->trans_mutex);
put_transaction(prev_trans);
}
}
while (trans->transaction->num_writers > 1) {
do {
joined = cur_trans->num_joined;
WARN_ON(cur_trans != trans->transaction);
prepare_to_wait(&trans->transaction->writer_wait, &wait,
prepare_to_wait(&cur_trans->writer_wait, &wait,
TASK_UNINTERRUPTIBLE);
if (trans->transaction->num_writers <= 1)
break;
if (cur_trans->num_writers > 1)
timeout = MAX_SCHEDULE_TIMEOUT;
else
timeout = 1;
mutex_unlock(&root->fs_info->fs_mutex);
mutex_unlock(&root->fs_info->trans_mutex);
schedule();
schedule_timeout(timeout);
mutex_lock(&root->fs_info->fs_mutex);
mutex_lock(&root->fs_info->trans_mutex);
finish_wait(&trans->transaction->writer_wait, &wait);
}
finish_wait(&trans->transaction->writer_wait, &wait);
finish_wait(&cur_trans->writer_wait, &wait);
} while (cur_trans->num_writers > 1 ||
(cur_trans->num_joined != joined));
WARN_ON(cur_trans != trans->transaction);
ret = add_dirty_roots(trans, &root->fs_info->fs_roots_radix,
&dirty_fs_roots);
......@@ -511,6 +530,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
btrfs_finish_extent_commit(trans, root, &pinned_copy);
mutex_lock(&root->fs_info->trans_mutex);
cur_trans->commit_done = 1;
root->fs_info->last_trans_committed = cur_trans->transid;
wake_up(&cur_trans->commit_wait);
put_transaction(cur_trans);
put_transaction(cur_trans);
......
......@@ -23,6 +23,7 @@
struct btrfs_transaction {
u64 transid;
unsigned long num_writers;
unsigned long num_joined;
int in_commit;
int use_count;
int commit_done;
......@@ -57,6 +58,12 @@ static inline void btrfs_update_inode_block_group(struct
BTRFS_I(inode)->block_group = trans->block_group;
}
static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
struct inode *inode)
{
BTRFS_I(inode)->last_trans = trans->transaction->transid;
}
int btrfs_end_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
......
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