btrfs_start_transaction: wait for commits in progress to finish

[safe/jmp/linux-2.6] / fs / btrfs / transaction.c

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 86a5acc..0582390 100644 (file)
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -62,6 +62,7 @@ static noinline int join_transaction(struct btrfs_root *root)
                init_waitqueue_head(&cur_trans->writer_wait);
                init_waitqueue_head(&cur_trans->commit_wait);
                cur_trans->in_commit = 0;
+               cur_trans->blocked = 0;
                cur_trans->use_count = 1;
                cur_trans->commit_done = 0;
                cur_trans->start_time = get_seconds();
@@ -99,14 +100,36 @@ static noinline int record_root_in_trans(struct btrfs_root *root)
        return 0;
 }
 
-struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
-                                                  int num_blocks)
+struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
+                                            int num_blocks, int join)
 {
        struct btrfs_trans_handle *h =
                kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
+       struct btrfs_transaction *cur_trans;
        int ret;
 
        mutex_lock(&root->fs_info->trans_mutex);
+       cur_trans = root->fs_info->running_transaction;
+       if (cur_trans && cur_trans->blocked && !join) {
+               DEFINE_WAIT(wait);
+               cur_trans->use_count++;
+               while(1) {
+                       prepare_to_wait(&root->fs_info->transaction_wait, &wait,
+                                       TASK_UNINTERRUPTIBLE);
+                       if (cur_trans->blocked) {
+                               mutex_unlock(&root->fs_info->trans_mutex);
+                               schedule();
+                               mutex_lock(&root->fs_info->trans_mutex);
+                               finish_wait(&root->fs_info->transaction_wait,
+                                           &wait);
+                       } else {
+                               finish_wait(&root->fs_info->transaction_wait,
+                                           &wait);
+                               break;
+                       }
+               }
+               put_transaction(cur_trans);
+       }
        ret = join_transaction(root);
        BUG_ON(ret);
 
@@ -123,6 +146,17 @@ struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
        return h;
 }
 
+struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
+                                                  int num_blocks)
+{
+       return start_transaction(root, num_blocks, 0);
+}
+struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root,
+                                                  int num_blocks)
+{
+       return start_transaction(root, num_blocks, 1);
+}
+
 static noinline int wait_for_commit(struct btrfs_root *root,
                                    struct btrfs_transaction *commit)
 {
@@ -156,7 +190,7 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
        if (waitqueue_active(&cur_trans->writer_wait))
                wake_up(&cur_trans->writer_wait);
 
-       if (cur_trans->in_commit && throttle) {
+       if (0 && cur_trans->in_commit && throttle) {
                DEFINE_WAIT(wait);
                mutex_unlock(&root->fs_info->trans_mutex);
                prepare_to_wait(&root->fs_info->transaction_throttle, &wait,
@@ -617,6 +651,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 
 printk("commit trans %Lu\n", trans->transid);
        trans->transaction->in_commit = 1;
+       trans->transaction->blocked = 1;
        cur_trans = trans->transaction;
        if (cur_trans->list.prev != &root->fs_info->trans_list) {
                prev_trans = list_entry(cur_trans->list.prev,
@@ -684,7 +719,9 @@ printk("commit trans %Lu\n", trans->transid);
 
        btrfs_copy_pinned(root, pinned_copy);
 
+       trans->transaction->blocked = 0;
        wake_up(&root->fs_info->transaction_throttle);
+       wake_up(&root->fs_info->transaction_wait);
 
        mutex_unlock(&root->fs_info->trans_mutex);
        ret = btrfs_write_and_wait_transaction(trans, root);