From patchwork Mon Mar 22 19:13:26 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sage Weil X-Patchwork-Id: 87489 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter.kernel.org (8.14.3/8.14.3) with ESMTP id o2MJDhto031885 for ; Mon, 22 Mar 2010 19:13:43 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755106Ab0CVTNk (ORCPT ); Mon, 22 Mar 2010 15:13:40 -0400 Received: from cobra.newdream.net ([66.33.216.30]:38142 "EHLO cobra.newdream.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754195Ab0CVTNi (ORCPT ); Mon, 22 Mar 2010 15:13:38 -0400 Received: from localhost.localdomain (ip-66-33-206-8.dreamhost.com [66.33.206.8]) by cobra.newdream.net (Postfix) with ESMTPA id 17833BC929; Mon, 22 Mar 2010 12:14:43 -0700 (PDT) From: Sage Weil To: linux-btrfs@vger.kernel.org Cc: Sage Weil Subject: [PATCH 1/5] Btrfs: async transaction commit Date: Mon, 22 Mar 2010 12:13:26 -0700 Message-Id: <1269285210-19085-2-git-send-email-sage@newdream.net> X-Mailer: git-send-email 1.6.6.1 In-Reply-To: <1269285210-19085-1-git-send-email-sage@newdream.net> References: <1269285210-19085-1-git-send-email-sage@newdream.net> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.3 (demeter.kernel.org [140.211.167.41]); Mon, 22 Mar 2010 19:13:43 +0000 (UTC) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 1111584..1d0d5f0 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -840,6 +840,7 @@ struct btrfs_fs_info { struct btrfs_transaction *running_transaction; wait_queue_head_t transaction_throttle; wait_queue_head_t transaction_wait; + wait_queue_head_t transaction_blocked_wait; wait_queue_head_t async_submit_wait; struct btrfs_super_block super_copy; diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 11d0ad3..6f3cb33 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1701,6 +1701,7 @@ struct btrfs_root *open_ctree(struct super_block *sb, init_waitqueue_head(&fs_info->transaction_throttle); init_waitqueue_head(&fs_info->transaction_wait); + init_waitqueue_head(&fs_info->transaction_blocked_wait); init_waitqueue_head(&fs_info->async_submit_wait); __setup_root(4096, 4096, 4096, 4096, tree_root, diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index e75cc84..52b5488 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -882,6 +882,123 @@ int btrfs_transaction_in_commit(struct btrfs_fs_info *info) return ret; } +/* + * wait for the current transaction commit to start and block subsequent + * transaction joins + */ +static void wait_current_trans_commit_start(struct btrfs_root *root, + struct btrfs_transaction *trans) +{ + DEFINE_WAIT(wait); + + if (trans->in_commit) + return; + + while (1) { + prepare_to_wait(&root->fs_info->transaction_blocked_wait, &wait, + TASK_UNINTERRUPTIBLE); + if (trans->in_commit) { + finish_wait(&root->fs_info->transaction_blocked_wait, + &wait); + break; + } + mutex_unlock(&root->fs_info->trans_mutex); + schedule(); + mutex_lock(&root->fs_info->trans_mutex); + finish_wait(&root->fs_info->transaction_blocked_wait, &wait); + } +} + +/* + * wait for the current transaction to start and then become unblocked. + * caller holds ref. + */ +static void wait_current_trans_commit_start_and_unblock(struct btrfs_root *root, + struct btrfs_transaction *trans) +{ + DEFINE_WAIT(wait); + + if (trans->commit_done || (trans->in_commit && !trans->blocked)) + return; + + while (1) { + prepare_to_wait(&root->fs_info->transaction_wait, &wait, + TASK_UNINTERRUPTIBLE); + if (trans->commit_done || + (trans->in_commit && !trans->blocked)) { + finish_wait(&root->fs_info->transaction_wait, + &wait); + break; + } + mutex_unlock(&root->fs_info->trans_mutex); + schedule(); + mutex_lock(&root->fs_info->trans_mutex); + finish_wait(&root->fs_info->transaction_wait, + &wait); + } +} + +/* + * commit transactions asynchronously. once btrfs_commit_transaction_async + * returns, any subsequent transaction will not be allowed to join. + */ +struct btrfs_async_commit { + struct btrfs_trans_handle *newtrans; + struct btrfs_root *root; + struct delayed_work work; +}; + +static void do_async_commit(struct work_struct *work) +{ + struct btrfs_async_commit *ac = + container_of(work, struct btrfs_async_commit, work.work); + + btrfs_commit_transaction(ac->newtrans, ac->root); + kfree(ac); +} + +int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + int wait_for_unblock) +{ + struct btrfs_async_commit *ac; + struct btrfs_transaction *cur_trans; + + ac = kmalloc(sizeof(*ac), GFP_NOFS); + BUG_ON(!ac); + + INIT_DELAYED_WORK(&ac->work, do_async_commit); + ac->root = root; + ac->newtrans = btrfs_join_transaction(root, 0); + + /* take transaction reference */ + mutex_lock(&root->fs_info->trans_mutex); + cur_trans = trans->transaction; + cur_trans->use_count++; + mutex_unlock(&root->fs_info->trans_mutex); + + btrfs_end_transaction(trans, root); + schedule_delayed_work(&ac->work, 0); + + /* wait for transaction to start and unblock */ + mutex_lock(&root->fs_info->trans_mutex); + if (wait_for_unblock) + wait_current_trans_commit_start_and_unblock(root, cur_trans); + else + wait_current_trans_commit_start(root, cur_trans); + put_transaction(cur_trans); + mutex_unlock(&root->fs_info->trans_mutex); + + return 0; +} + +/* + * btrfs_transaction state sequence: + * in_commit = 0, blocked = 0 (initial) + * in_commit = 1, blocked = 1 + * blocked = 0 + * commit_done = 1 + */ int btrfs_commit_transaction(struct btrfs_trans_handle *trans, struct btrfs_root *root) { @@ -931,6 +1048,8 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans, trans->transaction->in_commit = 1; trans->transaction->blocked = 1; + wake_up(&root->fs_info->transaction_blocked_wait); + if (cur_trans->list.prev != &root->fs_info->trans_list) { prev_trans = list_entry(cur_trans->list.prev, struct btrfs_transaction, list); diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h index 93c7ccb..f9c52f2 100644 --- a/fs/btrfs/transaction.h +++ b/fs/btrfs/transaction.h @@ -101,6 +101,9 @@ int btrfs_defrag_root(struct btrfs_root *root, int cacheonly); int btrfs_clean_old_snapshots(struct btrfs_root *root); int btrfs_commit_transaction(struct btrfs_trans_handle *trans, struct btrfs_root *root); +int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + int wait_for_unblock); int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans, struct btrfs_root *root); void btrfs_throttle(struct btrfs_root *root);