1 files changed, 50 insertions, 6 deletions

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 7827841b55c..741666a7676 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -137,11 +137,20 @@ static int start_log_trans(struct btrfs_trans_handle *trans,
 
         mutex_lock(&root->log_mutex);
         if (root->log_root) {
+                if (!root->log_start_pid) {
+                        root->log_start_pid = current->pid;
+                        root->log_multiple_pids = false;
+                } else if (root->log_start_pid != current->pid) {
+                        root->log_multiple_pids = true;
+                }
+
                 root->log_batch++;
                 atomic_inc(&root->log_writers);
                 mutex_unlock(&root->log_mutex);
                 return 0;
         }
+        root->log_multiple_pids = false;
+        root->log_start_pid = current->pid;
         mutex_lock(&root->fs_info->tree_log_mutex);
         if (!root->fs_info->log_root_tree) {
                 ret = btrfs_init_log_root_tree(trans, root->fs_info);
@@ -1971,6 +1980,7 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
         int ret;
         struct btrfs_root *log = root->log_root;
         struct btrfs_root *log_root_tree = root->fs_info->log_root_tree;
+        u64 log_transid = 0;
 
         mutex_lock(&root->log_mutex);
         index1 = root->log_transid % 2;
@@ -1987,10 +1997,11 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
 
         while (1) {
                 unsigned long batch = root->log_batch;
-                mutex_unlock(&root->log_mutex);
-                schedule_timeout_uninterruptible(1);
-                mutex_lock(&root->log_mutex);
-
+                if (root->log_multiple_pids) {
+                        mutex_unlock(&root->log_mutex);
+                        schedule_timeout_uninterruptible(1);
+                        mutex_lock(&root->log_mutex);
+                }
                 wait_for_writer(trans, root);
                 if (batch == root->log_batch)
                         break;
@@ -2003,14 +2014,19 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
                 goto out;
         }
 
-        ret = btrfs_write_and_wait_marked_extents(log, &log->dirty_log_pages);
+        /* we start IO on  all the marked extents here, but we don't actually
+         * wait for them until later.
+         */
+        ret = btrfs_write_marked_extents(log, &log->dirty_log_pages);
         BUG_ON(ret);
 
         btrfs_set_root_node(&log->root_item, log->node);
 
         root->log_batch = 0;
+        log_transid = root->log_transid;
         root->log_transid++;
         log->log_transid = root->log_transid;
+        root->log_start_pid = 0;
         smp_mb();
         /*
          * log tree has been flushed to disk, new modifications of
@@ -2036,6 +2052,7 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
 
         index2 = log_root_tree->log_transid % 2;
         if (atomic_read(&log_root_tree->log_commit[index2])) {
+                btrfs_wait_marked_extents(log, &log->dirty_log_pages);
                 wait_log_commit(trans, log_root_tree,
                                 log_root_tree->log_transid);
                 mutex_unlock(&log_root_tree->log_mutex);
@@ -2055,6 +2072,7 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
          * check the full commit flag again
          */
         if (root->fs_info->last_trans_log_full_commit == trans->transid) {
+                btrfs_wait_marked_extents(log, &log->dirty_log_pages);
                 mutex_unlock(&log_root_tree->log_mutex);
                 ret = -EAGAIN;
                 goto out_wake_log_root;
@@ -2063,6 +2081,7 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
         ret = btrfs_write_and_wait_marked_extents(log_root_tree,
                                 &log_root_tree->dirty_log_pages);
         BUG_ON(ret);
+        btrfs_wait_marked_extents(log, &log->dirty_log_pages);
 
         btrfs_set_super_log_root(&root->fs_info->super_for_commit,
                                 log_root_tree->node->start);
@@ -2082,9 +2101,14 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
          * the running transaction open, so a full commit can't hop
          * in and cause problems either.
          */
-        write_ctree_super(trans, root->fs_info->tree_root, 2);
+        write_ctree_super(trans, root->fs_info->tree_root, 1);
         ret = 0;
 
+        mutex_lock(&root->log_mutex);
+        if (root->last_log_commit < log_transid)
+                root->last_log_commit = log_transid;
+        mutex_unlock(&root->log_mutex);
+
 out_wake_log_root:
         atomic_set(&log_root_tree->log_commit[index2], 0);
         smp_mb();
@@ -2852,6 +2876,21 @@ out:
         return ret;
 }
 
+static int inode_in_log(struct btrfs_trans_handle *trans,
+                 struct inode *inode)
+{
+        struct btrfs_root *root = BTRFS_I(inode)->root;
+        int ret = 0;
+
+        mutex_lock(&root->log_mutex);
+        if (BTRFS_I(inode)->logged_trans == trans->transid &&
+            BTRFS_I(inode)->last_sub_trans <= root->last_log_commit)
+                ret = 1;
+        mutex_unlock(&root->log_mutex);
+        return ret;
+}
+
+
 /*
  * helper function around btrfs_log_inode to make sure newly created
  * parent directories also end up in the log.  A minimal inode and backref
@@ -2891,6 +2930,11 @@ int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
         if (ret)
                 goto end_no_trans;
 
+        if (inode_in_log(trans, inode)) {
+                ret = BTRFS_NO_LOG_SYNC;
+                goto end_no_trans;
+        }
+
         start_log_trans(trans, root);
 
         ret = btrfs_log_inode(trans, root, inode, inode_only);