Btrfs: Data ordered fixes

* In btrfs_delete_inode, wait for ordered extents after calling
truncate_inode_pages.  This is much faster, and more correct

* Properly clear our the PageChecked bit everywhere we redirty the page.

* Change the writepage fixup handler to lock the page range and check to
see if an ordered extent had been inserted since the improperly dirtied
page was discovered

* Wait for ordered extents outside the transaction.  This isn't required
for locking rules but does improve transaction latencies

* Reduce contention on the alloc_mutex by dropping it while incrementing
refs on a node/leaf and while dropping refs on a leaf.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 15 insertions, 3 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index be2aef1cb7ae..ccd49322f793 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -934,7 +934,6 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
         if (!root->ref_cows)
                 return 0;
 
-        mutex_lock(&root->fs_info->alloc_mutex);
         level = btrfs_header_level(buf);
         nritems = btrfs_header_nritems(buf);
         for (i = 0; i < nritems; i++) {
@@ -951,29 +950,36 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                         disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
                         if (disk_bytenr == 0)
                                 continue;
+
+                        mutex_lock(&root->fs_info->alloc_mutex);
                         ret = __btrfs_inc_extent_ref(trans, root, disk_bytenr,
                                     btrfs_file_extent_disk_num_bytes(buf, fi),
                                     root->root_key.objectid, trans->transid,
                                     key.objectid, key.offset);
+                        mutex_unlock(&root->fs_info->alloc_mutex);
                         if (ret) {
                                 faili = i;
+                                WARN_ON(1);
                                 goto fail;
                         }
                 } else {
                         bytenr = btrfs_node_blockptr(buf, i);
                         btrfs_node_key_to_cpu(buf, &key, i);
+
+                        mutex_lock(&root->fs_info->alloc_mutex);
                         ret = __btrfs_inc_extent_ref(trans, root, bytenr,
                                            btrfs_level_size(root, level - 1),
                                            root->root_key.objectid,
                                            trans->transid,
                                            level - 1, key.objectid);
+                        mutex_unlock(&root->fs_info->alloc_mutex);
                         if (ret) {
                                 faili = i;
+                                WARN_ON(1);
                                 goto fail;
                         }
                 }
         }
-        mutex_unlock(&root->fs_info->alloc_mutex);
         return 0;
 fail:
         WARN_ON(1);
@@ -1004,7 +1010,6 @@ fail:
                 }
         }
 #endif
-        mutex_unlock(&root->fs_info->alloc_mutex);
         return ret;
 }
 
@@ -2180,6 +2185,8 @@ static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans,
         leaf_owner = btrfs_header_owner(leaf);
         leaf_generation = btrfs_header_generation(leaf);
 
+        mutex_unlock(&root->fs_info->alloc_mutex);
+
         for (i = 0; i < nritems; i++) {
                 u64 disk_bytenr;
 
@@ -2197,12 +2204,17 @@ static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans,
                 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
                 if (disk_bytenr == 0)
                         continue;
+
+                mutex_lock(&root->fs_info->alloc_mutex);
                 ret = __btrfs_free_extent(trans, root, disk_bytenr,
                                 btrfs_file_extent_disk_num_bytes(leaf, fi),
                                 leaf_owner, leaf_generation,
                                 key.objectid, key.offset, 0);
+                mutex_unlock(&root->fs_info->alloc_mutex);
                 BUG_ON(ret);
         }
+
+        mutex_lock(&root->fs_info->alloc_mutex);
         return 0;
 }