Btrfs: Fix compile warning around num_online_cpus() in a min statement
[safe/jmp/linux-2.6] / fs / btrfs / transaction.c
index 202c1b6..4604178 100644 (file)
@@ -28,7 +28,6 @@
 #include "ref-cache.h"
 #include "tree-log.h"
 
-static int total_trans = 0;
 extern struct kmem_cache *btrfs_trans_handle_cachep;
 extern struct kmem_cache *btrfs_transaction_cachep;
 
@@ -39,8 +38,6 @@ static noinline void put_transaction(struct btrfs_transaction *transaction)
        WARN_ON(transaction->use_count == 0);
        transaction->use_count--;
        if (transaction->use_count == 0) {
-               WARN_ON(total_trans == 0);
-               total_trans--;
                list_del_init(&transaction->list);
                memset(transaction, 0, sizeof(*transaction));
                kmem_cache_free(btrfs_transaction_cachep, transaction);
@@ -57,7 +54,6 @@ static noinline int join_transaction(struct btrfs_root *root)
        if (!cur_trans) {
                cur_trans = kmem_cache_alloc(btrfs_transaction_cachep,
                                             GFP_NOFS);
-               total_trans++;
                BUG_ON(!cur_trans);
                root->fs_info->generation++;
                root->fs_info->last_alloc = 0;
@@ -186,7 +182,7 @@ static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
        h->transaction = root->fs_info->running_transaction;
        h->blocks_reserved = num_blocks;
        h->blocks_used = 0;
-       h->block_group = NULL;
+       h->block_group = 0;
        h->alloc_exclude_nr = 0;
        h->alloc_exclude_start = 0;
        root->fs_info->running_transaction->use_count++;
@@ -332,7 +328,6 @@ int btrfs_write_and_wait_marked_extents(struct btrfs_root *root,
        int werr = 0;
        struct page *page;
        struct inode *btree_inode = root->fs_info->btree_inode;
-       struct extent_io_tree *io_tree = &BTRFS_I(btree_inode)->io_tree;
        u64 start = 0;
        u64 end;
        unsigned long index;
@@ -373,11 +368,6 @@ int btrfs_write_and_wait_marked_extents(struct btrfs_root *root,
                        page_cache_release(page);
                }
        }
-       /*
-        * we unplug once and then use the wait_on_extent_bit for
-        * everything else
-        */
-       blk_run_address_space(btree_inode->i_mapping);
        while(1) {
                ret = find_first_extent_bit(dirty_pages, 0, &start, &end,
                                            EXTENT_DIRTY);
@@ -398,28 +388,7 @@ int btrfs_write_and_wait_marked_extents(struct btrfs_root *root,
                                if (err)
                                        werr = err;
                        }
-                       if (PageWriteback(page)) {
-                               /*
-                                * we don't wait on the page writeback bit
-                                * because that triggers a lot of unplugs.
-                                * The extent bits are much nicer to
-                                * the disks, but come with a slightly
-                                * higher latency because we aren't forcing
-                                * unplugs.
-                                */
-                               wait_on_extent_writeback(io_tree,
-                                        page_offset(page),
-                                        page_offset(page) +
-                                        PAGE_CACHE_SIZE - 1);
-                       }
-                       if (PageWriteback(page)) {
-                               /*
-                                * the state bits get cleared before the
-                                * page bits, lets add some extra
-                                * paranoia here
-                                */
-                               wait_on_page_writeback(page);
-                       }
+                       wait_on_page_writeback(page);
                        page_cache_release(page);
                        cond_resched();
                }
@@ -779,7 +748,6 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
        struct extent_buffer *tmp;
        struct extent_buffer *old;
        int ret;
-       int namelen;
        u64 objectid;
 
        new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
@@ -816,28 +784,63 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
        if (ret)
                goto fail;
 
+       key.offset = (u64)-1;
+       memcpy(&pending->root_key, &key, sizeof(key));
+fail:
+       kfree(new_root_item);
+       return ret;
+}
+
+static noinline int finish_pending_snapshot(struct btrfs_fs_info *fs_info,
+                                  struct btrfs_pending_snapshot *pending)
+{
+       int ret;
+       int namelen;
+       u64 index = 0;
+       struct btrfs_trans_handle *trans;
+       struct inode *parent_inode;
+       struct inode *inode;
+       struct btrfs_root *parent_root;
+
+       parent_inode = pending->dentry->d_parent->d_inode;
+       parent_root = BTRFS_I(parent_inode)->root;
+       trans = btrfs_start_transaction(parent_root, 1);
+
        /*
         * insert the directory item
         */
-       key.offset = (u64)-1;
        namelen = strlen(pending->name);
-       ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
-                                   pending->name, namelen,
-                                   root->fs_info->sb->s_root->d_inode->i_ino,
-                                   &key, BTRFS_FT_DIR, 0);
+       ret = btrfs_set_inode_index(parent_inode, &index);
+       ret = btrfs_insert_dir_item(trans, parent_root,
+                           pending->name, namelen,
+                           parent_inode->i_ino,
+                           &pending->root_key, BTRFS_FT_DIR, index);
 
        if (ret)
                goto fail;
 
-       ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
-                            pending->name, strlen(pending->name), objectid,
-                            root->fs_info->sb->s_root->d_inode->i_ino, 0);
+       /* add the backref first */
+       ret = btrfs_add_root_ref(trans, parent_root->fs_info->tree_root,
+                                pending->root_key.objectid,
+                                BTRFS_ROOT_BACKREF_KEY,
+                                parent_root->root_key.objectid,
+                                parent_inode->i_ino, index, pending->name,
+                                namelen);
+
+       BUG_ON(ret);
 
-       /* Invalidate existing dcache entry for new snapshot. */
-       btrfs_invalidate_dcache_root(root, pending->name, namelen);
+       /* now add the forward ref */
+       ret = btrfs_add_root_ref(trans, parent_root->fs_info->tree_root,
+                                parent_root->root_key.objectid,
+                                BTRFS_ROOT_REF_KEY,
+                                pending->root_key.objectid,
+                                parent_inode->i_ino, index, pending->name,
+                                namelen);
 
+       inode = btrfs_lookup_dentry(parent_inode, pending->dentry);
+       d_instantiate(pending->dentry, inode);
 fail:
-       kfree(new_root_item);
+       btrfs_end_transaction(trans, fs_info->fs_root);
        return ret;
 }
 
@@ -849,12 +852,28 @@ static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans,
 {
        struct btrfs_pending_snapshot *pending;
        struct list_head *head = &trans->transaction->pending_snapshots;
+       struct list_head *cur;
+       int ret;
+
+       list_for_each(cur, head) {
+               pending = list_entry(cur, struct btrfs_pending_snapshot, list);
+               ret = create_pending_snapshot(trans, fs_info, pending);
+               BUG_ON(ret);
+       }
+       return 0;
+}
+
+static noinline int finish_pending_snapshots(struct btrfs_trans_handle *trans,
+                                            struct btrfs_fs_info *fs_info)
+{
+       struct btrfs_pending_snapshot *pending;
+       struct list_head *head = &trans->transaction->pending_snapshots;
        int ret;
 
        while(!list_empty(head)) {
                pending = list_entry(head->next,
                                     struct btrfs_pending_snapshot, list);
-               ret = create_pending_snapshot(trans, fs_info, pending);
+               ret = finish_pending_snapshot(fs_info, pending);
                BUG_ON(ret);
                list_del(&pending->list);
                kfree(pending->name);
@@ -1019,7 +1038,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
        mutex_unlock(&root->fs_info->trans_mutex);
        ret = btrfs_write_and_wait_transaction(trans, root);
        BUG_ON(ret);
-       write_ctree_super(trans, root);
+       write_ctree_super(trans, root, 0);
 
        /*
         * the super is written, we can safely allow the tree-loggers
@@ -1033,11 +1052,15 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
        btrfs_drop_dead_reloc_roots(root);
        mutex_unlock(&root->fs_info->tree_reloc_mutex);
 
+       /* do the directory inserts of any pending snapshot creations */
+       finish_pending_snapshots(trans, root->fs_info);
+
        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);
 
@@ -1046,6 +1069,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
                list_splice_init(&root->fs_info->dead_roots, &dirty_fs_roots);
 
        mutex_unlock(&root->fs_info->trans_mutex);
+
        kmem_cache_free(btrfs_trans_handle_cachep, trans);
 
        if (root->fs_info->closing) {