new helper: mount_subtree()
[pandora-kernel.git] / fs / btrfs / transaction.c
index e24b796..6a0574e 100644 (file)
@@ -55,6 +55,7 @@ static noinline int join_transaction(struct btrfs_root *root, int nofail)
        struct btrfs_transaction *cur_trans;
 
        spin_lock(&root->fs_info->trans_lock);
+loop:
        if (root->fs_info->trans_no_join) {
                if (!nofail) {
                        spin_unlock(&root->fs_info->trans_lock);
@@ -75,16 +76,18 @@ static noinline int join_transaction(struct btrfs_root *root, int nofail)
        cur_trans = kmem_cache_alloc(btrfs_transaction_cachep, GFP_NOFS);
        if (!cur_trans)
                return -ENOMEM;
+
        spin_lock(&root->fs_info->trans_lock);
        if (root->fs_info->running_transaction) {
+               /*
+                * someone started a transaction after we unlocked.  Make sure
+                * to redo the trans_no_join checks above
+                */
                kmem_cache_free(btrfs_transaction_cachep, cur_trans);
                cur_trans = root->fs_info->running_transaction;
-               atomic_inc(&cur_trans->use_count);
-               atomic_inc(&cur_trans->num_writers);
-               cur_trans->num_joined++;
-               spin_unlock(&root->fs_info->trans_lock);
-               return 0;
+               goto loop;
        }
+
        atomic_set(&cur_trans->num_writers, 1);
        cur_trans->num_joined = 0;
        init_waitqueue_head(&cur_trans->writer_wait);
@@ -275,7 +278,7 @@ static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
         */
        if (num_items > 0 && root != root->fs_info->chunk_root) {
                num_bytes = btrfs_calc_trans_metadata_size(root, num_items);
-               ret = btrfs_block_rsv_add(NULL, root,
+               ret = btrfs_block_rsv_add(root,
                                          &root->fs_info->trans_block_rsv,
                                          num_bytes);
                if (ret)
@@ -418,8 +421,8 @@ static int should_end_transaction(struct btrfs_trans_handle *trans,
                                  struct btrfs_root *root)
 {
        int ret;
-       ret = btrfs_block_rsv_check(trans, root,
-                                   &root->fs_info->global_block_rsv, 0, 5);
+
+       ret = btrfs_block_rsv_check(root, &root->fs_info->global_block_rsv, 5);
        return ret ? 1 : 0;
 }
 
@@ -427,17 +430,26 @@ int btrfs_should_end_transaction(struct btrfs_trans_handle *trans,
                                 struct btrfs_root *root)
 {
        struct btrfs_transaction *cur_trans = trans->transaction;
+       struct btrfs_block_rsv *rsv = trans->block_rsv;
        int updates;
 
        smp_mb();
        if (cur_trans->blocked || cur_trans->delayed_refs.flushing)
                return 1;
 
+       /*
+        * We need to do this in case we're deleting csums so the global block
+        * rsv get's used instead of the csum block rsv.
+        */
+       trans->block_rsv = NULL;
+
        updates = trans->delayed_ref_updates;
        trans->delayed_ref_updates = 0;
        if (updates)
                btrfs_run_delayed_refs(trans, root, updates);
 
+       trans->block_rsv = rsv;
+
        return should_end_transaction(trans, root);
 }
 
@@ -453,6 +465,8 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
                return 0;
        }
 
+       btrfs_trans_release_metadata(trans, root);
+       trans->block_rsv = NULL;
        while (count < 4) {
                unsigned long cur = trans->delayed_ref_updates;
                trans->delayed_ref_updates = 0;
@@ -473,8 +487,6 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
                count++;
        }
 
-       btrfs_trans_release_metadata(trans, root);
-
        if (lock && !atomic_read(&root->fs_info->open_ioctl_trans) &&
            should_end_transaction(trans, root)) {
                trans->transaction->blocked = 1;
@@ -562,50 +574,21 @@ int btrfs_end_transaction_dmeta(struct btrfs_trans_handle *trans,
 int btrfs_write_marked_extents(struct btrfs_root *root,
                               struct extent_io_tree *dirty_pages, int mark)
 {
-       int ret;
        int err = 0;
        int werr = 0;
-       struct page *page;
-       struct inode *btree_inode = root->fs_info->btree_inode;
+       struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
        u64 start = 0;
        u64 end;
-       unsigned long index;
-
-       while (1) {
-               ret = find_first_extent_bit(dirty_pages, start, &start, &end,
-                                           mark);
-               if (ret)
-                       break;
-               while (start <= end) {
-                       cond_resched();
-
-                       index = start >> PAGE_CACHE_SHIFT;
-                       start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
-                       page = find_get_page(btree_inode->i_mapping, index);
-                       if (!page)
-                               continue;
-
-                       btree_lock_page_hook(page);
-                       if (!page->mapping) {
-                               unlock_page(page);
-                               page_cache_release(page);
-                               continue;
-                       }
 
-                       if (PageWriteback(page)) {
-                               if (PageDirty(page))
-                                       wait_on_page_writeback(page);
-                               else {
-                                       unlock_page(page);
-                                       page_cache_release(page);
-                                       continue;
-                               }
-                       }
-                       err = write_one_page(page, 0);
-                       if (err)
-                               werr = err;
-                       page_cache_release(page);
-               }
+       while (!find_first_extent_bit(dirty_pages, start, &start, &end,
+                                     mark)) {
+               convert_extent_bit(dirty_pages, start, end, EXTENT_NEED_WAIT, mark,
+                                  GFP_NOFS);
+               err = filemap_fdatawrite_range(mapping, start, end);
+               if (err)
+                       werr = err;
+               cond_resched();
+               start = end + 1;
        }
        if (err)
                werr = err;
@@ -621,39 +604,20 @@ int btrfs_write_marked_extents(struct btrfs_root *root,
 int btrfs_wait_marked_extents(struct btrfs_root *root,
                              struct extent_io_tree *dirty_pages, int mark)
 {
-       int ret;
        int err = 0;
        int werr = 0;
-       struct page *page;
-       struct inode *btree_inode = root->fs_info->btree_inode;
+       struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
        u64 start = 0;
        u64 end;
-       unsigned long index;
-
-       while (1) {
-               ret = find_first_extent_bit(dirty_pages, start, &start, &end,
-                                           mark);
-               if (ret)
-                       break;
 
-               clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS);
-               while (start <= end) {
-                       index = start >> PAGE_CACHE_SHIFT;
-                       start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
-                       page = find_get_page(btree_inode->i_mapping, index);
-                       if (!page)
-                               continue;
-                       if (PageDirty(page)) {
-                               btree_lock_page_hook(page);
-                               wait_on_page_writeback(page);
-                               err = write_one_page(page, 0);
-                               if (err)
-                                       werr = err;
-                       }
-                       wait_on_page_writeback(page);
-                       page_cache_release(page);
-                       cond_resched();
-               }
+       while (!find_first_extent_bit(dirty_pages, start, &start, &end,
+                                     EXTENT_NEED_WAIT)) {
+               clear_extent_bits(dirty_pages, start, end, EXTENT_NEED_WAIT, GFP_NOFS);
+               err = filemap_fdatawait_range(mapping, start, end);
+               if (err)
+                       werr = err;
+               cond_resched();
+               start = end + 1;
        }
        if (err)
                werr = err;
@@ -673,7 +637,12 @@ int btrfs_write_and_wait_marked_extents(struct btrfs_root *root,
 
        ret = btrfs_write_marked_extents(root, dirty_pages, mark);
        ret2 = btrfs_wait_marked_extents(root, dirty_pages, mark);
-       return ret || ret2;
+
+       if (ret)
+               return ret;
+       if (ret2)
+               return ret2;
+       return 0;
 }
 
 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
@@ -911,11 +880,10 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
        }
 
        btrfs_reloc_pre_snapshot(trans, pending, &to_reserve);
-       btrfs_orphan_pre_snapshot(trans, pending, &to_reserve);
 
        if (to_reserve > 0) {
-               ret = btrfs_block_rsv_add(trans, root, &pending->block_rsv,
-                                         to_reserve);
+               ret = btrfs_block_rsv_add_noflush(root, &pending->block_rsv,
+                                                 to_reserve);
                if (ret) {
                        pending->error = ret;
                        goto fail;
@@ -1002,7 +970,6 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
        BUG_ON(IS_ERR(pending->snap));
 
        btrfs_reloc_post_snapshot(trans, pending);
-       btrfs_orphan_post_snapshot(trans, pending);
 fail:
        kfree(new_root_item);
        trans->block_rsv = rsv;
@@ -1032,7 +999,7 @@ static void update_super_roots(struct btrfs_root *root)
        struct btrfs_root_item *root_item;
        struct btrfs_super_block *super;
 
-       super = &root->fs_info->super_copy;
+       super = root->fs_info->super_copy;
 
        root_item = &root->fs_info->chunk_root->root_item;
        super->chunk_root = root_item->bytenr;
@@ -1043,7 +1010,7 @@ static void update_super_roots(struct btrfs_root *root)
        super->root = root_item->bytenr;
        super->generation = root_item->generation;
        super->root_level = root_item->level;
-       if (super->cache_generation != 0 || btrfs_test_opt(root, SPACE_CACHE))
+       if (btrfs_test_opt(root, SPACE_CACHE))
                super->cache_generation = root_item->generation;
 }
 
@@ -1168,14 +1135,15 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 
        btrfs_run_ordered_operations(root, 0);
 
+       btrfs_trans_release_metadata(trans, root);
+       trans->block_rsv = NULL;
+
        /* make a pass through all the delayed refs we have so far
         * any runnings procs may add more while we are here
         */
        ret = btrfs_run_delayed_refs(trans, root, 0);
        BUG_ON(ret);
 
-       btrfs_trans_release_metadata(trans, root);
-
        cur_trans = trans->transaction;
        /*
         * set the flushing flag so procs in this transaction have to
@@ -1341,12 +1309,12 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
        update_super_roots(root);
 
        if (!root->fs_info->log_root_recovering) {
-               btrfs_set_super_log_root(&root->fs_info->super_copy, 0);
-               btrfs_set_super_log_root_level(&root->fs_info->super_copy, 0);
+               btrfs_set_super_log_root(root->fs_info->super_copy, 0);
+               btrfs_set_super_log_root_level(root->fs_info->super_copy, 0);
        }
 
-       memcpy(&root->fs_info->super_for_commit, &root->fs_info->super_copy,
-              sizeof(root->fs_info->super_copy));
+       memcpy(root->fs_info->super_for_commit, root->fs_info->super_copy,
+              sizeof(*root->fs_info->super_copy));
 
        trans->transaction->blocked = 0;
        spin_lock(&root->fs_info->trans_lock);