Btrfs: split up super.c

[linux-2.6-block.git] / fs / btrfs / disk-io.c

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 8a88404525e81f921a5fd336da476a3a05b23b01..96bf3ef3a798f17f42c551ff23ecc226a2c0e406 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -22,7 +22,7 @@ static int check_tree_block(struct btrfs_root *root, struct buffer_head *buf)
        if (bh_blocknr(buf) != btrfs_header_blocknr(&node->header)) {
                printk(KERN_CRIT "bh_blocknr(buf) is %Lu, header is %Lu\n",
                       bh_blocknr(buf), btrfs_header_blocknr(&node->header));
-               BUG();
+               return 1;
        }
        return 0;
 }
@@ -253,7 +253,7 @@ uptodate:
                set_buffer_checked(bh);
        }
        if (check_tree_block(root, bh))
-               BUG();
+               goto fail;
        return bh;
 fail:
        brelse(bh);
@@ -398,8 +398,13 @@ struct btrfs_root *open_ctree(struct super_block *sb)
        struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info),
                                                GFP_NOFS);
        int ret;
+       int err = -EIO;
        struct btrfs_super_block *disk_super;
 
+       if (!extent_root || !tree_root || !fs_info) {
+               err = -ENOMEM;
+               goto fail;
+       }
        init_bit_radix(&fs_info->pinned_radix);
        init_bit_radix(&fs_info->pending_del_radix);
        init_bit_radix(&fs_info->extent_map_radix);
@@ -431,9 +436,11 @@ struct btrfs_root *open_ctree(struct super_block *sb)
        mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
        fs_info->hash_tfm = crypto_alloc_hash("crc32c", 0, CRYPTO_ALG_ASYNC);
        spin_lock_init(&fs_info->hash_lock);
+
        if (!fs_info->hash_tfm || IS_ERR(fs_info->hash_tfm)) {
-               printk("failed to allocate digest hash\n");
-               return NULL;
+               printk("btrfs: failed hash setup, modprobe cryptomgr?\n");
+               err = -ENOMEM;
+               goto fail_iput;
        }
        mutex_init(&fs_info->trans_mutex);
        mutex_init(&fs_info->fs_mutex);
@@ -446,30 +453,53 @@ struct btrfs_root *open_ctree(struct super_block *sb)
                                             sb->s_blocksize);
 
        if (!fs_info->sb_buffer)
-               return NULL;
+               goto fail_iput;
        disk_super = (struct btrfs_super_block *)fs_info->sb_buffer->b_data;
+
        if (!btrfs_super_root(disk_super))
-               return NULL;
+               goto fail_sb_buffer;
 
        i_size_write(fs_info->btree_inode,
                     btrfs_super_total_blocks(disk_super) <<
                     fs_info->btree_inode->i_blkbits);
 
        fs_info->disk_super = disk_super;
+
+       if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
+                   sizeof(disk_super->magic))) {
+               printk("btrfs: valid FS not found on %s\n", sb->s_id);
+               goto fail_sb_buffer;
+       }
        tree_root->node = read_tree_block(tree_root,
                                          btrfs_super_root(disk_super));
-       BUG_ON(!tree_root->node);
+       if (!tree_root->node)
+               goto fail_sb_buffer;
 
        mutex_lock(&fs_info->fs_mutex);
        ret = find_and_setup_root(sb->s_blocksize, tree_root, fs_info,
                                  BTRFS_EXTENT_TREE_OBJECTID, extent_root);
-       BUG_ON(ret);
+       if (ret) {
+               mutex_unlock(&fs_info->fs_mutex);
+               goto fail_tree_root;
+       }
 
        btrfs_read_block_groups(extent_root);
 
        fs_info->generation = btrfs_super_generation(disk_super) + 1;
        mutex_unlock(&fs_info->fs_mutex);
        return tree_root;
+
+fail_tree_root:
+       btrfs_block_release(tree_root, tree_root->node);
+fail_sb_buffer:
+       btrfs_block_release(tree_root, fs_info->sb_buffer);
+fail_iput:
+       iput(fs_info->btree_inode);
+fail:
+       kfree(extent_root);
+       kfree(tree_root);
+       kfree(fs_info);
+       return ERR_PTR(err);
 }
 
 int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root