Btrfs: split up super.c

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

1 files changed, 38 insertions, 8 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 8a88404525e8..96bf3ef3a798 100644
--- 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