hfs: prevent btree data loss on ENOSPC

[linux-2.6-microblaze.git] / fs / hfs / btree.c

diff --git a/fs/hfs/btree.c b/fs/hfs/btree.c
index 374b568..98b96ff 100644 (file)
--- a/fs/hfs/btree.c
+++ b/fs/hfs/btree.c
@@ -220,25 +220,17 @@ static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx)
        return node;
 }
 
-struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree)
+/* Make sure @tree has enough space for the @rsvd_nodes */
+int hfs_bmap_reserve(struct hfs_btree *tree, int rsvd_nodes)
 {
-       struct hfs_bnode *node, *next_node;
-       struct page **pagep;
-       u32 nidx, idx;
-       unsigned off;
-       u16 off16;
-       u16 len;
-       u8 *data, byte, m;
-       int i;
-
-       while (!tree->free_nodes) {
-               struct inode *inode = tree->inode;
-               u32 count;
-               int res;
+       struct inode *inode = tree->inode;
+       u32 count;
+       int res;
 
+       while (tree->free_nodes < rsvd_nodes) {
                res = hfs_extend_file(inode);
                if (res)
-                       return ERR_PTR(res);
+                       return res;
                HFS_I(inode)->phys_size = inode->i_size =
                                (loff_t)HFS_I(inode)->alloc_blocks *
                                HFS_SB(tree->sb)->alloc_blksz;
@@ -246,9 +238,26 @@ struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree)
                                          tree->sb->s_blocksize_bits;
                inode_set_bytes(inode, inode->i_size);
                count = inode->i_size >> tree->node_size_shift;
-               tree->free_nodes = count - tree->node_count;
+               tree->free_nodes += count - tree->node_count;
                tree->node_count = count;
        }
+       return 0;
+}
+
+struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree)
+{
+       struct hfs_bnode *node, *next_node;
+       struct page **pagep;
+       u32 nidx, idx;
+       unsigned off;
+       u16 off16;
+       u16 len;
+       u8 *data, byte, m;
+       int i, res;
+
+       res = hfs_bmap_reserve(tree, 1);
+       if (res)
+               return ERR_PTR(res);
 
        nidx = 0;
        node = hfs_bnode_find(tree, nidx);