ext4: enable "punch hole" functionality

[pandora-kernel.git] / fs / ext4 / inode.c

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index fbe11e6..65576c0 100644 (file)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4418,6 +4418,31 @@ int ext4_can_truncate(struct inode *inode)
        return 0;
 }
 
+/*
+ * ext4_punch_hole: punches a hole in a file by releaseing the blocks
+ * associated with the given offset and length
+ *
+ * @inode:  File inode
+ * @offset: The offset where the hole will begin
+ * @len:    The length of the hole
+ *
+ * Returns: 0 on sucess or negative on failure
+ */
+
+int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
+{
+       struct inode *inode = file->f_path.dentry->d_inode;
+       if (!S_ISREG(inode->i_mode))
+               return -ENOTSUPP;
+
+       if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
+               /* TODO: Add support for non extent hole punching */
+               return -ENOTSUPP;
+       }
+
+       return ext4_ext_punch_hole(file, offset, length);
+}
+
 /*
  * ext4_truncate()
  *