System and method for performing an on-line check of a file system

1. A method for checking a file system implemented by a storage operating system while the file system is available for data access, the method comprising the steps of:

suspending data access to the file system;

unmounting a volume associated with the file system;

modifying a load function in the storage operating system so that the load function performs a checking procedure before returning a requested file system structure;

mounting the volume;

resuming data access to the file system;

loading a file system structure requested by the modified load function;

determining a type of the file system structure;

performing, in response to the file system structure being a directory, a directory checking procedure;

performing, in response to the file system structure being a regular file, an inode checking procedure;

verifying a set of pointers in a buffer tree associated with the inode;

removing any cross links within any buffer tree associated with the inode;

removing all but a first pointer to any block within a buffer tree associated with the inode; and

marking the inode as being checked.

2. The method of claim 1 wherein the step of marking the inode as being checked further comprises modifying an entry in a tracking file, the tracking file stored in the file system.

3. A method for checking a file system implemented by a storage operating system while the file system is available for data access, the method comprising the steps of:

suspending data access to the file system;

unmounting a volume associated with the file system;

modifying a load function in the storage operating system so that the load function performs a checking procedure before returning a requested file system structure;

mounting the volume;

resuming data access to the file system;

loading a file system structure requested by the modified load function;

determining a type of the file system structure;

performing, in response to the file system structure being a directory, a directory checking procedure;

performing, in response to the file system structure being a regular file, an inode checking procedure;

determining if the directory links to a root directory;

determining, in response to the directory not linking to the root directory, if the directory comprises of a special directory;

linking, in response to the directory not linking to the root directory and the directory not comprising a special directory, the directory to a lost and found directory;

loading, using the modified load function, all file system objects in a layer immediately beneath the directory;

verifying a set of pointers in a buffer tree associated with the directory;

removing any cross links within any buffer tree associated with the directory;

removing all but a first pointer to any block within a buffer tree associated with the directory; and

marking the directory as being checked.

4. The method of claim 3 wherein the file system objects in a layer immediately beneath the directory comprises directories.

5. The method of claim 3 wherein the file system objects in a layer immediately beneath the directory comprises files.