NAME

       undelete — attempt to recover a deleted file

LIBRARY

       Standard C Library (libc, -lc)

SYNOPSIS

       #include <unistd.h>

       int
       undelete(const char *path);

DESCRIPTION

       The  undelete()  system  call  attempts to recover the deleted file named by path.  Currently, this works
       only when the named object is a whiteout in a union file system.  The system call  removes  the  whiteout
       causing any objects in a lower layer of the union stack to become visible once more.

       Eventually,  the  undelete()  functionality may be expanded to other file systems able to recover deleted
       files such as the log-structured file system.

RETURN VALUES

       The undelete() function returns the value 0 if successful; otherwise the value -1  is  returned  and  the
       global variable errno is set to indicate the error.

ERRORS

       The undelete() succeeds unless:

       [ENOTDIR]          A component of the path prefix is not a directory.

       [ENAMETOOLONG]     A  component  of  a  pathname exceeded 255 characters, or an entire path name exceeded
                          1023 characters.

       [EEXIST]           The path does not reference a whiteout.

       [ENOENT]           The named whiteout does not exist.

       [EACCES]           Search permission is denied for a component of the path prefix.

       [EACCES]           Write permission is denied on the directory containing the name to be undeleted.

       [ELOOP]            Too many symbolic links were encountered in translating the pathname.

       [EPERM]            The directory containing the name is marked sticky, and the  containing  directory  is
                          not owned by the effective user ID.

       [EINVAL]           The last component of the path is ‘..’.

       [EIO]              An I/O error occurred while updating the directory entry.

       [EINTEGRITY]       Corrupted data was detected while reading from the file system.

       [EROFS]            The name resides on a read-only file system.

       [EFAULT]           The path argument points outside the process's allocated address space.

SEE ALSO

       unlink(2), mount_unionfs(8)

HISTORY

       The undelete() system call first appeared in 4.4BSD-Lite.

Debian                                           March 30, 2020                                      UNDELETE(2)