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.
- [
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.