HardenedBSD/lib/libsys/undelete.2

.\" Copyright (c) 1994
.\"	Jan-Simon Pendry
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.Dd March 30, 2020
.Dt UNDELETE 2
.Os
.Sh NAME
.Nm undelete
.Nd attempt to recover a deleted file
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In unistd.h
.Ft int
.Fn undelete "const char *path"
.Sh DESCRIPTION
The
.Fn undelete
system call attempts to recover the deleted file named by
.Fa 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.
.Pp
Eventually, the
.Fn undelete
functionality may be expanded to other file systems able to recover
deleted files such as the log-structured file system.
.Sh RETURN VALUES
.Rv -std undelete
.Sh ERRORS
The
.Fn undelete
succeeds unless:
.Bl -tag -width Er
.It Bq Er ENOTDIR
A component of the path prefix is not a directory.
.It Bq Er ENAMETOOLONG
A component of a pathname exceeded 255 characters,
or an entire path name exceeded 1023 characters.
.It Bq Er EEXIST
The path does not reference a whiteout.
.It Bq Er ENOENT
The named whiteout does not exist.
.It Bq Er EACCES
Search permission is denied for a component of the path prefix.
.It Bq Er EACCES
Write permission is denied on the directory containing the name
to be undeleted.
.It Bq Er ELOOP
Too many symbolic links were encountered in translating the pathname.
.It Bq Er EPERM
The directory containing the name is marked sticky,
and the containing directory is not owned by the effective user ID.
.It Bq Er EINVAL
The last component of the path is
.Ql .. .
.It Bq Er EIO
An I/O error occurred while updating the directory entry.
.It Bq Er EINTEGRITY
Corrupted data was detected while reading from the file system.
.It Bq Er EROFS
The name resides on a read-only file system.
.It Bq Er EFAULT
The
.Fa path
argument
points outside the process's allocated address space.
.El
.Sh SEE ALSO
.Xr unlink 2 ,
.Xr mount_unionfs 8
.Sh HISTORY
The
.Fn undelete
system call first appeared in
.Bx 4.4 Lite .
Import CSRG 4.4BSD-Lite2 lib/libc onto vendor branch 1997-03-11 12:29:42 +01:00			`.\" Copyright (c) 1994`
			`.\" Jan-Simon Pendry`
			`.\" The Regents of the University of California. All rights reserved.`
			`.\"`
			`.\" Redistribution and use in source and binary forms, with or without`
			`.\" modification, are permitted provided that the following conditions`
			`.\" are met:`
			`.\" 1. Redistributions of source code must retain the above copyright`
			`.\" notice, this list of conditions and the following disclaimer.`
			`.\" 2. Redistributions in binary form must reproduce the above copyright`
			`.\" notice, this list of conditions and the following disclaimer in the`
			`.\" documentation and/or other materials provided with the distribution.`
Renumber copyright clause 4 Renumber cluase 4 to 3, per what everybody else did when BSD granted them permission to remove clause 3. My insistance on keeping the same numbering for legal reasons is too pedantic, so give up on that point. Submitted by: Jan Schaumann <jschauma@stevens.edu> Pull Request: https://github.com/freebsd/freebsd/pull/96 2017-03-01 00:42:47 +01:00			`.\" 3. Neither the name of the University nor the names of its contributors`
Import CSRG 4.4BSD-Lite2 lib/libc onto vendor branch 1997-03-11 12:29:42 +01:00			`.\" may be used to endorse or promote products derived from this software`
			`.\" without specific prior written permission.`
			`.\"`
			.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
			`.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE`
			`.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE`
			`.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE`
			`.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL`
			`.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS`
			`.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)`
			`.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT`
			`.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY`
			`.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF`
			`.\" SUCH DAMAGE.`
			`.\"`
Document EINTEGRITY errors for many system calls. EINTEGRITY was previously documented as a UFS-specific error for mount(2). This documents EINTEGRITY as a filesystem-independent error that may be reported by the backing store of a filesystem. While here, document EIO as a filesystem-independent error for both mount(2) and posix_fadvise(2). EIO was previously only documented for UFS for mount(2). Reviewed by: mckusick Suggested by: mckusick MFC after: 2 weeks Sponsored by: Chelsio Communications Differential Revision: https://reviews.freebsd.org/D24168 2020-03-30 23:44:00 +02:00			`.Dd March 30, 2020`
Import CSRG 4.4BSD-Lite2 lib/libc onto vendor branch 1997-03-11 12:29:42 +01:00			`.Dt UNDELETE 2`
mdoc(7) police: removed HISTORY info from the .Os call. 2001-07-10 15:41:46 +02:00			`.Os`
Import CSRG 4.4BSD-Lite2 lib/libc onto vendor branch 1997-03-11 12:29:42 +01:00			`.Sh NAME`
			`.Nm undelete`
			`.Nd attempt to recover a deleted file`
Introduce ".Lb" macro to libc manpages. More libraries manpages updates following. 2000-04-21 11:42:15 +02:00			`.Sh LIBRARY`
			`.Lb libc`
Import CSRG 4.4BSD-Lite2 lib/libc onto vendor branch 1997-03-11 12:29:42 +01:00			`.Sh SYNOPSIS`
mdoc(7) police: Use the new .In macro for #include statements. 2001-10-01 18:09:29 +02:00			`.In unistd.h`
Import CSRG 4.4BSD-Lite2 lib/libc onto vendor branch 1997-03-11 12:29:42 +01:00			`.Ft int`
			`.Fn undelete "const char *path"`
			`.Sh DESCRIPTION`
			`The`
			`.Fn undelete`
mdoc(7) police: Tidy up the syscall language. Stop calling system calls "function calls". Use "The .Fn system call" a-la "The .Nm utility". When referring to a non-BSD implementation in the HISTORY section, call syscall a function, to be safe. 2002-12-18 10:22:32 +01:00			`system call attempts to recover the deleted file named by`
Import CSRG 4.4BSD-Lite2 lib/libc onto vendor branch 1997-03-11 12:29:42 +01:00			`.Fa path .`
			`Currently, this works only when the named object`
Uniformly refer to a file system as "file system". Approved by: re 2002-12-12 18:26:04 +01:00			`is a whiteout in a union file system.`
Import CSRG 4.4BSD-Lite2 lib/libc onto vendor branch 1997-03-11 12:29:42 +01:00			`The system call removes the whiteout causing`
			`any objects in a lower layer of the`
			`union stack to become visible once more.`
			`.Pp`
			`Eventually, the`
mdoc(7) police: Nm -> Fn where appropriate. 2000-11-20 15:11:46 +01:00			`.Fn undelete`
Uniformly refer to a file system as "file system". Approved by: re 2002-12-12 18:26:04 +01:00			`functionality may be expanded to other file systems able to recover`
			`deleted files such as the log-structured file system.`
Import CSRG 4.4BSD-Lite2 lib/libc onto vendor branch 1997-03-11 12:29:42 +01:00			`.Sh RETURN VALUES`
Use the ``.Rv -std'' mdoc(7) macro in appropriate cases. Reviewed by: ru 2001-08-09 15:32:13 +02:00			`.Rv -std undelete`
Import CSRG 4.4BSD-Lite2 lib/libc onto vendor branch 1997-03-11 12:29:42 +01:00			`.Sh ERRORS`
			`The`
			`.Fn undelete`
			`succeeds unless:`
Use `Er' variable to define first column width in ERRORS section. It was initially suggested by mdoc(7) style, but was broken over the years 2000-05-04 15:09:25 +02:00			`.Bl -tag -width Er`
Import CSRG 4.4BSD-Lite2 lib/libc onto vendor branch 1997-03-11 12:29:42 +01:00			`.It Bq Er ENOTDIR`
			`A component of the path prefix is not a directory.`
			`.It Bq Er ENAMETOOLONG`
			`A component of a pathname exceeded 255 characters,`
			`or an entire path name exceeded 1023 characters.`
			`.It Bq Er EEXIST`
			`The path does not reference a whiteout.`
			`.It Bq Er ENOENT`
			`The named whiteout does not exist.`
			`.It Bq Er EACCES`
			`Search permission is denied for a component of the path prefix.`
			`.It Bq Er EACCES`
			`Write permission is denied on the directory containing the name`
			`to be undeleted.`
			`.It Bq Er ELOOP`
			`Too many symbolic links were encountered in translating the pathname.`
			`.It Bq Er EPERM`
			`The directory containing the name is marked sticky,`
			`and the containing directory is not owned by the effective user ID.`
Back out the previous change to rename.2. The previous rename() behaviour of returning EINVAL when ".." is passed as either argument has been restored. rmdir("..") now returns EINVAL instead of EPERM. Document the previously undocumented behaviour of rmdir(".") returning EINVAL as required by POSIX and SUSv3. Bump the man page change date. undelete("..") now returns EINVAL instead of EPERM. Bump the man page change date. MFC after: 3 days 2006-01-22 20:49:37 +01:00			`.It Bq Er EINVAL`
			`The last component of the path is`
rename(), rmdir(), and undelete() fail with EPERM if the last component of the path is "..". MFC after: 3 days 2006-01-21 21:45:45 +01:00			`.Ql .. .`
Import CSRG 4.4BSD-Lite2 lib/libc onto vendor branch 1997-03-11 12:29:42 +01:00			`.It Bq Er EIO`
			`An I/O error occurred while updating the directory entry.`
Document EINTEGRITY errors for many system calls. EINTEGRITY was previously documented as a UFS-specific error for mount(2). This documents EINTEGRITY as a filesystem-independent error that may be reported by the backing store of a filesystem. While here, document EIO as a filesystem-independent error for both mount(2) and posix_fadvise(2). EIO was previously only documented for UFS for mount(2). Reviewed by: mckusick Suggested by: mckusick MFC after: 2 weeks Sponsored by: Chelsio Communications Differential Revision: https://reviews.freebsd.org/D24168 2020-03-30 23:44:00 +02:00			`.It Bq Er EINTEGRITY`
			`Corrupted data was detected while reading from the file system.`
Import CSRG 4.4BSD-Lite2 lib/libc onto vendor branch 1997-03-11 12:29:42 +01:00			`.It Bq Er EROFS`
			`The name resides on a read-only file system.`
			`.It Bq Er EFAULT`
mdoc(7) police: "The .Fa argument.". 2002-12-19 10:40:28 +01:00			`The`
			`.Fa path`
			`argument`
Import CSRG 4.4BSD-Lite2 lib/libc onto vendor branch 1997-03-11 12:29:42 +01:00			`points outside the process's allocated address space.`
			`.El`
			`.Sh SEE ALSO`
			`.Xr unlink 2 ,`
Rename (after a repo-copy) some mount(8) programs: mount_fdesc -> mount_fdescfs mount_null -> mount_nullfs mount_portal -> mount_portalfs mount_umap -> mount_umapfs mount_union -> mount_unionfs 2001-05-23 16:58:19 +02:00			`.Xr mount_unionfs 8`
Import CSRG 4.4BSD-Lite2 lib/libc onto vendor branch 1997-03-11 12:29:42 +01:00			`.Sh HISTORY`
mdoc(7) police: Tidy up the syscall language. Stop calling system calls "function calls". Use "The .Fn system call" a-la "The .Nm utility". When referring to a non-BSD implementation in the HISTORY section, call syscall a function, to be safe. 2002-12-18 10:22:32 +01:00			`The`
mdoc(7) police: Nm -> Fn where appropriate. 2000-11-20 15:11:46 +01:00			`.Fn undelete`
mdoc(7) police: Tidy up the syscall language. Stop calling system calls "function calls". Use "The .Fn system call" a-la "The .Nm utility". When referring to a non-BSD implementation in the HISTORY section, call syscall a function, to be safe. 2002-12-18 10:22:32 +01:00			`system call first appeared in`
mdoc(7) police: s/BSD/.Bx/ where appropriate. 2001-08-14 12:01:54 +02:00			`.Bx 4.4 Lite .`