> On Wed, Jan 15, 2014 at 7:23 PM, J. Bruce Fields <bfie...@fieldses.org> wrote:
> > Do you have a man page update somewhere for the two new flags?
Here's the updated man page (and attached the patch)
Michael, could you please review the interface?
I forgot to CC you when posing the patch series. I can resend it if you want,
or you can fetch the latest version of the cross-rename series from:
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs.git cross-rename
Thanks,
Miklos
----
RENAMEAT(2) Linux Programmer's Manual RENAMEAT(2)
NAME
renameat, renameat2 - rename a file relative to directory file descrip-
tors
SYNOPSIS
#include <fcntl.h> /* Definition of AT_* constants */
#include <stdio.h>
int renameat(int olddirfd, const char *oldpath,
int newdirfd, const char *newpath);
int renameat2(int olddirfd, const char *oldpath,
int newdirfd, const char *newpath, unsigned int flags);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
renameat():
Since glibc 2.10:
_XOPEN_SOURCE >= 700 || _POSIX_C_SOURCE >= 200809L
Before glibc 2.10:
_ATFILE_SOURCE
DESCRIPTION
The renameat() and renameat2() system calls operate in exactly the same
way as rename(2), except for the differences described in this manual
page.
If the pathname given in oldpath is relative, then it is interpreted
relative to the directory referred to by the file descriptor olddirfd
(rather than relative to the current working directory of the calling
process, as is done by rename(2) for a relative pathname).
If oldpath is relative and olddirfd is the special value AT_FDCWD, then
oldpath is interpreted relative to the current working directory of the
calling process (like rename(2)).
If oldpath is absolute, then olddirfd is ignored.
The interpretation of newpath is as for oldpath, except that a relative
pathname is interpreted relative to the directory referred to by the
file descriptor newdirfd.
renameat2() has an additional flags argument. renameat2() call with a
zero flags argument is equivalent to renameat().
The flags argument is a bitfield consisting of zero or more of the fol-
lowing constants defined in <linux/fs.h>:
RENAME_NOREPLACE
Don't overwrite the target of the rename. Return an error if
the target would be overwritten.
RENAME_EXCHANGE
Atomically exchange the source and destination. Both must exist
but may be of a different type (e.g. one a non-empty directory
and the other a symbolic link).
RETURN VALUE
On success, renameat() and renameat2() return 0. On error, -1 is
returned and errno is set to indicate the error.
ERRORS
The same errors that occur for rename(2) can also occur for renameat()
and renameat2(). The following additional errors can occur for
renameat() and renameat2():
EBADF olddirfd or newdirfd is not a valid file descriptor.
ENOTDIR
oldpath is relative and olddirfd is a file descriptor referring
to a file other than a directory; or similar for newpath and
newdirfd
The following additional errors are defined for renameat2():
EOPNOTSUPP
The filesystem does not support a flag in flags
EINVAL Invalid combination of flags
EEXIST flags contain RENAME_NOREPLACE and the target of the rename
exists
ENOENT flags contain RENAME_EXCHANGE and the target of the rename does
not exist
VERSIONS
renameat() was added to Linux in kernel 2.6.16; library support was
added to glibc in version 2.4.
CONFORMING TO
renameat() is specified in POSIX.1-2008.
NOTES
See openat(2) for an explanation of the need for renameat().
SEE ALSO
openat(2), rename(2), path_resolution(7)
Linux 2012-05-04 RENAMEAT(2)
diff --git a/man2/renameat.2 b/man2/renameat.2
index 432ddfd..e2f80d8 100644
--- a/man2/renameat.2
+++ b/man2/renameat.2
@@ -24,7 +24,7 @@
.\"
.TH RENAMEAT 2 2012-05-04 "Linux" "Linux Programmer's Manual"
.SH NAME
-renameat \- rename a file relative to directory file descriptors
+renameat, renameat2 \- rename a file relative to directory file descriptors
.SH SYNOPSIS
.nf
.B #include <fcntl.h> /* Definition of AT_* constants */
@@ -32,6 +32,9 @@ renameat \- rename a file relative to directory file descriptors
.sp
.BI "int renameat(int " olddirfd ", const char *" oldpath ,
.BI " int " newdirfd ", const char *" newpath );
+
+.BI "int renameat2(int " olddirfd ", const char *" oldpath ,
+.BI " int " newdirfd ", const char *" newpath ", unsigned int " flags );
.fi
.sp
.in -4n
@@ -55,7 +58,9 @@ _ATFILE_SOURCE
.SH DESCRIPTION
The
.BR renameat ()
-system call operates in exactly the same way as
+and
+.BR renameat2 ()
+system calls operate in exactly the same way as
.BR rename (2),
except for the differences described in this manual page.
@@ -94,10 +99,37 @@ is as for
except that a relative pathname is interpreted relative
to the directory referred to by the file descriptor
.IR newdirfd .
+
+.BR renameat2 ()
+has an additional
+.I flags
+argument.
+.BR renameat2 ()
+call with a zero
+.I flags
+argument is equivalent to
+.BR renameat ().
+
+The
+.I flags
+argument is a bitfield consisting of zero or more of the following
+constants defined in
+.IR <linux/fs.h> :
+.TP
+.B RENAME_NOREPLACE
+Don't overwrite the target of the rename. Return an error
+if the target would be overwritten.
+.TP
+.B RENAME_EXCHANGE
+Atomically exchange the source and destination. Both must exist
+but may be of a different type (e.g. one a non-empty directory
+and the other a symbolic link).
.SH RETURN VALUE
On success,
.BR renameat ()
-returns 0.
+and
+.BR renameat2 ()
+return 0.
On error, \-1 is returned and
.I errno
is set to indicate the error.
@@ -105,9 +137,13 @@ is set to indicate the error.
The same errors that occur for
.BR rename (2)
can also occur for
-.BR renameat ().
+.BR renameat ()
+and
+.BR renameat2 ().
The following additional errors can occur for
-.BR renameat ():
+.BR renameat ()
+and
+.BR renameat2 ():
.TP
.B EBADF
.I olddirfd
@@ -124,12 +160,37 @@ or similar for
.I newpath
and
.I newdirfd
+.RE
+.PP
+The following additional errors are defined for
+.BR renameat2 ():
+.TP
+.B EOPNOTSUPP
+The filesystem does not support a flag in
+.I flags
+.TP
+.B EINVAL
+Invalid combination of
+.I flags
+.TP
+.B EEXIST
+.I flags
+contain
+.B RENAME_NOREPLACE
+and the target of the rename exists
+.TP
+.B ENOENT
+.I flags
+contain
+.B RENAME_EXCHANGE
+and the target of the rename does not exist
.SH VERSIONS
.BR renameat ()
was added to Linux in kernel 2.6.16;
library support was added to glibc in version 2.4.
.SH CONFORMING TO
-POSIX.1-2008.
+.BR renameat ()
+is specified in POSIX.1-2008.
.SH NOTES
See
.BR openat (2)
