commit: 117869a1b0d19c5e3a6b59e9e43e6849ed92efd4
Author: Fabian Groffen <grobian <AT> gentoo <DOT> org>
AuthorDate: Sun Dec 26 13:48:49 2021 +0000
Commit: Fabian Groffen <grobian <AT> gentoo <DOT> org>
CommitDate: Sun Dec 26 13:48:49 2021 +0000
URL: https://gitweb.gentoo.org/proj/portage-utils.git/commit/?id=117869a1
libq/move_file: code to move a file or copy+remove it
This code originated from qmerge.c, it was adapted to be more generic in
a function.
Signed-off-by: Fabian Groffen <grobian <AT> gentoo.org>
libq/Makefile.am | 1 +
libq/move_file.c | 105 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
libq/move_file.h | 21 +++++++++++
3 files changed, 127 insertions(+)
diff --git a/libq/Makefile.am b/libq/Makefile.am
index da100b6..c0402a4 100644
--- a/libq/Makefile.am
+++ b/libq/Makefile.am
@@ -11,6 +11,7 @@ QFILES = \
hash.c hash.h \
human_readable.c human_readable.h \
i18n.h \
+ move_file.c move_file.h \
prelink.c prelink.h \
profile.c profile.h \
rmspace.c rmspace.h \
diff --git a/libq/move_file.c b/libq/move_file.c
new file mode 100644
index 0000000..07cf69f
--- /dev/null
+++ b/libq/move_file.c
@@ -0,0 +1,105 @@
+/*
+ * Copyright 2005-2021 Gentoo Authors
+ * Distributed under the terms of the GNU General Public License v2
+ *
+ * Copyright 2005-2010 Ned Ludd - <so...@gentoo.org>
+ * Copyright 2005-2014 Mike Frysinger - <vap...@gentoo.org>
+ * Copyright 2018- Fabian Groffen - <grob...@gentoo.org>
+ */
+
+#include "main.h"
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include "stat-time.h"
+
+#include "copy_file.h"
+#include "move_file.h"
+
+int
+move_file(int rootfd_src, const char *name_src,
+ int rootfd_dst, const char *name_dst,
+ struct stat *stat_src)
+{
+ /* first try fast path -- src/dst are same device, else
+ * fall back to slow path -- manual read/write */
+ if (renameat(rootfd_src, name_src, rootfd_dst, name_dst) != 0) {
+ int fd_src;
+ int fd_dst;
+ char tmpname_dst[_Q_PATH_MAX];
+ struct stat st;
+ struct timespec times[2];
+
+ fd_src = openat(rootfd_src, name_src, O_RDONLY|O_CLOEXEC);
+ if (fd_src < 0) {
+ warnp("could not read source file %s", name_src);
+ return fd_src;
+ }
+
+ if (stat_src == NULL) {
+ if (fstat(fd_src, &st) != 0) {
+ warnp("could not stat source file %s",
name_src);
+ return -1;
+ }
+
+ stat_src = &st;
+ }
+
+ /* do not write the file in place ...
+ * will fail with files that are in use
+ * plus it isn't atomic, so we could leave a mess */
+ snprintf(tmpname_dst, sizeof(tmpname_dst), ".%u.%s",
+ getpid(), name_dst);
+ fd_dst = openat(rootfd_dst, tmpname_dst,
+
O_WRONLY|O_CLOEXEC|O_CREAT|O_TRUNC,
+ stat_src->st_mode);
+ if (fd_dst < 0) {
+ warnp("could not open destination file %s (for %s)",
+ tmpname_dst, name_dst);
+ close(fd_src);
+ return fd_dst;
+ }
+
+ /* make sure owner/mode is sane before we write out data */
+ if (fchown(fd_dst, stat_src->st_uid, stat_src->st_gid) != 0) {
+ warnp("could not set ownership (%zu/%zu) for %s",
+ (size_t)stat_src->st_uid,
(size_t)stat_src->st_gid, name_dst);
+ return -1;
+ }
+ if (fchmod(fd_dst, stat_src->st_mode) != 0) {
+ warnp("could not set permission (%u) for %s",
+ (int)stat_src->st_mode, name_dst);
+ return -1;
+ }
+
+ /* do the actual data copy */
+ if (copy_file_fd(fd_src, fd_dst)) {
+ warnp("could not write to file %s", name_dst);
+ if (unlinkat(rootfd_dst, tmpname_dst, 0) != 0) {
+ /* don't care */;
+ }
+ close(fd_src);
+ close(fd_dst);
+ return -1;
+ }
+
+ /* Preserve the file times */
+ times[0] = get_stat_atime(&st);
+ times[1] = get_stat_mtime(&st);
+ futimens(fd_dst, times);
+
+ close(fd_src);
+ close(fd_dst);
+
+ /* finally move the new tmp dst file to the right place, which
+ * should be on the same FS/device now */
+ if (renameat(rootfd_dst, tmpname_dst, rootfd_dst, name_dst)) {
+ warnp("could not rename %s to %s", tmpname_dst,
name_dst);
+ return -1;
+ }
+ }
+
+ return 0;
+}
diff --git a/libq/move_file.h b/libq/move_file.h
new file mode 100644
index 0000000..a454165
--- /dev/null
+++ b/libq/move_file.h
@@ -0,0 +1,21 @@
+/*
+ * Copyright 2005-2021 Gentoo Authors
+ * Distributed under the terms of the GNU General Public License v2
+ *
+ * Copyright 2005-2010 Ned Ludd - <so...@gentoo.org>
+ * Copyright 2005-2014 Mike Frysinger - <vap...@gentoo.org>
+ * Copyright 2018- Fabian Groffen - <grob...@gentoo.org>
+ */
+
+#ifndef _MOVE_FILE_H
+
+#define _MOVE_FILE_H 1
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+int move_file(int rootfd_src, const char *name_src,
+ int rootfd_dst, const char *name_dst,
+ struct stat *stat_src);
+
+#endif
