busybox/libbb/remove_file.c
Chen Yu 05b18065ab remove_file: don't call rmdir if remove_file return failure
When deleting a directory, the directory should not be removed if the
file in the subdirectory fails to be deleted.

Background information:

When I tested the kernel using LTP (linux-test-project).I found the
mv command have some issue. The LTP test case use the mv command to
move the directory t1 in the cgroup file system to the /tmp directory.
becase files in the cgroup file system are not allowed to be removed.
so the mv reported "Permission denied", but I used the ls command to
view the results and found that the directory t1 had been removed
from the cgroup file system. For the same test case, I used the mv
tool in the GNU coreutils, and the directory t1 will not be removed.

the following testcase use busybox mv:

/ # mount -t cgroup -o cpu cgroup /cpu
/ # cd /cpu
/cpu # mkdir -p t1
/cpu # ls
cgroup.clone_children  cpu.cfs_period_us  cpu.stat  t1
cgroup.procs           cpu.cfs_quota_us   notify_on_release  tasks
cgroup.sane_behavior   cpu.shares         release_agent
/cpu # mv t1 /tmp
mv: can't remove 't1/cgroup.procs': Operation not permitted
mv: can't remove 't1/cpu.cfs_period_us': Operation not permitted
mv: can't remove 't1/cpu.stat': Operation not permitted
mv: can't remove 't1/cpu.shares': Operation not permitted
mv: can't remove 't1/cpu.cfs_quota_us': Operation not permitted
mv: can't remove 't1/tasks': Operation not permitted
mv: can't remove 't1/notify_on_release': Operation not permitted
mv: can't remove 't1/cgroup.clone_children': Operation not permitted
/cpu # ls
cgroup.clone_children  cpu.cfs_period_us  cpu.stat  cgroup.procs
cpu.cfs_quota_us       notify_on_release  tasks   cgroup.sane_behavior
cpu.shares             release_agent
/cpu #

This patch fixed it, don't call rmdir if remove_file return failure,
and under certain file systems, the mv could work normally.

Signed-off-by: Chen Yu <yu.chen3@zte.com.cn>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-09-09 20:16:04 +02:00

111 lines
2.2 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Mini remove_file implementation for busybox
*
* Copyright (C) 2001 Matt Kraai <kraai@alumni.carnegiemellon.edu>
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
#include "libbb.h"
/* Used from NOFORK applets. Must not allocate anything */
int FAST_FUNC remove_file(const char *path, int flags)
{
struct stat path_stat;
if (lstat(path, &path_stat) < 0) {
if (errno != ENOENT) {
bb_perror_msg("can't stat '%s'", path);
return -1;
}
if (!(flags & FILEUTILS_FORCE)) {
bb_perror_msg("can't remove '%s'", path);
return -1;
}
return 0;
}
if (S_ISDIR(path_stat.st_mode)) {
DIR *dp;
struct dirent *d;
int status = 0;
if (!(flags & FILEUTILS_RECUR)) {
bb_error_msg("'%s' is a directory", path);
return -1;
}
if ((!(flags & FILEUTILS_FORCE) && access(path, W_OK) < 0 && isatty(0))
|| (flags & FILEUTILS_INTERACTIVE)
) {
fprintf(stderr, "%s: descend into directory '%s'? ",
applet_name, path);
if (!bb_ask_y_confirmation())
return 0;
}
dp = opendir(path);
if (dp == NULL) {
return -1;
}
while ((d = readdir(dp)) != NULL) {
char *new_path;
new_path = concat_subpath_file(path, d->d_name);
if (new_path == NULL)
continue;
if (remove_file(new_path, flags) < 0)
status = -1;
free(new_path);
}
if (closedir(dp) < 0) {
bb_perror_msg("can't close '%s'", path);
return -1;
}
if (flags & FILEUTILS_INTERACTIVE) {
fprintf(stderr, "%s: remove directory '%s'? ",
applet_name, path);
if (!bb_ask_y_confirmation())
return status;
}
if (status == 0 && rmdir(path) < 0) {
bb_perror_msg("can't remove '%s'", path);
return -1;
}
if (flags & FILEUTILS_VERBOSE) {
printf("removed directory: '%s'\n", path);
}
return status;
}
/* !ISDIR */
if ((!(flags & FILEUTILS_FORCE)
&& access(path, W_OK) < 0
&& !S_ISLNK(path_stat.st_mode)
&& isatty(0))
|| (flags & FILEUTILS_INTERACTIVE)
) {
fprintf(stderr, "%s: remove '%s'? ", applet_name, path);
if (!bb_ask_y_confirmation())
return 0;
}
if (unlink(path) < 0) {
bb_perror_msg("can't remove '%s'", path);
return -1;
}
if (flags & FILEUTILS_VERBOSE) {
printf("removed '%s'\n", path);
}
return 0;
}