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a33228682c
Mount tmpfs with "nr_inodes=3" for easy check. Link: http://lkml.kernel.org/r/20190219215016.GA20084@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matej Kupljen <matej.kupljen@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
68 lines
2.0 KiB
C
68 lines
2.0 KiB
C
/*
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* Copyright (c) 2019 Alexey Dobriyan <adobriyan@gmail.com>
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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/* Test that open(O_TMPFILE), linkat() doesn't screw accounting. */
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#include <errno.h>
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#include <sched.h>
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#include <stdio.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <sys/mount.h>
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#include <unistd.h>
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int main(void)
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{
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int fd;
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if (unshare(CLONE_NEWNS) == -1) {
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if (errno == ENOSYS || errno == EPERM) {
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fprintf(stderr, "error: unshare, errno %d\n", errno);
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return 4;
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}
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fprintf(stderr, "error: unshare, errno %d\n", errno);
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return 1;
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}
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if (mount(NULL, "/", NULL, MS_PRIVATE|MS_REC, NULL) == -1) {
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fprintf(stderr, "error: mount '/', errno %d\n", errno);
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return 1;
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}
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/* Our heroes: 1 root inode, 1 O_TMPFILE inode, 1 permanent inode. */
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if (mount(NULL, "/tmp", "tmpfs", 0, "nr_inodes=3") == -1) {
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fprintf(stderr, "error: mount tmpfs, errno %d\n", errno);
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return 1;
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}
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fd = openat(AT_FDCWD, "/tmp", O_WRONLY|O_TMPFILE, 0600);
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if (fd == -1) {
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fprintf(stderr, "error: open 1, errno %d\n", errno);
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return 1;
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}
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if (linkat(fd, "", AT_FDCWD, "/tmp/1", AT_EMPTY_PATH) == -1) {
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fprintf(stderr, "error: linkat, errno %d\n", errno);
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return 1;
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}
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close(fd);
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fd = openat(AT_FDCWD, "/tmp", O_WRONLY|O_TMPFILE, 0600);
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if (fd == -1) {
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fprintf(stderr, "error: open 2, errno %d\n", errno);
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return 1;
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}
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return 0;
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}
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