Messages in this thread | | | Date | Sun, 04 Aug 2013 19:34:00 -0700 | From | Andy Lutomirski <> | Subject | O_TMPFILE fs corruption (Re: Linux 3.11-rc4) |
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On 08/04/2013 02:09 PM, Linus Torvalds wrote: > It's that time of the week again..
I still get filesystem corruption with O_TMPFILE. The program below, run as flinktest foo proc (or flinktest foo linkat if you're root) will produce a bogus inode. On ext4, once the inode is gone from cache, the inode will be impossible to delete and will require a fsck to fix
A patch (not necessarily the appropriate fix) is here:
http://article.gmane.org/gmane.linux.kernel/1537088
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#include <stdio.h> #include <err.h> #include <fcntl.h> #include <unistd.h> #include <string.h>
#define __O_TMPFILE 020000000 #define O_TMPFILE (__O_TMPFILE | O_DIRECTORY) #define AT_EMPTY_PATH 0x1000
int main(int argc, char **argv) { char buf[128];
if (argc != 3) errx(1, "Usage: flinktest PATH linkat|proc");
int fd = open(".", O_TMPFILE | O_RDWR, 0600); if (fd == -1) err(1, "O_TMPFILE"); write(fd, "test", 4);
if (!strcmp(argv[2], "linkat")) { if (linkat(fd, "", AT_FDCWD, argv[1], AT_EMPTY_PATH) != 0) err(1, "linkat"); } else if (!strcmp(argv[2], "proc")) { sprintf(buf, "/proc/self/fd/%d", fd); if (linkat(AT_FDCWD, buf, AT_FDCWD, argv[1], AT_SYMLINK_FOLLOW) != 0) err(1, "linkat"); } else { errx(1, "invalid mode"); } return 0; }
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