du dumps core on tmfs drive

[jonasaugust]

I wanted to find out how much space I'd need to restore a Mac backup called "pont" accessed using tmfs, so I tried to use du, but I got a core dump.

jonas@P9X79:~$ cd /mnt/time-machine-root/pont/
jonas@P9X79:/mnt/time-machine-root/pont$ ls -l
total 0
drwxr-xr-x 1 jonas jonas 6 Aug 27 17:16 2012-08-27-171617
drwxr-xr-x 1 jonas jonas 6 Aug 31 09:56 2012-08-31-095659
drwxr-xr-x 1 jonas jonas 6 Sep  2 19:28 2012-09-02-192834
drwxr-xr-x 1 jonas jonas 6 Sep  3 05:58 2012-09-03-055819
drwxr-xr-x 1 jonas jonas 6 Sep  5 11:28 2012-09-05-112759
drwxr-xr-x 1 jonas jonas 6 Sep  7 15:06 2012-09-07-150644
drwxr-xr-x 1 jonas jonas 6 Sep  7 15:06 Latest
jonas@P9X79:/mnt/time-machine-root/pont$ cd 2012-09-07-150644/
jonas@P9X79:/mnt/time-machine-root/pont/2012-09-07-150644$ ls
Macintosh HD
jonas@P9X79:/mnt/time-machine-root/pont/2012-09-07-150644$ du -s Macintosh\ HD/
Aborted (core dumped)

Specs: tmfs from today, Ubuntu 12.04 x64, boost 1.46.1, fuse 2.8.6.

[abique]

Thanks for the report, but it looks like a du bug?
Did tmfs crash?
Can you strace du so we'll get an idea of which stat reported wrong informations.

Thanks.

[jonasaugust]

Well it doesn't always fail. It may be that for smaller directory trees it works, but not for larger, as this example shows:

jonas@P9X79:/mnt/time-machine-root/pont/Latest/Macintosh HD/Users/jonas/Documents/julia$ du -sh
1.9G    .
jonas@P9X79:/mnt/time-machine-root/pont/Latest/Macintosh HD/Users/jonas/Documents/julia$ cd ..
jonas@P9X79:/mnt/time-machine-root/pont/Latest/Macintosh HD/Users/jonas/Documents$ du -sh
Aborted (core dumped)

Possible 32 vs 64 bit bug? (I'm on Ubuntu 12.04 AMD64.)

Here's the strace:

jonas@P9X79:/mnt/time-machine-root/pont/Latest/Macintosh HD/Users/jonas/Documents$ strace du -sh
execve("/usr/bin/du", ["du", "-sh"], [/* 37 vars */]) = 0
brk(0)                                  = 0x1ad1000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7feb2fa36000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=87090, ...}) = 0
mmap(NULL, 87090, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7feb2fa20000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\200\30\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1811128, ...}) = 0
mmap(NULL, 3925208, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7feb2f457000
mprotect(0x7feb2f60c000, 2093056, PROT_NONE) = 0
mmap(0x7feb2f80b000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1b4000) = 0x7feb2f80b000
mmap(0x7feb2f811000, 17624, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7feb2f811000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7feb2fa1f000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7feb2fa1e000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7feb2fa1d000
arch_prctl(ARCH_SET_FS, 0x7feb2fa1e700) = 0
mprotect(0x7feb2f80b000, 16384, PROT_READ) = 0
mprotect(0x617000, 4096, PROT_READ)     = 0
mprotect(0x7feb2fa38000, 4096, PROT_READ) = 0
munmap(0x7feb2fa20000, 87090)           = 0
brk(0)                                  = 0x1ad1000
brk(0x1af2000)                          = 0x1af2000
open("/usr/lib/locale/locale-archive", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=7220736, ...}) = 0
mmap(NULL, 7220736, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7feb2ed74000
close(3)                                = 0
newfstatat(AT_FDCWD, ".", {st_mode=S_IFDIR|0700, st_size=137, ...}, AT_SYMLINK_NOFOLLOW) = 0
openat(AT_FDCWD, ".", O_RDONLY|O_NOCTTY|O_NONBLOCK|O_DIRECTORY|O_NOFOLLOW) = 3
fcntl(3, F_GETFD)                       = 0
fcntl(3, F_SETFD, FD_CLOEXEC)           = 0
fstat(3, {st_mode=S_IFDIR|0700, st_size=137, ...}) = 0
fcntl(3, F_GETFL)                       = 0x38800 (flags O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_DIRECTORY|O_NOFOLLOW)
fcntl(3, F_SETFD, FD_CLOEXEC)           = 0
newfstatat(AT_FDCWD, ".", {st_mode=S_IFDIR|0700, st_size=137, ...}, AT_SYMLINK_NOFOLLOW) = 0
fcntl(3, F_DUPFD, 3)                    = 4
fcntl(4, F_GETFD)                       = 0
fcntl(4, F_SETFD, FD_CLOEXEC)           = 0
getdents(3, /* 81 entries */, 32768)    = 3680
getdents(3, /* 58 entries */, 32768)    = 2680
getdents(3, /* 0 entries */, 32768)     = 0
close(3)                                = 0
newfstatat(4, ".DS_Store", {st_mode=S_IFREG|0600, st_size=24580, ...}, AT_SYMLINK_NOFOLLOW) = 0
newfstatat(4, ".localized", {st_mode=S_IFREG|0644, st_size=0, ...}, AT_SYMLINK_NOFOLLOW) = 0
newfstatat(4, "About Stacks.pdf", {st_mode=S_IFREG|0600, st_size=303444, ...}, AT_SYMLINK_NOFOLLOW) = 0
newfstatat(4, "AdobeStockPhotos", {st_mode=S_IFDIR|0771, st_size=5, ...}, AT_SYMLINK_NOFOLLOW) = 0
openat(4, "AdobeStockPhotos", O_RDONLY|O_NOCTTY|O_NONBLOCK|O_DIRECTORY|O_NOFOLLOW) = 3
fcntl(3, F_GETFD)                       = 0
fcntl(3, F_SETFD, FD_CLOEXEC)           = 0
fstat(3, {st_mode=S_IFDIR|0771, st_size=5, ...}) = 0
fcntl(3, F_GETFL)                       = 0x38800 (flags O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_DIRECTORY|O_NOFOLLOW)
fcntl(3, F_SETFD, FD_CLOEXEC)           = 0
rt_sigprocmask(SIG_UNBLOCK, [ABRT], NULL, 8) = 0
gettid()                                = 3536
tgkill(3536, 3536, SIGABRT)             = 0
--- SIGABRT (Aborted) @ 0 (0) ---
+++ killed by SIGABRT (core dumped) +++
Aborted (core dumped)

Unfortunately I can't give this more time now. I ended up using tmutil restore on a Mac.

[jonasaugust]

I forgot to mention: tmfs itself doesn't crash when du dumps core.

[abique]

To me it is a du bug, as it should not crash even if stat/readdir reports broken data.

I forward the issue to bug-coreutils@gnu.org.

[abique]

By the way can you show me the output of du --version? Thanks.

[jonasaugust]

jonas@P9X79:~/pkg/tmfs/build$ du --version
du (GNU coreutils) 8.13

[abique]

This is not the last version of coreutils, if you have the time, can you check with coreutils 8.19?

[jonasaugust]

OK, I installed coreutils 8.19 from https://launchpad.net/~dns/+archive/gnu/+build/3794330 . Still get core dump:

root@P9X79:/home/jonas# du -hs /mnt/time-machine-root/pont/Latest/Macintosh\ HD/Users/jonas/Documents/julia/
1.9G    /mnt/time-machine-root/pont/Latest/Macintosh HD/Users/jonas/Documents/julia/
root@P9X79:/home/jonas# du -hs /mnt/time-machine-root/pont/Latest/Macintosh\ HD/Users/jonas/Documents/
Aborted (core dumped)
root@P9X79:/home/jonas# du --version
du (GNU coreutils) 8.19

[abique]

Jonasaugust, would you mind if we continue the conversation here: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=12601 ?

Also could you run du in gdb with debug symbols and get a backtrace with info locals for last level of the stack ?

Thanks ;)

[abique]

I guess the issue has been fixed on the coreutils by now.
Please re-open if not.