Ceph » CephFS

Empty pathnames are valid special cases as explained in man fchownat(2) and man statx(2). But corresponding APIs, ceph_chownat() and ceph_statxat(), crashes with the following backtrace:

#0  __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44
#1  0x00007fea2757f6d3 in __pthread_kill_internal (threadid=<optimized out>, signo=6) at pthread_kill.c:78
#2  0x00007fea27526c4e in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
#3  0x00007fea2750e902 in __GI_abort () at abort.c:79
#4  0x00007fea266dabf0 in std::__glibcxx_assert_fail (file=file@entry=0x7fea27849680 "/usr/include/c++/14/string_view", line=line@entry=256, 
    function=function@entry=0x7fea27849580 "constexpr const std::basic_string_view<_CharT, _Traits>::value_type& std::basic_string_view<_CharT, _Traits>::operator[](size_type) const [with _CharT = char; _Traits = std::char_traits<char>; const_r"..., condition=condition@entry=0x7fea27854568 "__pos < this->_M_len") at ../../../../../libstdc++-v3/src/c++11/assert_fail.cc:41
#5  0x00007fea2774f6df in std::basic_string_view<char, std::char_traits<char> >::operator[] (this=<optimized out>, __pos=<optimized out>) at /usr/include/c++/14/string_view:254
#6  std::basic_string_view<char, std::char_traits<char> >::operator[] (this=<synthetic pointer>, __pos=0) at /usr/include/c++/14/string_view:254
#7  filepath::set_path (this=0x7fff29cd1e30, s=...) at /usr/src/debug/ceph-18.2.4-1.fc40.x86_64/src/include/filepath.h:101
#8  filepath::filepath (this=<optimized out>, s=<optimized out>, this=<optimized out>, s=<optimized out>) at /usr/src/debug/ceph-18.2.4-1.fc40.x86_64/src/include/filepath.h:94
#9  0x00007fea277a4764 in Client::chownat (this=0x32794a40, dirfd=10, relpath=0x4020d0 "", new_uid=65534, new_gid=65534, flags=0, perms=...)
    at /usr/src/debug/ceph-18.2.4-1.fc40.x86_64/src/client/Client.cc:8835
#10 0x00007fea2772a0c3 in ceph_chownat (cmount=<optimized out>, dirfd=<optimized out>, relpath=<optimized out>, uid=<optimized out>, gid=<optimized out>, flags=<optimized out>)
    at /usr/src/debug/ceph-18.2.4-1.fc40.x86_64/src/libcephfs.cc:1181
#11 0x00000000004013e1 in main ()

#0  __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44
#1  0x00007f6528fc26d3 in __pthread_kill_internal (threadid=<optimized out>, signo=6) at pthread_kill.c:78
#2  0x00007f6528f69c4e in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
#3  0x00007f6528f51902 in __GI_abort () at abort.c:79
#4  0x00007f65280dabf0 in std::__glibcxx_assert_fail (file=file@entry=0x7f652928c680 "/usr/include/c++/14/string_view", line=line@entry=256, 
    function=function@entry=0x7f652928c580 "constexpr const std::basic_string_view<_CharT, _Traits>::value_type& std::basic_string_view<_CharT, _Traits>::operator[](size_type) const [with _CharT = char; _Traits = std::char_traits<char>; const_r"..., condition=condition@entry=0x7f6529297568 "__pos < this->_M_len") at ../../../../../libstdc++-v3/src/c++11/assert_fail.cc:41
#5  0x00007f65291926df in std::basic_string_view<char, std::char_traits<char> >::operator[] (this=<optimized out>, __pos=<optimized out>) at /usr/include/c++/14/string_view:254
#6  std::basic_string_view<char, std::char_traits<char> >::operator[] (this=<synthetic pointer>, __pos=0) at /usr/include/c++/14/string_view:254
#7  filepath::set_path (this=0x7ffe98822e10, s=...) at /usr/src/debug/ceph-18.2.4-1.fc40.x86_64/src/include/filepath.h:101
#8  filepath::filepath (this=<optimized out>, s=<optimized out>, this=<optimized out>, s=<optimized out>) at /usr/src/debug/ceph-18.2.4-1.fc40.x86_64/src/include/filepath.h:94
#9  0x00007f65291fad9e in Client::statxat (this=0x3bd71310, dirfd=10, relpath=0x4020d0 "", stx=0x7ffe98822ee0, perms=..., want=4095, flags=0)
    at /usr/src/debug/ceph-18.2.4-1.fc40.x86_64/src/client/Client.cc:11507
#10 0x00007f652916bd10 in ceph_statxat (cmount=<optimized out>, dirfd=<optimized out>, relpath=<optimized out>, stx=<optimized out>, want=<optimized out>, flags=<optimized out>)
    at /usr/src/debug/ceph-18.2.4-1.fc40.x86_64/src/libcephfs.cc:986
#11 0x0000000000401428 in main ()

See attachment for sample client programs to reproduce the crash.

• https://www.man7.org/linux/man-pages/man2/fchownat.2.html
• https://www.man7.org/linux/man-pages/man2/statx.2.html