lsds
Failing to mount filesystem in read only mode
Found issue while fixing chown04 testcase. mount() is failing with EBUSY while trying to mount filesystem in read only mode.
Code Snippet: SAFE_MOUNT(cleanup, device, "mntpoint", fs_type, MS_RDONLY, NULL);
[[ SGX-LKL ]] libc_start_main_stage2(): Calling app main: /ltp/testcases/kernel/syscalls/chown/chown04 chown04 1 TBROK : safe_macros.c:758: chown04.c:175: mount(/dev/vda, mntpoint, ext4, 1, 0) failed: errno=EBUSY(16): Resource busy chown04 2 TBROK : safe_macros.c:758: Remaining cases broken
Note: when 0 is passed as an argument instead of MS_RDONLY, it is mounting Ex: SAFE_MOUNT(cleanup, device, "mntpoint", fs_type, 0, NULL);
@prp , Please let me know if anything else needed.
mount() syscall is failing while trying to mount the filesystem in read-only mode. Code snippet: https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/syscalls/chown/chown04.c#L174%20L175
Stack trace:
[[ SGX-LKL ]] libc_start_main_stage2(): Calling app main: /ltp/testcases/kernel/syscalls/chown/chown04
[Switching to Thread 0x7fff8b7fe700 (LWP 5860)]
Thread 10 "ENCLAVE" hit Breakpoint 1, main (ac=1, av=0x7fff40b5eea0) at chown04.c:103
103 chown04.c: No such file or directory.
(gdb) c
Continuing.
[Switching to Thread 0x7fff9179e700 (LWP 5857)]
Thread 7 "ENCLAVE" hit Breakpoint 2, mount (special=0x7fff3dacd7c5 "/dev/vda", dir=0x7fff3dacd7bc "mntpoint",
fstype=0x7fff3dacd830 "ext4", flags=1, data=0x0) at src/linux/mount.c:6
6 return syscall(SYS_mount, special, dir, fstype, flags, data);
(gdb) bt
#0 mount (special=0x7fff3dacd7c5 "/dev/vda", dir=0x7fff3dacd7bc "mntpoint", fstype=0x7fff3dacd830 "ext4", flags=1, data=0x0)
at src/linux/mount.c:6
#1 0x00007fff3dac1caa in safe_mount (file=file@entry=0x7fff3dacd7b2 "chown04.c", lineno=lineno@entry=172,
cleanup_fn=cleanup_fn@entry=0x7fff3dabdce0 <cleanup>, source=source@entry=0x7fff3dacd7c5 "/dev/vda",
target=target@entry=0x7fff3dacd7bc "mntpoint", filesystemtype=filesystemtype@entry=0x7fff3dacd830 "ext4", mountflags=1,
data=0x0) at safe_macros.c:729
#2 0x00007fff3dabd9ff in setup () at chown04.c:172
#3 main (ac=<optimized out>, av=<optimized out>) at chown04.c:111
#4 0x00007fff00538402 in libc_start_main_stage2 (main=0x7fff3dabd820 <main>, argc=1, argv=0x7fff40b5eea0)
at src/env/__libc_start_main.c:168
#5 0x00007fff00538361 in __libc_start_main (main=0x7fff3dabd820 <main>, argc=1, argv=0x7fff40b5eea0)
at src/env/__libc_start_main.c:153
#6 0x00007fff3dabdbae in _start_c (p=<optimized out>) at crt/crt1.c:17
#7 0x00007fff3dabdb86 in _start ()
#8 0x0000000000000000 in ?? ()
(gdb) c
Continuing.
chown04 1 TBROK : safe_macros.c:758: chown04.c:172: mount(/dev/vda, mntpoint, ext4, 1, 0) failed: errno=EBUSY(16): Resource busy
chown04 2 TBROK : safe_macros.c:758: Remaining cases broken
cc: @hukoyu
