[LU-9468] incorrect stat from kthread with X86_X32 architecture

Tue, 13 Jun 2017 17:10:24 +0000

Under the following conditions, ll_getattr will flatten the inode number when it shouldn't:

the X86_X32 architecture is defined CONFIG_X86_X32, and not even used,
ll_getattr is called from a kernel thread (though vfs_stat for instance).

This has the result that inode numbers are different whether the same file is stat'ed from a kernel thread, or from a syscall. For instance, 4198401 vs. 144115205272502273.

ll_getattr calls ll_need_32bit_api to determine whether the task is 32 bits. When the combination is kthread+X86_X32, that function returns that the task is 32 bits, which is incorrect, as the kernel is 64 bits.

The solution is to check whether the call is from a kernel thread (which is 64 bits) and act consequently.

Whamcloud Community JIRA

[LU-9468] incorrect stat from kthread with X86_X32 architecture