On 2024/9/17 15:31, Al Viro wrote:
On Tue, Sep 17, 2024 at 03:14:58PM +0800, Gao Xiang wrote:
Sorry for my ignorance.
I mean i just borrowed the code from the fs/erofs/namei.c and i directly
translated that into Rust code. That might be a problem that also
exists in original working C code.
As for EROFS (an immutable fs), I think after d_splice_alias(), d_name is
still stable (since we don't have rename semantics likewise for now).
Even on corrupted images? If you have two directories with entries that
act as hardlinks to the same subdirectory, and keep hitting them on lookups,
it will have to transplant the subtree between the parents.
Oh, I missed unexpected directory hardlink corrupted cases.
But as the generic filesystem POV, d_name access is actually tricky under
RCU walk path indeed.
->lookup() is never called in RCU mode.
I know, I just said d_name access is tricky in RCU walk.
->lookup() is for real lookup, not search dcache as fast cached lookup
in the RCU context.
Thanks,
Gao Xiang
