vfs: remove unnecessary d_unhashed() check from __d_lookup_rcu

The check for d_unhashed() is not strictly incorrect, but at the same
time it is also not sensible.  The actual dentry removal from the dentry
hash chains is totally asynchronous to the __d_lookup_rcu() logic, and
we depend on __d_drop() updating the sequence number to invalidate any
lookup of an unhashed dentry.

So checking d_unhashed() is not incorrect, but it's not useful either:
the code has to work correctly even without it. So just remove it.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Linus Torvalds 2012-05-10 11:06:18 -07:00
parent 12f8ad4b05
commit 8c01a529b8

View File

@ -1871,8 +1871,6 @@ struct dentry *__d_lookup_rcu(const struct dentry *parent,
seq = raw_seqcount_begin(&dentry->d_seq);
if (dentry->d_parent != parent)
continue;
if (d_unhashed(dentry))
continue;
*seqp = seq;
if (unlikely(parent->d_flags & DCACHE_OP_COMPARE)) {