lookup_one_len_unlocked(): use lookup_dcache()

No need to lock parent just because of ->d_revalidate() on child;
contrary to the stale comment, lookup_dcache() *can* be used without
locking the parent.  Result can be moved as soon as we return, of
course, but the same is true for lookup_one_len_unlocked() itself.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2016-03-05 22:31:50 -05:00
parent 74ff0ffc7f
commit d6d95ded91

View File

@ -1444,8 +1444,6 @@ static int follow_dotdot(struct nameidata *nd)
* This looks up the name in dcache, possibly revalidates the old dentry and
* allocates a new one if not found or not valid. In the need_lookup argument
* returns whether i_op->lookup is necessary.
*
* dir->d_inode->i_mutex must be held
*/
static struct dentry *lookup_dcache(struct qstr *name, struct dentry *dir,
unsigned int flags)
@ -2351,15 +2349,7 @@ struct dentry *lookup_one_len_unlocked(const char *name,
if (err)
return ERR_PTR(err);
/*
* __d_lookup() is used to try to get a quick answer and avoid the
* mutex. A false-negative does no harm.
*/
ret = __d_lookup(base, &this);
if (ret && unlikely(ret->d_flags & DCACHE_OP_REVALIDATE)) {
dput(ret);
ret = NULL;
}
ret = lookup_dcache(&this, base, 0);
if (ret)
return ret;