From d41efb522e902364ab09c782d511c1bedc388ddd Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 4 Nov 2019 22:30:52 -0500 Subject: fs/namei.c: pull positivity check into follow_managed() There are 4 callers; two proceed to check if result is positive and fail with ENOENT if it isn't; one (in handle_lookup_down()) is guaranteed to yield positive and one (in lookup_fast()) is _preceded_ by positivity check. However, follow_managed() on a negative dentry is a (fairly cheap) no-op on anything other than autofs. And negative autofs dentries are never hashed, so lookup_fast() is not going to run into one of those. Moreover, successful follow_managed() on a _positive_ dentry never yields a negative one (and we significantly rely upon that in callers of lookup_fast()). In other words, we can easily transpose the positivity check and the call of follow_managed() in lookup_fast(). And that allows to fold the positivity check *into* follow_managed(), simplifying life for the code downstream of its calls. Signed-off-by: Al Viro --- include/linux/dcache.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux/dcache.h') diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 10090f11ab95..c1488cc84fd9 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -440,6 +440,11 @@ static inline bool d_is_negative(const struct dentry *dentry) return d_is_miss(dentry); } +static inline bool d_flags_negative(unsigned flags) +{ + return (flags & DCACHE_ENTRY_TYPE) == DCACHE_MISS_TYPE; +} + static inline bool d_is_positive(const struct dentry *dentry) { return !d_is_negative(dentry); -- cgit v1.2.3