vfs: make the string hashes salt the hash

We always mixed in the parent pointer into the dentry name hash, but we
did it late at lookup time.  It turns out that we can simplify that
lookup-time action by salting the hash with the parent pointer early
instead of late.

A few other users of our string hashes also wanted to mix in their own
pointers into the hash, and those are updated to use the same mechanism.

Hash users that don't have any particular initial salt can just use the
NULL pointer as a no-salt.

Cc: Vegard Nossum <[email protected]>
Cc: George Spelvin <[email protected]>
Cc: Al Viro <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Linus Torvalds 2016-06-10 07:51:30 -07:00
commit 8387ff2577
38 changed files with 99 additions and 89 deletions

View file

@ -154,7 +154,7 @@ const struct tomoyo_path_info *tomoyo_get_name(const char *name)
if (!name)
return NULL;
len = strlen(name) + 1;
hash = full_name_hash((const unsigned char *) name, len - 1);
hash = full_name_hash(NULL, (const unsigned char *) name, len - 1);
head = &tomoyo_name_list[hash_long(hash, TOMOYO_HASH_BITS)];
if (mutex_lock_interruptible(&tomoyo_policy_lock))
return NULL;

View file

@ -666,7 +666,7 @@ void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
ptr->const_len = tomoyo_const_part_length(name);
ptr->is_dir = len && (name[len - 1] == '/');
ptr->is_patterned = (ptr->const_len < len);
ptr->hash = full_name_hash(name, len);
ptr->hash = full_name_hash(NULL, name, len);
}
/**