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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-06-10 07:51:30 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-06-10 20:21:46 -0700 |
| commit | 8387ff2577eb9ed245df9a39947f66976c6bcd02 (patch) | |
| tree | 79fafcb5777f16e520d1c39e9389039f866b4c6d /fs/kernfs/dir.c | |
| parent | 147d9e7bcad3b8d5465f6eea6292731e7f35dee8 (diff) | |
| download | lwn-8387ff2577eb9ed245df9a39947f66976c6bcd02.tar.gz lwn-8387ff2577eb9ed245df9a39947f66976c6bcd02.zip | |
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 <vegard.nossum@oracle.com>
Cc: George Spelvin <linux@sciencehorizons.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/kernfs/dir.c')
| -rw-r--r-- | fs/kernfs/dir.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index 8a652404eef6..e57174d43683 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -336,11 +336,11 @@ struct kernfs_node *kernfs_get_parent(struct kernfs_node *kn) */ static unsigned int kernfs_name_hash(const char *name, const void *ns) { - unsigned long hash = init_name_hash(); + unsigned long hash = init_name_hash(ns); unsigned int len = strlen(name); while (len--) hash = partial_name_hash(*name++, hash); - hash = (end_name_hash(hash) ^ hash_ptr((void *)ns, 31)); + hash = end_name_hash(hash); hash &= 0x7fffffffU; /* Reserve hash numbers 0, 1 and INT_MAX for magic directory entries */ if (hash < 2) |