vfs: uninline full_name_hash()

.. and also use it in lookup_one_len() rather than open-coding it.

There aren't any performance-critical users, so inlining it is silly.
But it wouldn't matter if it wasn't for the fact that the word-at-a-time
dentry name patches want to conditionally replace the function, and
uninlining it sets the stage for that.

So again, this is a preparatory patch that doesn't change any semantics,
and only prepares for a much cleaner and testable word-at-a-time dentry
name accessor patch.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Linus Torvalds 2012-03-02 14:32:59 -08:00
parent 8966be9030
commit 0145acc202
2 changed files with 10 additions and 12 deletions

View file

@ -1374,6 +1374,14 @@ static inline int can_lookup(struct inode *inode)
return 1;
}
unsigned int full_name_hash(const unsigned char *name, unsigned int len)
{
unsigned long hash = init_name_hash();
while (len--)
hash = partial_name_hash(*name++, hash);
return end_name_hash(hash);
}
/*
* Name resolution.
* This is the basic name resolution function, turning a pathname into
@ -1775,24 +1783,21 @@ static struct dentry *lookup_hash(struct nameidata *nd)
struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
{
struct qstr this;
unsigned long hash;
unsigned int c;
WARN_ON_ONCE(!mutex_is_locked(&base->d_inode->i_mutex));
this.name = name;
this.len = len;
this.hash = full_name_hash(name, len);
if (!len)
return ERR_PTR(-EACCES);
hash = init_name_hash();
while (len--) {
c = *(const unsigned char *)name++;
if (c == '/' || c == '\0')
return ERR_PTR(-EACCES);
hash = partial_name_hash(c, hash);
}
this.hash = end_name_hash(hash);
/*
* See if the low-level filesystem might want
* to use its own hash..

View file

@ -89,14 +89,7 @@ static inline unsigned long end_name_hash(unsigned long hash)
}
/* Compute the hash for a name string. */
static inline unsigned int
full_name_hash(const unsigned char *name, unsigned int len)
{
unsigned long hash = init_name_hash();
while (len--)
hash = partial_name_hash(*name++, hash);
return end_name_hash(hash);
}
extern unsigned int full_name_hash(const unsigned char *, unsigned int);
/*
* Try to keep struct dentry aligned on 64 byte cachelines (this will