From 5a202bcd75bbd2397136397961babbd8463416af Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Tue, 8 Mar 2011 14:17:44 -0500
Subject: [PATCH] sanitize pathname component hash calculation
Lift it to lookup_one_len() and link_path_walk() resp. into the
same place where we calculated default hash function of the same
name.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/namei.c | 42 +++++++++++++++++++-----------------------
1 file changed, 19 insertions(+), 23 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index f6f3ef47bc743..d1a5dfeaf9995 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1216,16 +1216,6 @@ static int do_lookup(struct nameidata *nd, struct qstr *name,
struct inode *dir;
int err;
- /*
- * See if the low-level filesystem might want
- * to use its own hash..
- */
- if (unlikely(parent->d_flags & DCACHE_OP_HASH)) {
- err = parent->d_op->d_hash(parent, nd->inode, name);
- if (err < 0)
- return err;
- }
-
/*
* Rename seqlock is not required here because in the off chance
* of a false negative due to a concurrent rename, we're going to
@@ -1414,8 +1404,16 @@ static int link_path_walk(const char *name, struct nameidata *nd)
case 1:
type = LAST_DOT;
}
- if (likely(type == LAST_NORM))
+ if (likely(type == LAST_NORM)) {
+ struct dentry *parent = nd->path.dentry;
nd->flags &= ~LOOKUP_JUMPED;
+ if (unlikely(parent->d_flags & DCACHE_OP_HASH)) {
+ err = parent->d_op->d_hash(parent, nd->inode,
+ &this);
+ if (err < 0)
+ break;
+ }
+ }
/* remove trailing slashes? */
if (!c)
@@ -1722,17 +1720,6 @@ static struct dentry *__lookup_hash(struct qstr *name,
if (err)
return ERR_PTR(err);
- /*
- * See if the low-level filesystem might want
- * to use its own hash..
- */
- if (base->d_flags & DCACHE_OP_HASH) {
- err = base->d_op->d_hash(base, inode, name);
- dentry = ERR_PTR(err);
- if (err < 0)
- goto out;
- }
-
/*
* Don't bother with __d_lookup: callers are for creat as
* well as unlink, so a lot of the time it would cost
@@ -1745,7 +1732,7 @@ static struct dentry *__lookup_hash(struct qstr *name,
if (!dentry)
dentry = d_alloc_and_lookup(base, name, nd);
-out:
+
return dentry;
}
@@ -1791,6 +1778,15 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
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..
+ */
+ if (base->d_flags & DCACHE_OP_HASH) {
+ int err = base->d_op->d_hash(base, base->d_inode, &this);
+ if (err < 0)
+ return ERR_PTR(err);
+ }
return __lookup_hash(&this, base, NULL);
}
--
2.30.2