[PATCH 22/24] namei: trim the arguments of get_link()

Al Viro
2015-04-20T18:13:39Z

From: Al Viro <viro@zeniv.linux.org.uk>

same story as the previous commit

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/namei.c | 37 +++++++++++++++----------------------
1 file changed, 15 insertions(+), 22 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index a8d6751..425986a 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -878,10 +878,10 @@ static int may_linkat(struct path *link)
return -EPERM;
}

-static __always_inline char *
-get_link(struct path *link, struct nameidata *nd, void **p)
+static __always_inline char *get_link(struct nameidata *nd, struct path *next)
{
- struct dentry *dentry = link->dentry;
+ struct saved *last = nd->stack + nd->depth;
+ struct dentry *dentry = next->dentry;
struct inode *inode = dentry->d_inode;
void *cookie;
int error;
@@ -889,8 +889,10 @@ get_link(struct path *link, struct nameidata *nd, void **p)

BUG_ON(nd->flags & LOOKUP_RCU);

- if (link->mnt == nd->path.mnt)
- mntget(link->mnt);
+ if (next->mnt == nd->path.mnt)
+ mntget(next->mnt);
+
+ last->link = *next;

res = ERR_PTR(-ELOOP);
if (unlikely(nd->total_link_count >= 40))
@@ -899,7 +901,7 @@ get_link(struct path *link, struct nameidata *nd, void **p)
cond_resched();
nd->total_link_count++;

- touch_atime(link);
+ touch_atime(&last->link);
nd_set_link(NULL);

error = security_inode_follow_link(dentry);
@@ -914,16 +916,16 @@ get_link(struct path *link, struct nameidata *nd, void **p)

res = nd_get_link(nd);
if (!IS_ERR(res)) {
- *p = cookie;
+ last->cookie = cookie;
return res;
}

if (inode->i_op->put_link)
inode->i_op->put_link(dentry, res, cookie);
out:
- *p = NULL;
+ last->cookie = NULL;
path_put(&nd->path);
- path_put(link);
+ path_put(&last->link);
return res;
}

@@ -931,12 +933,10 @@ static int follow_link(struct nameidata *nd, struct path *link)
{
char *s;
int error = may_follow_link(link, nd);
- struct saved *last = nd->stack + nd->depth;
if (unlikely(error))
return error;
nd->flags |= LOOKUP_PARENT;
- last->link = *link;
- s = get_link(&last->link, nd, &last->cookie);
+ s = get_link(nd, link);
if (unlikely(IS_ERR(s)))
return PTR_ERR(s);
if (unlikely(!s))
@@ -1779,7 +1779,6 @@ static inline u64 hash_name(const char *name)
*/
static int link_path_walk(const char *name, struct nameidata *nd)
{
- struct saved *last = nd->stack;
struct path next;
int err;

@@ -1858,16 +1857,13 @@ Walked:

nd->depth++;
nd->link_count++;
- last++;

- last->link = next;
- s = get_link(&last->link, nd, &last->cookie);
+ s = get_link(nd, &next);

if (unlikely(IS_ERR(s))) {
err = PTR_ERR(s);
nd->link_count--;
nd->depth--;
- last--;
goto Err;
}
err = 0;
@@ -1876,7 +1872,6 @@ Walked:
put_link(nd);
nd->link_count--;
nd->depth--;
- last--;
} else {
if (*s == '/') {
if (!nd->root.mnt)
@@ -1889,7 +1884,7 @@ Walked:
;
}
nd->inode = nd->path.dentry->d_inode;
- last->name = name;
+ nd->stack[nd->depth].name = name;
if (!*s)
goto OK;
name = s;
@@ -1907,17 +1902,15 @@ Err:
put_link(nd);
nd->link_count--;
nd->depth--;
- last--;
}
return err;
OK:
if (unlikely(nd->depth)) {
- name = last->name;
+ name = nd->stack[nd->depth].name;
err = walk_component(nd, &next, LOOKUP_FOLLOW);
put_link(nd);
nd->link_count--;
nd->depth--;
- last--;
goto Walked;
}
return 0;
--
2.1.4