[PATCH v3 083/110] namei: kill nd->link

From: Al Viro
Date: Mon May 11 2015 - 14:20:05 EST


From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

Just store it in nd->stack[nd->depth].link right in pick_link().
Now that we make sure of stack expansion in pick_link(), we can
do so...

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
fs/namei.c | 18 ++++++++----------
1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 82cb1bc..277ca86 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -495,10 +495,7 @@ EXPORT_SYMBOL(path_put);
#define EMBEDDED_LEVELS 2
struct nameidata {
struct path path;
- union {
- struct qstr last;
- struct path link;
- };
+ struct qstr last;
struct path root;
struct inode *inode; /* path.dentry.d_inode */
unsigned int flags;
@@ -787,7 +784,7 @@ static inline int may_follow_link(struct nameidata *nd)
return 0;

/* Allowed if owner and follower match. */
- inode = nd->link.dentry->d_inode;
+ inode = nd->stack[0].link.dentry->d_inode;
if (uid_eq(current_cred()->fsuid, inode->i_uid))
return 0;

@@ -800,8 +797,8 @@ static inline int may_follow_link(struct nameidata *nd)
if (uid_eq(parent->i_uid, inode->i_uid))
return 0;

- audit_log_link_denied("follow_link", &nd->link);
- path_put(&nd->link);
+ audit_log_link_denied("follow_link", &nd->stack[0].link);
+ path_put(&nd->stack[0].link);
path_put(&nd->path);
return -EACCES;
}
@@ -879,14 +876,13 @@ static __always_inline
const char *get_link(struct nameidata *nd)
{
struct saved *last = nd->stack + nd->depth;
- struct dentry *dentry = nd->link.dentry;
+ struct dentry *dentry = last->link.dentry;
struct inode *inode = dentry->d_inode;
int error;
const char *res;

BUG_ON(nd->flags & LOOKUP_RCU);

- last->link = nd->link;
last->cookie = NULL;
nd->depth++;

@@ -1560,6 +1556,7 @@ static void terminate_walk(struct nameidata *nd)
static int pick_link(struct nameidata *nd, struct path *link)
{
int error;
+ struct saved *last;
if (unlikely(nd->total_link_count++ >= MAXSYMLINKS)) {
path_to_nameidata(link, nd);
return -ELOOP;
@@ -1578,7 +1575,8 @@ static int pick_link(struct nameidata *nd, struct path *link)
return error;
}

- nd->link = *link;
+ last = nd->stack + nd->depth;
+ last->link = *link;
return 1;
}

--
2.1.4

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