[PATCH v3 084/110] namei: take increment of nd->depth into pick_link()

From: Al Viro
Date: Mon May 11 2015 - 14:20:21 EST


From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

Makes the situation much more regular - we avoid a strange state
when the element just after the top of stack is used to store
struct path of symlink, but isn't counted in nd->depth. This
is much more regular, so the normal failure exits, etc., work
fine.

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
fs/namei.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 277ca86..6d4692d 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -798,8 +798,7 @@ static inline int may_follow_link(struct nameidata *nd)
return 0;

audit_log_link_denied("follow_link", &nd->stack[0].link);
- path_put(&nd->stack[0].link);
- path_put(&nd->path);
+ terminate_walk(nd);
return -EACCES;
}

@@ -875,7 +874,7 @@ static int may_linkat(struct path *link)
static __always_inline
const char *get_link(struct nameidata *nd)
{
- struct saved *last = nd->stack + nd->depth;
+ struct saved *last = nd->stack + nd->depth - 1;
struct dentry *dentry = last->link.dentry;
struct inode *inode = dentry->d_inode;
int error;
@@ -883,9 +882,6 @@ const char *get_link(struct nameidata *nd)

BUG_ON(nd->flags & LOOKUP_RCU);

- last->cookie = NULL;
- nd->depth++;
-
cond_resched();

touch_atime(&last->link);
@@ -1575,8 +1571,9 @@ static int pick_link(struct nameidata *nd, struct path *link)
return error;
}

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

--
2.1.4

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