[PATCH 72/79] namei: move link count check and stack allocation into pick_link()

From: Al Viro
Date: Tue May 05 2015 - 01:35:05 EST


From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
fs/namei.c | 27 ++++++++++++---------------
1 file changed, 12 insertions(+), 15 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 026d7df..9822b37 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -891,16 +891,10 @@ const char *get_link(struct nameidata *nd)
if (nd->link.mnt == nd->path.mnt)
mntget(nd->link.mnt);

- if (unlikely(current->total_link_count >= MAXSYMLINKS)) {
- path_put(&nd->link);
- return ERR_PTR(-ELOOP);
- }
-
last->link = nd->link;
last->cookie = NULL;

cond_resched();
- current->total_link_count++;

touch_atime(&last->link);

@@ -1560,12 +1554,23 @@ static void terminate_walk(struct nameidata *nd)

static int pick_link(struct nameidata *nd, struct path *link)
{
+ int error;
+ if (unlikely(current->total_link_count++ >= MAXSYMLINKS)) {
+ path_to_nameidata(link, nd);
+ return -ELOOP;
+ }
if (nd->flags & LOOKUP_RCU) {
if (unlikely(nd->path.mnt != link->mnt ||
unlazy_walk(nd, link->dentry))) {
return -ECHILD;
}
}
+ error = nd_alloc_stack(nd);
+ if (unlikely(error)) {
+ path_to_nameidata(link, nd);
+ return error;
+ }
+
nd->link = *link;
return 1;
}
@@ -1832,15 +1837,7 @@ OK:
break;

if (err) {
- const char *s;
-
- err = nd_alloc_stack(nd);
- if (unlikely(err)) {
- path_to_nameidata(&nd->link, nd);
- break;
- }
-
- s = get_link(nd);
+ const char *s = get_link(nd);

if (unlikely(IS_ERR(s))) {
err = PTR_ERR(s);
--
2.1.4

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