tidy the trailing symlinks traversal up
* pull the handling of current->total_link_count into
__do_follow_link()
* put the common "do ->put_link() if needed and path_put() the link"
stuff into a helper (put_link(nd, link, cookie))
* rename __do_follow_link() to follow_link(), while we are at it
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namei.c b/fs/namei.c
index 017c3fa..0a601ca 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -737,14 +737,31 @@
nd->path.dentry = path->dentry;
}
+static inline void put_link(struct nameidata *nd, struct path *link, void *cookie)
+{
+ struct inode *inode = link->dentry->d_inode;
+ if (!IS_ERR(cookie) && inode->i_op->put_link)
+ inode->i_op->put_link(link->dentry, nd, cookie);
+ path_put(link);
+}
+
static __always_inline int
-__do_follow_link(const struct path *link, struct nameidata *nd, void **p)
+follow_link(struct path *link, struct nameidata *nd, void **p)
{
int error;
struct dentry *dentry = link->dentry;
BUG_ON(nd->flags & LOOKUP_RCU);
+ if (unlikely(current->total_link_count >= 40)) {
+ *p = ERR_PTR(-ELOOP); /* no ->put_link(), please */
+ path_put_conditional(link, nd);
+ path_put(&nd->path);
+ return -ELOOP;
+ }
+ cond_resched();
+ current->total_link_count++;
+
touch_atime(link->mnt, dentry);
nd_set_link(nd, NULL);
@@ -1356,21 +1373,12 @@
do {
struct path link = *path;
void *cookie;
- if (unlikely(current->total_link_count >= 40)) {
- path_put_conditional(path, nd);
- path_put(&nd->path);
- res = -ELOOP;
- break;
- }
- cond_resched();
- current->total_link_count++;
- res = __do_follow_link(&link, nd, &cookie);
+
+ res = follow_link(&link, nd, &cookie);
if (!res)
res = walk_component(nd, path, &nd->last,
nd->last_type, LOOKUP_FOLLOW);
- if (!IS_ERR(cookie) && link.dentry->d_inode->i_op->put_link)
- link.dentry->d_inode->i_op->put_link(link.dentry, nd, cookie);
- path_put(&link);
+ put_link(nd, &link, cookie);
} while (res > 0);
current->link_count--;
@@ -1619,27 +1627,15 @@
err = link_path_walk(name, nd);
if (!err && !(flags & LOOKUP_PARENT)) {
- int count = 0;
err = lookup_last(nd, &path);
while (err > 0) {
void *cookie;
struct path link = path;
- struct inode *inode = link.dentry->d_inode;
-
- if (count++ > 32) {
- path_put_conditional(&path, nd);
- path_put(&nd->path);
- err = -ELOOP;
- break;
- }
- cond_resched();
nd->flags |= LOOKUP_PARENT;
- err = __do_follow_link(&link, nd, &cookie);
+ err = follow_link(&link, nd, &cookie);
if (!err)
err = lookup_last(nd, &path);
- if (!IS_ERR(cookie) && inode->i_op->put_link)
- inode->i_op->put_link(link.dentry, nd, cookie);
- path_put(&link);
+ put_link(nd, &link, cookie);
}
}
@@ -2298,7 +2294,6 @@
struct file *base = NULL;
struct file *filp;
struct path path;
- int count = 0;
int error;
filp = get_empty_filp();
@@ -2322,35 +2317,21 @@
filp = do_last(nd, &path, op, pathname);
while (unlikely(!filp)) { /* trailing symlink */
struct path link = path;
- struct inode *linki = link.dentry->d_inode;
void *cookie;
- if (!(nd->flags & LOOKUP_FOLLOW) || count++ == 32) {
+ if (!(nd->flags & LOOKUP_FOLLOW)) {
path_put_conditional(&path, nd);
path_put(&nd->path);
filp = ERR_PTR(-ELOOP);
break;
}
- /*
- * This is subtle. Instead of calling do_follow_link() we do
- * the thing by hands. The reason is that this way we have zero
- * link_count and path_walk() (called from ->follow_link)
- * honoring LOOKUP_PARENT. After that we have the parent and
- * last component, i.e. we are in the same situation as after
- * the first path_walk(). Well, almost - if the last component
- * is normal we get its copy stored in nd->last.name and we will
- * have to putname() it when we are done. Procfs-like symlinks
- * just set LAST_BIND.
- */
nd->flags |= LOOKUP_PARENT;
nd->flags &= ~(LOOKUP_OPEN|LOOKUP_CREATE|LOOKUP_EXCL);
- error = __do_follow_link(&link, nd, &cookie);
+ error = follow_link(&link, nd, &cookie);
if (unlikely(error))
filp = ERR_PTR(error);
else
filp = do_last(nd, &path, op, pathname);
- if (!IS_ERR(cookie) && linki->i_op->put_link)
- linki->i_op->put_link(link.dentry, nd, cookie);
- path_put(&link);
+ put_link(nd, &link, cookie);
}
out:
if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT))