fs: add nd_jump_link
Add a helper that abstracts out the jump to an already parsed struct path
from ->follow_link operation from procfs. Not only does this clean up
the code by moving the two sides of this game into a single helper, but
it also prepares for making struct nameidata private to namei.c
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namei.c b/fs/namei.c
index 2d4091d..0037587 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -615,6 +615,21 @@
nd->path.dentry = path->dentry;
}
+/*
+ * Helper to directly jump to a known parsed path from ->follow_link,
+ * caller must have taken a reference to path beforehand.
+ */
+void nd_jump_link(struct nameidata *nd, struct path *path)
+{
+ path_put(&nd->path);
+
+ nd->path = *path;
+ nd->inode = nd->path.dentry->d_inode;
+ nd->flags |= LOOKUP_JUMPED;
+
+ BUG_ON(nd->inode->i_op->follow_link);
+}
+
static inline void put_link(struct nameidata *nd, struct path *link, void *cookie)
{
struct inode *inode = link->dentry->d_inode;
@@ -659,17 +674,9 @@
s = nd_get_link(nd);
if (s) {
error = __vfs_follow_link(nd, s);
- } else if (nd->last_type == LAST_BIND) {
- nd->flags |= LOOKUP_JUMPED;
- nd->inode = nd->path.dentry->d_inode;
- if (nd->inode->i_op->follow_link) {
- /* stepped on a _really_ weird one */
- path_put(&nd->path);
- error = -ELOOP;
- }
+ if (unlikely(error))
+ put_link(nd, link, *p);
}
- if (unlikely(error))
- put_link(nd, link, *p);
return error;
diff --git a/fs/proc/base.c b/fs/proc/base.c
index c7e35cb..a8652a1 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1477,8 +1477,7 @@
if (error)
goto out;
- path_put(&nd->path);
- nd->path = path;
+ nd_jump_link(nd, &path);
return NULL;
out:
return ERR_PTR(error);
diff --git a/include/linux/namei.h b/include/linux/namei.h
index f8ed286..c070679 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -81,6 +81,8 @@
extern struct dentry *lock_rename(struct dentry *, struct dentry *);
extern void unlock_rename(struct dentry *, struct dentry *);
+extern void nd_jump_link(struct nameidata *nd, struct path *path);
+
static inline void nd_set_link(struct nameidata *nd, char *path)
{
nd->saved_names[nd->depth] = path;