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@xxxxxx>
---
fs/namei.c | 27 +++++++++++++++++----------
fs/proc/base.c | 3 +--
include/linux/namei.h | 2 ++
3 files changed, 20 insertions(+), 12 deletions(-)
Index: linux-2.6/fs/namei.c
===================================================================
--- linux-2.6.orig/fs/namei.c 2012-06-18 15:04:54.004355716 +0200
+++ linux-2.6/fs/namei.c 2012-06-18 15:08:29.572361238 +0200
@@ -586,6 +586,21 @@ static inline void path_to_nameidata(con
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;
@@ -630,17 +645,9 @@ follow_link(struct path *link, struct na
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;
Index: linux-2.6/include/linux/namei.h
===================================================================
--- linux-2.6.orig/include/linux/namei.h 2012-06-18 15:04:54.004355716 +0200
+++ linux-2.6/include/linux/namei.h 2012-06-18 15:05:41.292356924 +0200
@@ -80,6 +80,8 @@ extern int follow_up(struct path *);
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;
Index: linux-2.6/fs/proc/base.c
===================================================================
--- linux-2.6.orig/fs/proc/base.c 2012-06-18 15:04:54.004355716 +0200
+++ linux-2.6/fs/proc/base.c 2012-06-18 15:05:41.296356925 +0200
@@ -1438,8 +1438,7 @@ static void *proc_pid_follow_link(struct
if (error)
goto out;
- path_put(&nd->path);
- nd->path = path;
+ nd_jump_link(nd, &path);
return NULL;
out:
return ERR_PTR(error);
--
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