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authorChristoph Hellwig <hch@infradead.org>2012-06-18 10:47:04 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2012-07-14 16:35:40 +0400
commitb5fb63c18315c5510c1d0636179c057e0c761c77 (patch)
tree19e42c9aa285eb64c277ece4083d4834351b3d5b
parent408ef013cc9e2f94a14f7ccbbe52ddfb18437a99 (diff)
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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>
-rw-r--r--fs/namei.c27
-rw-r--r--fs/proc/base.c3
-rw-r--r--include/linux/namei.h2
3 files changed, 20 insertions, 12 deletions
diff --git a/fs/namei.c b/fs/namei.c
index a9b94c62c303..0e1b9c3eb36d 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -586,6 +586,21 @@ static inline void path_to_nameidata(const struct path *path,
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 nameidata *nd, void **p)
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 3bd5ac1ff018..2772208338f8 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1438,8 +1438,7 @@ static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
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 f5931489e150..d2ef8b34b967 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -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;