namei.c: take "jump to root" into a new helper
... and use it both in path_init() (for absolute pathnames) and
get_link() (for absolute symlinks).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namei.c b/fs/namei.c
index a08018b..0baf64b 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -841,6 +841,26 @@
nd->path.dentry = path->dentry;
}
+static int nd_jump_root(struct nameidata *nd)
+{
+ if (nd->flags & LOOKUP_RCU) {
+ struct dentry *d;
+ nd->path = nd->root;
+ d = nd->path.dentry;
+ nd->inode = d->d_inode;
+ nd->seq = nd->root_seq;
+ if (unlikely(read_seqcount_retry(&d->d_seq, nd->seq)))
+ return -ECHILD;
+ } else {
+ path_put(&nd->path);
+ nd->path = nd->root;
+ path_get(&nd->path);
+ nd->inode = nd->path.dentry->d_inode;
+ }
+ nd->flags |= LOOKUP_JUMPED;
+ return 0;
+}
+
/*
* Helper to directly jump to a known parsed path from ->follow_link,
* caller must have taken a reference to path beforehand.
@@ -1017,21 +1037,8 @@
if (*res == '/') {
if (!nd->root.mnt)
set_root(nd);
- if (nd->flags & LOOKUP_RCU) {
- struct dentry *d;
- nd->path = nd->root;
- d = nd->path.dentry;
- nd->inode = d->d_inode;
- nd->seq = nd->root_seq;
- if (unlikely(read_seqcount_retry(&d->d_seq, nd->seq)))
- return ERR_PTR(-ECHILD);
- } else {
- path_put(&nd->path);
- nd->path = nd->root;
- path_get(&nd->root);
- nd->inode = nd->path.dentry->d_inode;
- }
- nd->flags |= LOOKUP_JUMPED;
+ if (unlikely(nd_jump_root(nd)))
+ return ERR_PTR(-ECHILD);
while (unlikely(*++res == '/'))
;
}
@@ -2015,26 +2022,17 @@
}
nd->root.mnt = NULL;
+ nd->path.mnt = NULL;
+ nd->path.dentry = NULL;
nd->m_seq = read_seqbegin(&mount_lock);
if (*s == '/') {
if (flags & LOOKUP_RCU)
rcu_read_lock();
set_root(nd);
- if (flags & LOOKUP_RCU) {
- nd->seq = nd->root_seq;
- nd->path = nd->root;
- } else {
- path_get(&nd->root);
- nd->path = nd->root;
- }
- nd->inode = nd->path.dentry->d_inode;
- if (!(flags & LOOKUP_RCU))
+ if (likely(!nd_jump_root(nd)))
return s;
- if (likely(!read_seqcount_retry(&nd->path.dentry->d_seq, nd->seq)))
- return s;
- if (!(nd->flags & LOOKUP_ROOT))
- nd->root.mnt = NULL;
+ nd->root.mnt = NULL;
rcu_read_unlock();
return ERR_PTR(-ECHILD);
} else if (nd->dfd == AT_FDCWD) {