don't bugger nd->seq on set_root_rcu() from follow_dotdot_rcu()

[karo-tx-linux.git] / fs / namei.c

diff --git a/fs/namei.c b/fs/namei.c
index 3d1dc745f9d8c168b4b8500371482a2b04609139..fe47e6d8e85fd4b3ebee6352aae0e2c96e2a61eb 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -643,24 +643,22 @@ static int complete_walk(struct nameidata *nd)
 
 static __always_inline void set_root(struct nameidata *nd)
 {
-       if (!nd->root.mnt)
-               get_fs_root(current->fs, &nd->root);
+       get_fs_root(current->fs, &nd->root);
 }
 
 static int link_path_walk(const char *, struct nameidata *);
 
-static __always_inline void set_root_rcu(struct nameidata *nd)
+static __always_inline unsigned set_root_rcu(struct nameidata *nd)
 {
-       if (!nd->root.mnt) {
-               struct fs_struct *fs = current->fs;
-               unsigned seq;
+       struct fs_struct *fs = current->fs;
+       unsigned seq, res;
 
-               do {
-                       seq = read_seqcount_begin(&fs->seq);
-                       nd->root = fs->root;
-                       nd->seq = __read_seqcount_begin(&nd->root.dentry->d_seq);
-               } while (read_seqcount_retry(&fs->seq, seq));
-       }
+       do {
+               seq = read_seqcount_begin(&fs->seq);
+               nd->root = fs->root;
+               res = __read_seqcount_begin(&nd->root.dentry->d_seq);
+       } while (read_seqcount_retry(&fs->seq, seq));
+       return res;
 }
 
 static void path_put_conditional(struct path *path, struct nameidata *nd)
@@ -860,7 +858,8 @@ follow_link(struct path *link, struct nameidata *nd, void **p)
                        return PTR_ERR(s);
                }
                if (*s == '/') {
-                       set_root(nd);
+                       if (!nd->root.mnt)
+                               set_root(nd);
                        path_put(&nd->path);
                        nd->path = nd->root;
                        path_get(&nd->root);
@@ -1143,7 +1142,8 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path,
 
 static int follow_dotdot_rcu(struct nameidata *nd)
 {
-       set_root_rcu(nd);
+       if (!nd->root.mnt)
+               set_root_rcu(nd);
 
        while (1) {
                if (nd->path.dentry == nd->root.dentry &&
@@ -1256,7 +1256,8 @@ static void follow_mount(struct path *path)
 
 static void follow_dotdot(struct nameidata *nd)
 {
-       set_root(nd);
+       if (!nd->root.mnt)
+               set_root(nd);
 
        while(1) {
                struct dentry *old = nd->path.dentry;
@@ -1852,7 +1853,7 @@ static int path_init(int dfd, const char *name, unsigned int flags,
        if (*name=='/') {
                if (flags & LOOKUP_RCU) {
                        rcu_read_lock();
-                       set_root_rcu(nd);
+                       nd->seq = set_root_rcu(nd);
                } else {
                        set_root(nd);
                        path_get(&nd->root);