mfd: Fix cs5535 warning on x86-64

[firefly-linux-kernel-4.4.55.git] / fs / namei.c

diff --git a/fs/namei.c b/fs/namei.c
index 24ece10470b67b751f2cd7a48ed3b8ff2a1e2979..86643302079e33e010d29ae18d2fb392723c57bb 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -479,6 +479,14 @@ static int nameidata_dentry_drop_rcu(struct nameidata *nd, struct dentry *dentry
        struct fs_struct *fs = current->fs;
        struct dentry *parent = nd->path.dentry;
 
+       /*
+        * It can be possible to revalidate the dentry that we started
+        * the path walk with. force_reval_path may also revalidate the
+        * dentry already committed to the nameidata.
+        */
+       if (unlikely(parent == dentry))
+               return nameidata_drop_rcu(nd);
+
        BUG_ON(!(nd->flags & LOOKUP_RCU));
        if (nd->root.mnt) {
                spin_lock(&fs->lock);
@@ -583,6 +591,13 @@ void release_open_intent(struct nameidata *nd)
                fput(nd->intent.open.file);
 }
 
+/*
+ * Call d_revalidate and handle filesystems that request rcu-walk
+ * to be dropped. This may be called and return in rcu-walk mode,
+ * regardless of success or error. If -ECHILD is returned, the caller
+ * must return -ECHILD back up the path walk stack so path walk may
+ * be restarted in ref-walk mode.
+ */
 static int d_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
        int status;
@@ -673,6 +688,9 @@ force_reval_path(struct path *path, struct nameidata *nd)
                return 0;
 
        if (!status) {
+               /* Don't d_invalidate in rcu-walk mode */
+               if (nameidata_drop_rcu(nd))
+                       return -ECHILD;
                d_invalidate(dentry);
                status = -ESTALE;
        }
@@ -1950,8 +1968,9 @@ int may_open(struct path *path, int acc_mode, int flag)
        return break_lease(inode, flag);
 }
 
-static int handle_truncate(struct path *path)
+static int handle_truncate(struct file *filp)
 {
+       struct path *path = &filp->f_path;
        struct inode *inode = path->dentry->d_inode;
        int error = get_write_access(inode);
        if (error)
@@ -1965,7 +1984,7 @@ static int handle_truncate(struct path *path)
        if (!error) {
                error = do_truncate(path->dentry, 0,
                                    ATTR_MTIME|ATTR_CTIME|ATTR_OPEN,
-                                   NULL);
+                                   filp);
        }
        put_write_access(inode);
        return error;
@@ -2063,7 +2082,7 @@ static struct file *finish_open(struct nameidata *nd,
        }
        if (!IS_ERR(filp)) {
                if (will_truncate) {
-                       error = handle_truncate(&nd->path);
+                       error = handle_truncate(filp);
                        if (error) {
                                fput(filp);
                                filp = ERR_PTR(error);
@@ -2104,11 +2123,13 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
                dir = nd->path.dentry;
        case LAST_DOT:
                if (need_reval_dot(dir)) {
-                       error = d_revalidate(nd->path.dentry, nd);
-                       if (!error)
-                               error = -ESTALE;
-                       if (error < 0)
+                       int status = d_revalidate(nd->path.dentry, nd);
+                       if (!status)
+                               status = -ESTALE;
+                       if (status < 0) {
+                               error = status;
                                goto exit;
+                       }
                }
                /* fallthrough */
        case LAST_ROOT: