vfs: make path_openat take a struct filename pointer

[deliverable/linux.git] / fs / namei.c

diff --git a/fs/namei.c b/fs/namei.c
index 5dbc3f83693476396deccfd7d182ef04555f1f81..6bbd8fdfb1f55319a5d97bd023f19d3b7b3d7cf4 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1988,20 +1988,30 @@ static int path_lookupat(int dfd, const char *name,
        return err;
 }
 
-static int do_path_lookup(int dfd, const char *name,
+static int filename_lookup(int dfd, struct filename *name,
                                unsigned int flags, struct nameidata *nd)
 {
-       int retval = path_lookupat(dfd, name, flags | LOOKUP_RCU, nd);
+       int retval = path_lookupat(dfd, name->name, flags | LOOKUP_RCU, nd);
        if (unlikely(retval == -ECHILD))
-               retval = path_lookupat(dfd, name, flags, nd);
+               retval = path_lookupat(dfd, name->name, flags, nd);
        if (unlikely(retval == -ESTALE))
-               retval = path_lookupat(dfd, name, flags | LOOKUP_REVAL, nd);
+               retval = path_lookupat(dfd, name->name,
+                                               flags | LOOKUP_REVAL, nd);
 
        if (likely(!retval))
-               audit_inode(name, nd->path.dentry, flags & LOOKUP_PARENT);
+               audit_inode(name->name, nd->path.dentry,
+                                               flags & LOOKUP_PARENT);
        return retval;
 }
 
+static int do_path_lookup(int dfd, const char *name,
+                               unsigned int flags, struct nameidata *nd)
+{
+       struct filename filename = { .name = name };
+
+       return filename_lookup(dfd, &filename, flags, nd);
+}
+
 /* does lookup, returns the object with parent locked */
 struct dentry *kern_path_locked(const char *name, struct path *path)
 {
@@ -2125,7 +2135,7 @@ int user_path_at_empty(int dfd, const char __user *name, unsigned flags,
 
                BUG_ON(flags & LOOKUP_PARENT);
 
-               err = do_path_lookup(dfd, tmp->name, flags, &nd);
+               err = filename_lookup(dfd, tmp, flags, &nd);
                putname(tmp);
                if (!err)
                        *path = nd.path;
@@ -2139,6 +2149,12 @@ int user_path_at(int dfd, const char __user *name, unsigned flags,
        return user_path_at_empty(dfd, name, flags, path, NULL);
 }
 
+/*
+ * NB: most callers don't do anything directly with the reference to the
+ *     to struct filename, but the nd->last pointer points into the name string
+ *     allocated by getname. So we must hold the reference to it until all
+ *     path-walking is complete.
+ */
 static struct filename *
 user_path_parent(int dfd, const char __user *path, struct nameidata *nd)
 {
@@ -2148,7 +2164,7 @@ user_path_parent(int dfd, const char __user *path, struct nameidata *nd)
        if (IS_ERR(s))
                return s;
 
-       error = do_path_lookup(dfd, s->name, LOOKUP_PARENT, nd);
+       error = filename_lookup(dfd, s, LOOKUP_PARENT, nd);
        if (error) {
                putname(s);
                return ERR_PTR(error);
@@ -2646,7 +2662,7 @@ out_dput:
  */
 static int do_last(struct nameidata *nd, struct path *path,
                   struct file *file, const struct open_flags *op,
-                  int *opened, const char *pathname)
+                  int *opened, struct filename *name)
 {
        struct dentry *dir = nd->path.dentry;
        int open_flag = op->open_flag;
@@ -2658,6 +2674,7 @@ static int do_last(struct nameidata *nd, struct path *path,
        struct path save_parent = { .dentry = NULL, .mnt = NULL };
        bool retried = false;
        int error;
+       const char *pathname = name->name;
 
        nd->flags &= ~LOOKUP_PARENT;
        nd->flags |= op->intent;
@@ -2892,7 +2909,7 @@ stale_open:
        goto retry_lookup;
 }
 
-static struct file *path_openat(int dfd, const char *pathname,
+static struct file *path_openat(int dfd, struct filename *pathname,
                struct nameidata *nd, const struct open_flags *op, int flags)
 {
        struct file *base = NULL;
@@ -2907,12 +2924,12 @@ static struct file *path_openat(int dfd, const char *pathname,
 
        file->f_flags = op->open_flag;
 
-       error = path_init(dfd, pathname, flags | LOOKUP_PARENT, nd, &base);
+       error = path_init(dfd, pathname->name, flags | LOOKUP_PARENT, nd, &base);
        if (unlikely(error))
                goto out;
 
        current->total_link_count = 0;
-       error = link_path_walk(pathname, nd);
+       error = link_path_walk(pathname->name, nd);
        if (unlikely(error))
                goto out;
 
@@ -2958,7 +2975,7 @@ out:
        return file;
 }
 
-struct file *do_filp_open(int dfd, const char *pathname,
+struct file *do_filp_open(int dfd, struct filename *pathname,
                const struct open_flags *op, int flags)
 {
        struct nameidata nd;
@@ -2977,6 +2994,7 @@ struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt,
 {
        struct nameidata nd;
        struct file *file;
+       struct filename filename = { .name = name };
 
        nd.root.mnt = mnt;
        nd.root.dentry = dentry;
@@ -2986,11 +3004,11 @@ struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt,
        if (dentry->d_inode->i_op->follow_link && op->intent & LOOKUP_OPEN)
                return ERR_PTR(-ELOOP);
 
-       file = path_openat(-1, name, &nd, op, flags | LOOKUP_RCU);
+       file = path_openat(-1, &filename, &nd, op, flags | LOOKUP_RCU);
        if (unlikely(file == ERR_PTR(-ECHILD)))
-               file = path_openat(-1, name, &nd, op, flags);
+               file = path_openat(-1, &filename, &nd, op, flags);
        if (unlikely(file == ERR_PTR(-ESTALE)))
-               file = path_openat(-1, name, &nd, op, flags | LOOKUP_REVAL);
+               file = path_openat(-1, &filename, &nd, op, flags | LOOKUP_REVAL);
        return file;
 }