switch vfs_path_lookup() to struct path
[deliverable/linux.git] / fs / namei.c
index 94fd0fa2d6470a459d7c62e6631a555460f28a98..7e6ba8c80e77b7a9bfef3e20f79fcea0fc22a1e7 100644 (file)
@@ -664,7 +664,7 @@ static int follow_automount(struct path *path, unsigned flags,
        /* We don't want to mount if someone supplied AT_NO_AUTOMOUNT
         * and this is the terminal part of the path.
         */
-       if ((flags & LOOKUP_NO_AUTOMOUNT) && !(flags & LOOKUP_CONTINUE))
+       if ((flags & LOOKUP_NO_AUTOMOUNT) && !(flags & LOOKUP_PARENT))
                return -EISDIR; /* we actually want to stop here */
 
        /* We want to mount if someone is trying to open/create a file of any
@@ -676,7 +676,7 @@ static int follow_automount(struct path *path, unsigned flags,
         * appended a '/' to the name.
         */
        if (!(flags & LOOKUP_FOLLOW) &&
-           !(flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY |
+           !(flags & (LOOKUP_PARENT | LOOKUP_DIRECTORY |
                       LOOKUP_OPEN | LOOKUP_CREATE)))
                return -EISDIR;
 
@@ -695,7 +695,7 @@ static int follow_automount(struct path *path, unsigned flags,
                 * the path being looked up; if it wasn't then the remainder of
                 * the path is inaccessible and we should say so.
                 */
-               if (PTR_ERR(mnt) == -EISDIR && (flags & LOOKUP_CONTINUE))
+               if (PTR_ERR(mnt) == -EISDIR && (flags & LOOKUP_PARENT))
                        return -EREMOTE;
                return PTR_ERR(mnt);
        }
@@ -1281,7 +1281,6 @@ static int link_path_walk(const char *name, struct nameidata *nd)
 {
        struct path next;
        int err;
-       unsigned int lookup_flags = nd->flags;
        
        while (*name=='/')
                name++;
@@ -1295,8 +1294,6 @@ static int link_path_walk(const char *name, struct nameidata *nd)
                unsigned int c;
                int type;
 
-               nd->flags |= LOOKUP_CONTINUE;
-
                err = may_lookup(nd);
                if (err)
                        break;
@@ -1358,8 +1355,6 @@ static int link_path_walk(const char *name, struct nameidata *nd)
                /* here ends the main loop */
 
 last_component:
-               /* Clear LOOKUP_CONTINUE iff it was previously unset */
-               nd->flags &= lookup_flags | ~LOOKUP_CONTINUE;
                nd->last = this;
                nd->last_type = type;
                return 0;
@@ -1580,16 +1575,22 @@ int kern_path(const char *name, unsigned int flags, struct path *path)
  * @mnt: pointer to vfs mount of the base directory
  * @name: pointer to file name
  * @flags: lookup flags
- * @nd: pointer to nameidata
+ * @path: pointer to struct path to fill
  */
 int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt,
                    const char *name, unsigned int flags,
-                   struct nameidata *nd)
+                   struct path *path)
 {
-       nd->root.dentry = dentry;
-       nd->root.mnt = mnt;
+       struct nameidata nd;
+       int err;
+       nd.root.dentry = dentry;
+       nd.root.mnt = mnt;
+       BUG_ON(flags & LOOKUP_PARENT);
        /* the first argument of do_path_lookup() is ignored with LOOKUP_ROOT */
-       return do_path_lookup(AT_FDCWD, name, flags | LOOKUP_ROOT, nd);
+       err = do_path_lookup(AT_FDCWD, name, flags | LOOKUP_ROOT, &nd);
+       if (!err)
+               *path = nd.path;
+       return err;
 }
 
 static struct dentry *__lookup_hash(struct qstr *name,
@@ -1965,27 +1966,10 @@ static int handle_truncate(struct file *filp)
        return error;
 }
 
-/*
- * Note that while the flag value (low two bits) for sys_open means:
- *     00 - read-only
- *     01 - write-only
- *     10 - read-write
- *     11 - special
- * it is changed into
- *     00 - no permissions needed
- *     01 - read-permission
- *     10 - write-permission
- *     11 - read-write
- * for the internal routines (ie open_namei()/follow_link() etc)
- * This is more logical, and also allows the 00 "no perm needed"
- * to be used for symlinks (where the permissions are checked
- * later).
- *
-*/
 static inline int open_to_namei_flags(int flag)
 {
-       if ((flag+1) & O_ACCMODE)
-               flag++;
+       if ((flag & O_ACCMODE) == 3)
+               flag--;
        return flag;
 }
 
@@ -2280,35 +2264,29 @@ struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt,
        return file;
 }
 
-/**
- * lookup_create - lookup a dentry, creating it if it doesn't exist
- * @nd: nameidata info
- * @is_dir: directory flag
- *
- * Simple function to lookup and return a dentry and create it
- * if it doesn't exist.  Is SMP-safe.
- *
- * Returns with nd->path.dentry->d_inode->i_mutex locked.
- */
-struct dentry *lookup_create(struct nameidata *nd, int is_dir)
+struct dentry *kern_path_create(int dfd, const char *pathname, struct path *path, int is_dir)
 {
        struct dentry *dentry = ERR_PTR(-EEXIST);
+       struct nameidata nd;
+       int error = do_path_lookup(dfd, pathname, LOOKUP_PARENT, &nd);
+       if (error)
+               return ERR_PTR(error);
 
-       mutex_lock_nested(&nd->path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
        /*
         * Yucky last component or no last component at all?
         * (foo/., foo/.., /////)
         */
-       if (nd->last_type != LAST_NORM)
-               goto fail;
-       nd->flags &= ~LOOKUP_PARENT;
-       nd->flags |= LOOKUP_CREATE | LOOKUP_EXCL;
-       nd->intent.open.flags = O_EXCL;
+       if (nd.last_type != LAST_NORM)
+               goto out;
+       nd.flags &= ~LOOKUP_PARENT;
+       nd.flags |= LOOKUP_CREATE | LOOKUP_EXCL;
+       nd.intent.open.flags = O_EXCL;
 
        /*
         * Do the final lookup.
         */
-       dentry = lookup_hash(nd);
+       mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
+       dentry = lookup_hash(&nd);
        if (IS_ERR(dentry))
                goto fail;
 
@@ -2320,18 +2298,35 @@ struct dentry *lookup_create(struct nameidata *nd, int is_dir)
         * all is fine. Let's be bastards - you had / on the end, you've
         * been asking for (non-existent) directory. -ENOENT for you.
         */
-       if (unlikely(!is_dir && nd->last.name[nd->last.len])) {
+       if (unlikely(!is_dir && nd.last.name[nd.last.len])) {
                dput(dentry);
                dentry = ERR_PTR(-ENOENT);
+               goto fail;
        }
+       *path = nd.path;
        return dentry;
 eexist:
        dput(dentry);
        dentry = ERR_PTR(-EEXIST);
 fail:
+       mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
+out:
+       path_put(&nd.path);
        return dentry;
 }
-EXPORT_SYMBOL_GPL(lookup_create);
+EXPORT_SYMBOL(kern_path_create);
+
+struct dentry *user_path_create(int dfd, const char __user *pathname, struct path *path, int is_dir)
+{
+       char *tmp = getname(pathname);
+       struct dentry *res;
+       if (IS_ERR(tmp))
+               return ERR_CAST(tmp);
+       res = kern_path_create(dfd, tmp, path, is_dir);
+       putname(tmp);
+       return res;
+}
+EXPORT_SYMBOL(user_path_create);
 
 int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
 {
@@ -2381,54 +2376,46 @@ static int may_mknod(mode_t mode)
 SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, int, mode,
                unsigned, dev)
 {
-       int error;
-       char *tmp;
        struct dentry *dentry;
-       struct nameidata nd;
+       struct path path;
+       int error;
 
        if (S_ISDIR(mode))
                return -EPERM;
 
-       error = user_path_parent(dfd, filename, &nd, &tmp);
-       if (error)
-               return error;
+       dentry = user_path_create(dfd, filename, &path, 0);
+       if (IS_ERR(dentry))
+               return PTR_ERR(dentry);
 
-       dentry = lookup_create(&nd, 0);
-       if (IS_ERR(dentry)) {
-               error = PTR_ERR(dentry);
-               goto out_unlock;
-       }
-       if (!IS_POSIXACL(nd.path.dentry->d_inode))
+       if (!IS_POSIXACL(path.dentry->d_inode))
                mode &= ~current_umask();
        error = may_mknod(mode);
        if (error)
                goto out_dput;
-       error = mnt_want_write(nd.path.mnt);
+       error = mnt_want_write(path.mnt);
        if (error)
                goto out_dput;
-       error = security_path_mknod(&nd.path, dentry, mode, dev);
+       error = security_path_mknod(&path, dentry, mode, dev);
        if (error)
                goto out_drop_write;
        switch (mode & S_IFMT) {
                case 0: case S_IFREG:
-                       error = vfs_create(nd.path.dentry->d_inode,dentry,mode,NULL);
+                       error = vfs_create(path.dentry->d_inode,dentry,mode,NULL);
                        break;
                case S_IFCHR: case S_IFBLK:
-                       error = vfs_mknod(nd.path.dentry->d_inode,dentry,mode,
+                       error = vfs_mknod(path.dentry->d_inode,dentry,mode,
                                        new_decode_dev(dev));
                        break;
                case S_IFIFO: case S_IFSOCK:
-                       error = vfs_mknod(nd.path.dentry->d_inode,dentry,mode,0);
+                       error = vfs_mknod(path.dentry->d_inode,dentry,mode,0);
                        break;
        }
 out_drop_write:
-       mnt_drop_write(nd.path.mnt);
+       mnt_drop_write(path.mnt);
 out_dput:
        dput(dentry);
-out_unlock:
-       mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
-       path_put(&nd.path);
-       putname(tmp);
+       mutex_unlock(&path.dentry->d_inode->i_mutex);
+       path_put(&path);
 
        return error;
 }
@@ -2461,38 +2448,29 @@ int vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 
 SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, int, mode)
 {
-       int error = 0;
-       char * tmp;
        struct dentry *dentry;
-       struct nameidata nd;
-
-       error = user_path_parent(dfd, pathname, &nd, &tmp);
-       if (error)
-               goto out_err;
+       struct path path;
+       int error;
 
-       dentry = lookup_create(&nd, 1);
-       error = PTR_ERR(dentry);
+       dentry = user_path_create(dfd, pathname, &path, 1);
        if (IS_ERR(dentry))
-               goto out_unlock;
+               return PTR_ERR(dentry);
 
-       if (!IS_POSIXACL(nd.path.dentry->d_inode))
+       if (!IS_POSIXACL(path.dentry->d_inode))
                mode &= ~current_umask();
-       error = mnt_want_write(nd.path.mnt);
+       error = mnt_want_write(path.mnt);
        if (error)
                goto out_dput;
-       error = security_path_mkdir(&nd.path, dentry, mode);
+       error = security_path_mkdir(&path, dentry, mode);
        if (error)
                goto out_drop_write;
-       error = vfs_mkdir(nd.path.dentry->d_inode, dentry, mode);
+       error = vfs_mkdir(path.dentry->d_inode, dentry, mode);
 out_drop_write:
-       mnt_drop_write(nd.path.mnt);
+       mnt_drop_write(path.mnt);
 out_dput:
        dput(dentry);
-out_unlock:
-       mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
-       path_put(&nd.path);
-       putname(tmp);
-out_err:
+       mutex_unlock(&path.dentry->d_inode->i_mutex);
+       path_put(&path);
        return error;
 }
 
@@ -2752,38 +2730,31 @@ SYSCALL_DEFINE3(symlinkat, const char __user *, oldname,
 {
        int error;
        char *from;
-       char *to;
        struct dentry *dentry;
-       struct nameidata nd;
+       struct path path;
 
        from = getname(oldname);
        if (IS_ERR(from))
                return PTR_ERR(from);
 
-       error = user_path_parent(newdfd, newname, &nd, &to);
-       if (error)
-               goto out_putname;
-
-       dentry = lookup_create(&nd, 0);
+       dentry = user_path_create(newdfd, newname, &path, 0);
        error = PTR_ERR(dentry);
        if (IS_ERR(dentry))
-               goto out_unlock;
+               goto out_putname;
 
-       error = mnt_want_write(nd.path.mnt);
+       error = mnt_want_write(path.mnt);
        if (error)
                goto out_dput;
-       error = security_path_symlink(&nd.path, dentry, from);
+       error = security_path_symlink(&path, dentry, from);
        if (error)
                goto out_drop_write;
-       error = vfs_symlink(nd.path.dentry->d_inode, dentry, from);
+       error = vfs_symlink(path.dentry->d_inode, dentry, from);
 out_drop_write:
-       mnt_drop_write(nd.path.mnt);
+       mnt_drop_write(path.mnt);
 out_dput:
        dput(dentry);
-out_unlock:
-       mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
-       path_put(&nd.path);
-       putname(to);
+       mutex_unlock(&path.dentry->d_inode->i_mutex);
+       path_put(&path);
 out_putname:
        putname(from);
        return error;
@@ -2848,11 +2819,9 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname,
                int, newdfd, const char __user *, newname, int, flags)
 {
        struct dentry *new_dentry;
-       struct nameidata nd;
-       struct path old_path;
+       struct path old_path, new_path;
        int how = 0;
        int error;
-       char *to;
 
        if ((flags & ~(AT_SYMLINK_FOLLOW | AT_EMPTY_PATH)) != 0)
                return -EINVAL;
@@ -2874,32 +2843,27 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname,
        if (error)
                return error;
 
-       error = user_path_parent(newdfd, newname, &nd, &to);
-       if (error)
-               goto out;
-       error = -EXDEV;
-       if (old_path.mnt != nd.path.mnt)
-               goto out_release;
-       new_dentry = lookup_create(&nd, 0);
+       new_dentry = user_path_create(newdfd, newname, &new_path, 0);
        error = PTR_ERR(new_dentry);
        if (IS_ERR(new_dentry))
-               goto out_unlock;
-       error = mnt_want_write(nd.path.mnt);
+               goto out;
+
+       error = -EXDEV;
+       if (old_path.mnt != new_path.mnt)
+               goto out_dput;
+       error = mnt_want_write(new_path.mnt);
        if (error)
                goto out_dput;
-       error = security_path_link(old_path.dentry, &nd.path, new_dentry);
+       error = security_path_link(old_path.dentry, &new_path, new_dentry);
        if (error)
                goto out_drop_write;
-       error = vfs_link(old_path.dentry, nd.path.dentry->d_inode, new_dentry);
+       error = vfs_link(old_path.dentry, new_path.dentry->d_inode, new_dentry);
 out_drop_write:
-       mnt_drop_write(nd.path.mnt);
+       mnt_drop_write(new_path.mnt);
 out_dput:
        dput(new_dentry);
-out_unlock:
-       mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
-out_release:
-       path_put(&nd.path);
-       putname(to);
+       mutex_unlock(&new_path.dentry->d_inode->i_mutex);
+       path_put(&new_path);
 out:
        path_put(&old_path);
 
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