btrfs: use struct qstr for subvolume ioctl helpers

We pass name and length of subvolumes separately to the related
functions, while this can be a struct qstr which is otherwise used for
dentry interfaces.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index c49df25be7da6568e01f3bfcf5b29d7504f803d7..99c701ec58056b55df7601cb6daad707fd5b7615 100644 (file)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -894,22 +894,21 @@ static inline int btrfs_may_create(struct mnt_idmap *idmap,
  */
 static noinline int btrfs_mksubvol(const struct path *parent,
                                   struct mnt_idmap *idmap,
-                                  const char *name, int namelen,
-                                  struct btrfs_root *snap_src,
+                                  struct qstr *qname, struct btrfs_root *snap_src,
                                   bool readonly,
                                   struct btrfs_qgroup_inherit *inherit)
 {
        struct inode *dir = d_inode(parent->dentry);
        struct btrfs_fs_info *fs_info = inode_to_fs_info(dir);
        struct dentry *dentry;
-       struct fscrypt_str name_str = FSTR_INIT((char *)name, namelen);
+       struct fscrypt_str name_str = FSTR_INIT((char *)qname->name, qname->len);
        int ret;
 
        ret = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
        if (ret == -EINTR)
                return ret;
 
-       dentry = lookup_one(idmap, &QSTR_LEN(name, namelen), parent->dentry);
+       dentry = lookup_one(idmap, qname, parent->dentry);
        ret = PTR_ERR(dentry);
        if (IS_ERR(dentry))
                goto out_unlock;
@@ -949,7 +948,7 @@ out_unlock:
 
 static noinline int btrfs_mksnapshot(const struct path *parent,
                                   struct mnt_idmap *idmap,
-                                  const char *name, int namelen,
+                                  struct qstr *qname,
                                   struct btrfs_root *root,
                                   bool readonly,
                                   struct btrfs_qgroup_inherit *inherit)
@@ -976,8 +975,8 @@ static noinline int btrfs_mksnapshot(const struct path *parent,
 
        btrfs_wait_ordered_extents(root, U64_MAX, NULL);
 
-       ret = btrfs_mksubvol(parent, idmap, name, namelen,
-                            root, readonly, inherit);
+       ret = btrfs_mksubvol(parent, idmap, qname, root, readonly, inherit);
+
        atomic_dec(&root->snapshot_force_cow);
 out:
        btrfs_drew_read_unlock(&root->snapshot_lock);
@@ -1187,8 +1186,8 @@ static noinline int __btrfs_ioctl_snap_create(struct file *file,
                                bool readonly,
                                struct btrfs_qgroup_inherit *inherit)
 {
-       int namelen;
        int ret = 0;
+       struct qstr qname = QSTR_INIT(name, strlen(name));
 
        if (!S_ISDIR(file_inode(file)->i_mode))
                return -ENOTDIR;
@@ -1197,21 +1196,20 @@ static noinline int __btrfs_ioctl_snap_create(struct file *file,
        if (ret)
                goto out;
 
-       namelen = strlen(name);
        if (strchr(name, '/')) {
                ret = -EINVAL;
                goto out_drop_write;
        }
 
-       if (name[0] == '.' &&
-          (namelen == 1 || (name[1] == '.' && namelen == 2))) {
+       if (qname.name[0] == '.' &&
+          (qname.len == 1 || (qname.name[1] == '.' && qname.len == 2))) {
                ret = -EEXIST;
                goto out_drop_write;
        }
 
        if (subvol) {
-               ret = btrfs_mksubvol(&file->f_path, idmap, name,
-                                    namelen, NULL, readonly, inherit);
+               ret = btrfs_mksubvol(&file->f_path, idmap, &qname, NULL,
+                                    readonly, inherit);
        } else {
                CLASS(fd, src)(fd);
                struct inode *src_inode;
@@ -1241,8 +1239,7 @@ static noinline int __btrfs_ioctl_snap_create(struct file *file,
                         */
                        ret = -EINVAL;
                } else {
-                       ret = btrfs_mksnapshot(&file->f_path, idmap,
-                                              name, namelen,
+                       ret = btrfs_mksnapshot(&file->f_path, idmap, &qname,
                                               BTRFS_I(src_inode)->root,
                                               readonly, inherit);
                }