1 files changed, 41 insertions, 27 deletions

diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c
index d4298a751d4a..08f3f66e4b38 100644
--- a/fs/smb/server/vfs.c
+++ b/fs/smb/server/vfs.c
@@ -98,6 +98,13 @@ static int ksmbd_vfs_path_lookup_locked(struct ksmbd_share_config *share_conf,
 		return -ENOENT;
 	}
 
+	err = mnt_want_write(parent_path->mnt);
+	if (err) {
+		path_put(parent_path);
+		putname(filename);
+		return -ENOENT;
+	}
+
 	inode_lock_nested(parent_path->dentry->d_inode, I_MUTEX_PARENT);
 	d = lookup_one_qstr_excl(&last, parent_path->dentry, 0);
 	if (IS_ERR(d))
@@ -124,6 +131,7 @@ static int ksmbd_vfs_path_lookup_locked(struct ksmbd_share_config *share_conf,
 
 err_out:
 	inode_unlock(d_inode(parent_path->dentry));
+	mnt_drop_write(parent_path->mnt);
 	path_put(parent_path);
 	putname(filename);
 	return -ENOENT;
@@ -452,7 +460,8 @@ static int ksmbd_vfs_stream_write(struct ksmbd_file *fp, char *buf, loff_t *pos,
 				 fp->stream.name,
 				 (void *)stream_buf,
 				 size,
-				 0);
+				 0,
+				 true);
 	if (err < 0)
 		goto out;
 
@@ -594,10 +603,6 @@ int ksmbd_vfs_remove_file(struct ksmbd_work *work, const struct path *path)
 		goto out_err;
 	}
 
-	err = mnt_want_write(path->mnt);
-	if (err)
-		goto out_err;
-
 	user_ns = mnt_user_ns(path->mnt);
 	if (S_ISDIR(d_inode(path->dentry)->i_mode)) {
 		err = vfs_rmdir(user_ns, d_inode(parent), path->dentry);
@@ -608,7 +613,6 @@ int ksmbd_vfs_remove_file(struct ksmbd_work *work, const struct path *path)
 		if (err)
 			ksmbd_debug(VFS, "unlink failed, err %d\n", err);
 	}
-	mnt_drop_write(path->mnt);
 
 out_err:
 	ksmbd_revert_fsids(work);
@@ -908,18 +912,22 @@ ssize_t ksmbd_vfs_getxattr(struct user_namespace *user_ns,
  * @attr_value:	xattr value to set
  * @attr_size:	size of xattr value
  * @flags:	destination buffer length
+ * @get_write:	get write access to a mount
  *
  * Return:	0 on success, otherwise error
  */
 int ksmbd_vfs_setxattr(struct user_namespace *user_ns,
 		       const struct path *path, const char *attr_name,
-		       void *attr_value, size_t attr_size, int flags)
+		       void *attr_value, size_t attr_size, int flags,
+		       bool get_write)
 {
 	int err;
 
-	err = mnt_want_write(path->mnt);
-	if (err)
-		return err;
+	if (get_write == true) {
+		err = mnt_want_write(path->mnt);
+		if (err)
+			return err;
+	}
 
 	err = vfs_setxattr(user_ns,
 			   path->dentry,
@@ -929,7 +937,8 @@ int ksmbd_vfs_setxattr(struct user_namespace *user_ns,
 			   flags);
 	if (err)
 		ksmbd_debug(VFS, "setxattr failed, err %d\n", err);
-	mnt_drop_write(path->mnt);
+	if (get_write == true)
+		mnt_drop_write(path->mnt);
 	return err;
 }
 
@@ -1253,6 +1262,13 @@ out1:
 	}
 
 	if (!err) {
+		err = mnt_want_write(parent_path->mnt);
+		if (err) {
+			path_put(path);
+			path_put(parent_path);
+			return err;
+		}
+
 		err = ksmbd_vfs_lock_parent(parent_path->dentry, path->dentry);
 		if (err) {
 			path_put(path);
@@ -1262,6 +1278,14 @@ out1:
 	return err;
 }
 
+void ksmbd_vfs_kern_path_unlock(struct path *parent_path, struct path *path)
+{
+	inode_unlock(d_inode(parent_path->dentry));
+	mnt_drop_write(parent_path->mnt);
+	path_put(path);
+	path_put(parent_path);
+}
+
 struct dentry *ksmbd_vfs_kern_path_create(struct ksmbd_work *work,
 					  const char *name,
 					  unsigned int flags,
@@ -1411,7 +1435,8 @@ out:
 int ksmbd_vfs_set_sd_xattr(struct ksmbd_conn *conn,
 			   struct user_namespace *user_ns,
 			   const struct path *path,
-			   struct smb_ntsd *pntsd, int len)
+			   struct smb_ntsd *pntsd, int len,
+			   bool get_write)
 {
 	int rc;
 	struct ndr sd_ndr = {0}, acl_ndr = {0};
@@ -1471,7 +1496,7 @@ int ksmbd_vfs_set_sd_xattr(struct ksmbd_conn *conn,
 
 	rc = ksmbd_vfs_setxattr(user_ns, path,
 				XATTR_NAME_SD, sd_ndr.data,
-				sd_ndr.offset, 0);
+				sd_ndr.offset, 0, get_write);
 	if (rc < 0)
 		pr_err("Failed to store XATTR ntacl :%d\n", rc);
 
@@ -1560,7 +1585,8 @@ free_n_data:
 
 int ksmbd_vfs_set_dos_attrib_xattr(struct user_namespace *user_ns,
 				   const struct path *path,
-				   struct xattr_dos_attrib *da)
+				   struct xattr_dos_attrib *da,
+				   bool get_write)
 {
 	struct ndr n;
 	int err;
@@ -1570,7 +1596,7 @@ int ksmbd_vfs_set_dos_attrib_xattr(struct user_namespace *user_ns,
 		return err;
 
 	err = ksmbd_vfs_setxattr(user_ns, path, XATTR_NAME_DOS_ATTRIBUTE,
-				 (void *)n.data, n.offset, 0);
+				 (void *)n.data, n.offset, 0, get_write);
 	if (err)
 		ksmbd_debug(SMB, "failed to store dos attribute in xattr\n");
 	kfree(n.data);
@@ -1840,10 +1866,6 @@ int ksmbd_vfs_set_init_posix_acl(struct user_namespace *user_ns,
 	}
 	posix_state_to_acl(&acl_state, acls->a_entries);
 
-	rc = mnt_want_write(path->mnt);
-	if (rc)
-		goto out_err;
-
 	rc = set_posix_acl(user_ns, inode, ACL_TYPE_ACCESS, acls);
 	if (rc < 0)
 		ksmbd_debug(SMB, "Set posix acl(ACL_TYPE_ACCESS) failed, rc : %d\n",
@@ -1856,9 +1878,7 @@ int ksmbd_vfs_set_init_posix_acl(struct user_namespace *user_ns,
 			ksmbd_debug(SMB, "Set posix acl(ACL_TYPE_DEFAULT) failed, rc : %d\n",
 				    rc);
 	}
-	mnt_drop_write(path->mnt);
 
-out_err:
 	free_acl_state(&acl_state);
 	posix_acl_release(acls);
 	return rc;
@@ -1887,10 +1907,6 @@ int ksmbd_vfs_inherit_posix_acl(struct user_namespace *user_ns,
 		}
 	}
 
-	rc = mnt_want_write(path->mnt);
-	if (rc)
-		goto out_err;
-
 	rc = set_posix_acl(user_ns, inode, ACL_TYPE_ACCESS, acls);
 	if (rc < 0)
 		ksmbd_debug(SMB, "Set posix acl(ACL_TYPE_ACCESS) failed, rc : %d\n",
@@ -1902,9 +1918,7 @@ int ksmbd_vfs_inherit_posix_acl(struct user_namespace *user_ns,
 			ksmbd_debug(SMB, "Set posix acl(ACL_TYPE_DEFAULT) failed, rc : %d\n",
 				    rc);
 	}
-	mnt_drop_write(path->mnt);
 
-out_err:
 	posix_acl_release(acls);
 	return rc;
 }