vfs: create a generic checking function for FS_IOC_FSSETXATTR

Create a generic checking function for the incoming FS_IOC_FSSETXATTR
fsxattr values so that we can standardize some of the implementation
behaviors.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>

1 files changed, 40 insertions, 29 deletions

diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index d7dfc13f30f5..458a7043b4d2 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -879,37 +879,44 @@ xfs_di2lxflags(
 	return flags;
 }
 
-STATIC int
-xfs_ioc_fsgetxattr(
-	xfs_inode_t		*ip,
-	int			attr,
-	void			__user *arg)
+static void
+xfs_fill_fsxattr(
+	struct xfs_inode	*ip,
+	bool			attr,
+	struct fsxattr		*fa)
 {
-	struct fsxattr		fa;
-
-	memset(&fa, 0, sizeof(struct fsxattr));
-
-	xfs_ilock(ip, XFS_ILOCK_SHARED);
-	fa.fsx_xflags = xfs_ip2xflags(ip);
-	fa.fsx_extsize = ip->i_d.di_extsize << ip->i_mount->m_sb.sb_blocklog;
-	fa.fsx_cowextsize = ip->i_d.di_cowextsize <<
+	simple_fill_fsxattr(fa, xfs_ip2xflags(ip));
+	fa->fsx_extsize = ip->i_d.di_extsize << ip->i_mount->m_sb.sb_blocklog;
+	fa->fsx_cowextsize = ip->i_d.di_cowextsize <<
 			ip->i_mount->m_sb.sb_blocklog;
-	fa.fsx_projid = xfs_get_projid(ip);
+	fa->fsx_projid = xfs_get_projid(ip);
 
 	if (attr) {
 		if (ip->i_afp) {
 			if (ip->i_afp->if_flags & XFS_IFEXTENTS)
-				fa.fsx_nextents = xfs_iext_count(ip->i_afp);
+				fa->fsx_nextents = xfs_iext_count(ip->i_afp);
 			else
-				fa.fsx_nextents = ip->i_d.di_anextents;
+				fa->fsx_nextents = ip->i_d.di_anextents;
 		} else
-			fa.fsx_nextents = 0;
+			fa->fsx_nextents = 0;
 	} else {
 		if (ip->i_df.if_flags & XFS_IFEXTENTS)
-			fa.fsx_nextents = xfs_iext_count(&ip->i_df);
+			fa->fsx_nextents = xfs_iext_count(&ip->i_df);
 		else
-			fa.fsx_nextents = ip->i_d.di_nextents;
+			fa->fsx_nextents = ip->i_d.di_nextents;
 	}
+}
+
+STATIC int
+xfs_ioc_fsgetxattr(
+	xfs_inode_t		*ip,
+	int			attr,
+	void			__user *arg)
+{
+	struct fsxattr		fa;
+
+	xfs_ilock(ip, XFS_ILOCK_SHARED);
+	xfs_fill_fsxattr(ip, attr, &fa);
 	xfs_iunlock(ip, XFS_ILOCK_SHARED);
 
 	if (copy_to_user(arg, &fa, sizeof(fa)))
@@ -1035,15 +1042,6 @@ xfs_ioctl_setattr_xflags(
 	if ((fa->fsx_xflags & FS_XFLAG_DAX) && xfs_is_reflink_inode(ip))
 		return -EINVAL;
 
-	/*
-	 * Can't modify an immutable/append-only file unless
-	 * we have appropriate permission.
-	 */
-	if (((ip->i_d.di_flags & (XFS_DIFLAG_IMMUTABLE | XFS_DIFLAG_APPEND)) ||
-	     (fa->fsx_xflags & (FS_XFLAG_IMMUTABLE | FS_XFLAG_APPEND))) &&
-	    !capable(CAP_LINUX_IMMUTABLE))
-		return -EPERM;
-
 	/* diflags2 only valid for v3 inodes. */
 	di_flags2 = xfs_flags2diflags2(ip, fa->fsx_xflags);
 	if (di_flags2 && ip->i_d.di_version < 3)
@@ -1323,6 +1321,7 @@ xfs_ioctl_setattr(
 	xfs_inode_t		*ip,
 	struct fsxattr		*fa)
 {
+	struct fsxattr		old_fa;
 	struct xfs_mount	*mp = ip->i_mount;
 	struct xfs_trans	*tp;
 	struct xfs_dquot	*udqp = NULL;
@@ -1370,7 +1369,6 @@ xfs_ioctl_setattr(
 		goto error_free_dquots;
 	}
 
-
 	if (XFS_IS_QUOTA_RUNNING(mp) && XFS_IS_PQUOTA_ON(mp) &&
 	    xfs_get_projid(ip) != fa->fsx_projid) {
 		code = xfs_qm_vop_chown_reserve(tp, ip, udqp, NULL, pdqp,
@@ -1379,6 +1377,11 @@ xfs_ioctl_setattr(
 			goto error_trans_cancel;
 	}
 
+	xfs_fill_fsxattr(ip, false, &old_fa);
+	code = vfs_ioc_fssetxattr_check(VFS_I(ip), &old_fa, fa);
+	if (code)
+		goto error_trans_cancel;
+
 	code = xfs_ioctl_setattr_check_extsize(ip, fa);
 	if (code)
 		goto error_trans_cancel;
@@ -1489,6 +1492,7 @@ xfs_ioc_setxflags(
 {
 	struct xfs_trans	*tp;
 	struct fsxattr		fa;
+	struct fsxattr		old_fa;
 	unsigned int		flags;
 	int			join_flags = 0;
 	int			error;
@@ -1524,6 +1528,13 @@ xfs_ioc_setxflags(
 		goto out_drop_write;
 	}
 
+	xfs_fill_fsxattr(ip, false, &old_fa);
+	error = vfs_ioc_fssetxattr_check(VFS_I(ip), &old_fa, &fa);
+	if (error) {
+		xfs_trans_cancel(tp);
+		goto out_drop_write;
+	}
+
 	error = xfs_ioctl_setattr_xflags(tp, ip, &fa);
 	if (error) {
 		xfs_trans_cancel(tp);