Merge tag 'vfs-fix-ioctl-checking-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull common SETFLAGS/FSSETXATTR parameter checking from Darrick Wong:
 "Here's a patch series that sets up common parameter checking functions
  for the FS_IOC_SETFLAGS and FS_IOC_FSSETXATTR ioctl implementations.

  The goal here is to reduce the amount of behaviorial variance between
  the filesystems where those ioctls originated (ext2 and XFS,
  respectively) and everybody else.

   - Standardize parameter checking for the SETFLAGS and FSSETXATTR
     ioctls (which were the file attribute setters for ext4 and xfs and
     have now been hoisted to the vfs)

   - Only allow the DAX flag to be set on files and directories"

* tag 'vfs-fix-ioctl-checking-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  vfs: only allow FSSETXATTR to set DAX flag on files and dirs
  vfs: teach vfs_ioc_fssetxattr_check to check extent size hints
  vfs: teach vfs_ioc_fssetxattr_check to check project id info
  vfs: create a generic checking function for FS_IOC_FSSETXATTR
  vfs: create a generic checking and prep function for FS_IOC_SETFLAGS

1 files changed, 13 insertions, 38 deletions

diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 74648d42c69b..442f7ef873fc 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -312,16 +312,9 @@ static int ext4_ioctl_setflags(struct inode *inode,
 	/* The JOURNAL_DATA flag is modifiable only by root */
 	jflag = flags & EXT4_JOURNAL_DATA_FL;
 
-	/*
-	 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
-	 * the relevant capability.
-	 *
-	 * This test looks nicer. Thanks to Pauline Middelink
-	 */
-	if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
-		if (!capable(CAP_LINUX_IMMUTABLE))
-			goto flags_out;
-	}
+	err = vfs_ioc_setflags_prepare(inode, oldflags, flags);
+	if (err)
+		goto flags_out;
 
 	/*
 	 * The JOURNAL_DATA flag can only be changed by
@@ -741,28 +734,15 @@ group_add_out:
 	return err;
 }
 
-static int ext4_ioctl_check_project(struct inode *inode, struct fsxattr *fa)
+static void ext4_fill_fsxattr(struct inode *inode, struct fsxattr *fa)
 {
-	/*
-	 * Project Quota ID state is only allowed to change from within the init
-	 * namespace. Enforce that restriction only if we are trying to change
-	 * the quota ID state. Everything else is allowed in user namespaces.
-	 */
-	if (current_user_ns() == &init_user_ns)
-		return 0;
-
-	if (__kprojid_val(EXT4_I(inode)->i_projid) != fa->fsx_projid)
-		return -EINVAL;
+	struct ext4_inode_info *ei = EXT4_I(inode);
 
-	if (ext4_test_inode_flag(inode, EXT4_INODE_PROJINHERIT)) {
-		if (!(fa->fsx_xflags & FS_XFLAG_PROJINHERIT))
-			return -EINVAL;
-	} else {
-		if (fa->fsx_xflags & FS_XFLAG_PROJINHERIT)
-			return -EINVAL;
-	}
+	simple_fill_fsxattr(fa, ext4_iflags_to_xflags(ei->i_flags &
+						      EXT4_FL_USER_VISIBLE));
 
-	return 0;
+	if (ext4_has_feature_project(inode->i_sb))
+		fa->fsx_projid = from_kprojid(&init_user_ns, ei->i_projid);
 }
 
 long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
@@ -1139,13 +1119,7 @@ resizefs_out:
 	{
 		struct fsxattr fa;
 
-		memset(&fa, 0, sizeof(struct fsxattr));
-		fa.fsx_xflags = ext4_iflags_to_xflags(ei->i_flags & EXT4_FL_USER_VISIBLE);
-
-		if (ext4_has_feature_project(inode->i_sb)) {
-			fa.fsx_projid = (__u32)from_kprojid(&init_user_ns,
-				EXT4_I(inode)->i_projid);
-		}
+		ext4_fill_fsxattr(inode, &fa);
 
 		if (copy_to_user((struct fsxattr __user *)arg,
 				 &fa, sizeof(fa)))
@@ -1154,7 +1128,7 @@ resizefs_out:
 	}
 	case EXT4_IOC_FSSETXATTR:
 	{
-		struct fsxattr fa;
+		struct fsxattr fa, old_fa;
 		int err;
 
 		if (copy_from_user(&fa, (struct fsxattr __user *)arg,
@@ -1177,7 +1151,8 @@ resizefs_out:
 			return err;
 
 		inode_lock(inode);
-		err = ext4_ioctl_check_project(inode, &fa);
+		ext4_fill_fsxattr(inode, &old_fa);
+		err = vfs_ioc_fssetxattr_check(inode, &old_fa, &fa);
 		if (err)
 			goto out;
 		flags = (ei->i_flags & ~EXT4_FL_XFLAG_VISIBLE) |