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, 17 insertions, 9 deletions

diff --git a/fs/efivarfs/file.c b/fs/efivarfs/file.c
index ee3bc0c96b9d..e9e27a271af0 100644
--- a/fs/efivarfs/file.c
+++ b/fs/efivarfs/file.c
@@ -107,16 +107,22 @@ out_free:
 	return size;
 }
 
-static int
-efivarfs_ioc_getxflags(struct file *file, void __user *arg)
+static inline unsigned int efivarfs_getflags(struct inode *inode)
 {
-	struct inode *inode = file->f_mapping->host;
 	unsigned int i_flags;
 	unsigned int flags = 0;
 
 	i_flags = inode->i_flags;
 	if (i_flags & S_IMMUTABLE)
 		flags |= FS_IMMUTABLE_FL;
+	return flags;
+}
+
+static int
+efivarfs_ioc_getxflags(struct file *file, void __user *arg)
+{
+	struct inode *inode = file->f_mapping->host;
+	unsigned int flags = efivarfs_getflags(inode);
 
 	if (copy_to_user(arg, &flags, sizeof(flags)))
 		return -EFAULT;
@@ -129,6 +135,7 @@ efivarfs_ioc_setxflags(struct file *file, void __user *arg)
 	struct inode *inode = file->f_mapping->host;
 	unsigned int flags;
 	unsigned int i_flags = 0;
+	unsigned int oldflags = efivarfs_getflags(inode);
 	int error;
 
 	if (!inode_owner_or_capable(inode))
@@ -140,9 +147,6 @@ efivarfs_ioc_setxflags(struct file *file, void __user *arg)
 	if (flags & ~FS_IMMUTABLE_FL)
 		return -EOPNOTSUPP;
 
-	if (!capable(CAP_LINUX_IMMUTABLE))
-		return -EPERM;
-
 	if (flags & FS_IMMUTABLE_FL)
 		i_flags |= S_IMMUTABLE;
 
@@ -152,12 +156,16 @@ efivarfs_ioc_setxflags(struct file *file, void __user *arg)
 		return error;
 
 	inode_lock(inode);
+
+	error = vfs_ioc_setflags_prepare(inode, oldflags, flags);
+	if (error)
+		goto out;
+
 	inode_set_flags(inode, i_flags, S_IMMUTABLE);
+out:
 	inode_unlock(inode);
-
 	mnt_drop_write_file(file);
-
-	return 0;
+	return error;
 }
 
 static long