vfs: teach vfs_ioc_fssetxattr_check to check extent size hints

Move the extent size hint checks that aren't xfs-specific to the vfs.

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

fs/inode.c

@@ -2227,6 +2227,24 @@ int vfs_ioc_fssetxattr_check(struct inode *inode, const struct fsxattr *old_fa,
 			return -EINVAL;
 	}
 
+	/* Check extent size hints. */
+	if ((fa->fsx_xflags & FS_XFLAG_EXTSIZE) && !S_ISREG(inode->i_mode))
+		return -EINVAL;
+
+	if ((fa->fsx_xflags & FS_XFLAG_EXTSZINHERIT) &&
+			!S_ISDIR(inode->i_mode))
+		return -EINVAL;
+
+	if ((fa->fsx_xflags & FS_XFLAG_COWEXTSIZE) &&
+	    !S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
+		return -EINVAL;
+
+	/* Extent size hints of zero turn off the flags. */
+	if (fa->fsx_extsize == 0)
+		fa->fsx_xflags &= ~(FS_XFLAG_EXTSIZE | FS_XFLAG_EXTSZINHERIT);
+	if (fa->fsx_cowextsize == 0)
+		fa->fsx_xflags &= ~FS_XFLAG_COWEXTSIZE;
+
 	return 0;
 }
 EXPORT_SYMBOL(vfs_ioc_fssetxattr_check);