diff -wur a/fs/ext4/ext4.h b/fs/ext4/ext4.h
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1154,6 +1154,9 @@ struct ext4_inode_info {
 #define EXT4_MOUNT_DISCARD		0x40000000 /* Issue DISCARD requests */
 #define EXT4_MOUNT_INIT_INODE_TABLE	0x80000000 /* Initialize uninitialized itables */
 
+/* we know this is a Lustre mount thanks to the DIRDATA flag */
+#define IS_LUSTRE_MOUNT(sb)	test_opt((sb), DIRDATA)
+
 /*
  * Mount flags set either automatically (could not be set by mount option)
  * based on per file system feature or property or in special cases such as
diff -wur a/fs/ext4/xattr.c b/fs/ext4/xattr.c
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -654,6 +654,7 @@
 	up_read(&EXT4_I(inode)->xattr_sem);
 	return error;
 }
+EXPORT_SYMBOL(ext4_xattr_get);
 
 static int
 ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry,
@@ -1197,14 +1197,21 @@
 			ext4_handle_sync(handle);
 	}
 
+	if (!error && name_index == EXT4_XATTR_INDEX_ENCRYPTION &&
+	    strcmp(name, "c") == 0) {
+		EXT4_I(inode)->i_flags |= EXT4_ENCRYPT_FL;
+		mark_inode_dirty(inode);
+	}
+
 cleanup:
 	brelse(is.iloc.bh);
 	brelse(bs.bh);
 	if (no_expand == 0)
 		ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
 	up_write(&EXT4_I(inode)->xattr_sem);
 	return error;
 }
+EXPORT_SYMBOL(ext4_xattr_set_handle);
 
 /*
  * ext4_xattr_set()
diff -wur a/fs/ext4/xattr.h b/fs/ext4/xattr.h
--- a/fs/ext4/xattr.h
+++ b/fs/ext4/xattr.h
@@ -121,6 +121,9 @@
 extern const struct xattr_handler ext4_xattr_acl_default_handler;
 extern const struct xattr_handler ext4_xattr_security_handler;
 
+#define EXT4_XATTR_INDEX_ENCRYPTION		9
+#define EXT4_XATTR_NAME_ENCRYPTION_CONTEXT "c"
+
 extern ssize_t ext4_listxattr(struct dentry *, char *, size_t);
 
 extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t);
diff -wur a/fs/ext4/ext4.h b/fs/ext4/ext4.h
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -381,7 +378,8 @@ struct flex_groups {
 #define EXT4_DIRTY_FL			0x00000100
 #define EXT4_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
 #define EXT4_NOCOMPR_FL			0x00000400 /* Don't compress */
-#define EXT4_ECOMPR_FL			0x00000800 /* Compression error */
+/* nb: was previously EXT4_ECOMPR_FL */
+#define EXT4_ENCRYPT_FL                 0x00000800 /* encrypted file */
 /* End compression flags --- maybe not all used */
 #define EXT4_INDEX_FL			0x00001000 /* hash-indexed directory */
 #define EXT4_IMAGIC_FL			0x00002000 /* AFS directory */
@@ -447,7 +445,7 @@ enum {
 	EXT4_INODE_DIRTY	= 8,
 	EXT4_INODE_COMPRBLK	= 9,	/* One or more compressed clusters */
 	EXT4_INODE_NOCOMPR	= 10,	/* Don't compress */
-	EXT4_INODE_ECOMPR	= 11,	/* Compression error */
+	EXT4_INODE_ENCRYPT	= 11,	/* Encrypted file */
 /* End compression flags --- maybe not all used */
 	EXT4_INODE_INDEX	= 12,	/* hash-indexed directory */
 	EXT4_INODE_IMAGIC	= 13,	/* AFS directory */
@@ -493,7 +491,7 @@ static inline void ext4_check_flag_va
 	CHECK_FLAG_VALUE(DIRTY);
 	CHECK_FLAG_VALUE(COMPRBLK);
 	CHECK_FLAG_VALUE(NOCOMPR);
-	CHECK_FLAG_VALUE(ECOMPR);
+	CHECK_FLAG_VALUE(ENCRYPT);
 	CHECK_FLAG_VALUE(INDEX);
 	CHECK_FLAG_VALUE(IMAGIC);
 	CHECK_FLAG_VALUE(JOURNAL_DATA);