diff --git a/third_party/linux/external/0004-fsinfo-Allow-retrieval-of-superblock-devname-options.patch b/third_party/linux/external/0004-fsinfo-Allow-retrieval-of-superblock-devname-options.patch
new file mode 100644
index 0000000..86ba2cc
--- /dev/null
+++ b/third_party/linux/external/0004-fsinfo-Allow-retrieval-of-superblock-devname-options.patch
@@ -0,0 +1,183 @@
+From fa2ff1a0da263362a2c98c8cfe68bcac3a323ac4 Mon Sep 17 00:00:00 2001
+From: David Howells <dhowells@redhat.com>
+Date: Tue, 3 Mar 2020 14:29:27 +0000
+Subject: [PATCH 4/4] fsinfo: Allow retrieval of superblock devname, options
+ and stats
+
+Provide fsinfo() attributes to retrieve superblock device name, options,
+and statistics in string form.  The following attributes are defined:
+
+	FSINFO_ATTR_SOURCE		- Mount-specific device name
+	FSINFO_ATTR_CONFIGURATION	- Mount options
+	FSINFO_ATTR_FS_STATISTICS	- Filesystem statistics
+
+FSINFO_ATTR_SOURCE could be made indexable by params->Nth to handle the
+case where there is more than one source (e.g. the bcachefs filesystem).
+
+Signed-off-by: David Howells <dhowells@redhat.com>
+---
+ fs/fsinfo.c                 | 41 +++++++++++++++++++++++++++++++++++++
+ fs/internal.h               |  2 ++
+ fs/namespace.c              | 39 +++++++++++++++++++++++++++++++++++
+ include/uapi/linux/fsinfo.h |  3 +++
+ samples/vfs/test-fsinfo.c   |  4 ++++
+ 5 files changed, 89 insertions(+)
+
+diff --git a/fs/fsinfo.c b/fs/fsinfo.c
+index 1830c73f37a7..3ed43c5a10e8 100644
+--- a/fs/fsinfo.c
++++ b/fs/fsinfo.c
+@@ -188,6 +188,44 @@ static int fsinfo_generic_volume_id(struct path *path, struct fsinfo_context *ct
+ 	return fsinfo_string(path->dentry->d_sb->s_id, ctx);
+ }
+ 
++/*
++ * Retrieve the superblock configuration (mount options) as a comma-separated
++ * string.  The initial comma is stripped off.
++ */
++static int fsinfo_generic_seq_read(struct path *path, struct fsinfo_context *ctx)
++{
++	struct super_block *sb = path->dentry->d_sb;
++	struct seq_file m = {
++		.buf	= ctx->buffer,
++		.size	= ctx->buf_size,
++	};
++	int ret = 0;
++
++	switch (ctx->requested_attr) {
++	case FSINFO_ATTR_CONFIGURATION:
++		if (sb->s_op->show_options)
++			ret = sb->s_op->show_options(&m, path->mnt->mnt_root);
++		break;
++
++	case FSINFO_ATTR_FS_STATISTICS:
++		if (sb->s_op->show_stats)
++			ret = sb->s_op->show_stats(&m, path->mnt->mnt_root);
++		break;
++	}
++
++	if (ret < 0)
++		return ret;
++	if (seq_has_overflowed(&m))
++		return ctx->buf_size + PAGE_SIZE;
++	if (ctx->requested_attr == FSINFO_ATTR_CONFIGURATION) {
++		if (m.count > 0 && ((char *)ctx->buffer)[0] == ',') {
++			m.count--;
++			ctx->skip = 1;
++		}
++	}
++	return m.count;
++}
++
+ static const struct fsinfo_attribute fsinfo_common_attributes[] = {
+ 	FSINFO_VSTRUCT	(FSINFO_ATTR_STATFS,		fsinfo_generic_statfs),
+ 	FSINFO_VSTRUCT	(FSINFO_ATTR_IDS,		fsinfo_generic_ids),
+@@ -196,6 +234,9 @@ static const struct fsinfo_attribute fsinfo_common_attributes[] = {
+ 	FSINFO_VSTRUCT	(FSINFO_ATTR_TIMESTAMP_INFO,	fsinfo_generic_timestamp_info),
+ 	FSINFO_STRING	(FSINFO_ATTR_VOLUME_ID,		fsinfo_generic_volume_id),
+ 	FSINFO_VSTRUCT	(FSINFO_ATTR_VOLUME_UUID,	fsinfo_generic_volume_uuid),
++	FSINFO_STRING	(FSINFO_ATTR_SOURCE,		fsinfo_generic_mount_source),
++	FSINFO_STRING	(FSINFO_ATTR_CONFIGURATION,	fsinfo_generic_seq_read),
++	FSINFO_STRING	(FSINFO_ATTR_FS_STATISTICS,	fsinfo_generic_seq_read),
+ 
+ 	FSINFO_LIST	(FSINFO_ATTR_FSINFO_ATTRIBUTES,	(void *)123UL),
+ 	FSINFO_VSTRUCT_N(FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO, (void *)123UL),
+diff --git a/fs/internal.h b/fs/internal.h
+index a0d90f23593c..6f2cc77bf38d 100644
+--- a/fs/internal.h
++++ b/fs/internal.h
+@@ -91,6 +91,8 @@ extern int __mnt_want_write_file(struct file *);
+ extern void __mnt_drop_write_file(struct file *);
+ 
+ extern void dissolve_on_fput(struct vfsmount *);
++extern int fsinfo_generic_mount_source(struct path *, struct fsinfo_context *);
++
+ /*
+  * fs_struct.c
+  */
+diff --git a/fs/namespace.c b/fs/namespace.c
+index 85b5f7bea82e..b4951e2afae1 100644
+--- a/fs/namespace.c
++++ b/fs/namespace.c
+@@ -30,6 +30,7 @@
+ #include <uapi/linux/mount.h>
+ #include <linux/fs_context.h>
+ #include <linux/shmem_fs.h>
++#include <linux/fsinfo.h>
+ 
+ #include "pnode.h"
+ #include "internal.h"
+@@ -3975,3 +3976,41 @@ const struct proc_ns_operations mntns_operations = {
+ 	.install	= mntns_install,
+ 	.owner		= mntns_owner,
+ };
++
++#ifdef CONFIG_FSINFO
++static inline void mangle(struct seq_file *m, const char *s)
++{
++	seq_escape(m, s, " \t\n\\");
++}
++
++/*
++ * Return the mount source/device name as seen from this mountpoint.  Shared
++ * mounts may vary here and the filesystem is permitted to substitute its own
++ * rendering.
++ */
++int fsinfo_generic_mount_source(struct path *path, struct fsinfo_context *ctx)
++{
++	struct super_block *sb = path->mnt->mnt_sb;
++	struct mount *mnt = real_mount(path->mnt);
++	struct seq_file m = {
++		.buf	= ctx->buffer,
++		.size	= ctx->buf_size,
++	};
++	int ret;
++
++	if (sb->s_op->show_devname) {
++		ret = sb->s_op->show_devname(&m, mnt->mnt.mnt_root);
++		if (ret < 0)
++			return ret;
++	} else {
++		if (!mnt->mnt_devname)
++			return fsinfo_string("none", ctx);
++		mangle(&m, mnt->mnt_devname);
++	}
++
++	if (seq_has_overflowed(&m))
++		return ctx->buf_size + PAGE_SIZE;
++	return m.count;
++}
++
++#endif /* CONFIG_FSINFO */
+diff --git a/include/uapi/linux/fsinfo.h b/include/uapi/linux/fsinfo.h
+index e9b35b9b7629..d3722c7142a6 100644
+--- a/include/uapi/linux/fsinfo.h
++++ b/include/uapi/linux/fsinfo.h
+@@ -23,6 +23,9 @@
+ #define FSINFO_ATTR_VOLUME_ID		0x05	/* Volume ID (string) */
+ #define FSINFO_ATTR_VOLUME_UUID		0x06	/* Volume UUID (LE uuid) */
+ #define FSINFO_ATTR_VOLUME_NAME		0x07	/* Volume name (string) */
++#define FSINFO_ATTR_SOURCE		0x09	/* Superblock source/device name (string) */
++#define FSINFO_ATTR_CONFIGURATION	0x0a	/* Superblock configuration/options (string) */
++#define FSINFO_ATTR_FS_STATISTICS	0x0b	/* Superblock filesystem statistics (string) */
+ 
+ #define FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO 0x100	/* Information about attr N (for path) */
+ #define FSINFO_ATTR_FSINFO_ATTRIBUTES	0x101	/* List of supported attrs (for path) */
+diff --git a/samples/vfs/test-fsinfo.c b/samples/vfs/test-fsinfo.c
+index 2b53c735d330..1797f7b8d08a 100644
+--- a/samples/vfs/test-fsinfo.c
++++ b/samples/vfs/test-fsinfo.c
+@@ -289,6 +289,10 @@ static const struct fsinfo_attribute fsinfo_attributes[] = {
+ 	FSINFO_STRING	(FSINFO_ATTR_VOLUME_ID,		string),
+ 	FSINFO_VSTRUCT	(FSINFO_ATTR_VOLUME_UUID,	fsinfo_generic_volume_uuid),
+ 	FSINFO_STRING	(FSINFO_ATTR_VOLUME_NAME,	string),
++	FSINFO_STRING	(FSINFO_ATTR_SOURCE,		string),
++	FSINFO_STRING	(FSINFO_ATTR_CONFIGURATION,	string),
++	FSINFO_STRING	(FSINFO_ATTR_FS_STATISTICS,	string),
++
+ 	FSINFO_VSTRUCT_N(FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO, fsinfo_meta_attribute_info),
+ 	FSINFO_LIST	(FSINFO_ATTR_FSINFO_ATTRIBUTES,	fsinfo_meta_attributes),
+ 	{}
+-- 
+2.20.1
+