From: Palmer Dabbelt <palmer@dabbelt.com>
To: dm-devel@redhat.com, agk@redhat.com, snitzer@redhat.com
Cc: corbet@lwn.net, song@kernel.org,
Palmer Dabbelt <palmerdabbelt@google.com>,
shuah@kernel.org, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org,
linux-kselftest@vger.kernel.org, kernel-team@android.com
Subject: [PATCH v1 2/5] uapi: Add dm-user structure definition
Date: Thu, 3 Dec 2020 13:58:56 -0800 [thread overview]
Message-ID: <20201203215859.2719888-3-palmer@dabbelt.com> (raw)
In-Reply-To: <20201203215859.2719888-1-palmer@dabbelt.com>
From: Palmer Dabbelt <palmerdabbelt@google.com>
dm-user is a device mapper target that allows a userspace process to
handle each incoming BIO. Communication with userspace consists of a
stream of messages proxied over a misc device, the structure of each
message is defined in this header.
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
As it currently stands this isn't really sufficient to be a stable user
ABI. These are probably best discussed in the context of the dm-user
implementation, though, where they're largely called out as FIXMEs.
---
include/uapi/linux/dm-user.h | 67 ++++++++++++++++++++++++++++++++++++
1 file changed, 67 insertions(+)
create mode 100644 include/uapi/linux/dm-user.h
diff --git a/include/uapi/linux/dm-user.h b/include/uapi/linux/dm-user.h
new file mode 100644
index 000000000000..1806109518f4
--- /dev/null
+++ b/include/uapi/linux/dm-user.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: LGPL-2.0+ WITH Linux-syscall-note */
+/*
+ * Copyright (C) 2020 Palmer Dabbelt <palmerdabbelt@google.com>
+ */
+
+#ifndef _LINUX_DM_USER_H
+#define _LINUX_DM_USER_H
+
+#include <linux/types.h>
+
+/*
+ * dm-user proxies device mapper ops between the kernel and userspace. It's
+ * essentially just an RPC mechanism: all kernel calls create a request,
+ * userspace handles that with a response. Userspace obtains requests via
+ * read() and provides responses via write().
+ *
+ * See Documentation/block/dm-user.rst for more information.
+ */
+
+#define DM_USER_REQ_MAP_READ 0
+#define DM_USER_REQ_MAP_WRITE 1
+#define DM_USER_REQ_MAP_FLUSH 2
+#define DM_USER_REQ_MAP_DISCARD 3
+#define DM_USER_REQ_MAP_SECURE_ERASE 4
+#define DM_USER_REQ_MAP_WRITE_SAME 5
+#define DM_USER_REQ_MAP_WRITE_ZEROES 6
+#define DM_USER_REQ_MAP_ZONE_OPEN 7
+#define DM_USER_REQ_MAP_ZONE_CLOSE 8
+#define DM_USER_REQ_MAP_ZONE_FINISH 9
+#define DM_USER_REQ_MAP_ZONE_APPEND 10
+#define DM_USER_REQ_MAP_ZONE_RESET 11
+#define DM_USER_REQ_MAP_ZONE_RESET_ALL 12
+
+#define DM_USER_REQ_MAP_FLAG_FAILFAST_DEV 0x00001
+#define DM_USER_REQ_MAP_FLAG_FAILFAST_TRANSPORT 0x00002
+#define DM_USER_REQ_MAP_FLAG_FAILFAST_DRIVER 0x00004
+#define DM_USER_REQ_MAP_FLAG_SYNC 0x00008
+#define DM_USER_REQ_MAP_FLAG_META 0x00010
+#define DM_USER_REQ_MAP_FLAG_PRIO 0x00020
+#define DM_USER_REQ_MAP_FLAG_NOMERGE 0x00040
+#define DM_USER_REQ_MAP_FLAG_IDLE 0x00080
+#define DM_USER_REQ_MAP_FLAG_INTEGRITY 0x00100
+#define DM_USER_REQ_MAP_FLAG_FUA 0x00200
+#define DM_USER_REQ_MAP_FLAG_PREFLUSH 0x00400
+#define DM_USER_REQ_MAP_FLAG_RAHEAD 0x00800
+#define DM_USER_REQ_MAP_FLAG_BACKGROUND 0x01000
+#define DM_USER_REQ_MAP_FLAG_NOWAIT 0x02000
+#define DM_USER_REQ_MAP_FLAG_CGROUP_PUNT 0x04000
+#define DM_USER_REQ_MAP_FLAG_NOUNMAP 0x08000
+#define DM_USER_REQ_MAP_FLAG_HIPRI 0x10000
+#define DM_USER_REQ_MAP_FLAG_DRV 0x20000
+#define DM_USER_REQ_MAP_FLAG_SWAP 0x40000
+
+#define DM_USER_RESP_SUCCESS 0
+#define DM_USER_RESP_ERROR 1
+#define DM_USER_RESP_UNSUPPORTED 2
+
+struct dm_user_message {
+ __u64 seq;
+ __u64 type;
+ __u64 flags;
+ __u64 sector;
+ __u64 len;
+ __u8 buf[];
+};
+
+#endif
--
2.29.2.454.gaff20da3a2-goog
next prev parent reply other threads:[~2020-12-03 22:34 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-03 21:58 [PATCH v1 0/5] dm: dm-user: New target that proxies BIOs to userspace Palmer Dabbelt
2020-12-03 21:58 ` [PATCH v1 1/5] Documentation: Describe dm-user Palmer Dabbelt
2020-12-03 21:58 ` Palmer Dabbelt [this message]
2020-12-03 21:58 ` [PATCH v1 3/5] dm: dm-user: New target that proxies BIOs to userspace Palmer Dabbelt
2020-12-03 21:58 ` [PATCH v1 4/5] selftests/dm-user: A handful of tests for dm-user Palmer Dabbelt
2020-12-03 21:58 ` [PATCH v1 5/5] MAINTAINERS: Add myself as a dm-user maintainer Palmer Dabbelt
2020-12-04 10:33 ` [PATCH v1 0/5] dm: dm-user: New target that proxies BIOs to userspace Christoph Hellwig
2020-12-07 18:55 ` Palmer Dabbelt
2020-12-10 3:38 ` [dm-devel] " Bart Van Assche
2020-12-10 17:03 ` Josef Bacik
2020-12-15 3:00 ` Palmer Dabbelt
2020-12-16 18:24 ` Vitaly Mayatskih
2020-12-17 6:55 ` Palmer Dabbelt
2020-12-22 13:32 ` Christoph Hellwig
2020-12-22 14:36 ` Mike Snitzer
2020-12-22 20:38 ` Palmer Dabbelt
2020-12-23 7:48 ` Christoph Hellwig
2020-12-23 16:59 ` Bart Van Assche
2020-12-22 20:31 ` [dm-devel] " Palmer Dabbelt
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