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authorMikulas Patocka <mpatocka@redhat.com>2013-03-01 22:45:49 +0000
committerAlasdair G Kergon <agk@redhat.com>2013-03-01 22:45:49 +0000
commita26062416ef8add48f16fbadded2b5f6fb84d024 (patch)
tree4f960c51bd22d99e55a1f56cf28f86f018de01a3 /include/uapi/linux/dm-ioctl.h
parent02cde50b7ea74557d32ff778c73809322445ccd2 (diff)
downloadop-kernel-dev-a26062416ef8add48f16fbadded2b5f6fb84d024.zip
op-kernel-dev-a26062416ef8add48f16fbadded2b5f6fb84d024.tar.gz
dm ioctl: allow message to return data
This patch introduces enhanced message support that allows the device-mapper core to recognise messages that are common to all devices, and for messages to return data to userspace. Core messages are processed by the function "message_for_md". If the device mapper doesn't support the message, it is passed to the target driver. If the message returns data, the kernel sets the flag DM_MESSAGE_OUT_FLAG. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'include/uapi/linux/dm-ioctl.h')
-rw-r--r--include/uapi/linux/dm-ioctl.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/include/uapi/linux/dm-ioctl.h b/include/uapi/linux/dm-ioctl.h
index b8a6bdd..7e75b6f 100644
--- a/include/uapi/linux/dm-ioctl.h
+++ b/include/uapi/linux/dm-ioctl.h
@@ -336,4 +336,9 @@ enum {
*/
#define DM_SECURE_DATA_FLAG (1 << 15) /* In */
+/*
+ * If set, a message generated output data.
+ */
+#define DM_DATA_OUT_FLAG (1 << 16) /* Out */
+
#endif /* _LINUX_DM_IOCTL_H */
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