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| author | Mikulas Patocka <mpatocka@redhat.com> | 2013-03-01 22:45:49 +0000 |
|---|---|---|
| committer | Alasdair G Kergon <agk@redhat.com> | 2013-03-01 22:45:49 +0000 |
| commit | a26062416ef8add48f16fbadded2b5f6fb84d024 (patch) | |
| tree | 4f960c51bd22d99e55a1f56cf28f86f018de01a3 /include/uapi/linux | |
| parent | 02cde50b7ea74557d32ff778c73809322445ccd2 (diff) | |
| download | lwn-a26062416ef8add48f16fbadded2b5f6fb84d024.tar.gz lwn-a26062416ef8add48f16fbadded2b5f6fb84d024.zip | |
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')
| -rw-r--r-- | include/uapi/linux/dm-ioctl.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/include/uapi/linux/dm-ioctl.h b/include/uapi/linux/dm-ioctl.h index b8a6bddf0727..7e75b6fd8d45 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 */ |