Define some macros for recovery feature. Especially define a new state:
UBLK_S_DEV_QUIESCED which implies that ublk_device is quiesced
and is ready for recovery. This state can be observed by userspace.
UBLK_F_USER_RECOVERY implies that:
(1) ublk_drv enables recovery feature. It won't let monitor_work to
automatically abort rqs and release the device.
(2) With a dying ubq_daemon, ublk_drv ends(aborts) rqs issued to
userspace(ublksrv) before crash.
(3) With a dying ubq_daemon, in task work and ublk_queue_rq(),
ublk_drv requeues rqs.
UBLK_F_USER_RECOVERY_REISSUE implies that:
(1) everything UBLK_F_USER_RECOVERY implies except
(2) With a dying ubq_daemon, ublk_drv requeues rqs issued to
userspace(ublksrv) before crash.
UBLK_F_USER_RECOVERY_REISSUE is designed for backends which:
(1) tolerates double-writes because ublk_drv may issue the same rq
twice.
(2) does not let frontend users get I/O error. such as read-only FS
and VM backend.
Signed-off-by: ZiyangZhang <ZiyangZhang@xxxxxxxxxxxxxxxxx>
---
drivers/block/ublk_drv.c | 45 ++++++++++++++++++++++++++++++++++-
include/uapi/linux/ublk_cmd.h | 7 ++++++
2 files changed, 51 insertions(+), 1 deletion(-)
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 0c6db0978ed0..23337bd7c105 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -49,7 +49,9 @@
/* All UBLK_F_* have to be included into UBLK_F_ALL */
#define UBLK_F_ALL (UBLK_F_SUPPORT_ZERO_COPY \
| UBLK_F_URING_CMD_COMP_IN_TASK \
- | UBLK_F_NEED_GET_DATA)
+ | UBLK_F_NEED_GET_DATA \
+ | UBLK_F_USER_RECOVERY \
+ | UBLK_F_USER_RECOVERY_REISSUE)
/* All UBLK_PARAM_TYPE_* should be included here */
#define UBLK_PARAM_TYPE_ALL (UBLK_PARAM_TYPE_BASIC | UBLK_PARAM_TYPE_DISCARD)
@@ -323,6 +325,47 @@ static inline int ublk_queue_cmd_buf_size(struct ublk_device *ub, int q_id)
PAGE_SIZE);
}
+static inline bool ublk_queue_can_use_recovery(
+ struct ublk_queue *ubq)
+{
+ if (ubq->flags & UBLK_F_USER_RECOVERY)
+ return true;
+ return false;
+}
+
+static inline void ublk_disable_recovery(struct ublk_device *ub)
+{
+ int i;
+
+ for (i = 0; i < ub->dev_info.nr_hw_queues; i++) {
+ struct ublk_queue *ubq = ublk_get_queue(ub, i);
+
+ ubq->flags &= ~UBLK_F_USER_RECOVERY;
+ }
+}
+
+static inline bool ublk_can_use_recovery(struct ublk_device *ub)
+{
+ int i;
+
+ for (i = 0; i < ub->dev_info.nr_hw_queues; i++) {
+ struct ublk_queue *ubq = ublk_get_queue(ub, i);
+
+ if (!ublk_queue_can_use_recovery(ubq))
+ return false;
+ }
+ return true;
+}
+
+static inline bool ublk_queue_can_use_recovery_reissue(
+ struct ublk_queue *ubq)
+{
+ if (ublk_queue_can_use_recovery(ubq) &&
+ (ubq->flags & UBLK_F_USER_RECOVERY_REISSUE))
+ return true;
+ return false;
+}
+
static void ublk_free_disk(struct gendisk *disk)
{
struct ublk_device *ub = disk->private_data;
diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h
index 677edaab2b66..87204c39f1ee 100644
--- a/include/uapi/linux/ublk_cmd.h
+++ b/include/uapi/linux/ublk_cmd.h
@@ -17,6 +17,8 @@
#define UBLK_CMD_STOP_DEV 0x07
#define UBLK_CMD_SET_PARAMS 0x08
#define UBLK_CMD_GET_PARAMS 0x09
+#define UBLK_CMD_START_USER_RECOVERY 0x10
+#define UBLK_CMD_END_USER_RECOVERY 0x11
/*
* IO commands, issued by ublk server, and handled by ublk driver.
@@ -74,9 +76,14 @@
*/
#define UBLK_F_NEED_GET_DATA (1UL << 2)
+#define UBLK_F_USER_RECOVERY (1UL << 3)
+
+#define UBLK_F_USER_RECOVERY_REISSUE (1UL << 4)
+
/* device state */
#define UBLK_S_DEV_DEAD 0
#define UBLK_S_DEV_LIVE 1
+#define UBLK_S_DEV_QUIESCED 2
/* shipped via sqe->cmd of io_uring command */
struct ublksrv_ctrl_cmd {
--
2.27.0
