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| author | Ming Lei <ming.lei@redhat.com> | 2023-06-03 12:06:01 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2023-06-04 08:34:14 -0600 |
| commit | b5bbc52fd01278642773818642288999a0236cb6 (patch) | |
| tree | 7e269e6fb9c5ec307fc088cae0afe8a2c5230ac9 /drivers/block | |
| parent | 20d099756b98fa6b5b838448b1ffbce46f4f3283 (diff) | |
| download | linux-stable-b5bbc52fd01278642773818642288999a0236cb6.tar.gz linux-stable-b5bbc52fd01278642773818642288999a0236cb6.tar.bz2 linux-stable-b5bbc52fd01278642773818642288999a0236cb6.zip | |
ublk: add control command of UBLK_U_CMD_GET_FEATURES
Add control command of UBLK_U_CMD_GET_FEATURES for returning driver's
feature set or capability.
This way can simplify userspace for maintaining compatibility because
userspace doesn't need to send command to one device for querying driver
feature set any more. Such as, with the queried feature set, userspace
can choose to use:
- UBLK_CMD_GET_DEV_INFO2 or UBLK_CMD_GET_DEV_INFO,
- UBLK_U_CMD_* or UBLK_CMD_*
Userspace code:
https://github.com/ming1/ubdsrv/commits/features-cmd
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230603040601.775227-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/ublk_drv.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 539eada32861..222a0341913f 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -2343,6 +2343,21 @@ static int ublk_ctrl_end_recovery(struct ublk_device *ub, return ret; } +static int ublk_ctrl_get_features(struct io_uring_cmd *cmd) +{ + const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); + void __user *argp = (void __user *)(unsigned long)header->addr; + u64 features = UBLK_F_ALL & ~UBLK_F_SUPPORT_ZERO_COPY; + + if (header->len != UBLK_FEATURES_LEN || !header->addr) + return -EINVAL; + + if (copy_to_user(argp, &features, UBLK_FEATURES_LEN)) + return -EFAULT; + + return 0; +} + /* * All control commands are sent via /dev/ublk-control, so we have to check * the destination device's permission @@ -2423,6 +2438,7 @@ static int ublk_ctrl_uring_cmd_permission(struct ublk_device *ub, case UBLK_CMD_GET_DEV_INFO2: case UBLK_CMD_GET_QUEUE_AFFINITY: case UBLK_CMD_GET_PARAMS: + case (_IOC_NR(UBLK_U_CMD_GET_FEATURES)): mask = MAY_READ; break; case UBLK_CMD_START_DEV: @@ -2472,6 +2488,11 @@ static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd, if (ret) goto out; + if (cmd_op == UBLK_U_CMD_GET_FEATURES) { + ret = ublk_ctrl_get_features(cmd); + goto out; + } + if (_IOC_NR(cmd_op) != UBLK_CMD_ADD_DEV) { ret = -ENODEV; ub = ublk_get_device_from_id(header->dev_id); |