| Message ID | d90ff20a-b324-49b8-bc63-7d7a35afd1f6@nvidia.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] ublk: Add UBLK_U_CMD_UPDATE_SIZE | expand |
On 4/10/25 6:29 AM, Jared Holzman wrote: > @@ -3052,6 +3053,22 @@ static int ublk_ctrl_get_features(struct io_uring_cmd *cmd) > return 0; > } > > +static int ublk_ctrl_set_size(struct ublk_device *ub, > + struct io_uring_cmd *cmd) Minor style nit, but that would fit on a single line, doesn't need to be split in two. > +{ > + const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); > + struct ublk_param_basic *p = &ub->params.basic; > + size_t new_size = (int)header->data[0]; > + int ret = 0; > + > + p->dev_sectors = new_size; > + > + mutex_lock(&ub->mutex); > + set_capacity_and_notify(ub->ub_disk, p->dev_sectors); > + mutex_unlock(&ub->mutex); > + > + return ret; > +} Get rid of 'ret' here, it's entirely unused. In fact maybe just get rid of the return value in the first place, as the function can't fail?
On Thu, Apr 10, 2025 at 03:29:38PM +0300, Jared Holzman wrote: > Currently ublk only allows the size of the ublkb block device to be > set via UBLK_CMD_SET_PARAMS before UBLK_CMD_START_DEV is triggered. > > This does not provide support for extendable user-space block devices > without having to stop and restart the underlying ublkb block device > causing IO interruption. > > This patch adds a new ublk command UBLK_U_CMD_UPDATE_SIZE to allow the > ublk block device to be resized on-the-fly. > > Feature flag UBLK_F_UPDATE_SIZE is also added to indicate support for this > command. > > Signed-off-by: Omri Mann <omri@nvidia.com> > --- > drivers/block/ublk_drv.c | 23 ++++++++++++++++++++++- > include/uapi/linux/ublk_cmd.h | 7 +++++++ > 2 files changed, 29 insertions(+), 1 deletion(-) > > diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c > index 2fd05c1bd30b..acf8aa6c4452 100644 > --- a/drivers/block/ublk_drv.c > +++ b/drivers/block/ublk_drv.c > @@ -64,7 +64,8 @@ > | UBLK_F_CMD_IOCTL_ENCODE \ > | UBLK_F_USER_COPY \ > | UBLK_F_ZONED \ > - | UBLK_F_USER_RECOVERY_FAIL_IO) > + | UBLK_F_USER_RECOVERY_FAIL_IO \ > + | UBLK_F_UPDATE_SIZE) > > #define UBLK_F_ALL_RECOVERY_FLAGS (UBLK_F_USER_RECOVERY \ > | UBLK_F_USER_RECOVERY_REISSUE \ > @@ -3052,6 +3053,22 @@ static int ublk_ctrl_get_features(struct io_uring_cmd > *cmd) > return 0; > } > > +static int ublk_ctrl_set_size(struct ublk_device *ub, > + struct io_uring_cmd *cmd) > +{ > + const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); > + struct ublk_param_basic *p = &ub->params.basic; > + size_t new_size = (int)header->data[0]; > + int ret = 0; > + > + p->dev_sectors = new_size; The above line need to be protected by ub->mutex. thanks, Ming
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 2fd05c1bd30b..acf8aa6c4452 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -64,7 +64,8 @@ | UBLK_F_CMD_IOCTL_ENCODE \ | UBLK_F_USER_COPY \ | UBLK_F_ZONED \ - | UBLK_F_USER_RECOVERY_FAIL_IO) + | UBLK_F_USER_RECOVERY_FAIL_IO \ + | UBLK_F_UPDATE_SIZE) #define UBLK_F_ALL_RECOVERY_FLAGS (UBLK_F_USER_RECOVERY \ | UBLK_F_USER_RECOVERY_REISSUE \ @@ -3052,6 +3053,22 @@ static int ublk_ctrl_get_features(struct io_uring_cmd *cmd) return 0; } +static int ublk_ctrl_set_size(struct ublk_device *ub, + struct io_uring_cmd *cmd) +{ + const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); + struct ublk_param_basic *p = &ub->params.basic; + size_t new_size = (int)header->data[0]; + int ret = 0; + + p->dev_sectors = new_size; + + mutex_lock(&ub->mutex); + set_capacity_and_notify(ub->ub_disk, p->dev_sectors); + mutex_unlock(&ub->mutex); + + return ret; +} /* * All control commands are sent via /dev/ublk-control, so we have to check * the destination device's permission @@ -3137,6 +3154,7 @@ static int ublk_ctrl_uring_cmd_permission(struct ublk_device *ub, case UBLK_CMD_SET_PARAMS: case UBLK_CMD_START_USER_RECOVERY: case UBLK_CMD_END_USER_RECOVERY: + case _IOC_NR(UBLK_U_CMD_UPDATE_SIZE): mask = MAY_READ | MAY_WRITE; break; default: @@ -3228,6 +3246,9 @@ static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd, case UBLK_CMD_END_USER_RECOVERY: ret = ublk_ctrl_end_recovery(ub, cmd); break; + case _IOC_NR(UBLK_U_CMD_UPDATE_SIZE): + ret = ublk_ctrl_set_size(ub, cmd); + break; default: ret = -EOPNOTSUPP; break; diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h index 583b86681c93..0e40e497c28f 100644 --- a/include/uapi/linux/ublk_cmd.h +++ b/include/uapi/linux/ublk_cmd.h @@ -51,6 +51,8 @@ _IOR('u', 0x13, struct ublksrv_ctrl_cmd) #define UBLK_U_CMD_DEL_DEV_ASYNC \ _IOR('u', 0x14, struct ublksrv_ctrl_cmd) +#define UBLK_U_CMD_UPDATE_SIZE \ + _IOWR('u', 0x15, struct ublksrv_ctrl_cmd) /* * 64bits are enough now, and it should be easy to extend in case of @@ -211,6 +213,11 @@ */ #define UBLK_F_USER_RECOVERY_FAIL_IO (1ULL << 9) +/* + * Resisizing a block device is possible with UBLK_U_CMD_UPDATE_SIZE + */ +#define UBLK_F_UPDATE_SIZE (1ULL << 10) + /* device state */ #define UBLK_S_DEV_DEAD 0 #define UBLK_S_DEV_LIVE 1
Currently ublk only allows the size of the ublkb block device to be set via UBLK_CMD_SET_PARAMS before UBLK_CMD_START_DEV is triggered. This does not provide support for extendable user-space block devices without having to stop and restart the underlying ublkb block device causing IO interruption. This patch adds a new ublk command UBLK_U_CMD_UPDATE_SIZE to allow the ublk block device to be resized on-the-fly. Feature flag UBLK_F_UPDATE_SIZE is also added to indicate support for this command. Signed-off-by: Omri Mann <omri@nvidia.com> --- drivers/block/ublk_drv.c | 23 ++++++++++++++++++++++- include/uapi/linux/ublk_cmd.h | 7 +++++++ 2 files changed, 29 insertions(+), 1 deletion(-)