From: Ming Lei Date: Thu, 29 Jan 2026 16:19:51 +0000 (+0800) Subject: ublk: add UBLK_F_NO_AUTO_PART_SCAN feature flag X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8443e2087e7002fa25984faad6bbf5f63b280645;p=thirdparty%2Fkernel%2Flinux.git ublk: add UBLK_F_NO_AUTO_PART_SCAN feature flag Add a new feature flag UBLK_F_NO_AUTO_PART_SCAN to allow users to suppress automatic partition scanning when starting a ublk device. This is useful for some cases in which user don't want to scan partitions. Users still can manually trigger partition scanning later when appropriate using standard tools (e.g., partprobe, blockdev --rereadpt). Reported-by: Yoav Cohen Link: https://lore.kernel.org/linux-block/DM4PR12MB63280C5637917C071C2F0D65A9A8A@DM4PR12MB6328.namprd12.prod.outlook.com/ Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 92bd2351e3ad2..4fe754e7d1e8b 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -80,7 +80,8 @@ | UBLK_F_BUF_REG_OFF_DAEMON \ | (IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY) ? UBLK_F_INTEGRITY : 0) \ | UBLK_F_SAFE_STOP_DEV \ - | UBLK_F_BATCH_IO) + | UBLK_F_BATCH_IO \ + | UBLK_F_NO_AUTO_PART_SCAN) #define UBLK_F_ALL_RECOVERY_FLAGS (UBLK_F_USER_RECOVERY \ | UBLK_F_USER_RECOVERY_REISSUE \ @@ -4430,9 +4431,14 @@ static int ublk_ctrl_start_dev(struct ublk_device *ub, set_bit(UB_STATE_USED, &ub->state); - /* Schedule async partition scan for trusted daemons */ - if (!ub->unprivileged_daemons) - schedule_work(&ub->partition_scan_work); + /* Skip partition scan if disabled by user */ + if (ub->dev_info.flags & UBLK_F_NO_AUTO_PART_SCAN) { + clear_bit(GD_SUPPRESS_PART_SCAN, &disk->state); + } else { + /* Schedule async partition scan for trusted daemons */ + if (!ub->unprivileged_daemons) + schedule_work(&ub->partition_scan_work); + } out_put_cdev: if (ret) { diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h index 743d314913875..a888767568055 100644 --- a/include/uapi/linux/ublk_cmd.h +++ b/include/uapi/linux/ublk_cmd.h @@ -367,6 +367,9 @@ */ #define UBLK_F_SAFE_STOP_DEV (1ULL << 17) +/* Disable automatic partition scanning when device is started */ +#define UBLK_F_NO_AUTO_PART_SCAN (1ULL << 18) + /* device state */ #define UBLK_S_DEV_DEAD 0 #define UBLK_S_DEV_LIVE 1