From 72070e57b0a518ec8e562a2b68fdfc796ef5c040 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Fri, 4 Apr 2025 08:18:49 +0800 Subject: [PATCH 1/4] selftests: ublk: fix test_stripe_04 Commit 57ed58c13256 ("selftests: ublk: enable zero copy for stripe target") added test entry of test_stripe_04, but forgot to add the test script. So fix the test by adding the script file. Reported-by: Uday Shankar Signed-off-by: Ming Lei Reviewed-by: Uday Shankar Link: https://lore.kernel.org/r/20250404001849.1443064-1-ming.lei@redhat.com Signed-off-by: Jens Axboe --- .../testing/selftests/ublk/test_stripe_04.sh | 24 +++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100755 tools/testing/selftests/ublk/test_stripe_04.sh diff --git a/tools/testing/selftests/ublk/test_stripe_04.sh b/tools/testing/selftests/ublk/test_stripe_04.sh new file mode 100755 index 000000000000..1f2b642381d1 --- /dev/null +++ b/tools/testing/selftests/ublk/test_stripe_04.sh @@ -0,0 +1,24 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 + +. "$(cd "$(dirname "$0")" && pwd)"/test_common.sh + +TID="stripe_04" +ERR_CODE=0 + +_prep_test "stripe" "mkfs & mount & umount on zero copy" + +backfile_0=$(_create_backfile 256M) +backfile_1=$(_create_backfile 256M) +dev_id=$(_add_ublk_dev -t stripe -z -q 2 "$backfile_0" "$backfile_1") +_check_add_dev $TID $? "$backfile_0" "$backfile_1" + +_mkfs_mount_test /dev/ublkb"${dev_id}" +ERR_CODE=$? + +_cleanup_test "stripe" + +_remove_backfile "$backfile_0" +_remove_backfile "$backfile_1" + +_show_result $TID $ERR_CODE From 6ee6bd5d4fce502a5b5a2ea805e9ff16e6aa890f Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Wed, 9 Apr 2025 09:14:41 +0800 Subject: [PATCH 2/4] ublk: fix handling recovery & reissue in ublk_abort_queue() Commit 8284066946e6 ("ublk: grab request reference when the request is handled by userspace") doesn't grab request reference in case of recovery reissue. Then the request can be requeued & re-dispatch & failed when canceling uring command. If it is one zc request, the request can be freed before io_uring returns the zc buffer back, then cause kernel panic: [ 126.773061] BUG: kernel NULL pointer dereference, address: 00000000000000c8 [ 126.773657] #PF: supervisor read access in kernel mode [ 126.774052] #PF: error_code(0x0000) - not-present page [ 126.774455] PGD 0 P4D 0 [ 126.774698] Oops: Oops: 0000 [#1] SMP NOPTI [ 126.775034] CPU: 13 UID: 0 PID: 1612 Comm: kworker/u64:55 Not tainted 6.14.0_blk+ #182 PREEMPT(full) [ 126.775676] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39 04/01/2014 [ 126.776275] Workqueue: iou_exit io_ring_exit_work [ 126.776651] RIP: 0010:ublk_io_release+0x14/0x130 [ublk_drv] Fixes it by always grabbing request reference for aborting the request. Reported-by: Caleb Sander Mateos Closes: https://lore.kernel.org/linux-block/CADUfDZodKfOGUeWrnAxcZiLT+puaZX8jDHoj_sfHZCOZwhzz6A@mail.gmail.com/ Fixes: 8284066946e6 ("ublk: grab request reference when the request is handled by userspace") Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20250409011444.2142010-2-ming.lei@redhat.com Signed-off-by: Jens Axboe --- drivers/block/ublk_drv.c | 30 ++++++++++++++++++++++++++---- 1 file changed, 26 insertions(+), 4 deletions(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 2fd05c1bd30b..41bed67508f2 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -1140,6 +1140,25 @@ static void ublk_complete_rq(struct kref *ref) __ublk_complete_rq(req); } +static void ublk_do_fail_rq(struct request *req) +{ + struct ublk_queue *ubq = req->mq_hctx->driver_data; + + if (ublk_nosrv_should_reissue_outstanding(ubq->dev)) + blk_mq_requeue_request(req, false); + else + __ublk_complete_rq(req); +} + +static void ublk_fail_rq_fn(struct kref *ref) +{ + struct ublk_rq_data *data = container_of(ref, struct ublk_rq_data, + ref); + struct request *req = blk_mq_rq_from_pdu(data); + + ublk_do_fail_rq(req); +} + /* * Since ublk_rq_task_work_cb always fails requests immediately during * exiting, __ublk_fail_req() is only called from abort context during @@ -1153,10 +1172,13 @@ static void __ublk_fail_req(struct ublk_queue *ubq, struct ublk_io *io, { WARN_ON_ONCE(io->flags & UBLK_IO_FLAG_ACTIVE); - if (ublk_nosrv_should_reissue_outstanding(ubq->dev)) - blk_mq_requeue_request(req, false); - else - ublk_put_req_ref(ubq, req); + if (ublk_need_req_ref(ubq)) { + struct ublk_rq_data *data = blk_mq_rq_to_pdu(req); + + kref_put(&data->ref, ublk_fail_rq_fn); + } else { + ublk_do_fail_rq(req); + } } static void ubq_complete_io_cmd(struct ublk_io *io, int res, From 18461f2a02be04f8bbbe3b37fecfc702e3fa5bc2 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Wed, 9 Apr 2025 09:14:42 +0800 Subject: [PATCH 3/4] ublk: don't fail request for recovery & reissue in case of ubq->canceling ubq->canceling is set with request queue quiesced when io_uring context is exiting. USER_RECOVERY or !RECOVERY_FAIL_IO requires request to be re-queued and re-dispatch after device is recovered. However commit d796cea7b9f3 ("ublk: implement ->queue_rqs()") still may fail any request in case of ubq->canceling, this way breaks USER_RECOVERY or !RECOVERY_FAIL_IO. Fix it by calling __ublk_abort_rq() in case of ubq->canceling. Reviewed-by: Uday Shankar Reported-by: Uday Shankar Closes: https://lore.kernel.org/linux-block/Z%2FQkkTRHfRxtN%2FmB@dev-ushankar.dev.purestorage.com/ Fixes: d796cea7b9f3 ("ublk: implement ->queue_rqs()") Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20250409011444.2142010-3-ming.lei@redhat.com Signed-off-by: Jens Axboe --- drivers/block/ublk_drv.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 41bed67508f2..d6ca2f1097ad 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -1371,7 +1371,8 @@ static enum blk_eh_timer_return ublk_timeout(struct request *rq) return BLK_EH_RESET_TIMER; } -static blk_status_t ublk_prep_req(struct ublk_queue *ubq, struct request *rq) +static blk_status_t ublk_prep_req(struct ublk_queue *ubq, struct request *rq, + bool check_cancel) { blk_status_t res; @@ -1390,7 +1391,7 @@ static blk_status_t ublk_prep_req(struct ublk_queue *ubq, struct request *rq) if (ublk_nosrv_should_queue_io(ubq) && unlikely(ubq->force_abort)) return BLK_STS_IOERR; - if (unlikely(ubq->canceling)) + if (check_cancel && unlikely(ubq->canceling)) return BLK_STS_IOERR; /* fill iod to slot in io cmd buffer */ @@ -1409,7 +1410,7 @@ static blk_status_t ublk_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq = bd->rq; blk_status_t res; - res = ublk_prep_req(ubq, rq); + res = ublk_prep_req(ubq, rq, false); if (res != BLK_STS_OK) return res; @@ -1441,7 +1442,7 @@ static void ublk_queue_rqs(struct rq_list *rqlist) ublk_queue_cmd_list(ubq, &submit_list); ubq = this_q; - if (ublk_prep_req(ubq, req) == BLK_STS_OK) + if (ublk_prep_req(ubq, req, true) == BLK_STS_OK) rq_list_add_tail(&submit_list, req); else rq_list_add_tail(&requeue_list, req); From 843c6cec1af85f05971b7baf3704801895e77d76 Mon Sep 17 00:00:00 2001 From: Caleb Sander Mateos Date: Tue, 8 Apr 2025 19:29:26 -0600 Subject: [PATCH 4/4] ublk: pass ublksrv_ctrl_cmd * instead of io_uring_cmd * The ublk_ctrl_*() handlers all take struct io_uring_cmd *cmd but only use it to get struct ublksrv_ctrl_cmd *header from the io_uring SQE. Since the caller ublk_ctrl_uring_cmd() has already computed header, pass it instead of cmd. Signed-off-by: Caleb Sander Mateos Link: https://lore.kernel.org/r/20250409012928.3527198-1-csander@purestorage.com Signed-off-by: Jens Axboe --- drivers/block/ublk_drv.c | 46 +++++++++++++++++----------------------- 1 file changed, 19 insertions(+), 27 deletions(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index d6ca2f1097ad..cdb1543fa4a9 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -2436,9 +2436,9 @@ static struct ublk_device *ublk_get_device_from_id(int idx) return ub; } -static int ublk_ctrl_start_dev(struct ublk_device *ub, struct io_uring_cmd *cmd) +static int ublk_ctrl_start_dev(struct ublk_device *ub, + const struct ublksrv_ctrl_cmd *header) { - const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); const struct ublk_param_basic *p = &ub->params.basic; int ublksrv_pid = (int)header->data[0]; struct queue_limits lim = { @@ -2557,9 +2557,8 @@ static int ublk_ctrl_start_dev(struct ublk_device *ub, struct io_uring_cmd *cmd) } static int ublk_ctrl_get_queue_affinity(struct ublk_device *ub, - struct io_uring_cmd *cmd) + const struct ublksrv_ctrl_cmd *header) { - const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); void __user *argp = (void __user *)(unsigned long)header->addr; cpumask_var_t cpumask; unsigned long queue; @@ -2608,9 +2607,8 @@ static inline void ublk_dump_dev_info(struct ublksrv_ctrl_dev_info *info) info->nr_hw_queues, info->queue_depth); } -static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd) +static int ublk_ctrl_add_dev(const struct ublksrv_ctrl_cmd *header) { - const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); void __user *argp = (void __user *)(unsigned long)header->addr; struct ublksrv_ctrl_dev_info info; struct ublk_device *ub; @@ -2835,9 +2833,8 @@ static int ublk_ctrl_stop_dev(struct ublk_device *ub) } static int ublk_ctrl_get_dev_info(struct ublk_device *ub, - struct io_uring_cmd *cmd) + const struct ublksrv_ctrl_cmd *header) { - const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); void __user *argp = (void __user *)(unsigned long)header->addr; if (header->len < sizeof(struct ublksrv_ctrl_dev_info) || !header->addr) @@ -2866,9 +2863,8 @@ static void ublk_ctrl_fill_params_devt(struct ublk_device *ub) } static int ublk_ctrl_get_params(struct ublk_device *ub, - struct io_uring_cmd *cmd) + const struct ublksrv_ctrl_cmd *header) { - const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); void __user *argp = (void __user *)(unsigned long)header->addr; struct ublk_params_header ph; int ret; @@ -2897,9 +2893,8 @@ static int ublk_ctrl_get_params(struct ublk_device *ub, } static int ublk_ctrl_set_params(struct ublk_device *ub, - struct io_uring_cmd *cmd) + const struct ublksrv_ctrl_cmd *header) { - const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); void __user *argp = (void __user *)(unsigned long)header->addr; struct ublk_params_header ph; int ret = -EFAULT; @@ -2963,9 +2958,8 @@ static void ublk_queue_reinit(struct ublk_device *ub, struct ublk_queue *ubq) } static int ublk_ctrl_start_recovery(struct ublk_device *ub, - struct io_uring_cmd *cmd) + const struct ublksrv_ctrl_cmd *header) { - const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); int ret = -EINVAL; int i; @@ -3011,9 +3005,8 @@ static int ublk_ctrl_start_recovery(struct ublk_device *ub, } static int ublk_ctrl_end_recovery(struct ublk_device *ub, - struct io_uring_cmd *cmd) + const struct ublksrv_ctrl_cmd *header) { - const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); int ublksrv_pid = (int)header->data[0]; int ret = -EINVAL; int i; @@ -3060,9 +3053,8 @@ static int ublk_ctrl_end_recovery(struct ublk_device *ub, return ret; } -static int ublk_ctrl_get_features(struct io_uring_cmd *cmd) +static int ublk_ctrl_get_features(const struct ublksrv_ctrl_cmd *header) { - 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; @@ -3201,7 +3193,7 @@ static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd, goto out; if (cmd_op == UBLK_U_CMD_GET_FEATURES) { - ret = ublk_ctrl_get_features(cmd); + ret = ublk_ctrl_get_features(header); goto out; } @@ -3218,17 +3210,17 @@ static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd, switch (_IOC_NR(cmd_op)) { case UBLK_CMD_START_DEV: - ret = ublk_ctrl_start_dev(ub, cmd); + ret = ublk_ctrl_start_dev(ub, header); break; case UBLK_CMD_STOP_DEV: ret = ublk_ctrl_stop_dev(ub); break; case UBLK_CMD_GET_DEV_INFO: case UBLK_CMD_GET_DEV_INFO2: - ret = ublk_ctrl_get_dev_info(ub, cmd); + ret = ublk_ctrl_get_dev_info(ub, header); break; case UBLK_CMD_ADD_DEV: - ret = ublk_ctrl_add_dev(cmd); + ret = ublk_ctrl_add_dev(header); break; case UBLK_CMD_DEL_DEV: ret = ublk_ctrl_del_dev(&ub, true); @@ -3237,19 +3229,19 @@ static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd, ret = ublk_ctrl_del_dev(&ub, false); break; case UBLK_CMD_GET_QUEUE_AFFINITY: - ret = ublk_ctrl_get_queue_affinity(ub, cmd); + ret = ublk_ctrl_get_queue_affinity(ub, header); break; case UBLK_CMD_GET_PARAMS: - ret = ublk_ctrl_get_params(ub, cmd); + ret = ublk_ctrl_get_params(ub, header); break; case UBLK_CMD_SET_PARAMS: - ret = ublk_ctrl_set_params(ub, cmd); + ret = ublk_ctrl_set_params(ub, header); break; case UBLK_CMD_START_USER_RECOVERY: - ret = ublk_ctrl_start_recovery(ub, cmd); + ret = ublk_ctrl_start_recovery(ub, header); break; case UBLK_CMD_END_USER_RECOVERY: - ret = ublk_ctrl_end_recovery(ub, cmd); + ret = ublk_ctrl_end_recovery(ub, header); break; default: ret = -EOPNOTSUPP;