6.6-stable review patch. If anyone has any objections, please let me know.
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From: Ming Lei ming.lei@redhat.com
[ Upstream commit 85248d670b71d9edda9459ee14fdc85c8e9632c0 ]
ublk_cancel_dev() just calls ublk_cancel_queue() to cancel all pending io commands after ublk request queue is idle. The only protection is just the read & write of ubq->nr_io_ready and avoid duplicated command cancel, so add one per-queue lock with cancel flag for providing this protection, meantime move ublk_cancel_dev() out of ub->mutex.
Then we needn't to call io_uring_cmd_complete_in_task() to cancel pending command. And the same cancel logic will be re-used for cancelable uring command.
This patch basically reverts commit ac5902f84bb5 ("ublk: fix AB-BA lockdep warning").
Signed-off-by: Ming Lei ming.lei@redhat.com Link: https://lore.kernel.org/r/20231009093324.957829-4-ming.lei@redhat.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/block/ublk_drv.c | 40 +++++++++++++++++++++++----------------- 1 file changed, 23 insertions(+), 17 deletions(-)
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 630ddfe6657bc..f4e0573c47114 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -115,6 +115,9 @@ struct ublk_uring_cmd_pdu { */ #define UBLK_IO_FLAG_NEED_GET_DATA 0x08
+/* atomic RW with ubq->cancel_lock */ +#define UBLK_IO_FLAG_CANCELED 0x80000000 + struct ublk_io { /* userspace buffer address from io cmd */ __u64 addr; @@ -139,6 +142,7 @@ struct ublk_queue { bool force_abort; bool timeout; unsigned short nr_io_ready; /* how many ios setup */ + spinlock_t cancel_lock; struct ublk_device *dev; struct ublk_io ios[]; }; @@ -1477,28 +1481,28 @@ static inline bool ublk_queue_ready(struct ublk_queue *ubq) return ubq->nr_io_ready == ubq->q_depth; }
-static void ublk_cmd_cancel_cb(struct io_uring_cmd *cmd, unsigned issue_flags) -{ - io_uring_cmd_done(cmd, UBLK_IO_RES_ABORT, 0, issue_flags); -} - static void ublk_cancel_queue(struct ublk_queue *ubq) { int i;
- if (!ublk_queue_ready(ubq)) - return; - for (i = 0; i < ubq->q_depth; i++) { struct ublk_io *io = &ubq->ios[i];
- if (io->flags & UBLK_IO_FLAG_ACTIVE) - io_uring_cmd_complete_in_task(io->cmd, - ublk_cmd_cancel_cb); - } + if (io->flags & UBLK_IO_FLAG_ACTIVE) { + bool done;
- /* all io commands are canceled */ - ubq->nr_io_ready = 0; + spin_lock(&ubq->cancel_lock); + done = !!(io->flags & UBLK_IO_FLAG_CANCELED); + if (!done) + io->flags |= UBLK_IO_FLAG_CANCELED; + spin_unlock(&ubq->cancel_lock); + + if (!done) + io_uring_cmd_done(io->cmd, + UBLK_IO_RES_ABORT, 0, + IO_URING_F_UNLOCKED); + } + } }
/* Cancel all pending commands, must be called after del_gendisk() returns */ @@ -1545,7 +1549,6 @@ static void __ublk_quiesce_dev(struct ublk_device *ub) blk_mq_quiesce_queue(ub->ub_disk->queue); ublk_wait_tagset_rqs_idle(ub); ub->dev_info.state = UBLK_S_DEV_QUIESCED; - ublk_cancel_dev(ub); /* we are going to release task_struct of ubq_daemon and resets * ->ubq_daemon to NULL. So in monitor_work, check on ubq_daemon causes UAF. * Besides, monitor_work is not necessary in QUIESCED state since we have @@ -1568,6 +1571,7 @@ static void ublk_quiesce_work_fn(struct work_struct *work) __ublk_quiesce_dev(ub); unlock: mutex_unlock(&ub->mutex); + ublk_cancel_dev(ub); }
static void ublk_unquiesce_dev(struct ublk_device *ub) @@ -1607,8 +1611,8 @@ static void ublk_stop_dev(struct ublk_device *ub) put_disk(ub->ub_disk); ub->ub_disk = NULL; unlock: - ublk_cancel_dev(ub); mutex_unlock(&ub->mutex); + ublk_cancel_dev(ub); cancel_delayed_work_sync(&ub->monitor_work); }
@@ -1962,6 +1966,7 @@ static int ublk_init_queue(struct ublk_device *ub, int q_id) void *ptr; int size;
+ spin_lock_init(&ubq->cancel_lock); ubq->flags = ub->dev_info.flags; ubq->q_id = q_id; ubq->q_depth = ub->dev_info.queue_depth; @@ -2569,8 +2574,9 @@ static void ublk_queue_reinit(struct ublk_device *ub, struct ublk_queue *ubq) int i;
WARN_ON_ONCE(!(ubq->ubq_daemon && ubq_daemon_is_dying(ubq))); + /* All old ioucmds have to be completed */ - WARN_ON_ONCE(ubq->nr_io_ready); + ubq->nr_io_ready = 0; /* old daemon is PF_EXITING, put it now */ put_task_struct(ubq->ubq_daemon); /* We have to reset it to NULL, otherwise ub won't accept new FETCH_REQ */