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authorMing Lei <ming.lei@redhat.com>2023-05-17 21:34:08 +0800
committerJens Axboe <axboe@kernel.dk>2023-05-18 07:59:08 -0600
commitac5902f84bb546c64aea02c439c2579cbf40318f (patch)
tree71ca13b419a67723cb04adee229bedb4e557839e /drivers
parent56cdea92ed915f8eb37575331fb4a269991e8026 (diff)
ublk: fix AB-BA lockdep warning
When handling UBLK_IO_FETCH_REQ, ctx->uring_lock is grabbed first, then ub->mutex is acquired. When handling UBLK_CMD_STOP_DEV or UBLK_CMD_DEL_DEV, ub->mutex is grabbed first, then calling io_uring_cmd_done() for canceling uring command, in which ctx->uring_lock may be required. Real deadlock only happens when all the above commands are issued from same uring context, and in reality different uring contexts are often used for handing control command and IO command. Fix the issue by using io_uring_cmd_complete_in_task() to cancel command in ublk_cancel_dev(ublk_cancel_queue). Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com> Closes: https://lore.kernel.org/linux-block/becol2g7sawl4rsjq2dztsbc7mqypfqko6wzsyoyazqydoasml@rcxarzwidrhk Cc: Ziyang Zhang <ZiyangZhang@linux.alibaba.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Tested-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com> Link: https://lore.kernel.org/r/20230517133408.210944-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/block/ublk_drv.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index c7ed5d69e9ee..33d3298a0da1 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -1120,6 +1120,11 @@ 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;
@@ -1131,8 +1136,8 @@ static void ublk_cancel_queue(struct ublk_queue *ubq)
struct ublk_io *io = &ubq->ios[i];
if (io->flags & UBLK_IO_FLAG_ACTIVE)
- io_uring_cmd_done(io->cmd, UBLK_IO_RES_ABORT, 0,
- IO_URING_F_UNLOCKED);
+ io_uring_cmd_complete_in_task(io->cmd,
+ ublk_cmd_cancel_cb);
}
/* all io commands are canceled */