* [PATCH v2 0/2] Fix a deadlock in the ib_srp driver
@ 2022-02-15 21:05 Bart Van Assche
2022-02-15 21:05 ` [PATCH v2 1/2] ib_srp: Add more documentation Bart Van Assche
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: Bart Van Assche @ 2022-02-15 21:05 UTC (permalink / raw)
To: Jason Gunthorpe
Cc: Leon Romanovsky, linux-rdma, Tetsuo Handa, Bart Van Assche
Hi Jason,
This patch series fixes a deadlock in the ib_srp driver that was discovered
by syzbot. Please consider these patches for kernel v5.18.
Thanks,
Bart.
Changes compared to v1:
- Dropped patch 2/3, the patch that converts a spinlock into a mutex.
- Simplified patch 3/3 by removing a flush_work() loop.
Bart Van Assche (2):
ib_srp: Add more documentation
ib_srp: Fix a deadlock
drivers/infiniband/ulp/srp/ib_srp.c | 6 ++++--
drivers/infiniband/ulp/srp/ib_srp.h | 11 ++++++++++-
2 files changed, 14 insertions(+), 3 deletions(-)
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v2 1/2] ib_srp: Add more documentation
2022-02-15 21:05 [PATCH v2 0/2] Fix a deadlock in the ib_srp driver Bart Van Assche
@ 2022-02-15 21:05 ` Bart Van Assche
2022-02-15 21:05 ` [PATCH v2 2/2] ib_srp: Fix a deadlock Bart Van Assche
2022-02-23 19:14 ` [PATCH v2 0/2] Fix a deadlock in the ib_srp driver Jason Gunthorpe
2 siblings, 0 replies; 5+ messages in thread
From: Bart Van Assche @ 2022-02-15 21:05 UTC (permalink / raw)
To: Jason Gunthorpe
Cc: Leon Romanovsky, linux-rdma, Tetsuo Handa, Bart Van Assche
Make it more clear what the different ib_srp data structures represent.
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
drivers/infiniband/ulp/srp/ib_srp.h | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/infiniband/ulp/srp/ib_srp.h b/drivers/infiniband/ulp/srp/ib_srp.h
index abccddeea1e3..55a575e2cace 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.h
+++ b/drivers/infiniband/ulp/srp/ib_srp.h
@@ -92,6 +92,9 @@ enum srp_iu_type {
};
/*
+ * RDMA adapter in the initiator system.
+ *
+ * @dev_list: List of RDMA ports associated with this RDMA adapter (srp_host).
* @mr_page_mask: HCA memory registration page mask.
* @mr_page_size: HCA memory registration page size.
* @mr_max_size: Maximum size in bytes of a single FR registration request.
@@ -109,6 +112,12 @@ struct srp_device {
bool use_fast_reg;
};
+/*
+ * One port of an RDMA adapter in the initiator system.
+ *
+ * @target_list: List of connected target ports (struct srp_target_port).
+ * @target_lock: Protects @target_list.
+ */
struct srp_host {
struct srp_device *srp_dev;
u8 port;
@@ -183,7 +192,7 @@ struct srp_rdma_ch {
};
/**
- * struct srp_target_port
+ * struct srp_target_port - RDMA port in the SRP target system
* @comp_vector: Completion vector used by the first RDMA channel created for
* this target port.
*/
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v2 2/2] ib_srp: Fix a deadlock
2022-02-15 21:05 [PATCH v2 0/2] Fix a deadlock in the ib_srp driver Bart Van Assche
2022-02-15 21:05 ` [PATCH v2 1/2] ib_srp: Add more documentation Bart Van Assche
@ 2022-02-15 21:05 ` Bart Van Assche
2022-02-16 7:04 ` Leon Romanovsky
2022-02-23 19:14 ` [PATCH v2 0/2] Fix a deadlock in the ib_srp driver Jason Gunthorpe
2 siblings, 1 reply; 5+ messages in thread
From: Bart Van Assche @ 2022-02-15 21:05 UTC (permalink / raw)
To: Jason Gunthorpe
Cc: Leon Romanovsky, linux-rdma, Tetsuo Handa, Bart Van Assche,
syzbot+831661966588c802aae9
Remove the flush_workqueue(system_long_wq) call since flushing
system_long_wq is deadlock-prone and since that call is redundant.
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Fixes: ef6c49d87c34 ("IB/srp: Eliminate state SRP_TARGET_DEAD")
Reported-by: syzbot+831661966588c802aae9@syzkaller.appspotmail.com
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
drivers/infiniband/ulp/srp/ib_srp.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index e174e853f8a4..285b766e4e70 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -4047,9 +4047,11 @@ static void srp_remove_one(struct ib_device *device, void *client_data)
spin_unlock(&host->target_lock);
/*
- * Wait for tl_err and target port removal tasks.
+ * srp_queue_remove_work() queues a call to
+ * srp_remove_target(). The latter function cancels
+ * target->tl_err_work so waiting for the remove works to
+ * finish is sufficient.
*/
- flush_workqueue(system_long_wq);
flush_workqueue(srp_remove_wq);
kfree(host);
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v2 2/2] ib_srp: Fix a deadlock
2022-02-15 21:05 ` [PATCH v2 2/2] ib_srp: Fix a deadlock Bart Van Assche
@ 2022-02-16 7:04 ` Leon Romanovsky
0 siblings, 0 replies; 5+ messages in thread
From: Leon Romanovsky @ 2022-02-16 7:04 UTC (permalink / raw)
To: Bart Van Assche
Cc: Jason Gunthorpe, linux-rdma, Tetsuo Handa, syzbot+831661966588c802aae9
On Tue, Feb 15, 2022 at 01:05:11PM -0800, Bart Van Assche wrote:
> Remove the flush_workqueue(system_long_wq) call since flushing
> system_long_wq is deadlock-prone and since that call is redundant.
>
> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
> Fixes: ef6c49d87c34 ("IB/srp: Eliminate state SRP_TARGET_DEAD")
> Reported-by: syzbot+831661966588c802aae9@syzkaller.appspotmail.com
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> ---
> drivers/infiniband/ulp/srp/ib_srp.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
Thanks,
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2 0/2] Fix a deadlock in the ib_srp driver
2022-02-15 21:05 [PATCH v2 0/2] Fix a deadlock in the ib_srp driver Bart Van Assche
2022-02-15 21:05 ` [PATCH v2 1/2] ib_srp: Add more documentation Bart Van Assche
2022-02-15 21:05 ` [PATCH v2 2/2] ib_srp: Fix a deadlock Bart Van Assche
@ 2022-02-23 19:14 ` Jason Gunthorpe
2 siblings, 0 replies; 5+ messages in thread
From: Jason Gunthorpe @ 2022-02-23 19:14 UTC (permalink / raw)
To: Bart Van Assche; +Cc: Leon Romanovsky, linux-rdma, Tetsuo Handa
On Tue, Feb 15, 2022 at 01:05:09PM -0800, Bart Van Assche wrote:
> Bart Van Assche (2):
> ib_srp: Add more documentation
Applied to for-next
> ib_srp: Fix a deadlock
Applied to for-rc
Jason
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2022-02-23 19:14 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2022-02-15 21:05 [PATCH v2 0/2] Fix a deadlock in the ib_srp driver Bart Van Assche
2022-02-15 21:05 ` [PATCH v2 1/2] ib_srp: Add more documentation Bart Van Assche
2022-02-15 21:05 ` [PATCH v2 2/2] ib_srp: Fix a deadlock Bart Van Assche
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2022-02-23 19:14 ` [PATCH v2 0/2] Fix a deadlock in the ib_srp driver Jason Gunthorpe
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