[PATCH for-next v2 3/3] RDMA/rtrs: Fix rxe_dealloc_pd warning

From: Li Zhijian
Date: Sat Apr 22 2023 - 21:27:55 EST


In current design:
1. PD and clt_path->s.dev are shared among connections.
2. every con[n]'s cleanup phase will call destroy_con_cq_qp()
3. clt_path->s.dev will be always decreased in destroy_con_cq_qp(), and
when clt_path->s.dev become zero, it will destroy PD.
4. when con[1] failed to create, con[1] will not take clt_path->s.dev,
but it try to decreased clt_path->s.dev

So, in case create_cm(con[0]) succeeds but create_cm(con[1])
fails, destroy_con_cq_qp(con[1]) will be called first which will destory
the PD while this PD is still taken by con[0].

Here, we refactor the error path of create_cm() and init_conns(), so that
we do the cleanup in the order they are created.

The warning occurs when destroying RXE PD whose reference count is not
zero.
-----------------------------------------------
rnbd_client L597: Mapping device /dev/nvme0n1 on session client, (access_mode: rw, nr_poll_queues: 0)
------------[ cut here ]------------
WARNING: CPU: 0 PID: 26407 at drivers/infiniband/sw/rxe/rxe_pool.c:256 __rxe_cleanup+0x13a/0x170 [rdma_rxe]
Modules linked in: rpcrdma rdma_ucm ib_iser rnbd_client libiscsi rtrs_client scsi_transport_iscsi rtrs_core rdma_cm iw_cm ib_cm crc32_generic rdma_rxe udp_tunnel ib_uverbs ib_core kmem device_dax nd_pmem dax_pmem nd_
vme crc32c_intel fuse nvme_core nfit libnvdimm dm_multipath scsi_dh_rdac scsi_dh_emc scsi_dh_alua dm_mirror dm_region_hash dm_log dm_mod
CPU: 0 PID: 26407 Comm: rnbd-client.sh Kdump: loaded Not tainted 6.2.0-rc6-roce-flush+ #53
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:__rxe_cleanup+0x13a/0x170 [rdma_rxe]
Code: 45 84 e4 0f 84 5a ff ff ff 48 89 ef e8 5f 18 71 f9 84 c0 75 90 be c8 00 00 00 48 89 ef e8 be 89 1f fa 85 c0 0f 85 7b ff ff ff <0f> 0b 41 bc ea ff ff ff e9 71 ff ff ff e8 84 7f 1f fa e9 d0 fe ff
RSP: 0018:ffffb09880b6f5f0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff99401f15d6a8 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffffbac8234b RDI: 00000000ffffffff
RBP: ffff99401f15d6d0 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000002d82 R11: 0000000000000000 R12: 0000000000000001
R13: ffff994101eff208 R14: ffffb09880b6f6a0 R15: 00000000fffffe00
FS: 00007fe113904740(0000) GS:ffff99413bc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff6cde656c8 CR3: 000000001f108004 CR4: 00000000001706f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
rxe_dealloc_pd+0x16/0x20 [rdma_rxe]
ib_dealloc_pd_user+0x4b/0x80 [ib_core]
rtrs_ib_dev_put+0x79/0xd0 [rtrs_core]
destroy_con_cq_qp+0x8a/0xa0 [rtrs_client]
init_path+0x1e7/0x9a0 [rtrs_client]
? __pfx_autoremove_wake_function+0x10/0x10
? lock_is_held_type+0xd7/0x130
? rcu_read_lock_sched_held+0x43/0x80
? pcpu_alloc+0x3dd/0x7d0
? rtrs_clt_init_stats+0x18/0x40 [rtrs_client]
rtrs_clt_open+0x24f/0x5a0 [rtrs_client]
? __pfx_rnbd_clt_link_ev+0x10/0x10 [rnbd_client]
rnbd_clt_map_device+0x6a5/0xe10 [rnbd_client]

Signed-off-by: Li Zhijian <lizhijian@xxxxxxxxxxx>
---
V2: refactor error path instead of introducing a new flag #Leon
---
drivers/infiniband/ulp/rtrs/rtrs-clt.c | 55 +++++++++++---------------
1 file changed, 23 insertions(+), 32 deletions(-)

diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
index c2065fc33a56..5234be5c6bf8 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
@@ -2039,6 +2039,7 @@ static int rtrs_clt_rdma_cm_handler(struct rdma_cm_id *cm_id,
return 0;
}

+/* The caller should the do the cleanup in case of error */
static int create_cm(struct rtrs_clt_con *con)
{
struct rtrs_path *s = con->c.path;
@@ -2061,14 +2062,14 @@ static int create_cm(struct rtrs_clt_con *con)
err = rdma_set_reuseaddr(cm_id, 1);
if (err != 0) {
rtrs_err(s, "Set address reuse failed, err: %d\n", err);
- goto destroy_cm;
+ return err;
}
err = rdma_resolve_addr(cm_id, (struct sockaddr *)&clt_path->s.src_addr,
(struct sockaddr *)&clt_path->s.dst_addr,
RTRS_CONNECT_TIMEOUT_MS);
if (err) {
rtrs_err(s, "Failed to resolve address, err: %d\n", err);
- goto destroy_cm;
+ return err;
}
/*
* Combine connection status and session events. This is needed
@@ -2083,29 +2084,15 @@ static int create_cm(struct rtrs_clt_con *con)
if (err == 0)
err = -ETIMEDOUT;
/* Timedout or interrupted */
- goto errr;
- }
- if (con->cm_err < 0) {
- err = con->cm_err;
- goto errr;
+ return err;
}
- if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTING) {
+ if (con->cm_err < 0)
+ return con->cm_err;
+ if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTING)
/* Device removal */
- err = -ECONNABORTED;
- goto errr;
- }
+ return -ECONNABORTED;

return 0;
-
-errr:
- stop_cm(con);
- mutex_lock(&con->con_mutex);
- destroy_con_cq_qp(con);
- mutex_unlock(&con->con_mutex);
-destroy_cm:
- destroy_cm(con);
-
- return err;
}

static void rtrs_clt_path_up(struct rtrs_clt_path *clt_path)
@@ -2333,7 +2320,7 @@ static void rtrs_clt_close_work(struct work_struct *work)
static int init_conns(struct rtrs_clt_path *clt_path)
{
unsigned int cid;
- int err;
+ int err, i;

/*
* On every new session connections increase reconnect counter
@@ -2349,10 +2336,8 @@ static int init_conns(struct rtrs_clt_path *clt_path)
goto destroy;

err = create_cm(to_clt_con(clt_path->s.con[cid]));
- if (err) {
- destroy_con(to_clt_con(clt_path->s.con[cid]));
+ if (err)
goto destroy;
- }
}
err = alloc_path_reqs(clt_path);
if (err)
@@ -2363,15 +2348,21 @@ static int init_conns(struct rtrs_clt_path *clt_path)
return 0;

destroy:
- while (cid--) {
- struct rtrs_clt_con *con = to_clt_con(clt_path->s.con[cid]);
+ /* Make sure we do the cleanup in the order they are created */
+ for (i = 0; i <= cid; i++) {
+ struct rtrs_clt_con *con;

- stop_cm(con);
+ if (!clt_path->s.con[i])
+ break;

- mutex_lock(&con->con_mutex);
- destroy_con_cq_qp(con);
- mutex_unlock(&con->con_mutex);
- destroy_cm(con);
+ con = to_clt_con(clt_path->s.con[i]);
+ if (con->c.cm_id) {
+ stop_cm(con);
+ mutex_lock(&con->con_mutex);
+ destroy_con_cq_qp(con);
+ mutex_unlock(&con->con_mutex);
+ destroy_cm(con);
+ }
destroy_con(con);
}
/*
--
2.29.2