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| author | Chuck Lever <chuck.lever@oracle.com> | 2018-01-31 20:34:13 +0300 |
|---|---|---|
| committer | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2018-02-02 21:31:04 +0300 |
| commit | e89e8d8fcdc6751e86ccad794b052fe67e6ad619 (patch) | |
| tree | 380964eac77d5b0c1dd873d5d2d2af0a4ac47ec9 /net/sunrpc | |
| parent | 1179e2c27efe21167ec9d882b14becefba2ee990 (diff) | |
| download | linux-e89e8d8fcdc6751e86ccad794b052fe67e6ad619.tar.xz | |
xprtrdma: Fix BUG after a device removal
Michal Kalderon reports a BUG that occurs just after device removal:
[ 169.112490] rpcrdma: removing device qedr0 for 192.168.110.146:20049
[ 169.143909] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
[ 169.181837] IP: rpcrdma_dma_unmap_regbuf+0xa/0x60 [rpcrdma]
The RPC/RDMA client transport attempts to allocate some resources
on demand. Registered buffers are one such resource. These are
allocated (or re-allocated) by xprt_rdma_allocate to hold RPC Call
and Reply messages. A hardware resource is associated with each of
these buffers, as they can be used for a Send or Receive Work
Request.
If a device is removed from under an NFS/RDMA mount, the transport
layer is responsible for releasing all hardware resources before
the device can be finally unplugged. A BUG results when the NFS
mount hasn't yet seen much activity: the transport tries to release
resources that haven't yet been allocated.
rpcrdma_free_regbuf() already checks for this case, so just move
that check to cover the DEVICE_REMOVAL case as well.
Reported-by: Michal Kalderon <Michal.Kalderon@cavium.com>
Fixes: bebd031866ca ("xprtrdma: Support unplugging an HCA ...")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Michal Kalderon <Michal.Kalderon@cavium.com>
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'net/sunrpc')
| -rw-r--r-- | net/sunrpc/xprtrdma/verbs.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index bb56b9d849c4..e6f84a6434a0 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -1502,6 +1502,9 @@ __rpcrdma_dma_map_regbuf(struct rpcrdma_ia *ia, struct rpcrdma_regbuf *rb) static void rpcrdma_dma_unmap_regbuf(struct rpcrdma_regbuf *rb) { + if (!rb) + return; + if (!rpcrdma_regbuf_is_mapped(rb)) return; @@ -1517,9 +1520,6 @@ rpcrdma_dma_unmap_regbuf(struct rpcrdma_regbuf *rb) void rpcrdma_free_regbuf(struct rpcrdma_regbuf *rb) { - if (!rb) - return; - rpcrdma_dma_unmap_regbuf(rb); kfree(rb); } |