linux/net/sunrpc
Chuck Lever e89e8d8fcd 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: bebd031866 ("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>
2018-02-02 13:31:04 -05:00
..
auth_gss kernel: make groups_sort calling a responsibility group_info allocators 2017-12-14 16:00:49 -08:00
xprtrdma xprtrdma: Fix BUG after a device removal 2018-02-02 13:31:04 -05:00
addr.c replace strict_strto calls 2014-07-12 18:45:49 -04:00
auth_generic.c NFS client updates for Linux 4.9 2016-10-13 21:28:20 -07:00
auth_null.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
auth_unix.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
auth.c sched/headers: Prepare to remove <linux/cred.h> inclusion from <linux/sched.h> 2017-03-02 08:42:31 +01:00
backchannel_rqst.c SUNRPC: Don't hold the transport lock when receiving backchannel data 2017-08-16 15:10:16 -04:00
cache.c sunrpc: make the function arg as const 2017-11-27 16:45:11 -05:00
clnt.c SUNRPC: Handle ENETDOWN errors 2017-11-30 11:52:52 -05:00
debugfs.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig svcrdma: Introduce local rdma_rw API helpers 2017-04-25 17:25:55 -04:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
netns.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
rpc_pipe.c sunrpc: remove net pointer from messages 2017-11-17 16:43:51 -05:00
rpcb_clnt.c sunrpc: remove net pointer from messages 2017-11-17 16:43:51 -05:00
sched.c SUNRPC: Micro-optimize __rpc_execute 2018-01-23 09:44:40 -05:00
socklib.c sunrpc: do not pull udp headers on receive 2016-04-11 15:31:33 -04:00
stats.c sunrpc: move pc_count out of struct svc_procinfo 2017-07-13 15:58:02 -04:00
sunrpc_syms.c sunrpc: exit_net cleanup check added 2017-11-17 16:43:50 -05:00
sunrpc.h SUNRPC: track whether a request is coming from a loop-back interface. 2014-05-22 15:59:18 -04:00
svc_xprt.c treewide: Remove TIMER_FUNC_TYPE and TIMER_DATA_TYPE casts 2017-11-21 16:35:54 -08:00
svc.c Modules updates for v4.15 2017-11-15 13:46:33 -08:00
svcauth_unix.c kernel: make groups_sort calling a responsibility group_info allocators 2017-12-14 16:00:49 -08:00
svcauth.c locking/atomic, kref: Implement kref_put_lock() 2017-01-18 10:03:29 +01:00
svcsock.c NFS client updates for Linux 4.14 2017-09-11 22:01:44 -07:00
sysctl.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
timer.c net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
xdr.c sunrpc: Fix xdr_init_decode_pages() documenting comment 2017-04-25 16:12:34 -04:00
xprt.c SUNRPC: Trace xprt_timer events 2018-01-23 09:44:39 -05:00
xprtmultipath.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xprtsock.c NFS client fixes for Linux 4.15-rc2 2017-12-01 20:04:20 -05:00