rpcb_getport_async() invokes rpcb_call_async(), which return the value
of rpc_run_task() to "child". Since rpc_run_task() is impossible to
return an ERR pointer, there is no need to add the IS_ERR() condition on
"child" here. So we need to remove it.
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
gss_mech_register() calls svcauth_gss_register_pseudoflavor() for each
flavour, but gss_mech_unregister() does not call auth_domain_put().
This is unbalanced and makes it impossible to reload the module.
Change svcauth_gss_register_pseudoflavor() to return the registered
auth_domain, and save it for later release.
Cc: stable@vger.kernel.org (v2.6.12+)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206651
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
There is no valid case for supporting duplicate pseudoflavor
registrations.
Currently the silent acceptance of such registrations is hiding a bug.
The rpcsec_gss_krb5 module registers 2 flavours but does not unregister
them, so if you load, unload, reload the module, it will happily
continue to use the old registration which now has pointers to the
memory were the module was originally loaded. This could lead to
unexpected results.
So disallow duplicate registrations.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206651
Cc: stable@vger.kernel.org (v2.6.12+)
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The domain table should be empty at module unload. If it isn't there is
a bug somewhere. So check and report.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206651
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Highlights of this series:
* Remove serialization of sending RPC/RDMA Replies
* Convert the TCP socket send path to use xdr_buf::bvecs (pre-requisite for
RPC-on-TLS)
* Fix svcrdma backchannel sendto return code
* Convert a number of dprintk call sites to use tracepoints
* Fix the "suggest braces around empty body in an 'else' statement" warning
- Rename these so they are easy to enable and search for as a set
- Move the tracepoints to get a more accurate sense of control flow
- Tracepoints should not fire on xprt shutdown
- Display memory address in case data structure had been corrupted
- Abandon dprintk in these paths
I haven't ever gotten one of these tracepoints to trigger. I wonder
if we should simply remove them.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up. At this point, we are not ready yet to support bio_vecs in
the UDP transport implementation. However, we can clean up
svc_udp_recvfrom() to match the tracing and straight-lining recently
changes made in svc_tcp_recvfrom().
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This function is not currently "generic" so remove the documenting
comment and rename it appropriately. Its internals are converted to
use bio_vecs for reading from the transport socket.
In existing typical sunrpc uses of bio_vecs, the bio_vec array is
allocated dynamically. Here, instead, an array of bio_vecs is added
to svc_rqst. The lifetime of this array can be greater than one call
to xpo_recvfrom():
- Multiple calls to xpo_recvfrom() might be needed to read an RPC
message completely.
- At some later point, rq_arg.bvecs will point to this array and it
will carry the received message into svc_process().
I also expect that a future optimization will remove either the
rq_vec or rq_pages array in favor of rq_bvec, thus conserving the
size of struct svc_rqst.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Refactor: svc_recvfrom() is going to be converted to read into
bio_vecs in a moment. Unhook the only other caller,
svc_tcp_recv_record(), which just wants to read the 4-byte stream
record marker into a kvec.
While we're in the area, streamline this helper by straight-lining
the hot path, replace dprintk call sites with tracepoints, and
reduce the number of atomic bit operations in this path.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up. I find the name of the svc_sock::sk_reclen field
confusing, so I've changed it to better reflect its function. This
field is not read directly to get the record length. Rather, it is
a buffer containing a record marker that needs to be decoded.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Report TCP socket state changes and accept failures via
tracepoints, replacing dprintk() call sites.
No tracepoint is added in svc_tcp_listen_data_ready. There's
no information available there that isn't also reported by the
svcsock_new_socket and the accept failure tracepoints.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
In addition to tracing recently-updated socket sendto events, this
commit adds a trace event class that can be used for additional
svcsock-related tracepoints in subsequent patches.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up: Commit 850cbaddb5 ("udp: use it's own memory accounting
schema") removed the last skb-related tracepoint from svcsock.c, so
it is no longer necessary to include trace/events/skb.h.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
In lieu of dprintks or tracepoints in each individual transport
implementation, introduce tracepoints in the generic part of the RPC
layer. These typically fire for connection lifetime events, so
shouldn't contribute a lot of noise.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Failure to accept a connection is typically due to a problem
specific to a transport type. Also, ->xpo_accept returns NULL
on error rather than reporting a specific problem.
So, add failure-specific tracepoints in svc_rdma_accept().
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up: After commit 1e091c3bbf ("svcrdma: Ignore source port
when computing DRC hash"), the IP address stored in xpt_remote
always has a port number of zero. Thus, there's no need to display
the port number when displaying the IP address of a remote NFS/RDMA
client.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up: Use a consistent naming convention so that these trace
points can be enabled quickly via a glob.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Way back when I was writing the RPC/RDMA server-side backchannel
code, I misread the TCP backchannel reply handler logic. When
svc_tcp_recvfrom() successfully receives a backchannel reply, it
does not return -EAGAIN. It sets XPT_DATA and returns zero.
Update svc_rdma_recvfrom() to return zero. Here, XPT_DATA doesn't
need to be set again: it is set whenever a new message is received,
behind a spin lock in a single threaded context.
Also, if handling the cb reply is not successful, the message is
simply dropped. There's no special message framing to deal with as
there is in the TCP case.
Now that the handle_bc_reply() return value is ignored, I've removed
the dprintk call sites in the error exit of handle_bc_reply() in
favor of trace points in other areas that already report the error
cases.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up: Replace a dprintk call site.
This is the last remaining dprintk call site in svc_rdma_rw.c, so
remove dprintk infrastructure as well.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
- De-duplicate code
- Rename the tracepoint with "_err" to allow enabling via glob
- Report the sg_cnt for the failing rw_ctx
- Fix a dumb signage issue
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
It appears that the RPC/RDMA transport does not need serialization
of calls to its xpo_sendto method. Move the mutex into the socket
methods that still need that serialization.
Tail latencies are unambiguously better with this patch applied.
fio randrw 8KB 70/30 on NFSv3, smaller numbers are better:
clat percentiles (usec):
With xpt_mutex:
r | 99.99th=[ 8848]
w | 99.99th=[ 9634]
Without xpt_mutex:
r | 99.99th=[ 8586]
w | 99.99th=[ 8979]
Serializing the construction of RPC/RDMA transport headers is not
really necessary at this point, because the Linux NFS server
implementation never changes its credit grant on a connection. If
that should change, then svc_rdma_sendto will need to serialize
access to the transport's credit grant fields.
Reported-by: kbuild test robot <lkp@intel.com>
[ cel: fix uninitialized variable warning ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Highlights include:
Stable fixes:
- nfs: fix NULL deference in nfs4_get_valid_delegation
Bugfixes:
- Fix corruption of the return value in cachefiles_read_or_alloc_pages()
- Fix several fscache cookie issues
- Fix a fscache queuing race that can trigger a BUG_ON
- NFS: Fix 2 use-after-free regressions due to the RPC_TASK_CRED_NOREF flag
- SUNRPC: Fix a use-after-free regression in rpc_free_client_work()
- SUNRPC: Fix a race when tearing down the rpc client debugfs directory
- SUNRPC: Signalled ASYNC tasks need to exit
- NFSv3: fix rpc receive buffer size for MOUNT call
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Merge tag 'nfs-for-5.7-5' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client bugfixes from Trond Myklebust:
"Highlights include:
Stable fixes:
- nfs: fix NULL deference in nfs4_get_valid_delegation
Bugfixes:
- Fix corruption of the return value in cachefiles_read_or_alloc_pages()
- Fix several fscache cookie issues
- Fix a fscache queuing race that can trigger a BUG_ON
- NFS: Fix two use-after-free regressions due to the RPC_TASK_CRED_NOREF flag
- SUNRPC: Fix a use-after-free regression in rpc_free_client_work()
- SUNRPC: Fix a race when tearing down the rpc client debugfs directory
- SUNRPC: Signalled ASYNC tasks need to exit
- NFSv3: fix rpc receive buffer size for MOUNT call"
* tag 'nfs-for-5.7-5' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
NFSv3: fix rpc receive buffer size for MOUNT call
SUNRPC: 'Directory with parent 'rpc_clnt' already present!'
NFS/pnfs: Don't use RPC_TASK_CRED_NOREF with pnfs
NFS: Don't use RPC_TASK_CRED_NOREF with delegreturn
SUNRPC: Signalled ASYNC tasks need to exit
nfs: fix NULL deference in nfs4_get_valid_delegation
SUNRPC: fix use-after-free in rpc_free_client_work()
cachefiles: Fix race between read_waiter and read_copier involving op->to_do
NFSv4: Fix fscache cookie aux_data to ensure change_attr is included
NFS: Fix fscache super_cookie allocation
NFS: Fix fscache super_cookie index_key from changing after umount
cachefiles: Fix corruption of the return value in cachefiles_read_or_alloc_pages()
Each rpc_client has a cl_clid which is allocated from a global ida, and
a debugfs directory which is named after cl_clid.
We're releasing the cl_clid before we free the debugfs directory named
after it. As soon as the cl_clid is released, that value is available
for another newly created client.
That leaves a window where another client may attempt to create a new
debugfs directory with the same name as the not-yet-deleted debugfs
directory from the dying client. Symptoms are log messages like
Directory 4 with parent 'rpc_clnt' already present!
Fixes: 7c4310ff56 "SUNRPC: defer slow parts of rpc_free_client() to a workqueue."
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
When I cat parameter '/sys/module/sunrpc/parameters/pool_mode', it
displays as follows. It is better to add a newline for easy reading.
[root@hulk-202 ~]# cat /sys/module/sunrpc/parameters/pool_mode
global[root@hulk-202 ~]#
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
- Resolve a data integrity problem with NFSD that I inadvertently
introduced last year. The change I made makes the NFS server's
duplicate reply cache ineffective when krb5i or krb5p are in use,
thus allowing the replay of non-idempotent NFS requests such as
RENAME, SETATTR, or even WRITEs.
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Merge tag 'nfsd-5.7-rc-2' of git://git.linux-nfs.org/projects/cel/cel-2.6
Pull nfsd fixes from Chuck Lever:
"Resolve a data integrity problem with NFSD that I inadvertently
introduced last year.
The change I made makes the NFS server's duplicate reply cache
ineffective when krb5i or krb5p are in use, thus allowing the replay
of non-idempotent NFS requests such as RENAME, SETATTR, or even
WRITEs"
* tag 'nfsd-5.7-rc-2' of git://git.linux-nfs.org/projects/cel/cel-2.6:
SUNRPC: Revert 241b1f419f ("SUNRPC: Remove xdr_buf_trim()")
SUNRPC: Fix GSS privacy computation of auth->au_ralign
SUNRPC: Add "@len" parameter to gss_unwrap()
Ensure that signalled ASYNC rpc_tasks exit immediately instead of
spinning until a timeout (or forever).
To avoid checking for the signal flag on every scheduler iteration,
the check is instead introduced in the client's finite state
machine.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Fixes: ae67bd3821 ("SUNRPC: Fix up task signalling")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Parts of rpc_free_client() were recently moved to
a separate rpc_free_clent_work(). This introduced
a use-after-free as rpc_clnt_remove_pipedir() calls
rpc_net_ns(), and that uses clnt->cl_xprt which has already
been freed.
So move the call to xprt_put() after the call to
rpc_clnt_remove_pipedir().
Reported-by: syzbot+22b5ef302c7c40d94ea8@syzkaller.appspotmail.com
Fixes: 7c4310ff56 ("SUNRPC: defer slow parts of rpc_free_client() to a workqueue.")
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
commit 49b28684fd ("nfsd: Remove deprecated nfsctl system call and related code.")
left behind this, remove it.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Highlights include:
Stable fixes
- fix handling of backchannel binding in BIND_CONN_TO_SESSION
Bugfixes
- Fix a credential use-after-free issue in pnfs_roc()
- Fix potential posix_acl refcnt leak in nfs3_set_acl
- defer slow parts of rpc_free_client() to a workqueue
- Fix an Oopsable race in __nfs_list_for_each_server()
- Fix trace point use-after-free race
- Regression: the RDMA client no longer responds to server disconnect requests
- Fix return values of xdr_stream_encode_item_{present, absent}
- _pnfs_return_layout() must always wait for layoutreturn completion
Cleanups
- Remove unreachable error conditions
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Merge tag 'nfs-for-5.7-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client bugfixes from Trond Myklebust:
"Highlights include:
Stable fixes:
- fix handling of backchannel binding in BIND_CONN_TO_SESSION
Bugfixes:
- Fix a credential use-after-free issue in pnfs_roc()
- Fix potential posix_acl refcnt leak in nfs3_set_acl
- defer slow parts of rpc_free_client() to a workqueue
- Fix an Oopsable race in __nfs_list_for_each_server()
- Fix trace point use-after-free race
- Regression: the RDMA client no longer responds to server disconnect
requests
- Fix return values of xdr_stream_encode_item_{present, absent}
- _pnfs_return_layout() must always wait for layoutreturn completion
Cleanups:
- Remove unreachable error conditions"
* tag 'nfs-for-5.7-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
NFS: Fix a race in __nfs_list_for_each_server()
NFSv4.1: fix handling of backchannel binding in BIND_CONN_TO_SESSION
SUNRPC: defer slow parts of rpc_free_client() to a workqueue.
NFSv4: Remove unreachable error condition due to rpc_run_task()
SUNRPC: Remove unreachable error condition
xprtrdma: Fix use of xdr_stream_encode_item_{present, absent}
xprtrdma: Fix trace point use-after-free race
xprtrdma: Restore wake-up-all to rpcrdma_cm_event_handler()
nfs: Fix potential posix_acl refcnt leak in nfs3_set_acl
NFS/pnfs: Fix a credential use-after-free issue in pnfs_roc()
NFS/pnfs: Ensure that _pnfs_return_layout() waits for layoutreturn completion
Bugfixes:
- Restore wake-up-all to rpcrdma_cm_event_handler()
- Otherwise the client won't respond to server disconnect requests
- Fix tracepoint use-after-free race
- Fix usage of xdr_stream_encode_item_{present, absent}
- These functions return a size on success, and not 0
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Merge tag 'nfs-rdma-for-5.7-2' of git://git.linux-nfs.org/projects/anna/linux-nfs
NFSoRDMA Client Fixes for Linux 5.7
Bugfixes:
- Restore wake-up-all to rpcrdma_cm_event_handler()
- Otherwise the client won't respond to server disconnect requests
- Fix tracepoint use-after-free race
- Fix usage of xdr_stream_encode_item_{present, absent}
- These functions return a size on success, and not 0
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
The rpciod workqueue is on the write-out path for freeing dirty memory,
so it is important that it never block waiting for memory to be
allocated - this can lead to a deadlock.
rpc_execute() - which is often called by an rpciod work item - calls
rcp_task_release_client() which can lead to rpc_free_client().
rpc_free_client() makes two calls which could potentially block wating
for memory allocation.
rpc_clnt_debugfs_unregister() calls into debugfs and will block while
any of the debugfs files are being accessed. In particular it can block
while any of the 'open' methods are being called and all of these use
malloc for one thing or another. So this can deadlock if the memory
allocation waits for NFS to complete some writes via rpciod.
rpc_clnt_remove_pipedir() can take the inode_lock() and while it isn't
obvious that memory allocations can happen while the lock it held, it is
safer to assume they might and to not let rpciod call
rpc_clnt_remove_pipedir().
So this patch moves these two calls (together with the final kfree() and
rpciod_down()) into a work-item to be run from the system work-queue.
rpciod can continue its important work, and the final stages of the free
can happen whenever they happen.
I have seen this deadlock on a 4.12 based kernel where debugfs used
synchronize_srcu() when removing objects. synchronize_srcu() requires a
workqueue and there were no free workther threads and none could be
allocated. While debugsfs no longer uses SRCU, I believe the deadlock
is still possible.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
I've noticed that when krb5i or krb5p security is in use,
retransmitted requests are missing the server's duplicate reply
cache. The computed checksum on the retransmitted request does not
match the cached checksum, resulting in the server performing the
retransmitted request again instead of returning the cached reply.
The assumptions made when removing xdr_buf_trim() were not correct.
In the send paths, the upper layer has already set the segment
lengths correctly, and shorting the buffer's content is simply a
matter of reducing buf->len.
xdr_buf_trim() is the right answer in the receive/unwrap path on
both the client and the server. The buffer segment lengths have to
be shortened one-by-one.
On the server side in particular, head.iov_len needs to be updated
correctly to enable nfsd_cache_csum() to work correctly. The simple
buf->len computation doesn't do that, and that results in
checksumming stale data in the buffer.
The problem isn't noticed until there's significant instability of
the RPC transport. At that point, the reliability of retransmit
detection on the server becomes crucial.
Fixes: 241b1f419f ("SUNRPC: Remove xdr_buf_trim()")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
When the au_ralign field was added to gss_unwrap_resp_priv, the
wrong calculation was used. Setting au_rslack == au_ralign is
probably correct for kerberos_v1 privacy, but kerberos_v2 privacy
adds additional GSS data after the clear text RPC message.
au_ralign needs to be smaller than au_rslack in that fairly common
case.
When xdr_buf_trim() is restored to gss_unwrap_kerberos_v2(), it does
exactly what I feared it would: it trims off part of the clear text
RPC message. However, that's because rpc_prepare_reply_pages() does
not set up the rq_rcv_buf's tail correctly because au_ralign is too
large.
Fixing the au_ralign computation also corrects the alignment of
rq_rcv_buf->pages so that the client does not have to shift reply
data payloads after they are received.
Fixes: 35e77d21ba ("SUNRPC: Add rpc_auth::au_ralign field")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Refactor: This is a pre-requisite to fixing the client-side ralign
computation in gss_unwrap_resp_priv().
The length value is passed in explicitly rather that as the value
of buf->len. This will subsequently allow gss_unwrap_kerberos_v1()
to compute a slack and align value, instead of computing it in
gss_unwrap_resp_priv().
Fixes: 35e77d21ba ("SUNRPC: Add rpc_auth::au_ralign field")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
rpc_clnt_test_and_add_xprt() invokes rpc_call_null_helper(), which
return the value of rpc_run_task() to "task". Since rpc_run_task() is
impossible to return an ERR pointer, there is no need to add the
IS_ERR() condition on "task" here. So we need to remove it.
Fixes: 7f55489058 ("SUNRPC: Allow addition of new transports to a struct rpc_clnt")
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
These new helpers do not return 0 on success, they return the
encoded size. Thus they are not a drop-in replacement for the
old helpers.
Fixes: 5c266df527 ("SUNRPC: Add encoders for list item discriminators")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
It's not safe to use resources pointed to by the @send_wr of
ib_post_send() _after_ that function returns. Those resources are
typically freed by the Send completion handler, which can run before
ib_post_send() returns.
Thus the trace points currently around ib_post_send() in the
client's RPC/RDMA transport are a hazard, even when they are
disabled. Rearrange them so that they touch the Work Request only
_before_ ib_post_send() is invoked.
Fixes: ab03eff58e ("xprtrdma: Add trace points in RPC Call transmit paths")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Commit e28ce90083 ("xprtrdma: kmalloc rpcrdma_ep separate from
rpcrdma_xprt") erroneously removed a xprt_force_disconnect()
call from the "transport disconnect" path. The result was that the
client no longer responded to server-side disconnect requests.
Restore that call.
Fixes: e28ce90083 ("xprtrdma: kmalloc rpcrdma_ep separate from rpcrdma_xprt")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Utilize the xpo_release_rqst transport method to ensure that each
rqstp's svc_rdma_recv_ctxt object is released even when the server
cannot return a Reply for that rqstp.
Without this fix, each RPC whose Reply cannot be sent leaks one
svc_rdma_recv_ctxt. This is a 2.5KB structure, a 4KB DMA-mapped
Receive buffer, and any pages that might be part of the Reply
message.
The leak is infrequent unless the network fabric is unreliable or
Kerberos is in use, as GSS sequence window overruns, which result
in connection loss, are more common on fast transports.
Fixes: 3a88092ee3 ("svcrdma: Preserve Receive buffer until svc_rdma_sendto")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Currently, after the forward channel connection goes away,
backchannel operations are causing soft lockups on the server
because call_transmit_status's SOFTCONN logic ignores ENOTCONN.
Such backchannel Calls are aggressively retried until the client
reconnects.
Backchannel Calls should use RPC_TASK_NOCONNECT rather than
RPC_TASK_SOFTCONN. If there is no forward connection, the server is
not capable of establishing a connection back to the client, thus
that backchannel request should fail before the server attempts to
send it. Commit 58255a4e3c ("NFSD: NFSv4 callback client should
use RPC_TASK_SOFTCONN") was merged several years before
RPC_TASK_NOCONNECT was available.
Because setup_callback_client() explicitly sets NOPING, the NFSv4.0
callback connection depends on the first callback RPC to initiate
a connection to the client. Thus NFSv4.0 needs to continue to use
RPC_TASK_SOFTCONN.
Suggested-by: Trond Myklebust <trondmy@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: <stable@vger.kernel.org> # v4.20+
Deleting list entry within hlist_for_each_entry_safe is not safe unless
next pointer (tmp) is protected too. It's not, because once hash_lock
is released, cache_clean may delete the entry that tmp points to. Then
cache_purge can walk to a deleted entry and tries to double free it.
Fix this bug by holding only the deleted entry's reference.
Suggested-by: NeilBrown <neilb@suse.de>
Signed-off-by: Yihao Wu <wuyihao@linux.alibaba.com>
Reviewed-by: NeilBrown <neilb@suse.de>
[ cel: removed unused variable ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
