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2021-04-26xprtrdma: Improve locking around rpcrdma_rep destructionChuck Lever
Currently rpcrdma_reps_destroy() assumes that, at transport tear-down, the content of the rb_free_reps list is the same as the content of the rb_all_reps list. Although that is usually true, using the rb_all_reps list should be more reliable because of the way it's managed. And, rpcrdma_reps_unmap() uses rb_all_reps; these two functions should both traverse the "all" list. Ensure that all rpcrdma_reps are always destroyed whether they are on the rep free list or not. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: Put flushed Receives on free list instead of destroying themChuck Lever
Defer destruction of an rpcrdma_rep until transport tear-down to preserve the rb_all_reps list while Receives flush. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Tom Talpey <tom@talpey.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: Do not refresh Receive Queue while it is drainingChuck Lever
Currently the Receive completion handler refreshes the Receive Queue whenever a successful Receive completion occurs. On disconnect, xprtrdma drains the Receive Queue. The first few Receive completions after a disconnect are typically successful, until the first flushed Receive. This means the Receive completion handler continues to post more Receive WRs after the drain sentinel has been posted. The late- posted Receives flush after the drain sentinel has completed, leading to a crash later in rpcrdma_xprt_disconnect(). To prevent this crash, xprtrdma has to ensure that the Receive handler stops posting Receives before ib_drain_rq() posts its drain sentinel. Suggested-by: Tom Talpey <tom@talpey.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: Avoid Receive Queue wrappingChuck Lever
Commit e340c2d6ef2a ("xprtrdma: Reduce the doorbell rate (Receive)") increased the number of Receive WRs that are posted by the client, but did not increase the size of the Receive Queue allocated during transport set-up. This is usually not an issue because RPCRDMA_BACKWARD_WRS is defined as (32) when SUNRPC_BACKCHANNEL is defined. In cases where it isn't, there is a real risk of Receive Queue wrapping. Fixes: e340c2d6ef2a ("xprtrdma: Reduce the doorbell rate (Receive)") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Tom Talpey <tom@talpey.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-23SUNRPC: Fix null pointer dereference in svc_rqst_free()Yunjian Wang
When alloc_pages_node() returns null in svc_rqst_alloc(), the null rq_scratch_page pointer will be dereferenced when calling put_page() in svc_rqst_free(). Fix it by adding a null check. Addresses-Coverity: ("Dereference after null check") Fixes: 5191955d6fc6 ("SUNRPC: Prepare for xdr_stream-style decoding on the server-side") Signed-off-by: Yunjian Wang <wangyunjian@huawei.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-04-22SUNRPC: fix ternary sign expansion bug in tracingDan Carpenter
This code is supposed to pass negative "err" values for tracing but it passes positive values instead. The problem is that the trace_svcsock_tcp_send() function takes a long but "err" is an int and "sent" is a u32. The negative is first type promoted to u32 so it becomes a high positive then it is promoted to long and it stays positive. Fix this by casting "err" directly to long. Fixes: 998024dee197 ("SUNRPC: Add more svcsock tracepoints") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-04-14svcrdma: Pass a useful error code to the send_err tracepointChuck Lever
Capture error codes in @ret, which is passed to the send_err tracepoint, so that they can be logged when something goes awry. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-04-14svcrdma: Rename goto labels in svc_rdma_sendto()Chuck Lever
Clean up: Make the goto labels consistent with other similar functions. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-04-14svcrdma: Don't leak send_ctxt on Send errorsChuck Lever
Address a rare send_ctxt leak in the svc_rdma_sendto() error paths. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-04-14SUNRPC: Handle major timeout in xprt_adjust_timeout()Chris Dion
Currently if a major timeout value is reached, but the minor value has not been reached, an ETIMEOUT will not be sent back to the caller. This can occur if the v4 server is not responding to requests and retrans is configured larger than the default of two. For example, A TCP mount with a configured timeout value of 50 and a retransmission count of 3 to a v4 server which is not responding: 1. Initial value and increment set to 5s, maxval set to 20s, retries at 3 2. Major timeout is set to 20s, minor timeout set to 5s initially 3. xport_adjust_timeout() is called after 5s, retry with 10s timeout, minor timeout is bumped to 10s 4. And again after another 10s, 15s total time with minor timeout set to 15s 5. After 20s total time xport_adjust_timeout is called as major timeout is reached, but skipped because the minor timeout is not reached - After this time the cpu spins continually calling xport_adjust_timeout() and returning 0 for 10 seconds. As seen on perf sched: 39243.913182 [0005] mount.nfs[3794] 4607.938 0.017 9746.863 6. This continues until the 15s minor timeout condition is reached (in this case for 10 seconds). After which the ETIMEOUT is processed back to the caller, the cpu spinning stops, and normal operations continue Fixes: 7de62bc09fe6 ("SUNRPC dont update timeout value on connection reset") Signed-off-by: Chris Dion <Christopher.Dion@dell.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-14SUNRPC: Remove trace_xprt_transmit_queuedChuck Lever
This tracepoint can crash when dereferencing snd_task because when some transports connect, they put a cookie in that field instead of a pointer to an rpc_task. BUG: KASAN: use-after-free in trace_event_raw_event_xprt_writelock_event+0x141/0x18e [sunrpc] Read of size 2 at addr ffff8881a83bd3a0 by task git/331872 CPU: 11 PID: 331872 Comm: git Tainted: G S 5.12.0-rc2-00007-g3ab6e585a7f9 #1453 Hardware name: Supermicro SYS-6028R-T/X10DRi, BIOS 1.1a 10/16/2015 Call Trace: dump_stack+0x9c/0xcf print_address_description.constprop.0+0x18/0x239 kasan_report+0x174/0x1b0 trace_event_raw_event_xprt_writelock_event+0x141/0x18e [sunrpc] xprt_prepare_transmit+0x8e/0xc1 [sunrpc] call_transmit+0x4d/0xc6 [sunrpc] Fixes: 9ce07ae5eb1d ("SUNRPC: Replace dprintk() call site in xprt_prepare_transmit") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-14SUNRPC: Add tracepoint that fires when an RPC is retransmittedChuck Lever
A separate tracepoint can be left enabled all the time to capture rare but important retransmission events. So for example: kworker/u26:3-568 [009] 156.967933: xprt_retransmit: task:44093@5 xid=0xa25dbc79 nfsv3 WRITE ntrans=2 Or, for example, enable all nfs and nfs4 tracepoints, and set up a trigger to disable tracing when xprt_retransmit fires to capture everything that leads up to it. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-14SUNRPC: Move fault injection call sitesChuck Lever
I've hit some crashes that occur in the xprt_rdma_inject_disconnect path. It appears that, for some provides, rdma_disconnect() can take so long that the transport can disconnect and release its hardware resources while rdma_disconnect() is still running, resulting in a UAF in the provider. The transport's fault injection method may depend on the stability of transport data structures. That means it needs to be invoked only from contexts that hold the transport write lock. Fixes: 4a0682583988 ("SUNRPC: Transport fault injection") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-06sunrpc: Remove unused function ip_map_lookupJiapeng Chong
Fix the following clang warnings: net/sunrpc/svcauth_unix.c:306:30: warning: unused function 'ip_map_lookup' [-Wunused-function]. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-04-05SUNRPC: Ensure the transport backchannel associationBenjamin Coddington
If the server sends CB_ calls on a connection that is not associated with the backchannel, refuse to process the call and shut down the connection. This avoids a NULL dereference crash in xprt_complete_bc_request(). There's not much more we can do in this situation unless we want to look into allowing all connections to be associated with the fore and back channel. Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-05sunrpc: honor rpc_task's timeout value in rpcb_create()Eryu Guan
Currently rpcbind client is created without setting rpc timeout (thus using the default value). But if the rpc_task already has a customized timeout in its tk_client field, it's also ignored. Let's use the same timeout setting in rpc_task->tk_client->cl_timeout for rpcbind connection. Signed-off-by: Eryu Guan <eguan@linux.alibaba.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-05SUNRPC: Set TCP_CORK until the transmit queue is emptyTrond Myklebust
When we have multiple RPC requests queued up, it makes sense to set the TCP_CORK option while the transmit queue is non-empty. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-03-31svcrdma: Clean up dto_q critical section in svc_rdma_recvfrom()Chuck Lever
This, to me, seems less cluttered and less redundant. I was hoping it could help reduce lock contention on the dto_q lock by reducing the size of the critical section, but alas, the only improvement is readability. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-31svcrdma: Remove svc_rdma_recv_ctxt::rc_pages and ::rc_argChuck Lever
These fields are no longer used. The size of struct svc_rdma_recv_ctxt is now less than 300 bytes on x86_64, down from 2440 bytes. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-31svcrdma: Remove sc_read_complete_qChuck Lever
Now that svc_rdma_recvfrom() waits for Read completion, sc_read_complete_q is no longer used. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-31svcrdma: Single-stage RDMA ReadChuck Lever
Currently the generic RPC server layer calls svc_rdma_recvfrom() twice to retrieve an RPC message that uses Read chunks. I'm not exactly sure why this design was chosen originally. Instead, let's wait for the Read chunk completion inline in the first call to svc_rdma_recvfrom(). The goal is to eliminate some page allocator churn. rdma_read_complete() replaces pages in the second svc_rqst by calling put_page() repeatedly while the upper layer waits for the request to be constructed, which adds unnecessary NFS WRITE round- trip latency. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Tom Talpey <tom@talpey.com>
2021-03-22SUNRPC: Move svc_xprt_received() call sitesChuck Lever
Currently, XPT_BUSY is not cleared until xpo_recvfrom returns. That effectively blocks the receipt and handling of the next RPC message until the current one has been taken off the transport. This strict ordering is a requirement for socket transports. For our kernel RPC/RDMA transport implementation, however, dequeuing an ingress message is nothing more than a list_del(). The transport can safely be marked un-busy as soon as that is done. To keep the changes simpler, this patch just moves the svc_xprt_received() call site from svc_handle_xprt() into the transports, so that the actual optimization can be done in a subsequent patch. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-22SUNRPC: Export svc_xprt_received()Chuck Lever
Prepare svc_xprt_received() to be called from transport code instead of from generic RPC server code. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-22svcrdma: Retain the page backing rq_res.head[0].iov_baseChuck Lever
svc_rdma_sendto() now waits for the NIC hardware to finish with the pages backing rq_res. We still have to release the page array in some cases, but now it's always safe to immediately re-use the page backing rq_res's head buffer. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-22svcrdma: Remove unused sc_pages fieldChuck Lever
Clean up. This significantly reduces the size of struct svc_rdma_send_ctxt. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-22svcrdma: Normalize Send page handlingChuck Lever
Currently svc_rdma_sendto() migrates xdr_buf pages into a separate page list and NULLs out a bunch of entries in rq_pages while the pages are under I/O. The Send completion handler then frees those pages later. Instead, let's wait for the Send completion, then handle page releasing in the nfsd thread. I'd like to avoid the cost of 250+ put_page() calls in the Send completion handler, which is single- threaded. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-22svcrdma: Add a "deferred close" helperChuck Lever
Refactor a bit of commonly used logic so that every site that wants a close deferred to an nfsd thread does all the right things (set_bit(XPT_CLOSE) then enqueue). Also, once XPT_CLOSE is set on a transport, it is never cleared. If XPT_CLOSE is already set, then the close is already being handled and the enqueue can be skipped. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-22svcrdma: Maintain a Receive water markChuck Lever
Post more Receives when the number of pending Receives drops below a water mark. The batch mechanism is disabled if the underlying device cannot support a reasonably-sized Receive Queue. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-22svcrdma: Use svc_rdma_refresh_recvs() in wc_receiveChuck Lever
Replace svc_rdma_post_recv() with the new batch receive mechanism. For the moment it is posting just a single Receive WR at a time, so no change in behavior is expected. Since svc_rdma_wc_receive() was the last call site for svc_rdma_post_recv(), it is removed. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-22svcrdma: Add a batch Receive posting mechanismChuck Lever
Introduce a server-side mechanism similar to commit e340c2d6ef2a ("xprtrdma: Reduce the doorbell rate (Receive)") to post Receive WRs in batch. Its first consumer is svc_rdma_post_recvs(), which posts the initial set of Receive WRs. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-22svcrdma: Remove stale comment for svc_rdma_wc_receive()Chuck Lever
xprt pinning was removed in commit 365e9992b90f ("svcrdma: Remove transport reference counting"), but this comment was not updated to reflect that change. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-22svcrdma: Provide an explanatory comment in CMA event handlerChuck Lever
Clean up: explain why svc_xprt_enqueue() is invoked in the event handler even though no xpt_flags bits are toggled here. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-22svcrdma: RPCDBG_FACILITY is no longer usedChuck Lever
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-16Merge tag 'nfsd-5.12-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux Pull nfsd fixes from Chuck Lever: "Miscellaneous NFSD fixes for v5.12-rc" * tag 'nfsd-5.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: svcrdma: Revert "svcrdma: Reduce Receive doorbell rate" NFSD: fix error handling in NFSv4.0 callbacks NFSD: fix dest to src mount in inter-server COPY Revert "nfsd4: a client's own opens needn't prevent delegations" Revert "nfsd4: remove check_conflicting_opens warning" rpc: fix NULL dereference on kmalloc failure sunrpc: fix refcount leak for rpc auth modules NFSD: Repair misuse of sv_lock in 5.10.16-rt30. nfsd: don't abort copies early fs: nfsd: fix kconfig dependency warning for NFSD_V4 svcrdma: disable timeouts on rdma backchannel nfsd: Don't keep looking up unhashed files in the nfsd file cache
2021-03-11svcrdma: Revert "svcrdma: Reduce Receive doorbell rate"Chuck Lever
I tested commit 43042b90cae1 ("svcrdma: Reduce Receive doorbell rate") with mlx4 (IB) and software iWARP and didn't find any issues. However, I recently got my hardware iWARP setup back on line (FastLinQ) and it's crashing hard on this commit (confirmed via bisect). The failure mode is complex. - After a connection is established, the first Receive completes normally. - But the second and third Receives have garbage in their Receive buffers. The server responds with ERR_VERS as a result. - When the client tears down the connection to retry, a couple of posted Receives flush twice, and that corrupts the recv_ctxt free list. - __svc_rdma_free then faults or loops infinitely while destroying the xprt's recv_ctxts. Since 43042b90cae1 ("svcrdma: Reduce Receive doorbell rate") does not fix a bug but is a scalability enhancement, it's safe and appropriate to revert it while working on a replacement. Fixes: 43042b90cae1 ("svcrdma: Reduce Receive doorbell rate") Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-08SUNRPC: Set memalloc_nofs_save() for sync tasksBenjamin Coddington
We could recurse into NFS doing memory reclaim while sending a sync task, which might result in a deadlock. Set memalloc_nofs_save for sync task execution. Fixes: a1231fda7e94 ("SUNRPC: Set memalloc_nofs_save() on all rpciod/xprtiod jobs") Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2021-03-06rpc: fix NULL dereference on kmalloc failureJ. Bruce Fields
I think this is unlikely but possible: svc_authenticate sets rq_authop and calls svcauth_gss_accept. The kmalloc(sizeof(*svcdata), GFP_KERNEL) fails, leaving rq_auth_data NULL, and returning SVC_DENIED. This causes svc_process_common to go to err_bad_auth, and eventually call svc_authorise. That calls ->release == svcauth_gss_release, which tries to dereference rq_auth_data. Signed-off-by: J. Bruce Fields <bfields@redhat.com> Link: https://lore.kernel.org/linux-nfs/3F1B347F-B809-478F-A1E9-0BE98E22B0F0@oracle.com/T/#t Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-06sunrpc: fix refcount leak for rpc auth modulesDaniel Kobras
If an auth module's accept op returns SVC_CLOSE, svc_process_common() enters a call path that does not call svc_authorise() before leaving the function, and thus leaks a reference on the auth module's refcount. Hence, make sure calls to svc_authenticate() and svc_authorise() are paired for all call paths, to make sure rpc auth modules can be unloaded. Signed-off-by: Daniel Kobras <kobras@puzzle-itc.de> Fixes: 4d712ef1db05 ("svcauth_gss: Close connection when dropping an incoming message") Link: https://lore.kernel.org/linux-nfs/3F1B347F-B809-478F-A1E9-0BE98E22B0F0@oracle.com/T/#t Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-06NFSD: Repair misuse of sv_lock in 5.10.16-rt30.Joe Korty
[ This problem is in mainline, but only rt has the chops to be able to detect it. ] Lockdep reports a circular lock dependency between serv->sv_lock and softirq_ctl.lock on system shutdown, when using a kernel built with CONFIG_PREEMPT_RT=y, and a nfs mount exists. This is due to the definition of spin_lock_bh on rt: local_bh_disable(); rt_spin_lock(lock); which forces a softirq_ctl.lock -> serv->sv_lock dependency. This is not a problem as long as _every_ lock of serv->sv_lock is a: spin_lock_bh(&serv->sv_lock); but there is one of the form: spin_lock(&serv->sv_lock); This is what is causing the circular dependency splat. The spin_lock() grabs the lock without first grabbing softirq_ctl.lock via local_bh_disable. If later on in the critical region, someone does a local_bh_disable, we get a serv->sv_lock -> softirq_ctrl.lock dependency established. Deadlock. Fix is to make serv->sv_lock be locked with spin_lock_bh everywhere, no exceptions. [ OK ] Stopped target NFS client services. Stopping Logout off all iSCSI sessions on shutdown... Stopping NFS server and services... [ 109.442380] [ 109.442385] ====================================================== [ 109.442386] WARNING: possible circular locking dependency detected [ 109.442387] 5.10.16-rt30 #1 Not tainted [ 109.442389] ------------------------------------------------------ [ 109.442390] nfsd/1032 is trying to acquire lock: [ 109.442392] ffff994237617f60 ((softirq_ctrl.lock).lock){+.+.}-{2:2}, at: __local_bh_disable_ip+0xd9/0x270 [ 109.442405] [ 109.442405] but task is already holding lock: [ 109.442406] ffff994245cb00b0 (&serv->sv_lock){+.+.}-{0:0}, at: svc_close_list+0x1f/0x90 [ 109.442415] [ 109.442415] which lock already depends on the new lock. [ 109.442415] [ 109.442416] [ 109.442416] the existing dependency chain (in reverse order) is: [ 109.442417] [ 109.442417] -> #1 (&serv->sv_lock){+.+.}-{0:0}: [ 109.442421] rt_spin_lock+0x2b/0xc0 [ 109.442428] svc_add_new_perm_xprt+0x42/0xa0 [ 109.442430] svc_addsock+0x135/0x220 [ 109.442434] write_ports+0x4b3/0x620 [ 109.442438] nfsctl_transaction_write+0x45/0x80 [ 109.442440] vfs_write+0xff/0x420 [ 109.442444] ksys_write+0x4f/0xc0 [ 109.442446] do_syscall_64+0x33/0x40 [ 109.442450] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 109.442454] [ 109.442454] -> #0 ((softirq_ctrl.lock).lock){+.+.}-{2:2}: [ 109.442457] __lock_acquire+0x1264/0x20b0 [ 109.442463] lock_acquire+0xc2/0x400 [ 109.442466] rt_spin_lock+0x2b/0xc0 [ 109.442469] __local_bh_disable_ip+0xd9/0x270 [ 109.442471] svc_xprt_do_enqueue+0xc0/0x4d0 [ 109.442474] svc_close_list+0x60/0x90 [ 109.442476] svc_close_net+0x49/0x1a0 [ 109.442478] svc_shutdown_net+0x12/0x40 [ 109.442480] nfsd_destroy+0xc5/0x180 [ 109.442482] nfsd+0x1bc/0x270 [ 109.442483] kthread+0x194/0x1b0 [ 109.442487] ret_from_fork+0x22/0x30 [ 109.442492] [ 109.442492] other info that might help us debug this: [ 109.442492] [ 109.442493] Possible unsafe locking scenario: [ 109.442493] [ 109.442493] CPU0 CPU1 [ 109.442494] ---- ---- [ 109.442495] lock(&serv->sv_lock); [ 109.442496] lock((softirq_ctrl.lock).lock); [ 109.442498] lock(&serv->sv_lock); [ 109.442499] lock((softirq_ctrl.lock).lock); [ 109.442501] [ 109.442501] *** DEADLOCK *** [ 109.442501] [ 109.442501] 3 locks held by nfsd/1032: [ 109.442503] #0: ffffffff93b49258 (nfsd_mutex){+.+.}-{3:3}, at: nfsd+0x19a/0x270 [ 109.442508] #1: ffff994245cb00b0 (&serv->sv_lock){+.+.}-{0:0}, at: svc_close_list+0x1f/0x90 [ 109.442512] #2: ffffffff93a81b20 (rcu_read_lock){....}-{1:2}, at: rt_spin_lock+0x5/0xc0 [ 109.442518] [ 109.442518] stack backtrace: [ 109.442519] CPU: 0 PID: 1032 Comm: nfsd Not tainted 5.10.16-rt30 #1 [ 109.442522] Hardware name: Supermicro X9DRL-3F/iF/X9DRL-3F/iF, BIOS 3.2 09/22/2015 [ 109.442524] Call Trace: [ 109.442527] dump_stack+0x77/0x97 [ 109.442533] check_noncircular+0xdc/0xf0 [ 109.442546] __lock_acquire+0x1264/0x20b0 [ 109.442553] lock_acquire+0xc2/0x400 [ 109.442564] rt_spin_lock+0x2b/0xc0 [ 109.442570] __local_bh_disable_ip+0xd9/0x270 [ 109.442573] svc_xprt_do_enqueue+0xc0/0x4d0 [ 109.442577] svc_close_list+0x60/0x90 [ 109.442581] svc_close_net+0x49/0x1a0 [ 109.442585] svc_shutdown_net+0x12/0x40 [ 109.442588] nfsd_destroy+0xc5/0x180 [ 109.442590] nfsd+0x1bc/0x270 [ 109.442595] kthread+0x194/0x1b0 [ 109.442600] ret_from_fork+0x22/0x30 [ 109.518225] nfsd: last server has exited, flushing export cache [ OK ] Stopped NFSv4 ID-name mapping service. [ OK ] Stopped GSSAPI Proxy Daemon. [ OK ] Stopped NFS Mount Daemon. [ OK ] Stopped NFS status monitor for NFSv2/3 locking.. Fixes: 719f8bcc883e ("svcrpc: fix xpt_list traversal locking on shutdown") Signed-off-by: Joe Korty <joe.korty@concurrent-rt.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-06svcrdma: disable timeouts on rdma backchannelTimo Rothenpieler
This brings it in line with the regular tcp backchannel, which also has all those timeouts disabled. Prevents the backchannel from timing out, getting some async operations like server side copying getting stuck indefinitely on the client side. Signed-off-by: Timo Rothenpieler <timo@rothenpieler.org> Fixes: 5d252f90a800 ("svcrdma: Add class for RDMA backwards direction transport") Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-02-26Merge tag 'nfs-for-5.12-1' of git://git.linux-nfs.org/projects/anna/linux-nfsLinus Torvalds
Pull NFS Client Updates from Anna Schumaker: "New Features: - Support for eager writes, and the write=eager and write=wait mount options - Other Bugfixes and Cleanups: - Fix typos in some comments - Fix up fall-through warnings for Clang - Cleanups to the NFS readpage codepath - Remove FMR support in rpcrdma_convert_iovs() - Various other cleanups to xprtrdma - Fix xprtrdma pad optimization for servers that don't support RFC 8797 - Improvements to rpcrdma tracepoints - Fix up nfs4_bitmask_adjust() - Optimize sparse writes past the end of files" * tag 'nfs-for-5.12-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (27 commits) NFS: Support the '-owrite=' option in /proc/self/mounts and mountinfo NFS: Set the stable writes flag when initialising the super block NFS: Add mount options supporting eager writes NFS: Add support for eager writes NFS: 'flags' field should be unsigned in struct nfs_server NFS: Don't set NFS_INO_INVALID_XATTR if there is no xattr cache NFS: Always clear an invalid mapping when attempting a buffered write NFS: Optimise sparse writes past the end of file NFS: Fix documenting comment for nfs_revalidate_file_size() NFSv4: Fixes for nfs4_bitmask_adjust() xprtrdma: Clean up rpcrdma_prepare_readch() rpcrdma: Capture bytes received in Receive completion tracepoints xprtrdma: Pad optimization, revisited rpcrdma: Fix comments about reverse-direction operation xprtrdma: Refactor invocations of offset_in_page() xprtrdma: Simplify rpcrdma_convert_kvec() and frwr_map() xprtrdma: Remove FMR support in rpcrdma_convert_iovs() NFS: Add nfs_pageio_complete_read() and remove nfs_readpage_async() NFS: Call readpage_async_filler() from nfs_readpage_async() NFS: Refactor nfs_readpage() and nfs_readpage_async() to use nfs_readdesc ...
2021-02-22Merge tag 'nfsd-5.12-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux Pull more nfsd updates from Chuck Lever: "Here are a few additional NFSD commits for the merge window: Optimization: - Cork the socket while there are queued replies Fixes: - DRC shutdown ordering - svc_rdma_accept() lockdep splat" * tag 'nfsd-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: SUNRPC: Further clean up svc_tcp_sendmsg() SUNRPC: Remove redundant socket flags from svc_tcp_sendmsg() SUNRPC: Use TCP_CORK to optimise send performance on the server svcrdma: Hold private mutex while invoking rdma_accept() nfsd: register pernet ops last, unregister first
2021-02-21Merge tag 'nfsd-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linuxLinus Torvalds
Pull nfsd updates from Chuck Lever: - Update NFSv2 and NFSv3 XDR decoding functions - Further improve support for re-exporting NFS mounts - Convert NFSD stats to per-CPU counters - Add batch Receive posting to the server's RPC/RDMA transport * tag 'nfsd-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (65 commits) nfsd: skip some unnecessary stats in the v4 case nfs: use change attribute for NFS re-exports NFSv4_2: SSC helper should use its own config. nfsd: cstate->session->se_client -> cstate->clp nfsd: simplify nfsd4_check_open_reclaim nfsd: remove unused set_client argument nfsd: find_cpntf_state cleanup nfsd: refactor set_client nfsd: rename lookup_clientid->set_client nfsd: simplify nfsd_renew nfsd: simplify process_lock nfsd4: simplify process_lookup1 SUNRPC: Correct a comment svcrdma: DMA-sync the receive buffer in svc_rdma_recvfrom() svcrdma: Reduce Receive doorbell rate svcrdma: Deprecate stat variables that are no longer used svcrdma: Restore read and write stats svcrdma: Convert rdma_stat_sq_starve to a per-CPU counter svcrdma: Convert rdma_stat_recv to a per-CPU counter svcrdma: Refactor svc_rdma_init() and svc_rdma_clean_up() ...
2021-02-16SUNRPC: Further clean up svc_tcp_sendmsg()Chuck Lever
Clean up: The msghdr is no longer needed in the caller. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-02-16SUNRPC: Remove redundant socket flags from svc_tcp_sendmsg()Trond Myklebust
Now that the caller controls the TCP_CORK socket option, it is redundant to set MSG_MORE and MSG_SENDPAGE_NOTLAST in the calls to kernel_sendpage(). Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-02-16SUNRPC: Use TCP_CORK to optimise send performance on the serverTrond Myklebust
Use a counter to keep track of how many requests are queued behind the xprt->xpt_mutex, and keep TCP_CORK set until the queue is empty. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Link: https://lore.kernel.org/linux-nfs/20210213202532.23146-1-trondmy@kernel.org/T/#u Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-02-15svcrdma: Hold private mutex while invoking rdma_accept()Chuck Lever
RDMA core mutex locking was restructured by commit d114c6feedfe ("RDMA/cma: Add missing locking to rdma_accept()") [Aug 2020]. When lock debugging is enabled, the RPC/RDMA server trips over the new lockdep assertion in rdma_accept() because it doesn't call rdma_accept() from its CM event handler. As a temporary fix, have svc_rdma_accept() take the handler_mutex explicitly. In the meantime, let's consider how to restructure the RPC/RDMA transport to invoke rdma_accept() from the proper context. Calls to svc_rdma_accept() are serialized with calls to svc_rdma_free() by the generic RPC server layer. Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/linux-rdma/20210209154014.GO4247@nvidia.com/ Fixes: d114c6feedfe ("RDMA/cma: Add missing locking to rdma_accept()") Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-02-05xprtrdma: Clean up rpcrdma_prepare_readch()Chuck Lever
Since commit 9ed5af268e88 ("SUNRPC: Clean up the handling of page padding in rpc_prepare_reply_pages()") [Dec 2020] the NFS client passes payload data to the transport with the padding in xdr->pages instead of in the send buffer's tail kvec. There's no need for the extra logic to advance the base of the tail kvec because the upper layer no longer places XDR padding there. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2021-02-05xprtrdma: Pad optimization, revisitedChuck Lever
The NetApp Linux team discovered that with NFS/RDMA servers that do not support RFC 8797, the Linux client is forming NFSv4.x WRITE requests incorrectly. In this case, the Linux NFS client disables implicit chunk round-up for odd-length Read and Write chunks. The goal was to support old servers that needed that padding to be sent explicitly by clients. In that case the Linux NFS included the tail kvec in the Read chunk, since the tail contains any needed padding. That meant a separate memory registration is needed for the tail kvec, adding to the cost of forming such requests. To avoid that cost for a mere 3 bytes of zeroes that are always ignored by receivers, we try to use implicit roundup when possible. For NFSv4.x, the tail kvec also sometimes contains a trailing GETATTR operation. The Linux NFS client unintentionally includes that GETATTR operation in the Read chunk as well as inline. The fix is simply to /never/ include the tail kvec when forming a data payload Read chunk. The padding is thus now always present. Note that since commit 9ed5af268e88 ("SUNRPC: Clean up the handling of page padding in rpc_prepare_reply_pages()") [Dec 2020] the NFS client passes payload data to the transport with the padding in xdr->pages instead of in the send buffer's tail kvec. So now the Linux NFS client appends XDR padding to all odd-sized Read chunks. This shouldn't be a problem because: - RFC 8166-compliant servers are supposed to work with or without that XDR padding in Read chunks. - Since the padding is now in the same memory region as the data payload, a separate memory registration is not needed. In addition, the link layer extends data in RDMA Read responses to 4-byte boundaries anyway. Thus there is now no savings when the padding is not included. Because older kernels include the payload's XDR padding in the tail kvec, a fix there will be more complicated. Thus backporting this patch is not recommended. Reported by: Olga Kornievskaia <Olga.Kornievskaia@netapp.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Tom Talpey <tom@talpey.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2021-02-05rpcrdma: Fix comments about reverse-direction operationChuck Lever
During the final stages of publication of RFC 8167, reviewers requested that we use the term "reverse direction" rather than "backwards direction". Update comments to reflect this preference. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Tom Talpey <tom@talpey.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>