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2017-04-20sunrpc: don't check for failure from mempool_alloc()NeilBrown1-8/+0
When mempool_alloc() is allowed to sleep (GFP_NOIO allows sleeping) it cannot fail. So rpc_alloc_task() cannot fail, so rpc_new_task doesn't need to test for failure. Consequently rpc_new_task() cannot fail, so the callers don't need to test. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-02-09NFSv4: Set the connection timeout to match the lease periodTrond Myklebust1-4/+6
Set the timeout for TCP connections to be 1 lease period to ensure that we don't lose our lease due to a faulty TCP connection. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-02-09SUNRPC: Allow changing of the TCP timeout parameters on the flyTrond Myklebust1-7/+23
When the NFSv4 server tells us the lease period, we usually want to adjust down the timeout parameters on the TCP connection to ensure that we don't miss lease renewals due to a faulty connection. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-02-09SUNRPC: Remove unused function rpc_get_timeout()Trond Myklebust1-15/+0
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-01-24SUNRPC: cleanup ida information when removing sunrpc moduleKinglong Mee1-0/+5
After removing sunrpc module, I get many kmemleak information as, unreferenced object 0xffff88003316b1e0 (size 544): comm "gssproxy", pid 2148, jiffies 4294794465 (age 4200.081s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffffb0cfb58a>] kmemleak_alloc+0x4a/0xa0 [<ffffffffb03507fe>] kmem_cache_alloc+0x15e/0x1f0 [<ffffffffb0639baa>] ida_pre_get+0xaa/0x150 [<ffffffffb0639cfd>] ida_simple_get+0xad/0x180 [<ffffffffc06054fb>] nlmsvc_lookup_host+0x4ab/0x7f0 [lockd] [<ffffffffc0605e1d>] lockd+0x4d/0x270 [lockd] [<ffffffffc06061e5>] param_set_timeout+0x55/0x100 [lockd] [<ffffffffc06cba24>] svc_defer+0x114/0x3f0 [sunrpc] [<ffffffffc06cbbe7>] svc_defer+0x2d7/0x3f0 [sunrpc] [<ffffffffc06c71da>] rpc_show_info+0x8a/0x110 [sunrpc] [<ffffffffb044a33f>] proc_reg_write+0x7f/0xc0 [<ffffffffb038e41f>] __vfs_write+0xdf/0x3c0 [<ffffffffb0390f1f>] vfs_write+0xef/0x240 [<ffffffffb0392fbd>] SyS_write+0xad/0x130 [<ffffffffb0d06c37>] entry_SYSCALL_64_fastpath+0x1a/0xa9 [<ffffffffffffffff>] 0xffffffffffffffff I found, the ida information (dynamic memory) isn't cleanup. Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> Fixes: 2f048db4680a ("SUNRPC: Add an identifier for struct rpc_clnt") Cc: stable@vger.kernel.org # v3.12+ Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-12-01sunrpc: Don't engage exponential backoff when connection attempt is rejected.NeilBrown1-0/+2
xs_connect() contains an exponential backoff mechanism so the repeated connection attempts are delayed by longer and longer amounts. This is appropriate when the connection failed due to a timeout, but it not appropriate when a definitive "no" answer is received. In such cases, call_connect_status() imposes a minimum 3-second back-off, so not having the exponetial back-off will never result in immediate retries. The current situation is a problem when the NFS server tries to register with rpcbind but rpcbind isn't running. All connection attempts are made on the same "xprt" and as the connection is never "closed", the exponential back delays successive attempts to register, or de-register, different protocols. This results in a multi-minute delay with no benefit. So, when call_connect_status() receives a definitive "no", use xprt_conditional_disconnect() to cancel the previous connection attempt. This will set XPRT_CLOSE_WAIT so that xprt->ops->close() calls xs_close() which resets the reestablish_timeout. To ensure xprt_conditional_disconnect() does the right thing, we ensure that rq_connect_cookie is set before a connection attempt, and allow xprt_conditional_disconnect() to complete even when the transport is not fully connected. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-11-07SUNRPC: Fix suspicious RCU usageAnna Schumaker1-2/+5
We need to hold the rcu_read_lock() when calling rcu_dereference(), otherwise we can't guarantee that the object being dereferenced still exists. Fixes: 39e5d2df ("SUNRPC search xprt switch for sockaddr") Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-09-19SUNRPC: Separate buffer pointers for RPC Call and Reply messagesChuck Lever1-1/+1
For xprtrdma, the RPC Call and Reply buffers are involved in real I/O operations. To start with, the DMA direction of the I/O for a Call is opposite that of a Reply. In the current arrangement, the Reply buffer address is on a four-byte alignment just past the call buffer. Would be friendlier on some platforms if that was at a DMA cache alignment instead. Because the current arrangement allocates a single memory region which contains both buffers, the RPC Reply buffer often contains a page boundary in it when the Call buffer is large enough (which is frequent). It would be a little nicer for setting up DMA operations (and possible registration of the Reply buffer) if the two buffers were separated, well-aligned, and contained as few page boundaries as possible. Now, I could just pad out the single memory region used for the pair of buffers. But frequently that would mean a lot of unused space to ensure the Reply buffer did not have a page boundary. Add a separate pointer to rpc_rqst that points right to the RPC Reply buffer. This makes no difference to xprtsock, but it will help xprtrdma in subsequent patches. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-09-19SUNRPC: Generalize the RPC buffer allocation APIChuck Lever1-4/+8
xprtrdma needs to allocate the Call and Reply buffers separately. TBH, the reliance on using a single buffer for the pair of XDR buffers is transport implementation-specific. Transports that want to allocate separate Call and Reply buffers will ignore the "size" argument anyway. Don't bother passing it. The buf_alloc method can't return two pointers. Instead, make the method's return value an error code, and set the rq_buffer pointer in the method itself. This gives call_allocate an opportunity to terminate an RPC instead of looping forever when a permanent problem occurs. If a request is just bogus, or the transport is in a state where it can't allocate resources for any request, there needs to be a way to kill the RPC right there and not loop. This immediately fixes a rare problem in the backchannel send path, which loops if the server happens to send a CB request whose call+reply size is larger than a page (which it shouldn't do yet). One more issue: looks like xprt_inject_disconnect was incorrectly placed in the failure path in call_allocate. It needs to be in the success path, as it is for other call-sites. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-09-19SUNRPC: Refactor rpc_xdr_buf_init()Chuck Lever1-18/+6
Clean up: there is some XDR initialization logic that is common to the forward channel and backchannel. Move it to an XDR header so it can be shared. rpc_rqst::rq_buffer points to a buffer containing big-endian data. Update its annotation as part of the clean up. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-09-19SUNRPC: rpc_clnt_add_xprt setup function for NFS layerAndy Adamson1-0/+64
Use a setup function to call into the NFS layer to test an rpc_xprt for session trunking so as to not leak the rpc_xprt_switch into the nfs layer. Search for the address in the rpc_xprt_switch first so as not to put an unnecessary EXCHANGE_ID on the wire. Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-09-19SUNRPC search xprt switch for sockaddrAndy Adamson1-0/+15
Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-09-19SUNRPC rpc_clnt_xprt_switch_add_xprtAndy Adamson1-0/+7
Give the NFS layer access to the rpc_xprt_switch_add_xprt function Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-09-19SUNRPC rpc_clnt_xprt_switch_putAndy Adamson1-0/+6
Give the NFS layer access to the xprt_switch_put function Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-09-19SUNRPC remove rpc_task_release_client from rpc_task_set_clientAndy Adamson1-1/+0
rpc_task_set_client is only called from rpc_run_task after rpc_new_task and rpc_task_release_client is not needed as the task is new. When called from rpc_new_task, rpc_task_set_client also removed the assigned rpc_xprt which is not desired. Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-09-19sunrpc: Remove unnecessary variableAmitoj Kaur Chawla1-2/+1
The variable `err` is not used anywhere and just returns the predefined value `0` at the end of the function. Hence, remove the variable and return 0 explicitly. Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-08-24SUNRPC: Silence WARN_ON when NFSv4.1 over RDMA is in useChuck Lever1-2/+2
Using NFSv4.1 on RDMA should be safe, so broaden the new checks in rpc_create(). WARN_ON_ONCE is used, matching most other WARN call sites in clnt.c. Fixes: 39a9beab5acb ("rpc: share one xps between all backchannels") Fixes: d50039ea5ee6 ("nfsd4/rpc: move backchannel create logic...") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: J. Bruce Fields <bfields@fieldses.org> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-08-05NFSv4: Cap the transport reconnection timer at 1/2 lease periodTrond Myklebust1-0/+21
We don't want to miss a lease period renewal due to the TCP connection failing to reconnect in a timely fashion. To ensure this doesn't happen, cap the reconnection timer so that we retry the connection attempt at least every 1/2 lease period. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-08-05SUNRPC: Limit the reconnect backoff timer to the max RPC message timeoutTrond Myklebust1-0/+3
...and ensure that we propagate it to new transports on the same client. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-07-24Merge branch 'sunrpc'Trond Myklebust1-1/+1
2016-07-24SUNRPC: Fix a compiler warning in fs/nfs/clnt.cTrond Myklebust1-1/+1
Fix the report: net/sunrpc/clnt.c:2580:1: warning: ‘static’ is not at beginning of declaration [-Wold-style-declaration] Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-06-15rpc: share one xps between all backchannelsJ. Bruce Fields1-4/+14
The spec allows backchannels for multiple clients to share the same tcp connection. When that happens, we need to use the same xprt for all of them. Similarly, we need the same xps. This fixes list corruption introduced by the multipath code. Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com> Acked-by: Trond Myklebust <trondmy@primarydata.com>
2016-06-15nfsd4/rpc: move backchannel create logic into rpc codeJ. Bruce Fields1-2/+10
Also simplify the logic a bit. Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com> Acked-by: Trond Myklebust <trondmy@primarydata.com>
2016-06-15SUNRPC: fix xprt leak on xps allocation failureJ. Bruce Fields1-2/+3
Callers of rpc_create_xprt expect it to put the xprt on success and failure. Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com> Acked-by: Trond Myklebust <trondmy@primarydata.com>
2016-05-17sunrpc: Advertise maximum backchannel payload sizeChuck Lever1-0/+17
RPC-over-RDMA transports have a limit on how large a backward direction (backchannel) RPC message can be. Ensure that the NFSv4.x CREATE_SESSION operation advertises this limit to servers. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-02-05SUNRPC: Allow addition of new transports to a struct rpc_clntTrond Myklebust1-2/+131
Add a function to allow creation and addition of a new transport to an existing rpc_clnt Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-02-05SUNRPC: Make NFS swap work with multipathTrond Myklebust1-42/+24
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-02-05SUNRPC: Add a helper to apply a function to all the rpc_clnt's transportsTrond Myklebust1-0/+51
Add a helper for tasks that require us to apply a function to all the transports in an rpc_clnt. An example of a usecase would be BIND_CONN_TO_SESSION, where we want to send one RPC call down each transport. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-02-05SUNRPC: Use the multipath iterator to assign a transport to each taskTrond Myklebust1-18/+20
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-02-05SUNRPC: Make rpc_clnt store the multipath iteratorsTrond Myklebust1-3/+29
This is a pre-patch for the RPC multipath code. It sets up the storage in struct rpc_clnt for the multipath code. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-01-31SUNRPC: Remove unused function rpc_task_reset_clientTrond Myklebust1-8/+0
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-30SUNRPC: Fix a missing break in rpc_anyaddr()Trond Myklebust1-0/+1
The missing break means that we always return EAFNOSUPPORT when faced with a request for an IPv6 loopback address. Reported-by: coverity (CID 401987) Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-07-03SUNRPC: Don't reencode message if transmission failed with ENOBUFSTrond Myklebust1-2/+3
If we're running out of buffer memory when transmitting data, then we want to just delay for a moment, and then continue transmitting the remainder of the message. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-06-19SUNRPC: Handle connection issues correctly on the back channelTrond Myklebust1-1/+7
If the back channel is disconnected, we can and should just fail the transmission. The expectation is that the NFSv4.1 server will always retransmit any outstanding callbacks once the connection is re-established. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-06-10SUNRPC: Transport fault injectionChuck Lever1-0/+1
It has been exceptionally useful to exercise the logic that handles local immediate errors and RDMA connection loss. To enable developers to test this regularly and repeatably, add logic to simulate connection loss every so often. Fault injection is disabled by default. It is enabled with $ sudo echo xxx > /sys/kernel/debug/sunrpc/inject_fault/disconnect where "xxx" is a large positive number of transport method calls before a disconnect. A value of several thousand is usually a good number that allows reasonable forward progress while still causing a lot of connection drops. These hooks are disabled when SUNRPC_DEBUG is turned off. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-06-10sunrpc: turn swapper_enable/disable functions into rpc_xprt_opsJeff Layton1-2/+2
RDMA xprts don't have a sock_xprt, but an rdma_xprt, so the xs_swapper_enable/disable functions will likely oops when fed an RDMA xprt. Turn these functions into rpc_xprt_ops so that that doesn't occur. For now the RDMA versions are no-ops that just return -EINVAL on an attempt to swapon. Cc: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Reviewed-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-06-10sunrpc: make xprt->swapper an atomic_tJeff Layton1-2/+2
Split xs_swapper into enable/disable functions and eliminate the "enable" flag. Currently, it's racy if you have multiple swapon/swapoff operations running in parallel over the same xprt. Also fix it so that we only set it to a memalloc socket on a 0->1 transition and only clear it on a 1->0 transition. Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Reviewed-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-06-10sunrpc: keep a count of swapfiles associated with the rpc_clntJeff Layton1-9/+58
Jerome reported seeing a warning pop when working with a swapfile on NFS. The nfs_swap_activate can end up calling sk_set_memalloc while holding the rcu_read_lock and that function can sleep. To fix that, we need to take a reference to the xprt while holding the rcu_read_lock, set the socket up for swapping and then drop that reference. But, xprt_put is not exported and having NFS deal with the underlying xprt is a bit of layering violation anyway. Fix this by adding a set of activate/deactivate functions that take a rpc_clnt pointer instead of an rpc_xprt, and have nfs_swap_activate and nfs_swap_deactivate call those. Also, add a per-rpc_clnt atomic counter to keep track of the number of active swapfiles associated with it. When the counter does a 0->1 transition, we enable swapping on the xprt, when we do a 1->0 transition we disable swapping on it. This also allows us to be a bit more selective with the RPC_TASK_SWAPPER flag. If non-swapper and swapper clnts are sharing a xprt, then we only need to flag the tasks from the swapper clnt with that flag. Acked-by: Mel Gorman <mgorman@suse.de> Reported-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Reviewed-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-06-05SUNRPC: Remove unused argument 'tk_ops' in rpc_run_bc_taskTrond Myklebust1-4/+2
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-06-02SUNRPC: Backchannel handle socket nospaceTrond Myklebust1-11/+16
If the socket was busy due to a socket nospace error, then we should retry the send. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-03-31sunrpc: make debugfs file creation failure non-fatalJeff Layton1-3/+1
We currently have a problem that SELinux policy is being enforced when creating debugfs files. If a debugfs file is created as a side effect of doing some syscall, then that creation can fail if the SELinux policy for that process prevents it. This seems wrong. We don't do that for files under /proc, for instance, so Bruce has proposed a patch to fix that. While discussing that patch however, Greg K.H. stated: "No kernel code should care / fail if a debugfs function fails, so please fix up the sunrpc code first." This patch converts all of the sunrpc debugfs setup code to be void return functins, and the callers to not look for errors from those functions. This should allow rpc_clnt and rpc_xprt creation to work, even if the kernel fails to create debugfs files for some reason. Symptoms were failing krb5 mounts on systems using gss-proxy and selinux. Fixes: 388f0c776781 "sunrpc: add a debugfs rpc_xprt directory..." Cc: stable@vger.kernel.org Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-02-08SUNRPC: Handle EADDRINUSE on connectTrond Myklebust1-0/+3
Now that we're setting SO_REUSEPORT, we still need to handle the case where a connect() is attempted, but the old socket is still lingering. Essentially, all we want to do here is handle the error by waiting a few seconds and then retrying. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-02-03SUNRPC: NULL utsname dereference on NFS umount during namespace cleanupTrond Myklebust1-5/+7
Fix an Oopsable condition when nsm_mon_unmon is called as part of the namespace cleanup, which now apparently happens after the utsname has been freed. Link: http://lkml.kernel.org/r/20150125220604.090121ae@neptune.home Reported-by: Bruno Prémont <bonbons@linux-vserver.org> Cc: stable@vger.kernel.org # 3.18 Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-11-27sunrpc: add debugfs file for displaying client rpc_task queueJeff Layton1-1/+9
It's possible to get a dump of the RPC task queue by writing a value to /proc/sys/sunrpc/rpc_debug. If you write any value to that file, you get a dump of the RPC client task list into the log buffer. This is a rather inconvenient interface however, and makes it hard to get immediate info about the task queue. Add a new directory hierarchy under debugfs: sunrpc/ rpc_clnt/ <clientid>/ Within each clientid directory we create a new "tasks" file that will dump info similar to what shows up in the log buffer, but with a few small differences -- we avoid printing raw kernel addresses in favor of symbolic names and the XID is also displayed. Signed-off-by: Jeff Layton <jlayton@primarydata.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-11-24sunrpc: eliminate RPC_DEBUGJeff Layton1-3/+3
It's always set to whatever CONFIG_SUNRPC_DEBUG is, so just use that. Signed-off-by: Jeff Layton <jlayton@primarydata.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-09-30Merge branch 'bugfixes' into linux-nextTrond Myklebust1-0/+3
* bugfixes: NFSv4.1: Fix an NFSv4.1 state renewal regression NFSv4: fix open/lock state recovery error handling NFSv4: Fix lock recovery when CREATE_SESSION/SETCLIENTID_CONFIRM fails NFS: Fabricate fscache server index key correctly SUNRPC: Add missing support for RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT nfs: fix duplicate proc entries
2014-09-25SUNRPC: Add missing support for RPC_CLNT_CREATE_NO_RETRANS_TIMEOUTTrond Myklebust1-0/+3
The flag RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT was intended introduced in order to allow NFSv4 clients to disable resend timeouts. Since those cause the RPC layer to break the connection, they mess up the duplicate reply caches that remain indexed on the port number in NFSv4.. This patch includes the code that was missing in the original to set the appropriate flag in struct rpc_clnt, when the caller of rpc_create() sets RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT. Fixes: 8a19a0b6cb2e (SUNRPC: Add RPC task and client level options to...) Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-09-24rpc: Add -EPERM processing for xs_udp_send_request()Jason Baron1-0/+2
If an iptables drop rule is added for an nfs server, the client can end up in a softlockup. Because of the way that xs_sendpages() is structured, the -EPERM is ignored since the prior bits of the packet may have been successfully queued and thus xs_sendpages() returns a non-zero value. Then, xs_udp_send_request() thinks that because some bits were queued it should return -EAGAIN. We then try the request again and again, resulting in cpu spinning. Reproducer: 1) open a file on the nfs server '/nfs/foo' (mounted using udp) 2) iptables -A OUTPUT -d <nfs server ip> -j DROP 3) write to /nfs/foo 4) close /nfs/foo 5) iptables -D OUTPUT -d <nfs server ip> -j DROP The softlockup occurs in step 4 above. The previous patch, allows xs_sendpages() to return both a sent count and any error values that may have occurred. Thus, if we get an -EPERM, return that to the higher level code. With this patch in place we can successfully abort the above sequence and avoid the softlockup. I also tried the above test case on an nfs mount on tcp and although the system does not softlockup, I still ended up with the 'hung_task' firing after 120 seconds, due to the i/o being stuck. The tcp case appears a bit harder to fix, since -EPERM appears to get ignored much lower down in the stack and does not propogate up to xs_sendpages(). This case is not quite as insidious as the softlockup and it is not addressed here. Reported-by: Yigong Lou <ylou@akamai.com> Signed-off-by: Jason Baron <jbaron@akamai.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-07-03SUNRPC: Handle EPIPE in xprt_connect_statusTrond Myklebust1-0/+1
The callback handler xs_error_report() can end up propagating an EPIPE error by means of the call to xprt_wake_pending_tasks(). Ensure that xprt_connect_status() does not automatically convert this into an EIO error. Reported-by: Weston Andros Adamson <dros@primarydata.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-06-30SUNRPC: Ensure that we handle ENOBUFS errors correctly.Trond Myklebust1-0/+4
Currently, an ENOBUFS error will result in a fatal error for the RPC call. Normally, we will just want to wait and then retry. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
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