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2019-03-09SUNRPC: Remove redundant calls to RPC_IS_QUEUED()Trond Myklebust1-2/+1
The RPC task wakeup calls all check for RPC_IS_QUEUED() before taking any locks. In addition, rpc_exit() already calls rpc_wake_up_queued_task(). Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-03-02SUNRPC: Convert remaining GFP_NOIO, and GFP_NOWAIT sites in sunrpcTrond Myklebust1-5/+2
Convert the remaining gfp_flags arguments in sunrpc to standard reclaiming allocations, now that we set memalloc_nofs_save() as appropriate. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-02-20SUNRPC: Set memalloc_nofs_save() on all rpciod/xprtiod jobsTrond Myklebust1-0/+7
Set memalloc_nofs_save() on all the rpciod/xprtiod jobs so that we ensure memory allocations for asynchronous rpc calls don't ever end up recursing back to the NFS layer for memory reclaim. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-12-19NFS/NFSD/SUNRPC: replace generic creds with 'struct cred'.NeilBrown1-1/+1
SUNRPC has two sorts of credentials, both of which appear as "struct rpc_cred". There are "generic credentials" which are supplied by clients such as NFS and passed in 'struct rpc_message' to indicate which user should be used to authorize the request, and there are low-level credentials such as AUTH_NULL, AUTH_UNIX, AUTH_GSS which describe the credential to be sent over the wires. This patch replaces all the generic credentials by 'struct cred' pointers - the credential structure used throughout Linux. For machine credentials, there is a special 'struct cred *' pointer which is statically allocated and recognized where needed as having a special meaning. A look-up of a low-level cred will map this to a machine credential. Signed-off-by: NeilBrown <neilb@suse.com> Acked-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-12-19SUNRPC: add side channel to use non-generic cred for rpc call.NeilBrown1-0/+3
The credential passed in rpc_message.rpc_cred is always a generic credential except in one instance. When gss_destroying_context() calls rpc_call_null(), it passes a specific credential that it needs to destroy. In this case the RPC acts *on* the credential rather than being authorized by it. This special case deserves explicit support and providing that will mean that rpc_message.rpc_cred is *always* generic, allowing some optimizations. So add "tk_op_cred" to rpc_task and "rpc_op_cred" to the setup data. Use this to pass the cred down from rpc_call_null(), and have rpcauth_bindcred() notice it and bind it in place. Credit to kernel test robot <fengguang.wu@intel.com> for finding a bug in earlier version of this patch. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-09-30SUNRPC: Fix priority queue fairnessTrond Myklebust1-55/+54
Fix up the priority queue to not batch by owner, but by queue, so that we allow '1 << priority' elements to be dequeued before switching to the next priority queue. The owner field is still used to wake up requests in round robin order by owner to avoid single processes hogging the RPC layer by loading the queues. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Test whether the task is queued before grabbing the queue spinlocksTrond Myklebust1-0/+4
When asked to wake up an RPC task, it makes sense to test whether or not the task is still queued. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30SUNRPC: Add a helper to wake up a sleeping rpc_task and set its statusTrond Myklebust1-10/+55
Add a helper that will wake up a task that is sleeping on a specific queue, and will set the value of task->tk_status. This is mainly intended for use by the transport layer to notify the task of an error condition. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-04-10sunrpc: Simplify synopsis of some trace pointsChuck Lever1-5/+5
Clean up: struct rpc_task carries a pointer to a struct rpc_clnt, and in fact task->tk_client is always what is passed into trace points that are already passing @task. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-02-08fix parallelism for rpc tasksOlga Kornievskaia1-1/+1
Hi folks, On a multi-core machine, is it expected that we can have parallel RPCs handled by each of the per-core workqueue? In testing a read workload, observing via "top" command that a single "kworker" thread is running servicing the requests (no parallelism). It's more prominent while doing these operations over krb5p mount. What has been suggested by Bruce is to try this and in my testing I see then the read workload spread among all the kworker threads. Signed-off-by: Olga Kornievskaia <kolga@netapp.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2018-02-07Make the xprtiod workqueue unbounded.Trond Myklebust1-1/+1
This should help reduce the latency on replies. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2018-02-07SUNRPC: Queue latency-sensitive socket tasks to xprtiodTrond Myklebust1-0/+12
The response to a write_space notification is very latency sensitive, so we should queue it to the lower latency xprtiod_workqueue. This is something we already do for the other cases where an rpc task holds the transport XPRT_LOCKED bitlock. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2018-01-23SUNRPC: Micro-optimize __rpc_executeChuck Lever1-13/+11
The common case: There are 13 to 14 actions per RPC, and tk_callback is non-NULL in only one of them. There's no need to store a NULL in the tk_callback field during each FSM step. This slightly improves throughput results in dbench and other multi- threaded benchmarks on my two-socket client on 56Gb InfiniBand, but will probably be inconsequential on slower systems. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-23SUNRPC: task_run_action should display tk_callbackChuck Lever1-1/+1
This shows up in every RPC: kworker/4:1-19772 [004] 3467.373443: rpc_task_run_action: task:4711@2 flags=0e81 state=0005 status=0 action=call_status kworker/4:1-19772 [004] 3467.373444: rpc_task_run_action: task:4711@2 flags=0e81 state=0005 status=0 action=call_status What's actually going on is that the first iteration of the RPC scheduler is invoking the function in tk_callback (in this case, xprt_timer), then invoking call_status on the next iteration. Feeding do_action, rather than tk_action, to the "task_run_action" trace point will now always display the correct FSM step. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17Merge tag 'nfs-for-4.15-1' of git://git.linux-nfs.org/projects/anna/linux-nfsLinus Torvalds1-2/+1
Pull NFS client updates from Anna Schumaker: "Stable bugfixes: - Revalidate "." and ".." correctly on open - Avoid RCU usage in tracepoints - Fix ugly referral attributes - Fix a typo in nomigration mount option - Revert "NFS: Move the flock open mode check into nfs_flock()" Features: - Implement a stronger send queue accounting system for NFS over RDMA - Switch some atomics to the new refcount_t type Other bugfixes and cleanups: - Clean up access mode bits - Remove special-case revalidations in nfs_opendir() - Improve invalidating NFS over RDMA memory for async operations that time out - Handle NFS over RDMA replies with a worqueue - Handle NFS over RDMA sends with a workqueue - Fix up replaying interrupted requests - Remove dead NFS over RDMA definitions - Update NFS over RDMA copyright information - Be more consistent with bool initialization and comparisons - Mark expected switch fall throughs - Various sunrpc tracepoint cleanups - Fix various OPEN races - Fix a typo in nfs_rename() - Use common error handling code in nfs_lock_and_join_request() - Check that some structures are properly cleaned up during net_exit() - Remove net pointer from dprintk()s" * tag 'nfs-for-4.15-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (62 commits) NFS: Revert "NFS: Move the flock open mode check into nfs_flock()" NFS: Fix typo in nomigration mount option nfs: Fix ugly referral attributes NFS: super: mark expected switch fall-throughs sunrpc: remove net pointer from messages nfs: remove net pointer from messages sunrpc: exit_net cleanup check added nfs client: exit_net cleanup check added nfs/write: Use common error handling code in nfs_lock_and_join_requests() NFSv4: Replace closed stateids with the "invalid special stateid" NFSv4: nfs_set_open_stateid must not trigger state recovery for closed state NFSv4: Check the open stateid when searching for expired state NFSv4: Clean up nfs4_delegreturn_done NFSv4: cleanup nfs4_close_done NFSv4: Retry NFS4ERR_OLD_STATEID errors in layoutreturn pNFS: Retry NFS4ERR_OLD_STATEID errors in layoutreturn-on-close NFSv4: Don't try to CLOSE if the stateid 'other' field has changed NFSv4: Retry CLOSE and DELEGRETURN on NFS4ERR_OLD_STATEID. NFS: Fix a typo in nfs_rename() NFSv4: Fix open create exclusive when the server reboots ...
2017-11-17sunrpc: Fix rpc_task_begin trace pointChuck Lever1-2/+1
The rpc_task_begin trace point always display a task ID of zero. Move the trace point call site so that it picks up the new task ID. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-10-18sunrpc: Convert timers to use timer_setup()Kees Cook1-4/+4
In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. Cc: Trond Myklebust <trond.myklebust@primarydata.com> Cc: Anna Schumaker <anna.schumaker@netapp.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Jeff Layton <jlayton@poochiereds.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: linux-nfs@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-20sunrpc: don't check for failure from mempool_alloc()NeilBrown1-5/+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>
2016-09-19SUNRPC: Separate buffer pointers for RPC Call and Reply messagesChuck Lever1-0/+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 release APIChuck Lever1-6/+4
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. Instead of passing just the rq_buffer into the buf_free method, pass the task structure and let buf_free take care of freeing both XDR buffers at once. There's a micro-optimization here. In the common case, both xprt_release and the transport's buf_free method were checking if rq_buffer was NULL. Now the check is done only once per RPC. 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 Lever1-9/+15
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>
2016-06-13SUNRPC: Reduce latency when send queue is congestedTrond Myklebust1-10/+33
Use the low latency transport workqueue to process the task that is next in line on the xprt->sending queue. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-06-13SUNRPC: RPC transport queue must be low latencyTrond Myklebust1-4/+20
rpciod can easily get congested due to the long list of queued rpc_tasks. Having the receive queue wait in turn for those tasks to complete can therefore be a bottleneck. Address the problem by separating the workqueues into: - rpciod: manages rpc_tasks - xprtiod: manages transport related work. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-02-05SUNRPC: Allow caller to specify the transport to useTrond Myklebust1-0/+2
This is needed in order to allow the NFSv4.1 backchannel and BIND_CONN_TO_SESSION function to work. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-13sched/wait: Fix the signal handling fixPeter Zijlstra1-3/+3
Jan Stancek reported that I wrecked things for him by fixing things for Vladimir :/ His report was due to an UNINTERRUPTIBLE wait getting -EINTR, which should not be possible, however my previous patch made this possible by unconditionally checking signal_pending(). We cannot use current->state as was done previously, because the instruction after the store to that variable it can be changed. We must instead pass the initial state along and use that. Fixes: 68985633bccb ("sched/wait: Fix signal handling in bit wait helpers") Reported-by: Jan Stancek <jstancek@redhat.com> Reported-by: Chris Mason <clm@fb.com> Tested-by: Jan Stancek <jstancek@redhat.com> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> Tested-by: Chris Mason <clm@fb.com> Reviewed-by: Paul Turner <pjt@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: tglx@linutronix.de Cc: Oleg Nesterov <oleg@redhat.com> Cc: hpa@zytor.com Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-25Merge tag 'nfs-for-4.3-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds1-8/+4
Pull NFS client bugfixes from Trond Myklebust: "Highlights include: Stable patches: - fix v4.2 SEEK on files over 2 gigs - Fix a layout segment reference leak when pNFS I/O falls back to inband I/O. - Fix recovery of recalled read delegations Bugfixes: - Fix a case where NFSv4 fails to send CLOSE after a server reboot - Fix sunrpc to wait for connections to complete before retrying - Fix sunrpc races between transport connect/disconnect and shutdown - Fix an infinite loop when layoutget fail with BAD_STATEID - nfs/filelayout: Fix NULL reference caused by double freeing of fh_array - Fix a bogus WARN_ON_ONCE() in O_DIRECT when layout commit_through_mds is set - Fix layoutreturn/close ordering issues" * tag 'nfs-for-4.3-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: NFS41: make close wait for layoutreturn NFS: Skip checking ds_cinfo.buckets when lseg's commit_through_mds is set NFSv4.x/pnfs: Don't try to recover stateids twice in layoutget NFSv4: Recovery of recalled read delegations is broken NFS: Fix an infinite loop when layoutget fail with BAD_STATEID NFS: Do cleanup before resetting pageio read/write to mds SUNRPC: xs_sock_mark_closed() does not need to trigger socket autoclose SUNRPC: Lock the transport layer on shutdown nfs/filelayout: Fix NULL reference caused by double freeing of fh_array SUNRPC: Ensure that we wait for connections to complete before retrying SUNRPC: drop null test before destroy functions nfs: fix v4.2 SEEK on files over 2 gigs SUNRPC: Fix races between socket connection and destroy code nfs: fix pg_test page count calculation Failing to send a CLOSE if file is opened WRONLY and server reboots on a 4.x mount
2015-09-22userfaultfd: revert "userfaultfd: waitqueue: add nr wake parameter to __wake_up_locked_key"Andrea Arcangeli1-1/+1
This reverts commit 51360155eccb907ff8635bd10fc7de876408c2e0 and adapts fs/userfaultfd.c to use the old version of that function. It didn't look robust to call __wake_up_common with "nr == 1" when we absolutely require wakeall semantics, but we've full control of what we insert in the two waitqueue heads of the blocked userfaults. No exclusive waitqueue risks to be inserted into those two waitqueue heads so we can as well stick to "nr == 1" of the old code and we can rely purely on the fact no waitqueue inserted in one of the two waitqueue heads we must enforce as wakeall, has wait->flags WQ_FLAG_EXCLUSIVE set. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Shuah Khan <shuahkh@osg.samsung.com> Cc: Thierry Reding <treding@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-17SUNRPC: drop null test before destroy functionsJulia Lawall1-8/+4
Remove unneeded NULL test. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ expression x; @@ -if (x != NULL) \(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x); // </smpl> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-09-04userfaultfd: waitqueue: add nr wake parameter to __wake_up_locked_keyAndrea Arcangeli1-1/+1
userfaultfd needs to wake all waitqueues (pass 0 as nr parameter), instead of the current hardcoded 1 (that would wake just the first waitqueue in the head list). Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com> Cc: zhang.zhanghailiang@huawei.com Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Andres Lagar-Cavilla <andreslc@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Feiner <pfeiner@google.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-03-13SUNRPC: fix build-warning due to format missmatchNicholas Mc Guire1-2/+2
fix build-warning introduced by commit: f0eede10fd4 ("SUNRPC: use jiffies_to_msecs for converting jiffies") which did not fixup the format properly (my bad). Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-03-12SUNRPC: use jiffies_to_msecs for converting jiffiesNicholas Mc Guire1-1/+1
Use jiffies_to_msecs for converting jiffies as it handles all of the corner cases reliably and also helps readability. Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-01-24SUNRPC: Allow waiting on memory allocationTrond Myklebust1-2/+2
We should be safe now, as long as we don't do GFP_IO or higher allocations Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-01-24SUNRPC: Adjust rpciod workqueue parametersTrond Myklebust1-1/+2
Increase the concurrency level for rpciod threads to allow for allocations etc that happen in the RPCSEC_GSS layer. Also note that the NFSv4 byte range locks may now need to allocate memory from inside rpciod. Add the WQ_HIGHPRI flag to improve latency guarantees while we're at it. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-11-24sunrpc: eliminate RPC_TRACEPOINTSJeff Layton1-1/+1
It's always set to the same value as CONFIG_TRACEPOINTS, so we can just use that instead. Signed-off-by: Jeff Layton <jlayton@primarydata.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-11-24sunrpc: eliminate RPC_DEBUGJeff Layton1-2/+2
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>
2014-09-25NFS/SUNRPC: Remove other deadlock-avoidance mechanisms in nfs_release_page()NeilBrown1-2/+0
Now that nfs_release_page() doesn't block indefinitely, other deadlock avoidance mechanisms aren't needed. - it doesn't hurt for kswapd to block occasionally. If it doesn't want to block it would clear __GFP_WAIT. The current_is_kswapd() was only added to avoid deadlocks and we have a new approach for that. - memory allocation in the SUNRPC layer can very rarely try to ->releasepage() a page it is trying to handle. The deadlock is removed as nfs_release_page() doesn't block indefinitely. So we don't need to set PF_FSTRANS for sunrpc network operations any more. Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: Jeff Layton <jlayton@primarydata.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-07-16sched: Allow wait_on_bit_action() functions to support a timeoutNeilBrown1-2/+2
It is currently not possible for various wait_on_bit functions to implement a timeout. While the "action" function that is called to do the waiting could certainly use schedule_timeout(), there is no way to carry forward the remaining timeout after a false wake-up. As false-wakeups a clearly possible at least due to possible hash collisions in bit_waitqueue(), this is a real problem. The 'action' function is currently passed a pointer to the word containing the bit being waited on. No current action functions use this pointer. So changing it to something else will be a little noisy but will have no immediate effect. This patch changes the 'action' function to take a pointer to the "struct wait_bit_key", which contains a pointer to the word containing the bit so nothing is really lost. It also adds a 'private' field to "struct wait_bit_key", which is initialized to zero. An action function can now implement a timeout with something like static int timed_out_waiter(struct wait_bit_key *key) { unsigned long waited; if (key->private == 0) { key->private = jiffies; if (key->private == 0) key->private -= 1; } waited = jiffies - key->private; if (waited > 10 * HZ) return -EAGAIN; schedule_timeout(waited - 10 * HZ); return 0; } If any other need for context in a waiter were found it would be easy to use ->private for some other purpose, or even extend "struct wait_bit_key". My particular need is to support timeouts in nfs_release_page() to avoid deadlocks with loopback mounted NFS. While wait_on_bit_timeout() would be a cleaner interface, it will not meet my need. I need the timeout to be sensitive to the state of the connection with the server, which could change. So I need to use an 'action' interface. Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steve French <sfrench@samba.org> Cc: David Howells <dhowells@redhat.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140707051604.28027.41257.stgit@notabene.brown Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-29net, sunrpc: suppress allocation warning in rpc_malloc()David Rientjes1-2/+3
rpc_malloc() allocates with GFP_NOWAIT without making any attempt at reclaim so it easily fails when low on memory. This ends up spamming the kernel log: SLAB: Unable to allocate memory on node 0 (gfp=0x4000) cache: kmalloc-8192, object size: 8192, order: 1 node 0: slabs: 207/207, objs: 207/207, free: 0 rekonq: page allocation failure: order:1, mode:0x204000 CPU: 2 PID: 14321 Comm: rekonq Tainted: G O 3.15.0-rc3-12.gfc9498b-desktop+ #6 Hardware name: System manufacturer System Product Name/M4A785TD-V EVO, BIOS 2105 07/23/2010 0000000000000000 ffff880010ff17d0 ffffffff815e693c 0000000000204000 ffff880010ff1858 ffffffff81137bd2 0000000000000000 0000001000000000 ffff88011ffebc38 0000000000000001 0000000000204000 ffff88011ffea000 Call Trace: [<ffffffff815e693c>] dump_stack+0x4d/0x6f [<ffffffff81137bd2>] warn_alloc_failed+0xd2/0x140 [<ffffffff8113be19>] __alloc_pages_nodemask+0x7e9/0xa30 [<ffffffff811824a8>] kmem_getpages+0x58/0x140 [<ffffffff81183de6>] fallback_alloc+0x1d6/0x210 [<ffffffff81183be3>] ____cache_alloc_node+0x123/0x150 [<ffffffff81185953>] __kmalloc+0x203/0x490 [<ffffffffa06b0ee2>] rpc_malloc+0x32/0xa0 [sunrpc] [<ffffffffa06a6999>] call_allocate+0xb9/0x170 [sunrpc] [<ffffffffa06b19d8>] __rpc_execute+0x88/0x460 [sunrpc] [<ffffffffa06b2da9>] rpc_execute+0x59/0xc0 [sunrpc] [<ffffffffa06a932b>] rpc_run_task+0x6b/0x90 [sunrpc] [<ffffffffa077b5c1>] nfs4_call_sync_sequence+0x51/0x80 [nfsv4] [<ffffffffa077d45d>] _nfs4_do_setattr+0x1ed/0x280 [nfsv4] [<ffffffffa0782a72>] nfs4_do_setattr+0x72/0x180 [nfsv4] [<ffffffffa078334c>] nfs4_proc_setattr+0xbc/0x140 [nfsv4] [<ffffffffa074a7e8>] nfs_setattr+0xd8/0x240 [nfs] [<ffffffff811baa71>] notify_change+0x231/0x380 [<ffffffff8119cf5c>] chmod_common+0xfc/0x120 [<ffffffff8119df80>] SyS_chmod+0x40/0x90 [<ffffffff815f4cfd>] system_call_fastpath+0x1a/0x1f ... If the allocation fails, simply return NULL and avoid spamming the kernel log. Reported-by: Marc Dietrich <marvin24@gmx.de> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-03-20SUNRPC: Don't let rpc_delay() clobber non-timeout errorsTrond Myklebust1-1/+2
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2013-09-04SUNRPC: Ensure rpc_task->tk_pid is available for tracepointsTrond Myklebust1-1/+1
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-07-09Merge tag 'nfs-for-3.11-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds1-16/+3
Pull NFS client updates from Trond Myklebust: "Feature highlights include: - Add basic client support for NFSv4.2 - Add basic client support for Labeled NFS (selinux for NFSv4.2) - Fix the use of credentials in NFSv4.1 stateful operations, and add support for NFSv4.1 state protection. Bugfix highlights: - Fix another NFSv4 open state recovery race - Fix an NFSv4.1 back channel session regression - Various rpc_pipefs races - Fix another issue with NFSv3 auth negotiation Please note that Labeled NFS does require some additional support from the security subsystem. The relevant changesets have all been reviewed and acked by James Morris." * tag 'nfs-for-3.11-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (54 commits) NFS: Set NFS_CS_MIGRATION for NFSv4 mounts NFSv4.1 Refactor nfs4_init_session and nfs4_init_channel_attrs nfs: have NFSv3 try server-specified auth flavors in turn nfs: have nfs_mount fake up a auth_flavs list when the server didn't provide it nfs: move server_authlist into nfs_try_mount_request nfs: refactor "need_mount" code out of nfs_try_mount SUNRPC: PipeFS MOUNT notification optimization for dying clients SUNRPC: split client creation routine into setup and registration SUNRPC: fix races on PipeFS UMOUNT notifications SUNRPC: fix races on PipeFS MOUNT notifications NFSv4.1 use pnfs_device maxcount for the objectlayout gdia_maxcount NFSv4.1 use pnfs_device maxcount for the blocklayout gdia_maxcount NFSv4.1 Fix gdia_maxcount calculation to fit in ca_maxresponsesize NFS: Improve legacy idmapping fallback NFSv4.1 end back channel session draining NFS: Apply v4.1 capabilities to v4.2 NFSv4.1: Clean up layout segment comparison helper names NFSv4.1: layout segment comparison helpers should take 'const' parameters NFSv4: Move the DNS resolver into the NFSv4 module rpc_pipefs: only set rpc_dentry_ops if d_op isn't already set ...
2013-06-28Merge branch 'freezer'Rafael J. Wysocki1-1/+1
* freezer: af_unix: use freezable blocking calls in read sigtimedwait: use freezable blocking call nanosleep: use freezable blocking call futex: use freezable blocking call select: use freezable blocking call epoll: use freezable blocking call binder: use freezable blocking calls freezer: add new freezable helpers using freezer_do_not_count() freezer: convert freezable helpers to static inline where possible freezer: convert freezable helpers to freezer_do_not_count() freezer: skip waking up tasks with PF_FREEZER_SKIP set freezer: shorten freezer sleep time using exponential backoff lockdep: check that no locks held at freeze time lockdep: remove task argument from debug_check_no_locks_held freezer: add unsafe versions of freezable helpers for CIFS freezer: add unsafe versions of freezable helpers for NFS
2013-06-06SUNRPC: Remove redundant call to rpc_set_running() in __rpc_execute()Trond Myklebust1-1/+0
The RPC_TASK_RUNNING flag will always have been set in rpc_make_runnable() once we get past the test for out_of_line_wait_on_bit() returning ERESTARTSYS. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-06-06SUNRPC: Remove unused function rpc_queue_emptyTrond Myklebust1-14/+0
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-06-06SUNRPC: Fix a potential race in rpc_executeTrond Myklebust1-1/+3
If the rpc_task is asynchronous, it could theoretically finish executing on the workqueue it was assigned by rpc_make_runnable() before we get round to testing RPC_IS_ASYNC() in rpc_execute. In practice, however, all the existing callers hold a reference to the rpc_task, so this can't happen today... Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-05-22SUNRPC: Prevent an rpc_task wakeup raceTrond Myklebust1-1/+7
The lockless RPC_IS_QUEUED() test in __rpc_execute means that we need to be careful about ordering the calls to rpc_test_and_set_running(task) and rpc_clear_queued(task). If we get the order wrong, then we may end up testing the RPC_TASK_RUNNING flag after __rpc_execute() has looped and changed the state of the rpc_task. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@vger.kernel.org
2013-05-12freezer: add unsafe versions of freezable helpers for NFSColin Cross1-1/+1
NFS calls the freezable helpers with locks held, which is unsafe and will cause lockdep warnings when 6aa9707 "lockdep: check that no locks held at freeze time" is reapplied (it was reverted in dbf520a). NFS shouldn't be doing this, but it has long-running syscalls that must hold a lock but also shouldn't block suspend. Until NFS freeze handling is rewritten to use a signal to exit out of the critical section, add new *_unsafe versions of the helpers that will not run the lockdep test when 6aa9707 is reapplied, and call them from NFS. In practice the likley result of holding the lock while freezing is that a second task blocked on the lock will never freeze, aborting suspend, but it is possible to manufacture a case using the cgroup freezer, the lock, and the suspend freezer to create a deadlock. Silencing the lockdep warning here will allow problems to be found in other drivers that may have a more serious deadlock risk, and prevent new problems from being added. Signed-off-by: Colin Cross <ccross@android.com> Acked-by: Pavel Machek <pavel@ucw.cz> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-25SUNRPC: Add barriers to ensure read ordering in rpc_wake_up_task_queue_lockedTrond Myklebust1-2/+7
We need to be careful when testing task->tk_waitqueue in rpc_wake_up_task_queue_locked, because it can be changed while we are holding the queue->lock. By adding appropriate memory barriers, we can ensure that it is safe to test task->tk_waitqueue for equality if the RPC_TASK_QUEUED bit is set. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@vger.kernel.org
2013-01-30SUNRPC: When changing the queue priority, ensure that we change the ownerTrond Myklebust1-1/+17
This fixes a livelock in the xprt->sending queue where we end up never making progress on lower priority tasks because sleep_on_priority() keeps adding new tasks with the same owner to the head of the queue, and priority bumps mean that we keep resetting the queue->owner to whatever task is at the head of the queue. Regression introduced by commit c05eecf636101dd4347b2d8fa457626bf0088e0a (SUNRPC: Don't allow low priority tasks to pre-empt higher priority ones). Reported-by: Andy Adamson <andros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-01-08SUNRPC: Ensure we release the socket write lock if the rpc_task exits earlyTrond Myklebust1-2/+1
If the rpc_task exits while holding the socket write lock before it has allocated an rpc slot, then the usual mechanism for releasing the write lock in xprt_release() is defeated. The problem occurs if the call to xprt_lock_write() initially fails, so that the rpc_task is put on the xprt->sending wait queue. If the task exits after being assigned the lock by __xprt_lock_write_func, but before it has retried the call to xprt_lock_and_alloc_slot(), then it calls xprt_release() while holding the write lock, but will immediately exit due to the test for task->tk_rqstp != NULL. Reported-by: Chris Perl <chris.perl@gmail.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@vger.kernel.org [>= 3.1]
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