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2021-07-20SUNRPC: Should wake up the privileged task firstly.Zhang Xiaoxu
commit 5483b904bf336948826594610af4c9bbb0d9e3aa upstream. When find a task from wait queue to wake up, a non-privileged task may be found out, rather than the privileged. This maybe lead a deadlock same as commit dfe1fe75e00e ("NFSv4: Fix deadlock between nfs4_evict_inode() and nfs4_opendata_get_inode()"): Privileged delegreturn task is queued to privileged list because all the slots are assigned. If there has no enough slot to wake up the non-privileged batch tasks(session less than 8 slot), then the privileged delegreturn task maybe lost waked up because the found out task can't get slot since the session is on draining. So we should treate the privileged task as the emergency task, and execute it as for as we can. Reported-by: Hulk Robot <hulkci@huawei.com> Fixes: 5fcdfacc01f3 ("NFSv4: Return delegations synchronously in evict_inode") Cc: stable@vger.kernel.org Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-20SUNRPC: Fix the batch tasks count wraparound.Zhang Xiaoxu
commit fcb170a9d825d7db4a3fb870b0300f5a40a8d096 upstream. The 'queue->nr' will wraparound from 0 to 255 when only current priority queue has tasks. This maybe lead a deadlock same as commit dfe1fe75e00e ("NFSv4: Fix deadlock between nfs4_evict_inode() and nfs4_opendata_get_inode()"): Privileged delegreturn task is queued to privileged list because all the slots are assigned. When non-privileged task complete and release the slot, a non-privileged maybe picked out. It maybe allocate slot failed when the session on draining. If the 'queue->nr' has wraparound to 255, and no enough slot to service it, then the privileged delegreturn will lost to wake up. So we should avoid the wraparound on 'queue->nr'. Reported-by: Hulk Robot <hulkci@huawei.com> Fixes: 5fcdfacc01f3 ("NFSv4: Return delegations synchronously in evict_inode") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-25SUNRPC: Fix priority queue fairnessTrond Myklebust
[ Upstream commit f42f7c283078ce3c1e8368b140e270755b1ae313 ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2017-12-16sunrpc: Fix rpc_task_begin trace pointChuck Lever
[ Upstream commit b2bfe5915d5fe7577221031a39ac722a0a2a1199 ] 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> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-13sched/wait: Fix the signal handling fixPeter Zijlstra
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>
2015-09-22userfaultfd: revert "userfaultfd: waitqueue: add nr wake parameter to ↵Andrea Arcangeli
__wake_up_locked_key" 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 Lawall
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 Arcangeli
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 Guire
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 Guire
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 Myklebust
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 Myklebust
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 Layton
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 Layton
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()NeilBrown
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 timeoutNeilBrown
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 Rientjes
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 Myklebust
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2013-09-04SUNRPC: Ensure rpc_task->tk_pid is available for tracepointsTrond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-06-06SUNRPC: Remove redundant call to rpc_set_running() in __rpc_execute()Trond Myklebust
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 Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-06-06SUNRPC: Fix a potential race in rpc_executeTrond Myklebust
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 Myklebust
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 Cross
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 Myklebust
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 Myklebust
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 Myklebust
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]
2013-01-04SUNRPC: Ensure that we free the rpc_task after cleanups are doneTrond Myklebust
This patch ensures that we free the rpc_task after the cleanup callbacks are done in order to avoid a deadlock problem that can be triggered if the callback needs to wait for another workqueue item to complete. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Weston Andros Adamson <dros@netapp.com> Cc: Tejun Heo <tj@kernel.org> Cc: Bruce Fields <bfields@fieldses.org> Cc: stable@vger.kernel.org
2012-12-06SUNRPC: Don't allow low priority tasks to pre-empt higher priority onesTrond Myklebust
Currently, the priority queues attempt to be 'fair' to lower priority tasks by scheduling them after a certain number of higher priority tasks have run. The problem is that both the transport send queue and the NFSv4.1 session slot queue have strong ordering requirements. This patch therefore removes the fairness code in favour of strong ordering of task priorities. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-12-06NFSv4.1: Don't mess with task priorities in nfs41_setup_sequenceTrond Myklebust
We want to preserve the rpc_task priority for things like writebacks, that may have differing levels of urgency. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-11-04SUNRPC: remove BUG_ON in rpc_release_taskWeston Andros Adamson
Replace BUG_ON() with WARN_ON_ONCE(). Signed-off-by: Weston Andros Adamson <dros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-11-04SUNRPC: remove BUG_ONs checking RPC_IS_QUEUEDWeston Andros Adamson
Replace two BUG_ON() calls with WARN_ON_ONCE() and early returns. Signed-off-by: Weston Andros Adamson <dros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-11-04SUNRPC: remove BUG_ON from __rpc_sleep_on_priorityWeston Andros Adamson
Replace BUG_ON() with WARN_ON_ONCE(). Signed-off-by: Weston Andros Adamson <dros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-11-04SUNRPC: remove BUG_ON from rpc_sleep_on*Weston Andros Adamson
Replace BUG_ON() with WARN_ON_ONCE() and clean up after inactive task. Signed-off-by: Weston Andros Adamson <dros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-09-28SUNRPC: Limit the rpciod workqueue concurrencyTrond Myklebust
We shouldn't need more than 1 worker thread per cpu, since rpciod is designed to run without sleeping in most cases. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-31nfs: enable swap on NFSMel Gorman
Implement the new swapfile a_ops for NFS and hook up ->direct_IO. This will set the NFS socket to SOCK_MEMALLOC and run socket reconnect under PF_MEMALLOC as well as reset SOCK_MEMALLOC before engaging the protocol ->connect() method. PF_MEMALLOC should allow the allocation of struct socket and related objects and the early (re)setting of SOCK_MEMALLOC should allow us to receive the packets required for the TCP connection buildup. [jlayton@redhat.com: Restore PF_MEMALLOC task flags in all cases] [dfeng@redhat.com: Fix handling of multiple swap files] [a.p.zijlstra@chello.nl: Original patch] Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David S. Miller <davem@davemloft.net> Cc: Eric B Munson <emunson@mgebm.net> Cc: Eric Paris <eparis@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Neil Brown <neilb@suse.de> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Xiaotian Feng <dfeng@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30nfs: skip commit in releasepage if we're freeing memory for fs-related reasonsJeff Layton
We've had some reports of a deadlock where rpciod ends up with a stack trace like this: PID: 2507 TASK: ffff88103691ab40 CPU: 14 COMMAND: "rpciod/14" #0 [ffff8810343bf2f0] schedule at ffffffff814dabd9 #1 [ffff8810343bf3b8] nfs_wait_bit_killable at ffffffffa038fc04 [nfs] #2 [ffff8810343bf3c8] __wait_on_bit at ffffffff814dbc2f #3 [ffff8810343bf418] out_of_line_wait_on_bit at ffffffff814dbcd8 #4 [ffff8810343bf488] nfs_commit_inode at ffffffffa039e0c1 [nfs] #5 [ffff8810343bf4f8] nfs_release_page at ffffffffa038bef6 [nfs] #6 [ffff8810343bf528] try_to_release_page at ffffffff8110c670 #7 [ffff8810343bf538] shrink_page_list.clone.0 at ffffffff81126271 #8 [ffff8810343bf668] shrink_inactive_list at ffffffff81126638 #9 [ffff8810343bf818] shrink_zone at ffffffff8112788f #10 [ffff8810343bf8c8] do_try_to_free_pages at ffffffff81127b1e #11 [ffff8810343bf958] try_to_free_pages at ffffffff8112812f #12 [ffff8810343bfa08] __alloc_pages_nodemask at ffffffff8111fdad #13 [ffff8810343bfb28] kmem_getpages at ffffffff81159942 #14 [ffff8810343bfb58] fallback_alloc at ffffffff8115a55a #15 [ffff8810343bfbd8] ____cache_alloc_node at ffffffff8115a2d9 #16 [ffff8810343bfc38] kmem_cache_alloc at ffffffff8115b09b #17 [ffff8810343bfc78] sk_prot_alloc at ffffffff81411808 #18 [ffff8810343bfcb8] sk_alloc at ffffffff8141197c #19 [ffff8810343bfce8] inet_create at ffffffff81483ba6 #20 [ffff8810343bfd38] __sock_create at ffffffff8140b4a7 #21 [ffff8810343bfd98] xs_create_sock at ffffffffa01f649b [sunrpc] #22 [ffff8810343bfdd8] xs_tcp_setup_socket at ffffffffa01f6965 [sunrpc] #23 [ffff8810343bfe38] worker_thread at ffffffff810887d0 #24 [ffff8810343bfee8] kthread at ffffffff8108dd96 #25 [ffff8810343bff48] kernel_thread at ffffffff8100c1ca rpciod is trying to allocate memory for a new socket to talk to the server. The VM ends up calling ->releasepage to get more memory, and it tries to do a blocking commit. That commit can't succeed however without a connected socket, so we deadlock. Fix this by setting PF_FSTRANS on the workqueue task prior to doing the socket allocation, and having nfs_release_page check for that flag when deciding whether to do a commit call. Also, set PF_FSTRANS unconditionally in rpc_async_schedule since that function can also do allocations sometimes. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@vger.kernel.org
2012-07-30sunrpc: clarify comments on rpc_make_runnableJeff Layton
rpc_make_runnable is not generally called with the queue lock held, unless it's waking up a task that has been sitting on a waitqueue. This is safe when the task has not entered the FSM yet, but the comments don't really spell this out. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-03-19SUNRPC: We must not use list_for_each_entry_safe() in rpc_wake_up()Trond Myklebust
The problem is that for the case of priority queues, we have to assume that __rpc_remove_wait_queue_priority will move new elements from the tk_wait.links lists into the queue->tasks[] list. We therefore cannot use list_for_each_entry_safe() on queue->tasks[], since that will skip these new tasks that __rpc_remove_wait_queue_priority is adding. Without this fix, rpc_wake_up and rpc_wake_up_status will both fail to wake up all functions on priority wait queues, which can result in some nasty hangs. Reported-by: Andy Adamson <andros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@vger.kernel.org
2012-02-15SUNRPC: Ensure that we can trace waitqueues when !defined(CONFIG_SYSCTL)Trond Myklebust
The tracepoint code relies on the queue->name being defined in order to be able to display the name of the waitqueue on which an RPC task is sleeping. Reported-by: Randy Dunlap <rdunlap@xenotime.net> Reported-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Randy Dunlap <rdunlap@xenotime.net>
2012-01-31SUNRPC: Add trace events to the sunrpc subsystemTrond Myklebust
Add declarations to allow tracing of RPC call creation, running, sleeping, and destruction. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-01-31SUNRPC: Fix potential races in xprt_lock_write_next()Trond Myklebust
We have to ensure that the wake up from the waitqueue and the assignment of xprt->snd_task are atomic. We can do this by assigning the snd_task while under the waitqueue spinlock. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-12-06Freezer / sunrpc / NFS: don't allow TASK_KILLABLE sleeps to block the freezerJeff Layton
Allow the freezer to skip wait_on_bit_killable sleeps in the sunrpc layer. This should allow suspend and hibernate events to proceed, even when there are RPC's pending on the wire. Also, wrap the TASK_KILLABLE sleeps in NFS layer in freezer_do_not_count and freezer_count calls. This allows the freezer to skip tasks that are sleeping while looping on EJUKEBOX or NFS4ERR_DELAY sorts of errors. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-12-01SUNRPC: Fix the execution time statistics in the face of RPC restartsTrond Myklebust
If the rpc_task gets restarted, then we want to ensure that we don't double-count the execution time statistics, timeout data, etc. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-07-17SUNRPC: Allow caller of rpc_sleep_on() to select priority levelsTrond Myklebust
Currently, the caller has to change the value of task->tk_priority if it wants to select on which priority level the task will sleep. This patch allows the caller to select a priority level at sleep time rather than always using task->tk_priority. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-07-07SUNRPC: Fix a race between work-queue and rpc_killall_tasksTrond Myklebust
Since rpc_killall_tasks may modify the rpc_task's tk_action field without any locking, we need to be careful when dereferencing it. Reported-by: Ben Greear <greearb@candelatech.com> Tested-by: Ben Greear <greearb@candelatech.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@kernel.org
2011-06-15NLM: Don't hang forever on NLM unlock requestsTrond Myklebust
If the NLM daemon is killed on the NFS server, we can currently end up hanging forever on an 'unlock' request, instead of aborting. Basically, if the rpcbind request fails, or the server keeps returning garbage, we really want to quit instead of retrying. Tested-by: Vasily Averin <vvs@sw.ru> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@kernel.org
2011-03-27NFS: Ensure that rpc_release_resources_task() can be called twice.OGAWA Hirofumi
BUG: atomic_dec_and_test(): -1: atomic counter underflow at: Pid: 2827, comm: mount.nfs Not tainted 2.6.38 #1 Call Trace: [<ffffffffa02223a0>] ? put_rpccred+0x44/0x14e [sunrpc] [<ffffffffa021bbe9>] ? rpc_ping+0x4e/0x58 [sunrpc] [<ffffffffa021c4a5>] ? rpc_create+0x481/0x4fc [sunrpc] [<ffffffffa022298a>] ? rpcauth_lookup_credcache+0xab/0x22d [sunrpc] [<ffffffffa028be8c>] ? nfs_create_rpc_client+0xa6/0xeb [nfs] [<ffffffffa028c660>] ? nfs4_set_client+0xc2/0x1f9 [nfs] [<ffffffffa028cd3c>] ? nfs4_create_server+0xf2/0x2a6 [nfs] [<ffffffffa0295d07>] ? nfs4_remote_mount+0x4e/0x14a [nfs] [<ffffffff810dd570>] ? vfs_kern_mount+0x6e/0x133 [<ffffffffa029605a>] ? nfs_do_root_mount+0x76/0x95 [nfs] [<ffffffffa029643d>] ? nfs4_try_mount+0x56/0xaf [nfs] [<ffffffffa0297434>] ? nfs_get_sb+0x435/0x73c [nfs] [<ffffffff810dd59b>] ? vfs_kern_mount+0x99/0x133 [<ffffffff810dd693>] ? do_kern_mount+0x48/0xd8 [<ffffffff810f5b75>] ? do_mount+0x6da/0x741 [<ffffffff810f5c5f>] ? sys_mount+0x83/0xc0 [<ffffffff8100293b>] ? system_call_fastpath+0x16/0x1b Well, so, I think this is real bug of nfs codes somewhere. With some review, the code rpc_call_sync() rpc_run_task rpc_execute() __rpc_execute() rpc_release_task() rpc_release_resources_task() put_rpccred() <= release cred rpc_put_task rpc_do_put_task() rpc_release_resources_task() put_rpccred() <= release cred again seems to be release cred unintendedly. Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-17SUNRPC: Ensure we always run the tk_callback before tk_actionTrond Myklebust
This fixes a race in which the task->tk_callback() puts the rpc_task to sleep, setting a new callback. Under certain circumstances, the current code may end up executing the task->tk_action before it gets round to the callback. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@kernel.org
2011-03-11RPC: clarify rpc_run_task error handlingFred Isaman
rpc_run_task can only fail if it is not passed in a preallocated task. However, that is not at all clear with the current code. So remove several impossible to occur failure checks. Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
generated by cgit v1.2.3 (git 2.25.1) at 2025-12-16 04:32:46 +0000