diff options
author | Jeff Layton <jlayton@redhat.com> | 2012-07-23 13:58:51 -0400 |
---|---|---|
committer | Ben Hutchings <ben@decadent.org.uk> | 2012-08-10 00:24:59 +0100 |
commit | 1c88c581bfe3afd2d21a14b6dee7011af8512f91 (patch) | |
tree | 7e0fac1468c39e221d7593e142878328ebd9352c /net/sunrpc | |
parent | c929e9bc8cadd3dd1e914498e3905d3d4cc43f85 (diff) |
nfs: skip commit in releasepage if we're freeing memory for fs-related reasons
commit 5cf02d09b50b1ee1c2d536c9cf64af5a7d433f56 upstream.
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>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'net/sunrpc')
-rw-r--r-- | net/sunrpc/sched.c | 2 | ||||
-rw-r--r-- | net/sunrpc/xprtrdma/transport.c | 3 | ||||
-rw-r--r-- | net/sunrpc/xprtsock.c | 10 |
3 files changed, 14 insertions, 1 deletions
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c index 4e2b3b454ab..c90b83252ec 100644 --- a/net/sunrpc/sched.c +++ b/net/sunrpc/sched.c @@ -755,7 +755,9 @@ void rpc_execute(struct rpc_task *task) static void rpc_async_schedule(struct work_struct *work) { + current->flags |= PF_FSTRANS; __rpc_execute(container_of(work, struct rpc_task, u.tk_work)); + current->flags &= ~PF_FSTRANS; } /** diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c index b446e100286..06cdbff79e4 100644 --- a/net/sunrpc/xprtrdma/transport.c +++ b/net/sunrpc/xprtrdma/transport.c @@ -200,6 +200,7 @@ xprt_rdma_connect_worker(struct work_struct *work) int rc = 0; if (!xprt->shutdown) { + current->flags |= PF_FSTRANS; xprt_clear_connected(xprt); dprintk("RPC: %s: %sconnect\n", __func__, @@ -212,10 +213,10 @@ xprt_rdma_connect_worker(struct work_struct *work) out: xprt_wake_pending_tasks(xprt, rc); - out_clear: dprintk("RPC: %s: exit\n", __func__); xprt_clear_connecting(xprt); + current->flags &= ~PF_FSTRANS; } /* diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 55472c48825..1a6edc7e8c8 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -1895,6 +1895,8 @@ static void xs_local_setup_socket(struct work_struct *work) if (xprt->shutdown) goto out; + current->flags |= PF_FSTRANS; + clear_bit(XPRT_CONNECTION_ABORT, &xprt->state); status = __sock_create(xprt->xprt_net, AF_LOCAL, SOCK_STREAM, 0, &sock, 1); @@ -1928,6 +1930,7 @@ static void xs_local_setup_socket(struct work_struct *work) out: xprt_clear_connecting(xprt); xprt_wake_pending_tasks(xprt, status); + current->flags &= ~PF_FSTRANS; } static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock) @@ -1970,6 +1973,8 @@ static void xs_udp_setup_socket(struct work_struct *work) if (xprt->shutdown) goto out; + current->flags |= PF_FSTRANS; + /* Start by resetting any existing state */ xs_reset_transport(transport); sock = xs_create_sock(xprt, transport, @@ -1988,6 +1993,7 @@ static void xs_udp_setup_socket(struct work_struct *work) out: xprt_clear_connecting(xprt); xprt_wake_pending_tasks(xprt, status); + current->flags &= ~PF_FSTRANS; } /* @@ -2113,6 +2119,8 @@ static void xs_tcp_setup_socket(struct work_struct *work) if (xprt->shutdown) goto out; + current->flags |= PF_FSTRANS; + if (!sock) { clear_bit(XPRT_CONNECTION_ABORT, &xprt->state); sock = xs_create_sock(xprt, transport, @@ -2162,6 +2170,7 @@ static void xs_tcp_setup_socket(struct work_struct *work) case -EINPROGRESS: case -EALREADY: xprt_clear_connecting(xprt); + current->flags &= ~PF_FSTRANS; return; case -EINVAL: /* Happens, for instance, if the user specified a link @@ -2174,6 +2183,7 @@ out_eagain: out: xprt_clear_connecting(xprt); xprt_wake_pending_tasks(xprt, status); + current->flags &= ~PF_FSTRANS; } /** |