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authorWeston Andros Adamson <dros@netapp.com>2013-12-17 12:16:11 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-02-13 13:48:01 -0800
commit42e0de9d0e77debb0a34024729cd34068af68bd8 (patch)
tree8a6c834661291b1935321d2dac338007523126a6
parent305a7c624df026dbdde23eb880549db7df0ad7b9 (diff)
sunrpc: Fix infinite loop in RPC state machine
commit 6ff33b7dd0228b7d7ed44791bbbc98b03fd15d9d upstream. When a task enters call_refreshresult with status 0 from call_refresh and !rpcauth_uptodatecred(task) it enters call_refresh again with no rate-limiting or max number of retries. Instead of trying forever, make use of the retry path that other errors use. This only seems to be possible when the crrefresh callback is gss_refresh_null, which only happens when destroying the context. To reproduce: 1) mount with sec=krb5 (or sec=sys with krb5 negotiated for non FSID specific operations). 2) reboot - the client will be stuck and will need to be hard rebooted BUG: soft lockup - CPU#0 stuck for 22s! [kworker/0:2:46] Modules linked in: rpcsec_gss_krb5 nfsv4 nfs fscache ppdev crc32c_intel aesni_intel aes_x86_64 glue_helper lrw gf128mul ablk_helper cryptd serio_raw i2c_piix4 i2c_core e1000 parport_pc parport shpchp nfsd auth_rpcgss oid_registry exportfs nfs_acl lockd sunrpc autofs4 mptspi scsi_transport_spi mptscsih mptbase ata_generic floppy irq event stamp: 195724 hardirqs last enabled at (195723): [<ffffffff814a925c>] restore_args+0x0/0x30 hardirqs last disabled at (195724): [<ffffffff814b0a6a>] apic_timer_interrupt+0x6a/0x80 softirqs last enabled at (195722): [<ffffffff8103f583>] __do_softirq+0x1df/0x276 softirqs last disabled at (195717): [<ffffffff8103f852>] irq_exit+0x53/0x9a CPU: 0 PID: 46 Comm: kworker/0:2 Not tainted 3.13.0-rc3-branch-dros_testing+ #4 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/31/2013 Workqueue: rpciod rpc_async_schedule [sunrpc] task: ffff8800799c4260 ti: ffff880079002000 task.ti: ffff880079002000 RIP: 0010:[<ffffffffa0064fd4>] [<ffffffffa0064fd4>] __rpc_execute+0x8a/0x362 [sunrpc] RSP: 0018:ffff880079003d18 EFLAGS: 00000246 RAX: 0000000000000005 RBX: 0000000000000007 RCX: 0000000000000007 RDX: 0000000000000007 RSI: ffff88007aecbae8 RDI: ffff8800783d8900 RBP: ffff880079003d78 R08: ffff88006e30e9f8 R09: ffffffffa005a3d7 R10: ffff88006e30e7b0 R11: ffff8800783d8900 R12: ffffffffa006675e R13: ffff880079003ce8 R14: ffff88006e30e7b0 R15: ffff8800783d8900 FS: 0000000000000000(0000) GS:ffff88007f200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3072333000 CR3: 0000000001a0b000 CR4: 00000000001407f0 Stack: ffff880079003d98 0000000000000246 0000000000000000 ffff88007a9a4830 ffff880000000000 ffffffff81073f47 ffff88007f212b00 ffff8800799c4260 ffff8800783d8988 ffff88007f212b00 ffffe8ffff604800 0000000000000000 Call Trace: [<ffffffff81073f47>] ? trace_hardirqs_on_caller+0x145/0x1a1 [<ffffffffa00652d3>] rpc_async_schedule+0x27/0x32 [sunrpc] [<ffffffff81052974>] process_one_work+0x211/0x3a5 [<ffffffff810528d5>] ? process_one_work+0x172/0x3a5 [<ffffffff81052eeb>] worker_thread+0x134/0x202 [<ffffffff81052db7>] ? rescuer_thread+0x280/0x280 [<ffffffff81052db7>] ? rescuer_thread+0x280/0x280 [<ffffffff810584a0>] kthread+0xc9/0xd1 [<ffffffff810583d7>] ? __kthread_parkme+0x61/0x61 [<ffffffff814afd6c>] ret_from_fork+0x7c/0xb0 [<ffffffff810583d7>] ? __kthread_parkme+0x61/0x61 Code: e8 87 63 fd e0 c6 05 10 dd 01 00 01 48 8b 43 70 4c 8d 6b 70 45 31 e4 a8 02 0f 85 d5 02 00 00 4c 8b 7b 48 48 c7 43 48 00 00 00 00 <4c> 8b 4b 50 4d 85 ff 75 0c 4d 85 c9 4d 89 cf 0f 84 32 01 00 00 And the output of "rpcdebug -m rpc -s all": RPC: 61 call_refresh (status 0) RPC: 61 call_refresh (status 0) RPC: 61 refreshing RPCSEC_GSS cred ffff88007a413cf0 RPC: 61 refreshing RPCSEC_GSS cred ffff88007a413cf0 RPC: 61 call_refreshresult (status 0) RPC: 61 refreshing RPCSEC_GSS cred ffff88007a413cf0 RPC: 61 call_refreshresult (status 0) RPC: 61 refreshing RPCSEC_GSS cred ffff88007a413cf0 RPC: 61 call_refresh (status 0) RPC: 61 call_refreshresult (status 0) RPC: 61 call_refresh (status 0) RPC: 61 call_refresh (status 0) RPC: 61 refreshing RPCSEC_GSS cred ffff88007a413cf0 RPC: 61 call_refreshresult (status 0) RPC: 61 call_refresh (status 0) RPC: 61 refreshing RPCSEC_GSS cred ffff88007a413cf0 RPC: 61 call_refresh (status 0) RPC: 61 refreshing RPCSEC_GSS cred ffff88007a413cf0 RPC: 61 refreshing RPCSEC_GSS cred ffff88007a413cf0 RPC: 61 call_refreshresult (status 0) RPC: 61 call_refresh (status 0) RPC: 61 call_refresh (status 0) RPC: 61 call_refresh (status 0) RPC: 61 call_refresh (status 0) RPC: 61 call_refreshresult (status 0) RPC: 61 refreshing RPCSEC_GSS cred ffff88007a413cf0 Signed-off-by: Weston Andros Adamson <dros@netapp.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/sunrpc/clnt.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 5b1bf7b530f..3524a8b5004 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1402,9 +1402,13 @@ call_refreshresult(struct rpc_task *task)
task->tk_action = call_refresh;
switch (status) {
case 0:
- if (rpcauth_uptodatecred(task))
+ if (rpcauth_uptodatecred(task)) {
task->tk_action = call_allocate;
- return;
+ return;
+ }
+ /* Use rate-limiting and a max number of retries if refresh
+ * had status 0 but failed to update the cred.
+ */
case -ETIMEDOUT:
rpc_delay(task, 3*HZ);
case -EAGAIN: