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authorAndy Adamson <andros@netapp.com>2013-11-15 16:36:16 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-12-20 07:45:11 -0800
commit39be1c3dd03ee291a006189fe1cf43a5322a6eaf (patch)
tree9b01f323a24e2bb20ba0977fdc0fd1d36e900c46
parent8a8e917f784930fe2f18a5b559f3860446d5a32b (diff)
downloadlinux-rt-39be1c3dd03ee291a006189fe1cf43a5322a6eaf.tar.gz
NFSv4 wait on recovery for async session errors
commit 4a82fd7c4e78a1b7a224f9ae8bb7e1fd95f670e0 upstream. When the state manager is processing the NFS4CLNT_DELEGRETURN flag, session draining is off, but DELEGRETURN can still get a session error. The async handler calls nfs4_schedule_session_recovery returns -EAGAIN, and the DELEGRETURN done then restarts the RPC task in the prepare state. With the state manager still processing the NFS4CLNT_DELEGRETURN flag with session draining off, these DELEGRETURNs will cycle with errors filling up the session slots. This prevents OPEN reclaims (from nfs_delegation_claim_opens) required by the NFS4CLNT_DELEGRETURN state manager processing from completing, hanging the state manager in the __rpc_wait_for_completion_task in nfs4_run_open_task as seen in this kernel thread dump: kernel: 4.12.32.53-ma D 0000000000000000 0 3393 2 0x00000000 kernel: ffff88013995fb60 0000000000000046 ffff880138cc5400 ffff88013a9df140 kernel: ffff8800000265c0 ffffffff8116eef0 ffff88013fc10080 0000000300000001 kernel: ffff88013a4ad058 ffff88013995ffd8 000000000000fbc8 ffff88013a4ad058 kernel: Call Trace: kernel: [<ffffffff8116eef0>] ? cache_alloc_refill+0x1c0/0x240 kernel: [<ffffffffa0358110>] ? rpc_wait_bit_killable+0x0/0xa0 [sunrpc] kernel: [<ffffffffa0358152>] rpc_wait_bit_killable+0x42/0xa0 [sunrpc] kernel: [<ffffffff8152914f>] __wait_on_bit+0x5f/0x90 kernel: [<ffffffffa0358110>] ? rpc_wait_bit_killable+0x0/0xa0 [sunrpc] kernel: [<ffffffff815291f8>] out_of_line_wait_on_bit+0x78/0x90 kernel: [<ffffffff8109b520>] ? wake_bit_function+0x0/0x50 kernel: [<ffffffffa035810d>] __rpc_wait_for_completion_task+0x2d/0x30 [sunrpc] kernel: [<ffffffffa040d44c>] nfs4_run_open_task+0x11c/0x160 [nfs] kernel: [<ffffffffa04114e7>] nfs4_open_recover_helper+0x87/0x120 [nfs] kernel: [<ffffffffa0411646>] nfs4_open_recover+0xc6/0x150 [nfs] kernel: [<ffffffffa040cc6f>] ? nfs4_open_recoverdata_alloc+0x2f/0x60 [nfs] kernel: [<ffffffffa0414e1a>] nfs4_open_delegation_recall+0x6a/0xa0 [nfs] kernel: [<ffffffffa0424020>] nfs_end_delegation_return+0x120/0x2e0 [nfs] kernel: [<ffffffff8109580f>] ? queue_work+0x1f/0x30 kernel: [<ffffffffa0424347>] nfs_client_return_marked_delegations+0xd7/0x110 [nfs] kernel: [<ffffffffa04225d8>] nfs4_run_state_manager+0x548/0x620 [nfs] kernel: [<ffffffffa0422090>] ? nfs4_run_state_manager+0x0/0x620 [nfs] kernel: [<ffffffff8109b0f6>] kthread+0x96/0xa0 kernel: [<ffffffff8100c20a>] child_rip+0xa/0x20 kernel: [<ffffffff8109b060>] ? kthread+0x0/0xa0 kernel: [<ffffffff8100c200>] ? child_rip+0x0/0x20 The state manager can not therefore process the DELEGRETURN session errors. Change the async handler to wait for recovery on session errors. Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/nfs/nfs4proc.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 23881380dc6f..75e49d42a7fb 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -4222,8 +4222,7 @@ nfs4_async_handle_error(struct rpc_task *task, const struct nfs_server *server,
dprintk("%s ERROR %d, Reset session\n", __func__,
task->tk_status);
nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
- task->tk_status = 0;
- return -EAGAIN;
+ goto wait_on_recovery;
#endif /* CONFIG_NFS_V4_1 */
case -NFS4ERR_DELAY:
nfs_inc_server_stats(server, NFSIOS_DELAY);