From df807fffaabde625fa9adb82e3e5b88cdaa5709a Mon Sep 17 00:00:00 2001 From: Kinglong Mee Date: Thu, 27 Apr 2017 11:13:38 +0800 Subject: NFSv4.x/callback: Create the callback service through svc_create_pooled As the comments for svc_set_num_threads() said, " Destroying threads relies on the service threads filling in rqstp->rq_task, which only the nfs ones do. Assumes the serv has been created using svc_create_pooled()." If creating service through svc_create(), the svc_pool_map_put() will be called in svc_destroy(), but the pool map isn't used. So that, the reference of pool map will be drop, the next using of pool map will get a zero npools. [ 137.992130] divide error: 0000 [#1] SMP [ 137.992148] Modules linked in: nfsd(E) nfsv4 nfs fscache fuse tun bridge stp llc ip_set nfnetlink vmw_vsock_vmci_transport vsock snd_seq_midi snd_seq_midi_event vmw_balloon coretemp crct10dif_pclmul crc32_pclmul ppdev ghash_clmulni_intel intel_rapl_perf joydev snd_ens1371 gameport snd_ac97_codec ac97_bus snd_seq snd_pcm snd_rawmidi snd_timer snd_seq_device snd soundcore parport_pc parport nfit acpi_cpufreq tpm_tis tpm_tis_core tpm vmw_vmci i2c_piix4 shpchp auth_rpcgss nfs_acl lockd(E) grace sunrpc(E) xfs libcrc32c vmwgfx drm_kms_helper ttm crc32c_intel drm e1000 mptspi scsi_transport_spi serio_raw mptscsih mptbase ata_generic pata_acpi [last unloaded: nfsd] [ 137.992336] CPU: 0 PID: 4514 Comm: rpc.nfsd Tainted: G E 4.11.0-rc8+ #536 [ 137.992777] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/02/2015 [ 137.993757] task: ffff955984101d00 task.stack: ffff9873c2604000 [ 137.994231] RIP: 0010:svc_pool_for_cpu+0x2b/0x80 [sunrpc] [ 137.994768] RSP: 0018:ffff9873c2607c18 EFLAGS: 00010246 [ 137.995227] RAX: 0000000000000000 RBX: ffff95598376f000 RCX: 0000000000000002 [ 137.995673] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9559944aec00 [ 137.996156] RBP: ffff9873c2607c18 R08: ffff9559944aec28 R09: 0000000000000000 [ 137.996609] R10: 0000000001080002 R11: 0000000000000000 R12: ffff95598376f010 [ 137.997063] R13: ffff95598376f018 R14: ffff9559944aec28 R15: ffff9559944aec00 [ 137.997584] FS: 00007f755529eb40(0000) GS:ffff9559bb600000(0000) knlGS:0000000000000000 [ 137.998048] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 137.998548] CR2: 000055f3aecd9660 CR3: 0000000084290000 CR4: 00000000001406f0 [ 137.999052] Call Trace: [ 137.999517] svc_xprt_do_enqueue+0xef/0x260 [sunrpc] [ 138.000028] svc_xprt_received+0x47/0x90 [sunrpc] [ 138.000487] svc_add_new_perm_xprt+0x76/0x90 [sunrpc] [ 138.000981] svc_addsock+0x14b/0x200 [sunrpc] [ 138.001424] ? recalc_sigpending+0x1b/0x50 [ 138.001860] ? __getnstimeofday64+0x41/0xd0 [ 138.002346] ? do_gettimeofday+0x29/0x90 [ 138.002779] write_ports+0x255/0x2c0 [nfsd] [ 138.003202] ? _copy_from_user+0x4e/0x80 [ 138.003676] ? write_recoverydir+0x100/0x100 [nfsd] [ 138.004098] nfsctl_transaction_write+0x48/0x80 [nfsd] [ 138.004544] __vfs_write+0x37/0x160 [ 138.004982] ? selinux_file_permission+0xd7/0x110 [ 138.005401] ? security_file_permission+0x3b/0xc0 [ 138.005865] vfs_write+0xb5/0x1a0 [ 138.006267] SyS_write+0x55/0xc0 [ 138.006654] entry_SYSCALL_64_fastpath+0x1a/0xa9 [ 138.007071] RIP: 0033:0x7f7554b9dc30 [ 138.007437] RSP: 002b:00007ffc9f92c788 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 138.007807] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f7554b9dc30 [ 138.008168] RDX: 0000000000000002 RSI: 00005640cd536640 RDI: 0000000000000003 [ 138.008573] RBP: 00007ffc9f92c780 R08: 0000000000000001 R09: 0000000000000002 [ 138.008918] R10: 0000000000000064 R11: 0000000000000246 R12: 0000000000000004 [ 138.009254] R13: 00005640cdbf77a0 R14: 00005640cdbf7720 R15: 00007ffc9f92c238 [ 138.009610] Code: 0f 1f 44 00 00 48 8b 87 98 00 00 00 55 48 89 e5 48 83 78 08 00 74 10 8b 05 07 42 02 00 83 f8 01 74 40 83 f8 02 74 19 31 c0 31 d2 b7 88 00 00 00 5d 89 d0 48 c1 e0 07 48 03 87 90 00 00 00 c3 [ 138.010664] RIP: svc_pool_for_cpu+0x2b/0x80 [sunrpc] RSP: ffff9873c2607c18 [ 138.011061] ---[ end trace b3468224cafa7d11 ]--- Signed-off-by: Kinglong Mee Signed-off-by: J. Bruce Fields --- fs/nfs/callback.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/nfs') diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c index 773774531aff..c5e27ebd8da8 100644 --- a/fs/nfs/callback.c +++ b/fs/nfs/callback.c @@ -280,7 +280,7 @@ static struct svc_serv *nfs_callback_create_svc(int minorversion) printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n", cb_info->users); - serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, sv_ops); + serv = svc_create_pooled(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, sv_ops); if (!serv) { printk(KERN_ERR "nfs_callback_create_svc: create service failed\n"); return ERR_PTR(-ENOMEM); -- cgit v1.2.3-59-g8ed1b From ed6473ddc704a2005b9900ca08e236ebb2d8540a Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Wed, 26 Apr 2017 11:55:27 -0400 Subject: NFSv4: Fix callback server shutdown We want to use kthread_stop() in order to ensure the threads are shut down before we tear down the nfs_callback_info in nfs_callback_down. Tested-and-reviewed-by: Kinglong Mee Reported-by: Kinglong Mee Fixes: bb6aeba736ba9 ("NFSv4.x: Switch to using svc_set_num_threads()...") Signed-off-by: Trond Myklebust Signed-off-by: J. Bruce Fields --- fs/nfs/callback.c | 24 ++++++++++++++++-------- include/linux/sunrpc/svc.h | 1 + net/sunrpc/svc.c | 38 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 55 insertions(+), 8 deletions(-) (limited to 'fs/nfs') diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c index c5e27ebd8da8..73a1f928226c 100644 --- a/fs/nfs/callback.c +++ b/fs/nfs/callback.c @@ -76,7 +76,10 @@ nfs4_callback_svc(void *vrqstp) set_freezable(); - while (!kthread_should_stop()) { + while (!kthread_freezable_should_stop(NULL)) { + + if (signal_pending(current)) + flush_signals(current); /* * Listen for a request on the socket */ @@ -85,6 +88,8 @@ nfs4_callback_svc(void *vrqstp) continue; svc_process(rqstp); } + svc_exit_thread(rqstp); + module_put_and_exit(0); return 0; } @@ -103,9 +108,10 @@ nfs41_callback_svc(void *vrqstp) set_freezable(); - while (!kthread_should_stop()) { - if (try_to_freeze()) - continue; + while (!kthread_freezable_should_stop(NULL)) { + + if (signal_pending(current)) + flush_signals(current); prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE); spin_lock_bh(&serv->sv_cb_lock); @@ -121,11 +127,13 @@ nfs41_callback_svc(void *vrqstp) error); } else { spin_unlock_bh(&serv->sv_cb_lock); - schedule(); + if (!kthread_should_stop()) + schedule(); finish_wait(&serv->sv_cb_waitq, &wq); } - flush_signals(current); } + svc_exit_thread(rqstp); + module_put_and_exit(0); return 0; } @@ -221,14 +229,14 @@ err_bind: static struct svc_serv_ops nfs40_cb_sv_ops = { .svo_function = nfs4_callback_svc, .svo_enqueue_xprt = svc_xprt_do_enqueue, - .svo_setup = svc_set_num_threads, + .svo_setup = svc_set_num_threads_sync, .svo_module = THIS_MODULE, }; #if defined(CONFIG_NFS_V4_1) static struct svc_serv_ops nfs41_cb_sv_ops = { .svo_function = nfs41_callback_svc, .svo_enqueue_xprt = svc_xprt_do_enqueue, - .svo_setup = svc_set_num_threads, + .svo_setup = svc_set_num_threads_sync, .svo_module = THIS_MODULE, }; diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h index 6ef19cf658b4..94631026f79c 100644 --- a/include/linux/sunrpc/svc.h +++ b/include/linux/sunrpc/svc.h @@ -473,6 +473,7 @@ void svc_pool_map_put(void); struct svc_serv * svc_create_pooled(struct svc_program *, unsigned int, struct svc_serv_ops *); int svc_set_num_threads(struct svc_serv *, struct svc_pool *, int); +int svc_set_num_threads_sync(struct svc_serv *, struct svc_pool *, int); int svc_pool_stats_open(struct svc_serv *serv, struct file *file); void svc_destroy(struct svc_serv *); void svc_shutdown_net(struct svc_serv *, struct net *); diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c index 98dc33ae738b..bc0f5a0ecbdc 100644 --- a/net/sunrpc/svc.c +++ b/net/sunrpc/svc.c @@ -795,6 +795,44 @@ svc_set_num_threads(struct svc_serv *serv, struct svc_pool *pool, int nrservs) } EXPORT_SYMBOL_GPL(svc_set_num_threads); +/* destroy old threads */ +static int +svc_stop_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs) +{ + struct task_struct *task; + unsigned int state = serv->sv_nrthreads-1; + + /* destroy old threads */ + do { + task = choose_victim(serv, pool, &state); + if (task == NULL) + break; + kthread_stop(task); + nrservs++; + } while (nrservs < 0); + return 0; +} + +int +svc_set_num_threads_sync(struct svc_serv *serv, struct svc_pool *pool, int nrservs) +{ + if (pool == NULL) { + /* The -1 assumes caller has done a svc_get() */ + nrservs -= (serv->sv_nrthreads-1); + } else { + spin_lock_bh(&pool->sp_lock); + nrservs -= pool->sp_nrthreads; + spin_unlock_bh(&pool->sp_lock); + } + + if (nrservs > 0) + return svc_start_kthreads(serv, pool, nrservs); + if (nrservs < 0) + return svc_stop_kthreads(serv, pool, nrservs); + return 0; +} +EXPORT_SYMBOL_GPL(svc_set_num_threads_sync); + /* * Called from a server thread as it's exiting. Caller must hold the "service * mutex" for the service. -- cgit v1.2.3-59-g8ed1b