Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-qc0-f180.google.com ([209.85.216.180]:40413 "EHLO mail-qc0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751277AbaKZTo6 (ORCPT ); Wed, 26 Nov 2014 14:44:58 -0500 Received: by mail-qc0-f180.google.com with SMTP id i8so2532794qcq.25 for ; Wed, 26 Nov 2014 11:44:58 -0800 (PST) From: Jeff Layton To: trond.myklebust@primarydata.com Cc: Anna Schumaker , bfields@fieldses.org, linux-nfs@vger.kernel.org Subject: [PATCH v3 4/5] sunrpc: add debugfs file for displaying client rpc_task queue Date: Wed, 26 Nov 2014 14:44:43 -0500 Message-Id: <1417031084-17576-5-git-send-email-jlayton@primarydata.com> In-Reply-To: <1417031084-17576-1-git-send-email-jlayton@primarydata.com> References: <1416942060-6724-1-git-send-email-jlayton@primarydata.com> <1417031084-17576-1-git-send-email-jlayton@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: It's possible to get a dump of the RPC task queue by writing a value to /proc/sys/sunrpc/rpc_debug. If you write any value to that file, you get a dump of the RPC client task list into the log buffer. This is a rather inconvenient interface however, and makes it hard to get immediate info about the task queue. Add a new directory hierarchy under debugfs: sunrpc/ rpc_clnt/ / Within each clientid directory we create a new "tasks" file that will dump info similar to what shows up in the log buffer, but with a few small differences -- we avoid printing raw kernel addresses in favor of symbolic names and the XID is also displayed. Signed-off-by: Jeff Layton --- include/linux/sunrpc/clnt.h | 4 + include/linux/sunrpc/debug.h | 31 +++++++ net/sunrpc/Kconfig | 1 + net/sunrpc/Makefile | 1 + net/sunrpc/clnt.c | 10 ++- net/sunrpc/debugfs.c | 191 +++++++++++++++++++++++++++++++++++++++++++ net/sunrpc/sunrpc_syms.c | 8 ++ 7 files changed, 245 insertions(+), 1 deletion(-) create mode 100644 net/sunrpc/debugfs.c diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h index 70736b98c721..d86acc63b25f 100644 --- a/include/linux/sunrpc/clnt.h +++ b/include/linux/sunrpc/clnt.h @@ -63,6 +63,9 @@ struct rpc_clnt { struct rpc_rtt cl_rtt_default; struct rpc_timeout cl_timeout_default; const struct rpc_program *cl_program; +#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) + struct dentry *cl_debugfs; /* debugfs directory */ +#endif }; /* @@ -176,5 +179,6 @@ size_t rpc_peeraddr(struct rpc_clnt *, struct sockaddr *, size_t); const char *rpc_peeraddr2str(struct rpc_clnt *, enum rpc_display_format_t); int rpc_localaddr(struct rpc_clnt *, struct sockaddr *, size_t); +const char *rpc_proc_name(const struct rpc_task *task); #endif /* __KERNEL__ */ #endif /* _LINUX_SUNRPC_CLNT_H */ diff --git a/include/linux/sunrpc/debug.h b/include/linux/sunrpc/debug.h index 43f38ee9668c..835339707094 100644 --- a/include/linux/sunrpc/debug.h +++ b/include/linux/sunrpc/debug.h @@ -53,9 +53,40 @@ extern unsigned int nlm_debug; /* * Sysctl interface for RPC debugging */ + +struct rpc_clnt; + #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) void rpc_register_sysctl(void); void rpc_unregister_sysctl(void); +int sunrpc_debugfs_init(void); +void sunrpc_debugfs_exit(void); +int rpc_clnt_debugfs_register(struct rpc_clnt *); +void rpc_clnt_debugfs_unregister(struct rpc_clnt *); +#else +static inline int +sunrpc_debugfs_init(void) +{ + return 0; +} + +static inline void +sunrpc_debugfs_exit(void) +{ + return; +} + +static inline int +rpc_clnt_debugfs_register(struct rpc_clnt *clnt) +{ + return 0; +} + +static inline void +rpc_clnt_debugfs_unregister(struct rpc_clnt *clnt) +{ + return; +} #endif #endif /* _LINUX_SUNRPC_DEBUG_H_ */ diff --git a/net/sunrpc/Kconfig b/net/sunrpc/Kconfig index 0754d0f466d2..fb78117b896c 100644 --- a/net/sunrpc/Kconfig +++ b/net/sunrpc/Kconfig @@ -35,6 +35,7 @@ config RPCSEC_GSS_KRB5 config SUNRPC_DEBUG bool "RPC: Enable dprintk debugging" depends on SUNRPC && SYSCTL + select DEBUG_FS help This option enables a sysctl-based debugging interface that is be used by the 'rpcdebug' utility to turn on or off diff --git a/net/sunrpc/Makefile b/net/sunrpc/Makefile index e5a7a1cac8f3..15e6f6c23c5d 100644 --- a/net/sunrpc/Makefile +++ b/net/sunrpc/Makefile @@ -14,6 +14,7 @@ sunrpc-y := clnt.o xprt.o socklib.o xprtsock.o sched.o \ addr.o rpcb_clnt.o timer.o xdr.o \ sunrpc_syms.o cache.o rpc_pipe.o \ svc_xprt.o +sunrpc-$(CONFIG_SUNRPC_DEBUG) += debugfs.o sunrpc-$(CONFIG_SUNRPC_BACKCHANNEL) += backchannel_rqst.o bc_svc.o sunrpc-$(CONFIG_PROC_FS) += stats.o sunrpc-$(CONFIG_SYSCTL) += sysctl.o diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index 36c64ef460cf..05da12a33945 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -305,6 +305,10 @@ static int rpc_client_register(struct rpc_clnt *clnt, struct super_block *pipefs_sb; int err; + err = rpc_clnt_debugfs_register(clnt); + if (err) + return err; + pipefs_sb = rpc_get_sb_net(net); if (pipefs_sb) { err = rpc_setup_pipedir(pipefs_sb, clnt); @@ -331,6 +335,7 @@ err_auth: out: if (pipefs_sb) rpc_put_sb_net(net); + rpc_clnt_debugfs_unregister(clnt); return err; } @@ -670,6 +675,7 @@ int rpc_switch_client_transport(struct rpc_clnt *clnt, rpc_unregister_client(clnt); __rpc_clnt_remove_pipedir(clnt); + rpc_clnt_debugfs_unregister(clnt); /* * A new transport was created. "clnt" therefore @@ -771,6 +777,7 @@ rpc_free_client(struct rpc_clnt *clnt) rcu_dereference(clnt->cl_xprt)->servername); if (clnt->cl_parent != clnt) parent = clnt->cl_parent; + rpc_clnt_debugfs_unregister(clnt); rpc_clnt_remove_pipedir(clnt); rpc_unregister_client(clnt); rpc_free_iostats(clnt->cl_metrics); @@ -1397,7 +1404,8 @@ rpc_restart_call(struct rpc_task *task) EXPORT_SYMBOL_GPL(rpc_restart_call); #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) -static const char *rpc_proc_name(const struct rpc_task *task) +const char +*rpc_proc_name(const struct rpc_task *task) { const struct rpc_procinfo *proc = task->tk_msg.rpc_proc; diff --git a/net/sunrpc/debugfs.c b/net/sunrpc/debugfs.c new file mode 100644 index 000000000000..3d7745683ca3 --- /dev/null +++ b/net/sunrpc/debugfs.c @@ -0,0 +1,191 @@ +/** + * debugfs interface for sunrpc + * + * (c) 2014 Jeff Layton + */ + +#include +#include +#include +#include "netns.h" + +static struct dentry *topdir; +static struct dentry *rpc_clnt_dir; + +struct rpc_clnt_iter { + struct rpc_clnt *clnt; + loff_t pos; +}; + +static int +tasks_show(struct seq_file *f, void *v) +{ + u32 xid = 0; + struct rpc_task *task = v; + struct rpc_clnt *clnt = task->tk_client; + const char *rpc_waitq = "none"; + + if (RPC_IS_QUEUED(task)) + rpc_waitq = rpc_qname(task->tk_waitqueue); + + if (task->tk_rqstp) + xid = be32_to_cpu(task->tk_rqstp->rq_xid); + + seq_printf(f, "%5u %04x %6d 0x%x 0x%x %8ld %ps %sv%u %s a:%ps q:%s\n", + task->tk_pid, task->tk_flags, task->tk_status, + clnt->cl_clid, xid, task->tk_timeout, task->tk_ops, + clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task), + task->tk_action, rpc_waitq); + return 0; +} + +static void * +tasks_start(struct seq_file *f, loff_t *ppos) + __acquires(&clnt->cl_lock) +{ + struct rpc_clnt_iter *iter = f->private; + loff_t pos = *ppos; + struct rpc_clnt *clnt = iter->clnt; + struct rpc_task *task; + + iter->pos = pos + 1; + spin_lock(&clnt->cl_lock); + list_for_each_entry(task, &clnt->cl_tasks, tk_task) + if (pos-- == 0) + return task; + return NULL; +} + +static void * +tasks_next(struct seq_file *f, void *v, loff_t *pos) +{ + struct rpc_clnt_iter *iter = f->private; + struct rpc_clnt *clnt = iter->clnt; + struct rpc_task *task = v; + struct list_head *next = task->tk_task.next; + + ++iter->pos; + ++*pos; + + /* If there's another task on list, return it */ + if (next == &clnt->cl_tasks) + return NULL; + return list_entry(next, struct rpc_task, tk_task); +} + +static void +tasks_stop(struct seq_file *f, void *v) + __releases(&clnt->cl_lock) +{ + struct rpc_clnt_iter *iter = f->private; + struct rpc_clnt *clnt = iter->clnt; + + spin_unlock(&clnt->cl_lock); +} + +static const struct seq_operations tasks_seq_operations = { + .start = tasks_start, + .next = tasks_next, + .stop = tasks_stop, + .show = tasks_show, +}; + +static int tasks_open(struct inode *inode, struct file *filp) +{ + int ret = seq_open_private(filp, &tasks_seq_operations, + sizeof(struct rpc_clnt_iter)); + + if (!ret) { + struct seq_file *seq = filp->private_data; + struct rpc_clnt_iter *iter = seq->private; + + iter->clnt = inode->i_private; + + if (!atomic_inc_not_zero(&iter->clnt->cl_count)) { + seq_release_private(inode, filp); + ret = -EINVAL; + } + } + + return ret; +} + +static int +tasks_release(struct inode *inode, struct file *filp) +{ + struct seq_file *seq = filp->private_data; + struct rpc_clnt_iter *iter = seq->private; + + rpc_release_client(iter->clnt); + return seq_release_private(inode, filp); +} + +static const struct file_operations tasks_fops = { + .owner = THIS_MODULE, + .open = tasks_open, + .read = seq_read, + .llseek = seq_lseek, + .release = tasks_release, +}; + +int +rpc_clnt_debugfs_register(struct rpc_clnt *clnt) +{ + int len; + char name[9]; /* 8 for hex digits + NULL terminator */ + + /* Already registered? */ + if (clnt->cl_debugfs) + return 0; + + len = snprintf(name, sizeof(name), "%x", clnt->cl_clid); + if (len >= sizeof(name)) + return -EINVAL; + + /* make the per-client dir */ + clnt->cl_debugfs = debugfs_create_dir(name, rpc_clnt_dir); + if (!clnt->cl_debugfs) + return -ENOMEM; + + /* make tasks file */ + if (!debugfs_create_file("tasks", S_IFREG | S_IRUSR, clnt->cl_debugfs, + clnt, &tasks_fops)) { + debugfs_remove_recursive(clnt->cl_debugfs); + clnt->cl_debugfs = NULL; + return -ENOMEM; + } + + return 0; +} + +void +rpc_clnt_debugfs_unregister(struct rpc_clnt *clnt) +{ + debugfs_remove_recursive(clnt->cl_debugfs); + clnt->cl_debugfs = NULL; +} + +void __exit +sunrpc_debugfs_exit(void) +{ + debugfs_remove_recursive(topdir); +} + +int __init +sunrpc_debugfs_init(void) +{ + topdir = debugfs_create_dir("sunrpc", NULL); + if (!topdir) + goto out; + + rpc_clnt_dir = debugfs_create_dir("rpc_clnt", topdir); + if (!rpc_clnt_dir) + goto out_remove; + + return 0; +out_remove: + debugfs_remove_recursive(topdir); + topdir = NULL; +out: + return -ENOMEM; +} diff --git a/net/sunrpc/sunrpc_syms.c b/net/sunrpc/sunrpc_syms.c index f632e476ab6c..e37fbed87956 100644 --- a/net/sunrpc/sunrpc_syms.c +++ b/net/sunrpc/sunrpc_syms.c @@ -97,6 +97,11 @@ init_sunrpc(void) err = register_rpc_pipefs(); if (err) goto out4; + + err = sunrpc_debugfs_init(); + if (err) + goto out5; + #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) rpc_register_sysctl(); #endif @@ -104,6 +109,8 @@ init_sunrpc(void) init_socket_xprt(); /* clnt sock transport */ return 0; +out5: + unregister_rpc_pipefs(); out4: unregister_pernet_subsys(&sunrpc_net_ops); out3: @@ -120,6 +127,7 @@ cleanup_sunrpc(void) rpcauth_remove_module(); cleanup_socket_xprt(); svc_cleanup_xprt_sock(); + sunrpc_debugfs_exit(); unregister_rpc_pipefs(); rpc_destroy_mempool(); unregister_pernet_subsys(&sunrpc_net_ops); -- 2.1.0