From b4b9d2ccf0be61c69213f6ae4e33377c05194ef4 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Wed, 26 Nov 2014 14:44:43 -0500 Subject: sunrpc: add debugfs file for displaying client rpc_task queue 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 Signed-off-by: Trond Myklebust --- net/sunrpc/debugfs.c | 191 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 191 insertions(+) create mode 100644 net/sunrpc/debugfs.c (limited to 'net/sunrpc/debugfs.c') diff --git a/net/sunrpc/debugfs.c b/net/sunrpc/debugfs.c new file mode 100644 index 0000000..3d77456 --- /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; +} -- cgit v1.1