linux/net/sunrpc/debugfs.c
Fedor Tokarev 35a6d39672 net: sunrpc: Fix 'snprintf' return value check in 'do_xprt_debugfs'
'snprintf' returns the number of characters which would have been written
if enough space had been available, excluding the terminating null byte.
Thus, the return value of 'sizeof(buf)' means that the last character
has been dropped.

Signed-off-by: Fedor Tokarev <ftokarev@gmail.com>
Fixes: 2f34b8bfae ("SUNRPC: add links for all client xprts to debugfs")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-12-02 14:05:54 -05:00

325 lines
7.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* debugfs interface for sunrpc
*
* (c) 2014 Jeff Layton <jlayton@primarydata.com>
*/
#include <linux/debugfs.h>
#include <linux/sunrpc/sched.h>
#include <linux/sunrpc/clnt.h>
#include "netns.h"
static struct dentry *topdir;
static struct dentry *rpc_clnt_dir;
static struct dentry *rpc_xprt_dir;
unsigned int rpc_inject_disconnect;
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, rpc_task_timeout(task), 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 *clnt = f->private;
loff_t pos = *ppos;
struct rpc_task *task;
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 *clnt = f->private;
struct rpc_task *task = v;
struct list_head *next = task->tk_task.next;
++*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 *clnt = f->private;
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(filp, &tasks_seq_operations);
if (!ret) {
struct seq_file *seq = filp->private_data;
struct rpc_clnt *clnt = seq->private = inode->i_private;
if (!atomic_inc_not_zero(&clnt->cl_count)) {
seq_release(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 *clnt = seq->private;
rpc_release_client(clnt);
return seq_release(inode, filp);
}
static const struct file_operations tasks_fops = {
.owner = THIS_MODULE,
.open = tasks_open,
.read = seq_read,
.llseek = seq_lseek,
.release = tasks_release,
};
static int do_xprt_debugfs(struct rpc_clnt *clnt, struct rpc_xprt *xprt, void *numv)
{
int len;
char name[24]; /* enough for "../../rpc_xprt/ + 8 hex digits + NULL */
char link[9]; /* enough for 8 hex digits + NULL */
int *nump = numv;
if (IS_ERR_OR_NULL(xprt->debugfs))
return 0;
len = snprintf(name, sizeof(name), "../../rpc_xprt/%s",
xprt->debugfs->d_name.name);
if (len >= sizeof(name))
return -1;
if (*nump == 0)
strcpy(link, "xprt");
else {
len = snprintf(link, sizeof(link), "xprt%d", *nump);
if (len >= sizeof(link))
return -1;
}
debugfs_create_symlink(link, clnt->cl_debugfs, name);
(*nump)++;
return 0;
}
void
rpc_clnt_debugfs_register(struct rpc_clnt *clnt)
{
int len;
char name[9]; /* enough for 8 hex digits + NULL */
int xprtnum = 0;
len = snprintf(name, sizeof(name), "%x", clnt->cl_clid);
if (len >= sizeof(name))
return;
/* make the per-client dir */
clnt->cl_debugfs = debugfs_create_dir(name, rpc_clnt_dir);
/* make tasks file */
debugfs_create_file("tasks", S_IFREG | 0400, clnt->cl_debugfs, clnt,
&tasks_fops);
rpc_clnt_iterate_for_each_xprt(clnt, do_xprt_debugfs, &xprtnum);
}
void
rpc_clnt_debugfs_unregister(struct rpc_clnt *clnt)
{
debugfs_remove_recursive(clnt->cl_debugfs);
clnt->cl_debugfs = NULL;
}
static int
xprt_info_show(struct seq_file *f, void *v)
{
struct rpc_xprt *xprt = f->private;
seq_printf(f, "netid: %s\n", xprt->address_strings[RPC_DISPLAY_NETID]);
seq_printf(f, "addr: %s\n", xprt->address_strings[RPC_DISPLAY_ADDR]);
seq_printf(f, "port: %s\n", xprt->address_strings[RPC_DISPLAY_PORT]);
seq_printf(f, "state: 0x%lx\n", xprt->state);
return 0;
}
static int
xprt_info_open(struct inode *inode, struct file *filp)
{
int ret;
struct rpc_xprt *xprt = inode->i_private;
ret = single_open(filp, xprt_info_show, xprt);
if (!ret) {
if (!xprt_get(xprt)) {
single_release(inode, filp);
ret = -EINVAL;
}
}
return ret;
}
static int
xprt_info_release(struct inode *inode, struct file *filp)
{
struct rpc_xprt *xprt = inode->i_private;
xprt_put(xprt);
return single_release(inode, filp);
}
static const struct file_operations xprt_info_fops = {
.owner = THIS_MODULE,
.open = xprt_info_open,
.read = seq_read,
.llseek = seq_lseek,
.release = xprt_info_release,
};
void
rpc_xprt_debugfs_register(struct rpc_xprt *xprt)
{
int len, id;
static atomic_t cur_id;
char name[9]; /* 8 hex digits + NULL term */
id = (unsigned int)atomic_inc_return(&cur_id);
len = snprintf(name, sizeof(name), "%x", id);
if (len >= sizeof(name))
return;
/* make the per-client dir */
xprt->debugfs = debugfs_create_dir(name, rpc_xprt_dir);
/* make tasks file */
debugfs_create_file("info", S_IFREG | 0400, xprt->debugfs, xprt,
&xprt_info_fops);
atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect);
}
void
rpc_xprt_debugfs_unregister(struct rpc_xprt *xprt)
{
debugfs_remove_recursive(xprt->debugfs);
xprt->debugfs = NULL;
}
static int
fault_open(struct inode *inode, struct file *filp)
{
filp->private_data = kmalloc(128, GFP_KERNEL);
if (!filp->private_data)
return -ENOMEM;
return 0;
}
static int
fault_release(struct inode *inode, struct file *filp)
{
kfree(filp->private_data);
return 0;
}
static ssize_t
fault_disconnect_read(struct file *filp, char __user *user_buf,
size_t len, loff_t *offset)
{
char *buffer = (char *)filp->private_data;
size_t size;
size = sprintf(buffer, "%u\n", rpc_inject_disconnect);
return simple_read_from_buffer(user_buf, len, offset, buffer, size);
}
static ssize_t
fault_disconnect_write(struct file *filp, const char __user *user_buf,
size_t len, loff_t *offset)
{
char buffer[16];
if (len >= sizeof(buffer))
len = sizeof(buffer) - 1;
if (copy_from_user(buffer, user_buf, len))
return -EFAULT;
buffer[len] = '\0';
if (kstrtouint(buffer, 10, &rpc_inject_disconnect))
return -EINVAL;
return len;
}
static const struct file_operations fault_disconnect_fops = {
.owner = THIS_MODULE,
.open = fault_open,
.read = fault_disconnect_read,
.write = fault_disconnect_write,
.release = fault_release,
};
void __exit
sunrpc_debugfs_exit(void)
{
debugfs_remove_recursive(topdir);
topdir = NULL;
rpc_clnt_dir = NULL;
rpc_xprt_dir = NULL;
}
void __init
sunrpc_debugfs_init(void)
{
struct dentry *rpc_fault_dir;
topdir = debugfs_create_dir("sunrpc", NULL);
rpc_clnt_dir = debugfs_create_dir("rpc_clnt", topdir);
rpc_xprt_dir = debugfs_create_dir("rpc_xprt", topdir);
rpc_fault_dir = debugfs_create_dir("inject_fault", topdir);
debugfs_create_file("disconnect", S_IFREG | 0400, rpc_fault_dir, NULL,
&fault_disconnect_fops);
}