net/sunrpc/debugfs.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /**
   3  * debugfs interface for sunrpc
   4  *
   5  * (c) 2014 Jeff Layton <jlayton@primarydata.com>
   6  */
   7
   8 #include <linux/debugfs.h>
   9 #include <linux/sunrpc/sched.h>
  10 #include <linux/sunrpc/clnt.h>
  11 #include "netns.h"
  12
  13 static struct dentry *topdir;
  14 static struct dentry *rpc_fault_dir;
  15 static struct dentry *rpc_clnt_dir;
  16 static struct dentry *rpc_xprt_dir;
  17
  18 unsigned int rpc_inject_disconnect;
  19
  20 static int
  21 tasks_show(struct seq_file *f, void *v)
  22 {
  23         u32 xid = 0;
  24         struct rpc_task *task = v;
  25         struct rpc_clnt *clnt = task->tk_client;
  26         const char *rpc_waitq = "none";
  27
  28         if (RPC_IS_QUEUED(task))
  29                 rpc_waitq = rpc_qname(task->tk_waitqueue);
  30
  31         if (task->tk_rqstp)
  32                 xid = be32_to_cpu(task->tk_rqstp->rq_xid);
  33
  34         seq_printf(f, "%5u %04x %6d 0x%x 0x%x %8ld %ps %sv%u %s a:%ps q:%s\n",
  35                 task->tk_pid, task->tk_flags, task->tk_status,
  36                 clnt->cl_clid, xid, task->tk_timeout, task->tk_ops,
  37                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
  38                 task->tk_action, rpc_waitq);
  39         return 0;
  40 }
  41
  42 static void *
  43 tasks_start(struct seq_file *f, loff_t *ppos)
  44         __acquires(&clnt->cl_lock)
  45 {
  46         struct rpc_clnt *clnt = f->private;
  47         loff_t pos = *ppos;
  48         struct rpc_task *task;
  49
  50         spin_lock(&clnt->cl_lock);
  51         list_for_each_entry(task, &clnt->cl_tasks, tk_task)
  52                 if (pos-- == 0)
  53                         return task;
  54         return NULL;
  55 }
  56
  57 static void *
  58 tasks_next(struct seq_file *f, void *v, loff_t *pos)
  59 {
  60         struct rpc_clnt *clnt = f->private;
  61         struct rpc_task *task = v;
  62         struct list_head *next = task->tk_task.next;
  63
  64         ++*pos;
  65
  66         /* If there's another task on list, return it */
  67         if (next == &clnt->cl_tasks)
  68                 return NULL;
  69         return list_entry(next, struct rpc_task, tk_task);
  70 }
  71
  72 static void
  73 tasks_stop(struct seq_file *f, void *v)
  74         __releases(&clnt->cl_lock)
  75 {
  76         struct rpc_clnt *clnt = f->private;
  77         spin_unlock(&clnt->cl_lock);
  78 }
  79
  80 static const struct seq_operations tasks_seq_operations = {
  81         .start  = tasks_start,
  82         .next   = tasks_next,
  83         .stop   = tasks_stop,
  84         .show   = tasks_show,
  85 };
  86
  87 static int tasks_open(struct inode *inode, struct file *filp)
  88 {
  89         int ret = seq_open(filp, &tasks_seq_operations);
  90         if (!ret) {
  91                 struct seq_file *seq = filp->private_data;
  92                 struct rpc_clnt *clnt = seq->private = inode->i_private;
  93
  94                 if (!atomic_inc_not_zero(&clnt->cl_count)) {
  95                         seq_release(inode, filp);
  96                         ret = -EINVAL;
  97                 }
  98         }
  99
 100         return ret;
 101 }
 102
 103 static int
 104 tasks_release(struct inode *inode, struct file *filp)
 105 {
 106         struct seq_file *seq = filp->private_data;
 107         struct rpc_clnt *clnt = seq->private;
 108
 109         rpc_release_client(clnt);
 110         return seq_release(inode, filp);
 111 }
 112
 113 static const struct file_operations tasks_fops = {
 114         .owner          = THIS_MODULE,
 115         .open           = tasks_open,
 116         .read           = seq_read,
 117         .llseek         = seq_lseek,
 118         .release        = tasks_release,
 119 };
 120
 121 void
 122 rpc_clnt_debugfs_register(struct rpc_clnt *clnt)
 123 {
 124         int len;
 125         char name[24]; /* enough for "../../rpc_xprt/ + 8 hex digits + NULL */
 126         struct rpc_xprt *xprt;
 127
 128         /* Already registered? */
 129         if (clnt->cl_debugfs || !rpc_clnt_dir)
 130                 return;
 131
 132         len = snprintf(name, sizeof(name), "%x", clnt->cl_clid);
 133         if (len >= sizeof(name))
 134                 return;
 135
 136         /* make the per-client dir */
 137         clnt->cl_debugfs = debugfs_create_dir(name, rpc_clnt_dir);
 138         if (!clnt->cl_debugfs)
 139                 return;
 140
 141         /* make tasks file */
 142         if (!debugfs_create_file("tasks", S_IFREG | 0400, clnt->cl_debugfs,
 143                                  clnt, &tasks_fops))
 144                 goto out_err;
 145
 146         rcu_read_lock();
 147         xprt = rcu_dereference(clnt->cl_xprt);
 148         /* no "debugfs" dentry? Don't bother with the symlink. */
 149         if (IS_ERR_OR_NULL(xprt->debugfs)) {
 150                 rcu_read_unlock();
 151                 return;
 152         }
 153         len = snprintf(name, sizeof(name), "../../rpc_xprt/%s",
 154                         xprt->debugfs->d_name.name);
 155         rcu_read_unlock();
 156
 157         if (len >= sizeof(name))
 158                 goto out_err;
 159
 160         if (!debugfs_create_symlink("xprt", clnt->cl_debugfs, name))
 161                 goto out_err;
 162
 163         return;
 164 out_err:
 165         debugfs_remove_recursive(clnt->cl_debugfs);
 166         clnt->cl_debugfs = NULL;
 167 }
 168
 169 void
 170 rpc_clnt_debugfs_unregister(struct rpc_clnt *clnt)
 171 {
 172         debugfs_remove_recursive(clnt->cl_debugfs);
 173         clnt->cl_debugfs = NULL;
 174 }
 175
 176 static int
 177 xprt_info_show(struct seq_file *f, void *v)
 178 {
 179         struct rpc_xprt *xprt = f->private;
 180
 181         seq_printf(f, "netid: %s\n", xprt->address_strings[RPC_DISPLAY_NETID]);
 182         seq_printf(f, "addr:  %s\n", xprt->address_strings[RPC_DISPLAY_ADDR]);
 183         seq_printf(f, "port:  %s\n", xprt->address_strings[RPC_DISPLAY_PORT]);
 184         seq_printf(f, "state: 0x%lx\n", xprt->state);
 185         return 0;
 186 }
 187
 188 static int
 189 xprt_info_open(struct inode *inode, struct file *filp)
 190 {
 191         int ret;
 192         struct rpc_xprt *xprt = inode->i_private;
 193
 194         ret = single_open(filp, xprt_info_show, xprt);
 195
 196         if (!ret) {
 197                 if (!xprt_get(xprt)) {
 198                         single_release(inode, filp);
 199                         ret = -EINVAL;
 200                 }
 201         }
 202         return ret;
 203 }
 204
 205 static int
 206 xprt_info_release(struct inode *inode, struct file *filp)
 207 {
 208         struct rpc_xprt *xprt = inode->i_private;
 209
 210         xprt_put(xprt);
 211         return single_release(inode, filp);
 212 }
 213
 214 static const struct file_operations xprt_info_fops = {
 215         .owner          = THIS_MODULE,
 216         .open           = xprt_info_open,
 217         .read           = seq_read,
 218         .llseek         = seq_lseek,
 219         .release        = xprt_info_release,
 220 };
 221
 222 void
 223 rpc_xprt_debugfs_register(struct rpc_xprt *xprt)
 224 {
 225         int len, id;
 226         static atomic_t cur_id;
 227         char            name[9]; /* 8 hex digits + NULL term */
 228
 229         if (!rpc_xprt_dir)
 230                 return;
 231
 232         id = (unsigned int)atomic_inc_return(&cur_id);
 233
 234         len = snprintf(name, sizeof(name), "%x", id);
 235         if (len >= sizeof(name))
 236                 return;
 237
 238         /* make the per-client dir */
 239         xprt->debugfs = debugfs_create_dir(name, rpc_xprt_dir);
 240         if (!xprt->debugfs)
 241                 return;
 242
 243         /* make tasks file */
 244         if (!debugfs_create_file("info", S_IFREG | 0400, xprt->debugfs,
 245                                  xprt, &xprt_info_fops)) {
 246                 debugfs_remove_recursive(xprt->debugfs);
 247                 xprt->debugfs = NULL;
 248         }
 249
 250         atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect);
 251 }
 252
 253 void
 254 rpc_xprt_debugfs_unregister(struct rpc_xprt *xprt)
 255 {
 256         debugfs_remove_recursive(xprt->debugfs);
 257         xprt->debugfs = NULL;
 258 }
 259
 260 static int
 261 fault_open(struct inode *inode, struct file *filp)
 262 {
 263         filp->private_data = kmalloc(128, GFP_KERNEL);
 264         if (!filp->private_data)
 265                 return -ENOMEM;
 266         return 0;
 267 }
 268
 269 static int
 270 fault_release(struct inode *inode, struct file *filp)
 271 {
 272         kfree(filp->private_data);
 273         return 0;
 274 }
 275
 276 static ssize_t
 277 fault_disconnect_read(struct file *filp, char __user *user_buf,
 278                       size_t len, loff_t *offset)
 279 {
 280         char *buffer = (char *)filp->private_data;
 281         size_t size;
 282
 283         size = sprintf(buffer, "%u\n", rpc_inject_disconnect);
 284         return simple_read_from_buffer(user_buf, len, offset, buffer, size);
 285 }
 286
 287 static ssize_t
 288 fault_disconnect_write(struct file *filp, const char __user *user_buf,
 289                        size_t len, loff_t *offset)
 290 {
 291         char buffer[16];
 292
 293         if (len >= sizeof(buffer))
 294                 len = sizeof(buffer) - 1;
 295         if (copy_from_user(buffer, user_buf, len))
 296                 return -EFAULT;
 297         buffer[len] = '\0';
 298         if (kstrtouint(buffer, 10, &rpc_inject_disconnect))
 299                 return -EINVAL;
 300         return len;
 301 }
 302
 303 static const struct file_operations fault_disconnect_fops = {
 304         .owner          = THIS_MODULE,
 305         .open           = fault_open,
 306         .read           = fault_disconnect_read,
 307         .write          = fault_disconnect_write,
 308         .release        = fault_release,
 309 };
 310
 311 static struct dentry *
 312 inject_fault_dir(struct dentry *topdir)
 313 {
 314         struct dentry *faultdir;
 315
 316         faultdir = debugfs_create_dir("inject_fault", topdir);
 317         if (!faultdir)
 318                 return NULL;
 319
 320         if (!debugfs_create_file("disconnect", S_IFREG | 0400, faultdir,
 321                                  NULL, &fault_disconnect_fops))
 322                 return NULL;
 323
 324         return faultdir;
 325 }
 326
 327 void __exit
 328 sunrpc_debugfs_exit(void)
 329 {
 330         debugfs_remove_recursive(topdir);
 331         topdir = NULL;
 332         rpc_fault_dir = NULL;
 333         rpc_clnt_dir = NULL;
 334         rpc_xprt_dir = NULL;
 335 }
 336
 337 void __init
 338 sunrpc_debugfs_init(void)
 339 {
 340         topdir = debugfs_create_dir("sunrpc", NULL);
 341         if (!topdir)
 342                 return;
 343
 344         rpc_fault_dir = inject_fault_dir(topdir);
 345         if (!rpc_fault_dir)
 346                 goto out_remove;
 347
 348         rpc_clnt_dir = debugfs_create_dir("rpc_clnt", topdir);
 349         if (!rpc_clnt_dir)
 350                 goto out_remove;
 351
 352         rpc_xprt_dir = debugfs_create_dir("rpc_xprt", topdir);
 353         if (!rpc_xprt_dir)
 354                 goto out_remove;
 355
 356         return;
 357 out_remove:
 358         debugfs_remove_recursive(topdir);
 359         topdir = NULL;
 360         rpc_fault_dir = NULL;
 361         rpc_clnt_dir = NULL;
 362 }