net/sunrpc/debugfs.c

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