Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ]
Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 /*
  2  * proc/fs/generic.c --- generic routines for the proc-fs
  3  *
  4  * This file contains generic proc-fs routines for handling
  5  * directories and files.
  6  * 
  7  * Copyright (C) 1991, 1992 Linus Torvalds.
  8  * Copyright (C) 1997 Theodore Ts'o
  9  */
 10 
 11 #include <linux/errno.h>
 12 #include <linux/time.h>
 13 #include <linux/proc_fs.h>
 14 #include <linux/stat.h>
 15 #include <linux/module.h>
 16 #include <linux/mount.h>
 17 #include <linux/smp_lock.h>
 18 #include <linux/init.h>
 19 #include <linux/idr.h>
 20 #include <linux/namei.h>
 21 #include <linux/bitops.h>
 22 #include <linux/spinlock.h>
 23 #include <linux/completion.h>
 24 #include <asm/uaccess.h>
 25 
 26 #include "internal.h"
 27 
 28 DEFINE_SPINLOCK(proc_subdir_lock);
 29 
 30 static int proc_match(int len, const char *name, struct proc_dir_entry *de)
 31 {
 32         if (de->namelen != len)
 33                 return 0;
 34         return !memcmp(name, de->name, len);
 35 }
 36 
 37 /* buffer size is one page but our output routines use some slack for overruns */
 38 #define PROC_BLOCK_SIZE (PAGE_SIZE - 1024)
 39 
 40 static ssize_t
 41 proc_file_read(struct file *file, char __user *buf, size_t nbytes,
 42                loff_t *ppos)
 43 {
 44         struct inode * inode = file->f_path.dentry->d_inode;
 45         char    *page;
 46         ssize_t retval=0;
 47         int     eof=0;
 48         ssize_t n, count;
 49         char    *start;
 50         struct proc_dir_entry * dp;
 51         unsigned long long pos;
 52 
 53         /*
 54          * Gaah, please just use "seq_file" instead. The legacy /proc
 55          * interfaces cut loff_t down to off_t for reads, and ignore
 56          * the offset entirely for writes..
 57          */
 58         pos = *ppos;
 59         if (pos > MAX_NON_LFS)
 60                 return 0;
 61         if (nbytes > MAX_NON_LFS - pos)
 62                 nbytes = MAX_NON_LFS - pos;
 63 
 64         dp = PDE(inode);
 65         if (!(page = (char*) __get_free_page(GFP_TEMPORARY)))
 66                 return -ENOMEM;
 67 
 68         while ((nbytes > 0) && !eof) {
 69                 count = min_t(size_t, PROC_BLOCK_SIZE, nbytes);
 70 
 71                 start = NULL;
 72                 if (dp->get_info) {
 73                         /* Handle old net routines */
 74                         n = dp->get_info(page, &start, *ppos, count);
 75                         if (n < count)
 76                                 eof = 1;
 77                 } else if (dp->read_proc) {
 78                         /*
 79                          * How to be a proc read function
 80                          * ------------------------------
 81                          * Prototype:
 82                          *    int f(char *buffer, char **start, off_t offset,
 83                          *          int count, int *peof, void *dat)
 84                          *
 85                          * Assume that the buffer is "count" bytes in size.
 86                          *
 87                          * If you know you have supplied all the data you
 88                          * have, set *peof.
 89                          *
 90                          * You have three ways to return data:
 91                          * 0) Leave *start = NULL.  (This is the default.)
 92                          *    Put the data of the requested offset at that
 93                          *    offset within the buffer.  Return the number (n)
 94                          *    of bytes there are from the beginning of the
 95                          *    buffer up to the last byte of data.  If the
 96                          *    number of supplied bytes (= n - offset) is 
 97                          *    greater than zero and you didn't signal eof
 98                          *    and the reader is prepared to take more data
 99                          *    you will be called again with the requested
100                          *    offset advanced by the number of bytes 
101                          *    absorbed.  This interface is useful for files
102                          *    no larger than the buffer.
103                          * 1) Set *start = an unsigned long value less than
104                          *    the buffer address but greater than zero.
105                          *    Put the data of the requested offset at the
106                          *    beginning of the buffer.  Return the number of
107                          *    bytes of data placed there.  If this number is
108                          *    greater than zero and you didn't signal eof
109                          *    and the reader is prepared to take more data
110                          *    you will be called again with the requested
111                          *    offset advanced by *start.  This interface is
112                          *    useful when you have a large file consisting
113                          *    of a series of blocks which you want to count
114                          *    and return as wholes.
115                          *    (Hack by Paul.Russell@rustcorp.com.au)
116                          * 2) Set *start = an address within the buffer.
117                          *    Put the data of the requested offset at *start.
118                          *    Return the number of bytes of data placed there.
119                          *    If this number is greater than zero and you
120                          *    didn't signal eof and the reader is prepared to
121                          *    take more data you will be called again with the
122                          *    requested offset advanced by the number of bytes
123                          *    absorbed.
124                          */
125                         n = dp->read_proc(page, &start, *ppos,
126                                           count, &eof, dp->data);
127                 } else
128                         break;
129 
130                 if (n == 0)   /* end of file */
131                         break;
132                 if (n < 0) {  /* error */
133                         if (retval == 0)
134                                 retval = n;
135                         break;
136                 }
137 
138                 if (start == NULL) {
139                         if (n > PAGE_SIZE) {
140                                 printk(KERN_ERR
141                                        "proc_file_read: Apparent buffer overflow!\n");
142                                 n = PAGE_SIZE;
143                         }
144                         n -= *ppos;
145                         if (n <= 0)
146                                 break;
147                         if (n > count)
148                                 n = count;
149                         start = page + *ppos;
150                 } else if (start < page) {
151                         if (n > PAGE_SIZE) {
152                                 printk(KERN_ERR
153                                        "proc_file_read: Apparent buffer overflow!\n");
154                                 n = PAGE_SIZE;
155                         }
156                         if (n > count) {
157                                 /*
158                                  * Don't reduce n because doing so might
159                                  * cut off part of a data block.
160                                  */
161                                 printk(KERN_WARNING
162                                        "proc_file_read: Read count exceeded\n");
163                         }
164                 } else /* start >= page */ {
165                         unsigned long startoff = (unsigned long)(start - page);
166                         if (n > (PAGE_SIZE - startoff)) {
167                                 printk(KERN_ERR
168                                        "proc_file_read: Apparent buffer overflow!\n");
169                                 n = PAGE_SIZE - startoff;
170                         }
171                         if (n > count)
172                                 n = count;
173                 }
174                 
175                 n -= copy_to_user(buf, start < page ? page : start, n);
176                 if (n == 0) {
177                         if (retval == 0)
178                                 retval = -EFAULT;
179                         break;
180                 }
181 
182                 *ppos += start < page ? (unsigned long)start : n;
183                 nbytes -= n;
184                 buf += n;
185                 retval += n;
186         }
187         free_page((unsigned long) page);
188         return retval;
189 }
190 
191 static ssize_t
192 proc_file_write(struct file *file, const char __user *buffer,
193                 size_t count, loff_t *ppos)
194 {
195         struct inode *inode = file->f_path.dentry->d_inode;
196         struct proc_dir_entry * dp;
197         
198         dp = PDE(inode);
199 
200         if (!dp->write_proc)
201                 return -EIO;
202 
203         /* FIXME: does this routine need ppos?  probably... */
204         return dp->write_proc(file, buffer, count, dp->data);
205 }
206 
207 
208 static loff_t
209 proc_file_lseek(struct file *file, loff_t offset, int orig)
210 {
211         loff_t retval = -EINVAL;
212         switch (orig) {
213         case 1:
214                 offset += file->f_pos;
215         /* fallthrough */
216         case 0:
217                 if (offset < 0 || offset > MAX_NON_LFS)
218                         break;
219                 file->f_pos = retval = offset;
220         }
221         return retval;
222 }
223 
224 static const struct file_operations proc_file_operations = {
225         .llseek         = proc_file_lseek,
226         .read           = proc_file_read,
227         .write          = proc_file_write,
228 };
229 
230 static int proc_notify_change(struct dentry *dentry, struct iattr *iattr)
231 {
232         struct inode *inode = dentry->d_inode;
233         struct proc_dir_entry *de = PDE(inode);
234         int error;
235 
236         error = inode_change_ok(inode, iattr);
237         if (error)
238                 goto out;
239 
240         error = inode_setattr(inode, iattr);
241         if (error)
242                 goto out;
243         
244         de->uid = inode->i_uid;
245         de->gid = inode->i_gid;
246         de->mode = inode->i_mode;
247 out:
248         return error;
249 }
250 
251 static int proc_getattr(struct vfsmount *mnt, struct dentry *dentry,
252                         struct kstat *stat)
253 {
254         struct inode *inode = dentry->d_inode;
255         struct proc_dir_entry *de = PROC_I(inode)->pde;
256         if (de && de->nlink)
257                 inode->i_nlink = de->nlink;
258 
259         generic_fillattr(inode, stat);
260         return 0;
261 }
262 
263 static const struct inode_operations proc_file_inode_operations = {
264         .setattr        = proc_notify_change,
265 };
266 
267 /*
268  * This function parses a name such as "tty/driver/serial", and
269  * returns the struct proc_dir_entry for "/proc/tty/driver", and
270  * returns "serial" in residual.
271  */
272 static int xlate_proc_name(const char *name,
273                            struct proc_dir_entry **ret, const char **residual)
274 {
275         const char              *cp = name, *next;
276         struct proc_dir_entry   *de;
277         int                     len;
278         int                     rtn = 0;
279 
280         spin_lock(&proc_subdir_lock);
281         de = &proc_root;
282         while (1) {
283                 next = strchr(cp, '/');
284                 if (!next)
285                         break;
286 
287                 len = next - cp;
288                 for (de = de->subdir; de ; de = de->next) {
289                         if (proc_match(len, cp, de))
290                                 break;
291                 }
292                 if (!de) {
293                         rtn = -ENOENT;
294                         goto out;
295                 }
296                 cp += len + 1;
297         }
298         *residual = cp;
299         *ret = de;
300 out:
301         spin_unlock(&proc_subdir_lock);
302         return rtn;
303 }
304 
305 static DEFINE_IDR(proc_inum_idr);
306 static DEFINE_SPINLOCK(proc_inum_lock); /* protects the above */
307 
308 #define PROC_DYNAMIC_FIRST 0xF0000000UL
309 
310 /*
311  * Return an inode number between PROC_DYNAMIC_FIRST and
312  * 0xffffffff, or zero on failure.
313  */
314 static unsigned int get_inode_number(void)
315 {
316         int i, inum = 0;
317         int error;
318 
319 retry:
320         if (idr_pre_get(&proc_inum_idr, GFP_KERNEL) == 0)
321                 return 0;
322 
323         spin_lock(&proc_inum_lock);
324         error = idr_get_new(&proc_inum_idr, NULL, &i);
325         spin_unlock(&proc_inum_lock);
326         if (error == -EAGAIN)
327                 goto retry;
328         else if (error)
329                 return 0;
330 
331         inum = (i & MAX_ID_MASK) + PROC_DYNAMIC_FIRST;
332 
333         /* inum will never be more than 0xf0ffffff, so no check
334          * for overflow.
335          */
336 
337         return inum;
338 }
339 
340 static void release_inode_number(unsigned int inum)
341 {
342         int id = (inum - PROC_DYNAMIC_FIRST) | ~MAX_ID_MASK;
343 
344         spin_lock(&proc_inum_lock);
345         idr_remove(&proc_inum_idr, id);
346         spin_unlock(&proc_inum_lock);
347 }
348 
349 static void *proc_follow_link(struct dentry *dentry, struct nameidata *nd)
350 {
351         nd_set_link(nd, PDE(dentry->d_inode)->data);
352         return NULL;
353 }
354 
355 static const struct inode_operations proc_link_inode_operations = {
356         .readlink       = generic_readlink,
357         .follow_link    = proc_follow_link,
358 };
359 
360 /*
361  * As some entries in /proc are volatile, we want to 
362  * get rid of unused dentries.  This could be made 
363  * smarter: we could keep a "volatile" flag in the 
364  * inode to indicate which ones to keep.
365  */
366 static int proc_delete_dentry(struct dentry * dentry)
367 {
368         return 1;
369 }
370 
371 static struct dentry_operations proc_dentry_operations =
372 {
373         .d_delete       = proc_delete_dentry,
374 };
375 
376 /*
377  * Don't create negative dentries here, return -ENOENT by hand
378  * instead.
379  */
380 struct dentry *proc_lookup_de(struct proc_dir_entry *de, struct inode *dir,
381                 struct dentry *dentry)
382 {
383         struct inode *inode = NULL;
384         int error = -ENOENT;
385 
386         lock_kernel();
387         spin_lock(&proc_subdir_lock);
388         if (de) {
389                 for (de = de->subdir; de ; de = de->next) {
390                         if (de->namelen != dentry->d_name.len)
391                                 continue;
392                         if (!memcmp(dentry->d_name.name, de->name, de->namelen)) {
393                                 unsigned int ino;
394 
395                                 ino = de->low_ino;
396                                 de_get(de);
397                                 spin_unlock(&proc_subdir_lock);
398                                 error = -EINVAL;
399                                 inode = proc_get_inode(dir->i_sb, ino, de);
400                                 goto out_unlock;
401                         }
402                 }
403         }
404         spin_unlock(&proc_subdir_lock);
405 out_unlock:
406         unlock_kernel();
407 
408         if (inode) {
409                 dentry->d_op = &proc_dentry_operations;
410                 d_add(dentry, inode);
411                 return NULL;
412         }
413         de_put(de);
414         return ERR_PTR(error);
415 }
416 
417 struct dentry *proc_lookup(struct inode *dir, struct dentry *dentry,
418                 struct nameidata *nd)
419 {
420         return proc_lookup_de(PDE(dir), dir, dentry);
421 }
422 
423 /*
424  * This returns non-zero if at EOF, so that the /proc
425  * root directory can use this and check if it should
426  * continue with the <pid> entries..
427  *
428  * Note that the VFS-layer doesn't care about the return
429  * value of the readdir() call, as long as it's non-negative
430  * for success..
431  */
432 int proc_readdir_de(struct proc_dir_entry *de, struct file *filp, void *dirent,
433                 filldir_t filldir)
434 {
435         unsigned int ino;
436         int i;
437         struct inode *inode = filp->f_path.dentry->d_inode;
438         int ret = 0;
439 
440         lock_kernel();
441 
442         ino = inode->i_ino;
443         if (!de) {
444                 ret = -EINVAL;
445                 goto out;
446         }
447         i = filp->f_pos;
448         switch (i) {
449                 case 0:
450                         if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
451                                 goto out;
452                         i++;
453                         filp->f_pos++;
454                         /* fall through */
455                 case 1:
456                         if (filldir(dirent, "..", 2, i,
457                                     parent_ino(filp->f_path.dentry),
458                                     DT_DIR) < 0)
459                                 goto out;
460                         i++;
461                         filp->f_pos++;
462                         /* fall through */
463                 default:
464                         spin_lock(&proc_subdir_lock);
465                         de = de->subdir;
466                         i -= 2;
467                         for (;;) {
468                                 if (!de) {
469                                         ret = 1;
470                                         spin_unlock(&proc_subdir_lock);
471                                         goto out;
472                                 }
473                                 if (!i)
474                                         break;
475                                 de = de->next;
476                                 i--;
477                         }
478 
479                         do {
480                                 struct proc_dir_entry *next;
481 
482                                 /* filldir passes info to user space */
483                                 de_get(de);
484                                 spin_unlock(&proc_subdir_lock);
485                                 if (filldir(dirent, de->name, de->namelen, filp->f_pos,
486                                             de->low_ino, de->mode >> 12) < 0) {
487                                         de_put(de);
488                                         goto out;
489                                 }
490                                 spin_lock(&proc_subdir_lock);
491                                 filp->f_pos++;
492                                 next = de->next;
493                                 de_put(de);
494                                 de = next;
495                         } while (de);
496                         spin_unlock(&proc_subdir_lock);
497         }
498         ret = 1;
499 out:    unlock_kernel();
500         return ret;     
501 }
502 
503 int proc_readdir(struct file *filp, void *dirent, filldir_t filldir)
504 {
505         struct inode *inode = filp->f_path.dentry->d_inode;
506 
507         return proc_readdir_de(PDE(inode), filp, dirent, filldir);
508 }
509 
510 /*
511  * These are the generic /proc directory operations. They
512  * use the in-memory "struct proc_dir_entry" tree to parse
513  * the /proc directory.
514  */
515 static const struct file_operations proc_dir_operations = {
516         .read                   = generic_read_dir,
517         .readdir                = proc_readdir,
518 };
519 
520 /*
521  * proc directories can do almost nothing..
522  */
523 static const struct inode_operations proc_dir_inode_operations = {
524         .lookup         = proc_lookup,
525         .getattr        = proc_getattr,
526         .setattr        = proc_notify_change,
527 };
528 
529 static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp)
530 {
531         unsigned int i;
532         struct proc_dir_entry *tmp;
533         
534         i = get_inode_number();
535         if (i == 0)
536                 return -EAGAIN;
537         dp->low_ino = i;
538 
539         if (S_ISDIR(dp->mode)) {
540                 if (dp->proc_iops == NULL) {
541                         dp->proc_fops = &proc_dir_operations;
542                         dp->proc_iops = &proc_dir_inode_operations;
543                 }
544                 dir->nlink++;
545         } else if (S_ISLNK(dp->mode)) {
546                 if (dp->proc_iops == NULL)
547                         dp->proc_iops = &proc_link_inode_operations;
548         } else if (S_ISREG(dp->mode)) {
549                 if (dp->proc_fops == NULL)
550                         dp->proc_fops = &proc_file_operations;
551                 if (dp->proc_iops == NULL)
552                         dp->proc_iops = &proc_file_inode_operations;
553         }
554 
555         spin_lock(&proc_subdir_lock);
556 
557         for (tmp = dir->subdir; tmp; tmp = tmp->next)
558                 if (strcmp(tmp->name, dp->name) == 0) {
559                         printk(KERN_WARNING "proc_dir_entry '%s' already "
560                                         "registered\n", dp->name);
561                         dump_stack();
562                         break;
563                 }
564 
565         dp->next = dir->subdir;
566         dp->parent = dir;
567         dir->subdir = dp;
568         spin_unlock(&proc_subdir_lock);
569 
570         return 0;
571 }
572 
573 static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent,
574                                           const char *name,
575                                           mode_t mode,
576                                           nlink_t nlink)
577 {
578         struct proc_dir_entry *ent = NULL;
579         const char *fn = name;
580         int len;
581 
582         /* make sure name is valid */
583         if (!name || !strlen(name)) goto out;
584 
585         if (!(*parent) && xlate_proc_name(name, parent, &fn) != 0)
586                 goto out;
587 
588         /* At this point there must not be any '/' characters beyond *fn */
589         if (strchr(fn, '/'))
590                 goto out;
591 
592         len = strlen(fn);
593 
594         ent = kmalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL);
595         if (!ent) goto out;
596 
597         memset(ent, 0, sizeof(struct proc_dir_entry));
598         memcpy(((char *) ent) + sizeof(struct proc_dir_entry), fn, len + 1);
599         ent->name = ((char *) ent) + sizeof(*ent);
600         ent->namelen = len;
601         ent->mode = mode;
602         ent->nlink = nlink;
603         atomic_set(&ent->count, 1);
604         ent->pde_users = 0;
605         spin_lock_init(&ent->pde_unload_lock);
606         ent->pde_unload_completion = NULL;
607  out:
608         return ent;
609 }
610 
611 struct proc_dir_entry *proc_symlink(const char *name,
612                 struct proc_dir_entry *parent, const char *dest)
613 {
614         struct proc_dir_entry *ent;
615 
616         ent = __proc_create(&parent, name,
617                           (S_IFLNK | S_IRUGO | S_IWUGO | S_IXUGO),1);
618 
619         if (ent) {
620                 ent->data = kmalloc((ent->size=strlen(dest))+1, GFP_KERNEL);
621                 if (ent->data) {
622                         strcpy((char*)ent->data,dest);
623                         if (proc_register(parent, ent) < 0) {
624                                 kfree(ent->data);
625                                 kfree(ent);
626                                 ent = NULL;
627                         }
628                 } else {
629                         kfree(ent);
630                         ent = NULL;
631                 }
632         }
633         return ent;
634 }
635 
636 struct proc_dir_entry *proc_mkdir_mode(const char *name, mode_t mode,
637                 struct proc_dir_entry *parent)
638 {
639         struct proc_dir_entry *ent;
640 
641         ent = __proc_create(&parent, name, S_IFDIR | mode, 2);
642         if (ent) {
643                 if (proc_register(parent, ent) < 0) {
644                         kfree(ent);
645                         ent = NULL;
646                 }
647         }
648         return ent;
649 }
650 
651 struct proc_dir_entry *proc_mkdir(const char *name,
652                 struct proc_dir_entry *parent)
653 {
654         return proc_mkdir_mode(name, S_IRUGO | S_IXUGO, parent);
655 }
656 
657 struct proc_dir_entry *create_proc_entry(const char *name, mode_t mode,
658                                          struct proc_dir_entry *parent)
659 {
660         struct proc_dir_entry *ent;
661         nlink_t nlink;
662 
663         if (S_ISDIR(mode)) {
664                 if ((mode & S_IALLUGO) == 0)
665                         mode |= S_IRUGO | S_IXUGO;
666                 nlink = 2;
667         } else {
668                 if ((mode & S_IFMT) == 0)
669                         mode |= S_IFREG;
670                 if ((mode & S_IALLUGO) == 0)
671                         mode |= S_IRUGO;
672                 nlink = 1;
673         }
674 
675         ent = __proc_create(&parent, name, mode, nlink);
676         if (ent) {
677                 if (proc_register(parent, ent) < 0) {
678                         kfree(ent);
679                         ent = NULL;
680                 }
681         }
682         return ent;
683 }
684 
685 struct proc_dir_entry *proc_create(const char *name, mode_t mode,
686                                    struct proc_dir_entry *parent,
687                                    const struct file_operations *proc_fops)
688 {
689         struct proc_dir_entry *pde;
690         nlink_t nlink;
691 
692         if (S_ISDIR(mode)) {
693                 if ((mode & S_IALLUGO) == 0)
694                         mode |= S_IRUGO | S_IXUGO;
695                 nlink = 2;
696         } else {
697                 if ((mode & S_IFMT) == 0)
698                         mode |= S_IFREG;
699                 if ((mode & S_IALLUGO) == 0)
700                         mode |= S_IRUGO;
701                 nlink = 1;
702         }
703 
704         pde = __proc_create(&parent, name, mode, nlink);
705         if (!pde)
706                 goto out;
707         pde->proc_fops = proc_fops;
708         if (proc_register(parent, pde) < 0)
709                 goto out_free;
710         return pde;
711 out_free:
712         kfree(pde);
713 out:
714         return NULL;
715 }
716 
717 void free_proc_entry(struct proc_dir_entry *de)
718 {
719         unsigned int ino = de->low_ino;
720 
721         if (ino < PROC_DYNAMIC_FIRST)
722                 return;
723 
724         release_inode_number(ino);
725 
726         if (S_ISLNK(de->mode))
727                 kfree(de->data);
728         kfree(de);
729 }
730 
731 /*
732  * Remove a /proc entry and free it if it's not currently in use.
733  */
734 void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
735 {
736         struct proc_dir_entry **p;
737         struct proc_dir_entry *de;
738         const char *fn = name;
739         int len;
740 
741         if (!parent && xlate_proc_name(name, &parent, &fn) != 0)
742                 goto out;
743         len = strlen(fn);
744 
745         spin_lock(&proc_subdir_lock);
746         for (p = &parent->subdir; *p; p=&(*p)->next ) {
747                 if (!proc_match(len, fn, *p))
748                         continue;
749                 de = *p;
750                 *p = de->next;
751                 de->next = NULL;
752 
753                 spin_lock(&de->pde_unload_lock);
754                 /*
755                  * Stop accepting new callers into module. If you're
756                  * dynamically allocating ->proc_fops, save a pointer somewhere.
757                  */
758                 de->proc_fops = NULL;
759                 /* Wait until all existing callers into module are done. */
760                 if (de->pde_users > 0) {
761                         DECLARE_COMPLETION_ONSTACK(c);
762 
763                         if (!de->pde_unload_completion)
764                                 de->pde_unload_completion = &c;
765 
766                         spin_unlock(&de->pde_unload_lock);
767                         spin_unlock(&proc_subdir_lock);
768 
769                         wait_for_completion(de->pde_unload_completion);
770 
771                         spin_lock(&proc_subdir_lock);
772                         goto continue_removing;
773                 }
774                 spin_unlock(&de->pde_unload_lock);
775 
776 continue_removing:
777                 if (S_ISDIR(de->mode))
778                         parent->nlink--;
779                 de->nlink = 0;
780                 WARN_ON(de->subdir);
781                 if (atomic_dec_and_test(&de->count))
782                         free_proc_entry(de);
783                 break;
784         }
785         spin_unlock(&proc_subdir_lock);
786 out:
787         return;
788 }
789 
  This page was automatically generated by the LXR engine.