1 /* devfs (Device FileSystem) driver.
3 Copyright (C) 1998-2002 Richard Gooch
5 This library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Library General Public
7 License as published by the Free Software Foundation; either
8 version 2 of the License, or (at your option) any later version.
10 This library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Library General Public License for more details.
15 You should have received a copy of the GNU Library General Public
16 License along with this library; if not, write to the Free
17 Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 Richard Gooch may be reached by email at rgooch@atnf.csiro.au
20 The postal address is:
21 Richard Gooch, c/o ATNF, P. O. Box 76, Epping, N.S.W., 2121, Australia.
25 19980110 Richard Gooch <rgooch@atnf.csiro.au>
28 19980111 Richard Gooch <rgooch@atnf.csiro.au>
29 Created per-fs inode table rather than using inode->u.generic_ip
31 19980111 Richard Gooch <rgooch@atnf.csiro.au>
32 Created .epoch inode which has a ctime of 0.
33 Fixed loss of named pipes when dentries lost.
34 Fixed loss of inode data when devfs_register() follows mknod().
36 19980111 Richard Gooch <rgooch@atnf.csiro.au>
37 Fix for when compiling with CONFIG_KERNELD.
38 19980112 Richard Gooch <rgooch@atnf.csiro.au>
39 Fix for readdir() which sometimes didn't show entries.
40 Added <<tolerant>> option to <devfs_register>.
42 19980113 Richard Gooch <rgooch@atnf.csiro.au>
43 Created <devfs_fill_file> function.
45 19980115 Richard Gooch <rgooch@atnf.csiro.au>
46 Added subdirectory support. Major restructuring.
47 19980116 Richard Gooch <rgooch@atnf.csiro.au>
48 Fixed <find_by_dev> to not search major=0,minor=0.
49 Added symlink support.
51 19980120 Richard Gooch <rgooch@atnf.csiro.au>
52 Created <devfs_mk_dir> function and support directory unregister
53 19980120 Richard Gooch <rgooch@atnf.csiro.au>
54 Auto-ownership uses real uid/gid rather than effective uid/gid.
56 19980121 Richard Gooch <rgooch@atnf.csiro.au>
57 Supported creation of sockets.
59 19980122 Richard Gooch <rgooch@atnf.csiro.au>
60 Added DEVFS_FL_HIDE_UNREG flag.
61 Interface change to <devfs_mk_symlink>.
62 Created <devfs_symlink> to support symlink(2).
64 19980123 Richard Gooch <rgooch@atnf.csiro.au>
65 Added check to <devfs_fill_file> to check inode is in devfs.
66 Added optional traversal of symlinks.
68 19980124 Richard Gooch <rgooch@atnf.csiro.au>
69 Created <devfs_get_flags> and <devfs_set_flags>.
71 19980125 C. Scott Ananian <cananian@alumni.princeton.edu>
72 Created <devfs_find_handle>.
73 19980125 Richard Gooch <rgooch@atnf.csiro.au>
74 Allow removal of symlinks.
76 19980125 Richard Gooch <rgooch@atnf.csiro.au>
77 Created <devfs_set_symlink_destination>.
78 19980126 Richard Gooch <rgooch@atnf.csiro.au>
79 Moved DEVFS_SUPER_MAGIC into header file.
80 Added DEVFS_FL_HIDE flag.
81 Created <devfs_get_maj_min>.
82 Created <devfs_get_handle_from_inode>.
83 Fixed minor bug in <find_by_dev>.
84 19980127 Richard Gooch <rgooch@atnf.csiro.au>
85 Changed interface to <find_by_dev>, <find_entry>,
86 <devfs_unregister>, <devfs_fill_file> and <devfs_find_handle>.
87 Fixed inode times when symlink created with symlink(2).
89 19980129 C. Scott Ananian <cananian@alumni.princeton.edu>
90 Exported <devfs_set_symlink_destination>, <devfs_get_maj_min>
91 and <devfs_get_handle_from_inode>.
92 19980129 Richard Gooch <rgooch@atnf.csiro.au>
93 Created <devfs_unlink> to support unlink(2).
95 19980129 Richard Gooch <rgooch@atnf.csiro.au>
96 Fixed kerneld support for entries in devfs subdirectories.
97 19980130 Richard Gooch <rgooch@atnf.csiro.au>
98 Bugfixes in <call_kerneld>.
100 19980207 Richard Gooch <rgooch@atnf.csiro.au>
101 Call kerneld when looking up unregistered entries.
103 19980326 Richard Gooch <rgooch@atnf.csiro.au>
104 Modified interface to <devfs_find_handle> for symlink traversal.
106 19980331 Richard Gooch <rgooch@atnf.csiro.au>
107 Fixed persistence bug with device numbers for manually created
109 Fixed problem with recreating symlinks with different content.
111 19980401 Richard Gooch <rgooch@atnf.csiro.au>
112 Changed to CONFIG_KMOD.
113 Hide entries which are manually unlinked.
114 Always invalidate devfs dentry cache when registering entries.
115 Created <devfs_rmdir> to support rmdir(2).
116 Ensure directories created by <devfs_mk_dir> are visible.
118 19980402 Richard Gooch <rgooch@atnf.csiro.au>
119 Invalidate devfs dentry cache when making directories.
120 Invalidate devfs dentry cache when removing entries.
121 Fixed persistence bug with fifos.
123 19980421 Richard Gooch <rgooch@atnf.csiro.au>
124 Print process command when debugging kerneld/kmod.
125 Added debugging for register/unregister/change operations.
126 19980422 Richard Gooch <rgooch@atnf.csiro.au>
127 Added "devfs=" boot options.
129 19980426 Richard Gooch <rgooch@atnf.csiro.au>
130 No longer lock/unlock superblock in <devfs_put_super>.
131 Drop negative dentries when they are released.
132 Manage dcache more efficiently.
134 19980427 Richard Gooch <rgooch@atnf.csiro.au>
135 Added DEVFS_FL_AUTO_DEVNUM flag.
137 19980430 Richard Gooch <rgooch@atnf.csiro.au>
138 No longer set unnecessary methods.
140 19980504 Richard Gooch <rgooch@atnf.csiro.au>
141 Added PID display to <call_kerneld> debugging message.
142 Added "after" debugging message to <call_kerneld>.
143 19980519 Richard Gooch <rgooch@atnf.csiro.au>
144 Added "diread" and "diwrite" boot options.
145 19980520 Richard Gooch <rgooch@atnf.csiro.au>
146 Fixed persistence problem with permissions.
148 19980602 Richard Gooch <rgooch@atnf.csiro.au>
149 Support legacy device nodes.
150 Fixed bug where recreated inodes were hidden.
152 19980602 Richard Gooch <rgooch@atnf.csiro.au>
153 Improved debugging in <get_vfs_inode>.
154 19980607 Richard Gooch <rgooch@atnf.csiro.au>
155 No longer free old dentries in <devfs_mk_dir>.
156 Free all dentries for a given entry when deleting inodes.
158 19980627 Richard Gooch <rgooch@atnf.csiro.au>
159 Limit auto-device numbering to majors 128 to 239.
161 19980629 Richard Gooch <rgooch@atnf.csiro.au>
162 Fixed inode times persistence problem.
164 19980704 Richard Gooch <rgooch@atnf.csiro.au>
165 Fixed spelling in <devfs_readlink> debug.
166 Fixed bug in <devfs_setup> parsing "dilookup".
168 19980705 Richard Gooch <rgooch@atnf.csiro.au>
169 Fixed devfs inode leak when manually recreating inodes.
170 Fixed permission persistence problem when recreating inodes.
172 19980727 Richard Gooch <rgooch@atnf.csiro.au>
173 Removed harmless "unused variable" compiler warning.
174 Fixed modes for manually recreated device nodes.
176 19980728 Richard Gooch <rgooch@atnf.csiro.au>
177 Added NULL devfs inode warning in <devfs_read_inode>.
178 Force all inode nlink values to 1.
180 19980730 Richard Gooch <rgooch@atnf.csiro.au>
181 Added "dimknod" boot option.
182 Set inode nlink to 0 when freeing dentries.
183 Fixed modes for manually recreated symlinks.
185 19980802 Richard Gooch <rgooch@atnf.csiro.au>
186 Fixed bugs in recreated directories and symlinks.
188 19980806 Richard Gooch <rgooch@atnf.csiro.au>
189 Fixed bugs in recreated device nodes.
190 19980807 Richard Gooch <rgooch@atnf.csiro.au>
191 Fixed bug in currently unused <devfs_get_handle_from_inode>.
192 Defined new <devfs_handle_t> type.
193 Improved debugging when getting entries.
194 Fixed bug where directories could be emptied.
196 19980809 Richard Gooch <rgooch@atnf.csiro.au>
197 Replaced dummy .epoch inode with .devfsd character device.
198 19980810 Richard Gooch <rgooch@atnf.csiro.au>
199 Implemented devfsd protocol revision 0.
201 19980819 Richard Gooch <rgooch@atnf.csiro.au>
202 Added soothing message to warning in <devfs_d_iput>.
204 19980829 Richard Gooch <rgooch@atnf.csiro.au>
205 Use GCC extensions for structure initialisations.
206 Implemented async open notification.
207 Incremented devfsd protocol revision to 1.
209 19980908 Richard Gooch <rgooch@atnf.csiro.au>
210 Moved async open notification to end of <devfs_open>.
212 19980910 Richard Gooch <rgooch@atnf.csiro.au>
213 Prepended "/dev/" to module load request.
214 Renamed <call_kerneld> to <call_kmod>.
216 19980910 Richard Gooch <rgooch@atnf.csiro.au>
217 Fixed typo "AYSNC" -> "ASYNC".
219 19980910 Richard Gooch <rgooch@atnf.csiro.au>
220 Added open flag for files.
222 19980927 Richard Gooch <rgooch@atnf.csiro.au>
223 Set i_blocks=0 and i_blksize=1024 in <devfs_read_inode>.
225 19981005 Richard Gooch <rgooch@atnf.csiro.au>
226 Added test for empty <<name>> in <devfs_find_handle>.
227 Renamed <generate_path> to <devfs_generate_path> and published.
229 19981006 Richard Gooch <rgooch@atnf.csiro.au>
230 Created <devfs_get_fops>.
232 19981007 Richard Gooch <rgooch@atnf.csiro.au>
233 Limit auto-device numbering to majors 144 to 239.
235 19981010 Richard Gooch <rgooch@atnf.csiro.au>
236 Updated <devfs_follow_link> for VFS change in 2.1.125.
238 19981022 Richard Gooch <rgooch@atnf.csiro.au>
239 Created DEVFS_ FL_COMPAT flag.
241 19981023 Richard Gooch <rgooch@atnf.csiro.au>
242 Created "nocompat" boot option.
244 19981025 Richard Gooch <rgooch@atnf.csiro.au>
245 Replaced "mount" boot option with "nomount".
247 19981110 Richard Gooch <rgooch@atnf.csiro.au>
248 Created "only" boot option.
250 19981112 Richard Gooch <rgooch@atnf.csiro.au>
251 Added DEVFS_FL_REMOVABLE flag.
253 19981114 Richard Gooch <rgooch@atnf.csiro.au>
254 Only call <scan_dir_for_removable> on first call to
257 19981205 Richard Gooch <rgooch@atnf.csiro.au>
258 Updated <devfs_rmdir> for VFS change in 2.1.131.
260 19981218 Richard Gooch <rgooch@atnf.csiro.au>
261 Created <devfs_mk_compat>.
262 19981220 Richard Gooch <rgooch@atnf.csiro.au>
263 Check for partitions on removable media in <devfs_lookup>.
265 19990118 Richard Gooch <rgooch@atnf.csiro.au>
266 Added support for registering regular files.
267 Created <devfs_set_file_size>.
268 Update devfs inodes from entries if not changed through FS.
270 19990124 Richard Gooch <rgooch@atnf.csiro.au>
271 Fixed <devfs_fill_file> to only initialise temporary inodes.
272 Trap for NULL fops in <devfs_register>.
273 Return -ENODEV in <devfs_fill_file> for non-driver inodes.
275 19990126 Richard Gooch <rgooch@atnf.csiro.au>
276 Switched from PATH_MAX to DEVFS_PATHLEN.
278 19990127 Richard Gooch <rgooch@atnf.csiro.au>
279 Created "nottycompat" boot option.
281 19990318 Richard Gooch <rgooch@atnf.csiro.au>
282 Fixed <devfsd_read> to not overrun event buffer.
284 19990329 Richard Gooch <rgooch@atnf.csiro.au>
285 Created <devfs_auto_unregister>.
287 19990330 Richard Gooch <rgooch@atnf.csiro.au>
288 Don't return unregistred entries in <devfs_find_handle>.
289 Panic in <devfs_unregister> if entry unregistered.
290 19990401 Richard Gooch <rgooch@atnf.csiro.au>
291 Don't panic in <devfs_auto_unregister> for duplicates.
293 19990402 Richard Gooch <rgooch@atnf.csiro.au>
294 Don't unregister already unregistered entries in <unregister>.
296 19990510 Richard Gooch <rgooch@atnf.csiro.au>
297 Disable warning messages when unable to read partition table for
300 19990512 Richard Gooch <rgooch@atnf.csiro.au>
301 Updated <devfs_lookup> for VFS change in 2.3.1-pre1.
302 Created "oops-on-panic" boot option.
303 Improved debugging in <devfs_register> and <devfs_unregister>.
305 19990519 Richard Gooch <rgooch@atnf.csiro.au>
306 Added documentation for some functions.
307 19990525 Richard Gooch <rgooch@atnf.csiro.au>
308 Removed "oops-on-panic" boot option: now always Oops.
310 19990531 Richard Gooch <rgooch@atnf.csiro.au>
311 Improved debugging in <devfs_register>.
313 19990604 Richard Gooch <rgooch@atnf.csiro.au>
314 Added "diunlink" and "nokmod" boot options.
315 Removed superfluous warning message in <devfs_d_iput>.
317 19990611 Richard Gooch <rgooch@atnf.csiro.au>
318 Took account of change to <d_alloc_root>.
320 19990614 Richard Gooch <rgooch@atnf.csiro.au>
321 Created separate event queue for each mounted devfs.
322 Removed <devfs_invalidate_dcache>.
323 Created new ioctl()s.
324 Incremented devfsd protocol revision to 3.
325 Fixed bug when re-creating directories: contents were lost.
326 Block access to inodes until devfsd updates permissions.
327 19990615 Richard Gooch <rgooch@atnf.csiro.au>
328 Support 2.2.x kernels.
330 19990623 Richard Gooch <rgooch@atnf.csiro.au>
331 Switched to sending process uid/gid to devfsd.
332 Renamed <call_kmod> to <try_modload>.
333 Added DEVFSD_NOTIFY_LOOKUP event.
334 19990624 Richard Gooch <rgooch@atnf.csiro.au>
335 Added DEVFSD_NOTIFY_CHANGE event.
336 Incremented devfsd protocol revision to 4.
338 19990713 Richard Gooch <rgooch@atnf.csiro.au>
339 Return EISDIR rather than EINVAL for read(2) on directories.
341 19990809 Richard Gooch <rgooch@atnf.csiro.au>
342 Changed <devfs_setup> to new __init scheme.
344 19990901 Richard Gooch <rgooch@atnf.csiro.au>
345 Changed remaining function declarations to new __init scheme.
347 19991013 Richard Gooch <rgooch@atnf.csiro.au>
348 Created <devfs_get_info>, <devfs_set_info>,
349 <devfs_get_first_child> and <devfs_get_next_sibling>.
350 Added <<dir>> parameter to <devfs_register>, <devfs_mk_compat>,
351 <devfs_mk_dir> and <devfs_find_handle>.
352 Work sponsored by SGI.
354 19991017 Richard Gooch <rgooch@atnf.csiro.au>
355 Allow multiple unregistrations.
356 Work sponsored by SGI.
358 19991026 Richard Gooch <rgooch@atnf.csiro.au>
359 Added major and minor number to devfsd protocol.
360 Incremented devfsd protocol revision to 5.
361 Work sponsored by SGI.
363 19991030 Richard Gooch <rgooch@atnf.csiro.au>
364 Support info pointer for all devfs entry types.
365 Added <<info>> parameter to <devfs_mk_dir> and
367 Work sponsored by SGI.
369 19991031 Richard Gooch <rgooch@atnf.csiro.au>
370 Support "../" when searching devfs namespace.
371 Work sponsored by SGI.
373 19991101 Richard Gooch <rgooch@atnf.csiro.au>
374 Created <devfs_get_unregister_slave>.
375 Work sponsored by SGI.
377 19991103 Richard Gooch <rgooch@atnf.csiro.au>
378 Exported <devfs_get_parent>.
379 Work sponsored by SGI.
381 19991104 Richard Gooch <rgooch@atnf.csiro.au>
382 Removed unused <devfs_set_symlink_destination>.
383 19991105 Richard Gooch <rgooch@atnf.csiro.au>
384 Do not hide entries from devfsd or children.
385 Removed DEVFS_ FL_TTY_COMPAT flag.
386 Removed "nottycompat" boot option.
387 Removed <devfs_mk_compat>.
388 Work sponsored by SGI.
390 19991107 Richard Gooch <rgooch@atnf.csiro.au>
391 Added DEVFS_FL_WAIT flag.
392 Work sponsored by SGI.
394 19991107 Richard Gooch <rgooch@atnf.csiro.au>
395 Support new "disc" naming scheme in <get_removable_partition>.
396 Allow NULL fops in <devfs_register>.
397 Work sponsored by SGI.
399 19991110 Richard Gooch <rgooch@atnf.csiro.au>
400 Fall back to major table if NULL fops given to <devfs_register>.
401 Work sponsored by SGI.
403 19991204 Richard Gooch <rgooch@atnf.csiro.au>
404 Support fifos when unregistering.
405 Work sponsored by SGI.
407 19991209 Richard Gooch <rgooch@atnf.csiro.au>
408 Removed obsolete DEVFS_ FL_COMPAT and DEVFS_ FL_TOLERANT flags.
409 Work sponsored by SGI.
411 19991214 Richard Gooch <rgooch@atnf.csiro.au>
412 Removed kmod support.
413 Work sponsored by SGI.
415 19991216 Richard Gooch <rgooch@atnf.csiro.au>
416 Improved debugging in <get_vfs_inode>.
417 Ensure dentries created by devfsd will be cleaned up.
418 Work sponsored by SGI.
420 19991223 Richard Gooch <rgooch@atnf.csiro.au>
421 Created <devfs_get_name>.
422 Work sponsored by SGI.
424 20000203 Richard Gooch <rgooch@atnf.csiro.au>
425 Ported to kernel 2.3.42.
426 Removed <devfs_fill_file>.
427 Work sponsored by SGI.
429 20000306 Richard Gooch <rgooch@atnf.csiro.au>
430 Added DEVFS_ FL_NO_PERSISTENCE flag.
431 Removed unnecessary call to <update_devfs_inode_from_entry> in
433 Work sponsored by SGI.
435 20000413 Richard Gooch <rgooch@atnf.csiro.au>
436 Set inode->i_size to correct size for symlinks.
437 20000414 Richard Gooch <rgooch@atnf.csiro.au>
438 Only give lookup() method to directories to comply with new VFS
440 Work sponsored by SGI.
441 20000415 Richard Gooch <rgooch@atnf.csiro.au>
442 Remove unnecessary tests in symlink methods.
443 Don't kill existing block ops in <devfs_read_inode>.
444 Work sponsored by SGI.
446 20000424 Richard Gooch <rgooch@atnf.csiro.au>
447 Don't create missing directories in <devfs_find_handle>.
448 Work sponsored by SGI.
450 20000430 Richard Gooch <rgooch@atnf.csiro.au>
451 Added CONFIG_DEVFS_MOUNT.
452 Work sponsored by SGI.
454 20000608 Richard Gooch <rgooch@atnf.csiro.au>
455 Disabled multi-mount capability (use VFS bindings instead).
456 Work sponsored by SGI.
458 20000610 Richard Gooch <rgooch@atnf.csiro.au>
459 Switched to FS_SINGLE to disable multi-mounts.
460 20000612 Richard Gooch <rgooch@atnf.csiro.au>
461 Removed module support.
462 Removed multi-mount code.
463 Removed compatibility macros: VFS has changed too much.
464 Work sponsored by SGI.
466 20000614 Richard Gooch <rgooch@atnf.csiro.au>
467 Merged devfs inode into devfs entry.
468 Work sponsored by SGI.
470 20000619 Richard Gooch <rgooch@atnf.csiro.au>
471 Removed dead code in <devfs_register> which used to call
473 Work sponsored by SGI.
475 20000621 Richard Gooch <rgooch@atnf.csiro.au>
476 Changed interface to <devfs_register>.
477 Work sponsored by SGI.
479 20000622 Richard Gooch <rgooch@atnf.csiro.au>
480 Simplified interface to <devfs_mk_symlink> and <devfs_mk_dir>.
481 Simplified interface to <devfs_find_handle>.
482 Work sponsored by SGI.
484 20010519 Richard Gooch <rgooch@atnf.csiro.au>
485 Ensure <devfs_generate_path> terminates string for root entry.
486 Exported <devfs_get_name> to modules.
487 20010520 Richard Gooch <rgooch@atnf.csiro.au>
488 Make <devfs_mk_symlink> send events to devfsd.
489 Cleaned up option processing in <devfs_setup>.
490 20010521 Richard Gooch <rgooch@atnf.csiro.au>
491 Fixed bugs in handling symlinks: could leak or cause Oops.
492 20010522 Richard Gooch <rgooch@atnf.csiro.au>
493 Cleaned up directory handling by separating fops.
495 20010601 Richard Gooch <rgooch@atnf.csiro.au>
496 Fixed handling of inverted options in <devfs_setup>.
498 20010604 Richard Gooch <rgooch@atnf.csiro.au>
499 Adjusted <try_modload> to account for <devfs_generate_path> fix.
501 20010617 Richard Gooch <rgooch@atnf.csiro.au>
502 Answered question posed by Al Viro and removed his comments.
503 Moved setting of registered flag after other fields are changed.
504 Fixed race between <devfsd_close> and <devfsd_notify_one>.
505 Global VFS changes added bogus BKL to <devfsd_close>: removed.
506 Widened locking in <devfs_readlink> and <devfs_follow_link>.
507 Replaced <devfsd_read> stack usage with <devfsd_ioctl> kmalloc.
508 Simplified locking in <devfsd_ioctl> and fixed memory leak.
510 20010709 Richard Gooch <rgooch@atnf.csiro.au>
511 Removed broken devnum allocation and use <devfs_alloc_devnum>.
512 Fixed old devnum leak by calling new <devfs_dealloc_devnum>.
514 20010712 Richard Gooch <rgooch@atnf.csiro.au>
515 Fixed bug in <devfs_setup> which could hang boot process.
517 20010730 Richard Gooch <rgooch@atnf.csiro.au>
518 Added DEVFSD_NOTIFY_DELETE event.
519 20010801 Richard Gooch <rgooch@atnf.csiro.au>
520 Removed #include <asm/segment.h>.
522 20010807 Richard Gooch <rgooch@atnf.csiro.au>
523 Fixed inode table races by removing it and using
524 inode->u.generic_ip instead.
525 Moved <devfs_read_inode> into <get_vfs_inode>.
526 Moved <devfs_write_inode> into <devfs_notify_change>.
528 20010808 Richard Gooch <rgooch@atnf.csiro.au>
529 Fixed race in <devfs_do_symlink> for uni-processor.
531 20010818 Richard Gooch <rgooch@atnf.csiro.au>
532 Removed remnant of multi-mount support in <devfs_mknod>.
533 Removed unused DEVFS_FL_SHOW_UNREG flag.
535 20010820 Richard Gooch <rgooch@atnf.csiro.au>
536 Removed nlink field from struct devfs_inode.
538 20010823 Richard Gooch <rgooch@atnf.csiro.au>
539 Replaced BKL with global rwsem to protect symlink data (quick
542 20010827 Richard Gooch <rgooch@atnf.csiro.au>
543 Replaced global rwsem for symlink with per-link refcount.
545 20010919 Richard Gooch <rgooch@atnf.csiro.au>
546 Set inode->i_mapping->a_ops for block nodes in <get_vfs_inode>.
548 20011008 Richard Gooch <rgooch@atnf.csiro.au>
549 Fixed overrun in <devfs_link> by removing function (not needed).
550 20011009 Richard Gooch <rgooch@atnf.csiro.au>
551 Fixed buffer underrun in <try_modload>.
552 20011029 Richard Gooch <rgooch@atnf.csiro.au>
553 Fixed race in <devfsd_ioctl> when setting event mask.
554 20011114 Richard Gooch <rgooch@atnf.csiro.au>
555 First release of new locking code.
557 20011117 Richard Gooch <rgooch@atnf.csiro.au>
558 Discard temporary buffer, now use "%s" for dentry names.
559 20011118 Richard Gooch <rgooch@atnf.csiro.au>
560 Don't generate path in <try_modload>: use fake entry instead.
561 Use "existing" directory in <_devfs_make_parent_for_leaf>.
562 20011122 Richard Gooch <rgooch@atnf.csiro.au>
563 Use slab cache rather than fixed buffer for devfsd events.
565 20011125 Richard Gooch <rgooch@atnf.csiro.au>
566 Send DEVFSD_NOTIFY_REGISTERED events in <devfs_mk_dir>.
567 20011127 Richard Gooch <rgooch@atnf.csiro.au>
568 Fixed locking bug in <devfs_d_revalidate_wait> due to typo.
569 Do not send CREATE, CHANGE, ASYNC_OPEN or DELETE events from
572 20011202 Richard Gooch <rgooch@atnf.csiro.au>
573 Fixed bug in <devfsd_read>: was dereferencing freed pointer.
575 20011203 Richard Gooch <rgooch@atnf.csiro.au>
576 Fixed bug in <devfsd_close>: was dereferencing freed pointer.
577 Added process group check for devfsd privileges.
579 20011204 Richard Gooch <rgooch@atnf.csiro.au>
580 Use SLAB_ATOMIC in <devfsd_notify_de> from <devfs_d_delete>.
582 20011211 Richard Gooch <rgooch@atnf.csiro.au>
583 Return old entry in <devfs_mk_dir> for 2.4.x kernels.
584 20011212 Richard Gooch <rgooch@atnf.csiro.au>
585 Increment refcount on module in <check_disc_changed>.
586 20011215 Richard Gooch <rgooch@atnf.csiro.au>
587 Created <devfs_get_handle> and exported <devfs_put>.
588 Increment refcount on module in <devfs_get_ops>.
589 Created <devfs_put_ops>.
591 20011216 Richard Gooch <rgooch@atnf.csiro.au>
592 Added poisoning to <devfs_put>.
593 Improved debugging messages.
595 20011221 Richard Gooch <rgooch@atnf.csiro.au>
596 Corrected (made useful) debugging message in <unregister>.
597 Moved <kmem_cache_create> in <mount_devfs_fs> to <init_devfs_fs>
598 20011224 Richard Gooch <rgooch@atnf.csiro.au>
599 Added magic number to guard against scribbling drivers.
600 20011226 Richard Gooch <rgooch@atnf.csiro.au>
601 Only return old entry in <devfs_mk_dir> if a directory.
602 Defined macros for error and debug messages.
604 20020113 Richard Gooch <rgooch@atnf.csiro.au>
605 Fixed (rare, old) race in <devfs_lookup>.
607 20020120 Richard Gooch <rgooch@atnf.csiro.au>
608 Fixed deadlock bug in <devfs_d_revalidate_wait>.
609 Tag VFS deletable in <devfs_mk_symlink> if handle ignored.
611 20020129 Richard Gooch <rgooch@atnf.csiro.au>
612 Added KERN_* to remaining messages.
613 Cleaned up declaration of <stat_read>.
615 20020219 Richard Gooch <rgooch@atnf.csiro.au>
616 Changed <devfs_rmdir> to allow later additions if not yet empty.
618 20020514 Richard Gooch <rgooch@atnf.csiro.au>
619 Added BKL to <devfs_open> because drivers still need it.
620 Protected <scan_dir_for_removable> and <get_removable_partition>
621 from changing directory contents.
623 20020721 Richard Gooch <rgooch@atnf.csiro.au>
624 Switched to ISO C structure field initialisers.
625 Switch to set_current_state() and move before add_wait_queue().
626 20020722 Richard Gooch <rgooch@atnf.csiro.au>
627 Fixed devfs entry leak in <devfs_readdir> when *readdir fails.
629 20020818 Richard Gooch <rgooch@atnf.csiro.au>
630 Fixed module unload race in <devfs_open>.
633 #include <linux/types.h>
634 #include <linux/errno.h>
635 #include <linux/sched.h>
636 #include <linux/tty.h>
637 #include <linux/timer.h>
638 #include <linux/config.h>
639 #include <linux/kernel.h>
640 #include <linux/wait.h>
641 #include <linux/string.h>
642 #include <linux/slab.h>
643 #include <linux/ioport.h>
644 #include <linux/delay.h>
645 #include <linux/ctype.h>
646 #include <linux/mm.h>
647 #include <linux/module.h>
648 #include <linux/init.h>
649 #include <linux/devfs_fs.h>
650 #include <linux/devfs_fs_kernel.h>
651 #include <linux/smp_lock.h>
652 #include <linux/smp.h>
653 #include <linux/version.h>
654 #include <linux/rwsem.h>
656 #include <asm/uaccess.h>
658 #include <asm/processor.h>
659 #include <asm/system.h>
660 #include <asm/pgtable.h>
661 #include <asm/bitops.h>
662 #include <asm/atomic.h>
664 #define DEVFS_VERSION "1.12c (20020818)"
666 #define DEVFS_NAME "devfs"
668 #define FIRST_INODE 1
670 #define STRING_LENGTH 256
671 #define FAKE_BLOCK_SIZE 1024
672 #define POISON_PTR ( *(void **) poison_array )
673 #define MAGIC_VALUE 0x327db823
680 #define MODE_DIR (S_IFDIR | S_IWUSR | S_IRUGO | S_IXUGO)
682 #define IS_HIDDEN(de) ( (de)->hide && !is_devfsd_or_child(fs_info) )
684 #define DEBUG_NONE 0x0000000
685 #define DEBUG_MODULE_LOAD 0x0000001
686 #define DEBUG_REGISTER 0x0000002
687 #define DEBUG_UNREGISTER 0x0000004
688 #define DEBUG_FREE 0x0000008
689 #define DEBUG_SET_FLAGS 0x0000010
690 #define DEBUG_S_READ 0x0000100 /* Break */
691 #define DEBUG_I_LOOKUP 0x0001000 /* Break */
692 #define DEBUG_I_CREATE 0x0002000
693 #define DEBUG_I_GET 0x0004000
694 #define DEBUG_I_CHANGE 0x0008000
695 #define DEBUG_I_UNLINK 0x0010000
696 #define DEBUG_I_RLINK 0x0020000
697 #define DEBUG_I_FLINK 0x0040000
698 #define DEBUG_I_MKNOD 0x0080000
699 #define DEBUG_F_READDIR 0x0100000 /* Break */
700 #define DEBUG_D_DELETE 0x1000000 /* Break */
701 #define DEBUG_D_RELEASE 0x2000000
702 #define DEBUG_D_IPUT 0x4000000
703 #define DEBUG_ALL 0xfffffff
704 #define DEBUG_DISABLED DEBUG_NONE
706 #define OPTION_NONE 0x00
707 #define OPTION_MOUNT 0x01
708 #define OPTION_ONLY 0x02
710 #define PRINTK(format, args...) \
711 {printk (KERN_ERR "%s" format, __FUNCTION__ , ## args);}
713 #define OOPS(format, args...) \
714 {printk (KERN_CRIT "%s" format, __FUNCTION__ , ## args); \
715 printk ("Forcing Oops\n"); \
718 #ifdef CONFIG_DEVFS_DEBUG
719 # define VERIFY_ENTRY(de) \
720 {if ((de) && (de)->magic_number != MAGIC_VALUE) \
721 OOPS ("(%p): bad magic value: %x\n", (de), (de)->magic_number);}
722 # define WRITE_ENTRY_MAGIC(de,magic) (de)->magic_number = (magic)
723 # define DPRINTK(flag, format, args...) \
724 {if (devfs_debug & flag) \
725 printk (KERN_INFO "%s" format, __FUNCTION__ , ## args);}
727 # define VERIFY_ENTRY(de)
728 # define WRITE_ENTRY_MAGIC(de,magic)
729 # define DPRINTK(flag, format, args...)
733 struct directory_type
735 rwlock_t lock; /* Lock for searching(R)/updating(W) */
736 struct devfs_entry *first;
737 struct devfs_entry *last;
738 unsigned short num_removable; /* Lock for writing but not reading */
739 unsigned char no_more_additions:1;
749 unsigned short major;
750 unsigned short minor;
753 struct fcb_type /* File, char, block type */
758 struct file_type file;
759 struct device_type device;
762 unsigned char auto_owner:1;
763 unsigned char aopen_notify:1;
764 unsigned char removable:1; /* Belongs in device_type, but save space */
765 unsigned char open:1; /* Not entirely correct */
766 unsigned char autogen:1; /* Belongs in device_type, but save space */
771 unsigned int length; /* Not including the NULL-termimator */
772 char *linkname; /* This is NULL-terminated */
775 struct devfs_inode /* This structure is for "persistent" inode storage */
777 struct dentry *dentry;
781 unsigned int ino; /* Inode number as seen in the VFS */
788 #ifdef CONFIG_DEVFS_DEBUG
789 unsigned int magic_number;
792 atomic_t refcount; /* When this drops to zero, it's unused */
795 struct directory_type dir;
797 struct symlink_type symlink;
798 const char *name; /* Only used for (mode == 0) */
801 struct devfs_entry *prev; /* Previous entry in the parent directory */
802 struct devfs_entry *next; /* Next entry in the parent directory */
803 struct devfs_entry *parent; /* The parent directory */
804 struct devfs_entry *slave; /* Another entry to unregister */
805 struct devfs_inode inode;
807 unsigned short namelen; /* I think 64k+ filenames are a way off... */
808 unsigned char hide:1;
809 unsigned char vfs_deletable:1;/* Whether the VFS may delete the entry */
810 char name[1]; /* This is just a dummy: the allocated array
811 is bigger. This is NULL-terminated */
814 /* The root of the device tree */
815 static struct devfs_entry *root_entry;
817 struct devfsd_buf_entry
819 struct devfs_entry *de; /* The name is generated with this */
820 unsigned short type; /* The type of event */
824 struct devfsd_buf_entry *next;
827 struct fs_info /* This structure is for the mounted devfs */
829 struct super_block *sb;
830 spinlock_t devfsd_buffer_lock; /* Lock when inserting/deleting events */
831 struct devfsd_buf_entry *devfsd_first_event;
832 struct devfsd_buf_entry *devfsd_last_event;
833 volatile int devfsd_sleeping;
834 volatile struct task_struct *devfsd_task;
835 volatile pid_t devfsd_pgrp;
836 volatile struct file *devfsd_file;
837 struct devfsd_notify_struct *devfsd_info;
838 volatile unsigned long devfsd_event_mask;
839 atomic_t devfsd_overrun_count;
840 wait_queue_head_t devfsd_wait_queue; /* Wake devfsd on input */
841 wait_queue_head_t revalidate_wait_queue; /* Wake when devfsd sleeps */
844 static struct fs_info fs_info = {devfsd_buffer_lock: SPIN_LOCK_UNLOCKED};
845 static kmem_cache_t *devfsd_buf_cache;
846 #ifdef CONFIG_DEVFS_DEBUG
847 static unsigned int devfs_debug_init __initdata = DEBUG_NONE;
848 static unsigned int devfs_debug = DEBUG_NONE;
849 static spinlock_t stat_lock = SPIN_LOCK_UNLOCKED;
850 static unsigned int stat_num_entries;
851 static unsigned int stat_num_bytes;
853 static unsigned char poison_array[8] =
854 {0x5a, 0x5a, 0x5a, 0x5a, 0x5a, 0x5a, 0x5a, 0x5a};
856 #ifdef CONFIG_DEVFS_MOUNT
857 static unsigned int boot_options = OPTION_MOUNT;
859 static unsigned int boot_options = OPTION_NONE;
862 /* Forward function declarations */
863 static devfs_handle_t _devfs_walk_path (struct devfs_entry *dir,
864 const char *name, int namelen,
865 int traverse_symlink);
866 static ssize_t devfsd_read (struct file *file, char *buf, size_t len,
868 static int devfsd_ioctl (struct inode *inode, struct file *file,
869 unsigned int cmd, unsigned long arg);
870 static int devfsd_close (struct inode *inode, struct file *file);
871 #ifdef CONFIG_DEVFS_DEBUG
872 static ssize_t stat_read (struct file *file, char *buf, size_t len,
874 static struct file_operations stat_fops =
881 /* Devfs daemon file operations */
882 static struct file_operations devfsd_fops =
885 .ioctl = devfsd_ioctl,
886 .release = devfsd_close,
890 /* Support functions follow */
894 * devfs_get - Get a reference to a devfs entry.
895 * @de: The devfs entry.
898 static struct devfs_entry *devfs_get (struct devfs_entry *de)
901 if (de) atomic_inc (&de->refcount);
903 } /* End Function devfs_get */
906 * devfs_put - Put (release) a reference to a devfs entry.
907 * @de: The handle to the devfs entry.
910 void devfs_put (devfs_handle_t de)
914 if (de->info == POISON_PTR) OOPS ("(%p): poisoned pointer\n", de);
915 if ( !atomic_dec_and_test (&de->refcount) ) return;
916 if (de == root_entry) OOPS ("(%p): root entry being freed\n", de);
917 DPRINTK (DEBUG_FREE, "(%s): de: %p, parent: %p \"%s\"\n",
918 de->name, de, de->parent,
919 de->parent ? de->parent->name : "no parent");
920 if ( S_ISLNK (de->mode) ) kfree (de->u.symlink.linkname);
921 if ( ( S_ISCHR (de->mode) || S_ISBLK (de->mode) ) && de->u.fcb.autogen )
923 devfs_dealloc_devnum ( S_ISCHR (de->mode) ? DEVFS_SPECIAL_CHR :
925 mk_kdev (de->u.fcb.u.device.major,
926 de->u.fcb.u.device.minor) );
928 WRITE_ENTRY_MAGIC (de, 0);
929 #ifdef CONFIG_DEVFS_DEBUG
930 spin_lock (&stat_lock);
932 stat_num_bytes -= sizeof *de + de->namelen;
933 if ( S_ISLNK (de->mode) ) stat_num_bytes -= de->u.symlink.length + 1;
934 spin_unlock (&stat_lock);
936 de->info = POISON_PTR;
938 } /* End Function devfs_put */
941 * _devfs_search_dir - Search for a devfs entry in a directory.
942 * @dir: The directory to search.
943 * @name: The name of the entry to search for.
944 * @namelen: The number of characters in @name.
946 * Search for a devfs entry in a directory and returns a pointer to the entry
947 * on success, else %NULL. The directory must be locked already.
948 * An implicit devfs_get() is performed on the returned entry.
951 static struct devfs_entry *_devfs_search_dir (struct devfs_entry *dir,
953 unsigned int namelen)
955 struct devfs_entry *curr;
957 if ( !S_ISDIR (dir->mode) )
959 PRINTK ("(%s): not a directory\n", dir->name);
962 for (curr = dir->u.dir.first; curr != NULL; curr = curr->next)
964 if (curr->namelen != namelen) continue;
965 if (memcmp (curr->name, name, namelen) == 0) break;
966 /* Not found: try the next one */
968 return devfs_get (curr);
969 } /* End Function _devfs_search_dir */
973 * _devfs_alloc_entry - Allocate a devfs entry.
974 * @name: The name of the entry.
975 * @namelen: The number of characters in @name.
977 * Allocate a devfs entry and returns a pointer to the entry on success, else
981 static struct devfs_entry *_devfs_alloc_entry (const char *name,
982 unsigned int namelen,
985 struct devfs_entry *new;
986 static unsigned long inode_counter = FIRST_INODE;
987 static spinlock_t counter_lock = SPIN_LOCK_UNLOCKED;
989 if ( name && (namelen < 1) ) namelen = strlen (name);
990 if ( ( new = kmalloc (sizeof *new + namelen, GFP_KERNEL) ) == NULL )
992 memset (new, 0, sizeof *new + namelen); /* Will set '\0' on name */
994 if ( S_ISDIR (mode) ) rwlock_init (&new->u.dir.lock);
995 atomic_set (&new->refcount, 1);
996 spin_lock (&counter_lock);
997 new->inode.ino = inode_counter++;
998 spin_unlock (&counter_lock);
999 if (name) memcpy (new->name, name, namelen);
1000 new->namelen = namelen;
1001 WRITE_ENTRY_MAGIC (new, MAGIC_VALUE);
1002 #ifdef CONFIG_DEVFS_DEBUG
1003 spin_lock (&stat_lock);
1005 stat_num_bytes += sizeof *new + namelen;
1006 spin_unlock (&stat_lock);
1009 } /* End Function _devfs_alloc_entry */
1013 * _devfs_append_entry - Append a devfs entry to a directory's child list.
1014 * @dir: The directory to add to.
1015 * @de: The devfs entry to append.
1016 * @removable: If TRUE, increment the count of removable devices for %dir.
1017 * @old_de: If an existing entry exists, it will be written here. This may
1018 * be %NULL. An implicit devfs_get() is performed on this entry.
1020 * Append a devfs entry to a directory's list of children, checking first to
1021 * see if an entry of the same name exists. The directory will be locked.
1022 * The value 0 is returned on success, else a negative error code.
1023 * On failure, an implicit devfs_put() is performed on %de.
1026 static int _devfs_append_entry (devfs_handle_t dir, devfs_handle_t de,
1027 int removable, devfs_handle_t *old_de)
1031 if (old_de) *old_de = NULL;
1032 if ( !S_ISDIR (dir->mode) )
1034 PRINTK ("(%s): dir: \"%s\" is not a directory\n", de->name, dir->name);
1038 write_lock (&dir->u.dir.lock);
1039 if (dir->u.dir.no_more_additions) retval = -ENOENT;
1042 struct devfs_entry *old;
1044 old = _devfs_search_dir (dir, de->name, de->namelen);
1045 if (old_de) *old_de = old;
1046 else devfs_put (old);
1050 de->prev = dir->u.dir.last;
1051 /* Append to the directory's list of children */
1052 if (dir->u.dir.first == NULL) dir->u.dir.first = de;
1053 else dir->u.dir.last->next = de;
1054 dir->u.dir.last = de;
1055 if (removable) ++dir->u.dir.num_removable;
1058 else retval = -EEXIST;
1060 write_unlock (&dir->u.dir.lock);
1061 if (retval) devfs_put (de);
1063 } /* End Function _devfs_append_entry */
1067 * _devfs_get_root_entry - Get the root devfs entry.
1069 * Returns the root devfs entry on success, else %NULL.
1072 static struct devfs_entry *_devfs_get_root_entry (void)
1075 struct devfs_entry *new;
1076 static spinlock_t root_lock = SPIN_LOCK_UNLOCKED;
1078 /* Always ensure the root is created */
1079 if (root_entry) return root_entry;
1080 if ( ( new = _devfs_alloc_entry (NULL, 0,MODE_DIR) ) == NULL ) return NULL;
1081 spin_lock (&root_lock);
1084 spin_unlock (&root_lock);
1086 return (root_entry);
1089 spin_unlock (&root_lock);
1090 /* And create the entry for ".devfsd" */
1091 if ( ( new = _devfs_alloc_entry (".devfsd", 0, S_IFCHR |S_IRUSR |S_IWUSR) )
1092 == NULL ) return NULL;
1093 devnum = devfs_alloc_devnum (DEVFS_SPECIAL_CHR);
1094 new->u.fcb.u.device.major = major (devnum);
1095 new->u.fcb.u.device.minor = minor (devnum);
1096 new->u.fcb.ops = &devfsd_fops;
1097 _devfs_append_entry (root_entry, new, FALSE, NULL);
1098 #ifdef CONFIG_DEVFS_DEBUG
1099 if ( ( new = _devfs_alloc_entry (".stat", 0, S_IFCHR | S_IRUGO | S_IWUGO) )
1100 == NULL ) return NULL;
1101 devnum = devfs_alloc_devnum (DEVFS_SPECIAL_CHR);
1102 new->u.fcb.u.device.major = major (devnum);
1103 new->u.fcb.u.device.minor = minor (devnum);
1104 new->u.fcb.ops = &stat_fops;
1105 _devfs_append_entry (root_entry, new, FALSE, NULL);
1108 } /* End Function _devfs_get_root_entry */
1112 * _devfs_descend - Descend down a tree using the next component name.
1113 * @dir: The directory to search.
1114 * @name: The component name to search for.
1115 * @namelen: The length of %name.
1116 * @next_pos: The position of the next '/' or '\0' is written here.
1118 * Descend into a directory, searching for a component. This function forms
1119 * the core of a tree-walking algorithm. The directory will be locked.
1120 * The devfs entry corresponding to the component is returned. If there is
1121 * no matching entry, %NULL is returned.
1122 * An implicit devfs_get() is performed on the returned entry.
1125 static struct devfs_entry *_devfs_descend (struct devfs_entry *dir,
1126 const char *name, int namelen,
1129 const char *stop, *ptr;
1130 struct devfs_entry *entry;
1132 if ( (namelen >= 3) && (strncmp (name, "../", 3) == 0) )
1133 { /* Special-case going to parent directory */
1135 return devfs_get (dir->parent);
1137 stop = name + namelen;
1138 /* Search for a possible '/' */
1139 for (ptr = name; (ptr < stop) && (*ptr != '/'); ++ptr);
1140 *next_pos = ptr - name;
1141 read_lock (&dir->u.dir.lock);
1142 entry = _devfs_search_dir (dir, name, *next_pos);
1143 read_unlock (&dir->u.dir.lock);
1145 } /* End Function _devfs_descend */
1148 static devfs_handle_t _devfs_make_parent_for_leaf (struct devfs_entry *dir,
1150 int namelen, int *leaf_pos)
1154 if (dir == NULL) dir = _devfs_get_root_entry ();
1155 if (dir == NULL) return NULL;
1157 /* Search for possible trailing component and ignore it */
1158 for (--namelen; (namelen > 0) && (name[namelen] != '/'); --namelen);
1159 *leaf_pos = (name[namelen] == '/') ? (namelen + 1) : 0;
1160 for (; namelen > 0; name += next_pos, namelen -= next_pos)
1162 struct devfs_entry *de, *old;
1164 if ( ( de = _devfs_descend (dir, name, namelen, &next_pos) ) == NULL )
1166 de = _devfs_alloc_entry (name, next_pos, MODE_DIR);
1168 if ( !de || _devfs_append_entry (dir, de, FALSE, &old) )
1171 if ( !old || !S_ISDIR (old->mode) )
1177 de = old; /* Use the existing directory */
1180 if (de == dir->parent)
1188 if (name[next_pos] == '/') ++next_pos;
1191 } /* End Function _devfs_make_parent_for_leaf */
1194 static devfs_handle_t _devfs_prepare_leaf (devfs_handle_t *dir,
1195 const char *name, umode_t mode)
1197 int namelen, leaf_pos;
1198 struct devfs_entry *de;
1200 namelen = strlen (name);
1201 if ( ( *dir = _devfs_make_parent_for_leaf (*dir, name, namelen,
1202 &leaf_pos) ) == NULL )
1204 PRINTK ("(%s): could not create parent path\n", name);
1207 if ( ( de = _devfs_alloc_entry (name + leaf_pos, namelen - leaf_pos,mode) )
1210 PRINTK ("(%s): could not allocate entry\n", name);
1215 } /* End Function _devfs_prepare_leaf */
1218 static devfs_handle_t _devfs_walk_path (struct devfs_entry *dir,
1219 const char *name, int namelen,
1220 int traverse_symlink)
1224 if (dir == NULL) dir = _devfs_get_root_entry ();
1225 if (dir == NULL) return NULL;
1227 for (; namelen > 0; name += next_pos, namelen -= next_pos)
1229 struct devfs_entry *de, *link;
1231 if ( ( de = _devfs_descend (dir, name, namelen, &next_pos) ) == NULL )
1236 if (S_ISLNK (de->mode) && traverse_symlink)
1237 { /* Need to follow the link: this is a stack chomper */
1238 link = _devfs_walk_path (dir, de->u.symlink.linkname,
1239 de->u.symlink.length, TRUE);
1250 if (name[next_pos] == '/') ++next_pos;
1253 } /* End Function _devfs_walk_path */
1257 * _devfs_find_by_dev - Find a devfs entry in a directory.
1258 * @dir: The directory where to search
1259 * @major: The major number to search for.
1260 * @minor: The minor number to search for.
1261 * @type: The type of special file to search for. This may be either
1262 * %DEVFS_SPECIAL_CHR or %DEVFS_SPECIAL_BLK.
1264 * Returns the devfs_entry pointer on success, else %NULL. An implicit
1265 * devfs_get() is performed.
1268 static struct devfs_entry *_devfs_find_by_dev (struct devfs_entry *dir,
1270 unsigned int minor, char type)
1272 struct devfs_entry *entry, *de;
1275 if (dir == NULL) return NULL;
1276 if ( !S_ISDIR (dir->mode) )
1278 PRINTK ("(%p): not a directory\n", dir);
1282 /* First search files in this directory */
1283 read_lock (&dir->u.dir.lock);
1284 for (entry = dir->u.dir.first; entry != NULL; entry = entry->next)
1286 if ( !S_ISCHR (entry->mode) && !S_ISBLK (entry->mode) ) continue;
1287 if ( S_ISCHR (entry->mode) && (type != DEVFS_SPECIAL_CHR) ) continue;
1288 if ( S_ISBLK (entry->mode) && (type != DEVFS_SPECIAL_BLK) ) continue;
1289 if ( (entry->u.fcb.u.device.major == major) &&
1290 (entry->u.fcb.u.device.minor == minor) )
1293 read_unlock (&dir->u.dir.lock);
1297 /* Not found: try the next one */
1299 /* Now recursively search the subdirectories: this is a stack chomper */
1300 for (entry = dir->u.dir.first; entry != NULL; entry = entry->next)
1302 if ( !S_ISDIR (entry->mode) ) continue;
1303 de = _devfs_find_by_dev (entry, major, minor, type);
1306 read_unlock (&dir->u.dir.lock);
1311 read_unlock (&dir->u.dir.lock);
1314 } /* End Function _devfs_find_by_dev */
1318 * _devfs_find_entry - Find a devfs entry.
1319 * @dir: The handle to the parent devfs directory entry. If this is %NULL the
1320 * name is relative to the root of the devfs.
1321 * @name: The name of the entry. This may be %NULL.
1322 * @major: The major number. This is used if lookup by @name fails.
1323 * @minor: The minor number. This is used if lookup by @name fails.
1324 * NOTE: If @major and @minor are both 0, searching by major and minor
1325 * numbers is disabled.
1326 * @type: The type of special file to search for. This may be either
1327 * %DEVFS_SPECIAL_CHR or %DEVFS_SPECIAL_BLK.
1328 * @traverse_symlink: If %TRUE then symbolic links are traversed.
1330 * Returns the devfs_entry pointer on success, else %NULL. An implicit
1331 * devfs_get() is performed.
1334 static struct devfs_entry *_devfs_find_entry (devfs_handle_t dir,
1338 char type, int traverse_symlink)
1340 struct devfs_entry *entry;
1344 unsigned int namelen = strlen (name);
1348 /* Skip leading pathname component */
1351 PRINTK ("(%s): too short\n", name);
1354 for (++name, --namelen; (*name != '/') && (namelen > 0);
1358 PRINTK ("(%s): too short\n", name);
1364 entry = _devfs_walk_path (dir, name, namelen, traverse_symlink);
1365 if (entry != NULL) return entry;
1367 /* Have to search by major and minor: slow */
1368 if ( (major == 0) && (minor == 0) ) return NULL;
1369 return _devfs_find_by_dev (root_entry, major, minor, type);
1370 } /* End Function _devfs_find_entry */
1372 static struct devfs_entry *get_devfs_entry_from_vfs_inode (struct inode *inode)
1374 if (inode == NULL) return NULL;
1375 VERIFY_ENTRY ( (struct devfs_entry *) inode->u.generic_ip );
1376 return inode->u.generic_ip;
1377 } /* End Function get_devfs_entry_from_vfs_inode */
1381 * free_dentry - Free the dentry for a device entry and invalidate inode.
1384 * This must only be called after the entry has been unhooked from it's
1388 static void free_dentry (struct devfs_entry *de)
1390 struct dentry *dentry = de->inode.dentry;
1392 if (!dentry) return;
1393 spin_lock (&dcache_lock);
1394 dget_locked (dentry);
1395 spin_unlock (&dcache_lock);
1396 /* Forcefully remove the inode */
1397 if (dentry->d_inode != NULL) dentry->d_inode->i_nlink = 0;
1400 } /* End Function free_dentry */
1404 * is_devfsd_or_child - Test if the current process is devfsd or one of its children.
1405 * @fs_info: The filesystem information.
1407 * Returns %TRUE if devfsd or child, else %FALSE.
1410 static int is_devfsd_or_child (struct fs_info *fs_info)
1412 struct task_struct *p;
1414 if (current == fs_info->devfsd_task) return (TRUE);
1415 if (current->pgrp == fs_info->devfsd_pgrp) return (TRUE);
1416 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,1)
1417 for (p = current->p_opptr; p != &init_task; p = p->p_opptr)
1419 if (p == fs_info->devfsd_task) return (TRUE);
1423 } /* End Function is_devfsd_or_child */
1427 * devfsd_queue_empty - Test if devfsd has work pending in its event queue.
1428 * @fs_info: The filesystem information.
1430 * Returns %TRUE if the queue is empty, else %FALSE.
1433 static inline int devfsd_queue_empty (struct fs_info *fs_info)
1435 return (fs_info->devfsd_last_event) ? FALSE : TRUE;
1436 } /* End Function devfsd_queue_empty */
1440 * wait_for_devfsd_finished - Wait for devfsd to finish processing its event queue.
1441 * @fs_info: The filesystem information.
1443 * Returns %TRUE if no more waiting will be required, else %FALSE.
1446 static int wait_for_devfsd_finished (struct fs_info *fs_info)
1448 DECLARE_WAITQUEUE (wait, current);
1450 if (fs_info->devfsd_task == NULL) return (TRUE);
1451 if (devfsd_queue_empty (fs_info) && fs_info->devfsd_sleeping) return TRUE;
1452 if ( is_devfsd_or_child (fs_info) ) return (FALSE);
1453 set_current_state (TASK_UNINTERRUPTIBLE);
1454 add_wait_queue (&fs_info->revalidate_wait_queue, &wait);
1455 if (!devfsd_queue_empty (fs_info) || !fs_info->devfsd_sleeping)
1456 if (fs_info->devfsd_task) schedule ();
1457 remove_wait_queue (&fs_info->revalidate_wait_queue, &wait);
1458 __set_current_state (TASK_RUNNING);
1460 } /* End Function wait_for_devfsd_finished */
1464 * devfsd_notify_de - Notify the devfsd daemon of a change.
1465 * @de: The devfs entry that has changed. This and all parent entries will
1466 * have their reference counts incremented if the event was queued.
1467 * @type: The type of change.
1468 * @mode: The mode of the entry.
1469 * @uid: The user ID.
1470 * @gid: The group ID.
1471 * @fs_info: The filesystem info.
1473 * Returns %TRUE if an event was queued and devfsd woken up, else %FALSE.
1476 static int devfsd_notify_de (struct devfs_entry *de,
1477 unsigned short type, umode_t mode,
1478 uid_t uid, gid_t gid, struct fs_info *fs_info,
1481 struct devfsd_buf_entry *entry;
1482 struct devfs_entry *curr;
1484 if ( !( fs_info->devfsd_event_mask & (1 << type) ) ) return (FALSE);
1485 if ( ( entry = kmem_cache_alloc (devfsd_buf_cache,
1486 atomic ? SLAB_ATOMIC : SLAB_KERNEL) )
1489 atomic_inc (&fs_info->devfsd_overrun_count);
1492 for (curr = de; curr != NULL; curr = curr->parent) devfs_get (curr);
1499 spin_lock (&fs_info->devfsd_buffer_lock);
1500 if (!fs_info->devfsd_first_event) fs_info->devfsd_first_event = entry;
1501 if (fs_info->devfsd_last_event) fs_info->devfsd_last_event->next = entry;
1502 fs_info->devfsd_last_event = entry;
1503 spin_unlock (&fs_info->devfsd_buffer_lock);
1504 wake_up_interruptible (&fs_info->devfsd_wait_queue);
1506 } /* End Function devfsd_notify_de */
1510 * devfsd_notify - Notify the devfsd daemon of a change.
1511 * @de: The devfs entry that has changed.
1512 * @type: The type of change event.
1513 * @wait: If TRUE, the function waits for the daemon to finish processing
1517 static void devfsd_notify (struct devfs_entry *de,unsigned short type,int wait)
1519 if (devfsd_notify_de (de, type, de->mode, current->euid,
1520 current->egid, &fs_info, 0) && wait)
1521 wait_for_devfsd_finished (&fs_info);
1522 } /* End Function devfsd_notify */
1526 * devfs_register - Register a device entry.
1527 * @dir: The handle to the parent devfs directory entry. If this is %NULL the
1528 * new name is relative to the root of the devfs.
1529 * @name: The name of the entry.
1530 * @flags: A set of bitwise-ORed flags (DEVFS_FL_*).
1531 * @major: The major number. Not needed for regular files.
1532 * @minor: The minor number. Not needed for regular files.
1533 * @mode: The default file mode.
1534 * @ops: The &file_operations or &block_device_operations structure.
1535 * This must not be externally deallocated.
1536 * @info: An arbitrary pointer which will be written to the @private_data
1537 * field of the &file structure passed to the device driver. You can set
1538 * this to whatever you like, and change it once the file is opened (the next
1539 * file opened will not see this change).
1541 * Returns a handle which may later be used in a call to devfs_unregister().
1542 * On failure %NULL is returned.
1545 devfs_handle_t devfs_register (devfs_handle_t dir, const char *name,
1547 unsigned int major, unsigned int minor,
1548 umode_t mode, void *ops, void *info)
1550 char devtype = S_ISCHR (mode) ? DEVFS_SPECIAL_CHR : DEVFS_SPECIAL_BLK;
1552 kdev_t devnum = NODEV;
1553 struct devfs_entry *de;
1557 PRINTK ("(): NULL name pointer\n");
1562 if ( S_ISBLK (mode) ) ops = (void *) get_blkfops (major);
1565 PRINTK ("(%s): NULL ops pointer\n", name);
1568 PRINTK ("(%s): NULL ops, got %p from major table\n", name, ops);
1570 if ( S_ISDIR (mode) )
1572 PRINTK ("(%s): creating directories is not allowed\n", name);
1575 if ( S_ISLNK (mode) )
1577 PRINTK ("(%s): creating symlinks is not allowed\n", name);
1580 if ( ( S_ISCHR (mode) || S_ISBLK (mode) ) &&
1581 (flags & DEVFS_FL_AUTO_DEVNUM) )
1583 if ( kdev_none ( devnum = devfs_alloc_devnum (devtype) ) )
1585 PRINTK ("(%s): exhausted %s device numbers\n",
1586 name, S_ISCHR (mode) ? "char" : "block");
1589 major = major (devnum);
1590 minor = minor (devnum);
1592 if ( ( de = _devfs_prepare_leaf (&dir, name, mode) ) == NULL )
1594 PRINTK ("(%s): could not prepare leaf\n", name);
1595 if ( !kdev_none (devnum) ) devfs_dealloc_devnum (devtype, devnum);
1598 if ( S_ISCHR (mode) || S_ISBLK (mode) )
1600 de->u.fcb.u.device.major = major;
1601 de->u.fcb.u.device.minor = minor;
1602 de->u.fcb.autogen = kdev_none (devnum) ? FALSE : TRUE;
1604 else if ( !S_ISREG (mode) )
1606 PRINTK ("(%s): illegal mode: %x\n", name, mode);
1612 if (flags & DEVFS_FL_CURRENT_OWNER)
1614 de->inode.uid = current->uid;
1615 de->inode.gid = current->gid;
1622 de->u.fcb.ops = ops;
1623 de->u.fcb.auto_owner = (flags & DEVFS_FL_AUTO_OWNER) ? TRUE : FALSE;
1624 de->u.fcb.aopen_notify = (flags & DEVFS_FL_AOPEN_NOTIFY) ? TRUE : FALSE;
1625 de->hide = (flags & DEVFS_FL_HIDE) ? TRUE : FALSE;
1626 if (flags & DEVFS_FL_REMOVABLE) de->u.fcb.removable = TRUE;
1627 if ( ( err = _devfs_append_entry (dir, de, de->u.fcb.removable, NULL) )
1630 PRINTK ("(%s): could not append to parent, err: %d\n", name, err);
1632 if ( !kdev_none (devnum) ) devfs_dealloc_devnum (devtype, devnum);
1635 DPRINTK (DEBUG_REGISTER, "(%s): de: %p dir: %p \"%s\" pp: %p\n",
1636 name, de, dir, dir->name, dir->parent);
1637 devfsd_notify (de, DEVFSD_NOTIFY_REGISTERED, flags & DEVFS_FL_WAIT);
1640 } /* End Function devfs_register */
1644 * _devfs_unhook - Unhook a device entry from its parents list
1645 * @de: The entry to unhook.
1647 * Returns %TRUE if the entry was unhooked, else %FALSE if it was
1648 * previously unhooked.
1649 * The caller must have a write lock on the parent directory.
1652 static int _devfs_unhook (struct devfs_entry *de)
1654 struct devfs_entry *parent;
1656 if ( !de || (de->prev == de) ) return FALSE;
1657 parent = de->parent;
1658 if (de->prev == NULL) parent->u.dir.first = de->next;
1659 else de->prev->next = de->next;
1660 if (de->next == NULL) parent->u.dir.last = de->prev;
1661 else de->next->prev = de->prev;
1662 de->prev = de; /* Indicate we're unhooked */
1663 de->next = NULL; /* Force early termination for <devfs_readdir> */
1664 if ( ( S_ISREG (de->mode) || S_ISCHR (de->mode) || S_ISBLK (de->mode) ) &&
1665 de->u.fcb.removable )
1666 --parent->u.dir.num_removable;
1668 } /* End Function _devfs_unhook */
1672 * _devfs_unregister - Unregister a device entry from it's parent.
1673 * @dir: The parent directory.
1674 * @de: The entry to unregister.
1676 * The caller must have a write lock on the parent directory, which is
1677 * unlocked by this function.
1680 static void _devfs_unregister (struct devfs_entry *dir, struct devfs_entry *de)
1682 int unhooked = _devfs_unhook (de);
1684 write_unlock (&dir->u.dir.lock);
1685 if (!unhooked) return;
1687 devfs_unregister (de->slave); /* Let it handle the locking */
1688 devfsd_notify (de, DEVFSD_NOTIFY_UNREGISTERED, 0);
1691 if ( !S_ISDIR (de->mode) ) return;
1692 while (TRUE) /* Recursively unregister: this is a stack chomper */
1694 struct devfs_entry *child;
1696 write_lock (&de->u.dir.lock);
1697 de->u.dir.no_more_additions = TRUE;
1698 child = de->u.dir.first;
1699 VERIFY_ENTRY (child);
1700 _devfs_unregister (de, child);
1702 DPRINTK (DEBUG_UNREGISTER, "(%s): child: %p refcount: %d\n",
1703 child->name, child, atomic_read (&child->refcount) );
1706 } /* End Function _devfs_unregister */
1710 * devfs_unregister - Unregister a device entry.
1711 * @de: A handle previously created by devfs_register() or returned from
1712 * devfs_get_handle(). If this is %NULL the routine does nothing.
1715 void devfs_unregister (devfs_handle_t de)
1718 if ( (de == NULL) || (de->parent == NULL) ) return;
1719 DPRINTK (DEBUG_UNREGISTER, "(%s): de: %p refcount: %d\n",
1720 de->name, de, atomic_read (&de->refcount) );
1721 write_lock (&de->parent->u.dir.lock);
1722 _devfs_unregister (de->parent, de);
1724 } /* End Function devfs_unregister */
1726 static int devfs_do_symlink (devfs_handle_t dir, const char *name,
1727 unsigned int flags, const char *link,
1728 devfs_handle_t *handle, void *info)
1731 unsigned int linklength;
1733 struct devfs_entry *de;
1735 if (handle != NULL) *handle = NULL;
1738 PRINTK ("(): NULL name pointer\n");
1743 PRINTK ("(%s): NULL link pointer\n", name);
1746 linklength = strlen (link);
1747 if ( ( newlink = kmalloc (linklength + 1, GFP_KERNEL) ) == NULL )
1749 memcpy (newlink, link, linklength);
1750 newlink[linklength] = '\0';
1751 if ( ( de = _devfs_prepare_leaf (&dir, name, S_IFLNK | S_IRUGO | S_IXUGO) )
1754 PRINTK ("(%s): could not prepare leaf\n", name);
1759 de->hide = (flags & DEVFS_FL_HIDE) ? TRUE : FALSE;
1760 de->u.symlink.linkname = newlink;
1761 de->u.symlink.length = linklength;
1762 if ( ( err = _devfs_append_entry (dir, de, FALSE, NULL) ) != 0 )
1764 PRINTK ("(%s): could not append to parent, err: %d\n", name, err);
1769 #ifdef CONFIG_DEVFS_DEBUG
1770 spin_lock (&stat_lock);
1771 stat_num_bytes += linklength + 1;
1772 spin_unlock (&stat_lock);
1774 if (handle != NULL) *handle = de;
1776 } /* End Function devfs_do_symlink */
1780 * devfs_mk_symlink Create a symbolic link in the devfs namespace.
1781 * @dir: The handle to the parent devfs directory entry. If this is %NULL the
1782 * new name is relative to the root of the devfs.
1783 * @name: The name of the entry.
1784 * @flags: A set of bitwise-ORed flags (DEVFS_FL_*).
1785 * @link: The destination name.
1786 * @handle: The handle to the symlink entry is written here. This may be %NULL.
1787 * @info: An arbitrary pointer which will be associated with the entry.
1789 * Returns 0 on success, else a negative error code is returned.
1792 int devfs_mk_symlink (devfs_handle_t dir, const char *name, unsigned int flags,
1793 const char *link, devfs_handle_t *handle, void *info)
1798 if (handle != NULL) *handle = NULL;
1799 DPRINTK (DEBUG_REGISTER, "(%s)\n", name);
1800 err = devfs_do_symlink (dir, name, flags, link, &de, info);
1801 if (err) return err;
1802 if (handle == NULL) de->vfs_deletable = TRUE;
1804 devfsd_notify (de, DEVFSD_NOTIFY_REGISTERED, flags & DEVFS_FL_WAIT);
1806 } /* End Function devfs_mk_symlink */
1810 * devfs_mk_dir - Create a directory in the devfs namespace.
1811 * @dir: The handle to the parent devfs directory entry. If this is %NULL the
1812 * new name is relative to the root of the devfs.
1813 * @name: The name of the entry.
1814 * @info: An arbitrary pointer which will be associated with the entry.
1816 * Use of this function is optional. The devfs_register() function
1817 * will automatically create intermediate directories as needed. This function
1818 * is provided for efficiency reasons, as it provides a handle to a directory.
1819 * Returns a handle which may later be used in a call to devfs_unregister().
1820 * On failure %NULL is returned.
1823 devfs_handle_t devfs_mk_dir (devfs_handle_t dir, const char *name, void *info)
1826 struct devfs_entry *de, *old;
1830 PRINTK ("(): NULL name pointer\n");
1833 if ( ( de = _devfs_prepare_leaf (&dir, name, MODE_DIR) ) == NULL )
1835 PRINTK ("(%s): could not prepare leaf\n", name);
1839 if ( ( err = _devfs_append_entry (dir, de, FALSE, &old) ) != 0 )
1841 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,1)
1842 if ( old && S_ISDIR (old->mode) )
1844 PRINTK ("(%s): using old entry in dir: %p \"%s\"\n",
1845 name, dir, dir->name);
1846 old->vfs_deletable = FALSE;
1851 PRINTK ("(%s): could not append to dir: %p \"%s\", err: %d\n",
1852 name, dir, dir->name, err);
1857 DPRINTK (DEBUG_REGISTER, "(%s): de: %p dir: %p \"%s\"\n",
1858 name, de, dir, dir->name);
1859 devfsd_notify (de, DEVFSD_NOTIFY_REGISTERED, 0);
1862 } /* End Function devfs_mk_dir */
1866 * devfs_get_handle - Find the handle of a devfs entry.
1867 * @dir: The handle to the parent devfs directory entry. If this is %NULL the
1868 * name is relative to the root of the devfs.
1869 * @name: The name of the entry.
1870 * @major: The major number. This is used if @name is %NULL.
1871 * @minor: The minor number. This is used if @name is %NULL.
1872 * @type: The type of special file to search for. This may be either
1873 * %DEVFS_SPECIAL_CHR or %DEVFS_SPECIAL_BLK.
1874 * @traverse_symlinks: If %TRUE then symlink entries in the devfs namespace are
1875 * traversed. Symlinks pointing out of the devfs namespace will cause a
1876 * failure. Symlink traversal consumes stack space.
1878 * Returns a handle which may later be used in a call to
1879 * devfs_unregister(), devfs_get_flags(), or devfs_set_flags(). A
1880 * subsequent devfs_put() is required to decrement the refcount.
1881 * On failure %NULL is returned.
1884 devfs_handle_t devfs_get_handle (devfs_handle_t dir, const char *name,
1885 unsigned int major, unsigned int minor,
1886 char type, int traverse_symlinks)
1888 if ( (name != NULL) && (name[0] == '\0') ) name = NULL;
1889 return _devfs_find_entry (dir, name, major, minor, type,traverse_symlinks);
1890 } /* End Function devfs_get_handle */
1893 /* Compatibility function. Will be removed in sometime in 2.5 */
1895 devfs_handle_t devfs_find_handle (devfs_handle_t dir, const char *name,
1896 unsigned int major, unsigned int minor,
1897 char type, int traverse_symlinks)
1901 de = devfs_get_handle (dir, name, major, minor, type, traverse_symlinks);
1904 } /* End Function devfs_find_handle */
1908 * devfs_get_flags - Get the flags for a devfs entry.
1909 * @de: The handle to the device entry.
1910 * @flags: The flags are written here.
1912 * Returns 0 on success, else a negative error code.
1915 int devfs_get_flags (devfs_handle_t de, unsigned int *flags)
1917 unsigned int fl = 0;
1919 if (de == NULL) return -EINVAL;
1921 if (de->hide) fl |= DEVFS_FL_HIDE;
1922 if ( S_ISCHR (de->mode) || S_ISBLK (de->mode) || S_ISREG (de->mode) )
1924 if (de->u.fcb.auto_owner) fl |= DEVFS_FL_AUTO_OWNER;
1925 if (de->u.fcb.aopen_notify) fl |= DEVFS_FL_AOPEN_NOTIFY;
1926 if (de->u.fcb.removable) fl |= DEVFS_FL_REMOVABLE;
1930 } /* End Function devfs_get_flags */
1934 * devfs_set_flags - Set the flags for a devfs entry.
1935 * @de: The handle to the device entry.
1936 * @flags: The flags to set. Unset flags are cleared.
1938 * Returns 0 on success, else a negative error code.
1941 int devfs_set_flags (devfs_handle_t de, unsigned int flags)
1943 if (de == NULL) return -EINVAL;
1945 DPRINTK (DEBUG_SET_FLAGS, "(%s): flags: %x\n", de->name, flags);
1946 de->hide = (flags & DEVFS_FL_HIDE) ? TRUE : FALSE;
1947 if ( S_ISCHR (de->mode) || S_ISBLK (de->mode) || S_ISREG (de->mode) )
1949 de->u.fcb.auto_owner = (flags & DEVFS_FL_AUTO_OWNER) ? TRUE : FALSE;
1950 de->u.fcb.aopen_notify = (flags & DEVFS_FL_AOPEN_NOTIFY) ? TRUE:FALSE;
1953 } /* End Function devfs_set_flags */
1957 * devfs_get_maj_min - Get the major and minor numbers for a devfs entry.
1958 * @de: The handle to the device entry.
1959 * @major: The major number is written here. This may be %NULL.
1960 * @minor: The minor number is written here. This may be %NULL.
1962 * Returns 0 on success, else a negative error code.
1965 int devfs_get_maj_min (devfs_handle_t de, unsigned int *major,
1966 unsigned int *minor)
1968 if (de == NULL) return -EINVAL;
1970 if ( S_ISDIR (de->mode) ) return -EISDIR;
1971 if ( !S_ISCHR (de->mode) && !S_ISBLK (de->mode) ) return -EINVAL;
1972 if (major != NULL) *major = de->u.fcb.u.device.major;
1973 if (minor != NULL) *minor = de->u.fcb.u.device.minor;
1975 } /* End Function devfs_get_maj_min */
1979 * devfs_get_handle_from_inode - Get the devfs handle for a VFS inode.
1980 * @inode: The VFS inode.
1982 * Returns the devfs handle on success, else %NULL.
1985 devfs_handle_t devfs_get_handle_from_inode (struct inode *inode)
1987 if (!inode || !inode->i_sb) return NULL;
1988 if (inode->i_sb->s_magic != DEVFS_SUPER_MAGIC) return NULL;
1989 return get_devfs_entry_from_vfs_inode (inode);
1990 } /* End Function devfs_get_handle_from_inode */
1994 * devfs_generate_path - Generate a pathname for an entry, relative to the devfs root.
1995 * @de: The devfs entry.
1996 * @path: The buffer to write the pathname to. The pathname and '\0'
1997 * terminator will be written at the end of the buffer.
1998 * @buflen: The length of the buffer.
2000 * Returns the offset in the buffer where the pathname starts on success,
2001 * else a negative error code.
2004 int devfs_generate_path (devfs_handle_t de, char *path, int buflen)
2007 #define NAMEOF(de) ( (de)->mode ? (de)->name : (de)->u.name )
2009 if (de == NULL) return -EINVAL;
2011 if (de->namelen >= buflen) return -ENAMETOOLONG; /* Must be first */
2012 path[buflen - 1] = '\0';
2013 if (de->parent == NULL) return buflen - 1; /* Don't prepend root */
2014 pos = buflen - de->namelen - 1;
2015 memcpy (path + pos, NAMEOF (de), de->namelen);
2016 for (de = de->parent; de->parent != NULL; de = de->parent)
2018 if (pos - de->namelen - 1 < 0) return -ENAMETOOLONG;
2021 memcpy (path + pos, NAMEOF (de), de->namelen);
2024 } /* End Function devfs_generate_path */
2028 * devfs_get_ops - Get the device operations for a devfs entry.
2029 * @de: The handle to the device entry.
2031 * Returns a pointer to the device operations on success, else NULL.
2032 * The use count for the module owning the operations will be incremented.
2035 void *devfs_get_ops (devfs_handle_t de)
2037 struct module *owner;
2039 if (de == NULL) return NULL;
2041 if ( !S_ISCHR (de->mode) && !S_ISBLK (de->mode) && !S_ISREG (de->mode) )
2043 if (de->u.fcb.ops == NULL) return NULL;
2044 read_lock (&de->parent->u.dir.lock); /* Prevent module from unloading */
2045 if (de->next == de) owner = NULL; /* Ops pointer is already stale */
2046 else if ( S_ISCHR (de->mode) || S_ISREG (de->mode) )
2047 owner = ( (struct file_operations *) de->u.fcb.ops )->owner;
2048 else owner = ( (struct block_device_operations *) de->u.fcb.ops )->owner;
2049 if ( (de->next == de) || !try_inc_mod_count (owner) )
2050 { /* Entry is already unhooked or module is unloading */
2051 read_unlock (&de->parent->u.dir.lock);
2054 read_unlock (&de->parent->u.dir.lock); /* Module can continue unloading*/
2055 return de->u.fcb.ops;
2056 } /* End Function devfs_get_ops */
2060 * devfs_put_ops - Put the device operations for a devfs entry.
2061 * @de: The handle to the device entry.
2063 * The use count for the module owning the operations will be decremented.
2066 void devfs_put_ops (devfs_handle_t de)
2068 struct module *owner;
2070 if (de == NULL) return;
2072 if ( !S_ISCHR (de->mode) && !S_ISBLK (de->mode) && !S_ISREG (de->mode) )
2074 if (de->u.fcb.ops == NULL) return;
2075 if ( S_ISCHR (de->mode) || S_ISREG (de->mode) )
2076 owner = ( (struct file_operations *) de->u.fcb.ops )->owner;
2077 else owner = ( (struct block_device_operations *) de->u.fcb.ops )->owner;
2078 if (owner) __MOD_DEC_USE_COUNT (owner);
2079 } /* End Function devfs_put_ops */
2083 * devfs_set_file_size - Set the file size for a devfs regular file.
2084 * @de: The handle to the device entry.
2085 * @size: The new file size.
2087 * Returns 0 on success, else a negative error code.
2090 int devfs_set_file_size (devfs_handle_t de, unsigned long size)
2092 if (de == NULL) return -EINVAL;
2094 if ( !S_ISREG (de->mode) ) return -EINVAL;
2095 if (de->u.fcb.u.file.size == size) return 0;
2096 de->u.fcb.u.file.size = size;
2097 if (de->inode.dentry == NULL) return 0;
2098 if (de->inode.dentry->d_inode == NULL) return 0;
2099 de->inode.dentry->d_inode->i_size = size;
2101 } /* End Function devfs_set_file_size */
2105 * devfs_get_info - Get the info pointer written to private_data of @de upon open.
2106 * @de: The handle to the device entry.
2108 * Returns the info pointer.
2110 void *devfs_get_info (devfs_handle_t de)
2112 if (de == NULL) return NULL;
2115 } /* End Function devfs_get_info */
2119 * devfs_set_info - Set the info pointer written to private_data upon open.
2120 * @de: The handle to the device entry.
2121 * @info: pointer to the data
2123 * Returns 0 on success, else a negative error code.
2125 int devfs_set_info (devfs_handle_t de, void *info)
2127 if (de == NULL) return -EINVAL;
2131 } /* End Function devfs_set_info */
2135 * devfs_get_parent - Get the parent device entry.
2136 * @de: The handle to the device entry.
2138 * Returns the parent device entry if it exists, else %NULL.
2140 devfs_handle_t devfs_get_parent (devfs_handle_t de)
2142 if (de == NULL) return NULL;
2145 } /* End Function devfs_get_parent */
2149 * devfs_get_first_child - Get the first leaf node in a directory.
2150 * @de: The handle to the device entry.
2152 * Returns the leaf node device entry if it exists, else %NULL.
2155 devfs_handle_t devfs_get_first_child (devfs_handle_t de)
2157 if (de == NULL) return NULL;
2159 if ( !S_ISDIR (de->mode) ) return NULL;
2160 return de->u.dir.first;
2161 } /* End Function devfs_get_first_child */
2165 * devfs_get_next_sibling - Get the next sibling leaf node. for a device entry.
2166 * @de: The handle to the device entry.
2168 * Returns the leaf node device entry if it exists, else %NULL.
2171 devfs_handle_t devfs_get_next_sibling (devfs_handle_t de)
2173 if (de == NULL) return NULL;
2176 } /* End Function devfs_get_next_sibling */
2180 * devfs_auto_unregister - Configure a devfs entry to be automatically unregistered.
2181 * @master: The master devfs entry. Only one slave may be registered.
2182 * @slave: The devfs entry which will be automatically unregistered when the
2183 * master entry is unregistered. It is illegal to call devfs_unregister()
2187 void devfs_auto_unregister (devfs_handle_t master, devfs_handle_t slave)
2189 if (master == NULL) return;
2190 VERIFY_ENTRY (master);
2191 VERIFY_ENTRY (slave);
2192 if (master->slave != NULL)
2194 /* Because of the dumbness of the layers above, ignore duplicates */
2195 if (master->slave == slave) return;
2196 PRINTK ("(%s): only one slave allowed\n", master->name);
2197 OOPS ("(): old slave: \"%s\" new slave: \"%s\"\n",
2198 master->slave->name, slave->name);
2200 master->slave = slave;
2201 } /* End Function devfs_auto_unregister */
2205 * devfs_get_unregister_slave - Get the slave entry which will be automatically unregistered.
2206 * @master: The master devfs entry.
2208 * Returns the slave which will be unregistered when @master is unregistered.
2211 devfs_handle_t devfs_get_unregister_slave (devfs_handle_t master)
2213 if (master == NULL) return NULL;
2214 VERIFY_ENTRY (master);
2215 return master->slave;
2216 } /* End Function devfs_get_unregister_slave */
2220 * devfs_get_name - Get the name for a device entry in its parent directory.
2221 * @de: The handle to the device entry.
2222 * @namelen: The length of the name is written here. This may be %NULL.
2224 * Returns the name on success, else %NULL.
2227 const char *devfs_get_name (devfs_handle_t de, unsigned int *namelen)
2229 if (de == NULL) return NULL;
2231 if (namelen != NULL) *namelen = de->namelen;
2233 } /* End Function devfs_get_name */
2237 * devfs_register_chrdev - Optionally register a conventional character driver.
2238 * @major: The major number for the driver.
2239 * @name: The name of the driver (as seen in /proc/devices).
2240 * @fops: The &file_operations structure pointer.
2242 * This function will register a character driver provided the "devfs=only"
2243 * option was not provided at boot time.
2244 * Returns 0 on success, else a negative error code on failure.
2247 int devfs_register_chrdev (unsigned int major, const char *name,
2248 struct file_operations *fops)
2250 if (boot_options & OPTION_ONLY) return 0;
2251 return register_chrdev (major, name, fops);
2252 } /* End Function devfs_register_chrdev */
2256 * devfs_register_blkdev - Optionally register a conventional block driver.
2257 * @major: The major number for the driver.
2258 * @name: The name of the driver (as seen in /proc/devices).
2259 * @bdops: The &block_device_operations structure pointer.
2261 * This function will register a block driver provided the "devfs=only"
2262 * option was not provided at boot time.
2263 * Returns 0 on success, else a negative error code on failure.
2266 int devfs_register_blkdev (unsigned int major, const char *name,
2267 struct block_device_operations *bdops)
2269 if (boot_options & OPTION_ONLY) return 0;
2270 return register_blkdev (major, name, bdops);
2271 } /* End Function devfs_register_blkdev */
2275 * devfs_unregister_chrdev - Optionally unregister a conventional character driver.
2276 * @major: The major number for the driver.
2277 * @name: The name of the driver (as seen in /proc/devices).
2279 * This function will unregister a character driver provided the "devfs=only"
2280 * option was not provided at boot time.
2281 * Returns 0 on success, else a negative error code on failure.
2284 int devfs_unregister_chrdev (unsigned int major, const char *name)
2286 if (boot_options & OPTION_ONLY) return 0;
2287 return unregister_chrdev (major, name);
2288 } /* End Function devfs_unregister_chrdev */
2292 * devfs_unregister_blkdev - Optionally unregister a conventional block driver.
2293 * @major: The major number for the driver.
2294 * @name: The name of the driver (as seen in /proc/devices).
2296 * This function will unregister a block driver provided the "devfs=only"
2297 * option was not provided at boot time.
2298 * Returns 0 on success, else a negative error code on failure.
2301 int devfs_unregister_blkdev (unsigned int major, const char *name)
2303 if (boot_options & OPTION_ONLY) return 0;
2304 return unregister_blkdev (major, name);
2305 } /* End Function devfs_unregister_blkdev */
2308 * devfs_setup - Process kernel boot options.
2309 * @str: The boot options after the "devfs=".
2312 static int __init devfs_setup (char *str)
2319 } devfs_options_tab[] __initdata =
2321 #ifdef CONFIG_DEVFS_DEBUG
2322 {"dall", DEBUG_ALL, &devfs_debug_init},
2323 {"dmod", DEBUG_MODULE_LOAD, &devfs_debug_init},
2324 {"dreg", DEBUG_REGISTER, &devfs_debug_init},
2325 {"dunreg", DEBUG_UNREGISTER, &devfs_debug_init},
2326 {"dfree", DEBUG_FREE, &devfs_debug_init},
2327 {"diget", DEBUG_I_GET, &devfs_debug_init},
2328 {"dchange", DEBUG_SET_FLAGS, &devfs_debug_init},
2329 {"dsread", DEBUG_S_READ, &devfs_debug_init},
2330 {"dichange", DEBUG_I_CHANGE, &devfs_debug_init},
2331 {"dimknod", DEBUG_I_MKNOD, &devfs_debug_init},
2332 {"dilookup", DEBUG_I_LOOKUP, &devfs_debug_init},
2333 {"diunlink", DEBUG_I_UNLINK, &devfs_debug_init},
2334 #endif /* CONFIG_DEVFS_DEBUG */
2335 {"only", OPTION_ONLY, &boot_options},
2336 {"mount", OPTION_MOUNT, &boot_options},
2340 while ( (*str != '\0') && !isspace (*str) )
2342 int i, found = 0, invert = 0;
2344 if (strncmp (str, "no", 2) == 0)
2349 for (i = 0; devfs_options_tab[i].name != NULL; i++)
2351 int len = strlen (devfs_options_tab[i].name);
2353 if (strncmp (str, devfs_options_tab[i].name, len) == 0)
2356 *devfs_options_tab[i].opt &= ~devfs_options_tab[i].mask;
2358 *devfs_options_tab[i].opt |= devfs_options_tab[i].mask;
2364 if (!found) return 0; /* No match */
2365 if (*str != ',') return 0; /* No more options */
2369 } /* End Function devfs_setup */
2371 __setup("devfs=", devfs_setup);
2373 EXPORT_SYMBOL(devfs_put);
2374 EXPORT_SYMBOL(devfs_register);
2375 EXPORT_SYMBOL(devfs_unregister);
2376 EXPORT_SYMBOL(devfs_mk_symlink);
2377 EXPORT_SYMBOL(devfs_mk_dir);
2378 EXPORT_SYMBOL(devfs_get_handle);
2379 EXPORT_SYMBOL(devfs_find_handle);
2380 EXPORT_SYMBOL(devfs_get_flags);
2381 EXPORT_SYMBOL(devfs_set_flags);
2382 EXPORT_SYMBOL(devfs_get_maj_min);
2383 EXPORT_SYMBOL(devfs_get_handle_from_inode);
2384 EXPORT_SYMBOL(devfs_generate_path);
2385 EXPORT_SYMBOL(devfs_get_ops);
2386 EXPORT_SYMBOL(devfs_set_file_size);
2387 EXPORT_SYMBOL(devfs_get_info);
2388 EXPORT_SYMBOL(devfs_set_info);
2389 EXPORT_SYMBOL(devfs_get_parent);
2390 EXPORT_SYMBOL(devfs_get_first_child);
2391 EXPORT_SYMBOL(devfs_get_next_sibling);
2392 EXPORT_SYMBOL(devfs_auto_unregister);
2393 EXPORT_SYMBOL(devfs_get_unregister_slave);
2394 EXPORT_SYMBOL(devfs_get_name);
2395 EXPORT_SYMBOL(devfs_register_chrdev);
2396 EXPORT_SYMBOL(devfs_register_blkdev);
2397 EXPORT_SYMBOL(devfs_unregister_chrdev);
2398 EXPORT_SYMBOL(devfs_unregister_blkdev);
2402 * try_modload - Notify devfsd of an inode lookup by a non-devfsd process.
2403 * @parent: The parent devfs entry.
2404 * @fs_info: The filesystem info.
2405 * @name: The device name.
2406 * @namelen: The number of characters in @name.
2407 * @buf: A working area that will be used. This must not go out of scope
2408 * until devfsd is idle again.
2410 * Returns 0 on success (event was queued), else a negative error code.
2413 static int try_modload (struct devfs_entry *parent, struct fs_info *fs_info,
2414 const char *name, unsigned namelen,
2415 struct devfs_entry *buf)
2417 if ( !( fs_info->devfsd_event_mask & (1 << DEVFSD_NOTIFY_LOOKUP) ) )
2419 if ( is_devfsd_or_child (fs_info) ) return -ENOENT;
2420 memset (buf, 0, sizeof *buf);
2421 atomic_set (&buf->refcount, 1);
2422 buf->parent = parent;
2423 buf->namelen = namelen;
2425 WRITE_ENTRY_MAGIC (buf, MAGIC_VALUE);
2426 if ( !devfsd_notify_de (buf, DEVFSD_NOTIFY_LOOKUP, 0,
2427 current->euid, current->egid, fs_info, 0) )
2429 /* Possible success: event has been queued */
2431 } /* End Function try_modload */
2435 * check_disc_changed - Check if a removable disc was changed.
2438 * Returns 1 if the media was changed, else 0.
2440 * This function may block, and may indirectly cause the parent directory
2441 * contents to be changed due to partition re-reading.
2444 static int check_disc_changed (struct devfs_entry *de)
2448 kdev_t dev = mk_kdev (de->u.fcb.u.device.major, de->u.fcb.u.device.minor);
2449 struct block_device_operations *bdops;
2450 extern int warn_no_part;
2452 if ( !S_ISBLK (de->mode) ) return 0;
2453 bdops = devfs_get_ops (de);
2454 if (!bdops) return 0;
2455 if (bdops->check_media_change == NULL) goto out;
2456 if ( !bdops->check_media_change (dev) ) goto out;
2458 printk (KERN_DEBUG "VFS: Disk change detected on device %s\n",
2460 if ( invalidate_device (dev, 0) )
2461 printk (KERN_WARNING "VFS: busy inodes on changed media..\n");
2462 /* Ugly hack to disable messages about unable to read partition table */
2465 if (bdops->revalidate) bdops->revalidate (dev);
2470 } /* End Function check_disc_changed */
2474 * scan_dir_for_removable - Scan a directory for removable media devices and check media.
2475 * @dir: The directory.
2477 * This function may block, and may indirectly cause the directory
2478 * contents to be changed due to partition re-reading. The directory will
2479 * be locked for reading.
2482 static void scan_dir_for_removable (struct devfs_entry *dir)
2484 struct devfs_entry *de;
2486 read_lock (&dir->u.dir.lock);
2487 if (dir->u.dir.num_removable < 1) de = NULL;
2490 for (de = dir->u.dir.first; de != NULL; de = de->next)
2492 if (S_ISBLK (de->mode) && de->u.fcb.removable) break;
2496 read_unlock (&dir->u.dir.lock);
2497 if (de) check_disc_changed (de);
2499 } /* End Function scan_dir_for_removable */
2502 * get_removable_partition - Get removable media partition.
2503 * @dir: The parent directory.
2504 * @name: The name of the entry.
2505 * @namelen: The number of characters in <<name>>.
2507 * Returns 1 if the media was changed, else 0.
2509 * This function may block, and may indirectly cause the directory
2510 * contents to be changed due to partition re-reading. The directory must
2511 * be locked for reading upon entry, and will be unlocked upon exit.
2514 static int get_removable_partition (struct devfs_entry *dir, const char *name,
2515 unsigned int namelen)
2518 struct devfs_entry *de;
2520 if (dir->u.dir.num_removable < 1)
2522 read_unlock (&dir->u.dir.lock);
2525 for (de = dir->u.dir.first; de != NULL; de = de->next)
2527 if (!S_ISBLK (de->mode) || !de->u.fcb.removable) continue;
2528 if (strcmp (de->name, "disc") == 0) break;
2529 /* Support for names where the partition is appended to the disc name
2531 if (de->namelen >= namelen) continue;
2532 if (strncmp (de->name, name, de->namelen) == 0) break;
2535 read_unlock (&dir->u.dir.lock);
2536 retval = de ? check_disc_changed (de) : 0;
2539 } /* End Function get_removable_partition */
2542 /* Superblock operations follow */
2544 static struct inode_operations devfs_iops;
2545 static struct inode_operations devfs_dir_iops;
2546 static struct file_operations devfs_fops;
2547 static struct file_operations devfs_dir_fops;
2548 static struct inode_operations devfs_symlink_iops;
2550 static int devfs_notify_change (struct dentry *dentry, struct iattr *iattr)
2553 struct devfs_entry *de;
2554 struct inode *inode = dentry->d_inode;
2555 struct fs_info *fs_info = inode->i_sb->u.generic_sbp;
2557 de = get_devfs_entry_from_vfs_inode (inode);
2558 if (de == NULL) return -ENODEV;
2559 retval = inode_change_ok (inode, iattr);
2560 if (retval != 0) return retval;
2561 retval = inode_setattr (inode, iattr);
2562 if (retval != 0) return retval;
2563 DPRINTK (DEBUG_I_CHANGE, "(%d): VFS inode: %p devfs_entry: %p\n",
2564 (int) inode->i_ino, inode, de);
2565 DPRINTK (DEBUG_I_CHANGE, "(): mode: 0%o uid: %d gid: %d\n",
2566 (int) inode->i_mode, (int) inode->i_uid, (int) inode->i_gid);
2567 /* Inode is not on hash chains, thus must save permissions here rather
2568 than in a write_inode() method */
2569 if ( ( !S_ISREG (inode->i_mode) && !S_ISCHR (inode->i_mode) &&
2570 !S_ISBLK (inode->i_mode) ) || !de->u.fcb.auto_owner )
2572 de->mode = inode->i_mode;
2573 de->inode.uid = inode->i_uid;
2574 de->inode.gid = inode->i_gid;
2576 de->inode.atime = inode->i_atime;
2577 de->inode.mtime = inode->i_mtime;
2578 de->inode.ctime = inode->i_ctime;
2579 if ( ( iattr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID) ) &&
2580 !is_devfsd_or_child (fs_info) )
2581 devfsd_notify_de (de, DEVFSD_NOTIFY_CHANGE, inode->i_mode,
2582 inode->i_uid, inode->i_gid, fs_info, 0);
2584 } /* End Function devfs_notify_change */
2586 static int devfs_statfs (struct super_block *sb, struct statfs *buf)
2588 buf->f_type = DEVFS_SUPER_MAGIC;
2589 buf->f_bsize = FAKE_BLOCK_SIZE;
2593 buf->f_namelen = NAME_MAX;
2595 } /* End Function devfs_statfs */
2597 static void devfs_clear_inode (struct inode *inode)
2599 if ( S_ISBLK (inode->i_mode) ) bdput (inode->i_bdev);
2600 } /* End Function devfs_clear_inode */
2602 static struct super_operations devfs_sops =
2604 .put_inode = force_delete,
2605 .clear_inode = devfs_clear_inode,
2606 .statfs = devfs_statfs,
2611 * _devfs_get_vfs_inode - Get a VFS inode.
2612 * @sb: The super block.
2613 * @de: The devfs inode.
2614 * @dentry: The dentry to register with the devfs inode.
2616 * Returns the inode on success, else %NULL. An implicit devfs_get() is
2617 * performed if the inode is created.
2620 static struct inode *_devfs_get_vfs_inode (struct super_block *sb,
2621 struct devfs_entry *de,
2622 struct dentry *dentry)
2625 struct inode *inode;
2627 if (de->prev == de) return NULL; /* Quick check to see if unhooked */
2628 if ( ( inode = new_inode (sb) ) == NULL )
2630 PRINTK ("(%s): new_inode() failed, de: %p\n", de->name, de);
2635 read_lock (&de->parent->u.dir.lock);
2636 if (de->prev != de) de->inode.dentry = dentry; /* Not unhooked */
2637 read_unlock (&de->parent->u.dir.lock);
2639 else de->inode.dentry = dentry; /* Root: no locking needed */
2640 if (de->inode.dentry != dentry)
2641 { /* Must have been unhooked */
2645 inode->u.generic_ip = devfs_get (de);
2646 inode->i_ino = de->inode.ino;
2647 DPRINTK (DEBUG_I_GET, "(%d): VFS inode: %p devfs_entry: %p\n",
2648 (int) inode->i_ino, inode, de);
2649 inode->i_blocks = 0;
2650 inode->i_blksize = FAKE_BLOCK_SIZE;
2651 inode->i_op = &devfs_iops;
2652 inode->i_fop = &devfs_fops;
2653 inode->i_rdev = NODEV;
2654 if ( S_ISCHR (de->mode) )
2656 inode->i_rdev = mk_kdev (de->u.fcb.u.device.major,
2657 de->u.fcb.u.device.minor);
2658 inode->i_cdev = cdget ( kdev_t_to_nr (inode->i_rdev) );
2661 else if ( S_ISBLK (de->mode) )
2663 inode->i_rdev = mk_kdev (de->u.fcb.u.device.major,
2664 de->u.fcb.u.device.minor);
2665 if (bd_acquire (inode) == 0)
2667 if (!inode->i_bdev->bd_op && de->u.fcb.ops)
2668 inode->i_bdev->bd_op = de->u.fcb.ops;
2670 else PRINTK ("(%d): no block device from bdget()\n",(int)inode->i_ino);
2673 else if ( S_ISFIFO (de->mode) ) inode->i_fop = &def_fifo_fops;
2674 else if ( S_ISREG (de->mode) )
2676 inode->i_size = de->u.fcb.u.file.size;
2679 else if ( S_ISDIR (de->mode) )
2681 inode->i_op = &devfs_dir_iops;
2682 inode->i_fop = &devfs_dir_fops;
2684 else if ( S_ISLNK (de->mode) )
2686 inode->i_op = &devfs_symlink_iops;
2687 inode->i_size = de->u.symlink.length;
2689 if (is_fcb && de->u.fcb.auto_owner)
2690 inode->i_mode = (de->mode & S_IFMT) | S_IRUGO | S_IWUGO;
2691 else inode->i_mode = de->mode;
2692 inode->i_uid = de->inode.uid;
2693 inode->i_gid = de->inode.gid;
2694 inode->i_atime = de->inode.atime;
2695 inode->i_mtime = de->inode.mtime;
2696 inode->i_ctime = de->inode.ctime;
2697 DPRINTK (DEBUG_I_GET, "(): mode: 0%o uid: %d gid: %d\n",
2698 (int) inode->i_mode, (int) inode->i_uid, (int) inode->i_gid);
2700 } /* End Function _devfs_get_vfs_inode */
2703 /* File operations for device entries follow */
2705 static int devfs_readdir (struct file *file, void *dirent, filldir_t filldir)
2709 struct fs_info *fs_info;
2710 struct devfs_entry *parent, *de, *next = NULL;
2711 struct inode *inode = file->f_dentry->d_inode;
2713 fs_info = inode->i_sb->u.generic_sbp;
2714 parent = get_devfs_entry_from_vfs_inode (file->f_dentry->d_inode);
2715 if ( (long) file->f_pos < 0 ) return -EINVAL;
2716 DPRINTK (DEBUG_F_READDIR, "(%s): fs_info: %p pos: %ld\n",
2717 parent->name, fs_info, (long) file->f_pos);
2718 switch ( (long) file->f_pos )
2721 scan_dir_for_removable (parent);
2722 err = (*filldir) (dirent, "..", 2, file->f_pos,
2723 file->f_dentry->d_parent->d_inode->i_ino, DT_DIR);
2724 if (err == -EINVAL) break;
2725 if (err < 0) return err;
2730 err = (*filldir) (dirent, ".", 1, file->f_pos, inode->i_ino, DT_DIR);
2731 if (err == -EINVAL) break;
2732 if (err < 0) return err;
2738 count = file->f_pos - 2;
2739 read_lock (&parent->u.dir.lock);
2740 for (de = parent->u.dir.first; de && (count > 0); de = de->next)
2741 if ( !IS_HIDDEN (de) ) --count;
2743 read_unlock (&parent->u.dir.lock);
2744 /* Now add all remaining entries */
2747 if ( IS_HIDDEN (de) ) err = 0;
2750 err = (*filldir) (dirent, de->name, de->namelen,
2751 file->f_pos, de->inode.ino, de->mode >> 12);
2752 if (err < 0) devfs_put (de);
2759 if (err == -EINVAL) break;
2760 if (err < 0) return err;
2761 read_lock (&parent->u.dir.lock);
2762 next = devfs_get (de->next);
2763 read_unlock (&parent->u.dir.lock);
2770 } /* End Function devfs_readdir */
2772 static int devfs_open (struct inode *inode, struct file *file)
2775 struct fcb_type *df;
2776 struct devfs_entry *de;
2777 struct fs_info *fs_info = inode->i_sb->u.generic_sbp;
2780 de = get_devfs_entry_from_vfs_inode (inode);
2781 if (de == NULL) return -ENODEV;
2782 if ( S_ISDIR (de->mode) ) return 0;
2784 file->private_data = de->info;
2785 ops = devfs_get_ops (de); /* Now have module refcount */
2786 if ( S_ISBLK (inode->i_mode) )
2788 file->f_op = &def_blk_fops;
2789 if (ops) inode->i_bdev->bd_op = ops;
2790 err = def_blk_fops.open (inode, file); /* This bumps module refcount */
2791 devfs_put_ops (de); /* So drop my refcount */
2799 err = file->f_op->open ? (*file->f_op->open) (inode, file) : 0;
2803 { /* Fallback to legacy scheme (I don't have a module refcount) */
2804 if ( S_ISCHR (inode->i_mode) ) err = chrdev_open (inode, file);
2808 if (err < 0) return err;
2809 /* Open was successful */
2810 if (df->open) return 0;
2811 df->open = TRUE; /* This is the first open */
2814 /* Change the ownership/protection to what driver specified */
2815 inode->i_mode = de->mode;
2816 inode->i_uid = current->euid;
2817 inode->i_gid = current->egid;
2819 if ( df->aopen_notify && !is_devfsd_or_child (fs_info) )
2820 devfsd_notify_de (de, DEVFSD_NOTIFY_ASYNC_OPEN, inode->i_mode,
2821 current->euid, current->egid, fs_info, 0);
2823 } /* End Function devfs_open */
2825 static struct file_operations devfs_fops =
2830 static struct file_operations devfs_dir_fops =
2832 .read = generic_read_dir,
2833 .readdir = devfs_readdir,
2838 /* Dentry operations for device entries follow */
2842 * devfs_d_release - Callback for when a dentry is freed.
2843 * @dentry: The dentry.
2846 static void devfs_d_release (struct dentry *dentry)
2848 DPRINTK (DEBUG_D_RELEASE, "(%p): inode: %p\n", dentry, dentry->d_inode);
2849 } /* End Function devfs_d_release */
2852 * devfs_d_iput - Callback for when a dentry loses its inode.
2853 * @dentry: The dentry.
2854 * @inode: The inode.
2857 static void devfs_d_iput (struct dentry *dentry, struct inode *inode)
2859 struct devfs_entry *de;
2861 de = get_devfs_entry_from_vfs_inode (inode);
2862 DPRINTK (DEBUG_D_IPUT,"(%s): dentry: %p inode: %p de: %p de->dentry: %p\n",
2863 de->name, dentry, inode, de, de->inode.dentry);
2864 if ( de->inode.dentry && (de->inode.dentry != dentry) )
2865 OOPS ("(%s): de: %p dentry: %p de->dentry: %p\n",
2866 de->name, de, dentry, de->inode.dentry);
2867 de->inode.dentry = NULL;
2870 } /* End Function devfs_d_iput */
2872 static int devfs_d_delete (struct dentry *dentry);
2874 static struct dentry_operations devfs_dops =
2876 .d_delete = devfs_d_delete,
2877 .d_release = devfs_d_release,
2878 .d_iput = devfs_d_iput,
2881 static int devfs_d_revalidate_wait (struct dentry *dentry, int flags);
2883 static struct dentry_operations devfs_wait_dops =
2885 .d_delete = devfs_d_delete,
2886 .d_release = devfs_d_release,
2887 .d_iput = devfs_d_iput,
2888 .d_revalidate = devfs_d_revalidate_wait,
2892 * devfs_d_delete - Callback for when all files for a dentry are closed.
2893 * @dentry: The dentry.
2896 static int devfs_d_delete (struct dentry *dentry)
2898 struct inode *inode = dentry->d_inode;
2899 struct devfs_entry *de;
2900 struct fs_info *fs_info;
2902 if (dentry->d_op == &devfs_wait_dops) dentry->d_op = &devfs_dops;
2903 /* Unhash dentry if negative (has no inode) */
2906 DPRINTK (DEBUG_D_DELETE, "(%p): dropping negative dentry\n", dentry);
2909 fs_info = inode->i_sb->u.generic_sbp;
2910 de = get_devfs_entry_from_vfs_inode (inode);
2911 DPRINTK (DEBUG_D_DELETE, "(%p): inode: %p devfs_entry: %p\n",
2913 if (de == NULL) return 0;
2914 if ( !S_ISCHR (de->mode) && !S_ISBLK (de->mode) && !S_ISREG (de->mode) )
2916 if (!de->u.fcb.open) return 0;
2917 de->u.fcb.open = FALSE;
2918 if (de->u.fcb.aopen_notify)
2919 devfsd_notify_de (de, DEVFSD_NOTIFY_CLOSE, inode->i_mode,
2920 current->euid, current->egid, fs_info, 1);
2921 if (!de->u.fcb.auto_owner) return 0;
2922 /* Change the ownership/protection back */
2923 inode->i_mode = (de->mode & S_IFMT) | S_IRUGO | S_IWUGO;
2924 inode->i_uid = de->inode.uid;
2925 inode->i_gid = de->inode.gid;
2927 } /* End Function devfs_d_delete */
2929 struct devfs_lookup_struct
2932 wait_queue_head_t wait_queue;
2935 static int devfs_d_revalidate_wait (struct dentry *dentry, int flags)
2937 struct inode *dir = dentry->d_parent->d_inode;
2938 struct fs_info *fs_info = dir->i_sb->u.generic_sbp;
2939 devfs_handle_t parent = get_devfs_entry_from_vfs_inode (dir);
2940 struct devfs_lookup_struct *lookup_info = dentry->d_fsdata;
2941 DECLARE_WAITQUEUE (wait, current);
2943 if ( is_devfsd_or_child (fs_info) )
2945 devfs_handle_t de = lookup_info->de;
2946 struct inode *inode;
2948 DPRINTK (DEBUG_I_LOOKUP,
2949 "(%s): dentry: %p inode: %p de: %p by: \"%s\"\n",
2950 dentry->d_name.name, dentry, dentry->d_inode, de,
2952 if (dentry->d_inode) return 1;
2955 read_lock (&parent->u.dir.lock);
2956 de = _devfs_search_dir (parent, dentry->d_name.name,
2957 dentry->d_name.len);
2958 read_unlock (&parent->u.dir.lock);
2959 if (de == NULL) return 1;
2960 lookup_info->de = de;
2962 /* Create an inode, now that the driver information is available */
2963 inode = _devfs_get_vfs_inode (dir->i_sb, de, dentry);
2964 if (!inode) return 1;
2965 DPRINTK (DEBUG_I_LOOKUP,
2966 "(%s): new VFS inode(%u): %p de: %p by: \"%s\"\n",
2967 de->name, de->inode.ino, inode, de, current->comm);
2968 d_instantiate (dentry, inode);
2971 if (lookup_info == NULL) return 1; /* Early termination */
2972 read_lock (&parent->u.dir.lock);
2973 if (dentry->d_fsdata)
2975 set_current_state (TASK_UNINTERRUPTIBLE);
2976 add_wait_queue (&lookup_info->wait_queue, &wait);
2977 read_unlock (&parent->u.dir.lock);
2980 else read_unlock (&parent->u.dir.lock);
2982 } /* End Function devfs_d_revalidate_wait */
2985 /* Inode operations for device entries follow */
2987 static struct dentry *devfs_lookup (struct inode *dir, struct dentry *dentry)
2989 struct devfs_entry tmp; /* Must stay in scope until devfsd idle again */
2990 struct devfs_lookup_struct lookup_info;
2991 struct fs_info *fs_info = dir->i_sb->u.generic_sbp;
2992 struct devfs_entry *parent, *de;
2993 struct inode *inode;
2994 struct dentry *retval = NULL;
2996 /* Set up the dentry operations before anything else, to ensure cleaning
2998 dentry->d_op = &devfs_dops;
2999 /* First try to get the devfs entry for this directory */
3000 parent = get_devfs_entry_from_vfs_inode (dir);
3001 DPRINTK (DEBUG_I_LOOKUP, "(%s): dentry: %p parent: %p by: \"%s\"\n",
3002 dentry->d_name.name, dentry, parent, current->comm);
3003 if (parent == NULL) return ERR_PTR (-ENOENT);
3004 read_lock (&parent->u.dir.lock);
3005 de = _devfs_search_dir (parent, dentry->d_name.name, dentry->d_name.len);
3006 if (de) read_unlock (&parent->u.dir.lock);
3008 { /* Try re-reading the partition (media may have changed) */
3009 if ( get_removable_partition (parent, dentry->d_name.name,
3010 dentry->d_name.len) ) /* Unlocks */
3011 { /* Media did change */
3012 read_lock (&parent->u.dir.lock);
3013 de = _devfs_search_dir (parent, dentry->d_name.name,
3014 dentry->d_name.len);
3015 read_unlock (&parent->u.dir.lock);
3018 lookup_info.de = de;
3019 init_waitqueue_head (&lookup_info.wait_queue);
3020 dentry->d_fsdata = &lookup_info;
3022 { /* Try with devfsd. For any kind of failure, leave a negative dentry
3023 so someone else can deal with it (in the case where the sysadmin
3024 does a mknod()). It's important to do this before hashing the
3025 dentry, so that the devfsd queue is filled before revalidates
3027 if (try_modload (parent, fs_info,
3028 dentry->d_name.name, dentry->d_name.len, &tmp) < 0)
3029 { /* Lookup event was not queued to devfsd */
3030 d_add (dentry, NULL);
3034 dentry->d_op = &devfs_wait_dops;
3035 d_add (dentry, NULL); /* Open the floodgates */
3036 /* Unlock directory semaphore, which will release any waiters. They
3037 will get the hashed dentry, and may be forced to wait for
3040 wait_for_devfsd_finished (fs_info); /* If I'm not devfsd, must wait */
3041 down (&dir->i_sem); /* Grab it again because them's the rules */
3042 de = lookup_info.de;
3043 /* If someone else has been so kind as to make the inode, we go home
3045 if (dentry->d_inode) goto out;
3048 read_lock (&parent->u.dir.lock);
3049 de = _devfs_search_dir (parent, dentry->d_name.name,
3050 dentry->d_name.len);
3051 read_unlock (&parent->u.dir.lock);
3052 if (de == NULL) goto out;
3053 /* OK, there's an entry now, but no VFS inode yet */
3055 /* Create an inode, now that the driver information is available */
3056 inode = _devfs_get_vfs_inode (dir->i_sb, de, dentry);
3059 retval = ERR_PTR (-ENOMEM);
3062 DPRINTK (DEBUG_I_LOOKUP, "(%s): new VFS inode(%u): %p de: %p by: \"%s\"\n",
3063 de->name, de->inode.ino, inode, de, current->comm);
3064 d_instantiate (dentry, inode);
3066 dentry->d_op = &devfs_dops;
3067 dentry->d_fsdata = NULL;
3068 write_lock (&parent->u.dir.lock);
3069 wake_up (&lookup_info.wait_queue);
3070 write_unlock (&parent->u.dir.lock);
3073 } /* End Function devfs_lookup */
3075 static int devfs_unlink (struct inode *dir, struct dentry *dentry)
3078 struct devfs_entry *de;
3079 struct inode *inode = dentry->d_inode;
3080 struct fs_info *fs_info = dir->i_sb->u.generic_sbp;
3082 de = get_devfs_entry_from_vfs_inode (inode);
3083 DPRINTK (DEBUG_I_UNLINK, "(%s): de: %p\n", dentry->d_name.name, de);
3084 if (de == NULL) return -ENOENT;
3085 if (!de->vfs_deletable) return -EPERM;
3086 write_lock (&de->parent->u.dir.lock);
3087 unhooked = _devfs_unhook (de);
3088 write_unlock (&de->parent->u.dir.lock);
3089 if (!unhooked) return -ENOENT;
3090 if ( !is_devfsd_or_child (fs_info) )
3091 devfsd_notify_de (de, DEVFSD_NOTIFY_DELETE, inode->i_mode,
3092 inode->i_uid, inode->i_gid, fs_info, 0);
3096 } /* End Function devfs_unlink */
3098 static int devfs_symlink (struct inode *dir, struct dentry *dentry,
3099 const char *symname)
3102 struct fs_info *fs_info = dir->i_sb->u.generic_sbp;
3103 struct devfs_entry *parent, *de;
3104 struct inode *inode;
3106 /* First try to get the devfs entry for this directory */
3107 parent = get_devfs_entry_from_vfs_inode (dir);
3108 if (parent == NULL) return -ENOENT;
3109 err = devfs_do_symlink (parent, dentry->d_name.name, DEVFS_FL_NONE,
3110 symname, &de, NULL);
3111 DPRINTK (DEBUG_DISABLED, "(%s): errcode from <devfs_do_symlink>: %d\n",
3112 dentry->d_name.name, err);
3113 if (err < 0) return err;
3114 de->vfs_deletable = TRUE;
3115 de->inode.uid = current->euid;
3116 de->inode.gid = current->egid;
3117 de->inode.atime = CURRENT_TIME;
3118 de->inode.mtime = CURRENT_TIME;
3119 de->inode.ctime = CURRENT_TIME;
3120 if ( ( inode = _devfs_get_vfs_inode (dir->i_sb, de, dentry) ) == NULL )
3122 DPRINTK (DEBUG_DISABLED, "(%s): new VFS inode(%u): %p dentry: %p\n",
3123 dentry->d_name.name, de->inode.ino, inode, dentry);
3124 d_instantiate (dentry, inode);
3125 if ( !is_devfsd_or_child (fs_info) )
3126 devfsd_notify_de (de, DEVFSD_NOTIFY_CREATE, inode->i_mode,
3127 inode->i_uid, inode->i_gid, fs_info, 0);
3129 } /* End Function devfs_symlink */
3131 static int devfs_mkdir (struct inode *dir, struct dentry *dentry, int mode)
3134 struct fs_info *fs_info = dir->i_sb->u.generic_sbp;
3135 struct devfs_entry *parent, *de;
3136 struct inode *inode;
3138 mode = (mode & ~S_IFMT) | S_IFDIR; /* VFS doesn't pass S_IFMT part */
3139 parent = get_devfs_entry_from_vfs_inode (dir);
3140 if (parent == NULL) return -ENOENT;
3141 de = _devfs_alloc_entry (dentry->d_name.name, dentry->d_name.len, mode);
3142 if (!de) return -ENOMEM;
3143 de->vfs_deletable = TRUE;
3144 if ( ( err = _devfs_append_entry (parent, de, FALSE, NULL) ) != 0 )
3146 de->inode.uid = current->euid;
3147 de->inode.gid = current->egid;
3148 de->inode.atime = CURRENT_TIME;
3149 de->inode.mtime = CURRENT_TIME;
3150 de->inode.ctime = CURRENT_TIME;
3151 if ( ( inode = _devfs_get_vfs_inode (dir->i_sb, de, dentry) ) == NULL )
3153 DPRINTK (DEBUG_DISABLED, "(%s): new VFS inode(%u): %p dentry: %p\n",
3154 dentry->d_name.name, de->inode.ino, inode, dentry);
3155 d_instantiate (dentry, inode);
3156 if ( !is_devfsd_or_child (fs_info) )
3157 devfsd_notify_de (de, DEVFSD_NOTIFY_CREATE, inode->i_mode,
3158 inode->i_uid, inode->i_gid, fs_info, 0);
3160 } /* End Function devfs_mkdir */
3162 static int devfs_rmdir (struct inode *dir, struct dentry *dentry)
3165 struct devfs_entry *de;
3166 struct fs_info *fs_info = dir->i_sb->u.generic_sbp;
3167 struct inode *inode = dentry->d_inode;
3169 if (dir->i_sb->u.generic_sbp != inode->i_sb->u.generic_sbp) return -EINVAL;
3170 de = get_devfs_entry_from_vfs_inode (inode);
3171 if (de == NULL) return -ENOENT;
3172 if ( !S_ISDIR (de->mode) ) return -ENOTDIR;
3173 if (!de->vfs_deletable) return -EPERM;
3174 /* First ensure the directory is empty and will stay that way */
3175 write_lock (&de->u.dir.lock);
3176 if (de->u.dir.first) err = -ENOTEMPTY;
3177 else de->u.dir.no_more_additions = TRUE;
3178 write_unlock (&de->u.dir.lock);
3179 if (err) return err;
3180 /* Now unhook the directory from it's parent */
3181 write_lock (&de->parent->u.dir.lock);
3182 if ( !_devfs_unhook (de) ) err = -ENOENT;
3183 write_unlock (&de->parent->u.dir.lock);
3184 if (err) return err;
3185 if ( !is_devfsd_or_child (fs_info) )
3186 devfsd_notify_de (de, DEVFSD_NOTIFY_DELETE, inode->i_mode,
3187 inode->i_uid, inode->i_gid, fs_info, 0);
3191 } /* End Function devfs_rmdir */
3193 static int devfs_mknod (struct inode *dir, struct dentry *dentry, int mode,
3197 struct fs_info *fs_info = dir->i_sb->u.generic_sbp;
3198 struct devfs_entry *parent, *de;
3199 struct inode *inode;
3201 DPRINTK (DEBUG_I_MKNOD, "(%s): mode: 0%o dev: %d\n",
3202 dentry->d_name.name, mode, rdev);
3203 parent = get_devfs_entry_from_vfs_inode (dir);
3204 if (parent == NULL) return -ENOENT;
3205 de = _devfs_alloc_entry (dentry->d_name.name, dentry->d_name.len, mode);
3206 if (!de) return -ENOMEM;
3207 de->vfs_deletable = TRUE;
3208 if ( S_ISBLK (mode) || S_ISCHR (mode) )
3210 de->u.fcb.u.device.major = MAJOR (rdev);
3211 de->u.fcb.u.device.minor = MINOR (rdev);
3213 if ( ( err = _devfs_append_entry (parent, de, FALSE, NULL) ) != 0 )
3215 de->inode.uid = current->euid;
3216 de->inode.gid = current->egid;
3217 de->inode.atime = CURRENT_TIME;
3218 de->inode.mtime = CURRENT_TIME;
3219 de->inode.ctime = CURRENT_TIME;
3220 if ( ( inode = _devfs_get_vfs_inode (dir->i_sb, de, dentry) ) == NULL )
3222 DPRINTK (DEBUG_I_MKNOD, ": new VFS inode(%u): %p dentry: %p\n",
3223 de->inode.ino, inode, dentry);
3224 d_instantiate (dentry, inode);
3225 if ( !is_devfsd_or_child (fs_info) )
3226 devfsd_notify_de (de, DEVFSD_NOTIFY_CREATE, inode->i_mode,
3227 inode->i_uid, inode->i_gid, fs_info, 0);
3229 } /* End Function devfs_mknod */
3231 static int devfs_readlink (struct dentry *dentry, char *buffer, int buflen)
3234 struct devfs_entry *de;
3236 de = get_devfs_entry_from_vfs_inode (dentry->d_inode);
3237 if (!de) return -ENODEV;
3238 err = vfs_readlink (dentry, buffer, buflen, de->u.symlink.linkname);
3240 } /* End Function devfs_readlink */
3242 static int devfs_follow_link (struct dentry *dentry, struct nameidata *nd)
3245 struct devfs_entry *de;
3247 de = get_devfs_entry_from_vfs_inode (dentry->d_inode);
3248 if (!de) return -ENODEV;
3249 err = vfs_follow_link (nd, de->u.symlink.linkname);
3251 } /* End Function devfs_follow_link */
3253 static struct inode_operations devfs_iops =
3255 .setattr = devfs_notify_change,
3258 static struct inode_operations devfs_dir_iops =
3260 .lookup = devfs_lookup,
3261 .unlink = devfs_unlink,
3262 .symlink = devfs_symlink,
3263 .mkdir = devfs_mkdir,
3264 .rmdir = devfs_rmdir,
3265 .mknod = devfs_mknod,
3266 .setattr = devfs_notify_change,
3269 static struct inode_operations devfs_symlink_iops =
3271 .readlink = devfs_readlink,
3272 .follow_link = devfs_follow_link,
3273 .setattr = devfs_notify_change,
3276 static struct super_block *devfs_read_super (struct super_block *sb,
3277 void *data, int silent)
3279 struct inode *root_inode = NULL;
3281 if (_devfs_get_root_entry () == NULL) goto out_no_root;
3282 atomic_set (&fs_info.devfsd_overrun_count, 0);
3283 init_waitqueue_head (&fs_info.devfsd_wait_queue);
3284 init_waitqueue_head (&fs_info.revalidate_wait_queue);
3286 sb->u.generic_sbp = &fs_info;
3287 sb->s_blocksize = 1024;
3288 sb->s_blocksize_bits = 10;
3289 sb->s_magic = DEVFS_SUPER_MAGIC;
3290 sb->s_op = &devfs_sops;
3291 if ( ( root_inode = _devfs_get_vfs_inode (sb, root_entry, NULL) ) == NULL )
3293 sb->s_root = d_alloc_root (root_inode);
3294 if (!sb->s_root) goto out_no_root;
3295 DPRINTK (DEBUG_S_READ, "(): made devfs ptr: %p\n", sb->u.generic_sbp);
3299 PRINTK ("(): get root inode failed\n");
3300 if (root_inode) iput (root_inode);
3302 } /* End Function devfs_read_super */
3305 static DECLARE_FSTYPE (devfs_fs_type, DEVFS_NAME, devfs_read_super, FS_SINGLE);
3308 /* File operations for devfsd follow */
3310 static ssize_t devfsd_read (struct file *file, char *buf, size_t len,
3315 loff_t pos, devname_offset, tlen, rpos;
3317 struct devfsd_buf_entry *entry;
3318 struct fs_info *fs_info = file->f_dentry->d_inode->i_sb->u.generic_sbp;
3319 struct devfsd_notify_struct *info = fs_info->devfsd_info;
3320 DECLARE_WAITQUEUE (wait, current);
3322 /* Can't seek (pread) on this device */
3323 if (ppos != &file->f_pos) return -ESPIPE;
3324 /* Verify the task has grabbed the queue */
3325 if (fs_info->devfsd_task != current) return -EPERM;
3328 /* Block for a new entry */
3329 set_current_state (TASK_INTERRUPTIBLE);
3330 add_wait_queue (&fs_info->devfsd_wait_queue, &wait);
3331 while ( devfsd_queue_empty (fs_info) )
3333 fs_info->devfsd_sleeping = TRUE;
3334 wake_up (&fs_info->revalidate_wait_queue);
3336 fs_info->devfsd_sleeping = FALSE;
3337 if ( signal_pending (current) )
3339 remove_wait_queue (&fs_info->devfsd_wait_queue, &wait);
3340 __set_current_state (TASK_RUNNING);
3343 set_current_state (TASK_INTERRUPTIBLE);
3345 remove_wait_queue (&fs_info->devfsd_wait_queue, &wait);
3346 __set_current_state (TASK_RUNNING);
3347 /* Now play with the data */
3348 ival = atomic_read (&fs_info->devfsd_overrun_count);
3349 info->overrun_count = ival;
3350 entry = fs_info->devfsd_first_event;
3351 info->type = entry->type;
3352 info->mode = entry->mode;
3353 info->uid = entry->uid;
3354 info->gid = entry->gid;
3356 if ( S_ISCHR (de->mode) || S_ISBLK (de->mode) )
3358 info->major = de->u.fcb.u.device.major;
3359 info->minor = de->u.fcb.u.device.minor;
3361 pos = devfs_generate_path (de, info->devname, DEVFS_PATHLEN);
3362 if (pos < 0) return pos;
3363 info->namelen = DEVFS_PATHLEN - pos - 1;
3364 if (info->mode == 0) info->mode = de->mode;
3365 devname_offset = info->devname - (char *) info;
3367 if (rpos < devname_offset)
3369 /* Copy parts of the header */
3370 tlen = devname_offset - rpos;
3371 if (tlen > len) tlen = len;
3372 if ( copy_to_user (buf, (char *) info + rpos, tlen) )
3380 if ( (rpos >= devname_offset) && (len > 0) )
3383 tlen = info->namelen + 1;
3384 if (tlen > len) tlen = len;
3386 if ( copy_to_user (buf, info->devname + pos + rpos - devname_offset,
3393 tlen = rpos - *ppos;
3396 devfs_handle_t parent;
3398 spin_lock (&fs_info->devfsd_buffer_lock);
3399 fs_info->devfsd_first_event = entry->next;
3400 if (entry->next == NULL) fs_info->devfsd_last_event = NULL;
3401 spin_unlock (&fs_info->devfsd_buffer_lock);
3402 for (; de != NULL; de = parent)
3404 parent = de->parent;
3407 kmem_cache_free (devfsd_buf_cache, entry);
3408 if (ival > 0) atomic_sub (ival, &fs_info->devfsd_overrun_count);
3413 } /* End Function devfsd_read */
3415 static int devfsd_ioctl (struct inode *inode, struct file *file,
3416 unsigned int cmd, unsigned long arg)
3419 struct fs_info *fs_info = inode->i_sb->u.generic_sbp;
3423 case DEVFSDIOC_GET_PROTO_REV:
3424 ival = DEVFSD_PROTOCOL_REVISION_KERNEL;
3425 if ( copy_to_user ( (void *)arg, &ival, sizeof ival ) ) return -EFAULT;
3427 case DEVFSDIOC_SET_EVENT_MASK:
3428 /* Ensure only one reader has access to the queue. This scheme will
3429 work even if the global kernel lock were to be removed, because it
3430 doesn't matter who gets in first, as long as only one gets it */
3431 if (fs_info->devfsd_task == NULL)
3433 static spinlock_t lock = SPIN_LOCK_UNLOCKED;
3435 if ( !spin_trylock (&lock) ) return -EBUSY;
3436 if (fs_info->devfsd_task != NULL)
3437 { /* We lost the race... */
3438 spin_unlock (&lock);
3441 fs_info->devfsd_task = current;
3442 spin_unlock (&lock);
3443 fs_info->devfsd_pgrp = (current->pgrp == current->pid) ?
3445 fs_info->devfsd_file = file;
3446 fs_info->devfsd_info = kmalloc (sizeof *fs_info->devfsd_info,
3448 if (!fs_info->devfsd_info)
3450 devfsd_close (inode, file);
3454 else if (fs_info->devfsd_task != current) return -EBUSY;
3455 fs_info->devfsd_event_mask = arg; /* Let the masses come forth */
3457 case DEVFSDIOC_RELEASE_EVENT_QUEUE:
3458 if (fs_info->devfsd_file != file) return -EPERM;
3459 return devfsd_close (inode, file);
3461 #ifdef CONFIG_DEVFS_DEBUG
3462 case DEVFSDIOC_SET_DEBUG_MASK:
3463 if ( copy_from_user (&ival, (void *) arg, sizeof ival) )return -EFAULT;
3468 return -ENOIOCTLCMD;
3471 } /* End Function devfsd_ioctl */
3473 static int devfsd_close (struct inode *inode, struct file *file)
3475 struct devfsd_buf_entry *entry, *next;
3476 struct fs_info *fs_info = inode->i_sb->u.generic_sbp;
3478 if (fs_info->devfsd_file != file) return 0;
3479 fs_info->devfsd_event_mask = 0;
3480 fs_info->devfsd_file = NULL;
3481 spin_lock (&fs_info->devfsd_buffer_lock);
3482 entry = fs_info->devfsd_first_event;
3483 fs_info->devfsd_first_event = NULL;
3484 fs_info->devfsd_last_event = NULL;
3485 if (fs_info->devfsd_info)
3487 kfree (fs_info->devfsd_info);
3488 fs_info->devfsd_info = NULL;
3490 spin_unlock (&fs_info->devfsd_buffer_lock);
3491 fs_info->devfsd_pgrp = 0;
3492 fs_info->devfsd_task = NULL;
3493 wake_up (&fs_info->revalidate_wait_queue);
3494 for (; entry; entry = next)
3497 kmem_cache_free (devfsd_buf_cache, entry);
3500 } /* End Function devfsd_close */
3502 #ifdef CONFIG_DEVFS_DEBUG
3503 static ssize_t stat_read (struct file *file, char *buf, size_t len,
3509 num = sprintf (txt, "Number of entries: %u number of bytes: %u\n",
3510 stat_num_entries, stat_num_bytes) + 1;
3511 /* Can't seek (pread) on this device */
3512 if (ppos != &file->f_pos) return -ESPIPE;
3513 if (*ppos >= num) return 0;
3514 if (*ppos + len > num) len = num - *ppos;
3515 if ( copy_to_user (buf, txt + *ppos, len) ) return -EFAULT;
3518 } /* End Function stat_read */
3522 static int __init init_devfs_fs (void)
3526 printk (KERN_INFO "%s: v%s Richard Gooch (rgooch@atnf.csiro.au)\n",
3527 DEVFS_NAME, DEVFS_VERSION);
3528 devfsd_buf_cache = kmem_cache_create ("devfsd_event",
3529 sizeof (struct devfsd_buf_entry),
3531 if (!devfsd_buf_cache) OOPS ("(): unable to allocate event slab\n");
3532 #ifdef CONFIG_DEVFS_DEBUG
3533 devfs_debug = devfs_debug_init;
3534 printk (KERN_INFO "%s: devfs_debug: 0x%0x\n", DEVFS_NAME, devfs_debug);
3536 printk (KERN_INFO "%s: boot_options: 0x%0x\n", DEVFS_NAME, boot_options);
3537 err = register_filesystem (&devfs_fs_type);
3540 struct vfsmount *devfs_mnt = kern_mount (&devfs_fs_type);
3541 err = PTR_ERR (devfs_mnt);
3542 if ( !IS_ERR (devfs_mnt) ) err = 0;
3545 } /* End Function init_devfs_fs */
3547 void __init mount_devfs_fs (void)
3551 if ( !(boot_options & OPTION_MOUNT) ) return;
3552 err = do_mount ("none", "/dev", "devfs", 0, "");
3553 if (err == 0) printk (KERN_INFO "Mounted devfs on /dev\n");
3554 else PRINTK ("(): unable to mount devfs, err: %d\n", err);
3555 } /* End Function mount_devfs_fs */
3557 module_init(init_devfs_fs)