+++ /dev/null
-/* devfs (Device FileSystem) driver.
-
- Copyright (C) 1998-2002 Richard Gooch
-
- This library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Library General Public
- License as published by the Free Software Foundation; either
- version 2 of the License, or (at your option) any later version.
-
- This library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Library General Public License for more details.
-
- You should have received a copy of the GNU Library General Public
- License along with this library; if not, write to the Free
- Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-
- Richard Gooch may be reached by email at rgooch@atnf.csiro.au
- The postal address is:
- Richard Gooch, c/o ATNF, P. O. Box 76, Epping, N.S.W., 2121, Australia.
-
- ChangeLog
-
- 19980110 Richard Gooch <rgooch@atnf.csiro.au>
- Original version.
- v0.1
- 19980111 Richard Gooch <rgooch@atnf.csiro.au>
- Created per-fs inode table rather than using inode->u.generic_ip
- v0.2
- 19980111 Richard Gooch <rgooch@atnf.csiro.au>
- Created .epoch inode which has a ctime of 0.
- Fixed loss of named pipes when dentries lost.
- Fixed loss of inode data when devfs_register() follows mknod().
- v0.3
- 19980111 Richard Gooch <rgooch@atnf.csiro.au>
- Fix for when compiling with CONFIG_KERNELD.
- 19980112 Richard Gooch <rgooch@atnf.csiro.au>
- Fix for readdir() which sometimes didn't show entries.
- Added <<tolerant>> option to <devfs_register>.
- v0.4
- 19980113 Richard Gooch <rgooch@atnf.csiro.au>
- Created <devfs_fill_file> function.
- v0.5
- 19980115 Richard Gooch <rgooch@atnf.csiro.au>
- Added subdirectory support. Major restructuring.
- 19980116 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed <find_by_dev> to not search major=0,minor=0.
- Added symlink support.
- v0.6
- 19980120 Richard Gooch <rgooch@atnf.csiro.au>
- Created <devfs_mk_dir> function and support directory unregister
- 19980120 Richard Gooch <rgooch@atnf.csiro.au>
- Auto-ownership uses real uid/gid rather than effective uid/gid.
- v0.7
- 19980121 Richard Gooch <rgooch@atnf.csiro.au>
- Supported creation of sockets.
- v0.8
- 19980122 Richard Gooch <rgooch@atnf.csiro.au>
- Added DEVFS_FL_HIDE_UNREG flag.
- Interface change to <devfs_mk_symlink>.
- Created <devfs_symlink> to support symlink(2).
- v0.9
- 19980123 Richard Gooch <rgooch@atnf.csiro.au>
- Added check to <devfs_fill_file> to check inode is in devfs.
- Added optional traversal of symlinks.
- v0.10
- 19980124 Richard Gooch <rgooch@atnf.csiro.au>
- Created <devfs_get_flags> and <devfs_set_flags>.
- v0.11
- 19980125 C. Scott Ananian <cananian@alumni.princeton.edu>
- Created <devfs_find_handle>.
- 19980125 Richard Gooch <rgooch@atnf.csiro.au>
- Allow removal of symlinks.
- v0.12
- 19980125 Richard Gooch <rgooch@atnf.csiro.au>
- Created <devfs_set_symlink_destination>.
- 19980126 Richard Gooch <rgooch@atnf.csiro.au>
- Moved DEVFS_SUPER_MAGIC into header file.
- Added DEVFS_FL_HIDE flag.
- Created <devfs_get_maj_min>.
- Created <devfs_get_handle_from_inode>.
- Fixed minor bug in <find_by_dev>.
- 19980127 Richard Gooch <rgooch@atnf.csiro.au>
- Changed interface to <find_by_dev>, <find_entry>,
- <devfs_unregister>, <devfs_fill_file> and <devfs_find_handle>.
- Fixed inode times when symlink created with symlink(2).
- v0.13
- 19980129 C. Scott Ananian <cananian@alumni.princeton.edu>
- Exported <devfs_set_symlink_destination>, <devfs_get_maj_min>
- and <devfs_get_handle_from_inode>.
- 19980129 Richard Gooch <rgooch@atnf.csiro.au>
- Created <devfs_unlink> to support unlink(2).
- v0.14
- 19980129 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed kerneld support for entries in devfs subdirectories.
- 19980130 Richard Gooch <rgooch@atnf.csiro.au>
- Bugfixes in <call_kerneld>.
- v0.15
- 19980207 Richard Gooch <rgooch@atnf.csiro.au>
- Call kerneld when looking up unregistered entries.
- v0.16
- 19980326 Richard Gooch <rgooch@atnf.csiro.au>
- Modified interface to <devfs_find_handle> for symlink traversal.
- v0.17
- 19980331 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed persistence bug with device numbers for manually created
- device files.
- Fixed problem with recreating symlinks with different content.
- v0.18
- 19980401 Richard Gooch <rgooch@atnf.csiro.au>
- Changed to CONFIG_KMOD.
- Hide entries which are manually unlinked.
- Always invalidate devfs dentry cache when registering entries.
- Created <devfs_rmdir> to support rmdir(2).
- Ensure directories created by <devfs_mk_dir> are visible.
- v0.19
- 19980402 Richard Gooch <rgooch@atnf.csiro.au>
- Invalidate devfs dentry cache when making directories.
- Invalidate devfs dentry cache when removing entries.
- Fixed persistence bug with fifos.
- v0.20
- 19980421 Richard Gooch <rgooch@atnf.csiro.au>
- Print process command when debugging kerneld/kmod.
- Added debugging for register/unregister/change operations.
- 19980422 Richard Gooch <rgooch@atnf.csiro.au>
- Added "devfs=" boot options.
- v0.21
- 19980426 Richard Gooch <rgooch@atnf.csiro.au>
- No longer lock/unlock superblock in <devfs_put_super>.
- Drop negative dentries when they are released.
- Manage dcache more efficiently.
- v0.22
- 19980427 Richard Gooch <rgooch@atnf.csiro.au>
- Added DEVFS_FL_AUTO_DEVNUM flag.
- v0.23
- 19980430 Richard Gooch <rgooch@atnf.csiro.au>
- No longer set unnecessary methods.
- v0.24
- 19980504 Richard Gooch <rgooch@atnf.csiro.au>
- Added PID display to <call_kerneld> debugging message.
- Added "after" debugging message to <call_kerneld>.
- 19980519 Richard Gooch <rgooch@atnf.csiro.au>
- Added "diread" and "diwrite" boot options.
- 19980520 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed persistence problem with permissions.
- v0.25
- 19980602 Richard Gooch <rgooch@atnf.csiro.au>
- Support legacy device nodes.
- Fixed bug where recreated inodes were hidden.
- v0.26
- 19980602 Richard Gooch <rgooch@atnf.csiro.au>
- Improved debugging in <get_vfs_inode>.
- 19980607 Richard Gooch <rgooch@atnf.csiro.au>
- No longer free old dentries in <devfs_mk_dir>.
- Free all dentries for a given entry when deleting inodes.
- v0.27
- 19980627 Richard Gooch <rgooch@atnf.csiro.au>
- Limit auto-device numbering to majors 128 to 239.
- v0.28
- 19980629 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed inode times persistence problem.
- v0.29
- 19980704 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed spelling in <devfs_readlink> debug.
- Fixed bug in <devfs_setup> parsing "dilookup".
- v0.30
- 19980705 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed devfs inode leak when manually recreating inodes.
- Fixed permission persistence problem when recreating inodes.
- v0.31
- 19980727 Richard Gooch <rgooch@atnf.csiro.au>
- Removed harmless "unused variable" compiler warning.
- Fixed modes for manually recreated device nodes.
- v0.32
- 19980728 Richard Gooch <rgooch@atnf.csiro.au>
- Added NULL devfs inode warning in <devfs_read_inode>.
- Force all inode nlink values to 1.
- v0.33
- 19980730 Richard Gooch <rgooch@atnf.csiro.au>
- Added "dimknod" boot option.
- Set inode nlink to 0 when freeing dentries.
- Fixed modes for manually recreated symlinks.
- v0.34
- 19980802 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed bugs in recreated directories and symlinks.
- v0.35
- 19980806 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed bugs in recreated device nodes.
- 19980807 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed bug in currently unused <devfs_get_handle_from_inode>.
- Defined new <devfs_handle_t> type.
- Improved debugging when getting entries.
- Fixed bug where directories could be emptied.
- v0.36
- 19980809 Richard Gooch <rgooch@atnf.csiro.au>
- Replaced dummy .epoch inode with .devfsd character device.
- 19980810 Richard Gooch <rgooch@atnf.csiro.au>
- Implemented devfsd protocol revision 0.
- v0.37
- 19980819 Richard Gooch <rgooch@atnf.csiro.au>
- Added soothing message to warning in <devfs_d_iput>.
- v0.38
- 19980829 Richard Gooch <rgooch@atnf.csiro.au>
- Use GCC extensions for structure initialisations.
- Implemented async open notification.
- Incremented devfsd protocol revision to 1.
- v0.39
- 19980908 Richard Gooch <rgooch@atnf.csiro.au>
- Moved async open notification to end of <devfs_open>.
- v0.40
- 19980910 Richard Gooch <rgooch@atnf.csiro.au>
- Prepended "/dev/" to module load request.
- Renamed <call_kerneld> to <call_kmod>.
- v0.41
- 19980910 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed typo "AYSNC" -> "ASYNC".
- v0.42
- 19980910 Richard Gooch <rgooch@atnf.csiro.au>
- Added open flag for files.
- v0.43
- 19980927 Richard Gooch <rgooch@atnf.csiro.au>
- Set i_blocks=0 and i_blksize=1024 in <devfs_read_inode>.
- v0.44
- 19981005 Richard Gooch <rgooch@atnf.csiro.au>
- Added test for empty <<name>> in <devfs_find_handle>.
- Renamed <generate_path> to <devfs_generate_path> and published.
- v0.45
- 19981006 Richard Gooch <rgooch@atnf.csiro.au>
- Created <devfs_get_fops>.
- v0.46
- 19981007 Richard Gooch <rgooch@atnf.csiro.au>
- Limit auto-device numbering to majors 144 to 239.
- v0.47
- 19981010 Richard Gooch <rgooch@atnf.csiro.au>
- Updated <devfs_follow_link> for VFS change in 2.1.125.
- v0.48
- 19981022 Richard Gooch <rgooch@atnf.csiro.au>
- Created DEVFS_ FL_COMPAT flag.
- v0.49
- 19981023 Richard Gooch <rgooch@atnf.csiro.au>
- Created "nocompat" boot option.
- v0.50
- 19981025 Richard Gooch <rgooch@atnf.csiro.au>
- Replaced "mount" boot option with "nomount".
- v0.51
- 19981110 Richard Gooch <rgooch@atnf.csiro.au>
- Created "only" boot option.
- v0.52
- 19981112 Richard Gooch <rgooch@atnf.csiro.au>
- Added DEVFS_FL_REMOVABLE flag.
- v0.53
- 19981114 Richard Gooch <rgooch@atnf.csiro.au>
- Only call <scan_dir_for_removable> on first call to
- <devfs_readdir>.
- v0.54
- 19981205 Richard Gooch <rgooch@atnf.csiro.au>
- Updated <devfs_rmdir> for VFS change in 2.1.131.
- v0.55
- 19981218 Richard Gooch <rgooch@atnf.csiro.au>
- Created <devfs_mk_compat>.
- 19981220 Richard Gooch <rgooch@atnf.csiro.au>
- Check for partitions on removable media in <devfs_lookup>.
- v0.56
- 19990118 Richard Gooch <rgooch@atnf.csiro.au>
- Added support for registering regular files.
- Created <devfs_set_file_size>.
- Update devfs inodes from entries if not changed through FS.
- v0.57
- 19990124 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed <devfs_fill_file> to only initialise temporary inodes.
- Trap for NULL fops in <devfs_register>.
- Return -ENODEV in <devfs_fill_file> for non-driver inodes.
- v0.58
- 19990126 Richard Gooch <rgooch@atnf.csiro.au>
- Switched from PATH_MAX to DEVFS_PATHLEN.
- v0.59
- 19990127 Richard Gooch <rgooch@atnf.csiro.au>
- Created "nottycompat" boot option.
- v0.60
- 19990318 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed <devfsd_read> to not overrun event buffer.
- v0.61
- 19990329 Richard Gooch <rgooch@atnf.csiro.au>
- Created <devfs_auto_unregister>.
- v0.62
- 19990330 Richard Gooch <rgooch@atnf.csiro.au>
- Don't return unregistred entries in <devfs_find_handle>.
- Panic in <devfs_unregister> if entry unregistered.
- 19990401 Richard Gooch <rgooch@atnf.csiro.au>
- Don't panic in <devfs_auto_unregister> for duplicates.
- v0.63
- 19990402 Richard Gooch <rgooch@atnf.csiro.au>
- Don't unregister already unregistered entries in <unregister>.
- v0.64
- 19990510 Richard Gooch <rgooch@atnf.csiro.au>
- Disable warning messages when unable to read partition table for
- removable media.
- v0.65
- 19990512 Richard Gooch <rgooch@atnf.csiro.au>
- Updated <devfs_lookup> for VFS change in 2.3.1-pre1.
- Created "oops-on-panic" boot option.
- Improved debugging in <devfs_register> and <devfs_unregister>.
- v0.66
- 19990519 Richard Gooch <rgooch@atnf.csiro.au>
- Added documentation for some functions.
- 19990525 Richard Gooch <rgooch@atnf.csiro.au>
- Removed "oops-on-panic" boot option: now always Oops.
- v0.67
- 19990531 Richard Gooch <rgooch@atnf.csiro.au>
- Improved debugging in <devfs_register>.
- v0.68
- 19990604 Richard Gooch <rgooch@atnf.csiro.au>
- Added "diunlink" and "nokmod" boot options.
- Removed superfluous warning message in <devfs_d_iput>.
- v0.69
- 19990611 Richard Gooch <rgooch@atnf.csiro.au>
- Took account of change to <d_alloc_root>.
- v0.70
- 19990614 Richard Gooch <rgooch@atnf.csiro.au>
- Created separate event queue for each mounted devfs.
- Removed <devfs_invalidate_dcache>.
- Created new ioctl()s.
- Incremented devfsd protocol revision to 3.
- Fixed bug when re-creating directories: contents were lost.
- Block access to inodes until devfsd updates permissions.
- 19990615 Richard Gooch <rgooch@atnf.csiro.au>
- Support 2.2.x kernels.
- v0.71
- 19990623 Richard Gooch <rgooch@atnf.csiro.au>
- Switched to sending process uid/gid to devfsd.
- Renamed <call_kmod> to <try_modload>.
- Added DEVFSD_NOTIFY_LOOKUP event.
- 19990624 Richard Gooch <rgooch@atnf.csiro.au>
- Added DEVFSD_NOTIFY_CHANGE event.
- Incremented devfsd protocol revision to 4.
- v0.72
- 19990713 Richard Gooch <rgooch@atnf.csiro.au>
- Return EISDIR rather than EINVAL for read(2) on directories.
- v0.73
- 19990809 Richard Gooch <rgooch@atnf.csiro.au>
- Changed <devfs_setup> to new __init scheme.
- v0.74
- 19990901 Richard Gooch <rgooch@atnf.csiro.au>
- Changed remaining function declarations to new __init scheme.
- v0.75
- 19991013 Richard Gooch <rgooch@atnf.csiro.au>
- Created <devfs_get_info>, <devfs_set_info>,
- <devfs_get_first_child> and <devfs_get_next_sibling>.
- Added <<dir>> parameter to <devfs_register>, <devfs_mk_compat>,
- <devfs_mk_dir> and <devfs_find_handle>.
- Work sponsored by SGI.
- v0.76
- 19991017 Richard Gooch <rgooch@atnf.csiro.au>
- Allow multiple unregistrations.
- Work sponsored by SGI.
- v0.77
- 19991026 Richard Gooch <rgooch@atnf.csiro.au>
- Added major and minor number to devfsd protocol.
- Incremented devfsd protocol revision to 5.
- Work sponsored by SGI.
- v0.78
- 19991030 Richard Gooch <rgooch@atnf.csiro.au>
- Support info pointer for all devfs entry types.
- Added <<info>> parameter to <devfs_mk_dir> and
- <devfs_mk_symlink>.
- Work sponsored by SGI.
- v0.79
- 19991031 Richard Gooch <rgooch@atnf.csiro.au>
- Support "../" when searching devfs namespace.
- Work sponsored by SGI.
- v0.80
- 19991101 Richard Gooch <rgooch@atnf.csiro.au>
- Created <devfs_get_unregister_slave>.
- Work sponsored by SGI.
- v0.81
- 19991103 Richard Gooch <rgooch@atnf.csiro.au>
- Exported <devfs_get_parent>.
- Work sponsored by SGI.
- v0.82
- 19991104 Richard Gooch <rgooch@atnf.csiro.au>
- Removed unused <devfs_set_symlink_destination>.
- 19991105 Richard Gooch <rgooch@atnf.csiro.au>
- Do not hide entries from devfsd or children.
- Removed DEVFS_ FL_TTY_COMPAT flag.
- Removed "nottycompat" boot option.
- Removed <devfs_mk_compat>.
- Work sponsored by SGI.
- v0.83
- 19991107 Richard Gooch <rgooch@atnf.csiro.au>
- Added DEVFS_FL_WAIT flag.
- Work sponsored by SGI.
- v0.84
- 19991107 Richard Gooch <rgooch@atnf.csiro.au>
- Support new "disc" naming scheme in <get_removable_partition>.
- Allow NULL fops in <devfs_register>.
- Work sponsored by SGI.
- v0.85
- 19991110 Richard Gooch <rgooch@atnf.csiro.au>
- Fall back to major table if NULL fops given to <devfs_register>.
- Work sponsored by SGI.
- v0.86
- 19991204 Richard Gooch <rgooch@atnf.csiro.au>
- Support fifos when unregistering.
- Work sponsored by SGI.
- v0.87
- 19991209 Richard Gooch <rgooch@atnf.csiro.au>
- Removed obsolete DEVFS_ FL_COMPAT and DEVFS_ FL_TOLERANT flags.
- Work sponsored by SGI.
- v0.88
- 19991214 Richard Gooch <rgooch@atnf.csiro.au>
- Removed kmod support.
- Work sponsored by SGI.
- v0.89
- 19991216 Richard Gooch <rgooch@atnf.csiro.au>
- Improved debugging in <get_vfs_inode>.
- Ensure dentries created by devfsd will be cleaned up.
- Work sponsored by SGI.
- v0.90
- 19991223 Richard Gooch <rgooch@atnf.csiro.au>
- Created <devfs_get_name>.
- Work sponsored by SGI.
- v0.91
- 20000203 Richard Gooch <rgooch@atnf.csiro.au>
- Ported to kernel 2.3.42.
- Removed <devfs_fill_file>.
- Work sponsored by SGI.
- v0.92
- 20000306 Richard Gooch <rgooch@atnf.csiro.au>
- Added DEVFS_ FL_NO_PERSISTENCE flag.
- Removed unnecessary call to <update_devfs_inode_from_entry> in
- <devfs_readdir>.
- Work sponsored by SGI.
- v0.93
- 20000413 Richard Gooch <rgooch@atnf.csiro.au>
- Set inode->i_size to correct size for symlinks.
- 20000414 Richard Gooch <rgooch@atnf.csiro.au>
- Only give lookup() method to directories to comply with new VFS
- assumptions.
- Work sponsored by SGI.
- 20000415 Richard Gooch <rgooch@atnf.csiro.au>
- Remove unnecessary tests in symlink methods.
- Don't kill existing block ops in <devfs_read_inode>.
- Work sponsored by SGI.
- v0.94
- 20000424 Richard Gooch <rgooch@atnf.csiro.au>
- Don't create missing directories in <devfs_find_handle>.
- Work sponsored by SGI.
- v0.95
- 20000430 Richard Gooch <rgooch@atnf.csiro.au>
- Added CONFIG_DEVFS_MOUNT.
- Work sponsored by SGI.
- v0.96
- 20000608 Richard Gooch <rgooch@atnf.csiro.au>
- Disabled multi-mount capability (use VFS bindings instead).
- Work sponsored by SGI.
- v0.97
- 20000610 Richard Gooch <rgooch@atnf.csiro.au>
- Switched to FS_SINGLE to disable multi-mounts.
- 20000612 Richard Gooch <rgooch@atnf.csiro.au>
- Removed module support.
- Removed multi-mount code.
- Removed compatibility macros: VFS has changed too much.
- Work sponsored by SGI.
- v0.98
- 20000614 Richard Gooch <rgooch@atnf.csiro.au>
- Merged devfs inode into devfs entry.
- Work sponsored by SGI.
- v0.99
- 20000619 Richard Gooch <rgooch@atnf.csiro.au>
- Removed dead code in <devfs_register> which used to call
- <free_dentries>.
- Work sponsored by SGI.
- v0.100
- 20000621 Richard Gooch <rgooch@atnf.csiro.au>
- Changed interface to <devfs_register>.
- Work sponsored by SGI.
- v0.101
- 20000622 Richard Gooch <rgooch@atnf.csiro.au>
- Simplified interface to <devfs_mk_symlink> and <devfs_mk_dir>.
- Simplified interface to <devfs_find_handle>.
- Work sponsored by SGI.
- v0.102
- 20010519 Richard Gooch <rgooch@atnf.csiro.au>
- Ensure <devfs_generate_path> terminates string for root entry.
- Exported <devfs_get_name> to modules.
- 20010520 Richard Gooch <rgooch@atnf.csiro.au>
- Make <devfs_mk_symlink> send events to devfsd.
- Cleaned up option processing in <devfs_setup>.
- 20010521 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed bugs in handling symlinks: could leak or cause Oops.
- 20010522 Richard Gooch <rgooch@atnf.csiro.au>
- Cleaned up directory handling by separating fops.
- v0.103
- 20010601 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed handling of inverted options in <devfs_setup>.
- v0.104
- 20010604 Richard Gooch <rgooch@atnf.csiro.au>
- Adjusted <try_modload> to account for <devfs_generate_path> fix.
- v0.105
- 20010617 Richard Gooch <rgooch@atnf.csiro.au>
- Answered question posed by Al Viro and removed his comments.
- Moved setting of registered flag after other fields are changed.
- Fixed race between <devfsd_close> and <devfsd_notify_one>.
- Global VFS changes added bogus BKL to <devfsd_close>: removed.
- Widened locking in <devfs_readlink> and <devfs_follow_link>.
- Replaced <devfsd_read> stack usage with <devfsd_ioctl> kmalloc.
- Simplified locking in <devfsd_ioctl> and fixed memory leak.
- v0.106
- 20010709 Richard Gooch <rgooch@atnf.csiro.au>
- Removed broken devnum allocation and use <devfs_alloc_devnum>.
- Fixed old devnum leak by calling new <devfs_dealloc_devnum>.
- v0.107
- 20010712 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed bug in <devfs_setup> which could hang boot process.
- v0.108
- 20010730 Richard Gooch <rgooch@atnf.csiro.au>
- Added DEVFSD_NOTIFY_DELETE event.
- 20010801 Richard Gooch <rgooch@atnf.csiro.au>
- Removed #include <asm/segment.h>.
- v0.109
- 20010807 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed inode table races by removing it and using
- inode->u.generic_ip instead.
- Moved <devfs_read_inode> into <get_vfs_inode>.
- Moved <devfs_write_inode> into <devfs_notify_change>.
- v0.110
- 20010808 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed race in <devfs_do_symlink> for uni-processor.
- v0.111
- 20010818 Richard Gooch <rgooch@atnf.csiro.au>
- Removed remnant of multi-mount support in <devfs_mknod>.
- Removed unused DEVFS_FL_SHOW_UNREG flag.
- v0.112
- 20010820 Richard Gooch <rgooch@atnf.csiro.au>
- Removed nlink field from struct devfs_inode.
- v0.113
- 20010823 Richard Gooch <rgooch@atnf.csiro.au>
- Replaced BKL with global rwsem to protect symlink data (quick
- and dirty hack).
- v0.114
- 20010827 Richard Gooch <rgooch@atnf.csiro.au>
- Replaced global rwsem for symlink with per-link refcount.
- v0.115
- 20010919 Richard Gooch <rgooch@atnf.csiro.au>
- Set inode->i_mapping->a_ops for block nodes in <get_vfs_inode>.
- v0.116
- 20011008 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed overrun in <devfs_link> by removing function (not needed).
- 20011009 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed buffer underrun in <try_modload>.
- 20011029 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed race in <devfsd_ioctl> when setting event mask.
- 20011114 Richard Gooch <rgooch@atnf.csiro.au>
- First release of new locking code.
- v1.0
- 20011117 Richard Gooch <rgooch@atnf.csiro.au>
- Discard temporary buffer, now use "%s" for dentry names.
- 20011118 Richard Gooch <rgooch@atnf.csiro.au>
- Don't generate path in <try_modload>: use fake entry instead.
- Use "existing" directory in <_devfs_make_parent_for_leaf>.
- 20011122 Richard Gooch <rgooch@atnf.csiro.au>
- Use slab cache rather than fixed buffer for devfsd events.
- v1.1
- 20011125 Richard Gooch <rgooch@atnf.csiro.au>
- Send DEVFSD_NOTIFY_REGISTERED events in <devfs_mk_dir>.
- 20011127 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed locking bug in <devfs_d_revalidate_wait> due to typo.
- Do not send CREATE, CHANGE, ASYNC_OPEN or DELETE events from
- devfsd or children.
- v1.2
- 20011202 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed bug in <devfsd_read>: was dereferencing freed pointer.
- v1.3
- 20011203 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed bug in <devfsd_close>: was dereferencing freed pointer.
- Added process group check for devfsd privileges.
- v1.4
- 20011204 Richard Gooch <rgooch@atnf.csiro.au>
- Use SLAB_ATOMIC in <devfsd_notify_de> from <devfs_d_delete>.
- v1.5
- 20011211 Richard Gooch <rgooch@atnf.csiro.au>
- Return old entry in <devfs_mk_dir> for 2.4.x kernels.
- 20011212 Richard Gooch <rgooch@atnf.csiro.au>
- Increment refcount on module in <check_disc_changed>.
- 20011215 Richard Gooch <rgooch@atnf.csiro.au>
- Created <devfs_get_handle> and exported <devfs_put>.
- Increment refcount on module in <devfs_get_ops>.
- Created <devfs_put_ops>.
- v1.6
- 20011216 Richard Gooch <rgooch@atnf.csiro.au>
- Added poisoning to <devfs_put>.
- Improved debugging messages.
- v1.7
- 20011221 Richard Gooch <rgooch@atnf.csiro.au>
- Corrected (made useful) debugging message in <unregister>.
- Moved <kmem_cache_create> in <mount_devfs_fs> to <init_devfs_fs>
- 20011224 Richard Gooch <rgooch@atnf.csiro.au>
- Added magic number to guard against scribbling drivers.
- 20011226 Richard Gooch <rgooch@atnf.csiro.au>
- Only return old entry in <devfs_mk_dir> if a directory.
- Defined macros for error and debug messages.
- v1.8
- 20020113 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed (rare, old) race in <devfs_lookup>.
- v1.9
- 20020120 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed deadlock bug in <devfs_d_revalidate_wait>.
- Tag VFS deletable in <devfs_mk_symlink> if handle ignored.
- v1.10
- 20020129 Richard Gooch <rgooch@atnf.csiro.au>
- Added KERN_* to remaining messages.
- Cleaned up declaration of <stat_read>.
- v1.11
- 20020219 Richard Gooch <rgooch@atnf.csiro.au>
- Changed <devfs_rmdir> to allow later additions if not yet empty.
- v1.12
- 20020406 Richard Gooch <rgooch@atnf.csiro.au>
- Removed silently introduced calls to lock_kernel() and
- unlock_kernel() due to recent VFS locking changes. BKL isn't
- required in devfs.
- v1.13
- 20020428 Richard Gooch <rgooch@atnf.csiro.au>
- Removed 2.4.x compatibility code.
- v1.14
- 20020510 Richard Gooch <rgooch@atnf.csiro.au>
- Added BKL to <devfs_open> because drivers still need it.
- v1.15
- 20020512 Richard Gooch <rgooch@atnf.csiro.au>
- Protected <scan_dir_for_removable> and <get_removable_partition>
- from changing directory contents.
- v1.16
- 20020514 Richard Gooch <rgooch@atnf.csiro.au>
- Minor cleanup of <scan_dir_for_removable>.
- v1.17
- 20020721 Richard Gooch <rgooch@atnf.csiro.au>
- Switched to ISO C structure field initialisers.
- Switch to set_current_state() and move before add_wait_queue().
- 20020722 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed devfs entry leak in <devfs_readdir> when *readdir fails.
- v1.18
- 20020725 Richard Gooch <rgooch@atnf.csiro.au>
- Created <devfs_find_and_unregister>.
- v1.19
- 20020728 Richard Gooch <rgooch@atnf.csiro.au>
- Removed deprecated <devfs_find_handle>.
- v1.20
- 20020820 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed module unload race in <devfs_open>.
- v1.21
- 20021013 Richard Gooch <rgooch@atnf.csiro.au>
- Removed DEVFS_ FL_AUTO_OWNER.
- Switched lingering structure field initialiser to ISO C.
- Added locking when updating FCB flags.
- v1.22
-*/
-#include <linux/types.h>
-#include <linux/errno.h>
-#include <linux/time.h>
-#include <linux/tty.h>
-#include <linux/timer.h>
-#include <linux/config.h>
-#include <linux/kernel.h>
-#include <linux/wait.h>
-#include <linux/string.h>
-#include <linux/slab.h>
-#include <linux/ioport.h>
-#include <linux/delay.h>
-#include <linux/ctype.h>
-#include <linux/mm.h>
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/devfs_fs.h>
-#include <linux/devfs_fs_kernel.h>
-#include <linux/smp_lock.h>
-#include <linux/smp.h>
-#include <linux/rwsem.h>
-#include <linux/sched.h>
-#include <linux/namei.h>
-#include <linux/bitops.h>
-
-#include <asm/uaccess.h>
-#include <asm/io.h>
-#include <asm/processor.h>
-#include <asm/system.h>
-#include <asm/pgtable.h>
-#include <asm/atomic.h>
-
-#define DEVFS_VERSION "2004-01-31"
-
-#define DEVFS_NAME "devfs"
-
-#define FIRST_INODE 1
-
-#define STRING_LENGTH 256
-#define FAKE_BLOCK_SIZE 1024
-#define POISON_PTR ( *(void **) poison_array )
-#define MAGIC_VALUE 0x327db823
-
-#ifndef TRUE
-# define TRUE 1
-# define FALSE 0
-#endif
-
-#define MODE_DIR (S_IFDIR | S_IWUSR | S_IRUGO | S_IXUGO)
-
-#define DEBUG_NONE 0x0000000
-#define DEBUG_MODULE_LOAD 0x0000001
-#define DEBUG_REGISTER 0x0000002
-#define DEBUG_UNREGISTER 0x0000004
-#define DEBUG_FREE 0x0000008
-#define DEBUG_SET_FLAGS 0x0000010
-#define DEBUG_S_READ 0x0000100 /* Break */
-#define DEBUG_I_LOOKUP 0x0001000 /* Break */
-#define DEBUG_I_CREATE 0x0002000
-#define DEBUG_I_GET 0x0004000
-#define DEBUG_I_CHANGE 0x0008000
-#define DEBUG_I_UNLINK 0x0010000
-#define DEBUG_I_RLINK 0x0020000
-#define DEBUG_I_FLINK 0x0040000
-#define DEBUG_I_MKNOD 0x0080000
-#define DEBUG_F_READDIR 0x0100000 /* Break */
-#define DEBUG_D_DELETE 0x1000000 /* Break */
-#define DEBUG_D_RELEASE 0x2000000
-#define DEBUG_D_IPUT 0x4000000
-#define DEBUG_ALL 0xfffffff
-#define DEBUG_DISABLED DEBUG_NONE
-
-#define OPTION_NONE 0x00
-#define OPTION_MOUNT 0x01
-
-#define PRINTK(format, args...) \
- {printk (KERN_ERR "%s" format, __FUNCTION__ , ## args);}
-
-#define OOPS(format, args...) \
- {printk (KERN_CRIT "%s" format, __FUNCTION__ , ## args); \
- printk ("Forcing Oops\n"); \
- BUG();}
-
-#ifdef CONFIG_DEVFS_DEBUG
-# define VERIFY_ENTRY(de) \
- {if ((de) && (de)->magic_number != MAGIC_VALUE) \
- OOPS ("(%p): bad magic value: %x\n", (de), (de)->magic_number);}
-# define WRITE_ENTRY_MAGIC(de,magic) (de)->magic_number = (magic)
-# define DPRINTK(flag, format, args...) \
- {if (devfs_debug & flag) \
- printk (KERN_INFO "%s" format, __FUNCTION__ , ## args);}
-#else
-# define VERIFY_ENTRY(de)
-# define WRITE_ENTRY_MAGIC(de,magic)
-# define DPRINTK(flag, format, args...)
-#endif
-
-typedef struct devfs_entry *devfs_handle_t;
-
-struct directory_type {
- rwlock_t lock; /* Lock for searching(R)/updating(W) */
- struct devfs_entry *first;
- struct devfs_entry *last;
- unsigned char no_more_additions:1;
-};
-
-struct symlink_type {
- unsigned int length; /* Not including the NULL-termimator */
- char *linkname; /* This is NULL-terminated */
-};
-
-struct devfs_inode { /* This structure is for "persistent" inode storage */
- struct dentry *dentry;
- struct timespec atime;
- struct timespec mtime;
- struct timespec ctime;
- unsigned int ino; /* Inode number as seen in the VFS */
- uid_t uid;
- gid_t gid;
-};
-
-struct devfs_entry {
-#ifdef CONFIG_DEVFS_DEBUG
- unsigned int magic_number;
-#endif
- void *info;
- atomic_t refcount; /* When this drops to zero, it's unused */
- union {
- struct directory_type dir;
- dev_t dev;
- struct symlink_type symlink;
- const char *name; /* Only used for (mode == 0) */
- } u;
- struct devfs_entry *prev; /* Previous entry in the parent directory */
- struct devfs_entry *next; /* Next entry in the parent directory */
- struct devfs_entry *parent; /* The parent directory */
- struct devfs_inode inode;
- umode_t mode;
- unsigned short namelen; /* I think 64k+ filenames are a way off... */
- unsigned char vfs:1; /* Whether the VFS may delete the entry */
- char name[1]; /* This is just a dummy: the allocated array
- is bigger. This is NULL-terminated */
-};
-
-/* The root of the device tree */
-static struct devfs_entry *root_entry;
-
-struct devfsd_buf_entry {
- struct devfs_entry *de; /* The name is generated with this */
- unsigned short type; /* The type of event */
- umode_t mode;
- uid_t uid;
- gid_t gid;
- struct devfsd_buf_entry *next;
-};
-
-struct fs_info { /* This structure is for the mounted devfs */
- struct super_block *sb;
- spinlock_t devfsd_buffer_lock; /* Lock when inserting/deleting events */
- struct devfsd_buf_entry *devfsd_first_event;
- struct devfsd_buf_entry *devfsd_last_event;
- volatile int devfsd_sleeping;
- volatile struct task_struct *devfsd_task;
- volatile pid_t devfsd_pgrp;
- volatile struct file *devfsd_file;
- struct devfsd_notify_struct *devfsd_info;
- volatile unsigned long devfsd_event_mask;
- atomic_t devfsd_overrun_count;
- wait_queue_head_t devfsd_wait_queue; /* Wake devfsd on input */
- wait_queue_head_t revalidate_wait_queue; /* Wake when devfsd sleeps */
-};
-
-static struct fs_info fs_info = {.devfsd_buffer_lock = SPIN_LOCK_UNLOCKED };
-static kmem_cache_t *devfsd_buf_cache;
-#ifdef CONFIG_DEVFS_DEBUG
-static unsigned int devfs_debug_init __initdata = DEBUG_NONE;
-static unsigned int devfs_debug = DEBUG_NONE;
-static DEFINE_SPINLOCK(stat_lock);
-static unsigned int stat_num_entries;
-static unsigned int stat_num_bytes;
-#endif
-static unsigned char poison_array[8] =
- { 0x5a, 0x5a, 0x5a, 0x5a, 0x5a, 0x5a, 0x5a, 0x5a };
-
-#ifdef CONFIG_DEVFS_MOUNT
-static unsigned int boot_options = OPTION_MOUNT;
-#else
-static unsigned int boot_options = OPTION_NONE;
-#endif
-
-/* Forward function declarations */
-static devfs_handle_t _devfs_walk_path(struct devfs_entry *dir,
- const char *name, int namelen,
- int traverse_symlink);
-static ssize_t devfsd_read(struct file *file, char __user *buf, size_t len,
- loff_t * ppos);
-static int devfsd_ioctl(struct inode *inode, struct file *file,
- unsigned int cmd, unsigned long arg);
-static int devfsd_close(struct inode *inode, struct file *file);
-#ifdef CONFIG_DEVFS_DEBUG
-static ssize_t stat_read(struct file *file, char __user *buf, size_t len,
- loff_t * ppos);
-static const struct file_operations stat_fops = {
- .open = nonseekable_open,
- .read = stat_read,
-};
-#endif
-
-/* Devfs daemon file operations */
-static const struct file_operations devfsd_fops = {
- .open = nonseekable_open,
- .read = devfsd_read,
- .ioctl = devfsd_ioctl,
- .release = devfsd_close,
-};
-
-/* Support functions follow */
-
-/**
- * devfs_get - Get a reference to a devfs entry.
- * @de: The devfs entry.
- */
-
-static struct devfs_entry *devfs_get(struct devfs_entry *de)
-{
- VERIFY_ENTRY(de);
- if (de)
- atomic_inc(&de->refcount);
- return de;
-} /* End Function devfs_get */
-
-/**
- * devfs_put - Put (release) a reference to a devfs entry.
- * @de: The handle to the devfs entry.
- */
-
-static void devfs_put(devfs_handle_t de)
-{
- if (!de)
- return;
- VERIFY_ENTRY(de);
- if (de->info == POISON_PTR)
- OOPS("(%p): poisoned pointer\n", de);
- if (!atomic_dec_and_test(&de->refcount))
- return;
- if (de == root_entry)
- OOPS("(%p): root entry being freed\n", de);
- DPRINTK(DEBUG_FREE, "(%s): de: %p, parent: %p \"%s\"\n",
- de->name, de, de->parent,
- de->parent ? de->parent->name : "no parent");
- if (S_ISLNK(de->mode))
- kfree(de->u.symlink.linkname);
- WRITE_ENTRY_MAGIC(de, 0);
-#ifdef CONFIG_DEVFS_DEBUG
- spin_lock(&stat_lock);
- --stat_num_entries;
- stat_num_bytes -= sizeof *de + de->namelen;
- if (S_ISLNK(de->mode))
- stat_num_bytes -= de->u.symlink.length + 1;
- spin_unlock(&stat_lock);
-#endif
- de->info = POISON_PTR;
- kfree(de);
-} /* End Function devfs_put */
-
-/**
- * _devfs_search_dir - Search for a devfs entry in a directory.
- * @dir: The directory to search.
- * @name: The name of the entry to search for.
- * @namelen: The number of characters in @name.
- *
- * Search for a devfs entry in a directory and returns a pointer to the entry
- * on success, else %NULL. The directory must be locked already.
- * An implicit devfs_get() is performed on the returned entry.
- */
-
-static struct devfs_entry *_devfs_search_dir(struct devfs_entry *dir,
- const char *name,
- unsigned int namelen)
-{
- struct devfs_entry *curr;
-
- if (!S_ISDIR(dir->mode)) {
- PRINTK("(%s): not a directory\n", dir->name);
- return NULL;
- }
- for (curr = dir->u.dir.first; curr != NULL; curr = curr->next) {
- if (curr->namelen != namelen)
- continue;
- if (memcmp(curr->name, name, namelen) == 0)
- break;
- /* Not found: try the next one */
- }
- return devfs_get(curr);
-} /* End Function _devfs_search_dir */
-
-/**
- * _devfs_alloc_entry - Allocate a devfs entry.
- * @name: the name of the entry
- * @namelen: the number of characters in @name
- * @mode: the mode for the entry
- *
- * Allocate a devfs entry and returns a pointer to the entry on success, else
- * %NULL.
- */
-
-static struct devfs_entry *_devfs_alloc_entry(const char *name,
- unsigned int namelen,
- umode_t mode)
-{
- struct devfs_entry *new;
- static unsigned long inode_counter = FIRST_INODE;
- static DEFINE_SPINLOCK(counter_lock);
-
- if (name && (namelen < 1))
- namelen = strlen(name);
- if ((new = kmalloc(sizeof *new + namelen, GFP_KERNEL)) == NULL)
- return NULL;
- memset(new, 0, sizeof *new + namelen); /* Will set '\0' on name */
- new->mode = mode;
- if (S_ISDIR(mode))
- rwlock_init(&new->u.dir.lock);
- atomic_set(&new->refcount, 1);
- spin_lock(&counter_lock);
- new->inode.ino = inode_counter++;
- spin_unlock(&counter_lock);
- if (name)
- memcpy(new->name, name, namelen);
- new->namelen = namelen;
- WRITE_ENTRY_MAGIC(new, MAGIC_VALUE);
-#ifdef CONFIG_DEVFS_DEBUG
- spin_lock(&stat_lock);
- ++stat_num_entries;
- stat_num_bytes += sizeof *new + namelen;
- spin_unlock(&stat_lock);
-#endif
- return new;
-} /* End Function _devfs_alloc_entry */
-
-/**
- * _devfs_append_entry - Append a devfs entry to a directory's child list.
- * @dir: The directory to add to.
- * @de: The devfs entry to append.
- * @old_de: If an existing entry exists, it will be written here. This may
- * be %NULL. An implicit devfs_get() is performed on this entry.
- *
- * Append a devfs entry to a directory's list of children, checking first to
- * see if an entry of the same name exists. The directory will be locked.
- * The value 0 is returned on success, else a negative error code.
- * On failure, an implicit devfs_put() is performed on %de.
- */
-
-static int _devfs_append_entry(devfs_handle_t dir, devfs_handle_t de,
- devfs_handle_t * old_de)
-{
- int retval;
-
- if (old_de)
- *old_de = NULL;
- if (!S_ISDIR(dir->mode)) {
- PRINTK("(%s): dir: \"%s\" is not a directory\n", de->name,
- dir->name);
- devfs_put(de);
- return -ENOTDIR;
- }
- write_lock(&dir->u.dir.lock);
- if (dir->u.dir.no_more_additions)
- retval = -ENOENT;
- else {
- struct devfs_entry *old;
-
- old = _devfs_search_dir(dir, de->name, de->namelen);
- if (old_de)
- *old_de = old;
- else
- devfs_put(old);
- if (old == NULL) {
- de->parent = dir;
- de->prev = dir->u.dir.last;
- /* Append to the directory's list of children */
- if (dir->u.dir.first == NULL)
- dir->u.dir.first = de;
- else
- dir->u.dir.last->next = de;
- dir->u.dir.last = de;
- retval = 0;
- } else
- retval = -EEXIST;
- }
- write_unlock(&dir->u.dir.lock);
- if (retval)
- devfs_put(de);
- return retval;
-} /* End Function _devfs_append_entry */
-
-/**
- * _devfs_get_root_entry - Get the root devfs entry.
- *
- * Returns the root devfs entry on success, else %NULL.
- *
- * TODO it must be called asynchronously due to the fact
- * that devfs is initialized relatively late. Proper way
- * is to remove module_init from init_devfs_fs and manually
- * call it early enough during system init
- */
-
-static struct devfs_entry *_devfs_get_root_entry(void)
-{
- struct devfs_entry *new;
- static DEFINE_SPINLOCK(root_lock);
-
- if (root_entry)
- return root_entry;
-
- new = _devfs_alloc_entry(NULL, 0, MODE_DIR);
- if (new == NULL)
- return NULL;
-
- spin_lock(&root_lock);
- if (root_entry) {
- spin_unlock(&root_lock);
- devfs_put(new);
- return root_entry;
- }
- root_entry = new;
- spin_unlock(&root_lock);
-
- return root_entry;
-} /* End Function _devfs_get_root_entry */
-
-/**
- * _devfs_descend - Descend down a tree using the next component name.
- * @dir: The directory to search.
- * @name: The component name to search for.
- * @namelen: The length of %name.
- * @next_pos: The position of the next '/' or '\0' is written here.
- *
- * Descend into a directory, searching for a component. This function forms
- * the core of a tree-walking algorithm. The directory will be locked.
- * The devfs entry corresponding to the component is returned. If there is
- * no matching entry, %NULL is returned.
- * An implicit devfs_get() is performed on the returned entry.
- */
-
-static struct devfs_entry *_devfs_descend(struct devfs_entry *dir,
- const char *name, int namelen,
- int *next_pos)
-{
- const char *stop, *ptr;
- struct devfs_entry *entry;
-
- if ((namelen >= 3) && (strncmp(name, "../", 3) == 0)) { /* Special-case going to parent directory */
- *next_pos = 3;
- return devfs_get(dir->parent);
- }
- stop = name + namelen;
- /* Search for a possible '/' */
- for (ptr = name; (ptr < stop) && (*ptr != '/'); ++ptr) ;
- *next_pos = ptr - name;
- read_lock(&dir->u.dir.lock);
- entry = _devfs_search_dir(dir, name, *next_pos);
- read_unlock(&dir->u.dir.lock);
- return entry;
-} /* End Function _devfs_descend */
-
-static devfs_handle_t _devfs_make_parent_for_leaf(struct devfs_entry *dir,
- const char *name,
- int namelen, int *leaf_pos)
-{
- int next_pos = 0;
-
- if (dir == NULL)
- dir = _devfs_get_root_entry();
- if (dir == NULL)
- return NULL;
- devfs_get(dir);
- /* Search for possible trailing component and ignore it */
- for (--namelen; (namelen > 0) && (name[namelen] != '/'); --namelen) ;
- *leaf_pos = (name[namelen] == '/') ? (namelen + 1) : 0;
- for (; namelen > 0; name += next_pos, namelen -= next_pos) {
- struct devfs_entry *de, *old = NULL;
-
- if ((de =
- _devfs_descend(dir, name, namelen, &next_pos)) == NULL) {
- de = _devfs_alloc_entry(name, next_pos, MODE_DIR);
- devfs_get(de);
- if (!de || _devfs_append_entry(dir, de, &old)) {
- devfs_put(de);
- if (!old || !S_ISDIR(old->mode)) {
- devfs_put(old);
- devfs_put(dir);
- return NULL;
- }
- de = old; /* Use the existing directory */
- }
- }
- if (de == dir->parent) {
- devfs_put(dir);
- devfs_put(de);
- return NULL;
- }
- devfs_put(dir);
- dir = de;
- if (name[next_pos] == '/')
- ++next_pos;
- }
- return dir;
-} /* End Function _devfs_make_parent_for_leaf */
-
-static devfs_handle_t _devfs_prepare_leaf(devfs_handle_t * dir,
- const char *name, umode_t mode)
-{
- int namelen, leaf_pos;
- struct devfs_entry *de;
-
- namelen = strlen(name);
- if ((*dir = _devfs_make_parent_for_leaf(*dir, name, namelen,
- &leaf_pos)) == NULL) {
- PRINTK("(%s): could not create parent path\n", name);
- return NULL;
- }
- if ((de = _devfs_alloc_entry(name + leaf_pos, namelen - leaf_pos, mode))
- == NULL) {
- PRINTK("(%s): could not allocate entry\n", name);
- devfs_put(*dir);
- return NULL;
- }
- return de;
-} /* End Function _devfs_prepare_leaf */
-
-static devfs_handle_t _devfs_walk_path(struct devfs_entry *dir,
- const char *name, int namelen,
- int traverse_symlink)
-{
- int next_pos = 0;
-
- if (dir == NULL)
- dir = _devfs_get_root_entry();
- if (dir == NULL)
- return NULL;
- devfs_get(dir);
- for (; namelen > 0; name += next_pos, namelen -= next_pos) {
- struct devfs_entry *de, *link;
-
- if (!S_ISDIR(dir->mode)) {
- devfs_put(dir);
- return NULL;
- }
-
- if ((de =
- _devfs_descend(dir, name, namelen, &next_pos)) == NULL) {
- devfs_put(dir);
- return NULL;
- }
- if (S_ISLNK(de->mode) && traverse_symlink) { /* Need to follow the link: this is a stack chomper */
- /* FIXME what if it puts outside of mounted tree? */
- link = _devfs_walk_path(dir, de->u.symlink.linkname,
- de->u.symlink.length, TRUE);
- devfs_put(de);
- if (!link) {
- devfs_put(dir);
- return NULL;
- }
- de = link;
- }
- devfs_put(dir);
- dir = de;
- if (name[next_pos] == '/')
- ++next_pos;
- }
- return dir;
-} /* End Function _devfs_walk_path */
-
-/**
- * _devfs_find_entry - Find a devfs entry.
- * @dir: The handle to the parent devfs directory entry. If this is %NULL the
- * name is relative to the root of the devfs.
- * @name: The name of the entry. This may be %NULL.
- * @traverse_symlink: If %TRUE then symbolic links are traversed.
- *
- * Returns the devfs_entry pointer on success, else %NULL. An implicit
- * devfs_get() is performed.
- */
-
-static struct devfs_entry *_devfs_find_entry(devfs_handle_t dir,
- const char *name,
- int traverse_symlink)
-{
- unsigned int namelen = strlen(name);
-
- if (name[0] == '/') {
- /* Skip leading pathname component */
- if (namelen < 2) {
- PRINTK("(%s): too short\n", name);
- return NULL;
- }
- for (++name, --namelen; (*name != '/') && (namelen > 0);
- ++name, --namelen) ;
- if (namelen < 2) {
- PRINTK("(%s): too short\n", name);
- return NULL;
- }
- ++name;
- --namelen;
- }
- return _devfs_walk_path(dir, name, namelen, traverse_symlink);
-} /* End Function _devfs_find_entry */
-
-static struct devfs_entry *get_devfs_entry_from_vfs_inode(struct inode *inode)
-{
- if (inode == NULL)
- return NULL;
- VERIFY_ENTRY((struct devfs_entry *)inode->u.generic_ip);
- return inode->u.generic_ip;
-} /* End Function get_devfs_entry_from_vfs_inode */
-
-/**
- * free_dentry - Free the dentry for a device entry and invalidate inode.
- * @de: The entry.
- *
- * This must only be called after the entry has been unhooked from its
- * parent directory.
- */
-
-static void free_dentry(struct devfs_entry *de)
-{
- struct dentry *dentry = de->inode.dentry;
-
- if (!dentry)
- return;
- spin_lock(&dcache_lock);
- dget_locked(dentry);
- spin_unlock(&dcache_lock);
- /* Forcefully remove the inode */
- if (dentry->d_inode != NULL)
- dentry->d_inode->i_nlink = 0;
- d_drop(dentry);
- dput(dentry);
-} /* End Function free_dentry */
-
-/**
- * is_devfsd_or_child - Test if the current process is devfsd or one of its children.
- * @fs_info: The filesystem information.
- *
- * Returns %TRUE if devfsd or child, else %FALSE.
- */
-
-static int is_devfsd_or_child(struct fs_info *fs_info)
-{
- struct task_struct *p = current;
-
- if (p == fs_info->devfsd_task)
- return (TRUE);
- if (process_group(p) == fs_info->devfsd_pgrp)
- return (TRUE);
- read_lock(&tasklist_lock);
- for (; p != &init_task; p = p->real_parent) {
- if (p == fs_info->devfsd_task) {
- read_unlock(&tasklist_lock);
- return (TRUE);
- }
- }
- read_unlock(&tasklist_lock);
- return (FALSE);
-} /* End Function is_devfsd_or_child */
-
-/**
- * devfsd_queue_empty - Test if devfsd has work pending in its event queue.
- * @fs_info: The filesystem information.
- *
- * Returns %TRUE if the queue is empty, else %FALSE.
- */
-
-static inline int devfsd_queue_empty(struct fs_info *fs_info)
-{
- return (fs_info->devfsd_last_event) ? FALSE : TRUE;
-} /* End Function devfsd_queue_empty */
-
-/**
- * wait_for_devfsd_finished - Wait for devfsd to finish processing its event queue.
- * @fs_info: The filesystem information.
- *
- * Returns %TRUE if no more waiting will be required, else %FALSE.
- */
-
-static int wait_for_devfsd_finished(struct fs_info *fs_info)
-{
- DECLARE_WAITQUEUE(wait, current);
-
- if (fs_info->devfsd_task == NULL)
- return (TRUE);
- if (devfsd_queue_empty(fs_info) && fs_info->devfsd_sleeping)
- return TRUE;
- if (is_devfsd_or_child(fs_info))
- return (FALSE);
- set_current_state(TASK_UNINTERRUPTIBLE);
- add_wait_queue(&fs_info->revalidate_wait_queue, &wait);
- if (!devfsd_queue_empty(fs_info) || !fs_info->devfsd_sleeping)
- if (fs_info->devfsd_task)
- schedule();
- remove_wait_queue(&fs_info->revalidate_wait_queue, &wait);
- __set_current_state(TASK_RUNNING);
- return (TRUE);
-} /* End Function wait_for_devfsd_finished */
-
-/**
- * devfsd_notify_de - Notify the devfsd daemon of a change.
- * @de: The devfs entry that has changed. This and all parent entries will
- * have their reference counts incremented if the event was queued.
- * @type: The type of change.
- * @mode: The mode of the entry.
- * @uid: The user ID.
- * @gid: The group ID.
- * @fs_info: The filesystem info.
- *
- * Returns %TRUE if an event was queued and devfsd woken up, else %FALSE.
- */
-
-static int devfsd_notify_de(struct devfs_entry *de,
- unsigned short type, umode_t mode,
- uid_t uid, gid_t gid, struct fs_info *fs_info)
-{
- struct devfsd_buf_entry *entry;
- struct devfs_entry *curr;
-
- if (!(fs_info->devfsd_event_mask & (1 << type)))
- return (FALSE);
- if ((entry = kmem_cache_alloc(devfsd_buf_cache, SLAB_KERNEL)) == NULL) {
- atomic_inc(&fs_info->devfsd_overrun_count);
- return (FALSE);
- }
- for (curr = de; curr != NULL; curr = curr->parent)
- devfs_get(curr);
- entry->de = de;
- entry->type = type;
- entry->mode = mode;
- entry->uid = uid;
- entry->gid = gid;
- entry->next = NULL;
- spin_lock(&fs_info->devfsd_buffer_lock);
- if (!fs_info->devfsd_first_event)
- fs_info->devfsd_first_event = entry;
- if (fs_info->devfsd_last_event)
- fs_info->devfsd_last_event->next = entry;
- fs_info->devfsd_last_event = entry;
- spin_unlock(&fs_info->devfsd_buffer_lock);
- wake_up_interruptible(&fs_info->devfsd_wait_queue);
- return (TRUE);
-} /* End Function devfsd_notify_de */
-
-/**
- * devfsd_notify - Notify the devfsd daemon of a change.
- * @de: The devfs entry that has changed.
- * @type: The type of change event.
- * @wait: If TRUE, the function waits for the daemon to finish processing
- * the event.
- */
-
-static void devfsd_notify(struct devfs_entry *de, unsigned short type)
-{
- devfsd_notify_de(de, type, de->mode, current->euid,
- current->egid, &fs_info);
-}
-
-static int devfs_mk_dev(dev_t dev, umode_t mode, const char *fmt, va_list args)
-{
- struct devfs_entry *dir = NULL, *de;
- char buf[64];
- int error, n;
-
- n = vsnprintf(buf, sizeof(buf), fmt, args);
- if (n >= sizeof(buf) || !buf[0]) {
- printk(KERN_WARNING "%s: invalid format string %s\n",
- __FUNCTION__, fmt);
- return -EINVAL;
- }
-
- de = _devfs_prepare_leaf(&dir, buf, mode);
- if (!de) {
- printk(KERN_WARNING "%s: could not prepare leaf for %s\n",
- __FUNCTION__, buf);
- return -ENOMEM; /* could be more accurate... */
- }
-
- de->u.dev = dev;
-
- error = _devfs_append_entry(dir, de, NULL);
- if (error) {
- printk(KERN_WARNING "%s: could not append to parent for %s\n",
- __FUNCTION__, buf);
- goto out;
- }
-
- devfsd_notify(de, DEVFSD_NOTIFY_REGISTERED);
- out:
- devfs_put(dir);
- return error;
-}
-
-int devfs_mk_bdev(dev_t dev, umode_t mode, const char *fmt, ...)
-{
- va_list args;
-
- if (!S_ISBLK(mode)) {
- printk(KERN_WARNING "%s: invalide mode (%u) for %s\n",
- __FUNCTION__, mode, fmt);
- return -EINVAL;
- }
-
- va_start(args, fmt);
- return devfs_mk_dev(dev, mode, fmt, args);
-}
-
-EXPORT_SYMBOL(devfs_mk_bdev);
-
-int devfs_mk_cdev(dev_t dev, umode_t mode, const char *fmt, ...)
-{
- va_list args;
-
- if (!S_ISCHR(mode)) {
- printk(KERN_WARNING "%s: invalide mode (%u) for %s\n",
- __FUNCTION__, mode, fmt);
- return -EINVAL;
- }
-
- va_start(args, fmt);
- return devfs_mk_dev(dev, mode, fmt, args);
-}
-
-EXPORT_SYMBOL(devfs_mk_cdev);
-
-/**
- * _devfs_unhook - Unhook a device entry from its parents list
- * @de: The entry to unhook.
- *
- * Returns %TRUE if the entry was unhooked, else %FALSE if it was
- * previously unhooked.
- * The caller must have a write lock on the parent directory.
- */
-
-static int _devfs_unhook(struct devfs_entry *de)
-{
- struct devfs_entry *parent;
-
- if (!de || (de->prev == de))
- return FALSE;
- parent = de->parent;
- if (de->prev == NULL)
- parent->u.dir.first = de->next;
- else
- de->prev->next = de->next;
- if (de->next == NULL)
- parent->u.dir.last = de->prev;
- else
- de->next->prev = de->prev;
- de->prev = de; /* Indicate we're unhooked */
- de->next = NULL; /* Force early termination for <devfs_readdir> */
- return TRUE;
-} /* End Function _devfs_unhook */
-
-/**
- * _devfs_unregister - Unregister a device entry from its parent.
- * @dir: The parent directory.
- * @de: The entry to unregister.
- *
- * The caller must have a write lock on the parent directory, which is
- * unlocked by this function.
- */
-
-static void _devfs_unregister(struct devfs_entry *dir, struct devfs_entry *de)
-{
- int unhooked = _devfs_unhook(de);
-
- write_unlock(&dir->u.dir.lock);
- if (!unhooked)
- return;
- devfs_get(dir);
- devfsd_notify(de, DEVFSD_NOTIFY_UNREGISTERED);
- free_dentry(de);
- devfs_put(dir);
- if (!S_ISDIR(de->mode))
- return;
- while (TRUE) { /* Recursively unregister: this is a stack chomper */
- struct devfs_entry *child;
-
- write_lock(&de->u.dir.lock);
- de->u.dir.no_more_additions = TRUE;
- child = de->u.dir.first;
- VERIFY_ENTRY(child);
- _devfs_unregister(de, child);
- if (!child)
- break;
- DPRINTK(DEBUG_UNREGISTER, "(%s): child: %p refcount: %d\n",
- child->name, child, atomic_read(&child->refcount));
- devfs_put(child);
- }
-} /* End Function _devfs_unregister */
-
-static int devfs_do_symlink(devfs_handle_t dir, const char *name,
- const char *link, devfs_handle_t * handle)
-{
- int err;
- unsigned int linklength;
- char *newlink;
- struct devfs_entry *de;
-
- if (handle != NULL)
- *handle = NULL;
- if (name == NULL) {
- PRINTK("(): NULL name pointer\n");
- return -EINVAL;
- }
- if (link == NULL) {
- PRINTK("(%s): NULL link pointer\n", name);
- return -EINVAL;
- }
- linklength = strlen(link);
- if ((newlink = kmalloc(linklength + 1, GFP_KERNEL)) == NULL)
- return -ENOMEM;
- memcpy(newlink, link, linklength);
- newlink[linklength] = '\0';
- if ((de = _devfs_prepare_leaf(&dir, name, S_IFLNK | S_IRUGO | S_IXUGO))
- == NULL) {
- PRINTK("(%s): could not prepare leaf\n", name);
- kfree(newlink);
- return -ENOTDIR;
- }
- de->info = NULL;
- de->u.symlink.linkname = newlink;
- de->u.symlink.length = linklength;
- if ((err = _devfs_append_entry(dir, de, NULL)) != 0) {
- PRINTK("(%s): could not append to parent, err: %d\n", name,
- err);
- devfs_put(dir);
- return err;
- }
- devfs_put(dir);
-#ifdef CONFIG_DEVFS_DEBUG
- spin_lock(&stat_lock);
- stat_num_bytes += linklength + 1;
- spin_unlock(&stat_lock);
-#endif
- if (handle != NULL)
- *handle = de;
- return 0;
-} /* End Function devfs_do_symlink */
-
-/**
- * devfs_mk_symlink Create a symbolic link in the devfs namespace.
- * @from: The name of the entry.
- * @to: Name of the destination
- *
- * Returns 0 on success, else a negative error code is returned.
- */
-
-int devfs_mk_symlink(const char *from, const char *to)
-{
- devfs_handle_t de;
- int err;
-
- err = devfs_do_symlink(NULL, from, to, &de);
- if (!err) {
- de->vfs = TRUE;
- devfsd_notify(de, DEVFSD_NOTIFY_REGISTERED);
- }
-
- return err;
-}
-
-/**
- * devfs_mk_dir - Create a directory in the devfs namespace.
- * new name is relative to the root of the devfs.
- * @fmt: The name of the entry.
- *
- * Use of this function is optional. The devfs_register() function
- * will automatically create intermediate directories as needed. This function
- * is provided for efficiency reasons, as it provides a handle to a directory.
- * On failure %NULL is returned.
- */
-
-int devfs_mk_dir(const char *fmt, ...)
-{
- struct devfs_entry *dir = NULL, *de = NULL, *old;
- char buf[64];
- va_list args;
- int error, n;
-
- va_start(args, fmt);
- n = vsnprintf(buf, 64, fmt, args);
- if (n >= 64 || !buf[0]) {
- printk(KERN_WARNING "%s: invalid argument.", __FUNCTION__);
- return -EINVAL;
- }
-
- de = _devfs_prepare_leaf(&dir, buf, MODE_DIR);
- if (!de) {
- PRINTK("(%s): could not prepare leaf\n", buf);
- return -EINVAL;
- }
-
- error = _devfs_append_entry(dir, de, &old);
- if (error == -EEXIST && S_ISDIR(old->mode)) {
- /*
- * devfs_mk_dir() of an already-existing directory will
- * return success.
- */
- error = 0;
- goto out_put;
- } else if (error) {
- PRINTK("(%s): could not append to dir: %p \"%s\"\n",
- buf, dir, dir->name);
- devfs_put(old);
- goto out_put;
- }
-
- devfsd_notify(de, DEVFSD_NOTIFY_REGISTERED);
-
- out_put:
- devfs_put(dir);
- return error;
-}
-
-void devfs_remove(const char *fmt, ...)
-{
- char buf[64];
- va_list args;
- int n;
-
- va_start(args, fmt);
- n = vsnprintf(buf, sizeof(buf), fmt, args);
- if (n < sizeof(buf) && buf[0]) {
- devfs_handle_t de = _devfs_find_entry(NULL, buf, 0);
-
- if (!de) {
- printk(KERN_ERR "%s: %s not found, cannot remove\n",
- __FUNCTION__, buf);
- dump_stack();
- return;
- }
-
- write_lock(&de->parent->u.dir.lock);
- _devfs_unregister(de->parent, de);
- devfs_put(de);
- devfs_put(de);
- }
-}
-
-/**
- * devfs_generate_path - Generate a pathname for an entry, relative to the devfs root.
- * @de: The devfs entry.
- * @path: The buffer to write the pathname to. The pathname and '\0'
- * terminator will be written at the end of the buffer.
- * @buflen: The length of the buffer.
- *
- * Returns the offset in the buffer where the pathname starts on success,
- * else a negative error code.
- */
-
-static int devfs_generate_path(devfs_handle_t de, char *path, int buflen)
-{
- int pos;
-#define NAMEOF(de) ( (de)->mode ? (de)->name : (de)->u.name )
-
- if (de == NULL)
- return -EINVAL;
- VERIFY_ENTRY(de);
- if (de->namelen >= buflen)
- return -ENAMETOOLONG; /* Must be first */
- path[buflen - 1] = '\0';
- if (de->parent == NULL)
- return buflen - 1; /* Don't prepend root */
- pos = buflen - de->namelen - 1;
- memcpy(path + pos, NAMEOF(de), de->namelen);
- for (de = de->parent; de->parent != NULL; de = de->parent) {
- if (pos - de->namelen - 1 < 0)
- return -ENAMETOOLONG;
- path[--pos] = '/';
- pos -= de->namelen;
- memcpy(path + pos, NAMEOF(de), de->namelen);
- }
- return pos;
-} /* End Function devfs_generate_path */
-
-/**
- * devfs_setup - Process kernel boot options.
- * @str: The boot options after the "devfs=".
- */
-
-static int __init devfs_setup(char *str)
-{
- static struct {
- char *name;
- unsigned int mask;
- unsigned int *opt;
- } devfs_options_tab[] __initdata = {
-#ifdef CONFIG_DEVFS_DEBUG
- {
- "dall", DEBUG_ALL, &devfs_debug_init}, {
- "dmod", DEBUG_MODULE_LOAD, &devfs_debug_init}, {
- "dreg", DEBUG_REGISTER, &devfs_debug_init}, {
- "dunreg", DEBUG_UNREGISTER, &devfs_debug_init}, {
- "dfree", DEBUG_FREE, &devfs_debug_init}, {
- "diget", DEBUG_I_GET, &devfs_debug_init}, {
- "dchange", DEBUG_SET_FLAGS, &devfs_debug_init}, {
- "dsread", DEBUG_S_READ, &devfs_debug_init}, {
- "dichange", DEBUG_I_CHANGE, &devfs_debug_init}, {
- "dimknod", DEBUG_I_MKNOD, &devfs_debug_init}, {
- "dilookup", DEBUG_I_LOOKUP, &devfs_debug_init}, {
- "diunlink", DEBUG_I_UNLINK, &devfs_debug_init},
-#endif /* CONFIG_DEVFS_DEBUG */
- {
- "mount", OPTION_MOUNT, &boot_options}, {
- NULL, 0, NULL}
- };
-
- while ((*str != '\0') && !isspace(*str)) {
- int i, found = 0, invert = 0;
-
- if (strncmp(str, "no", 2) == 0) {
- invert = 1;
- str += 2;
- }
- for (i = 0; devfs_options_tab[i].name != NULL; i++) {
- int len = strlen(devfs_options_tab[i].name);
-
- if (strncmp(str, devfs_options_tab[i].name, len) == 0) {
- if (invert)
- *devfs_options_tab[i].opt &=
- ~devfs_options_tab[i].mask;
- else
- *devfs_options_tab[i].opt |=
- devfs_options_tab[i].mask;
- str += len;
- found = 1;
- break;
- }
- }
- if (!found)
- return 0; /* No match */
- if (*str != ',')
- return 0; /* No more options */
- ++str;
- }
- return 1;
-} /* End Function devfs_setup */
-
-__setup("devfs=", devfs_setup);
-
-EXPORT_SYMBOL(devfs_mk_dir);
-EXPORT_SYMBOL(devfs_remove);
-
-/**
- * try_modload - Notify devfsd of an inode lookup by a non-devfsd process.
- * @parent: The parent devfs entry.
- * @fs_info: The filesystem info.
- * @name: The device name.
- * @namelen: The number of characters in @name.
- * @buf: A working area that will be used. This must not go out of scope
- * until devfsd is idle again.
- *
- * Returns 0 on success (event was queued), else a negative error code.
- */
-
-static int try_modload(struct devfs_entry *parent, struct fs_info *fs_info,
- const char *name, unsigned namelen,
- struct devfs_entry *buf)
-{
- if (!(fs_info->devfsd_event_mask & (1 << DEVFSD_NOTIFY_LOOKUP)))
- return -ENOENT;
- if (is_devfsd_or_child(fs_info))
- return -ENOENT;
- memset(buf, 0, sizeof *buf);
- atomic_set(&buf->refcount, 1);
- buf->parent = parent;
- buf->namelen = namelen;
- buf->u.name = name;
- WRITE_ENTRY_MAGIC(buf, MAGIC_VALUE);
- if (!devfsd_notify_de(buf, DEVFSD_NOTIFY_LOOKUP, 0,
- current->euid, current->egid, fs_info))
- return -ENOENT;
- /* Possible success: event has been queued */
- return 0;
-} /* End Function try_modload */
-
-/* Superblock operations follow */
-
-static struct inode_operations devfs_iops;
-static struct inode_operations devfs_dir_iops;
-static const struct file_operations devfs_fops;
-static const struct file_operations devfs_dir_fops;
-static struct inode_operations devfs_symlink_iops;
-
-static int devfs_notify_change(struct dentry *dentry, struct iattr *iattr)
-{
- int retval;
- struct devfs_entry *de;
- struct inode *inode = dentry->d_inode;
- struct fs_info *fs_info = inode->i_sb->s_fs_info;
-
- de = get_devfs_entry_from_vfs_inode(inode);
- if (de == NULL)
- return -ENODEV;
- retval = inode_change_ok(inode, iattr);
- if (retval != 0)
- return retval;
- retval = inode_setattr(inode, iattr);
- if (retval != 0)
- return retval;
- DPRINTK(DEBUG_I_CHANGE, "(%d): VFS inode: %p devfs_entry: %p\n",
- (int)inode->i_ino, inode, de);
- DPRINTK(DEBUG_I_CHANGE, "(): mode: 0%o uid: %d gid: %d\n",
- (int)inode->i_mode, (int)inode->i_uid, (int)inode->i_gid);
- /* Inode is not on hash chains, thus must save permissions here rather
- than in a write_inode() method */
- de->mode = inode->i_mode;
- de->inode.uid = inode->i_uid;
- de->inode.gid = inode->i_gid;
- de->inode.atime = inode->i_atime;
- de->inode.mtime = inode->i_mtime;
- de->inode.ctime = inode->i_ctime;
- if ((iattr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) &&
- !is_devfsd_or_child(fs_info))
- devfsd_notify_de(de, DEVFSD_NOTIFY_CHANGE, inode->i_mode,
- inode->i_uid, inode->i_gid, fs_info);
- return 0;
-} /* End Function devfs_notify_change */
-
-static struct super_operations devfs_sops = {
- .drop_inode = generic_delete_inode,
- .statfs = simple_statfs,
-};
-
-/**
- * _devfs_get_vfs_inode - Get a VFS inode.
- * @sb: The super block.
- * @de: The devfs inode.
- * @dentry: The dentry to register with the devfs inode.
- *
- * Returns the inode on success, else %NULL. An implicit devfs_get() is
- * performed if the inode is created.
- */
-
-static struct inode *_devfs_get_vfs_inode(struct super_block *sb,
- struct devfs_entry *de,
- struct dentry *dentry)
-{
- struct inode *inode;
-
- if (de->prev == de)
- return NULL; /* Quick check to see if unhooked */
- if ((inode = new_inode(sb)) == NULL) {
- PRINTK("(%s): new_inode() failed, de: %p\n", de->name, de);
- return NULL;
- }
- if (de->parent) {
- read_lock(&de->parent->u.dir.lock);
- if (de->prev != de)
- de->inode.dentry = dentry; /* Not unhooked */
- read_unlock(&de->parent->u.dir.lock);
- } else
- de->inode.dentry = dentry; /* Root: no locking needed */
- if (de->inode.dentry != dentry) { /* Must have been unhooked */
- iput(inode);
- return NULL;
- }
- /* FIXME where is devfs_put? */
- inode->u.generic_ip = devfs_get(de);
- inode->i_ino = de->inode.ino;
- DPRINTK(DEBUG_I_GET, "(%d): VFS inode: %p devfs_entry: %p\n",
- (int)inode->i_ino, inode, de);
- inode->i_blocks = 0;
- inode->i_blksize = FAKE_BLOCK_SIZE;
- inode->i_op = &devfs_iops;
- inode->i_mode = de->mode;
- if (S_ISDIR(de->mode)) {
- inode->i_op = &devfs_dir_iops;
- inode->i_fop = &devfs_dir_fops;
- } else if (S_ISLNK(de->mode)) {
- inode->i_op = &devfs_symlink_iops;
- inode->i_size = de->u.symlink.length;
- } else if (S_ISCHR(de->mode) || S_ISBLK(de->mode)) {
- init_special_inode(inode, de->mode, de->u.dev);
- } else if (S_ISFIFO(de->mode) || S_ISSOCK(de->mode)) {
- init_special_inode(inode, de->mode, 0);
- } else {
- PRINTK("(%s): unknown mode %o de: %p\n",
- de->name, de->mode, de);
- iput(inode);
- devfs_put(de);
- return NULL;
- }
-
- inode->i_uid = de->inode.uid;
- inode->i_gid = de->inode.gid;
- inode->i_atime = de->inode.atime;
- inode->i_mtime = de->inode.mtime;
- inode->i_ctime = de->inode.ctime;
- DPRINTK(DEBUG_I_GET, "(): mode: 0%o uid: %d gid: %d\n",
- (int)inode->i_mode, (int)inode->i_uid, (int)inode->i_gid);
- return inode;
-} /* End Function _devfs_get_vfs_inode */
-
-/* File operations for device entries follow */
-
-static int devfs_readdir(struct file *file, void *dirent, filldir_t filldir)
-{
- int err, count;
- int stored = 0;
- struct fs_info *fs_info;
- struct devfs_entry *parent, *de, *next = NULL;
- struct inode *inode = file->f_dentry->d_inode;
-
- fs_info = inode->i_sb->s_fs_info;
- parent = get_devfs_entry_from_vfs_inode(file->f_dentry->d_inode);
- if ((long)file->f_pos < 0)
- return -EINVAL;
- DPRINTK(DEBUG_F_READDIR, "(%s): fs_info: %p pos: %ld\n",
- parent->name, fs_info, (long)file->f_pos);
- switch ((long)file->f_pos) {
- case 0:
- err = (*filldir) (dirent, "..", 2, file->f_pos,
- parent_ino(file->f_dentry), DT_DIR);
- if (err == -EINVAL)
- break;
- if (err < 0)
- return err;
- file->f_pos++;
- ++stored;
- /* Fall through */
- case 1:
- err =
- (*filldir) (dirent, ".", 1, file->f_pos, inode->i_ino,
- DT_DIR);
- if (err == -EINVAL)
- break;
- if (err < 0)
- return err;
- file->f_pos++;
- ++stored;
- /* Fall through */
- default:
- /* Skip entries */
- count = file->f_pos - 2;
- read_lock(&parent->u.dir.lock);
- for (de = parent->u.dir.first; de && (count > 0); de = de->next)
- --count;
- devfs_get(de);
- read_unlock(&parent->u.dir.lock);
- /* Now add all remaining entries */
- while (de) {
- err = (*filldir) (dirent, de->name, de->namelen,
- file->f_pos, de->inode.ino,
- de->mode >> 12);
- if (err < 0)
- devfs_put(de);
- else {
- file->f_pos++;
- ++stored;
- }
- if (err == -EINVAL)
- break;
- if (err < 0)
- return err;
- read_lock(&parent->u.dir.lock);
- next = devfs_get(de->next);
- read_unlock(&parent->u.dir.lock);
- devfs_put(de);
- de = next;
- }
- break;
- }
- return stored;
-} /* End Function devfs_readdir */
-
-/* Open devfs specific special files */
-static int devfs_open(struct inode *inode, struct file *file)
-{
- int err;
- int minor = MINOR(inode->i_rdev);
- struct file_operations *old_fops, *new_fops;
-
- switch (minor) {
- case 0: /* /dev/.devfsd */
- new_fops = fops_get(&devfsd_fops);
- break;
-#ifdef CONFIG_DEVFS_DEBUG
- case 1: /* /dev/.stat */
- new_fops = fops_get(&stat_fops);
- break;
-#endif
- default:
- return -ENODEV;
- }
-
- if (new_fops == NULL)
- return -ENODEV;
- old_fops = file->f_op;
- file->f_op = new_fops;
- err = new_fops->open ? new_fops->open(inode, file) : 0;
- if (err) {
- file->f_op = old_fops;
- fops_put(new_fops);
- } else
- fops_put(old_fops);
- return err;
-} /* End Function devfs_open */
-
-static const struct file_operations devfs_fops = {
- .open = devfs_open,
-};
-
-static const struct file_operations devfs_dir_fops = {
- .read = generic_read_dir,
- .readdir = devfs_readdir,
-};
-
-/* Dentry operations for device entries follow */
-
-/**
- * devfs_d_release - Callback for when a dentry is freed.
- * @dentry: The dentry.
- */
-
-static void devfs_d_release(struct dentry *dentry)
-{
- DPRINTK(DEBUG_D_RELEASE, "(%p): inode: %p\n", dentry, dentry->d_inode);
-} /* End Function devfs_d_release */
-
-/**
- * devfs_d_iput - Callback for when a dentry loses its inode.
- * @dentry: The dentry.
- * @inode: The inode.
- */
-
-static void devfs_d_iput(struct dentry *dentry, struct inode *inode)
-{
- struct devfs_entry *de;
-
- de = get_devfs_entry_from_vfs_inode(inode);
- DPRINTK(DEBUG_D_IPUT,
- "(%s): dentry: %p inode: %p de: %p de->dentry: %p\n", de->name,
- dentry, inode, de, de->inode.dentry);
- if (de->inode.dentry && (de->inode.dentry != dentry))
- OOPS("(%s): de: %p dentry: %p de->dentry: %p\n",
- de->name, de, dentry, de->inode.dentry);
- de->inode.dentry = NULL;
- iput(inode);
- devfs_put(de);
-} /* End Function devfs_d_iput */
-
-static int devfs_d_delete(struct dentry *dentry);
-
-static struct dentry_operations devfs_dops = {
- .d_delete = devfs_d_delete,
- .d_release = devfs_d_release,
- .d_iput = devfs_d_iput,
-};
-
-static int devfs_d_revalidate_wait(struct dentry *dentry, struct nameidata *);
-
-static struct dentry_operations devfs_wait_dops = {
- .d_delete = devfs_d_delete,
- .d_release = devfs_d_release,
- .d_iput = devfs_d_iput,
- .d_revalidate = devfs_d_revalidate_wait,
-};
-
-/**
- * devfs_d_delete - Callback for when all files for a dentry are closed.
- * @dentry: The dentry.
- */
-
-static int devfs_d_delete(struct dentry *dentry)
-{
- struct inode *inode = dentry->d_inode;
-
- if (dentry->d_op == &devfs_wait_dops)
- dentry->d_op = &devfs_dops;
- /* Unhash dentry if negative (has no inode) */
- if (inode == NULL) {
- DPRINTK(DEBUG_D_DELETE, "(%p): dropping negative dentry\n",
- dentry);
- return 1;
- }
- return 0;
-} /* End Function devfs_d_delete */
-
-struct devfs_lookup_struct {
- devfs_handle_t de;
- wait_queue_head_t wait_queue;
-};
-
-/* XXX: this doesn't handle the case where we got a negative dentry
- but a devfs entry has been registered in the meanwhile */
-static int devfs_d_revalidate_wait(struct dentry *dentry, struct nameidata *nd)
-{
- struct inode *dir = dentry->d_parent->d_inode;
- struct fs_info *fs_info = dir->i_sb->s_fs_info;
- devfs_handle_t parent = get_devfs_entry_from_vfs_inode(dir);
- struct devfs_lookup_struct *lookup_info = dentry->d_fsdata;
- DECLARE_WAITQUEUE(wait, current);
- int need_lock;
-
- /*
- * FIXME HACK
- *
- * make sure that
- * d_instantiate always runs under lock
- * we release i_mutex lock before going to sleep
- *
- * unfortunately sometimes d_revalidate is called with
- * and sometimes without i_mutex lock held. The following checks
- * attempt to deduce when we need to add (and drop resp.) lock
- * here. This relies on current (2.6.2) calling coventions:
- *
- * lookup_hash is always run under i_mutex and is passing NULL
- * as nd
- *
- * open(...,O_CREATE,...) calls _lookup_hash under i_mutex
- * and sets flags to LOOKUP_OPEN|LOOKUP_CREATE
- *
- * all other invocations of ->d_revalidate seem to happen
- * outside of i_mutex
- */
- need_lock = nd &&
- (!(nd->flags & LOOKUP_CREATE) || (nd->flags & LOOKUP_PARENT));
-
- if (need_lock)
- mutex_lock(&dir->i_mutex);
-
- if (is_devfsd_or_child(fs_info)) {
- devfs_handle_t de = lookup_info->de;
- struct inode *inode;
-
- DPRINTK(DEBUG_I_LOOKUP,
- "(%s): dentry: %p inode: %p de: %p by: \"%s\"\n",
- dentry->d_name.name, dentry, dentry->d_inode, de,
- current->comm);
- if (dentry->d_inode)
- goto out;
- if (de == NULL) {
- read_lock(&parent->u.dir.lock);
- de = _devfs_search_dir(parent, dentry->d_name.name,
- dentry->d_name.len);
- read_unlock(&parent->u.dir.lock);
- if (de == NULL)
- goto out;
- lookup_info->de = de;
- }
- /* Create an inode, now that the driver information is available */
- inode = _devfs_get_vfs_inode(dir->i_sb, de, dentry);
- if (!inode)
- goto out;
- DPRINTK(DEBUG_I_LOOKUP,
- "(%s): new VFS inode(%u): %p de: %p by: \"%s\"\n",
- de->name, de->inode.ino, inode, de, current->comm);
- d_instantiate(dentry, inode);
- goto out;
- }
- if (lookup_info == NULL)
- goto out; /* Early termination */
- read_lock(&parent->u.dir.lock);
- if (dentry->d_fsdata) {
- set_current_state(TASK_UNINTERRUPTIBLE);
- add_wait_queue(&lookup_info->wait_queue, &wait);
- read_unlock(&parent->u.dir.lock);
- /* at this point it is always (hopefully) locked */
- mutex_unlock(&dir->i_mutex);
- schedule();
- mutex_lock(&dir->i_mutex);
- /*
- * This does not need nor should remove wait from wait_queue.
- * Wait queue head is never reused - nothing is ever added to it
- * after all waiters have been waked up and head itself disappears
- * very soon after it. Moreover it is local variable on stack that
- * is likely to have already disappeared so any reference to it
- * at this point is buggy.
- */
-
- } else
- read_unlock(&parent->u.dir.lock);
-
- out:
- if (need_lock)
- mutex_unlock(&dir->i_mutex);
- return 1;
-} /* End Function devfs_d_revalidate_wait */
-
-/* Inode operations for device entries follow */
-
-static struct dentry *devfs_lookup(struct inode *dir, struct dentry *dentry,
- struct nameidata *nd)
-{
- struct devfs_entry tmp; /* Must stay in scope until devfsd idle again */
- struct devfs_lookup_struct lookup_info;
- struct fs_info *fs_info = dir->i_sb->s_fs_info;
- struct devfs_entry *parent, *de;
- struct inode *inode;
- struct dentry *retval = NULL;
-
- /* Set up the dentry operations before anything else, to ensure cleaning
- up on any error */
- dentry->d_op = &devfs_dops;
- /* First try to get the devfs entry for this directory */
- parent = get_devfs_entry_from_vfs_inode(dir);
- DPRINTK(DEBUG_I_LOOKUP, "(%s): dentry: %p parent: %p by: \"%s\"\n",
- dentry->d_name.name, dentry, parent, current->comm);
- if (parent == NULL)
- return ERR_PTR(-ENOENT);
- read_lock(&parent->u.dir.lock);
- de = _devfs_search_dir(parent, dentry->d_name.name, dentry->d_name.len);
- read_unlock(&parent->u.dir.lock);
- lookup_info.de = de;
- init_waitqueue_head(&lookup_info.wait_queue);
- dentry->d_fsdata = &lookup_info;
- if (de == NULL) { /* Try with devfsd. For any kind of failure, leave a negative dentry
- so someone else can deal with it (in the case where the sysadmin
- does a mknod()). It's important to do this before hashing the
- dentry, so that the devfsd queue is filled before revalidates
- can start */
- if (try_modload(parent, fs_info, dentry->d_name.name, dentry->d_name.len, &tmp) < 0) { /* Lookup event was not queued to devfsd */
- d_add(dentry, NULL);
- return NULL;
- }
- }
- dentry->d_op = &devfs_wait_dops;
- d_add(dentry, NULL); /* Open the floodgates */
- /* Unlock directory semaphore, which will release any waiters. They
- will get the hashed dentry, and may be forced to wait for
- revalidation */
- mutex_unlock(&dir->i_mutex);
- wait_for_devfsd_finished(fs_info); /* If I'm not devfsd, must wait */
- mutex_lock(&dir->i_mutex); /* Grab it again because them's the rules */
- de = lookup_info.de;
- /* If someone else has been so kind as to make the inode, we go home
- early */
- if (dentry->d_inode)
- goto out;
- if (de == NULL) {
- read_lock(&parent->u.dir.lock);
- de = _devfs_search_dir(parent, dentry->d_name.name,
- dentry->d_name.len);
- read_unlock(&parent->u.dir.lock);
- if (de == NULL)
- goto out;
- /* OK, there's an entry now, but no VFS inode yet */
- }
- /* Create an inode, now that the driver information is available */
- inode = _devfs_get_vfs_inode(dir->i_sb, de, dentry);
- if (!inode) {
- retval = ERR_PTR(-ENOMEM);
- goto out;
- }
- DPRINTK(DEBUG_I_LOOKUP,
- "(%s): new VFS inode(%u): %p de: %p by: \"%s\"\n", de->name,
- de->inode.ino, inode, de, current->comm);
- d_instantiate(dentry, inode);
- out:
- write_lock(&parent->u.dir.lock);
- dentry->d_op = &devfs_dops;
- dentry->d_fsdata = NULL;
- wake_up(&lookup_info.wait_queue);
- write_unlock(&parent->u.dir.lock);
- devfs_put(de);
- return retval;
-} /* End Function devfs_lookup */
-
-static int devfs_unlink(struct inode *dir, struct dentry *dentry)
-{
- int unhooked;
- struct devfs_entry *de;
- struct inode *inode = dentry->d_inode;
- struct fs_info *fs_info = dir->i_sb->s_fs_info;
-
- de = get_devfs_entry_from_vfs_inode(inode);
- DPRINTK(DEBUG_I_UNLINK, "(%s): de: %p\n", dentry->d_name.name, de);
- if (de == NULL)
- return -ENOENT;
- if (!de->vfs)
- return -EPERM;
- write_lock(&de->parent->u.dir.lock);
- unhooked = _devfs_unhook(de);
- write_unlock(&de->parent->u.dir.lock);
- if (!unhooked)
- return -ENOENT;
- if (!is_devfsd_or_child(fs_info))
- devfsd_notify_de(de, DEVFSD_NOTIFY_DELETE, inode->i_mode,
- inode->i_uid, inode->i_gid, fs_info);
- free_dentry(de);
- devfs_put(de);
- return 0;
-} /* End Function devfs_unlink */
-
-static int devfs_symlink(struct inode *dir, struct dentry *dentry,
- const char *symname)
-{
- int err;
- struct fs_info *fs_info = dir->i_sb->s_fs_info;
- struct devfs_entry *parent, *de;
- struct inode *inode;
-
- /* First try to get the devfs entry for this directory */
- parent = get_devfs_entry_from_vfs_inode(dir);
- if (parent == NULL)
- return -ENOENT;
- err = devfs_do_symlink(parent, dentry->d_name.name, symname, &de);
- DPRINTK(DEBUG_DISABLED, "(%s): errcode from <devfs_do_symlink>: %d\n",
- dentry->d_name.name, err);
- if (err < 0)
- return err;
- de->vfs = TRUE;
- de->inode.uid = current->euid;
- de->inode.gid = current->egid;
- de->inode.atime = CURRENT_TIME;
- de->inode.mtime = CURRENT_TIME;
- de->inode.ctime = CURRENT_TIME;
- if ((inode = _devfs_get_vfs_inode(dir->i_sb, de, dentry)) == NULL)
- return -ENOMEM;
- DPRINTK(DEBUG_DISABLED, "(%s): new VFS inode(%u): %p dentry: %p\n",
- dentry->d_name.name, de->inode.ino, inode, dentry);
- d_instantiate(dentry, inode);
- if (!is_devfsd_or_child(fs_info))
- devfsd_notify_de(de, DEVFSD_NOTIFY_CREATE, inode->i_mode,
- inode->i_uid, inode->i_gid, fs_info);
- return 0;
-} /* End Function devfs_symlink */
-
-static int devfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
-{
- int err;
- struct fs_info *fs_info = dir->i_sb->s_fs_info;
- struct devfs_entry *parent, *de;
- struct inode *inode;
-
- mode = (mode & ~S_IFMT) | S_IFDIR; /* VFS doesn't pass S_IFMT part */
- parent = get_devfs_entry_from_vfs_inode(dir);
- if (parent == NULL)
- return -ENOENT;
- de = _devfs_alloc_entry(dentry->d_name.name, dentry->d_name.len, mode);
- if (!de)
- return -ENOMEM;
- de->vfs = TRUE;
- if ((err = _devfs_append_entry(parent, de, NULL)) != 0)
- return err;
- de->inode.uid = current->euid;
- de->inode.gid = current->egid;
- de->inode.atime = CURRENT_TIME;
- de->inode.mtime = CURRENT_TIME;
- de->inode.ctime = CURRENT_TIME;
- if ((inode = _devfs_get_vfs_inode(dir->i_sb, de, dentry)) == NULL)
- return -ENOMEM;
- DPRINTK(DEBUG_DISABLED, "(%s): new VFS inode(%u): %p dentry: %p\n",
- dentry->d_name.name, de->inode.ino, inode, dentry);
- d_instantiate(dentry, inode);
- if (!is_devfsd_or_child(fs_info))
- devfsd_notify_de(de, DEVFSD_NOTIFY_CREATE, inode->i_mode,
- inode->i_uid, inode->i_gid, fs_info);
- return 0;
-} /* End Function devfs_mkdir */
-
-static int devfs_rmdir(struct inode *dir, struct dentry *dentry)
-{
- int err = 0;
- struct devfs_entry *de;
- struct fs_info *fs_info = dir->i_sb->s_fs_info;
- struct inode *inode = dentry->d_inode;
-
- if (dir->i_sb->s_fs_info != inode->i_sb->s_fs_info)
- return -EINVAL;
- de = get_devfs_entry_from_vfs_inode(inode);
- if (de == NULL)
- return -ENOENT;
- if (!S_ISDIR(de->mode))
- return -ENOTDIR;
- if (!de->vfs)
- return -EPERM;
- /* First ensure the directory is empty and will stay that way */
- write_lock(&de->u.dir.lock);
- if (de->u.dir.first)
- err = -ENOTEMPTY;
- else
- de->u.dir.no_more_additions = TRUE;
- write_unlock(&de->u.dir.lock);
- if (err)
- return err;
- /* Now unhook the directory from its parent */
- write_lock(&de->parent->u.dir.lock);
- if (!_devfs_unhook(de))
- err = -ENOENT;
- write_unlock(&de->parent->u.dir.lock);
- if (err)
- return err;
- if (!is_devfsd_or_child(fs_info))
- devfsd_notify_de(de, DEVFSD_NOTIFY_DELETE, inode->i_mode,
- inode->i_uid, inode->i_gid, fs_info);
- free_dentry(de);
- devfs_put(de);
- return 0;
-} /* End Function devfs_rmdir */
-
-static int devfs_mknod(struct inode *dir, struct dentry *dentry, int mode,
- dev_t rdev)
-{
- int err;
- struct fs_info *fs_info = dir->i_sb->s_fs_info;
- struct devfs_entry *parent, *de;
- struct inode *inode;
-
- DPRINTK(DEBUG_I_MKNOD, "(%s): mode: 0%o dev: %u:%u\n",
- dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
- parent = get_devfs_entry_from_vfs_inode(dir);
- if (parent == NULL)
- return -ENOENT;
- de = _devfs_alloc_entry(dentry->d_name.name, dentry->d_name.len, mode);
- if (!de)
- return -ENOMEM;
- de->vfs = TRUE;
- if (S_ISCHR(mode) || S_ISBLK(mode))
- de->u.dev = rdev;
- if ((err = _devfs_append_entry(parent, de, NULL)) != 0)
- return err;
- de->inode.uid = current->euid;
- de->inode.gid = current->egid;
- de->inode.atime = CURRENT_TIME;
- de->inode.mtime = CURRENT_TIME;
- de->inode.ctime = CURRENT_TIME;
- if ((inode = _devfs_get_vfs_inode(dir->i_sb, de, dentry)) == NULL)
- return -ENOMEM;
- DPRINTK(DEBUG_I_MKNOD, ": new VFS inode(%u): %p dentry: %p\n",
- de->inode.ino, inode, dentry);
- d_instantiate(dentry, inode);
- if (!is_devfsd_or_child(fs_info))
- devfsd_notify_de(de, DEVFSD_NOTIFY_CREATE, inode->i_mode,
- inode->i_uid, inode->i_gid, fs_info);
- return 0;
-} /* End Function devfs_mknod */
-
-static void *devfs_follow_link(struct dentry *dentry, struct nameidata *nd)
-{
- struct devfs_entry *p = get_devfs_entry_from_vfs_inode(dentry->d_inode);
- nd_set_link(nd, p ? p->u.symlink.linkname : ERR_PTR(-ENODEV));
- return NULL;
-} /* End Function devfs_follow_link */
-
-static struct inode_operations devfs_iops = {
- .setattr = devfs_notify_change,
-};
-
-static struct inode_operations devfs_dir_iops = {
- .lookup = devfs_lookup,
- .unlink = devfs_unlink,
- .symlink = devfs_symlink,
- .mkdir = devfs_mkdir,
- .rmdir = devfs_rmdir,
- .mknod = devfs_mknod,
- .setattr = devfs_notify_change,
-};
-
-static struct inode_operations devfs_symlink_iops = {
- .readlink = generic_readlink,
- .follow_link = devfs_follow_link,
- .setattr = devfs_notify_change,
-};
-
-static int devfs_fill_super(struct super_block *sb, void *data, int silent)
-{
- struct inode *root_inode = NULL;
-
- if (_devfs_get_root_entry() == NULL)
- goto out_no_root;
- atomic_set(&fs_info.devfsd_overrun_count, 0);
- init_waitqueue_head(&fs_info.devfsd_wait_queue);
- init_waitqueue_head(&fs_info.revalidate_wait_queue);
- fs_info.sb = sb;
- sb->s_fs_info = &fs_info;
- sb->s_blocksize = 1024;
- sb->s_blocksize_bits = 10;
- sb->s_magic = DEVFS_SUPER_MAGIC;
- sb->s_op = &devfs_sops;
- sb->s_time_gran = 1;
- if ((root_inode = _devfs_get_vfs_inode(sb, root_entry, NULL)) == NULL)
- goto out_no_root;
- sb->s_root = d_alloc_root(root_inode);
- if (!sb->s_root)
- goto out_no_root;
- DPRINTK(DEBUG_S_READ, "(): made devfs ptr: %p\n", sb->s_fs_info);
- return 0;
-
- out_no_root:
- PRINTK("(): get root inode failed\n");
- if (root_inode)
- iput(root_inode);
- return -EINVAL;
-} /* End Function devfs_fill_super */
-
-static int devfs_get_sb(struct file_system_type *fs_type,
- int flags, const char *dev_name,
- void *data, struct vfsmount *mnt)
-{
- return get_sb_single(fs_type, flags, data, devfs_fill_super, mnt);
-}
-
-static struct file_system_type devfs_fs_type = {
- .name = DEVFS_NAME,
- .get_sb = devfs_get_sb,
- .kill_sb = kill_anon_super,
-};
-
-/* File operations for devfsd follow */
-
-static ssize_t devfsd_read(struct file *file, char __user *buf, size_t len,
- loff_t * ppos)
-{
- int done = FALSE;
- int ival;
- loff_t pos, devname_offset, tlen, rpos;
- devfs_handle_t de;
- struct devfsd_buf_entry *entry;
- struct fs_info *fs_info = file->f_dentry->d_inode->i_sb->s_fs_info;
- struct devfsd_notify_struct *info = fs_info->devfsd_info;
- DECLARE_WAITQUEUE(wait, current);
-
- /* Verify the task has grabbed the queue */
- if (fs_info->devfsd_task != current)
- return -EPERM;
- info->major = 0;
- info->minor = 0;
- /* Block for a new entry */
- set_current_state(TASK_INTERRUPTIBLE);
- add_wait_queue(&fs_info->devfsd_wait_queue, &wait);
- while (devfsd_queue_empty(fs_info)) {
- fs_info->devfsd_sleeping = TRUE;
- wake_up(&fs_info->revalidate_wait_queue);
- schedule();
- fs_info->devfsd_sleeping = FALSE;
- if (signal_pending(current)) {
- remove_wait_queue(&fs_info->devfsd_wait_queue, &wait);
- __set_current_state(TASK_RUNNING);
- return -EINTR;
- }
- set_current_state(TASK_INTERRUPTIBLE);
- }
- remove_wait_queue(&fs_info->devfsd_wait_queue, &wait);
- __set_current_state(TASK_RUNNING);
- /* Now play with the data */
- ival = atomic_read(&fs_info->devfsd_overrun_count);
- info->overrun_count = ival;
- entry = fs_info->devfsd_first_event;
- info->type = entry->type;
- info->mode = entry->mode;
- info->uid = entry->uid;
- info->gid = entry->gid;
- de = entry->de;
- if (S_ISCHR(de->mode) || S_ISBLK(de->mode)) {
- info->major = MAJOR(de->u.dev);
- info->minor = MINOR(de->u.dev);
- }
- pos = devfs_generate_path(de, info->devname, DEVFS_PATHLEN);
- if (pos < 0)
- return pos;
- info->namelen = DEVFS_PATHLEN - pos - 1;
- if (info->mode == 0)
- info->mode = de->mode;
- devname_offset = info->devname - (char *)info;
- rpos = *ppos;
- if (rpos < devname_offset) {
- /* Copy parts of the header */
- tlen = devname_offset - rpos;
- if (tlen > len)
- tlen = len;
- if (copy_to_user(buf, (char *)info + rpos, tlen)) {
- return -EFAULT;
- }
- rpos += tlen;
- buf += tlen;
- len -= tlen;
- }
- if ((rpos >= devname_offset) && (len > 0)) {
- /* Copy the name */
- tlen = info->namelen + 1;
- if (tlen > len)
- tlen = len;
- else
- done = TRUE;
- if (copy_to_user
- (buf, info->devname + pos + rpos - devname_offset, tlen)) {
- return -EFAULT;
- }
- rpos += tlen;
- }
- tlen = rpos - *ppos;
- if (done) {
- devfs_handle_t parent;
-
- spin_lock(&fs_info->devfsd_buffer_lock);
- fs_info->devfsd_first_event = entry->next;
- if (entry->next == NULL)
- fs_info->devfsd_last_event = NULL;
- spin_unlock(&fs_info->devfsd_buffer_lock);
- for (; de != NULL; de = parent) {
- parent = de->parent;
- devfs_put(de);
- }
- kmem_cache_free(devfsd_buf_cache, entry);
- if (ival > 0)
- atomic_sub(ival, &fs_info->devfsd_overrun_count);
- *ppos = 0;
- } else
- *ppos = rpos;
- return tlen;
-} /* End Function devfsd_read */
-
-static int devfsd_ioctl(struct inode *inode, struct file *file,
- unsigned int cmd, unsigned long arg)
-{
- int ival;
- struct fs_info *fs_info = inode->i_sb->s_fs_info;
-
- switch (cmd) {
- case DEVFSDIOC_GET_PROTO_REV:
- ival = DEVFSD_PROTOCOL_REVISION_KERNEL;
- if (copy_to_user((void __user *)arg, &ival, sizeof ival))
- return -EFAULT;
- break;
- case DEVFSDIOC_SET_EVENT_MASK:
- /* Ensure only one reader has access to the queue. This scheme will
- work even if the global kernel lock were to be removed, because it
- doesn't matter who gets in first, as long as only one gets it */
- if (fs_info->devfsd_task == NULL) {
- static DEFINE_SPINLOCK(lock);
-
- if (!spin_trylock(&lock))
- return -EBUSY;
- if (fs_info->devfsd_task != NULL) { /* We lost the race... */
- spin_unlock(&lock);
- return -EBUSY;
- }
- fs_info->devfsd_task = current;
- spin_unlock(&lock);
- fs_info->devfsd_pgrp =
- (process_group(current) ==
- current->pid) ? process_group(current) : 0;
- fs_info->devfsd_file = file;
- fs_info->devfsd_info =
- kmalloc(sizeof *fs_info->devfsd_info, GFP_KERNEL);
- if (!fs_info->devfsd_info) {
- devfsd_close(inode, file);
- return -ENOMEM;
- }
- } else if (fs_info->devfsd_task != current)
- return -EBUSY;
- fs_info->devfsd_event_mask = arg; /* Let the masses come forth */
- break;
- case DEVFSDIOC_RELEASE_EVENT_QUEUE:
- if (fs_info->devfsd_file != file)
- return -EPERM;
- return devfsd_close(inode, file);
- /*break; */
-#ifdef CONFIG_DEVFS_DEBUG
- case DEVFSDIOC_SET_DEBUG_MASK:
- if (copy_from_user(&ival, (void __user *)arg, sizeof ival))
- return -EFAULT;
- devfs_debug = ival;
- break;
-#endif
- default:
- return -ENOIOCTLCMD;
- }
- return 0;
-} /* End Function devfsd_ioctl */
-
-static int devfsd_close(struct inode *inode, struct file *file)
-{
- struct devfsd_buf_entry *entry, *next;
- struct fs_info *fs_info = inode->i_sb->s_fs_info;
-
- if (fs_info->devfsd_file != file)
- return 0;
- fs_info->devfsd_event_mask = 0;
- fs_info->devfsd_file = NULL;
- spin_lock(&fs_info->devfsd_buffer_lock);
- entry = fs_info->devfsd_first_event;
- fs_info->devfsd_first_event = NULL;
- fs_info->devfsd_last_event = NULL;
- kfree(fs_info->devfsd_info);
- fs_info->devfsd_info = NULL;
- spin_unlock(&fs_info->devfsd_buffer_lock);
- fs_info->devfsd_pgrp = 0;
- fs_info->devfsd_task = NULL;
- wake_up(&fs_info->revalidate_wait_queue);
- for (; entry; entry = next) {
- next = entry->next;
- kmem_cache_free(devfsd_buf_cache, entry);
- }
- return 0;
-} /* End Function devfsd_close */
-
-#ifdef CONFIG_DEVFS_DEBUG
-static ssize_t stat_read(struct file *file, char __user *buf, size_t len,
- loff_t * ppos)
-{
- ssize_t num;
- char txt[80];
-
- num = sprintf(txt, "Number of entries: %u number of bytes: %u\n",
- stat_num_entries, stat_num_bytes) + 1;
- if (*ppos >= num)
- return 0;
- if (*ppos + len > num)
- len = num - *ppos;
- if (copy_to_user(buf, txt + *ppos, len))
- return -EFAULT;
- *ppos += len;
- return len;
-} /* End Function stat_read */
-#endif
-
-static int __init init_devfs_fs(void)
-{
- int err;
- int major;
- struct devfs_entry *devfsd;
-#ifdef CONFIG_DEVFS_DEBUG
- struct devfs_entry *stat;
-#endif
-
- if (_devfs_get_root_entry() == NULL)
- return -ENOMEM;
-
- printk(KERN_INFO "%s: %s Richard Gooch (rgooch@atnf.csiro.au)\n",
- DEVFS_NAME, DEVFS_VERSION);
- devfsd_buf_cache = kmem_cache_create("devfsd_event",
- sizeof(struct devfsd_buf_entry),
- 0, 0, NULL, NULL);
- if (!devfsd_buf_cache)
- OOPS("(): unable to allocate event slab\n");
-#ifdef CONFIG_DEVFS_DEBUG
- devfs_debug = devfs_debug_init;
- printk(KERN_INFO "%s: devfs_debug: 0x%0x\n", DEVFS_NAME, devfs_debug);
-#endif
- printk(KERN_INFO "%s: boot_options: 0x%0x\n", DEVFS_NAME, boot_options);
-
- /* register special device for devfsd communication */
- major = register_chrdev(0, "devfs", &devfs_fops);
- if (major < 0)
- return major;
-
- /* And create the entry for ".devfsd" */
- devfsd = _devfs_alloc_entry(".devfsd", 0, S_IFCHR | S_IRUSR | S_IWUSR);
- if (devfsd == NULL)
- return -ENOMEM;
- devfsd->u.dev = MKDEV(major, 0);
- _devfs_append_entry(root_entry, devfsd, NULL);
-
-#ifdef CONFIG_DEVFS_DEBUG
- stat = _devfs_alloc_entry(".stat", 0, S_IFCHR | S_IRUGO);
- if (stat == NULL)
- return -ENOMEM;
- stat->u.dev = MKDEV(major, 1);
- _devfs_append_entry(root_entry, stat, NULL);
-#endif
-
- err = register_filesystem(&devfs_fs_type);
- return err;
-} /* End Function init_devfs_fs */
-
-void __init mount_devfs_fs(void)
-{
- int err;
-
- if (!(boot_options & OPTION_MOUNT))
- return;
- err = do_mount("none", "/dev", "devfs", 0, NULL);
- if (err == 0)
- printk(KERN_INFO "Mounted devfs on /dev\n");
- else
- PRINTK("(): unable to mount devfs, err: %d\n", err);
-} /* End Function mount_devfs_fs */
-
-module_init(init_devfs_fs)
projects / linux-2.6 / commitdiff