base.c
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- /* 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
- 20020514 Richard Gooch <rgooch@atnf.csiro.au>
- Added BKL to <devfs_open> because drivers still need it.
- Protected <scan_dir_for_removable> and <get_removable_partition>
- from changing directory contents.
- v1.12a
- 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.
- v1.12b
- 20020818 Richard Gooch <rgooch@atnf.csiro.au>
- Fixed module unload race in <devfs_open>.
- v1.12c
- */
- #include <linux/types.h>
- #include <linux/errno.h>
- #include <linux/sched.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/version.h>
- #include <linux/rwsem.h>
- #include <asm/uaccess.h>
- #include <asm/io.h>
- #include <asm/processor.h>
- #include <asm/system.h>
- #include <asm/pgtable.h>
- #include <asm/bitops.h>
- #include <asm/atomic.h>
- #define DEVFS_VERSION "1.12c (20020818)"
- #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 IS_HIDDEN(de) ( (de)->hide && !is_devfsd_or_child(fs_info) )
- #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 OPTION_ONLY 0x02
- #define PRINTK(format, args...)
- {printk (KERN_ERR "%s" format, __FUNCTION__ , ## args);}
- #define OOPS(format, args...)
- {printk (KERN_CRIT "%s" format, __FUNCTION__ , ## args);
- printk ("Forcing Oopsn");
- BUG();}
- #ifdef CONFIG_DEVFS_DEBUG
- # define VERIFY_ENTRY(de)
- {if ((de) && (de)->magic_number != MAGIC_VALUE)
- OOPS ("(%p): bad magic value: %xn", (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
- struct directory_type
- {
- rwlock_t lock; /* Lock for searching(R)/updating(W) */
- struct devfs_entry *first;
- struct devfs_entry *last;
- unsigned short num_removable; /* Lock for writing but not reading */
- unsigned char no_more_additions:1;
- };
- struct file_type
- {
- unsigned long size;
- };
- struct device_type
- {
- unsigned short major;
- unsigned short minor;
- };
- struct fcb_type /* File, char, block type */
- {
- void *ops;
- union
- {
- struct file_type file;
- struct device_type device;
- }
- u;
- unsigned char auto_owner:1;
- unsigned char aopen_notify:1;
- unsigned char removable:1; /* Belongs in device_type, but save space */
- unsigned char open:1; /* Not entirely correct */
- unsigned char autogen:1; /* Belongs in device_type, but save space */
- };
- 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;
- time_t atime;
- time_t mtime;
- time_t 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;
- struct fcb_type fcb;
- 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_entry *slave; /* Another entry to unregister */
- struct devfs_inode inode;
- umode_t mode;
- unsigned short namelen; /* I think 64k+ filenames are a way off... */
- unsigned char hide:1;
- unsigned char vfs_deletable: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 spinlock_t stat_lock = SPIN_LOCK_UNLOCKED;
- 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 *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 *buf, size_t len,
- loff_t *ppos);
- static struct file_operations stat_fops =
- {
- .read = stat_read,
- };
- #endif
- /* Devfs daemon file operations */
- static struct file_operations devfsd_fops =
- {
- .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.
- */
- void devfs_put (devfs_handle_t de)
- {
- if (!de) return;
- VERIFY_ENTRY (de);
- if (de->info == POISON_PTR) OOPS ("(%p): poisoned pointern", de);
- if ( !atomic_dec_and_test (&de->refcount) ) return;
- if (de == root_entry) OOPS ("(%p): root entry being freedn", 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);
- if ( ( S_ISCHR (de->mode) || S_ISBLK (de->mode) ) && de->u.fcb.autogen )
- {
- devfs_dealloc_devnum ( S_ISCHR (de->mode) ? DEVFS_SPECIAL_CHR :
- DEVFS_SPECIAL_BLK,
- mk_kdev (de->u.fcb.u.device.major,
- de->u.fcb.u.device.minor) );
- }
- 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 directoryn", 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.
- *
- * 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 spinlock_t counter_lock = SPIN_LOCK_UNLOCKED;
- 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 ' ' 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.
- * @removable: If TRUE, increment the count of removable devices for %dir.
- * @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,
- int removable, 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 directoryn", 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;
- if (removable) ++dir->u.dir.num_removable;
- 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.
- */
- static struct devfs_entry *_devfs_get_root_entry (void)
- {
- kdev_t devnum;
- struct devfs_entry *new;
- static spinlock_t root_lock = SPIN_LOCK_UNLOCKED;
- /* Always ensure the root is created */
- if (root_entry) return root_entry;
- if ( ( new = _devfs_alloc_entry (NULL, 0,MODE_DIR) ) == 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);
- /* And create the entry for ".devfsd" */
- if ( ( new = _devfs_alloc_entry (".devfsd", 0, S_IFCHR |S_IRUSR |S_IWUSR) )
- == NULL ) return NULL;
- devnum = devfs_alloc_devnum (DEVFS_SPECIAL_CHR);
- new->u.fcb.u.device.major = major (devnum);
- new->u.fcb.u.device.minor = minor (devnum);
- new->u.fcb.ops = &devfsd_fops;
- _devfs_append_entry (root_entry, new, FALSE, NULL);
- #ifdef CONFIG_DEVFS_DEBUG
- if ( ( new = _devfs_alloc_entry (".stat", 0, S_IFCHR | S_IRUGO | S_IWUGO) )
- == NULL ) return NULL;
- devnum = devfs_alloc_devnum (DEVFS_SPECIAL_CHR);
- new->u.fcb.u.device.major = major (devnum);
- new->u.fcb.u.device.minor = minor (devnum);
- new->u.fcb.ops = &stat_fops;
- _devfs_append_entry (root_entry, new, FALSE, NULL);
- #endif
- 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 ' ' 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;
- 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, FALSE, &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 pathn", name);
- return NULL;
- }
- if ( ( de = _devfs_alloc_entry (name + leaf_pos, namelen - leaf_pos,mode) )
- == NULL )
- {
- PRINTK ("(%s): could not allocate entryn", 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 ( ( 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 */
- 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_by_dev - Find a devfs entry in a directory.
- * @dir: The directory where to search
- * @major: The major number to search for.
- * @minor: The minor number to search for.
- * @type: The type of special file to search for. This may be either
- * %DEVFS_SPECIAL_CHR or %DEVFS_SPECIAL_BLK.
- *
- * Returns the devfs_entry pointer on success, else %NULL. An implicit
- * devfs_get() is performed.
- */
- static struct devfs_entry *_devfs_find_by_dev (struct devfs_entry *dir,
- unsigned int major,
- unsigned int minor, char type)
- {
- struct devfs_entry *entry, *de;
- devfs_get (dir);
- if (dir == NULL) return NULL;
- if ( !S_ISDIR (dir->mode) )
- {
- PRINTK ("(%p): not a directoryn", dir);
- devfs_put (dir);
- return NULL;
- }
- /* First search files in this directory */
- read_lock (&dir->u.dir.lock);
- for (entry = dir->u.dir.first; entry != NULL; entry = entry->next)
- {
- if ( !S_ISCHR (entry->mode) && !S_ISBLK (entry->mode) ) continue;
- if ( S_ISCHR (entry->mode) && (type != DEVFS_SPECIAL_CHR) ) continue;
- if ( S_ISBLK (entry->mode) && (type != DEVFS_SPECIAL_BLK) ) continue;
- if ( (entry->u.fcb.u.device.major == major) &&
- (entry->u.fcb.u.device.minor == minor) )
- {
- devfs_get (entry);
- read_unlock (&dir->u.dir.lock);
- devfs_put (dir);
- return entry;
- }
- /* Not found: try the next one */
- }
- /* Now recursively search the subdirectories: this is a stack chomper */
- for (entry = dir->u.dir.first; entry != NULL; entry = entry->next)
- {
- if ( !S_ISDIR (entry->mode) ) continue;
- de = _devfs_find_by_dev (entry, major, minor, type);
- if (de)
- {
- read_unlock (&dir->u.dir.lock);
- devfs_put (dir);
- return de;
- }
- }
- read_unlock (&dir->u.dir.lock);
- devfs_put (dir);
- return NULL;
- } /* End Function _devfs_find_by_dev */
- /**
- * _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.
- * @major: The major number. This is used if lookup by @name fails.
- * @minor: The minor number. This is used if lookup by @name fails.
- * NOTE: If @major and @minor are both 0, searching by major and minor
- * numbers is disabled.
- * @type: The type of special file to search for. This may be either
- * %DEVFS_SPECIAL_CHR or %DEVFS_SPECIAL_BLK.
- * @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,
- unsigned int major,
- unsigned int minor,
- char type, int traverse_symlink)
- {
- struct devfs_entry *entry;
- if (name != NULL)
- {
- unsigned int namelen = strlen (name);
- if (name[0] == '/')
- {
- /* Skip leading pathname component */
- if (namelen < 2)
- {
- PRINTK ("(%s): too shortn", name);
- return NULL;
- }
- for (++name, --namelen; (*name != '/') && (namelen > 0);
- ++name, --namelen);
- if (namelen < 2)
- {
- PRINTK ("(%s): too shortn", name);
- return NULL;
- }
- ++name;
- --namelen;
- }
- entry = _devfs_walk_path (dir, name, namelen, traverse_symlink);
- if (entry != NULL) return entry;
- }
- /* Have to search by major and minor: slow */
- if ( (major == 0) && (minor == 0) ) return NULL;
- return _devfs_find_by_dev (root_entry, major, minor, type);
- } /* 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 it's
- * 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;
- if (current == fs_info->devfsd_task) return (TRUE);
- if (current->pgrp == fs_info->devfsd_pgrp) return (TRUE);
- #if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,1)
- for (p = current->p_opptr; p != &init_task; p = p->p_opptr)
- {
- if (p == fs_info->devfsd_task) return (TRUE);
- }
- #endif
- 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,
- int atomic)
- {
- 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,
- atomic ? SLAB_ATOMIC : 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,int wait)
- {
- if (devfsd_notify_de (de, type, de->mode, current->euid,
- current->egid, &fs_info, 0) && wait)
- wait_for_devfsd_finished (&fs_info);
- } /* End Function devfsd_notify */
- /**
- * devfs_register - Register a device entry.
- * @dir: The handle to the parent devfs directory entry. If this is %NULL the
- * new name is relative to the root of the devfs.
- * @name: The name of the entry.
- * @flags: A set of bitwise-ORed flags (DEVFS_FL_*).
- * @major: The major number. Not needed for regular files.
- * @minor: The minor number. Not needed for regular files.
- * @mode: The default file mode.
- * @ops: The &file_operations or &block_device_operations structure.
- * This must not be externally deallocated.
- * @info: An arbitrary pointer which will be written to the @private_data
- * field of the &file structure passed to the device driver. You can set
- * this to whatever you like, and change it once the file is opened (the next
- * file opened will not see this change).
- *
- * Returns a handle which may later be used in a call to devfs_unregister().
- * On failure %NULL is returned.
- */
- devfs_handle_t devfs_register (devfs_handle_t dir, const char *name,
- unsigned int flags,
- unsigned int major, unsigned int minor,
- umode_t mode, void *ops, void *info)
- {
- char devtype = S_ISCHR (mode) ? DEVFS_SPECIAL_CHR : DEVFS_SPECIAL_BLK;
- int err;
- kdev_t devnum = NODEV;
- struct devfs_entry *de;
- if (name == NULL)
- {
- PRINTK ("(): NULL name pointern");
- return NULL;
- }
- if (ops == NULL)
- {
- if ( S_ISBLK (mode) ) ops = (void *) get_blkfops (major);
- if (ops == NULL)
- {
- PRINTK ("(%s): NULL ops pointern", name);
- return NULL;
- }
- PRINTK ("(%s): NULL ops, got %p from major tablen", name, ops);
- }
- if ( S_ISDIR (mode) )
- {
- PRINTK ("(%s): creating directories is not allowedn", name);
- return NULL;
- }
- if ( S_ISLNK (mode) )
- {
- PRINTK ("(%s): creating symlinks is not allowedn", name);
- return NULL;
- }
- if ( ( S_ISCHR (mode) || S_ISBLK (mode) ) &&
- (flags & DEVFS_FL_AUTO_DEVNUM) )
- {
- if ( kdev_none ( devnum = devfs_alloc_devnum (devtype) ) )
- {
- PRINTK ("(%s): exhausted %s device numbersn",
- name, S_ISCHR (mode) ? "char" : "block");
- return NULL;
- }
- major = major (devnum);
- minor = minor (devnum);
- }
- if ( ( de = _devfs_prepare_leaf (&dir, name, mode) ) == NULL )
- {
- PRINTK ("(%s): could not prepare leafn", name);
- if ( !kdev_none (devnum) ) devfs_dealloc_devnum (devtype, devnum);
- return NULL;
- }
- if ( S_ISCHR (mode) || S_ISBLK (mode) )
- {
- de->u.fcb.u.device.major = major;
- de->u.fcb.u.device.minor = minor;
- de->u.fcb.autogen = kdev_none (devnum) ? FALSE : TRUE;
- }
- else if ( !S_ISREG (mode) )
- {
- PRINTK ("(%s): illegal mode: %xn", name, mode);
- devfs_put (de);
- devfs_put (dir);
- return (NULL);
- }
- de->info = info;
- if (flags & DEVFS_FL_CURRENT_OWNER)
- {
- de->inode.uid = current->uid;
- de->inode.gid = current->gid;
- }
- else
- {
- de->inode.uid = 0;
- de->inode.gid = 0;
- }
- de->u.fcb.ops = ops;
- de->u.fcb.auto_owner = (flags & DEVFS_FL_AUTO_OWNER) ? TRUE : FALSE;
- de->u.fcb.aopen_notify = (flags & DEVFS_FL_AOPEN_NOTIFY) ? TRUE : FALSE;
- de->hide = (flags & DEVFS_FL_HIDE) ? TRUE : FALSE;
- if (flags & DEVFS_FL_REMOVABLE) de->u.fcb.removable = TRUE;
- if ( ( err = _devfs_append_entry (dir, de, de->u.fcb.removable, NULL) )
- != 0 )
- {
- PRINTK ("(%s): could not append to parent, err: %dn", name, err);
- devfs_put (dir);
- if ( !kdev_none (devnum) ) devfs_dealloc_devnum (devtype, devnum);
- return NULL;
- }
- DPRINTK (DEBUG_REGISTER, "(%s): de: %p dir: %p "%s" pp: %pn",
- name, de, dir, dir->name, dir->parent);
- devfsd_notify (de, DEVFSD_NOTIFY_REGISTERED, flags & DEVFS_FL_WAIT);
- devfs_put (dir);
- return de;
- } /* End Function devfs_register */
- /**
- * _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> */
- if ( ( S_ISREG (de->mode) || S_ISCHR (de->mode) || S_ISBLK (de->mode) ) &&
- de->u.fcb.removable )
- --parent->u.dir.num_removable;
- return TRUE;
- } /* End Function _devfs_unhook */
- /**
- * _devfs_unregister - Unregister a device entry from it's 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);
- devfs_unregister (de->slave); /* Let it handle the locking */
- devfsd_notify (de, DEVFSD_NOTIFY_UNREGISTERED, 0);
- 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: %dn",
- child->name, child, atomic_read (&child->refcount) );
- devfs_put (child);
- }
- } /* End Function _devfs_unregister */
- /**
- * devfs_unregister - Unregister a device entry.
- * @de: A handle previously created by devfs_register() or returned from
- * devfs_get_handle(). If this is %NULL the routine does nothing.
- */
- void devfs_unregister (devfs_handle_t de)
- {
- VERIFY_ENTRY (de);
- if ( (de == NULL) || (de->parent == NULL) ) return;
- DPRINTK (DEBUG_UNREGISTER, "(%s): de: %p refcount: %dn",
- de->name, de, atomic_read (&de->refcount) );
- write_lock (&de->parent->u.dir.lock);
- _devfs_unregister (de->parent, de);
- devfs_put (de);
- } /* End Function devfs_unregister */
- static int devfs_do_symlink (devfs_handle_t dir, const char *name,
- unsigned int flags, const char *link,
- devfs_handle_t *handle, void *info)
- {
- int err;
- unsigned int linklength;
- char *newlink;
- struct devfs_entry *de;
- if (handle != NULL) *handle = NULL;
- if (name == NULL)
- {
- PRINTK ("(): NULL name pointern");
- return -EINVAL;
- }
- if (link == NULL)
- {
- PRINTK ("(%s): NULL link pointern", name);
- return -EINVAL;
- }
- linklength = strlen (link);
- if ( ( newlink = kmalloc (linklength + 1, GFP_KERNEL) ) == NULL )
- return -ENOMEM;
- memcpy (newlink, link, linklength);
- newlink[linklength] = ' ';
- if ( ( de = _devfs_prepare_leaf (&dir, name, S_IFLNK | S_IRUGO | S_IXUGO) )
- == NULL )
- {
- PRINTK ("(%s): could not prepare leafn", name);
- kfree (newlink);
- return -ENOTDIR;
- }
- de->info = info;
- de->hide = (flags & DEVFS_FL_HIDE) ? TRUE : FALSE;
- de->u.symlink.linkname = newlink;
- de->u.symlink.length = linklength;
- if ( ( err = _devfs_append_entry (dir, de, FALSE, NULL) ) != 0 )
- {
- PRINTK ("(%s): could not append to parent, err: %dn", 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.
- * @dir: The handle to the parent devfs directory entry. If this is %NULL the
- * new name is relative to the root of the devfs.
- * @name: The name of the entry.
- * @flags: A set of bitwise-ORed flags (DEVFS_FL_*).
- * @link: The destination name.
- * @handle: The handle to the symlink entry is written here. This may be %NULL.
- * @info: An arbitrary pointer which will be associated with the entry.
- *
- * Returns 0 on success, else a negative error code is returned.
- */
- int devfs_mk_symlink (devfs_handle_t dir, const char *name, unsigned int flags,
- const char *link, devfs_handle_t *handle, void *info)
- {
- int err;
- devfs_handle_t de;
- if (handle != NULL) *handle = NULL;
- DPRINTK (DEBUG_REGISTER, "(%s)n", name);
- err = devfs_do_symlink (dir, name, flags, link, &de, info);
- if (err) return err;
- if (handle == NULL) de->vfs_deletable = TRUE;
- else *handle = de;
- devfsd_notify (de, DEVFSD_NOTIFY_REGISTERED, flags & DEVFS_FL_WAIT);
- return 0;
- } /* End Function devfs_mk_symlink */
- /**
- * devfs_mk_dir - Create a directory in the devfs namespace.
- * @dir: The handle to the parent devfs directory entry. If this is %NULL the
- * new name is relative to the root of the devfs.
- * @name: The name of the entry.
- * @info: An arbitrary pointer which will be associated with 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.
- * Returns a handle which may later be used in a call to devfs_unregister().
- * On failure %NULL is returned.
- */
- devfs_handle_t devfs_mk_dir (devfs_handle_t dir, const char *name, void *info)
- {
- int err;
- struct devfs_entry *de, *old;
- if (name == NULL)
- {
- PRINTK ("(): NULL name pointern");
- return NULL;
- }
- if ( ( de = _devfs_prepare_leaf (&dir, name, MODE_DIR) ) == NULL )
- {
- PRINTK ("(%s): could not prepare leafn", name);
- return NULL;
- }
- de->info = info;
- if ( ( err = _devfs_append_entry (dir, de, FALSE, &old) ) != 0 )
- {
- #if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,1)
- if ( old && S_ISDIR (old->mode) )
- {
- PRINTK ("(%s): using old entry in dir: %p "%s"n",
- name, dir, dir->name);
- old->vfs_deletable = FALSE;
- devfs_put (dir);
- return old;
- }
- #endif
- PRINTK ("(%s): could not append to dir: %p "%s", err: %dn",
- name, dir, dir->name, err);
- devfs_put (old);
- devfs_put (dir);
- return NULL;
- }
- DPRINTK (DEBUG_REGISTER, "(%s): de: %p dir: %p "%s"n",
- name, de, dir, dir->name);
- devfsd_notify (de, DEVFSD_NOTIFY_REGISTERED, 0);
- devfs_put (dir);
- return de;
- } /* End Function devfs_mk_dir */
- /**
- * devfs_get_handle - Find the handle of 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.
- * @major: The major number. This is used if @name is %NULL.
- * @minor: The minor number. This is used if @name is %NULL.
- * @type: The type of special file to search for. This may be either
- * %DEVFS_SPECIAL_CHR or %DEVFS_SPECIAL_BLK.
- * @traverse_symlinks: If %TRUE then symlink entries in the devfs namespace are
- * traversed. Symlinks pointing out of the devfs namespace will cause a
- * failure. Symlink traversal consumes stack space.
- *
- * Returns a handle which may later be used in a call to
- * devfs_unregister(), devfs_get_flags(), or devfs_set_flags(). A
- * subsequent devfs_put() is required to decrement the refcount.
- * On failure %NULL is returned.
- */
- devfs_handle_t devfs_get_handle (devfs_handle_t dir, const char *name,
- unsigned int major, unsigned int minor,
- char type, int traverse_symlinks)
- {
- if ( (name != NULL) && (name[0] == ' ') ) name = NULL;
- return _devfs_find_entry (dir, name, major, minor, type,traverse_symlinks);
- } /* End Function devfs_get_handle */
- /* Compatibility function. Will be removed in sometime in 2.5 */
- devfs_handle_t devfs_find_handle (devfs_handle_t dir, const char *name,
- unsigned int major, unsigned int minor,
- char type, int traverse_symlinks)
- {
- devfs_handle_t de;
- de = devfs_get_handle (dir, name, major, minor, type, traverse_symlinks);
- devfs_put (de);
- return de;
- } /* End Function devfs_find_handle */
- /**
- * devfs_get_flags - Get the flags for a devfs entry.
- * @de: The handle to the device entry.
- * @flags: The flags are written here.
- *
- * Returns 0 on success, else a negative error code.
- */
- int devfs_get_flags (devfs_handle_t de, unsigned int *flags)
- {
- unsigned int fl = 0;
- if (de == NULL) return -EINVAL;
- VERIFY_ENTRY (de);
- if (de->hide) fl |= DEVFS_FL_HIDE;
- if ( S_ISCHR (de->mode) || S_ISBLK (de->mode) || S_ISREG (de->mode) )
- {
- if (de->u.fcb.auto_owner) fl |= DEVFS_FL_AUTO_OWNER;
- if (de->u.fcb.aopen_notify) fl |= DEVFS_FL_AOPEN_NOTIFY;
- if (de->u.fcb.removable) fl |= DEVFS_FL_REMOVABLE;
- }
- *flags = fl;
- return 0;
- } /* End Function devfs_get_flags */
- /*
- * devfs_set_flags - Set the flags for a devfs entry.
- * @de: The handle to the device entry.
- * @flags: The flags to set. Unset flags are cleared.
- *
- * Returns 0 on success, else a negative error code.
- */
- int devfs_set_flags (devfs_handle_t de, unsigned int flags)
- {
- if (de == NULL) return -EINVAL;
- VERIFY_ENTRY (de);
- DPRINTK (DEBUG_SET_FLAGS, "(%s): flags: %xn", de->name, flags);
- de->hide = (flags & DEVFS_FL_HIDE) ? TRUE : FALSE;
- if ( S_ISCHR (de->mode) || S_ISBLK (de->mode) || S_ISREG (de->mode) )
- {
- de->u.fcb.auto_owner = (flags & DEVFS_FL_AUTO_OWNER) ? TRUE : FALSE;
- de->u.fcb.aopen_notify = (flags & DEVFS_FL_AOPEN_NOTIFY) ? TRUE:FALSE;
- }
- return 0;
- } /* End Function devfs_set_flags */
- /**
- * devfs_get_maj_min - Get the major and minor numbers for a devfs entry.
- * @de: The handle to the device entry.
- * @major: The major number is written here. This may be %NULL.
- * @minor: The minor number is written here. This may be %NULL.
- *
- * Returns 0 on success, else a negative error code.
- */
- int devfs_get_maj_min (devfs_handle_t de, unsigned int *major,
- unsigned int *minor)
- {
- if (de == NULL) return -EINVAL;
- VERIFY_ENTRY (de);
- if ( S_ISDIR (de->mode) ) return -EISDIR;
- if ( !S_ISCHR (de->mode) && !S_ISBLK (de->mode) ) return -EINVAL;
- if (major != NULL) *major = de->u.fcb.u.device.major;
- if (minor != NULL) *minor = de->u.fcb.u.device.minor;
- return 0;
- } /* End Function devfs_get_maj_min */
- /**
- * devfs_get_handle_from_inode - Get the devfs handle for a VFS inode.
- * @inode: The VFS inode.
- *
- * Returns the devfs handle on success, else %NULL.
- */
- devfs_handle_t devfs_get_handle_from_inode (struct inode *inode)
- {
- if (!inode || !inode->i_sb) return NULL;
- if (inode->i_sb->s_magic != DEVFS_SUPER_MAGIC) return NULL;
- return get_devfs_entry_from_vfs_inode (inode);
- } /* End Function devfs_get_handle_from_inode */
- /**
- * 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 ' '
- * 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.
- */
- 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] = ' ';
- 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_get_ops - Get the device operations for a devfs entry.
- * @de: The handle to the device entry.
- *
- * Returns a pointer to the device operations on success, else NULL.
- * The use count for the module owning the operations will be incremented.
- */
- void *devfs_get_ops (devfs_handle_t de)
- {
- struct module *owner;
- if (de == NULL) return NULL;
- VERIFY_ENTRY (de);
- if ( !S_ISCHR (de->mode) && !S_ISBLK (de->mode) && !S_ISREG (de->mode) )
- return NULL;
- if (de->u.fcb.ops == NULL) return NULL;
- read_lock (&de->parent->u.dir.lock); /* Prevent module from unloading */
- if (de->next == de) owner = NULL; /* Ops pointer is already stale */
- else if ( S_ISCHR (de->mode) || S_ISREG (de->mode) )
- owner = ( (struct file_operations *) de->u.fcb.ops )->owner;
- else owner = ( (struct block_device_operations *) de->u.fcb.ops )->owner;
- if ( (de->next == de) || !try_inc_mod_count (owner) )
- { /* Entry is already unhooked or module is unloading */
- read_unlock (&de->parent->u.dir.lock);
- return NULL;
- }
- read_unlock (&de->parent->u.dir.lock); /* Module can continue unloading*/
- return de->u.fcb.ops;
- } /* End Function devfs_get_ops */
- /**
- * devfs_put_ops - Put the device operations for a devfs entry.
- * @de: The handle to the device entry.
- *
- * The use count for the module owning the operations will be decremented.
- */
- void devfs_put_ops (devfs_handle_t de)
- {
- struct module *owner;
- if (de == NULL) return;
- VERIFY_ENTRY (de);
- if ( !S_ISCHR (de->mode) && !S_ISBLK (de->mode) && !S_ISREG (de->mode) )
- return;
- if (de->u.fcb.ops == NULL) return;
- if ( S_ISCHR (de->mode) || S_ISREG (de->mode) )
- owner = ( (struct file_operations *) de->u.fcb.ops )->owner;
- else owner = ( (struct block_device_operations *) de->u.fcb.ops )->owner;
- if (owner) __MOD_DEC_USE_COUNT (owner);
- } /* End Function devfs_put_ops */
- /**
- * devfs_set_file_size - Set the file size for a devfs regular file.
- * @de: The handle to the device entry.
- * @size: The new file size.
- *
- * Returns 0 on success, else a negative error code.
- */
- int devfs_set_file_size (devfs_handle_t de, unsigned long size)
- {
- if (de == NULL) return -EINVAL;
- VERIFY_ENTRY (de);
- if ( !S_ISREG (de->mode) ) return -EINVAL;
- if (de->u.fcb.u.file.size == size) return 0;
- de->u.fcb.u.file.size = size;
- if (de->inode.dentry == NULL) return 0;
- if (de->inode.dentry->d_inode == NULL) return 0;
- de->inode.dentry->d_inode->i_size = size;
- return 0;
- } /* End Function devfs_set_file_size */
- /**
- * devfs_get_info - Get the info pointer written to private_data of @de upon open.
- * @de: The handle to the device entry.
- *
- * Returns the info pointer.
- */
- void *devfs_get_info (devfs_handle_t de)
- {
- if (de == NULL) return NULL;
- VERIFY_ENTRY (de);
- return de->info;
- } /* End Function devfs_get_info */
- /**
- * devfs_set_info - Set the info pointer written to private_data upon open.
- * @de: The handle to the device entry.
- * @info: pointer to the data
- *
- * Returns 0 on success, else a negative error code.
- */
- int devfs_set_info (devfs_handle_t de, void *info)
- {
- if (de == NULL) return -EINVAL;
- VERIFY_ENTRY (de);
- de->info = info;
- return 0;
- } /* End Function devfs_set_info */
- /**
- * devfs_get_parent - Get the parent device entry.
- * @de: The handle to the device entry.
- *
- * Returns the parent device entry if it exists, else %NULL.
- */
- devfs_handle_t devfs_get_parent (devfs_handle_t de)
- {
- if (de == NULL) return NULL;
- VERIFY_ENTRY (de);
- return de->parent;
- } /* End Function devfs_get_parent */
- /**
- * devfs_get_first_child - Get the first leaf node in a directory.
- * @de: The handle to the device entry.
- *
- * Returns the leaf node device entry if it exists, else %NULL.
- */
- devfs_handle_t devfs_get_first_child (devfs_handle_t de)
- {
- if (de == NULL) return NULL;
- VERIFY_ENTRY (de);
- if ( !S_ISDIR (de->mode) ) return NULL;
- return de->u.dir.first;
- } /* End Function devfs_get_first_child */
- /**
- * devfs_get_next_sibling - Get the next sibling leaf node. for a device entry.
- * @de: The handle to the device entry.
- *
- * Returns the leaf node device entry if it exists, else %NULL.
- */
- devfs_handle_t devfs_get_next_sibling (devfs_handle_t de)
- {
- if (de == NULL) return NULL;
- VERIFY_ENTRY (de);
- return de->next;
- } /* End Function devfs_get_next_sibling */
- /**
- * devfs_auto_unregister - Configure a devfs entry to be automatically unregistered.
- * @master: The master devfs entry. Only one slave may be registered.
- * @slave: The devfs entry which will be automatically unregistered when the
- * master entry is unregistered. It is illegal to call devfs_unregister()
- * on this entry.
- */
- void devfs_auto_unregister (devfs_handle_t master, devfs_handle_t slave)
- {
- if (master == NULL) return;
- VERIFY_ENTRY (master);
- VERIFY_ENTRY (slave);
- if (master->slave != NULL)
- {
- /* Because of the dumbness of the layers above, ignore duplicates */
- if (master->slave == slave) return;
- PRINTK ("(%s): only one slave allowedn", master->name);
- OOPS ("(): old slave: "%s" new slave: "%s"n",
- master->slave->name, slave->name);
- }
- master->slave = slave;
- } /* End Function devfs_auto_unregister */
- /**
- * devfs_get_unregister_slave - Get the slave entry which will be automatically unregistered.
- * @master: The master devfs entry.
- *
- * Returns the slave which will be unregistered when @master is unregistered.
- */
- devfs_handle_t devfs_get_unregister_slave (devfs_handle_t master)
- {
- if (master == NULL) return NULL;
- VERIFY_ENTRY (master);
- return master->slave;
- } /* End Function devfs_get_unregister_slave */
- /**
- * devfs_get_name - Get the name for a device entry in its parent directory.
- * @de: The handle to the device entry.
- * @namelen: The length of the name is written here. This may be %NULL.
- *
- * Returns the name on success, else %NULL.
- */
- const char *devfs_get_name (devfs_handle_t de, unsigned int *namelen)
- {
- if (de == NULL) return NULL;
- VERIFY_ENTRY (de);
- if (namelen != NULL) *namelen = de->namelen;
- return de->name;
- } /* End Function devfs_get_name */
- /**
- * devfs_register_chrdev - Optionally register a conventional character driver.
- * @major: The major number for the driver.
- * @name: The name of the driver (as seen in /proc/devices).
- * @fops: The &file_operations structure pointer.
- *
- * This function will register a character driver provided the "devfs=only"
- * option was not provided at boot time.
- * Returns 0 on success, else a negative error code on failure.
- */
- int devfs_register_chrdev (unsigned int major, const char *name,
- struct file_operations *fops)
- {
- if (boot_options & OPTION_ONLY) return 0;
- return register_chrdev (major, name, fops);
- } /* End Function devfs_register_chrdev */
- /**
- * devfs_register_blkdev - Optionally register a conventional block driver.
- * @major: The major number for the driver.
- * @name: The name of the driver (as seen in /proc/devices).
- * @bdops: The &block_device_operations structure pointer.
- *
- * This function will register a block driver provided the "devfs=only"
- * option was not provided at boot time.
- * Returns 0 on success, else a negative error code on failure.
- */
- int devfs_register_blkdev (unsigned int major, const char *name,
- struct block_device_operations *bdops)
- {
- if (boot_options & OPTION_ONLY) return 0;
- return register_blkdev (major, name, bdops);
- } /* End Function devfs_register_blkdev */
- /**
- * devfs_unregister_chrdev - Optionally unregister a conventional character driver.
- * @major: The major number for the driver.
- * @name: The name of the driver (as seen in /proc/devices).
- *
- * This function will unregister a character driver provided the "devfs=only"
- * option was not provided at boot time.
- * Returns 0 on success, else a negative error code on failure.
- */
- int devfs_unregister_chrdev (unsigned int major, const char *name)
- {
- if (boot_options & OPTION_ONLY) return 0;
- return unregister_chrdev (major, name);
- } /* End Function devfs_unregister_chrdev */
- /**
- * devfs_unregister_blkdev - Optionally unregister a conventional block driver.
- * @major: The major number for the driver.
- * @name: The name of the driver (as seen in /proc/devices).
- *
- * This function will unregister a block driver provided the "devfs=only"
- * option was not provided at boot time.
- * Returns 0 on success, else a negative error code on failure.
- */
- int devfs_unregister_blkdev (unsigned int major, const char *name)
- {
- if (boot_options & OPTION_ONLY) return 0;
- return unregister_blkdev (major, name);
- } /* End Function devfs_unregister_blkdev */
- /**
- * 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 */
- {"only", OPTION_ONLY, &boot_options},
- {"mount", OPTION_MOUNT, &boot_options},
- {NULL, 0, NULL}
- };
- while ( (*str != ' ') && !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_put);
- EXPORT_SYMBOL(devfs_register);
- EXPORT_SYMBOL(devfs_unregister);
- EXPORT_SYMBOL(devfs_mk_symlink);
- EXPORT_SYMBOL(devfs_mk_dir);
- EXPORT_SYMBOL(devfs_get_handle);
- EXPORT_SYMBOL(devfs_find_handle);
- EXPORT_SYMBOL(devfs_get_flags);
- EXPORT_SYMBOL(devfs_set_flags);
- EXPORT_SYMBOL(devfs_get_maj_min);
- EXPORT_SYMBOL(devfs_get_handle_from_inode);
- EXPORT_SYMBOL(devfs_generate_path);
- EXPORT_SYMBOL(devfs_get_ops);
- EXPORT_SYMBOL(devfs_set_file_size);
- EXPORT_SYMBOL(devfs_get_info);
- EXPORT_SYMBOL(devfs_set_info);
- EXPORT_SYMBOL(devfs_get_parent);
- EXPORT_SYMBOL(devfs_get_first_child);
- EXPORT_SYMBOL(devfs_get_next_sibling);
- EXPORT_SYMBOL(devfs_auto_unregister);
- EXPORT_SYMBOL(devfs_get_unregister_slave);
- EXPORT_SYMBOL(devfs_get_name);
- EXPORT_SYMBOL(devfs_register_chrdev);
- EXPORT_SYMBOL(devfs_register_blkdev);
- EXPORT_SYMBOL(devfs_unregister_chrdev);
- EXPORT_SYMBOL(devfs_unregister_blkdev);
- /**
- * 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, 0) )
- return -ENOENT;
- /* Possible success: event has been queued */
- return 0;
- } /* End Function try_modload */
- /**
- * check_disc_changed - Check if a removable disc was changed.
- * @de: The device.
- *
- * Returns 1 if the media was changed, else 0.
- *
- * This function may block, and may indirectly cause the parent directory
- * contents to be changed due to partition re-reading.
- */
- static int check_disc_changed (struct devfs_entry *de)
- {
- int tmp;
- int retval = 0;
- kdev_t dev = mk_kdev (de->u.fcb.u.device.major, de->u.fcb.u.device.minor);
- struct block_device_operations *bdops;
- extern int warn_no_part;
- if ( !S_ISBLK (de->mode) ) return 0;
- bdops = devfs_get_ops (de);
- if (!bdops) return 0;
- if (bdops->check_media_change == NULL) goto out;
- if ( !bdops->check_media_change (dev) ) goto out;
- retval = 1;
- printk (KERN_DEBUG "VFS: Disk change detected on device %sn",
- kdevname (dev) );
- if ( invalidate_device (dev, 0) )
- printk (KERN_WARNING "VFS: busy inodes on changed media..n");
- /* Ugly hack to disable messages about unable to read partition table */
- tmp = warn_no_part;
- warn_no_part = 0;
- if (bdops->revalidate) bdops->revalidate (dev);
- warn_no_part = tmp;
- out:
- devfs_put_ops (de);
- return retval;
- } /* End Function check_disc_changed */
- /**
- * scan_dir_for_removable - Scan a directory for removable media devices and check media.
- * @dir: The directory.
- *
- * This function may block, and may indirectly cause the directory
- * contents to be changed due to partition re-reading. The directory will
- * be locked for reading.
- */
- static void scan_dir_for_removable (struct devfs_entry *dir)
- {
- struct devfs_entry *de;
- read_lock (&dir->u.dir.lock);
- if (dir->u.dir.num_removable < 1) de = NULL;
- else
- {
- for (de = dir->u.dir.first; de != NULL; de = de->next)
- {
- if (S_ISBLK (de->mode) && de->u.fcb.removable) break;
- }
- devfs_get (de);
- }
- read_unlock (&dir->u.dir.lock);
- if (de) check_disc_changed (de);
- devfs_put (de);
- } /* End Function scan_dir_for_removable */
- /**
- * get_removable_partition - Get removable media partition.
- * @dir: The parent directory.
- * @name: The name of the entry.
- * @namelen: The number of characters in <<name>>.
- *
- * Returns 1 if the media was changed, else 0.
- *
- * This function may block, and may indirectly cause the directory
- * contents to be changed due to partition re-reading. The directory must
- * be locked for reading upon entry, and will be unlocked upon exit.
- */
- static int get_removable_partition (struct devfs_entry *dir, const char *name,
- unsigned int namelen)
- {
- int retval;
- struct devfs_entry *de;
- if (dir->u.dir.num_removable < 1)
- {
- read_unlock (&dir->u.dir.lock);
- return 0;
- }
- for (de = dir->u.dir.first; de != NULL; de = de->next)
- {
- if (!S_ISBLK (de->mode) || !de->u.fcb.removable) continue;
- if (strcmp (de->name, "disc") == 0) break;
- /* Support for names where the partition is appended to the disc name
- */
- if (de->namelen >= namelen) continue;
- if (strncmp (de->name, name, de->namelen) == 0) break;
- }
- devfs_get (de);
- read_unlock (&dir->u.dir.lock);
- retval = de ? check_disc_changed (de) : 0;
- devfs_put (de);
- return retval;
- } /* End Function get_removable_partition */
- /* Superblock operations follow */
- static struct inode_operations devfs_iops;
- static struct inode_operations devfs_dir_iops;
- static struct file_operations devfs_fops;
- static 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->u.generic_sbp;
- 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: %pn",
- (int) inode->i_ino, inode, de);
- DPRINTK (DEBUG_I_CHANGE, "(): mode: 0%o uid: %d gid: %dn",
- (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 */
- if ( ( !S_ISREG (inode->i_mode) && !S_ISCHR (inode->i_mode) &&
- !S_ISBLK (inode->i_mode) ) || !de->u.fcb.auto_owner )
- {
- 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, 0);
- return 0;
- } /* End Function devfs_notify_change */
- static int devfs_statfs (struct super_block *sb, struct statfs *buf)
- {
- buf->f_type = DEVFS_SUPER_MAGIC;
- buf->f_bsize = FAKE_BLOCK_SIZE;
- buf->f_bfree = 0;
- buf->f_bavail = 0;
- buf->f_ffree = 0;
- buf->f_namelen = NAME_MAX;
- return 0;
- } /* End Function devfs_statfs */
- static void devfs_clear_inode (struct inode *inode)
- {
- if ( S_ISBLK (inode->i_mode) ) bdput (inode->i_bdev);
- } /* End Function devfs_clear_inode */
- static struct super_operations devfs_sops =
- {
- .put_inode = force_delete,
- .clear_inode = devfs_clear_inode,
- .statfs = devfs_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)
- {
- int is_fcb = FALSE;
- 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: %pn", 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;
- }
- inode->u.generic_ip = devfs_get (de);
- inode->i_ino = de->inode.ino;
- DPRINTK (DEBUG_I_GET, "(%d): VFS inode: %p devfs_entry: %pn",
- (int) inode->i_ino, inode, de);
- inode->i_blocks = 0;
- inode->i_blksize = FAKE_BLOCK_SIZE;
- inode->i_op = &devfs_iops;
- inode->i_fop = &devfs_fops;
- inode->i_rdev = NODEV;
- if ( S_ISCHR (de->mode) )
- {
- inode->i_rdev = mk_kdev (de->u.fcb.u.device.major,
- de->u.fcb.u.device.minor);
- inode->i_cdev = cdget ( kdev_t_to_nr (inode->i_rdev) );
- is_fcb = TRUE;
- }
- else if ( S_ISBLK (de->mode) )
- {
- inode->i_rdev = mk_kdev (de->u.fcb.u.device.major,
- de->u.fcb.u.device.minor);
- if (bd_acquire (inode) == 0)
- {
- if (!inode->i_bdev->bd_op && de->u.fcb.ops)
- inode->i_bdev->bd_op = de->u.fcb.ops;
- }
- else PRINTK ("(%d): no block device from bdget()n",(int)inode->i_ino);
- is_fcb = TRUE;
- }
- else if ( S_ISFIFO (de->mode) ) inode->i_fop = &def_fifo_fops;
- else if ( S_ISREG (de->mode) )
- {
- inode->i_size = de->u.fcb.u.file.size;
- is_fcb = TRUE;
- }
- else 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;
- }
- if (is_fcb && de->u.fcb.auto_owner)
- inode->i_mode = (de->mode & S_IFMT) | S_IRUGO | S_IWUGO;
- else inode->i_mode = de->mode;
- 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: %dn",
- (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->u.generic_sbp;
- 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: %ldn",
- parent->name, fs_info, (long) file->f_pos);
- switch ( (long) file->f_pos )
- {
- case 0:
- scan_dir_for_removable (parent);
- err = (*filldir) (dirent, "..", 2, file->f_pos,
- file->f_dentry->d_parent->d_inode->i_ino, 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)
- if ( !IS_HIDDEN (de) ) --count;
- devfs_get (de);
- read_unlock (&parent->u.dir.lock);
- /* Now add all remaining entries */
- while (de)
- {
- if ( IS_HIDDEN (de) ) err = 0;
- else
- {
- 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 */
- static int devfs_open (struct inode *inode, struct file *file)
- {
- int err;
- struct fcb_type *df;
- struct devfs_entry *de;
- struct fs_info *fs_info = inode->i_sb->u.generic_sbp;
- void *ops;
- de = get_devfs_entry_from_vfs_inode (inode);
- if (de == NULL) return -ENODEV;
- if ( S_ISDIR (de->mode) ) return 0;
- df = &de->u.fcb;
- file->private_data = de->info;
- ops = devfs_get_ops (de); /* Now have module refcount */
- if ( S_ISBLK (inode->i_mode) )
- {
- file->f_op = &def_blk_fops;
- if (ops) inode->i_bdev->bd_op = ops;
- err = def_blk_fops.open (inode, file); /* This bumps module refcount */
- devfs_put_ops (de); /* So drop my refcount */
- }
- else
- {
- file->f_op = ops;
- if (file->f_op)
- {
- lock_kernel ();
- err = file->f_op->open ? (*file->f_op->open) (inode, file) : 0;
- unlock_kernel ();
- }
- else
- { /* Fallback to legacy scheme (I don't have a module refcount) */
- if ( S_ISCHR (inode->i_mode) ) err = chrdev_open (inode, file);
- else err = -ENODEV;
- }
- }
- if (err < 0) return err;
- /* Open was successful */
- if (df->open) return 0;
- df->open = TRUE; /* This is the first open */
- if (df->auto_owner)
- {
- /* Change the ownership/protection to what driver specified */
- inode->i_mode = de->mode;
- inode->i_uid = current->euid;
- inode->i_gid = current->egid;
- }
- if ( df->aopen_notify && !is_devfsd_or_child (fs_info) )
- devfsd_notify_de (de, DEVFSD_NOTIFY_ASYNC_OPEN, inode->i_mode,
- current->euid, current->egid, fs_info, 0);
- return 0;
- } /* End Function devfs_open */
- static struct file_operations devfs_fops =
- {
- .open = devfs_open,
- };
- static struct file_operations devfs_dir_fops =
- {
- .read = generic_read_dir,
- .readdir = devfs_readdir,
- .open = devfs_open,
- };
- /* 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: %pn", 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: %pn",
- de->name, dentry, inode, de, de->inode.dentry);
- if ( de->inode.dentry && (de->inode.dentry != dentry) )
- OOPS ("(%s): de: %p dentry: %p de->dentry: %pn",
- 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, int flags);
- 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;
- struct devfs_entry *de;
- struct fs_info *fs_info;
- 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 dentryn", dentry);
- return 1;
- }
- fs_info = inode->i_sb->u.generic_sbp;
- de = get_devfs_entry_from_vfs_inode (inode);
- DPRINTK (DEBUG_D_DELETE, "(%p): inode: %p devfs_entry: %pn",
- dentry, inode, de);
- if (de == NULL) return 0;
- if ( !S_ISCHR (de->mode) && !S_ISBLK (de->mode) && !S_ISREG (de->mode) )
- return 0;
- if (!de->u.fcb.open) return 0;
- de->u.fcb.open = FALSE;
- if (de->u.fcb.aopen_notify)
- devfsd_notify_de (de, DEVFSD_NOTIFY_CLOSE, inode->i_mode,
- current->euid, current->egid, fs_info, 1);
- if (!de->u.fcb.auto_owner) return 0;
- /* Change the ownership/protection back */
- inode->i_mode = (de->mode & S_IFMT) | S_IRUGO | S_IWUGO;
- inode->i_uid = de->inode.uid;
- inode->i_gid = de->inode.gid;
- return 0;
- } /* End Function devfs_d_delete */
- struct devfs_lookup_struct
- {
- devfs_handle_t de;
- wait_queue_head_t wait_queue;
- };
- static int devfs_d_revalidate_wait (struct dentry *dentry, int flags)
- {
- struct inode *dir = dentry->d_parent->d_inode;
- struct fs_info *fs_info = dir->i_sb->u.generic_sbp;
- devfs_handle_t parent = get_devfs_entry_from_vfs_inode (dir);
- struct devfs_lookup_struct *lookup_info = dentry->d_fsdata;
- DECLARE_WAITQUEUE (wait, current);
- 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) return 1;
- 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) return 1;
- 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) return 1;
- 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);
- return 1;
- }
- if (lookup_info == NULL) return 1; /* 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);
- schedule ();
- }
- else read_unlock (&parent->u.dir.lock);
- 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 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->u.generic_sbp;
- 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);
- if (de) read_unlock (&parent->u.dir.lock);
- else
- { /* Try re-reading the partition (media may have changed) */
- if ( get_removable_partition (parent, dentry->d_name.name,
- dentry->d_name.len) ) /* Unlocks */
- { /* Media did change */
- 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 */
- up (&dir->i_sem);
- wait_for_devfsd_finished (fs_info); /* If I'm not devfsd, must wait */
- down (&dir->i_sem); /* 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:
- dentry->d_op = &devfs_dops;
- dentry->d_fsdata = NULL;
- write_lock (&parent->u.dir.lock);
- 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->u.generic_sbp;
- de = get_devfs_entry_from_vfs_inode (inode);
- DPRINTK (DEBUG_I_UNLINK, "(%s): de: %pn", dentry->d_name.name, de);
- if (de == NULL) return -ENOENT;
- if (!de->vfs_deletable) 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, 0);
- 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->u.generic_sbp;
- 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, DEVFS_FL_NONE,
- symname, &de, NULL);
- DPRINTK (DEBUG_DISABLED, "(%s): errcode from <devfs_do_symlink>: %dn",
- dentry->d_name.name, err);
- if (err < 0) return err;
- de->vfs_deletable = 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: %pn",
- 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, 0);
- 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->u.generic_sbp;
- 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_deletable = TRUE;
- if ( ( err = _devfs_append_entry (parent, de, FALSE, 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: %pn",
- 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, 0);
- 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->u.generic_sbp;
- struct inode *inode = dentry->d_inode;
- if (dir->i_sb->u.generic_sbp != inode->i_sb->u.generic_sbp) 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_deletable) 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 it's 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, 0);
- free_dentry (de);
- devfs_put (de);
- return 0;
- } /* End Function devfs_rmdir */
- static int devfs_mknod (struct inode *dir, struct dentry *dentry, int mode,
- int rdev)
- {
- int err;
- struct fs_info *fs_info = dir->i_sb->u.generic_sbp;
- struct devfs_entry *parent, *de;
- struct inode *inode;
- DPRINTK (DEBUG_I_MKNOD, "(%s): mode: 0%o dev: %dn",
- dentry->d_name.name, mode, 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_deletable = TRUE;
- if ( S_ISBLK (mode) || S_ISCHR (mode) )
- {
- de->u.fcb.u.device.major = MAJOR (rdev);
- de->u.fcb.u.device.minor = MINOR (rdev);
- }
- if ( ( err = _devfs_append_entry (parent, de, FALSE, 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: %pn",
- 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, 0);
- return 0;
- } /* End Function devfs_mknod */
- static int devfs_readlink (struct dentry *dentry, char *buffer, int buflen)
- {
- int err;
- struct devfs_entry *de;
- de = get_devfs_entry_from_vfs_inode (dentry->d_inode);
- if (!de) return -ENODEV;
- err = vfs_readlink (dentry, buffer, buflen, de->u.symlink.linkname);
- return err;
- } /* End Function devfs_readlink */
- static int devfs_follow_link (struct dentry *dentry, struct nameidata *nd)
- {
- int err;
- struct devfs_entry *de;
- de = get_devfs_entry_from_vfs_inode (dentry->d_inode);
- if (!de) return -ENODEV;
- err = vfs_follow_link (nd, de->u.symlink.linkname);
- return err;
- } /* 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 = devfs_readlink,
- .follow_link = devfs_follow_link,
- .setattr = devfs_notify_change,
- };
- static struct super_block *devfs_read_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->u.generic_sbp = &fs_info;
- sb->s_blocksize = 1024;
- sb->s_blocksize_bits = 10;
- sb->s_magic = DEVFS_SUPER_MAGIC;
- sb->s_op = &devfs_sops;
- 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: %pn", sb->u.generic_sbp);
- return sb;
- out_no_root:
- PRINTK ("(): get root inode failedn");
- if (root_inode) iput (root_inode);
- return NULL;
- } /* End Function devfs_read_super */
- static DECLARE_FSTYPE (devfs_fs_type, DEVFS_NAME, devfs_read_super, FS_SINGLE);
- /* File operations for devfsd follow */
- static ssize_t devfsd_read (struct file *file, char *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->u.generic_sbp;
- struct devfsd_notify_struct *info = fs_info->devfsd_info;
- DECLARE_WAITQUEUE (wait, current);
- /* Can't seek (pread) on this device */
- if (ppos != &file->f_pos) return -ESPIPE;
- /* 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 = de->u.fcb.u.device.major;
- info->minor = de->u.fcb.u.device.minor;
- }
- 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->u.generic_sbp;
- switch (cmd)
- {
- case DEVFSDIOC_GET_PROTO_REV:
- ival = DEVFSD_PROTOCOL_REVISION_KERNEL;
- if ( copy_to_user ( (void *)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 spinlock_t lock = SPIN_LOCK_UNLOCKED;
- 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 = (current->pgrp == current->pid) ?
- current->pgrp : 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 *) 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->u.generic_sbp;
- 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;
- if (fs_info->devfsd_info)
- {
- 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 *buf, size_t len,
- loff_t *ppos)
- {
- ssize_t num;
- char txt[80];
- num = sprintf (txt, "Number of entries: %u number of bytes: %un",
- stat_num_entries, stat_num_bytes) + 1;
- /* Can't seek (pread) on this device */
- if (ppos != &file->f_pos) return -ESPIPE;
- 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;
- printk (KERN_INFO "%s: v%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 slabn");
- #ifdef CONFIG_DEVFS_DEBUG
- devfs_debug = devfs_debug_init;
- printk (KERN_INFO "%s: devfs_debug: 0x%0xn", DEVFS_NAME, devfs_debug);
- #endif
- printk (KERN_INFO "%s: boot_options: 0x%0xn", DEVFS_NAME, boot_options);
- err = register_filesystem (&devfs_fs_type);
- if (!err)
- {
- struct vfsmount *devfs_mnt = kern_mount (&devfs_fs_type);
- err = PTR_ERR (devfs_mnt);
- if ( !IS_ERR (devfs_mnt) ) err = 0;
- }
- 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, "");
- if (err == 0) printk (KERN_INFO "Mounted devfs on /devn");
- else PRINTK ("(): unable to mount devfs, err: %dn", err);
- } /* End Function mount_devfs_fs */
- module_init(init_devfs_fs)
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