diff options
Diffstat (limited to 'fs/devfs/base.c')
| -rw-r--r-- | fs/devfs/base.c | 2836 |
1 files changed, 0 insertions, 2836 deletions
diff --git a/fs/devfs/base.c b/fs/devfs/base.c deleted file mode 100644 index 51a97f13274..00000000000 --- a/fs/devfs/base.c +++ /dev/null @@ -1,2836 +0,0 @@ -/* devfs (Device FileSystem) driver. - - Copyright (C) 1998-2002 Richard Gooch - - This library is free software; you can redistribute it and/or - modify it under the terms of the GNU Library General Public - License as published by the Free Software Foundation; either - version 2 of the License, or (at your option) any later version. - - This library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Library General Public License for more details. - - You should have received a copy of the GNU Library General Public - License along with this library; if not, write to the Free - Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - - Richard Gooch may be reached by email at rgooch@atnf.csiro.au - The postal address is: - Richard Gooch, c/o ATNF, P. O. Box 76, Epping, N.S.W., 2121, Australia. - - ChangeLog - - 19980110 Richard Gooch <rgooch@atnf.csiro.au> - Original version. - v0.1 - 19980111 Richard Gooch <rgooch@atnf.csiro.au> - Created per-fs inode table rather than using inode->u.generic_ip - v0.2 - 19980111 Richard Gooch <rgooch@atnf.csiro.au> - Created .epoch inode which has a ctime of 0. - Fixed loss of named pipes when dentries lost. - Fixed loss of inode data when devfs_register() follows mknod(). - v0.3 - 19980111 Richard Gooch <rgooch@atnf.csiro.au> - Fix for when compiling with CONFIG_KERNELD. - 19980112 Richard Gooch <rgooch@atnf.csiro.au> - Fix for readdir() which sometimes didn't show entries. - Added <<tolerant>> option to <devfs_register>. - v0.4 - 19980113 Richard Gooch <rgooch@atnf.csiro.au> - Created <devfs_fill_file> function. - v0.5 - 19980115 Richard Gooch <rgooch@atnf.csiro.au> - Added subdirectory support. Major restructuring. - 19980116 Richard Gooch <rgooch@atnf.csiro.au> - Fixed <find_by_dev> to not search major=0,minor=0. - Added symlink support. - v0.6 - 19980120 Richard Gooch <rgooch@atnf.csiro.au> - Created <devfs_mk_dir> function and support directory unregister - 19980120 Richard Gooch <rgooch@atnf.csiro.au> - Auto-ownership uses real uid/gid rather than effective uid/gid. - v0.7 - 19980121 Richard Gooch <rgooch@atnf.csiro.au> - Supported creation of sockets. - v0.8 - 19980122 Richard Gooch <rgooch@atnf.csiro.au> - Added DEVFS_FL_HIDE_UNREG flag. - Interface change to <devfs_mk_symlink>. - Created <devfs_symlink> to support symlink(2). - v0.9 - 19980123 Richard Gooch <rgooch@atnf.csiro.au> - Added check to <devfs_fill_file> to check inode is in devfs. - Added optional traversal of symlinks. - v0.10 - 19980124 Richard Gooch <rgooch@atnf.csiro.au> - Created <devfs_get_flags> and <devfs_set_flags>. - v0.11 - 19980125 C. Scott Ananian <cananian@alumni.princeton.edu> - Created <devfs_find_handle>. - 19980125 Richard Gooch <rgooch@atnf.csiro.au> - Allow removal of symlinks. - v0.12 - 19980125 Richard Gooch <rgooch@atnf.csiro.au> - Created <devfs_set_symlink_destination>. - 19980126 Richard Gooch <rgooch@atnf.csiro.au> - Moved DEVFS_SUPER_MAGIC into header file. - Added DEVFS_FL_HIDE flag. - Created <devfs_get_maj_min>. - Created <devfs_get_handle_from_inode>. - Fixed minor bug in <find_by_dev>. - 19980127 Richard Gooch <rgooch@atnf.csiro.au> - Changed interface to <find_by_dev>, <find_entry>, - <devfs_unregister>, <devfs_fill_file> and <devfs_find_handle>. - Fixed inode times when symlink created with symlink(2). - v0.13 - 19980129 C. Scott Ananian <cananian@alumni.princeton.edu> - Exported <devfs_set_symlink_destination>, <devfs_get_maj_min> - and <devfs_get_handle_from_inode>. - 19980129 Richard Gooch <rgooch@atnf.csiro.au> - Created <devfs_unlink> to support unlink(2). - v0.14 - 19980129 Richard Gooch <rgooch@atnf.csiro.au> - Fixed kerneld support for entries in devfs subdirectories. - 19980130 Richard Gooch <rgooch@atnf.csiro.au> - Bugfixes in <call_kerneld>. - v0.15 - 19980207 Richard Gooch <rgooch@atnf.csiro.au> - Call kerneld when looking up unregistered entries. - v0.16 - 19980326 Richard Gooch <rgooch@atnf.csiro.au> - Modified interface to <devfs_find_handle> for symlink traversal. - v0.17 - 19980331 Richard Gooch <rgooch@atnf.csiro.au> - Fixed persistence bug with device numbers for manually created - device files. - Fixed problem with recreating symlinks with different content. - v0.18 - 19980401 Richard Gooch <rgooch@atnf.csiro.au> - Changed to CONFIG_KMOD. - Hide entries which are manually unlinked. - Always invalidate devfs dentry cache when registering entries. - Created <devfs_rmdir> to support rmdir(2). - Ensure directories created by <devfs_mk_dir> are visible. - v0.19 - 19980402 Richard Gooch <rgooch@atnf.csiro.au> - Invalidate devfs dentry cache when making directories. - Invalidate devfs dentry cache when removing entries. - Fixed persistence bug with fifos. - v0.20 - 19980421 Richard Gooch <rgooch@atnf.csiro.au> - Print process command when debugging kerneld/kmod. - Added debugging for register/unregister/change operations. - 19980422 Richard Gooch <rgooch@atnf.csiro.au> - Added "devfs=" boot options. - v0.21 - 19980426 Richard Gooch <rgooch@atnf.csiro.au> - No longer lock/unlock superblock in <devfs_put_super>. - Drop negative dentries when they are released. - Manage dcache more efficiently. - v0.22 - 19980427 Richard Gooch <rgooch@atnf.csiro.au> - Added DEVFS_FL_AUTO_DEVNUM flag. - v0.23 - 19980430 Richard Gooch <rgooch@atnf.csiro.au> - No longer set unnecessary methods. - v0.24 - 19980504 Richard Gooch <rgooch@atnf.csiro.au> - Added PID display to <call_kerneld> debugging message. - Added "after" debugging message to <call_kerneld>. - 19980519 Richard Gooch <rgooch@atnf.csiro.au> - Added "diread" and "diwrite" boot options. - 19980520 Richard Gooch <rgooch@atnf.csiro.au> - Fixed persistence problem with permissions. - v0.25 - 19980602 Richard Gooch <rgooch@atnf.csiro.au> - Support legacy device nodes. - Fixed bug where recreated inodes were hidden. - v0.26 - 19980602 Richard Gooch <rgooch@atnf.csiro.au> - Improved debugging in <get_vfs_inode>. - 19980607 Richard Gooch <rgooch@atnf.csiro.au> - No longer free old dentries in <devfs_mk_dir>. - Free all dentries for a given entry when deleting inodes. - v0.27 - 19980627 Richard Gooch <rgooch@atnf.csiro.au> - Limit auto-device numbering to majors 128 to 239. - v0.28 - 19980629 Richard Gooch <rgooch@atnf.csiro.au> - Fixed inode times persistence problem. - v0.29 - 19980704 Richard Gooch <rgooch@atnf.csiro.au> - Fixed spelling in <devfs_readlink> debug. - Fixed bug in <devfs_setup> parsing "dilookup". - v0.30 - 19980705 Richard Gooch <rgooch@atnf.csiro.au> - Fixed devfs inode leak when manually recreating inodes. - Fixed permission persistence problem when recreating inodes. - v0.31 - 19980727 Richard Gooch <rgooch@atnf.csiro.au> - Removed harmless "unused variable" compiler warning. - Fixed modes for manually recreated device nodes. - v0.32 - 19980728 Richard Gooch <rgooch@atnf.csiro.au> - Added NULL devfs inode warning in <devfs_read_inode>. - Force all inode nlink values to 1. - v0.33 - 19980730 Richard Gooch <rgooch@atnf.csiro.au> - Added "dimknod" boot option. - Set inode nlink to 0 when freeing dentries. - Fixed modes for manually recreated symlinks. - v0.34 - 19980802 Richard Gooch <rgooch@atnf.csiro.au> - Fixed bugs in recreated directories and symlinks. - v0.35 - 19980806 Richard Gooch <rgooch@atnf.csiro.au> - Fixed bugs in recreated device nodes. - 19980807 Richard Gooch <rgooch@atnf.csiro.au> - Fixed bug in currently unused <devfs_get_handle_from_inode>. - Defined new <devfs_handle_t> type. - Improved debugging when getting entries. - Fixed bug where directories could be emptied. - v0.36 - 19980809 Richard Gooch <rgooch@atnf.csiro.au> - Replaced dummy .epoch inode with .devfsd character device. - 19980810 Richard Gooch <rgooch@atnf.csiro.au> - Implemented devfsd protocol revision 0. - v0.37 - 19980819 Richard Gooch <rgooch@atnf.csiro.au> - Added soothing message to warning in <devfs_d_iput>. - v0.38 - 19980829 Richard Gooch <rgooch@atnf.csiro.au> - Use GCC extensions for structure initialisations. - Implemented async open notification. - Incremented devfsd protocol revision to 1. - v0.39 - 19980908 Richard Gooch <rgooch@atnf.csiro.au> - Moved async open notification to end of <devfs_open>. - v0.40 - 19980910 Richard Gooch <rgooch@atnf.csiro.au> - Prepended "/dev/" to module load request. - Renamed <call_kerneld> to <call_kmod>. - v0.41 - 19980910 Richard Gooch <rgooch@atnf.csiro.au> - Fixed typo "AYSNC" -> "ASYNC". - v0.42 - 19980910 Richard Gooch <rgooch@atnf.csiro.au> - Added open flag for files. - v0.43 - 19980927 Richard Gooch <rgooch@atnf.csiro.au> - Set i_blocks=0 and i_blksize=1024 in <devfs_read_inode>. - v0.44 - 19981005 Richard Gooch <rgooch@atnf.csiro.au> - Added test for empty <<name>> in <devfs_find_handle>. - Renamed <generate_path> to <devfs_generate_path> and published. - v0.45 - 19981006 Richard Gooch <rgooch@atnf.csiro.au> - Created <devfs_get_fops>. - v0.46 - 19981007 Richard Gooch <rgooch@atnf.csiro.au> - Limit auto-device numbering to majors 144 to 239. - v0.47 - 19981010 Richard Gooch <rgooch@atnf.csiro.au> - Updated <devfs_follow_link> for VFS change in 2.1.125. - v0.48 - 19981022 Richard Gooch <rgooch@atnf.csiro.au> - Created DEVFS_ FL_COMPAT flag. - v0.49 - 19981023 Richard Gooch <rgooch@atnf.csiro.au> - Created "nocompat" boot option. - v0.50 - 19981025 Richard Gooch <rgooch@atnf.csiro.au> - Replaced "mount" boot option with "nomount". - v0.51 - 19981110 Richard Gooch <rgooch@atnf.csiro.au> - Created "only" boot option. - v0.52 - 19981112 Richard Gooch <rgooch@atnf.csiro.au> - Added DEVFS_FL_REMOVABLE flag. - v0.53 - 19981114 Richard Gooch <rgooch@atnf.csiro.au> - Only call <scan_dir_for_removable> on first call to - <devfs_readdir>. - v0.54 - 19981205 Richard Gooch <rgooch@atnf.csiro.au> - Updated <devfs_rmdir> for VFS change in 2.1.131. - v0.55 - 19981218 Richard Gooch <rgooch@atnf.csiro.au> - Created <devfs_mk_compat>. - 19981220 Richard Gooch <rgooch@atnf.csiro.au> - Check for partitions on removable media in <devfs_lookup>. - v0.56 - 19990118 Richard Gooch <rgooch@atnf.csiro.au> - Added support for registering regular files. - Created <devfs_set_file_size>. - Update devfs inodes from entries if not changed through FS. - v0.57 - 19990124 Richard Gooch <rgooch@atnf.csiro.au> - Fixed <devfs_fill_file> to only initialise temporary inodes. - Trap for NULL fops in <devfs_register>. - Return -ENODEV in <devfs_fill_file> for non-driver inodes. - v0.58 - 19990126 Richard Gooch <rgooch@atnf.csiro.au> - Switched from PATH_MAX to DEVFS_PATHLEN. - v0.59 - 19990127 Richard Gooch <rgooch@atnf.csiro.au> - Created "nottycompat" boot option. - v0.60 - 19990318 Richard Gooch <rgooch@atnf.csiro.au> - Fixed <devfsd_read> to not overrun event buffer. - v0.61 - 19990329 Richard Gooch <rgooch@atnf.csiro.au> - Created <devfs_auto_unregister>. - v0.62 - 19990330 Richard Gooch <rgooch@atnf.csiro.au> - Don't return unregistred entries in <devfs_find_handle>. - Panic in <devfs_unregister> if entry unregistered. - 19990401 Richard Gooch <rgooch@atnf.csiro.au> - Don't panic in <devfs_auto_unregister> for duplicates. - v0.63 - 19990402 Richard Gooch <rgooch@atnf.csiro.au> - Don't unregister already unregistered entries in <unregister>. - v0.64 - 19990510 Richard Gooch <rgooch@atnf.csiro.au> - Disable warning messages when unable to read partition table for - removable media. - v0.65 - 19990512 Richard Gooch <rgooch@atnf.csiro.au> - Updated <devfs_lookup> for VFS change in 2.3.1-pre1. - Created "oops-on-panic" boot option. - Improved debugging in <devfs_register> and <devfs_unregister>. - v0.66 - 19990519 Richard Gooch <rgooch@atnf.csiro.au> - Added documentation for some functions. - 19990525 Richard Gooch <rgooch@atnf.csiro.au> - Removed "oops-on-panic" boot option: now always Oops. - v0.67 - 19990531 Richard Gooch <rgooch@atnf.csiro.au> - Improved debugging in <devfs_register>. - v0.68 - 19990604 Richard Gooch <rgooch@atnf.csiro.au> - Added "diunlink" and "nokmod" boot options. - Removed superfluous warning message in <devfs_d_iput>. - v0.69 - 19990611 Richard Gooch <rgooch@atnf.csiro.au> - Took account of change to <d_alloc_root>. - v0.70 - 19990614 Richard Gooch <rgooch@atnf.csiro.au> - Created separate event queue for each mounted devfs. - Removed <devfs_invalidate_dcache>. - Created new ioctl()s. - Incremented devfsd protocol revision to 3. - Fixed bug when re-creating directories: contents were lost. - Block access to inodes until devfsd updates permissions. - 19990615 Richard Gooch <rgooch@atnf.csiro.au> - Support 2.2.x kernels. - v0.71 - 19990623 Richard Gooch <rgooch@atnf.csiro.au> - Switched to sending process uid/gid to devfsd. - Renamed <call_kmod> to <try_modload>. - Added DEVFSD_NOTIFY_LOOKUP event. - 19990624 Richard Gooch <rgooch@atnf.csiro.au> - Added DEVFSD_NOTIFY_CHANGE event. - Incremented devfsd protocol revision to 4. - v0.72 - 19990713 Richard Gooch <rgooch@atnf.csiro.au> - Return EISDIR rather than EINVAL for read(2) on directories. - v0.73 - 19990809 Richard Gooch <rgooch@atnf.csiro.au> - Changed <devfs_setup> to new __init scheme. - v0.74 - 19990901 Richard Gooch <rgooch@atnf.csiro.au> - Changed remaining function declarations to new __init scheme. - v0.75 - 19991013 Richard Gooch <rgooch@atnf.csiro.au> - Created <devfs_get_info>, <devfs_set_info>, - <devfs_get_first_child> and <devfs_get_next_sibling>. - Added <<dir>> parameter to <devfs_register>, <devfs_mk_compat>, - <devfs_mk_dir> and <devfs_find_handle>. - Work sponsored by SGI. - v0.76 - 19991017 Richard Gooch <rgooch@atnf.csiro.au> - Allow multiple unregistrations. - Work sponsored by SGI. - v0.77 - 19991026 Richard Gooch <rgooch@atnf.csiro.au> - Added major and minor number to devfsd protocol. - Incremented devfsd protocol revision to 5. - Work sponsored by SGI. - v0.78 - 19991030 Richard Gooch <rgooch@atnf.csiro.au> - Support info pointer for all devfs entry types. - Added <<info>> parameter to <devfs_mk_dir> and - <devfs_mk_symlink>. - Work sponsored by SGI. - v0.79 - 19991031 Richard Gooch <rgooch@atnf.csiro.au> - Support "../" when searching devfs namespace. - Work sponsored by SGI. - v0.80 - 19991101 Richard Gooch <rgooch@atnf.csiro.au> - Created <devfs_get_unregister_slave>. - Work sponsored by SGI. - v0.81 - 19991103 Richard Gooch <rgooch@atnf.csiro.au> - Exported <devfs_get_parent>. - Work sponsored by SGI. - v0.82 - 19991104 Richard Gooch <rgooch@atnf.csiro.au> - Removed unused <devfs_set_symlink_destination>. - 19991105 Richard Gooch <rgooch@atnf.csiro.au> - Do not hide entries from devfsd or children. - Removed DEVFS_ FL_TTY_COMPAT flag. - Removed "nottycompat" boot option. - Removed <devfs_mk_compat>. - Work sponsored by SGI. - v0.83 - 19991107 Richard Gooch <rgooch@atnf.csiro.au> - Added DEVFS_FL_WAIT flag. - Work sponsored by SGI. - v0.84 - 19991107 Richard Gooch <rgooch@atnf.csiro.au> - Support new "disc" naming scheme in <get_removable_partition>. - Allow NULL fops in <devfs_register>. - Work sponsored by SGI. - v0.85 - 19991110 Richard Gooch <rgooch@atnf.csiro.au> - Fall back to major table if NULL fops given to <devfs_register>. - Work sponsored by SGI. - v0.86 - 19991204 Richard Gooch <rgooch@atnf.csiro.au> - Support fifos when unregistering. - Work sponsored by SGI. - v0.87 - 19991209 Richard Gooch <rgooch@atnf.csiro.au> - Removed obsolete DEVFS_ FL_COMPAT and DEVFS_ FL_TOLERANT flags. - Work sponsored by SGI. - v0.88 - 19991214 Richard Gooch <rgooch@atnf.csiro.au> - Removed kmod support. - Work sponsored by SGI. - v0.89 - 19991216 Richard Gooch <rgooch@atnf.csiro.au> - Improved debugging in <get_vfs_inode>. - Ensure dentries created by devfsd will be cleaned up. - Work sponsored by SGI. - v0.90 - 19991223 Richard Gooch <rgooch@atnf.csiro.au> - Created <devfs_get_name>. - Work sponsored by SGI. - v0.91 - 20000203 Richard Gooch <rgooch@atnf.csiro.au> - Ported to kernel 2.3.42. - Removed <devfs_fill_file>. - Work sponsored by SGI. - v0.92 - 20000306 Richard Gooch <rgooch@atnf.csiro.au> - Added DEVFS_ FL_NO_PERSISTENCE flag. - Removed unnecessary call to <update_devfs_inode_from_entry> in - <devfs_readdir>. - Work sponsored by SGI. - v0.93 - 20000413 Richard Gooch <rgooch@atnf.csiro.au> - Set inode->i_size to correct size for symlinks. - 20000414 Richard Gooch <rgooch@atnf.csiro.au> - Only give lookup() method to directories to comply with new VFS - assumptions. - Work sponsored by SGI. - 20000415 Richard Gooch <rgooch@atnf.csiro.au> - Remove unnecessary tests in symlink methods. - Don't kill existing block ops in <devfs_read_inode>. - Work sponsored by SGI. - v0.94 - 20000424 Richard Gooch <rgooch@atnf.csiro.au> - Don't create missing directories in <devfs_find_handle>. - Work sponsored by SGI. - v0.95 - 20000430 Richard Gooch <rgooch@atnf.csiro.au> - Added CONFIG_DEVFS_MOUNT. - Work sponsored by SGI. - v0.96 - 20000608 Richard Gooch <rgooch@atnf.csiro.au> - Disabled multi-mount capability (use VFS bindings instead). - Work sponsored by SGI. - v0.97 - 20000610 Richard Gooch <rgooch@atnf.csiro.au> - Switched to FS_SINGLE to disable multi-mounts. - 20000612 Richard Gooch <rgooch@atnf.csiro.au> - Removed module support. - Removed multi-mount code. - Removed compatibility macros: VFS has changed too much. - Work sponsored by SGI. - v0.98 - 20000614 Richard Gooch <rgooch@atnf.csiro.au> - Merged devfs inode into devfs entry. - Work sponsored by SGI. - v0.99 - 20000619 Richard Gooch <rgooch@atnf.csiro.au> - Removed dead code in <devfs_register> which used to call - <free_dentries>. - Work sponsored by SGI. - v0.100 - 20000621 Richard Gooch <rgooch@atnf.csiro.au> - Changed interface to <devfs_register>. - Work sponsored by SGI. - v0.101 - 20000622 Richard Gooch <rgooch@atnf.csiro.au> - Simplified interface to <devfs_mk_symlink> and <devfs_mk_dir>. - Simplified interface to <devfs_find_handle>. - Work sponsored by SGI. - v0.102 - 20010519 Richard Gooch <rgooch@atnf.csiro.au> - Ensure <devfs_generate_path> terminates string for root entry. - Exported <devfs_get_name> to modules. - 20010520 Richard Gooch <rgooch@atnf.csiro.au> - Make <devfs_mk_symlink> send events to devfsd. - Cleaned up option processing in <devfs_setup>. - 20010521 Richard Gooch <rgooch@atnf.csiro.au> - Fixed bugs in handling symlinks: could leak or cause Oops. - 20010522 Richard Gooch <rgooch@atnf.csiro.au> - Cleaned up directory handling by separating fops. - v0.103 - 20010601 Richard Gooch <rgooch@atnf.csiro.au> - Fixed handling of inverted options in <devfs_setup>. - v0.104 - 20010604 Richard Gooch <rgooch@atnf.csiro.au> - Adjusted <try_modload> to account for <devfs_generate_path> fix. - v0.105 - 20010617 Richard Gooch <rgooch@atnf.csiro.au> - Answered question posed by Al Viro and removed his comments. - Moved setting of registered flag after other fields are changed. - Fixed race between <devfsd_close> and <devfsd_notify_one>. - Global VFS changes added bogus BKL to <devfsd_close>: removed. - Widened locking in <devfs_readlink> and <devfs_follow_link>. - Replaced <devfsd_read> stack usage with <devfsd_ioctl> kmalloc. - Simplified locking in <devfsd_ioctl> and fixed memory leak. - v0.106 - 20010709 Richard Gooch <rgooch@atnf.csiro.au> - Removed broken devnum allocation and use <devfs_alloc_devnum>. - Fixed old devnum leak by calling new <devfs_dealloc_devnum>. - v0.107 - 20010712 Richard Gooch <rgooch@atnf.csiro.au> - Fixed bug in <devfs_setup> which could hang boot process. - v0.108 - 20010730 Richard Gooch <rgooch@atnf.csiro.au> - Added DEVFSD_NOTIFY_DELETE event. - 20010801 Richard Gooch <rgooch@atnf.csiro.au> - Removed #include <asm/segment.h>. - v0.109 - 20010807 Richard Gooch <rgooch@atnf.csiro.au> - Fixed inode table races by removing it and using - inode->u.generic_ip instead. - Moved <devfs_read_inode> into <get_vfs_inode>. - Moved <devfs_write_inode> into <devfs_notify_change>. - v0.110 - 20010808 Richard Gooch <rgooch@atnf.csiro.au> - Fixed race in <devfs_do_symlink> for uni-processor. - v0.111 - 20010818 Richard Gooch <rgooch@atnf.csiro.au> - Removed remnant of multi-mount support in <devfs_mknod>. - Removed unused DEVFS_FL_SHOW_UNREG flag. - v0.112 - 20010820 Richard Gooch <rgooch@atnf.csiro.au> - Removed nlink field from struct devfs_inode. - v0.113 - 20010823 Richard Gooch <rgooch@atnf.csiro.au> - Replaced BKL with global rwsem to protect symlink data (quick - and dirty hack). - v0.114 - 20010827 Richard Gooch <rgooch@atnf.csiro.au> - Replaced global rwsem for symlink with per-link refcount. - v0.115 - 20010919 Richard Gooch <rgooch@atnf.csiro.au> - Set inode->i_mapping->a_ops for block nodes in <get_vfs_inode>. - v0.116 - 20011008 Richard Gooch <rgooch@atnf.csiro.au> - Fixed overrun in <devfs_link> by removing function (not needed). - 20011009 Richard Gooch <rgooch@atnf.csiro.au> - Fixed buffer underrun in <try_modload>. - 20011029 Richard Gooch <rgooch@atnf.csiro.au> - Fixed race in <devfsd_ioctl> when setting event mask. - 20011114 Richard Gooch <rgooch@atnf.csiro.au> - First release of new locking code. - v1.0 - 20011117 Richard Gooch <rgooch@atnf.csiro.au> - Discard temporary buffer, now use "%s" for dentry names. - 20011118 Richard Gooch <rgooch@atnf.csiro.au> - Don't generate path in <try_modload>: use fake entry instead. - Use "existing" directory in <_devfs_make_parent_for_leaf>. - 20011122 Richard Gooch <rgooch@atnf.csiro.au> - Use slab cache rather than fixed buffer for devfsd events. - v1.1 - 20011125 Richard Gooch <rgooch@atnf.csiro.au> - Send DEVFSD_NOTIFY_REGISTERED events in <devfs_mk_dir>. - 20011127 Richard Gooch <rgooch@atnf.csiro.au> - Fixed locking bug in <devfs_d_revalidate_wait> due to typo. - Do not send CREATE, CHANGE, ASYNC_OPEN or DELETE events from - devfsd or children. - v1.2 - 20011202 Richard Gooch <rgooch@atnf.csiro.au> - Fixed bug in <devfsd_read>: was dereferencing freed pointer. - v1.3 - 20011203 Richard Gooch <rgooch@atnf.csiro.au> - Fixed bug in <devfsd_close>: was dereferencing freed pointer. - Added process group check for devfsd privileges. - v1.4 - 20011204 Richard Gooch <rgooch@atnf.csiro.au> - Use SLAB_ATOMIC in <devfsd_notify_de> from <devfs_d_delete>. - v1.5 - 20011211 Richard Gooch <rgooch@atnf.csiro.au> - Return old entry in <devfs_mk_dir> for 2.4.x kernels. - 20011212 Richard Gooch <rgooch@atnf.csiro.au> - Increment refcount on module in <check_disc_changed>. - 20011215 Richard Gooch <rgooch@atnf.csiro.au> - Created <devfs_get_handle> and exported <devfs_put>. - Increment refcount on module in <devfs_get_ops>. - Created <devfs_put_ops>. - v1.6 - 20011216 Richard Gooch <rgooch@atnf.csiro.au> - Added poisoning to <devfs_put>. - Improved debugging messages. - v1.7 - 20011221 Richard Gooch <rgooch@atnf.csiro.au> - Corrected (made useful) debugging message in <unregister>. - Moved <kmem_cache_create> in <mount_devfs_fs> to <init_devfs_fs> - 20011224 Richard Gooch <rgooch@atnf.csiro.au> - Added magic number to guard against scribbling drivers. - 20011226 Richard Gooch <rgooch@atnf.csiro.au> - Only return old entry in <devfs_mk_dir> if a directory. - Defined macros for error and debug messages. - v1.8 - 20020113 Richard Gooch <rgooch@atnf.csiro.au> - Fixed (rare, old) race in <devfs_lookup>. - v1.9 - 20020120 Richard Gooch <rgooch@atnf.csiro.au> - Fixed deadlock bug in <devfs_d_revalidate_wait>. - Tag VFS deletable in <devfs_mk_symlink> if handle ignored. - v1.10 - 20020129 Richard Gooch <rgooch@atnf.csiro.au> - Added KERN_* to remaining messages. - Cleaned up declaration of <stat_read>. - v1.11 - 20020219 Richard Gooch <rgooch@atnf.csiro.au> - Changed <devfs_rmdir> to allow later additions if not yet empty. - v1.12 - 20020406 Richard Gooch <rgooch@atnf.csiro.au> - Removed silently introduced calls to lock_kernel() and - unlock_kernel() due to recent VFS locking changes. BKL isn't - required in devfs. - v1.13 - 20020428 Richard Gooch <rgooch@atnf.csiro.au> - Removed 2.4.x compatibility code. - v1.14 - 20020510 Richard Gooch <rgooch@atnf.csiro.au> - Added BKL to <devfs_open> because drivers still need it. - v1.15 - 20020512 Richard Gooch <rgooch@atnf.csiro.au> - Protected <scan_dir_for_removable> and <get_removable_partition> - from changing directory contents. - v1.16 - 20020514 Richard Gooch <rgooch@atnf.csiro.au> - Minor cleanup of <scan_dir_for_removable>. - v1.17 - 20020721 Richard Gooch <rgooch@atnf.csiro.au> - Switched to ISO C structure field initialisers. - Switch to set_current_state() and move before add_wait_queue(). - 20020722 Richard Gooch <rgooch@atnf.csiro.au> - Fixed devfs entry leak in <devfs_readdir> when *readdir fails. - v1.18 - 20020725 Richard Gooch <rgooch@atnf.csiro.au> - Created <devfs_find_and_unregister>. - v1.19 - 20020728 Richard Gooch <rgooch@atnf.csiro.au> - Removed deprecated <devfs_find_handle>. - v1.20 - 20020820 Richard Gooch <rgooch@atnf.csiro.au> - Fixed module unload race in <devfs_open>. - v1.21 - 20021013 Richard Gooch <rgooch@atnf.csiro.au> - Removed DEVFS_ FL_AUTO_OWNER. - Switched lingering structure field initialiser to ISO C. - Added locking when updating FCB flags. - v1.22 -*/ -#include <linux/types.h> -#include <linux/errno.h> -#include <linux/time.h> -#include <linux/tty.h> -#include <linux/timer.h> -#include <linux/config.h> -#include <linux/kernel.h> -#include <linux/wait.h> -#include <linux/string.h> -#include <linux/slab.h> -#include <linux/ioport.h> -#include <linux/delay.h> -#include <linux/ctype.h> -#include <linux/mm.h> -#include <linux/module.h> -#include <linux/init.h> -#include <linux/devfs_fs.h> -#include <linux/devfs_fs_kernel.h> -#include <linux/smp_lock.h> -#include <linux/smp.h> -#include <linux/rwsem.h> -#include <linux/sched.h> -#include <linux/namei.h> -#include <linux/bitops.h> - -#include <asm/uaccess.h> -#include <asm/io.h> -#include <asm/processor.h> -#include <asm/system.h> -#include <asm/pgtable.h> -#include <asm/atomic.h> - -#define DEVFS_VERSION "2004-01-31" - -#define DEVFS_NAME "devfs" - -#define FIRST_INODE 1 - -#define STRING_LENGTH 256 -#define FAKE_BLOCK_SIZE 1024 -#define POISON_PTR ( *(void **) poison_array ) -#define MAGIC_VALUE 0x327db823 - -#ifndef TRUE -# define TRUE 1 -# define FALSE 0 -#endif - -#define MODE_DIR (S_IFDIR | S_IWUSR | S_IRUGO | S_IXUGO) - -#define DEBUG_NONE 0x0000000 -#define DEBUG_MODULE_LOAD 0x0000001 -#define DEBUG_REGISTER 0x0000002 -#define DEBUG_UNREGISTER 0x0000004 -#define DEBUG_FREE 0x0000008 -#define DEBUG_SET_FLAGS 0x0000010 -#define DEBUG_S_READ 0x0000100 /* Break */ -#define DEBUG_I_LOOKUP 0x0001000 /* Break */ -#define DEBUG_I_CREATE 0x0002000 -#define DEBUG_I_GET 0x0004000 -#define DEBUG_I_CHANGE 0x0008000 -#define DEBUG_I_UNLINK 0x0010000 -#define DEBUG_I_RLINK 0x0020000 -#define DEBUG_I_FLINK 0x0040000 -#define DEBUG_I_MKNOD 0x0080000 -#define DEBUG_F_READDIR 0x0100000 /* Break */ -#define DEBUG_D_DELETE 0x1000000 /* Break */ -#define DEBUG_D_RELEASE 0x2000000 -#define DEBUG_D_IPUT 0x4000000 -#define DEBUG_ALL 0xfffffff -#define DEBUG_DISABLED DEBUG_NONE - -#define OPTION_NONE 0x00 -#define OPTION_MOUNT 0x01 - -#define PRINTK(format, args...) \ - {printk (KERN_ERR "%s" format, __FUNCTION__ , ## args);} - -#define OOPS(format, args...) \ - {printk (KERN_CRIT "%s" format, __FUNCTION__ , ## args); \ - printk ("Forcing Oops\n"); \ - BUG();} - -#ifdef CONFIG_DEVFS_DEBUG -# define VERIFY_ENTRY(de) \ - {if ((de) && (de)->magic_number != MAGIC_VALUE) \ - OOPS ("(%p): bad magic value: %x\n", (de), (de)->magic_number);} -# define WRITE_ENTRY_MAGIC(de,magic) (de)->magic_number = (magic) -# define DPRINTK(flag, format, args...) \ - {if (devfs_debug & flag) \ - printk (KERN_INFO "%s" format, __FUNCTION__ , ## args);} -#else -# define VERIFY_ENTRY(de) -# define WRITE_ENTRY_MAGIC(de,magic) -# define DPRINTK(flag, format, args...) -#endif - -typedef struct devfs_entry *devfs_handle_t; - -struct directory_type { - rwlock_t lock; /* Lock for searching(R)/updating(W) */ - struct devfs_entry *first; - struct devfs_entry *last; - unsigned char no_more_additions:1; -}; - -struct symlink_type { - unsigned int length; /* Not including the NULL-termimator */ - char *linkname; /* This is NULL-terminated */ -}; - -struct devfs_inode { /* This structure is for "persistent" inode storage */ - struct dentry *dentry; - struct timespec atime; - struct timespec mtime; - struct timespec ctime; - unsigned int ino; /* Inode number as seen in the VFS */ - uid_t uid; - gid_t gid; -}; - -struct devfs_entry { -#ifdef CONFIG_DEVFS_DEBUG - unsigned int magic_number; -#endif - void *info; - atomic_t refcount; /* When this drops to zero, it's unused */ - union { - struct directory_type dir; - dev_t dev; - struct symlink_type symlink; - const char *name; /* Only used for (mode == 0) */ - } u; - struct devfs_entry *prev; /* Previous entry in the parent directory */ - struct devfs_entry *next; /* Next entry in the parent directory */ - struct devfs_entry *parent; /* The parent directory */ - struct devfs_inode inode; - umode_t mode; - unsigned short namelen; /* I think 64k+ filenames are a way off... */ - unsigned char vfs:1; /* Whether the VFS may delete the entry */ - char name[1]; /* This is just a dummy: the allocated array - is bigger. This is NULL-terminated */ -}; - -/* The root of the device tree */ -static struct devfs_entry *root_entry; - -struct devfsd_buf_entry { - struct devfs_entry *de; /* The name is generated with this */ - unsigned short type; /* The type of event */ - umode_t mode; - uid_t uid; - gid_t gid; - struct devfsd_buf_entry *next; -}; - -struct fs_info { /* This structure is for the mounted devfs */ - struct super_block *sb; - spinlock_t devfsd_buffer_lock; /* Lock when inserting/deleting events */ - struct devfsd_buf_entry *devfsd_first_event; - struct devfsd_buf_entry *devfsd_last_event; - volatile int devfsd_sleeping; - volatile struct task_struct *devfsd_task; - volatile pid_t devfsd_pgrp; - volatile struct file *devfsd_file; - struct devfsd_notify_struct *devfsd_info; - volatile unsigned long devfsd_event_mask; - atomic_t devfsd_overrun_count; - wait_queue_head_t devfsd_wait_queue; /* Wake devfsd on input */ - wait_queue_head_t revalidate_wait_queue; /* Wake when devfsd sleeps */ -}; - -static struct fs_info fs_info = {.devfsd_buffer_lock = SPIN_LOCK_UNLOCKED }; -static kmem_cache_t *devfsd_buf_cache; -#ifdef CONFIG_DEVFS_DEBUG -static unsigned int devfs_debug_init __initdata = DEBUG_NONE; -static unsigned int devfs_debug = DEBUG_NONE; -static DEFINE_SPINLOCK(stat_lock); -static unsigned int stat_num_entries; -static unsigned int stat_num_bytes; -#endif -static unsigned char poison_array[8] = - { 0x5a, 0x5a, 0x5a, 0x5a, 0x5a, 0x5a, 0x5a, 0x5a }; - -#ifdef CONFIG_DEVFS_MOUNT -static unsigned int boot_options = OPTION_MOUNT; -#else -static unsigned int boot_options = OPTION_NONE; -#endif - -/* Forward function declarations */ -static devfs_handle_t _devfs_walk_path(struct devfs_entry *dir, - const char *name, int namelen, - int traverse_symlink); -static ssize_t devfsd_read(struct file *file, char __user *buf, size_t len, - loff_t * ppos); -static int devfsd_ioctl(struct inode *inode, struct file *file, - unsigned int cmd, unsigned long arg); -static int devfsd_close(struct inode *inode, struct file *file); -#ifdef CONFIG_DEVFS_DEBUG -static ssize_t stat_read(struct file *file, char __user *buf, size_t len, - loff_t * ppos); -static const struct file_operations stat_fops = { - .open = nonseekable_open, - .read = stat_read, -}; -#endif - -/* Devfs daemon file operations */ -static const struct file_operations devfsd_fops = { - .open = nonseekable_open, - .read = devfsd_read, - .ioctl = devfsd_ioctl, - .release = devfsd_close, -}; - -/* Support functions follow */ - -/** - * devfs_get - Get a reference to a devfs entry. - * @de: The devfs entry. - */ - -static struct devfs_entry *devfs_get(struct devfs_entry *de) -{ - VERIFY_ENTRY(de); - if (de) - atomic_inc(&de->refcount); - return de; -} /* End Function devfs_get */ - -/** - * devfs_put - Put (release) a reference to a devfs entry. - * @de: The handle to the devfs entry. - */ - -static void devfs_put(devfs_handle_t de) -{ - if (!de) - return; - VERIFY_ENTRY(de); - if (de->info == POISON_PTR) - OOPS("(%p): poisoned pointer\n", de); - if (!atomic_dec_and_test(&de->refcount)) - return; - if (de == root_entry) - OOPS("(%p): root entry being freed\n", de); - DPRINTK(DEBUG_FREE, "(%s): de: %p, parent: %p \"%s\"\n", - de->name, de, de->parent, - de->parent ? de->parent->name : "no parent"); - if (S_ISLNK(de->mode)) - kfree(de->u.symlink.linkname); - WRITE_ENTRY_MAGIC(de, 0); -#ifdef CONFIG_DEVFS_DEBUG - spin_lock(&stat_lock); - --stat_num_entries; - stat_num_bytes -= sizeof *de + de->namelen; - if (S_ISLNK(de->mode)) - stat_num_bytes -= de->u.symlink.length + 1; - spin_unlock(&stat_lock); -#endif - de->info = POISON_PTR; - kfree(de); -} /* End Function devfs_put */ - -/** - * _devfs_search_dir - Search for a devfs entry in a directory. - * @dir: The directory to search. - * @name: The name of the entry to search for. - * @namelen: The number of characters in @name. - * - * Search for a devfs entry in a directory and returns a pointer to the entry - * on success, else %NULL. The directory must be locked already. - * An implicit devfs_get() is performed on the returned entry. - */ - -static struct devfs_entry *_devfs_search_dir(struct devfs_entry *dir, - const char *name, - unsigned int namelen) -{ - struct devfs_entry *curr; - - if (!S_ISDIR(dir->mode)) { - PRINTK("(%s): not a directory\n", dir->name); - return NULL; - } - for (curr = dir->u.dir.first; curr != NULL; curr = curr->next) { - if (curr->namelen != namelen) - continue; - if (memcmp(curr->name, name, namelen) == 0) - break; - /* Not found: try the next one */ - } - return devfs_get(curr); -} /* End Function _devfs_search_dir */ - -/** - * _devfs_alloc_entry - Allocate a devfs entry. - * @name: the name of the entry - * @namelen: the number of characters in @name - * @mode: the mode for the entry - * - * Allocate a devfs entry and returns a pointer to the entry on success, else - * %NULL. - */ - -static struct devfs_entry *_devfs_alloc_entry(const char *name, - unsigned int namelen, - umode_t mode) -{ - struct devfs_entry *new; - static unsigned long inode_counter = FIRST_INODE; - static DEFINE_SPINLOCK(counter_lock); - - if (name && (namelen < 1)) - namelen = strlen(name); - if ((new = kmalloc(sizeof *new + namelen, GFP_KERNEL)) == NULL) - return NULL; - memset(new, 0, sizeof *new + namelen); /* Will set '\0' on name */ - new->mode = mode; - if (S_ISDIR(mode)) - rwlock_init(&new->u.dir.lock); - atomic_set(&new->refcount, 1); - spin_lock(&counter_lock); - new->inode.ino = inode_counter++; - spin_unlock(&counter_lock); - if (name) - memcpy(new->name, name, namelen); - new->namelen = namelen; - WRITE_ENTRY_MAGIC(new, MAGIC_VALUE); -#ifdef CONFIG_DEVFS_DEBUG - spin_lock(&stat_lock); - ++stat_num_entries; - stat_num_bytes += sizeof *new + namelen; - spin_unlock(&stat_lock); -#endif - return new; -} /* End Function _devfs_alloc_entry */ - -/** - * _devfs_append_entry - Append a devfs entry to a directory's child list. - * @dir: The directory to add to. - * @de: The devfs entry to append. - * @old_de: If an existing entry exists, it will be written here. This may - * be %NULL. An implicit devfs_get() is performed on this entry. - * - * Append a devfs entry to a directory's list of children, checking first to - * see if an entry of the same name exists. The directory will be locked. - * The value 0 is returned on success, else a negative error code. - * On failure, an implicit devfs_put() is performed on %de. - */ - -static int _devfs_append_entry(devfs_handle_t dir, devfs_handle_t de, - devfs_handle_t * old_de) -{ - int retval; - - if (old_de) - *old_de = NULL; - if (!S_ISDIR(dir->mode)) { - PRINTK("(%s): dir: \"%s\" is not a directory\n", de->name, - dir->name); - devfs_put(de); - return -ENOTDIR; - } - write_lock(&dir->u.dir.lock); - if (dir->u.dir.no_more_additions) - retval = -ENOENT; - else { - struct devfs_entry *old; - - old = _devfs_search_dir(dir, de->name, de->namelen); - if (old_de) - *old_de = old; - else - devfs_put(old); - if (old == NULL) { - de->parent = dir; - de->prev = dir->u.dir.last; - /* Append to the directory's list of children */ - if (dir->u.dir.first == NULL) - dir->u.dir.first = de; - else - dir->u.dir.last->next = de; - dir->u.dir.last = de; - retval = 0; - } else - retval = -EEXIST; - } - write_unlock(&dir->u.dir.lock); - if (retval) - devfs_put(de); - return retval; -} /* End Function _devfs_append_entry */ - -/** - * _devfs_get_root_entry - Get the root devfs entry. - * - * Returns the root devfs entry on success, else %NULL. - * - * TODO it must be called asynchronously due to the fact - * that devfs is initialized relatively late. Proper way - * is to remove module_init from init_devfs_fs and manually - * call it early enough during system init - */ - -static struct devfs_entry *_devfs_get_root_entry(void) -{ - struct devfs_entry *new; - static DEFINE_SPINLOCK(root_lock); - - if (root_entry) - return root_entry; - - new = _devfs_alloc_entry(NULL, 0, MODE_DIR); - if (new == NULL) - return NULL; - - spin_lock(&root_lock); - if (root_entry) { - spin_unlock(&root_lock); - devfs_put(new); - return root_entry; - } - root_entry = new; - spin_unlock(&root_lock); - - return root_entry; -} /* End Function _devfs_get_root_entry */ - -/** - * _devfs_descend - Descend down a tree using the next component name. - * @dir: The directory to search. - * @name: The component name to search for. - * @namelen: The length of %name. - * @next_pos: The position of the next '/' or '\0' is written here. - * - * Descend into a directory, searching for a component. This function forms - * the core of a tree-walking algorithm. The directory will be locked. - * The devfs entry corresponding to the component is returned. If there is - * no matching entry, %NULL is returned. - * An implicit devfs_get() is performed on the returned entry. - */ - -static struct devfs_entry *_devfs_descend(struct devfs_entry *dir, - const char *name, int namelen, - int *next_pos) -{ - const char *stop, *ptr; - struct devfs_entry *entry; - - if ((namelen >= 3) && (strncmp(name, "../", 3) == 0)) { /* Special-case going to parent directory */ - *next_pos = 3; - return devfs_get(dir->parent); - } - stop = name + namelen; - /* Search for a possible '/' */ - for (ptr = name; (ptr < stop) && (*ptr != '/'); ++ptr) ; - *next_pos = ptr - name; - read_lock(&dir->u.dir.lock); - entry = _devfs_search_dir(dir, name, *next_pos); - read_unlock(&dir->u.dir.lock); - return entry; -} /* End Function _devfs_descend */ - -static devfs_handle_t _devfs_make_parent_for_leaf(struct devfs_entry *dir, - const char *name, - int namelen, int *leaf_pos) -{ - int next_pos = 0; - - if (dir == NULL) - dir = _devfs_get_root_entry(); - if (dir == NULL) - return NULL; - devfs_get(dir); - /* Search for possible trailing component and ignore it */ - for (--namelen; (namelen > 0) && (name[namelen] != '/'); --namelen) ; - *leaf_pos = (name[namelen] == '/') ? (namelen + 1) : 0; - for (; namelen > 0; name += next_pos, namelen -= next_pos) { - struct devfs_entry *de, *old = NULL; - - if ((de = - _devfs_descend(dir, name, namelen, &next_pos)) == NULL) { - de = _devfs_alloc_entry(name, next_pos, MODE_DIR); - devfs_get(de); - if (!de || _devfs_append_entry(dir, de, &old)) { - devfs_put(de); - if (!old || !S_ISDIR(old->mode)) { - devfs_put(old); - devfs_put(dir); - return NULL; - } - de = old; /* Use the existing directory */ - } - } - if (de == dir->parent) { - devfs_put(dir); - devfs_put(de); - return NULL; - } - devfs_put(dir); - dir = de; - if (name[next_pos] == '/') - ++next_pos; - } - return dir; -} /* End Function _devfs_make_parent_for_leaf */ - -static devfs_handle_t _devfs_prepare_leaf(devfs_handle_t * dir, - const char *name, umode_t mode) -{ - int namelen, leaf_pos; - struct devfs_entry *de; - - namelen = strlen(name); - if ((*dir = _devfs_make_parent_for_leaf(*dir, name, namelen, - &leaf_pos)) == NULL) { - PRINTK("(%s): could not create parent path\n", name); - return NULL; - } - if ((de = _devfs_alloc_entry(name + leaf_pos, namelen - leaf_pos, mode)) - == NULL) { - PRINTK("(%s): could not allocate entry\n", name); - devfs_put(*dir); - return NULL; - } - return de; -} /* End Function _devfs_prepare_leaf */ - -static devfs_handle_t _devfs_walk_path(struct devfs_entry *dir, - const char *name, int namelen, - int traverse_symlink) -{ - int next_pos = 0; - - if (dir == NULL) - dir = _devfs_get_root_entry(); - if (dir == NULL) - return NULL; - devfs_get(dir); - for (; namelen > 0; name += next_pos, namelen -= next_pos) { - struct devfs_entry *de, *link; - - if (!S_ISDIR(dir->mode)) { - devfs_put(dir); - return NULL; - } - - if ((de = - _devfs_descend(dir, name, namelen, &next_pos)) == NULL) { - devfs_put(dir); - return NULL; - } - if (S_ISLNK(de->mode) && traverse_symlink) { /* Need to follow the link: this is a stack chomper */ - /* FIXME what if it puts outside of mounted tree? */ - link = _devfs_walk_path(dir, de->u.symlink.linkname, - de->u.symlink.length, TRUE); - devfs_put(de); - if (!link) { - devfs_put(dir); - return NULL; - } - de = link; - } - devfs_put(dir); - dir = de; - if (name[next_pos] == '/') - ++next_pos; - } - return dir; -} /* End Function _devfs_walk_path */ - -/** - * _devfs_find_entry - Find a devfs entry. - * @dir: The handle to the parent devfs directory entry. If this is %NULL the - * name is relative to the root of the devfs. - * @name: The name of the entry. This may be %NULL. - * @traverse_symlink: If %TRUE then symbolic links are traversed. - * - * Returns the devfs_entry pointer on success, else %NULL. An implicit - * devfs_get() is performed. - */ - -static struct devfs_entry *_devfs_find_entry(devfs_handle_t dir, - const char *name, - int traverse_symlink) -{ - unsigned int namelen = strlen(name); - - if (name[0] == '/') { - /* Skip leading pathname component */ - if (namelen < 2) { - PRINTK("(%s): too short\n", name); - return NULL; - } - for (++name, --namelen; (*name != '/') && (namelen > 0); - ++name, --namelen) ; - if (namelen < 2) { - PRINTK("(%s): too short\n", name); - return NULL; - } - ++name; - --namelen; - } - return _devfs_walk_path(dir, name, namelen, traverse_symlink); -} /* End Function _devfs_find_entry */ - -static struct devfs_entry *get_devfs_entry_from_vfs_inode(struct inode *inode) -{ - if (inode == NULL) - return NULL; - VERIFY_ENTRY((struct devfs_entry *)inode->u.generic_ip); - return inode->u.generic_ip; -} /* End Function get_devfs_entry_from_vfs_inode */ - -/** - * free_dentry - Free the dentry for a device entry and invalidate inode. - * @de: The entry. - * - * This must only be called after the entry has been unhooked from its - * parent directory. - */ - -static void free_dentry(struct devfs_entry *de) -{ - struct dentry *dentry = de->inode.dentry; - - if (!dentry) - return; - spin_lock(&dcache_lock); - dget_locked(dentry); - spin_unlock(&dcache_lock); - /* Forcefully remove the inode */ - if (dentry->d_inode != NULL) - dentry->d_inode->i_nlink = 0; - d_drop(dentry); - dput(dentry); -} /* End Function free_dentry */ - -/** - * is_devfsd_or_child - Test if the current process is devfsd or one of its children. - * @fs_info: The filesystem information. - * - * Returns %TRUE if devfsd or child, else %FALSE. - */ - -static int is_devfsd_or_child(struct fs_info *fs_info) -{ - struct task_struct *p = current; - - if (p == fs_info->devfsd_task) - return (TRUE); - if (process_group(p) == fs_info->devfsd_pgrp) - return (TRUE); - read_lock(&tasklist_lock); - for (; p != &init_task; p = p->real_parent) { - if (p == fs_info->devfsd_task) { - read_unlock(&tasklist_lock); - return (TRUE); - } - } - read_unlock(&tasklist_lock); - return (FALSE); -} /* End Function is_devfsd_or_child */ - -/** - * devfsd_queue_empty - Test if devfsd has work pending in its event queue. - * @fs_info: The filesystem information. - * - * Returns %TRUE if the queue is empty, else %FALSE. - */ - -static inline int devfsd_queue_empty(struct fs_info *fs_info) -{ - return (fs_info->devfsd_last_event) ? FALSE : TRUE; -} /* End Function devfsd_queue_empty */ - -/** - * wait_for_devfsd_finished - Wait for devfsd to finish processing its event queue. - * @fs_info: The filesystem information. - * - * Returns %TRUE if no more waiting will be required, else %FALSE. - */ - -static int wait_for_devfsd_finished(struct fs_info *fs_info) -{ - DECLARE_WAITQUEUE(wait, current); - - if (fs_info->devfsd_task == NULL) - return (TRUE); - if (devfsd_queue_empty(fs_info) && fs_info->devfsd_sleeping) - return TRUE; - if (is_devfsd_or_child(fs_info)) - return (FALSE); - set_current_state(TASK_UNINTERRUPTIBLE); - add_wait_queue(&fs_info->revalidate_wait_queue, &wait); - if (!devfsd_queue_empty(fs_info) || !fs_info->devfsd_sleeping) - if (fs_info->devfsd_task) - schedule(); - remove_wait_queue(&fs_info->revalidate_wait_queue, &wait); - __set_current_state(TASK_RUNNING); - return (TRUE); -} /* End Function wait_for_devfsd_finished */ - -/** - * devfsd_notify_de - Notify the devfsd daemon of a change. - * @de: The devfs entry that has changed. This and all parent entries will - * have their reference counts incremented if the event was queued. - * @type: The type of change. - * @mode: The mode of the entry. - * @uid: The user ID. - * @gid: The group ID. - * @fs_info: The filesystem info. - * - * Returns %TRUE if an event was queued and devfsd woken up, else %FALSE. - */ - -static int devfsd_notify_de(struct devfs_entry *de, - unsigned short type, umode_t mode, - uid_t uid, gid_t gid, struct fs_info *fs_info) -{ - struct devfsd_buf_entry *entry; - struct devfs_entry *curr; - - if (!(fs_info->devfsd_event_mask & (1 << type))) - return (FALSE); - if ((entry = kmem_cache_alloc(devfsd_buf_cache, SLAB_KERNEL)) == NULL) { - atomic_inc(&fs_info->devfsd_overrun_count); - return (FALSE); - } - for (curr = de; curr != NULL; curr = curr->parent) - devfs_get(curr); - entry->de = de; - entry->type = type; - entry->mode = mode; - entry->uid = uid; - entry->gid = gid; - entry->next = NULL; - spin_lock(&fs_info->devfsd_buffer_lock); - if (!fs_info->devfsd_first_event) - fs_info->devfsd_first_event = entry; - if (fs_info->devfsd_last_event) - fs_info->devfsd_last_event->next = entry; - fs_info->devfsd_last_event = entry; - spin_unlock(&fs_info->devfsd_buffer_lock); - wake_up_interruptible(&fs_info->devfsd_wait_queue); - return (TRUE); -} /* End Function devfsd_notify_de */ - -/** - * devfsd_notify - Notify the devfsd daemon of a change. - * @de: The devfs entry that has changed. - * @type: The type of change event. - * @wait: If TRUE, the function waits for the daemon to finish processing - * the event. - */ - -static void devfsd_notify(struct devfs_entry *de, unsigned short type) -{ - devfsd_notify_de(de, type, de->mode, current->euid, - current->egid, &fs_info); -} - -static int devfs_mk_dev(dev_t dev, umode_t mode, const char *fmt, va_list args) -{ - struct devfs_entry *dir = NULL, *de; - char buf[64]; - int error, n; - - n = vsnprintf(buf, sizeof(buf), fmt, args); - if (n >= sizeof(buf) || !buf[0]) { - printk(KERN_WARNING "%s: invalid format string %s\n", - __FUNCTION__, fmt); - return -EINVAL; - } - - de = _devfs_prepare_leaf(&dir, buf, mode); - if (!de) { - printk(KERN_WARNING "%s: could not prepare leaf for %s\n", - __FUNCTION__, buf); - return -ENOMEM; /* could be more accurate... */ - } - - de->u.dev = dev; - - error = _devfs_append_entry(dir, de, NULL); - if (error) { - printk(KERN_WARNING "%s: could not append to parent for %s\n", - __FUNCTION__, buf); - goto out; - } - - devfsd_notify(de, DEVFSD_NOTIFY_REGISTERED); - out: - devfs_put(dir); - return error; -} - -int devfs_mk_bdev(dev_t dev, umode_t mode, const char *fmt, ...) -{ - va_list args; - - if (!S_ISBLK(mode)) { - printk(KERN_WARNING "%s: invalide mode (%u) for %s\n", - __FUNCTION__, mode, fmt); - return -EINVAL; - } - - va_start(args, fmt); - return devfs_mk_dev(dev, mode, fmt, args); -} - -EXPORT_SYMBOL(devfs_mk_bdev); - -int devfs_mk_cdev(dev_t dev, umode_t mode, const char *fmt, ...) -{ - va_list args; - - if (!S_ISCHR(mode)) { - printk(KERN_WARNING "%s: invalide mode (%u) for %s\n", - __FUNCTION__, mode, fmt); - return -EINVAL; - } - - va_start(args, fmt); - return devfs_mk_dev(dev, mode, fmt, args); -} - -EXPORT_SYMBOL(devfs_mk_cdev); - -/** - * _devfs_unhook - Unhook a device entry from its parents list - * @de: The entry to unhook. - * - * Returns %TRUE if the entry was unhooked, else %FALSE if it was - * previously unhooked. - * The caller must have a write lock on the parent directory. - */ - -static int _devfs_unhook(struct devfs_entry *de) -{ - struct devfs_entry *parent; - - if (!de || (de->prev == de)) - return FALSE; - parent = de->parent; - if (de->prev == NULL) - parent->u.dir.first = de->next; - else - de->prev->next = de->next; - if (de->next == NULL) - parent->u.dir.last = de->prev; - else - de->next->prev = de->prev; - de->prev = de; /* Indicate we're unhooked */ - de->next = NULL; /* Force early termination for <devfs_readdir> */ - return TRUE; -} /* End Function _devfs_unhook */ - -/** - * _devfs_unregister - Unregister a device entry from its parent. - * @dir: The parent directory. - * @de: The entry to unregister. - * - * The caller must have a write lock on the parent directory, which is - * unlocked by this function. - */ - -static void _devfs_unregister(struct devfs_entry *dir, struct devfs_entry *de) -{ - int unhooked = _devfs_unhook(de); - - write_unlock(&dir->u.dir.lock); - if (!unhooked) - return; - devfs_get(dir); - devfsd_notify(de, DEVFSD_NOTIFY_UNREGISTERED); - free_dentry(de); - devfs_put(dir); - if (!S_ISDIR(de->mode)) - return; - while (TRUE) { /* Recursively unregister: this is a stack chomper */ - struct devfs_entry *child; - - write_lock(&de->u.dir.lock); - de->u.dir.no_more_additions = TRUE; - child = de->u.dir.first; - VERIFY_ENTRY(child); - _devfs_unregister(de, child); - if (!child) - break; - DPRINTK(DEBUG_UNREGISTER, "(%s): child: %p refcount: %d\n", - child->name, child, atomic_read(&child->refcount)); - devfs_put(child); - } -} /* End Function _devfs_unregister */ - -static int devfs_do_symlink(devfs_handle_t dir, const char *name, - const char *link, devfs_handle_t * handle) -{ - int err; - unsigned int linklength; - char *newlink; - struct devfs_entry *de; - - if (handle != NULL) - *handle = NULL; - if (name == NULL) { - PRINTK("(): NULL name pointer\n"); - return -EINVAL; - } - if (link == NULL) { - PRINTK("(%s): NULL link pointer\n", name); - return -EINVAL; - } - linklength = strlen(link); - if ((newlink = kmalloc(linklength + 1, GFP_KERNEL)) == NULL) - return -ENOMEM; - memcpy(newlink, link, linklength); - newlink[linklength] = '\0'; - if ((de = _devfs_prepare_leaf(&dir, name, S_IFLNK | S_IRUGO | S_IXUGO)) - == NULL) { - PRINTK("(%s): could not prepare leaf\n", name); - kfree(newlink); - return -ENOTDIR; - } - de->info = NULL; - de->u.symlink.linkname = newlink; - de->u.symlink.length = linklength; - if ((err = _devfs_append_entry(dir, de, NULL)) != 0) { - PRINTK("(%s): could not append to parent, err: %d\n", name, - err); - devfs_put(dir); - return err; - } - devfs_put(dir); -#ifdef CONFIG_DEVFS_DEBUG - spin_lock(&stat_lock); - stat_num_bytes += linklength + 1; - spin_unlock(&stat_lock); -#endif - if (handle != NULL) - *handle = de; - return 0; -} /* End Function devfs_do_symlink */ - -/** - * devfs_mk_symlink Create a symbolic link in the devfs namespace. - * @from: The name of the entry. - * @to: Name of the destination - * - * Returns 0 on success, else a negative error code is returned. - */ - -int devfs_mk_symlink(const char *from, const char *to) -{ - devfs_handle_t de; - int err; - - err = devfs_do_symlink(NULL, from, to, &de); - if (!err) { - de->vfs = TRUE; - devfsd_notify(de, DEVFSD_NOTIFY_REGISTERED); - } - - return err; -} - -/** - * devfs_mk_dir - Create a directory in the devfs namespace. - * new name is relative to the root of the devfs. - * @fmt: The name of the entry. - * - * Use of this function is optional. The devfs_register() function - * will automatically create intermediate directories as needed. This function - * is provided for efficiency reasons, as it provides a handle to a directory. - * On failure %NULL is returned. - */ - -int devfs_mk_dir(const char *fmt, ...) -{ - struct devfs_entry *dir = NULL, *de = NULL, *old; - char buf[64]; - va_list args; - int error, n; - - va_start(args, fmt); - n = vsnprintf(buf, 64, fmt, args); - if (n >= 64 || !buf[0]) { - printk(KERN_WARNING "%s: invalid argument.", __FUNCTION__); - return -EINVAL; - } - - de = _devfs_prepare_leaf(&dir, buf, MODE_DIR); - if (!de) { - PRINTK("(%s): could not prepare leaf\n", buf); - return -EINVAL; - } - - error = _devfs_append_entry(dir, de, &old); - if (error == -EEXIST && S_ISDIR(old->mode)) { - /* - * devfs_mk_dir() of an already-existing directory will - * return success. - */ - error = 0; - goto out_put; - } else if (error) { - PRINTK("(%s): could not append to dir: %p \"%s\"\n", - buf, dir, dir->name); - devfs_put(old); - goto out_put; - } - - devfsd_notify(de, DEVFSD_NOTIFY_REGISTERED); - - out_put: - devfs_put(dir); - return error; -} - -void devfs_remove(const char *fmt, ...) -{ - char buf[64]; - va_list args; - int n; - - va_start(args, fmt); - n = vsnprintf(buf, sizeof(buf), fmt, args); - if (n < sizeof(buf) && buf[0]) { - devfs_handle_t de = _devfs_find_entry(NULL, buf, 0); - - if (!de) { - printk(KERN_ERR "%s: %s not found, cannot remove\n", - __FUNCTION__, buf); - dump_stack(); - return; - } - - write_lock(&de->parent->u.dir.lock); - _devfs_unregister(de->parent, de); - devfs_put(de); - devfs_put(de); - } -} - -/** - * devfs_generate_path - Generate a pathname for an entry, relative to the devfs root. - * @de: The devfs entry. - * @path: The buffer to write the pathname to. The pathname and '\0' - * terminator will be written at the end of the buffer. - * @buflen: The length of the buffer. - * - * Returns the offset in the buffer where the pathname starts on success, - * else a negative error code. - */ - -static int devfs_generate_path(devfs_handle_t de, char *path, int buflen) -{ - int pos; -#define NAMEOF(de) ( (de)->mode ? (de)->name : (de)->u.name ) - - if (de == NULL) - return -EINVAL; - VERIFY_ENTRY(de); - if (de->namelen >= buflen) - return -ENAMETOOLONG; /* Must be first */ - path[buflen - 1] = '\0'; - if (de->parent == NULL) - return buflen - 1; /* Don't prepend root */ - pos = buflen - de->namelen - 1; - memcpy(path + pos, NAMEOF(de), de->namelen); - for (de = de->parent; de->parent != NULL; de = de->parent) { - if (pos - de->namelen - 1 < 0) - return -ENAMETOOLONG; - path[--pos] = '/'; - pos -= de->namelen; - memcpy(path + pos, NAMEOF(de), de->namelen); - } - return pos; -} /* End Function devfs_generate_path */ - -/** - * devfs_setup - Process kernel boot options. - * @str: The boot options after the "devfs=". - */ - -static int __init devfs_setup(char *str) -{ - static struct { - char *name; - unsigned int mask; - unsigned int *opt; - } devfs_options_tab[] __initdata = { -#ifdef CONFIG_DEVFS_DEBUG - { - "dall", DEBUG_ALL, &devfs_debug_init}, { - "dmod", DEBUG_MODULE_LOAD, &devfs_debug_init}, { - "dreg", DEBUG_REGISTER, &devfs_debug_init}, { - "dunreg", DEBUG_UNREGISTER, &devfs_debug_init}, { - "dfree", DEBUG_FREE, &devfs_debug_init}, { - "diget", DEBUG_I_GET, &devfs_debug_init}, { - "dchange", DEBUG_SET_FLAGS, &devfs_debug_init}, { - "dsread", DEBUG_S_READ, &devfs_debug_init}, { - "dichange", DEBUG_I_CHANGE, &devfs_debug_init}, { - "dimknod", DEBUG_I_MKNOD, &devfs_debug_init}, { - "dilookup", DEBUG_I_LOOKUP, &devfs_debug_init}, { - "diunlink", DEBUG_I_UNLINK, &devfs_debug_init}, -#endif /* CONFIG_DEVFS_DEBUG */ - { - "mount", OPTION_MOUNT, &boot_options}, { - NULL, 0, NULL} - }; - - while ((*str != '\0') && !isspace(*str)) { - int i, found = 0, invert = 0; - - if (strncmp(str, "no", 2) == 0) { - invert = 1; - str += 2; - } - for (i = 0; devfs_options_tab[i].name != NULL; i++) { - int len = strlen(devfs_options_tab[i].name); - - if (strncmp(str, devfs_options_tab[i].name, len) == 0) { - if (invert) - *devfs_options_tab[i].opt &= - ~devfs_options_tab[i].mask; - else - *devfs_options_tab[i].opt |= - devfs_options_tab[i].mask; - str += len; - found = 1; - break; - } - } - if (!found) - return 0; /* No match */ - if (*str != ',') - return 0; /* No more options */ - ++str; - } - return 1; -} /* End Function devfs_setup */ - -__setup("devfs=", devfs_setup); - -EXPORT_SYMBOL(devfs_mk_dir); -EXPORT_SYMBOL(devfs_remove); - -/** - * try_modload - Notify devfsd of an inode lookup by a non-devfsd process. - * @parent: The parent devfs entry. - * @fs_info: The filesystem info. - * @name: The device name. - * @namelen: The number of characters in @name. - * @buf: A working area that will be used. This must not go out of scope - * until devfsd is idle again. - * - * Returns 0 on success (event was queued), else a negative error code. - */ - -static int try_modload(struct devfs_entry *parent, struct fs_info *fs_info, - const char *name, unsigned namelen, - struct devfs_entry *buf) -{ - if (!(fs_info->devfsd_event_mask & (1 << DEVFSD_NOTIFY_LOOKUP))) - return -ENOENT; - if (is_devfsd_or_child(fs_info)) - return -ENOENT; - memset(buf, 0, sizeof *buf); - atomic_set(&buf->refcount, 1); - buf->parent = parent; - buf->namelen = namelen; - buf->u.name = name; - WRITE_ENTRY_MAGIC(buf, MAGIC_VALUE); - if (!devfsd_notify_de(buf, DEVFSD_NOTIFY_LOOKUP, 0, - current->euid, current->egid, fs_info)) - return -ENOENT; - /* Possible success: event has been queued */ - return 0; -} /* End Function try_modload */ - -/* Superblock operations follow */ - -static struct inode_operations devfs_iops; -static struct inode_operations devfs_dir_iops; -static const struct file_operations devfs_fops; -static const struct file_operations devfs_dir_fops; -static struct inode_operations devfs_symlink_iops; - -static int devfs_notify_change(struct dentry *dentry, struct iattr *iattr) -{ - int retval; - struct devfs_entry *de; - struct inode *inode = dentry->d_inode; - struct fs_info *fs_info = inode->i_sb->s_fs_info; - - de = get_devfs_entry_from_vfs_inode(inode); - if (de == NULL) - return -ENODEV; - retval = inode_change_ok(inode, iattr); - if (retval != 0) - return retval; - retval = inode_setattr(inode, iattr); - if (retval != 0) - return retval; - DPRINTK(DEBUG_I_CHANGE, "(%d): VFS inode: %p devfs_entry: %p\n", - (int)inode->i_ino, inode, de); - DPRINTK(DEBUG_I_CHANGE, "(): mode: 0%o uid: %d gid: %d\n", - (int)inode->i_mode, (int)inode->i_uid, (int)inode->i_gid); - /* Inode is not on hash chains, thus must save permissions here rather - than in a write_inode() method */ - de->mode = inode->i_mode; - de->inode.uid = inode->i_uid; - de->inode.gid = inode->i_gid; - de->inode.atime = inode->i_atime; - de->inode.mtime = inode->i_mtime; - de->inode.ctime = inode->i_ctime; - if ((iattr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) && - !is_devfsd_or_child(fs_info)) - devfsd_notify_de(de, DEVFSD_NOTIFY_CHANGE, inode->i_mode, - inode->i_uid, inode->i_gid, fs_info); - return 0; -} /* End Function devfs_notify_change */ - -static struct super_operations devfs_sops = { - .drop_inode = generic_delete_inode, - .statfs = simple_statfs, -}; - -/** - * _devfs_get_vfs_inode - Get a VFS inode. - * @sb: The super block. - * @de: The devfs inode. - * @dentry: The dentry to register with the devfs inode. - * - * Returns the inode on success, else %NULL. An implicit devfs_get() is - * performed if the inode is created. - */ - -static struct inode *_devfs_get_vfs_inode(struct super_block *sb, - struct devfs_entry *de, - struct dentry *dentry) -{ - struct inode *inode; - - if (de->prev == de) - return NULL; /* Quick check to see if unhooked */ - if ((inode = new_inode(sb)) == NULL) { - PRINTK("(%s): new_inode() failed, de: %p\n", de->name, de); - return NULL; - } - if (de->parent) { - read_lock(&de->parent->u.dir.lock); - if (de->prev != de) - de->inode.dentry = dentry; /* Not unhooked */ - read_unlock(&de->parent->u.dir.lock); - } else - de->inode.dentry = dentry; /* Root: no locking needed */ - if (de->inode.dentry != dentry) { /* Must have been unhooked */ - iput(inode); - return NULL; - } - /* FIXME where is devfs_put? */ - inode->u.generic_ip = devfs_get(de); - inode->i_ino = de->inode.ino; - DPRINTK(DEBUG_I_GET, "(%d): VFS inode: %p devfs_entry: %p\n", - (int)inode->i_ino, inode, de); - inode->i_blocks = 0; - inode->i_blksize = FAKE_BLOCK_SIZE; - inode->i_op = &devfs_iops; - inode->i_mode = de->mode; - if (S_ISDIR(de->mode)) { - inode->i_op = &devfs_dir_iops; - inode->i_fop = &devfs_dir_fops; - } else if (S_ISLNK(de->mode)) { - inode->i_op = &devfs_symlink_iops; - inode->i_size = de->u.symlink.length; - } else if (S_ISCHR(de->mode) || S_ISBLK(de->mode)) { - init_special_inode(inode, de->mode, de->u.dev); - } else if (S_ISFIFO(de->mode) || S_ISSOCK(de->mode)) { - init_special_inode(inode, de->mode, 0); - } else { - PRINTK("(%s): unknown mode %o de: %p\n", - de->name, de->mode, de); - iput(inode); - devfs_put(de); - return NULL; - } - - inode->i_uid = de->inode.uid; - inode->i_gid = de->inode.gid; - inode->i_atime = de->inode.atime; - inode->i_mtime = de->inode.mtime; - inode->i_ctime = de->inode.ctime; - DPRINTK(DEBUG_I_GET, "(): mode: 0%o uid: %d gid: %d\n", - (int)inode->i_mode, (int)inode->i_uid, (int)inode->i_gid); - return inode; -} /* End Function _devfs_get_vfs_inode */ - -/* File operations for device entries follow */ - -static int devfs_readdir(struct file *file, void *dirent, filldir_t filldir) -{ - int err, count; - int stored = 0; - struct fs_info *fs_info; - struct devfs_entry *parent, *de, *next = NULL; - struct inode *inode = file->f_dentry->d_inode; - - fs_info = inode->i_sb->s_fs_info; - parent = get_devfs_entry_from_vfs_inode(file->f_dentry->d_inode); - if ((long)file->f_pos < 0) - return -EINVAL; - DPRINTK(DEBUG_F_READDIR, "(%s): fs_info: %p pos: %ld\n", - parent->name, fs_info, (long)file->f_pos); - switch ((long)file->f_pos) { - case 0: - err = (*filldir) (dirent, "..", 2, file->f_pos, - parent_ino(file->f_dentry), DT_DIR); - if (err == -EINVAL) - break; - if (err < 0) - return err; - file->f_pos++; - ++stored; - /* Fall through */ - case 1: - err = - (*filldir) (dirent, ".", 1, file->f_pos, inode->i_ino, - DT_DIR); - if (err == -EINVAL) - break; - if (err < 0) - return err; - file->f_pos++; - ++stored; - /* Fall through */ - default: - /* Skip entries */ - count = file->f_pos - 2; - read_lock(&parent->u.dir.lock); - for (de = parent->u.dir.first; de && (count > 0); de = de->next) - --count; - devfs_get(de); - read_unlock(&parent->u.dir.lock); - /* Now add all remaining entries */ - while (de) { - err = (*filldir) (dirent, de->name, de->namelen, - file->f_pos, de->inode.ino, - de->mode >> 12); - if (err < 0) - devfs_put(de); - else { - file->f_pos++; - ++stored; - } - if (err == -EINVAL) - break; - if (err < 0) - return err; - read_lock(&parent->u.dir.lock); - next = devfs_get(de->next); - read_unlock(&parent->u.dir.lock); - devfs_put(de); - de = next; - } - break; - } - return stored; -} /* End Function devfs_readdir */ - -/* Open devfs specific special files */ -static int devfs_open(struct inode *inode, struct file *file) -{ - int err; - int minor = MINOR(inode->i_rdev); - struct file_operations *old_fops, *new_fops; - - switch (minor) { - case 0: /* /dev/.devfsd */ - new_fops = fops_get(&devfsd_fops); - break; -#ifdef CONFIG_DEVFS_DEBUG - case 1: /* /dev/.stat */ - new_fops = fops_get(&stat_fops); - break; -#endif - default: - return -ENODEV; - } - - if (new_fops == NULL) - return -ENODEV; - old_fops = file->f_op; - file->f_op = new_fops; - err = new_fops->open ? new_fops->open(inode, file) : 0; - if (err) { - file->f_op = old_fops; - fops_put(new_fops); - } else - fops_put(old_fops); - return err; -} /* End Function devfs_open */ - -static const struct file_operations devfs_fops = { - .open = devfs_open, -}; - -static const struct file_operations devfs_dir_fops = { - .read = generic_read_dir, - .readdir = devfs_readdir, -}; - -/* Dentry operations for device entries follow */ - -/** - * devfs_d_release - Callback for when a dentry is freed. - * @dentry: The dentry. - */ - -static void devfs_d_release(struct dentry *dentry) -{ - DPRINTK(DEBUG_D_RELEASE, "(%p): inode: %p\n", dentry, dentry->d_inode); -} /* End Function devfs_d_release */ - -/** - * devfs_d_iput - Callback for when a dentry loses its inode. - * @dentry: The dentry. - * @inode: The inode. - */ - -static void devfs_d_iput(struct dentry *dentry, struct inode *inode) -{ - struct devfs_entry *de; - - de = get_devfs_entry_from_vfs_inode(inode); - DPRINTK(DEBUG_D_IPUT, - "(%s): dentry: %p inode: %p de: %p de->dentry: %p\n", de->name, - dentry, inode, de, de->inode.dentry); - if (de->inode.dentry && (de->inode.dentry != dentry)) - OOPS("(%s): de: %p dentry: %p de->dentry: %p\n", - de->name, de, dentry, de->inode.dentry); - de->inode.dentry = NULL; - iput(inode); - devfs_put(de); -} /* End Function devfs_d_iput */ - -static int devfs_d_delete(struct dentry *dentry); - -static struct dentry_operations devfs_dops = { - .d_delete = devfs_d_delete, - .d_release = devfs_d_release, - .d_iput = devfs_d_iput, -}; - -static int devfs_d_revalidate_wait(struct dentry *dentry, struct nameidata *); - -static struct dentry_operations devfs_wait_dops = { - .d_delete = devfs_d_delete, - .d_release = devfs_d_release, - .d_iput = devfs_d_iput, - .d_revalidate = devfs_d_revalidate_wait, -}; - -/** - * devfs_d_delete - Callback for when all files for a dentry are closed. - * @dentry: The dentry. - */ - -static int devfs_d_delete(struct dentry *dentry) -{ - struct inode *inode = dentry->d_inode; - - if (dentry->d_op == &devfs_wait_dops) - dentry->d_op = &devfs_dops; - /* Unhash dentry if negative (has no inode) */ - if (inode == NULL) { - DPRINTK(DEBUG_D_DELETE, "(%p): dropping negative dentry\n", - dentry); - return 1; - } - return 0; -} /* End Function devfs_d_delete */ - -struct devfs_lookup_struct { - devfs_handle_t de; - wait_queue_head_t wait_queue; -}; - -/* XXX: this doesn't handle the case where we got a negative dentry - but a devfs entry has been registered in the meanwhile */ -static int devfs_d_revalidate_wait(struct dentry *dentry, struct nameidata *nd) -{ - struct inode *dir = dentry->d_parent->d_inode; - struct fs_info *fs_info = dir->i_sb->s_fs_info; - devfs_handle_t parent = get_devfs_entry_from_vfs_inode(dir); - struct devfs_lookup_struct *lookup_info = dentry->d_fsdata; - DECLARE_WAITQUEUE(wait, current); - int need_lock; - - /* - * FIXME HACK - * - * make sure that - * d_instantiate always runs under lock - * we release i_mutex lock before going to sleep - * - * unfortunately sometimes d_revalidate is called with - * and sometimes without i_mutex lock held. The following checks - * attempt to deduce when we need to add (and drop resp.) lock - * here. This relies on current (2.6.2) calling coventions: - * - * lookup_hash is always run under i_mutex and is passing NULL - * as nd - * - * open(...,O_CREATE,...) calls _lookup_hash under i_mutex - * and sets flags to LOOKUP_OPEN|LOOKUP_CREATE - * - * all other invocations of ->d_revalidate seem to happen - * outside of i_mutex - */ - need_lock = nd && - (!(nd->flags & LOOKUP_CREATE) || (nd->flags & LOOKUP_PARENT)); - - if (need_lock) - mutex_lock(&dir->i_mutex); - - if (is_devfsd_or_child(fs_info)) { - devfs_handle_t de = lookup_info->de; - struct inode *inode; - - DPRINTK(DEBUG_I_LOOKUP, - "(%s): dentry: %p inode: %p de: %p by: \"%s\"\n", - dentry->d_name.name, dentry, dentry->d_inode, de, - current->comm); - if (dentry->d_inode) - goto out; - if (de == NULL) { - read_lock(&parent->u.dir.lock); - de = _devfs_search_dir(parent, dentry->d_name.name, - dentry->d_name.len); - read_unlock(&parent->u.dir.lock); - if (de == NULL) - goto out; - lookup_info->de = de; - } - /* Create an inode, now that the driver information is available */ - inode = _devfs_get_vfs_inode(dir->i_sb, de, dentry); - if (!inode) - goto out; - DPRINTK(DEBUG_I_LOOKUP, - "(%s): new VFS inode(%u): %p de: %p by: \"%s\"\n", - de->name, de->inode.ino, inode, de, current->comm); - d_instantiate(dentry, inode); - goto out; - } - if (lookup_info == NULL) - goto out; /* Early termination */ - read_lock(&parent->u.dir.lock); - if (dentry->d_fsdata) { - set_current_state(TASK_UNINTERRUPTIBLE); - add_wait_queue(&lookup_info->wait_queue, &wait); - read_unlock(&parent->u.dir.lock); - /* at this point it is always (hopefully) locked */ - mutex_unlock(&dir->i_mutex); - schedule(); - mutex_lock(&dir->i_mutex); - /* - * This does not need nor should remove wait from wait_queue. - * Wait queue head is never reused - nothing is ever added to it - * after all waiters have been waked up and head itself disappears - * very soon after it. Moreover it is local variable on stack that - * is likely to have already disappeared so any reference to it - * at this point is buggy. - */ - - } else - read_unlock(&parent->u.dir.lock); - - out: - if (need_lock) - mutex_unlock(&dir->i_mutex); - return 1; -} /* End Function devfs_d_revalidate_wait */ - -/* Inode operations for device entries follow */ - -static struct dentry *devfs_lookup(struct inode *dir, struct dentry *dentry, - struct nameidata *nd) -{ - struct devfs_entry tmp; /* Must stay in scope until devfsd idle again */ - struct devfs_lookup_struct lookup_info; - struct fs_info *fs_info = dir->i_sb->s_fs_info; - struct devfs_entry *parent, *de; - struct inode *inode; - struct dentry *retval = NULL; - - /* Set up the dentry operations before anything else, to ensure cleaning - up on any error */ - dentry->d_op = &devfs_dops; - /* First try to get the devfs entry for this directory */ - parent = get_devfs_entry_from_vfs_inode(dir); - DPRINTK(DEBUG_I_LOOKUP, "(%s): dentry: %p parent: %p by: \"%s\"\n", - dentry->d_name.name, dentry, parent, current->comm); - if (parent == NULL) - return ERR_PTR(-ENOENT); - read_lock(&parent->u.dir.lock); - de = _devfs_search_dir(parent, dentry->d_name.name, dentry->d_name.len); - read_unlock(&parent->u.dir.lock); - lookup_info.de = de; - init_waitqueue_head(&lookup_info.wait_queue); - dentry->d_fsdata = &lookup_info; - if (de == NULL) { /* Try with devfsd. For any kind of failure, leave a negative dentry - so someone else can deal with it (in the case where the sysadmin - does a mknod()). It's important to do this before hashing the - dentry, so that the devfsd queue is filled before revalidates - can start */ - if (try_modload(parent, fs_info, dentry->d_name.name, dentry->d_name.len, &tmp) < 0) { /* Lookup event was not queued to devfsd */ - d_add(dentry, NULL); - return NULL; - } - } - dentry->d_op = &devfs_wait_dops; - d_add(dentry, NULL); /* Open the floodgates */ - /* Unlock directory semaphore, which will release any waiters. They - will get the hashed dentry, and may be forced to wait for - revalidation */ - mutex_unlock(&dir->i_mutex); - wait_for_devfsd_finished(fs_info); /* If I'm not devfsd, must wait */ - mutex_lock(&dir->i_mutex); /* Grab it again because them's the rules */ - de = lookup_info.de; - /* If someone else has been so kind as to make the inode, we go home - early */ - if (dentry->d_inode) - goto out; - if (de == NULL) { - read_lock(&parent->u.dir.lock); - de = _devfs_search_dir(parent, dentry->d_name.name, - dentry->d_name.len); - read_unlock(&parent->u.dir.lock); - if (de == NULL) - goto out; - /* OK, there's an entry now, but no VFS inode yet */ - } - /* Create an inode, now that the driver information is available */ - inode = _devfs_get_vfs_inode(dir->i_sb, de, dentry); - if (!inode) { - retval = ERR_PTR(-ENOMEM); - goto out; - } - DPRINTK(DEBUG_I_LOOKUP, - "(%s): new VFS inode(%u): %p de: %p by: \"%s\"\n", de->name, - de->inode.ino, inode, de, current->comm); - d_instantiate(dentry, inode); - out: - write_lock(&parent->u.dir.lock); - dentry->d_op = &devfs_dops; - dentry->d_fsdata = NULL; - wake_up(&lookup_info.wait_queue); - write_unlock(&parent->u.dir.lock); - devfs_put(de); - return retval; -} /* End Function devfs_lookup */ - -static int devfs_unlink(struct inode *dir, struct dentry *dentry) -{ - int unhooked; - struct devfs_entry *de; - struct inode *inode = dentry->d_inode; - struct fs_info *fs_info = dir->i_sb->s_fs_info; - - de = get_devfs_entry_from_vfs_inode(inode); - DPRINTK(DEBUG_I_UNLINK, "(%s): de: %p\n", dentry->d_name.name, de); - if (de == NULL) - return -ENOENT; - if (!de->vfs) - return -EPERM; - write_lock(&de->parent->u.dir.lock); - unhooked = _devfs_unhook(de); - write_unlock(&de->parent->u.dir.lock); - if (!unhooked) - return -ENOENT; - if (!is_devfsd_or_child(fs_info)) - devfsd_notify_de(de, DEVFSD_NOTIFY_DELETE, inode->i_mode, - inode->i_uid, inode->i_gid, fs_info); - free_dentry(de); - devfs_put(de); - return 0; -} /* End Function devfs_unlink */ - -static int devfs_symlink(struct inode *dir, struct dentry *dentry, - const char *symname) -{ - int err; - struct fs_info *fs_info = dir->i_sb->s_fs_info; - struct devfs_entry *parent, *de; - struct inode *inode; - - /* First try to get the devfs entry for this directory */ - parent = get_devfs_entry_from_vfs_inode(dir); - if (parent == NULL) - return -ENOENT; - err = devfs_do_symlink(parent, dentry->d_name.name, symname, &de); - DPRINTK(DEBUG_DISABLED, "(%s): errcode from <devfs_do_symlink>: %d\n", - dentry->d_name.name, err); - if (err < 0) - return err; - de->vfs = TRUE; - de->inode.uid = current->euid; - de->inode.gid = current->egid; - de->inode.atime = CURRENT_TIME; - de->inode.mtime = CURRENT_TIME; - de->inode.ctime = CURRENT_TIME; - if ((inode = _devfs_get_vfs_inode(dir->i_sb, de, dentry)) == NULL) - return -ENOMEM; - DPRINTK(DEBUG_DISABLED, "(%s): new VFS inode(%u): %p dentry: %p\n", - dentry->d_name.name, de->inode.ino, inode, dentry); - d_instantiate(dentry, inode); - if (!is_devfsd_or_child(fs_info)) - devfsd_notify_de(de, DEVFSD_NOTIFY_CREATE, inode->i_mode, - inode->i_uid, inode->i_gid, fs_info); - return 0; -} /* End Function devfs_symlink */ - -static int devfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) -{ - int err; - struct fs_info *fs_info = dir->i_sb->s_fs_info; - struct devfs_entry *parent, *de; - struct inode *inode; - - mode = (mode & ~S_IFMT) | S_IFDIR; /* VFS doesn't pass S_IFMT part */ - parent = get_devfs_entry_from_vfs_inode(dir); - if (parent == NULL) - return -ENOENT; - de = _devfs_alloc_entry(dentry->d_name.name, dentry->d_name.len, mode); - if (!de) - return -ENOMEM; - de->vfs = TRUE; - if ((err = _devfs_append_entry(parent, de, NULL)) != 0) - return err; - de->inode.uid = current->euid; - de->inode.gid = current->egid; - de->inode.atime = CURRENT_TIME; - de->inode.mtime = CURRENT_TIME; - de->inode.ctime = CURRENT_TIME; - if ((inode = _devfs_get_vfs_inode(dir->i_sb, de, dentry)) == NULL) - return -ENOMEM; - DPRINTK(DEBUG_DISABLED, "(%s): new VFS inode(%u): %p dentry: %p\n", - dentry->d_name.name, de->inode.ino, inode, dentry); - d_instantiate(dentry, inode); - if (!is_devfsd_or_child(fs_info)) - devfsd_notify_de(de, DEVFSD_NOTIFY_CREATE, inode->i_mode, - inode->i_uid, inode->i_gid, fs_info); - return 0; -} /* End Function devfs_mkdir */ - -static int devfs_rmdir(struct inode *dir, struct dentry *dentry) -{ - int err = 0; - struct devfs_entry *de; - struct fs_info *fs_info = dir->i_sb->s_fs_info; - struct inode *inode = dentry->d_inode; - - if (dir->i_sb->s_fs_info != inode->i_sb->s_fs_info) - return -EINVAL; - de = get_devfs_entry_from_vfs_inode(inode); - if (de == NULL) - return -ENOENT; - if (!S_ISDIR(de->mode)) - return -ENOTDIR; - if (!de->vfs) - return -EPERM; - /* First ensure the directory is empty and will stay that way */ - write_lock(&de->u.dir.lock); - if (de->u.dir.first) - err = -ENOTEMPTY; - else - de->u.dir.no_more_additions = TRUE; - write_unlock(&de->u.dir.lock); - if (err) - return err; - /* Now unhook the directory from its parent */ - write_lock(&de->parent->u.dir.lock); - if (!_devfs_unhook(de)) - err = -ENOENT; - write_unlock(&de->parent->u.dir.lock); - if (err) - return err; - if (!is_devfsd_or_child(fs_info)) - devfsd_notify_de(de, DEVFSD_NOTIFY_DELETE, inode->i_mode, - inode->i_uid, inode->i_gid, fs_info); - free_dentry(de); - devfs_put(de); - return 0; -} /* End Function devfs_rmdir */ - -static int devfs_mknod(struct inode *dir, struct dentry *dentry, int mode, - dev_t rdev) -{ - int err; - struct fs_info *fs_info = dir->i_sb->s_fs_info; - struct devfs_entry *parent, *de; - struct inode *inode; - - DPRINTK(DEBUG_I_MKNOD, "(%s): mode: 0%o dev: %u:%u\n", - dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev)); - parent = get_devfs_entry_from_vfs_inode(dir); - if (parent == NULL) - return -ENOENT; - de = _devfs_alloc_entry(dentry->d_name.name, dentry->d_name.len, mode); - if (!de) - return -ENOMEM; - de->vfs = TRUE; - if (S_ISCHR(mode) || S_ISBLK(mode)) - de->u.dev = rdev; - if ((err = _devfs_append_entry(parent, de, NULL)) != 0) - return err; - de->inode.uid = current->euid; - de->inode.gid = current->egid; - de->inode.atime = CURRENT_TIME; - de->inode.mtime = CURRENT_TIME; - de->inode.ctime = CURRENT_TIME; - if ((inode = _devfs_get_vfs_inode(dir->i_sb, de, dentry)) == NULL) - return -ENOMEM; - DPRINTK(DEBUG_I_MKNOD, ": new VFS inode(%u): %p dentry: %p\n", - de->inode.ino, inode, dentry); - d_instantiate(dentry, inode); - if (!is_devfsd_or_child(fs_info)) - devfsd_notify_de(de, DEVFSD_NOTIFY_CREATE, inode->i_mode, - inode->i_uid, inode->i_gid, fs_info); - return 0; -} /* End Function devfs_mknod */ - -static void *devfs_follow_link(struct dentry *dentry, struct nameidata *nd) -{ - struct devfs_entry *p = get_devfs_entry_from_vfs_inode(dentry->d_inode); - nd_set_link(nd, p ? p->u.symlink.linkname : ERR_PTR(-ENODEV)); - return NULL; -} /* End Function devfs_follow_link */ - -static struct inode_operations devfs_iops = { - .setattr = devfs_notify_change, -}; - -static struct inode_operations devfs_dir_iops = { - .lookup = devfs_lookup, - .unlink = devfs_unlink, - .symlink = devfs_symlink, - .mkdir = devfs_mkdir, - .rmdir = devfs_rmdir, - .mknod = devfs_mknod, - .setattr = devfs_notify_change, -}; - -static struct inode_operations devfs_symlink_iops = { - .readlink = generic_readlink, - .follow_link = devfs_follow_link, - .setattr = devfs_notify_change, -}; - -static int devfs_fill_super(struct super_block *sb, void *data, int silent) -{ - struct inode *root_inode = NULL; - - if (_devfs_get_root_entry() == NULL) - goto out_no_root; - atomic_set(&fs_info.devfsd_overrun_count, 0); - init_waitqueue_head(&fs_info.devfsd_wait_queue); - init_waitqueue_head(&fs_info.revalidate_wait_queue); - fs_info.sb = sb; - sb->s_fs_info = &fs_info; - sb->s_blocksize = 1024; - sb->s_blocksize_bits = 10; - sb->s_magic = DEVFS_SUPER_MAGIC; - sb->s_op = &devfs_sops; - sb->s_time_gran = 1; - if ((root_inode = _devfs_get_vfs_inode(sb, root_entry, NULL)) == NULL) - goto out_no_root; - sb->s_root = d_alloc_root(root_inode); - if (!sb->s_root) - goto out_no_root; - DPRINTK(DEBUG_S_READ, "(): made devfs ptr: %p\n", sb->s_fs_info); - return 0; - - out_no_root: - PRINTK("(): get root inode failed\n"); - if (root_inode) - iput(root_inode); - return -EINVAL; -} /* End Function devfs_fill_super */ - -static int devfs_get_sb(struct file_system_type *fs_type, - int flags, const char *dev_name, - void *data, struct vfsmount *mnt) -{ - return get_sb_single(fs_type, flags, data, devfs_fill_super, mnt); -} - -static struct file_system_type devfs_fs_type = { - .name = DEVFS_NAME, - .get_sb = devfs_get_sb, - .kill_sb = kill_anon_super, -}; - -/* File operations for devfsd follow */ - -static ssize_t devfsd_read(struct file *file, char __user *buf, size_t len, - loff_t * ppos) -{ - int done = FALSE; - int ival; - loff_t pos, devname_offset, tlen, rpos; - devfs_handle_t de; - struct devfsd_buf_entry *entry; - struct fs_info *fs_info = file->f_dentry->d_inode->i_sb->s_fs_info; - struct devfsd_notify_struct *info = fs_info->devfsd_info; - DECLARE_WAITQUEUE(wait, current); - - /* Verify the task has grabbed the queue */ - if (fs_info->devfsd_task != current) - return -EPERM; - info->major = 0; - info->minor = 0; - /* Block for a new entry */ - set_current_state(TASK_INTERRUPTIBLE); - add_wait_queue(&fs_info->devfsd_wait_queue, &wait); - while (devfsd_queue_empty(fs_info)) { - fs_info->devfsd_sleeping = TRUE; - wake_up(&fs_info->revalidate_wait_queue); - schedule(); - fs_info->devfsd_sleeping = FALSE; - if (signal_pending(current)) { - remove_wait_queue(&fs_info->devfsd_wait_queue, &wait); - __set_current_state(TASK_RUNNING); - return -EINTR; - } - set_current_state(TASK_INTERRUPTIBLE); - } - remove_wait_queue(&fs_info->devfsd_wait_queue, &wait); - __set_current_state(TASK_RUNNING); - /* Now play with the data */ - ival = atomic_read(&fs_info->devfsd_overrun_count); - info->overrun_count = ival; - entry = fs_info->devfsd_first_event; - info->type = entry->type; - info->mode = entry->mode; - info->uid = entry->uid; - info->gid = entry->gid; - de = entry->de; - if (S_ISCHR(de->mode) || S_ISBLK(de->mode)) { - info->major = MAJOR(de->u.dev); - info->minor = MINOR(de->u.dev); - } - pos = devfs_generate_path(de, info->devname, DEVFS_PATHLEN); - if (pos < 0) - return pos; - info->namelen = DEVFS_PATHLEN - pos - 1; - if (info->mode == 0) - info->mode = de->mode; - devname_offset = info->devname - (char *)info; - rpos = *ppos; - if (rpos < devname_offset) { - /* Copy parts of the header */ - tlen = devname_offset - rpos; - if (tlen > len) - tlen = len; - if (copy_to_user(buf, (char *)info + rpos, tlen)) { - return -EFAULT; - } - rpos += tlen; - buf += tlen; - len -= tlen; - } - if ((rpos >= devname_offset) && (len > 0)) { - /* Copy the name */ - tlen = info->namelen + 1; - if (tlen > len) - tlen = len; - else - done = TRUE; - if (copy_to_user - (buf, info->devname + pos + rpos - devname_offset, tlen)) { - return -EFAULT; - } - rpos += tlen; - } - tlen = rpos - *ppos; - if (done) { - devfs_handle_t parent; - - spin_lock(&fs_info->devfsd_buffer_lock); - fs_info->devfsd_first_event = entry->next; - if (entry->next == NULL) - fs_info->devfsd_last_event = NULL; - spin_unlock(&fs_info->devfsd_buffer_lock); - for (; de != NULL; de = parent) { - parent = de->parent; - devfs_put(de); - } - kmem_cache_free(devfsd_buf_cache, entry); - if (ival > 0) - atomic_sub(ival, &fs_info->devfsd_overrun_count); - *ppos = 0; - } else - *ppos = rpos; - return tlen; -} /* End Function devfsd_read */ - -static int devfsd_ioctl(struct inode *inode, struct file *file, - unsigned int cmd, unsigned long arg) -{ - int ival; - struct fs_info *fs_info = inode->i_sb->s_fs_info; - - switch (cmd) { - case DEVFSDIOC_GET_PROTO_REV: - ival = DEVFSD_PROTOCOL_REVISION_KERNEL; - if (copy_to_user((void __user *)arg, &ival, sizeof ival)) - return -EFAULT; - break; - case DEVFSDIOC_SET_EVENT_MASK: - /* Ensure only one reader has access to the queue. This scheme will - work even if the global kernel lock were to be removed, because it - doesn't matter who gets in first, as long as only one gets it */ - if (fs_info->devfsd_task == NULL) { - static DEFINE_SPINLOCK(lock); - - if (!spin_trylock(&lock)) - return -EBUSY; - if (fs_info->devfsd_task != NULL) { /* We lost the race... */ - spin_unlock(&lock); - return -EBUSY; - } - fs_info->devfsd_task = current; - spin_unlock(&lock); - fs_info->devfsd_pgrp = - (process_group(current) == - current->pid) ? process_group(current) : 0; - fs_info->devfsd_file = file; - fs_info->devfsd_info = - kmalloc(sizeof *fs_info->devfsd_info, GFP_KERNEL); - if (!fs_info->devfsd_info) { - devfsd_close(inode, file); - return -ENOMEM; - } - } else if (fs_info->devfsd_task != current) - return -EBUSY; - fs_info->devfsd_event_mask = arg; /* Let the masses come forth */ - break; - case DEVFSDIOC_RELEASE_EVENT_QUEUE: - if (fs_info->devfsd_file != file) - return -EPERM; - return devfsd_close(inode, file); - /*break; */ -#ifdef CONFIG_DEVFS_DEBUG - case DEVFSDIOC_SET_DEBUG_MASK: - if (copy_from_user(&ival, (void __user *)arg, sizeof ival)) - return -EFAULT; - devfs_debug = ival; - break; -#endif - default: - return -ENOIOCTLCMD; - } - return 0; -} /* End Function devfsd_ioctl */ - -static int devfsd_close(struct inode *inode, struct file *file) -{ - struct devfsd_buf_entry *entry, *next; - struct fs_info *fs_info = inode->i_sb->s_fs_info; - - if (fs_info->devfsd_file != file) - return 0; - fs_info->devfsd_event_mask = 0; - fs_info->devfsd_file = NULL; - spin_lock(&fs_info->devfsd_buffer_lock); - entry = fs_info->devfsd_first_event; - fs_info->devfsd_first_event = NULL; - fs_info->devfsd_last_event = NULL; - kfree(fs_info->devfsd_info); - fs_info->devfsd_info = NULL; - spin_unlock(&fs_info->devfsd_buffer_lock); - fs_info->devfsd_pgrp = 0; - fs_info->devfsd_task = NULL; - wake_up(&fs_info->revalidate_wait_queue); - for (; entry; entry = next) { - next = entry->next; - kmem_cache_free(devfsd_buf_cache, entry); - } - return 0; -} /* End Function devfsd_close */ - -#ifdef CONFIG_DEVFS_DEBUG -static ssize_t stat_read(struct file *file, char __user *buf, size_t len, - loff_t * ppos) -{ - ssize_t num; - char txt[80]; - - num = sprintf(txt, "Number of entries: %u number of bytes: %u\n", - stat_num_entries, stat_num_bytes) + 1; - if (*ppos >= num) - return 0; - if (*ppos + len > num) - len = num - *ppos; - if (copy_to_user(buf, txt + *ppos, len)) - return -EFAULT; - *ppos += len; - return len; -} /* End Function stat_read */ -#endif - -static int __init init_devfs_fs(void) -{ - int err; - int major; - struct devfs_entry *devfsd; -#ifdef CONFIG_DEVFS_DEBUG - struct devfs_entry *stat; -#endif - - if (_devfs_get_root_entry() == NULL) - return -ENOMEM; - - printk(KERN_INFO "%s: %s Richard Gooch (rgooch@atnf.csiro.au)\n", - DEVFS_NAME, DEVFS_VERSION); - devfsd_buf_cache = kmem_cache_create("devfsd_event", - sizeof(struct devfsd_buf_entry), - 0, 0, NULL, NULL); - if (!devfsd_buf_cache) - OOPS("(): unable to allocate event slab\n"); -#ifdef CONFIG_DEVFS_DEBUG - devfs_debug = devfs_debug_init; - printk(KERN_INFO "%s: devfs_debug: 0x%0x\n", DEVFS_NAME, devfs_debug); -#endif - printk(KERN_INFO "%s: boot_options: 0x%0x\n", DEVFS_NAME, boot_options); - - /* register special device for devfsd communication */ - major = register_chrdev(0, "devfs", &devfs_fops); - if (major < 0) - return major; - - /* And create the entry for ".devfsd" */ - devfsd = _devfs_alloc_entry(".devfsd", 0, S_IFCHR | S_IRUSR | S_IWUSR); - if (devfsd == NULL) - return -ENOMEM; - devfsd->u.dev = MKDEV(major, 0); - _devfs_append_entry(root_entry, devfsd, NULL); - -#ifdef CONFIG_DEVFS_DEBUG - stat = _devfs_alloc_entry(".stat", 0, S_IFCHR | S_IRUGO); - if (stat == NULL) - return -ENOMEM; - stat->u.dev = MKDEV(major, 1); - _devfs_append_entry(root_entry, stat, NULL); -#endif - - err = register_filesystem(&devfs_fs_type); - return err; -} /* End Function init_devfs_fs */ - -void __init mount_devfs_fs(void) -{ - int err; - - if (!(boot_options & OPTION_MOUNT)) - return; - err = do_mount("none", "/dev", "devfs", 0, NULL); - if (err == 0) - printk(KERN_INFO "Mounted devfs on /dev\n"); - else - PRINTK("(): unable to mount devfs, err: %d\n", err); -} /* End Function mount_devfs_fs */ - -module_init(init_devfs_fs) |