Patch from "Adam J. Richter" This patch reduces include/linux/devfs*.h and fs/devfs from 3655 lines to 1239, a reduction of 2450 lines, nearly a factor three. That may not be as impressive as the original 5X reduction, but that is mostly because I've restored a bunch of functionality that I hope to eliminate in the future. I'd like to thank Richard Gooch for writing devfs. I think it was a great idea and the effort involved in implementing it, especially when it was not clear that it could work well, was probably about 30-100 times my effort in shrinking it. I immediately became a convert within a day of trying it. I'd be happy for Richard to take over this code and continue maintaining devfs. If he doesn't want to, I'm willing to and I'm also happy to let someone else do it if they want. This is nearly the same patch that I attempted to post on January 2, but apparently some well intentioned spam filter blocked it. I had this problem once before, also when submitting a big patch with a lot of deletions sent as a MIME attachment. This time I'm submitting the patch as part of the text of my message. The there are no code changes between this version and the one that I tried to post on January 2. In the meantime, I've used it and stared at it more, and now I'm posting this as a candiate for integration into Linus's kernel. The January 2 version introduced two significant changes: isolating the filesystem driver to a separate file that only exports two symbols (devfs_vfsmount and init_devfs_fs), and making that patch a change to fs/devfs rather than a new filesystem. (If anyone would prefer that I submit this as a separate file system, please let me know.) If you want devfsd functionality (well, at least the "REGISTER" and "LOOKUP" events), you can get my user level program devfs_helper, which is a reduced functionality replacement program for devfsd from the following URL. ftp://ftp.yggdrasil.com/pub/dist/device_control/devfs/ devfs_helper is program that is exec'ed on each event rather than being a daemon that waits on events. When the new module_param code is further developed, I will default the devfs_helper to be turned off until a user level program sets the name of the program. Finally, I'd like to move forward toward getting this into Linus's kernel. Any blessings, curses, requests for changes or advice on the best way to proceed would be appreciated. devfs/Makefile | 2 devfs/base.c | 3175 +++--------------------------------------------- devfs/fs.c | 259 +++ namei.c | 2 linux/devfs_fs_kernel.h | 2 5 files changed, 495 insertions(+), 2945 deletions(-) diff -puN fs/devfs/base.c~smalldevfs fs/devfs/base.c --- 25/fs/devfs/base.c~smalldevfs 2003-02-11 16:03:20.000000000 -0800 +++ 25-akpm/fs/devfs/base.c 2003-02-11 16:04:09.000000000 -0800 @@ -1,6 +1,12 @@ -/* devfs (Device FileSystem) driver. +/* + Device File System (devfs) - device interface routines - Copyright (C) 1998-2002 Richard Gooch + This file is a reimplementation by Adam J. Richter of part of a + design and implementation originally written by Richard Gooch. + + + + Copyright 2002-2003 Yggdrasil Computing, Inc. This library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public @@ -15,3033 +21,318 @@ 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 - Original version. - v0.1 - 19980111 Richard Gooch - Created per-fs inode table rather than using inode->u.generic_ip - v0.2 - 19980111 Richard Gooch - 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 - Fix for when compiling with CONFIG_KERNELD. - 19980112 Richard Gooch - Fix for readdir() which sometimes didn't show entries. - Added <> option to . - v0.4 - 19980113 Richard Gooch - Created function. - v0.5 - 19980115 Richard Gooch - Added subdirectory support. Major restructuring. - 19980116 Richard Gooch - Fixed to not search major=0,minor=0. - Added symlink support. - v0.6 - 19980120 Richard Gooch - Created function and support directory unregister - 19980120 Richard Gooch - Auto-ownership uses real uid/gid rather than effective uid/gid. - v0.7 - 19980121 Richard Gooch - Supported creation of sockets. - v0.8 - 19980122 Richard Gooch - Added DEVFS_FL_HIDE_UNREG flag. - Interface change to . - Created to support symlink(2). - v0.9 - 19980123 Richard Gooch - Added check to to check inode is in devfs. - Added optional traversal of symlinks. - v0.10 - 19980124 Richard Gooch - Created and . - v0.11 - 19980125 C. Scott Ananian - Created . - 19980125 Richard Gooch - Allow removal of symlinks. - v0.12 - 19980125 Richard Gooch - Created . - 19980126 Richard Gooch - Moved DEVFS_SUPER_MAGIC into header file. - Added DEVFS_FL_HIDE flag. - Created . - Created . - Fixed minor bug in . - 19980127 Richard Gooch - Changed interface to , , - , and . - Fixed inode times when symlink created with symlink(2). - v0.13 - 19980129 C. Scott Ananian - Exported , - and . - 19980129 Richard Gooch - Created to support unlink(2). - v0.14 - 19980129 Richard Gooch - Fixed kerneld support for entries in devfs subdirectories. - 19980130 Richard Gooch - Bugfixes in . - v0.15 - 19980207 Richard Gooch - Call kerneld when looking up unregistered entries. - v0.16 - 19980326 Richard Gooch - Modified interface to for symlink traversal. - v0.17 - 19980331 Richard Gooch - Fixed persistence bug with device numbers for manually created - device files. - Fixed problem with recreating symlinks with different content. - v0.18 - 19980401 Richard Gooch - Changed to CONFIG_KMOD. - Hide entries which are manually unlinked. - Always invalidate devfs dentry cache when registering entries. - Created to support rmdir(2). - Ensure directories created by are visible. - v0.19 - 19980402 Richard Gooch - Invalidate devfs dentry cache when making directories. - Invalidate devfs dentry cache when removing entries. - Fixed persistence bug with fifos. - v0.20 - 19980421 Richard Gooch - Print process command when debugging kerneld/kmod. - Added debugging for register/unregister/change operations. - 19980422 Richard Gooch - Added "devfs=" boot options. - v0.21 - 19980426 Richard Gooch - No longer lock/unlock superblock in . - Drop negative dentries when they are released. - Manage dcache more efficiently. - v0.22 - 19980427 Richard Gooch - Added DEVFS_FL_AUTO_DEVNUM flag. - v0.23 - 19980430 Richard Gooch - No longer set unnecessary methods. - v0.24 - 19980504 Richard Gooch - Added PID display to debugging message. - Added "after" debugging message to . - 19980519 Richard Gooch - Added "diread" and "diwrite" boot options. - 19980520 Richard Gooch - Fixed persistence problem with permissions. - v0.25 - 19980602 Richard Gooch - Support legacy device nodes. - Fixed bug where recreated inodes were hidden. - v0.26 - 19980602 Richard Gooch - Improved debugging in . - 19980607 Richard Gooch - No longer free old dentries in . - Free all dentries for a given entry when deleting inodes. - v0.27 - 19980627 Richard Gooch - Limit auto-device numbering to majors 128 to 239. - v0.28 - 19980629 Richard Gooch - Fixed inode times persistence problem. - v0.29 - 19980704 Richard Gooch - Fixed spelling in debug. - Fixed bug in parsing "dilookup". - v0.30 - 19980705 Richard Gooch - Fixed devfs inode leak when manually recreating inodes. - Fixed permission persistence problem when recreating inodes. - v0.31 - 19980727 Richard Gooch - Removed harmless "unused variable" compiler warning. - Fixed modes for manually recreated device nodes. - v0.32 - 19980728 Richard Gooch - Added NULL devfs inode warning in . - Force all inode nlink values to 1. - v0.33 - 19980730 Richard Gooch - Added "dimknod" boot option. - Set inode nlink to 0 when freeing dentries. - Fixed modes for manually recreated symlinks. - v0.34 - 19980802 Richard Gooch - Fixed bugs in recreated directories and symlinks. - v0.35 - 19980806 Richard Gooch - Fixed bugs in recreated device nodes. - 19980807 Richard Gooch - Fixed bug in currently unused . - Defined new type. - Improved debugging when getting entries. - Fixed bug where directories could be emptied. - v0.36 - 19980809 Richard Gooch - Replaced dummy .epoch inode with .devfsd character device. - 19980810 Richard Gooch - Implemented devfsd protocol revision 0. - v0.37 - 19980819 Richard Gooch - Added soothing message to warning in . - v0.38 - 19980829 Richard Gooch - Use GCC extensions for structure initialisations. - Implemented async open notification. - Incremented devfsd protocol revision to 1. - v0.39 - 19980908 Richard Gooch - Moved async open notification to end of . - v0.40 - 19980910 Richard Gooch - Prepended "/dev/" to module load request. - Renamed to . - v0.41 - 19980910 Richard Gooch - Fixed typo "AYSNC" -> "ASYNC". - v0.42 - 19980910 Richard Gooch - Added open flag for files. - v0.43 - 19980927 Richard Gooch - Set i_blocks=0 and i_blksize=1024 in . - v0.44 - 19981005 Richard Gooch - Added test for empty <> in . - Renamed to and published. - v0.45 - 19981006 Richard Gooch - Created . - v0.46 - 19981007 Richard Gooch - Limit auto-device numbering to majors 144 to 239. - v0.47 - 19981010 Richard Gooch - Updated for VFS change in 2.1.125. - v0.48 - 19981022 Richard Gooch - Created DEVFS_ FL_COMPAT flag. - v0.49 - 19981023 Richard Gooch - Created "nocompat" boot option. - v0.50 - 19981025 Richard Gooch - Replaced "mount" boot option with "nomount". - v0.51 - 19981110 Richard Gooch - Created "only" boot option. - v0.52 - 19981112 Richard Gooch - Added DEVFS_FL_REMOVABLE flag. - v0.53 - 19981114 Richard Gooch - Only call on first call to - . - v0.54 - 19981205 Richard Gooch - Updated for VFS change in 2.1.131. - v0.55 - 19981218 Richard Gooch - Created . - 19981220 Richard Gooch - Check for partitions on removable media in . - v0.56 - 19990118 Richard Gooch - Added support for registering regular files. - Created . - Update devfs inodes from entries if not changed through FS. - v0.57 - 19990124 Richard Gooch - Fixed to only initialise temporary inodes. - Trap for NULL fops in . - Return -ENODEV in for non-driver inodes. - v0.58 - 19990126 Richard Gooch - Switched from PATH_MAX to DEVFS_PATHLEN. - v0.59 - 19990127 Richard Gooch - Created "nottycompat" boot option. - v0.60 - 19990318 Richard Gooch - Fixed to not overrun event buffer. - v0.61 - 19990329 Richard Gooch - Created . - v0.62 - 19990330 Richard Gooch - Don't return unregistred entries in . - Panic in if entry unregistered. - 19990401 Richard Gooch - Don't panic in for duplicates. - v0.63 - 19990402 Richard Gooch - Don't unregister already unregistered entries in . - v0.64 - 19990510 Richard Gooch - Disable warning messages when unable to read partition table for - removable media. - v0.65 - 19990512 Richard Gooch - Updated for VFS change in 2.3.1-pre1. - Created "oops-on-panic" boot option. - Improved debugging in and . - v0.66 - 19990519 Richard Gooch - Added documentation for some functions. - 19990525 Richard Gooch - Removed "oops-on-panic" boot option: now always Oops. - v0.67 - 19990531 Richard Gooch - Improved debugging in . - v0.68 - 19990604 Richard Gooch - Added "diunlink" and "nokmod" boot options. - Removed superfluous warning message in . - v0.69 - 19990611 Richard Gooch - Took account of change to . - v0.70 - 19990614 Richard Gooch - Created separate event queue for each mounted devfs. - Removed . - 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 - Support 2.2.x kernels. - v0.71 - 19990623 Richard Gooch - Switched to sending process uid/gid to devfsd. - Renamed to . - Added DEVFSD_NOTIFY_LOOKUP event. - 19990624 Richard Gooch - Added DEVFSD_NOTIFY_CHANGE event. - Incremented devfsd protocol revision to 4. - v0.72 - 19990713 Richard Gooch - Return EISDIR rather than EINVAL for read(2) on directories. - v0.73 - 19990809 Richard Gooch - Changed to new __init scheme. - v0.74 - 19990901 Richard Gooch - Changed remaining function declarations to new __init scheme. - v0.75 - 19991013 Richard Gooch - Created , , - and . - Added <> parameter to , , - and . - Work sponsored by SGI. - v0.76 - 19991017 Richard Gooch - Allow multiple unregistrations. - Work sponsored by SGI. - v0.77 - 19991026 Richard Gooch - Added major and minor number to devfsd protocol. - Incremented devfsd protocol revision to 5. - Work sponsored by SGI. - v0.78 - 19991030 Richard Gooch - Support info pointer for all devfs entry types. - Added <> parameter to and - . - Work sponsored by SGI. - v0.79 - 19991031 Richard Gooch - Support "../" when searching devfs namespace. - Work sponsored by SGI. - v0.80 - 19991101 Richard Gooch - Created . - Work sponsored by SGI. - v0.81 - 19991103 Richard Gooch - Exported . - Work sponsored by SGI. - v0.82 - 19991104 Richard Gooch - Removed unused . - 19991105 Richard Gooch - Do not hide entries from devfsd or children. - Removed DEVFS_ FL_TTY_COMPAT flag. - Removed "nottycompat" boot option. - Removed . - Work sponsored by SGI. - v0.83 - 19991107 Richard Gooch - Added DEVFS_FL_WAIT flag. - Work sponsored by SGI. - v0.84 - 19991107 Richard Gooch - Support new "disc" naming scheme in . - Allow NULL fops in . - Work sponsored by SGI. - v0.85 - 19991110 Richard Gooch - Fall back to major table if NULL fops given to . - Work sponsored by SGI. - v0.86 - 19991204 Richard Gooch - Support fifos when unregistering. - Work sponsored by SGI. - v0.87 - 19991209 Richard Gooch - Removed obsolete DEVFS_ FL_COMPAT and DEVFS_ FL_TOLERANT flags. - Work sponsored by SGI. - v0.88 - 19991214 Richard Gooch - Removed kmod support. - Work sponsored by SGI. - v0.89 - 19991216 Richard Gooch - Improved debugging in . - Ensure dentries created by devfsd will be cleaned up. - Work sponsored by SGI. - v0.90 - 19991223 Richard Gooch - Created . - Work sponsored by SGI. - v0.91 - 20000203 Richard Gooch - Ported to kernel 2.3.42. - Removed . - Work sponsored by SGI. - v0.92 - 20000306 Richard Gooch - Added DEVFS_ FL_NO_PERSISTENCE flag. - Removed unnecessary call to in - . - Work sponsored by SGI. - v0.93 - 20000413 Richard Gooch - Set inode->i_size to correct size for symlinks. - 20000414 Richard Gooch - Only give lookup() method to directories to comply with new VFS - assumptions. - Work sponsored by SGI. - 20000415 Richard Gooch - Remove unnecessary tests in symlink methods. - Don't kill existing block ops in . - Work sponsored by SGI. - v0.94 - 20000424 Richard Gooch - Don't create missing directories in . - Work sponsored by SGI. - v0.95 - 20000430 Richard Gooch - Added CONFIG_DEVFS_MOUNT. - Work sponsored by SGI. - v0.96 - 20000608 Richard Gooch - Disabled multi-mount capability (use VFS bindings instead). - Work sponsored by SGI. - v0.97 - 20000610 Richard Gooch - Switched to FS_SINGLE to disable multi-mounts. - 20000612 Richard Gooch - Removed module support. - Removed multi-mount code. - Removed compatibility macros: VFS has changed too much. - Work sponsored by SGI. - v0.98 - 20000614 Richard Gooch - Merged devfs inode into devfs entry. - Work sponsored by SGI. - v0.99 - 20000619 Richard Gooch - Removed dead code in which used to call - . - Work sponsored by SGI. - v0.100 - 20000621 Richard Gooch - Changed interface to . - Work sponsored by SGI. - v0.101 - 20000622 Richard Gooch - Simplified interface to and . - Simplified interface to . - Work sponsored by SGI. - v0.102 - 20010519 Richard Gooch - Ensure terminates string for root entry. - Exported to modules. - 20010520 Richard Gooch - Make send events to devfsd. - Cleaned up option processing in . - 20010521 Richard Gooch - Fixed bugs in handling symlinks: could leak or cause Oops. - 20010522 Richard Gooch - Cleaned up directory handling by separating fops. - v0.103 - 20010601 Richard Gooch - Fixed handling of inverted options in . - v0.104 - 20010604 Richard Gooch - Adjusted to account for fix. - v0.105 - 20010617 Richard Gooch - Answered question posed by Al Viro and removed his comments. - Moved setting of registered flag after other fields are changed. - Fixed race between and . - Global VFS changes added bogus BKL to : removed. - Widened locking in and . - Replaced stack usage with kmalloc. - Simplified locking in and fixed memory leak. - v0.106 - 20010709 Richard Gooch - Removed broken devnum allocation and use . - Fixed old devnum leak by calling new . - v0.107 - 20010712 Richard Gooch - Fixed bug in which could hang boot process. - v0.108 - 20010730 Richard Gooch - Added DEVFSD_NOTIFY_DELETE event. - 20010801 Richard Gooch - Removed #include . - v0.109 - 20010807 Richard Gooch - Fixed inode table races by removing it and using - inode->u.generic_ip instead. - Moved into . - Moved into . - v0.110 - 20010808 Richard Gooch - Fixed race in for uni-processor. - v0.111 - 20010818 Richard Gooch - Removed remnant of multi-mount support in . - Removed unused DEVFS_FL_SHOW_UNREG flag. - v0.112 - 20010820 Richard Gooch - Removed nlink field from struct devfs_inode. - v0.113 - 20010823 Richard Gooch - Replaced BKL with global rwsem to protect symlink data (quick - and dirty hack). - v0.114 - 20010827 Richard Gooch - Replaced global rwsem for symlink with per-link refcount. - v0.115 - 20010919 Richard Gooch - Set inode->i_mapping->a_ops for block nodes in . - v0.116 - 20011008 Richard Gooch - Fixed overrun in by removing function (not needed). - 20011009 Richard Gooch - Fixed buffer underrun in . - 20011029 Richard Gooch - Fixed race in when setting event mask. - 20011114 Richard Gooch - First release of new locking code. - v1.0 - 20011117 Richard Gooch - Discard temporary buffer, now use "%s" for dentry names. - 20011118 Richard Gooch - Don't generate path in : use fake entry instead. - Use "existing" directory in <_devfs_make_parent_for_leaf>. - 20011122 Richard Gooch - Use slab cache rather than fixed buffer for devfsd events. - v1.1 - 20011125 Richard Gooch - Send DEVFSD_NOTIFY_REGISTERED events in . - 20011127 Richard Gooch - Fixed locking bug in due to typo. - Do not send CREATE, CHANGE, ASYNC_OPEN or DELETE events from - devfsd or children. - v1.2 - 20011202 Richard Gooch - Fixed bug in : was dereferencing freed pointer. - v1.3 - 20011203 Richard Gooch - Fixed bug in : was dereferencing freed pointer. - Added process group check for devfsd privileges. - v1.4 - 20011204 Richard Gooch - Use SLAB_ATOMIC in from . - v1.5 - 20011211 Richard Gooch - Return old entry in for 2.4.x kernels. - 20011212 Richard Gooch - Increment refcount on module in . - 20011215 Richard Gooch - Created and exported . - Increment refcount on module in . - Created . - v1.6 - 20011216 Richard Gooch - Added poisoning to . - Improved debugging messages. - v1.7 - 20011221 Richard Gooch - Corrected (made useful) debugging message in . - Moved in to - 20011224 Richard Gooch - Added magic number to guard against scribbling drivers. - 20011226 Richard Gooch - Only return old entry in if a directory. - Defined macros for error and debug messages. - v1.8 - 20020113 Richard Gooch - Fixed (rare, old) race in . - v1.9 - 20020120 Richard Gooch - Fixed deadlock bug in . - Tag VFS deletable in if handle ignored. - v1.10 - 20020129 Richard Gooch - Added KERN_* to remaining messages. - Cleaned up declaration of . - v1.11 - 20020219 Richard Gooch - Changed to allow later additions if not yet empty. - v1.12 - 20020406 Richard Gooch - 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 - Removed 2.4.x compatibility code. - v1.14 - 20020510 Richard Gooch - Added BKL to because drivers still need it. - v1.15 - 20020512 Richard Gooch - Protected and - from changing directory contents. - v1.16 - 20020514 Richard Gooch - Minor cleanup of . - v1.17 - 20020721 Richard Gooch - Switched to ISO C structure field initialisers. - Switch to set_current_state() and move before add_wait_queue(). - 20020722 Richard Gooch - Fixed devfs entry leak in when *readdir fails. - v1.18 - 20020725 Richard Gooch - Created . - v1.19 - 20020728 Richard Gooch - Removed deprecated . - v1.20 - 20020820 Richard Gooch - Fixed module unload race in . - v1.21 - 20021013 Richard Gooch - Removed DEVFS_ FL_AUTO_OWNER. - Switched lingering structure field initialiser to ISO C. - Added locking when updating FCB flags. - v1.22 */ -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include + #include +#include +#include +#include +#include #include -#include -#include +#include #include -#include -#include -#include +#include +#include +#include +#include #include -#include -#include -#include -#include -#include -#include +#include #include "internal.h" -#define DEVFS_VERSION "1.22 (20021013)" - -#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 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 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 - - -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 -{ - struct file_operations *ops; - unsigned long size; -}; - -struct bdev_type -{ - struct block_device_operations *ops; - dev_t dev; - unsigned char autogen:1; - unsigned char removable:1; -}; - -struct cdev_type -{ - struct file_operations *ops; - dev_t dev; - unsigned char autogen: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; - struct file_type file; - struct bdev_type bdev; - struct cdev_type cdev; - 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_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}; +extern struct vfsmount *devfs_vfsmount; +extern int __init init_devfs_fs(void); -#ifdef CONFIG_DEVFS_MOUNT -static unsigned int boot_options = OPTION_MOUNT; -#else -static unsigned int boot_options = OPTION_NONE; -#endif +/* TODO: Move this to some .h file or, more likely, use a slightly + different interface from lookup_create. */ +extern struct dentry *lookup_create(struct nameidata *nd, int is_dir); -/* 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 = +static int walk_parents_mkdir(const char **path, struct nameidata *nd, + int is_dir) { - .read = stat_read, -}; -#endif + char *slash; + char buf[strlen(*path)+1]; + int err; + while ((slash = strchr(*path, '/')) != NULL) { + int len = slash - *path; + memcpy(buf, *path, len); + buf[len] = '\0'; -/* Devfs daemon file operations */ -static struct file_operations devfsd_fops = -{ - .read = devfsd_read, - .ioctl = devfsd_ioctl, - .release = devfsd_close, -}; + spin_lock(&dcache_lock); + err = link_path_walk(buf, nd); /* releases dcache_lock */ + if (err) + return err; -/* Support functions follow */ + nd->dentry = lookup_create(nd, is_dir); + if (IS_ERR(nd->dentry)) + return PTR_ERR(nd->dentry); -/** - * devfs_get - Get a reference to a devfs entry. - * @de: The devfs entry. - */ + if (!nd->dentry->d_inode) + err = vfs_mkdir(nd->dentry->d_parent->d_inode, + nd->dentry, 0755); + + up(&nd->dentry->d_parent->d_inode->i_sem); -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. - */ + if (err) + return err; -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); - if ( S_ISCHR (de->mode) && de->u.cdev.autogen ) - devfs_dealloc_devnum (de->mode, de->u.cdev.dev); - if ( S_ISBLK (de->mode) && de->u.bdev.autogen ) - devfs_dealloc_devnum (de->mode, de->u.bdev.dev); - 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; + *path += len + 1; + } + return 0; +} - 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. - * - * 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) +/* On success, returns with (*parent_inode)->i_sem taken. */ +static int devfs_decode(devfs_handle_t dir, const char *name, int is_dir, + struct inode **parent_inode, struct dentry **dentry) { - 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 '\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 */ - + struct nameidata nd; + int err; -/** - * _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. - */ + if (dir == NULL) { + if (devfs_vfsmount == NULL && init_devfs_fs() != 0) + BUG(); -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 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; - if (removable) ++dir->u.dir.num_removable; - retval = 0; + dir = devfs_vfsmount->mnt_sb->s_root; } - else retval = -EEXIST; - } - write_unlock (&dir->u.dir.lock); - if (retval) devfs_put (de); - return retval; -} /* End Function _devfs_append_entry */ + memset(&nd, 0, sizeof(nd)); + nd.flags = LOOKUP_PARENT; + nd.mnt = devfs_vfsmount; + nd.dentry = dir; -/** - * _devfs_get_root_entry - Get the root devfs entry. - * - * Returns the root devfs entry on success, else %NULL. - */ + err = walk_parents_mkdir(&name, &nd, is_dir); + if (err) + return err; -static struct devfs_entry *_devfs_get_root_entry (void) -{ - struct devfs_entry *new; - static spinlock_t root_lock = SPIN_LOCK_UNLOCKED; + spin_lock(&dcache_lock); + err = link_path_walk(name, &nd); + if (err) + return err; - /* 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; - new->u.cdev.dev = devfs_alloc_devnum (S_IFCHR |S_IRUSR |S_IWUSR); - new->u.cdev.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; - new->u.cdev.dev = devfs_alloc_devnum (S_IFCHR | S_IRUGO | S_IWUGO); - new->u.cdev.ops = &stat_fops; - _devfs_append_entry (root_entry, new, FALSE, NULL); -#endif - return root_entry; -} /* End Function _devfs_get_root_entry */ + *dentry = lookup_create(&nd, is_dir); + if (IS_ERR(*dentry)) + return PTR_ERR(*dentry); + else { + *parent_inode = (*dentry)->d_parent->d_inode; + return 0; + } +} -/** - * _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; +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) +{ + struct inode *parent_inode; + struct dentry *dentry; + int err; + dev_t devnum; + + if (flags & DEVFS_FL_AUTO_DEVNUM) { + BUG_ON(!S_ISCHR(mode) && !S_ISBLK(mode)); + devnum = devfs_alloc_devnum(mode); + if (!devnum) { + printk ("(%s): exhausted %s device numbers\n", + name, S_ISCHR (mode) ? "char" : "block"); + return NULL; + } + } else + devnum = MKDEV(major, minor); - 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, FALSE, &old) ) - { - devfs_put (de); - if ( !old || !S_ISDIR (old->mode) ) - { - devfs_put (old); - devfs_put (dir); - return NULL; + err = devfs_decode(dir, name, 0, &parent_inode, &dentry); + if (err) + goto err_free_devnum; + + err = vfs_mknod(parent_inode, dentry, mode, devnum); + if (!err) { + /* FIXME? Is DEVFS_FL_CURRENT_OWNER useful? Don't we + already set uid and gid to current->fs{uid,gid}? */ + if (flags & DEVFS_FL_CURRENT_OWNER) { + dentry->d_inode->i_uid = current->uid; + dentry->d_inode->i_gid = current->gid; } - de = old; /* Use the existing directory */ - } - } - if (de == dir->parent) - { - devfs_put (dir); - devfs_put (de); - return NULL; + up(&parent_inode->i_sem); + return dentry; } - devfs_put (dir); - dir = de; - if (name[next_pos] == '/') ++next_pos; - } - return dir; -} /* End Function _devfs_make_parent_for_leaf */ + up(&parent_inode->i_sem); + dput(dentry); -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); + err_free_devnum: + if (flags & DEVFS_FL_AUTO_DEVNUM) + devfs_dealloc_devnum(mode, devnum); + 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; +} +EXPORT_SYMBOL(devfs_register); - 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_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) +void devfs_unregister (devfs_handle_t de) { - unsigned int namelen = strlen (name); + mode_t mode = de->d_inode->i_mode; + if (S_ISDIR(mode)) + vfs_rmdir(de->d_parent->d_inode, de); + else { + if (S_ISCHR(mode) || S_ISBLK(mode)) + devfs_dealloc_devnum(mode, mode); - 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; + vfs_unlink(de->d_parent->d_inode, de); } - ++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 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) -{ - if (current == fs_info->devfsd_task) return (TRUE); - if (current->pgrp == fs_info->devfsd_pgrp) return (TRUE); - 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. - * @atomic: If TRUE, an atomic allocation is required. - * - * 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. - */ +} +EXPORT_SYMBOL(devfs_unregister); -static void devfsd_notify (struct devfs_entry *de,unsigned short type,int wait) +void devfs_put (devfs_handle_t de) { - 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. - */ + dput(de); +} +EXPORT_SYMBOL(devfs_put); -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) +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; - dev_t devnum = 0, dev = MKDEV(major, minor); - struct devfs_entry *de; + struct inode *parent_inode; + struct dentry *dentry; + int err = devfs_decode(dir, name, 0, &parent_inode, &dentry); - if (name == NULL) - { - PRINTK ("(): NULL name pointer\n"); - return NULL; - } - if (ops == NULL) - { - PRINTK ("(%s): NULL ops pointer\n", name); - return NULL; - } - if ( S_ISDIR (mode) ) - { - PRINTK ("(%s): creating directories is not allowed\n", name); - return NULL; - } - if ( S_ISLNK (mode) ) - { - PRINTK ("(%s): creating symlinks is not allowed\n", name); - return NULL; - } - if ( ( S_ISCHR (mode) || S_ISBLK (mode) ) && - (flags & DEVFS_FL_AUTO_DEVNUM) ) - { - devnum = devfs_alloc_devnum (mode); - if (!devnum) { - PRINTK ("(%s): exhausted %s device numbers\n", - name, S_ISCHR (mode) ? "char" : "block"); - return NULL; + if (!err) { + err = vfs_symlink(parent_inode, dentry, link); + up(&parent_inode->i_sem); } - dev = devnum; - } - if ( ( de = _devfs_prepare_leaf (&dir, name, mode) ) == NULL ) - { - PRINTK ("(%s): could not prepare leaf\n", name); - if (devnum) devfs_dealloc_devnum (mode, devnum); - return NULL; - } - if (S_ISCHR (mode)) { - de->u.cdev.dev = dev; - de->u.cdev.autogen = devnum != 0; - de->u.cdev.ops = ops; - } else if (S_ISBLK (mode)) { - de->u.bdev.dev = dev; - de->u.cdev.autogen = devnum != 0; - de->u.bdev.ops = ops; - if (flags & DEVFS_FL_REMOVABLE) de->u.bdev.removable = TRUE; - } else if ( S_ISREG (mode) ) { - de->u.file.ops = ops; - } else { - PRINTK ("(%s): illegal mode: %x\n", 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; - } - err = _devfs_append_entry(dir, de, flags & DEVFS_FL_REMOVABLE, NULL); - if (err) - { - PRINTK ("(%s): could not append to parent, err: %d\n", name, err); - devfs_put (dir); - if (devnum) devfs_dealloc_devnum (mode, devnum); - return NULL; - } - DPRINTK (DEBUG_REGISTER, "(%s): de: %p dir: %p \"%s\" pp: %p\n", - 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 */ - if (S_ISBLK (de->mode) && de->u.bdev.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); - 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: %d\n", - 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: %d\n", - 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 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 = info; - 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: %d\n", name, err); - devfs_put (dir); + dput(dentry); 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. - */ +} +EXPORT_SYMBOL(devfs_mk_symlink); 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 pointer\n"); - return NULL; - } - if ( ( de = _devfs_prepare_leaf (&dir, name, MODE_DIR) ) == NULL ) - { - PRINTK ("(%s): could not prepare leaf\n", name); - return NULL; - } - de->info = info; - if ( ( err = _devfs_append_entry (dir, de, FALSE, &old) ) != 0 ) - { - PRINTK ("(%s): could not append to dir: %p \"%s\", err: %d\n", - 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 */ - + struct inode *parent_inode; + struct dentry *dentry; + int err = devfs_decode(dir, name, 1, &parent_inode, &dentry); + + if (!err) { + err = vfs_mkdir(parent_inode, dentry, 0755); + up(&parent_inode->i_sem); + if (err) + dput(dentry); + } + return err ? NULL : dentry; +} +EXPORT_SYMBOL(devfs_mk_dir); +/* From fs/devfs/base.c: */ void devfs_remove(const char *fmt, ...) { char buf[64]; va_list args; - int n; + int len; + struct nameidata nd; + int err; va_start(args, fmt); - n = vsnprintf(buf, 64, fmt, args); - if (n < 64 && buf[0]) { - devfs_handle_t de = _devfs_find_entry(NULL, buf, 0); - devfs_unregister(de); - devfs_put(de); + len = vsnprintf(buf, sizeof(buf), fmt, args); + if (len >= sizeof(buf)) + return; + + buf[sizeof(buf)-1] = '\0'; + + memset(&nd, 0, sizeof(nd)); + nd.mnt = devfs_vfsmount; + nd.dentry = devfs_vfsmount->mnt_sb->s_root; + + spin_lock(&dcache_lock); + err = link_path_walk(buf, &nd); + if (!err) { + devfs_unregister(nd.dentry); + devfs_put(nd.dentry); } } - - -/** - * 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. - */ - -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_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. - */ - -static struct file_operations *devfs_get_ops (devfs_handle_t de) -{ - struct module *owner; - struct file_operations *ops; - - if (de == NULL) return NULL; - VERIFY_ENTRY (de); - if (S_ISCHR (de->mode)) - ops = de->u.cdev.ops; - else - ops = de->u.file.ops; - if (!ops) - return NULL; - owner = ops->owner; - read_lock (&de->parent->u.dir.lock); /* Prevent module from unloading */ - if ( (de->next == de) || !try_module_get (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 ops; -} /* End Function devfs_get_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.file.size == size) return 0; - de->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_only - returns true if "devfs=only" is a boot option - * - * If "devfs=only" this function will return 1, otherwise 0 is returned. - */ - -int devfs_only (void) -{ - return (boot_options & OPTION_ONLY) ? 1 : 0; -} /* End Function devfs_only */ - - -/** - * 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 != '\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_put); -EXPORT_SYMBOL(devfs_register); -EXPORT_SYMBOL(devfs_unregister); -EXPORT_SYMBOL(devfs_mk_symlink); -EXPORT_SYMBOL(devfs_mk_dir); EXPORT_SYMBOL(devfs_remove); -EXPORT_SYMBOL(devfs_generate_path); - - -/** - * 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; - dev_t dev = de->u.bdev.dev; - extern int warn_no_part; - - if (!S_ISBLK(de->mode)) - return 0; - /* Ugly hack to disable messages about unable to read partition table */ - tmp = warn_no_part; - warn_no_part = 0; - retval = __check_disk_change(dev); - warn_no_part = tmp; - 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.bdev.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 <>. - * - * 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 devfs_only(void) { - 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.bdev.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->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, 0); - return 0; -} /* End Function devfs_notify_change */ - -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 = -{ - .drop_inode = generic_delete_inode, - .clear_inode = devfs_clear_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) +void __init mount_devfs_fs (void) { - 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; - } - 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_fop = &devfs_fops; - inode->i_rdev = NODEV; - if ( S_ISCHR (de->mode) ) - { - inode->i_rdev = to_kdev_t(de->u.cdev.dev); - inode->i_cdev = cdget(de->u.cdev.dev); - } - else if ( S_ISBLK (de->mode) ) - { - inode->i_rdev = to_kdev_t(de->u.bdev.dev); - if (bd_acquire (inode) != 0) - PRINTK ("(%d): no block device from bdget()\n",(int)inode->i_ino); - } - else if ( S_ISFIFO (de->mode) ) inode->i_fop = &def_fifo_fops; - else if ( S_ISREG (de->mode) ) - { - inode->i_size = de->u.file.size; - } - 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; - } - 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: %d\n", - (int) inode->i_mode, (int) inode->i_uid, (int) inode->i_gid); - return inode; -} /* End Function _devfs_get_vfs_inode */ - +#ifdef CONFIG_DEVFS_MOUNT + int err; -/* File operations for device entries follow */ + err = do_mount ("none", "/dev", "devfs", 0, ""); + if (err == 0) printk (KERN_INFO "Mounted devfs on /dev\n"); + else printk ("(): unable to mount devfs, err: %d\n", err); +#endif +} /* End Function mount_devfs_fs */ -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: - scan_dir_for_removable (parent); - 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 */ -static int devfs_open (struct inode *inode, struct file *file) +static int path_len (struct dentry *de, struct dentry *root) { - int err = -ENODEV; - struct devfs_entry *de; - struct file_operations *ops; - - de = get_devfs_entry_from_vfs_inode (inode); - if (de == NULL) return -ENODEV; - if ( S_ISDIR (de->mode) ) return 0; - file->private_data = de->info; - if ( S_ISBLK (inode->i_mode) ) - { - file->f_op = &def_blk_fops; - err = def_blk_fops.open (inode, file); /* Module refcount unchanged */ - } else if (S_ISCHR(inode->i_mode)) { - ops = devfs_get_ops (de); /* Now have module refcount */ - 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 - err = chrdev_open (inode, file); - } else if (S_ISREG(inode->i_mode)) { - ops = devfs_get_ops (de); /* Now have module refcount */ - file->f_op = ops; - if (file->f_op) - { - lock_kernel (); - err = file->f_op->open ? (*file->f_op->open) (inode, file) : 0; - unlock_kernel (); + int len = 0; + while (de != root) { + len += de->d_name.len + 1; /* count the '/' */ + de = de->d_parent; } - } - return err; -} /* 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: %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, 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; - - 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 */ + return len; /* -1 because we omit the leading '/', + +1 because we include trailing '\0' */ +} -struct devfs_lookup_struct +int devfs_generate_path (devfs_handle_t de, char *path, int buflen) { - devfs_handle_t de; - wait_queue_head_t wait_queue; -}; + struct dentry *devfs_root; + int len; + char *path_orig = path; -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->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); - - 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 */ + return -EINVAL; + devfs_root = devfs_vfsmount->mnt_sb->s_root; -/* Inode operations for device entries follow */ + if (de == devfs_root) + return -EINVAL; -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->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); - 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; + spin_lock(&dcache_lock); + len = path_len(de, devfs_root); + if (len > buflen) { + spin_unlock(&dcache_lock); + return -ENAMETOOLONG; } - } - 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->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_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->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, DEVFS_FL_NONE, - symname, &de, NULL); - DPRINTK (DEBUG_DISABLED, "(%s): errcode from : %d\n", - 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: %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, 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->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_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: %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, 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->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_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, - 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: %d\n", - 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_ISCHR (mode)) - de->u.cdev.dev = rdev; - else if (S_ISBLK (mode)) - de->u.bdev.dev = 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: %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, 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 int devfs_fill_super (struct super_block *sb, void *data, int silent) -{ - struct inode *root_inode = NULL; + path += len - 1; + *path = '\0'; - 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; - 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 struct super_block *devfs_get_sb (struct file_system_type *fs_type, - int flags, char *dev_name, void *data) -{ - return get_sb_single (fs_type, flags, data, devfs_fill_super); -} - -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 *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); - - /* 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)) { - info->major = MAJOR(de->u.cdev.dev); - info->minor = MINOR(de->u.cdev.dev); - } else if (S_ISBLK (de->mode)) { - info->major = MAJOR(de->u.bdev.dev); - info->minor = MINOR(de->u.bdev.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; + for (;;) { + path -= de->d_name.len; + memcpy(path, de->d_name.name, de->d_name.len); + de = de->d_parent; + if (de == devfs_root) + break; + *(--path) = '/'; } - 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 *)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->s_fs_info; + + spin_unlock(&dcache_lock); - 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: %u\n", - 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 + BUG_ON(path != path_orig); + return 0; +} -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 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); - 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 devfs_set_file_size (devfs_handle_t de, unsigned long size) { - int err; - - if ( !(boot_options & OPTION_MOUNT) ) return; - err = do_mount ("none", "/dev", "devfs", 0, ""); - 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) + /* FIXME? Locking? Is this right? */ + if (de != NULL && de->d_inode != NULL) + de->d_inode->i_size = size; + return -1; +} +EXPORT_SYMBOL(devfs_set_file_size); diff -puN /dev/null fs/devfs/fs.c --- /dev/null 2002-08-30 16:31:37.000000000 -0700 +++ 25-akpm/fs/devfs/fs.c 2003-02-11 16:04:09.000000000 -0800 @@ -0,0 +1,259 @@ +/* + * Stripped down Device File System (devfs) + * Adapted from ramfs by Adam J. Richter. Ramfs was written by + * Linus Torvalds. The original devfs was written by Richard Gooch. + * + * Copyright (C) 2000 Linus Torvalds. + * 2000 Transmeta Corp. + * 2002 Yggdrasil Computing, Inc. + * + * Usage limits added to ramfs by David Gibson, Linuxcare Australia. + * This file is released under the GPL. + * + * devfs is split into three parts: + * fs.c - a ramfs-based filesystem. It only exports two symbols: + * devfs_vfsmount and init_devfs_fs(). + * api.c - The part of the devfs programming interface that was rewritten. + * util.c - Almost completely unmodified from Richard Gooch's devfs. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +struct vfsmount *devfs_vfsmount; + +static struct super_operations devfs_ops; +static struct address_space_operations devfs_aops; +static struct file_operations devfs_file_operations; +static struct inode_operations devfs_dir_inode_operations; + +static char devfs_helper[150] = "/sbin/devfs_helper"; +module_param_string(devfs_helper, devfs_helper, sizeof(devfs_helper), 0644); + +static struct backing_dev_info devfs_backing_dev_info = { + .ra_pages = 0, /* No readahead */ + .memory_backed = 1, /* Does not contribute to dirty memory */ +}; + +static void devfs_event(const char *event, struct dentry *dentry) +{ + char path[64]; + + if (devfs_generate_path(dentry, path, sizeof(path)) == 0) { + const char *argv[] = { devfs_helper, event, path, NULL }; + static char *envp[] = {"PATH=/bin:/sbin:/usr/bin:/usr/sbin", + "HOME=/", NULL }; + + /* FIXME: Change the call_usermodehelper prototype so + that argv and envp are type const so we won't have + to cast the type of argv. */ + call_usermodehelper(devfs_helper, (char**) argv, envp); + } +} + +static struct inode *devfs_get_inode(struct super_block *sb, int mode, dev_t dev) +{ + struct inode * inode = new_inode(sb); + + if (!inode) + return NULL; + + inode->i_mode = mode; + inode->i_uid = current->fsuid; + inode->i_gid = current->fsgid; + inode->i_blksize = PAGE_CACHE_SIZE; + inode->i_blocks = 0; + inode->i_rdev = NODEV; + inode->i_mapping->a_ops = &devfs_aops; + inode->i_mapping->backing_dev_info = &devfs_backing_dev_info; + inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; + + switch (mode & S_IFMT) { + default: + init_special_inode(inode, mode, dev); + break; + case S_IFREG: + inode->i_fop = &devfs_file_operations; + break; + case S_IFDIR: + inode->i_op = &devfs_dir_inode_operations; + inode->i_fop = &simple_dir_operations; + + /* directory inodes start off with i_nlink == 2 (for "." entry) */ + inode->i_nlink++; + break; + case S_IFLNK: + inode->i_op = &page_symlink_inode_operations; + break; + } + + return inode; +} + +static struct dentry * devfs_lookup(struct inode *inode, struct dentry *dentry) +{ + devfs_event("LOOKUP", dentry); + return simple_lookup(inode, dentry); +} + + +/* + * File creation. Allocate an inode, and we're done.. + */ +/* SMP-safe */ +static int +devfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) +{ + struct inode * inode = devfs_get_inode(dir->i_sb, mode, dev); + int error = -ENOSPC; + + if (inode) { + d_instantiate(dentry, inode); + dget(dentry); /* Extra count - pin the dentry in core */ + error = 0; + devfs_event("REGISTER", dentry); + } + + return error; +} + +static int devfs_mkdir(struct inode * dir, struct dentry * dentry, int mode) +{ + int retval = devfs_mknod(dir, dentry, mode | S_IFDIR, 0); + if (!retval) + dir->i_nlink++; + return retval; +} + +static int devfs_create(struct inode *dir, struct dentry *dentry, int mode) +{ + return devfs_mknod(dir, dentry, mode | S_IFREG, 0); +} + + +static int devfs_symlink(struct inode * dir, struct dentry *dentry, const char * symname) +{ + struct inode *inode; + int error = -ENOSPC; + + inode = devfs_get_inode(dir->i_sb, S_IFLNK|S_IRWXUGO, 0); + if (inode) { + int l = strlen(symname)+1; + error = page_symlink(inode, symname, l); + if (!error) { + d_instantiate(dentry, inode); + dget(dentry); + } else + iput(inode); + } + return error; +} + +static struct address_space_operations devfs_aops = { + .readpage = simple_readpage, + .prepare_write = simple_prepare_write, + .commit_write = simple_commit_write +}; + +static struct file_operations devfs_file_operations = { + .read = generic_file_read, + .write = generic_file_write, + .mmap = generic_file_mmap, + .fsync = simple_sync_file, + .sendfile = generic_file_sendfile, +}; + +static struct inode_operations devfs_dir_inode_operations = { + .create = devfs_create, + .lookup = devfs_lookup, + .link = simple_link, + .unlink = simple_unlink, + .symlink = devfs_symlink, + .mkdir = devfs_mkdir, + .rmdir = simple_rmdir, + .mknod = devfs_mknod, + .rename = simple_rename, +}; + +static struct super_operations devfs_ops = { + .statfs = simple_statfs, + .drop_inode = generic_delete_inode, +}; + +static int devfs_fill_super(struct super_block * sb, void * data, int silent) +{ + struct inode *inode; + struct dentry *root; + + sb->s_blocksize = PAGE_CACHE_SIZE; + sb->s_blocksize_bits = PAGE_CACHE_SHIFT; + sb->s_magic = DEVFS_SUPER_MAGIC; + sb->s_op = &devfs_ops; + inode = devfs_get_inode(sb, S_IFDIR | 0755, 0); + if (!inode) + return -ENOMEM; + + root = d_alloc_root(inode); + if (!root) { + iput(inode); + return -ENOMEM; + } + sb->s_root = root; + return 0; +} + +static struct super_block *devfs_get_sb(struct file_system_type *fs_type, + int flags, char *dev_name, void *data) +{ + return get_sb_single(fs_type, flags, data, devfs_fill_super); +} + +static struct file_system_type devfs_fs_type = { + .name = "devfs", + .get_sb = devfs_get_sb, + .kill_sb = kill_litter_super, +}; + +int __init init_devfs_fs(void) +{ + int err; + + if (devfs_vfsmount != NULL) + return 0; + + err = register_filesystem(&devfs_fs_type); + if (err) + return err; + + devfs_vfsmount = kern_mount(&devfs_fs_type); + + if (IS_ERR(devfs_vfsmount)) { + unregister_filesystem(&devfs_fs_type); + return PTR_ERR(devfs_vfsmount); + } + else + return 0; +} + +static void __exit exit_devfs_fs(void) +{ + unregister_filesystem(&devfs_fs_type); +} + +module_init(init_devfs_fs) +module_exit(exit_devfs_fs) + +MODULE_LICENSE("GPL"); diff -puN fs/namei.c~smalldevfs fs/namei.c --- 25/fs/namei.c~smalldevfs 2003-02-11 16:03:20.000000000 -0800 +++ 25-akpm/fs/namei.c 2003-02-11 16:04:09.000000000 -0800 @@ -1348,7 +1348,7 @@ do_link: } /* SMP-safe */ -static struct dentry *lookup_create(struct nameidata *nd, int is_dir) +struct dentry *lookup_create(struct nameidata *nd, int is_dir) { struct dentry *dentry; diff -puN include/linux/devfs_fs_kernel.h~smalldevfs include/linux/devfs_fs_kernel.h --- 25/include/linux/devfs_fs_kernel.h~smalldevfs 2003-02-11 16:03:20.000000000 -0800 +++ 25-akpm/include/linux/devfs_fs_kernel.h 2003-02-11 16:04:09.000000000 -0800 @@ -21,7 +21,7 @@ #define DEVFS_FL_DEFAULT DEVFS_FL_NONE -typedef struct devfs_entry * devfs_handle_t; +typedef struct dentry * devfs_handle_t; #ifdef CONFIG_DEVFS_FS diff -puN fs/devfs/Makefile~smalldevfs fs/devfs/Makefile --- 25/fs/devfs/Makefile~smalldevfs 2003-02-11 16:03:20.000000000 -0800 +++ 25-akpm/fs/devfs/Makefile 2003-02-11 16:04:09.000000000 -0800 @@ -4,5 +4,5 @@ obj-$(CONFIG_DEVFS_FS) += devfs.o -devfs-objs := base.o util.o +devfs-objs := fs.o base.o util.o _