14 our @ISA = qw(Exporter DynaLoader);
16 # Items to export into callers namespace by default. Note: do not export
17 # names by default without a very good reason. Use EXPORT_OK instead.
18 # Do not simply export all your public functions/methods/constants.
20 # This allows declaration use Fuse ':all';
21 # If you do not need this, moving things directly into @EXPORT or @EXPORT_OK
24 'all' => [ qw(XATTR_CREATE XATTR_REPLACE) ],
25 'xattr' => [ qw(XATTR_CREATE XATTR_REPLACE) ]
28 our @EXPORT_OK = ( @{ $EXPORT_TAGS{'all'} } );
31 our $VERSION = '0.07_1';
34 # This AUTOLOAD is used to 'autoload' constants from the constant()
35 # XS function. If a constant is not found then control is passed
36 # to the AUTOLOAD in AutoLoader.
40 ($constname = $AUTOLOAD) =~ s/.*:://;
41 croak "& not defined" if $constname eq 'constant';
42 my $val = constant($constname, @_ ? $_[0] : 0);
45 $AutoLoader::AUTOLOAD = $AUTOLOAD;
46 goto &AutoLoader::AUTOLOAD;
49 croak "Your vendor has not defined Fuse macro $constname";
54 # Fixed between 5.005_53 and 5.005_61
56 *$AUTOLOAD = sub () { $val };
59 *$AUTOLOAD = sub { $val };
75 bootstrap Fuse $VERSION;
78 my (@subs) = (undef,undef,undef,undef,undef,undef,undef,undef,undef,undef,
79 undef,undef,undef,undef,undef,undef,undef,undef,undef,undef,
80 undef,undef,undef,undef,undef);
81 my (@names) = qw(getattr readlink getdir mknod mkdir unlink rmdir symlink
82 rename link chmod chown truncate utime open read write statfs
83 flush release fsync setxattr getxattr listxattr removexattr);
84 my (@validOpts) = qw(allow_other);
86 my (%mapping) = map { $_ => $tmp++ } (@names);
87 my (%optmap) = map { $_ => 1 } (@validOpts);
88 my (%otherargs) = (debug=>0, threaded=>0, mountpoint=>"", mountopts=>"");
89 while(my $name = shift) {
91 if(exists($otherargs{$name})) {
92 $otherargs{$name} = $subref;
94 croak "There is no function $name" unless exists($mapping{$name});
95 croak "Usage: Fuse::main(getattr => \"main::my_getattr\", ...)" unless $subref;
96 $subs[$mapping{$name}] = $subref;
99 foreach my $opt ( split(/,/,$otherargs{mountopts}) ) {
100 if ( ! exists($optmap{$opt}) ) {
101 croak "Use of an invalid mountopt argument";
104 if($otherargs{threaded}) {
105 # make sure threads are both available, and loaded.
106 if($Config{useithreads}) {
107 if(exists($threads::{VERSION})) {
108 if(exists($threads::shared::{VERSION})) {
111 carp("Thread support requires you to use threads::shared.\nThreads are disabled.\n");
112 $otherargs{threaded} = 0;
115 carp("Thread support requires you to use threads and threads::shared.\nThreads are disabled.\n");
116 $otherargs{threaded} = 0;
119 carp("Thread support was not compiled into this build of perl.\nThreads are disabled.\n");
120 $otherargs{threaded} = 0;
123 perl_fuse_main($otherargs{debug},$otherargs{threaded},$otherargs{mountpoint},$otherargs{mountopts},@subs);
126 # Autoload methods go after =cut, and are processed by the autosplit program.
133 Fuse - write filesystems in Perl using FUSE
138 my ($mountpoint) = "";
139 $mountpoint = shift(@ARGV) if @ARGV;
140 Fuse::main(mountpoint=>$mountpoint, getattr=>"main::my_getattr", getdir=>"main::my_getdir", ...);
144 This lets you implement filesystems in perl, through the FUSE
145 (Filesystem in USErspace) kernel/lib interface.
147 FUSE expects you to implement callbacks for the various functions.
149 In the following definitions, "errno" can be 0 (for a success),
150 -EINVAL, -ENOENT, -EONFIRE, any integer less than 1 really.
152 You can import standard error constants by saying something like
153 "use POSIX qw(EDOTDOT ENOANO);".
155 Every constant you need (file types, open() flags, error values,
156 etc) can be imported either from POSIX or from Fcntl, often both.
157 See their respective documentations, for more information.
159 =head2 EXPORTED SYMBOLS
163 You can request all exportable symbols by using the tag ":all".
165 You can request the extended attribute symbols by using the tag ":xattr".
166 This will export XATTR_CREATE and XATTR_REPLACE.
172 Takes arguments in the form of hash key=>value pairs. There are
173 many valid keys. Most of them correspond with names of callback
174 functions, as described in section 'FUNCTIONS YOUR FILESYSTEM MAY IMPLEMENT'.
175 A few special keys also exist:
182 This turns FUSE call tracing on and off. Default is 0 (which means off).
190 The point at which to mount this filesystem. There is no default, you must
191 specify this. An example would be '/mnt'.
199 This is a comma seperated list of mount options to pass to the FUSE kernel
202 At present, it allows the specification of the allow_other
203 argument when mounting the new FUSE filesystem. To use this, you will also
204 need 'user_allow_other' in /etc/fuse.conf as per the FUSE documention
206 mountopts => "allow_other" or
215 This turns FUSE multithreading on and off. The default is 0, meaning your FUSE
216 script will run in single-threaded mode. Note that single-threaded mode also
217 means that you will not have to worry about reentrancy, though you will have to
218 worry about recursive lookups. In single-threaded mode, FUSE holds a global
219 lock on your filesystem, and will wait for one callback to return before
220 calling another. This can lead to deadlocks, if your script makes any attempt
221 to access files or directories in the filesystem it is providing. (This
222 includes calling stat() on the mount-point, statfs() calls from the 'df'
223 command, and so on and so forth.) It is worth paying a little attention and
224 being careful about this.
226 Enabling multithreading will cause FUSE to make multiple simultaneous calls
227 into the various callback functions of your perl script. If you enable
228 threaded mode, you can enjoy all the parallel execution and interactive
229 response benefits of threads, and you get to enjoy all the benefits of race
230 conditions and locking bugs, too. Please also ensure any other perl modules
231 you're using are also thread-safe.
233 (If enabled, this option will cause a warning if your perl interpreter was not
234 built with USE_ITHREADS, or if you have failed to use threads or
239 =head2 FUNCTIONS YOUR FILESYSTEM MAY IMPLEMENT
244 Returns a list, very similar to the 'stat' function (see
245 perlfunc). On error, simply return a single numeric scalar
246 value (e.g. "return -ENOENT();").
248 FIXME: the "ino" field is currently ignored. I tried setting it to 0
249 in an example script, which consistently caused segfaults.
251 Fields (the following was stolen from perlfunc(1) with apologies):
253 ($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size,
254 $atime,$mtime,$ctime,$blksize,$blocks)
255 = getattr($filename);
257 Here are the meaning of the fields:
259 0 dev device number of filesystem
261 2 mode file mode (type and permissions)
262 3 nlink number of (hard) links to the file
263 4 uid numeric user ID of file's owner
264 5 gid numeric group ID of file's owner
265 6 rdev the device identifier (special files only)
266 7 size total size of file, in bytes
267 8 atime last access time in seconds since the epoch
268 9 mtime last modify time in seconds since the epoch
269 10 ctime inode change time (NOT creation time!) in seconds
271 11 blksize preferred block size for file system I/O
272 12 blocks actual number of blocks allocated
274 (The epoch was at 00:00 January 1, 1970 GMT.)
278 Arguments: link pathname.
279 Returns a scalar: either a numeric constant, or a text string.
281 This is called when dereferencing symbolic links, to learn the target.
283 example rv: return "/proc/self/fd/stdin";
287 Arguments: Containing directory name.
288 Returns a list: 0 or more text strings (the filenames), followed by a numeric errno (usually 0).
290 This is used to obtain directory listings. Its opendir(), readdir(), filldir() and closedir() all in one call.
292 example rv: return ('.', 'a', 'b', 0);
296 Arguments: Filename, numeric modes, numeric device
297 Returns an errno (0 upon success, as usual).
299 This function is called for all non-directory, non-symlink nodes,
304 Arguments: New directory pathname, numeric modes.
307 Called to create a directory.
314 Called to remove a file, device, or symlink.
321 Called to remove a directory.
325 Arguments: Existing filename, symlink name.
328 Called to create a symbolic link.
332 Arguments: old filename, new filename.
335 Called to rename a file, and/or move a file from one directory to another.
339 Arguments: Existing filename, hardlink name.
342 Called to create hard links.
346 Arguments: Pathname, numeric modes.
349 Called to change permissions on a file/directory/device/symlink.
353 Arguments: Pathname, numeric uid, numeric gid.
356 Called to change ownership of a file/directory/device/symlink.
360 Arguments: Pathname, numeric offset.
363 Called to truncate a file, at the given offset.
367 Arguments: Pathname, numeric actime, numeric modtime.
370 Called to change access/modification times for a file/directory/device/symlink.
374 Arguments: Pathname, numeric flags (which is an OR-ing of stuff like O_RDONLY
375 and O_SYNC, constants you can import from POSIX).
378 No creation, or trunctation flags (O_CREAT, O_EXCL, O_TRUNC) will be passed to open().
379 Your open() method needs only check if the operation is permitted for the given flags, and return 0 for success.
383 Arguments: Pathname, numeric requestedsize, numeric offset.
384 Returns a numeric errno, or a string scalar with up to $requestedsize bytes of data.
386 Called in an attempt to fetch a portion of the file.
390 Arguments: Pathname, scalar buffer, numeric offset. You can use length($buffer) to
394 Called in an attempt to write (or overwrite) a portion of the file. Be prepared because $buffer could contain random binary data with NULLs and all sorts of other wonderful stuff.
399 Returns any of the following:
405 $namelen, $files, $files_free, $blocks, $blocks_avail, $blocksize
409 -ENOANO(), $namelen, $files, $files_free, $blocks, $blocks_avail, $blocksize
414 Returns an errno or 0 on success.
416 Called to synchronise any cached data. This is called before the file
417 is closed. It may be called multiple times before a file is closed.
421 Arguments: Pathname, numeric flags passed to open
422 Returns an errno or 0 on success.
424 Called to indicate that there are no more references to the file. Called once
425 for every file with the same pathname and flags as were passed to open.
429 Arguments: Pathname, numeric flags
430 Returns an errno or 0 on success.
432 Called to synchronise the file's contents. If flags is non-zero,
433 only synchronise the user data. Otherwise synchronise the user and meta data.
437 Arguments: Pathname, extended attribute's name, extended attribute's value, numeric flags (which is an OR-ing of XATTR_CREATE and XATTR_REPLACE
438 Returns an errno or 0 on success.
440 Called to set the value of the named extended attribute.
442 If you wish to reject setting of a particular form of extended attribute name
443 (e.g.: regexps matching user\..* or security\..*), then return - EOPNOTSUPP.
445 If flags is set to XATTR_CREATE and the extended attribute already exists,
446 this should fail with - EEXIST. If flags is set to XATTR_REPLACE
447 and the extended attribute doesn't exist, this should fail with - ENOATTR.
449 XATTR_CREATE and XATTR_REPLACE are provided by this module, but not exported
450 by default. To import them:
460 Arguments: Pathname, extended attribute's name
461 Returns an errno, 0 if there was no value, or the extended attribute's value.
463 Called to get the value of the named extended attribute.
468 Returns a list: 0 or more text strings (the extended attribute names), followed by a numeric errno (usually 0).
472 Arguments: Pathname, extended attribute's name
473 Returns an errno or 0 on success.
477 Mark Glines, E<lt>mark@glines.orgE<gt>
481 L<perl>, the FUSE documentation.