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 fuse_get_context fuse_version) ],
25 'xattr' => [ qw(XATTR_CREATE XATTR_REPLACE) ]
28 our @EXPORT_OK = ( @{ $EXPORT_TAGS{'all'} } );
31 our $VERSION = '0.11';
34 # This AUTOLOAD is used to 'autoload' constants from the constant()
35 # XS function. If a constant is not found then control is passed
36 # to the AUTOLOAD in AutoLoader.
40 ($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 @names = qw(getattr readlink getdir mknod mkdir unlink rmdir symlink
79 rename link chmod chown truncate utime open read write statfs
80 flush release fsync setxattr getxattr listxattr removexattr opendir readdir releasedir fsyncdir);
81 my @subs = map {undef} @names;
83 my %mapping = map { $_ => $tmp++ } @names;
84 my @otherargs = qw(debug threaded mountpoint mountopts);
85 my %otherargs = (debug=>0, threaded=>0, mountpoint=>"", mountopts=>"");
86 while(my $name = shift) {
88 if(exists($otherargs{$name})) {
89 $otherargs{$name} = $subref;
91 croak "There is no function $name" unless exists($mapping{$name});
92 croak "Usage: Fuse::main(getattr => \"main::my_getattr\", ...)" unless $subref;
93 $subs[$mapping{$name}] = $subref;
96 if($otherargs{threaded}) {
97 # make sure threads are both available, and loaded.
98 if($Config{useithreads}) {
99 if(exists($threads::{VERSION})) {
100 if(exists($threads::shared::{VERSION})) {
103 carp("Thread support requires you to use threads::shared.\nThreads are disabled.\n");
104 $otherargs{threaded} = 0;
107 carp("Thread support requires you to use threads and threads::shared.\nThreads are disabled.\n");
108 $otherargs{threaded} = 0;
111 carp("Thread support was not compiled into this build of perl.\nThreads are disabled.\n");
112 $otherargs{threaded} = 0;
115 perl_fuse_main(@otherargs{@otherargs},@subs);
118 # Autoload methods go after =cut, and are processed by the autosplit program.
125 Fuse - write filesystems in Perl using FUSE
130 my ($mountpoint) = "";
131 $mountpoint = shift(@ARGV) if @ARGV;
132 Fuse::main(mountpoint=>$mountpoint, getattr=>"main::my_getattr", getdir=>"main::my_getdir", ...);
136 This lets you implement filesystems in perl, through the FUSE
137 (Filesystem in USErspace) kernel/lib interface.
139 FUSE expects you to implement callbacks for the various functions.
141 In the following definitions, "errno" can be 0 (for a success),
142 -EINVAL, -ENOENT, -EONFIRE, any integer less than 1 really.
144 You can import standard error constants by saying something like
145 "use POSIX qw(EDOTDOT ENOANO);".
147 Every constant you need (file types, open() flags, error values,
148 etc) can be imported either from POSIX or from Fcntl, often both.
149 See their respective documentations, for more information.
151 =head2 EXPORTED SYMBOLS
155 You can request all exportable symbols by using the tag ":all".
157 You can request the extended attribute symbols by using the tag ":xattr".
158 This will export XATTR_CREATE and XATTR_REPLACE.
164 Takes arguments in the form of hash key=>value pairs. There are
165 many valid keys. Most of them correspond with names of callback
166 functions, as described in section 'FUNCTIONS YOUR FILESYSTEM MAY IMPLEMENT'.
167 A few special keys also exist:
174 This turns FUSE call tracing on and off. Default is 0 (which means off).
182 The point at which to mount this filesystem. There is no default, you must
183 specify this. An example would be '/mnt'.
191 This is a comma seperated list of mount options to pass to the FUSE kernel
194 At present, it allows the specification of the allow_other
195 argument when mounting the new FUSE filesystem. To use this, you will also
196 need 'user_allow_other' in /etc/fuse.conf as per the FUSE documention
198 mountopts => "allow_other" or
207 This turns FUSE multithreading on and off. The default is 0, meaning your FUSE
208 script will run in single-threaded mode. Note that single-threaded mode also
209 means that you will not have to worry about reentrancy, though you will have to
210 worry about recursive lookups. In single-threaded mode, FUSE holds a global
211 lock on your filesystem, and will wait for one callback to return before
212 calling another. This can lead to deadlocks, if your script makes any attempt
213 to access files or directories in the filesystem it is providing. (This
214 includes calling stat() on the mount-point, statfs() calls from the 'df'
215 command, and so on and so forth.) It is worth paying a little attention and
216 being careful about this.
218 Enabling multithreading will cause FUSE to make multiple simultaneous calls
219 into the various callback functions of your perl script. If you enable
220 threaded mode, you can enjoy all the parallel execution and interactive
221 response benefits of threads, and you get to enjoy all the benefits of race
222 conditions and locking bugs, too. Please also ensure any other perl modules
223 you're using are also thread-safe.
225 (If enabled, this option will cause a warning if your perl interpreter was not
226 built with USE_ITHREADS, or if you have failed to use threads or
231 =head3 Fuse::fuse_get_context
233 use Fuse "fuse_get_context";
234 my $caller_uid = fuse_get_context()->{"uid"};
235 my $caller_gid = fuse_get_context()->{"gid"};
236 my $caller_pid = fuse_get_context()->{"pid"};
238 Access context information about the current Fuse operation.
240 =head3 Fuse::fuse_version
242 Indicates the Fuse version in use; more accurately, indicates the version
243 of the Fuse API in use at build time. Returned as a decimal value; i.e.,
244 for Fuse API v2.6, will return "2.6".
246 =head2 FUNCTIONS YOUR FILESYSTEM MAY IMPLEMENT
251 Returns a list, very similar to the 'stat' function (see
252 perlfunc). On error, simply return a single numeric scalar
253 value (e.g. "return -ENOENT();").
255 FIXME: the "ino" field is currently ignored. I tried setting it to 0
256 in an example script, which consistently caused segfaults.
258 Fields (the following was stolen from perlfunc(1) with apologies):
260 ($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size,
261 $atime,$mtime,$ctime,$blksize,$blocks)
262 = getattr($filename);
264 Here are the meaning of the fields:
266 0 dev device number of filesystem
268 2 mode file mode (type and permissions)
269 3 nlink number of (hard) links to the file
270 4 uid numeric user ID of file's owner
271 5 gid numeric group ID of file's owner
272 6 rdev the device identifier (special files only)
273 7 size total size of file, in bytes
274 8 atime last access time in seconds since the epoch
275 9 mtime last modify time in seconds since the epoch
276 10 ctime inode change time (NOT creation time!) in seconds
278 11 blksize preferred block size for file system I/O
279 12 blocks actual number of blocks allocated
281 (The epoch was at 00:00 January 1, 1970 GMT.)
285 Arguments: link pathname.
286 Returns a scalar: either a numeric constant, or a text string.
288 This is called when dereferencing symbolic links, to learn the target.
290 example rv: return "/proc/self/fd/stdin";
294 Arguments: Containing directory name.
295 Returns a list: 0 or more text strings (the filenames), followed by a numeric errno (usually 0).
297 This is used to obtain directory listings. It's opendir(), readdir(), filldir() and closedir() all in one call.
299 example rv: return ('.', 'a', 'b', 0);
303 Arguments: Directory name, offset
304 Returns: filename, offset to the next dirent, numeric errno 0 or -ENOENT()
308 Arguments: Filename, numeric modes, numeric device
309 Returns an errno (0 upon success, as usual).
311 This function is called for all non-directory, non-symlink nodes,
316 Arguments: New directory pathname, numeric modes.
319 Called to create a directory.
326 Called to remove a file, device, or symlink.
333 Called to remove a directory.
337 Arguments: Existing filename, symlink name.
340 Called to create a symbolic link.
344 Arguments: old filename, new filename.
347 Called to rename a file, and/or move a file from one directory to another.
351 Arguments: Existing filename, hardlink name.
354 Called to create hard links.
358 Arguments: Pathname, numeric modes.
361 Called to change permissions on a file/directory/device/symlink.
365 Arguments: Pathname, numeric uid, numeric gid.
368 Called to change ownership of a file/directory/device/symlink.
372 Arguments: Pathname, numeric offset.
375 Called to truncate a file, at the given offset.
379 Arguments: Pathname, numeric actime, numeric modtime.
382 Called to change access/modification times for a file/directory/device/symlink.
386 Arguments: Pathname, numeric flags (which is an OR-ing of stuff like O_RDONLY
387 and O_SYNC, constants you can import from POSIX), fileinfo hash reference.
388 Returns an errno, a file handle (optional).
390 No creation, or trunctation flags (O_CREAT, O_EXCL, O_TRUNC) will be passed to open().
391 The fileinfo hash reference contains flags from the Fuse open call which may be modified by the module. The only fields presently supported are:
392 direct_io (version 2.4 onwards)
393 keep_cache (version 2.4 onwards)
394 nonseekable (version 2.9 onwards)
395 Your open() method needs only check if the operation is permitted for the given flags, and return 0 for success.
396 Optionally a file handle may be returned, which will be passed to subsequent read, write, flush, fsync and release calls.
400 Arguments: Pathname, numeric requested size, numeric offset, file handle
401 Returns a numeric errno, or a string scalar with up to $requestedsize bytes of data.
403 Called in an attempt to fetch a portion of the file.
407 Arguments: Pathname, scalar buffer, numeric offset, file handle. You can use length($buffer) to
409 Returns length($buffer) if successful (number of bytes written).
411 Called in an attempt to write (or overwrite) a portion of the file. Be prepared because $buffer could contain random binary data with NULs and all sorts of other wonderful stuff.
416 Returns any of the following:
422 $namelen, $files, $files_free, $blocks, $blocks_avail, $blocksize
426 -ENOANO(), $namelen, $files, $files_free, $blocks, $blocks_avail, $blocksize
430 Arguments: Pathname, file handle
431 Returns an errno or 0 on success.
433 Called to synchronise any cached data. This is called before the file
434 is closed. It may be called multiple times before a file is closed.
438 Arguments: Pathname, numeric flags passed to open, file handle
439 Returns an errno or 0 on success.
441 Called to indicate that there are no more references to the file. Called once
442 for every file with the same pathname and flags as were passed to open.
446 Arguments: Pathname, numeric flags
447 Returns an errno or 0 on success.
449 Called to synchronise the file's contents. If flags is non-zero,
450 only synchronise the user data. Otherwise synchronise the user and meta data.
454 Arguments: Pathname, extended attribute's name, extended attribute's value, numeric flags (which is an OR-ing of XATTR_CREATE and XATTR_REPLACE
455 Returns an errno or 0 on success.
457 Called to set the value of the named extended attribute.
459 If you wish to reject setting of a particular form of extended attribute name
460 (e.g.: regexps matching user\..* or security\..*), then return - EOPNOTSUPP.
462 If flags is set to XATTR_CREATE and the extended attribute already exists,
463 this should fail with - EEXIST. If flags is set to XATTR_REPLACE
464 and the extended attribute doesn't exist, this should fail with - ENOATTR.
466 XATTR_CREATE and XATTR_REPLACE are provided by this module, but not exported
467 by default. To import them:
477 Arguments: Pathname, extended attribute's name
478 Returns an errno, 0 if there was no value, or the extended attribute's value.
480 Called to get the value of the named extended attribute.
485 Returns a list: 0 or more text strings (the extended attribute names), followed by a numeric errno (usually 0).
489 Arguments: Pathname, extended attribute's name
490 Returns an errno or 0 on success.
494 Mark Glines, E<lt>mark@glines.orgE<gt>
498 L<perl>, the FUSE documentation.