1 |
mszeredi |
4 |
package Fuse; |
2 |
|
|
|
3 |
|
|
use 5.006; |
4 |
|
|
use strict; |
5 |
|
|
use warnings; |
6 |
|
|
use Errno; |
7 |
|
|
use Carp; |
8 |
|
|
|
9 |
|
|
require Exporter; |
10 |
|
|
require DynaLoader; |
11 |
|
|
use AutoLoader; |
12 |
|
|
use Data::Dumper; |
13 |
|
|
our @ISA = qw(Exporter DynaLoader); |
14 |
|
|
|
15 |
|
|
# Items to export into callers namespace by default. Note: do not export |
16 |
|
|
# names by default without a very good reason. Use EXPORT_OK instead. |
17 |
|
|
# Do not simply export all your public functions/methods/constants. |
18 |
|
|
|
19 |
|
|
# This allows declaration use Fuse ':all'; |
20 |
|
|
# If you do not need this, moving things directly into @EXPORT or @EXPORT_OK |
21 |
|
|
# will save memory. |
22 |
|
|
our %EXPORT_TAGS = ( 'all' => [ qw( |
23 |
|
|
FUSE_DEBUG |
24 |
|
|
) ] ); |
25 |
|
|
|
26 |
|
|
our @EXPORT_OK = ( @{ $EXPORT_TAGS{'all'} } ); |
27 |
|
|
|
28 |
|
|
our @EXPORT = qw( |
29 |
|
|
FUSE_DEBUG |
30 |
|
|
); |
31 |
dpavlin |
7 |
our $VERSION = '0.04'; |
32 |
mszeredi |
4 |
|
33 |
|
|
sub AUTOLOAD { |
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. |
37 |
|
|
|
38 |
|
|
my $constname; |
39 |
|
|
our $AUTOLOAD; |
40 |
|
|
($constname = $AUTOLOAD) =~ s/.*:://; |
41 |
|
|
croak "& not defined" if $constname eq 'constant'; |
42 |
|
|
my $val = constant($constname, @_ ? $_[0] : 0); |
43 |
|
|
if ($! != 0) { |
44 |
|
|
if ($!{EINVAL}) { |
45 |
|
|
$AutoLoader::AUTOLOAD = $AUTOLOAD; |
46 |
|
|
goto &AutoLoader::AUTOLOAD; |
47 |
|
|
} |
48 |
|
|
else { |
49 |
|
|
croak "Your vendor has not defined Fuse macro $constname"; |
50 |
|
|
} |
51 |
|
|
} |
52 |
|
|
{ |
53 |
|
|
no strict 'refs'; |
54 |
|
|
# Fixed between 5.005_53 and 5.005_61 |
55 |
|
|
if ($] >= 5.00561) { |
56 |
|
|
*$AUTOLOAD = sub () { $val }; |
57 |
|
|
} |
58 |
|
|
else { |
59 |
|
|
*$AUTOLOAD = sub { $val }; |
60 |
|
|
} |
61 |
|
|
} |
62 |
|
|
goto &$AUTOLOAD; |
63 |
|
|
} |
64 |
|
|
|
65 |
|
|
bootstrap Fuse $VERSION; |
66 |
|
|
|
67 |
|
|
sub main { |
68 |
|
|
my (@subs) = (0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0); |
69 |
|
|
my (@names) = qw(getattr readlink getdir mknod mkdir unlink rmdir symlink |
70 |
|
|
rename link chmod chown truncate utime open read write statfs); |
71 |
|
|
my ($tmp) = 0; |
72 |
|
|
my (%mapping) = map { $_ => $tmp++ } (@names); |
73 |
|
|
my (%otherargs) = (debug=>0, mountpoint=>""); |
74 |
|
|
while(my $name = shift) { |
75 |
|
|
my ($subref) = shift; |
76 |
|
|
if(exists($otherargs{$name})) { |
77 |
|
|
$otherargs{$name} = $subref; |
78 |
|
|
} else { |
79 |
|
|
croak "There is no function $name" unless exists($mapping{$name}); |
80 |
|
|
croak "Usage: Fuse::main(getattr => &my_getattr, ...)" unless $subref; |
81 |
|
|
croak "Usage: Fuse::main(getattr => &my_getattr, ...)" unless ref($subref); |
82 |
|
|
croak "Usage: Fuse::main(getattr => &my_getattr, ...)" unless ref($subref) eq "CODE"; |
83 |
|
|
$subs[$mapping{$name}] = $subref; |
84 |
|
|
} |
85 |
|
|
} |
86 |
|
|
perl_fuse_main($otherargs{debug},$otherargs{mountpoint},@subs); |
87 |
|
|
} |
88 |
|
|
|
89 |
|
|
# Autoload methods go after =cut, and are processed by the autosplit program. |
90 |
|
|
|
91 |
|
|
1; |
92 |
|
|
__END__ |
93 |
|
|
|
94 |
|
|
=head1 NAME |
95 |
|
|
|
96 |
|
|
Fuse - write filesystems in Perl using FUSE |
97 |
|
|
|
98 |
|
|
=head1 SYNOPSIS |
99 |
|
|
|
100 |
|
|
use Fuse; |
101 |
|
|
my ($mountpoint) = ""; |
102 |
|
|
$mountpoint = shift(@ARGV) if @ARGV; |
103 |
|
|
Fuse::main(mountpoint=>$mountpoint, getattr=>\&my_getattr, getdir=>\&my_getdir, ...); |
104 |
|
|
|
105 |
|
|
=head1 DESCRIPTION |
106 |
|
|
|
107 |
|
|
This lets you implement filesystems in perl, through the FUSE |
108 |
|
|
(Filesystem in USErspace) kernel/lib interface. |
109 |
|
|
|
110 |
|
|
FUSE expects you to implement callbacks for the various functions. |
111 |
|
|
|
112 |
|
|
NOTE: I have only tested the things implemented in example.pl! |
113 |
|
|
It should work, but some things may not. |
114 |
|
|
|
115 |
|
|
In the following definitions, "errno" can be 0 (for a success), |
116 |
|
|
-EINVAL, -ENOENT, -EONFIRE, any integer less than 1 really. |
117 |
|
|
|
118 |
|
|
You can import standard error constants by saying something like |
119 |
|
|
"use POSIX qw(EDOTDOT ENOANO);". |
120 |
|
|
|
121 |
|
|
Every constant you need (file types, open() flags, error values, |
122 |
|
|
etc) can be imported either from POSIX or from Fcntl, often both. |
123 |
|
|
See their respective documentations, for more information. |
124 |
|
|
|
125 |
|
|
=head2 EXPORT |
126 |
|
|
|
127 |
|
|
None by default. |
128 |
|
|
|
129 |
|
|
=head2 EXPORTABLE CONSTANTS |
130 |
|
|
|
131 |
|
|
None. |
132 |
|
|
|
133 |
|
|
=head2 FUNCTIONS |
134 |
|
|
|
135 |
|
|
=head3 Fuse::main |
136 |
|
|
|
137 |
|
|
Takes arguments in the form of hash key=>value pairs. There are |
138 |
|
|
many valid keys. Most of them correspond with names of callback |
139 |
|
|
functions, as described in section 'FUNCTIONS YOUR FILESYSTEM MAY IMPLEMENT'. |
140 |
|
|
A few special keys also exist: |
141 |
|
|
|
142 |
|
|
|
143 |
|
|
debug => boolean |
144 |
|
|
|
145 |
|
|
=over 1 |
146 |
|
|
|
147 |
|
|
This turns FUSE call tracing on and off. Default is 0 (which means off). |
148 |
|
|
|
149 |
|
|
=back |
150 |
|
|
|
151 |
|
|
mountpoint => string |
152 |
|
|
|
153 |
|
|
=over 1 |
154 |
|
|
|
155 |
|
|
The point at which to mount this filesystem. There is no default, you must |
156 |
|
|
specify this. An example would be '/mnt'. |
157 |
|
|
|
158 |
|
|
=back |
159 |
|
|
|
160 |
|
|
unthreaded => boolean |
161 |
|
|
|
162 |
|
|
=over 1 |
163 |
|
|
|
164 |
|
|
This turns FUSE multithreading off and on. NOTE: This perlmodule does not |
165 |
|
|
currently work properly in multithreaded mode! The author is unfortunately |
166 |
|
|
not familiar enough with perl-threads internals, and according to the |
167 |
|
|
documentation available at time of writing (2002-03-08), those internals are |
168 |
|
|
subject to changing anyway. Note that singlethreaded mode also means that |
169 |
|
|
you will not have to worry about reentrancy, though you will have to worry |
170 |
|
|
about recursive lookups (since the kernel holds a global lock on your |
171 |
|
|
filesystem and blocks waiting for one callback to complete before calling |
172 |
|
|
another). |
173 |
|
|
|
174 |
|
|
I hope to add full multithreading functionality later, but for now, I |
175 |
|
|
recommend you leave this option at the default, 1 (which means |
176 |
|
|
unthreaded, no threads will be used and no reentrancy is needed). |
177 |
|
|
|
178 |
|
|
=back |
179 |
|
|
|
180 |
|
|
=head2 FUNCTIONS YOUR FILESYSTEM MAY IMPLEMENT |
181 |
|
|
|
182 |
|
|
=head3 getattr |
183 |
|
|
|
184 |
|
|
Arguments: filename. |
185 |
|
|
Returns a list, very similar to the 'stat' function (see |
186 |
|
|
perlfunc). On error, simply return a single numeric scalar |
187 |
|
|
value (e.g. "return -ENOENT();"). |
188 |
|
|
|
189 |
|
|
FIXME: the "ino" field is currently ignored. I tried setting it to 0 |
190 |
|
|
in an example script, which consistently caused segfaults. |
191 |
|
|
|
192 |
|
|
Fields (the following was stolen from perlfunc(1) with apologies): |
193 |
|
|
|
194 |
|
|
($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size, |
195 |
|
|
$atime,$mtime,$ctime,$blksize,$blocks) |
196 |
|
|
= getattr($filename); |
197 |
|
|
|
198 |
|
|
Here are the meaning of the fields: |
199 |
|
|
|
200 |
|
|
0 dev device number of filesystem |
201 |
|
|
1 ino inode number |
202 |
|
|
2 mode file mode (type and permissions) |
203 |
|
|
3 nlink number of (hard) links to the file |
204 |
|
|
4 uid numeric user ID of file's owner |
205 |
|
|
5 gid numeric group ID of file's owner |
206 |
|
|
6 rdev the device identifier (special files only) |
207 |
|
|
7 size total size of file, in bytes |
208 |
|
|
8 atime last access time in seconds since the epoch |
209 |
|
|
9 mtime last modify time in seconds since the epoch |
210 |
|
|
10 ctime inode change time (NOT creation time!) in seconds |
211 |
|
|
since the epoch |
212 |
|
|
11 blksize preferred block size for file system I/O |
213 |
|
|
12 blocks actual number of blocks allocated |
214 |
|
|
|
215 |
|
|
(The epoch was at 00:00 January 1, 1970 GMT.) |
216 |
|
|
|
217 |
|
|
=head3 readlink |
218 |
|
|
|
219 |
|
|
Arguments: link pathname. |
220 |
|
|
Returns a scalar: either a numeric constant, or a text string. |
221 |
|
|
|
222 |
|
|
This is called when dereferencing symbolic links, to learn the target. |
223 |
|
|
|
224 |
|
|
example rv: return "/proc/self/fd/stdin"; |
225 |
|
|
|
226 |
|
|
=head3 getdir |
227 |
|
|
|
228 |
|
|
Arguments: Containing directory name. |
229 |
|
|
Returns a list: 0 or more text strings (the filenames), followed by a numeric errno (usually 0). |
230 |
|
|
|
231 |
|
|
This is used to obtain directory listings. Its opendir(), readdir(), filldir() and closedir() all in one call. |
232 |
|
|
|
233 |
|
|
example rv: return ('.', 'a', 'b', 0); |
234 |
|
|
|
235 |
|
|
=head3 mknod |
236 |
|
|
|
237 |
|
|
Arguments: Filename, numeric modes, numeric device |
238 |
|
|
Returns an errno (0 upon success, as usual). |
239 |
|
|
|
240 |
|
|
This function is called for all non-directory, non-symlink nodes, |
241 |
|
|
not just devices. |
242 |
|
|
|
243 |
|
|
=head3 mkdir |
244 |
|
|
|
245 |
|
|
Arguments: New directory pathname, numeric modes. |
246 |
|
|
Returns an errno. |
247 |
|
|
|
248 |
|
|
Called to create a directory. |
249 |
|
|
|
250 |
|
|
=head3 unlink |
251 |
|
|
|
252 |
|
|
Arguments: Filename. |
253 |
|
|
Returns an errno. |
254 |
|
|
|
255 |
|
|
Called to remove a file, device, or symlink. |
256 |
|
|
|
257 |
|
|
=head3 rmdir |
258 |
|
|
|
259 |
|
|
Arguments: Pathname. |
260 |
|
|
Returns an errno. |
261 |
|
|
|
262 |
|
|
Called to remove a directory. |
263 |
|
|
|
264 |
|
|
=head3 symlink |
265 |
|
|
|
266 |
|
|
Arguments: Existing filename, symlink name. |
267 |
|
|
Returns an errno. |
268 |
|
|
|
269 |
|
|
Called to create a symbolic link. |
270 |
|
|
|
271 |
|
|
=head3 rename |
272 |
|
|
|
273 |
|
|
Arguments: old filename, new filename. |
274 |
|
|
Returns an errno. |
275 |
|
|
|
276 |
|
|
Called to rename a file, and/or move a file from one directory to another. |
277 |
|
|
|
278 |
|
|
=head3 link |
279 |
|
|
|
280 |
|
|
Arguments: Existing filename, hardlink name. |
281 |
|
|
Returns an errno. |
282 |
|
|
|
283 |
|
|
Called to create hard links. |
284 |
|
|
|
285 |
|
|
=head3 chmod |
286 |
|
|
|
287 |
|
|
Arguments: Pathname, numeric modes. |
288 |
|
|
Returns an errno. |
289 |
|
|
|
290 |
|
|
Called to change permissions on a file/directory/device/symlink. |
291 |
|
|
|
292 |
|
|
=head3 chown |
293 |
|
|
|
294 |
|
|
Arguments: Pathname, numeric uid, numeric gid. |
295 |
|
|
Returns an errno. |
296 |
|
|
|
297 |
|
|
Called to change ownership of a file/directory/device/symlink. |
298 |
|
|
|
299 |
|
|
=head3 truncate |
300 |
|
|
|
301 |
|
|
Arguments: Pathname, numeric offset. |
302 |
|
|
Returns an errno. |
303 |
|
|
|
304 |
|
|
Called to truncate a file, at the given offset. |
305 |
|
|
|
306 |
|
|
=head3 utime |
307 |
|
|
|
308 |
|
|
Arguments: Pathname, numeric actime, numeric modtime. |
309 |
|
|
Returns an errno. |
310 |
|
|
|
311 |
|
|
Called to change access/modification times for a file/directory/device/symlink. |
312 |
|
|
|
313 |
|
|
=head3 open |
314 |
|
|
|
315 |
|
|
Arguments: Pathname, numeric flags (which is an OR-ing of stuff like O_RDONLY |
316 |
|
|
and O_SYNC, constants you can import from POSIX). |
317 |
|
|
Returns an errno. |
318 |
|
|
|
319 |
|
|
No creation, or trunctation flags (O_CREAT, O_EXCL, O_TRUNC) will be passed to open(). |
320 |
|
|
Your open() method needs only check if the operation is permitted for the given flags, and return 0 for success. |
321 |
|
|
|
322 |
|
|
=head3 read |
323 |
|
|
|
324 |
|
|
Arguments: Pathname, numeric requestedsize, numeric offset. |
325 |
|
|
Returns a numeric errno, or a string scalar with up to $requestedsize bytes of data. |
326 |
|
|
|
327 |
|
|
Called in an attempt to fetch a portion of the file. |
328 |
|
|
|
329 |
|
|
=head3 write |
330 |
|
|
|
331 |
|
|
Arguments: Pathname, scalar buffer, numeric offset. You can use length($buffer) to |
332 |
|
|
find the buffersize. |
333 |
|
|
Returns an errno. |
334 |
|
|
|
335 |
|
|
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. |
336 |
|
|
|
337 |
|
|
=head3 statfs |
338 |
|
|
|
339 |
|
|
Arguments: none |
340 |
|
|
Returns any of the following: |
341 |
|
|
|
342 |
|
|
-ENOANO() |
343 |
|
|
|
344 |
|
|
or |
345 |
|
|
|
346 |
|
|
$namelen, $files, $files_free, $blocks, $blocks_avail, $blocksize |
347 |
|
|
|
348 |
|
|
or |
349 |
|
|
|
350 |
|
|
-ENOANO(), $namelen, $files, $files_free, $blocks, $blocks_avail, $blocksize |
351 |
|
|
|
352 |
|
|
=head1 AUTHOR |
353 |
|
|
|
354 |
|
|
Mark Glines, E<lt>mark@glines.orgE<gt> |
355 |
|
|
|
356 |
|
|
=head1 SEE ALSO |
357 |
|
|
|
358 |
|
|
L<perl>, the FUSE documentation. |
359 |
|
|
|
360 |
|
|
=cut |