added example filesystem which uses Filesys::Statvfs to implement statfs

git-svn-id: svn+ssh://llin/home/dpavlin/private/svn/fuse/perl-llin@30 6e4b0b00-1209-0410-87b2-b275959b5705

diff --git a/examples/loopback-statvfs.pl b/examples/loopback-statvfs.pl
new file mode 100755 (executable)
index 0000000..66f1abf
--- /dev/null
+++ b/examples/loopback-statvfs.pl
@@ -0,0 +1,158 @@
+#!/usr/bin/perl
+
+use strict;
+use blib;
+use Fuse;
+use IO::File;
+use POSIX qw(ENOENT ENOSYS EEXIST EPERM O_RDONLY O_RDWR O_APPEND O_CREAT);
+use Fcntl qw(S_ISBLK S_ISCHR S_ISFIFO SEEK_SET);
+require 'syscall.ph'; # for SYS_mknod and SYS_lchown
+use Filesys::Statvfs;
+
+my $tmp_path = "/tmp/fusetest-" . $ENV{LOGNAME};
+if (! -e $tmp_path) {
+       mkdir($tmp_path) || die "can't create $tmp_path: $!";
+}
+
+sub fixup { return $tmp_path . shift }
+
+sub x_getattr {
+       my ($file) = fixup(shift);
+       my (@list) = lstat($file);
+       return -$! unless @list;
+       return @list;
+}
+
+sub x_getdir {
+       my ($dirname) = fixup(shift);
+       unless(opendir(DIRHANDLE,$dirname)) {
+               return -ENOENT();
+       }
+       my (@files) = readdir(DIRHANDLE);
+       closedir(DIRHANDLE);
+       return (@files, 0);
+}
+
+sub x_open {
+       my ($file) = fixup(shift);
+       my ($mode) = shift;
+       return -$! unless sysopen(FILE,$file,$mode);
+       close(FILE);
+       return 0;
+}
+
+sub x_read {
+       my ($file,$bufsize,$off) = @_;
+       my ($rv) = -ENOSYS();
+       my ($handle) = new IO::File;
+       return -ENOENT() unless -e ($file = fixup($file));
+       my ($fsize) = -s $file;
+       return -ENOSYS() unless open($handle,$file);
+       if(seek($handle,$off,SEEK_SET)) {
+               read($handle,$rv,$bufsize);
+       }
+       return $rv;
+}
+
+sub x_write {
+       my ($file,$buf,$off) = @_;
+       my ($rv);
+       return -ENOENT() unless -e ($file = fixup($file));
+       my ($fsize) = -s $file;
+       return -ENOSYS() unless open(FILE,'+<',$file);
+       if($rv = seek(FILE,$off,SEEK_SET)) {
+               $rv = print(FILE $buf);
+       }
+       $rv = -ENOSYS() unless $rv;
+       close(FILE);
+       return length($buf);
+}
+
+sub err { return (-shift || -$!) }
+
+sub x_readlink { return readlink(fixup(shift)                 ); }
+sub x_unlink { return unlink(fixup(shift)) ? 0 : -$!;          }
+sub x_rmdir { return err(rmdir(fixup(shift))               ); }
+
+sub x_symlink { print "symlink\n"; return symlink(shift,fixup(shift)) ? 0 : -$!; }
+
+sub x_rename {
+       my ($old) = fixup(shift);
+       my ($new) = fixup(shift);
+       my ($err) = rename($old,$new) ? 0 : -ENOENT();
+       return $err;
+}
+sub x_link {
+       my ($from) = shift;
+       my ($to) = shift;
+       print "link $from -> $to\n";
+       my ($err) = link(fixup($from),fixup($to)) ? 0 : -$!;
+       return $err;
+}
+sub x_chown {
+       my ($fn) = fixup(shift);
+       print "nonexistent $fn\n" unless -e $fn;
+       my ($uid,$gid) = @_;
+       # perl's chown() does not chown symlinks, it chowns the symlink's
+       # target.  it fails when the link's target doesn't exist, because
+       # the stat64() syscall fails.
+       # this causes error messages when unpacking symlinks in tarballs.
+       my ($err) = syscall(&SYS_lchown,$fn,$uid,$gid,$fn) ? -$! : 0;
+       return $err;
+}
+sub x_chmod {
+       my ($fn) = fixup(shift);
+       my ($mode) = shift;
+       my ($err) = chmod($mode,$fn) ? 0 : -$!;
+       return $err;
+}
+sub x_truncate { return truncate(fixup(shift),shift) ? 0 : -$! ; }
+sub x_utime { return utime($_[1],$_[2],fixup($_[0])) ? 0:-$!; }
+
+sub x_mkdir { my ($name, $perm) = @_; return 0 if mkdir(fixup($name),$perm); return -$!; }
+sub x_rmdir { return 0 if rmdir fixup(shift); return -$!; }
+
+sub x_mknod {
+       # since this is called for ALL files, not just devices, I'll do some checks
+       # and possibly run the real mknod command.
+       my ($file, $modes, $dev) = @_;
+       $file = fixup($file);
+       $! = 0;
+       syscall(&SYS_mknod,$file,$modes,$dev);
+       return -$!;
+}
+
+# kludge
+sub x_statfs {
+       my $name = fixup(shift);
+       my($bsize, $frsize, $blocks, $bfree, $bavail,
+               $files, $ffree, $favail, $fsid, $basetype, $flag,
+               $namemax, $fstr) = statvfs("/tmp") || return -$!;
+       return ($namemax, $files, $ffree, $blocks, $bavail, $bsize);
+}
+       
+my ($mountpoint) = "";
+$mountpoint = shift(@ARGV) if @ARGV;
+Fuse::main(
+       mountpoint=>$mountpoint,
+       getattr =>"main::x_getattr",
+       readlink=>"main::x_readlink",
+       getdir  =>"main::x_getdir",
+       mknod   =>"main::x_mknod",
+       mkdir   =>"main::x_mkdir",
+       unlink  =>"main::x_unlink",
+       rmdir   =>"main::x_rmdir",
+       symlink =>"main::x_symlink",
+       rename  =>"main::x_rename",
+       link    =>"main::x_link",
+       chmod   =>"main::x_chmod",
+       chown   =>"main::x_chown",
+       truncate=>"main::x_truncate",
+       utime   =>"main::x_utime",
+       open    =>"main::x_open",
+       read    =>"main::x_read",
+       write   =>"main::x_write",
+       statfs  =>"main::x_statfs",
+       threaded=>0,
+       debug => 1,
+);