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#!/opt/bin/perl |
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|
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my ($cachemeta, $cachedata, $sizegb, $orig, $apply) = @ARGV |
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or die "Usage: $0 /cache/meta /cache/data size_gb origdevice\n"; |
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|
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use common::sense; |
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|
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use IO::AIO (); |
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use Coro::AIO (); |
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|
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use Linux::NBD; |
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use Linux::NBD::Server; |
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|
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use POSIX (); |
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|
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use IO::Socket::UNIX; |
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|
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sub BLKSIZE() { 512 } |
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|
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my $blocks = qx<blockdev --getsz \Q$orig> * 512 / BLKSIZE; |
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|
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sysopen my $orig_fh, $orig, IO::AIO::O_RDWR |
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or die "$orig: $!"; |
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|
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sysopen my $meta_fh, "$cachemeta", IO::AIO::O_RDWR | IO::AIO::O_CREAT |
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or die "$cachemeta: $!"; |
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|
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sysopen my $data_fh, "$cachedata", IO::AIO::O_RDWR | IO::AIO::O_CREAT |
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or die "$cachedata: $!"; |
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|
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my $cacheblocks = $sizegb * 1024 * 1024 * 1024 / BLKSIZE; |
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|
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my $meta_data; |
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my $data_data; |
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|
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sub mapin { |
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Coro::AIO::aio_truncate $meta_fh, $blocks * 4; |
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Coro::AIO::aio_truncate $data_fh, $cacheblocks * BLKSIZE; |
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|
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IO::AIO::mmap $meta_data, $blocks * 4 , IO::AIO::PROT_READ | IO::AIO::PROT_WRITE, IO::AIO::MAP_SHARED, $meta_fh, 0; |
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IO::AIO::mmap $data_data, $cacheblocks * BLKSIZE, IO::AIO::PROT_READ | IO::AIO::PROT_WRITE, IO::AIO::MAP_SHARED, $data_fh, 0; |
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} |
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|
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system "chattr", "+C", $cachemeta; |
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system "chattr", "+C", $cachedata; |
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|
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mapin; |
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|
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IO::AIO::mmap my $orig_data, $blocks * BLKSIZE, IO::AIO::PROT_READ | IO::AIO::PROT_WRITE, IO::AIO::MAP_SHARED, $orig_fh, 0; |
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|
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package myserver; |
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|
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use common::sense; |
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|
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sub BLKSIZE() { 512 } |
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|
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our @ISA = Linux::NBD::Server::; |
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|
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my $alloc = 0; |
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#my $need_sync = 0; |
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|
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sub apply { |
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my ($reset) = @_; |
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|
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my ($blk, $idx); |
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|
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my ($blk_nxt, $blk_buf, $blk_total); |
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|
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my $blk_flush = sub { |
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return unless length $blk_buf; |
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|
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$blk_nxt -= (length $blk_buf) / BLKSIZE; |
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$blk_total += length $blk_buf; |
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|
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printf "write back blk %d len %d (total: %.3fGiB)\n", $blk_nxt, length $blk_buf, $blk_total * (1 << 30); |
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Coro::AIO::aio_write $orig_fh, $blk_nxt * BLKSIZE, undef, $blk_buf, 0; |
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#substr $orig_data, $blk_nxt * BLKSIZE, length $blk_buf, $blk_buf; |
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|
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$blk_buf = ""; |
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}; |
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|
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my $nul = (pack "L", 0) x 65536; |
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for (my $base = 0; $base * 4 < length $meta_data; $base += 65536) { |
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if ($nul ne substr $meta_data, $base * 4, 65536 * 4) { |
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for $blk ($base .. $base + 65535) { |
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$idx = unpack "L", substr $meta_data, $blk * 4, 4; |
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|
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if ($idx) { |
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if ($blk_nxt != $blk or (64 * 1024 * 1024) <= length $blk_buf) { |
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$blk_flush->(); |
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} |
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|
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#warn "apply cache blk $idx to orig blk $blk\n"; |
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$blk_nxt = $blk + 1; |
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$blk_buf .= substr $data_data, $idx * BLKSIZE, BLKSIZE; |
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|
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#IO::AIO::aio_write $orig_fh, $blk * BLKSIZE, BLKSIZE, $data_data, $idx * BLKSIZE, sub { }; |
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#substr $orig_data, $blk * BLKSIZE, BLKSIZE, substr $data_data, $idx * BLKSIZE, BLKSIZE; |
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} |
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} |
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} |
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} |
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|
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print "done, syncing...\n"; |
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$blk_flush->(); |
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Coro::AIO::aio_fsync $orig_fh; |
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|
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if ($reset) { |
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print "resetting\n"; |
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|
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undef $meta_data; |
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undef $data_data; |
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|
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Coro::AIO::aio_truncate $meta_fh, 0; |
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Coro::AIO::aio_truncate $data_fh, 0; |
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|
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::mapin; |
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|
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Coro::AIO::aio_fsync $meta_fh; |
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Coro::AIO::aio_fsync $data_fh; |
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} |
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|
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$alloc = 0; |
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} |
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|
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apply $apply eq "r" if $apply; |
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|
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{ |
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my $nul = "\x00" x 65536; |
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for (my $ofs = 0; $ofs < length $meta_data; $ofs += 65536) { |
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if ($nul ne substr $meta_data, $ofs, 65536) { |
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for (unpack "L*", substr $meta_data, $ofs, 65536) { |
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$alloc = $_ if $_ > $alloc; |
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} |
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} |
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} |
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} |
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|
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print "ALLOC is $alloc\n"; |
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|
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sub sync { |
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Coro::AIO::aio_fsync $data_fh; |
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Coro::AIO::aio_fsync $meta_fh; |
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} |
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|
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sub req_read { |
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my ($self, $handle, $ofs, $len) = @_; |
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|
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# warn "get read $ofs,$len\n";#d# |
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|
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my $buf; |
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|
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die if $ofs & (BLKSIZE - 1); |
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die if $len & (BLKSIZE - 1); |
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|
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$ofs /= BLKSIZE; |
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$len /= BLKSIZE; |
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|
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while ($len > 0) { |
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my $idx = unpack "L", substr $meta_data, $ofs * 4, 4; |
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|
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if ($idx) { |
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$buf .= substr $data_data, $idx * BLKSIZE, BLKSIZE; |
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} else { |
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$buf .= substr $orig_data, $ofs * BLKSIZE, BLKSIZE; |
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} |
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|
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++$ofs; |
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--$len; |
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} |
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|
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$self->reply ($handle, 0, $buf); |
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} |
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|
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sub req_write { |
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my ($self, $handle, $ofs, $buf) = @_; |
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|
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# print "write $ofs, ", length $buf, "\n"; |
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|
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die if $ofs & (BLKSIZE - 1); |
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die if (length $buf) & (BLKSIZE - 1); |
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|
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$ofs /= BLKSIZE; |
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|
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my $len = (length $buf) / BLKSIZE; |
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|
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while (length $buf) { |
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my $idx = unpack "L", substr $meta_data, $ofs * 4, 4; |
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|
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if ($idx) { |
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substr $data_data, $idx * BLKSIZE, BLKSIZE, substr $buf, 0, BLKSIZE; |
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} else { |
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if ($alloc + 1 >= $cacheblocks) { |
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print "cache full, applying...\n"; |
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#$need_sync = 1; |
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sync; |
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apply 1; |
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print "cache applied\n"; |
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} |
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|
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$idx = ++$alloc; |
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|
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substr $data_data, $idx * BLKSIZE, BLKSIZE, substr $buf, 0, BLKSIZE; |
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substr $meta_data,$ofs * 4, 4, pack "L", $idx; |
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} |
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|
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++$ofs; |
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substr $buf, 0, BLKSIZE, ""; |
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} |
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|
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$self->reply ($handle, 0); |
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} |
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|
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sub req_flush { |
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my ($self, $handle) = @_; |
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|
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# sync if $need_sync; |
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|
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$self->reply ($handle, 0); |
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|
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#print "flushed.\n"; |
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} |
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|
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package main; |
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|
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#my $listen = new IO::Socket::INET LocalPort => 10809, Listen => 1; |
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unlink "/tmp/nbdsock"; |
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my $listen = new IO::Socket::UNIX Local => "/tmp/nbdsock", Listen => 1; |
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|
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while () { |
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print "waiting for connections...\n"; |
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my $fh = $listen->accept; |
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print "accepted.\n"; |
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|
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syswrite $fh, |
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("NBDMAGIC\x00\x00\x42\x02\x81\x86\x12\x53") |
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. (pack "Q> N x124", $blocks * BLKSIZE, 1 + 4); # has_flags + can_flush |
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|
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my $server = new myserver socket => $fh; |
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|
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$server->run; |
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} |
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|
