Merge branch 'dev-michel' of gitlab.bytemark.co.uk:open-source/flexnbd-c into dev-michel

Calculate and return bytes_left in migration statistics

.gitignore

@@ -0,0 +1,9 @@
+**/*.o
+**/*~
+flexnbd
+build/
+pkg/
+**/*.orig
+**/.*.swp
+cscope.out
+valgrind.out

.gitlab-ci.yml

@@ -0,0 +1,27 @@
+stages:
+  - package
+  - publish
+ 
+package:jessie: &package
+  stage: package
+  image: $CI_REGISTRY/docker-images/layers:$DISTRO-deb
+  variables:
+    DISTRO: jessie
+  script:
+    - package
+  artifacts:
+    paths:
+      - pkg/
+
+package:stretch:
+  <<: *package
+  variables:
+    DISTRO: stretch
+
+publish:
+  stage: publish
+  tags: 
+    - shell
+  script:
+    - publish
+

.hgignore

@@ -1,9 +0,0 @@
-.o$
-~$
-^flexnbd$
-^build/
-^pkg/
-\.orig$
-.*\.swp$
-cscope.out$
-valgrind.out$

Makefile

@@ -1,10 +1,116 @@
 #!/usr/bin/make -f
 
-all:
-	rake build
+VPATH=src:tests/unit
+DESTDIR?=/
+PREFIX?=/usr/local/bin
+INSTALLDIR=$(DESTDIR)/$(PREFIX)
+	
+ifdef DEBUG
+	CFLAGS_EXTRA=-g -DDEBUG
+	LDFLAGS_EXTRA=-g
+else
+	CFLAGS_EXTRA=-O2
+endif
 
-all-debug:
-	DEBUG=1 rake build
+CFLAGS_EXTRA  += -fPIC --std=gnu99
+LDFLAGS_EXTRA += -Wl,--relax,--gc-sections -L$(LIB) -Wl,-rpath-link,$(LIB)
+
+# The -Wunreachable-code warning is only implemented in clang, but it
+# doesn't break anything for gcc to see it.
+WARNINGS=-Wall \
+				 -Wextra \
+				 -Werror-implicit-function-declaration \
+				 -Wstrict-prototypes \
+				 -Wno-missing-field-initializers \
+				 -Wunreachable-code
+
+CCFLAGS=-D_GNU_SOURCE=1 $(WARNINGS) $(CFLAGS_EXTRA) $(CFLAGS)
+LLDFLAGS=-lm -lrt -lev $(LDFLAGS_EXTRA) $(LDFLAGS)
+
+CC?=gcc
+
+LIBS=-lpthread
+INC=-I/usr/include/libev -Isrc/common -Isrc/server -Isrc/proxy
+COMPILE=$(CC) -MMD $(INC) -c $(CCFLAGS)
+LINK=$(CC) $(LLDFLAGS) -Isrc $(LIBS)
+
+LIB=build/
+
+COMMON_SRC  := $(wildcard src/common/*.c)
+SERVER_SRC := $(wildcard src/server/*.c)
+PROXY_SRC   := $(wildcard src/proxy/*.c)
+
+COMMON_OBJ  := $(COMMON_SRC:src/%.c=build/%.o)
+SERVER_OBJ := $(SERVER_SRC:src/%.c=build/%.o)
+PROXY_OBJ   := $(PROXY_SRC:src/%.c=build/%.o)
+
+SRCS := $(COMMON_SRC) $(SERVER_SRC) $(PROXY_SRC)
+OBJS := $(COMMON_OBJ) $(SERVER_OBJ) $(PROXY_OBJ)
+
+
+all: build doc
+
+build: server proxy
+
+build/%.o: %.c
+	mkdir -p $(dir $@)
+	$(COMPILE) $< -o $@
+
+objs: $(OBJS)
+
+build/flexnbd: $(COMMON_OBJ) $(SERVER_OBJ) build/main.o
+	$(LINK) $^ -o $@
+
+build/flexnbd-proxy: $(COMMON_OBJ) $(PROXY_OBJ) build/proxy-main.o
+	$(LINK) $^ -o $@
+
+server: build/flexnbd
+
+proxy: build/flexnbd-proxy
+
+CHECK_SRC := $(wildcard tests/unit/*.c)
+CHECK_OBJ := $(CHECK_SRC:tests/unit/%.c=build/%.o)
+# Why can't we reuse the build/%.o rule above? Not sure.
+
+CHECK_BINS := $(CHECK_SRC:tests/unit/%.c=build/%)
+
+build/check_%: build/check_%.o
+	$(LINK) $^ -o $@ $(COMMON_OBJ) $(SERVER_OBJ) -lcheck -lsubunit
+
+check_objs: $(CHECK_OBJ)
+
+check_bins: $(CHECK_BINS)
+
+check: $(OBJS) $(CHECK_BINS)
+	r=true ; for bin in $(CHECK_BINS); do $$bin || r=false; done ; $$r
+
+acceptance: build
+	cd tests/acceptance && RUBYOPT='-I.' ruby nbd_scenarios -v
+
+test: check acceptance
+
+build/flexnbd.1: README.txt
+	txt2man -t flexnbd -s 1 $< > $@
+
+build/flexnbd-proxy.1: README.proxy.txt
+	txt2man -t flexnbd-proxy -s 1 $< > $@
+
+# If we don't pipe to file, gzip clobbers the original, causing make
+# to rebuild each time
+%.1.gz: %.1
+	gzip -c -f $< > $@
+
+doc: build/flexnbd.1.gz build/flexnbd-proxy.1.gz
+
+install:
+	mkdir -p $(INSTALLDIR)
+	cp build/flexnbd build/flexnbd-proxy $(INSTALLDIR)
 
 clean:
-	rake clean
+	rm -rf build/*
+
+
+.PHONY: clean objs check_objs all server proxy check_bins check doc build test acceptance
+
+# Include extra dependencies at the end, NOT before 'all'
+-include $(wildcard build/*.d)

README.proxy.txt

@@ -1,19 +1,14 @@
-FLEXNBD-PROXY(1)
-================
-:doctype: manpage
-
 NAME
-----
 
-flexnbd-proxy - A simple NBD proxy
+ flexnbd-proxy - A simple NBD proxy
 
 SYNOPSIS
---------
 
-*flexnbd-proxy* ['OPTIONS']
+  flexnbd-proxy --addr ADDR [--port PORT] --conn-addr ADDR
+    --conn-port PORT [--bind ADDR] [--cache[=CACHE_BYTES]] 
+    [--help] [--verbose] [--quiet]
 
 DESCRIPTION
------------
 
 flexnbd-proxy is a simple NBD proxy server that implements resilient
 connection logic for the client. It connects to an upstream NBD server
@@ -25,10 +20,6 @@ of view of the client) reconnects and retransmits the request, before
 returning the response to the client.
 
 USAGE
------
-
-  $ flexnbd-proxy --addr <ADDR> [ --port <PORT> ]
-    --conn-addr <ADDR> --conn-port <PORT> [--bind <ADDR>] [option]*
 
 Proxy requests from an NBD client to an NBD server, resiliently. Only one
 client can be connected at a time, and ACLs cannot be applied to the client, as they 
@@ -57,71 +48,73 @@ Only one request may be in-flight at a time under the current architecture; that
 doesn't seem to slow things down much relative to alternative options, but may
 be changed in the future if it becomes an issue.
 
-Options
-~~~~~~~
+OPTIONS
 
-*--addr, -l ADDR*:
+  --addr, -l ADDR  
     The address to listen on. If this begins with a '/', it is assumed to be
     a UNIX domain socket to create. Otherwise, it should be an IPv4 or IPv6
     address.
-*--port, -p PORT*:
+
+  --port, -p PORT  
     The port to listen on, if --addr is not a UNIX socket. 
 
-*--conn-addr, -C ADDR*:
+  --conn-addr, -C ADDR  
     The address of the NBD server to connect to. Required.
 
-*--conn-port, -P PORT*:
+  --conn-port, -P PORT  
     The port of the NBD server to connect to. Required.
 
-*--help, -h* :
+  --cache, -c=CACHE_BYTES  
+    If given, the size in bytes of read cache to use. CACHE_BYTES
+    defaults to 4096.
+
+  --help, -h  
     Show command or global help.
 
-*--verbose, -v* :
+  --verbose, -v  
     Output all available log information to STDERR.
 
-*--quiet, -q* :
+  --quiet, -q  
     Output as little log information as possible to STDERR.
 
-
 LOGGING
--------
-Log output is sent to STDERR.  If --quiet is set, no output will be seen
-unless the program termintes abnormally.  If neither --quiet nor
+
+Log output is sent to STDERR. If --quiet is set, no output will be
+seen unless the program termintes abnormally. If neither --quiet nor
 --verbose are set, no output will be seen unless something goes wrong
-with a specific request.  If --verbose is given, every available log
-message will be seen (which, for a debug build, is many).  It is not an
-error to set both --verbose and --quiet.  The last one wins.
+with a specific request. If --verbose is given, every available log
+message will be seen (which, for a debug build, is many). It is not an
+error to set both --verbose and --quiet. The last one wins.
 
 The log line format is:
 
-  <TIMESTAMP>:<LEVEL>:<PID> <THREAD> <SOURCEFILE>:<SOURCELINE>: <MSG>
+    <TIMESTAMP>:<LEVEL>:<PID> <THREAD> <SOURCEFILE>:<SOURCELINE>: <MSG>
 
-*TIMESTAMP*:
+<TIMESTAMP>  
   Time the log entry was made. This is expressed in terms of monotonic ms
 
-*LEVEL*:
+<LEVEL>  
   This will be one of 'D', 'I', 'W', 'E', 'F' in increasing order of
-severity.  If flexnbd is started with the --quiet flag, only 'F' will be
-seen.  If it is started with the --verbose flag, any from 'I' upwards
-will be seen.  Only if you have a debug build and start it with
---verbose will you see 'D' entries.
+  severity. If flexnbd is started with the --quiet flag, only 'F' will
+  be seen. If it is started with the --verbose flag, any from 'I'
+  upwards will be seen. Only if you have a debug build and start it
+  with --verbose will you see 'D' entries.
 
-*PID*:
+<PID>  
   This is the process ID.
 
-*THREAD*:
-  flexnbd-proxy is currently single-threaded, so this should be the same
-for all lines. That may not be the case in the future.
+<THREAD>  
+  flexnbd-proxy is currently single-threaded, so this should be the
+  same for all lines. That may not be the case in the future.
 
-*SOURCEFILE:SOURCELINE*:
+<SOURCEFILE:SOURCELINE>  
   Identifies where in the source code this log line can be found.
 
-*MSG*:
+<MSG>  
   A short message describing what's happening, how it's being done, or
-if you're very lucky *why* it's going on.
+  if you're very lucky why it's going on.
 
-Proxying
-~~~~~~~~
+EXAMPLES
 
 The main point of the proxy mode is to allow clients that would otherwise break
 when the NBD server goes away (during a migration, for instance) to see a
@@ -154,31 +147,60 @@ The proxy notices and reconnects, fulfiling any request it has in its buffer.
 The data in myfile has been moved between physical servers without the nbd
 client process having to be disturbed at all.
 
-BUGS
-----
+READ CACHE
 
-Should be reported to nick@bytemark.co.uk.
+If the --cache option is given at the command line, either without an
+argument or with an argument greater than 0, flexnbd-proxy will use a
+read-ahead cache. The cache as currently implemented doubles each read
+request size, up to a maximum of 2xCACHE_BYTES, and retains the latter
+half in a buffer. If the next read request from the client exactly
+matches the region held in the buffer, flexnbd-proxy responds from the
+cache without making a request to the server.
+
+This pattern is designed to match sequential reads, such as those
+performed by a booting virtual machine.
+
+Note: If specifying a cache size, you must use this form:
+
+  nbd-client$ flexnbd-proxy --cache=XXXX
+
+That is, the '=' is required. This is a limitation of getopt-long.
+
+If no cache size is given, a size of 4096 bytes is assumed. Caching can
+be explicitly disabled by setting a size of 0.
+
+BUGS
+
+Should be reported via GitHub.
+
+* https://github.com/BytemarkHosting/flexnbd-c/issues
 
 Current issues include:
 
-* Only old-style NBD negotiation is supported
-* Only one request may be in-flight at a time
-* All I/O is blocking, and signals terminate the process immediately
-* UNIX socket support is limited to the listen address
-* FLUSH and TRIM commands, and the FUA flag, are not supported
-* DISCONNECT requests do not get passed through to the NBD server
-* No active timeout-retry of requests - we trust the kernel's idea of failure
+* only old-style NBD negotiation is supported;
+* only one request may be in-flight at a time;
+* all I/O is blocking, and signals terminate the process immediately;
+* UNIX socket support is limited to the listen address;
+* FLUSH and TRIM commands, and the FUA flag, are not supported;
+* DISCONNECT requests do not get passed through to the NBD server;
+* no active timeout-retry of requests - we trust the kernel's idea of
+  failure.
 
 AUTHOR
-------
-Written by Alex Young <alex@bytemark.co.uk>.
+
+Originally written by Alex Young <alex@blackkettle.org>.
 Original concept and core code by Matthew Bloch <matthew@bytemark.co.uk>.
-Proxy mode written by Nick Thomas <nick@bytemark.co.uk>
+Proxy mode written by Nick Thomas <me@ur.gs>.
 
-COPYING
--------
+The full commit history is available on GitHub.
 
-Copyright (c) 2012 Bytemark Hosting Ltd. Free use of this software is
-granted under the terms of the GNU General Public License version 3 or
-later.
+SEE ALSO
+
+flexnbd(1), nbd-client(8), xnbd-server(8), xnbd-client(8)
+
+COPYRIGHT
+
+Copyright (c) 2012-2016 Bytemark Hosting Ltd. Free use of this
+software is granted under the terms of the GNU General Public License
+version 3 or later.
 

README.txt

@@ -1,17 +1,36 @@
-FLEXNBD(1)
-==========
-:doctype: manpage
-
 NAME
-----
+
 flexnbd - A fast NBD server
 
 SYNOPSIS
---------
-*flexnbd* 'COMMAND' ['OPTIONS']
+
+  flexnbd MODE [ ARGS ]
+
+  flexnbd serve --addr ADDR --port PORT --file FILE [--sock SOCK]
+    [--default-deny] [--killswitch] [global_option]* [acl_entry]*
+
+  flexnbd listen --addr ADDR --port PORT --file FILE [--sock SOCK]
+    [--default-deny] [global_option]* [acl_entry]*
+
+  flexnbd mirror --addr ADDR --port PORT --sock SOCK [--unlink]
+    [--bind BIND_ADDR] [global_option]*
+
+  flexnbd acl --sock SOCK [acl_entry]+ [global_option]*
+
+  flexnbd break --sock SOCK [global_option]*
+
+  flexnbd status --sock SOCK [global_option]*
+
+  flexnbd read --addr ADDR --port PORT --from OFFSET --size SIZE
+    [--bind BIND_ADDR] [global_option]*
+
+  flexnbd write --addr ADDR --port PORT --from OFFSET --size SIZE
+    [--bind BIND_ADDR] [global_option]*
+
+  flexnbd help [mode] [global_option]*
 
 DESCRIPTION
------------
+
 Flexnbd is a fast NBD server which supports live migration. Live
 migration is performed by writing the data to a new server. A failed
 migration will be invisible to any connected clients.
@@ -19,298 +38,290 @@ migration will be invisible to any connected clients.
 Flexnbd tries quite hard to preserve sparsity of files it is serving,
 even across migrations.
 
-COMMANDS
---------
+SERVE MODE
+
+Serve a file.
 
-serve
-~~~~~
   $ flexnbd serve --addr <ADDR> --port <PORT> --file <FILE>
-    [--sock <SOCK>] [--default-deny] [global option]* [acl entry]*
+      [--sock <SOCK>] [--default-deny] [-k] [global_option]*
+      [acl_entry]*
 
-Serve a file. If any ACL entries are given (which should be IP
+If any ACL entries are given (which should be IP
 addresses), only those clients listed will be permitted to connect.
 
 flexnbd will continue to serve until a SIGINT, SIGQUIT, or a successful
 migration.
 
-Options
-^^^^^^^
+  OPTIONS
 
-*--addr, -l ADDR*:
+  --addr, -l ADDR  
     The address to listen on. Required.
 
-*--port, -p PORT*:
+  --port, -p PORT  
     The port to listen on. Required.
 
-*--file, -f FILE*:
+  --file, -f FILE  
     The file to serve. Must already exist. Required.
 
-*--sock, -s SOCK*:
-    Path to a control socket to open.  You will need this if you want to
+  --sock, -s SOCK  
+    Path to a control socket to open. You will need this if you want to
     migrate, get the current status, or manipulate the access control
     list.
 
-*--default-deny, -d*:
-    How to interpret an empty ACL.  If --default-deny is given, an
-    empty ACL will let no clients connect.  If it is not given, an
+  --default-deny, -d  
+    How to interpret an empty ACL. If --default-deny is given, an
+    empty ACL will let no clients connect. If it is not given, an
     empty ACL will let any client connect.
 
-listen
-~~~~~~
+  --killswitch, -k  
+    If set, we implement a 2-minute timeout on NBD requests and
+    responses. If a request takes longer than that to complete,
+    the client is disconnected. This is useful to keep broken
+    clients from breaking migrations, among other things.
 
-  $ flexnbd listen --addr <ADDR> --port <PORT> --file <FILE>
-    [--sock <SOCK>] [--default-deny] [global option]* [acl entry]*
+LISTEN MODE
 
 Listen for an inbound migration, and quit with a status of 0 on
 completion.
 
+  $ flexnbd listen --addr ADDR --port PORT --file FILE
+      [--sock SOCK] [--default-deny] [global_option]* 
+      [acl_entry]*
+
 flexnbd will wait for a successful migration, and then quit. The file
 to write the inbound migration data to must already exist before you
 run 'flexnbd listen'.
 
 Only one sender may connect to send data, and if the sender
 disconnects part-way through the migration, the destination will
-expect it to reconnect and retry the whole migration.  It isn't safe
+expect it to reconnect and retry the whole migration. It isn't safe
 to assume that a partial migration can be resumed because the
 destination has no knowledge of whether a client has made a write to
 the source in the interim.
 
-If the migration fails for a reason which the `flexnbd listen` process
+If the migration fails for a reason which the 'flexnbd listen' process
 can't fix (say, a failed local write), it will exit with an error
-status.  In this case, the sender will continually retry the migration
-until it succeeds, and you will need to restart the `flexnbd listen`
+status. In this case, the sender will continually retry the migration
+until it succeeds, and you will need to restart the 'flexnbd listen'
 process to allow that to happen.
 
-Options
-^^^^^^^
-As for 'serve'.
+  OPTIONS
 
-mirror
-~~~~~~
+As for serve.
 
-  $ flexnbd mirror --addr <ADDR> --port <PORT> --sock SOCK
-      [--unlink] [--bind <BIND-ADDR>] [global option]*
+MIRROR MODE
 
 Start a migration from the server with control socket SOCK to the server
 listening at ADDR:PORT.
 
+  $ flexnbd mirror --addr ADDR --port PORT --sock SOCK [--unlink]
+      [--bind BIND_ADDR] [global_option]*
+
 Migration can be a slow process. Rather than block the 'flexnbd mirror'
 process until it completes, it will exit with a message of "Migration
 started" once it has confirmation that the local server was able to
-connect to ADDR:PORT and got an NBD header back.  To check on the
+connect to ADDR:PORT and got an NBD header back. To check on the
 progress of a running migration, use 'flexnbd status'.
 
 If the destination unexpectedly disconnects part-way through the
 migration, the source will attempt to reconnect and start the migration
-again.  It is not safe to resume the migration from where it left off
+again. It is not safe to resume the migration from where it left off
 because the source can't see that the backing store behind the
 destination is intact, or even on the same machine.
 
-If the `--unlink` option is given, the local file will be deleted
-immediately before the mirror connection is terminated.  This allows
+If the --unlink option is given, the local file will be deleted
+immediately before the mirror connection is terminated. This allows
 an otherwise-ambiguous situation to be resolved: if you don't unlink
 the file and the flexnbd process at either end is terminated, it's not
-possible to tell which copy of the data is canonical.  Since the
+possible to tell which copy of the data is canonical. Since the
 unlink happens as soon as the sender knows that it has transmitted all
 the data, there can be no ambiguity.
 
 Note: files smaller than 4096 bytes cannot be mirrored.
 
-Options
-^^^^^^^
+  OPTIONS
 
-*--addr, -l ADDR*:
-  The address of the remote server to migrate to. Required.
+  --addr, -l ADDR  
+    The address of the remote server to migrate to. Required.
 
-*--port, -p PORT*:
-  The port of the remote server to migrate to. Required.
+  --port, -p PORT  
+    The port of the remote server to migrate to. Required.
 
-*--sock, -s SOCK*:
-  The control socket of the local server to migrate from. Required.
+  --sock, -s SOCK  
+    The control socket of the local server to migrate from. Required.
 
-*--unlink, -u*:
-  Unlink the served file from the local filesystem after successfully
-  mirroring.
+  --unlink, -u  
+    Unlink the served file from the local filesystem after
+    successfully mirroring.
 
-*--bind, -b BIND-ADDR*:
-  The local address to bind to. You may need this if the remote server
-  is using an access control list.
+  --bind, -b BIND_ADDR  
+    The local address to bind to. You may need this if the remote
+    server is using an access control list.
 
-break
-~~~~~
-
-  $ flexnbd mirror --sock SOCK [global option]*
+BREAK MODE
 
 Stop a running migration.
 
-Options
-^^^^^^^
+  $ flexnbd break --sock SOCK [global_option]*
 
-*--sock, -s SOCK*:
-  The control socket of the local server whose emigration to stop.
-  Required.
+  OPTIONS
 
+  --sock, -s SOCK  
+    The control socket of the local server whose migration to stop.
+    Required.
 
-acl
-~~~
-
-  $ flexnbd acl --sock <SOCK> [acl entry]+ [global option]*
+ACL MODE
 
 Set the access control list of the server with the control socket SOCK
 to the given access control list entries.
 
+  $ flexnbd acl --sock SOCK [acl_entry]+ [global_option]*
+
 ACL entries are given as IP addresses.
 
-Options
-^^^^^^^
+  OPTIONS
 
-*--sock, -s SOCK*:
-  The control socket of the server whose ACL to replace.
+  --sock, -s SOCK  
+    The control socket of the server whose ACL to replace. Required
 
-status
-~~~~~~
-
-  $ flexnbd status --sock <SOCK> [global option]*
+STATUS MODE
 
 Get the current status of the server with control socket SOCK.
 
-The status will be printed to STDOUT.  It is a space-separated list of
-key=value pairs.  The space character will never appear in a key or
-value.  Currently reported values are:
+  $ flexnbd status --sock SOCK [global_option]*
 
-*pid*:
+The status will be printed to STDOUT. It is a space-separated list of
+key=value pairs. The space character will never appear in a key or
+value. Currently reported values are:
+
+pid  
   The process id of the server listening on SOCK.
 
-*is_mirroring*:
+is_mirroring  
   'true' if this server is sending migration data, 'false' otherwise.
 
-*has_control*:
+has_control  
   'false' if this server was started in 'listen' mode. 'true' otherwise.
 
-read
-~~~~
+  OPTIONS
 
-  $ flexnbd read --addr <ADDR> --port <PORT> --from <OFFSET>
-    --size <SIZE>  [--bind BIND-ADDR] [global option]*
+  --sock, -s SOCK  
+    The control socket of the server of interest. Required.
+
+READ MODE
 
 Connect to the server at ADDR:PORT, and read SIZE bytes starting at
-OFFSET in a single NBD query.  The returned data will be echoed to
-STDOUT.  In case of a remote ACL, set the local source address to
-BIND-ADDR.
+OFFSET in a single NBD query.
 
-Options
-^^^^^^^
+  $ flexnbd read --addr ADDR --port PORT --from OFFSET --size SIZE
+      [--bind BIND_ADDR] [global_option]*
 
-*--addr, -l ADDR*:
-  The address of the remote server.  Required.
+The returned data will be echoed to STDOUT. In case of a remote ACL,
+set the local source address to BIND_ADDR.
 
-*--port, -p PORT*:
-  The port of the remote server.  Required.
+  OPTIONS
 
-*--from, -F OFFSET*:
-  The byte offset to start reading from. Required. Maximum 2^62.
+  --addr, -l ADDR  
+    The address of the remote server. Required.
 
-*--size, -S SIZE*:
-  The number of bytes to read. Required.  Maximum 2^30.
+  --port, -p PORT  
+    The port of the remote server. Required.
 
-*--bind, -b BIND-ADDR*:
-  The local address to bind to. You may need this if the remote server
-  is using an access control list.
+  --from, -F OFFSET  
+    The byte offset to start reading from. Required.  Maximum 2^62.
 
-write
-~~~~~
+  --size, -S SIZE  
+    The number of bytes to read. Required. Maximum 2^30.
 
-  $ cat ... | flexnbd write --addr <ADDR> --port <PORT> --from <OFFSET>
-    --size <SIZE>  [--bind BIND-ADDR] [global option]*
+  --bind, -b BIND_ADDR  
+    The local address to bind to. You may need this if the remote
+    server is using an access control list.
+
+WRITE MODE
 
 Connect to the server at ADDR:PORT, and write SIZE bytes from STDIN
-starting at OFFSET in a single NBD query.  In case of a remote ACL, set
-the local source address to BIND-ADDR.
+starting at OFFSET in a single NBD query.
 
-Options
-^^^^^^^
+  $ cat ... | flexnbd write --addr ADDR --port PORT --from OFFSET
+      --size SIZE  [--bind BIND_ADDR] [global_option]*
 
-*--addr, -l ADDR*:
-  The address of the remote server.  Required.
+In case of a remote ACL, set the local source address to BIND_ADDR.
 
-*--port, -p PORT*:
-  The port of the remote server.  Required.
+  OPTIONS
 
-*--from, -F OFFSET*:
-  The byte offset to start writing from. Required. Maximum 2^62.
+  --addr, -l ADDR  
+    The address of the remote server. Required.
 
-*--size, -S SIZE*:
-  The number of bytes to write. Required.  Maximum 2^30.
+  --port, -p PORT  
+    The port of the remote server. Required.
 
-*--bind, -b BIND-ADDR*:
-  The local address to bind to. You may need this if the remote server
-  is using an access control list.
+  --from, -F OFFSET  
+    The byte offset to start writing from. Required.  Maximum 2^62.
 
-help
-~~~~
+  --size, -S SIZE  
+    The number of bytes to write. Required. Maximum 2^30.
 
-  $ flexnbd help [command] [global option]*
+  --bind, -b BIND_ADDR  
+    The local address to bind to. You may need this if the remote
+    server is using an access control list.
 
-Without 'command', show the list of available commands.  With 'command',
-show help for that command.
+HELP MODE
+
+  $ flexnbd help [mode] [global_option]*
+
+Without mode, show the list of available modes. With mode, show help for that mode.
 
 GLOBAL OPTIONS
---------------
 
-*--help, -h* :
-    Show command or global help.
+--help, -h  Show mode or global help.
 
-*--verbose, -v* :
-    Output all available log information to STDERR.
-
-*--quiet, -q* :
-    Output as little log information as possible to STDERR.
+--verbose, -v  Output all available log information to STDERR.
 
+--quiet, -q  Output as little log information as possible to STDERR.
 
 LOGGING
--------
-Log output is sent to STDERR.  If --quiet is set, no output will be seen
-unless the program termintes abnormally.  If neither --quiet nor
+
+Log output is sent to STDERR. If --quiet is set, no output will be
+seen unless the program termintes abnormally. If neither --quiet nor
 --verbose are set, no output will be seen unless something goes wrong
-with a specific request.  If --verbose is given, every available log
-message will be seen (which, for a debug build, is many).  It is not an
-error to set both --verbose and --quiet.  The last one wins.
+with a specific request. If --verbose is given, every available log
+message will be seen (which, for a debug build, is many). It is not an
+error to set both --verbose and --quiet. The last one wins.
 
 The log line format is:
 
-  <TIMESTAMP>:<LEVEL>:<PID> <THREAD> <SOURCEFILE>:<SOURCELINE>: <MSG>
+  <TIMESTAMP>:<LEVEL>:<PID> <THREAD> <SOURCEFILE:SOURCELINE>: <MSG>
 
-*TIMESTAMP*:
-  Time the log entry was made. This is expressed in terms of monotonic ms.
+<TIMESTAMP>  
+  Time the log entry was made. This is expressed in terms of monotonic
+  ms.
 
-*LEVEL*:
+<LEVEL>  
   This will be one of 'D', 'I', 'W', 'E', 'F' in increasing order of
-severity.  If flexnbd is started with the --quiet flag, only 'F' will be
-seen.  If it is started with the --verbose flag, any from 'I' upwards
-will be seen.  Only if you have a debug build and start it with
---verbose will you see 'D' entries.
+  severity. If flexnbd is started with the --quiet flag, only 'F'
+  will be seen. If it is started with the --verbose flag, any from 'I'
+  upwards will be seen. Only if you have a debug build and start it
+  with --verbose will you see 'D' entries.
 
-*PID*:
+<PID>  
   This is the process ID.
 
-*THREAD*:
-  There are several pthreads per flexnbd process: a main thread, a serve
-thread, a thread per client, and possibly a pair of mirror threads and a
-control thread.  This field identifies which thread was responsible for
-the log line.
+<THREAD>  
+  There are several pthreads per flexnbd process: a main thread, a
+  serve thread, a thread per client, and possibly a pair of mirror
+  threads and a control thread. This field identifies which thread was
+  responsible for the log line.
 
-*SOURCEFILE:SOURCELINE*:
+<SOURCEFILE:SOURCELINE>  
   Identifies where in the source code this log line can be found.
 
-*MSG*:
+<MSG>  
   A short message describing what's happening, how it's being done, or
-if you're very lucky *why* it's going on.
+  if you're very lucky why it's going on.
 
 EXAMPLES
---------
 
-Serving a file
-~~~~~~~~~~~~~~
+  SERVING A FILE
 
 The simplest case is serving a file on the default nbd port:
 
@@ -320,8 +331,7 @@ The simplest case is serving a file on the default nbd port:
   root:x:
   $
 
-Reading server status
-~~~~~~~~~~~~~~~~~~~~~
+  READING SERVER STATUS
 
 In order to read a server's status, we need it to open a control socket.
 
@@ -329,13 +339,12 @@ In order to read a server's status, we need it to open a control socket.
     --sock /tmp/flexnbd.sock
   $ flexnbd status --sock /tmp/flexnbd.sock
   pid=9635 is_mirroring=false has_control=true
-
+  
   $
 
 Note that the status output is newline-terminated.
 
-Migrating
-~~~~~~~~~
+  MIGRATING
 
 To migrate, we need to provide a destination file of the right size.
 
@@ -361,8 +370,8 @@ With this knowledge in hand, we can start the migration:
   $ flexnbd mirror --addr 127.0.0.1 --port 4779 \
       --sock /tmp/flex-source.sock
   Migration started
-  [1]  + 9648 done       build/flexnbd serve --addr 0.0.0.0 --port 4778
-  [2]  + 9651 done       build/flexnbd listen --addr 0.0.0.0 --port 4779
+  [1]  + 9648 done       flexnbd serve --addr 0.0.0.0 --port 4778
+  [2]  + 9651 done       flexnbd listen --addr 0.0.0.0 --port 4779
   $
 
 Note that because the file is so small in this case, we see the source
@@ -370,21 +379,25 @@ server quit soon after we start the migration, and the destination
 exited at roughly the same time.
 
 BUGS
-----
 
-Should be reported to alex@bytemark.co.uk.
+Should be reported on GitHub at
+
+ * https://github.com/BytemarkHosting/flexnbd-c/issues
 
 AUTHOR
-------
 
-Written by Alex Young <alex@bytemark.co.uk>.
+Originally written by Alex Young <alex@blackkettle.org>.
 Original concept and core code by Matthew Bloch <matthew@bytemark.co.uk>.
-Some additions by Nick Thomas <nick@bytemark.co.uk>
+Proxy mode written by Nick Thomas <me@ur.gs>.
 
-COPYING
--------
+The full commit history is available on GitHub.
 
-Copyright (c) 2012 Bytemark Hosting Ltd. Free use of this software is
-granted under the terms of the GNU General Public License version 3 or
-later.
+SEE ALSO
 
+flexnbd-proxy(1), nbd-client(8), xnbd-server(8), xnbd-client(8)
+
+COPYRIGHT
+
+Copyright (c) 2012-2016 Bytemark Hosting Ltd. Free use of this
+software is granted under the terms of the GNU General Public License
+version 3 or later.

Rakefile

@@ -1,312 +0,0 @@
-$: << '../rake_utils/lib'
-require 'rake_utils/debian'
-include RakeUtils::DSL
-
-CC=ENV['CC'] || "gcc"
-
-DEBUG  = ENV.has_key?('DEBUG') &&
-  %w|yes y ok 1 true t|.include?(ENV['DEBUG'])
-
-ALL_SOURCES = FileList['src/*']
-
-PROXY_ONLY_SOURCES = FileList['src/{proxy-main,proxy}.c']
-PROXY_ONLY_OBJECTS = PROXY_ONLY_SOURCES.pathmap( "%{^src,build}X.o" )
-
-SOURCES = ALL_SOURCES.select { |c| c =~ /\.c$/ } - PROXY_ONLY_SOURCES
-OBJECTS = SOURCES.pathmap( "%{^src,build}X.o" ) - PROXY_ONLY_OBJECTS
-
-PROXY_SOURCES = FileList['src/{ioutil,nbdtypes,readwrite,sockutil,util,parse}.c'] + PROXY_ONLY_SOURCES
-PROXY_OBJECTS = PROXY_SOURCES.pathmap( "%{^src,build}X.o" )
-
-TEST_SOURCES = FileList['tests/unit/*.c']
-TEST_OBJECTS = TEST_SOURCES.pathmap( "%{^tests/unit,build/tests}X.o" )
-
-LIBS    = %w( pthread )
-LDFLAGS = ["-lrt -lev"]
-CCFLAGS = %w(
-             -D_GNU_SOURCE=1
-             -Wall
-             -Wextra
-             -Werror-implicit-function-declaration
-             -Wstrict-prototypes
-             -Wno-missing-field-initializers
-            ) + # Added -Wno-missing-field-initializers to shut GCC up over {0} struct initialisers
-            [ENV['CFLAGS']]
-
-LIBCHECK = File.exists?("/usr/lib/libcheck.a") ?
-  "/usr/lib/libcheck.a" :
-  "/usr/local/lib/libcheck.a"
-
-TEST_MODULES = Dir["tests/unit/check_*.c"].map { |n|
-  File.basename( n )[%r{check_(.+)\.c},1] }
-
-if DEBUG
-  LDFLAGS << ["-g"]
-  CCFLAGS << ["-g -DDEBUG"]
-else
-  CCFLAGS << "-O2"
-end
-
-desc "Build the binary and man page"
-task :build => [:flexnbd, :flexnbd_proxy, :man]
-task :default => :build
-
-desc "Build just the flexnbd binary"
-task :flexnbd => "build/flexnbd"
-
-desc "Build just the flexnbd-proxy binary"
-task :flexnbd_proxy => "build/flexnbd-proxy"
-
-def check(m)
-  "build/tests/check_#{m}"
-end
-
-file "README.txt"
-file "README.proxy.txt"
-
-def manpage(name, src)
-  FileUtils.mkdir_p( "build" )
-  sh "a2x --destination-dir build --format manpage #{src}"
-  sh "gzip -f build/#{name}"
-end
-
-file "build/flexnbd.1.gz" => "README.txt" do
-  manpage("flexnbd.1", "README.txt")
-end
-
-file "build/flexnbd-proxy.1.gz" => "README.proxy.txt" do
-  manpage("flexnbd-proxy.1", "README.proxy.txt")
-end
-
-desc "Build just the man page"
-task :man => ["build/flexnbd.1.gz", "build/flexnbd-proxy.1.gz"]
-
-
-namespace "test" do
-  desc "Run all tests"
-  task 'run' => ["unit", "scenarios"]
-
-  desc "Build C tests"
-  task 'build' => TEST_MODULES.map { |n| check n}
-
-  TEST_MODULES.each do |m|
-    desc "Run tests for #{m}"
-    task "check_#{m}" => check(m) do
-      sh check m
-    end
-  end
-
-  desc "Run C tests"
-  task 'unit' => 'build' do
-    TEST_MODULES.each do |n|
-      ENV['EF_DISABLE_BANNER'] = '1'
-      sh check n
-    end
-  end
-
-  desc "Run NBD test scenarios"
-  task 'scenarios' => ['build/flexnbd', 'build/flexnbd-proxy'] do
-    sh "cd tests/acceptance; ruby nbd_scenarios -v"
-  end
-end
-
-
-
-def gcc_compile( target, source )
-  FileUtils.mkdir_p File.dirname( target )
-  sh "#{CC} -Isrc -c #{CCFLAGS.join(' ')} -o #{target} #{source} "
-end
-
-def gcc_link(target, objects)
-  FileUtils.mkdir_p File.dirname( target )
-
-  sh "#{CC} #{LDFLAGS.join(' ')} "+
-    " -Isrc " +
-    " -o #{target} "+
-    objects.join(" ") +
-    " "+LIBS.map { |l| "-l#{l}" }.join(" ")
-end
-
-def headers(c)
-  `#{CC} -Isrc -MM #{c}`.gsub("\\\n", " ").split(" ")[2..-1]
-end
-
-rule 'build/flexnbd-proxy' => PROXY_OBJECTS do |t|
-  gcc_link(t.name, t.sources)
-end
-
-rule 'build/flexnbd' => OBJECTS do |t|
-  gcc_link(t.name, t.sources)
-end
-
-
-file check("client") =>
-%w{build/tests/check_client.o
-  build/self_pipe.o
-  build/nbdtypes.o
-  build/flexnbd.o
-  build/flexthread.o
-  build/control.o
-  build/readwrite.o
-  build/parse.o
-  build/client.o
-  build/serve.o
-  build/acl.o
-  build/ioutil.o
-  build/mbox.o
-  build/mirror.o
-  build/status.o
-  build/sockutil.o
-  build/util.o} do |t|
-  gcc_link t.name, t.prerequisites + [LIBCHECK]
-end
-
-file check("acl") =>
-%w{build/tests/check_acl.o
-  build/parse.o
-  build/acl.o
-  build/util.o} do |t|
-  gcc_link t.name, t.prerequisites + [LIBCHECK]
-end
-
-file check( "util" ) =>
-%w{build/tests/check_util.o
-  build/util.o
-  build/self_pipe.o} do |t|
-  gcc_link t.name, t.prerequisites + [LIBCHECK]
-end
-
-file check("serve") =>
-%w{build/tests/check_serve.o
-  build/self_pipe.o
-  build/nbdtypes.o
-  build/control.o
-  build/readwrite.o
-  build/parse.o
-  build/client.o
-  build/flexthread.o
-  build/serve.o
-  build/flexnbd.o
-  build/mirror.o
-  build/status.o
-  build/acl.o
-  build/mbox.o
-  build/ioutil.o
-  build/sockutil.o
-  build/util.o} do |t|
-  gcc_link t.name, t.prerequisites + [LIBCHECK]
-end
-
-file check("status") =>
-%w{
-build/tests/check_status.o
-  build/self_pipe.o
-  build/nbdtypes.o
-  build/control.o
-  build/readwrite.o
-  build/parse.o
-  build/client.o
-  build/flexthread.o
-  build/serve.o
-  build/flexnbd.o
-  build/mirror.o
-  build/status.o
-  build/acl.o
-  build/mbox.o
-  build/ioutil.o
-  build/sockutil.o
-  build/util.o
-} do |t|
-  gcc_link t.name, t.prerequisites + [LIBCHECK]
-end
-
-
-file check("readwrite") =>
-%w{build/tests/check_readwrite.o
-  build/readwrite.o
-  build/client.o
-  build/self_pipe.o
-  build/serve.o
-  build/parse.o
-  build/acl.o
-  build/flexthread.o
-  build/control.o
-  build/flexnbd.o
-  build/mirror.o
-  build/status.o
-  build/nbdtypes.o
-  build/mbox.o
-  build/ioutil.o
-  build/sockutil.o
-  build/util.o} do |t|
-  gcc_link t.name, t.prerequisites + [LIBCHECK]
-end
-
-
-file check("flexnbd") =>
-%w{build/tests/check_flexnbd.o
-  build/flexnbd.o
-  build/ioutil.o
-  build/sockutil.o
-  build/util.o
-  build/control.o
-  build/mbox.o
-  build/flexthread.o
-  build/status.o
-  build/self_pipe.o
-  build/client.o
-  build/acl.o
-  build/parse.o
-  build/nbdtypes.o
-  build/readwrite.o
-  build/mirror.o
-  build/serve.o} do |t|
-  gcc_link t.name, t.prerequisites + [LIBCHECK]
-end
-
-
-file check("control") =>
-  %w{build/tests/check_control.o} + OBJECTS - ["build/main.o", 'build/proxy-main.o', 'build/proxy.o'] do |t|
-  gcc_link t.name, t.prerequisites + [LIBCHECK]
-end
-
-(TEST_MODULES- %w{status control flexnbd acl client serve readwrite util}).each do |m|
-  tgt = "build/tests/check_#{m}.o"
-  maybe_obj_name = "build/#{m}.o"
-  # Take it out in case we're testing one of the utils
-  deps = ["build/ioutil.o", "build/util.o", "build/sockutil.o"] - [maybe_obj_name]
-
-  # Add it back in if it's something we need to compile
-  deps << maybe_obj_name if OBJECTS.include?( maybe_obj_name )
-
-  file check( m ) => deps + [tgt] do |t|
-    gcc_link(t.name, deps + [tgt, LIBCHECK])
-  end
-end
-
-
-OBJECTS.zip( SOURCES ).each do |o,c|
-  file o => [c]+headers(c) do |t| gcc_compile( o, c ) end
-end
-
-PROXY_ONLY_OBJECTS.zip( PROXY_ONLY_SOURCES).each do |o, c|
-  file o => [c]+headers(c) do |t| gcc_compile( o, c ) end
-end
-
-TEST_OBJECTS.zip( TEST_SOURCES ).each do |o,c|
-  file o => [c] + headers(c) do |t| gcc_compile( o, c ) end
-end
-
-desc "Remove all build targets, binaries and temporary files"
-task :clean do
-  sh "rm -rf *~ build"
-end
-
-namespace :pkg do
-  deb do |t|
-    t.code_files = ALL_SOURCES + ["Rakefile", "README.txt", "README.proxy.txt"]
-    t.pkg_name = "flexnbd"
-    t.generate_changelog!
-  end
-end
-

debian/control

@@ -1,14 +1,14 @@
 Source: flexnbd
-Section: unknown
+Section: web
 Priority: extra
-Maintainer: Alex Young <alex@bytemark.co.uk>
-Build-Depends: cdbs, debhelper (>= 7.0.50), ruby, rake, gcc, libev-dev
+Maintainer: Patrick J Cherry <patrick@bytemark.co.uk> 
+Build-Depends: debhelper (>= 7.0.50), ruby, gcc, libev-dev, txt2man, check, net-tools, libsubunit-dev, ruby-test-unit
 Standards-Version: 3.8.1
-Homepage: http://bigv.io/
+Homepage: https://github.com/BytemarkHosting/flexnbd-c
 
 Package: flexnbd
 Architecture: any
-Depends: ${shlibs:Depends}, ${misc:Depends}, libev3
+Depends: ${shlibs:Depends}, ${misc:Depends}, libev4 | libev3
 Description: FlexNBD server
   An NBD server offering push-mirroring and intelligent sparse file handling
 

debian/flexnbd.install

@@ -1,5 +1,3 @@
 build/flexnbd             usr/bin
 build/flexnbd-proxy       usr/bin
-build/flexnbd.1.gz        usr/share/man/man1
-build/flexnbd-proxy.1.gz  usr/share/man/man1
 

debian/flexnbd.manpages

@@ -0,0 +1,2 @@
+build/flexnbd.1.gz
+build/flexnbd-proxy.1.gz

debian/rules

@@ -7,12 +7,13 @@
 %:
 	dh $@ 
 
-override_dh_auto_build:
-	rake build
-
-override_dh_auto_clean:
-	rake clean
-
-.PHONY: override_dh_strip
 override_dh_strip:
 	dh_strip --dbg-package=flexnbd-dbg
+
+#
+# TODO: The ruby test suites don't work during buiding in a chroot, so leave
+# them out for now.
+#
+#override_dh_auto_test:
+#	rake test:run
+

src/common/fifo_declare.h

@@ -0,0 +1,189 @@
+/*
+	fido_declare.h
+	Copyright (C) 2003-2012 Michel Pollet <buserror@gmail.com>
+
+	This library is free software; you can redistribute it and/or
+	modify it under the terms of the GNU Lesser General Public
+	License as published by the Free Software Foundation; either
+	version 2.1 of the License, or (at your option) any later version.
+
+	This library is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+	Lesser General Public License for more details.
+
+	You should have received a copy of the GNU Lesser General Public
+	License along with this library; if not, write to the Free Software
+	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+/*
+ * FIFO helpers, aka circular buffers
+ *
+ * these macros define accessories for FIFOs of any name, type and
+ * any (power of two) size
+ */
+
+#ifndef __FIFO_DECLARE__
+#define __FIFO_DECLARE__
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+	doing a :
+	DECLARE_FIFO(uint8_t, myfifo, 128);
+
+	will declare :
+	enum : myfifo_overflow_f
+	type : myfifo_t
+	functions:
+		// write a byte into the fifo, return 1 if there was room, 0 if there wasn't
+		int myfifo_write(myfifo_t *c, uint8_t b);
+		// reads a byte from the fifo, return 0 if empty. Use myfifo_isempty() to check beforehand
+		uint8_t myfifo_read(myfifo_t *c);
+		int myfifo_isfull(myfifo_t *c);
+		int myfifo_isempty(myfifo_t *c);
+		// returns number of items to read now
+		uint16_t myfifo_get_read_size(myfifo_t *c);
+		// read item at offset o from read cursor, no cursor advance
+		uint8_t myfifo_read_at(myfifo_t *c, uint16_t o);
+		// write b at offset o compared to current write cursor, no cursor advance
+		void myfifo_write_at(myfifo_t *c, uint16_t o, uint8_t b);
+
+	In your .c you need to 'implement' the fifo:
+	DEFINE_FIFO(uint8_t, myfifo)
+
+	To use the fifo, you must declare at least one :
+	myfifo_t fifo = FIFO_NULL;
+
+	while (!myfifo_isfull(&fifo))
+		myfifo_write(&fifo, 0xaa);
+	....
+	while (!myfifo_isempty(&fifo))
+		b = myfifo_read(&fifo);
+ */
+
+#include <stdint.h>
+
+#if __AVR__
+#define FIFO_CURSOR_TYPE	uint8_t
+#define FIFO_BOOL_TYPE	char
+#define FIFO_INLINE
+#define FIFO_SYNC
+#endif
+
+#ifndef	FIFO_CURSOR_TYPE
+#define FIFO_CURSOR_TYPE	uint16_t
+#endif
+#ifndef	FIFO_BOOL_TYPE
+#define FIFO_BOOL_TYPE	int
+#endif
+#ifndef	FIFO_INLINE
+#define FIFO_INLINE	inline
+#endif
+
+/* We should not need volatile */
+#ifndef FIFO_VOLATILE
+#define FIFO_VOLATILE
+#endif
+#ifndef FIFO_SYNC
+#define FIFO_SYNC __sync_synchronize()
+#endif
+
+#ifndef FIFO_ZERO_INIT
+#define FIFO_ZERO_INIT {0}
+#endif
+#define FIFO_NULL { FIFO_ZERO_INIT, 0, 0, 0 }
+
+/* New compilers don't like unused static functions. However,
+ * we do like 'static inlines' for these small accessors,
+ * so we mark them as 'unused'. It stops it complaining */
+#ifdef __GNUC__
+#define FIFO_DECL static __attribute__ ((unused))
+#else
+#define FIFO_DECL static
+#endif
+
+#define DECLARE_FIFO(__type, __name, __size) \
+enum { __name##_overflow_f = (1 << 0) }; \
+enum { __name##_fifo_size = (__size) }; \
+typedef struct __name##_t {			\
+	__type		buffer[__name##_fifo_size];		\
+	FIFO_VOLATILE FIFO_CURSOR_TYPE	read;		\
+	FIFO_VOLATILE FIFO_CURSOR_TYPE	write;		\
+	FIFO_VOLATILE uint8_t	flags;		\
+} __name##_t
+
+#define DEFINE_FIFO(__type, __name) \
+FIFO_DECL FIFO_INLINE FIFO_BOOL_TYPE __name##_write(__name##_t * c, __type b)\
+{\
+	FIFO_CURSOR_TYPE now = c->write;\
+	FIFO_CURSOR_TYPE next = (now + 1) & (__name##_fifo_size-1);\
+	if (c->read != next) {	\
+		c->buffer[now] = b;\
+		FIFO_SYNC; \
+		c->write = next;\
+		return 1;\
+	}\
+	return 0;\
+}\
+FIFO_DECL FIFO_INLINE FIFO_BOOL_TYPE __name##_isfull(__name##_t *c)\
+{\
+	FIFO_CURSOR_TYPE next = (c->write + 1) & (__name##_fifo_size-1);\
+	return c->read == next;\
+}\
+FIFO_DECL FIFO_INLINE FIFO_BOOL_TYPE __name##_isempty(__name##_t * c)\
+{\
+	return c->read == c->write;\
+}\
+FIFO_DECL FIFO_INLINE __type __name##_read(__name##_t * c)\
+{\
+	__type res = FIFO_ZERO_INIT; \
+	FIFO_CURSOR_TYPE read = c->read;\
+	if (read == c->write)\
+		return res;\
+	res = c->buffer[read];\
+	FIFO_SYNC; \
+	c->read = (read + 1) & (__name##_fifo_size-1);\
+	return res;\
+}\
+FIFO_DECL FIFO_INLINE FIFO_CURSOR_TYPE __name##_get_read_size(__name##_t *c)\
+{\
+	return ((c->write + __name##_fifo_size) - c->read) & (__name##_fifo_size-1);\
+}\
+FIFO_DECL FIFO_INLINE FIFO_CURSOR_TYPE __name##_get_write_size(__name##_t *c)\
+{\
+	return (__name##_fifo_size-1) - __name##_get_read_size(c);\
+}\
+FIFO_DECL FIFO_INLINE void __name##_read_offset(__name##_t *c, FIFO_CURSOR_TYPE o)\
+{\
+	FIFO_SYNC; \
+	c->read = (c->read + o) & (__name##_fifo_size-1);\
+}\
+FIFO_DECL FIFO_INLINE __type __name##_read_at(__name##_t *c, FIFO_CURSOR_TYPE o)\
+{\
+	return c->buffer[(c->read + o) & (__name##_fifo_size-1)];\
+}\
+FIFO_DECL FIFO_INLINE void __name##_write_at(__name##_t *c, FIFO_CURSOR_TYPE o, __type b)\
+{\
+	c->buffer[(c->write + o) & (__name##_fifo_size-1)] = b;\
+}\
+FIFO_DECL FIFO_INLINE void __name##_write_offset(__name##_t *c, FIFO_CURSOR_TYPE o)\
+{\
+	FIFO_SYNC; \
+	c->write = (c->write + o) & (__name##_fifo_size-1);\
+}\
+FIFO_DECL FIFO_INLINE void __name##_reset(__name##_t *c)\
+{\
+	FIFO_SYNC; \
+	c->read = c->write = c->flags = 0;\
+}\
+struct __name##_t
+
+#ifdef __cplusplus
+};
+#endif
+
+#endif

src/common/ioutil.c

@@ -9,7 +9,7 @@
 #include <fcntl.h>
 
 #include "util.h"
-#include "bitset.h"
+#include "bitstream.h"
 #include "ioutil.h"
 
 
@@ -31,8 +31,6 @@ int build_allocation_map(struct bitset * allocation_map, int fd)
 
 	for (offset = 0; offset < allocation_map->size; ) {
 
-		unsigned int i;
-
 		fiemap->fm_start = offset;
 
 		fiemap->fm_length = max_length;
@@ -49,7 +47,7 @@ int build_allocation_map(struct bitset * allocation_map, int fd)
 			return 0; /* it's up to the caller to free the map */
 		}
 		else {
-			for ( i = 0; i < fiemap->fm_mapped_extents; i++ ) {
+			for ( unsigned int i = 0; i < fiemap->fm_mapped_extents; i++ ) {
 				bitset_set_range( allocation_map,
 						  fiemap->fm_extents[i].fe_logical,
 						  fiemap->fm_extents[i].fe_length );
@@ -71,22 +69,23 @@ int build_allocation_map(struct bitset * allocation_map, int fd)
 		}
 	}
 
-	debug("Successfully built allocation map");
+	info("Successfully built allocation map");
 	return 1;
 }
 
 
-int open_and_mmap(const char* filename, int* out_fd, off64_t *out_size, void **out_map)
+int open_and_mmap(const char* filename, int* out_fd, uint64_t *out_size, void **out_map)
 {
+	/* 
+	 * size and out_size are intentionally of different types.
+	 * lseek64() uses off64_t to signal errors in the sign bit.
+	 * Since we check for these errors before trying to assign to
+	 * *out_size, we know *out_size can never go negative.
+	 */
 	off64_t size;
 
-	/* O_DIRECT seems to be intermittently supported.  Leaving it as
-	 * a compile-time option for now. */
-#ifdef DIRECT_IO
-	*out_fd = open(filename, O_RDWR | O_DIRECT | O_SYNC );
-#else
+	/* O_DIRECT should not be used with mmap() */
 	*out_fd = open(filename, O_RDWR | O_SYNC );
-#endif
 
 	if (*out_fd < 1) {
 		warn("open(%s) failed: does it exist?", filename);
@@ -109,8 +108,11 @@ int open_and_mmap(const char* filename, int* out_fd, off64_t *out_size, void **o
 			warn("mmap64() failed");
 			return -1;
 		}
+		debug("opened %s size %ld on fd %d @ %p", filename, size, *out_fd, *out_map);
+	}
+	else {
+		debug("opened %s size %ld on fd %d", filename, size, *out_fd);
 	}
-	debug("opened %s size %ld on fd %d @ %p", filename, size, *out_fd, *out_map);
 
 	return 0;
 }
@@ -139,7 +141,7 @@ int readloop(int filedes, void *buffer, size_t size)
 		ssize_t result = read(filedes, buffer+readden, size-readden);
 
 		if ( result == 0 /* EOF */ ) {
-			warn( "end-of-file detected while reading" );
+			warn( "end-of-file detected while reading after %i bytes", readden );
 			return -1;
 		}
 
@@ -347,4 +349,3 @@ ssize_t iobuf_write( int fd, struct iobuf *iobuf )
 
 	return count;
 }
-

src/common/ioutil.h

@@ -65,7 +65,7 @@ int read_lines_until_blankline(int fd, int max_line_length, char ***lines);
   * ''out_size'' and the address of the mmap in ''out_map''.  If anything goes
   * wrong, returns -1 setting errno, otherwise 0.
   */
-int open_and_mmap( const char* filename, int* out_fd, off64_t *out_size, void **out_map);
+int open_and_mmap( const char* filename, int* out_fd, uint64_t* out_size, void **out_map);
 
 
 /** Check to see whether the given file descriptor is closed.

src/common/mode.h

@@ -7,8 +7,9 @@ void mode(char* mode, int argc, char **argv);
 
 #include <getopt.h>
 
-#define GETOPT_ARG(x,s)  {(x), 1, 0, (s)}
-#define GETOPT_FLAG(x,v) {(x), 0, 0, (v)}
+#define GETOPT_ARG(x,s)    {(x), required_argument, 0, (s)}
+#define GETOPT_FLAG(x,v)   {(x), no_argument, 0, (v)}
+#define GETOPT_OPTARG(x,s) {(x), optional_argument, 0, (s)}
 
 #define OPT_HELP "help"
 #define OPT_ADDR "addr"
@@ -19,6 +20,7 @@ void mode(char* mode, int argc, char **argv);
 #define OPT_FROM "from"
 #define OPT_SIZE "size"
 #define OPT_DENY "default-deny"
+#define OPT_CACHE "cache"
 #define OPT_UNLINK "unlink"
 #define OPT_CONNECT_ADDR "conn-addr"
 #define OPT_CONNECT_PORT "conn-port"
@@ -52,6 +54,7 @@ void mode(char* mode, int argc, char **argv);
 #define GETOPT_FROM GETOPT_ARG( OPT_FROM, 'F' )
 #define GETOPT_SIZE GETOPT_ARG( OPT_SIZE, 'S' )
 #define GETOPT_BIND GETOPT_ARG( OPT_BIND, 'b' )
+#define GETOPT_CACHE GETOPT_OPTARG( OPT_CACHE, 'c' )
 #define GETOPT_UNLINK GETOPT_ARG( OPT_UNLINK, 'u' )
 #define GETOPT_CONNECT_ADDR GETOPT_ARG( OPT_CONNECT_ADDR, 'C' )
 #define GETOPT_CONNECT_PORT GETOPT_ARG( OPT_CONNECT_PORT, 'P' )

src/common/nbdtypes.c

@@ -27,7 +27,7 @@ void nbd_r2h_request( struct nbd_request_raw *from, struct nbd_request * to )
 {
 	to->magic = htobe32( from->magic );
 	to->type = htobe32( from->type );
-	memcpy( to->handle, from->handle, 8 );
+	to->handle.w = from->handle.w;
 	to->from = htobe64( from->from );
 	to->len = htobe32( from->len );
 }
@@ -36,7 +36,7 @@ void nbd_h2r_request( struct nbd_request * from, struct nbd_request_raw * to )
 {
 	to->magic = be32toh( from->magic );
 	to->type = be32toh( from->type );
-	memcpy( to->handle, from->handle, 8 );
+	to->handle.w = from->handle.w;
 	to->from = be64toh( from->from );
 	to->len = be32toh( from->len );
 }
@@ -46,13 +46,13 @@ void nbd_r2h_reply( struct nbd_reply_raw * from, struct nbd_reply * to )
 {
 	to->magic = htobe32( from->magic );
 	to->error = htobe32( from->error );
-	memcpy( to->handle, from->handle, 8 );
+	to->handle.w = from->handle.w;
 }
 
 void nbd_h2r_reply( struct nbd_reply * from, struct nbd_reply_raw * to )
 {
 	to->magic = be32toh( from->magic );
 	to->error = be32toh( from->error );
-	memcpy( to->handle, from->handle, 8 );
+	to->handle.w = from->handle.w;
 }
 

src/common/nbdtypes.h

@@ -24,6 +24,11 @@
 #include <linux/types.h>
 #include <inttypes.h>
 
+typedef union nbd_handle_t {
+	uint8_t b[8];
+	uint64_t w;
+} nbd_handle_t;
+
 /* The _raw types are the types as they appear on the wire.  Non-_raw
  * types are in host-format.
  * Conversion functions are _r2h_ for converting raw to host, and _h2r_
@@ -39,7 +44,7 @@ struct nbd_init_raw {
 struct nbd_request_raw {
 	__be32 magic;
 	__be32 type;    /* == READ || == WRITE  */
-	char handle[8];
+	nbd_handle_t handle;
 	__be64 from;
 	__be32 len;
 } __attribute__((packed));
@@ -47,7 +52,7 @@ struct nbd_request_raw {
 struct nbd_reply_raw {
 	__be32 magic;
 	__be32 error;           /* 0 = ok, else error   */
-	char handle[8];         /* handle you got from request  */
+	nbd_handle_t handle;         /* handle you got from request  */
 };
 
 
@@ -62,7 +67,7 @@ struct nbd_init {
 struct nbd_request {
 	uint32_t magic;
 	uint32_t type;    /* == READ || == WRITE || == DISCONNECT */
-	char handle[8];
+	nbd_handle_t handle;
 	uint64_t from;
 	uint32_t len;
 } __attribute__((packed));
@@ -70,7 +75,7 @@ struct nbd_request {
 struct nbd_reply {
 	uint32_t magic;
 	uint32_t error;           /* 0 = ok, else error   */
-	char handle[8];         /* handle you got from request  */
+	nbd_handle_t handle;      /* handle you got from request  */
 };
 
 void nbd_r2h_init( struct nbd_init_raw * from, struct nbd_init * to );

src/common/readwrite.c

@@ -41,7 +41,7 @@ int socket_connect(struct sockaddr* to, struct sockaddr* from)
 	return fd;
 }
 
-int nbd_check_hello( struct nbd_init_raw* init_raw, off64_t* out_size )
+int nbd_check_hello( struct nbd_init_raw* init_raw, uint64_t* out_size )
 {
 	if ( strncmp( init_raw->passwd, INIT_PASSWD, 8 ) != 0 ) {
 		warn( "wrong passwd" );
@@ -62,7 +62,7 @@ fail:
 
 }
 
-int socket_nbd_read_hello( int fd, off64_t* out_size )
+int socket_nbd_read_hello( int fd, uint64_t* out_size )
 {
 	struct nbd_init_raw init_raw;
 
@@ -101,12 +101,11 @@ int socket_nbd_write_hello(int fd, off64_t out_size)
 	return 1;
 }
 
-void fill_request(struct nbd_request *request, int type, off64_t from, int len)
+void fill_request(struct nbd_request *request, int type, uint64_t from, uint32_t len)
 {
 	request->magic  = htobe32(REQUEST_MAGIC);
 	request->type   = htobe32(type);
-	((int*) request->handle)[0] = rand();
-	((int*) request->handle)[1] = rand();
+	request->handle.w = (((uint64_t)rand()) << 32) | ((uint64_t)rand());
 	request->from   = htobe64(from);
 	request->len    = htobe32(len);
 }
@@ -126,7 +125,7 @@ void read_reply(int fd, struct nbd_request *request, struct nbd_reply *reply)
 	if (reply->error != 0) {
 		error("Server replied with error %d", reply->error);
 	}
-	if (strncmp(request->handle, reply->handle, 8) != 0) {
+	if (request->handle.w != reply->handle.w) {
 		error("Did not reply with correct handle");
 	}
 }
@@ -149,7 +148,7 @@ void wait_for_data( int fd, int timeout_secs )
 }
 
 
-void socket_nbd_read(int fd, off64_t from, int len, int out_fd, void* out_buf, int timeout_secs)
+void socket_nbd_read(int fd, uint64_t from, uint32_t len, int out_fd, void* out_buf, int timeout_secs)
 {
 	struct nbd_request request;
 	struct nbd_reply   reply;
@@ -173,7 +172,7 @@ void socket_nbd_read(int fd, off64_t from, int len, int out_fd, void* out_buf, i
 	}
 }
 
-void socket_nbd_write(int fd, off64_t from, int len, int in_fd, void* in_buf, int timeout_secs)
+void socket_nbd_write(int fd, uint64_t from, uint32_t len, int in_fd, void* in_buf, int timeout_secs)
 {
 	struct nbd_request request;
 	struct nbd_reply   reply;
@@ -213,10 +212,12 @@ int socket_nbd_disconnect( int fd )
 }
 
 #define CHECK_RANGE(error_type) { \
-	off64_t size;\
+	uint64_t size;\
 	int success = socket_nbd_read_hello(params->client, &size); \
 	if ( success ) {\
-		if (params->from < 0 || (params->from + params->len) > size) {\
+		uint64_t endpoint = params->from + params->len; \
+		if (endpoint > size || \
+				endpoint < params->from ) { /* this happens on overflow */ \
 			fatal(error_type \
 			  " request %d+%d is out of range given size %d", \
 			  params->from, params->len, size\

src/common/readwrite.h

@@ -0,0 +1,23 @@
+#ifndef READWRITE_H
+
+#define READWRITE_H
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include "nbdtypes.h"
+
+int socket_connect(struct sockaddr* to, struct sockaddr* from);
+int socket_nbd_read_hello(int fd, uint64_t* size);
+int socket_nbd_write_hello(int fd, uint64_t size);
+void socket_nbd_read(int fd, uint64_t from, uint32_t len, int out_fd, void* out_buf, int timeout_secs);
+void socket_nbd_write(int fd, uint64_t from, uint32_t len, int out_fd, void* out_buf, int timeout_secs);
+int socket_nbd_disconnect( int fd );
+
+/* as you can see, we're slowly accumulating code that should really be in an
+ * NBD library */
+
+void nbd_hello_to_buf( struct nbd_init_raw* buf, uint64_t out_size );
+int nbd_check_hello( struct nbd_init_raw* init_raw, uint64_t* out_size );
+
+#endif
+

src/common/remote.c

@@ -63,7 +63,5 @@ void do_remote_command(char* command, char* socket_name, int argc, char** argv)
 	print_response( response );
 
 	exit(atoi(response));
-
-	close(remote);
 }
 

src/common/self_pipe.c

@@ -51,7 +51,6 @@ struct self_pipe * self_pipe_create(void)
 {
 	struct self_pipe *sig = xmalloc( sizeof( struct self_pipe ) );
 	int fds[2];
-	int fcntl_err;
 	
 	if ( NULL == sig ) { return NULL; }
 
@@ -62,7 +61,7 @@ struct self_pipe * self_pipe_create(void)
 	}
 
 	if ( fcntl( fds[0], F_SETFL, O_NONBLOCK ) || fcntl( fds[1], F_SETFL, O_NONBLOCK ) ) {
-		fcntl_err = errno;
+		int fcntl_err = errno;
 		while( close( fds[0] ) == -1 && errno == EINTR );
 		while( close( fds[1] ) == -1 && errno == EINTR );
 		free( sig );

src/common/sockutil.c

@@ -39,7 +39,6 @@ const char* sockaddr_address_string( const struct sockaddr* sa, char* dest, size
 	struct sockaddr_un*  un  = ( struct sockaddr_un*  ) sa;
 
 	unsigned short real_port = ntohs( in->sin_port ); // common to in and in6
-	size_t size;
 	const char* ret = NULL;
 
 	memset( dest, 0, len );
@@ -57,7 +56,7 @@ const char* sockaddr_address_string( const struct sockaddr* sa, char* dest, size
 	}
 
 	if ( NULL != ret && real_port > 0 && sa->sa_family != AF_UNIX ) {
-		size = strlen( dest );
+		size_t size = strlen( dest );
 		snprintf( dest + size, len - size, " port %d", real_port );
 	}
 
@@ -75,6 +74,11 @@ int sock_set_tcp_nodelay( int fd, int optval )
 	return setsockopt( fd, IPPROTO_TCP, TCP_NODELAY, &optval, sizeof(optval) );
 }
 
+int sock_set_tcp_cork( int fd, int optval )
+{
+	return setsockopt( fd, IPPROTO_TCP, TCP_CORK, &optval, sizeof(optval) );
+}
+
 int sock_set_nonblock( int fd, int optval )
 {
 	int flags = fcntl( fd, F_GETFL );
@@ -96,7 +100,7 @@ int sock_try_bind( int fd, const struct sockaddr* sa )
 {
 	int bind_result;
 	char s_address[256];
-	int retry = 1;
+	int retry = 10;
 
 	sockaddr_address_string( sa, &s_address[0], 256 );
 
@@ -122,8 +126,11 @@ int sock_try_bind( int fd, const struct sockaddr* sa )
 				 * will cope with it.
 				 */
 				case EADDRNOTAVAIL:
-					debug( "retrying" );
-					sleep( 1 );
+					retry--;
+					if (retry) {
+						debug( "retrying" );
+						sleep( 1 );
+					}
 					continue;
 				case EADDRINUSE:
 					warn( "%s in use, giving up.", s_address );

src/common/sockutil.h

@@ -20,8 +20,8 @@ int sock_set_reuseaddr(int fd, int optval);
 /* Set the tcp_nodelay option */
 int sock_set_tcp_nodelay(int fd, int optval);
 
-/* TODO: Set the tcp_cork option */
-// int sock_set_cork(int fd, int optval);
+/* Set the tcp_cork option */
+int sock_set_tcp_cork(int fd, int optval);
 
 int sock_set_nonblock(int fd, int optval);
 

src/common/util.h

@@ -116,6 +116,7 @@ uint64_t monotonic_time_ms(void);
 #define fatal(msg, ...) do { \
 	myloglev(4, msg, ##__VA_ARGS__); \
 	error_handler(1); \
+	exit(1); /* never-reached, this is to make static code analizer happy */ \
 } while(0)
 
 

src/main.c

@@ -2,12 +2,16 @@
 #include "mode.h"
 
 #include <signal.h>
+#include <stdlib.h>
+#include <time.h>
 
 int main(int argc, char** argv)
 {
 	signal(SIGPIPE, SIG_IGN); /* calls to splice() unhelpfully throw this */
 	error_init();
 
+	srand(time(NULL));
+
 	if (argc < 2) {
 		exit_err( help_help_text );
 	}

src/mbox.c

@@ -1,77 +0,0 @@
-#include "mbox.h"
-#include "util.h"
-
-#include <pthread.h>
-
-struct mbox * mbox_create( void )
-{
-	struct mbox * mbox = xmalloc( sizeof( struct mbox ) );
-	FATAL_UNLESS( 0 == pthread_cond_init( &mbox->filled_cond, NULL ),
-			"Failed to initialise a condition variable" );
-	FATAL_UNLESS( 0 == pthread_cond_init( &mbox->emptied_cond, NULL ),
-			"Failed to initialise a condition variable" );
-	FATAL_UNLESS( 0 == pthread_mutex_init( &mbox->mutex, NULL ),
-			"Failed to initialise a mutex" );
-	return mbox;
-}
-
-void mbox_post( struct mbox * mbox, void * contents )
-{
-	pthread_mutex_lock( &mbox->mutex );
-	{
-		if (mbox->full){
-			pthread_cond_wait( &mbox->emptied_cond, &mbox->mutex );
-		}
-		mbox->contents = contents;
-		mbox->full = 1;
-		while( 0 != pthread_cond_signal( &mbox->filled_cond ) );
-	}
-	pthread_mutex_unlock( &mbox->mutex );
-}
-
-
-void * mbox_contents( struct mbox * mbox )
-{
-	return mbox->contents;
-}
-
-
-int mbox_is_full( struct mbox * mbox )
-{
-	return mbox->full;
-}
-
-
-void * mbox_receive( struct mbox * mbox )
-{
-	NULLCHECK( mbox );
-	void * result;
-
-	pthread_mutex_lock( &mbox->mutex );
-	{
-		if ( !mbox->full ) {
-			pthread_cond_wait( &mbox->filled_cond, &mbox->mutex );
-		}
-		mbox->full = 0;
-		result = mbox->contents;
-		mbox->contents = NULL;
-
-		while( 0 != pthread_cond_signal( &mbox->emptied_cond));
-	}
-	pthread_mutex_unlock( &mbox->mutex );
-
-	return result;
-}
-
-
-void mbox_destroy( struct mbox * mbox )
-{
-	NULLCHECK( mbox );
-
-	while( 0 != pthread_cond_destroy( &mbox->emptied_cond ) );
-	while( 0 != pthread_cond_destroy( &mbox->filled_cond ) );
-
-	while( 0 != pthread_mutex_destroy( &mbox->mutex ) );
-
-	free( mbox );
-}

src/prefetch.h

@@ -1,14 +0,0 @@
-#ifndef PREFETCH_H
-#define PREFETCH_H
-
-#define PREFETCH_BUFSIZE 4096
-
-struct prefetch {
-        int is_full;
-        __be64 from;
-        __be32 len;
-
-        char buffer[PREFETCH_BUFSIZE];
-};
-
-#endif

src/proxy-main.c

@@ -1,4 +1,6 @@
 #include <signal.h>
+#include <stdlib.h>
+#include <time.h>
 
 #include "mode.h"
 #include "util.h"
@@ -12,6 +14,7 @@ static struct option proxy_options[] = {
 	GETOPT_CONNECT_ADDR,
 	GETOPT_CONNECT_PORT,
 	GETOPT_BIND,
+	GETOPT_CACHE,
 	GETOPT_QUIET,
 	GETOPT_VERBOSE,
 	{0}
@@ -27,22 +30,25 @@ static char proxy_help_text[] =
 	"\t--" OPT_CONNECT_ADDR ",-C <ADDR>\tAddress of the proxied server.\n"
 	"\t--" OPT_CONNECT_PORT ",-P <PORT>\tPort of the proxied server.\n"
 	"\t--" OPT_BIND ",-b <ADDR>\tThe address we connect from, as a proxy.\n"
+	"\t--" OPT_CACHE ",-c[=<CACHE-BYTES>]\tUse a RAM read cache of the given size.\n"
 	QUIET_LINE
 	VERBOSE_LINE;
 
+static char proxy_default_cache_size[] = "4096";
+
 void read_proxy_param(
 			int c,
 			char **downstream_addr,
 			char **downstream_port,
 			char **upstream_addr,
 			char **upstream_port,
-			char **bind_addr )
+			char **bind_addr,
+			char **cache_bytes)
 {
 	switch( c ) {
 		case 'h' :
 			fprintf( stdout, "%s\n", proxy_help_text );
 			exit( 0 );
-			break;
 		case 'l':
 			*downstream_addr = optarg;
 			break;
@@ -58,6 +64,9 @@ void read_proxy_param(
 		case 'b':
 			*bind_addr = optarg;
 			break;
+		case 'c':
+			*cache_bytes = optarg ? optarg : proxy_default_cache_size;
+			break;
 		case 'q':
 			log_level = QUIET_LOG_LEVEL;
 			break;
@@ -89,6 +98,7 @@ int main( int argc, char *argv[] )
 	char *upstream_addr   = NULL;
 	char *upstream_port   = NULL;
 	char *bind_addr       = NULL;
+	char *cache_bytes     = NULL;
 	int success;
 
 	sigset_t mask;
@@ -103,6 +113,8 @@ int main( int argc, char *argv[] )
 	exit_action.sa_mask = mask;
 	exit_action.sa_flags = 0;
 
+	srand(time(NULL));
+
 	while (1) {
 		c = getopt_long( argc, argv, proxy_short_options, proxy_options, NULL );
 		if ( -1 == c ) { break; }
@@ -111,7 +123,8 @@ int main( int argc, char *argv[] )
 				&downstream_port,
 				&upstream_addr,
 				&upstream_port,
-				&bind_addr
+				&bind_addr,
+				&cache_bytes
 		);
 	}
 
@@ -128,7 +141,8 @@ int main( int argc, char *argv[] )
 		downstream_port,
 		upstream_addr,
 		upstream_port,
-		bind_addr
+		bind_addr,
+		cache_bytes
 	);
 
 	/* Set these *after* proxy has been assigned to */

src/proxy/prefetch.c

@@ -0,0 +1,68 @@
+#include "prefetch.h"
+#include "util.h"
+
+
+struct prefetch* prefetch_create( size_t size_bytes ){
+
+	struct prefetch* out = xmalloc( sizeof( struct prefetch ) );
+	NULLCHECK( out );
+	
+	out->buffer = xmalloc( size_bytes );
+	NULLCHECK( out->buffer );
+
+	out->size = size_bytes;
+	out->is_full = 0;
+	out->from = 0;
+	out->len = 0;
+
+	return out;
+
+}
+
+void prefetch_destroy( struct prefetch *prefetch ) {
+	if( prefetch ) {
+		free( prefetch->buffer );
+		free( prefetch );
+	}
+}
+
+size_t prefetch_size( struct prefetch *prefetch){
+	if ( prefetch ) {
+		return prefetch->size;
+	} else {
+		return 0;
+	}
+}
+
+void prefetch_set_is_empty( struct prefetch *prefetch ){
+	prefetch_set_full( prefetch, 0 );
+}
+
+void prefetch_set_is_full( struct prefetch *prefetch ){
+	prefetch_set_full( prefetch, 1 );
+}
+
+void prefetch_set_full( struct prefetch *prefetch, int val ){
+	if( prefetch ) {
+		prefetch->is_full = val;
+	}
+}
+
+int prefetch_is_full( struct prefetch *prefetch ){
+	if( prefetch ) {
+		return prefetch->is_full;
+	} else {
+		return 0;
+	}
+}
+
+int prefetch_contains( struct prefetch *prefetch, uint64_t from, uint32_t len ){
+	NULLCHECK( prefetch );
+	return from >= prefetch->from &&
+		from + len <= prefetch->from + prefetch->len;
+}
+
+char *prefetch_offset( struct prefetch *prefetch, uint64_t from ){
+	NULLCHECK( prefetch );
+	return prefetch->buffer + (from - prefetch->from);
+}

src/proxy/prefetch.h

@@ -0,0 +1,33 @@
+#ifndef PREFETCH_H
+#define PREFETCH_H
+
+#include <stdint.h>
+#include <stddef.h>
+
+#define PREFETCH_BUFSIZE 4096
+
+struct prefetch {
+	/* True if there is data in the buffer. */
+        int is_full;
+	/* The start point of the current content of buffer */
+        uint64_t from;
+	/* The length of the current content of buffer */
+        uint32_t len;
+
+	/* The total size of the buffer, in bytes. */
+	size_t size;
+
+        char *buffer;
+};
+
+struct prefetch* prefetch_create( size_t size_bytes );
+void prefetch_destroy( struct prefetch *prefetch );
+size_t prefetch_size( struct prefetch *);
+void prefetch_set_is_empty( struct prefetch *prefetch );
+void prefetch_set_is_full( struct prefetch *prefetch );
+void prefetch_set_full( struct prefetch *prefetch, int val );
+int prefetch_is_full( struct prefetch *prefetch );
+int prefetch_contains( struct prefetch *prefetch, uint64_t from, uint32_t len );
+char *prefetch_offset( struct prefetch *prefetch, uint64_t from );
+
+#endif

src/proxy/proxy.c

@@ -1,9 +1,7 @@
 #include "proxy.h"
 #include "readwrite.h"
 
-#ifdef PREFETCH
 #include "prefetch.h"
-#endif
 
 
 #include "ioutil.h"
@@ -20,7 +18,8 @@ struct proxier* proxy_create(
 	char* s_downstream_port,
 	char* s_upstream_address,
 	char* s_upstream_port,
-	char* s_upstream_bind )
+	char* s_upstream_bind,
+	char* s_cache_bytes )
 {
 	struct proxier* out;
 	out = xmalloc( sizeof( struct proxier ) );
@@ -65,9 +64,16 @@ struct proxier* proxy_create(
 	out->downstream_fd = -1;
 	out->upstream_fd = -1;
 
-#ifdef PREFETCH
-	out->prefetch = xmalloc( sizeof( struct prefetch ) );
-#endif
+	out->prefetch = NULL;
+	if ( s_cache_bytes ){
+		int cache_bytes = atoi( s_cache_bytes );
+		/* leaving this off or setting a cache size of zero or
+		 * less results in no cache.
+		 */
+		if ( cache_bytes >= 0 ) {
+			out->prefetch = prefetch_create( cache_bytes );
+		}
+	}
 
 	out->init.buf = xmalloc( sizeof( struct nbd_init_raw ) );
 	out->req.buf  = xmalloc( NBD_MAX_SIZE );
@@ -76,20 +82,28 @@ struct proxier* proxy_create(
 	return out;
 }
 
+int proxy_prefetches( struct proxier* proxy ) {
+	NULLCHECK( proxy );
+	return proxy->prefetch != NULL;
+}
+
+int proxy_prefetch_bufsize( struct proxier* proxy ){
+	NULLCHECK( proxy );
+	return prefetch_size( proxy->prefetch );
+}
+
 void proxy_destroy( struct proxier* proxy )
 {
 	free( proxy->init.buf );
 	free( proxy->req.buf );
 	free( proxy->rsp.buf );
-#ifdef PREFETCH
-	free( proxy->prefetch );
-#endif
+	prefetch_destroy( proxy->prefetch );
 
 	free( proxy );
 }
 
 /* Shared between our two different connect_to_upstream paths */
-void proxy_finish_connect_to_upstream( struct proxier *proxy, off64_t size );
+void proxy_finish_connect_to_upstream( struct proxier *proxy, uint64_t size );
 
 /* Try to establish a connection to our upstream server. Return 1 on success,
  * 0 on failure. this is a blocking call that returns a non-blocking socket.
@@ -102,7 +116,7 @@ int proxy_connect_to_upstream( struct proxier* proxy )
 	}
 
 	int fd = socket_connect( &proxy->connect_to.generic, connect_from );
-	off64_t size = 0;
+	uint64_t size = 0;
 
 	if ( -1 == fd ) {
 		return 0;
@@ -174,7 +188,7 @@ error:
 	return;
 }
 
-void proxy_finish_connect_to_upstream( struct proxier *proxy, off64_t size ) {
+void proxy_finish_connect_to_upstream( struct proxier *proxy, uint64_t size ) {
 
 	if ( proxy->upstream_size == 0 ) {
 		info( "Size of upstream image is %"PRIu64" bytes", size );
@@ -186,6 +200,13 @@ void proxy_finish_connect_to_upstream( struct proxier *proxy, off64_t size ) {
 	}
 
 	proxy->upstream_size = size;
+
+	if ( AF_UNIX != proxy->connect_to.family ) {
+		if ( sock_set_tcp_nodelay( proxy->upstream_fd, 1 ) == -1 ) {
+			warn( SHOW_ERRNO( "Failed to set TCP_NODELAY" ) );
+		}
+	}
+
 	info( "Connected to upstream on fd %i", proxy->upstream_fd );
 
 	return;
@@ -272,10 +293,9 @@ static inline int proxy_state_upstream( int state )
 	       state == WRITE_TO_UPSTREAM   || state == READ_FROM_UPSTREAM;
 }
 
-#ifdef PREFETCH
-
 int proxy_prefetch_for_request( struct proxier* proxy, int state )
 {
+	NULLCHECK( proxy );
 	struct nbd_request* req = &proxy->req_hdr;
 	struct nbd_reply* rsp = &proxy->rsp_hdr;
 
@@ -284,23 +304,11 @@ int proxy_prefetch_for_request( struct proxier* proxy, int state )
 
 	int is_read = ( req->type & REQUEST_MASK ) == REQUEST_READ;
 
-	int prefetch_start = req->from;
-	int prefetch_end = req->from + ( req->len * 2 );
-
-	/* We only want to consider prefetching if we know we're not
-	 * getting too much data back, if it's a read request, and if
-	 * the prefetch won't try to read past the end of the file.
-	 */
-
-	int prefetching = req->len <= PREFETCH_BUFSIZE && is_read &&
-		prefetch_start < prefetch_end && prefetch_end <= proxy->upstream_size;
-
 	if ( is_read ) {
 		/* See if we can respond with what's in our prefetch
 		 * cache */
-		if ( proxy->prefetch->is_full &&
-		    req->from == proxy->prefetch->from &&
-		    req->len  == proxy->prefetch->len ) {
+		if ( prefetch_is_full( proxy->prefetch ) &&
+			prefetch_contains( proxy->prefetch, req->from, req->len ) ) {
 			/* HUZZAH!  A match! */
 			debug( "Prefetch hit!" );
 
@@ -315,10 +323,11 @@ int proxy_prefetch_for_request( struct proxier* proxy, int state )
 			/* and the data */
 			memcpy(
 				proxy->rsp.buf + NBD_REPLY_SIZE,
-				proxy->prefetch->buffer, proxy->prefetch->len
+				prefetch_offset( proxy->prefetch, req->from ),
+				req->len
 			);
 
-			proxy->rsp.size = NBD_REPLY_SIZE + proxy->prefetch->len;
+			proxy->rsp.size = NBD_REPLY_SIZE + req->len;
 			proxy->rsp.needle = 0;
 
 			/* return early, our work here is done */
@@ -332,11 +341,24 @@ int proxy_prefetch_for_request( struct proxier* proxy, int state )
 		 * whether we can keep it or not.
 		 */
 		debug( "Blowing away prefetch cache on type %d request.", req->type );
-		proxy->prefetch->is_full = 0;
+		prefetch_set_is_empty( proxy->prefetch );
 	}
 
 	debug( "Prefetch cache MISS!");
 
+	uint64_t prefetch_start = req->from;
+	/* We prefetch what we expect to be the next request. */
+	uint64_t prefetch_end = req->from + ( req->len * 2 );
+
+	/* We only want to consider prefetching if we know we're not
+	 * getting too much data back, if it's a read request, and if
+	 * the prefetch won't try to read past the end of the file.
+	 */
+	int prefetching = 
+		req->len <= prefetch_size( proxy->prefetch ) && 
+		is_read &&
+		prefetch_start < prefetch_end && 
+		prefetch_end <= proxy->upstream_size; 
 
 	/* We pull the request out of the proxy struct, rewrite the
 	 * request size, and write it back.
@@ -347,7 +369,8 @@ int proxy_prefetch_for_request( struct proxier* proxy, int state )
 
 		req->len *= 2;
 
-		debug( "Prefetching %"PRIu32" bytes", req->len - proxy->prefetch_req_orig_len );
+		debug( "Prefetching additional %"PRIu32" bytes", 
+				req->len - proxy->prefetch_req_orig_len );
 		nbd_h2r_request( req, req_raw );
 	}
 
@@ -364,10 +387,10 @@ int proxy_prefetch_for_reply( struct proxier* proxy, int state )
 
 	prefetched_bytes = proxy->req_hdr.len - proxy->prefetch_req_orig_len;
 
-	debug( "Prefetched %d bytes", prefetched_bytes );
+	debug( "Prefetched additional %d bytes", prefetched_bytes );
 	memcpy(
-		proxy->rsp.buf + proxy->prefetch_req_orig_len,
-		&(proxy->prefetch->buffer),
+		proxy->prefetch->buffer,
+		proxy->rsp.buf + proxy->prefetch_req_orig_len + NBD_REPLY_SIZE,
 		prefetched_bytes
 	);
 
@@ -382,13 +405,12 @@ int proxy_prefetch_for_reply( struct proxier* proxy, int state )
 	proxy->rsp.size -= prefetched_bytes;
 
 	/* And we need to reset these */
-	proxy->prefetch->is_full = 1;
+	prefetch_set_is_full( proxy->prefetch );
 	proxy->is_prefetch_req = 0;
 
 	return state;
 }
 
-#endif
 
 
 int proxy_read_from_downstream( struct proxier *proxy, int state )
@@ -469,10 +491,8 @@ int proxy_continue_connecting_to_upstream( struct proxier* proxy, int state )
 		return state;
 	}
 
-#ifdef PREFETCH
 	/* Data may have changed while we were disconnected */
-	proxy->prefetch->is_full = 0;
-#endif
+	prefetch_set_is_empty( proxy->prefetch );
 
 	info( "Connected to upstream on fd %i", proxy->upstream_fd );
 	return READ_INIT_FROM_UPSTREAM;
@@ -492,7 +512,7 @@ int proxy_read_init_from_upstream( struct proxier* proxy, int state )
 	}
 
 	if ( proxy->init.needle == proxy->init.size ) {
-		off64_t upstream_size;
+		uint64_t upstream_size;
 		if ( !nbd_check_hello( (struct nbd_init_raw*) proxy->init.buf, &upstream_size ) ) {
 			warn( "Upstream sent invalid init" );
 			goto disconnect;
@@ -518,11 +538,22 @@ int proxy_write_to_upstream( struct proxier* proxy, int state )
 	ssize_t count;
 
 //	assert( state == WRITE_TO_UPSTREAM );
+
+	/* FIXME: We may set cork=1 multiple times as a result of this idiom.
+	 * Not a serious problem, but we could do better
+	 */
+	if ( proxy->req.needle == 0 && AF_UNIX != proxy->connect_to.family ) {
+		if ( sock_set_tcp_cork( proxy->upstream_fd, 1 ) == -1 ) {
+			warn( SHOW_ERRNO( "Failed to set TCP_CORK" ) );
+		}
+	}
+
 	count = iobuf_write( proxy->upstream_fd, &proxy->req );
 
 	if ( count == -1 ) {
 		warn( SHOW_ERRNO( "Failed to send request to upstream" ) );
 		proxy->req.needle = 0;
+		// We're throwing the socket away so no need to uncork
 		return CONNECT_TO_UPSTREAM;
 	}
 
@@ -531,6 +562,14 @@ int proxy_write_to_upstream( struct proxier* proxy, int state )
 		 * still need req.size if reading the reply fails - we disconnect
 		 * and resend the reply in that case - so keep it around for now. */
 		proxy->req.needle = 0;
+
+		if ( AF_UNIX != proxy->connect_to.family ) {
+			if ( sock_set_tcp_cork( proxy->upstream_fd, 0 ) == -1 ) {
+				warn( SHOW_ERRNO( "Failed to unset TCP_CORK" ) );
+				// TODO: should we return to CONNECT_TO_UPSTREAM in this instance?
+			}
+		}
+
 		return READ_FROM_UPSTREAM;
 	}
 
@@ -670,7 +709,7 @@ void proxy_session( struct proxier* proxy )
 			state_started = monotonic_time_ms();
 
 			debug(
-				"State transitition from %s to %s",
+				"State transition from %s to %s",
 				proxy_session_state_names[old_state],
 				proxy_session_state_names[state]
 			);
@@ -736,14 +775,12 @@ void proxy_session( struct proxier* proxy )
 			case READ_FROM_DOWNSTREAM:
 				if ( FD_ISSET( proxy->downstream_fd, &rfds ) ) {
 					state = proxy_read_from_downstream( proxy, state );
-#ifdef PREFETCH
 					/* Check if we can fulfil the request from prefetch, or
 					 * rewrite the request to fill the prefetch buffer if needed
 					 */
-					if ( state == WRITE_TO_UPSTREAM ) {
+					if ( proxy_prefetches( proxy ) && state == WRITE_TO_UPSTREAM ) {
 						state = proxy_prefetch_for_request( proxy, state );
 					}
-#endif
 				}
 				break;
 			case CONNECT_TO_UPSTREAM:
@@ -774,12 +811,10 @@ void proxy_session( struct proxier* proxy )
 				if ( FD_ISSET( proxy->upstream_fd, &rfds ) ) {
 					state = proxy_read_from_upstream( proxy, state );
 				}
-# ifdef PREFETCH
 				/* Fill the prefetch buffer and rewrite the reply, if needed */
-				if ( state == WRITE_TO_DOWNSTREAM ) {
+				if ( proxy_prefetches( proxy ) && state == WRITE_TO_DOWNSTREAM ) {
 					state = proxy_prefetch_for_reply( proxy, state );
 				}
-#endif
 				break;
 			case WRITE_TO_DOWNSTREAM:
 				if ( FD_ISSET( proxy->downstream_fd, &wfds ) ) {
@@ -797,6 +832,13 @@ void proxy_session( struct proxier* proxy )
 					proxy_session_state_names[state]
 				);
 				state = CONNECT_TO_UPSTREAM;
+
+				/* Since we've timed out, we won't have gone through the timeout logic
+				 * in the various state handlers that resets these appropriately... */
+				proxy->init.size = 0;
+				proxy->init.needle = 0;
+				proxy->rsp.size = 0;
+				proxy->rsp.needle = 0;
 			}
 		}
 	}

src/proxy/proxy.h

@@ -5,7 +5,6 @@
 #include <unistd.h>
 
 #include "ioutil.h"
-#include "flexnbd.h"
 #include "parse.h"
 #include "nbdtypes.h"
 #include "self_pipe.h"
@@ -21,9 +20,6 @@
 #define UPSTREAM_TIMEOUT 30 * 1000
 
 struct proxier {
-	/* The flexnbd wrapper this proxier is attached to */
-	struct flexnbd*   flexnbd;
-
 	/** address/port to bind to */
 	union mysockaddr  listen_on;
 
@@ -48,7 +44,7 @@ struct proxier {
 	int               upstream_fd;
 
 	/* This is the size we advertise to the downstream server */
-	off64_t           upstream_size;
+	uint64_t          upstream_size;
 
 	/* We transform the raw request header into here */
 	struct nbd_request req_hdr;
@@ -73,7 +69,8 @@ struct proxier {
 	uint64_t req_count;
 	int hello_sent;
 
-#ifdef PREFETCH
+	/** These are only used if we pass --cache on the command line */
+
 	/* While the in-flight request has been munged by prefetch, these two are
 	 * set to true, and the original length of the request, respectively */
 	int is_prefetch_req;
@@ -81,7 +78,8 @@ struct proxier {
 
 	/* And here, we actually store the prefetched data once it's returned */
 	struct prefetch *prefetch;
-#endif
+
+	/** */
 };
 
 struct proxier* proxy_create(
@@ -89,7 +87,8 @@ struct proxier* proxy_create(
 	char* s_downstream_port,
 	char* s_upstream_address,
 	char* s_upstream_port,
-	char* s_upstream_bind );
+	char* s_upstream_bind,
+	char* s_cache_bytes);
 int do_proxy( struct proxier* proxy );
 void proxy_cleanup( struct proxier* proxy );
 void proxy_destroy( struct proxier* proxy );

src/readwrite.h

@@ -1,23 +0,0 @@
-#ifndef READWRITE_H
-
-#define READWRITE_H
-
-#include <sys/types.h>
-#include <sys/socket.h>
-#include "nbdtypes.h"
-
-int socket_connect(struct sockaddr* to, struct sockaddr* from);
-int socket_nbd_read_hello(int fd, off64_t * size);
-int socket_nbd_write_hello(int fd, off64_t size);
-void socket_nbd_read(int fd, off64_t from, int len, int out_fd, void* out_buf, int timeout_secs);
-void socket_nbd_write(int fd, off64_t from, int len, int out_fd, void* out_buf, int timeout_secs);
-int socket_nbd_disconnect( int fd );
-
-/* as you can see, we're slowly accumulating code that should really be in an
- * NBD library */
-
-void nbd_hello_to_buf( struct nbd_init_raw* buf, off64_t out_size );
-int nbd_check_hello( struct nbd_init_raw* init_raw, off64_t* out_size );
-
-#endif
-

src/server/acl.c

@@ -31,7 +31,7 @@ static int is_included_in_acl(int list_length, struct ip_and_mask (*list)[], uni
 	for (i=0; i < list_length; i++) {
 		struct ip_and_mask *entry = &(*list)[i];
 		int testbits;
-		unsigned char *raw_address1, *raw_address2;
+		unsigned char *raw_address1 = NULL, *raw_address2 = NULL;
 
 		debug("checking acl entry %d (%d/%d)", i, test->generic.sa_family, entry->ip.family);
 

src/server/bitset.h

@@ -0,0 +1,135 @@
+#ifndef BITSET_H
+#define BITSET_H
+
+#include "util.h"
+
+#include <inttypes.h>
+#include <string.h>
+#include <pthread.h>
+
+/*
+ * Make the bitfield words 'opaque' to prevent code
+ * poking at the bits directly without using these
+ * accessors/macros
+ */
+typedef uint64_t	bitfield_word_t;
+typedef bitfield_word_t * bitfield_p;
+
+#define BITFIELD_WORD_SIZE	sizeof(bitfield_word_t)
+#define BITS_PER_WORD	(BITFIELD_WORD_SIZE * 8)
+
+#define BIT_MASK(_idx)	\
+			(1LL << ((_idx) & (BITS_PER_WORD - 1)))
+#define BIT_WORD(_b, _idx)	\
+			((bitfield_word_t*)(_b))[(_idx) / BITS_PER_WORD]
+
+/* Calculates the number of words needed to store _bytes number of bytes
+ * this is added to accommodate code that wants to use bytes sizes
+ */
+#define BIT_WORDS_FOR_SIZE(_bytes) \
+			((_bytes + (BITFIELD_WORD_SIZE-1)) / BITFIELD_WORD_SIZE)
+
+/** Return the bit value ''idx'' in array ''b'' */
+static inline int bit_get(bitfield_p b, uint64_t idx) {
+	return (BIT_WORD(b, idx) >> (idx & (BITS_PER_WORD-1))) & 1;
+}
+
+/** Return 1 if the bit at ''idx'' in array ''b'' is set */
+static inline int bit_is_set(bitfield_p b, uint64_t idx) {
+	return bit_get(b, idx);
+}
+/** Return 1 if the bit at ''idx'' in array ''b'' is clear */
+static inline int bit_is_clear(bitfield_p b, uint64_t idx) {
+	return !bit_get(b, idx);
+}
+/** Tests whether the bit at ''idx'' in array ''b'' has value ''value'' */
+static inline int bit_has_value(bitfield_p b, uint64_t idx, int value) {
+	return bit_get(b, idx) == !!value;
+}
+/** Sets the bit ''idx'' in array ''b'' */
+static inline void bit_set(bitfield_p b, uint64_t idx) {
+	BIT_WORD(b, idx) |= BIT_MASK(idx);
+}
+/** Clears the bit ''idx'' in array ''b'' */
+static inline void bit_clear(bitfield_p b, uint64_t idx) {
+	BIT_WORD(b, idx) &= ~BIT_MASK(idx);
+}
+/** Sets ''len'' bits in array ''b'' starting at offset ''from'' */
+static inline void bit_set_range(bitfield_p b, uint64_t from, uint64_t len)
+{
+	for ( ; (from % BITS_PER_WORD) != 0 && len > 0 ; len-- ) {
+		bit_set( b, from++ );
+	}
+
+	if (len >= BITS_PER_WORD) {
+		memset(&BIT_WORD(b, from), 0xff, len / 8 );
+		from += len;
+		len = len % BITS_PER_WORD;
+		from -= len;
+	}
+
+	for ( ; len > 0 ; len-- ) {
+		bit_set( b, from++ );
+	}
+}
+/** Clears ''len'' bits in array ''b'' starting at offset ''from'' */
+static inline void bit_clear_range(bitfield_p b, uint64_t from, uint64_t len)
+{
+	for ( ; (from % BITS_PER_WORD) != 0 && len > 0 ; len-- ) {
+		bit_clear( b, from++ );
+	}
+
+	if (len >= BITS_PER_WORD) {
+		memset(&BIT_WORD(b, from), 0, len / 8 );
+		from += len;
+		len = len % BITS_PER_WORD;
+		from -= len;
+	}
+
+	for ( ; len > 0 ; len-- ) {
+		bit_clear( b, from++ );
+	}
+}
+
+/** Counts the number of contiguous bits in array ''b'', starting at ''from''
+  * up to a maximum number of bits ''len''.  Returns the number of contiguous
+  * bits that are the same as the first one specified. If ''run_is_set'' is
+  * non-NULL, the value of that bit is placed into it.
+  */
+static inline uint64_t bit_run_count(bitfield_p b, uint64_t from, uint64_t len, int *run_is_set) {
+	uint64_t count = 0;
+	int first_value = bit_get(b, from);
+	bitfield_word_t word_match = first_value ? -1 : 0;
+
+	if ( run_is_set != NULL ) {
+		*run_is_set = first_value;
+	}
+
+	for ( ; ((from + count) % BITS_PER_WORD) != 0 && len > 0; len--) {
+		if (bit_has_value(b, from + count, first_value)) {
+			count++;
+		} else {
+			return count;
+		}
+	}
+
+	for ( ; len >= BITS_PER_WORD ; len -= BITS_PER_WORD ) {
+		if (BIT_WORD(b, from + count) == word_match) {
+			count += BITS_PER_WORD;
+		} else {
+			break;
+		}
+	}
+
+	for ( ; len > 0; len-- ) {
+		if ( bit_has_value(b, from + count, first_value) ) {
+			count++;
+		}
+	}
+
+	return count;
+}
+
+
+#endif
+

src/server/bitstream.h

@@ -1,114 +1,14 @@
-#ifndef BITSET_H
-#define BITSET_H
+/*
+ * bitstream.h
+ *
+ *  Created on: 13 Oct 2016
+ *      Author: michel
+ */
 
-#include "util.h"
+#ifndef SRC_SERVER_BITSTREAM_H_
+#define SRC_SERVER_BITSTREAM_H_
 
-#include <inttypes.h>
-#include <string.h>
-#include <pthread.h>
-
-
-static inline char char_with_bit_set(uint64_t num) { return 1<<(num%8); }
-
-/** Return 1 if the bit at ''idx'' in array ''b'' is set */
-static inline int bit_is_set(char* b, uint64_t idx) {
-	return (b[idx/8] & char_with_bit_set(idx)) != 0;
-}
-/** Return 1 if the bit at ''idx'' in array ''b'' is clear */
-static inline int bit_is_clear(char* b, uint64_t idx) {
-	return !bit_is_set(b, idx);
-}
-/** Tests whether the bit at ''idx'' in array ''b'' has value ''value'' */
-static inline int bit_has_value(char* b, uint64_t idx, int value) {
-	if (value) { return bit_is_set(b, idx); }
-	else { return bit_is_clear(b, idx); }
-}
-/** Sets the bit ''idx'' in array ''b'' */
-static inline void bit_set(char* b, uint64_t idx) {
-	b[idx/8] |= char_with_bit_set(idx);
-	//__sync_fetch_and_or(b+(idx/8), char_with_bit_set(idx));
-}
-/** Clears the bit ''idx'' in array ''b'' */
-static inline void bit_clear(char* b, uint64_t idx) {
-	b[idx/8] &= ~char_with_bit_set(idx);
-	//__sync_fetch_and_nand(b+(idx/8), char_with_bit_set(idx));
-}
-/** Sets ''len'' bits in array ''b'' starting at offset ''from'' */
-static inline void bit_set_range(char* b, uint64_t from, uint64_t len)
-{
-	for ( ; from%8 != 0 && len > 0 ; len-- ) {
-		bit_set( b, from++ );
-	}
-
-	if (len >= 8) {
-		memset(b+(from/8), 255, len/8 );
-		from += len;
-		len = (len%8);
-		from -= len;
-	}
-
-	for ( ; len > 0 ; len-- ) {
-		bit_set( b, from++ );
-	}
-}
-/** Clears ''len'' bits in array ''b'' starting at offset ''from'' */
-static inline void bit_clear_range(char* b, uint64_t from, uint64_t len)
-{
-	for ( ; from%8 != 0 && len > 0 ; len-- ) {
-		bit_clear( b, from++ );
-	}
-
-	if (len >= 8) {
-		memset(b+(from/8), 0, len/8 );
-		from += len;
-		len = (len%8);
-		from -= len;
-	}
-
-	for ( ; len > 0 ; len-- ) {
-		bit_clear( b, from++ );
-	}
-}
-
-/** Counts the number of contiguous bits in array ''b'', starting at ''from''
-  * up to a maximum number of bits ''len''.  Returns the number of contiguous
-  * bits that are the same as the first one specified. If ''run_is_set'' is
-  * non-NULL, the value of that bit is placed into it.
-  */
-static inline uint64_t bit_run_count(char* b, uint64_t from, uint64_t len, int *run_is_set) {
-	uint64_t* current_block;
-	uint64_t count = 0;
-	int first_value = bit_is_set(b, from);
-
-	if ( run_is_set != NULL ) {
-		*run_is_set = first_value;
-	}
-
-	for ( ; (from+count) % 64 != 0 && len > 0; len--) {
-		if (bit_has_value(b, from+count, first_value)) {
-			count++;
-		} else {
-			return count;
-		}
-	}
-
-	for ( ; len >= 64 ; len -= 64 ) {
-		current_block = (uint64_t*) (b + ((from+count)/8));
-		if (*current_block == ( first_value ? UINT64_MAX : 0 ) ) {
-			count += 64;
-		} else {
-			break;
-		}
-	}
-
-	for ( ; len > 0; len-- ) {
-		if ( bit_has_value(b, from+count, first_value) ) {
-			count++;
-		}
-	}
-
-	return count;
-}
+#include "bitset.h"
 
 enum bitset_stream_events {
   BITSET_STREAM_UNSET = 0,
@@ -116,6 +16,7 @@ enum bitset_stream_events {
   BITSET_STREAM_ON = 2,
   BITSET_STREAM_OFF = 3
 };
+#define BITSET_STREAM_EVENTS_ENUM_SIZE 4
 
 struct bitset_stream_entry {
 	enum bitset_stream_events event;
@@ -138,6 +39,7 @@ struct bitset_stream {
 	pthread_mutex_t mutex;
 	pthread_cond_t cond_not_full;
 	pthread_cond_t cond_not_empty;
+	uint64_t queued_bytes[BITSET_STREAM_EVENTS_ENUM_SIZE];
 };
 
 
@@ -152,7 +54,7 @@ struct bitset {
 	int resolution;
 	struct bitset_stream *stream;
 	int stream_enabled;
-	char bits[];
+	bitfield_word_t bits[];
 };
 
 /** Allocate a bitset for a file of the given size, and chunks of the
@@ -160,9 +62,12 @@ struct bitset {
   */
 static inline struct bitset *bitset_alloc( uint64_t size, int resolution )
 {
-	struct bitset *bitset = xmalloc(
-		sizeof( struct bitset ) + ( size + resolution - 1 ) / resolution
-	);
+	// calculate a size to allocate that is a multiple of the size of the
+	// bitfield word
+	size_t bitfield_size =
+			BIT_WORDS_FOR_SIZE((( size + resolution - 1 ) / resolution)) * sizeof( bitfield_word_t );
+	struct bitset *bitset = xmalloc(sizeof( struct bitset ) + ( bitfield_size / 8 ) );
+
 	bitset->size = size;
 	bitset->resolution = resolution;
 	/* don't actually need to call pthread_mutex_destroy '*/
@@ -217,13 +122,14 @@ static inline void bitset_stream_enqueue(
 	stream->entries[stream->in].event = event;
 	stream->entries[stream->in].from = from;
 	stream->entries[stream->in].len = len;
+	stream->queued_bytes[event] += len;
 
 	stream->size++;
 	stream->in++;
 	stream->in %= BITSET_STREAM_SIZE;
 
 	pthread_mutex_unlock( & stream->mutex );
-	pthread_cond_broadcast( &stream->cond_not_empty );
+	pthread_cond_signal( &stream->cond_not_empty );
 
 	return;
 }
@@ -234,6 +140,7 @@ static inline void bitset_stream_dequeue(
 )
 {
 	struct bitset_stream * stream = set->stream;
+	struct bitset_stream_entry * dequeued;
 
 	pthread_mutex_lock( &stream->mutex );
 
@@ -241,18 +148,21 @@ static inline void bitset_stream_dequeue(
 		pthread_cond_wait( &stream->cond_not_empty, &stream->mutex );
 	}
 
+	dequeued = &stream->entries[stream->out];
+
 	if ( out != NULL ) {
-		out->event = stream->entries[stream->out].event;
-		out->from  = stream->entries[stream->out].from;
-		out->len   = stream->entries[stream->out].len;
+		out->event = dequeued->event;
+		out->from  = dequeued->from;
+		out->len   = dequeued->len;
 	}
 
+	stream->queued_bytes[dequeued->event] -= dequeued->len;
 	stream->size--;
 	stream->out++;
 	stream->out %= BITSET_STREAM_SIZE;
 
 	pthread_mutex_unlock( &stream->mutex );
-	pthread_cond_broadcast( &stream->cond_not_full );
+	pthread_cond_signal( &stream->cond_not_full );
 
 	return;
 }
@@ -273,17 +183,10 @@ static inline uint64_t bitset_stream_queued_bytes(
 	enum bitset_stream_events event
 )
 {
-	uint64_t total = 0;
-	int i;
+	uint64_t total;
 
 	pthread_mutex_lock( &set->stream->mutex );
-
-	for ( i = set->stream->out; i < set->stream->in ; i++ ) {
-		if ( set->stream->entries[i].event == event ) {
-			total += set->stream->entries[i].len;
-		}
-	}
-
+	total = set->stream->queued_bytes[event];
 	pthread_mutex_unlock( &set->stream->mutex );
 
 	return total;
@@ -411,5 +314,4 @@ static inline int bitset_is_set_at( struct bitset * set, uint64_t at )
 }
 
 
-#endif
-
+#endif /* SRC_SERVER_BITSTREAM_H_ */

src/server/client.c

@@ -3,7 +3,7 @@
 #include "ioutil.h"
 #include "sockutil.h"
 #include "util.h"
-#include "bitset.h"
+#include "bitstream.h"
 #include "nbdtypes.h"
 #include "self_pipe.h"
 
@@ -15,6 +15,20 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 
+
+// When this signal is invoked, we call shutdown() on the client fd, which
+// results in the thread being wound up
+void client_killswitch_hit(int signal __attribute__ ((unused)), siginfo_t *info, void *ptr __attribute__ ((unused)))
+{
+	int fd = info->si_value.sival_int;
+	warn( "Killswitch for fd %i activated, calling shutdown on socket", fd );
+
+	FATAL_IF(
+		-1 == shutdown( fd, SHUT_RDWR ),
+		SHOW_ERRNO( "Failed to shutdown() the socket, killing the server" )
+	 );
+}
+
 struct client *client_create( struct server *serve, int socket )
 {
 	NULLCHECK( serve );
@@ -25,6 +39,13 @@ struct client *client_create( struct server *serve, int socket )
 		.sigev_signo = CLIENT_KILLSWITCH_SIGNAL
 	};
 
+	/*
+	 * Our killswitch closes this socket, forcing read() and write() calls
+	 * blocked on it to return with an error. The thread then close()s the
+	 * socket itself, avoiding races.
+	 */
+	evp.sigev_value.sival_int = socket;
+
 	c = xmalloc( sizeof( struct client ) );
 	c->stopped = 0;
 	c->socket = socket;
@@ -105,7 +126,9 @@ void write_not_zeroes(struct client* client, uint64_t from, uint64_t len)
 			debug("(run adjusted to %d)", run);
 		}
 
-		if (0) /* useful but expensive */
+		/* 
+		// Useful but expensive
+		if (0) 
 		{
 			uint64_t i;
 			fprintf(stderr, "full map resolution=%d: ", map->resolution);
@@ -118,6 +141,7 @@ void write_not_zeroes(struct client* client, uint64_t from, uint64_t len)
 			}
 			fprintf(stderr, "\n");
 		}
+		*/
 
 		#define DO_READ(dst, len) ERROR_IF_NEGATIVE( \
 			readloop( \
@@ -199,36 +223,6 @@ int client_read_request( struct client * client , struct nbd_request *out_reques
 	NULLCHECK( out_request );
 
 	struct nbd_request_raw request_raw;
-	fd_set                 fds;
-	struct timeval *       ptv = NULL;
-	int                    fd_count;
-
-	/* We want a timeout if this is an inbound migration, but not otherwise.
-	 * This is compile-time selectable, as it will break mirror max_bps
-	 */
-#ifdef HAS_LISTEN_TIMEOUT
-	struct timeval         tv = {CLIENT_MAX_WAIT_SECS, 0};
-
-	if ( !server_is_in_control( client->serve ) ) {
-		ptv = &tv;
-	}
-#endif
-
-	FD_ZERO(&fds);
-	FD_SET(client->socket, &fds);
-	self_pipe_fd_set( client->stop_signal, &fds );
-	fd_count = sock_try_select(FD_SETSIZE, &fds, NULL, NULL, ptv);
-	if ( fd_count == 0 ) {
-		/* This "can't ever happen" */
-		if ( NULL == ptv ) { fatal( "No FDs selected, and no timeout!" ); }
-		else { error("Timed out waiting for I/O"); }
-	}
-	else if ( fd_count < 0 ) { fatal( "Select failed" ); }
-
-	if ( self_pipe_fd_isset( client->stop_signal, &fds ) ){
-		debug("Client received stop signal.");
-		return 0;
-	}
 
 	if (fd_read_request(client->socket, &request_raw) == -1) {
 		*disconnected = 1;
@@ -255,21 +249,20 @@ int client_read_request( struct client * client , struct nbd_request *out_reques
 	}
 
 	nbd_r2h_request( &request_raw, out_request );
-
 	return 1;
 }
 
-int fd_write_reply( int fd, char *handle, int error )
+int fd_write_reply( int fd, uint64_t handle, int error )
 {
 	struct nbd_reply     reply;
 	struct nbd_reply_raw reply_raw;
 
 	reply.magic = REPLY_MAGIC;
 	reply.error = error;
-	memcpy( reply.handle, handle, 8 );
+	reply.handle.w = handle;
 
 	nbd_h2r_reply( &reply, &reply_raw );
-	debug( "Replying with %s, %d", handle, error );
+	debug( "Replying with handle=0x%08X, error=%"PRIu32, handle, error );
 
 	if( -1 == writeloop( fd, &reply_raw, sizeof( reply_raw ) ) ) {
 		switch( errno ) {
@@ -298,7 +291,7 @@ int fd_write_reply( int fd, char *handle, int error )
  */
 int client_write_reply( struct client * client, struct nbd_request *request, int error )
 {
-	return fd_write_reply( client->socket, request->handle, error);
+	return fd_write_reply( client->socket, request->handle.w, error);
 }
 
 
@@ -307,7 +300,7 @@ void client_write_init( struct client * client, uint64_t size )
 	struct nbd_init init = {{0}};
 	struct nbd_init_raw init_raw = {{0}};
 
-	memcpy( init.passwd, INIT_PASSWD, sizeof( INIT_PASSWD ) );
+	memcpy( init.passwd, INIT_PASSWD, sizeof( init.passwd ) );
 	init.magic = INIT_MAGIC;
 	init.size = size;
 	memset( init.reserved, 0, 128 );
@@ -379,15 +372,15 @@ int client_request_needs_reply( struct client * client,
 	 * forever.
 	 */
 	if (request.magic != REQUEST_MAGIC) {
-		warn("Bad magic 0x%08x from client", request.magic);
+		warn("Bad magic 0x%08X from client", request.magic);
 		client_write_reply( client, &request, EBADMSG );
 		client->disconnect = 1; // no need to flush
 		return 0;
 	}
 
 	debug(
-		"request type=%"PRIu32", from=%"PRIu64", len=%"PRIu32,
-		request.type, request.from, request.len
+		"request type=%"PRIu32", from=%"PRIu64", len=%"PRIu32", handle=0x%08X",
+		request.type, request.from, request.len, request.handle
 	);
 
 	/* check it's not out of range */
@@ -416,7 +409,7 @@ int client_request_needs_reply( struct client * client,
 		return 0;
 
 	default:
-		fatal("Unknown request %08x", request.type);
+		fatal("Unknown request 0x%08X", request.type);
 	}
 	return 1;
 }
@@ -427,7 +420,8 @@ void client_reply_to_read( struct client* client, struct nbd_request request )
 	off64_t offset;
 
 	debug("request read %ld+%d", request.from, request.len);
-	client_write_reply( client, &request, 0);
+	sock_set_tcp_cork( client->socket, 1 );
+	client_write_reply( client, &request, 0 );
 
 	offset = request.from;
 
@@ -443,12 +437,14 @@ void client_reply_to_read( struct client* client, struct nbd_request request )
 			"sendfile failed from=%ld, len=%d",
 			offset,
 			request.len);
+
+	sock_set_tcp_cork( client->socket, 0 );
 }
 
 
 void client_reply_to_write( struct client* client, struct nbd_request request )
 {
-	debug("request write %ld+%d", request.from, request.len);
+	debug("request write from=%"PRIu64", len=%"PRIu32", handle=0x%08X", request.from, request.len, request.handle);
 	if (client->serve->allocation_map_built) {
 		write_not_zeroes( client, request.from, request.len );
 	}
@@ -553,35 +549,79 @@ int client_serve_request(struct client* client)
 	struct nbd_request    request = {0};
 	int                   stop = 1;
 	int                   disconnected = 0;
+	fd_set                rfds, efds;
+	int                   fd_count;
 
-	if ( !client_read_request( client, &request, &disconnected ) ) { return stop; }
-	if ( disconnected ) { return stop; }
-	if ( !client_request_needs_reply( client, request ) )  {
+	/* wait until there are some bytes on the fd before committing to reads
+	 * FIXME: this whole scheme is broken because we're using blocking reads.
+	 * read() can block directly after a select anyway, and it's possible that,
+	 * without the killswitch, we'd hang forever. With the killswitch, we just
+	 * hang for "a while". The Right Thing to do is to rewrite client.c to be
+	 * non-blocking.
+	 */
+
+	FD_ZERO( &rfds );
+	FD_SET( client->socket, &rfds );
+	self_pipe_fd_set( client->stop_signal, &rfds );
+
+	FD_ZERO( &efds );
+	FD_SET( client->socket, &efds );
+
+	fd_count = sock_try_select( FD_SETSIZE, &rfds, NULL, &efds, NULL );
+
+	if ( fd_count == 0 ) {
+		/* This "can't ever happen" */
+		fatal( "No FDs selected, and no timeout!" );
+	}
+	else if ( fd_count < 0 ) { fatal( "Select failed" ); }
+
+	if ( self_pipe_fd_isset( client->stop_signal, &rfds ) ){
+		debug("Client received stop signal.");
+		return 1; // Don't try to serve more requests
+	}
+
+	if ( FD_ISSET( client->socket, &efds ) ) {
+		debug( "Client connection closed" );
+		return 1;
+	}
+
+
+	/* We arm / disarm around the whole request cycle. The reason for this is
+	 * that the remote peer could uncleanly die at any point; if we're stuck on
+	 * a blocking read(), then that will hang for (almost) forever. This is bad
+	 * in general, makes the server respond only to kill -9, and breaks
+	 * outward mirroring in a most unpleasant way.
+	 *
+	 * Don't forget to disarm before exiting, no matter what!
+	 *
+	 * The replication is simple: open a connection to the flexnbd server, write
+	 * a single byte, and then wait.
+	 *
+	 */
+	client_arm_killswitch( client );
+
+	if ( !client_read_request( client, &request, &disconnected ) ) {
+		client_disarm_killswitch( client );
+		return stop;
+	}
+	if ( disconnected ) {
+		client_disarm_killswitch( client );
+		return stop;
+	}
+
+	if ( !client_request_needs_reply( client, request ) ) {
+		client_disarm_killswitch( client );
 		return client->disconnect;
 	}
 
 	{
 		if ( !server_is_closed( client->serve ) ) {
-			/* We arm / disarm around client_reply() to catch cases where the
-			 * remote peer sends part of a write request data before dying,
-			 * and cases where we send part of read reply data before they die.
-			 *
-			 * That last is theoretical right now, but could break us in the
-			 * same way as a half-write (which causes us to sit in read forever)
-			 *
-			 * We only arm/disarm inside the server io lock because it's common
-			 * during migrations for us to be hanging on that mutex for quite
-			 * a while while the final pass happens - it's held for the entire
-			 * time.
-			 */
-			client_arm_killswitch( client );
 			client_reply( client, request );
-			client_disarm_killswitch( client );
 			stop = 0;
 		}
 	}
 
-
+	client_disarm_killswitch( client );
 	return stop;
 }
 
@@ -596,6 +636,9 @@ void client_cleanup(struct client* client,
 {
 	info("client cleanup for client %p", client);
 
+	/* If the thread hits an error, we need to ensure this is off */
+	client_disarm_killswitch( client );
+
 	if (client->socket) {
 		FATAL_IF_NEGATIVE( close(client->socket),
 			"Error closing client socket %d",

src/server/client.h

@@ -4,18 +4,6 @@
 #include <signal.h>
 #include <time.h>
 
-#ifdef HAS_LISTEN_TIMEOUT
-
-/** CLIENT_MAX_WAIT_SECS
- * This is the length of time an inbound migration will wait for a fresh
- * write before assuming the source has Gone Away.  Note: it is *not*
- * the time from one write to the next, it is the gap between the end of
- * one write and the start of the next.
- */
-#define CLIENT_MAX_WAIT_SECS 5
-
-#endif
-
 /** CLIENT_HANDLER_TIMEOUT
  * This is the length of time (in seconds) any request can be outstanding for.
  * If we spend longer than this in a request, the whole server is killed.
@@ -24,8 +12,7 @@
 
 /** CLIENT_KILLSWITCH_SIGNAL
  * The signal number we use to kill the server when *any* killswitch timer
- * fires. We don't actually need to install a signal handler for it, the default
- * behaviour is perfectly fine.
+ * fires. The handler gets the fd of the client socket to work with.
  */
 #define CLIENT_KILLSWITCH_SIGNAL ( SIGRTMIN + 1 )
 
@@ -58,6 +45,7 @@ struct client {
 
 };
 
+void client_killswitch_hit(int signal, siginfo_t *info, void *ptr);
 
 void* client_serve(void* client_uncast);
 struct client * client_create( struct server * serve, int socket );

src/server/control.c

@@ -83,7 +83,7 @@ void control_destroy( struct control * control )
 struct control_client * control_client_create(
 		struct flexnbd * flexnbd,
 		int client_fd ,
-		struct mbox * state_mbox )
+		struct mbox_t * state_mbox )
 {
 	NULLCHECK( flexnbd );
 
@@ -256,7 +256,7 @@ void * control_runner( void * control_uncast )
 
 #define write_socket(msg) write(client_fd, (msg "\n"), strlen((msg))+1)
 
-void control_write_mirror_response( enum mirror_state mirror_state, int client_fd )
+void control_write_mirror_response( mirror_state_t mirror_state, int client_fd )
 {
 	switch (mirror_state) {
 		case MS_INIT:
@@ -290,22 +290,16 @@ void control_write_mirror_response( enum mirror_state mirror_state, int client_f
 
 
 /* Call this in the thread where you want to receive the mirror state */
-enum mirror_state control_client_mirror_wait(
+mirror_state_t control_client_mirror_wait(
 		struct control_client* client)
 {
 	NULLCHECK( client );
 	NULLCHECK( client->mirror_state_mbox );
 
-	struct mbox * mbox = client->mirror_state_mbox;
-	enum mirror_state mirror_state;
-	enum mirror_state * contents;
+	struct mbox_t * mbox = client->mirror_state_mbox;
+	mirror_state_t mirror_state;
 
-	contents = (enum mirror_state*)mbox_receive( mbox );
-	NULLCHECK( contents );
-
-	mirror_state = *contents;
-
-	free( contents );
+	mirror_state = mbox_receive( mbox ).i;
 
 	return mirror_state;
 }
@@ -425,7 +419,7 @@ int control_mirror(struct control_client* client, int linesc, char** lines)
 			);
 
 		debug("Control thread mirror super waiting");
-		enum mirror_state state =
+		mirror_state_t state =
 			control_client_mirror_wait( client );
 		debug("Control thread writing response");
 		control_write_mirror_response( state, client->socket );

src/server/control.h

@@ -31,7 +31,7 @@ struct control {
 	 * process (and we can only have a mirror thread if the control
 	 * thread has started it).
 	 */
-	struct mbox * mirror_state_mbox;
+	struct mbox_t * mirror_state_mbox;
 };
 
 struct control_client{
@@ -41,7 +41,7 @@ struct control_client{
 	/* Passed in on creation.  We know it's all right to do this
 	 * because we know there's only ever one control_client.
 	 */
-	struct mbox * mirror_state_mbox;
+	struct mbox_t * mirror_state_mbox;
 };
 
 struct control * control_create(

src/server/flexnbd.c

@@ -101,12 +101,24 @@ struct flexnbd * flexnbd_create_serving(
 			max_nbd_clients,
 			use_killswitch,
 			1);
-	flexnbd_create_shared( flexnbd,
-			s_ctrl_sock );
+	flexnbd_create_shared( flexnbd, s_ctrl_sock );
+
+	// Beats installing one handler per client instance
+	if ( use_killswitch ) {
+		struct sigaction act = {
+			.sa_sigaction = client_killswitch_hit,
+			.sa_flags = SA_RESTART | SA_SIGINFO
+		};
+
+		FATAL_UNLESS(
+			0 == sigaction( CLIENT_KILLSWITCH_SIGNAL, &act, NULL ),
+			"Installing client killswitch signal failed"
+		);
+	}
+
 	return flexnbd;
 }
 
-
 struct flexnbd * flexnbd_create_listening(
 		char* s_ip_address,
 		char* s_port,
@@ -127,6 +139,10 @@ struct flexnbd * flexnbd_create_listening(
 			s_acl_entries,
 			1, 0, 0);
 	flexnbd_create_shared( flexnbd, s_ctrl_sock );
+
+	// listen can't use killswitch, as mirror may pause on sending things
+	// for a very long time.
+
 	return flexnbd;
 }
 

src/server/flexnbd.h

@@ -5,6 +5,7 @@
 #include "mirror.h"
 #include "serve.h"
 #include "proxy.h"
+#include "client.h"
 #include "self_pipe.h"
 #include "mbox.h"
 #include "control.h"

src/server/mbox.c

@@ -0,0 +1,73 @@
+
+#include "mbox.h"
+#include "util.h"
+
+#include <sys/socket.h>
+#include <pthread.h>
+
+DEFINE_FIFO(mbox_item_t, mbox_fifo);
+
+#define ARRAY_SIZE(w) (sizeof(w) / sizeof((w)[0]))
+
+mbox_p  mbox_create( void )
+{
+	mbox_p  mbox = xmalloc( sizeof( struct mbox_t ) );
+
+	int sv[2];
+	FATAL_UNLESS(socketpair(AF_UNIX, SOCK_STREAM, 0, sv) == 0,
+			"Failed to socketpair");
+	mbox->signalw = sv[0];
+	mbox->signalr = sv[1];
+
+	return mbox;
+}
+
+void mbox_post( mbox_p  mbox, mbox_item_t item )
+{
+	mbox_fifo_write(&mbox->fifo, item);
+	{
+		uint8_t w;
+		FATAL_UNLESS((write(mbox->signalw, &w, 1)) == 1,
+				"Write to socketpair");
+	}
+}
+
+
+mbox_item_t mbox_contents( mbox_p  mbox )
+{
+	const mbox_item_t zero = {0};
+
+	return mbox_fifo_isempty(&mbox->fifo) ?
+				zero :
+				mbox_fifo_read_at(&mbox->fifo, 0);
+}
+
+
+int mbox_is_full( mbox_p  mbox )
+{
+	return mbox_fifo_isfull(&mbox->fifo);
+}
+
+
+mbox_item_t mbox_receive( mbox_p  mbox )
+{
+	NULLCHECK( mbox );
+
+	while (mbox_fifo_isempty(&mbox->fifo)) {
+		uint8_t w;
+		FATAL_UNLESS((read(mbox->signalr, &w, 1)) == 1,
+				"Read from socketpair");
+	}
+
+	return mbox_fifo_read(&mbox->fifo);
+}
+
+
+void mbox_destroy( mbox_p  mbox )
+{
+	NULLCHECK( mbox );
+
+	close(mbox->signalw);
+	close(mbox->signalr);
+	free( mbox );
+}

src/server/mbox.h

@@ -11,45 +11,43 @@
 
 
 #include <pthread.h>
+#include <stdint.h>
+#include "fifo_declare.h"
+
+typedef union {
+	uint64_t i;
+	void * p;
+} mbox_item_t;
+
+DECLARE_FIFO(mbox_item_t, mbox_fifo, 8);
+
+typedef struct mbox_t {
+	mbox_fifo_t	fifo;
+	// socketpair() ends
+	int		signalw, signalr;
+} mbox_t, *mbox_p;
 
 
-struct mbox {
-	void * contents;
-
-	/** Marker to tell us if there's content in the box.
-	 * Keeping this separate allows us to use NULL for the contents.
-	 */
-	int full;
-
-	/** This gets signaled by mbox_post, and waited on by
-	 * mbox_receive */
-	pthread_cond_t filled_cond;
-	/** This is signaled by mbox_receive, and waited on by mbox_post */
-	pthread_cond_t emptied_cond;
-	pthread_mutex_t mutex;
-};
-
-
-/* Create an mbox. */
-struct mbox * mbox_create(void);
+/* Create an mbox_t. */
+mbox_p  mbox_create(void);
 
 /* Put something in the mbox, blocking if it's already full.
  * That something can be NULL if you want.
  */
-void mbox_post( struct mbox *, void *);
+void mbox_post( mbox_p , mbox_item_t item);
 
 /* See what's in the mbox.  This isn't thread-safe. */
-void * mbox_contents( struct mbox *);
+mbox_item_t mbox_contents( mbox_p );
 
 /* See if anything has been put into the mbox.  This isn't thread-safe.
  * */
-int mbox_is_full( struct mbox *);
+int mbox_is_full( mbox_p );
 
 /* Get the contents from the mbox, blocking if there's nothing there. */
-void * mbox_receive( struct mbox *);
+mbox_item_t mbox_receive( mbox_p );
 
 /* Free the mbox and destroy the associated pthread bits. */
-void mbox_destroy( struct mbox *);
+void mbox_destroy( mbox_p );
 
 
 #endif

src/server/mirror.c

@@ -22,7 +22,7 @@
 #include "sockutil.h"
 #include "parse.h"
 #include "readwrite.h"
-#include "bitset.h"
+#include "bitstream.h"
 #include "self_pipe.h"
 #include "status.h"
 
@@ -66,10 +66,11 @@ struct xfer {
 
 struct mirror_ctrl {
 	struct server *serve;
-	struct mirror *mirror;
+	mirror_p mirror;
 
 	/* libev stuff */
 	struct ev_loop *ev_loop;
+	ev_timer begin_watcher;
 	ev_io read_watcher;
 	ev_io write_watcher;
 	ev_timer timeout_watcher;
@@ -89,16 +90,16 @@ struct mirror_ctrl {
 
 };
 
-struct mirror * mirror_alloc(
+mirror_p mirror_alloc(
 		union mysockaddr * connect_to,
 		union mysockaddr * connect_from,
 		uint64_t max_Bps,
-		enum mirror_finish_action action_at_finish,
-		struct mbox * commit_signal)
+		mirror_finish_action_t action_at_finish,
+		mbox_p  commit_signal)
 {
-	struct mirror * mirror;
+	mirror_p mirror;
 
-	mirror = xmalloc(sizeof(struct mirror));
+	mirror = xmalloc(sizeof(mirror_t));
 	mirror->connect_to = connect_to;
 	mirror->connect_from = connect_from;
 	mirror->max_bytes_per_second = max_Bps;
@@ -115,7 +116,7 @@ struct mirror * mirror_alloc(
 	return mirror;
 }
 
-void mirror_set_state_f( struct mirror * mirror, enum mirror_state state )
+void mirror_set_state_f( mirror_p mirror, mirror_state_t state )
 {
 	NULLCHECK( mirror );
 	mirror->commit_state = state;
@@ -126,7 +127,7 @@ void mirror_set_state_f( struct mirror * mirror, enum mirror_state state )
 	mirror_set_state_f( mirror, state );\
 } while(0)
 
-enum mirror_state mirror_get_state( struct mirror * mirror )
+mirror_state_t mirror_get_state( mirror_p mirror )
 {
 	NULLCHECK( mirror );
 	return mirror->commit_state;
@@ -135,10 +136,10 @@ enum mirror_state mirror_get_state( struct mirror * mirror )
 #define mirror_state_is( mirror, state ) mirror_get_state( mirror ) == state
 
 
-void mirror_init( struct mirror * mirror, const char * filename )
+void mirror_init( mirror_p mirror, const char * filename )
 {
 	int map_fd;
-	off64_t size;
+	uint64_t size;
 
 	NULLCHECK( mirror );
 	NULLCHECK( filename );
@@ -162,7 +163,7 @@ void mirror_init( struct mirror * mirror, const char * filename )
 
 
 /* Call this before a mirror attempt. */
-void mirror_reset( struct mirror * mirror )
+void mirror_reset( mirror_p mirror )
 {
 	NULLCHECK( mirror );
 	mirror_set_state( mirror, MS_INIT );
@@ -175,16 +176,16 @@ void mirror_reset( struct mirror * mirror )
 }
 
 
-struct mirror * mirror_create(
+mirror_p mirror_create(
 		const char * filename,
 		union mysockaddr * connect_to,
 		union mysockaddr * connect_from,
 		uint64_t max_Bps,
 		int action_at_finish,
-		struct mbox * commit_signal)
+		mbox_p  commit_signal)
 {
 	/* FIXME: shouldn't map_fd get closed? */
-	struct mirror * mirror;
+	mirror_p mirror;
 
 	mirror = mirror_alloc( connect_to,
 			connect_from,
@@ -200,7 +201,7 @@ struct mirror * mirror_create(
 }
 
 
-void mirror_destroy( struct mirror *mirror )
+void mirror_destroy( mirror_p mirror )
 {
 	NULLCHECK( mirror );
 	self_pipe_destroy( mirror->abandon_signal );
@@ -213,18 +214,6 @@ void mirror_destroy( struct mirror *mirror )
 /** The mirror code will split NBD writes, making them this long as a maximum */
 static const int mirror_longest_write = 8<<20;
 
-/** If, during a mirror pass, we have sent this number of bytes or fewer, we
- *  go to freeze the I/O and finish it off.  This is just a guess.
- */
-static const unsigned int mirror_last_pass_after_bytes_written = 100<<20;
-
-/** The largest number of full passes we'll do - the last one will always
- *  cause the I/O to freeze, however many bytes are left to copy.
- */
-static const int mirror_maximum_passes = 7;
-#define mirror_last_pass (mirror_maximum_passes - 1)
-
-
 /* This must not be called if there's any chance of further I/O. Methods to
  * ensure this include:
  *   - Ensure image size is 0
@@ -265,7 +254,7 @@ void mirror_cleanup( struct server * serve,
 		int fatal __attribute__((unused)))
 {
 	NULLCHECK( serve );
-	struct mirror * mirror = serve->mirror;
+	mirror_p mirror = serve->mirror;
 	NULLCHECK( mirror );
 	info( "Cleaning up mirror thread");
 
@@ -281,7 +270,7 @@ void mirror_cleanup( struct server * serve,
 }
 
 
-int mirror_connect( struct mirror * mirror, off64_t local_size )
+int mirror_connect( mirror_p mirror, uint64_t local_size )
 {
 	struct sockaddr * connect_from = NULL;
 	int connected =  0;
@@ -303,7 +292,7 @@ int mirror_connect( struct mirror * mirror, off64_t local_size )
 				"Select failed." );
 
 		if( FD_ISSET( mirror->client, &fds ) ){
-			off64_t remote_size;
+			uint64_t remote_size;
 			if ( socket_nbd_read_hello( mirror->client, &remote_size ) ) {
 				if( remote_size == local_size ){
 					connected = 1;
@@ -336,7 +325,7 @@ int mirror_connect( struct mirror * mirror, off64_t local_size )
 }
 
 
-int mirror_should_quit( struct mirror * mirror )
+int mirror_should_quit( mirror_p mirror )
 {
 	switch( mirror->action_at_finish ) {
 		case ACTION_EXIT:
@@ -347,6 +336,19 @@ int mirror_should_quit( struct mirror * mirror )
 	}
 }
 
+/* Bandwidth limiting - we hang around if bps is too high, unless we need to
+ * empty out the bitset stream a bit */
+int mirror_should_wait( struct mirror_ctrl *ctrl )
+{
+	int bps_over = server_mirror_bps( ctrl->serve ) >
+		ctrl->serve->mirror->max_bytes_per_second;
+
+	int stream_full = bitset_stream_size( ctrl->serve->allocation_map ) >
+		( BITSET_STREAM_SIZE / 2 );
+
+	return bps_over && !stream_full;
+}
+
 /*
  * If there's an event in the bitset stream of the serve allocation map, we
  * use it to construct the next transfer request, covering precisely the area
@@ -357,7 +359,7 @@ int mirror_should_quit( struct mirror * mirror )
  * next transfer, then puts it together. */
 int mirror_setup_next_xfer( struct mirror_ctrl *ctrl )
 {
-	struct mirror* mirror = ctrl->mirror;
+	mirror_p mirror = ctrl->mirror;
 	struct server* serve = ctrl->serve;
 	struct bitset_stream_entry e = { .event = BITSET_STREAM_UNSET };
 	uint64_t current = mirror->offset, run = 0, size = serve->size;
@@ -369,7 +371,7 @@ int mirror_setup_next_xfer( struct mirror_ctrl *ctrl )
 	 * full, and stop when it's a quarter full. This stops a busy client from
 	 * stalling a migration forever. FIXME: made-up numbers.
 	 */
-	if ( bitset_stream_size( serve->allocation_map ) > BITSET_STREAM_SIZE / 2 ) {
+	if ( mirror->offset < serve->size && bitset_stream_size( serve->allocation_map ) > BITSET_STREAM_SIZE / 2 ) {
 		ctrl->clear_events = 1;
 	}
 
@@ -410,7 +412,7 @@ int mirror_setup_next_xfer( struct mirror_ctrl *ctrl )
 	struct nbd_request req = {
 		.magic = REQUEST_MAGIC,
 		.type = REQUEST_WRITE,
-		.handle = ".MIRROR.",
+		.handle.b = ".MIRROR.",
 		.from = current,
 		.len = run
 	};
@@ -425,24 +427,6 @@ int mirror_setup_next_xfer( struct mirror_ctrl *ctrl )
 	return 1;
 }
 
-uint64_t mirror_current_bps( struct mirror * mirror )
-{
- 	uint64_t duration_ms = monotonic_time_ms() - mirror->migration_started;
-	return mirror->all_dirty / ( ( duration_ms / 1000 ) + 1 );
-}
-
-int mirror_exceeds_max_bps( struct mirror * mirror )
-{
-	uint64_t mig_speed = mirror_current_bps( mirror );
-	debug( "current_bps: %"PRIu64"; max_bps: %"PRIu64, mig_speed, mirror->max_bytes_per_second );
-
-	if ( mig_speed > mirror->max_bytes_per_second ) {
-		return 1;
-	}
-
-	return 0;
-}
-
 // ONLY CALL THIS AFTER CLOSING CLIENTS
 void mirror_complete( struct server *serve )
 {
@@ -478,6 +462,12 @@ static void mirror_write_cb( struct ev_loop *loop, ev_io *w, int revents )
 
 	debug( "Mirror write callback invoked with events %d. fd: %i", revents, ctrl->mirror->client );
 
+	/* FIXME: We can end up corking multiple times in unusual circumstances; this
+	 * is annoying, but harmless */
+	if ( xfer->written == 0 ) {
+		sock_set_tcp_cork( ctrl->mirror->client, 1 );
+	}
+
 	if ( xfer->written < hdr_size ) {
 		data_loc = ( (char*) &xfer->hdr.req_raw ) + ctrl->xfer.written;
 		to_write = hdr_size - xfer->written;
@@ -486,7 +476,7 @@ static void mirror_write_cb( struct ev_loop *loop, ev_io *w, int revents )
 		to_write = xfer->len - ( ctrl->xfer.written - hdr_size );
 	}
 
-	// Actually read some bytes
+	// Actually write some bytes
 	if ( ( count = write( ctrl->mirror->client, data_loc, to_write ) ) < 0 ) {
 		if ( errno != EAGAIN && errno != EWOULDBLOCK && errno != EINTR ) {
 			warn( SHOW_ERRNO( "Couldn't write to listener" ) );
@@ -496,13 +486,16 @@ static void mirror_write_cb( struct ev_loop *loop, ev_io *w, int revents )
 	}
 	debug( "Wrote %"PRIu64" bytes", count );
 	debug( "to_write was %"PRIu64", xfer->written was %"PRIu64, to_write, xfer->written );
-	ctrl->xfer.written += count;
 
-	// We wrote some bytes, so reset the timer
-	ev_timer_again( ctrl->ev_loop, &ctrl->timeout_watcher );
+	// We wrote some bytes, so reset the timer and keep track for the next pass
+	if ( count > 0 ) {
+		ctrl->xfer.written += count;
+		ev_timer_again( ctrl->ev_loop, &ctrl->timeout_watcher );
+	}
 
 	// All bytes written, so now we need to read the NBD reply back.
 	if ( ctrl->xfer.written == ctrl->xfer.len + hdr_size ) {
+	  sock_set_tcp_cork( ctrl->mirror->client, 0 ) ;
 		ev_io_start( loop, &ctrl->read_watcher  );
 		ev_io_stop(  loop, &ctrl->write_watcher );
 	}
@@ -515,7 +508,7 @@ static void mirror_read_cb( struct ev_loop *loop, ev_io *w, int revents )
 	struct mirror_ctrl* ctrl = (struct mirror_ctrl*) w->data;
 	NULLCHECK( ctrl );
 
-	struct mirror *m = ctrl->mirror;
+	mirror_p m = ctrl->mirror;
 	NULLCHECK( m );
 
 	struct xfer *xfer = &ctrl->xfer;
@@ -575,7 +568,7 @@ static void mirror_read_cb( struct ev_loop *loop, ev_io *w, int revents )
 		return;
 	}
 
-	if ( memcmp( ".MIRROR.", &rsp.handle[0], 8 ) != 0 ) {
+	if ( memcmp( ".MIRROR.", rsp.handle.b, 8 ) != 0 ) {
 		warn( "Bad handle returned from listener" );
 		ev_break( loop, EVBREAK_ONE );
 		return;
@@ -584,10 +577,17 @@ static void mirror_read_cb( struct ev_loop *loop, ev_io *w, int revents )
 	/* transfer was completed, so now we need to either set up the next
 	 * transfer of this pass, set up the first transfer of the next pass, or
 	 * complete the migration */
-	m->all_dirty += xfer->len;
 	xfer->read = 0;
 	xfer->written = 0;
 
+	/* We don't account for bytes written in this mode, to stop high-throughput
+	 * discs getting stuck in "drain the event queue!" mode forever
+	 */
+	if ( !ctrl->clear_events ) {
+		m->all_dirty += xfer->len;
+	}
+
+
 	/* This next bit could take a little while, which is fine */
 	ev_timer_stop( ctrl->ev_loop, &ctrl->timeout_watcher );
 
@@ -601,17 +601,15 @@ static void mirror_read_cb( struct ev_loop *loop, ev_io *w, int revents )
 	int next_xfer = mirror_setup_next_xfer( ctrl );
 	debug( "next_xfer: %d", next_xfer );
 
-	/* Regardless of time estimates, if there's no waiting transfer, we can
-	 *  */
-	if ( !ctrl->clients_closed && ( !next_xfer || server_mirror_eta( ctrl->serve ) < 60 ) ) {
+	/* Regardless of time estimates, if there's no waiting transfer, we can start closing clients down. */
+	if ( !ctrl->clients_closed && ( !next_xfer || server_mirror_eta( ctrl->serve ) < MS_CONVERGE_TIME_SECS ) ) {
 		info( "Closing clients to allow mirroring to converge" );
 		server_forbid_new_clients( ctrl->serve );
 		server_close_clients( ctrl->serve );
 		server_join_clients( ctrl->serve );
 		ctrl->clients_closed = 1;
 
-		/* One more try - a new event may have been pushed since our last check
-		 */
+		/* One more try - a new event may have been pushed since our last check  */
 		if ( !next_xfer ) {
 			next_xfer = mirror_setup_next_xfer( ctrl );
 		}
@@ -630,7 +628,7 @@ static void mirror_read_cb( struct ev_loop *loop, ev_io *w, int revents )
 
 	/* FIXME: Should we ignore the bwlimit after server_close_clients has been called? */
 
-	if ( mirror_exceeds_max_bps( m ) ) {
+	if ( mirror_should_wait( ctrl ) ) {
 		/* We're over the bandwidth limit, so don't move onto the next transfer
 		 * yet. Our limit_watcher will move us on once we're OK. timeout_watcher
 		 * was disabled further up, so don't need to stop it here too */
@@ -645,7 +643,7 @@ static void mirror_read_cb( struct ev_loop *loop, ev_io *w, int revents )
 	return;
 }
 
-void mirror_timeout_cb( struct ev_loop *loop, ev_timer *w __attribute__((unused)), int revents )
+static void mirror_timeout_cb( struct ev_loop *loop, ev_timer *w __attribute__((unused)), int revents )
 {
 	if ( !(revents & EV_TIMER ) ) {
 		warn( "Mirror timeout called but no timer event signalled" );
@@ -657,7 +655,7 @@ void mirror_timeout_cb( struct ev_loop *loop, ev_timer *w __attribute__((unused)
 	return;
 }
 
-void mirror_abandon_cb( struct ev_loop *loop, ev_io *w, int revents )
+static void mirror_abandon_cb( struct ev_loop *loop, ev_io *w, int revents )
 {
 	struct mirror_ctrl* ctrl = (struct mirror_ctrl*) w->data;
 	NULLCHECK( ctrl );
@@ -674,7 +672,8 @@ void mirror_abandon_cb( struct ev_loop *loop, ev_io *w, int revents )
 	return;
 }
 
-void mirror_limit_cb( struct ev_loop *loop, ev_timer *w, int revents )
+
+static void mirror_limit_cb( struct ev_loop *loop, ev_timer *w, int revents )
 {
 	struct mirror_ctrl* ctrl = (struct mirror_ctrl*) w->data;
 	NULLCHECK( ctrl );
@@ -684,7 +683,7 @@ void mirror_limit_cb( struct ev_loop *loop, ev_timer *w, int revents )
 		return;
 	}
 
-	if ( mirror_exceeds_max_bps( ctrl->mirror ) ) {
+	if ( mirror_should_wait( ctrl ) ) {
 		debug( "max_bps exceeded, waiting", ctrl->mirror->max_bytes_per_second );
 		ev_timer_again( loop, w );
 	} else {
@@ -698,12 +697,43 @@ void mirror_limit_cb( struct ev_loop *loop, ev_timer *w, int revents )
 	return;
 }
 
+/* We use this to periodically check whether the allocation map has built, and
+ * if it has, start migrating. If it's not finished, then enabling the bitset
+ * stream does not go well for us.
+ */
+static void mirror_begin_cb( struct ev_loop *loop, ev_timer *w, int revents )
+{
+	struct mirror_ctrl* ctrl = (struct mirror_ctrl*) w->data;
+	NULLCHECK( ctrl );
+
+	if ( !(revents & EV_TIMER ) ) {
+		warn( "Mirror limit callback executed but no timer event signalled" );
+		return;
+	}
+
+	if ( ctrl->serve->allocation_map_built || ctrl->serve->allocation_map_not_built ) {
+		info( "allocation map builder is finished, beginning migration" );
+		ev_timer_stop( loop, w );
+		/* Start by writing xfer 0 to the listener */
+		ev_io_start( loop, &ctrl->write_watcher );
+		/* We want to timeout during the first write as well as subsequent ones */
+		ev_timer_again( loop, &ctrl->timeout_watcher );
+		/* We're now interested in events */
+		bitset_enable_stream( ctrl->serve->allocation_map );
+	} else {
+		/* not done yet, so wait another second */
+		ev_timer_again( loop, w );
+	}
+
+	return;
+}
+
 void mirror_run( struct server *serve )
 {
 	NULLCHECK( serve );
 	NULLCHECK( serve->mirror );
 
-	struct mirror *m = serve->mirror;
+	mirror_p m = serve->mirror;
 
 	m->migration_started = monotonic_time_ms();
 	info("Starting mirror" );
@@ -727,7 +757,12 @@ void mirror_run( struct server *serve )
 
 	ctrl.ev_loop = EV_DEFAULT;
 
-	/* gcc warns on -O2. clang is fine. Seems to be the fault of ev.h */
+	/* gcc warns with -Wstrict-aliasing on -O2. clang doesn't
+	 * implement this warning. Seems to be the fault of ev.h */
+	ev_init( &ctrl.begin_watcher, mirror_begin_cb );
+	ctrl.begin_watcher.repeat = 1.0; // We check bps every second. seems sane.
+	ctrl.begin_watcher.data = (void*) &ctrl;
+
 	ev_io_init( &ctrl.read_watcher, mirror_read_cb, m->client, EV_READ  );
 	ctrl.read_watcher.data = (void*) &ctrl;
 
@@ -735,7 +770,22 @@ void mirror_run( struct server *serve )
 	ctrl.write_watcher.data = (void*) &ctrl;
 
 	ev_init( &ctrl.timeout_watcher, mirror_timeout_cb );
-	ctrl.timeout_watcher.repeat = MS_REQUEST_LIMIT_SECS_F ;
+
+	char * env_request_limit = getenv( "FLEXNBD_MS_REQUEST_LIMIT_SECS" );
+	double timeout_limit = MS_REQUEST_LIMIT_SECS_F;
+
+	if ( NULL != env_request_limit ) {
+		char *endptr = NULL;
+		errno = 0;
+		double limit = strtod( env_request_limit, &endptr );
+		warn( SHOW_ERRNO( "Got %f from strtod", limit ) );
+
+		if ( errno == 0 ) {
+			timeout_limit = limit;
+		}
+	}
+
+	ctrl.timeout_watcher.repeat = timeout_limit;
 
 	ev_init( &ctrl.limit_watcher, mirror_limit_cb );
 	ctrl.limit_watcher.repeat = 1.0; // We check bps every second. seems sane.
@@ -751,19 +801,23 @@ void mirror_run( struct server *serve )
 		"Couldn't find first transfer for mirror!"
 	);
 
-	/* Start by writing xfer 0 to the listener */
-	ev_io_start( ctrl.ev_loop, &ctrl.write_watcher );
 
-	/* We want to timeout during the first write as well as subsequent ones */
-	ev_timer_again( ctrl.ev_loop, &ctrl.timeout_watcher );
+	if ( serve->allocation_map_built ) {
+		/* Start by writing xfer 0 to the listener */
+		ev_io_start( ctrl.ev_loop, &ctrl.write_watcher );
+		/* We want to timeout during the first write as well as subsequent ones */
+		ev_timer_again( ctrl.ev_loop, &ctrl.timeout_watcher );
+		bitset_enable_stream( serve->allocation_map );
+	} else {
+		debug( "Waiting for allocation map to be built" );
+		ev_timer_again( ctrl.ev_loop, &ctrl.begin_watcher );
+	}
 
 	/* Everything up to here is blocking. We switch to non-blocking so we
 	 * can handle rate-limiting and weird error conditions better. TODO: We
 	 * should expand the event loop upwards so we can do the same there too */
 	sock_set_nonblock( m->client, 1 );
 
-	bitset_enable_stream( serve->allocation_map );
-
 	info( "Entering event loop" );
 	ev_run( ctrl.ev_loop, 0 );
 	info( "Exited event loop" );
@@ -784,30 +838,28 @@ void mirror_run( struct server *serve )
 	 * call retries the migration from scratch. */
 
 	if ( m->commit_state != MS_DONE ) {
-		error( "Event loop exited, but mirroring is not complete" );
-
 		/* mirror_reset will be called before a retry, so keeping hold of events
 		 * between now and our next mirroring attempt is not useful
 		 */
 		bitset_disable_stream( serve->allocation_map );
+		error( "Event loop exited, but mirroring is not complete" );
 	}
 
 	return;
 }
 
 
-void mbox_post_mirror_state( struct mbox * mbox, enum mirror_state st )
+void mbox_post_mirror_state( mbox_p  mbox, mirror_state_t st )
 {
 	NULLCHECK( mbox );
-	enum mirror_state * contents = xmalloc( sizeof( enum mirror_state ) );
 
-	*contents = st;
+	mbox_item_t ste = { .i = st };
 
-	mbox_post( mbox, contents );
+	mbox_post( mbox, ste );
 }
 
 
-void mirror_signal_commit( struct mirror * mirror )
+void mirror_signal_commit( mirror_p mirror )
 {
 	NULLCHECK( mirror );
 
@@ -834,7 +886,7 @@ void* mirror_runner(void* serve_params_uncast)
 
 	NULLCHECK( serve );
 	NULLCHECK( serve->mirror );
-	struct mirror * mirror = serve->mirror;
+	mirror_p mirror = serve->mirror;
 
 	error_set_handler( (cleanup_handler *) mirror_cleanup, serve );
 
@@ -869,7 +921,7 @@ void* mirror_runner(void* serve_params_uncast)
 	 * for us ). But if we've failed and are going to retry on the next run, we
 	 * must close this socket here to have any chance of it succeeding.
 	 */
-	if ( !mirror->client < 0 ) {
+	if ( !(mirror->client < 0) ) {
 		sock_try_close( mirror->client );
 		mirror->client = -1;
 	}
@@ -879,15 +931,15 @@ abandon_mirror:
 }
 
 
-struct mirror_super * mirror_super_create(
+mirror_super_p mirror_super_create(
 		const char * filename,
 		union mysockaddr * connect_to,
 		union mysockaddr * connect_from,
 		uint64_t max_Bps,
-		enum mirror_finish_action action_at_finish,
-		struct mbox * state_mbox)
+		mirror_finish_action_t action_at_finish,
+		mbox_p  state_mbox)
 {
-	struct mirror_super * super = xmalloc( sizeof( struct mirror_super) );
+	mirror_super_p super = xmalloc( sizeof( struct mirror_super_t) );
 	super->mirror = mirror_create(
 			filename,
 			connect_to,
@@ -902,8 +954,8 @@ struct mirror_super * mirror_super_create(
 
 /* Post the current state of the mirror into super->state_mbox.*/
 void mirror_super_signal_committed(
-		struct mirror_super * super ,
-		enum mirror_state commit_state )
+		mirror_super_p super ,
+		mirror_state_t commit_state )
 {
 	NULLCHECK( super );
 	NULLCHECK( super->state_mbox );
@@ -914,7 +966,7 @@ void mirror_super_signal_committed(
 }
 
 
-void mirror_super_destroy( struct mirror_super * super )
+void mirror_super_destroy( mirror_super_p super )
 {
 	NULLCHECK( super );
 
@@ -940,8 +992,8 @@ void * mirror_super_runner( void * serve_uncast )
 	int should_retry = 0;
 	int success = 0, abandoned = 0;
 
-	struct mirror * mirror = serve->mirror;
-	struct mirror_super *  super  = serve->mirror_super;
+	mirror_p mirror = serve->mirror;
+	mirror_super_p  super  = serve->mirror_super;
 
 	do {
 		FATAL_IF( 0 != pthread_create(
@@ -952,8 +1004,8 @@ void * mirror_super_runner( void * serve_uncast )
 				"Failed to create mirror thread");
 
 		debug("Supervisor waiting for commit signal");
-		enum mirror_state * commit_state =
-			mbox_receive( mirror->commit_signal );
+		mirror_state_t commit_state =
+			mbox_receive( mirror->commit_signal ).i;
 
 		debug( "Supervisor got commit signal" );
 		if ( first_pass ) {
@@ -962,18 +1014,14 @@ void * mirror_super_runner( void * serve_uncast )
 			 * retry behind the scenes. This may race with migration completing
 			 * but since we "shouldn't retry" in that case either, that's fine
 			 */
-			should_retry = *commit_state == MS_GO;
+			should_retry = commit_state == MS_GO;
 
 			/* Only send this signal the first time */
 			mirror_super_signal_committed(
 					super,
-					*commit_state);
+					commit_state);
 			debug("Mirror supervisor committed");
 		}
-		/* We only care about the value of the commit signal on
-		 * the first pass, so this is ok
-		 */
-		free( commit_state );
 
 		debug("Supervisor waiting for mirror thread" );
 		pthread_join( mirror->thread, NULL );
@@ -1016,4 +1064,3 @@ void * mirror_super_runner( void * serve_uncast )
 
 	return NULL;
 }
-

src/server/mirror.h

@@ -7,7 +7,7 @@
 
 #include "bitset.h"
 #include "self_pipe.h"
-enum mirror_state;
+
 #include "serve.h"
 #include "mbox.h"
 
@@ -18,6 +18,18 @@ enum mirror_state;
  */
 #define MS_CONNECT_TIME_SECS 60
 
+/* MS_MAX_DOWNTIME_SECS
+ * The length of time a migration must be estimated to have remaining for us to
+ * disconnect clients for convergence
+ *
+ * TODO: Make this configurable so refusing-to-converge clients can be manually
+ *       fixed.
+ * TODO: Make this adaptive - 5 seconds is fine, as long as we can guarantee
+ *       that all migrations will be able to converge in time. We'd add a new
+ *       state between open and closed, where gradually-increasing latency is
+ *       added to client requests to allow the mirror to be faster.
+ */
+#define MS_CONVERGE_TIME_SECS 5
 
 /* MS_HELLO_TIME_SECS
  * The length of time the sender will wait for the NBD hello message
@@ -38,18 +50,21 @@ enum mirror_state;
  * request, this is the time between the end of the NBD request and the
  * start of the NBD reply.  For a write request, this is the time
  * between the end of the written data and the start of the NBD reply.
+ * Can be overridden by the environment variable:
+ * FLEXNBD_MS_REQUEST_LIMIT_SECS
  */
-#define MS_REQUEST_LIMIT_SECS 4
-#define MS_REQUEST_LIMIT_SECS_F 4.0
 
-enum mirror_finish_action {
-	ACTION_EXIT,
+#define MS_REQUEST_LIMIT_SECS 60
+#define MS_REQUEST_LIMIT_SECS_F 60.0
+
+typedef enum {
+	ACTION_EXIT = 0,
 	ACTION_UNLINK,
 	ACTION_NOTHING
-};
+} mirror_finish_action_t;
 
-enum mirror_state {
-	MS_UNKNOWN,
+typedef enum {
+	MS_UNKNOWN = 0,
 	MS_INIT,
 	MS_GO,
 	MS_ABANDONED,
@@ -58,9 +73,9 @@ enum mirror_state {
 	MS_FAIL_REJECTED,
 	MS_FAIL_NO_HELLO,
 	MS_FAIL_SIZE_MISMATCH
-};
+} mirror_state_t;
 
-struct mirror {
+typedef struct mirror_t {
 	pthread_t            thread;
 
 	/* Signal to this then join the thread if you want to abandon mirroring */
@@ -75,19 +90,19 @@ struct mirror {
 	 * over the network) are considered */
 	uint64_t              max_bytes_per_second;
 
-	enum mirror_finish_action action_at_finish;
+	mirror_finish_action_t action_at_finish;
 
 	char                 *mapped;
 
 	/* We need to send every byte at least once; we do so by  */
 	uint64_t offset;
 
-	enum mirror_state    commit_state;
+	mirror_state_t    commit_state;
 
 	/* commit_signal is sent immediately after attempting to connect
 	 * and checking the remote size, whether successful or not.
 	 */
-	struct mbox *        commit_signal;
+	struct mbox_t *        commit_signal;
 
 	/* The time (from monotonic_time_ms()) the migration was started. Can be
 	 * used to calculate bps, etc. */
@@ -95,14 +110,14 @@ struct mirror {
 
 	/* Running count of all bytes we've transferred */
 	uint64_t all_dirty;
-};
+} mirror_t, *mirror_p;
 
 
-struct mirror_super {
-	struct mirror * mirror;
+typedef struct mirror_super_t {
+	mirror_p mirror;
 	pthread_t thread;
-	struct mbox * state_mbox;
-};
+	struct mbox_t * state_mbox;
+} mirror_super_t, *mirror_super_p;
 
 
 
@@ -112,17 +127,15 @@ struct mirror_super {
 struct server;
 struct flexnbd;
 
-struct mirror_super * mirror_super_create(
+mirror_super_p mirror_super_create(
 		const char * filename,
 		union mysockaddr * connect_to,
 		union mysockaddr * connect_from,
 		uint64_t max_Bps,
-		enum mirror_finish_action action_at_finish,
-		struct mbox * state_mbox
+		mirror_finish_action_t action_at_finish,
+		struct mbox_t * state_mbox
 		);
 void * mirror_super_runner( void * serve_uncast );
 
-uint64_t mirror_current_bps( struct mirror * mirror );
-
 #endif
 

src/server/mode.c

@@ -220,7 +220,6 @@ void read_serve_param( int c, char **ip_addr, char **ip_port, char **file, char
 		case 'h':
 			fprintf(stdout, "%s\n", serve_help_text );
 			exit( 0 );
-			break;
 		case 'l':
 			*ip_addr = optarg;
 			break;
@@ -263,7 +262,6 @@ void read_listen_param( int c,
 		case 'h':
 			fprintf(stdout, "%s\n", listen_help_text );
 			exit(0);
-			break;
 		case 'l':
 			*ip_addr = optarg;
 			break;
@@ -297,7 +295,6 @@ void read_readwrite_param( int c, char **ip_addr, char **ip_port, char **bind_ad
 		case 'h':
 			fprintf(stdout, "%s\n", err_text );
 			exit( 0 );
-			break;
 		case 'l':
 			*ip_addr = optarg;
 			break;
@@ -331,7 +328,6 @@ void read_sock_param( int c, char **sock, char *help_text )
 		case 'h':
 			fprintf( stdout, "%s\n", help_text );
 			exit( 0 );
-			break;
 		case 's':
 			*sock = optarg;
 			break;
@@ -362,7 +358,6 @@ void read_mirror_speed_param(
 		case 'h':
 			fprintf( stdout, "%s\n", mirror_speed_help_text );
 			exit( 0 );
-			break;
 		case 's':
 			*sock = optarg;
 			break;
@@ -394,7 +389,6 @@ void read_mirror_param(
 		case 'h':
 			fprintf( stdout, "%s\n", mirror_help_text );
 			exit( 0 );
-			break;
 		case 's':
 			*sock = optarg;
 			break;
@@ -428,7 +422,6 @@ void read_break_param( int c, char **sock )
 		case 'h':
 			fprintf( stdout, "%s\n", break_help_text );
 			exit( 0 );
-			break;
 		case 's':
 			*sock = optarg;
 			break;
@@ -580,7 +573,10 @@ void params_readwrite(
 
 	parse_port( s_port, &out->connect_to.v4 );
 
-	out->from  = atol(s_from);
+	long signed_from = atol(s_from);
+	FATAL_IF_NEGATIVE( signed_from,
+			"Can't read from a negative offset %d.", signed_from);
+	out->from  = signed_from;
 
 	if (write_not_read) {
 		if (s_length_or_filename[0]-48 < 10) {
@@ -592,9 +588,10 @@ void params_readwrite(
 			  s_length_or_filename, O_RDONLY);
 			FATAL_IF_NEGATIVE(out->data_fd,
 			  "Couldn't open %s", s_length_or_filename);
-			out->len = lseek64(out->data_fd, 0, SEEK_END);
-			FATAL_IF_NEGATIVE(out->len,
+			off64_t signed_len = lseek64(out->data_fd, 0, SEEK_END);
+			FATAL_IF_NEGATIVE(signed_len,
 			  "Couldn't find length of %s", s_length_or_filename);
+			out->len = signed_len;
 			FATAL_IF_NEGATIVE(
 				lseek64(out->data_fd, 0, SEEK_SET),
 				"Couldn't rewind %s", s_length_or_filename
@@ -787,7 +784,7 @@ int mode_break( int argc, char *argv[] )
 
 	if ( NULL == sock ){
 		fprintf( stderr, "--sock is required.\n" );
-		exit_err( acl_help_text );
+		exit_err( break_help_text );
 	}
 
 	do_remote_command( "break", sock, argc - optind, argv + optind );
@@ -808,7 +805,7 @@ int mode_status( int argc, char *argv[] )
 
 	if ( NULL == sock ){
 		fprintf( stderr, "--sock is required.\n" );
-		exit_err( acl_help_text );
+		exit_err( status_help_text );
 	}
 
 	do_remote_command( "status", sock, argc - optind, argv + optind );

src/server/serve.c

@@ -4,7 +4,7 @@
 #include "ioutil.h"
 #include "sockutil.h"
 #include "util.h"
-#include "bitset.h"
+#include "bitstream.h"
 #include "control.h"
 #include "self_pipe.h"
 
@@ -233,7 +233,6 @@ int tryjoin_client_thread( struct client_tbl_entry *entry, int (*joinfunc)(pthre
 
 	int was_closed = 0;
 	void * status=NULL;
-	int join_errno;
 
 	if (entry->thread != 0) {
 		char s_client_address[128];
@@ -241,7 +240,7 @@ int tryjoin_client_thread( struct client_tbl_entry *entry, int (*joinfunc)(pthre
 		sockaddr_address_string( &entry->address.generic, &s_client_address[0], 128 );
 
 		debug( "%s(%p,...)", joinfunc == pthread_join ? "joining" : "tryjoining", entry->thread );
-		join_errno = joinfunc(entry->thread, &status);
+		int join_errno = joinfunc(entry->thread, &status);
 
 		/* join_errno can legitimately be ESRCH if the thread is
 		 * already dead, but the client still needs tidying up. */
@@ -256,7 +255,7 @@ int tryjoin_client_thread( struct client_tbl_entry *entry, int (*joinfunc)(pthre
 			debug("nbd thread %016x exited (%s) with status %ld",
 					entry->thread,
 					s_client_address,
-					(uint64_t)status);
+					(uintptr_t)status);
 			client_destroy( entry->client );
 			entry->client = NULL;
 			entry->thread = 0;
@@ -598,7 +597,6 @@ int server_accept( struct server * params )
 {
 	NULLCHECK( params );
 	debug("accept loop starting");
-	int              client_fd;
 	union mysockaddr client_address;
 	fd_set           fds;
 	socklen_t        socklen=sizeof(client_address);
@@ -638,7 +636,7 @@ int server_accept( struct server * params )
 	}
 
 	if ( FD_ISSET( params->server_fd, &fds ) ){
-		client_fd = accept( params->server_fd, &client_address.generic, &socklen );
+		int client_fd = accept( params->server_fd, &client_address.generic, &socklen );
 
 		if ( params->allow_new_clients ) {
 			debug("Accepted nbd client socket fd %d", client_fd);
@@ -686,6 +684,7 @@ void* build_allocation_map_thread(void* serve_uncast)
 		 * the future, we'll need to wait for the allocation map to finish or
 		 * fail before we can complete the migration.
 		 */
+		serve->allocation_map_not_built = 1;
 		warn( "Didn't build allocation map for %s", serve->filename );
 	}
 
@@ -740,11 +739,11 @@ void server_join_clients( struct server * serve ) {
 
 	for (i=0; i < serve->max_nbd_clients; i++) {
 		pthread_t thread_id = serve->nbd_client[i].thread;
-		int err = 0;
 
 		if (thread_id != 0) {
 			debug( "joining thread %p", thread_id );
-			if ( 0 == (err = pthread_join( thread_id, &status ) ) ) {
+			int err = pthread_join( thread_id, &status );
+			if ( 0 == err ) {
 				serve->nbd_client[i].thread = 0;
 			} else {
 				warn( "Error %s (%i) joining thread %p", strerror( err ), err, thread_id );
@@ -878,7 +877,19 @@ uint64_t server_mirror_eta( struct server * serve )
 {
 	if ( server_is_mirroring( serve ) ) {
 		uint64_t bytes_to_xfer = server_mirror_bytes_remaining( serve );
-		return bytes_to_xfer / ( mirror_current_bps( serve->mirror ) + 1 );
+		return bytes_to_xfer / ( server_mirror_bps( serve ) + 1 );
+	}
+
+	return 0;
+}
+
+uint64_t server_mirror_bps( struct server * serve )
+{
+	if ( server_is_mirroring( serve ) ) {
+	 	uint64_t duration_ms =
+	 		monotonic_time_ms() - serve->mirror->migration_started;
+
+		return serve->mirror->all_dirty / ( ( duration_ms / 1000 ) + 1 );
 	}
 
 	return 0;
@@ -941,4 +952,3 @@ int do_serve( struct server* params, struct self_pipe * open_signal )
 
 	return success;
 }
-

src/server/serve.h

@@ -53,8 +53,8 @@ struct server {
 	 * shutting down on a SIGTERM. */
 	struct flexthread_mutex *   l_start_mirror;
 
-	struct mirror* mirror;
-	struct mirror_super * mirror_super;
+	struct mirror_t * mirror;
+	struct mirror_super_t * mirror_super;
 	/* This is used to stop the mirror from starting after we
 	 * receive a SIGTERM */
 	int mirror_can_start;
@@ -76,8 +76,10 @@ struct server {
 	struct bitset * allocation_map;
 	/* when starting up, this thread builds the allocation_map */
 	pthread_t               allocation_map_builder_thread;
+
 	/* when the thread has finished, it sets this to 1 */
 	volatile sig_atomic_t  allocation_map_built;
+	volatile sig_atomic_t  allocation_map_not_built;
 
 	int                  max_nbd_clients;
 	struct client_tbl_entry *nbd_client;
@@ -126,6 +128,7 @@ int server_is_mirroring( struct server * serve );
 
 uint64_t server_mirror_bytes_remaining( struct server * serve );
 uint64_t server_mirror_eta( struct server * serve );
+uint64_t server_mirror_bps( struct server * serve );
 
 void server_abandon_mirror( struct server * serve );
 void server_prevent_mirror_start( struct server *serve );
@@ -151,8 +154,10 @@ int do_serve( struct server *, struct self_pipe * );
 struct mode_readwrite_params {
 	union mysockaddr     connect_to;
 	union mysockaddr     connect_from;
-	off64_t              from;
-	off64_t              len;
+
+	uint64_t             from;
+	uint32_t             len;
+
 	int                  data_fd;
 	int                  client;
 };

src/server/status.c

@@ -27,10 +27,11 @@ struct status * status_create( struct server * serve )
 			status->migration_duration = 0;
 		}
 		status->migration_duration /= 1000;
-		status->migration_speed = serve->mirror->all_dirty / ( status->migration_duration + 1 );
+		status->migration_speed = server_mirror_bps( serve );
 		status->migration_speed_limit = serve->mirror->max_bytes_per_second;
 
 		status->migration_seconds_left = server_mirror_eta( serve );
+		status->migration_bytes_left = server_mirror_bytes_remaining( serve );
 	}
 
 	server_unlock_start_mirror( serve );
@@ -60,6 +61,7 @@ int status_write( struct status * status, int fd )
 		PRINT_UINT64( migration_speed );
 		PRINT_UINT64( migration_duration );
 		PRINT_UINT64( migration_seconds_left );
+		PRINT_UINT64( migration_bytes_left );
 		if ( status->migration_speed_limit < UINT64_MAX ) {
 			PRINT_UINT64( migration_speed_limit );
 		};

src/server/status.h

@@ -64,6 +64,8 @@
  *   Our current best estimate of how many seconds are left before the migration
  *   migration is finished.
  *
+ * migration_bytes_left:
+ *   The number of bytes remaining to migrate.
  */
 
 
@@ -84,6 +86,7 @@ struct status {
 	uint64_t migration_speed;
 	uint64_t migration_speed_limit;
 	uint64_t migration_seconds_left;
+	uint64_t migration_bytes_left;
 };
 
 /** Create a status object for the given server. */

tests/acceptance/environment.rb

@@ -21,6 +21,11 @@ class Environment
     @fake_pid = nil
   end
 
+  def prefetch_proxy!
+    @nbd1.prefetch_proxy = true
+    @nbd2.prefetch_proxy = true
+  end
+
   def proxy1(port=@port2)
     @nbd1.proxy(@ip, port)
   end

tests/acceptance/fakes/dest/hang_after_write.rb

@@ -20,7 +20,13 @@ t = Thread.start do
   client2.close
 end
 
-sleep( FlexNBD::MS_REQUEST_LIMIT_SECS + 2 )
+sleep_time = if ENV.has_key?('FLEXNBD_MS_REQUEST_LIMIT_SECS')
+  ENV['FLEXNBD_MS_REQUEST_LIMIT_SECS'].to_f
+else
+  FlexNBD::MS_REQUEST_LIMIT_SECS
+end
+
+sleep( sleep_time + 2.0 )
 client1.close
 
 t.join

tests/acceptance/flexnbd.rb

@@ -198,6 +198,8 @@ module FlexNBD
       end
     end
 
+    attr_accessor :prefetch_proxy
+
     def initialize( bin, ip, port )
       @bin  = bin
       @do_debug = ENV['DEBUG']
@@ -208,6 +210,7 @@ module FlexNBD
       @ip = ip
       @port = port
       @kill = []
+      @prefetch_proxy = false
     end
 
 
@@ -247,6 +250,7 @@ module FlexNBD
         "--port #{port} "\
         "--conn-addr #{connect_ip} "\
         "--conn-port #{connect_port} "\
+        "#{prefetch_proxy ? "--cache " : ""}"\
         "#{@debug}"
     end
 
@@ -458,12 +462,18 @@ module FlexNBD
 
     def maybe_timeout(cmd, timeout=nil )
       stdout, stderr = "",""
+      stat = nil
       run = Proc.new do
-        Open3.popen3( cmd ) do |io_in, io_out, io_err|
+        # Ruby 1.9 changed the popen3 api. instead of 3 args, the block
+        # gets 4. Not only that, but it no longer sets $?, so we have to
+        # go elsewhere for the process' exit status.
+        Open3.popen3( cmd ) do |io_in, io_out, io_err, maybe_thr|
           io_in.close
           stdout.replace io_out.read
           stderr.replace io_err.read
+          stat = maybe_thr.value if maybe_thr
         end
+        stat ||= $?
       end
 
       if timeout
@@ -472,13 +482,13 @@ module FlexNBD
         run.call
       end
 
-      [stdout, stderr]
+      [stdout, stderr, stat]
     end
 
 
     def mirror(dest_ip, dest_port, bandwidth=nil, action=nil)
-      stdout, stderr = mirror_unchecked( dest_ip, dest_port, bandwidth, action )
-      raise IOError.new( "Migrate command failed\n" + stderr) unless $?.success?
+      stdout, stderr, status = mirror_unchecked( dest_ip, dest_port, bandwidth, action )
+      raise IOError.new( "Migrate command failed\n" + stderr) unless status.success?
 
       stdout
     end

tests/acceptance/flexnbd/constants.rb

@@ -2,6 +2,14 @@
 
 module FlexNBD
 
+  def self.binary( str )
+    if str.respond_to? :force_encoding
+      str.force_encoding "ASCII-8BIT"
+    else
+      str
+    end
+  end
+
   # eeevil is his one and only name...
   def self.read_constants
     parents = []
@@ -17,14 +25,14 @@ module FlexNBD
 
     fail "No source root!" unless source_root
 
-    headers = Dir[File.join( source_root, "src", "*.h" ) ]
+    headers = Dir[File.join( source_root, "src", "{common,proxy,server}","*.h" ) ]
 
     headers.each do |header_filename|
       txt_lines = File.readlines( header_filename )
       txt_lines.each do |line|
         if line =~ /^#\s*define\s+([A-Z0-9_]+)\s+(\d+)\s*$/
           # Bodge until I can figure out what to do with #ifdefs
-          const_set($1, $2.to_i) unless constants.include?( $1 )
+          const_set($1, $2.to_i) unless const_defined?( $1 )
         end
       end
     end
@@ -33,8 +41,8 @@ module FlexNBD
 
   read_constants()
 
-  REQUEST_MAGIC = "\x25\x60\x95\x13" unless defined?(REQUEST_MAGIC)
-  REPLY_MAGIC = "\x67\x44\x66\x98" unless defined?(REPLY_MAGIC)
+  REQUEST_MAGIC = binary("\x25\x60\x95\x13") unless defined?(REQUEST_MAGIC)
+  REPLY_MAGIC = binary("\x67\x44\x66\x98") unless defined?(REPLY_MAGIC)
 
 end # module FlexNBD
 

tests/acceptance/flexnbd/fake_dest.rb

@@ -138,7 +138,7 @@ module FlexNBD
     end
 
 
-    def accept( err_msg = "Timed out waiting for a connection", timeout = 2)
+    def accept( err_msg = "Timed out waiting for a connection", timeout = 5)
       client_sock = nil
 
       begin

tests/acceptance/proxy_tests.rb

@@ -0,0 +1,194 @@
+# encoding: utf-8
+require 'flexnbd/fake_source'
+require 'flexnbd/fake_dest'
+
+module ProxyTests
+  def b
+    "\xFF".b
+  end
+
+  def with_proxied_client( override_size = nil )
+    @env.serve1 unless @server_up
+    @env.proxy2 unless @proxy_up
+    @env.nbd2.can_die(0)
+    client = FlexNBD::FakeSource.new(@env.ip, @env.port2, "Couldn't connect to proxy")
+    begin
+
+      result = client.read_hello
+      assert_equal "NBDMAGIC", result[:magic]
+      assert_equal override_size || @env.file1.size, result[:size]
+
+      yield client
+    ensure
+      client.close rescue nil
+    end
+  end
+
+  def test_exits_with_error_when_cannot_connect_to_upstream_on_start
+    assert_raises(RuntimeError) { @env.proxy1 }
+  end
+
+  def test_read_requests_successfully_proxied
+    with_proxied_client do |client|
+      (0..3).each do |n|
+        offset = n * 4096
+        client.write_read_request(offset, 4096, "myhandle")
+        rsp = client.read_response
+
+        assert_equal ::FlexNBD::REPLY_MAGIC, rsp[:magic]
+        assert_equal "myhandle", rsp[:handle]
+        assert_equal 0, rsp[:error]
+
+        orig_data = @env.file1.read(offset, 4096)
+        data = client.read_raw(4096)
+
+        assert_equal 4096, orig_data.size
+        assert_equal 4096, data.size
+
+        assert_equal( orig_data, data,
+                      "Returned data does not match on request #{n+1}" )
+      end
+    end
+  end
+
+  def test_write_requests_successfully_proxied
+    with_proxied_client do |client|
+      (0..3).each do |n|
+        offset = n * 4096
+        client.write(offset, b * 4096)
+        rsp = client.read_response
+
+        assert_equal FlexNBD::REPLY_MAGIC, rsp[:magic]
+        assert_equal "myhandle", rsp[:handle]
+        assert_equal 0, rsp[:error]
+
+        data = @env.file1.read(offset, 4096)
+
+        assert_equal( ( b * 4096 ), data, "Data not written correctly (offset is #{n})" )
+      end
+    end
+  end
+
+  def make_fake_server
+    server = FlexNBD::FakeDest.new(@env.ip, @env.port1)
+    @server_up = true
+
+    # We return a thread here because accept() and connect() both block for us
+    Thread.new do
+      sc = server.accept # just tell the supervisor we're up
+      sc.write_hello
+
+      [ server, sc ]
+    end
+  end
+
+  def test_read_request_retried_when_upstream_dies_partway
+    maker = make_fake_server
+
+    with_proxied_client(4096) do |client|
+      server, sc1 = maker.value
+
+      # Send the read request to the proxy
+      client.write_read_request( 0, 4096 )
+
+      # ensure we're given the read request
+      req1 = sc1.read_request
+      assert_equal ::FlexNBD::REQUEST_MAGIC, req1[:magic]
+      assert_equal ::FlexNBD::REQUEST_READ, req1[:type]
+      assert_equal 0, req1[:from]
+      assert_not_equal 0, req1[:len]
+
+      # Kill the server again, now we're sure the read request has been sent once
+      sc1.close
+
+      # We expect the proxy to reconnect without our client doing anything.
+      sc2 = server.accept
+      sc2.write_hello
+
+      # And once reconnected, it should resend an identical request.
+      req2 = sc2.read_request
+      assert_equal req1, req2
+
+      # The reply should be proxied back to the client.
+      sc2.write_reply( req2[:handle] )
+      sc2.write_data( b * 4096 )
+
+      # Check it to make sure it's correct
+      rsp = timeout(15) { client.read_response }
+      assert_equal ::FlexNBD::REPLY_MAGIC, rsp[:magic]
+      assert_equal 0, rsp[:error]
+      assert_equal req1[:handle], rsp[:handle]
+
+      data = client.read_raw( 4096 )
+      assert_equal( (b * 4096), data, "Wrong data returned" )
+
+      sc2.close
+      server.close
+    end
+
+  end
+
+  def test_write_request_retried_when_upstream_dies_partway
+    maker = make_fake_server
+
+    with_proxied_client(4096) do |client|
+      server, sc1 = maker.value
+
+      # Send the read request to the proxy
+      client.write( 0, ( b * 4096 ) )
+
+      # ensure we're given the read request
+      req1 = sc1.read_request
+      assert_equal ::FlexNBD::REQUEST_MAGIC, req1[:magic]
+      assert_equal ::FlexNBD::REQUEST_WRITE, req1[:type]
+      assert_equal 0, req1[:from]
+      assert_equal 4096, req1[:len]
+      data1 = sc1.read_data( 4096 )
+      assert_equal( ( b * 4096 ), data1, "Data not proxied successfully" )
+
+      # Kill the server again, now we're sure the read request has been sent once
+      sc1.close
+
+      # We expect the proxy to reconnect without our client doing anything.
+      sc2 = server.accept
+      sc2.write_hello
+
+      # And once reconnected, it should resend an identical request.
+      req2 = sc2.read_request
+      assert_equal req1, req2
+      data2 = sc2.read_data( 4096 )
+      assert_equal data1, data2
+
+      # The reply should be proxied back to the client.
+      sc2.write_reply( req2[:handle] )
+
+      # Check it to make sure it's correct
+      rsp = timeout(15) { client.read_response }
+      assert_equal ::FlexNBD::REPLY_MAGIC, rsp[:magic]
+      assert_equal 0, rsp[:error]
+      assert_equal req1[:handle], rsp[:handle]
+
+      sc2.close
+      server.close
+    end
+  end
+
+  def test_only_one_client_can_connect_to_proxy_at_a_time
+    with_proxied_client do |client|
+
+      c2 = nil
+      assert_raises(Timeout::Error) do
+        timeout(1) do
+          c2 = FlexNBD::FakeSource.new(@env.ip, @env.port2, "Couldn't connect to proxy (2)")
+          c2.read_hello
+        end
+      end
+      c2.close rescue nil if c2
+    end
+
+
+  end
+
+end
+
+

tests/acceptance/test_happy_path.rb

@@ -2,12 +2,17 @@
 
 require 'test/unit'
 require 'environment'
+require 'flexnbd/constants'
 
 class TestHappyPath < Test::Unit::TestCase
   def setup
     @env = Environment.new
   end
 
+  def bin(str)
+    FlexNBD.binary str
+  end
+
   def teardown
     @env.nbd1.can_die(0)
     @env.nbd2.can_die(0)
@@ -22,13 +27,13 @@ class TestHappyPath < Test::Unit::TestCase
     [0, 12, 63].each do |num|
 
       assert_equal(
-        @env.nbd1.read(num*@env.blocksize, @env.blocksize),
-        @env.file1.read(num*@env.blocksize, @env.blocksize)
+        bin( @env.nbd1.read(num*@env.blocksize, @env.blocksize) ),
+        bin( @env.file1.read(num*@env.blocksize, @env.blocksize) )
       )
     end
 
     [124, 1200, 10028, 25488].each do |num|
-      assert_equal(@env.nbd1.read(num, 4), @env.file1.read(num, 4))
+      assert_equal(bin(@env.nbd1.read(num, 4)), bin(@env.file1.read(num, 4)))
     end
   end
 
@@ -102,7 +107,7 @@ class TestHappyPath < Test::Unit::TestCase
     assert_no_match( /unrecognized/, stderr )
 
 
-    Timeout.timeout(2) do @env.nbd1.join end
+    Timeout.timeout(10) do @env.nbd1.join end
 
     assert !File.file?( @env.filename1 )
   end
@@ -110,6 +115,11 @@ class TestHappyPath < Test::Unit::TestCase
 
 
   def test_write_to_high_block
+		# 
+		# This test does not work on 32 bit platforms.
+		#
+		skip("Not relevant on 32-bit platforms") if ( ["a"].pack("p").size < 8 )
+
     # Create a large file, then try to write to somewhere after the 2G boundary
     @env.truncate1 "4G"
     @env.serve1

tests/acceptance/test_prefetch_proxy_mode.rb

@@ -0,0 +1,22 @@
+require 'test/unit'
+require 'environment'
+require 'proxy_tests'
+
+
+class TestPrefetchProxyMode < Test::Unit::TestCase
+  include ProxyTests
+
+  def setup
+    super
+    @env = Environment.new
+    @env.prefetch_proxy!
+    @env.writefile1( "f" * 16 )
+  end
+
+  def teardown
+    @env.cleanup
+    super
+  end
+end
+
+

tests/acceptance/test_proxy_mode.rb

@@ -1,200 +1,20 @@
 require 'test/unit'
 require 'environment'
-require 'flexnbd/fake_source'
-require 'flexnbd/fake_dest'
+require 'proxy_tests'
+
 
 class TestProxyMode < Test::Unit::TestCase
+  include ProxyTests
+
   def setup
     super
     @env = Environment.new
-    @env.writefile1( "0" * 16 )
+    @env.writefile1( "f" * 16 )
   end
 
   def teardown
     @env.cleanup
     super
   end
-
-  def with_proxied_client( override_size = nil )
-    @env.serve1 unless @server_up
-    @env.proxy2 unless @proxy_up
-    @env.nbd2.can_die(0)
-    client = FlexNBD::FakeSource.new(@env.ip, @env.port2, "Couldn't connect to proxy")
-    begin
-
-      result = client.read_hello
-      assert_equal "NBDMAGIC", result[:magic]
-      assert_equal override_size || @env.file1.size, result[:size]
-
-      yield client
-    ensure
-      client.close rescue nil
-    end
-  end
-
-  def test_exits_with_error_when_cannot_connect_to_upstream_on_start
-    assert_raises(RuntimeError) { @env.proxy1 }
-  end
-
-  def test_read_requests_successfully_proxied
-    with_proxied_client do |client|
-      (0..3).each do |n|
-        offset = n * 4096
-        client.write_read_request(offset, 4096, "myhandle")
-        rsp = client.read_response
-
-        assert_equal ::FlexNBD::REPLY_MAGIC, rsp[:magic]
-        assert_equal "myhandle", rsp[:handle]
-        assert_equal 0, rsp[:error]
-
-        orig_data = @env.file1.read(offset, 4096)
-        data = client.read_raw(4096)
-
-        assert_equal 4096, orig_data.size
-        assert_equal 4096, data.size
-
-        assert_equal( orig_data, data, "Returned data does not match" )
-      end
-    end
-  end
-
-  def test_write_requests_successfully_proxied
-    with_proxied_client do |client|
-      (0..3).each do |n|
-        offset = n * 4096
-        client.write(offset, "\xFF" * 4096)
-        rsp = client.read_response
-
-        assert_equal FlexNBD::REPLY_MAGIC, rsp[:magic]
-        assert_equal "myhandle", rsp[:handle]
-        assert_equal 0, rsp[:error]
-
-        data = @env.file1.read(offset, 4096)
-
-        assert_equal( ( "\xFF" * 4096 ), data, "Data not written correctly (offset is #{n})" )
-      end
-    end
-  end
-
-  def make_fake_server
-    server = FlexNBD::FakeDest.new(@env.ip, @env.port1)
-    @server_up = true
-
-    # We return a thread here because accept() and connect() both block for us
-    Thread.new do
-      sc = server.accept # just tell the supervisor we're up
-      sc.write_hello
-
-      [ server, sc ]
-    end
-  end
-
-  def test_read_request_retried_when_upstream_dies_partway
-    maker = make_fake_server
-
-    with_proxied_client(4096) do |client|
-      server, sc1 = maker.value
-
-      # Send the read request to the proxy
-      client.write_read_request( 0, 4096 )
-
-      # ensure we're given the read request
-      req1 = sc1.read_request
-      assert_equal ::FlexNBD::REQUEST_MAGIC, req1[:magic]
-      assert_equal ::FlexNBD::REQUEST_READ, req1[:type]
-      assert_equal 0, req1[:from]
-      assert_not_equal 0, req1[:len]
-
-      # Kill the server again, now we're sure the read request has been sent once
-      sc1.close
-
-      # We expect the proxy to reconnect without our client doing anything.
-      sc2 = server.accept
-      sc2.write_hello
-
-      # And once reconnected, it should resend an identical request.
-      req2 = sc2.read_request
-      assert_equal req1, req2
-
-      # The reply should be proxied back to the client.
-      sc2.write_reply( req2[:handle] )
-      sc2.write_data( "\xFF" * 4096 )
-
-      # Check it to make sure it's correct
-      rsp = timeout(15) { client.read_response }
-      assert_equal ::FlexNBD::REPLY_MAGIC, rsp[:magic]
-      assert_equal 0, rsp[:error]
-      assert_equal req1[:handle], rsp[:handle]
-
-      data = client.read_raw( 4096 )
-      assert_equal( ("\xFF" * 4096), data, "Wrong data returned" )
-
-      sc2.close
-      server.close
-    end
-
-  end
-
-  def test_write_request_retried_when_upstream_dies_partway
-    maker = make_fake_server
-
-    with_proxied_client(4096) do |client|
-      server, sc1 = maker.value
-
-      # Send the read request to the proxy
-      client.write( 0, ( "\xFF" * 4096 ) )
-
-      # ensure we're given the read request
-      req1 = sc1.read_request
-      assert_equal ::FlexNBD::REQUEST_MAGIC, req1[:magic]
-      assert_equal ::FlexNBD::REQUEST_WRITE, req1[:type]
-      assert_equal 0, req1[:from]
-      assert_equal 4096, req1[:len]
-      data1 = sc1.read_data( 4096 )
-      assert_equal( ( "\xFF" * 4096 ), data1, "Data not proxied successfully" )
-
-      # Kill the server again, now we're sure the read request has been sent once
-      sc1.close
-
-      # We expect the proxy to reconnect without our client doing anything.
-      sc2 = server.accept
-      sc2.write_hello
-
-      # And once reconnected, it should resend an identical request.
-      req2 = sc2.read_request
-      assert_equal req1, req2
-      data2 = sc2.read_data( 4096 )
-      assert_equal data1, data2
-
-      # The reply should be proxied back to the client.
-      sc2.write_reply( req2[:handle] )
-
-      # Check it to make sure it's correct
-      rsp = timeout(15) { client.read_response }
-      assert_equal ::FlexNBD::REPLY_MAGIC, rsp[:magic]
-      assert_equal 0, rsp[:error]
-      assert_equal req1[:handle], rsp[:handle]
-
-      sc2.close
-      server.close
-    end
-  end
-
-  def test_only_one_client_can_connect_to_proxy_at_a_time
-    with_proxied_client do |client|
-
-      c2 = nil
-      assert_raises(Timeout::Error) do
-        timeout(1) do
-          c2 = FlexNBD::FakeSource.new(@env.ip, @env.port2, "Couldn't connect to proxy (2)")
-          c2.read_hello
-        end
-      end
-      c2.close rescue nil if c2
-    end
-
-
-  end
-
 end
 

tests/acceptance/test_serve_mode.rb

@@ -6,6 +6,7 @@ class TestServeMode < Test::Unit::TestCase
 
   def setup
     super
+    @b = "\xFF".b
     @env = Environment.new
     @env.writefile1( "0" )
     @env.serve1
@@ -53,18 +54,18 @@ class TestServeMode < Test::Unit::TestCase
       assert_equal FlexNBD::REPLY_MAGIC, rsp[:magic]
       assert_equal 0, rsp[:error]
 
-      client.write( 0, "\xFF" )
+      client.write( 0, @b )
       rsp = client.read_response
       assert_equal FlexNBD::REPLY_MAGIC, rsp[:magic]
       assert_equal 0, rsp[:error]
 
-      client.write( 0, "\xFF\xFF" )
+      client.write( 0, @b * 2 )
       rsp = client.read_response
       assert_equal FlexNBD::REPLY_MAGIC, rsp[:magic]
       assert_equal 0, rsp[:error]
     end
 
-    assert_equal "\xFF\xFF", @env.file1.read( 0, 2 )
+    assert_equal @b * 2, @env.file1.read( 0, 2 )
   end
 
 

tests/acceptance/test_source_error_handling.rb

@@ -7,6 +7,9 @@ require 'environment'
 class TestSourceErrorHandling < Test::Unit::TestCase
 
   def setup
+    @old_env = ENV['FLEXNBD_MS_REQUEST_LIMIT_SECS']
+    ENV['FLEXNBD_MS_REQUEST_LIMIT_SECS'] = "4.0"
+
     @env = Environment.new
     @env.writefile1( "f" * 4 )
     @env.serve1
@@ -16,6 +19,7 @@ class TestSourceErrorHandling < Test::Unit::TestCase
   def teardown
     @env.nbd1.can_die(0)
     @env.cleanup
+    ENV['FLEXNBD_MS_REQUEST_LIMIT_SECS'] = @old_env
   end
 
 

tests/unit/check_bitset.c

@@ -10,7 +10,7 @@
 START_TEST(test_bit_set)
 {
 	uint64_t num = 0;
-	char *bits = (char*) #
+	bitfield_p bits = (bitfield_p) #
 
 #define TEST_BIT_SET(bit, newvalue) \
 	bit_set(bits, (bit)); \
@@ -27,7 +27,7 @@ END_TEST
 START_TEST(test_bit_clear)
 {
 	uint64_t num = 0xffffffffffffffff;
-	char *bits = (char*) #
+	bitfield_p bits = (bitfield_p) #
 
 #define TEST_BIT_CLEAR(bit, newvalue) \
 	bit_clear(bits, (bit)); \
@@ -44,7 +44,7 @@ END_TEST
 START_TEST(test_bit_tests)
 {
 	uint64_t num = 0x5555555555555555;
-	char *bits = (char*) #
+	bitfield_p bits = (bitfield_p) #
 
 	fail_unless(bit_has_value(bits, 0, 1), "bit_has_value malfunction");
 	fail_unless(bit_has_value(bits, 1, 0), "bit_has_value malfunction");
@@ -58,8 +58,8 @@ END_TEST
 
 START_TEST(test_bit_ranges)
 {
-	char buffer[4160];
-	uint64_t  *longs = (unsigned long*) buffer;
+	bitfield_word_t buffer[BIT_WORDS_FOR_SIZE(4160)];
+	uint64_t  *longs = (uint64_t *) buffer;
 	uint64_t i;
 
 	memset(buffer, 0, 4160);
@@ -67,9 +67,9 @@ START_TEST(test_bit_ranges)
 	for (i=0; i<64; i++) {
 		bit_set_range(buffer, i*64, i);
 		fail_unless(
-			longs[i] == (1UL<<i)-1,
+			longs[i] == (1ULL<<i)-1,
 			"longs[%ld] = %lx SHOULD BE %lx",
-			i, longs[i], (1L<<i)-1
+			i, longs[i], (1ULL<<i)-1
 		);
 
 		fail_unless(longs[i+1] == 0, "bit_set_range overshot at i=%d", i);
@@ -84,7 +84,7 @@ END_TEST
 
 START_TEST(test_bit_runs)
 {
-	char buffer[256];
+	bitfield_word_t buffer[BIT_WORDS_FOR_SIZE(256)];
 	int i, ptr=0, runs[] = {
 		56,97,22,12,83,1,45,80,85,51,64,40,63,67,75,64,94,81,79,62
 	};

tests/unit/check_client.c

@@ -76,8 +76,8 @@ START_TEST( test_read_request_quits_on_stop_signal )
 	
 	client_signal_stop( c );
 
-	int client_read_request( struct client *, struct nbd_request *);
-	fail_unless( 0 == client_read_request( c, &nbdr ), "Didn't quit on stop." );
+	int client_serve_request( struct client *);
+	fail_unless( 1 == client_serve_request( c ), "Didn't quit on stop." );
 
 	close( fds[0] );
 	close( fds[1] );

tests/unit/check_mbox.c

@@ -6,7 +6,7 @@
 
 START_TEST( test_allocs_cvar )
 {
-	struct mbox * mbox = mbox_create();
+	struct mbox_t * mbox = mbox_create();
 	fail_if( NULL == mbox, "Nothing allocated" );
 
 	pthread_cond_t cond_zero;
@@ -22,7 +22,7 @@ END_TEST
 
 START_TEST( test_post_stores_value )
 {
-	struct mbox * mbox = mbox_create();
+	struct mbox_t * mbox = mbox_create();
 	
 	void * deadbeef = (void *)0xDEADBEEF;
 	mbox_post( mbox, deadbeef );
@@ -33,19 +33,18 @@ START_TEST( test_post_stores_value )
 END_TEST
 
 
-void * mbox_receive_runner( void * mbox_uncast )
+mbox_item_t mbox_receive_runner( void * mbox_uncast )
 {
-	struct mbox * mbox = (struct mbox *)mbox_uncast;
+	struct mbox_t * mbox = (struct mbox_t *)mbox_uncast;
 	void * contents = NULL;
 
-	contents = mbox_receive( mbox );
-	return contents;
+	return mbox_receive( mbox );
 }
 
 
 START_TEST( test_receive_blocks_until_post )
 {
-	struct mbox * mbox = mbox_create();
+	struct mbox_t * mbox = mbox_create();
 	pthread_t receiver;
 	pthread_create( &receiver, NULL, mbox_receive_runner, mbox );
 	
@@ -66,9 +65,9 @@ START_TEST( test_receive_blocks_until_post )
 END_TEST
 
 
-Suite* acl_suite(void)
+Suite* mbox_suite(void)
 {
-	Suite *s = suite_create("acl");
+	Suite *s = suite_create("mbox");
 	TCase *tc_create = tcase_create("create");
 	TCase *tc_post = tcase_create("post");
 
@@ -93,7 +92,7 @@ int main(void)
 	log_level = 2;
 #endif
 	int number_failed;
-	Suite *s = acl_suite();
+	Suite *s = mbox_suite();
 	SRunner *sr = srunner_create(s);
 	srunner_run_all(sr, CK_NORMAL);
 	log_level = 0;

tests/unit/check_nbdtypes.c

@@ -88,14 +88,14 @@ START_TEST(test_request_handle)
 	struct nbd_request_raw request_raw;
 	struct nbd_request     request;
 
-	memcpy( request_raw.handle, "MYHANDLE", 8 );
+	memcpy( request_raw.handle.b, "MYHANDLE", 8 );
 	
 	nbd_r2h_request( &request_raw, &request );
-	memset( request_raw.handle, 0, 8 );
+	request_raw.handle.w = 0;
 	nbd_h2r_request( &request, &request_raw );
   
-	fail_unless( memcmp( request.handle, "MYHANDLE", 8 ) == 0, "The handle was not copied." );
-	fail_unless( memcmp( request_raw.handle, "MYHANDLE", 8 ) == 0, "The handle was not copied back." );
+	fail_unless( memcmp( request.handle.b, "MYHANDLE", 8 ) == 0, "The handle was not copied." );
+	fail_unless( memcmp( request_raw.handle.b, "MYHANDLE", 8 ) == 0, "The handle was not copied back." );
 }
 END_TEST
 
@@ -170,14 +170,14 @@ START_TEST(test_reply_handle)
 	struct nbd_reply_raw reply_raw;
 	struct nbd_reply     reply;
 
-	memcpy( reply_raw.handle, "MYHANDLE", 8 );
+	memcpy( reply_raw.handle.b, "MYHANDLE", 8 );
 	
 	nbd_r2h_reply( &reply_raw, &reply );
-	memset( reply_raw.handle, 0, 8 );
+	reply_raw.handle.w = 0;
 	nbd_h2r_reply( &reply, &reply_raw );
   
-	fail_unless( memcmp( reply.handle, "MYHANDLE", 8 ) == 0, "The handle was not copied." );
-	fail_unless( memcmp( reply_raw.handle, "MYHANDLE", 8 ) == 0, "The handle was not copied back." );
+	fail_unless( memcmp( reply.handle.b, "MYHANDLE", 8 ) == 0, "The handle was not copied." );
+	fail_unless( memcmp( reply_raw.handle.b, "MYHANDLE", 8 ) == 0, "The handle was not copied back." );
 }
 END_TEST
 
@@ -188,14 +188,15 @@ START_TEST( test_convert_from )
 	 * nbd_request_raw */
 	struct nbd_request_raw request_raw;
 	struct nbd_request     request;
-	char readbuf[] = {0x80, 0, 0, 0, 0, 0, 0, 0};
 
-	memcpy( &request_raw.from, readbuf, 8 );
+	uint64_t target = 0x8000000000000000;
 
+	/* this is stored big-endian */
+	request_raw.from = htobe64(target);
+
+	/* We expect this to convert big-endian to the host format */
 	nbd_r2h_request( &request_raw, &request );
 
-	uint64_t target = 1;
-	target <<= 63;
 	fail_unless( target == request.from, "from was wrong" );
 }	
 END_TEST

tests/unit/check_readwrite.c

@@ -22,7 +22,7 @@
 
 
 int fd_read_request( int, struct nbd_request_raw *);
-int fd_write_reply( int, char *, int );
+int fd_write_reply( int, uint64_t, int );
 
 int marker;
 
@@ -46,8 +46,7 @@ void * responder( void *respond_uncast )
 	struct respond * resp = (struct respond *) respond_uncast;
 	int sock_fd = resp->sock_fds[1];
 	struct nbd_request_raw request_raw;
-	char wrong_handle[] = "WHOOPSIE";
-
+	uint64_t wrong_handle = 0x80;
 
 	if( fd_read_request( sock_fd, &request_raw ) == -1){
 		fprintf(stderr, "Problem with fd_read_request\n");
@@ -57,7 +56,7 @@ void * responder( void *respond_uncast )
 			fd_write_reply( sock_fd, wrong_handle, 0 );
 		}
 		else {
-			fd_write_reply( sock_fd, resp->received.handle, 0 );
+			fd_write_reply( sock_fd, resp->received.handle.w, 0 );
 		}
 		write( sock_fd, "12345678", 8 );
 	}
@@ -150,7 +149,7 @@ END_TEST
 
 Suite* readwrite_suite(void)
 {
-	Suite *s = suite_create("acl");
+	Suite *s = suite_create("readwrite");
 	TCase *tc_transfer = tcase_create("entrust");
 	TCase *tc_disconnect = tcase_create("disconnect");
 

tests/unit/check_serve.c

@@ -93,7 +93,7 @@ END_TEST
 
 int connect_client( char *addr, int actual_port, char *source_addr )
 {
-	int client_fd;
+	int client_fd = -1;
 
 	struct addrinfo hint;
 	struct addrinfo *ailist, *aip;

tests/unit/check_sockutil.c

@@ -72,9 +72,11 @@ START_TEST( test_sockaddr_address_string_doesnt_overflow_short_buffer )
 	char testbuf[128];
 	const char* result;
 
+	memset( testbuf, 0, 128 );
 	v4->sin_family = AF_INET;
 	v4->sin_port = htons( 4777 );
 	ck_assert_int_eq( 1, inet_pton( AF_INET, "192.168.0.1", &v4->sin_addr ));
+	memset( &testbuf, 0, 128 );
 
 	result = sockaddr_address_string( &sa, &testbuf[0], 2 );
 	ck_assert( result == NULL );

tests/unit/check_status.c

@@ -308,6 +308,7 @@ START_TEST( test_renders_migration_statistics )
 	status.migration_speed = 40000000;
 	status.migration_speed_limit = 40000001;
 	status.migration_seconds_left = 1;
+	status.migration_bytes_left = 5000;
 
 	status_write( &status, fds[1] );
 	fail_if_rendered( fds[0], "migration_duration" );
@@ -335,6 +336,9 @@ START_TEST( test_renders_migration_statistics )
 	status_write( &status, fds[1] );
 	fail_unless_rendered( fds[0], "migration_seconds_left=1" );
 
+	status_write( &status, fds[1] );
+	fail_unless_rendered( fds[0], "migration_bytes_left=5000" );
+
 	status.migration_speed_limit = UINT64_MAX;
 
 	status_write( &status, fds[1] );

tests/unit/check_util.c

@@ -71,11 +71,12 @@ START_TEST( test_fatal_kills_process )
 		sleep(10);
 	} 
 	else {
-		int kidstatus;
-		int result;
-		result = waitpid( pid, &kidstatus, 0 );
+		int kidret, kidstatus, result;
+		result = waitpid( pid, &kidret, 0 );
 		fail_if(  result < 0, "Wait failed." );
-		fail_unless( kidstatus == 6, "Kid was not aborted." );
+		fail_unless( WIFSIGNALED( kidret ), "Process didn't exit via signal" );
+		kidstatus = WTERMSIG( kidret );
+		ck_assert_int_eq( kidstatus, SIGABRT );
 	}
 
 }
@@ -140,9 +141,9 @@ START_TEST( test_fatal_doesnt_call_handler )
 END_TEST
 
 
-Suite* error_suite(void)
+Suite* util_suite(void)
 {
-	Suite *s = suite_create("error");
+	Suite *s = suite_create("util");
 	TCase *tc_process = tcase_create("process");
 	TCase *tc_handler = tcase_create("handler");
 
@@ -162,7 +163,7 @@ Suite* error_suite(void)
 int main(void)
 {
 	int number_failed;
-	Suite *s = error_suite();
+	Suite *s = util_suite();
 	SRunner *sr = srunner_create(s);
 	srunner_run_all(sr, CK_NORMAL);
 	number_failed = srunner_ntests_failed(sr);

tools/Makefile

@@ -0,0 +1,18 @@
+
+CPPFLAGS = -Wall -I../src/server -I../src/common -I../src/proxy \
+			-Doff64_t=__off64_t \
+			-Wunused-const-variable=0 -Wformat=0
+		
+CFLAGS = $(CPPFLAGS) -g -O3 -std=gnu99
+
+all: holemap semtest
+
+# holemap requires libmhash-dev for md5 calculation
+holemap: holemap.c ../src/server/*.h
+	$(CC) $(CFLAGS) -o $@ $^ ${shell pkg-config mhash --cflags --libs}
+
+semtest: semtest.c
+	$(CC) $(CFLAGS) -o $@ $^ -lpthread
+
+clean:
+	rm -f holemap semtest

tools/holemap.c

@@ -0,0 +1,271 @@
+
+#define _GNU_SOURCE
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include "bitset.h"
+
+#include <mhash.h>
+
+static int verbose = 0;
+
+static const char * fstr(const char *fname, const char *error) {
+	char * ret;
+	asprintf(&ret, "%s:%s", fname, error);
+	return strdup(ret); // leaks on purpose; it's before we exit() anyway
+}
+
+static void
+fill_check_pages(
+		uint8_t *map,
+		bitfield_p zmap,
+		uint64_t current,
+		uint64_t count,
+		uint64_t blksize)
+{
+	uint64_t * base = (uint64_t*)(map + (current * blksize));
+	const int wordcount = blksize / sizeof(uint64_t);
+
+	while (count--) {
+		int is_zero = 1;
+
+		if (is_zero) {
+			uint64_t *cur = base;
+			for (int z = 0; z < wordcount && is_zero; z++)
+				is_zero = 0 == *cur++;
+		}
+		if (!is_zero)
+			bit_set(zmap, current);
+		base += wordcount;
+		current++;
+	}
+}
+
+static int
+read_file_data_ranges(
+		int fd,
+		bitfield_p bmap,
+		struct stat st)
+{
+	off_t off = 0;
+	int whence = SEEK_DATA;
+
+	while (off < st.st_size) {
+		if (verbose > 1)
+			printf("offset %llu\n", off);
+
+		off_t res = lseek(fd, off, whence);
+		if (res == -1) {
+			// end of file is OK
+			if (errno == ENXIO)
+				return 0;
+			fprintf(stderr, "lseek fails at %llu/%llu\n", off, st.st_size);
+			return res;
+		}
+		if (res > off && verbose)
+			printf("%s from %llu to %llu\n",
+					whence == SEEK_DATA ? "hole" : "data", off, res);
+		if (whence != SEEK_DATA) {
+			if (res > off) {
+				uint64_t from = off / st.st_blksize,
+						cnt = ((res + st.st_blksize - 1) - off) / st.st_blksize;
+				bit_set_range(bmap, from, cnt);
+				if (verbose > 1)
+					printf("set bits from %u cnt %u\n", from, cnt);
+			}
+		}
+		whence = whence == SEEK_DATA ? SEEK_HOLE : SEEK_DATA;
+		off = res;
+	}
+	return 0;
+}
+
+int main(int argc, const char *argv[])
+{
+	int dohash = 0;
+
+	for (int i = 1; i < argc; i++) {
+		if (argv[i][0] == '-') {
+			if (!strcmp(argv[i], "-v") || !strcmp(argv[i], "--verbose")) {
+				verbose++;
+				continue;
+			} else if (!strcmp(argv[i], "-h") || !strcmp(argv[i], "--hash")) {
+				dohash++;
+				continue;
+			}
+
+			fprintf(stderr, "%s: invalid argument: %s\n", argv[0], argv[i]);
+			exit(1);
+		}
+		const char *fname = argv[i];
+		struct stat st;
+		if (stat(fname, &st)) {
+			perror(fname);
+			exit(1);
+		}
+		int fd = open(fname, O_RDONLY);
+		if (fd == -1) {
+			perror(fname);
+			exit(1);
+		}
+		if (verbose)
+			printf("%s is %u (%u times %u)\n", fname,
+				st.st_size, st.st_blocks, st.st_blksize);
+
+		/* number of used blocks for this file size, also number of bits in bitmaps */
+		size_t maxblocks = (st.st_size + st.st_blksize -1) / st.st_blksize;
+
+		/* this is the original bitmap made using the operating system */
+		bitfield_p bmap = (bitfield_p)calloc(
+				1 + (maxblocks / BITS_PER_WORD), BITFIELD_WORD_SIZE);
+
+		if (read_file_data_ranges(fd, bmap, st)) {
+			perror(fstr(fname, "read_file_data_ranges"));
+			exit(1);
+		}
+
+		if (verbose > 3) {
+			printf("original map: ");
+			for (int z = 0; z <= (maxblocks / BITS_PER_WORD); z++)
+				printf("%016llx ", bmap[z]);
+			printf("\n");
+		}
+
+		uint8_t * map = mmap(NULL, maxblocks * st.st_blksize,
+								PROT_READ, MAP_PRIVATE,
+								fd, 0);
+		if (map == MAP_FAILED) {
+			perror(fname);
+			exit(1);
+		}
+		/* This one bitmap will have a subset, or be a copy of the bmap one when
+		 * we're done
+		 */
+		bitfield_p zmap = (bitfield_p)calloc(
+				1 + (maxblocks / BITS_PER_WORD), BITFIELD_WORD_SIZE);
+		{
+			uint64_t current = 0, count;
+			int which;
+
+			while (current < maxblocks &&
+					(count = bit_run_count(bmap, current, maxblocks - current, &which)) > 0) {
+				if (verbose)
+					printf("map is %s from %u to %u\n",
+						which ? "set" : "zero",
+						current * st.st_blksize,
+						(current+count) * st.st_blksize);
+				/* if bits were sets in the extents, double check them */
+				if (which)
+					fill_check_pages(map, zmap, current, count, st.st_blksize);
+
+				current += count;
+			}
+		}
+		if (verbose > 2) {
+			printf("optimized map: ");
+			for (int z = 0; z <= (maxblocks / BITS_PER_WORD); z++)
+				printf("%016llx ", zmap[z]);
+			printf("\n");
+		}
+
+		{
+			bitfield_p b[2] = { bmap, zmap };
+			uint64_t set[2] = {0};
+
+			for (int bs = 0; bs < 2; bs++) {
+				for (int z = 0; z <= (maxblocks / BITS_PER_WORD); z++)
+					set[bs] += __builtin_popcountll(b[bs][z]);
+			}
+
+			printf("%s is %d%% sparse, saving %llu blocks (%lluMB)\n", fname,
+					100 - ((set[0] * 100) / maxblocks),
+					100 - (maxblocks - set[0]),
+					((maxblocks - set[0]) * st.st_blksize) / (1024*1024));
+			if (set[1] < set[0])
+				printf("%s could be %d%% sparse, saving %llu blocks (%lluMB)\n", fname,
+						100 - ((set[1] * 100) / maxblocks),
+						100 - (maxblocks - set[1]),
+						((maxblocks - set[1]) * st.st_blksize) / (1024*1024));
+		}
+
+
+		if (dohash) {
+			const int hs = mhash_get_block_size(MHASH_MD5);
+			struct {
+				char h[hs + 1];
+			} hash[3];
+			MHASH td;
+
+			if (verbose)
+				printf("%s: calculating hashes, be patient\n", argv[i]);
+			td = mhash_init(MHASH_MD5);
+			mhash(td, map, maxblocks * st.st_blksize);
+			mhash_deinit(td, hash[0].h);
+
+			if (verbose)
+				printf("%s: hash 1/3 done\n", argv[i]);
+
+			{
+				uint64_t current = 0, count;
+				int which;
+
+				td = mhash_init(MHASH_MD5);
+
+				while (current < maxblocks &&
+						(count = bit_run_count(bmap, current, maxblocks - current, &which)) > 0) {
+					/* if bits were sets in the extents, double check them */
+					if (which)
+						mhash(td, map + (current * st.st_blksize),
+								count * st.st_blksize);
+					current += count;
+				}
+				mhash_deinit(td, hash[1].h);
+			}
+			if (verbose)
+				printf("%s: hash 2/3 done\n", argv[i]);
+
+			{
+				uint64_t current = 0, count;
+				int which;
+
+				td = mhash_init(MHASH_MD5);
+
+				while (current < maxblocks &&
+						(count = bit_run_count(zmap, current, maxblocks - current, &which)) > 0) {
+					/* if bits were sets in the extents, double check them */
+					if (which)
+						mhash(td, map + (current * st.st_blksize),
+								count * st.st_blksize);
+					current += count;
+				}
+				mhash_deinit(td, hash[2].h);
+			}
+			if (memcmp(hash[0].h, hash[1].h, hs) || memcmp(hash[0].h, hash[2].h, hs)) {
+				fprintf(stderr, "%s: hash mismatch: ", argv[i]);
+				for (int h = 0; h < 3; h++) {
+					for (int hb = 0; hb < hs; hb++)
+						fprintf(stderr, "%.2x", (uint8_t)hash[h].h[hb]);
+					fprintf(stderr, " ");
+				}
+				fprintf(stderr, "\n");
+			} else if (verbose) {
+				fprintf(stdout, "%s: hash 3/3 match: ", argv[i]);
+				for (int hb = 0; hb < hs; hb++)
+					fprintf(stdout, "%.2x", (uint8_t)hash[0].h[hb]);
+				fprintf(stdout, "\n");
+			}
+		}
+		munmap(map, maxblocks * st.st_blksize);
+		close(fd);
+		free(bmap);
+		free(zmap);
+	}
+	
+	
+}

tools/semtest.c

@@ -0,0 +1,122 @@
+/*
+ * Latency test for pthread 'conditions' vs using a good ol'
+ * pair of linked sockets.
+ * gcc -o semtest -O2 -g --std=c99 semtest.c -lpthread
+ * 
+ */
+#include <sys/socket.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <pthread.h>
+#include <unistd.h>
+
+#define TESTCOUNT	10000000
+
+pthread_mutex_t mutex;
+pthread_cond_t kidwake, dadwake;
+int flag_passed = 0;
+
+static void *thread_semaphore(void * param)
+{
+	printf("kid started\n");
+	pthread_mutex_lock(&mutex);
+	pthread_cond_signal( &dadwake );
+	pthread_mutex_unlock(&mutex);			
+	do {
+		pthread_mutex_lock(&mutex);
+		while (flag_passed == 0)
+			pthread_cond_wait( &kidwake, &mutex );
+		flag_passed = 0;
+		pthread_cond_signal( &dadwake );
+		pthread_mutex_unlock(&mutex);			
+	} while (1);
+	return NULL;
+}
+
+int sock[2];
+
+static void * thread_socket(void * param)
+{
+	printf("kid started\n");
+	do {
+		char b = 0;
+		int r = read(sock[1], &b, 1);
+		if (r != 1)
+			perror("read");
+		b = 0;
+		write(sock[1], &b, 1);	// tell the kid
+	} while (1);
+	
+	return NULL;
+}
+
+
+int main(int argc, char ** argv)
+{
+	int test = 0;
+	for (int i = 1; i < argc; i++) {
+		if (!strcmp(argv[i], "socket"))
+			test = 1;
+		else if (!strcmp(argv[i], "semaphore"))
+			test = 2;
+		else
+			goto usage;
+	}
+	if (!test)
+		goto usage;
+
+	if (test == 1) {
+		if (socketpair(PF_LOCAL, SOCK_STREAM, 0, sock)) {
+			perror("socketpair");
+			exit(1);
+		}
+		printf("Socket test start:\n");
+		pthread_t t;
+		pthread_create(&t, NULL, thread_socket, NULL);
+
+		for (int ti = 0; ti < TESTCOUNT; ti++) {
+			char b = 1;
+			write(sock[0], &b, 1);	// tell the kid
+			int r = read(sock[0], &b, 1);
+			if (r != 1)
+				perror("read");
+
+			if (!(ti % 100000)) {
+				printf("."); fflush(stdout);
+			}
+		}		
+	} else {
+		pthread_mutex_init(&mutex, NULL);
+		pthread_cond_init( &kidwake, NULL );
+		pthread_cond_init( &dadwake, NULL );
+
+		printf("Semaphore test start:\n");
+		pthread_t t;
+		pthread_create(&t, NULL, thread_semaphore, NULL);
+
+		pthread_mutex_lock(&mutex);
+		printf("dad wait for kid\n");
+		pthread_cond_wait( &dadwake, &mutex );
+		pthread_mutex_unlock(&mutex);
+		printf("dad has kid ready\n");
+		
+		for (int ti = 0; ti < TESTCOUNT; ti++) {
+			pthread_mutex_lock(&mutex);
+			flag_passed = 1;
+			pthread_cond_signal( &kidwake );
+			while (flag_passed == 1)
+				pthread_cond_wait( &dadwake, &mutex );
+			pthread_mutex_unlock(&mutex);
+			if (!(ti % 100000)) {
+				printf("."); fflush(stdout);
+			}
+		}
+	}
+	printf("\nDone\n");
+	exit(0);
+usage:
+	fprintf(stderr, "%s socket -- run semaphore latency test with sockets\n", argv[0]);
+	fprintf(stderr, "%s semaphore -- run semaphore latency test with sockets\n", argv[0]);
+	exit(1);
+}