create fio plugin for cstor replica (openzfs#42)

.travis.yml

@@ -10,11 +10,11 @@ env:
     - ZFS_BUILD_TAGS=0
     - ZFS_BUILD_TAGS=1
 before_install:
-  # sudo apt-get -qq update
+    # sudo apt-get -qq update
     - sudo apt-get install --yes -qq build-essential autoconf libtool gawk alien fakeroot linux-headers-$(uname -r) libaio-dev
     - sudo apt-get install --yes -qq zlib1g-dev uuid-dev libattr1-dev libblkid-dev libselinux-dev libudev-dev libssl-dev
     - sudo apt-get install --yes -qq lcov libjemalloc-dev
-  # packages for tests
+    # packages for tests
     - sudo apt-get install --yes -qq parted lsscsi ksh attr acl nfs-kernel-server fio
     - sudo apt-get install --yes -qq libgtest-dev cmake
 install:
@@ -25,6 +25,12 @@ install:
     - sudo cp *.a /usr/lib
     - popd
     - cd ..
+    # we need fio repo to build zfs replica fio engine
+    - git clone https://github.com/axboe/fio
+    - cd fio
+    - ./configure
+    - make
+    - cd ..
     - git clone https://github.com/openebs/spl
     - cd spl
     - git checkout spl-0.7.4
@@ -39,7 +45,7 @@ install:
     - cd ../zfs
     - sh autogen.sh
     - if [ $ZFS_BUILD_TAGS = 0 ]; then
-        ./configure --enable-code-coverage=yes --enable-debug --enable-uzfs=yes --with-jemalloc || travis_terminate 1;
+        ./configure --enable-code-coverage=yes --enable-debug --enable-uzfs=yes --with-jemalloc --with-fio=$PWD/../fio || travis_terminate 1;
         make;
       else
         ./configure --enable-code-coverage=yes --enable-debug || travis_terminate 1;
@@ -52,6 +58,7 @@ script:
     # run ztest and test supported zio backends
     - if [ $ZFS_BUILD_TAGS = 0 ]; then
         sudo mkdir /etc/zfs;
+        export FIO_SRCDIR=$PWD/../fio;
         travis_wait 60 sudo bash ./tests/cbtest/script/test_uzfs.sh || travis_terminate 1;
       else
         sudo /sbin/modprobe zfs;

config/user-fio.m4

@@ -0,0 +1,11 @@
+AC_DEFUN([ZFS_AC_CONFIG_USER_FIO], [
+	AC_ARG_WITH(fio,
+		[AC_HELP_STRING([--with-fio=dir],
+		    [build with FIO engine for replica protocol])],
+		[AC_CHECK_FILE($withval/fio.h,
+		    [FIO_SRCDIR=$withval],
+		    [AC_MSG_FAILURE([Not a valid fio repository])])])
+	])
+
+	AC_SUBST([FIO_SRCDIR])
+])

config/user.m4

@@ -20,6 +20,7 @@ AC_DEFUN([ZFS_AC_CONFIG_USER], [
 	ZFS_AC_CONFIG_USER_NO_FORMAT_TRUNCATION
 	ZFS_AC_CONFIG_USER_LIBAIO
 	ZFS_AC_CONFIG_USER_JEMALLOC
+	ZFS_AC_CONFIG_USER_FIO
 
 	ZFS_AC_TEST_FRAMEWORK
 

config/zfs-build.m4

@@ -122,6 +122,7 @@ AC_DEFUN([ZFS_AC_CONFIG], [
 	    [test "x$qatsrc" != x ])
 	AM_CONDITIONAL([WANT_DEVNAME2DEVID], [test "x$user_libudev" = xyes ])
 	AM_CONDITIONAL([WANT_MMAP_LIBAIO], [test "x$user_libaio" = xyes ])
+	AM_CONDITIONAL([CONFIG_FIO], [test x$FIO_SRCDIR != x ])
 ])
 
 dnl #

configure.ac

@@ -99,6 +99,7 @@ AC_CONFIG_FILES([
 	lib/libzfs/Makefile
 	lib/libzfs_core/Makefile
 	lib/libshare/Makefile
+	lib/fio/Makefile
 	cmd/Makefile
 	cmd/uzfs_test/Makefile
 	cmd/zdb/Makefile

lib/Makefile.am

@@ -5,3 +5,7 @@ SUBDIRS = libspl libavl libefi libshare libunicode libicp
 # These four libraries, which are installed as the final build product,
 # incorporate the six convenience libraries given above.
 SUBDIRS += libuutil libnvpair libzpool libzfs_core libzfs
+
+if CONFIG_FIO
+SUBDIRS += fio
+endif

lib/fio/Makefile.am

@@ -0,0 +1,12 @@
+include $(top_srcdir)/config/Rules.am
+
+DEFAULT_INCLUDES += \
+	-I$(top_srcdir)/include \
+	-I$(FIO_SRCDIR)
+
+lib_LTLIBRARIES = replica.la
+
+replica_la_SOURCES = replica.c
+replica_la_LDFLAGS = -module
+# required for fio external plugins on linux
+replica_la_CFLAGS = -D_GNU_SOURCE -DCONFIG_STRSEP

lib/fio/README.md

@@ -0,0 +1,31 @@
+
+This is a fio engine for zfs replica using replica network protocol to
+configure data connections and issue IOs over them.
+
+# Build
+
+Use `--with-fio=DIR` in addition to `--enable-uzfs` configure option to
+enable building it. `DIR` is a path to fio repository with fio include
+files.
+
+# Run
+
+We assume that fio command is executed from the fio's repository directory.
+In following command change path to zfs repository as appropriate:
+
+```bash
+LD_LIBRARY_PATH=/repos/zfs/lib/fio/.libs ./fio replica.fio
+```
+
+fio should get stuck and print a message `waiting for connection from replica`.
+In another window start zfs replica and instruct it to connect to "fio
+target" which is listening on loopback interface:
+
+```bash
+sudo /repos/zfs/cmd/zrepl/zrepl 127.0.0.1
+```
+
+At most after 5 secs `zrepl` will connect to fio and IO will start flowing.
+`address` and `port` replica fio engine configuration options can be used
+to avoid the listening phase and create data connection directly from fio
+engine to zfs replica.