unfs3: Add a NFSv3 user mode server for use with runqemu

The user mode nfs server allows the use of runqemu without any root
privileges and may even be accelerated with kvm.

Example:

runqemu-extract-sdk tmp-eglibc/deploy/images/qemux86-64/core-image-minimal-qemux86-64.tar.bz2 rootfs

runqemu qemux86-64 `pwd`/rootfs nographic slirp kvm

[YOCTO #5639]

(From OE-Core rev: 24183f5ec9c71db936e75060387941463d30d962)

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 61 insertions, 0 deletions

diff --git a/meta/recipes-devtools/unfs3/unfs3/fix_pid_race_parent_writes_child_pid.patch b/meta/recipes-devtools/unfs3/unfs3/fix_pid_race_parent_writes_child_pid.patch
new file mode 100644
index 0000000000..76d7555ea9
--- /dev/null
+++ b/meta/recipes-devtools/unfs3/unfs3/fix_pid_race_parent_writes_child_pid.patch
@@ -0,0 +1,61 @@
+daemon.c: Fix race window for writing of the pid file
+
+The parent process should write the pid file such that the pid file
+will can be checked immediately following exit of the fork from the
+parent.
+
+This allows external monitoring applications to watch the daemon
+without having to add sleep calls to wait for the pid file be written
+on a busy system.
+
+Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
+
+Upstream-Status: Pending
+
+---
+ daemon.c |   12 +++++++++---
+ 1 file changed, 9 insertions(+), 3 deletions(-)
+
+--- a/daemon.c
++++ b/daemon.c
+@@ -153,7 +153,7 @@ int get_socket_type(struct svc_req *rqst
+ /*
+  * write current pid to a file
+  */
+-static void create_pid_file(void)
++static void create_pid_file(int pid)
+ {
+     char buf[16];
+     int fd, res, len;
+@@ -175,7 +175,7 @@ static void create_pid_file(void)
+     }
+ #endif
+ 
+-    sprintf(buf, "%i\n", backend_getpid());
++    sprintf(buf, "%i\n", pid);
+     len = strlen(buf);
+ 
+     res = backend_pwrite(fd, buf, len, 0);
+@@ -970,6 +970,10 @@ int main(int argc, char **argv)
+            fprintf(stderr, "could not fork into background\n");
+            daemon_exit(0);
+        }
++       if (pid)
++           create_pid_file(pid);
++    } else {
++       create_pid_file(backend_getpid());
+     }
+ #endif                                /* WIN32 */
+ 
+@@ -1006,8 +1010,10 @@ int main(int argc, char **argv)
+        /* no umask to not screw up create modes */
+        umask(0);
+ 
++#ifdef WIN32
+        /* create pid file if wanted */
+-       create_pid_file();
++       create_pid_file(backend_getpid());
++#endif
+ 
+        /* initialize internal stuff */
+        fh_cache_init();