[RFC PATCH v2 7/7] Add support for the nfsd root directory to exportfs

[Trond Myklebust <trondmy@gmail.com>]

Ensure that exportfs also resolves paths relative to the nfsd root
directory

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 utils/exportfs/Makefile.am |  2 +-
 utils/exportfs/exportfs.c  | 32 ++++++++++++++++++++++++++++++--
 2 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/utils/exportfs/Makefile.am b/utils/exportfs/Makefile.am
index 4b291610d19b..96524c729359 100644
--- a/utils/exportfs/Makefile.am
+++ b/utils/exportfs/Makefile.am
@@ -10,6 +10,6 @@ exportfs_SOURCES = exportfs.c
 exportfs_LDADD = ../../support/export/libexport.a \
 	       	 ../../support/nfs/libnfs.la \
 		 ../../support/misc/libmisc.a \
-		 $(LIBWRAP) $(LIBNSL)
+		 $(LIBWRAP) $(LIBNSL) $(LIBPTHREAD)
 
 MAINTAINERCLEANFILES = Makefile.in
diff --git a/utils/exportfs/exportfs.c b/utils/exportfs/exportfs.c
index 333eadcd0228..05481ad3f896 100644
--- a/utils/exportfs/exportfs.c
+++ b/utils/exportfs/exportfs.c
@@ -33,8 +33,10 @@
 
 #include "sockaddr.h"
 #include "misc.h"
+#include "nfsd_path.h"
 #include "nfslib.h"
 #include "exportfs.h"
+#include "workqueue.h"
 #include "xlog.h"
 #include "conffile.h"
 
@@ -52,6 +54,29 @@ static const char *lockfile = EXP_LOCKFILE;
 static int _lockfd = -1;
 
 struct state_paths etab;
+static struct xthread_workqueue *exportfs_wq;
+
+static ssize_t exportfs_write(int fd, const char *buf, size_t len)
+{
+	if (exportfs_wq)
+		return xthread_write(exportfs_wq, fd, buf, len);
+	return write(fd, buf, len);
+}
+
+static void
+exportfs_setup_workqueue(void)
+{
+	const char *chroot = nfsd_path_nfsd_rootdir();
+
+	if (!chroot || chroot[0] == '\0')
+		return;
+	if (chroot[0] == '/' && chroot[1] == '\0')
+		return;
+	exportfs_wq = xthread_workqueue_alloc();
+	if (!exportfs_wq)
+		return;
+	xthread_workqueue_chroot(exportfs_wq, chroot);
+}
 
 /*
  * If we aren't careful, changes made by exportfs can be lost
@@ -109,6 +134,7 @@ main(int argc, char **argv)
 
 	conf_init_file(NFS_CONFFILE);
 	xlog_from_conffile("exportfs");
+	nfsd_path_init();
 
 	/* NOTE: following uses "mountd" section of nfs.conf !!!! */
 	s = conf_get_str("mountd", "state-directory-path");
@@ -181,6 +207,8 @@ main(int argc, char **argv)
 		}
 	}
 
+	exportfs_setup_workqueue();
+
 	/*
 	 * Serialize things as best we can
 	 */
@@ -505,7 +533,7 @@ static int test_export(nfs_export *exp, int with_fsid)
 	fd = open("/proc/net/rpc/nfsd.export/channel", O_WRONLY);
 	if (fd < 0)
 		return 0;
-	n = write(fd, buf, strlen(buf));
+	n = exportfs_write(fd, buf, strlen(buf));
 	close(fd);
 	if (n < 0)
 		return 0;
@@ -521,7 +549,7 @@ validate_export(nfs_export *exp)
 	 * otherwise trial-export to '-test-client-' and check for failure.
 	 */
 	struct stat stb;
-	char *path = exp->m_export.e_path;
+	char *path = exportent_realpath(&exp->m_export);
 	struct statfs64 stf;
 	int fs_has_fsid = 0;
 
-- 
2.21.0