If the underlying provider doesn't support BIO_FLUSH, log it only once

and don't bother trying in the future.

MFC after:	3 days

4 files changed, 24 insertions, 4 deletions

diff --git a/sbin/hastd/hast.h b/sbin/hastd/hast.h
index 7bfef4c..d82783b 100644
--- a/sbin/hastd/hast.h
+++ b/sbin/hastd/hast.h
@@ -167,6 +167,8 @@ struct hast_resource {
 	off_t	hr_local_mediasize;
 	/* Sector size of local provider. */
 	unsigned int hr_local_sectorsize;
+	/* Is flushing write cache supported by the local provider? */
+	bool	hr_localflush;
 	/* Flush write cache on metadata updates? */
 	int	hr_metaflush;
 
diff --git a/sbin/hastd/parse.y b/sbin/hastd/parse.y
index e548a85..15b1143 100644
--- a/sbin/hastd/parse.y
+++ b/sbin/hastd/parse.y
@@ -788,6 +788,7 @@ resource_start:	STR
 		curres->hr_provname[0] = '\0';
 		curres->hr_localpath[0] = '\0';
 		curres->hr_localfd = -1;
+		curres->hr_localflush = true;
 		curres->hr_metaflush = -1;
 		curres->hr_remoteaddr[0] = '\0';
 		curres->hr_sourceaddr[0] = '\0';
diff --git a/sbin/hastd/primary.c b/sbin/hastd/primary.c
index 08c3329..4a3c51f 100644
--- a/sbin/hastd/primary.c
+++ b/sbin/hastd/primary.c
@@ -1304,8 +1304,15 @@ local_send_thread(void *arg)
 			}
 			break;
 		case BIO_FLUSH:
+			if (!res->hr_localflush) {
+				ret = -1;
+				errno = EOPNOTSUPP;
+				break;
+			}
 			ret = g_flush(res->hr_localfd);
 			if (ret < 0) {
+				if (errno == EOPNOTSUPP)
+					res->hr_localflush = false;
 				hio->hio_errors[ncomp] = errno;
 				reqlog(LOG_WARNING, 0, ggio,
 				    "Local request failed (%s): ",
diff --git a/sbin/hastd/secondary.c b/sbin/hastd/secondary.c
index 0ec4c6e..c761143 100644
--- a/sbin/hastd/secondary.c
+++ b/sbin/hastd/secondary.c
@@ -664,7 +664,7 @@ disk_thread(void *arg)
 	struct hast_resource *res = arg;
 	struct hio *hio;
 	ssize_t ret;
-	bool clear_activemap;
+	bool clear_activemap, logerror;
 
 	clear_activemap = true;
 
@@ -702,6 +702,7 @@ disk_thread(void *arg)
 			break;
 		}
 		reqlog(LOG_DEBUG, 2, -1, hio, "disk: (%p) Got request: ", hio);
+		logerror = true;
 		/* Handle the actual request. */
 		switch (hio->hio_cmd) {
 		case HIO_READ:
@@ -736,14 +737,23 @@ disk_thread(void *arg)
 				hio->hio_error = 0;
 			break;
 		case HIO_FLUSH:
+			if (!res->hr_localflush) {
+				ret = -1;
+				hio->hio_error = EOPNOTSUPP;
+				logerror = false;
+				break;
+			}
 			ret = g_flush(res->hr_localfd);
-			if (ret < 0)
+			if (ret < 0) {
+				if (errno == EOPNOTSUPP)
+					res->hr_localflush = false;
 				hio->hio_error = errno;
-			else
+			} else {
 				hio->hio_error = 0;
+			}
 			break;
 		}
-		if (hio->hio_error != 0) {
+		if (logerror && hio->hio_error != 0) {
 			reqlog(LOG_ERR, 0, hio->hio_error, hio,
 			    "Request failed: ");
 		}