From: Andreas Dilger <andreas.dilger@intel.com>
Date: Wed, 1 Apr 2015 16:35:29 +0000 (-0400)
Subject: LU-5888 utils: limit max_sectors_kb tunable setting
X-Git-Tag: 2.7.58~40
X-Git-Url: https://git.whamcloud.com/?a=commitdiff_plain;h=0484a16883a951f27c30ee926c9a1c305f7cf489;p=fs%2Flustre-release.git

LU-5888 utils: limit max_sectors_kb tunable setting

Properly limit the max_sectors_kb tunable if larger than 32MB, as
added in commit 73bd456e896 (http://review.whamcloud.com/12723).
It was using the old value in "buf" instead of the updated "newval".

Change write_file() to use a file descriptor directly instead of
streams, since it only writes a single value before closing again.

Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Change-Id: I43a5b4c9d0e45649e0666fd58634286de53ebbe5
Reviewed-on: http://review.whamcloud.com/13240
Tested-by: Jenkins
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
---

diff --git a/lustre/utils/mount_utils_ldiskfs.c b/lustre/utils/mount_utils_ldiskfs.c
index e7e39a5..d07e996 100644
--- a/lustre/utils/mount_utils_ldiskfs.c
+++ b/lustre/utils/mount_utils_ldiskfs.c
@@ -974,15 +974,16 @@ static int read_file(const char *path, char *buf, int size)
 
 static int write_file(const char *path, const char *buf)
 {
-	FILE *fd;
+	int fd, rc;
 
-	fd = fopen(path, "w");
-	if (fd == NULL)
+	fd = open(path, O_WRONLY);
+	if (fd < 0)
 		return errno;
 
-	fputs(buf, fd);
-	fclose(fd);
-	return 0;
+	rc = write(fd, buf, strlen(buf));
+	close(fd);
+
+	return rc < 0 ? errno : 0;
 }
 
 static int set_blockdev_scheduler(const char *path, const char *scheduler)
@@ -1156,7 +1157,7 @@ set_params:
 			snprintf(buf, sizeof(buf), "%d",
 				 mop->mo_md_stripe_cache_size);
 			rc = write_file(real_path, buf);
-			if (rc && verbose)
+			if (rc != 0 && verbose)
 				fprintf(stderr, "warning: opening %s: %s\n",
 					real_path, strerror(errno));
 		}
@@ -1195,9 +1196,11 @@ set_params:
 			goto subdevs;
 
 		/* Don't increase IO request size limit past 32MB.  It is about
-		 * 2x PTLRPC_MAX_BRW_SIZE, but that isn't defined publicly. */
-		if (newval > 32 * 1024)
+		 * 2x PTLRPC_MAX_BRW_SIZE, but that isn't in a public header. */
+		if (newval > 32 * 1024) {
 			newval = 32 * 1024;
+			snprintf(buf, sizeof(buf), "%llu", newval);
+		}
 
 		oldval = strtoull(oldbuf, &end, 0);
 		/* Don't shrink the current limit. */
@@ -1205,7 +1208,7 @@ set_params:
 			goto subdevs;
 
 		rc = write_file(real_path, buf);
-		if (rc) {
+		if (rc != 0) {
 			if (verbose)
 				fprintf(stderr, "warning: writing to %s: %s\n",
 					real_path, strerror(errno));