From: Marc Vef <mvef@whamcloud.com>
Date: Sun, 15 Dec 2024 20:15:49 +0000 (+0100)
Subject: LU-18560 utils: Fix ldiskfs_write_dd Coverity warnings
X-Git-Tag: 2.16.52~95
X-Git-Url: https://git.whamcloud.com/?a=commitdiff_plain;h=52105a555f55b399a115f3158b3827eb0db726f6;p=fs%2Flustre-release.git

LU-18560 utils: Fix ldiskfs_write_dd Coverity warnings

Coverity has reported issues with the "ldiskfs_write_ldd()" function.
In particular OVERRUN, INTEGER_OVERFLOW, NO_EFFECT, and
ARRAY_VS_SINGLETON warnings.

This patch fixes these warnings.

Fixes: 7687e22af35d ("LU-9936 utils: Improve ldiskfs_write_dd() writing mount data")
Signed-off-by: Marc Vef <mvef@whamcloud.com>
Change-Id: Id1379d9c6d53e697ff2ee12570b4569c4bce5e73
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/57449
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Mikhail Pershin <mpershin@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
---

diff --git a/lustre/utils/libmount_utils_ldiskfs.c b/lustre/utils/libmount_utils_ldiskfs.c
index 70b267c..01036df 100644
--- a/lustre/utils/libmount_utils_ldiskfs.c
+++ b/lustre/utils/libmount_utils_ldiskfs.c
@@ -142,10 +142,10 @@ int ldiskfs_write_ldd(struct mkfs_opts *mop)
 	char mntpt[] = "/tmp/mntXXXXXX";
 	char filepnm[192];
 	char *dev;
-	int ret = 0;
+	size_t total_written, remaining;
+	ssize_t write_cnt;
 	int fd;
-	size_t total_written;
-	size_t write_cnt;
+	int ret = 0;
 
 	/* Mount this device temporarily in order to write these files */
 	if (!mkdtemp(mntpt)) {
@@ -223,10 +223,13 @@ int ldiskfs_write_ldd(struct mkfs_opts *mop)
 		ret = errno;
 		goto out_umnt;
 	}
+
 	total_written = 0;
-	while (total_written < sizeof(mop->mo_ldd)) {
-		write_cnt = write(fd, &mop->mo_ldd + total_written,
-				  sizeof(mop->mo_ldd) - total_written);
+	remaining = sizeof(mop->mo_ldd);
+	while (remaining > 0) {
+		write_cnt = write(fd,
+				  (const char *)&mop->mo_ldd + total_written,
+				  remaining);
 		if (write_cnt < 0) {
 			fprintf(stderr,
 				"%s: Unable to write to file (%s): %s\n",
@@ -235,7 +238,9 @@ int ldiskfs_write_ldd(struct mkfs_opts *mop)
 			goto close_fd;
 		}
 		total_written += write_cnt;
+		remaining -= write_cnt;
 	}
+
 	if (fsync(fd) < 0) {
 		fprintf(stderr, "%s: Unable to fsync file (%s): %s\n", progname,
 			filepnm, strerror(errno));