Fix coverity defects: CID 147548

CID 147548: Type:Dereference null return value

Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: cao.xuewen <[email protected]>
Closes #5321 

3 files changed, 7 insertions, 5 deletions

diff --git a/include/sys/fs/zfs.h b/include/sys/fs/zfs.h
index d1d0a275d..2a630ec53 100644
--- a/include/sys/fs/zfs.h
+++ b/include/sys/fs/zfs.h
@@ -917,6 +917,7 @@ typedef struct ddt_histogram {
 #define	ZVOL_DRIVER	"zvol"
 #define	ZFS_DRIVER	"zfs"
 #define	ZFS_DEV		"/dev/zfs"
+#define	ZFS_SHARETAB	"/etc/dfs/sharetab"
 
 /* general zvol path */
 #define	ZVOL_DIR	"/dev"
diff --git a/lib/libshare/libshare.c b/lib/libshare/libshare.c
index 89a4fe9aa..0eb4ae00d 100644
--- a/lib/libshare/libshare.c
+++ b/lib/libshare/libshare.c
@@ -113,7 +113,7 @@ parse_sharetab(sa_handle_impl_t impl_handle) {
 	char line[512];
 	char *eol, *pathname, *resource, *fstype, *options, *description;
 
-	fp = fopen("/etc/dfs/sharetab", "r");
+	fp = fopen(ZFS_SHARETAB, "r");
 
 	if (fp == NULL)
 		return;
@@ -170,7 +170,7 @@ update_sharetab(sa_handle_impl_t impl_handle)
 	sa_share_impl_t impl_share;
 	int temp_fd;
 	FILE *temp_fp;
-	char tempfile[] = "/etc/dfs/sharetab.XXXXXX";
+	char tempfile[] = ZFS_SHARETAB".XXXXXX";
 	sa_fstype_t *fstype;
 	const char *resource;
 
@@ -215,7 +215,7 @@ update_sharetab(sa_handle_impl_t impl_handle)
 	fsync(temp_fd);
 	fclose(temp_fp);
 
-	(void) rename(tempfile, "/etc/dfs/sharetab");
+	(void) rename(tempfile, ZFS_SHARETAB);
 }
 
 typedef struct update_cookie_s {
diff --git a/lib/libzfs/libzfs_util.c b/lib/libzfs/libzfs_util.c
index ca32e7a7f..6f5dae6c3 100644
--- a/lib/libzfs/libzfs_util.c
+++ b/lib/libzfs/libzfs_util.c
@@ -863,12 +863,13 @@ libzfs_init(void)
 		return (NULL);
 	}
 
-	hdl->libzfs_sharetab = fopen("/etc/dfs/sharetab", "r");
+	hdl->libzfs_sharetab = fopen(ZFS_SHARETAB, "r");
 
 	if (libzfs_core_init() != 0) {
 		(void) close(hdl->libzfs_fd);
 		(void) fclose(hdl->libzfs_mnttab);
-		(void) fclose(hdl->libzfs_sharetab);
+		if (hdl->libzfs_sharetab)
+			(void) fclose(hdl->libzfs_sharetab);
 		free(hdl);
 		return (NULL);
 	}