From: Karel Zak <kzak@redhat.com>
Date: Thu, 21 Jun 2012 08:40:43 +0000 (+0200)
Subject: lib/loopdev: use warn_unused_result forimportant functions
X-Git-Tag: v2.22-rc1~248
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=defa0710b63096f96b5616090c262d30b01bc60c;p=thirdparty%2Futil-linux.git

lib/loopdev: use warn_unused_result forimportant functions

Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/include/loopdev.h b/include/loopdev.h
index 143c0d30ff..5c45878031 100644
--- a/include/loopdev.h
+++ b/include/loopdev.h
@@ -141,11 +141,13 @@ extern int loopdev_count_by_backing_file(const char *filename, char **loopdev);
 /*
  * Low-level
  */
-extern int loopcxt_init(struct loopdev_cxt *lc, int flags);
+extern int loopcxt_init(struct loopdev_cxt *lc, int flags)
+				__attribute__ ((warn_unused_result));
 extern void loopcxt_deinit(struct loopdev_cxt *lc);
 extern void loopcxt_enable_debug(struct loopdev_cxt *lc, int enable);
 
-extern int loopcxt_set_device(struct loopdev_cxt *lc, const char *device);
+extern int loopcxt_set_device(struct loopdev_cxt *lc, const char *device)
+				__attribute__ ((warn_unused_result));
 extern int loopcxt_has_device(struct loopdev_cxt *lc);
 extern char *loopcxt_strdup_device(struct loopdev_cxt *lc);
 extern const char *loopcxt_get_device(struct loopdev_cxt *lc);
diff --git a/lib/loopdev.c b/lib/loopdev.c
index 8e57067358..b759f0c28a 100644
--- a/lib/loopdev.c
+++ b/lib/loopdev.c
@@ -148,6 +148,7 @@ int loopcxt_has_device(struct loopdev_cxt *lc)
  */
 int loopcxt_init(struct loopdev_cxt *lc, int flags)
 {
+	int rc;
 	struct stat st;
 	struct loopdev_cxt dummy = UL_LOOPDEVCXT_EMPTY;
 
@@ -156,7 +157,10 @@ int loopcxt_init(struct loopdev_cxt *lc, int flags)
 
 	memcpy(lc, &dummy, sizeof(dummy));
 	lc->flags = flags;
-	loopcxt_set_device(lc, NULL);
+
+	rc = loopcxt_set_device(lc, NULL);
+	if (rc)
+		return rc;
 
 	if (!(lc->flags & LOOPDEV_FL_NOSYSFS) &&
 	    get_linux_version() >= KERNEL_VERSION(2,6,37))
@@ -188,7 +192,7 @@ void loopcxt_deinit(struct loopdev_cxt *lc)
 	free(lc->filename);
 	lc->filename = NULL;
 
-	loopcxt_set_device(lc, NULL);
+	ignore_result( loopcxt_set_device(lc, NULL) );
 	loopcxt_deinit_iterator(lc);
 
 	errno = errsv;
@@ -378,8 +382,8 @@ static int loopiter_set_device(struct loopdev_cxt *lc, const char *device)
 	if ((lc->iter.flags & LOOPITER_FL_FREE) && !used)
 		return 0;
 
-	DBG(lc, loopdev_debug("iter: setting device"));
-	loopcxt_set_device(lc, NULL);
+	DBG(lc, loopdev_debug("iter: unset device"));
+	ignore_result( loopcxt_set_device(lc, NULL) );
 	return 1;
 }
 
@@ -1274,27 +1278,29 @@ int loopdev_is_autoclear(const char *device)
 	if (!device)
 		return 0;
 
-	loopcxt_init(&lc, 0);
-	loopcxt_set_device(&lc, device);
-	rc = loopcxt_is_autoclear(&lc);
-	loopcxt_deinit(&lc);
+	rc = loopcxt_init(&lc, 0);
+	if (!rc)
+		rc = loopcxt_set_device(&lc, device);
+	if (!rc)
+		rc = loopcxt_is_autoclear(&lc);
 
+	loopcxt_deinit(&lc);
 	return rc;
 }
 
 char *loopdev_get_backing_file(const char *device)
 {
 	struct loopdev_cxt lc;
-	char *res;
+	char *res = NULL;
 
 	if (!device)
 		return NULL;
+	if (loopcxt_init(&lc, 0))
+		return NULL;
+	if (loopcxt_set_device(&lc, device) == 0)
+		res = loopcxt_get_backing_file(&lc);
 
-	loopcxt_init(&lc, 0);
-	loopcxt_set_device(&lc, device);
-	res = loopcxt_get_backing_file(&lc);
 	loopcxt_deinit(&lc);
-
 	return res;
 }
 
@@ -1311,8 +1317,11 @@ int loopdev_is_used(const char *device, const char *filename,
 	if (!device || !filename)
 		return 0;
 
-	loopcxt_init(&lc, 0);
-	loopcxt_set_device(&lc, device);
+	rc = loopcxt_init(&lc, 0);
+	if (!rc)
+		rc = loopcxt_set_device(&lc, device);
+	if (rc)
+		return rc;
 
 	rc = !stat(filename, &st);
 	rc = loopcxt_is_used(&lc, rc ? &st : NULL, filename, offset, flags);
@@ -1329,8 +1338,9 @@ int loopdev_delete(const char *device)
 	if (!device)
 		return -EINVAL;
 
-	loopcxt_init(&lc, 0);
-	rc = loopcxt_set_device(&lc, device);
+	rc = loopcxt_init(&lc, 0);
+	if (!rc)
+		rc = loopcxt_set_device(&lc, device);
 	if (!rc)
 		rc = loopcxt_delete_device(&lc);
 	loopcxt_deinit(&lc);
@@ -1377,7 +1387,8 @@ char *loopdev_find_by_backing_file(const char *filename, uint64_t offset, int fl
 	if (!filename)
 		return NULL;
 
-	loopcxt_init(&lc, 0);
+	if (loopcxt_init(&lc, 0))
+		return NULL;
 	if (loopcxt_find_by_backing_file(&lc, filename, offset, flags))
 		res = loopcxt_strdup_device(&lc);
 	loopcxt_deinit(&lc);
@@ -1393,12 +1404,14 @@ char *loopdev_find_by_backing_file(const char *filename, uint64_t offset, int fl
 int loopdev_count_by_backing_file(const char *filename, char **loopdev)
 {
 	struct loopdev_cxt lc;
-	int count = 0;
+	int count = 0, rc;
 
 	if (!filename)
 		return -1;
 
-	loopcxt_init(&lc, 0);
+	rc = loopcxt_init(&lc, 0);
+	if (rc)
+		return rc;
 	if (loopcxt_init_iterator(&lc, LOOPITER_FL_USED))
 		return -1;
 
@@ -1436,7 +1449,8 @@ static void test_loop_info(const char *device, int flags, int debug)
 	char *p;
 	uint64_t u64;
 
-	loopcxt_init(&lc, flags);
+	if (loopcxt_init(&lc, flags))
+		return
 	loopcxt_enable_debug(&lc, debug);
 
 	if (loopcxt_set_device(&lc, device))
@@ -1462,7 +1476,8 @@ static void test_loop_scan(int flags, int debug)
 	struct loopdev_cxt lc;
 	int rc;
 
-	loopcxt_init(&lc, 0);
+	if (loopcxt_init(&lc, 0))
+		return;
 	loopcxt_enable_debug(&lc, debug);
 
 	if (loopcxt_init_iterator(&lc, flags))
@@ -1488,9 +1503,11 @@ static void test_loop_scan(int flags, int debug)
 static int test_loop_setup(const char *filename, const char *device, int debug)
 {
 	struct loopdev_cxt lc;
-	int rc = 0;
+	int rc;
 
-	loopcxt_init(&lc, 0);
+	rc = loopcxt_init(&lc, 0);
+	if (rc)
+		return rc;
 	loopcxt_enable_debug(&lc, debug);
 
 	if (device) {
diff --git a/libmount/src/cache.c b/libmount/src/cache.c
index fe9c821e17..220a1465ef 100644
--- a/libmount/src/cache.c
+++ b/libmount/src/cache.c
@@ -487,8 +487,8 @@ char *mnt_pretty_path(const char *path, struct libmnt_cache *cache)
 	if (strncmp(pretty, "/dev/loop", 9) == 0) {
 		struct loopdev_cxt lc;
 
-		loopcxt_init(&lc, 0);
-		loopcxt_set_device(&lc, pretty);
+		if (loopcxt_init(&lc, 0) || loopcxt_set_device(&lc, pretty))
+			goto done;
 
 		if (loopcxt_is_autoclear(&lc)) {
 			char *tmp = loopcxt_get_backing_file(&lc);
@@ -502,6 +502,7 @@ char *mnt_pretty_path(const char *path, struct libmnt_cache *cache)
 
 	}
 
+done:
 	/* don't return pointer to the cache, allocate a new string */
 	return cache ? strdup(pretty) : pretty;
 }
diff --git a/libmount/src/context_loopdev.c b/libmount/src/context_loopdev.c
index 290e0d3d26..da246e3bbc 100644
--- a/libmount/src/context_loopdev.c
+++ b/libmount/src/context_loopdev.c
@@ -155,7 +155,9 @@ int mnt_context_setup_loopdev(struct libmnt_context *cxt)
 		lo_flags |= LO_FLAGS_READ_ONLY;
 	}
 
-	loopcxt_init(&lc, 0);
+	rc = loopcxt_init(&lc, 0);
+	if (rc)
+		return rc;
 
 	ON_DBG(CXT, loopcxt_enable_debug(&lc, 1));
 
diff --git a/partx/partx.c b/partx/partx.c
index fd8e4400ce..0c3f8f9808 100644
--- a/partx/partx.c
+++ b/partx/partx.c
@@ -102,7 +102,8 @@ static void assoc_loopdev(const char *fname)
 {
 	int rc;
 
-	loopcxt_init(&lc, 0);
+	if (loopcxt_init(&lc, 0))
+		err(EXIT_FAILURE, _("failed to initialize loopcxt"));
 
 	rc = loopcxt_find_unused(&lc);
 	if (rc)
diff --git a/sys-utils/losetup.c b/sys-utils/losetup.c
index bc9e6c68ae..48af8ebcac 100644
--- a/sys-utils/losetup.c
+++ b/sys-utils/losetup.c
@@ -254,7 +254,9 @@ int main(int argc, char **argv)
 	textdomain(PACKAGE);
 	atexit(close_stdout);
 
-	loopcxt_init(&lc, 0);
+	if (loopcxt_init(&lc, 0))
+		err(EXIT_FAILURE, _("failed to initialize loopcxt"));
+
 	loopcxt_enable_debug(&lc, getenv("LOOPDEV_DEBUG") ? TRUE : FALSE);
 
 	while ((c = getopt_long(argc, argv, "ac:d:De:E:fhj:o:p:PrvV",
@@ -267,7 +269,9 @@ int main(int argc, char **argv)
 		case 'c':
 			exclusive_option(&excl_any, EXCL_SET_CAPACITY, EXCL_ERROR);
 			act = A_SET_CAPACITY;
-			loopcxt_set_device(&lc, optarg);
+			if (loopcxt_set_device(&lc, optarg))
+				err(EXIT_FAILURE, _("%s: failed to use device"),
+						optarg);
 			break;
 		case 'r':
 			lo_flags |= LO_FLAGS_READ_ONLY;
@@ -275,7 +279,9 @@ int main(int argc, char **argv)
 		case 'd':
 			exclusive_option(&excl_any, EXCL_DETACH, EXCL_ERROR);
 			act = A_DELETE;
-			loopcxt_set_device(&lc, optarg);
+			if (loopcxt_set_device(&lc, optarg))
+				err(EXIT_FAILURE, _("%s: failed to use device"),
+						optarg);
 			break;
 		case 'D':
 			exclusive_option(&excl_any, EXCL_DETACH_ALL, EXCL_ERROR);
@@ -341,7 +347,10 @@ int main(int argc, char **argv)
 		 * losetup <device>
 		 */
 		act = A_SHOW_ONE;
-		loopcxt_set_device(&lc, argv[optind++]);
+		if (loopcxt_set_device(&lc, argv[optind]))
+			err(EXIT_FAILURE, _("%s: failed to use device"),
+					argv[optind]);
+		optind++;
 	}
 	if (!act) {
 		/*
@@ -351,7 +360,10 @@ int main(int argc, char **argv)
 
 		if (optind >= argc)
 			errx(EXIT_FAILURE, _("no loop device specified"));
-		loopcxt_set_device(&lc, argv[optind++]);
+		if (loopcxt_set_device(&lc, argv[optind]))
+			err(EXIT_FAILURE, _("%s failed to use device"),
+					argv[optind]);
+		optind++;
 
 		if (optind >= argc)
 			errx(EXIT_FAILURE, _("no file specified"));
@@ -425,7 +437,10 @@ int main(int argc, char **argv)
 	case A_DELETE:
 		res = delete_loop(&lc);
 		while (optind < argc) {
-			loopcxt_set_device(&lc, argv[optind++]);
+			if (loopcxt_set_device(&lc, argv[optind]))
+				warn(_("%s: failed to use device"),
+						argv[optind]);
+			optind++;
 			res += delete_loop(&lc);
 		}
 		break;