libswap.c: Check free space with correct mnt path

The tst_fs_has_free should check fs size of mnt point.
But current code check ".", that means check /tmp/LTP_xxx
instead of /tmp/LTP_xxx/mntpoint.

Also tst_fs_has_free's "size" parameter's type is unsigned int,
it will overflow if encounter big filesystem block size (such as Btrfs
can use 64k).

Link: https://lore.kernel.org/ltp/20240301015037.22061-1-wegao@suse.com/
Reviewed-by: Li Wang <liwang@redhat.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Wei Gao <wegao@suse.com>
[ pvorel: check for sscanf() return value ]
Signed-off-by: Petr Vorel <pvorel@suse.cz>

include/tst_fs.h

@@ -60,7 +60,7 @@ enum {
  * @mult: mult should be TST_KB, TST_MB or TST_GB
  * the required free space is calculated by @size * @mult
  */
-int tst_fs_has_free_(void (*cleanup)(void), const char *path, unsigned int size,
+int tst_fs_has_free_(void (*cleanup)(void), const char *path, uint64_t size,
 		     unsigned int mult);
 
 /*
@@ -225,7 +225,7 @@ static inline long tst_fs_type(const char *path)
 	return tst_fs_type_(NULL, path);
 }
 
-static inline int tst_fs_has_free(const char *path, unsigned int size,
+static inline int tst_fs_has_free(const char *path, uint64_t size,
 				  unsigned int mult)
 {
 	return tst_fs_has_free_(NULL, path, size, mult);
@@ -252,7 +252,7 @@ static inline long tst_fs_type(void (*cleanup)(void), const char *path)
 }
 
 static inline int tst_fs_has_free(void (*cleanup)(void), const char *path,
-				  unsigned int size, unsigned int mult)
+				  uint64_t size, unsigned int mult)
 {
 	return tst_fs_has_free_(cleanup, path, size, mult);
 }

lib/tst_fs_has_free.c

@@ -27,7 +27,7 @@
 #include "tst_fs.h"
 
 int tst_fs_has_free_(void (*cleanup)(void), const char *path,
-		     unsigned int size, unsigned int mult)
+		     uint64_t size, unsigned int mult)
 {
 	struct statfs sf;
 

libs/libltpswap/libswap.c

@@ -137,6 +137,7 @@ int make_swapfile(const char *swapfile, int blocks, int safe)
 	struct statvfs fs_info;
 	unsigned long blk_size, bs;
 	size_t pg_size = sysconf(_SC_PAGESIZE);
+	char mnt_path[100];
 
 	if (statvfs(".", &fs_info) == -1)
 		return -1;
@@ -149,7 +150,10 @@ int make_swapfile(const char *swapfile, int blocks, int safe)
 	else
 		bs = blk_size;
 
-	if (!tst_fs_has_free(".", bs * blocks, TST_BYTES))
+	if (sscanf(swapfile, "%[^/]", mnt_path) != 1)
+		tst_brk(TBROK, "sscanf failed");
+
+	if (!tst_fs_has_free(mnt_path, bs * blocks, TST_BYTES))
 		tst_brk(TCONF, "Insufficient disk space to create swap file");
 
 	/* create file */