AP_HAL_Linux: file descriptor leaking and other issues in "Storage" o…

…f Linux.

- Fixed the fd leaking issue in "_storage_create" found by @peterbarker
- Remove the unnecessary call of "unlinkat" in "_storage_create"
- Simplify the implementation of "init"

Signed-off-by: junan <[email protected]>

libraries/AP_HAL_Linux/Storage.cpp

@@ -101,7 +101,6 @@ int Storage::_storage_create(const char *dpath)
         return -1;
     }
 
-    unlinkat(dfd, dpath, 0);
     int fd = openat(dfd, STORAGE_FILE, O_RDWR|O_CREAT|O_CLOEXEC, 0666);
 
     if (fd == -1) {
@@ -114,6 +113,7 @@ int Storage::_storage_create(const char *dpath)
     if (ftruncate(fd, sizeof(_buffer)) == -1) {
         fprintf(stderr, "Failed to set file size to %u kB (%m)\n",
                 unsigned(sizeof(_buffer) / 1024));
+        close(fd);
         goto fail;
     }
 
@@ -145,26 +145,16 @@ void Storage::init()
         dpath = HAL_BOARD_STORAGE_DIRECTORY;
     }
 
-    int fd = open(dpath, O_RDWR|O_CLOEXEC);
+    int fd = _storage_create(dpath);
     if (fd == -1) {
-        fd = _storage_create(dpath);
-        if (fd == -1) {
-            AP_HAL::panic("Cannot create storage %s (%m)", dpath);
-        }
+        AP_HAL::panic("Cannot create storage %s (%m)", dpath);
     }
 
     ssize_t ret = read(fd, _buffer, sizeof(_buffer));
 
     if (ret != sizeof(_buffer)) {
         close(fd);
-        _storage_create(dpath);
-        fd = open(dpath, O_RDONLY|O_CLOEXEC);
-        if (fd == -1) {
-            AP_HAL::panic("Failed to open %s (%m)", dpath);
-        }
-        if (read(fd, _buffer, sizeof(_buffer)) != sizeof(_buffer)) {
-            AP_HAL::panic("Failed to read %s (%m)", dpath);
-        }
+        AP_HAL::panic("Failed to read %s (%m)", dpath);
     }
 
     _fd = fd;