diff options
| author |   reyk <reyk@openbsd.org> | 2016-01-26 07:58:35 +0000 |
|---|---|---|
| committer | reyk <reyk@openbsd.org> | 2016-01-26 07:58:35 +0000 |
| commit | e7d3405c174ea7227d9cc787159ec249c549f2bf (patch) | |
| tree | 564fb8b3e0b6c9f30ffd90b8fed8b0206b5ce12b | |
| parent | The division "res->size /= 1024 / 1024" is a no-op: 1024 / 1024 is (diff) | |
| download | wireguard-openbsd-e7d3405c174ea7227d9cc787159ec249c549f2bf.tar.xz wireguard-openbsd-e7d3405c174ea7227d9cc787159ec249c549f2bf.zip | |
lseek() + write() can be replaced by a slightly shorter ftruncate()
call. Note that using ftruncate() to extend a file is not portable
(POSIX allows either zero-filling until the given size is reached, or
alternatively erroring out), but that shouldn't be a proble as vmm(4)
isn't cross-platform either. unlink() the image file when extending
it fails for consistency with the other error case (the file can't be
created).
From Martin Natano
OK mlarkin@
| -rw-r--r-- | usr.sbin/vmctl/vmctl.c | 20 |
1 files changed, 5 insertions, 15 deletions
diff --git a/usr.sbin/vmctl/vmctl.c b/usr.sbin/vmctl/vmctl.c index b28d2d369ee..7f5e8829b97 100644 --- a/usr.sbin/vmctl/vmctl.c +++ b/usr.sbin/vmctl/vmctl.c @@ -1,4 +1,4 @@ -/* $OpenBSD: vmctl.c,v 1.11 2016/01/13 13:08:20 reyk Exp $ */ +/* $OpenBSD: vmctl.c,v 1.12 2016/01/26 07:58:35 reyk Exp $ */ /* * Copyright (c) 2014 Mike Larkin <mlarkin@openbsd.org> @@ -390,7 +390,7 @@ vm_console(struct vmop_info_result *list, size_t ct) * * Parameters: * imgfile_path: path to the image file to create - * imgsize : size of the image file to create + * imgsize : size of the image file to create (in MB) * * Return: * EEXIST: The requested image file already exists @@ -401,8 +401,6 @@ int create_imagefile(const char *imgfile_path, long imgsize) { int fd, ret; - off_t ofs; - char ch = '\0'; /* Refuse to overwrite an existing image */ fd = open(imgfile_path, O_RDWR | O_CREAT | O_TRUNC | O_EXCL, @@ -410,19 +408,11 @@ create_imagefile(const char *imgfile_path, long imgsize) if (fd == -1) return (errno); - ofs = (imgsize * 1024 * 1024) - 1; - - /* Set fd pos at desired size */ - if (lseek(fd, ofs, SEEK_SET) == -1) { - ret = errno; - close(fd); - return (ret); - } - - /* Write one byte to fill out the extent */ - if (write(fd, &ch, 1) == -1) { + /* Extend to desired size */ + if (ftruncate(fd, (off_t)imgsize * 1024 * 1024) == -1) { ret = errno; close(fd); + unlink(imgfile_path); return (ret); } |