Re: [Libguestfs] [PATCH v2 4/4] file: Zero for block devices on old kernels

On 08/03/2018 02:28 PM, Nir Soffer wrote: > fallocate(FALLOC_FL_ZERO_RANGE) is supportd for block devices with s/supportd/supported/ > modern kernel, but when it is not, we fall back to manual zeroing. > > For block device, try also to use ioctl(BLKZEROOUT) if offset and count > are aligned to block device sector size. > > Here is an example run without this change on RHEL 7.5: > > +++ b/plugins/file/file.c > @@ -41,14 +41,21 @@ > #include <unistd.h> > #include <sys/types.h> > #include <sys/stat.h> > +#include <sys/ioctl.h> Linux-specific header; will it cause grief on BSD compilation?

(POSIX declares ioctl() in <stropts.h>, but for the obsolete STREAMS extension that no one but Solaris ever implemented, and which no one uses today - and thus which has little bearing on the Linux use of ioctl). Otherwise looks okay. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 <(919)%20301-3266> Virtualization: qemu.org | libvirt.org