posix_fallocate() might be not supported by a filesystem, for example, it's not supported by ZFS. In that case it fails with return code 22 (EINVAL), and thus safezero_posix_fallocate() returns -1. As safezero_posix_fallocate() is the first function tried by safezero() and it tries other functions only when it returns -2, it fails immediately without falling back to other methods, such as safezero_slow(). Fix that by returning -2 if posix_fallocate() returns EINVAL, to give safezero() a chance to try other functions. Signed-off-by: Roman Bogorodskiy <bogorodskiy(a)gmail.com&gt; --- src/util/virfile.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/src/util/virfile.c b/src/util/virfile.c index 609cafdd34..67a350deb3 100644 --- a/src/util/virfile.c +++ b/src/util/virfile.c @@ -1119,6 +1119,16 @@ safezero_posix_fallocate(int fd, off_t offset, off_t len) int ret = posix_fallocate(fd, offset, len); if (ret == 0) return 0; + else if (ret == EINVAL) + /* EINVAL is returned when either: + - Operation is not supported by the underlying filesystem, + - offset or len argument values are invalid. + Assuming that offset and len are valid, this error means + the operation is not supported, and we need to fall back + to other methods. + */ + return -2; + errno = ret; return -1; } -- 2.30.0