From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57057) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZtBHJ-00074J-3q for qemu-devel@nongnu.org; Mon, 02 Nov 2015 04:19:50 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZtBHE-0003mF-Mb for qemu-devel@nongnu.org; Mon, 02 Nov 2015 04:19:49 -0500 Received: from mga02.intel.com ([134.134.136.20]:17515) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZtBHE-0003lY-71 for qemu-devel@nongnu.org; Mon, 02 Nov 2015 04:19:44 -0500 From: Xiao Guangrong Date: Mon, 2 Nov 2015 17:13:14 +0800 Message-Id: <1446455617-129562-13-git-send-email-guangrong.xiao@linux.intel.com> In-Reply-To: <1446455617-129562-1-git-send-email-guangrong.xiao@linux.intel.com> References: <1446455617-129562-1-git-send-email-guangrong.xiao@linux.intel.com> Subject: [Qemu-devel] [PATCH v7 12/35] util: let qemu_fd_getlength support block device List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: pbonzini@redhat.com, imammedo@redhat.com Cc: vsementsov@virtuozzo.com, Xiao Guangrong , ehabkost@redhat.com, kvm@vger.kernel.org, mst@redhat.com, gleb@kernel.org, mtosatti@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com, dan.j.williams@intel.com, rth@twiddle.net lseek can not work for all block devices as the man page says: | Some devices are incapable of seeking and POSIX does not specify | which devices must support lseek(). This patch tries to add the support on Linux by using BLKGETSIZE64 ioctl Signed-off-by: Xiao Guangrong --- util/osdep.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/util/osdep.c b/util/osdep.c index 5a61e19..b20c793 100644 --- a/util/osdep.c +++ b/util/osdep.c @@ -45,6 +45,11 @@ extern int madvise(caddr_t, size_t, int); #endif +#ifdef CONFIG_LINUX +#include +#include +#endif + #include "qemu-common.h" #include "qemu/sockets.h" #include "qemu/error-report.h" @@ -433,6 +438,21 @@ int64_t qemu_fd_getlength(int fd) { int64_t size; +#ifdef CONFIG_LINUX + struct stat stat_buf; + if (fstat(fd, &stat_buf) < 0) { + return -errno; + } + + if ((S_ISBLK(stat_buf.st_mode)) && !ioctl(fd, BLKGETSIZE64, &size)) { + /* The size of block device is larger than max int64_t? */ + if (size < 0) { + return -EOVERFLOW; + } + return size; + } +#endif + size = lseek(fd, 0, SEEK_END); if (size < 0) { return -errno; -- 1.8.3.1