From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42514) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1df52R-0000Lc-04 for qemu-devel@nongnu.org; Tue, 08 Aug 2017 09:59:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1df52L-0002B2-9e for qemu-devel@nongnu.org; Tue, 08 Aug 2017 09:59:15 -0400 From: Kevin Wolf Date: Tue, 8 Aug 2017 15:58:30 +0200 Message-Id: <20170808135838.11525-11-kwolf@redhat.com> In-Reply-To: <20170808135838.11525-1-kwolf@redhat.com> References: <20170808135838.11525-1-kwolf@redhat.com> Subject: [Qemu-devel] [PULL 10/18] block: respect error code from bdrv_getlength in handle_aiocb_write_zeroes List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, qemu-devel@nongnu.org, peter.maydell@linaro.org From: "Denis V. Lunev" Original idea beyond the code in question was the following: we have failed to write zeroes with fallocate(FALLOC_FL_ZERO_RANGE) as the simplest approach and via fallocate(FALLOC_FL_PUNCH_HOLE)/fallocate(0). We have the only chance now: if the request comes beyond end of the file. Thus we should calculate file length and respect the error code from that op. Signed-off-by: Denis V. Lunev CC: Markus Armbruster CC: Kevin Wolf CC: Max Reitz CC: Stefan Hajnoczi Signed-off-by: Kevin Wolf Reviewed-by: Eric Blake --- block/file-posix.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/block/file-posix.c b/block/file-posix.c index cfbb236f6f..f4de022ae0 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -1339,6 +1339,9 @@ static ssize_t handle_aiocb_write_zeroes(RawPosixAIOData *aiocb) #if defined(CONFIG_FALLOCATE) || defined(CONFIG_XFS) BDRVRawState *s = aiocb->bs->opaque; #endif +#ifdef CONFIG_FALLOCATE + int64_t len; +#endif if (aiocb->aio_type & QEMU_AIO_BLKDEV) { return handle_aiocb_write_zeroes_block(aiocb); @@ -1381,7 +1384,10 @@ static ssize_t handle_aiocb_write_zeroes(RawPosixAIOData *aiocb) #endif #ifdef CONFIG_FALLOCATE - if (s->has_fallocate && aiocb->aio_offset >= bdrv_getlength(aiocb->bs)) { + /* Last resort: we are trying to extend the file with zeroed data. This + * can be done via fallocate(fd, 0) */ + len = bdrv_getlength(aiocb->bs); + if (s->has_fallocate && len >= 0 && aiocb->aio_offset >= len) { int ret = do_fallocate(s->fd, 0, aiocb->aio_offset, aiocb->aio_nbytes); if (ret == 0 || ret != -ENOTSUP) { return ret; -- 2.13.4