From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37511) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1em3zk-0002KO-Pg for qemu-devel@nongnu.org; Wed, 14 Feb 2018 15:49:37 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1em3zj-0001wS-UF for qemu-devel@nongnu.org; Wed, 14 Feb 2018 15:49:36 -0500 From: Max Reitz Date: Wed, 14 Feb 2018 21:49:12 +0100 Message-Id: <20180214204915.7980-1-mreitz@redhat.com> Subject: [Qemu-devel] [PATCH 0/3] block/ssh: Add basic .bdrv_truncate() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, Max Reitz , Kevin Wolf , "Richard W . M . Jones" , Jeff Cody For (x-)blockdev-create, all protocol drivers that support image creation also need to offer a .bdrv_truncate() implementation that matches in features. A previous series of mine brought gluster's and sheepdog's implementation up to par regarding preallocated truncation; but I forgot about drivers that have a .bdrv_create() but no .bdrv_truncate() at all. There is only one of these, and that is ssh. Since libssh2 does not seem to know any way of truncating files, we can only support growing files -- but that is what we need for (x-)blockdev-create. Note that there are also drivers which do not support growing files, namely iscsi and file-posix for host devices (maybe more? I hope not). But these also pretty much ignore the specified size on .bdrv_create() and just use the size of the existing device. They just check that the specified size does not exceed the actual size, so that pretty much matches what their .bdrv_truncate() supports, and we should be fine there. Max Reitz (3): block/ssh: Pull ssh_grow_file() from ssh_create() block/ssh: Make ssh_grow_file() blocking block/ssh: Add basic .bdrv_truncate() block/ssh.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 53 insertions(+), 8 deletions(-) -- 2.14.3