libssh2 does not seem to offer real truncation support, so we can only grow files -- but that is better than nothing.
Signed-off-by: Max Reitz <mre...@redhat.com> --- block/ssh.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/block/ssh.c b/block/ssh.c index ff8576f21e..c235eec255 100644 --- a/block/ssh.c +++ b/block/ssh.c @@ -1219,6 +1219,29 @@ static int64_t ssh_getlength(BlockDriverState *bs) return length; } +static int ssh_truncate(BlockDriverState *bs, int64_t offset, + PreallocMode prealloc, Error **errp) +{ + BDRVSSHState *s = bs->opaque; + + if (prealloc != PREALLOC_MODE_OFF) { + error_setg(errp, "Unsupported preallocation mode '%s'", + PreallocMode_str(prealloc)); + return -ENOTSUP; + } + + if (offset < s->attrs.filesize) { + error_setg(errp, "ssh driver does not support shrinking files"); + return -ENOTSUP; + } + + if (offset == s->attrs.filesize) { + return 0; + } + + return ssh_grow_file(s, offset, errp); +} + static BlockDriver bdrv_ssh = { .format_name = "ssh", .protocol_name = "ssh", @@ -1231,6 +1254,7 @@ static BlockDriver bdrv_ssh = { .bdrv_co_readv = ssh_co_readv, .bdrv_co_writev = ssh_co_writev, .bdrv_getlength = ssh_getlength, + .bdrv_truncate = ssh_truncate, .bdrv_co_flush_to_disk = ssh_co_flush, .create_opts = &ssh_create_opts, }; -- 2.14.3