block/ssh: Pull ssh_grow_file() from ssh_create()

If we ever want to offer even rudimentary truncation functionality for
ssh, we should put the respective code into a reusable function.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20180214204915.7980-2-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Max Reitz 2018-02-14 21:49:13 +01:00
parent be8fbd4763
commit 2b12a756ac

View File

@ -803,6 +803,26 @@ static int ssh_file_open(BlockDriverState *bs, QDict *options, int bdrv_flags,
return ret;
}
static int ssh_grow_file(BDRVSSHState *s, int64_t offset, Error **errp)
{
ssize_t ret;
char c[1] = { '\0' };
/* offset must be strictly greater than the current size so we do
* not overwrite anything */
assert(offset > 0 && offset > s->attrs.filesize);
libssh2_sftp_seek64(s->sftp_handle, offset - 1);
ret = libssh2_sftp_write(s->sftp_handle, c, 1);
if (ret < 0) {
sftp_error_setg(errp, s, "Failed to grow file");
return -EIO;
}
s->attrs.filesize = offset;
return 0;
}
static QemuOptsList ssh_create_opts = {
.name = "ssh-create-opts",
.head = QTAILQ_HEAD_INITIALIZER(ssh_create_opts.head),
@ -823,8 +843,6 @@ static int coroutine_fn ssh_co_create_opts(const char *filename, QemuOpts *opts,
int64_t total_size = 0;
QDict *uri_options = NULL;
BDRVSSHState s;
ssize_t r2;
char c[1] = { '\0' };
ssh_state_init(&s);
@ -850,14 +868,10 @@ static int coroutine_fn ssh_co_create_opts(const char *filename, QemuOpts *opts,
}
if (total_size > 0) {
libssh2_sftp_seek64(s.sftp_handle, total_size-1);
r2 = libssh2_sftp_write(s.sftp_handle, c, 1);
if (r2 < 0) {
sftp_error_setg(errp, &s, "truncate failed");
ret = -EINVAL;
ret = ssh_grow_file(&s, total_size, errp);
if (ret < 0) {
goto out;
}
s.attrs.filesize = total_size;
}
ret = 0;