From: Max Reitz <mreitz@redhat.com>
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>
block/ssh.c | 30 ++++++++++++++++++++++--------
1 file changed, 22 insertions(+), 8 deletions(-)
diff --git a/block/ssh.c b/block/ssh.c
index 36d5d888d5..d6a68cb880 100644
@@ -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;
--
2.13.6