From 2b12a756ac2a5d3af5aa8116e3a3e62a1501ad61 Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Wed, 14 Feb 2018 21:49:13 +0100 Subject: [PATCH] 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 Message-id: 20180214204915.7980-2-mreitz@redhat.com Reviewed-by: Eric Blake Reviewed-by: Richard W.M. Jones Signed-off-by: Max Reitz --- 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 --- a/block/ssh.c +++ b/block/ssh.c @@ -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; -- 2.11.4.GIT