Commit 624f3006 authored by Max Reitz's avatar Max Reitz
Browse files

block/ssh: Add basic .bdrv_truncate() 



libssh2 does not seem to offer real truncation support, so we can only
grow files -- but that is better than nothing.

Signed-off-by: default avatarMax Reitz <mreitz@redhat.com>
Message-id: 20180214204915.7980-4-mreitz@redhat.com
Reviewed-by: default avatarEric Blake <eblake@redhat.com>
Reviewed-by: default avatarRichard W.M. Jones <rjones@redhat.com>
Signed-off-by: default avatarMax Reitz <mreitz@redhat.com>
parent bd8e0e32

block/ssh.c

+24 −0
Original line number Diff line number Diff line
@@ -1220,6 +1220,29 @@ 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",
@@ -1232,6 +1255,7 @@ 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,

};