block/nfs: fix potential segfault on early callback

it will happen in the future that the callback of a libnfs call
directly invokes the callback. In this case we end up in a segfault
because the NFSRPC is gone when we the BH is scheduled.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
QemuOpts: move find_desc_by_name ahead for later calling

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
QemuOpts: repurpose qemu_opts_print to replace print_option_parameters

Currently this function is not used anywhere. In later patches, it will
replace print_option_parameters. To avoid print info changes, change
qemu_opts_print from fprintf stderr to printf, and remove last printf.

Signed-off-by: Chunyan Liu <cyliu@suse.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
QemuOpts: add def_value_str to QemuOptDesc

Add def_value_str (default value) to QemuOptDesc, to replace function of the
default value in QEMUOptionParameter.

Improve qemu_opts_get_* functions: if find opt, return opt->str; otherwise,
if desc->def_value_str is set, return desc->def_value_str; otherwise, return
input defval.

Improve qemu_opts_print: if option is set, print opt->str; otherwise, if
desc->def_value_str is set, print it.

Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
qapi: output def_value_str when query command line options

Change qapi interfaces to output the newly added def_value_str when querying
command line options.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Leandro Dorileo <l@dorileo.org>
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
QemuOpts: change opt->name|str from (const char *) to (char *)

qemu_opt_del() already assumes that all QemuOpt instances contain
malloc'd name and value; but it had to cast away const because
opts_start_struct() was doing its own thing and using static storage
instead.  By using the correct type and malloced strings everywhere, the
usage of this struct becomes clearer.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Leandro Dorileo <l@dorileo.org>
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
QemuOpts: move qemu_opt_del ahead for later calling

In later patch, qemu_opt_get_del functions will be added, they will
first get the option value, then call qemu_opt_del to remove the option
from opt list. To prepare for that purpose, move qemu_opt_del ahead first.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Leandro Dorileo <l@dorileo.org>
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
QemuOpts: add qemu_opt_get_*_del functions for replace work

Add qemu_opt_get_del, qemu_opt_get_bool_del, qemu_opt_get_number_del and
qemu_opt_get_size_del to replace the same handling of QEMUOptionParameter
(get and delete).

Several drivers are coded to parse a known subset of options, then
remove them from the list before handing all remaining options to a
second driver for further option processing.  get_*_del makes it easier
to retrieve a known option (or its default) and remove it from the list
all in one action.

Share common helper function:

For qemu_opt_get_bool/size/number, they and their get_*_del counterpart
could share most of the code except whether or not deleting the opt from
option list, so generate common helper functions.

For qemu_opt_get and qemu_opt_get_del, keep code duplication, since
1. qemu_opt_get_del returns malloc'd memory while qemu_opt_get returns
in-place memory
2. qemu_opt_get_del returns (char *), qemu_opt_get returns (const char *),
and could not change to (char *), since in one case, it will return
desc->def_value_str, which is (const char *).

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
QemuOpts: add qemu_opts_print_help to replace print_option_help

print_option_help takes QEMUOptionParameter as parameter, add
qemu_opts_print_help to take QemuOptsList as parameter for later
replace work.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Leandro Dorileo <l@dorileo.org>
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
QemuOpts: add conversion between QEMUOptionParameter to QemuOpts

Add two temp conversion functions between QEMUOptionParameter to QemuOpts,
so that next patch can use it. It will simplify later patch for easier
review. And will be finally removed after all backend drivers switch to
QemuOpts.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Leandro Dorileo <l@dorileo.org>
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
QemuOpts: add qemu_opts_append to replace append_option_parameters

For later merge .create_opts of drv and proto_drv in qemu-img commands.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Leandro Dorileo <l@dorileo.org>
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
QemuOpts: check NULL input for qemu_opts_del

To simplify later using of qemu_opts_del, accept NULL input.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Leandro Dorileo <l@dorileo.org>
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
change block layer to support both QemuOpts and QEMUOptionParamter

Change block layer to support both QemuOpts and QEMUOptionParameter.
After this patch, it will change backend drivers one by one. At the end,
QEMUOptionParameter will be removed and only QemuOpts is kept.

Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
vvfat.c: handle cross_driver's create_options and create_opts

vvfat shares create options of qcow driver. To avoid vvfat breaking when
qcow driver changes from QEMUOptionParameter to QemuOpts, let it able
to handle both cases.

Signed-off-by: Chunyan Liu <cyliu@suse.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
cow.c: replace QEMUOptionParameter with QemuOpts

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
gluster.c: replace QEMUOptionParameter with QemuOpts

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
iscsi.c: replace QEMUOptionParameter with QemuOpts

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
nfs.c: replace QEMUOptionParameter with QemuOpts

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
qcow.c: replace QEMUOptionParameter with QemuOpts

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
QemuOpts: export qemu_opt_find

Export qemu_opt_find for qcow2 driver using it.
After replacing QEMUOptionParameter with QemuOpts, qcow2 driver will
use qemu_opt_find to judge if an option is explicitly set, to replace
the usage of .assigned in QEMUOptionParameter.

Signed-off-by: Chunyan Liu <cyliu@suse.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>