Commit 3d4b2f9c added -x to force qemu-nbd to use new-style
negotiation, but while it documented it in the man page, it
omitted docs in the --help output.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1459908128-11925-1-git-send-email-eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move declarations out of qemu-common.h for functions declared in
utils/ files: e.g. include/qemu/path.h for utils/path.c.
Move inline functions out of qemu-common.h and into new files (e.g.
include/qemu/bcd.h)
Signed-off-by: Veronia Bahaa <veroniabahaa@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the
Error typedef. Since then, we've moved to include qemu/osdep.h
everywhere. Its file comment explains: "To avoid getting into
possible circular include dependencies, this file should not include
any other QEMU headers, with the exceptions of config-host.h,
compiler.h, os-posix.h and os-win32.h, all of which are doing a
similar job to this file and are under similar constraints."
qapi/error.h doesn't do a similar job, and it doesn't adhere to
similar constraints: it includes qapi-types.h. That's in excess of
100KiB of crap most .c files don't actually need.
Add the typedef to qemu/typedefs.h, and include that instead of
qapi/error.h. Include qapi/error.h in .c files that need it and don't
get it now. Include qapi-types.h in qom/object.h for uint16List.
Update scripts/clean-includes accordingly. Update it further to match
reality: replace config.h by config-target.h, add sysemu/os-posix.h,
sysemu/os-win32.h. Update the list of includes in the qemu/osdep.h
comment quoted above similarly.
This reduces the number of objects depending on qapi/error.h from "all
of them" to less than a third. Unfortunately, the number depending on
qapi-types.h shrinks only a little. More work is needed for that one.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
[Fix compilation without the spice devel packages. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Simple unions were carrying a special case that hid their 'data'
QMP member from the resulting C struct, via the hack method
QAPISchemaObjectTypeVariant.simple_union_type(). But by using
the work we started by unboxing flat union and alternate
branches, coupled with the ability to visit the members of an
implicit type, we can now expose the simple union's implicit
type in qapi-types.h:
| struct q_obj_ImageInfoSpecificQCow2_wrapper {
| ImageInfoSpecificQCow2 *data;
| };
|
| struct q_obj_ImageInfoSpecificVmdk_wrapper {
| ImageInfoSpecificVmdk *data;
| };
...
| struct ImageInfoSpecific {
| ImageInfoSpecificKind type;
| union { /* union tag is @type */
| void *data;
|- ImageInfoSpecificQCow2 *qcow2;
|- ImageInfoSpecificVmdk *vmdk;
|+ q_obj_ImageInfoSpecificQCow2_wrapper qcow2;
|+ q_obj_ImageInfoSpecificVmdk_wrapper vmdk;
| } u;
| };
Doing this removes asymmetry between QAPI's QMP side and its
C side (both sides now expose 'data'), and means that the
treatment of a simple union as sugar for a flat union is now
equivalent in both languages (previously the two approaches used
a different layer of dereferencing, where the simple union could
be converted to a flat union with equivalent C layout but
different {} on the wire, or to an equivalent QMP wire form
but with different C representation). Using the implicit type
also lets us get rid of the simple_union_type() hack.
Of course, now all clients of simple unions have to adjust from
using su->u.member to using su->u.member.data; while this touches
a number of files in the tree, some earlier cleanup patches
helped minimize the change to the initialization of a temporary
variable rather than every single member access. The generated
qapi-visit.c code is also affected by the layout change:
|@@ -7393,10 +7393,10 @@ void visit_type_ImageInfoSpecific_member
| }
| switch (obj->type) {
| case IMAGE_INFO_SPECIFIC_KIND_QCOW2:
|- visit_type_ImageInfoSpecificQCow2(v, "data", &obj->u.qcow2, &err);
|+ visit_type_q_obj_ImageInfoSpecificQCow2_wrapper_members(v, &obj->u.qcow2, &err);
| break;
| case IMAGE_INFO_SPECIFIC_KIND_VMDK:
|- visit_type_ImageInfoSpecificVmdk(v, "data", &obj->u.vmdk, &err);
|+ visit_type_q_obj_ImageInfoSpecificVmdk_wrapper_members(v, &obj->u.vmdk, &err);
| break;
| default:
| abort();
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1458254921-17042-13-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Before this patch, blk_new() automatically assigned a name to the new
BlockBackend and considered it referenced by the monitor. This patch
removes the implicit monitor_add_blk() call from blk_new() (and
consequently the monitor_remove_blk() call from blk_delete(), too) and
thus blk_new() (and related functions) no longer take a BB name
argument.
In fact, there is only a single point where blk_new()/blk_new_open() is
called and the new BB is monitor-owned, and that is in blockdev_init().
Besides thus relieving us from having to invent names for all of the BBs
we use in qemu-img, this fixes a bug where qemu cannot create a new
image if there already is a monitor-owned BB named "image".
If a BB and its BDS tree are created in a single operation, as of this
patch the BDS tree will be created before the BB is given a name
(whereas it was the other way around before). This results in minor
change to the output of iotest 087, whose reference output is amended
accordingly.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
An upcoming patch will alter how simple unions, like SocketAddress,
are laid out, which will impact all lines of the form 'addr->u.XXX'
(expanding it to the longer 'addr->u.XXX.data'). For better
legibility in that patch, and less need for line wrapping, it's better
to use a temporary variable to reduce the effect of a layout change to
just the variable initializations, rather than every reference within
a SocketAddress. Also, take advantage of some C99 initialization where
it makes sense (simplifying g_new0() to g_new()).
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1457021813-10704-7-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.
This commit was created with scripts/clean-includes.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
When declaring the 'struct option' array, use the standard
constants no_argument/required_argument, instead of magic
values 0 and 1.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
When defining values for long options, the normal practice is
to start numbering from 256, to avoid overlap with the range
of valid values for short options.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Currently qemu-nbd allows an image filename to be passed on the
command line, but unless using the JSON format, it does not have
a way to set any options except the format eg
qemu-nbd https://127.0.0.1/images/centos7.iso
qemu-nbd /home/berrange/demo.qcow2
This adds a --image-opts arg that indicates that the positional
filename should be interpreted as a full option string, not
just a filename.
qemu-nbd --image-opts driver=https,url=https://127.0.0.1/images,sslverify=off
qemu-nbd --image-opts driver=file,filename=/home/berrange/demo.qcow2
This flag is mutually exclusive with the '-f' flag.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This modifies the qemu-nbd program so that it is possible to
request the use of TLS with the server. It simply adds a new
command line option --tls-creds which is used to provide the
ID of a QCryptoTLSCreds object previously created via the
--object command line option.
For example
qemu-nbd --object tls-creds-x509,id=tls0,endpoint=server,\
dir=/home/berrange/security/qemutls \
--tls-creds tls0 \
--exportname default
TLS requires the new style NBD protocol, so if no export name
is set (via --export-name), then we use the default NBD protocol
export name ""
TLS is only supported when using an IPv4/IPv6 socket listener.
It is not possible to use with UNIX sockets, which includes
when connecting the NBD server to a host device.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1455129674-17255-16-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This extends the NBD protocol handling code so that it is capable
of negotiating TLS support during the connection setup. This involves
requesting the STARTTLS protocol option before any other NBD options.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1455129674-17255-14-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The qemu-nbd server currently always uses the old style protocol
since it never sets any export name. This is a problem because
future TLS support will require use of the new style protocol
negotiation.
This adds "--exportname NAME" / "-x NAME" arguments to qemu-nbd
which allow the user to set an explicit export name. When an
export name is set the server will always use the new style
NBD protocol.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1455129674-17255-11-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Now that all callers are converted to use I/O channels for
initial connection setup, it is possible to switch the core
NBD protocol handling core over to use QIOChannel APIs for
actual sockets I/O.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1455129674-17255-7-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This converts the qemu-nbd server to use the QIOChannelSocket
class for initial listener socket setup and accepting of client
connections. Actual I/O is still being performed against the
socket file descriptor using the POSIX socket APIs.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1455129674-17255-5-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Allow creation of user creatable object types with qemu-nbd
via a new --object command line arg. This will be used to supply
passwords and/or encryption keys to the various block driver
backends via the recently added 'secret' object type.
# printf letmein > mypasswd.txt
# qemu-nbd --object secret,id=sec0,file=mypasswd.txt \
...other nbd args...
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1455129674-17255-3-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.
This commit was created with scripts/clean-includes.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1454089805-5470-16-git-send-email-peter.maydell@linaro.org
Rename the parameter "close" to "close_fn" to disambiguous with
close(2).
This unifies error handling paths of NBDClient allocation:
nbd_client_new will shutdown the socket and call the "close_fn" callback
if negotiation failed, so the caller don't need a different path than
the normal close.
The returned pointer is never used, make it void in preparation for the
next patch.
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <1452760863-25350-2-git-send-email-famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The arguments of error_report() should yield a short error string
without newlines.
A few places try to print additional help after the error message by
embedding newlines in the error string. That's nice, but let's do it
the right way. Commit 474c213 cleaned up some, but they keep coming
back. Offenders tracked down with the Coccinelle semantic patch from
commit 312fd5f.
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Pavel Fedin <p.fedin@samsung.com>
Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Commit 6daf194d, be62a2eb and 312fd5f got rid of a bunch, but they
keep coming back. Tracked down with the Coccinelle semantic patch
from commit 312fd5f.
Cc: Fam Zheng <famz@redhat.com>
Cc: Peter Crosthwaite <crosthwaitepeter@gmail.com>
Cc: Bharata B Rao <bharata@linux.vnet.ibm.com>
Cc: Dominik Dingel <dingel@linux.vnet.ibm.com>
Cc: David Hildenbrand <dahi@linux.vnet.ibm.com>
Cc: Jason J. Herne <jjherne@linux.vnet.ibm.com>
Cc: Stefan Berger <stefanb@linux.vnet.ibm.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Changchun Ouyang <changchun.ouyang@intel.com>
Cc: zhanghailiang <zhang.zhanghailiang@huawei.com>
Cc: Pavel Fedin <p.fedin@samsung.com>
Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Acked-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1450452927-8346-17-git-send-email-armbru@redhat.com>
Just three instances left.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1450452927-8346-16-git-send-email-armbru@redhat.com>
Done with this Coccinelle semantic patch
@@
expression FMT, E, S;
expression list ARGS;
@@
- error_report(FMT, ARGS, error_get_pretty(E));
+ error_reportf_err(E, FMT/*@@@*/, ARGS);
(
- error_free(E);
|
exit(S);
|
abort();
)
followed by a replace of '%s"/*@@@*/' by '"' and some line rewrapping,
because I can't figure out how to make Coccinelle transform strings.
We now use the error whole instead of just its message obtained with
error_get_pretty(). This avoids suppressing its hint (see commit
50b7b00), but I can't see how the errors touched in this commit could
come with hints.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1450452927-8346-12-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
bdrv_snapshot_load_tmp() sets an error and returns -errno on failure.
We report both even though the error message is self-contained. Drop
the redundant strerror().
While there: setting errno right before exit() is pointless, so drop
that, too.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1450452927-8346-8-git-send-email-armbru@redhat.com>
Unlike ad hoc prints, error_report_err() uses the error whole instead
of just its message obtained with error_get_pretty(). This avoids
suppressing its hint (see commit 50b7b00). Example:
$ bld/ivshmem-server -l 42@
Parameter 'shm_size' expects a size
You may use k, M, G or T suffixes for kilobytes, megabytes, gigabytes and terabytes.
The last line is new with this patch.
While there, drop a "cannot parse shm size: " message prefix; it's
redundant, because the error message proper is always of the form
"Parameter 'shm_size' expects ...".
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1450452927-8346-5-git-send-email-armbru@redhat.com>
Same Coccinelle semantic patch as in commit 565f65d.
We now use the original error whole instead of just its message
obtained with error_get_pretty(). This avoids suppressing its hint
(see commit 50b7b00), but I don't think the errors touched in this
commit can come with hints.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1450452927-8346-3-git-send-email-armbru@redhat.com>
Coccinelle semantic patch
@@
expression E;
expression list ARGS;
@@
- errx(E, ARGS);
+ error_report(ARGS);
+ exit(E);
@@
expression E, FMT;
expression list ARGS;
@@
- err(E, FMT, ARGS);
+ error_report(FMT /*": %s"*/, ARGS, strerror(errno));
+ exit(E);
followed by a replace of '"/*": %s"*/' by ' : %s"', because I can't
figure out how to make Coccinelle transform strings.
A few of the error messages touched have trailing newlines. They'll
be stripped later in this series.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1450452927-8346-2-git-send-email-armbru@redhat.com>
Now that we guarantee the user doesn't have any enum values
beginning with a single underscore, we can use that for our
own purposes. Renaming ENUM_MAX to ENUM__MAX makes it obvious
that the sentinel is generated.
This patch was mostly generated by applying a temporary patch:
|diff --git a/scripts/qapi.py b/scripts/qapi.py
|index e6d014b..b862ec9 100644
|--- a/scripts/qapi.py
|+++ b/scripts/qapi.py
|@@ -1570,6 +1570,7 @@ const char *const %(c_name)s_lookup[] = {
| max_index = c_enum_const(name, 'MAX', prefix)
| ret += mcgen('''
| [%(max_index)s] = NULL,
|+// %(max_index)s
| };
| ''',
| max_index=max_index)
then running:
$ cat qapi-{types,event}.c tests/test-qapi-types.c |
sed -n 's,^// \(.*\)MAX,s|\1MAX|\1_MAX|g,p' > list
$ git grep -l _MAX | xargs sed -i -f list
The only things not generated are the changes in scripts/qapi.py.
Rejecting enum members named 'MAX' is now useless, and will be dropped
in the next patch.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-23-git-send-email-eblake@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
[Rebased to current master, commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
We have two issues with our qapi union layout:
1) Even though the QMP wire format spells the tag 'type', the
C code spells it 'kind', requiring some hacks in the generator.
2) The C struct uses an anonymous union, which places all tag
values in the same namespace as all non-variant members. This
leads to spurious collisions if a tag value matches a non-variant
member's name.
Make the conversion to the new layout for socket-related code.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-17-git-send-email-eblake@redhat.com>
[Commit message tweaked slightly]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
The --aio=MODE option enables Linux AIO or Windows overlapped I/O.
The #ifdef CONFIG_LINUX_AIO was a layering violation that also prevented
Windows overlapped I/O from being used.
Now that raw-posix.c prints an error when Linux AIO has not been
compiled in, we can unconditionally compile the option into qemu-nbd.
After this patch qemu-nbd --aio=native works on Windows.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The qemu-nbd program currently uses a QemuOpts objects
when setting up sockets. Switch it over to use the
QAPI SocketAddress objects instead.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1442411543-28513-3-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This was needed when qemu-nbd was using qemu_set_fd_handler2. It is
not needed anymore now that nbd_update_server_fd_handler is called
whenever nbd_can_accept() can change from false to true.
nbd_update_server_fd_handler will call qemu_set_fd_handler(),
which will call qemu_notify_event().
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
qerror_report_err() is a transitional interface to help with
converting existing monitor commands to QMP. It should not be used
elsewhere.
The only remaining user in qemu-option.c is qemu_opts_parse(). Is it
used in QMP context? If not, we can simply replace
qerror_report_err() by error_report_err().
The uses in qemu-img.c, qemu-io.c, qemu-nbd.c and under tests/ are
clearly not in QMP context.
The uses in vl.c aren't either, because the only QMP command handlers
there are qmp_query_status() and qmp_query_machines(), and they don't
call it.
Remaining uses:
* drive_def(): Command line -drive and such, HMP drive_add and pci_add
* hmp_chardev_add(): HMP chardev-add
* monitor_parse_command(): HMP core
* tmp_config_parse(): Command line -tpmdev
* net_host_device_add(): HMP host_net_add
* net_client_parse(): Command line -net and -netdev
* qemu_global_option(): Command line -global
* vnc_parse_func(): Command line -display, -vnc, default display, HMP
change, QMP change. Bummer.
* qemu_pci_hot_add_nic(): HMP pci_add
* usb_net_init(): Command line -usbdevice, HMP usb_add
Propagate errors through qemu_opts_parse(). Create a convenience
function qemu_opts_parse_noisily() that passes errors to
error_report_err(). Switch all non-QMP users outside tests to it.
That leaves vnc_parse_func(). Propagate errors through it. Since I'm
touching it anyway, rename it to vnc_parse().
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
Achieved by:
- Remembering the server fd with a global variable, in order to access
it from nbd_client_closed.
- Checking nbd_can_accept() and updating server_fd handler whenever
client connects or disconnects.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1432032670-15124-3-git-send-email-famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <1424887718-10800-13-git-send-email-mreitz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <1424887718-10800-11-git-send-email-mreitz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
It is very unlikely, but it is possible.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <1424887718-10800-10-git-send-email-mreitz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <1424887718-10800-9-git-send-email-mreitz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Unused partitions do not necessarily have a total sector count of 0
(although they should have), but they always do have the system field
set to 0, so use that for testing whether a partition is in use rather
than the sector count field alone.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <1424887718-10800-3-git-send-email-mreitz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch makes use of the Error object for nbd_receive_negotiate() so
that errors during negotiation look nicer.
Furthermore, this patch adds an additional error message if the received
magic was wrong, but would be correct for the other protocol version,
respectively: So if an export name was specified, but the NBD server
magic corresponds to an old handshake, this condition is explicitly
signaled to the user, and vice versa.
As these messages are now part of the "Could not open image" error
message, additional filtering has to be employed in iotest 083, which
this patch does as well.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Because qemu-nbd creates the BlockBackend by itself, it should create
the according BlockDriverState tree by itself as well; that means, it
has call bdrv_open() on its own. This is one of the places where
qemu-nbd still needs to use a BlockDriverState directly (the root BDS
below the BB); other places are the configuration of zero detection
(which may be lifted into the BB eventually, but is not yet) and
temporarily loading a snapshot.
Everywhere else, though, qemu-nbd can and thus should use BlockBackend.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1416309679-333-7-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Substitute BlockDriverState by BlockBackend in every globally visible
function provided by nbd.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1416309679-333-5-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
On BlockBackend destruction, unref its BlockDriverState. Replaces the
callers' unrefs.
This turns the pointer from BlockBackend to BlockDriverState into a
strong reference, managed with bdrv_ref() / bdrv_unref(). The
back-pointer remains weak.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Convenience function blk_new_with_bs() creates a BlockBackend with its
BlockDriverState. Callers have to unref both. The commit after next
will relieve them of the need to unref the BlockDriverState.
Complication: due to the silly way drive_del works, we need a way to
hide a BlockBackend, just like bdrv_make_anon(). To emphasize its
"special" status, give the function a suitably off-putting name:
blk_hide_on_behalf_of_do_drive_del(). Unfortunately, hiding turns the
BlockBackend's name into the empty string. Can't avoid that without
breaking the blk->bs->device_name equals blk->name invariant.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
A block device consists of a frontend device model and a backend.
A block backend has a tree of block drivers doing the actual work.
The tree is managed by the block layer.
We currently use a single abstraction BlockDriverState both for tree
nodes and the backend as a whole. Drawbacks:
* Its API includes both stuff that makes sense only at the block
backend level (root of the tree) and stuff that's only for use
within the block layer. This makes the API bigger and more complex
than necessary. Moreover, it's not obvious which interfaces are
meant for device models, and which really aren't.
* Since device models keep a reference to their backend, the backend
object can't just be destroyed. But for media change, we need to
replace the tree. Our solution is to make the BlockDriverState
generic, with actual driver state in a separate object, pointed to
by member opaque. That lets us replace the tree by deinitializing
and reinitializing its root. This special need of the root makes
the data structure awkward everywhere in the tree.
The general plan is to separate the APIs into "block backend", for use
by device models, monitor and whatever other code dealing with block
backends, and "block driver", for use by the block layer and whatever
other code (if any) dealing with trees and tree nodes.
Code dealing with block backends, device models in particular, should
become completely oblivious of BlockDriverState. This should let us
clean up both APIs, and the tree data structures.
This commit is a first step. It creates a minimal "block backend"
API: type BlockBackend and functions to create, destroy and find them.
BlockBackend objects are created and destroyed exactly when root
BlockDriverState objects are created and destroyed. "Root" in the
sense of "in bdrv_states". They're not yet used for anything; that'll
come shortly.
A root BlockDriverState is created with bdrv_new_root(), so where to
create a BlockBackend is obvious. Where these roots get destroyed
isn't always as obvious.
It is obvious in qemu-img.c, qemu-io.c and qemu-nbd.c, and in error
paths of blockdev_init(), blk_connect(). That leaves destruction of
objects successfully created by blockdev_init() and blk_connect().
blockdev_init() is used only by drive_new() and qmp_blockdev_add().
Objects created by the latter are currently indestructible (see commit
48f364d "blockdev: Refuse to drive_del something added with
blockdev-add" and commit 2d246f0 "blockdev: Introduce
DriveInfo.enable_auto_del"). Objects created by the former get
destroyed by drive_del().
Objects created by blk_connect() get destroyed by blk_disconnect().
BlockBackend is reference-counted. Its reference count never exceeds
one so far, but that's going to change.
In drive_del(), the BB's reference count is surely one now. The BDS's
reference count is greater than one when something else is holding a
reference, such as a block job. In this case, the BB is destroyed
right away, but the BDS lives on until all extra references get
dropped.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Eric Blake
Kevin Wolf
Veronia Bahaa
Markus Armbruster
Max Reitz
Peter Maydell
Daniel P. Berrange
Fam Zheng
Stefan Hajnoczi
Andrey Korolyov
Paolo Bonzini