Do not force exit within qemu_set_log; return bool and pass
an Error value back up the stack as per usual.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-5-richard.henderson@linaro.org>
To implement this, we reuse the existing daemonizing functions from the
system emulator, which mainly do the following:
- Fork off a child process, and set up a pipe between parent and child
- The parent process waits until the child sends a status byte over the
pipe (0 means that the child was set up successfully; anything else
(including errors or EOF) means that the child was not set up
successfully), and then exits with an appropriate exit status
- The child process enters a new session (forking off again), changes
the umask, and will ignore terminal signals from then on
- Once set-up is complete, the child will chdir to /, redirect all
standard I/O streams to /dev/null, and tell the parent that set-up has
been completed successfully
In contrast to qemu-nbd's --fork implementation, during the set up
phase, error messages are not piped through the parent process.
qemu-nbd mainly does this to detect errors, though (while os_daemonize()
has the child explicitly signal success after set up); because we do not
redirect stderr after forking, error messages continue to appear on
whatever the parent's stderr was (until set up is complete).
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220303164814.284974-4-hreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
In contrast to qemu-nbd (where it is called --fork) and the system
emulator, QSD does not have a --daemonize switch yet. Just like them,
QSD allows setting up block devices and exports on the command line.
When doing so, it is often necessary for whoever invoked the QSD to wait
until these exports are fully set up. A --daemonize switch allows
precisely this, by virtue of the parent process exiting once everything
is set up.
Note that there are alternative ways of waiting for all exports to be
set up, for example:
- Passing the --pidfile option and waiting until the respective file
exists (but I do not know if there is a way of implementing this
without a busy wait loop)
- Set up some network server (e.g. on a Unix socket) and have the QSD
connect to it after all arguments have been processed by appending
corresponding --chardev and --monitor options to the command line,
and then wait until the QSD connects
Having a --daemonize option would make this simpler, though, without
having to rely on additional tools (to set up a network server) or busy
waiting.
Implementing a --daemonize switch means having to fork the QSD process.
Ideally, we should do this as early as possible: All the parent process
has to do is to wait for the child process to signal completion of its
set-up phase, and therefore there is basically no initialization that
needs to be done before the fork. On the other hand, forking after
initialization steps means having to consider how those steps (like
setting up the block layer or QMP) interact with a later fork, which is
often not trivial.
In order to fork this early, we must scan the command line for
--daemonize long before our current process_options() call. Instead of
adding custom new code to do so, just reuse process_options() and give
it a @pre_init_pass argument to distinguish the two passes. I believe
there are some other switches but --daemonize that deserve parsing in
the first pass:
- --help and --version are supposed to only print some text and then
immediately exit (so any initialization we do would be for naught).
This changes behavior, because now "--blockdev inv-drv --help" will
print a help text instead of complaining about the --blockdev
argument.
Note that this is similar in behavior to other tools, though: "--help"
is generally immediately acted upon when finding it in the argument
list, potentially before other arguments (even ones before it) are
acted on. For example, "ls /does-not-exist --help" prints a help text
and does not complain about ENOENT.
- --pidfile does not need initialization, and is already exempted from
the sequential order that process_options() claims to strictly follow
(the PID file is only created after all arguments are processed, not
at the time the --pidfile argument appears), so it makes sense to
include it in the same category as --daemonize.
- Invalid arguments should always be reported as soon as possible. (The
same caveat with --help applies: That means that "--blockdev inv-drv
--inv-arg" will now complain about --inv-arg, not inv-drv.)
This patch does make some references to --daemonize without having
implemented it yet, but that will happen in the next patch.
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20220303164814.284974-3-hreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We did not add documentation to the storage daemon's man page for fuse's
allow-other option when it was introduced, so do that now.
Fixes: 8fc54f9428 ("export/fuse: Add allow-other option")
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220131103124.20325-1-hreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The syntax of the fd passing case misses the "addr.type=" key. Add it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20220125151514.49035-1-kwolf@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Add missing vhost-user-blk help:
$ qemu-storage-daemon -h
...
--export [type=]vhost-user-blk,id=<id>,node-name=<node-name>,
addr.type=unix,addr.path=<socket-path>[,writable=on|off]
[,logical-block-size=<block-size>][,num-queues=<num-queues>]
export the specified block node as a
vhosts-user-blk device over UNIX domain socket
--export [type=]vhost-user-blk,id=<id>,node-name=<node-name>,
fd,addr.str=<fd>[,writable=on|off]
[,logical-block-size=<block-size>][,num-queues=<num-queues>]
export the specified block node as a
vhosts-user-blk device over file descriptor
...
Fixes: 90fc91d50b ("convert vhost-user-blk server to block export API")
Reported-by: Qing Wang <qinwang@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220107105420.395011-3-f4bug@amsat.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The code to check command policy can see special feature flag
'deprecated' as command flag QCO_DEPRECATED. I want to make feature
flag 'unstable' visible there as well, so I can add policy for it.
To let me make it visible, add member @special_features (a bitset of
QapiSpecialFeature) to QmpCommand, and adjust the generator to pass it
through qmp_register_command(). Then replace "QCO_DEPRECATED in
@flags" by QAPI_DEPRECATED in @special_features", and drop
QCO_DEPRECATED.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: John Snow <jsnow@redhat.com>
Message-Id: <20211028102520.747396-7-armbru@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
When configuring QEMU with --disable-fuse, the qemu-storage-daemon
still reports FUSE command line options in its help:
$ qemu-storage-daemon -h
Usage: qemu-storage-daemon [options]
QEMU storage daemon
--export [type=]fuse,id=<id>,node-name=<node-name>,mountpoint=<file>
[,growable=on|off][,writable=on|off]
export the specified block node over FUSE
Remove this help message when FUSE is disabled, to avoid:
$ qemu-storage-daemon --export fuse
qemu-storage-daemon: --export fuse: Invalid parameter 'fuse'
Reported-by: Qing Wang <qinwang@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210816180442.2000642-1-philmd@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Implementing FUSE exports required no changes to the storage daemon, so
we forgot to document them there. Considering that both NBD and
vhost-user-blk exports are documented in its man page (and NBD exports
in its --help text), we should probably do the same for FUSE.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210217115844.62661-1-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
QMP commands return their response as a generated QAPI type, which the
monitor core converts to JSON via QObject.
query-qmp-schema's response is the generated introspection data. This
is a QLitObject since commit 7d0f982bfb "qapi: generate a literal
qobject for introspection", v2.12). Before, it was a string. Instead
of converting QLitObject / string -> QObject -> QAPI type
SchemaInfoList -> QObject -> JSON, we take a shortcut: the command is
'gen': false, so it can return the QObject instead of the QAPI type.
Slightly simpler and more efficient.
The next commit will filter the response for output policy, and this
is easier in the SchemaInfoList representation. Drop the shortcut.
This replaces the manual command registration by a generated one. The
manual registration makes the command available before the machine is
built by passing flag QCO_ALLOW_PRECONFIG. To keep it available
there, we need need to add 'allow-preconfig': true to its definition
in the schema.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210318155519.1224118-7-armbru@redhat.com>
The implementation for --object can be shared between
qemu-storage-daemon and other binaries, so move it into a function in
qom/object_interfaces.c that is accessible from everywhere.
This also requires moving the implementation of qmp_object_add() into a
new user_creatable_add_qapi(), because qom/qom-qmp-cmds.c is not linked
for tools.
user_creatable_print_help_from_qdict() can become static now.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
This QAPIfies --object and ensures that QMP and the command line option
behave the same.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
This converts object-add from 'gen': false to the ObjectOptions QAPI
type. As an immediate benefit, clients can now use QAPI schema
introspection for user creatable QOM objects.
It is also the first step towards making the QAPI schema the only
external interface for the creation of user creatable objects. Once all
other places (HMP and command lines of the system emulator and all
tools) go through QAPI, too, some object implementations can be
simplified because some checks (e.g. that mandatory options are set) are
already performed by QAPI, and in another step, QOM boilerplate code
could be generated from the schema.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
bdrv_close_all() asserts that no jobs are running any more, so we need
to cancel all jobs first to avoid failing the assertion.
Fixes: b55a3c8860
Reported-by: Nini Gu <ngu@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210309121814.31078-1-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Daemons often have a --pidfile option where the pid is written to a file
so that scripts can stop the daemon by sending a signal.
The pid file also acts as a lock to prevent multiple instances of the
daemon from launching for a given pid file.
QEMU, qemu-nbd, qemu-ga, virtiofsd, and qemu-pr-helper all support the
--pidfile option. Add it to qemu-storage-daemon too.
Reported-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20210302142746.170535-1-stefanha@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Use the location management facilities that the emulator uses, so that
the current command line option appears in the error message.
Before:
$ storage-daemon/qemu-storage-daemon --nbd key..=
qemu-storage-daemon: Invalid parameter 'key..'
After:
$ storage-daemon/qemu-storage-daemon --nbd key..=
qemu-storage-daemon: --nbd key..=: Invalid parameter 'key..'
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210301152844.291799-3-pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
If the first character of optstring is '-', then each nonoption argv
element is handled as if it were the argument of an option with character
code 1. This removes the reordering of the argv array, and enables usage
of loc_set_cmdline to provide better error messages.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210301152844.291799-2-pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
As we don't have a fully QAPIfied version of object-add yet and it still
has 'gen': false in the schema, it needs to be registered explicitly in
init_qmp_commands() to be available for users.
Fixes: 2af282ec51
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210204072137.19663-1-kwolf@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Move blk_exp_close_all() from bdrv_close() to qemu_cleanup(), before
bdrv_drain_all_begin().
Export drivers may have coroutines yielding at some point in the block
layer, so we need to shut them down before draining the block layer,
as otherwise they may get stuck blk_wait_while_drained().
RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1900505
Signed-off-by: Sergio Lopez <slp@redhat.com>
Message-Id: <20210201125032.44713-3-slp@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Otherwise, exports and block devices are not properly shut down and
closed, unless the users explicitly issues blockdev-del and
block-export-del commands for each of them.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20201027190600.192171-17-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
It is not needed, all the callers are just saving what was
retrieved from -trace and trace_init_file can retrieve it
on its own.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20201102115841.4017692-1-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The command line parser for --object parses the input twice: Once into
QemuOpts just for detecting help options, and then again into a QDict
using the keyval parser for actually creating the object.
Now that the keyval parser can also detect help options, we can simplify
this and remove the QemuOpts part.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201007164903.282198-5-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds a special meaning for 'help' and '?' as options to the keyval
parser. Instead of being an error (because of a missing value) or a
value for an implied key, they now request help, which is a new boolean
output of the parser in addition to the QDict.
A new parameter 'p_help' is added to keyval_parse() that contains on
return whether help was requested. If NULL is passed, requesting help
results in an error and all other cases work like before.
Turning previous error cases into help is a compatible extension. The
behaviour potentially changes for implied keys: They could previously
get 'help' as their value, which is now interpreted as requesting help.
This is not a problem in practice because 'help' and '?' are not a valid
values for the implied key of any option parsed with keyval_parse():
* audiodev: union Audiodev, implied key "driver" is enum AudiodevDriver,
"help" and "?" are not among its values
* display: union DisplayOptions, implied key "type" is enum
DisplayType, "help" and "?" are not among its values
* blockdev: union BlockdevOptions, implied key "driver is enum
BlockdevDriver, "help" and "?" are not among its values
* export: union BlockExport, implied key "type" is enum BlockExportType,
"help" and "?" are not among its values
* monitor: struct MonitorOptions, implied key "mode" is enum MonitorMode,
"help" and "?" are not among its values
* nbd-server: struct NbdServerOptions, no implied key.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201011073505.1185335-5-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Commit 5f479a8d renamed the 'device' option of --export into
'node-name', but forgot to update the help in qemu-storage-daemon.
Fixes: 5f479a8dc086bfa42c9f94e9ab69962f256e207f
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200930133909.58820-1-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We'll need an id to identify block exports in monitor commands. This
adds one.
Note that this is different from the 'name' option in the NBD server,
which is the externally visible export name. While block export ids need
to be unique in the whole process, export names must be unique only for
the same server. Different export types or (potentially in the future)
multiple NBD servers can have the same export name externally, but still
need different block export ids internally.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200924152717.287415-19-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This is a QMP equivalent of qemu-nbd's --shared option, limiting the
maximum number of clients that can attach at the same time.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200924152717.287415-9-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
No reason to duplicate the functionality locally, we can now just reuse
the QMP command block-export-add for --export.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200924152717.287415-6-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The name BlockExport will be used for the struct containing the runtime
state of block exports, so change the name of export creation options.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200924152717.287415-4-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Move all block export related types and commands from block-core to the
new QAPI module block-export.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200924152717.287415-3-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
