On a system with a low limit of open files the initialization
of the event notifier could fail and QEMU exits without printing any
error information to the user.
The problem can be easily reproduced by enforcing a low limit of open
files and start QEMU with enough I/O threads to hit this limit.
The same problem raises, without the creation of I/O threads, while
QEMU initializes the main event loop by enforcing an even lower limit of
open files.
This commit adds an error message on failure:
# qemu [...] -object iothread,id=iothread0 -object iothread,id=iothread1
qemu: Failed to initialize event notifier: Too many open files in system
Signed-off-by: Chrysostomos Nanakos <cnanakos@grnet.gr>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This forces finishing data sending to client before closing the socket like in
exports listing or replying with NBD_REP_ERR_UNSUP cases.
Signed-off-by: Hani Benhabiles <kroosec@gmail.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
qerror_report() is a transitional interface to help with converting
existing HMP commands to QMP. It should not be used elsewhere.
Replace by error_report().
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Otherwise, the nbd client may hang waiting for the server response.
Signed-off-by: Hani Benhabiles <hani@linux.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
This patch adds an errp parameter to bdrv_new() and updates all its
callers. The next patches will make use of this in order to check for
duplicate IDs. Most of the callers know that their ID is fine, so they
can simply assert that there is no error.
Behaviour doesn't change with this patch yet as bdrv_new() doesn't
actually assign errors to errp.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
There are two issues in qemu-nbd: a missing return value check after
calling accept(), and file descriptor leaks in nbd_client_thread.
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=ZaDG
-----END PGP SIGNATURE-----
Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging
Block patches
# gpg: Signature made Fri 21 Feb 2014 21:42:24 GMT using RSA key ID C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
* remotes/kevin/tags/for-upstream: (54 commits)
iotests: Mixed quorum child device specifications
quorum: Simplify quorum_open()
quorum: Add unit test.
quorum: Add quorum_open() and quorum_close().
quorum: Implement recursive .bdrv_recurse_is_first_non_filter in quorum.
quorum: Add quorum_co_flush().
quorum: Add quorum_invalidate_cache().
quorum: Add quorum_getlength().
quorum: Add quorum mechanism.
quorum: Add quorum_aio_readv.
blkverify: Extract qemu_iovec_clone() and qemu_iovec_compare() from blkverify.
quorum: Add quorum_aio_writev and its dependencies.
quorum: Create BDRVQuorumState and BlkDriver and do init.
quorum: Create quorum.c, add QuorumChildRequest and QuorumAIOCB.
check-qdict: Test termination of qdict_array_split()
check-qdict: Adjust test for qdict_array_split()
qdict: Extract non-QDicts in qdict_array_split()
qemu-config: Sections must consist of keys
qemu-iotests: Check qemu-img command line parsing
qemu-img: Allow -o help with incomplete argument list
...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
qemu-nbd is one of the few valid users of qerror_report_err. Move
the error-reporting socket wrappers there.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Allow bdrv_open() to handle references to existing block devices just as
bdrv_file_open() is already capable of.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Make bdrv_open() take a pointer to a BDS pointer, similarly to
bdrv_file_open(). If a pointer to a NULL pointer is given, bdrv_open()
will create a new BDS with an empty name; if the BDS pointer is not
NULL, that existing BDS will be reused (in the same way as bdrv_open()
already did).
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
With this change, main() calls qemu_init_exec_dir and uses argv[0] to
init exec_dir. The saved value can be retrieved with
qemu_get_exec_dir later. It will be reused by module loading.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Now it is possible to directly export an internal snapshot, which
can be used to probe the snapshot's contents without qemu-img
convert.
Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Add an Error ** parameter to bdrv_open, bdrv_file_open and associated
functions to allow more specific error messages.
Signed-off-by: Max Reitz <mreitz@redhat.com>
include/qemu/timer.h has no need to include main-loop.h and
doing so causes an issue for the next patch. Unfortunately
various files assume including timers.h will pull in main-loop.h.
Untangle this mess.
Signed-off-by: Alex Bligh <alex@alex.org.uk>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Currently the qemu-nbd program will auto-detect the format of
any disk it is given. This behaviour is known to be insecure.
For example, if qemu-nbd initially exposes a 'raw' file to an
unprivileged app, and that app runs
'qemu-img create -f qcow2 -o backing_file=/etc/shadow /dev/nbd0'
then the next time the app is started, the qemu-nbd will now
detect it as a 'qcow2' file and expose /etc/shadow to the
unprivileged app.
The only way to avoid this is to explicitly tell qemu-nbd what
disk format to use on the command line, completely disabling
auto-detection. This patch adds a '-f' / '--format' arg for
this purpose, mirroring what is already available via qemu-img
and qemu commands.
qemu-nbd --format raw -p 9000 evil.img
will now always use raw, regardless of what format 'evil.img'
looks like it contains
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
[Use errx, not err. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
It doesn't do anything yet except storing the options QDict in the
BlockDriverState.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Similar to --cache and --aio, this option mimics the discard suboption
of "-drive".
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Use a simple state machine with the following states:
- RUNNING => accepting connections
- TERMINATE => main loop must call nbd_export_close/put, and not accept
connections anymore
- TERMINATING => waiting for pending requests to finish
- TERMINATED => the NBDExport has been closed
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In order to exit cleanly from qemu-nbd, add a callback that triggers
when an NBDExport is closed. In the case of qemu-nbd it will exit the
main loop.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We will use a similar two-phase destruction for NBDExport, so we need
each NBDClient to add a reference to NBDExport.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add two options to tune the I/O implementation of qemu-nbd, matching
the possibilities given by the QEMU -drive option.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch separates qemu-nbd's options in logical groups, thus making
the help message easier to read.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In the next patch we need to look at the return code of nbd_wr_sync.
To avoid percolating the socket_error() ugliness all around, let's
handle errors by returning negative errno values.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When qemu-nbd becomes a daemon it calls daemon(3) with
nochdir=0, so daemon(3) changes current directory to /.
But at this time, qemu-nbd did not open any user-specified
files yet, so by changing current directory, all non-absolute
paths becomes wrong. The solution is to pass nochdir=1 to
daemon(3) function, and to chdir("/") after all init has
been performed, before entering the main loop, -- just like
a good daemon should do.
This patch is applicable for -stable.
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
For some reason nbd_client_thread() has a do..while loop which can never
loop, the condition is bogus because we would take a goto instead. Drop
the loop.
Reported-by: Dr David Alan Gilbert <davidagilbert@uk.ibm.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
This patch sets up the fd handler in nbd.c instead of qemu-nbd.c. It
introduces NBDClient, which wraps the arguments to nbd_trip in a single
structure, so that we can add a notifier to it. This way, qemu-nbd can
know about disconnections.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Using a single main loop for sockets will help yielding from the socket
coroutine back to the main loop, and later reentering it.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This is cleaner, because we do not need to close the block device when
there is an error opening /dev/nbdX. It was done this way only to
print errors before daemonizing.
At the same time, use atexit to ensure that the block device is closed
whenever we exit.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Now that the client and server are in the same process, there is
no need to race on the creation of the socket. We can open the
listening socket before starting the client thread.
This avoids that "qemu-nbd -v -c" prints this once before connecting
successfully to the socket:
connect(unix:/var/lock/qemu-nbd-nbd0): No such file or directory
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
In order to get nice error messages, keep the qemu-nbd process running
until before issuing NBD_DO_IT and connected to the daemon with a pipe.
This lets the qemu-nbd process relay error messages from the daemon and
exit with a nonzero status if appropriate.
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This avoids that qemu-nbd uses both forking and threads, which do
not behave well together.
qemu-nbd is already Unix only, and there is no qemu_thread_join,
so for now use pthreads.
Since the parent and child no longer have separate file descriptors,
we can open the NBD device before daemonizing, instead of checking
with access(2) and restricting the open to the client only.
Reported-by: Pierre Riteau <pierre.riteau@irisa.fr>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
It will be moved to a global variable by the next patch, and it
would conflict with the socket function.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The client process right now uses SIGTERM to interrupt the server side.
This does not affect the exit status of "qemu-nbd -v -c" because the
server is a child process. This will change when both sides will be
in the same process, and anyway cleaning up things nicely upon SIGTERM
is good practice.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
nbd supports writing flags in bytes 24...27 of the header,
and uses that for the read-only flag. Add support for it
in qemu-nbd.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* qemu-common.h is not a system include file, so it should be included
with "" instead of <>. Otherwise incremental builds might fail
because only local include files are checked for changes.
* linux-user/syscall.c included the file twice.
Cc: Riku Voipio <riku.voipio@iki.fi>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Changes since v1: create a wrapper function named qemu_daemon() in oslib-posix.c
instead of putting the OS specific workaround in qemu-nbd.c directly.
On OSX >= 10.5, daemon() is deprecated, resulting in the following warning:
----8<----
qemu-nbd.c: In function ‘main’:
qemu-nbd.c:371: warning: ‘daemon’ is deprecated (declared at /usr/include/stdlib.h:289)
----8<----
The following trick, used in mDNSResponder, takes care of this warning:
http://www.opensource.apple.com/source/mDNSResponder/mDNSResponder-258.18/mDNSPosix/PosixDaemon.c
On OSX, it temporarily renames the daemon() function before including stdlib.h
and declares it manually as an extern function. This way, the compiler does not
see the declaration from stdlib.h and thus does not display the warning.
Signed-off-by: Alexandre Raymond <cerbere@gmail.com>
Cc: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Andreas Färber <andreas.faerber@web.de>
