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2014-05-09qga: Clean up fragile use of error_is_set()Markus Armbruster
Using error_is_set(ERRP) to find out whether a function failed is either wrong, fragile, or unnecessarily opaque. It's wrong when ERRP may be null, because errors go undetected when it is. It's fragile when proving ERRP non-null involves a non-local argument. Else, it's unnecessarily opaque (see commit 84d18f0). The error_is_set(errp) in the guest agent command handler functions are merely fragile, because all chall chains (do_qmp_dispatch() via the generated marshalling functions) pass a non-null errp argument. Make the code more robust and more obviously correct: receive the error in a local variable, then propagate it through the parameter. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-09qga: Use return values instead of error_is_set(errp)Markus Armbruster
Using error_is_set(errp) to check whether a function call failed is fragile: it breaks when errp is null. ga_get_fd_handle() and guest_file_handle_add() don't return a useful value when they fail, but that's just stupid. Fix that, and check them instead. As far as I can tell, errp can't be null there, but this is more robust and more obviously correct. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-09qga: Consistently name Error ** objects errp, and not errMarkus Armbruster
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-04-18qga: trivial fix for unclear documentation of guest-set-timeAmos Kong
We mixed the use of "guest time", "system time", "hardware time", "RTC" in documentation, it's unclear. This patch just added two remarks of RTC and replace two "guest time" by "guest's system time". Signed-off-by: Amos Kong <akong@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2014-02-23qga: Fix memory allocation pastoMarkus Armbruster
qmp_guest_file_seek() allocates memory for a GuestFileRead object instead of the GuestFileSeek object it actually uses. Harmless, because the GuestFileRead is slightly larger. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2014-02-23qga: Don't require 'time' argument in guest-set-time commandMichal Privoznik
As the description to the guest-set-time states, the command is there to ease time synchronization after resume. If guest was suspended for longer period of time, its system time can go off so badly, that even NTP refuses to set it. That's why the command was invented: to give users chance to set the time (not necessarily 100% correct). However, there's is no real need for us to require users to pass an arbitrary time. Especially if we can read the correct value from RTC (boiling down to reading host's time). Hence this commit enables logic: guest-set-time() == guest-set-time($now_from_rtc) Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2014-02-17Use error_is_set() only when necessaryMarkus Armbruster
error_is_set(&var) is the same as var != NULL, but it takes whole-program analysis to figure that out. Unnecessarily hard for optimizers, static checkers, and human readers. Dumb it down to obvious. Gets rid of several dozen Coverity false positives. Note that the obvious form is already used in many places. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Andreas Färber <afaerber@suse.de> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2013-11-21qga: Fix compiler warnings (missing format attribute, wrong format strings)Stefan Weil
gcc 4.8.2 reports this warning when extra warnings are enabled (-Wextra): CC qga/commands.o qga/commands.c: In function ‘slog’: qga/commands.c:28:5: error: function might be possible candidate for ‘gnu_printf’ format attribute [-Werror=suggest-attribute=format] g_logv("syslog", G_LOG_LEVEL_INFO, fmt, ap); ^ gcc 4.8.2 reports this warning when slog is declared with the gnu_printf format attribute: qga/commands-posix.c: In function ‘qmp_guest_file_open’: qga/commands-posix.c:404:5: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘int64_t’ [-Wformat=] slog("guest-file-open, handle: %d", handle); ^ On 32 bit hosts there are three more warnings which are also fixed here. Signed-off-by: Stefan Weil <sw@weilnetz.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-11-16qga: Fix shutdown command of guest agent to work with SysVwhitearchey
For now guest agent uses following command to shutdown system: shutdown -P +0 "blabla" but this syntax works only with shutdown command from systemd or upstart, because SysV shutdown requires -h switch. Following patch changes the command so it works with systemd, upstart and SysV With upstart/systemd qga use one of thee commands, depending on 'mode' parameter: shutdown -P +0 "..." shutdown -H +0 "..." shutdown -r +0 "..." SysV equivalents for these are: shutdown -h -P +0 "..." shutdown -h -H +0 "..." shutdown -h -r +0 "..." and these retain their meaning with upstart/systemd. According to FreeBSD manpages, shutdown does not accept -P and -H options. Commands should be: shutdown -p +0 "..." shutdown -h +0 "..." shutdown -r +0 "..." shutdown in Solaris does not accept any of -hHpPr and does not accept time in "+0" format Signed-off-by: Michael Avdienko <whitearchey@gmail.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2013-10-10qemu-ga: execute fsfreeze-freeze in reverse order of mountsTomoki Sekiyama
Currently, fsfreeze-freeze may cause deadlock if a guest has loopback mounts of image files in its disk; e.g.: # mount | grep ^/ /dev/vda1 / type ext4 (rw,noatime,seclabel,data=ordered) /tmp/disk.img on /mnt type ext4 (rw,relatime,seclabel) To avoid the deadlock, this freezes filesystems in reverse order of mounts. Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com> Reviewed-by: Eric Blake <eblake@redhat.com> *fix up commit msg Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-05-13qga: unlink just created guest-file if fchmod() or fdopen() fails on itLaszlo Ersek
We shouldn't allow guest filesystem pollution on error paths. Suggested-by: Eric Blake <eblake@redhat.com> Signed-off-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-05-13qga: distinguish binary modes in "guest_file_open_modes" mapLaszlo Ersek
In Windows guests this may make a difference. Since the original patch (commit c689b4f1) sought to be pedantic and to consider theoretical corner cases of portability, we should fix it up where it failed to come through in that pursuit. Suggested-by: Eric Blake <eblake@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-05-07qga: set umask 0077 when daemonizing (CVE-2013-2007)Laszlo Ersek
The qemu guest agent creates a bunch of files with insecure permissions when started in daemon mode. For example: -rw-rw-rw- 1 root root /var/log/qemu-ga.log -rw-rw-rw- 1 root root /var/run/qga.state -rw-rw-rw- 1 root root /var/log/qga-fsfreeze-hook.log In addition, at least all files created with the "guest-file-open" QMP command, and all files created with shell output redirection (or otherwise) by utilities invoked by the fsfreeze hook script are affected. For now mask all file mode bits for "group" and "others" in become_daemon(). Temporarily, for compatibility reasons, stick with the 0666 file-mode in case of files newly created by the "guest-file-open" QMP call. Do so without changing the umask temporarily. Signed-off-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-03-22Fix typos and misspellingsPeter Maydell
Fix various typos and misspellings. The bulk of these were found with codespell. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Stefan Weil <sw@weilnetz.de> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-11qga: implement qmp_guest_set_vcpus() for Linux with sysfsLaszlo Ersek
Signed-off-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-03-11qga: implement qmp_guest_get_vcpus() for Linux with sysfsLaszlo Ersek
Signed-off-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-03-11qga: introduce guest-get-vcpus / guest-set-vcpus with stubsLaszlo Ersek
Signed-off-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-03-11qga: add guest-set-time commandLei Li
Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com> *added stub for w32 Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-03-11qga: add guest-get-time commandLei Li
Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com> *added stub for w32 Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-03-11qemu-ga: use key-value store to avoid recycling fd handles after restartMichael Roth
Hosts hold on to handles provided by guest-file-open for periods that can span beyond the life of the qemu-ga process that issued them. Since these are issued starting from 0 on every restart, we run the risk of issuing duplicate handles after restarts/reboots. As a result, users with a stale copy of these handles may end up reading/writing corrupted data due to their existing handles effectively being re-assigned to an unexpected file or offset. We unfortunately do not issue handles as strings, but as integers, so a solution such as using UUIDs can't be implemented without introducing a new interface. As a workaround, we fix this by implementing a persistent key-value store that will be used to track the value of the last handle that was issued across restarts/reboots to avoid issuing duplicates. The store is automatically written to the same directory we currently set via --statedir to track fsfreeze state, and so should be applicable for stable releases where this flag is supported. A follow-up can use this same store for handling fsfreeze state, but that change is cosmetic and left out for now. Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> Cc: qemu-stable@nongnu.org * fixed guest_file_handle_add() return value from uint64_t to int64_t
2013-01-28qemu-ga: Plug leaks on qmp_guest_network_get_interfaces() error pathsMarkus Armbruster
Spotted by Coverity. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-01-28qemu-ga: Plug memory leak in guest_fsfreeze_cleanup()Markus Armbruster
Neglects to free errors allocated by qmp_guest_fsfreeze_thaw(). Spotted by Coverity. While there, drop the test whether return value is negative (it's never true), and improve logging. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-01-19Replace non-portable asprintf by g_strdup_printfStefan Weil
g_strdup_printf already handles OOM errors, so some error handling in QEMU code can be removed. Signed-off-by: Stefan Weil <sw@weilnetz.de> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2013-01-08qemu-ga: execute hook to quiesce the guest on fsfreeze-freeze/thawTomoki Sekiyama
To use the online disk snapshot for online-backup, application-level consistency of the snapshot image is required. However, currently the guest agent can provide only filesystem-level consistency, and the snapshot may contain dirty data, for example, incomplete transactions. This patch provides the opportunity to quiesce applications before snapshot is taken. If --fsfreeze-hook option is specified, the hook is executed with "freeze" argument before the filesystem is frozen by fsfreeze-freeze command. As for fsfreeze-thaw command, the hook is executed with "thaw" argument after the filesystem is thawed. This patch depends on patchset to improve error reporting by Luiz Capitulino: http://lists.gnu.org/archive/html/qemu-devel/2012-11/msg03016.html Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com> Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com> *clarified usage in help output Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-01-08qemu-ga: guest_suspend(): improve error reportingLuiz Capitulino
Most errors are QERR_UNDEFINED_ERROR today. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-01-08qemu-ga: bios_supports_mode(): improve error reportingLuiz Capitulino
Most errors are QERR_UNDEFINED_ERROR today. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-01-08qemu-ga: qmp_guest_network_get_interfaces(): get rid of snprintf() + error_set()Luiz Capitulino
Convert them to error_setg_errno(). Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-01-08qemu-ga: qmp_guest_fstrim(): get rid of sprintf() + error_set()Luiz Capitulino
Convert them to error_setg_errno(). Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-01-08qemu-ga: qmp_guest_fsfreeze_*(): get rid of sprintf() + error_set()Luiz Capitulino
Convert them to error_setg_errno(). Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-01-08qemu-ga: build_fs_mount_list(): take an Error argumentLuiz Capitulino
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-01-08qemu-ga: qmp_guest_shutdown(): improve error reportingLuiz Capitulino
Most errors are QERR_UNDEFINED_ERROR. Also, adds ga_wait_child() as a future commit will use it too. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-01-08qemu-ga: qmp_guest_file_*: improve error reportingLuiz Capitulino
Use error_setg_errno() when possible with an improved error description. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-01-08qemu-ga: qmp_guest_file_close(): fix fclose() error checkLuiz Capitulino
fclose() returns EOF on error. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-01-08qemu-ga: guest_file_handle_find(): take an Error argumentLuiz Capitulino
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com> *Fixed missing space character in error message Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2012-12-19misc: move include files to include/qemu/Paolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19qapi: move include files to include/qobject/Paolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-10-06Merge branch 'trivial-patches' of git://github.com/stefanha/qemuAurelien Jarno
* 'trivial-patches' of git://github.com/stefanha/qemu: versatilepb: Use symbolic indices for ARM PIC qdev: kill bogus comment qemu-barrier: Fix compiler version check for future gcc versions hw: Add missing 'static' attribute for QEMUMachine cleanup useless return sentence qemu-sockets: Fix compiler warning (regression for MinGW) vnc: Fix spelling (hellmen -> hellman) in comment slirp: Fix spelling in comment (enought -> enough, insure -> ensure) tcg/arm: Use tcg_out_mov_reg rather than inline equivalent code cpu: Add missing 'static' attribute to qemu_global_mutex configure: Support empty target list (--target-list=) hw: Fix return value check for bdrv_read, bdrv_write
2012-10-05cleanup useless return sentenceAmos Kong
This patch cleans up return sentences in the end of void functions. Reported-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Amos Kong <akong@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
2012-10-05qemu-ga: prefer pstrcpy: consistently NUL-terminate ifreq.ifr_nameJim Meyering
NUL-termination of the .ifr_name field is not required, but is fine (and preferable to using strncpy and leaving the reader to wonder), since the first thing the linux kernel does is to clear the last byte. Besides, using pstrcpy here makes this setting of ifr_name consistent with the other code (e.g., net/tap-linux.c) that does the same thing. Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Jim Meyering <meyering@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-06-21qemu-ga: add guest-fstrim commandPaolo Bonzini
FITRIM is a mounted filesystem feature to discard (or "trim") blocks which are not in use by the filesystem. This is useful for solid-state drives (SSDs) and thinly-provisioned storage. Provide access to the feature from the host so that filesystems can be trimmed periodically or before migration. Here is an example using scsi_debug: # modprobe scsi_debug lbpu=1 lbpws=1 # sg_vpd -p0xb2 /dev/sdb Logical block provisioning VPD page (SBC): Unmap command supported (LBPU): 1 Write same (16) with unmap bit supported (LBWS): 1 Write same (10) with unmap bit supported (LBWS10): 0 # mke2fs /dev/sdb # cat /sys/bus/pseudo/drivers/scsi_debug/map 1-616,16257-16383 # mount /dev/sdb /run/media/pbonzini/test # dd if=/dev/zero of=/run/media/pbonzini/test/file # cat map 1-616,645-1588,1599-4026,4029-16383 # rm /run/media/pbonzini/test/file # ./qemu-ga /dev/fd/0 {"execute":"guest-fstrim"} {"return": {}} # cat map 1-612 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2012-06-21qemu-ga: make names more generic for mount list functionsPaolo Bonzini
We will use these functions and types for more than FSFREEZE, so rename them. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2012-05-29qemu-ga: avoid blocking on atime update when reading /etc/mtabMichael Roth
Currently we re-read/re-process /etc/mtab to get an updated list of mounts when guest-fsfreeze-thaw is called. This can cause an atime update on /etc/mtab, which will block if we're in a frozen state. Instead, use /proc's version of mtab, which may not be up-to-date with options passed via -o remount, but is compatible for our use cases since we only care about the filesystem type. Reported-by: Matsuda, Daiki <matsudadik@intellilink.co.jp> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2012-05-29qemu-ga: Fix use of environ on DarwinAndreas Färber
Use _NSGetEnviron() helper to access the environment. Signed-off-by: Andreas Färber <andreas.faerber@web.de> Cc: Charlie Somerville <charlie@charliesomerville.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2012-05-24qemu-ga: Fix missing environ declarationLuiz Capitulino
Commit 3674838cd05268954bb6473239cd7f700a79bf0f uses the environ global variable, but is relying on environ to be declared somewhere else. This worked for me because on F16 environ is declared in <unistd.h>, but that doesn't happen in OpenBSD for example, causing a build failure. This commit fixes the build error by declaring environ if it hasn't being declared yet. Also fixes a build warning due to a missing <sys/wait.h> include. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2012-05-15qemu-ga: guest-shutdown: use only async-signal-safe functionsLuiz Capitulino
POSIX mandates[1] that a child process of a multi-thread program uses only async-signal-safe functions before exec(). We consider qemu-ga to be multi-thread, because it uses glib. However, qmp_guest_shutdown() uses functions that are not async-signal-safe. Fix it the following way: - fclose() -> reopen_fd_to_null() - execl() -> execle() - exit() -> _exit() - drop slog() usage (which is not safe) [1] http://pubs.opengroup.org/onlinepubs/009695399/functions/fork.html Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2012-05-15qemu-ga: guest-shutdown: become synchronousLuiz Capitulino
Last commit dropped qemu-ga's SIGCHLD handler, used to automatically reap terminated children processes. This introduced a bug to qmp_guest_shutdown(): it will generate zombies. This problem probably doesn't matter in the success case, as the VM will shutdown anyway, but let's do the right thing and reap the created process. This ultimately means that guest-shutdown is now a synchronous command. An interesting side effect is that guest-shutdown is now able to report an error to the client if shutting down fails. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2012-05-15qemu-ga: guest-suspend: make the API synchronousLuiz Capitulino
Currently, qemu-ga has a SIGCHLD handler that automatically reaps terminated children processes. The idea is to avoid having qemu-ga commands blocked waiting for children to terminate. That approach has two problems: 1. qemu-ga is unable to detect errors in the child, meaning that qemu-ga returns success even if the child fails to perform its task 2. if a command does depend on the child exit status, the command has to play tricks to bypass the automatic reaper Case 2 impacts the guest-suspend-* API, because it has to execute an external program to check for suspend support. Today, to bypass the automatic reaper, suspend code has to double fork and pass exit status information through a pipe. Besides being complex, this is prone to race condition bugs. Indeed, the current code does have such bugs. Making the guest-suspend-* API synchronous (ie. by dropping the SIGCHLD handler and calling waitpid() from commands) is a much simpler approach, which fixes current race conditions bugs and enables commands to detect errors in the child. This commit does just that. There's a side effect though, guest-shutdown will generate zombies if shutting down fails. This will be fixed by the next commit. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2012-05-15qemu-ga: make reopen_fd_to_null() publicLuiz Capitulino
The next commit wants to use it. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2012-05-14fix some common typosJim Meyering
These were identified using: http://github.com/lyda/misspell-check and run like this to create a bourne shell script using GNU sed's -i option: git ls-files|grep -vF .bin | misspellings -f - |grep -v '^ERROR:' |perl \ -pe 's/^(.*?)\[(\d+)\]: (\w+) -> "(.*?)"$/sed -i '\''${2}s!$3!$4!'\'' $1/' Manually eliding the FP, "rela->real" and resolving "addres" to address (not "adders") we get this: sed -i '450s!thru!through!' Changelog sed -i '260s!neccessary!necessary!' coroutine-sigaltstack.c sed -i '54s!miniscule!minuscule!' disas.c sed -i '1094s!thru!through!' hw/usb/hcd-ehci.c sed -i '1095s!thru!through!' hw/usb/hcd-ehci.c sed -i '21s!unecessary!unnecessary!' qapi-schema-guest.json sed -i '307s!explictly!explicitly!' qemu-ga.c sed -i '490s!preceeding!preceding!' qga/commands-posix.c sed -i '792s!addres!address!' qga/commands-posix.c sed -i '6s!beeing!being!' tests/tcg/test-mmap.c Also, manually fix "arithmentic", spotted by Peter Maydell: sed -i 's!arithmentic!arithmetic!' coroutine-sigaltstack.c Signed-off-by: Jim Meyering <meyering@redhat.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
2012-04-30qemu-ga: add a whitelist for fsfreeze-safe commandsMichael Roth
Currently we rely on fsfreeze/thaw commands disabling/enabling logging then having other commands check whether logging is disabled to avoid executing if they aren't safe for running while a filesystem is frozen. Instead, have an explicit whitelist of fsfreeze-safe commands, and consolidate logging and command enablement/disablement into a pair of helper functions: ga_set_frozen()/ga_unset_frozen() Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>