Event-driven programs want to wait until the xs_fileno triggers for
reading, and then repeatedly call xs_check_watch.
Also xs_read_watch exposes a useless "num" out parameter, which should
always (if things aren't going hideously wrong) be at least 2 and
which the caller shouldn't be interested in. So xs_check_watch
doesn't have one of those.
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
In order to read keys from xenstore, the xenstore libraries need to
write the request to the xenbus socket. This means that the socket
cannot be opened read-only.
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
Create two new variables called APPEND_ and PREPEND_ to add compile
flags at the beginning or at the end of the search path.
Added a new semantic for user defined compile flags, here is the list
of possible options:
PREPEND_LIB: add libraries to the search path before xen
(before xen installation folders).
PREPEND_INCLUDES: add headers to the search path before xen
(before xen installation folders).
APPEND_LIB: add libraries to the search path at the end
(after all xen installation folders have been added).
APPEND_INCLUDES: add libraries to the search path at the end
(after all xen installation folders have been added).
EXTRA_INCLUDES and EXTRA_LIB can still be used, and they will have the
same effect as PREPEND_INCLUDES and PREPEND_LIB.
Signed-off-by: Roger Pau Monne <roger.pau@entel.upc.edu>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
When a message with zero length is sent to xenstore, the body of the
message was not processed until the socket or ring had more data to
read; this will cause deadlocks if the requestor is waiting on a
response to continue.
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
During kexec all old watches have to be removed, otherwise the new
kernel will receive unexpected events. Allow a guest to reset itself
and cleanup all of its watches and transactions.
Add a new XS_RESET_WATCHES command to do the reset on behalf of the
guest.
(Changes by iwj: specify the argument to be a single nul byte. Permit
read-only clients to use the new command.)
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
This patch seems to have been applied by mistake, despite adverse
comments on the list and a lack of an appropriate ack.
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
During kexec all old watches have to be removed, otherwise the new
kernel will receive unexpected events. Allow a guest to introduce
itself
and cleanup all of its watches.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
hashtable.c has already been copied, forked and modified, there
doesn't seem much point in avoiding the same for the header until
someone feels motivated to properly refactor.
Add comments to the various duplicated files cross-referencing each
other for future reference and as a barrier to forking again...
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
Otherwise make can search the path relative to certain standard paths
such as /usr/include (e.g., the line '-include $(XEN_ROOT)/.config' in
Config.mk suffers from this).
Signed-off-by: Keir Fraser <keir@xen.org>
This makes the interface consistent with the changes made to the main
interface in 21483:779c0ef9682c.
Also fix some references to "struct xc_interface" which should have
been simply "xc_interface" in tools/xenpaging, and update QEMU_TAG to
pull in the corresponding qemu change.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
For now assume all such connections come from domain 0.
Failure to do this breaks various scripts which assume that they
operate relative to the domains "home directory".
This matches the behaviour of the ocaml xenstored.
Thanks to report from Olaf Hering.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
The "-s" option to xenstore-ls is used by the xencommons startup
script to check whether xenstored is already running, before starting
it.
Since 22498:a40455ae9ad3, "-s" has been a no-op, and libxenstore will
always fall back to using xenbus. The combined effect is that the
xencommons script deadlocks: xenstore-ls hangs waiting for xenstored,
which isn't started by xencommons because xencommons is waiting for
xenstore-ls.
In this patch, we:
* Introduce a new XS_OPEN_SOCKETONLY flag which disables the
fallback behaviour;
* Make the xenstore command line tools use the new xs_open call
rather than the old, deprecated xs_open_* calls (which are
now identical).
* Plumb the xenstore command line tools "-s" option to set the
XS_OPEN_SOCKETONLY flag.
* Change the type of the XS_OPEN_* flags so that they naturally have
type unsigned long.
The "-s" option to xenstore-ls et al, and the XS_OPEN_SOCKETONLY flag,
are intended for use by toolstack infrastructure and should not
normally be used by higher-level code.
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
# xenstore-watch x | while read w ; do
> echo "watch fired on $w"
> echo "value" $(xenstore-read $w)
> echo
> done
# xenstore-write x/y/z 42
output from while loop:
watch fired on x/t/z
value 42
[ also add line to .hgignore - iwj ]
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
If a multithreaded caller creates a thread which calls xs_read_watch,
before it has set any watches with xs_watch, the thread in
xs_read_watch will enter read_message and sit reading the xenstored fd
without the appropriate locks held. Other threads can then
concurrently read the xenstored fd, which naturally does not work very
well.
Symptoms of this bug which I have been able to reproduce include
failure of xend startup to finish, due to a deadlock; results could
also include reading corrupted data from xenstore.
In this patch we arrange for xs_read_watch to always rely on the
reader thread created by xs_watch. If no watches have been set, then
xs_read_watch will block until one has been. If the library is
compiled non-threaded xs_read_watch unconditionally does the reading
in the current thread.
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
The return value of read_message needs to be checked in order to avoid
waiting forever for a message if there is an error on the communication
channel with xenstore. Currently, this is only checked if USE_PTHREAD is
defined (by checking for read thread exit), and that path is prone to
deadlock if request_mutex is held while waiting.
Since the failure of read_message leaves the socket in an undefined
state, close the socket and force all threads waiting on a read to return.
This also fixes xs_read_watch in the case where a read thread is not
running (in particular, this will happen if !USE_PTHREAD) by having it
read from the communication channel in the same way as read_reply.
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Linker command lines are order-sensitive.
Move linker options -Lfoo -lfoo from LDFLAGS to LDLIBS and place this new
variable after the objects to link. This resolves build errors in xenpagin
and blktap with recent toolchains.
rename SHLIB_CFLAGS to SHLIB_LDFLAGS
rename LDFLAGS_* to LDLIBS_*
move LDFLAGS usage after CFLAGS in CC calls
remove stale comments in xenpaging Makefile
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
The OCaml xenstored supports the XS_RESTRICT operation, which
deprivileges a dom0 xenstore connection so it can only affect one
domain's entries. Add the relevant definitions to the C libraries
so that callers can use it.
Signed-off-by: Tim Deegan <Tim.Deegan@citrix.com>
This patch eliminate the global variables in libxenctrl (used for
logging and error reporting).
Instead the information which was in the global variables is now in a
new xc_interface* opaque structure, which xc_interface open returns
instead of the raw file descriptor; furthermore, logging is done via
xentoollog.
There are three new parameters to xc_interface_open to control the
logging, but existing callers can just pass "0" for all three to get
the old behaviour.
All libxc callers have been adjusted accordingly.
Also update QEMU_TAG for corresponding qemu change.
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Doing a pthread_cancel and join on the reader thread while holding all
the request/reply/watch mutexes can deadlock if the thread needs to
take any of those mutexes to exit. Kill off the reader thread before
taking any mutexes (which should be redundant if we're
single-threaded at that point).
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
If the read thread is terminated with pthread cancel, it must make
sure all memory is freed and mutexes are unlocked.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Provide a new function xs_daemon_destroy_postfork which can be called
by a libxenstore user who has called fork, to close the fd for the
connection to xenstored and free the memory, without trying to do
anything to any threads which libxenstore may have created.
Use this new function in libxl_fork, to avoid accidental use of a
xenstore connection in both parent and child.
Also, fix the doc comment for libxl_spawn_spawn to have the success
return codes the right way round.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Without this, gcc 4.5 complains with,
error: case value '3' not in enumerated type 'const enum xs_perm_type'
Signed-off-by: Charles Arnold <carnold@novell.com>
When option '-t' is used to do tidy remove, routine xs_directory()
will be called in order to check there are brother directories or not.
The returned pointer should be passed to free() after this check.
Signed-off-by: Yu Zhiguo <yuzg@cn.fujitsu.com>
Add long option '--flat' correspond to short option '-f',
and let it just can be used for subcommand 'ls' (because
in fact it's useless for subcommand 'read' and 'list').
And fix the usage of subcommands 'ls', 'list' and 'chmod'.
Signed-off-by: Yu Zhiguo <yuzg@cn.fujitsu.com>
To use, set CONFIG_OCAML_XENSTORED=y at build time.
Then the build system will automatically download the remote repo
to tools/ocaml-xenstored.
Signed-off-by: Alex Zeffertt <alex.zeffertt@eu.citrix.com>
Problem: Handling requests for one connection can not only zap the
connection itself, due to socket disconnects for example. It can also
zap *other* connections, due to domain release requests. Especially
it can zap the connection we have saved a pointer to in the "next"
variable.
From: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
If you use -MMD -MF then the correct .o filename is written to the
.*.d file as the compiler driver arranges everything. This was done
in 19010:275abe1c5d24 for the hypervisor.
In this patch we do the same elsewhere in the xen-unstable tree,
particularly tools/. Specifically:
* Change tools/Rules.mk to add -MMD -MF ... to CFLAGS and set DEPS.
* Remove -Wp,-MD... from every other Makefile
* Remove setting of DEPS from every other Makefile
* Ensure that every Makefile says -include $(DEPS)
* Ensure that every Makefile's clean target removes $(DEPS)
Some Makefiles were already halfway there, but often for a different
variable name eg PROG_DEP. The variable name is now standardised in
Rules.mk as DEPS.
I have done a test build with this change, on Debian etch.
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Attached patch uses calloc() for hash allocation.
This makes sure, the allocated memory is always initialized.
Also cleanup error handling a bit.
On *BSD avoid conflicts with BSD list macros.
Signed-off-by: Christoph Egger <Christoph.Egger@amd.com>
If a connection is dropped with pending input and output data then the
connection will be dereferenced by both handle_input and handle_output
resulting in a double free when the main loop dereferences the
connection.
Fix this issue by taking/releasing a reference over the calls to
handle_input and handle_output separately and checking the result of
talloc_free to see if the connection went away.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Ian Jackson
Daniel De Graaf
Roger Pau Monne
Olaf Hering
Ian Campbell
Juergen Gross
Keir Fraser
Stefano Stabellini
Keir Fraser