Using error_is_set(errp) to check whether a function call failed is
fragile: it breaks when errp is null. Check perfectly suitable return
values instead when possible. errp can't be null there now, but this
is more robust and more obviously correct
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Before:
$ ./qemu-io-old
qemu-io-old> open -r -o file.driver=nbd
one of path and host must be specified.
qemu-io-old: can't open device (null): Could not open image: Invalid argument
$ ./qemu-io-old
qemu-io-old> open -r -o file.driver=nbd,file.host=foo,file.path=bar
path and host may not be used at the same time.
qemu-io-old: can't open device (null): Could not open image: Invalid argument
After:
$ ./qemu-io
qemu-io> open -r -o file.driver=nbd
qemu-io: can't open device (null): one of path and host must be specified.
$ ./qemu-io
qemu-io> open -r -o file.driver=nbd,file.host=foo,file.path=bar
qemu-io: can't open device (null): path and host may not be used at the same time.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Before:
$ qemu-io-old
qemu-io-old> open -r -o file.driver=nbd
qemu-io-old: can't open device (null): Could not open image: Invalid argument
$ ./qemu-io-old
qemu-io-old> open -r -o file.driver=nbd,file.host=foo,file.path=bar
path and host may not be used at the same time.
qemu-io-old: can't open device (null): Could not open image: Invalid argument
After:
$ ./qemu-io
qemu-io> open -r -o file.driver=nbd
one of path and host must be specified.
qemu-io: can't open device (null): Could not open image: Invalid argument
$ ./qemu-io
qemu-io> open -r -o file.driver=nbd,file.host=foo,file.path=bar
path and host may not be used at the same time.
qemu-io: can't open device (null): Could not open image: Invalid argument
Next patch will fix the error propagation.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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>
This is a boiler-plate _nofail variant of qemu_opts_create. Remove and
use error_abort in call sites.
null/0 arguments needs to be added for the id and fail_if_exists fields
in affected callsites due to argument inconsistency between the normal and
no_fail variants.
Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
There is no need to keep the export name around, and it seems a better
fit as an argument in the init() call.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Add an Error ** parameter to BlockDriver.bdrv_open and
BlockDriver.bdrv_file_open to allow more specific error messages.
Signed-off-by: Max Reitz <mreitz@redhat.com>
The .io_flush() handler no longer exists and has no users. Drop the
io_flush argument to aio_set_fd_handler() and related functions.
The AioFlushEventNotifierHandler and AioFlushHandler typedefs are no
longer used and are dropped too.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
.io_flush() is no longer called so drop nbd_have_request(). We cannot
drop in_flight since it is still used by other block/nbd.c code.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Otherwise they would get passed to getaddrinfo and fail with:
address resolution failed for [::1]🔢 Name or service not known
(Broken by commit v1.4.0-736-gf17c90b)
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
# By Kevin Wolf (16) and Stefan Hajnoczi (4)
# Via Kevin Wolf
* kwolf/for-anthony:
qemu-iotests: add 053 unaligned compressed image size test
block: Allow overriding backing.file.filename
block: Remove filename parameter from .bdrv_file_open()
vvfat: Use bdrv_open options instead of filename
sheepdog: Use bdrv_open options instead of filename
rbd: Use bdrv_open options instead of filename
iscsi: Use bdrv_open options instead of filename
gluster: Use bdrv_open options instead of filename
curl: Use bdrv_open options instead of filename
blkverify: Use bdrv_open options instead of filename
blkdebug: Use bdrv_open options instead of filename
raw-win32: Use bdrv_open options instead of filename
raw-posix: Use bdrv_open options instead of filename
block: Enable filename option
block: Add driver-specific options for backing files
block: Fail gracefully when using a format driver on protocol level
qemu-iotests: Fix _filter_qemu
qemu-img: do not zero-pad the compressed write buffer
qcow: allow sub-cluster compressed write to last cluster
qcow2: allow sub-cluster compressed write to last cluster
Message-id: 1366630294-18984-1-git-send-email-kwolf@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Disable the Nagle algorithm to reduce latency. Note this means we must
also use TCP_CORK when sending header followed by payload to avoid
fragmenting lots of little packets. The previous patch took care of
that.
Suggested-by: Nick Thomas <nick@bytemark.co.uk>
Tested-by: Nick Thomas <nick@bytemark.co.uk>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use TCP_CORK to defer packet transmission until both the header and the
payload have been written.
Suggested-by: Nick Thomas <nick@bytemark.co.uk>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The fcntl(fd, F_SETFL, O_NONBLOCK) flag is not specific to sockets.
Rename to qemu_set_nonblock() just like qemu_set_cloexec().
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
A file name may only specified if no host or socket path is specified.
The latter two may not appear at the same time either.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
The URL method already takes care to apply the default port when none is
specfied. Directly specifying driver-specific options required the port
number until now. Allow leaving it out and apply the default.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
If a driver needs structured data and not just a string, it can provide
a .bdrv_parse_filename callback now that parses the command line string
into separate options. Keeping this separate from .bdrv_open_filename
ensures that the preferred way of directly specifying the options always
works as well if parsing the string works.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
The existing parsers for the file name now parse everything into the
bdrv_open() options QDict. Instead of using these parsers, you can now
directly specify the options on the command line, like this:
qemu-system-x86_64 -drive file=nbd:,file.port=1234,file.host=::1
Clearly the file=... part could use further improvement, but it's a
start.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
The NBD block supports an URL syntax, for which a URL parser returns
separate hostname and port fields. It also supports the traditional qemu
syntax encoded in a filename. Until now, after parsing the URL to get
each piece of information, a new string is built to be fed to socket
functions.
Instead of building a string in the URL case that is immediately parsed
again, parse the string in both cases and use the QemuOpts interface to
qemu-sockets.c.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
The URI syntax is consistent with the Gluster syntax. Export names
are specified in the path, preceded by one or more (otherwise unused)
slashes.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The same as for non-coroutine versions in previous
patches: rename arguments to be more obvious, change
type of arguments from int to size_t where appropriate,
and use common code for send and receive paths (with
one extra argument) since these are exactly the same.
Use common iov_send_recv() directly.
qemu_co_sendv(), qemu_co_recvv(), and qemu_co_recv()
are now trivial #define's merely adding one extra arg.
qemu_co_sendv() and qemu_co_recvv() callers are
converted to different argument order and extra
`iov_cnt' argument.
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
s->sock is assigned only afterwards, so we're really registering an
aio_fd_handler for file descriptor 0 here. Not exactly what we intended.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* kwolf/for-anthony: (38 commits)
qemu-iotests: Fix test 031 for qcow2 v3 support
qemu-iotests: Add -o and make v3 the default for qcow2
qcow2: Zero write support
qemu-iotests: Test backing file COW with zero clusters
qemu-iotests: add a simple test for write_zeroes
qcow2: Support for feature table header extension
qcow2: Support reading zero clusters
qcow2: Version 3 images
qcow2: Ignore reserved bits in check_refcounts
qcow2: Ignore reserved bits in refcount table entries
qcow2: Simplify count_cow_clusters
qcow2: Refactor qcow2_free_any_clusters
qcow2: Ignore reserved bits in L1/L2 entries
qcow2: Fail write_compressed when overwriting data
qcow2: Ignore reserved bits in count_contiguous_clusters()
qcow2: Ignore reserved bits in get_cluster_offset
qcow2: Save disk size in snapshot header
Specification for qcow2 version 3
qcow2: Fix refcount block allocation during qcow2_alloc_cluster_at()
iotests: Resolve test failures caused by hostname
...
Right now, nbd_wr_sync will hang if no data at all is available on the
socket and the other side is not going to provide any. Relax this by
making it loop only for writes or partial reads. This fixes a race
where one thread is executing qemu_aio_wait() and another is executing
main_loop_wait(). Then, the select() call in main_loop_wait() can return
stale data and call the "readable" callback with no data in the socket.
Reported-by: Laurent Vivier <laurent@vivier.eu>
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>
Allow sending up to 16 requests, and drive the replies to the coroutine
that did the request. The code is written to be exactly the same as
before this patch when MAX_NBD_REQUESTS == 1 (modulo the extra mutex
and state).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
qemu-nbd has a limit of slightly less than 1M per request. Work
around this in the nbd block driver.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Double semicolons should be single.
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
This does the first part of the conversion to coroutines, by
wrapping bdrv_write implementations to take the mutex.
Drivers that implement bdrv_write rather than bdrv_co_writev can
then benefit from asynchronous operation (at least if the underlying
protocol supports it, which is not the case for raw-win32), even
though they still operate with a bounce buffer.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This does the first part of the conversion to coroutines, by
wrapping bdrv_read implementations to take the mutex.
Drivers that implement bdrv_read rather than bdrv_co_readv can
then benefit from asynchronous operation (at least if the underlying
protocol supports it, which is not the case for raw-win32), even
though they still operate with a bounce buffer.
raw-win32 does not need the lock, because it cannot yield.
nbd also doesn't probably, but better be safe.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The big conversion of bdrv_read/write to coroutines caused the two
homonymous callbacks in BlockDriver to become reentrant. It goes
like this:
1) bdrv_read is now called in a coroutine, and calls bdrv_read or
bdrv_pread.
2) the nested bdrv_read goes through the fast path in bdrv_rw_co_entry;
3) in the common case when the protocol is file, bdrv_co_do_readv calls
bdrv_co_readv_em (and from here goes to bdrv_co_io_em), which yields
until the AIO operation is complete;
4) if bdrv_read had been called from a bottom half, the main loop
is free to iterate again: a device model or another bottom half
can then come and call bdrv_read again.
This applies to all four of read/write/flush/discard. It would also
apply to is_allocated, but it is not used from within coroutines:
besides qemu-img.c and qemu-io.c, which operate synchronously, the
only user is the monitor. Copy-on-read will introduce a use in the
block layer, and will require converting it.
The solution is "simply" to convert all drivers to coroutines! We
just need to add a CoMutex that is taken around affected operations.
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>
