Commit Graph

95 Commits

Author SHA1 Message Date
Max Reitz f21492817b nbd: Follow the BDS' AIO context
Keep the NBD server always in the same AIO context as the exported BDS
by calling bdrv_add_aio_context_notifier() and implementing the required
callbacks.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-29 10:48:45 +01:00
Max Reitz 958c717df9 nbd: Drop nbd_can_read()
There is no variant of aio_set_fd_handler() like qemu_set_fd_handler2(),
so we cannot give a can_read() callback function. Instead, unregister
the nbd_read() function whenever we cannot read and re-register it as
soon as we can read again.

All this is hidden behind the functions nbd_set_handlers() (which
registers all handlers for the AIO context and file descriptor belonging
to the given client), nbd_unset_handlers() (which unregisters them) and
nbd_update_can_read() (which checks whether NBD can read for the given
client and acts accordingly).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-29 10:48:45 +01:00
Paolo Bonzini 79d9b6566b qemu-coroutine-io: fix for Win32
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-29 10:46:58 +01:00
Hani Benhabiles 32d7d2e068 nbd: Handle NBD_OPT_LIST option.
Signed-off-by: Hani Benhabiles <kroosec@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-30 12:50:17 +02:00
Hani Benhabiles f5076b5a75 nbd: Handle fixed new-style clients.
When this flag is set, the server tells the client that it can send another
option if the server received a request with an option that it doesn't
understand instead of directly closing the connection.

Also add link to the most up-to-date documentation.

Signed-off-by: Hani Benhabiles <kroosec@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-30 12:50:17 +02:00
Hani Benhabiles 8c5d1abbb7 nbd: Don't validate from and len in NBD_CMD_DISC.
These values aren't used in this case.

Currently, the from field in the request sent by the nbd kernel module leading
to a false error message when ending the connection with the client.

$ qemu-nbd some.img -v
// After nbd-client -d /dev/nbd0
nbd.c:nbd_trip():L1031: From: 18446744073709551104, Len: 0, Size: 20971520,
Offset: 0
nbd.c:nbd_trip():L1032: requested operation past EOF--bad client?
nbd.c:nbd_receive_request():L638: read failed

Signed-off-by: Hani Benhabiles <kroosec@gmail.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-27 16:06:48 +02:00
Hani Benhabiles 5672ee54d5 nbd: Miscellaneous typo fixes.
Signed-off-by: Hani Benhabiles <hani@linux.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2014-05-24 00:07:29 +04:00
Paolo Bonzini 537b41f501 nbd: move socket wrappers to qemu-nbd
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>
2014-02-21 21:02:23 +01:00
Paolo Bonzini c06b72781d nbd: inline tcp_socket_incoming_spec into sole caller
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-02-21 21:02:22 +01:00
Paolo Bonzini 77e8b9ca64 nbd: correctly propagate errors
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>
2014-02-21 21:02:22 +01:00
Marc-André Lureau e53a18e488 nbd: don't change socket block during negotiate
The caller might handle non-blocking using coroutine. Leave the choice
to the caller to use a blocking or non-blocking negotiate.

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>
2013-12-16 10:12:20 +01:00
Fam Zheng 38b54b6dc1 nbd: use BlockDriverState refcnt
Previously, nbd calls drive_get_ref() on the drive of bs. A BDS doesn't
always have associated dinfo, which nbd doesn't care either. We already
have BDS ref count, so use it to make it safe for a BDS w/o blockdev.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-06 15:25:08 +02:00
Alex Bligh 6a1751b7aa aio / timers: Untangle include files
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>
2013-08-22 19:10:27 +02:00
Stefan Hajnoczi 2d82148859 nbd: support large NBD requests
The Linux nbd driver recently increased the maximum supported request
size up to 32 MB:

  commit 078be02b80359a541928c899c2631f39628f56df
  Author: Michal Belczyk <belczyk@bsd.krakow.pl>
  Date:   Tue Apr 30 15:28:28 2013 -0700

      nbd: increase default and max request sizes

      Raise the default max request size for nbd to 128KB (from 127KB) to get it
      4KB aligned.  This patch also allows the max request size to be increased
      (via /sys/block/nbd<x>/queue/max_sectors_kb) to 32MB.

QEMU's 1 MB buffers are too small to handle these requests.

This patch allocates data buffers dynamically and allows up to 32 MB per
request.

Reported-by: Nick Thomas <nick@bytemark.co.uk>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-05-03 13:05:49 +02:00
Stefan Hajnoczi e1adb27a83 nbd: use g_slice_new() instead of a freelist
Use GLib's efficient slice allocator instead of open-coding the request
freelist.  This patch simplifies the NBDRequest code.

Now we qemu_blockalign() the req->data buffer each time but the next
patch switches from a fixed size buffer to a dynamic size anyway.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-05-03 13:05:49 +02:00
Stefan Hajnoczi f9e8cacc55 oslib-posix: rename socket_set_nonblock() to qemu_set_nonblock()
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>
2013-04-02 11:47:37 -04:00
Kevin Wolf 197a4859b9 nbd: Remove unused functions
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2013-03-22 17:51:32 +01:00
Kevin Wolf f17c90bed1 nbd: Keep hostname and port separate
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>
2013-03-22 17:51:31 +01:00
Paolo Bonzini 1de7afc984 misc: move include files to include/qemu/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:32:39 +01:00
Paolo Bonzini 737e150e89 block: move include files to include/block/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:31:31 +01:00
Paolo Bonzini 8ffaaba0e9 nbd: fix use of two uninitialized bytes when connecting to a named export
Reported-by: Michal Privoznik <mprivoznik@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-11-28 11:56:35 +01:00
Paolo Bonzini c8969eded2 nbd: fixes to read-only handling
We do not need BLKROSET if the kernel supports setting flags.
Also, always do BLKROSET even for a read-write export, otherwise
the read-only state remains "sticky" after the invocation of
"qemu-nbd -r".

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-11-13 10:34:50 +01:00
Paolo Bonzini f8430e7621 nbd: ask and print error information from qemu-sockets
Before:

    $ qemu-system-x86_64 nbd:localhost:12345
    inet_connect_opts: connect(ipv4,yakj.usersys.redhat.com,127.0.0.1,12345): Connection refused
    qemu-system-x86_64: could not open disk image nbd:localhost:12345: Connection refused

After:

    $ x86_64-softmmu/qemu-system-x86_64 nbd:localhost:12345
    qemu-system-x86_64: Failed to connect to socket: Connection refused
    qemu-system-x86_64: could not open disk image nbd:localhost:12345: Connection refused

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-10-23 13:54:56 +02:00
Paolo Bonzini 7fc4e63ec0 qemu-sockets: add Error ** to all functions
This lets me adjust the clients to do proper error propagation first,
thus avoiding temporary regressions in the quality of the error messages.

Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-10-23 13:54:55 +02:00
Orit Wasserman 5db5f44cb4 Separate inet_connect into inet_connect (blocking) and inet_nonblocking_connect
No need to add non blocking parameters to the blocking inet_connect
add block parameter for inet_connect_opts instead of using QemuOpt "block".

Signed-off-by: Orit Wasserman <owasserm@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-09-25 19:05:55 -05:00
Paolo Bonzini 125afda8cb nbd: add nbd_export_get_blockdev
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-09-19 15:26:31 +02:00
Paolo Bonzini 6b8c01e781 nbd: negotiate with named exports
Allow negotiation to receive the name of the requested export from
the client.  Passing a NULL export to nbd_client_new will cause
the server to send the extended negotiation header.  The exp field
is then filled during negotiation.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-09-19 15:26:30 +02:00
Paolo Bonzini ee0a19ec2a nbd: register named exports
Add an API to register and find named exports.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-09-19 15:26:30 +02:00
Paolo Bonzini 0ddf08db22 nbd: add notification for closing an NBDExport
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>
2012-09-19 15:26:29 +02:00
Paolo Bonzini 4b9441f6b3 nbd: track clients into NBDExport
Track the NBDClients of each NBDExport, and use it to implement
nbd_export_close.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-09-19 15:26:29 +02:00
Paolo Bonzini 2c8d9f0655 nbd: add reference counting to NBDExport
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>
2012-09-19 15:26:28 +02:00
Paolo Bonzini ff2b68aa70 nbd: do not leak nbd_trip coroutines when a connection is torn down
Because nbd_client_close removes the I/O handlers for the client
socket, there is no way that any suspended coroutines are restarted.
This will be a problem with the QEMU embedded NBD server, because
we will have a QMP command to forcibly close all connections with
the clients.

Instead, we can exploit the reference counting of NBDClients; shutdown the
client socket, which will make it readable and writeable.  Also call the
close callback, which will release the user's reference.  The coroutines
then will fail and exit cleanly, and release all remaining references,
until the last refcount finally triggers the closure of the client.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-09-19 15:26:28 +02:00
Paolo Bonzini ce33967af7 nbd: make refcount interface public
After the next patch, the close callback will have to release its
reference.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-09-19 15:26:26 +02:00
Paolo Bonzini a4aab7b4cb nbd: do not close BlockDriverState in nbd_export_close
This is not desirable when embedding the NBD server inside QEMU.
Move the bdrv_close to qemu-nbd.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-09-19 15:26:15 +02:00
Paolo Bonzini 9a304d29a7 nbd: pass NBDClient to nbd_send_negotiate
We will need the NBDClient in nbd_send_negotiate to store the
export requested by the client.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-09-19 15:26:13 +02:00
Paolo Bonzini fa26c26b07 nbd: add more constants
Avoid magic numbers and magic size computations; hide them behind
constants.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-09-18 12:35:48 +02:00
Luiz Capitulino 02a08fef07 net: inet_connect(), inet_connect_opts(): add in_progress argument
It's used to indicate the special case where a valid file-descriptor
is returned (ie. success) but the connection can't be completed
w/o blocking.

This is needed because QERR_SOCKET_CONNECT_IN_PROGRESS is not
treated like an error and a future commit will drop it.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
2012-08-13 13:20:34 -03:00
Amos Kong 029409e5a9 sockets: use error class to pass listen error
Add a new argument in inet_listen()/inet_listen_opts()
to pass back listen error.

Change nbd, qemu-char, vnc to use new interface.

Signed-off-by: Amos Kong <akong@redhat.com>
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-05-10 12:37:57 -05:00
Amos Kong a6ba35b3be sockets: change inet_connect() to support nonblock socket
Add a bool argument to inet_connect() to assign if set socket
to block/nonblock, and delete original argument 'socktype'
that is unused.
Add a new argument to inet_connect()/inet_connect_opts(),
to pass back connect error by error class.

Retry to connect when -EINTR is got. Connect's successful
for nonblock socket when following errors are got, user
should wait for connecting by select():
  -EINPROGRESS
  -EWOULDBLOCK (win32)
  -WSAEALREADY (win32)

Change nbd, vnc to use new interface.

Signed-off-by: Amos Kong <akong@redhat.com>
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-05-10 12:37:57 -05:00
Paolo Bonzini e25ceb76e5 nbd: obey FUA on reads
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-04-19 17:19:37 +02:00
Paolo Bonzini 38ceff0412 nbd: do not include block_int.h
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-04-19 17:19:37 +02:00
Paolo Bonzini 7fe7b68b32 nbd: do not block in nbd_wr_sync if no data at all is available
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>
2012-04-19 16:36:43 +02:00
Paolo Bonzini 185b43386a nbd: consistently return negative errno values
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>
2012-04-19 16:36:43 +02:00
Paolo Bonzini fc19f8a02e nbd: consistently check for <0 or >=0
This prepares for the following patch, which changes -1 return values
to negative errno.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-04-19 16:36:43 +02:00
Paolo Bonzini 94e7340b5d nbd: consistently use ssize_t
GCC (pedantically, but correctly) considers that a negative ssize_t may
become positive when casted to int.  This may cause uninitialized variable
warnings when a function returns such a negative ssize_t and is inlined.
Propagate ssize_t return types to avoid this.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-04-19 16:36:43 +02:00
Stefan Weil 0fee8f3428 nbd: Fix compiler warning (w64)
Portable printing of dev_offset (data type off_t) needs a type cast.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
2012-04-15 21:25:18 +02:00
Paolo Bonzini 41996e3803 qemu-nbd: throttle requests
Limiting the number of in-flight requests is implemented very simply
with a can_read callback.  It does not require a semaphore, unlike the
client side in block/nbd.c, because we can throttle directly the creation
of coroutines.  The client side can have a coroutine created at any time
when an I/O request is made.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-12-22 11:53:59 +01:00
Paolo Bonzini 262db38871 qemu-nbd: asynchronous operation
Using coroutines enable asynchronous operation on both the network and
the block side.  Network can be owned by two coroutines at the same time,
one writing and one reading.  On the send side, mutual exclusion is
guaranteed by a CoMutex.  On the receive side, mutual exclusion is
guaranteed because new coroutines immediately start receiving data,
and no new coroutines are created as long as the previous one is receiving.

Between receive and send, qemu-nbd can have an arbitrary number of
in-flight block transfers.  Throttling is implemented by the next
patch.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-12-22 11:53:59 +01:00
Paolo Bonzini 72deddc5e6 qemu-nbd: add client pointer to NBDRequest
By attaching a client to an NBDRequest, we can avoid passing around the
socket descriptor and data buffer.

Also, we can now manage the reference count for the client in
nbd_request_get/put request instead of having to do it ourselved in
nbd_read.  This simplifies things when coroutines are used.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-12-22 11:53:59 +01:00
Paolo Bonzini 1743b51586 qemu-nbd: move client handling to nbd.c
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>
2011-12-22 11:53:59 +01:00