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2012-11-13nbd: fixes to read-only handlingPaolo Bonzini
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>
2012-10-23nbd: ask and print error information from qemu-socketsPaolo Bonzini
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>
2012-10-23qemu-sockets: add Error ** to all functionsPaolo Bonzini
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>
2012-09-25Separate inet_connect into inet_connect (blocking) and inet_nonblocking_connectOrit Wasserman
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>
2012-09-19nbd: add nbd_export_get_blockdevPaolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-09-19nbd: negotiate with named exportsPaolo Bonzini
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>
2012-09-19nbd: register named exportsPaolo Bonzini
Add an API to register and find named exports. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-09-19nbd: add notification for closing an NBDExportPaolo Bonzini
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>
2012-09-19nbd: track clients into NBDExportPaolo Bonzini
Track the NBDClients of each NBDExport, and use it to implement nbd_export_close. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-09-19nbd: add reference counting to NBDExportPaolo Bonzini
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>
2012-09-19nbd: do not leak nbd_trip coroutines when a connection is torn downPaolo Bonzini
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>
2012-09-19nbd: make refcount interface publicPaolo Bonzini
After the next patch, the close callback will have to release its reference. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-09-19nbd: do not close BlockDriverState in nbd_export_closePaolo Bonzini
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>
2012-09-19nbd: pass NBDClient to nbd_send_negotiatePaolo Bonzini
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>
2012-09-18nbd: add more constantsPaolo Bonzini
Avoid magic numbers and magic size computations; hide them behind constants. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-08-13net: inet_connect(), inet_connect_opts(): add in_progress argumentLuiz Capitulino
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>
2012-05-10sockets: use error class to pass listen errorAmos Kong
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>
2012-05-10sockets: change inet_connect() to support nonblock socketAmos Kong
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>
2012-04-19nbd: obey FUA on readsPaolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-04-19nbd: do not include block_int.hPaolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-04-19nbd: do not block in nbd_wr_sync if no data at all is availablePaolo Bonzini
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>
2012-04-19nbd: consistently return negative errno valuesPaolo Bonzini
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>
2012-04-19nbd: consistently check for <0 or >=0Paolo Bonzini
This prepares for the following patch, which changes -1 return values to negative errno. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-04-19nbd: consistently use ssize_tPaolo Bonzini
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>
2012-04-15nbd: Fix compiler warning (w64)Stefan Weil
Portable printing of dev_offset (data type off_t) needs a type cast. Signed-off-by: Stefan Weil <sw@weilnetz.de>
2011-12-22qemu-nbd: throttle requestsPaolo Bonzini
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>
2011-12-22qemu-nbd: asynchronous operationPaolo Bonzini
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>
2011-12-22qemu-nbd: add client pointer to NBDRequestPaolo Bonzini
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>
2011-12-22qemu-nbd: move client handling to nbd.cPaolo Bonzini
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>
2011-12-22qemu-nbd: introduce NBDRequestPaolo Bonzini
Move the buffer from NBDExport to a new structure, so that it will be possible to have multiple in-flight requests for the same export (and for the same client too---we get that for free). Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-12-22qemu-nbd: introduce NBDExportPaolo Bonzini
Wrap the common parameters of nbd_trip and nbd_negotiate in a single opaque struct. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-12-22qemu-nbd: introduce nbd_do_receive_requestPaolo Bonzini
Group the receiving of a response and the associated data into a new function. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-12-22qemu-nbd: more robust handling of invalid requestsPaolo Bonzini
Fail invalid requests with EINVAL instead of dropping them into the void. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-12-22qemu-nbd: introduce nbd_do_send_replyPaolo Bonzini
Group the sending of a reply and the associated data into a new function. Without corking, the caller would be forced to leave 12 free bytes at the beginning of the data pointer. Not too ugly, but still ugly. :) Using nbd_do_send_reply everywhere will help when the routine will set up the write handler that re-enters the send coroutine. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-12-22qemu-nbd: simplify nbd_tripPaolo Bonzini
Use TCP_CORK to remove a violation of encapsulation, that would later require nbd_trip to know too much about an NBD reply. We could also switch to sendmsg (qemu_co_sendv) later, it is even easier once coroutines are in. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-12-22qemu-nbd: remove data_size argument to nbd_tripPaolo Bonzini
The size of the buffer is in practice part of the protocol. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-12-22qemu-nbd: remove offset argument to nbd_tripPaolo Bonzini
The argument is write-only. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-12-22Update ioctl order in nbd_init() to detect EBUSYChunyan Liu
Update ioctl(s) in nbd_init() to detect device busy early. Current nbd_init() issues NBD_CLEAR_SOCKET before NBD_SET_SOCKET, if issuing "qemu-nbd -c /dev/nbd0 disk.img" twice, the second time won't detect EBUSY in nbd_init(), but in nbd_client will report EBUSY and do clear socket (the 1st time command will be affacted too because of no socket any more.) No change to previous version. Signed-off-by: Chunyan Liu <cyliu@suse.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-12-22nbd: add support for NBD_CMD_TRIMPaolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-12-22nbd: add support for NBD_CMD_FLUSHPaolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-12-22nbd: add support for NBD_CMD_FLAG_FUAPaolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-12-22nbd: fix error handling in the serverPaolo Bonzini
bdrv_read and bdrv_write return negative errno values, not -1. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-12-22nbd: switch to asynchronous operationPaolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-12-02fix spelling in main directoryDong Xu Wang
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-11-11nbd: treat EPIPE from NBD_DO_IT as successPaolo Bonzini
This can be seen with "qemu-nbd -v -c", which returns 1 instead of 0 when you disconnect with "qemu-nbd -d". Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-21nbd: fix non-Linux build failurePaolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-19nbd: support NBD_SET_FLAGS ioctlPaolo Bonzini
The nbd kernel module cannot enable DISCARD requests unless it is informed about it. The flags field in the header is used for this, and this patch adds support for it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-19nbd: sync API definitions with upstreamPaolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-19nbd: support feature negotiationPaolo Bonzini
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>
2011-09-12nbd: Clean up use of block_int.hMarkus Armbruster
Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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