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2016-07-20nbd: Convert to byte-based interfaceEric Blake1-13/+17
The NBD protocol doesn't have any notion of sectors, so it is a fairly easy conversion to use byte-based read and write. Signed-off-by: Eric Blake <eblake@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1468624988-423-19-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20nbd: Switch .bdrv_co_discard() to byte-basedEric Blake1-5/+6
Another step towards killing off sector-based block APIs. While at it, call directly into nbd-client.c instead of having a pointless trivial wrapper in nbd.c. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1468624988-423-14-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20nbd: Drop unused offset parameterEric Blake1-15/+16
Now that NBD relies on the block layer to fragment things, we no longer need to track an offset argument for which fragment of a request we are actually servicing. While at it, use true and false instead of 0 and 1 for a bool parameter. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1468607524-19021-6-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20nbd: Rely on block layer to break up large requestsEric Blake1-43/+8
Now that the block layer will honor max_transfer, we can simplify our code to rely on that guarantee. The readv code can call directly into nbd-client, just as the writev code has done since commit 52a4650. Interestingly enough, while qemu-io 'w 0 40m' splits into a 32M and 8M transaction, 'w -z 0 40m' splits into two 16M and an 8M, because the block layer caps the bounce buffer for writing zeroes at 16M. When we later introduce support for NBD_CMD_WRITE_ZEROES, we can get a full 32M zero write (or larger, if the client and server negotiate that write zeroes can use a larger size than ordinary writes). Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1468607524-19021-5-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-13coroutine: move entry argument to qemu_coroutine_createPaolo Bonzini1-3/+3
In practice the entry argument is always known at creation time, and it is confusing that sometimes qemu_coroutine_enter is used with a non-NULL argument to re-enter a coroutine (this happens in block/sheepdog.c and tests/test-coroutine.c). So pass the opaque value at creation time, for consistency with e.g. aio_bh_new. Mostly done with the following semantic patch: @ entry1 @ expression entry, arg, co; @@ - co = qemu_coroutine_create(entry); + co = qemu_coroutine_create(entry, arg); ... - qemu_coroutine_enter(co, arg); + qemu_coroutine_enter(co); @ entry2 @ expression entry, arg; identifier co; @@ - Coroutine *co = qemu_coroutine_create(entry); + Coroutine *co = qemu_coroutine_create(entry, arg); ... - qemu_coroutine_enter(co, arg); + qemu_coroutine_enter(co); @ entry3 @ expression entry, arg; @@ - qemu_coroutine_enter(qemu_coroutine_create(entry), arg); + qemu_coroutine_enter(qemu_coroutine_create(entry, arg)); @ reentry @ expression co; @@ - qemu_coroutine_enter(co, NULL); + qemu_coroutine_enter(co); except for the aforementioned few places where the semantic patch stumbled (as expected) and for test_co_queue, which would otherwise produce an uninitialized variable warning. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05nbd: Allow larger requestsEric Blake1-4/+0
The NBD layer was breaking up request at a limit of 2040 sectors (just under 1M) to cater to old qemu-nbd. But the server limit was raised to 32M in commit 2d8214885 to match the kernel, more than three years ago; and the upstream NBD Protocol is proposing documentation that without any explicit communication to state otherwise, a client should be able to safely assume that a 32M transaction will work. It is time to rely on the larger sizing, and any downstream distro that cares about maximum interoperability to older qemu-nbd servers can just tweak the value of #define NBD_MAX_SECTORS. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: qemu-stable@nongnu.org Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12nbd: Simplify client FUA handlingEric Blake1-4/+4
Now that the block layer honors per-bds FUA support, we don't have to duplicate the fallback flush at the NBD layer. The static function nbd_co_writev_flags() is no longer needed, and the driver can just directly use nbd_client_co_writev(). Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12block: Make supported_write_flags a per-bds propertyEric Blake1-0/+3
Pre-patch, .supported_write_flags lives at the driver level, which means we are blindly declaring that all block devices using a given driver will either equally support FUA, or that we need a fallback at the block layer. But there are drivers where FUA support is a per-block decision: the NBD block driver is dependent on the remote server advertising NBD_FLAG_SEND_FUA (and has fallback code to duplicate the flush that the block layer would do if NBD had not set .supported_write_flags); and the iscsi block driver is dependent on the mode sense bits advertised by the underlying device (and is currently silently ignoring FUA requests if the underlying device does not support FUA). The fix is to make supported flags as a per-BDS option, set during .bdrv_open(). This patch moves the variable and fixes NBD and iscsi to set it only conditionally; later patches will then further simplify the NBD driver to quit duplicating work done at the block layer, as well as tackle the fact that SCSI does not support FUA semantics on WRITESAME(10/16) but only on WRITE(10/16). Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-04-05nbd: don't request FUA on FLUSHEric Blake1-4/+0
The NBD protocol does not clearly document what will happen if a client sends NBD_CMD_FLAG_FUA on NBD_CMD_FLUSH. Historically, both the qemu and upstream NBD servers silently ignored that flag, but that feels a bit risky. Meanwhile, the qemu NBD client unconditionally sends the flag (without even bothering to check whether the caller cares; at least with NBD_CMD_WRITE the client only sends FUA if requested by a higher layer). There is ongoing discussion on the NBD list to fix the protocol documentation to require that the server MUST ignore the flag (unless the kernel folks can better explain what FUA means for a flush), but until those doc improvements land, the current nbd.git master was recently changed to reject the flag with EINVAL (see nbd commit ab22e082), which now makes it impossible for a qemu client to use FLUSH with an upstream NBD server. We should not send FUA with flush unless the upstream protocol documents what it will do, and even then, it should be something that the caller can opt into, rather than being unconditional. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1459526902-32561-1-git-send-email-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-30nbd: Support BDRV_REQ_FUAKevin Wolf1-6/+7
The NBD server already used to send a FUA flag when the writethrough mode was set. This code was a remnant from the times where protocol drivers actually had to implement writethrough modes. Since nowadays the block layer sends flushes in writethrough mode and non-root nodes are always writeback, this was mostly dead code - only mostly because if NBD was configured to be used without a format, we sent _both_ FUA and an explicit flush afterwards, which makes the code not technically dead, but useless overhead. This patch changes the code so that the block layer's FUA flag is recognised and translated into a NBD FUA flag. The additional flush is avoided now. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-02-16nbd: enable use of TLS with NBD block driverDaniel P. Berrange1-3/+7
This modifies the NBD driver so that it is possible to request use of TLS. This is done by providing the 'tls-creds' parameter with the ID of a previously created QCryptoTLSCreds object. For example $QEMU -object tls-creds-x509,id=tls0,endpoint=client,\ dir=/home/berrange/security/qemutls \ -drive driver=nbd,host=localhost,port=9000,tls-creds=tls0 The client will drop the connection if the NBD server does not provide TLS. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-Id: <1455129674-17255-15-git-send-email-berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16nbd: implement TLS support in the protocol negotiationDaniel P. Berrange1-3/+9
This extends the NBD protocol handling code so that it is capable of negotiating TLS support during the connection setup. This involves requesting the STARTTLS protocol option before any other NBD options. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-Id: <1455129674-17255-14-git-send-email-berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16nbd: convert to using I/O channels for actual socket I/ODaniel P. Berrange1-9/+10
Now that all callers are converted to use I/O channels for initial connection setup, it is possible to switch the core NBD protocol handling core over to use QIOChannel APIs for actual sockets I/O. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-Id: <1455129674-17255-7-git-send-email-berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16nbd: convert block client to use I/O channels for connection setupDaniel P. Berrange1-29/+47
This converts the NBD block driver client to use the QIOChannelSocket class for initial connection setup. The NbdClientSession struct has two pointers, one to the master QIOChannelSocket providing the raw data channel, and one to a QIOChannel which is the current channel used for I/O. Initially the two point to the same object, but when TLS support is added, they will point to different objects. The qemu-img & qemu-io tools now need to use MODULE_INIT_QOM to ensure the QIOChannel object classes are registered. The qemu-nbd tool already did this. In this initial conversion though, all I/O is still actually done using the raw POSIX sockets APIs. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-Id: <1455129674-17255-4-git-send-email-berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-01-20block: Clean up includesPeter Maydell1-0/+1
Clean up includes so that osdep.h is included first and headers which it implies are not included manually. This commit was created with scripts/clean-includes. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-10-23aio: Add "is_external" flag for event handlersFam Zheng1-4/+6
All callers pass in false, and the real external ones will switch to true in coming patches. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-03-18nbd: Set block size to BDRV_SECTOR_SIZEMax Reitz1-2/+1
Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <1424887718-10800-13-git-send-email-mreitz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-16nbd: fix the co_queue multi-adding bugBin Wu1-12/+13
When we tested the VM migartion between different hosts with NBD devices, we found if we sent a cancel command after the drive_mirror was just started, a coroutine re-enter error would occur. The stack was as follow: (gdb) bt 00) 0x00007fdfc744d885 in raise () from /lib64/libc.so.6 01) 0x00007fdfc744ee61 in abort () from /lib64/libc.so.6 02) 0x00007fdfca467cc5 in qemu_coroutine_enter (co=0x7fdfcaedb400, opaque=0x0) at qemu-coroutine.c:118 03) 0x00007fdfca467f6c in qemu_co_queue_run_restart (co=0x7fdfcaedb400) at qemu-coroutine-lock.c:59 04) 0x00007fdfca467be5 in coroutine_swap (from=0x7fdfcaf3c4e8, to=0x7fdfcaedb400) at qemu-coroutine.c:96 05) 0x00007fdfca467cea in qemu_coroutine_enter (co=0x7fdfcaedb400, opaque=0x0) at qemu-coroutine.c:123 06) 0x00007fdfca467f6c in qemu_co_queue_run_restart (co=0x7fdfcaedbdc0) at qemu-coroutine-lock.c:59 07) 0x00007fdfca467be5 in coroutine_swap (from=0x7fdfcaf3c4e8, to=0x7fdfcaedbdc0) at qemu-coroutine.c:96 08) 0x00007fdfca467cea in qemu_coroutine_enter (co=0x7fdfcaedbdc0, opaque=0x0) at qemu-coroutine.c:123 09) 0x00007fdfca4a1fa4 in nbd_recv_coroutines_enter_all (s=0x7fdfcaef7dd0) at block/nbd-client.c:41 10) 0x00007fdfca4a1ff9 in nbd_teardown_connection (client=0x7fdfcaef7dd0) at block/nbd-client.c:50 11) 0x00007fdfca4a20f0 in nbd_reply_ready (opaque=0x7fdfcaef7dd0) at block/nbd-client.c:92 12) 0x00007fdfca45ed80 in aio_dispatch (ctx=0x7fdfcae15e90) at aio-posix.c:144 13) 0x00007fdfca45ef1b in aio_poll (ctx=0x7fdfcae15e90, blocking=false) at aio-posix.c:222 14) 0x00007fdfca448c34 in aio_ctx_dispatch (source=0x7fdfcae15e90, callback=0x0, user_data=0x0) at async.c:212 15) 0x00007fdfc8f2f69a in g_main_context_dispatch () from /usr/lib64/libglib-2.0.so.0 16) 0x00007fdfca45c391 in glib_pollfds_poll () at main-loop.c:190 17) 0x00007fdfca45c489 in os_host_main_loop_wait (timeout=1483677098) at main-loop.c:235 18) 0x00007fdfca45c57b in main_loop_wait (nonblocking=0) at main-loop.c:484 19) 0x00007fdfca25f403 in main_loop () at vl.c:2249 20) 0x00007fdfca266fc2 in main (argc=42, argv=0x7ffff517d638, envp=0x7ffff517d790) at vl.c:4814 We find the nbd_recv_coroutines_enter_all function (triggered by a cancel command or a network connection breaking down) will enter a coroutine which is waiting for the sending lock. If the lock is still held by another coroutine, the entering coroutine will be added into the co_queue again. Latter, when the lock is released, a coroutine re-enter error will occur. This bug can be fixed simply by delaying the setting of recv_coroutine as suggested by paolo. After applying this patch, we have tested the cancel operation in mirror phase looply for more than 5 hous and everything is fine. Without this patch, a coroutine re-enter error will occur in 5 minutes. Signed-off-by: Bn Wu <wu.wubin@huawei.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1423552846-3896-1-git-send-email-wu.wubin@huawei.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-02-16nbd: Drop BDS backpointerMax Reitz1-49/+52
Before this patch, the "opaque" pointer in an NBD BDS points to a BDRVNBDState, which contains an NbdClientSession object, which in turn contains a pointer to the BDS. This pointer may become invalid due to bdrv_swap(), so drop it, and instead pass the BDS directly to the nbd-client.c functions which then retrieve the NbdClientSession object from there. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1423256778-3340-2-git-send-email-mreitz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-02-06nbd: Improve error messagesMax Reitz1-2/+2
This patch makes use of the Error object for nbd_receive_negotiate() so that errors during negotiation look nicer. Furthermore, this patch adds an additional error message if the received magic was wrong, but would be correct for the other protocol version, respectively: So if an export name was specified, but the NBD server magic corresponds to an old handshake, this condition is explicitly signaled to the user, and vice versa. As these messages are now part of the "Could not open image" error message, additional filtering has to be employed in iotest 083, which this patch does as well. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-06-04nbd: implement .bdrv_detach/attach_aio_context()Stefan Hajnoczi1-4/+20
Drop the assumption that we're using the main AioContext. Convert qemu_aio_set_fd_handler() calls to aio_set_fd_handler(). The .bdrv_detach/attach_aio_context() interfaces also need to be implemented to move the socket fd handler from the old to the new AioContext. Acked-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-14nbd: close socket if connection breaksStefan Hajnoczi1-15/+18
nbd_receive_reply() is called by the event loop whenever data is available or the socket has been closed by the remote side. This patch closes the socket when an error occurs to prevent the nbd_receive_reply() handler from being called indefinitely after the connection has failed. Note that we were already correctly returning EIO for pending requests but leaving the nbd_receive_reply() handler registered resulted in high CPU consumption and a flood of error messages. Reuse nbd_teardown_connection() to close the socket. Reported-by: Zhifeng Cai <bluewindow@h3c.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-12-16nbd: avoid uninitialized warningsMarc-André Lureau1-12/+9
==15815== Thread 1: ==15815== Syscall param socketcall.sendto(msg) points to uninitialised byte(s) ==15815== at 0x65AD5CB: send (send.c:31) ==15815== by 0x37F84B: nbd_wr_sync (nbd.c:145) ==15815== by 0x37F94B: write_sync (nbd.c:186) ==15815== by 0x380FA9: nbd_send_request (nbd.c:681) ==15815== by 0x1C4A2D: nbd_teardown_connection (nbd-client.c:337) ==15815== by 0x1C4AD8: nbd_client_session_close (nbd-client.c:354) ==15815== by 0x1ED2D8: close_socketpair (spicebd.c:132) ==15815== by 0x1EE265: spice_close (spicebd.c:457) ==15815== by 0x1ACBF6: bdrv_close (block.c:1519) ==15815== by 0x1AD804: bdrv_delete (block.c:1772) ==15815== by 0x1B4136: bdrv_unref (block.c:4476) ==15815== by 0x1ACCE0: bdrv_close (block.c:1541) ==15815== Address 0x7feffef98 is on thread 1's stack Signed-off-by: Marc-André Lureau <marcandre.lureau@gmail.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2013-12-16nbd: finish any pending coroutineMarc-André Lureau1-5/+16
Make sure all pending coroutines are finished when closing the session. Signed-off-by: Marc-André Lureau <marcandre.lureau@gmail.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2013-12-16nbd: make nbd_client_session_close() idempotentMarc-André Lureau1-0/+5
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>
2013-12-16nbd: pass export name as init argumentMarc-André Lureau1-5/+4
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>
2013-12-16nbd: don't change socket block during negotiateMarc-André Lureau1-0/+1
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>
2013-12-16Split nbd block client codeMarc-André Lureau1-0/+372
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>
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