Commit Graph

15 Commits

Author SHA1 Message Date
Daniel P. Berrange 064097d919 nbd: convert block client to use I/O channels for connection setup
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>
2016-02-16 17:13:22 +01:00
Peter Maydell 80c71a241a block: Clean up includes
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>
2016-01-20 13:36:23 +01:00
Fam Zheng dca21ef23b aio: Add "is_external" flag for event handlers
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>
2015-10-23 18:18:23 +02:00
Max Reitz 3f4726596d nbd: Set block size to BDRV_SECTOR_SIZE
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>
2015-03-18 12:07:01 +01:00
Bin Wu 141cabe6f1 nbd: fix the co_queue multi-adding bug
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>
2015-02-16 15:07:17 +00:00
Max Reitz f53a829bb9 nbd: Drop BDS backpointer
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>
2015-02-16 14:36:03 +00:00
Max Reitz 1ce52846d3 nbd: Improve error messages
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>
2015-02-06 17:24:22 +01:00
Stefan Hajnoczi 69447cd8f3 nbd: implement .bdrv_detach/attach_aio_context()
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>
2014-06-04 09:56:11 +02:00
Stefan Hajnoczi 4a41a2d68a nbd: close socket if connection breaks
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>
2014-03-14 16:28:28 +01:00
Marc-André Lureau b1b27b6426 nbd: avoid uninitialized warnings
==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>
2013-12-16 10:12:20 +01:00
Marc-André Lureau 69152c09d3 nbd: finish any pending coroutine
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>
2013-12-16 10:12:20 +01:00
Marc-André Lureau 5ad283ebb8 nbd: make nbd_client_session_close() idempotent
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
Marc-André Lureau e2bc625f9b nbd: pass export name as init argument
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>
2013-12-16 10:12:20 +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
Marc-André Lureau 2302c1cafb Split nbd block client code
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