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2020-06-10block: Call attention to truncation of long NBD exportsEric Blake1-8/+13
Commit 93676c88 relaxed our NBD client code to request export names up to the NBD protocol maximum of 4096 bytes without NUL terminator, even though the block layer can't store anything longer than 4096 bytes including NUL terminator for display to the user. Since this means there are some export names where we have to truncate things, we can at least try to make the truncation a bit more obvious for the user. Note that in spite of the truncated display name, we can still communicate with an NBD server using such a long export name; this was deemed nicer than refusing to even connect to such a server (since the server may not be under our control, and since determining our actual length limits gets tricky when nbd://host:port/export and nbd+unix:///export?socket=/path are themselves variable-length expansions beyond the export name but count towards the block layer name length). Reported-by: Xueqiang Wei <xuwei@redhat.com> Fixes: https://bugzilla.redhat.com/1843684 Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20200610163741.3745251-3-eblake@redhat.com>
2020-05-04block/nbd-client: drop max_block restriction from discardVladimir Sementsov-Ogievskiy1-1/+1
The NBD spec was updated (see nbd.git commit 9f30fedb) so that max_block doesn't relate to NBD_CMD_TRIM. So, drop the restriction. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20200401150112.9557-3-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: tweak commit message to call out NBD commit] Signed-off-by: Eric Blake <eblake@redhat.com>
2020-05-04block/nbd-client: drop max_block restriction from block_statusVladimir Sementsov-Ogievskiy1-3/+1
The NBD spec was updated (see nbd.git commit 9f30fedb) so that max_block doesn't relate to NBD_CMD_BLOCK_STATUS. So, drop the restriction. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200401150112.9557-2-vsementsov@virtuozzo.com> [eblake: tweak commit message to call out NBD commit] Signed-off-by: Eric Blake <eblake@redhat.com>
2020-03-26block: trickle down the fallback image creation function use to the block ↵Maxim Levitsky1-0/+6
drivers Instead of checking the .bdrv_co_create_opts to see if we need the fallback, just implement the .bdrv_co_create_opts in the drivers that need it. This way we don't break various places that need to know if the underlying protocol/format really supports image creation, and this way we still allow some drivers to not support image creation. Fixes: fd17146cd93d1704cd96d7c2757b325fc7aac6fd Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1816007 Note that technically this driver reverts the image creation fallback for the vxhs driver since I don't have a means to test it, and IMHO it is better to leave it not supported as it was prior to generic image creation patches. Also drop iscsi_create_opts which was left accidentally. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20200326011218.29230-3-mlevitsk@redhat.com> Reviewed-by: Denis V. Lunev <den@openvz.org> [mreitz: Fixed alignment, and moved bdrv_co_create_opts_simple() and bdrv_create_opts_simple from block.h into block_int.h] Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-02-26block/nbd: fix memory leak in nbd_open()Pan Nengyuan1-0/+1
In currently implementation there will be a memory leak when nbd_client_connect() returns error status. Here is an easy way to reproduce: 1. run qemu-iotests as follow and check the result with asan: ./check -raw 143 Following is the asan output backtrack: Direct leak of 40 byte(s) in 1 object(s) allocated from: #0 0x7f629688a560 in calloc (/usr/lib64/libasan.so.3+0xc7560) #1 0x7f6295e7e015 in g_malloc0 (/usr/lib64/libglib-2.0.so.0+0x50015) #2 0x56281dab4642 in qobject_input_start_struct /mnt/sdb/qemu-4.2.0-rc0/qapi/qobject-input-visitor.c:295 #3 0x56281dab1a04 in visit_start_struct /mnt/sdb/qemu-4.2.0-rc0/qapi/qapi-visit-core.c:49 #4 0x56281dad1827 in visit_type_SocketAddress qapi/qapi-visit-sockets.c:386 #5 0x56281da8062f in nbd_config /mnt/sdb/qemu-4.2.0-rc0/block/nbd.c:1716 #6 0x56281da8062f in nbd_process_options /mnt/sdb/qemu-4.2.0-rc0/block/nbd.c:1829 #7 0x56281da8062f in nbd_open /mnt/sdb/qemu-4.2.0-rc0/block/nbd.c:1873 Direct leak of 15 byte(s) in 1 object(s) allocated from: #0 0x7f629688a3a0 in malloc (/usr/lib64/libasan.so.3+0xc73a0) #1 0x7f6295e7dfbd in g_malloc (/usr/lib64/libglib-2.0.so.0+0x4ffbd) #2 0x7f6295e96ace in g_strdup (/usr/lib64/libglib-2.0.so.0+0x68ace) #3 0x56281da804ac in nbd_process_options /mnt/sdb/qemu-4.2.0-rc0/block/nbd.c:1834 #4 0x56281da804ac in nbd_open /mnt/sdb/qemu-4.2.0-rc0/block/nbd.c:1873 Indirect leak of 24 byte(s) in 1 object(s) allocated from: #0 0x7f629688a3a0 in malloc (/usr/lib64/libasan.so.3+0xc73a0) #1 0x7f6295e7dfbd in g_malloc (/usr/lib64/libglib-2.0.so.0+0x4ffbd) #2 0x7f6295e96ace in g_strdup (/usr/lib64/libglib-2.0.so.0+0x68ace) #3 0x56281dab41a3 in qobject_input_type_str_keyval /mnt/sdb/qemu-4.2.0-rc0/qapi/qobject-input-visitor.c:536 #4 0x56281dab2ee9 in visit_type_str /mnt/sdb/qemu-4.2.0-rc0/qapi/qapi-visit-core.c:297 #5 0x56281dad0fa1 in visit_type_UnixSocketAddress_members qapi/qapi-visit-sockets.c:141 #6 0x56281dad17b6 in visit_type_SocketAddress_members qapi/qapi-visit-sockets.c:366 #7 0x56281dad186a in visit_type_SocketAddress qapi/qapi-visit-sockets.c:393 #8 0x56281da8062f in nbd_config /mnt/sdb/qemu-4.2.0-rc0/block/nbd.c:1716 #9 0x56281da8062f in nbd_process_options /mnt/sdb/qemu-4.2.0-rc0/block/nbd.c:1829 #10 0x56281da8062f in nbd_open /mnt/sdb/qemu-4.2.0-rc0/block/nbd.c:1873 Fixes: 8f071c9db506e03ab Reported-by: Euler Robot <euler.robot@huawei.com> Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Cc: qemu-stable <qemu-stable@nongnu.org> Cc: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <1575517528-44312-3-git-send-email-pannengyuan@huawei.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2020-02-26block/nbd: extract the common cleanup codePan Nengyuan1-11/+15
The BDRVNBDState cleanup code is common in two places, add nbd_clear_bdrvstate() function to do these cleanups. Suggested-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <1575517528-44312-2-git-send-email-pannengyuan@huawei.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: fix compilation error and commit message] Signed-off-by: Eric Blake <eblake@redhat.com>
2020-02-26nbd-client: Support leading / in NBD URIEric Blake1-2/+4
The NBD URI specification [1] states that only one leading slash at the beginning of the URI path component is stripped, not all such slashes. This becomes important to a patch I just proposed to nbdkit [2], which would allow the exportname to select a file embedded within an ext2 image: ext2fs demands an absolute pathname beginning with '/', and because qemu was inadvertantly stripping it, my nbdkit patch had to work around the behavior. [1] https://github.com/NetworkBlockDevice/nbd/blob/master/doc/uri.md [2] https://www.redhat.com/archives/libguestfs/2020-February/msg00109.html Note that the qemu bug only affects handling of URIs such as nbd://host:port//abs/path (where '/abs/path' should be the export name); it is still possible to use --image-opts and pass the desired export name with a leading slash directly through JSON even without this patch. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200212023101.1162686-1-eblake@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com>
2020-02-20block/nbd: Fix hang in .bdrv_close()Max Reitz1-1/+13
When nbd_close() is called from a coroutine, the connection_co never gets to run, and thus nbd_teardown_connection() hangs. This is because aio_co_enter() only puts the connection_co into the main coroutine's wake-up queue, so this main coroutine needs to yield and wait for connection_co to terminate. Suggested-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200122164532.178040-2-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-12-18nbd: assert that Error** is not NULL in nbd_iter_channel_errorVladimir Sementsov-Ogievskiy1-0/+1
All callers of nbd_iter_channel_error() pass the address of a local_err variable, and only call this function if an error has already occurred, using this function to propagate that error. This is already implied by its name (local_err instead of the classic errp), but it is worth additionally stressing this by adding an assertion to make it part of the function contract. The local_err parameter is not here to return information about nbd_iter_channel_error failure. Instead it's assumed to be filled when passed to the function. This is already stressed by its name (local_err, instead of classic errp). Stress it additionally by assertion. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20191205174635.18758-22-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2019-11-18nbd: Don't send oversize stringsEric Blake1-0/+10
Qemu as server currently won't accept export names larger than 256 bytes, nor create dirty bitmap names longer than 1023 bytes, so most uses of qemu as client or server have no reason to get anywhere near the NBD spec maximum of a 4k limit per string. However, we weren't actually enforcing things, ignoring when the remote side violates the protocol on input, and also having several code paths where we send oversize strings on output (for example, qemu-nbd --description could easily send more than 4k). Tighten things up as follows: client: - Perform bounds check on export name and dirty bitmap request prior to handing it to server - Validate that copied server replies are not too long (ignoring NBD_INFO_* replies that are not copied is not too bad) server: - Perform bounds check on export name and description prior to advertising it to client - Reject client name or metadata query that is too long - Adjust things to allow full 4k name limit rather than previous 256 byte limit Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20191114024635.11363-4-eblake@redhat.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2019-10-22block/nbd: nbd reconnectVladimir Sementsov-Ogievskiy1-63/+268
Implement reconnect. To achieve this: 1. add new modes: connecting-wait: means, that reconnecting is in progress, and there were small number of reconnect attempts, so all requests are waiting for the connection. connecting-nowait: reconnecting is in progress, there were a lot of attempts of reconnect, all requests will return errors. two old modes are used too: connected: normal state quit: exiting after fatal error or on close Possible transitions are: * -> quit connecting-* -> connected connecting-wait -> connecting-nowait (transition is done after reconnect-delay seconds in connecting-wait mode) connected -> connecting-wait 2. Implement reconnect in connection_co. So, in connecting-* mode, connection_co, tries to reconnect unlimited times. 3. Retry nbd queries on channel error, if we are in connecting-wait state. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20191009084158.15614-3-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2019-10-10nbd: add empty .bdrv_reopen_prepareMaxim Levitsky1-0/+15
Fixes commit job / qemu-img commit, when commiting qcow2 file which is based on nbd export. Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1718727 Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-id: 20190930213820.29777-2-mlevitsk@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-09-05nbd: Implement client use of NBD FAST_ZEROEric Blake1-0/+7
The client side is fairly straightforward: if the server advertised fast zero support, then we can map that to BDRV_REQ_NO_FALLBACK support. A server that advertises FAST_ZERO but not WRITE_ZEROES is technically broken, but we can ignore that situation as it does not change our behavior. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20190823143726.27062-4-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2019-09-05nbd: Use g_autofree in a few placesEric Blake1-7/+4
Thanks to our recent move to use glib's g_autofree, I can join the bandwagon. Getting rid of gotos is fun ;) There are probably more places where we could register cleanup functions and get rid of more gotos; this patch just focuses on the labels that existed merely to call g_free. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20190824172813.29720-2-eblake@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2019-08-16Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2019-08-15' into ↵Peter Maydell1-82/+113
staging nbd patches for 2019-08-15 - Addition of InetSocketAddress keep-alive - Addition of BDRV_REQ_PREFETCH for more efficient copy-on-read - Initial refactoring in preparation of NBD reconnect # gpg: Signature made Thu 15 Aug 2019 19:28:41 BST # gpg: using RSA key A7A16B4A2527436A # gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full] # gpg: aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full] # gpg: aka "[jpeg image of size 6874]" [full] # Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2 F3AA A7A1 6B4A 2527 436A * remotes/ericb/tags/pull-nbd-2019-08-15: block/nbd: refactor nbd connection parameters block/nbd: add cmdline and qapi parameter reconnect-delay block/nbd: move from quit to state block/nbd: use non-blocking io channel for nbd negotiation block/nbd: split connection_co start out of nbd_client_connect nbd: improve CMD_CACHE: use BDRV_REQ_PREFETCH block/stream: use BDRV_REQ_PREFETCH block: implement BDRV_REQ_PREFETCH qapi: Add InetSocketAddress member keep-alive Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-08-16Include qemu/main-loop.h lessMarkus Armbruster1-0/+1
In my "build everything" tree, changing qemu/main-loop.h triggers a recompile of some 5600 out of 6600 objects (not counting tests and objects that don't depend on qemu/osdep.h). It includes block/aio.h, which in turn includes qemu/event_notifier.h, qemu/notify.h, qemu/processor.h, qemu/qsp.h, qemu/queue.h, qemu/thread-posix.h, qemu/thread.h, qemu/timer.h, and a few more. Include qemu/main-loop.h only where it's needed. Touching it now recompiles only some 1700 objects. For block/aio.h and qemu/event_notifier.h, these numbers drop from 5600 to 2800. For the others, they shrink only slightly. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20190812052359.30071-21-armbru@redhat.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-08-15block/nbd: refactor nbd connection parametersVladimir Sementsov-Ogievskiy1-61/+60
We'll need some connection parameters to be available all the time to implement nbd reconnect. So, let's refactor them: define additional parameters in BDRVNBDState, drop them from function parameters, drop nbd_client_init and separate options parsing instead from nbd_open. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20190618114328.55249-6-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: Drop useless 'if' before object_unref] Signed-off-by: Eric Blake <eblake@redhat.com>
2019-08-15block/nbd: add cmdline and qapi parameter reconnect-delayVladimir Sementsov-Ogievskiy1-1/+15
Reconnect will be implemented in the following commit, so for now, in semantics below, disconnect itself is a "serious error". Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20190618114328.55249-5-vsementsov@virtuozzo.com> [eblake: slipped from 4.1 to 4.2] Signed-off-by: Eric Blake <eblake@redhat.com>
2019-08-15block/nbd: move from quit to stateVladimir Sementsov-Ogievskiy1-21/+37
To implement reconnect we need several states for the client: CONNECTED, QUIT and two different CONNECTING states. CONNECTING states will be added in the following patches. This patch implements CONNECTED and QUIT. QUIT means, that we should close the connection and fail all current and further requests (like old quit = true). CONNECTED means that connection is ok, we can send requests (like old quit = false). For receiving loop we use a comparison of the current state with QUIT, because reconnect will be in the same loop, so it should be looping until the end. Opposite, for requests we use a comparison of the current state with CONNECTED, as we don't want to send requests in future CONNECTING states. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20190618114328.55249-4-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2019-08-15block/nbd: use non-blocking io channel for nbd negotiationVladimir Sementsov-Ogievskiy1-9/+7
No reason to use blocking channel for negotiation and we'll benefit in further reconnect feature, as qio_channel reads and writes will do qemu_coroutine_yield while waiting for io completion. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20190618114328.55249-3-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2019-08-15block/nbd: split connection_co start out of nbd_client_connectVladimir Sementsov-Ogievskiy1-9/+13
nbd_client_connect is going to be used from connection_co, so, let's refactor nbd_client_connect in advance, leaving io channel configuration all in nbd_client_connect. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20190618114328.55249-2-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2019-07-19nbd: Initialize reply on failureEric Blake1-3/+2
We've had two separate reports of different callers running into use of uninitialized data if s->quit is set (one detected by gcc -O3, another by valgrind), due to checking 'nbd_reply_is_simple(reply) || s->quit' in the wrong order. Rather than chasing down which callers need to pre-initialize reply, and whether there are any other uninitialized uses, it's easier to guarantee that reply will always be set by nbd_co_receive_one_chunk() even on failure. The uninitialized use happens to be harmless (the only time the variable is uninitialized is if s->quit is set, so the conditional results in the same action regardless of what was read from reply), and was introduced in commit 65e01d47. In fixing the problem, it can also be seen that all (one) callers pass in a non-NULL reply, so there is a dead conditional to also be cleaned up. Reported-by: Thomas Huth <thuth@redhat.com> Reported-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20190719172001.19770-1-eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-06-13block/nbd: merge NBDClientSession struct back to BDRVNBDStateVladimir Sementsov-Ogievskiy1-103/+94
No reason to keep it separate, it differs from others block driver behavior and therefore confuses. Instead of generic 'state = (State*)bs->opaque' we have to use special helper. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20190611102720.86114-4-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2019-06-13block/nbd: merge nbd-client.* to nbd.cVladimir Sementsov-Ogievskiy1-32/+1253
No reason for keeping driver handlers realization separate from driver structure. We can get rid of extra header file. While being here, fix comments style, restore forgotten comments for NBD_FOREACH_REPLY_CHUNK and nbd_reply_chunk_iter_receive, remove extra includes. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20190611102720.86114-3-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2019-03-30nbd/client: Lower min_block for block-status, unaligned sizeEric Blake1-1/+18
We have a latent bug in our NBD client code, tickled by the brand new nbdkit 1.11.10 block status support: $ nbdkit --filter=log --filter=truncate -U - \ data data="1" size=511 truncate=64K logfile=/dev/stdout \ --run 'qemu-img convert $nbd /var/tmp/out' ... qemu-img: block/io.c:2122: bdrv_co_block_status: Assertion `*pnum && QEMU_IS_ALIGNED(*pnum, align) && align > offset - aligned_offset' failed. The culprit? Our implementation of .bdrv_co_block_status can return unaligned block status for any server that operates with a lower actual alignment than what we tell the block layer in request_alignment, in violation of the block layer's constraints. To date, we've been unable to trip the bug, because qemu as NBD server always advertises block sizing (at which point it is a server bug if the server sends unaligned status - although qemu 3.1 is such a server and I've sent separate patches for 4.0 both to get the server to obey the spec, and to let the client to tolerate server oddities at EOF). But nbdkit does not (yet) advertise block sizing, and therefore is not in violation of the spec for returning block status at whatever boundaries it wants, and those unaligned results can occur anywhere rather than just at EOF. While we are still wise to avoid sending sub-sector read/write requests to a server of unknown origin, we MUST consider that a server telling us block status without an advertised block size is correct. So, we either have to munge unaligned answers from the server into aligned ones that we hand back to the block layer, or we have to tell the block layer about a smaller alignment. Similarly, if the server advertises an image size that is not sector-aligned, we might as well assume that the server intends to let us access those tail bytes, and therefore supports a minimum block size of 1, regardless of whether the server supports block status (although we still need more patches to fix the problem that with an unaligned image, we can send read or block status requests that exceed EOF to the server). Again, qemu as server cannot trip this problem (because it rounds images to sector alignment), but nbdkit advertised unaligned size even before it gained block status support. Solve both alignment problems at once by using better heuristics on what alignment to report to the block layer when the server did not give us something to work with. Note that very few NBD servers implement block status (to date, only qemu and nbdkit are known to do so); and as the NBD spec mentioned block sizing constraints prior to documenting block status, it can be assumed that any future implementations of block status are aware that they must advertise block size if they want a minimum size other than 1. We've had a long history of struggles with picking the right alignment to use in the block layer, as evidenced by the commit message of fd8d372d (v2.12) that introduced the current choice of forced 512-byte alignment. There is no iotest coverage for this fix, because qemu can't provoke it, and I didn't want to make test 241 dependent on nbdkit. Fixes: fd8d372d Reported-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20190329042750.14704-3-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Tested-by: Richard W.M. Jones <rjones@redhat.com>
2019-02-25block: Purify .bdrv_refresh_filename()Max Reitz1-22/+1
Currently, BlockDriver.bdrv_refresh_filename() is supposed to both refresh the filename (BDS.exact_filename) and set BDS.full_open_options. Now that we have generic code in the central bdrv_refresh_filename() for creating BDS.full_open_options, we can drop the latter part from all BlockDriver.bdrv_refresh_filename() implementations. This also means that we can drop all of the existing default code for this from the global bdrv_refresh_filename() itself. Furthermore, we now have to call BlockDriver.bdrv_refresh_filename() after having set BDS.full_open_options, because the block driver's implementation should now be allowed to depend on BDS.full_open_options being set correctly. Finally, with this patch we can drop the @options parameter from BlockDriver.bdrv_refresh_filename(); also, add a comment on this function's purpose in block/block_int.h while touching its interface. This completely obsoletes blklogwrite's implementation of .bdrv_refresh_filename(). Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190201192935.18394-25-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block: Add strong_runtime_opts to BlockDriverMax Reitz1-0/+14
This new field can be set by block drivers to list the runtime options they accept that may influence the contents of the respective BDS. As of a follow-up patch, this list will be used by the common bdrv_refresh_filename() implementation to decide which options to put into BDS.full_open_options (and consequently whether a JSON filename has to be created), thus freeing the drivers of having to implement that logic themselves. Additionally, this patch adds the field to all of the block drivers that need it and sets it accordingly. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20190201192935.18394-22-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25block/nbd: Make bdrv_dirname() return NULLMax Reitz1-0/+13
The generic bdrv_dirname() implementation would be able to generate some form of directory name for many NBD nodes, but it would be always wrong. Therefore, we have to explicitly make it an error (until NBD has some form of specification for export paths, if it ever will). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20190201192935.18394-18-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-04block/nbd: move connection code from block/nbd to block/nbd-clientVladimir Sementsov-Ogievskiy1-38/+2
Keep all connection code in one file, to be able to implement reconnect in further patches. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20190201130138.94525-3-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: format tweak] Signed-off-by: Eric Blake <eblake@redhat.com>
2018-07-28qstring: Move qstring_from_substr()'s @end one to the rightMarkus Armbruster1-1/+1
qstring_from_substr() takes the index of the substring's first and last character. qstring_from_substr(s, 0, SIZE_MAX) denotes an empty substring. Awkward. Shift the end index one to the right. This simplifies both qstring_from_substr() and its callers. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180727062204.10401-3-armbru@redhat.com>
2018-07-02nbd/client: Add x-dirty-bitmap to query bitmap from serverEric Blake1-2/+8
In order to test that the NBD server is properly advertising dirty bitmaps, we need a bare minimum client that can request and read the context. Since feature freeze for 3.0 is imminent, this is the smallest workable patch, which replaces the qemu block status report with the results of the NBD server's dirty bitmap (making it very easy to use 'qemu-img map --output=json' to learn where the dirty portions are). Note that the NBD protocol defines a dirty section with the same bit but opposite sense that normal "base:allocation" uses to report an allocated section; so in qemu-img map output, "data":true corresponds to clean, "data":false corresponds to dirty. A more complete solution that allows dirty bitmaps to be queried at the same time as normal block status will be required before this addition can lose the x- prefix. Until then, the fact that this replaces normal status with dirty status means actions like 'qemu-img convert' will likely misbehave due to treating dirty regions of the file as if they are unallocated. The next patch adds an iotest to exercise this new code. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20180702191458.28741-2-eblake@redhat.com>
2018-06-15block: Factor out qobject_input_visitor_new_flat_confused()Markus Armbruster1-5/+2
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-06-15block: Fix -drive for certain non-string scalarsMarkus Armbruster1-10/+2
The previous commit fixed -blockdev breakage due to misuse of the qobject input visitor's keyval flavor in bdrv_file_open(). The commit message explain why using the plain flavor would be just as wrong; it would break -drive. Turns out we break it in three places: nbd_open(), sd_open() and ssh_file_open(). They are even marked FIXME. Example breakage: $ qemu-system-x86 -drive node-name=n1,driver=nbd,server.type=inet,server.host=localhost,server.port=1234,server.numeric=off qemu-system-x86: -drive node-name=n1,driver=nbd,server.type=inet,server.host=localhost,server.port=1234,server.numeric=off: Invalid parameter type for 'numeric', expected: boolean Fix it the same way: replace qdict_crumple() by qdict_crumple_for_keyval_qiv(), and switch from plain to the keyval flavor. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-06-15block: Add block-specific QDict headerMax Reitz1-0/+1
There are numerous QDict functions that have been introduced for and are used only by the block layer. Move their declarations into an own header file to reflect that. While qdict_extract_subqdict() is in fact used outside of the block layer (in util/qemu-config.c), it is still a function related very closely to how the block layer works with nested QDicts, namely by sometimes flattening them. Therefore, its declaration is put into this header as well and util/qemu-config.c includes it with a comment stating exactly which function it needs. Suggested-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20180509165530.29561-7-mreitz@redhat.com> [Copyright note tweaked, superfluous includes dropped] Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-05-31block: use local path for local headersMichael S. Tsirkin1-1/+1
When pulling in headers that are in the same directory as the C file (as opposed to one in include/), we should use its relative path, without a directory. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2018-05-04qobject: Replace qobject_incref/QINCREF qobject_decref/QDECREFMarc-André Lureau1-2/+2
Now that we can safely call QOBJECT() on QObject * as well as its subtypes, we can have macros qobject_ref() / qobject_unref() that work everywhere instead of having to use QINCREF() / QDECREF() for QObject and qobject_incref() / qobject_decref() for its subtypes. The replacement is mechanical, except I broke a long line, and added a cast in monitor_qmp_cleanup_req_queue_locked(). Unlike qobject_decref(), qobject_unref() doesn't accept void *. Note that the new macros evaluate their argument exactly once, thus no need to shout them. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180419150145.24795-4-marcandre.lureau@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> [Rebased, semantic conflict resolved, commit message improved] Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-03-13nbd: BLOCK_STATUS for standard get_block_status function: client partVladimir Sementsov-Ogievskiy1-0/+3
Minimal realization: only one extent in server answer is supported. Flag NBD_CMD_FLAG_REQ_ONE is used to force this behavior. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20180312152126.286890-6-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: grammar tweaks, fix min_block check and 32-bit cap, use -1 instead of errno on failure in nbd_negotiate_simple_meta_context, ensure that block status makes progress on success] Signed-off-by: Eric Blake <eblake@redhat.com>
2018-03-02Include less of the generated modular QAPI headersMarkus Armbruster1-1/+1
In my "build everything" tree, a change to the types in qapi-schema.json triggers a recompile of about 4800 out of 5100 objects. The previous commit split up qmp-commands.h, qmp-event.h, qmp-visit.h, qapi-types.h. Each of these headers still includes all its shards. Reduce compile time by including just the shards we actually need. To illustrate the benefits: adding a type to qapi/migration.json now recompiles some 2300 instead of 4800 objects. The next commit will improve it further. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20180211093607.27351-24-armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> [eblake: rebase to master] Signed-off-by: Eric Blake <eblake@redhat.com>
2018-03-01nbd: Honor server's advertised minimum block sizeEric Blake1-0/+2
Commit 79ba8c98 (v2.7) changed the setting of request_alignment to occur only during bdrv_refresh_limits(), rather than at at bdrv_open() time; but at the time, NBD was unaffected, because it still used sector-based callbacks, so the block layer defaulted NBD to use 512 request_alignment. Later, commit 70c4fb26 (also v2.7) changed NBD to use byte-based callbacks, without setting request_alignment. This resulted in NBD using request_alignment of 1, which works great when the server supports it (as is the case for qemu-nbd), but falls apart miserably if the server requires alignment (but only if qemu actually sends a sub-sector request; qemu-io can do it, but most qemu operations still perform on sectors or larger). Even later, the NBD protocol was updated to document that clients should learn the server's minimum alignment during NBD_OPT_GO; and recommended that clients should assume a minimum size of 512 unless the server understands NBD_OPT_GO and replied with a smaller size. Commit 081dd1fe (v2.10) attempted to do that, by assigning request_alignment to whatever was learned from the server; but it has two flaws: the assignment is done during bdrv_open() so it gets unconditionally wiped out back to 1 during any later bdrv_refresh_limits(); and the code is not using a default of 512 when the server did not report a minimum size. Fix these issues by moving the assignment to request_alignment to the right function, and by using a sane default when the server does not advertise a minimum size. CC: qemu-stable@nongnu.org Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20180215032905.27146-1-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy<vsementsov@virtuozzo.com>
2018-02-09block: Simplify bdrv_can_write_zeroes_with_unmap()Eric Blake1-11/+0
We don't need the can_write_zeroes_with_unmap field in BlockDriverInfo, because it is redundant information with supported_zero_flags & BDRV_REQ_MAY_UNMAP. Note that BlockDriverInfo and supported_zero_flags are both per-device settings, rather than global state about the driver as a whole, which means one or both of these bits of information can already be conditional. Let's audit how they were set: crypto: always setting can_write_ to false is pointless (the struct starts life zero-initialized), no use of supported_ nbd: just recently fixed to set can_write_ if supported_ includes MAY_UNMAP (thus this commit effectively reverts bca80059e and solves the problem mentioned there in a more global way) file-posix, iscsi, qcow2: can_write_ is conditional, while supported_ was unconditional; but passing MAY_UNMAP would fail with ENOTSUP if the condition wasn't met qed: can_write_ is unconditional, but pwrite_zeroes lacks support for MAY_UNMAP and supported_ is not set. Perhaps support can be added later (since it would be similar to qcow2), but for now claiming false is no real loss all other drivers: can_write_ is not set, and supported_ is either unset or a passthrough Simplify the code by moving the conditional into supported_zero_flags for all drivers, then dropping the now-unused BDI field. For callers that relied on bdrv_can_write_zeroes_with_unmap(), we return the same per-device settings for drivers that had conditions (no observable change in behavior there); and can now return true (instead of false) for drivers that support passthrough (for example, the commit driver) which gives those drivers the same fix as nbd just got in bca80059e. For callers that relied on supported_zero_flags, we now have a few more places that can avoid a wasted call to pwrite_zeroes() that will just fail with ENOTSUP. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20180126193439.20219-1-eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-02-09Move include qemu/option.h from qemu-common.h to actual usersMarkus Armbruster1-0/+1
qemu-common.h includes qemu/option.h, but most places that include the former don't actually need the latter. Drop the include, and add it to the places that actually need it. While there, drop superfluous includes of both headers, and separate #include from file comment with a blank line. This cleanup makes the number of objects depending on qemu/option.h drop from 4545 (out of 4743) to 284 in my "build everything" tree. Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20180201111846.21846-20-armbru@redhat.com> [Semantic conflict with commit bdd6a90a9e in block/nvme.c resolved]
2018-02-09Drop superfluous includes of qapi/qmp/qjson.hMarkus Armbruster1-1/+0
Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20180201111846.21846-19-armbru@redhat.com>
2018-01-26nbd: implement bdrv_get_info callbackEdgar Kaziakhmedov1-0/+11
Since mirror job supports efficient zero out target mechanism (see in mirror_dirty_init()), implement bdrv_get_info to make it work over NBD. Such improvement will allow using the largest chunk possible and will decrease the number of NBD_CMD_WRITE_ZEROES requests on the wire. Signed-off-by: Edgar Kaziakhmedov <edgar.kaziakhmedov@virtuozzo.com> Message-Id: <20180118115158.17219-1-edgar.kaziakhmedov@virtuozzo.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2018-01-08block/nbd: fix segmentation fault when .desc is not null-terminatedMurilo Opsfelder Araujo1-0/+1
The find_desc_by_name() from util/qemu-option.c relies on the .name not being NULL to call strcmp(). This check becomes unsafe when the list is not NULL-terminated, which is the case of nbd_runtime_opts in block/nbd.c, and can result in segmentation fault when strcmp() tries to access an invalid memory: #0 0x00007fff8c75f7d4 in __strcmp_power9 () from /lib64/libc.so.6 #1 0x00000000102d3ec8 in find_desc_by_name (desc=0x1036d6f0, name=0x28e46670 "server.path") at util/qemu-option.c:166 #2 0x00000000102d93e0 in qemu_opts_absorb_qdict (opts=0x28e47a80, qdict=0x28e469a0, errp=0x7fffec247c98) at util/qemu-option.c:1026 #3 0x000000001012a2e4 in nbd_open (bs=0x28e42290, options=0x28e469a0, flags=24578, errp=0x7fffec247d80) at block/nbd.c:406 #4 0x00000000100144e8 in bdrv_open_driver (bs=0x28e42290, drv=0x1036e070 <bdrv_nbd_unix>, node_name=0x0, options=0x28e469a0, open_flags=24578, errp=0x7fffec247f50) at block.c:1135 #5 0x0000000010015b04 in bdrv_open_common (bs=0x28e42290, file=0x0, options=0x28e469a0, errp=0x7fffec247f50) at block.c:1395 >From gdb, the desc[i].name was not NULL and resulted in strcmp() accessing an invalid memory: >>> p desc[5] $8 = { name = 0x1037f098 "R27A", type = 1561964883, help = 0xc0bbb23e <error: Cannot access memory at address 0xc0bbb23e>, def_value_str = 0x2 <error: Cannot access memory at address 0x2> } >>> p desc[6] $9 = { name = 0x103dac78 <__gcov0.do_qemu_init_bdrv_nbd_init> "\001", type = 272101528, help = 0x29ec0b754403e31f <error: Cannot access memory at address 0x29ec0b754403e31f>, def_value_str = 0x81f343b9 <error: Cannot access memory at address 0x81f343b9> } This patch fixes the segmentation fault in strcmp() by adding a NULL element at the end of nbd_runtime_opts.desc list, which is the common practice to most of other structs like runtime_opts in block/null.c. Thus, the desc[i].name != NULL check becomes safe because it will not evaluate to true when .desc list reached its end. Reported-by: R. Nageswara Sastry <nasastry@in.ibm.com> Buglink: https://bugs.launchpad.net/qemu/+bug/1727259 Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.vnet.ibm.com> Message-Id: <20180105133241.14141-2-muriloo@linux.vnet.ibm.com> CC: qemu-stable@nongnu.org Fixes: 7ccc44fd7d1dfa62c4d6f3a680df809d6e7068ce Signed-off-by: Eric Blake <eblake@redhat.com>
2017-07-14nbd: Implement NBD_INFO_BLOCK_SIZE on clientEric Blake1-3/+11
The upstream NBD Protocol has defined a new extension to allow the server to advertise block sizes to the client, as well as a way for the client to inform the server whether it intends to obey block sizes. When using the block layer as the client, we will obey block sizes; but when used as 'qemu-nbd -c' to hand off to the kernel nbd module as the client, we are still waiting for the kernel to implement a way for us to learn if it will honor block sizes (perhaps by an addition to sysfs, rather than an ioctl), as well as any way to tell the kernel what additional block sizes to obey (NBD_SET_BLKSIZE appears to be accurate for the minimum size, but preferred and maximum sizes would probably be new ioctl()s), so until then, we need to make our request for block sizes conditional. When using ioctl(NBD_SET_BLKSIZE) to hand off to the kernel, use the minimum block size as the sector size if it is larger than 512, which also has the nice effect of cooperating with (non-qemu) servers that don't do read-modify-write when exposing a block device with 4k sectors; it might also allow us to visit a file larger than 2T on a 32-bit kernel. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20170707203049.534-10-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-14nbd: Create struct for tracking export infoEric Blake1-1/+1
The NBD Protocol is introducing some additional information about exports, such as minimum request size and alignment, as well as an advertised maximum request size. It will be easier to feed this information back to the block layer if we gather all the information into a struct, rather than adding yet more pointer parameters during negotiation. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20170707203049.534-2-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-26block: Do not strcmp() with NULL uri->schemeMax Reitz1-3/+3
uri_parse(...)->scheme may be NULL. In fact, probably every field may be NULL, and the callers do test this for all of the other fields but not for scheme (except for block/gluster.c; block/vxhs.c does not access that field at all). We can easily fix this by using g_strcmp0() instead of strcmp(). Cc: qemu-stable@nongnu.org Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20170613205726.13544-1-mreitz@redhat.com Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-06-20qapi: merge QInt and QFloat in QNumMarc-André Lureau1-1/+0
We would like to use a same QObject type to represent numbers, whether they are int, uint, or floats. Getters will allow some compatibility between the various types if the number fits other representations. Add a few more tests while at it. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20170607163635.17635-7-marcandre.lureau@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> [parse_stats_intervals() simplified a bit, comment in test_visitor_in_int_overflow() tidied up, suppress bogus warnings] Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-05-09sockets: Limit SocketAddressLegacy to external interfacesMarkus Armbruster1-3/+1
SocketAddressLegacy is a simple union, and simple unions are awkward: they have their variant members wrapped in a "data" object on the wire, and require additional indirections in C. SocketAddress is the equivalent flat union. Convert all users of SocketAddressLegacy to SocketAddress, except for existing external interfaces. See also commit fce5d53..9445673 and 85a82e8..c5f1ae3. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <1493192202-3184-7-git-send-email-armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> [Minor editing accident fixed, commit message and a comment tweaked] Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-05-09sockets: Rename SocketAddressFlat to SocketAddressMarkus Armbruster1-13/+13
Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <1493192202-3184-6-git-send-email-armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Prasanna Kumar Kalever <prasanna.kalever@redhat.com>