Commit Graph

306 Commits

Author SHA1 Message Date
Paolo Bonzini
5080152e2e block/iscsi: fix double-free on BUSY or similar statuses
Commit 8c460269aa ("iscsi: base all handling of check condition on
scsi_sense_to_errno", 2019-07-15) removed a "goto out" so that the
same coroutine is re-entered twice; once from iscsi_co_generic_cb,
once from the timer callback iscsi_retry_timer_expired.  This can
cause a crash.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1378
Reported-by: Grzegorz Zdanowski <https://gitlab.com/kiler129>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-02-10 14:12:06 +01:00
Emanuele Giuseppe Esposito
3d47eb0a2a block: Convert bdrv_get_info() to co_wrapper_mixed
bdrv_get_info() is categorized as an I/O function, and it currently
doesn't run in a coroutine. We should let it take a graph rdlock since
it traverses the block nodes graph, which however is only possible in a
coroutine.

Therefore turn it into a co_wrapper to move the actual function into a
coroutine where the lock can be taken.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-11-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-01 16:52:32 +01:00
Emanuele Giuseppe Esposito
c86422c554 block: Convert bdrv_refresh_total_sectors() to co_wrapper_mixed
BlockDriver->bdrv_getlength is categorized as IO callback, and it
currently doesn't run in a coroutine. We should let it take a graph
rdlock since the callback traverses the block nodes graph, which however
is only possible in a coroutine.

Therefore turn it into a co_wrapper to move the actual function into a
coroutine where the lock can be taken.

Because now this function creates a new coroutine and polls, we need to
take the AioContext lock where it is missing, for the only reason that
internally co_wrapper calls AIO_WAIT_WHILE and it expects to release the
AioContext lock.

This is especially messy when a co_wrapper creates a coroutine and polls
in bdrv_open_driver, because this function has so many callers in so
many context that it can easily lead to deadlocks. Therefore the new
rule for bdrv_open_driver is that the caller must always hold the
AioContext lock of the given bs (except if it is a coroutine), because
the function calls bdrv_refresh_total_sectors() which is now a
co_wrapper.

Once the rwlock is ultimated and placed in every place it needs to be,
we will poll using AIO_WAIT_WHILE_UNLOCKED and remove the AioContext
lock.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-7-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-01 16:52:32 +01:00
Markus Armbruster
e2c1c34f13 include/block: Untangle inclusion loops
We have two inclusion loops:

       block/block.h
    -> block/block-global-state.h
    -> block/block-common.h
    -> block/blockjob.h
    -> block/block.h

       block/block.h
    -> block/block-io.h
    -> block/block-common.h
    -> block/blockjob.h
    -> block/block.h

I believe these go back to Emanuele's reorganization of the block API,
merged a few months ago in commit d7e2fe4aac.

Fortunately, breaking them is merely a matter of deleting unnecessary
includes from headers, and adding them back in places where they are
now missing.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221221133551.3967339-2-armbru@redhat.com>
2023-01-20 07:24:28 +01:00
Paolo Bonzini
3d6dcf40ce iscsi: add missing coroutine_fn annotations
Callers of coroutine_fn must be coroutine_fn themselves, or the call
must be within "if (qemu_in_coroutine())".  Apply coroutine_fn to
functions where this holds.

Reviewed-by: Alberto Faria <afaria@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220922084924.201610-10-pbonzini@redhat.com>
[kwolf: Fixed up coding style]
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-07 12:11:40 +02:00
Denis V. Lunev
006e196244 block: use bdrv_is_sg() helper instead of raw bs->sg reading
I believe that if the helper exists, it must be used always for reading
of the value. It breaks expectations in the other case.

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Hanna Reitz <hreitz@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Fam Zheng <fam@euphon.net>
CC: Ronnie Sahlberg <ronniesahlberg@gmail.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Peter Lieven <pl@kamp.de>
CC: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20220817083736.40981-2-den@openvz.org>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-09-30 18:43:44 +02:00
Marc-André Lureau
89fc45d5c6 include: move qemu_get_vm_name() to sysemu.h
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-26-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-06 14:31:43 +02:00
Stefan Hajnoczi
826cc32423 aio-posix: split poll check from ready handler
Adaptive polling measures the execution time of the polling check plus
handlers called when a polled event becomes ready. Handlers can take a
significant amount of time, making it look like polling was running for
a long time when in fact the event handler was running for a long time.

For example, on Linux the io_submit(2) syscall invoked when a virtio-blk
device's virtqueue becomes ready can take 10s of microseconds. This
can exceed the default polling interval (32 microseconds) and cause
adaptive polling to stop polling.

By excluding the handler's execution time from the polling check we make
the adaptive polling calculation more accurate. As a result, the event
loop now stays in polling mode where previously it would have fallen
back to file descriptor monitoring.

The following data was collected with virtio-blk num-queues=2
event_idx=off using an IOThread. Before:

168k IOPS, IOThread syscalls:

  9837.115 ( 0.020 ms): IO iothread1/620155 io_submit(ctx_id: 140512552468480, nr: 16, iocbpp: 0x7fcb9f937db0)    = 16
  9837.158 ( 0.002 ms): IO iothread1/620155 write(fd: 103, buf: 0x556a2ef71b88, count: 8)                         = 8
  9837.161 ( 0.001 ms): IO iothread1/620155 write(fd: 104, buf: 0x556a2ef71b88, count: 8)                         = 8
  9837.163 ( 0.001 ms): IO iothread1/620155 ppoll(ufds: 0x7fcb90002800, nfds: 4, tsp: 0x7fcb9f1342d0, sigsetsize: 8) = 3
  9837.164 ( 0.001 ms): IO iothread1/620155 read(fd: 107, buf: 0x7fcb9f939cc0, count: 512)                        = 8
  9837.174 ( 0.001 ms): IO iothread1/620155 read(fd: 105, buf: 0x7fcb9f939cc0, count: 512)                        = 8
  9837.176 ( 0.001 ms): IO iothread1/620155 read(fd: 106, buf: 0x7fcb9f939cc0, count: 512)                        = 8
  9837.209 ( 0.035 ms): IO iothread1/620155 io_submit(ctx_id: 140512552468480, nr: 32, iocbpp: 0x7fca7d0cebe0)    = 32

174k IOPS (+3.6%), IOThread syscalls:

  9809.566 ( 0.036 ms): IO iothread1/623061 io_submit(ctx_id: 140539805028352, nr: 32, iocbpp: 0x7fd0cdd62be0)    = 32
  9809.625 ( 0.001 ms): IO iothread1/623061 write(fd: 103, buf: 0x5647cfba5f58, count: 8)                         = 8
  9809.627 ( 0.002 ms): IO iothread1/623061 write(fd: 104, buf: 0x5647cfba5f58, count: 8)                         = 8
  9809.663 ( 0.036 ms): IO iothread1/623061 io_submit(ctx_id: 140539805028352, nr: 32, iocbpp: 0x7fd0d0388b50)    = 32

Notice that ppoll(2) and eventfd read(2) syscalls are eliminated because
the IOThread stays in polling mode instead of falling back to file
descriptor monitoring.

As usual, polling is not implemented on Windows so this patch ignores
the new io_poll_read() callback in aio-win32.c.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20211207132336.36627-2-stefanha@redhat.com

[Fixed up aio_set_event_notifier() calls in
tests/unit/test-fdmon-epoll.c added after this series was queued.
--Stefan]

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-01-12 17:09:39 +00:00
Vladimir Sementsov-Ogievskiy
0c8022876f block: use int64_t instead of int in driver discard handlers
We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

So, convert driver discard handlers bytes parameter to int64_t.

The only caller of all updated function is bdrv_co_pdiscard in
block/io.c. It is already prepared to work with 64bit requests, but
pass at most max(bs->bl.max_pdiscard, INT_MAX) to the driver.

Let's look at all updated functions:

blkdebug: all calculations are still OK, thanks to
  bdrv_check_qiov_request().
  both rule_check and bdrv_co_pdiscard are 64bit

blklogwrites: pass to blk_loc_writes_co_log which is 64bit

blkreplay, copy-on-read, filter-compress: pass to bdrv_co_pdiscard, OK

copy-before-write: pass to bdrv_co_pdiscard which is 64bit and to
  cbw_do_copy_before_write which is 64bit

file-posix: one handler calls raw_account_discard() is 64bit and both
  handlers calls raw_do_pdiscard(). Update raw_do_pdiscard, which pass
  to RawPosixAIOData::aio_nbytes, which is 64bit (and calls
  raw_account_discard())

gluster: somehow, third argument of glfs_discard_async is size_t.
  Let's set max_pdiscard accordingly.

iscsi: iscsi_allocmap_set_invalid is 64bit,
  !is_byte_request_lun_aligned is 64bit.
  list.num is uint32_t. Let's clarify max_pdiscard and
  pdiscard_alignment.

mirror_top: pass to bdrv_mirror_top_do_write() which is
  64bit

nbd: protocol limitation. max_pdiscard is alredy set strict enough,
  keep it as is for now.

nvme: buf.nlb is uint32_t and we do shift. So, add corresponding limits
  to nvme_refresh_limits().

preallocate: pass to bdrv_co_pdiscard() which is 64bit.

rbd: pass to qemu_rbd_start_co() which is 64bit.

qcow2: calculations are still OK, thanks to bdrv_check_qiov_request(),
  qcow2_cluster_discard() is 64bit.

raw-format: raw_adjust_offset() is 64bit, bdrv_co_pdiscard too.

throttle: pass to bdrv_co_pdiscard() which is 64bit and to
  throttle_group_co_io_limits_intercept() which is 64bit as well.

test-block-iothread: bytes argument is unused

Great! Now all drivers are prepared to handle 64bit discard requests,
or else have explicit max_pdiscard limits.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210903102807.27127-11-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-09-29 13:46:32 -05:00
Vladimir Sementsov-Ogievskiy
f34b2bcf8c block: use int64_t instead of int in driver write_zeroes handlers
We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

So, convert driver write_zeroes handlers bytes parameter to int64_t.

The only caller of all updated function is bdrv_co_do_pwrite_zeroes().

bdrv_co_do_pwrite_zeroes() itself is of course OK with widening of
callee parameter type. Also, bdrv_co_do_pwrite_zeroes()'s
max_write_zeroes is limited to INT_MAX. So, updated functions all are
safe, they will not get "bytes" larger than before.

Still, let's look through all updated functions, and add assertions to
the ones which are actually unprepared to values larger than INT_MAX.
For these drivers also set explicit max_pwrite_zeroes limit.

Let's go:

blkdebug: calculations can't overflow, thanks to
  bdrv_check_qiov_request() in generic layer. rule_check() and
  bdrv_co_pwrite_zeroes() both have 64bit argument.

blklogwrites: pass to blk_log_writes_co_log() with 64bit argument.

blkreplay, copy-on-read, filter-compress: pass to
  bdrv_co_pwrite_zeroes() which is OK

copy-before-write: Calls cbw_do_copy_before_write() and
  bdrv_co_pwrite_zeroes, both have 64bit argument.

file-posix: both handler calls raw_do_pwrite_zeroes, which is updated.
  In raw_do_pwrite_zeroes() calculations are OK due to
  bdrv_check_qiov_request(), bytes go to RawPosixAIOData::aio_nbytes
  which is uint64_t.
  Check also where that uint64_t gets handed:
  handle_aiocb_write_zeroes_block() passes a uint64_t[2] to
  ioctl(BLKZEROOUT), handle_aiocb_write_zeroes() calls do_fallocate()
  which takes off_t (and we compile to always have 64-bit off_t), as
  does handle_aiocb_write_zeroes_unmap. All look safe.

gluster: bytes go to GlusterAIOCB::size which is int64_t and to
  glfs_zerofill_async works with off_t.

iscsi: Aha, here we deal with iscsi_writesame16_task() that has
  uint32_t num_blocks argument and iscsi_writesame16_task() has
  uint16_t argument. Make comments, add assertions and clarify
  max_pwrite_zeroes calculation.
  iscsi_allocmap_() functions already has int64_t argument
  is_byte_request_lun_aligned is simple to update, do it.

mirror_top: pass to bdrv_mirror_top_do_write which has uint64_t
  argument

nbd: Aha, here we have protocol limitation, and NBDRequest::len is
  uint32_t. max_pwrite_zeroes is cleanly set to 32bit value, so we are
  OK for now.

nvme: Again, protocol limitation. And no inherent limit for
  write-zeroes at all. But from code that calculates cdw12 it's obvious
  that we do have limit and alignment. Let's clarify it. Also,
  obviously the code is not prepared to handle bytes=0. Let's handle
  this case too.
  trace events already 64bit

preallocate: pass to handle_write() and bdrv_co_pwrite_zeroes(), both
  64bit.

rbd: pass to qemu_rbd_start_co() which is 64bit.

qcow2: offset + bytes and alignment still works good (thanks to
  bdrv_check_qiov_request()), so tail calculation is OK
  qcow2_subcluster_zeroize() has 64bit argument, should be OK
  trace events updated

qed: qed_co_request wants int nb_sectors. Also in code we have size_t
  used for request length which may be 32bit. So, let's just keep
  INT_MAX as a limit (aligning it down to pwrite_zeroes_alignment) and
  don't care.

raw-format: Is OK. raw_adjust_offset and bdrv_co_pwrite_zeroes are both
  64bit.

throttle: Both throttle_group_co_io_limits_intercept() and
  bdrv_co_pwrite_zeroes() are 64bit.

vmdk: pass to vmdk_pwritev which is 64bit

quorum: pass to quorum_co_pwritev() which is 64bit

Hooray!

At this point all block drivers are prepared to support 64bit
write-zero requests, or have explicitly set max_pwrite_zeroes.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210903102807.27127-8-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: use <= rather than < in assertions relying on max_pwrite_zeroes]
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-09-29 13:46:32 -05:00
Vladimir Sementsov-Ogievskiy
485350497b block: use int64_t instead of uint64_t in copy_range driver handlers
We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

So, convert driver copy_range handlers parameters which are already
64bit to signed type.

Now let's consider all callers. Simple

  git grep '\->bdrv_co_copy_range'

shows the only caller:

  bdrv_co_copy_range_internal(), which does bdrv_check_request32(),
  so everything is OK.

Still, the functions may be called directly, not only by drv->...
Let's check:

git grep '\.bdrv_co_copy_range_\(from\|to\)\s*=' | \
awk '{print $4}' | sed 's/,//' | sed 's/&//' | sort | uniq | \
while read func; do git grep "$func(" | \
grep -v "$func(BlockDriverState"; done

shows no more callers. So, we are done.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210903102807.27127-6-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-09-29 13:46:32 -05:00
Hanna Reitz
9dbf6455f4 block/iscsi: Do not force-cap *pnum
bdrv_co_block_status() does it for us, we do not need to do it here.

The advantage of not capping *pnum is that bdrv_co_block_status() can
cache larger data regions than requested by its caller.

Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210812084148.14458-7-hreitz@redhat.com>
2021-09-15 15:54:07 +02:00
Peter Maydell
729cc68373 Remove superfluous timer_del() calls
This commit is the result of running the timer-del-timer-free.cocci
script on the whole source tree.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Corey Minyard <cminyard@mvista.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201215154107.3255-4-peter.maydell@linaro.org
2021-01-08 15:13:38 +00:00
Gan Qixin
c208b0ef96 block/iscsi: Use lock guard macros
Replace manual lock()/unlock() calls with lock guard macros
(QEMU_LOCK_GUARD/WITH_QEMU_LOCK_GUARD) in block/iscsi.

Signed-off-by: Gan Qixin <ganqixin@huawei.com>
Message-Id: <20201203075055.127773-5-ganqixin@huawei.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-12-11 17:52:39 +01:00
Philippe Mathieu-Daudé
f68c01470b qapi: Restrict query-uuid command to machine code
Only qemu-system-FOO and qemu-storage-daemon provide QMP
monitors, therefore such declarations and definitions are
irrelevant for user-mode emulation.

Restricting the query-uuid command to machine.json pulls less
QAPI-generated code into user-mode.

Acked-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200913195348.1064154-6-philmd@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-09-29 15:41:35 +02:00
Xie Yongji
c58daf76a6 iscsi: return -EIO when sense fields are meaningless
When an I/O request failed, now we only return correct
value on scsi check condition. We should also have a
default errno such as -EIO in other case.

Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Message-Id: <20200701105444.3226-2-xieyongji@bytedance.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10 18:02:23 -04:00
Xie Yongji
dd3b00202a iscsi: handle check condition status in retry loop
The handling of check condition was incorrect because
we would only do it after retries exceed maximum.

Fixes: 8c460269aa ("iscsi: base all handling of check condition on scsi_sense_to_errno")
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Message-Id: <20200701105444.3226-1-xieyongji@bytedance.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10 18:02:23 -04:00
Markus Armbruster
af175e85f9 error: Eliminate error_propagate() with Coccinelle, part 2
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away.  The previous commit did that with a Coccinelle script I
consider fairly trustworthy.  This commit uses the same script with
the matching of return taken out, i.e. we convert

    if (!foo(..., &err)) {
        ...
        error_propagate(errp, err);
        ...
    }

to

    if (!foo(..., errp)) {
        ...
        ...
    }

This is unsound: @err could still be read between afterwards.  I don't
know how to express "no read of @err without an intervening write" in
Coccinelle.  Instead, I manually double-checked for uses of @err.

Suboptimal line breaks tweaked manually.  qdev_realize() simplified
further to placate scripts/checkpatch.pl.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-36-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
235e59cf03 qemu-option: Use returned bool to check for failure
The previous commit enables conversion of

    foo(..., &err);
    if (err) {
        ...
    }

to

    if (!foo(..., &err)) {
        ...
    }

for QemuOpts functions that now return true / false on success /
error.  Coccinelle script:

    @@
    identifier fun = {
        opts_do_parse, parse_option_bool, parse_option_number,
        parse_option_size, qemu_opt_parse, qemu_opt_rename, qemu_opt_set,
        qemu_opt_set_bool, qemu_opt_set_number, qemu_opts_absorb_qdict,
        qemu_opts_do_parse, qemu_opts_from_qdict_entry, qemu_opts_set,
        qemu_opts_validate
    };
    expression list args, args2;
    typedef Error;
    Error *err;
    @@
    -    fun(args, &err, args2);
    -    if (err)
    +    if (!fun(args, &err, args2))
         {
             ...
         }

A few line breaks tidied up manually.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-15-armbru@redhat.com>
[Conflict with commit 0b6786a9c1 "block/amend: refactor qcow2 amend
options" resolved by rerunning Coccinelle on master's version]
2020-07-10 15:17:35 +02:00
Vladimir Sementsov-Ogievskiy
32d293c8c6 block/iscsi: drop unallocated_blocks_are_zero
We set bdi->unallocated_blocks_are_zero = iscsilun->lbprz, but
iscsi_co_block_status doesn't return 0 in case of iscsilun->lbprz, it
returns ZERO when appropriate. So actually unallocated_blocks_are_zero
is useless (it doesn't affect the only user of the field:
bdrv_co_block_status()). Drop it now.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-7-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 10:34:14 +02:00
Daniel Brodsky
6e8a355de6 lockable: replaced locks with lock guard macros where appropriate
- ran regexp "qemu_mutex_lock\(.*\).*\n.*if" to find targets
- replaced result with QEMU_LOCK_GUARD if all unlocks at function end
- replaced result with WITH_QEMU_LOCK_GUARD if unlock not at end

Signed-off-by: Daniel Brodsky <dnbrdsky@gmail.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-id: 20200404042108.389635-3-dnbrdsky@gmail.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-05-04 16:07:43 +01:00
Kevin Wolf
92b92799dc block: Add flags to BlockDriver.bdrv_co_truncate()
This adds a new BdrvRequestFlags parameter to the .bdrv_co_truncate()
driver callbacks, and a supported_truncate_flags field in
BlockDriverState that allows drivers to advertise support for request
flags in the context of truncate.

For now, we always pass 0 and no drivers declare support for any flag.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200424125448.63318-2-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-04-30 17:51:07 +02:00
Chen Qun
ff0507c239 block/iscsi:fix heap-buffer-overflow in iscsi_aio_ioctl_cb
There is an overflow, the source 'datain.data[2]' is 100 bytes,
 but the 'ss' is 252 bytes.This may cause a security issue because
 we can access a lot of unrelated memory data.

The len for sbp copy data should take the minimum of mx_sb_len and
 sb_len_wr, not the maximum.

If we use iscsi device for VM backend storage, ASAN show stack:

READ of size 252 at 0xfffd149dcfc4 thread T0
    #0 0xaaad433d0d34 in __asan_memcpy (aarch64-softmmu/qemu-system-aarch64+0x2cb0d34)
    #1 0xaaad45f9d6d0 in iscsi_aio_ioctl_cb /qemu/block/iscsi.c:996:9
    #2 0xfffd1af0e2dc  (/usr/lib64/iscsi/libiscsi.so.8+0xe2dc)
    #3 0xfffd1af0d174  (/usr/lib64/iscsi/libiscsi.so.8+0xd174)
    #4 0xfffd1af19fac  (/usr/lib64/iscsi/libiscsi.so.8+0x19fac)
    #5 0xaaad45f9acc8 in iscsi_process_read /qemu/block/iscsi.c:403:5
    #6 0xaaad4623733c in aio_dispatch_handler /qemu/util/aio-posix.c:467:9
    #7 0xaaad4622f350 in aio_dispatch_handlers /qemu/util/aio-posix.c:510:20
    #8 0xaaad4622f350 in aio_dispatch /qemu/util/aio-posix.c:520
    #9 0xaaad46215944 in aio_ctx_dispatch /qemu/util/async.c:298:5
    #10 0xfffd1bed12f4 in g_main_context_dispatch (/lib64/libglib-2.0.so.0+0x512f4)
    #11 0xaaad46227de0 in glib_pollfds_poll /qemu/util/main-loop.c:219:9
    #12 0xaaad46227de0 in os_host_main_loop_wait /qemu/util/main-loop.c:242
    #13 0xaaad46227de0 in main_loop_wait /qemu/util/main-loop.c:518
    #14 0xaaad43d9d60c in qemu_main_loop /qemu/softmmu/vl.c:1662:9
    #15 0xaaad4607a5b0 in main /qemu/softmmu/main.c:49:5
    #16 0xfffd1a460b9c in __libc_start_main (/lib64/libc.so.6+0x20b9c)
    #17 0xaaad43320740 in _start (aarch64-softmmu/qemu-system-aarch64+0x2c00740)

0xfffd149dcfc4 is located 0 bytes to the right of 100-byte region [0xfffd149dcf60,0xfffd149dcfc4)
allocated by thread T0 here:
    #0 0xaaad433d1e70 in __interceptor_malloc (aarch64-softmmu/qemu-system-aarch64+0x2cb1e70)
    #1 0xfffd1af0e254  (/usr/lib64/iscsi/libiscsi.so.8+0xe254)
    #2 0xfffd1af0d174  (/usr/lib64/iscsi/libiscsi.so.8+0xd174)
    #3 0xfffd1af19fac  (/usr/lib64/iscsi/libiscsi.so.8+0x19fac)
    #4 0xaaad45f9acc8 in iscsi_process_read /qemu/block/iscsi.c:403:5
    #5 0xaaad4623733c in aio_dispatch_handler /qemu/util/aio-posix.c:467:9
    #6 0xaaad4622f350 in aio_dispatch_handlers /qemu/util/aio-posix.c:510:20
    #7 0xaaad4622f350 in aio_dispatch /qemu/util/aio-posix.c:520
    #8 0xaaad46215944 in aio_ctx_dispatch /qemu/util/async.c:298:5
    #9 0xfffd1bed12f4 in g_main_context_dispatch (/lib64/libglib-2.0.so.0+0x512f4)
    #10 0xaaad46227de0 in glib_pollfds_poll /qemu/util/main-loop.c:219:9
    #11 0xaaad46227de0 in os_host_main_loop_wait /qemu/util/main-loop.c:242
    #12 0xaaad46227de0 in main_loop_wait /qemu/util/main-loop.c:518
    #13 0xaaad43d9d60c in qemu_main_loop /qemu/softmmu/vl.c:1662:9
    #14 0xaaad4607a5b0 in main /qemu/softmmu/main.c:49:5
    #15 0xfffd1a460b9c in __libc_start_main (/lib64/libc.so.6+0x20b9c)
    #16 0xaaad43320740 in _start (aarch64-softmmu/qemu-system-aarch64+0x2c00740)

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200418062602.10776-1-kuhn.chenqun@huawei.com
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-04-20 11:31:46 +01:00
Chen Qun
34afc5c298 block/iscsi:use the flags in iscsi_open() prevent Clang warning
Clang static code analyzer show warning:
  block/iscsi.c:1920:9: warning: Value stored to 'flags' is never read
        flags &= ~BDRV_O_RDWR;
        ^        ~~~~~~~~~~~~

In iscsi_allocmap_init() only checks BDRV_O_NOCACHE, which
is the same in both of flags and bs->open_flags.
We can use the flags instead bs->open_flags to prevent Clang warning.

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200311032927.35092-1-kuhn.chenqun@huawei.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-03-27 14:47:23 +01:00
Maxim Levitsky
5a5e7f8cd8 block: trickle down the fallback image creation function use to the block 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: fd17146cd9
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>
2020-03-26 14:44:33 +01:00
Max Reitz
80f0900905 iscsi: Drop iscsi_co_create_opts()
The generic fallback implementation effectively does the same.

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200122164532.178040-5-mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-02-20 16:43:42 +01:00
Kevin Wolf
5fbf1d56c2 iscsi: Don't access non-existent scsi_lba_status_descriptor
In iscsi_co_block_status(), we may have received num_descriptors == 0
from the iscsi server. Therefore, we can't unconditionally access
lbas->descriptors[0]. Add the missing check.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Felipe Franciosi <felipe@nutanix.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
2020-01-27 17:19:53 +01:00
Felipe Franciosi
693fd2acdf iscsi: Cap block count from GET LBA STATUS (CVE-2020-1711)
When querying an iSCSI server for the provisioning status of blocks (via
GET LBA STATUS), Qemu only validates that the response descriptor zero's
LBA matches the one requested. Given the SCSI spec allows servers to
respond with the status of blocks beyond the end of the LUN, Qemu may
have its heap corrupted by clearing/setting too many bits at the end of
its allocmap for the LUN.

A malicious guest in control of the iSCSI server could carefully program
Qemu's heap (by selectively setting the bitmap) and then smash it.

This limits the number of bits that iscsi_co_block_status() will try to
update in the allocmap so it can't overflow the bitmap.

Fixes: CVE-2020-1711
Cc: qemu-stable@nongnu.org
Signed-off-by: Felipe Franciosi <felipe@nutanix.com>
Signed-off-by: Peter Turschmid <peter.turschm@nutanix.com>
Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-01-27 17:19:53 +01:00
Max Reitz
82325ae5f2 block: Evaluate @exact in protocol drivers
We have two protocol drivers that return success when trying to shrink a
block device even though they cannot shrink it.  This behavior is now
only allowed with exact=false, so they should return an error with
exact=true.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190918095144.955-6-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28 12:05:24 +01:00
Max Reitz
c80d8b06cf block: Add @exact parameter to bdrv_co_truncate()
We have two drivers (iscsi and file-posix) that (in some cases) return
success from their .bdrv_co_truncate() implementation if the block
device is larger than the requested offset, but cannot be shrunk.  Some
callers do not want that behavior, so this patch adds a new parameter
that they can use to turn off that behavior.

This patch just adds the parameter and lets the block/io.c and
block/block-backend.c functions pass it around.  All other callers
always pass false and none of the implementations evaluate it, so that
this patch does not change existing behavior.  Future patches take care
of that.

Suggested-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190918095144.955-5-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28 12:00:07 +01:00
Pavel Dovgalyuk
e4ec5ad464 replay: add BH oneshot event for block layer
Replay is capable of recording normal BH events, but sometimes
there are single use callbacks scheduled with aio_bh_schedule_oneshot
function. This patch enables recording and replaying such callbacks.
Block layer uses these events for calling the completion function.
Replaying these calls makes the execution deterministic.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-10-14 17:12:48 +02:00
Paolo Bonzini
8c460269aa iscsi: base all handling of check condition on scsi_sense_to_errno
Now that scsi-disk is not using scsi_sense_to_errno to separate guest-recoverable
sense codes, we can modify it to simplify iscsi's own sense handling.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-07-15 11:20:42 +02:00
Paolo Bonzini
00e3cccdf4 iscsi: fix busy/timeout/task set full
In this case, do_retry was set without calling aio_co_wake, thus never
waking up the coroutine.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-07-15 11:20:42 +02:00
Markus Armbruster
a8d2532645 Include qemu-common.h exactly where needed
No header includes qemu-common.h after this commit, as prescribed by
qemu-common.h's file comment.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-5-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c
block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c
target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h
target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h
target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h
target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and
net/tap-bsd.c fixed up]
2019-06-12 13:20:20 +02:00
Markus Armbruster
0b8fa32f55 Include qemu/module.h where needed, drop it from qemu-common.h
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-4-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
hw/usb/dev-hub.c hw/misc/exynos4210_rng.c hw/misc/bcm2835_rng.c
hw/misc/aspeed_scu.c hw/display/virtio-vga.c hw/arm/stm32f205_soc.c;
ui/cocoa.m fixed up]
2019-06-12 13:18:33 +02:00
Philippe Mathieu-Daudé
d4cef0c67c block/iscsi: Restrict Linux-specific code
Some Linux specific code is missing guards, leading to
build failure on OSX:

  $ sudo brew install libiscsi
  $ ./configure && make
  [...]
    CC      block/iscsi.o
  qemu/block/iscsi.c:338:24: error: 'iscsi_aiocb_info' defined but not used [-Werror=unused-const-variable=]
   static const AIOCBInfo iscsi_aiocb_info = {
                          ^~~~~~~~~~~~~~~~
  qemu/block/iscsi.c:168:1: error: 'iscsi_schedule_bh' defined but not used [-Werror=unused-function]
   iscsi_schedule_bh(IscsiAIOCB *acb)
   ^~~~~~~~~~~~~~~~~
  cc1: all warnings being treated as errors

Add guards to restrict this code for Linux.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190220000553.28438-1-philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-03-11 16:33:49 +01:00
Max Reitz
2654267cc1 block: Add strong_runtime_opts to BlockDriver
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>
2019-02-25 15:11:27 +01:00
Thomas Huth
df71ca84e4 block: Work-around a bug in libiscsi 1.9.0 when used in gnu99 mode
The header "scsi-lowlevel.h" of libiscsi 1.9.0 contains some bad
"inline" prototype definitions which GCC refuses to compile in its
gnu99 mode:

In file included from block/iscsi.c:52:0:
/usr/include/iscsi/scsi-lowlevel.h:810:13: error: inline function
‘scsi_set_uint16’ declared but never defined [-Werror]
 inline void scsi_set_uint16(unsigned char *c, uint16_t val);
             ^
/usr/include/iscsi/scsi-lowlevel.h:809:13: error: inline function
‘scsi_set_uint32’ declared but never defined [-Werror]
 inline void scsi_set_uint32(unsigned char *c, uint32_t val);
             ^
[...]

This has been fixed by upstream libiscsi in version 1.10.0 (see
https://github.com/sahlberg/libiscsi/commit/7692027d6c11 ), but
since we still want to support 1.9.0 for CentOS 7 / RHEL7, we
have to work-around the issue by redefining the "inline" keyword
to use the old "gnu89" mode behavior via "gnu_inline" instead.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2019-01-22 06:26:32 +01:00
Stefan Hajnoczi
88e94fd238 block/iscsi: cancel libiscsi task when ABORT TASK TMF completes
The libiscsi iscsi_task_mgmt_async() API documentation says:

  abort_task will also cancel the scsi task. The callback for the scsi
  task will be invoked with SCSI_STATUS_CANCELLED

The libiscsi implementation does not fulfil this promise.  The task's
callback is not invoked and its struct iscsi_pdu remains in the internal
list (effectively leaked).

This patch invokes the libiscsi iscsi_scsi_cancel_task() API to force
the task's callback to be invoked with SCSI_STATUS_CANCELLED when the
ABORT TASK TMF completes and the task's callback hasn't been invoked
yet.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20180215111526.2464-1-stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-01-11 13:57:24 +01:00
Stefan Hajnoczi
c100448790 block/iscsi: fix ioctl cancel use-after-free
iscsi_aio_cancel() does not increment the request's reference count,
causing a use-after-free when ABORT TASK finishes after the request has
already completed.

There are some additional issues with iscsi_aio_cancel():
1. Several ABORT TASKs may be sent for the same task if
   iscsi_aio_cancel() is invoked multiple times.  It's better to avoid
   this just in case the command identifier is reused.
2. The iscsilun->mutex protection is missing in iscsi_aio_cancel().

Reported-by: Felipe Franciosi <felipe@nutanix.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20180203061621.7033-4-stefanha@redhat.com>
Reviewed-by: Felipe Franciosi <felipe@nutanix.com>
Tested-by: Sreejith Mohanan <sreejit.mohanan@nutanix.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-01-11 13:57:24 +01:00
Stefan Hajnoczi
83d11973fa block/iscsi: take iscsilun->mutex in iscsi_timed_check_events()
Commit d045c466d9 ("iscsi: do not use
aio_context_acquire/release") introduced iscsilun->mutex but appears to
have overlooked iscsi_timed_check_events() when introducing the mutex.

iscsi_service() and iscsi_set_events() must be called with
iscsilun->mutex held.

iscsi_timed_check_events() is invoked from the AioContext and does not
take the mutex.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20180203061621.7033-3-stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-01-11 13:57:24 +01:00
Stefan Hajnoczi
f92fa85f98 block/iscsi: drop unused IscsiAIOCB->buf field
The IscsiAIOCB->buf field has not been used since commit
e49ab19fca ("block/iscsi: bump libiscsi
requirement to 1.9.0").  It used to be a linear buffer for old libiscsi
versions that didn't support scatter-gather.  The minimum libiscsi
version supports scatter-gather so we don't linearize buffers anymore.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20180203061621.7033-2-stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-01-11 13:57:24 +01:00
Kevin Wolf
8f3bf50d34 iscsi: Support auto-read-only option
If read-only=off, but auto-read-only=on is given, open the volume
read-write if we have the permissions, but instead of erroring out for
read-only volumes, just degrade to read-only.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2018-11-05 15:09:55 +01:00
Markus Armbruster
5197f44584 block: Use warn_report() & friends to report warnings
Calling error_report() in a function that takes an Error ** argument
is suspicious.  Convert a few that are actually warnings to
warn_report().

While there, split warnings consisting of multiple sentences to
conform to conventions spelled out in warn_report()'s contract, and
improve a rather useless warning in sheepdog.c.

Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Lieven <pl@kamp.de>
Cc: Liu Yuan <namei.unix@gmail.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20181017082702.5581-4-armbru@redhat.com>

Drop changes to "without an explicit read-only=on" warnings, because
there's a series removing them pending.  Also drop a cc: to a former
Sheepdog maintainer.

Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2018-10-19 14:51:34 +02:00
Fam Zheng
ecc983a507 block: Add copy offloading trace points
A few trace points that can help reveal what is happening in a copy
offloading I/O path.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-07-10 16:01:52 +02:00
Vladimir Sementsov-Ogievskiy
67b51fb998 block: split flags in copy_range
Pass read flags and write flags separately. This is needed to handle
coming BDRV_REQ_NO_SERIALISING clearly in following patches.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-07-10 13:04:25 +02:00
Eric Blake
8ee1cef459 iscsi: Avoid potential for get_status overflow
Detected by Coverity: Multiplying two 32-bit int and assigning
the result to a 64-bit number is a risk of overflow.  Prior to
the conversion to byte-based interfaces, the block layer took
care of ensuring that a status request never exceeded 2G in
the driver; but after that conversion, the block layer expects
drivers to deal with any size request (the driver can always
truncate the request size back down, as long as it makes
progress).  So, in the off-chance that someone makes a large
request, we are at the mercy of whether iscsi_get_lba_status_task()
will cap things to at most INT_MAX / iscsilun->block_size when
it populates lbasd->num_blocks; since I could not easily audit
that, it's better to be safe than sorry by just forcing a 64-bit
multiply.

Fixes: 92809c36
CC: qemu-stable@nongnu.org
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180508212718.1482663-1-eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2018-07-02 14:28:26 -05:00
Fam Zheng
1439b9c110 iscsi: Don't blindly use designator length in response for memcpy
Per SCSI definition the designator_length we receive from INQUIRY is 8,
12 or at most 16, but we should be careful because the remote iscsi
target may misbehave, otherwise we could have a buffer overflow.

Reported-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-06-29 14:20:56 +02:00
Kevin Wolf
061ca8a368 block: Convert .bdrv_truncate callback to coroutine_fn
bdrv_truncate() is an operation that can block (even for a quite long
time, depending on the PreallocMode) in I/O paths that shouldn't block.
Convert it to a coroutine_fn so that we have the infrastructure for
drivers to make their .bdrv_co_truncate implementation asynchronous.

This change could potentially introduce new race conditions because
bdrv_truncate() isn't necessarily executed atomically any more. Whether
this is a problem needs to be evaluated for each block driver that
supports truncate:

* file-posix/win32, gluster, iscsi, nfs, rbd, ssh, sheepdog: The
  protocol drivers are trivially safe because they don't actually yield
  yet, so there is no change in behaviour.

* copy-on-read, crypto, raw-format: Essentially just filter drivers that
  pass the request to a child node, no problem.

* qcow2: The implementation modifies metadata, so it needs to hold
  s->lock to be safe with concurrent I/O requests. In order to avoid
  double locking, this requires pulling the locking out into
  preallocate_co() and using qcow2_write_caches() instead of
  bdrv_flush().

* qed: Does a single header update, this is fine without locking.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-06-29 14:20:56 +02:00
Max Reitz
609f45ea95 block: Add block-specific QDict header
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>
2018-06-15 14:49:44 +02:00