The struct_size macro does the same calculation and is safe regarding
overflows. Though we're not expecting them to happen, use the helper for
clarity.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are temporary variables tracking the index of P and Q stripes, but
none of them is really used as such, merely for determining if the Q
stripe is present. This leads to compiler warnings with
-Wunused-but-set-variable and has been reported several times.
fs/btrfs/raid56.c: In function ‘finish_rmw’:
fs/btrfs/raid56.c:1199:6: warning: variable ‘p_stripe’ set but not used [-Wunused-but-set-variable]
1199 | int p_stripe = -1;
| ^~~~~~~~
fs/btrfs/raid56.c: In function ‘finish_parity_scrub’:
fs/btrfs/raid56.c:2356:6: warning: variable ‘p_stripe’ set but not used [-Wunused-but-set-variable]
2356 | int p_stripe = -1;
| ^~~~~~~~
Replace the two variables with one that has a clear meaning and also get
rid of the warnings. The logic that verifies that there are only 2
valid cases is unchanged.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In lock_stripe_add() we're caching the bucket for the stripe hash table
just for a single call to dereference the stripe hash.
If we just directly call rbio_bucket() we can safe the pointless local
variable.
Also move the dereferencing of the stripe hash outside of the variable
declaration block to not break over the 80 characters limit.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In lock_stripe_add() we're traversing the stripe hash list and check if
the current list element's raid_map equals is equal to the raid bio's
raid_map. If both are equal we continue processing.
If we'd check for inequality instead of equality we can reduce one level
of indentation.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Commit 9e0af23764 ("Btrfs: fix task hang under heavy compressed
write") worked around the issue that a recycled work item could get a
false dependency on the original work item due to how the workqueue code
guarantees non-reentrancy. It did so by giving different work functions
to different types of work.
However, the fixes in the previous few patches are more complete, as
they prevent a work item from being recycled at all (except for a tiny
window that the kernel workqueue code handles for us). This obsoletes
the previous fix, so we don't need the unique helpers for correctness.
The only other reason to keep them would be so they show up in stack
traces, but they always seem to be optimized to a tail call, so they
don't show up anyways. So, let's just get rid of the extra indirection.
While we're here, rename normal_work_helper() to the more informative
btrfs_work_helper().
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We only have two callers that need the integer loop iterator, and they
can easily maintain it themselves.
Suggested-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Acked-by: David Sterba <dsterba@suse.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Acked-by: Coly Li <colyli@suse.de>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Parity page is incorrectly unmapped in finish_parity_scrub(), triggering
a reference counter bug on i386, i.e.:
[ 157.662401] kernel BUG at mm/highmem.c:349!
[ 157.666725] invalid opcode: 0000 [#1] SMP PTI
The reason is that kunmap(p_page) was completely left out, so we never
did an unmap for the p_page and the loop unmapping the rbio page was
iterating over the wrong number of stripes: unmapping should be done
with nr_data instead of rbio->real_stripes.
Test case to reproduce the bug:
- create a raid5 btrfs filesystem:
# mkfs.btrfs -m raid5 -d raid5 /dev/sdb /dev/sdc /dev/sdd /dev/sde
- mount it:
# mount /dev/sdb /mnt
- run btrfs scrub in a loop:
# while :; do btrfs scrub start -BR /mnt; done
BugLink: https://bugs.launchpad.net/bugs/1812845
Fixes: 5a6ac9eacb ("Btrfs, raid56: support parity scrub on raid56")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This patch introduces one extra iterator variable to bio_for_each_segment_all(),
then we can allow bio_for_each_segment_all() to iterate over multi-page bvec.
Given it is just one mechannical & simple change on all bio_for_each_segment_all()
users, this patch does tree-wide change in one single patch, so that we can
avoid to use a temporary helper for this conversion.
Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The typos accumulate over time so once in a while time they get fixed in
a large patch.
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add fall-back code to catch failure of full_stripe_write. Proper error
handling from inside run_plug would need more code restructuring as it's
called at arbitrary points by io scheduler.
Signed-off-by: David Sterba <dsterba@suse.com>
Add helper that schedules a given function to run on the rmw workqueue.
This will replace several standalone helpers.
Signed-off-by: David Sterba <dsterba@suse.com>
In the quest to remove all stack VLA usage from the kernel[1], this
allocates the working buffers during regular init, instead of using stack
space. This refactors the allocation code a bit to make it easier
to review.
[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Remove GPL boilerplate text (long, short, one-line) and keep the rest,
ie. personal, company or original source copyright statements. Add the
SPDX header.
Signed-off-by: David Sterba <dsterba@suse.com>
Rebuild on missing device is as same as recover, after it's done, rbio
has data which is consistent with on-disk data, so it can be cached to
avoid further reads.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: David Sterba <dsterba@suse.com>
async_missing_raid56() is identical to async_read_rebuild().
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Before rbio_orig_end_io() goes to free rbio, rbio may get merged with
more bios from other rbios and rbio->bio_list becomes non-empty,
in that case, these newly merged bios don't end properly.
Once unlock_stripe() is done, rbio->bio_list will not be updated any
more and we can call bio_endio() on all queued bios.
It should only happen in error-out cases, the normal path of recover
and full stripe write have already set RBIO_RMW_LOCKED_BIT to disable
merge before doing IO, so rbio_orig_end_io() called by them doesn't
have the above issue.
Reported-by: Jérôme Carretero <cJ-ko@zougloub.eu>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since raid6 recover tries all possible combinations of failed stripes,
- when raid6 rebuild algorithm is used, i.e. raid6_datap_recov() and
raid6_2data_recov(), it may change the in-memory content of failed
stripes, if such a raid bio is cached, a later raid write rmw or recover
can steal @stripe_pages from it instead of reading from disks, such that
it carries the wrong content to do write rmw or recovery and ends up
with corruption or recovery failures.
- when raid5 rebuild algorithm is used, i.e. xor, raid bio can be cached
because the only failed stripe which contains @rbio->bio_pages gets
modified, others remain the same so that their in-memory content is
consistent with their on-disk content.
This adds a check to skip caching rbio if using raid6 recover.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Bio iterated by set_bio_pages_uptodate() is raid56 internal one, so it
will never be a BIO_CLONED bio, and since this is called by end_io
functions, bio->bi_iter.bi_size is zero, we mustn't use
bio_for_each_segment() as that is a no-op if bi_size is zero.
Fixes: 6592e58c6b ("Btrfs: fix write corruption due to bio cloning on raid5/6")
Cc: <stable@vger.kernel.org> # v4.12-rc6+
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since fail stripe index in rbio would be used to decide which
algorithm reconstruction would be run, we cannot merge rbios if
their's fail striped indexes are different, otherwise, one of the two
reconstructions would fail.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Given the above
'
if (last->operation != cur->operation)
return 0;
',
it's guaranteed that two operations are same.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There is a scenario that can end up with rebuild process failing to
return good content, i.e.
suppose that all disks can be read without problems and if the content
that was read out doesn't match its checksum, currently for raid6
btrfs at most retries twice,
- the 1st retry is to rebuild with all other stripes, it'll eventually
be a raid5 xor rebuild,
- if the 1st fails, the 2nd retry will deliberately fail parity p so
that it will do raid6 style rebuild,
however, the chances are that another non-parity stripe content also
has something corrupted, so that the above retries are not able to
return correct content, and users will think of this as data loss.
More seriouly, if the loss happens on some important internal btree
roots, it could refuse to mount.
This extends btrfs to do more retries and each retry fails only one
stripe. Since raid6 can tolerate 2 disk failures, if there is one
more failure besides the failure on which we're recovering, this can
always work.
The worst case is to retry as many times as the number of raid6 disks,
but given the fact that such a scenario is really rare in practice,
it's still acceptable.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In fact nobody is waiting on @wait's waitqueue, it can be safely
removed.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The defined wait is not used anywhere.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The local bio_list may have pending bios when doing cleanup, it can
end up with memory leak if they don't get freed.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
After mapping block with BTRFS_MAP_WRITE, parities have been sorted to
the end position, so this search can start from the first parity
stripe.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ copied changelog as a comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
Pull block layer updates from Jens Axboe:
"This is the first pull request for 4.14, containing most of the code
changes. It's a quiet series this round, which I think we needed after
the churn of the last few series. This contains:
- Fix for a registration race in loop, from Anton Volkov.
- Overflow complaint fix from Arnd for DAC960.
- Series of drbd changes from the usual suspects.
- Conversion of the stec/skd driver to blk-mq. From Bart.
- A few BFQ improvements/fixes from Paolo.
- CFQ improvement from Ritesh, allowing idling for group idle.
- A few fixes found by Dan's smatch, courtesy of Dan.
- A warning fixup for a race between changing the IO scheduler and
device remova. From David Jeffery.
- A few nbd fixes from Josef.
- Support for cgroup info in blktrace, from Shaohua.
- Also from Shaohua, new features in the null_blk driver to allow it
to actually hold data, among other things.
- Various corner cases and error handling fixes from Weiping Zhang.
- Improvements to the IO stats tracking for blk-mq from me. Can
drastically improve performance for fast devices and/or big
machines.
- Series from Christoph removing bi_bdev as being needed for IO
submission, in preparation for nvme multipathing code.
- Series from Bart, including various cleanups and fixes for switch
fall through case complaints"
* 'for-4.14/block' of git://git.kernel.dk/linux-block: (162 commits)
kernfs: checking for IS_ERR() instead of NULL
drbd: remove BIOSET_NEED_RESCUER flag from drbd_{md_,}io_bio_set
drbd: Fix allyesconfig build, fix recent commit
drbd: switch from kmalloc() to kmalloc_array()
drbd: abort drbd_start_resync if there is no connection
drbd: move global variables to drbd namespace and make some static
drbd: rename "usermode_helper" to "drbd_usermode_helper"
drbd: fix race between handshake and admin disconnect/down
drbd: fix potential deadlock when trying to detach during handshake
drbd: A single dot should be put into a sequence.
drbd: fix rmmod cleanup, remove _all_ debugfs entries
drbd: Use setup_timer() instead of init_timer() to simplify the code.
drbd: fix potential get_ldev/put_ldev refcount imbalance during attach
drbd: new disk-option disable-write-same
drbd: Fix resource role for newly created resources in events2
drbd: mark symbols static where possible
drbd: Send P_NEG_ACK upon write error in protocol != C
drbd: add explicit plugging when submitting batches
drbd: change list_for_each_safe to while(list_first_entry_or_null)
drbd: introduce drbd_recv_header_maybe_unplug
...
This fixes several instances of blk_status_t and bare errno ints being
mixed up, some of which are real bugs.
In the normal case, 0 matches BLK_STS_OK, so we don't observe any
effects of the missing conversion, but in case of errors or passes
through the repair/retry paths, the errors get mixed up.
The changes were identified using 'sparse', we don't have reports of the
buggy behaviour.
Fixes: 4e4cbee93d ("block: switch bios to blk_status_t")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This way we don't need a block_device structure to submit I/O. The
block_device has different life time rules from the gendisk and
request_queue and is usually only available when the block device node
is open. Other callers need to explicitly create one (e.g. the lightnvm
passthrough code, or the new nvme multipathing code).
For the actual I/O path all that we need is the gendisk, which exists
once per block device. But given that the block layer also does
partition remapping we additionally need a partition index, which is
used for said remapping in generic_make_request.
Note that all the block drivers generally want request_queue or
sometimes the gendisk, so this removes a layer of indirection all
over the stack.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull btrfs fixes from David Sterba:
"We've identified and fixed a silent corruption (introduced by code in
the first pull), a fixup after the blk_status_t merge and two fixes to
incremental send that Filipe has been hunting for some time"
* 'for-4.13-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
Btrfs: fix unexpected return value of bio_readpage_error
btrfs: btrfs_create_repair_bio never fails, skip error handling
btrfs: cloned bios must not be iterated by bio_for_each_segment_all
Btrfs: fix write corruption due to bio cloning on raid5/6
Btrfs: incremental send, fix invalid memory access
Btrfs: incremental send, fix invalid path for link commands
Pull btrfs updates from David Sterba:
"The core updates improve error handling (mostly related to bios), with
the usual incremental work on the GFP_NOFS (mis)use removal,
refactoring or cleanups. Except the two top patches, all have been in
for-next for an extensive amount of time.
User visible changes:
- statx support
- quota override tunable
- improved compression thresholds
- obsoleted mount option alloc_start
Core updates:
- bio-related updates:
- faster bio cloning
- no allocation failures
- preallocated flush bios
- more kvzalloc use, memalloc_nofs protections, GFP_NOFS updates
- prep work for btree_inode removal
- dir-item validation
- qgoup fixes and updates
- cleanups:
- removed unused struct members, unused code, refactoring
- argument refactoring (fs_info/root, caller -> callee sink)
- SEARCH_TREE ioctl docs"
* 'for-4.13-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (115 commits)
btrfs: Remove false alert when fiemap range is smaller than on-disk extent
btrfs: Don't clear SGID when inheriting ACLs
btrfs: fix integer overflow in calc_reclaim_items_nr
btrfs: scrub: fix target device intialization while setting up scrub context
btrfs: qgroup: Fix qgroup reserved space underflow by only freeing reserved ranges
btrfs: qgroup: Introduce extent changeset for qgroup reserve functions
btrfs: qgroup: Fix qgroup reserved space underflow caused by buffered write and quotas being enabled
btrfs: qgroup: Return actually freed bytes for qgroup release or free data
btrfs: qgroup: Cleanup btrfs_qgroup_prepare_account_extents function
btrfs: qgroup: Add quick exit for non-fs extents
Btrfs: rework delayed ref total_bytes_pinned accounting
Btrfs: return old and new total ref mods when adding delayed refs
Btrfs: always account pinned bytes when dropping a tree block ref
Btrfs: update total_bytes_pinned when pinning down extents
Btrfs: make BUG_ON() in add_pinned_bytes() an ASSERT()
Btrfs: make add_pinned_bytes() take an s64 num_bytes instead of u64
btrfs: fix validation of XATTR_ITEM dir items
btrfs: Verify dir_item in iterate_object_props
btrfs: Check name_len before in btrfs_del_root_ref
btrfs: Check name_len before reading btrfs_get_name
...
We can hardcode GFP_NOFS to btrfs_io_bio_alloc, although it means we
change it back from GFP_KERNEL in scrub. I'd rather save a few stack
bytes from not passing the gfp flags in the remaining, more imporatant,
contexts and the bio allocating API now looks more consistent.
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Update direct callers of btrfs_io_bio_alloc that do error handling, that
we can now remove.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The logic of kmalloc and vmalloc fallback is opencoded in
several places, we can now use the existing helper.
Signed-off-by: David Sterba <dsterba@suse.com>
Replace bi_error with a new bi_status to allow for a clear conversion.
Note that device mapper overloaded bi_error with a private value, which
we'll have to keep arround at least for now and thus propagate to a
proper blk_status_t value.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
When raid56 dev-replace is cancelled by running scrub, we will free
target device without waiting for in-flight bios, causing the following
NULL pointer deference or general protection failure.
BUG: unable to handle kernel NULL pointer dereference at 00000000000005e0
IP: generic_make_request_checks+0x4d/0x610
CPU: 1 PID: 11676 Comm: kworker/u4:14 Tainted: G O 4.11.0-rc2 #72
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-20170228_101828-anatol 04/01/2014
Workqueue: btrfs-endio-raid56 btrfs_endio_raid56_helper [btrfs]
task: ffff88002875b4c0 task.stack: ffffc90001334000
RIP: 0010:generic_make_request_checks+0x4d/0x610
Call Trace:
? generic_make_request+0xc7/0x360
generic_make_request+0x24/0x360
? generic_make_request+0xc7/0x360
submit_bio+0x64/0x120
? page_in_rbio+0x4d/0x80 [btrfs]
? rbio_orig_end_io+0x80/0x80 [btrfs]
finish_rmw+0x3f4/0x540 [btrfs]
validate_rbio_for_rmw+0x36/0x40 [btrfs]
raid_rmw_end_io+0x7a/0x90 [btrfs]
bio_endio+0x56/0x60
end_workqueue_fn+0x3c/0x40 [btrfs]
btrfs_scrubparity_helper+0xef/0x620 [btrfs]
btrfs_endio_raid56_helper+0xe/0x10 [btrfs]
process_one_work+0x2af/0x720
? process_one_work+0x22b/0x720
worker_thread+0x4b/0x4f0
kthread+0x10f/0x150
? process_one_work+0x720/0x720
? kthread_create_on_node+0x40/0x40
ret_from_fork+0x2e/0x40
RIP: generic_make_request_checks+0x4d/0x610 RSP: ffffc90001337bb8
In btrfs_dev_replace_finishing(), we will call
btrfs_rm_dev_replace_blocked() to wait bios before destroying the target
device when scrub is finished normally.
However when dev-replace is aborted, either due to error or cancelled by
scrub, we didn't wait for bios, this can lead to use-after-free if there
are bios holding the target device.
Furthermore, for raid56 scrub, at least 2 places are calling
btrfs_map_sblock() without protection of bio_counter, leading to the
problem.
This patch fixes the problem:
1) Wait for bio_counter before freeing target device when canceling
replace
2) When calling btrfs_map_sblock() for raid56, use bio_counter to
protect the call.
Cc: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In raid56 scenario, after trying parity recovery, we didn't set
mirror_num for btrfs_bio with failed mirror_num, hence
end_bio_extent_readpage() will report a random mirror_num in dmesg
log.
Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Variable 'walk' in lock_stripe_add() is not used. Remove it.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are loads of functions in btrfs that accept a root parameter
but only use it to obtain an fs_info pointer. Let's convert those to
just accept an fs_info pointer directly.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba
Johannes Thumshirn
Omar Sandoval
Christoph Hellwig
Linus Torvalds
Andrea Righi
Ming Lei
Andrea Gelmini
Kees Cook
Liu Bo
Liu Bo
Dmitriy Gorokh
Filipe Manana
Qu Wenruo
Elena Reshetova
Jeff Mahoney