io_uring/rsrc: remove io_rsrc_node::done

Kill io_rsrc_node::node and check refs instead, it's set when the nodes
refcount hits zero, and it won't change afterwards.

Signed-off-by: Pavel Begunkov <a

io_uring/rsrc: remove io_rsrc_node::done

Kill io_rsrc_node::node and check refs instead, it's set when the nodes
refcount hits zero, and it won't change afterwards.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/bbde361f4010f7e8bf196f1ecca27a763b79926f.1681395792.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

show more ...

io_uring/rsrc: use nospec'ed indexes

We use array_index_nospec() for registered buffer indexes, but don't use
it while poking into rsrc tags, fix that.

Fixes: 634d00df5e1cf ("io_uring: add full-fle

io_uring/rsrc: use nospec'ed indexes

We use array_index_nospec() for registered buffer indexes, but don't use
it while poking into rsrc tags, fix that.

Fixes: 634d00df5e1cf ("io_uring: add full-fledged dynamic buffers support")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f02fafc5a9c0dd69be2b0618c38831c078232ff0.1681395792.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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io_uring/rsrc: extract SCM file put helper

SCM file accounting is a slow path and is only used for UNIX files.
Extract a helper out of io_rsrc_file_put() that does the SCM
unaccounting.

Signed-off-

io_uring/rsrc: extract SCM file put helper

SCM file accounting is a slow path and is only used for UNIX files.
Extract a helper out of io_rsrc_file_put() that does the SCM
unaccounting.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/58cc7bffc2ee96bec8c2b89274a51febcbfa5556.1681210788.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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io_uring/rsrc: refactor io_rsrc_node_switch

We use io_rsrc_node_switch() coupled with io_rsrc_node_switch_start()
for a bunch of cases including initialising ctx->rsrc_node, i.e. by
passing NULL ins

io_uring/rsrc: refactor io_rsrc_node_switch

We use io_rsrc_node_switch() coupled with io_rsrc_node_switch_start()
for a bunch of cases including initialising ctx->rsrc_node, i.e. by
passing NULL instead of rsrc_data. Leave it to only deal with actual
node changing.

For that, first remove it from io_uring_create() and add a function
allocating the first node. Then also remove all calls to
io_rsrc_node_switch() from files/buffers register as we already have a
node installed and it does essentially nothing.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d146fe306ff98b1a5a60c997c252534f03d423d7.1681210788.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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io_uring/rsrc: zero node's rsrc data on alloc

struct io_rsrc_node::rsrc_data field is initialised on rsrc removal and
shouldn't be used before that, still let's play safe and zero the field
on alloc

io_uring/rsrc: zero node's rsrc data on alloc

struct io_rsrc_node::rsrc_data field is initialised on rsrc removal and
shouldn't be used before that, still let's play safe and zero the field
on alloc.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/09bd03cedc8da8a7974c5e6e4bf0489fd16593ab.1681210788.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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io_uring/rsrc: consolidate node caching

We store one pre-allocated rsrc node in ->rsrc_backup_node, merge it
with ->rsrc_node_cache.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: htt

io_uring/rsrc: consolidate node caching

We store one pre-allocated rsrc node in ->rsrc_backup_node, merge it
with ->rsrc_node_cache.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6d5410e51ccd29be7a716be045b51d6b371baef6.1681210788.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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io_uring/rsrc: add lockdep checks

Add a lockdep chek to make sure that file and buffer updates hold
->uring_lock.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.or

io_uring/rsrc: add lockdep checks

Add a lockdep chek to make sure that file and buffer updates hold
->uring_lock.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/961bbe6e433ec9bc0375127f23468b37b729df99.1681210788.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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io_uring/rsrc: optimise io_rsrc_data refcounting

Every struct io_rsrc_node takes a struct io_rsrc_data reference, which
means all rsrc updates do 2 extra atomics. Replace atomics refcounting
with a

io_uring/rsrc: optimise io_rsrc_data refcounting

Every struct io_rsrc_node takes a struct io_rsrc_data reference, which
means all rsrc updates do 2 extra atomics. Replace atomics refcounting
with a int as it's all done under ->uring_lock.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e73c3d6820cf679532696d790b5b8fae23537213.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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io_uring/rsrc: add lockdep sanity checks

We should hold ->uring_lock while putting nodes with io_put_rsrc_node(),
add a lockdep check for that.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com

io_uring/rsrc: add lockdep sanity checks

We should hold ->uring_lock while putting nodes with io_put_rsrc_node(),
add a lockdep check for that.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b50d5f156ac41450029796738c1dfd22a521df7a.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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io_uring/rsrc: cache struct io_rsrc_node

Add allocation cache for struct io_rsrc_node, it's always allocated and
put under ->uring_lock, so it doesn't need any extra synchronisation
around caches.

io_uring/rsrc: cache struct io_rsrc_node

Add allocation cache for struct io_rsrc_node, it's always allocated and
put under ->uring_lock, so it doesn't need any extra synchronisation
around caches.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/252a9d9ef9654e6467af30fdc02f57c0118fb76e.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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io_uring/rsrc: don't offload node free

struct delayed_work rsrc_put_work was previously used to offload node
freeing because io_rsrc_node_ref_zero() was previously called by RCU in
the IRQ context.

io_uring/rsrc: don't offload node free

struct delayed_work rsrc_put_work was previously used to offload node
freeing because io_rsrc_node_ref_zero() was previously called by RCU in
the IRQ context. Now, as percpu refcounting is gone, we can do it
eagerly at the spot without pushing it to a worker.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/13fb1aac1e8d068ad8fd4a0c6d0d157ab61b90c0.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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io_uring/rsrc: optimise io_rsrc_put allocation

Every io_rsrc_node keeps a list of items to put, and all entries are
kmalloc()'ed. However, it's quite often to queue up only one entry per
node, so le

io_uring/rsrc: optimise io_rsrc_put allocation

Every io_rsrc_node keeps a list of items to put, and all entries are
kmalloc()'ed. However, it's quite often to queue up only one entry per
node, so let's add an inline entry there to avoid extra allocations.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/c482c1c652c45c85ac52e67c974bc758a50fed5f.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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io_uring/rsrc: rename rsrc_list

We have too many "rsrc" around which makes the name of struct
io_rsrc_node::rsrc_list confusing. The field is responsible for keeping
a list of files or buffers, so c

io_uring/rsrc: rename rsrc_list

We have too many "rsrc" around which makes the name of struct
io_rsrc_node::rsrc_list confusing. The field is responsible for keeping
a list of files or buffers, so call it item_list and add comments
around.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/3e34d4dfc1fdbb6b520f904ee6187c2ccf680efe.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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io_uring/rsrc: kill rsrc_ref_lock

We use ->rsrc_ref_lock spinlock to protect ->rsrc_ref_list in
io_rsrc_node_ref_zero(). Now we removed pcpu refcounting, which means
io_rsrc_node_ref_zero() is not e

io_uring/rsrc: kill rsrc_ref_lock

We use ->rsrc_ref_lock spinlock to protect ->rsrc_ref_list in
io_rsrc_node_ref_zero(). Now we removed pcpu refcounting, which means
io_rsrc_node_ref_zero() is not executed from the irq context as an RCU
callback anymore, and we also put it under ->uring_lock.
io_rsrc_node_switch(), which queues up nodes into the list, is also
protected by ->uring_lock, so we can safely get rid of ->rsrc_ref_lock.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6b60af883c263551190b526a55ff2c9d5ae07141.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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io_uring/rsrc: protect node refs with uring_lock

Currently, for nodes we have an atomic counter and some cached
(non-atomic) refs protected by uring_lock. Let's put all ref
manipulations under uring

io_uring/rsrc: protect node refs with uring_lock

Currently, for nodes we have an atomic counter and some cached
(non-atomic) refs protected by uring_lock. Let's put all ref
manipulations under uring_lock and get rid of the atomic part.
It's free as in all cases we care about we already hold the lock.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/25b142feed7d831008257d90c8b17c0115d4fc15.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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io_uring/rsrc: keep cached refs per node

We cache refs of the current node (i.e. ctx->rsrc_node) in
ctx->rsrc_cached_refs. We'll be moving away from atomics, so move the
cached refs in struct io_rsr

io_uring/rsrc: keep cached refs per node

We cache refs of the current node (i.e. ctx->rsrc_node) in
ctx->rsrc_cached_refs. We'll be moving away from atomics, so move the
cached refs in struct io_rsrc_node for now. It's a prep patch and
shouldn't change anything in practise.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9edc3669c1d71b06c2dca78b2b2b8bb9292738b9.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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io_uring/rsrc: use non-pcpu refcounts for nodes

One problem with the current rsrc infra is that often updates will
generates lots of rsrc nodes, each carry pcpu refs. That takes quite a
lot of memor

io_uring/rsrc: use non-pcpu refcounts for nodes

One problem with the current rsrc infra is that often updates will
generates lots of rsrc nodes, each carry pcpu refs. That takes quite a
lot of memory, especially if there is a stall, and takes lots of CPU
cycles. Only pcpu allocations takes >50 of CPU with a naive benchmark
updating files in a loop.

Replace pcpu refs with normal refcounting. There is already a hot path
avoiding atomics / refs, but following patches will further improve it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e9ed8a9457b331a26555ff9443afc64cdaab7247.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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io_uring/rsrc: fix null-ptr-deref in io_file_bitmap_get()

When fixed files are unregistered, file_alloc_end and alloc_hint
are not cleared. This can later cause a NULL pointer dereference in
io_file

io_uring/rsrc: fix null-ptr-deref in io_file_bitmap_get()

When fixed files are unregistered, file_alloc_end and alloc_hint
are not cleared. This can later cause a NULL pointer dereference in
io_file_bitmap_get() if auto index selection is enabled via
IORING_FILE_INDEX_ALLOC:

[ 6.519129] BUG: kernel NULL pointer dereference, address: 0000000000000000
[...]
[ 6.541468] RIP: 0010:_find_next_zero_bit+0x1a/0x70
[...]
[ 6.560906] Call Trace:
[ 6.561322] <TASK>
[ 6.561672] io_file_bitmap_get+0x38/0x60
[ 6.562281] io_fixed_fd_install+0x63/0xb0
[ 6.562851] ? __pfx_io_socket+0x10/0x10
[ 6.563396] io_socket+0x93/0xf0
[ 6.563855] ? __pfx_io_socket+0x10/0x10
[ 6.564411] io_issue_sqe+0x5b/0x3d0
[ 6.564914] io_submit_sqes+0x1de/0x650
[ 6.565452] __do_sys_io_uring_enter+0x4fc/0xb20
[ 6.566083] ? __do_sys_io_uring_register+0x11e/0xd80
[ 6.566779] do_syscall_64+0x3c/0x90
[ 6.567247] entry_SYSCALL_64_after_hwframe+0x72/0xdc
[...]

To fix the issue, set file alloc range and alloc_hint to zero after
file tables are freed.

Cc: stable@vger.kernel.org
Fixes: 4278a0deb1f6 ("io_uring: defer alloc_hint update to io_file_bitmap_set()")
Signed-off-by: Savino Dicanosa <sd7.dev@pm.me>
[axboe: add explicit bitmap == NULL check as well]
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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io_uring/rsrc: fix folio accounting

| BUG: Bad page state in process kworker/u8:0 pfn:5c001
| page:00000000bfda61c8 refcount:0 mapcount:0 mapping:0000000000000000 index:0x20001 pfn:0x5c001
| head:0

io_uring/rsrc: fix folio accounting

| BUG: Bad page state in process kworker/u8:0 pfn:5c001
| page:00000000bfda61c8 refcount:0 mapcount:0 mapping:0000000000000000 index:0x20001 pfn:0x5c001
| head:0000000011409842 order:9 entire_mapcount:0 nr_pages_mapped:0 pincount:1
| anon flags: 0x3fffc00000b0004(uptodate|head|mappedtodisk|swapbacked|node=0|zone=0|lastcpupid=0xffff)
| raw: 03fffc0000000000 fffffc0000700001 ffffffff00700903 0000000100000000
| raw: 0000000000000200 0000000000000000 00000000ffffffff 0000000000000000
| head: 03fffc00000b0004 dead000000000100 dead000000000122 ffff00000a809dc1
| head: 0000000000020000 0000000000000000 00000000ffffffff 0000000000000000
| page dumped because: nonzero pincount
| CPU: 3 PID: 9 Comm: kworker/u8:0 Not tainted 6.3.0-rc2-00001-gc6811bf0cd87 #1
| Hardware name: linux,dummy-virt (DT)
| Workqueue: events_unbound io_ring_exit_work
| Call trace:
| dump_backtrace+0x13c/0x208
| show_stack+0x34/0x58
| dump_stack_lvl+0x150/0x1a8
| dump_stack+0x20/0x30
| bad_page+0xec/0x238
| free_tail_pages_check+0x280/0x350
| free_pcp_prepare+0x60c/0x830
| free_unref_page+0x50/0x498
| free_compound_page+0xcc/0x100
| free_transhuge_page+0x1f0/0x2b8
| destroy_large_folio+0x80/0xc8
| __folio_put+0xc4/0xf8
| gup_put_folio+0xd0/0x250
| unpin_user_page+0xcc/0x128
| io_buffer_unmap+0xec/0x2c0
| __io_sqe_buffers_unregister+0xa4/0x1e0
| io_ring_exit_work+0x68c/0x1188
| process_one_work+0x91c/0x1a58
| worker_thread+0x48c/0xe30
| kthread+0x278/0x2f0
| ret_from_fork+0x10/0x20

Mark reports an issue with the recent patches coalescing compound pages
while registering them in io_uring. The reason is that we try to drop
excessive references with folio_put_refs(), but pages were acquired
with pin_user_pages(), which has extra accounting and so should be put
down with matching unpin_user_pages() or at least gup_put_folio().

As a fix unpin_user_pages() all but first page instead, and let's figure
out a better API after.

Fixes: 57bebf807e2abcf8 ("io_uring/rsrc: optimise registered huge pages")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/10efd5507d6d1f05ea0f3c601830e08767e189bd.1678980230.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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io_uring: rsrc: Optimize return value variable 'ret'

The initialization assignment of the variable ret is changed to 0, only
in 'goto fail;' Use the ret variable as the function return value.

Signe

io_uring: rsrc: Optimize return value variable 'ret'

The initialization assignment of the variable ret is changed to 0, only
in 'goto fail;' Use the ret variable as the function return value.

Signed-off-by: Li zeming <zeming@nfschina.com>
Link: https://lore.kernel.org/r/20230317182538.3027-1-zeming@nfschina.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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net: reclaim skb->scm_io_uring bit

Commit 0091bfc81741 ("io_uring/af_unix: defer registered
files gc to io_uring release") added one bit to struct sk_buff.

This structure is critical for networking

net: reclaim skb->scm_io_uring bit

Commit 0091bfc81741 ("io_uring/af_unix: defer registered
files gc to io_uring release") added one bit to struct sk_buff.

This structure is critical for networking, and we try very hard
to not add bloat on it, unless absolutely required.

For instance, we can use a specific destructor as a wrapper
around unix_destruct_scm(), to identify skbs that unix_gc()
has to special case.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Cc: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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io_uring/rsrc: always initialize 'folio' to NULL

Smatch complains that:

smatch warnings:
io_uring/rsrc.c:1262 io_sqe_buffer_register() error: uninitialized symbol 'folio'.

'folio' may be used unin

io_uring/rsrc: always initialize 'folio' to NULL

Smatch complains that:

smatch warnings:
io_uring/rsrc.c:1262 io_sqe_buffer_register() error: uninitialized symbol 'folio'.

'folio' may be used uninitialized, which can happen if we end up with a
single page mapped. Ensure that we clear folio to NULL at the top so
it's always set.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/r/202302241432.YML1CD5C-lkp@intel.com/
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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io_uring/rsrc: optimise registered huge pages

When registering huge pages, internally io_uring will split them into
many PAGE_SIZE bvec entries. That's bad for performance as drivers need
to eventua

io_uring/rsrc: optimise registered huge pages

When registering huge pages, internally io_uring will split them into
many PAGE_SIZE bvec entries. That's bad for performance as drivers need
to eventually dma-map the data and will do it individually for each bvec
entry. Coalesce huge pages into one large bvec.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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io_uring/rsrc: optimise single entry advance

Iterating within the first bvec entry should be essentially free, but we
use iov_iter_advance() for that, which shows up in benchmark profiles
taking up

io_uring/rsrc: optimise single entry advance

Iterating within the first bvec entry should be essentially free, but we
use iov_iter_advance() for that, which shows up in benchmark profiles
taking up to 0.5% of CPU. Replace it with a hand coded version.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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io_uring/rsrc: disallow multi-source reg buffers

If two or more mappings go back to back to each other they can be passed
into io_uring to be registered as a single registered buffer. That would
eve

io_uring/rsrc: disallow multi-source reg buffers

If two or more mappings go back to back to each other they can be passed
into io_uring to be registered as a single registered buffer. That would
even work if mappings came from different sources, e.g. it's possible to
mix in this way anon pages and pages from shmem or hugetlb. That is not
a problem but it'd rather be less prone if we forbid such mixing.

Cc: <stable@vger.kernel.org>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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