Commit graph

1036 commits

Author SHA1 Message Date
Jens Axboe
200f3abd14 io_uring/eventfd: move eventfd handling to separate file
This is pretty nicely abstracted already, but let's move it to a separate
file rather than have it in the main io_uring file. With that, we can
also move the io_ev_fd struct and enum out of global scope.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-16 14:54:55 -06:00
Jens Axboe
60b6c075e8 io_uring/eventfd: move to more idiomatic RCU free usage
In some ways, it just "happens to work" currently with using the ops
field for both the free and signaling bit. But it depends on ordering
of operations in terms of freeing and signaling. Clean it up and use the
usual refs == 0 under RCU read side lock to determine if the ev_fd is
still valid, and use the reference to gate the freeing as well.

Fixes: 21a091b970 ("io_uring: signal registered eventfd to process deferred task work")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-16 14:54:55 -06:00
Gabriel Krisman Bertazi
f4eaf8eda8 io_uring/rsrc: Drop io_copy_iov in favor of iovec API
Instead of open coding an io_uring function to copy iovs from userspace,
rely on the existing iovec_from_user function.  While there, avoid
repeatedly zeroing the iov in the !arg case for io_sqe_buffer_register.

tested with liburing testsuite.

Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/20240523214535.31890-1-krisman@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-16 14:54:55 -06:00
Pavel Begunkov
f4a1254f2a io_uring: fix cancellation overwriting req->flags
Only the current owner of a request is allowed to write into req->flags.
Hence, the cancellation path should never touch it. Add a new field
instead of the flag, move it into the 3rd cache line because it should
always be initialised. poll_refs can move further as polling is an
involved process anyway.

It's a minimal patch, in the future we can and should find a better
place for it and remove now unused REQ_F_CANCEL_SEQ.

Fixes: 521223d7c2 ("io_uring/cancel: don't default to setting req->work.cancel_seq")
Cc: stable@vger.kernel.org
Reported-by: Li Shi <sl1589472800@gmail.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6827b129f8f0ad76fa9d1f0a773de938b240ffab.1718323430.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-13 19:25:28 -06:00
Pavel Begunkov
54559642b9 io_uring/rsrc: don't lock while !TASK_RUNNING
There is a report of io_rsrc_ref_quiesce() locking a mutex while not
TASK_RUNNING, which is due to forgetting restoring the state back after
io_run_task_work_sig() and attempts to break out of the waiting loop.

do not call blocking ops when !TASK_RUNNING; state=1 set at
[<ffffffff815d2494>] prepare_to_wait+0xa4/0x380
kernel/sched/wait.c:237
WARNING: CPU: 2 PID: 397056 at kernel/sched/core.c:10099
__might_sleep+0x114/0x160 kernel/sched/core.c:10099
RIP: 0010:__might_sleep+0x114/0x160 kernel/sched/core.c:10099
Call Trace:
 <TASK>
 __mutex_lock_common kernel/locking/mutex.c:585 [inline]
 __mutex_lock+0xb4/0x940 kernel/locking/mutex.c:752
 io_rsrc_ref_quiesce+0x590/0x940 io_uring/rsrc.c:253
 io_sqe_buffers_unregister+0xa2/0x340 io_uring/rsrc.c:799
 __io_uring_register io_uring/register.c:424 [inline]
 __do_sys_io_uring_register+0x5b9/0x2400 io_uring/register.c:613
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xd8/0x270 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x6f/0x77

Reported-by: Li Shi <sl1589472800@gmail.com>
Fixes: 4ea15b56f0 ("io_uring/rsrc: use wq for quiescing")
Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/77966bc104e25b0534995d5dbb152332bc8f31c0.1718196953.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-12 13:02:12 -06:00
Hagar Hemdan
73254a297c io_uring: fix possible deadlock in io_register_iowq_max_workers()
The io_register_iowq_max_workers() function calls io_put_sq_data(),
which acquires the sqd->lock without releasing the uring_lock.
Similar to the commit 009ad9f0c6 ("io_uring: drop ctx->uring_lock
before acquiring sqd->lock"), this can lead to a potential deadlock
situation.

To resolve this issue, the uring_lock is released before calling
io_put_sq_data(), and then it is re-acquired after the function call.

This change ensures that the locks are acquired in the correct
order, preventing the possibility of a deadlock.

Suggested-by: Maximilian Heyne <mheyne@amazon.de>
Signed-off-by: Hagar Hemdan <hagarhem@amazon.com>
Link: https://lore.kernel.org/r/20240604130527.3597-1-hagarhem@amazon.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-04 07:39:17 -06:00
Su Hui
91215f70ea io_uring/io-wq: avoid garbage value of 'match' in io_wq_enqueue()
Clang static checker (scan-build) warning:
o_uring/io-wq.c:line 1051, column 3
The expression is an uninitialized value. The computed value will
also be garbage.

'match.nr_pending' is used in io_acct_cancel_pending_work(), but it is
not fully initialized. Change the order of assignment for 'match' to fix
this problem.

Fixes: 42abc95f05 ("io-wq: decouple work_list protection from the big wqe->lock")
Signed-off-by: Su Hui <suhui@nfschina.com>
Link: https://lore.kernel.org/r/20240604121242.2661244-1-suhui@nfschina.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-04 07:39:00 -06:00
Jens Axboe
415ce0ea55 io_uring/napi: fix timeout calculation
Not quite sure what __io_napi_adjust_timeout() was attemping to do, it's
adjusting both the NAPI timeout and the general overall timeout, and
calculating a value that is never used. The overall timeout is a super
set of the NAPI timeout, and doesn't need adjusting. The only thing we
really need to care about is that the NAPI timeout doesn't exceed the
overall timeout. If a user asked for a timeout of eg 5 usec and NAPI
timeout is 10 usec, then we should not spin for 10 usec.

While in there, sanitize the time checking a bit. If we have a negative
value in the passed in timeout, discard it. Round up the value as well,
so we don't end up with a NAPI timeout for the majority of the wait,
with only a tiny sleep value at the end.

Hence the only case we need to care about is if the NAPI timeout is
larger than the overall timeout. If it is, cap the NAPI timeout at what
the overall timeout is.

Cc: stable@vger.kernel.org
Fixes: 8d0c12a80c ("io-uring: add napi busy poll support")
Reported-by: Lewis Baker <lewissbaker@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-04 07:32:45 -06:00
Jens Axboe
5fc16fa5f1 io_uring: check for non-NULL file pointer in io_file_can_poll()
In earlier kernels, it was possible to trigger a NULL pointer
dereference off the forced async preparation path, if no file had
been assigned. The trace leading to that looks as follows:

BUG: kernel NULL pointer dereference, address: 00000000000000b0
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP
CPU: 67 PID: 1633 Comm: buf-ring-invali Not tainted 6.8.0-rc3+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS unknown 2/2/2022
RIP: 0010:io_buffer_select+0xc3/0x210
Code: 00 00 48 39 d1 0f 82 ae 00 00 00 48 81 4b 48 00 00 01 00 48 89 73 70 0f b7 50 0c 66 89 53 42 85 ed 0f 85 d2 00 00 00 48 8b 13 <48> 8b 92 b0 00 00 00 48 83 7a 40 00 0f 84 21 01 00 00 4c 8b 20 5b
RSP: 0018:ffffb7bec38c7d88 EFLAGS: 00010246
RAX: ffff97af2be61000 RBX: ffff97af234f1700 RCX: 0000000000000040
RDX: 0000000000000000 RSI: ffff97aecfb04820 RDI: ffff97af234f1700
RBP: 0000000000000000 R08: 0000000000200030 R09: 0000000000000020
R10: ffffb7bec38c7dc8 R11: 000000000000c000 R12: ffffb7bec38c7db8
R13: ffff97aecfb05800 R14: ffff97aecfb05800 R15: ffff97af2be5e000
FS:  00007f852f74b740(0000) GS:ffff97b1eeec0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000b0 CR3: 000000016deab005 CR4: 0000000000370ef0
Call Trace:
 <TASK>
 ? __die+0x1f/0x60
 ? page_fault_oops+0x14d/0x420
 ? do_user_addr_fault+0x61/0x6a0
 ? exc_page_fault+0x6c/0x150
 ? asm_exc_page_fault+0x22/0x30
 ? io_buffer_select+0xc3/0x210
 __io_import_iovec+0xb5/0x120
 io_readv_prep_async+0x36/0x70
 io_queue_sqe_fallback+0x20/0x260
 io_submit_sqes+0x314/0x630
 __do_sys_io_uring_enter+0x339/0xbc0
 ? __do_sys_io_uring_register+0x11b/0xc50
 ? vm_mmap_pgoff+0xce/0x160
 do_syscall_64+0x5f/0x180
 entry_SYSCALL_64_after_hwframe+0x46/0x4e
RIP: 0033:0x55e0a110a67e
Code: ba cc 00 00 00 45 31 c0 44 0f b6 92 d0 00 00 00 31 d2 41 b9 08 00 00 00 41 83 e2 01 41 c1 e2 04 41 09 c2 b8 aa 01 00 00 0f 05 <c3> 90 89 30 eb a9 0f 1f 40 00 48 8b 42 20 8b 00 a8 06 75 af 85 f6

because the request is marked forced ASYNC and has a bad file fd, and
hence takes the forced async prep path.

Current kernels with the request async prep cleaned up can no longer hit
this issue, but for ease of backporting, let's add this safety check in
here too as it really doesn't hurt. For both cases, this will inevitably
end with a CQE posted with -EBADF.

Cc: stable@vger.kernel.org
Fixes: a76c0b31ee ("io_uring: commit non-pollable provided mapped buffers upfront")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-01 12:25:35 -06:00
Jens Axboe
18414a4a2e io_uring/net: assign kmsg inq/flags before buffer selection
syzbot reports that recv is using an uninitialized value:

=====================================================
BUG: KMSAN: uninit-value in io_req_cqe_overflow io_uring/io_uring.c:810 [inline]
BUG: KMSAN: uninit-value in io_req_complete_post io_uring/io_uring.c:937 [inline]
BUG: KMSAN: uninit-value in io_issue_sqe+0x1f1b/0x22c0 io_uring/io_uring.c:1763
 io_req_cqe_overflow io_uring/io_uring.c:810 [inline]
 io_req_complete_post io_uring/io_uring.c:937 [inline]
 io_issue_sqe+0x1f1b/0x22c0 io_uring/io_uring.c:1763
 io_wq_submit_work+0xa17/0xeb0 io_uring/io_uring.c:1860
 io_worker_handle_work+0xc04/0x2000 io_uring/io-wq.c:597
 io_wq_worker+0x447/0x1410 io_uring/io-wq.c:651
 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Uninit was stored to memory at:
 io_req_set_res io_uring/io_uring.h:215 [inline]
 io_recv_finish+0xf10/0x1560 io_uring/net.c:861
 io_recv+0x12ec/0x1ea0 io_uring/net.c:1175
 io_issue_sqe+0x429/0x22c0 io_uring/io_uring.c:1751
 io_wq_submit_work+0xa17/0xeb0 io_uring/io_uring.c:1860
 io_worker_handle_work+0xc04/0x2000 io_uring/io-wq.c:597
 io_wq_worker+0x447/0x1410 io_uring/io-wq.c:651
 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:3877 [inline]
 slab_alloc_node mm/slub.c:3918 [inline]
 __do_kmalloc_node mm/slub.c:4038 [inline]
 __kmalloc+0x6e4/0x1060 mm/slub.c:4052
 kmalloc include/linux/slab.h:632 [inline]
 io_alloc_async_data+0xc0/0x220 io_uring/io_uring.c:1662
 io_msg_alloc_async io_uring/net.c:166 [inline]
 io_recvmsg_prep_setup io_uring/net.c:725 [inline]
 io_recvmsg_prep+0xbe8/0x1a20 io_uring/net.c:806
 io_init_req io_uring/io_uring.c:2135 [inline]
 io_submit_sqe io_uring/io_uring.c:2182 [inline]
 io_submit_sqes+0x1135/0x2f10 io_uring/io_uring.c:2335
 __do_sys_io_uring_enter io_uring/io_uring.c:3246 [inline]
 __se_sys_io_uring_enter+0x40f/0x3c80 io_uring/io_uring.c:3183
 __x64_sys_io_uring_enter+0x11f/0x1a0 io_uring/io_uring.c:3183
 x64_sys_call+0x2c0/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:427
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

which appears to be io_recv_finish() reading kmsg->msg.msg_inq to decide
if it needs to set IORING_CQE_F_SOCK_NONEMPTY or not. If the recv is
entered with buffer selection, but no buffer is available, then we jump
error path which calls io_recv_finish() without having assigned
kmsg->msg_inq. This might cause an errant setting of the NONEMPTY flag
for a request get gets errored with -ENOBUFS.

Reported-by: syzbot+b1647099e82b3b349fbf@syzkaller.appspotmail.com
Fixes: 4a3223f7bf ("io_uring/net: switch io_recv() to using io_async_msghdr")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-30 14:04:37 -06:00
Breno Leitao
e112311615 io_uring/rw: Free iovec before cleaning async data
kmemleak shows that there is a memory leak in io_uring read operation,
where a buffer is allocated at iovec import, but never de-allocated.

The memory is allocated at io_async_rw->free_iovec, but, then
io_async_rw is kfreed, taking the allocated memory with it. I saw this
happening when the read operation fails with -11 (EAGAIN).

This is the kmemleak splat.

    unreferenced object 0xffff8881da591c00 (size 256):
...
      backtrace (crc 7a15bdee):
	[<00000000256f2de4>] __kmalloc+0x2d6/0x410
	[<000000007a9f5fc7>] iovec_from_user.part.0+0xc6/0x160
	[<00000000cecdf83a>] __import_iovec+0x50/0x220
	[<00000000d1d586a2>] __io_import_iovec+0x13d/0x220
	[<0000000054ee9bd2>] io_prep_rw+0x186/0x340
	[<00000000a9c0372d>] io_prep_rwv+0x31/0x120
	[<000000001d1170b9>] io_prep_readv+0xe/0x30
	[<0000000070b8eb67>] io_submit_sqes+0x1bd/0x780
	[<00000000812496d4>] __do_sys_io_uring_enter+0x3ed/0x5b0
	[<0000000081499602>] do_syscall_64+0x5d/0x170
	[<00000000de1c5a4d>] entry_SYSCALL_64_after_hwframe+0x76/0x7e

This occurs because the async data cleanup functions are not set for
read/write operations. As a result, the potentially allocated iovec in
the rw async data is not freed before the async data is released,
leading to a memory leak.

With this following patch, kmemleak does not show the leaked memory
anymore, and all liburing tests pass.

Fixes: a9165b83c1 ("io_uring/rw: always setup io_async_rw for read/write requests")
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20240530142340.1248216-1-leitao@debian.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-30 08:33:01 -06:00
Jens Axboe
06fe9b1df1 io_uring: don't attempt to mmap larger than what the user asks for
If IORING_FEAT_SINGLE_MMAP is ignored, as can happen if an application
uses an ancient liburing or does setup manually, then 3 mmap's are
required to map the ring into userspace. The kernel will still have
collapsed the mappings, however userspace may ask for mapping them
individually. If so, then we should not use the full number of ring
pages, as it may exceed the partial mapping. Doing so will yield an
-EFAULT from vm_insert_pages(), as we pass in more pages than what the
application asked for.

Cap the number of pages to match what the application asked for, for
the particular mapping operation.

Reported-by: Lucas Mülling <lmulling@proton.me>
Link: https://github.com/axboe/liburing/issues/1157
Fixes: 3ab1db3c60 ("io_uring: get rid of remap_pfn_range() for mapping rings/sqes")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-29 09:53:14 -06:00
Linus Torvalds
483a351ed4 io_uring-6.10-20240523
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Merge tag 'io_uring-6.10-20240523' of git://git.kernel.dk/linux

Pull io_uring fixes from Jens Axboe:
 "Single fix here for a regression in 6.9, and then a simple cleanup
  removing some dead code"

* tag 'io_uring-6.10-20240523' of git://git.kernel.dk/linux:
  io_uring: remove checks for NULL 'sq_offset'
  io_uring/sqpoll: ensure that normal task_work is also run timely
2024-05-23 13:41:49 -07:00
Jens Axboe
547988ad0f io_uring: remove checks for NULL 'sq_offset'
Since the 5.12 kernel release, nobody has been passing NULL as the
sq_offset pointer. Remove the checks for it being NULL or not, it will
always be valid.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-22 11:13:44 -06:00
Linus Torvalds
b6394d6f71 Assorted commits that had missed the last merge window...
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Merge tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull misc vfs updates from Al Viro:
 "Assorted commits that had missed the last merge window..."

* tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  remove call_{read,write}_iter() functions
  do_dentry_open(): kill inode argument
  kernel_file_open(): get rid of inode argument
  get_file_rcu(): no need to check for NULL separately
  fd_is_open(): move to fs/file.c
  close_on_exec(): pass files_struct instead of fdtable
2024-05-21 13:11:44 -07:00
Jens Axboe
d13ddd9c89 io_uring/sqpoll: ensure that normal task_work is also run timely
With the move to private task_work, SQPOLL neglected to also run the
normal task_work, if any is pending. This will eventually get run, but
we should run it with the private task_work to ensure that things like
a final fput() is processed in a timely fashion.

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/313824bc-799d-414f-96b7-e6de57c7e21d@gmail.com/
Reported-by: Andrew Udvare <audvare@gmail.com>
Fixes: af5d68f889 ("io_uring/sqpoll: manage task_work privately")
Tested-by: Christian Heusel <christian@heusel.eu>
Tested-by: Andrew Udvare <audvare@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-21 13:41:14 -06:00
Linus Torvalds
61307b7be4 The usual shower of singleton fixes and minor series all over MM,
documented (hopefully adequately) in the respective changelogs.  Notable
 series include:
 
 - Lucas Stach has provided some page-mapping
   cleanup/consolidation/maintainability work in the series "mm/treewide:
   Remove pXd_huge() API".
 
 - In the series "Allow migrate on protnone reference with
   MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
   MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one
   test.
 
 - In their series "Memory allocation profiling" Kent Overstreet and
   Suren Baghdasaryan have contributed a means of determining (via
   /proc/allocinfo) whereabouts in the kernel memory is being allocated:
   number of calls and amount of memory.
 
 - Matthew Wilcox has provided the series "Various significant MM
   patches" which does a number of rather unrelated things, but in largely
   similar code sites.
 
 - In his series "mm: page_alloc: freelist migratetype hygiene" Johannes
   Weiner has fixed the page allocator's handling of migratetype requests,
   with resulting improvements in compaction efficiency.
 
 - In the series "make the hugetlb migration strategy consistent" Baolin
   Wang has fixed a hugetlb migration issue, which should improve hugetlb
   allocation reliability.
 
 - Liu Shixin has hit an I/O meltdown caused by readahead in a
   memory-tight memcg.  Addressed in the series "Fix I/O high when memory
   almost met memcg limit".
 
 - In the series "mm/filemap: optimize folio adding and splitting" Kairui
   Song has optimized pagecache insertion, yielding ~10% performance
   improvement in one test.
 
 - Baoquan He has cleaned up and consolidated the early zone
   initialization code in the series "mm/mm_init.c: refactor
   free_area_init_core()".
 
 - Baoquan has also redone some MM initializatio code in the series
   "mm/init: minor clean up and improvement".
 
 - MM helper cleanups from Christoph Hellwig in his series "remove
   follow_pfn".
 
 - More cleanups from Matthew Wilcox in the series "Various page->flags
   cleanups".
 
 - Vlastimil Babka has contributed maintainability improvements in the
   series "memcg_kmem hooks refactoring".
 
 - More folio conversions and cleanups in Matthew Wilcox's series
 
 	"Convert huge_zero_page to huge_zero_folio"
 	"khugepaged folio conversions"
 	"Remove page_idle and page_young wrappers"
 	"Use folio APIs in procfs"
 	"Clean up __folio_put()"
 	"Some cleanups for memory-failure"
 	"Remove page_mapping()"
 	"More folio compat code removal"
 
 - David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb
   functions to work on folis".
 
 - Code consolidation and cleanup work related to GUP's handling of
   hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".
 
 - Rick Edgecombe has developed some fixes to stack guard gaps in the
   series "Cover a guard gap corner case".
 
 - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series
   "mm/ksm: fix ksm exec support for prctl".
 
 - Baolin Wang has implemented NUMA balancing for multi-size THPs.  This
   is a simple first-cut implementation for now.  The series is "support
   multi-size THP numa balancing".
 
 - Cleanups to vma handling helper functions from Matthew Wilcox in the
   series "Unify vma_address and vma_pgoff_address".
 
 - Some selftests maintenance work from Dev Jain in the series
   "selftests/mm: mremap_test: Optimizations and style fixes".
 
 - Improvements to the swapping of multi-size THPs from Ryan Roberts in
   the series "Swap-out mTHP without splitting".
 
 - Kefeng Wang has significantly optimized the handling of arm64's
   permission page faults in the series
 
 	"arch/mm/fault: accelerate pagefault when badaccess"
 	"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"
 
 - GUP cleanups from David Hildenbrand in "mm/gup: consistently call it
   GUP-fast".
 
 - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to
   use struct vm_fault".
 
 - selftests build fixes from John Hubbard in the series "Fix
   selftests/mm build without requiring "make headers"".
 
 - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
   series "Improved Memory Tier Creation for CPUless NUMA Nodes".  Fixes
   the initialization code so that migration between different memory types
   works as intended.
 
 - David Hildenbrand has improved follow_pte() and fixed an errant driver
   in the series "mm: follow_pte() improvements and acrn follow_pte()
   fixes".
 
 - David also did some cleanup work on large folio mapcounts in his
   series "mm: mapcount for large folios + page_mapcount() cleanups".
 
 - Folio conversions in KSM in Alex Shi's series "transfer page to folio
   in KSM".
 
 - Barry Song has added some sysfs stats for monitoring multi-size THP's
   in the series "mm: add per-order mTHP alloc and swpout counters".
 
 - Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled
   and limit checking cleanups".
 
 - Matthew Wilcox has been looking at buffer_head code and found the
   documentation to be lacking.  The series is "Improve buffer head
   documentation".
 
 - Multi-size THPs get more work, this time from Lance Yang.  His series
   "mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes
   the freeing of these things.
 
 - Kemeng Shi has added more userspace-visible writeback instrumentation
   in the series "Improve visibility of writeback".
 
 - Kemeng Shi then sent some maintenance work on top in the series "Fix
   and cleanups to page-writeback".
 
 - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the
   series "Improve anon_vma scalability for anon VMAs".  Intel's test bot
   reported an improbable 3x improvement in one test.
 
 - SeongJae Park adds some DAMON feature work in the series
 
 	"mm/damon: add a DAMOS filter type for page granularity access recheck"
 	"selftests/damon: add DAMOS quota goal test"
 
 - Also some maintenance work in the series
 
 	"mm/damon/paddr: simplify page level access re-check for pageout"
 	"mm/damon: misc fixes and improvements"
 
 - David Hildenbrand has disabled some known-to-fail selftests ni the
   series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL".
 
 - memcg metadata storage optimizations from Shakeel Butt in "memcg:
   reduce memory consumption by memcg stats".
 
 - DAX fixes and maintenance work from Vishal Verma in the series
   "dax/bus.c: Fixups for dax-bus locking".
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Merge tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull mm updates from Andrew Morton:
 "The usual shower of singleton fixes and minor series all over MM,
  documented (hopefully adequately) in the respective changelogs.
  Notable series include:

   - Lucas Stach has provided some page-mapping cleanup/consolidation/
     maintainability work in the series "mm/treewide: Remove pXd_huge()
     API".

   - In the series "Allow migrate on protnone reference with
     MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
     MPOL_PREFERRED_MANY mode, yielding almost doubled performance in
     one test.

   - In their series "Memory allocation profiling" Kent Overstreet and
     Suren Baghdasaryan have contributed a means of determining (via
     /proc/allocinfo) whereabouts in the kernel memory is being
     allocated: number of calls and amount of memory.

   - Matthew Wilcox has provided the series "Various significant MM
     patches" which does a number of rather unrelated things, but in
     largely similar code sites.

   - In his series "mm: page_alloc: freelist migratetype hygiene"
     Johannes Weiner has fixed the page allocator's handling of
     migratetype requests, with resulting improvements in compaction
     efficiency.

   - In the series "make the hugetlb migration strategy consistent"
     Baolin Wang has fixed a hugetlb migration issue, which should
     improve hugetlb allocation reliability.

   - Liu Shixin has hit an I/O meltdown caused by readahead in a
     memory-tight memcg. Addressed in the series "Fix I/O high when
     memory almost met memcg limit".

   - In the series "mm/filemap: optimize folio adding and splitting"
     Kairui Song has optimized pagecache insertion, yielding ~10%
     performance improvement in one test.

   - Baoquan He has cleaned up and consolidated the early zone
     initialization code in the series "mm/mm_init.c: refactor
     free_area_init_core()".

   - Baoquan has also redone some MM initializatio code in the series
     "mm/init: minor clean up and improvement".

   - MM helper cleanups from Christoph Hellwig in his series "remove
     follow_pfn".

   - More cleanups from Matthew Wilcox in the series "Various
     page->flags cleanups".

   - Vlastimil Babka has contributed maintainability improvements in the
     series "memcg_kmem hooks refactoring".

   - More folio conversions and cleanups in Matthew Wilcox's series:
	"Convert huge_zero_page to huge_zero_folio"
	"khugepaged folio conversions"
	"Remove page_idle and page_young wrappers"
	"Use folio APIs in procfs"
	"Clean up __folio_put()"
	"Some cleanups for memory-failure"
	"Remove page_mapping()"
	"More folio compat code removal"

   - David Hildenbrand chipped in with "fs/proc/task_mmu: convert
     hugetlb functions to work on folis".

   - Code consolidation and cleanup work related to GUP's handling of
     hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".

   - Rick Edgecombe has developed some fixes to stack guard gaps in the
     series "Cover a guard gap corner case".

   - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the
     series "mm/ksm: fix ksm exec support for prctl".

   - Baolin Wang has implemented NUMA balancing for multi-size THPs.
     This is a simple first-cut implementation for now. The series is
     "support multi-size THP numa balancing".

   - Cleanups to vma handling helper functions from Matthew Wilcox in
     the series "Unify vma_address and vma_pgoff_address".

   - Some selftests maintenance work from Dev Jain in the series
     "selftests/mm: mremap_test: Optimizations and style fixes".

   - Improvements to the swapping of multi-size THPs from Ryan Roberts
     in the series "Swap-out mTHP without splitting".

   - Kefeng Wang has significantly optimized the handling of arm64's
     permission page faults in the series
	"arch/mm/fault: accelerate pagefault when badaccess"
	"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"

   - GUP cleanups from David Hildenbrand in "mm/gup: consistently call
     it GUP-fast".

   - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault
     path to use struct vm_fault".

   - selftests build fixes from John Hubbard in the series "Fix
     selftests/mm build without requiring "make headers"".

   - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
     series "Improved Memory Tier Creation for CPUless NUMA Nodes".
     Fixes the initialization code so that migration between different
     memory types works as intended.

   - David Hildenbrand has improved follow_pte() and fixed an errant
     driver in the series "mm: follow_pte() improvements and acrn
     follow_pte() fixes".

   - David also did some cleanup work on large folio mapcounts in his
     series "mm: mapcount for large folios + page_mapcount() cleanups".

   - Folio conversions in KSM in Alex Shi's series "transfer page to
     folio in KSM".

   - Barry Song has added some sysfs stats for monitoring multi-size
     THP's in the series "mm: add per-order mTHP alloc and swpout
     counters".

   - Some zswap cleanups from Yosry Ahmed in the series "zswap
     same-filled and limit checking cleanups".

   - Matthew Wilcox has been looking at buffer_head code and found the
     documentation to be lacking. The series is "Improve buffer head
     documentation".

   - Multi-size THPs get more work, this time from Lance Yang. His
     series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free"
     optimizes the freeing of these things.

   - Kemeng Shi has added more userspace-visible writeback
     instrumentation in the series "Improve visibility of writeback".

   - Kemeng Shi then sent some maintenance work on top in the series
     "Fix and cleanups to page-writeback".

   - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in
     the series "Improve anon_vma scalability for anon VMAs". Intel's
     test bot reported an improbable 3x improvement in one test.

   - SeongJae Park adds some DAMON feature work in the series
	"mm/damon: add a DAMOS filter type for page granularity access recheck"
	"selftests/damon: add DAMOS quota goal test"

   - Also some maintenance work in the series
	"mm/damon/paddr: simplify page level access re-check for pageout"
	"mm/damon: misc fixes and improvements"

   - David Hildenbrand has disabled some known-to-fail selftests ni the
     series "selftests: mm: cow: flag vmsplice() hugetlb tests as
     XFAIL".

   - memcg metadata storage optimizations from Shakeel Butt in "memcg:
     reduce memory consumption by memcg stats".

   - DAX fixes and maintenance work from Vishal Verma in the series
     "dax/bus.c: Fixups for dax-bus locking""

* tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits)
  memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order
  selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime
  mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp
  mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault
  selftests: cgroup: add tests to verify the zswap writeback path
  mm: memcg: make alloc_mem_cgroup_per_node_info() return bool
  mm/damon/core: fix return value from damos_wmark_metric_value
  mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED
  selftests: cgroup: remove redundant enabling of memory controller
  Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree
  Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT
  Docs/mm/damon/design: use a list for supported filters
  Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command
  Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file
  selftests/damon: classify tests for functionalities and regressions
  selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None'
  selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts
  selftests/damon/_damon_sysfs: check errors from nr_schemes file reads
  mm/damon/core: initialize ->esz_bp from damos_quota_init_priv()
  selftests/damon: add a test for DAMOS quota goal
  ...
2024-05-19 09:21:03 -07:00
Linus Torvalds
89721e3038 net-accept-more-20240515
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Merge tag 'net-accept-more-20240515' of git://git.kernel.dk/linux

Pull more io_uring updates from Jens Axboe:
 "This adds support for IORING_CQE_F_SOCK_NONEMPTY for io_uring accept
  requests.

  This is very similar to previous work that enabled the same hint for
  doing receives on sockets. By far the majority of the work here is
  refactoring to enable the networking side to pass back whether or not
  the socket had more pending requests after accepting the current one,
  the last patch just wires it up for io_uring.

  Not only does this enable applications to know whether there are more
  connections to accept right now, it also enables smarter logic for
  io_uring multishot accept on whether to retry immediately or wait for
  a poll trigger"

* tag 'net-accept-more-20240515' of git://git.kernel.dk/linux:
  io_uring/net: wire up IORING_CQE_F_SOCK_NONEMPTY for accept
  net: pass back whether socket was empty post accept
  net: have do_accept() take a struct proto_accept_arg argument
  net: change proto and proto_ops accept type
2024-05-18 10:32:39 -07:00
Jens Axboe
ac287da2e0 io_uring/net: wire up IORING_CQE_F_SOCK_NONEMPTY for accept
If the given protocol supports passing back whether or not we had more
pending accept post this one, pass back this information to userspace.
This is done by setting IORING_CQE_F_SOCK_NONEMPTY in the CQE flags,
just like we do for recv/recvmsg if there's more data available post
a receive operation.

We can also use this information to be smarter about multishot retry,
as we don't need to do a pointless retry if we know for a fact that
there aren't any more connections to accept.

Suggested-by: Norman Maurer <norman_maurer@apple.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-13 18:19:23 -06:00
Jens Axboe
0645fbe760 net: have do_accept() take a struct proto_accept_arg argument
In preparation for passing in more information via this API, change
do_accept() to take a proto_accept_arg struct pointer rather than just
the file flags separately.

No functional changes in this patch.

Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-13 18:19:19 -06:00
Linus Torvalds
9961a78594 for-6.10/io_uring-20240511
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Merge tag 'for-6.10/io_uring-20240511' of git://git.kernel.dk/linux

Pull io_uring updates from Jens Axboe:

 - Greatly improve send zerocopy performance, by enabling coalescing of
   sent buffers.

   MSG_ZEROCOPY already does this with send(2) and sendmsg(2), but the
   io_uring side did not. In local testing, the crossover point for send
   zerocopy being faster is now around 3000 byte packets, and it
   performs better than the sync syscall variants as well.

   This feature relies on a shared branch with net-next, which was
   pulled into both branches.

 - Unification of how async preparation is done across opcodes.

   Previously, opcodes that required extra memory for async retry would
   allocate that as needed, using on-stack state until that was the
   case. If async retry was needed, the on-stack state was adjusted
   appropriately for a retry and then copied to the allocated memory.

   This led to some fragile and ugly code, particularly for read/write
   handling, and made storage retries more difficult than they needed to
   be. Allocate the memory upfront, as it's cheap from our pools, and
   use that state consistently both initially and also from the retry
   side.

 - Move away from using remap_pfn_range() for mapping the rings.

   This is really not the right interface to use and can cause lifetime
   issues or leaks. Additionally, it means the ring sq/cq arrays need to
   be physically contigious, which can cause problems in production with
   larger rings when services are restarted, as memory can be very
   fragmented at that point.

   Move to using vm_insert_page(s) for the ring sq/cq arrays, and apply
   the same treatment to mapped ring provided buffers. This also helps
   unify the code we have dealing with allocating and mapping memory.

   Hard to see in the diffstat as we're adding a few features as well,
   but this kills about ~400 lines of code from the codebase as well.

 - Add support for bundles for send/recv.

   When used with provided buffers, bundles support sending or receiving
   more than one buffer at the time, improving the efficiency by only
   needing to call into the networking stack once for multiple sends or
   receives.

 - Tweaks for our accept operations, supporting both a DONTWAIT flag for
   skipping poll arm and retry if we can, and a POLLFIRST flag that the
   application can use to skip the initial accept attempt and rely
   purely on poll for triggering the operation. Both of these have
   identical flags on the receive side already.

 - Make the task_work ctx locking unconditional.

   We had various code paths here that would do a mix of lock/trylock
   and set the task_work state to whether or not it was locked. All of
   that goes away, we lock it unconditionally and get rid of the state
   flag indicating whether it's locked or not.

   The state struct still exists as an empty type, can go away in the
   future.

 - Add support for specifying NOP completion values, allowing it to be
   used for error handling testing.

 - Use set/test bit for io-wq worker flags. Not strictly needed, but
   also doesn't hurt and helps silence a KCSAN warning.

 - Cleanups for io-wq locking and work assignments, closing a tiny race
   where cancelations would not be able to find the work item reliably.

 - Misc fixes, cleanups, and improvements

* tag 'for-6.10/io_uring-20240511' of git://git.kernel.dk/linux: (97 commits)
  io_uring: support to inject result for NOP
  io_uring: fail NOP if non-zero op flags is passed in
  io_uring/net: add IORING_ACCEPT_POLL_FIRST flag
  io_uring/net: add IORING_ACCEPT_DONTWAIT flag
  io_uring/filetable: don't unnecessarily clear/reset bitmap
  io_uring/io-wq: Use set_bit() and test_bit() at worker->flags
  io_uring/msg_ring: cleanup posting to IOPOLL vs !IOPOLL ring
  io_uring: Require zeroed sqe->len on provided-buffers send
  io_uring/notif: disable LAZY_WAKE for linked notifs
  io_uring/net: fix sendzc lazy wake polling
  io_uring/msg_ring: reuse ctx->submitter_task read using READ_ONCE instead of re-reading it
  io_uring/rw: reinstate thread check for retries
  io_uring/notif: implement notification stacking
  io_uring/notif: simplify io_notif_flush()
  net: add callback for setting a ubuf_info to skb
  net: extend ubuf_info callback to ops structure
  io_uring/net: support bundles for recv
  io_uring/net: support bundles for send
  io_uring/kbuf: add helpers for getting/peeking multiple buffers
  io_uring/net: add provided buffer support for IORING_OP_SEND
  ...
2024-05-13 12:48:06 -07:00
Linus Torvalds
1b0aabcc9a vfs-6.10.misc
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Merge tag 'vfs-6.10.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
 "This contains the usual miscellaneous features, cleanups, and fixes
  for vfs and individual fses.

  Features:

   - Free up FMODE_* bits. I've freed up bits 6, 7, 8, and 24. That
     means we now have six free FMODE_* bits in total (but bit #6
     already got used for FMODE_WRITE_RESTRICTED)

   - Add FOP_HUGE_PAGES flag (follow-up to FMODE_* cleanup)

   - Add fd_raw cleanup class so we can make use of automatic cleanup
     provided by CLASS(fd_raw, f)(fd) for O_PATH fds as well

   - Optimize seq_puts()

   - Simplify __seq_puts()

   - Add new anon_inode_getfile_fmode() api to allow specifying f_mode
     instead of open-coding it in multiple places

   - Annotate struct file_handle with __counted_by() and use
     struct_size()

   - Warn in get_file() whether f_count resurrection from zero is
     attempted (epoll/drm discussion)

   - Folio-sophize aio

   - Export the subvolume id in statx() for both btrfs and bcachefs

   - Relax linkat(AT_EMPTY_PATH) requirements

   - Add F_DUPFD_QUERY fcntl() allowing to compare two file descriptors
     for dup*() equality replacing kcmp()

  Cleanups:

   - Compile out swapfile inode checks when swap isn't enabled

   - Use (1 << n) notation for FMODE_* bitshifts for clarity

   - Remove redundant variable assignment in fs/direct-io

   - Cleanup uses of strncpy in orangefs

   - Speed up and cleanup writeback

   - Move fsparam_string_empty() helper into header since it's currently
     open-coded in multiple places

   - Add kernel-doc comments to proc_create_net_data_write()

   - Don't needlessly read dentry->d_flags twice

  Fixes:

   - Fix out-of-range warning in nilfs2

   - Fix ecryptfs overflow due to wrong encryption packet size
     calculation

   - Fix overly long line in xfs file_operations (follow-up to FMODE_*
     cleanup)

   - Don't raise FOP_BUFFER_{R,W}ASYNC for directories in xfs (follow-up
     to FMODE_* cleanup)

   - Don't call xfs_file_open from xfs_dir_open (follow-up to FMODE_*
     cleanup)

   - Fix stable offset api to prevent endless loops

   - Fix afs file server rotations

   - Prevent xattr node from overflowing the eraseblock in jffs2

   - Move fdinfo PTRACE_MODE_READ procfs check into the .permission()
     operation instead of .open() operation since this caused userspace
     regressions"

* tag 'vfs-6.10.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (39 commits)
  afs: Fix fileserver rotation getting stuck
  selftests: add F_DUPDFD_QUERY selftests
  fcntl: add F_DUPFD_QUERY fcntl()
  file: add fd_raw cleanup class
  fs: WARN when f_count resurrection is attempted
  seq_file: Simplify __seq_puts()
  seq_file: Optimize seq_puts()
  proc: Move fdinfo PTRACE_MODE_READ check into the inode .permission operation
  fs: Create anon_inode_getfile_fmode()
  xfs: don't call xfs_file_open from xfs_dir_open
  xfs: drop fop_flags for directories
  xfs: fix overly long line in the file_operations
  shmem: Fix shmem_rename2()
  libfs: Add simple_offset_rename() API
  libfs: Fix simple_offset_rename_exchange()
  jffs2: prevent xattr node from overflowing the eraseblock
  vfs, swap: compile out IS_SWAPFILE() on swapless configs
  vfs: relax linkat() AT_EMPTY_PATH - aka flink() - requirements
  fs/direct-io: remove redundant assignment to variable retval
  fs/dcache: Re-use value stored to dentry->d_flags instead of re-reading
  ...
2024-05-13 11:40:06 -07:00
Ming Lei
deb1e496a8 io_uring: support to inject result for NOP
Support to inject result for NOP so that we can inject failure from
userspace. It is very helpful for covering failure handling code in
io_uring core change.

With nop flags, it becomes possible to add more test features on NOP in
future.

Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20240510035031.78874-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-10 06:09:45 -06:00
Ming Lei
3d8f874bd6 io_uring: fail NOP if non-zero op flags is passed in
The NOP op flags should have been checked from beginning like any other
opcode, otherwise NOP may not be extended with the op flags.

Given both liburing and Rust io-uring crate always zeros SQE op flags, just
ignore users which play raw NOP uring interface without zeroing SQE, because
NOP is just for test purpose. Then we can save one NOP2 opcode.

Suggested-by: Jens Axboe <axboe@kernel.dk>
Fixes: 2b188cc1bb ("Add io_uring IO interface")
Cc: stable@vger.kernel.org
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20240510035031.78874-2-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-10 06:09:45 -06:00
Jens Axboe
d3da8e9859 io_uring/net: add IORING_ACCEPT_POLL_FIRST flag
Similarly to how polling first is supported for receive, it makes sense
to provide the same for accept. An accept operation does a lot of
expensive setup, like allocating an fd, a socket/inode, etc. If no
connection request is already pending, this is wasted and will just be
cleaned up and freed, only to retry via the usual poll trigger.

Add IORING_ACCEPT_POLL_FIRST, which tells accept to only initiate the
accept request if poll says we have something to accept.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-09 12:22:11 -06:00
Jens Axboe
7dcc758cca io_uring/net: add IORING_ACCEPT_DONTWAIT flag
This allows the caller to perform a non-blocking attempt, similarly to
how recvmsg has MSG_DONTWAIT. If set, and we get -EAGAIN on a connection
attempt, propagate the result to userspace rather than arm poll and
wait for a retry.

Suggested-by: Norman Maurer <norman_maurer@apple.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-09 12:22:03 -06:00
Jens Axboe
340f634aa4 io_uring/filetable: don't unnecessarily clear/reset bitmap
If we're updating an existing slot, we clear the slot bitmap only to
set it again right after. Just leave the bit set rather than toggle
it off and on, and move the unused slot setting into the branch of
not already having a file occupy this slot.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-08 08:27:45 -06:00
Breno Leitao
8a56530492 io_uring/io-wq: Use set_bit() and test_bit() at worker->flags
Utilize set_bit() and test_bit() on worker->flags within io_uring/io-wq
to address potential data races.

The structure io_worker->flags may be accessed through various data
paths, leading to concurrency issues. When KCSAN is enabled, it reveals
data races occurring in io_worker_handle_work and
io_wq_activate_free_worker functions.

	 BUG: KCSAN: data-race in io_worker_handle_work / io_wq_activate_free_worker
	 write to 0xffff8885c4246404 of 4 bytes by task 49071 on cpu 28:
	 io_worker_handle_work (io_uring/io-wq.c:434 io_uring/io-wq.c:569)
	 io_wq_worker (io_uring/io-wq.c:?)
<snip>

	 read to 0xffff8885c4246404 of 4 bytes by task 49024 on cpu 5:
	 io_wq_activate_free_worker (io_uring/io-wq.c:? io_uring/io-wq.c:285)
	 io_wq_enqueue (io_uring/io-wq.c:947)
	 io_queue_iowq (io_uring/io_uring.c:524)
	 io_req_task_submit (io_uring/io_uring.c:1511)
	 io_handle_tw_list (io_uring/io_uring.c:1198)
<snip>

Line numbers against commit 18daea77cc ("Merge tag 'for-linus' of
git://git.kernel.org/pub/scm/virt/kvm/kvm").

These races involve writes and reads to the same memory location by
different tasks running on different CPUs. To mitigate this, refactor
the code to use atomic operations such as set_bit(), test_bit(), and
clear_bit() instead of basic "and" and "or" operations. This ensures
thread-safe manipulation of worker flags.

Also, move `create_index` to avoid holes in the structure.

Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20240507170002.2269003-1-leitao@debian.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-07 13:17:19 -06:00
Jens Axboe
59b28a6e37 io_uring/msg_ring: cleanup posting to IOPOLL vs !IOPOLL ring
Move the posting outside the checking and locking, it's cleaner that
way.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-01 17:13:51 -06:00
Gabriel Krisman Bertazi
79996b45f7 io_uring: Require zeroed sqe->len on provided-buffers send
When sending from a provided buffer, we set sr->len to be the smallest
between the actual buffer size and sqe->len.  But, now that we
disconnect the buffer from the submission request, we can get in a
situation where the buffers and requests mismatch, and only part of a
buffer gets sent.  Assume:

* buf[1]->len = 128; buf[2]->len = 256
* sqe[1]->len = 128; sqe[2]->len = 256

If sqe1 runs first, it picks buff[1] and it's all good. But, if sqe[2]
runs first, sqe[1] picks buff[2], and the last half of buff[2] is
never sent.

While arguably the use-case of different-length sends is questionable,
it has already raised confusion with potential users of this
feature. Let's make the interface less tricky by forcing the length to
only come from the buffer ring entry itself.

Fixes: ac5f71a3d9 ("io_uring/net: add provided buffer support for IORING_OP_SEND")
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-01 14:56:36 -06:00
Pavel Begunkov
19352a1d39 io_uring/notif: disable LAZY_WAKE for linked notifs
Notifications may now be linked and thus a single tw can post multiple
CQEs, it's not safe to use LAZY_WAKE with them. Disable LAZY_WAKE for
now, if that'd prove to be a problem we can count them and pass the
expected number of CQEs into __io_req_task_work_add().

Fixes: 6fe4220912 ("io_uring/notif: implement notification stacking")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/0a5accdb7d2d0d27ebec14f8106e14e0192fae17.1714488419.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-30 13:06:27 -06:00
Pavel Begunkov
ef42b85a56 io_uring/net: fix sendzc lazy wake polling
SEND[MSG]_ZC produces multiple CQEs via notifications, LAZY_WAKE doesn't
handle it and so disable LAZY_WAKE for sendzc polling. It should be
fine, sends are not likely to be polled in the first place.

Fixes: 6ce4a93dbb ("io_uring/poll: use IOU_F_TWQ_LAZY_WAKE for wakeups")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/5b360fb352d91e3aec751d75c87dfb4753a084ee.1714488419.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-30 13:06:27 -06:00
linke li
a4d416dc60 io_uring/msg_ring: reuse ctx->submitter_task read using READ_ONCE instead of re-reading it
In io_msg_exec_remote(), ctx->submitter_task is read using READ_ONCE at
the beginning of the function, checked, and then re-read from
ctx->submitter_task, voiding all guarantees of the checks. Reuse the value
that was read by READ_ONCE to ensure the consistency of the task struct
throughout the function.

Signed-off-by: linke li <lilinke99@qq.com>
Link: https://lore.kernel.org/r/tencent_F9B2296C93928D6F68FF0C95C33475C68209@qq.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-26 07:40:12 -06:00
Rick Edgecombe
529ce23a76 mm: switch mm->get_unmapped_area() to a flag
The mm_struct contains a function pointer *get_unmapped_area(), which is
set to either arch_get_unmapped_area() or arch_get_unmapped_area_topdown()
during the initialization of the mm.

Since the function pointer only ever points to two functions that are
named the same across all arch's, a function pointer is not really
required.  In addition future changes will want to add versions of the
functions that take additional arguments.  So to save a pointers worth of
bytes in mm_struct, and prevent adding additional function pointers to
mm_struct in future changes, remove it and keep the information about
which get_unmapped_area() to use in a flag.

Add the new flag to MMF_INIT_MASK so it doesn't get clobbered on fork by
mmf_init_flags().  Most MM flags get clobbered on fork.  In the
pre-existing behavior mm->get_unmapped_area() would get copied to the new
mm in dup_mm(), so not clobbering the flag preserves the existing behavior
around inheriting the topdown-ness.

Introduce a helper, mm_get_unmapped_area(), to easily convert code that
refers to the old function pointer to instead select and call either
arch_get_unmapped_area() or arch_get_unmapped_area_topdown() based on the
flag.  Then drop the mm->get_unmapped_area() function pointer.  Leave the
get_unmapped_area() pointer in struct file_operations alone.  The main
purpose of this change is to reorganize in preparation for future changes,
but it also converts the calls of mm->get_unmapped_area() from indirect
branches into a direct ones.

The stress-ng bigheap benchmark calls realloc a lot, which calls through
get_unmapped_area() in the kernel.  On x86, the change yielded a ~1%
improvement there on a retpoline config.

In testing a few x86 configs, removing the pointer unfortunately didn't
result in any actual size reductions in the compiled layout of mm_struct. 
But depending on compiler or arch alignment requirements, the change could
shrink the size of mm_struct.

Link: https://lkml.kernel.org/r/20240326021656.202649-3-rick.p.edgecombe@intel.com
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Deepak Gupta <debug@rivosinc.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: H. Peter Anvin (Intel) <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:25 -07:00
Jens Axboe
039a2e800b io_uring/rw: reinstate thread check for retries
Allowing retries for everything is arguably the right thing to do, now
that every command type is async read from the start. But it's exposed a
few issues around missing check for a retry (which cca6571381 exposed),
and the fixup commit for that isn't necessarily 100% sound in terms of
iov_iter state.

For now, just revert these two commits. This unfortunately then re-opens
the fact that -EAGAIN can get bubbled to userspace for some cases where
the kernel very well could just sanely retry them. But until we have all
the conditions covered around that, we cannot safely enable that.

This reverts commit df604d2ad4.
This reverts commit cca6571381.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-25 09:04:32 -06:00
Pavel Begunkov
6fe4220912 io_uring/notif: implement notification stacking
The network stack allows only one ubuf_info per skb, and unlike
MSG_ZEROCOPY, each io_uring zerocopy send will carry a separate
ubuf_info. That means that send requests can't reuse a previosly
allocated skb and need to get one more or more of new ones. That's fine
for large sends, but otherwise it would spam the stack with lots of skbs
carrying just a little data each.

To help with that implement linking notification (i.e. an io_uring wrapper
around ubuf_info) into a list. Each is refcounted by skbs and the stack
as usual. additionally all non head entries keep a reference to the
head, which they put down when their refcount hits 0. When the head have
no more users, it'll efficiently put all notifications in a batch.

As mentioned previously about ->io_link_skb, the callback implementation
always allows to bind to an skb without a ubuf_info.

Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/bf1e7f9b72f9ecc99999fdc0d2cded5eea87fd0b.1713369317.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-22 19:31:18 -06:00
Pavel Begunkov
5a569469b9 io_uring/notif: simplify io_notif_flush()
io_notif_flush() is partially duplicating io_tx_ubuf_complete(), so
instead of duplicating it, make the flush call io_tx_ubuf_complete.

Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/19e41652c16718b946a5c80d2ad409df7682e47e.1713369317.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-22 19:31:18 -06:00
Jens Axboe
3830fff399 Merge branch 'for-uring-ubufops' of git://git.kernel.org/pub/scm/linux/kernel/git/kuba/linux into for-6.10/io_uring
Merge net changes required for the upcoming send zerocopy improvements.

* 'for-uring-ubufops' of git://git.kernel.org/pub/scm/linux/kernel/git/kuba/linux:
  net: add callback for setting a ubuf_info to skb
  net: extend ubuf_info callback to ops structure

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-22 19:30:05 -06:00
Pavel Begunkov
7ab4f16f9e net: extend ubuf_info callback to ops structure
We'll need to associate additional callbacks with ubuf_info, introduce
a structure holding ubuf_info callbacks. Apart from a more smarter
io_uring notification management introduced in next patches, it can be
used to generalise msg_zerocopy_put_abort() and also store
->sg_from_iter, which is currently passed in struct msghdr.

Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/all/a62015541de49c0e2a8a0377a1d5d0a5aeb07016.1713369317.git.asml.silence@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-22 16:21:35 -07:00
Jens Axboe
2f9c9515bd io_uring/net: support bundles for recv
If IORING_OP_RECV is used with provided buffers, the caller may also set
IORING_RECVSEND_BUNDLE to turn it into a multi-buffer recv. This grabs
buffers available and receives into them, posting a single completion for
all of it.

This can be used with multishot receive as well, or without it.

Now that both send and receive support bundles, add a feature flag for
it as well. If IORING_FEAT_RECVSEND_BUNDLE is set after registering the
ring, then the kernel supports bundles for recv and send.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-22 11:26:11 -06:00
Jens Axboe
a05d1f625c io_uring/net: support bundles for send
If IORING_OP_SEND is used with provided buffers, the caller may also
set IORING_RECVSEND_BUNDLE to turn it into a multi-buffer send. The idea
is that an application can fill outgoing buffers in a provided buffer
group, and then arm a single send that will service them all. Once
there are no more buffers to send, or if the requested length has
been sent, the request posts a single completion for all the buffers.

This only enables it for IORING_OP_SEND, IORING_OP_SENDMSG is coming
in a separate patch. However, this patch does do a lot of the prep
work that makes wiring up the sendmsg variant pretty trivial. They
share the prep side.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-22 11:26:05 -06:00
Jens Axboe
35c8711c8f io_uring/kbuf: add helpers for getting/peeking multiple buffers
Our provided buffer interface only allows selection of a single buffer.
Add an API that allows getting/peeking multiple buffers at the same time.

This is only implemented for the ring provided buffers. It could be added
for the legacy provided buffers as well, but since it's strongly
encouraged to use the new interface, let's keep it simpler and just
provide it for the new API. The legacy interface will always just select
a single buffer.

There are two new main functions:

io_buffers_select(), which selects up as many buffers as it can. The
caller supplies the iovec array, and io_buffers_select() may allocate a
bigger array if the 'out_len' being passed in is non-zero and bigger
than what fits in the provided iovec. Buffers grabbed with this helper
are permanently assigned.

io_buffers_peek(), which works like io_buffers_select(), except they can
be recycled, if needed. Callers using either of these functions should
call io_put_kbufs() rather than io_put_kbuf() at completion time. The
peek interface must be called with the ctx locked from peek to
completion.

This add a bit state for the request:

- REQ_F_BUFFERS_COMMIT, which means that the the buffers have been
  peeked and should be committed to the buffer ring head when they are
  put as part of completion. Prior to this, req->buf_list was cleared to
  NULL when committed.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-22 11:26:01 -06:00
Jens Axboe
ac5f71a3d9 io_uring/net: add provided buffer support for IORING_OP_SEND
It's pretty trivial to wire up provided buffer support for the send
side, just like how it's done the receive side. This enables setting up
a buffer ring that an application can use to push pending sends to,
and then have a send pick a buffer from that ring.

One of the challenges with async IO and networking sends is that you
can get into reordering conditions if you have more than one inflight
at the same time. Consider the following scenario where everything is
fine:

1) App queues sendA for socket1
2) App queues sendB for socket1
3) App does io_uring_submit()
4) sendA is issued, completes successfully, posts CQE
5) sendB is issued, completes successfully, posts CQE

All is fine. Requests are always issued in-order, and both complete
inline as most sends do.

However, if we're flooding socket1 with sends, the following could
also result from the same sequence:

1) App queues sendA for socket1
2) App queues sendB for socket1
3) App does io_uring_submit()
4) sendA is issued, socket1 is full, poll is armed for retry
5) Space frees up in socket1, this triggers sendA retry via task_work
6) sendB is issued, completes successfully, posts CQE
7) sendA is retried, completes successfully, posts CQE

Now we've sent sendB before sendA, which can make things unhappy. If
both sendA and sendB had been using provided buffers, then it would look
as follows instead:

1) App queues dataA for sendA, queues sendA for socket1
2) App queues dataB for sendB queues sendB for socket1
3) App does io_uring_submit()
4) sendA is issued, socket1 is full, poll is armed for retry
5) Space frees up in socket1, this triggers sendA retry via task_work
6) sendB is issued, picks first buffer (dataA), completes successfully,
   posts CQE (which says "I sent dataA")
7) sendA is retried, picks first buffer (dataB), completes successfully,
   posts CQE (which says "I sent dataB")

Now we've sent the data in order, and everybody is happy.

It's worth noting that this also opens the door for supporting multishot
sends, as provided buffers would be a prerequisite for that. Those can
trigger either when new buffers are added to the outgoing ring, or (if
stalled due to lack of space) when space frees up in the socket.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-22 11:25:56 -06:00
Jens Axboe
3e747dedd4 io_uring/net: add generic multishot retry helper
This is just moving io_recv_prep_retry() higher up so it can get used
for sends as well, and rename it to be generically useful for both
sends and receives.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-22 11:25:49 -06:00
Jens Axboe
df604d2ad4 io_uring/rw: ensure retry condition isn't lost
A previous commit removed the checking on whether or not it was possible
to retry a request, since it's now possible to retry any of them. This
would previously have caused the request to have been ended with an error,
but now the retry condition can simply get lost instead.

Cleanup the retry handling and always just punt it to task_work, which
will queue it with io-wq appropriately.

Reported-by: Changhui Zhong <czhong@redhat.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Fixes: cca6571381 ("io_uring/rw: cleanup retry path")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-17 09:23:55 -06:00
Gabriel Krisman Bertazi
24c3fc5c75 io-wq: Drop intermediate step between pending list and active work
next_work is only used to make the work visible for
cancellation. Instead, we can just directly write to cur_work before
dropping the acct_lock and avoid the extra hop.

Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/20240416021054.3940-3-krisman@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-17 08:20:32 -06:00
Gabriel Krisman Bertazi
068c27e32e io-wq: write next_work before dropping acct_lock
Commit 361aee450c ("io-wq: add intermediate work step between pending
list and active work") closed a race between a cancellation and the work
being removed from the wq for execution.  To ensure the request is
always reachable by the cancellation, we need to move it within the wq
lock, which also synchronizes the cancellation.  But commit
42abc95f05 ("io-wq: decouple work_list protection from the big
wqe->lock") replaced the wq lock here and accidentally reintroduced the
race by releasing the acct_lock too early.

In other words:

        worker                |     cancellation
work = io_get_next_work()     |
raw_spin_unlock(&acct->lock); |
			      |
                              | io_acct_cancel_pending_work
                              | io_wq_worker_cancel()
worker->next_work = work

Using acct_lock is still enough since we synchronize on it on
io_acct_cancel_pending_work.

Fixes: 42abc95f05 ("io-wq: decouple work_list protection from the big wqe->lock")
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/20240416021054.3940-2-krisman@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-17 08:20:32 -06:00
Miklos Szeredi
7c98f7cb8f remove call_{read,write}_iter() functions
These have no clear purpose.  This is effectively a revert of commit
bb7462b6fd ("vfs: use helpers for calling f_op->{read,write}_iter()").

The patch was created with the help of a coccinelle script.

Fixes: bb7462b6fd ("vfs: use helpers for calling f_op->{read,write}_iter()")
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-04-15 16:03:25 -04:00
Jens Axboe
c4ce0ab276 io_uring/sqpoll: work around a potential audit memory leak
kmemleak complains that there's a memory leak related to connect
handling:

unreferenced object 0xffff0001093bdf00 (size 128):
comm "iou-sqp-455", pid 457, jiffies 4294894164
hex dump (first 32 bytes):
02 00 fa ea 7f 00 00 01 00 00 00 00 00 00 00 00  ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
backtrace (crc 2e481b1a):
[<00000000c0a26af4>] kmemleak_alloc+0x30/0x38
[<000000009c30bb45>] kmalloc_trace+0x228/0x358
[<000000009da9d39f>] __audit_sockaddr+0xd0/0x138
[<0000000089a93e34>] move_addr_to_kernel+0x1a0/0x1f8
[<000000000b4e80e6>] io_connect_prep+0x1ec/0x2d4
[<00000000abfbcd99>] io_submit_sqes+0x588/0x1e48
[<00000000e7c25e07>] io_sq_thread+0x8a4/0x10e4
[<00000000d999b491>] ret_from_fork+0x10/0x20

which can can happen if:

1) The command type does something on the prep side that triggers an
   audit call.
2) The thread hasn't done any operations before this that triggered
   an audit call inside ->issue(), where we have audit_uring_entry()
   and audit_uring_exit().

Work around this by issuing a blanket NOP operation before the SQPOLL
does anything.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 13:06:19 -06:00
Pavel Begunkov
d6e295061f io_uring/notif: shrink account_pages to u32
->account_pages is the number of pages we account against the user
derived from unsigned len, it definitely fits into unsigned, which saves
some space in struct io_notif_data.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/19f2687fcb36daa74d86f4a27bfb3d35cffec318.1713185320.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:49 -06:00