Commit Graph

745 Commits

Author SHA1 Message Date
Jens Axboe
023464fe33 Revert "io_uring: fix IO hang in io_wq_put_and_exit from do_exit()"
This reverts commit b484a40dc1.

This commit cancels all requests with io-wq, not just the ones from the
originating task. This breaks use cases that have thread pools, or just
multiple tasks issuing requests on the same ring. The liburing
regression test for this also shows that problem:

$ test/thread-exit.t
cqe->res=-125, Expected 512

where an IO thread gets its request canceled rather than complete
successfully.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-07 09:41:49 -06:00
Pavel Begunkov
27122c079f io_uring: fix unprotected iopoll overflow
[   71.490669] WARNING: CPU: 3 PID: 17070 at io_uring/io_uring.c:769
io_cqring_event_overflow+0x47b/0x6b0
[   71.498381] Call Trace:
[   71.498590]  <TASK>
[   71.501858]  io_req_cqe_overflow+0x105/0x1e0
[   71.502194]  __io_submit_flush_completions+0x9f9/0x1090
[   71.503537]  io_submit_sqes+0xebd/0x1f00
[   71.503879]  __do_sys_io_uring_enter+0x8c5/0x2380
[   71.507360]  do_syscall_64+0x39/0x80

We decoupled CQ locking from ->task_complete but haven't fixed up places
forcing locking for CQ overflows.

Fixes: ec26c225f0 ("io_uring: merge iopoll and normal completion paths")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-07 09:02:29 -06:00
Pavel Begunkov
45500dc4e0 io_uring: break out of iowq iopoll on teardown
io-wq will retry iopoll even when it failed with -EAGAIN. If that
races with task exit, which sets TIF_NOTIFY_SIGNAL for all its workers,
such workers might potentially infinitely spin retrying iopoll again and
again and each time failing on some allocation / waiting / etc. Don't
keep spinning if io-wq is dying.

Fixes: 561fb04a6a ("io_uring: replace workqueue usage with io-wq")
Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-07 09:02:27 -06:00
Matteo Rizzo
76d3ccecfa io_uring: add a sysctl to disable io_uring system-wide
Introduce a new sysctl (io_uring_disabled) which can be either 0, 1, or
2. When 0 (the default), all processes are allowed to create io_uring
instances, which is the current behavior.  When 1, io_uring creation is
disabled (io_uring_setup() will fail with -EPERM) for unprivileged
processes not in the kernel.io_uring_group group.  When 2, calls to
io_uring_setup() fail with -EPERM regardless of privilege.

Signed-off-by: Matteo Rizzo <matteorizzo@google.com>
[JEM: modified to add io_uring_group]
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Link: https://lore.kernel.org/r/x49y1i42j1z.fsf@segfault.boston.devel.redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-05 08:34:07 -06:00
Jens Axboe
32f5dea040 io_uring/fdinfo: only print ->sq_array[] if it's there
If a ring is setup with IORING_SETUP_NO_SQARRAY, then we don't have
the SQ array. Don't try to dump info from it through fdinfo if that
is the case.

Reported-by: syzbot+216e2ea6e0bf4a0acdd7@syzkaller.appspotmail.com
Fixes: 2af89abda7 ("io_uring: add option to remove SQ indirection")
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-01 15:08:29 -06:00
Ming Lei
b484a40dc1 io_uring: fix IO hang in io_wq_put_and_exit from do_exit()
io_wq_put_and_exit() is called from do_exit(), but all FIXED_FILE requests
in io_wq aren't canceled in io_uring_cancel_generic() called from do_exit().
Meantime io_wq IO code path may share resource with normal iopoll code
path.

So if any HIPRI request is submittd via io_wq, this request may not get resouce
for moving on, given iopoll isn't possible in io_wq_put_and_exit().

The issue can be triggered when terminating 't/io_uring -n4 /dev/nullb0'
with default null_blk parameters.

Fix it by always cancelling all requests in io_wq by adding helper of
io_uring_cancel_wq(), and this way is reasonable because io_wq destroying
follows canceling requests immediately.

Closes: https://lore.kernel.org/linux-block/3893581.1691785261@warthog.procyon.org.uk/
Reported-by: David Howells <dhowells@redhat.com>
Cc: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230901134916.2415386-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-01 07:54:06 -06:00
Gabriel Krisman Bertazi
bd6fc5da4c io_uring: Don't set affinity on a dying sqpoll thread
Syzbot reported a null-ptr-deref of sqd->thread inside
io_sqpoll_wq_cpu_affinity.  It turns out the sqd->thread can go away
from under us during io_uring_register, in case the process gets a
fatal signal during io_uring_register.

It is not particularly hard to hit the race, and while I am not sure
this is the exact case hit by syzbot, it solves it.  Finally, checking
->thread is enough to close the race because we locked sqd while
"parking" the thread, thus preventing it from going away.

I reproduced it fairly consistently with a program that does:

int main(void) {
  ...
  io_uring_queue_init(RING_LEN, &ring1, IORING_SETUP_SQPOLL);
  while (1) {
    io_uring_register_iowq_aff(ring, 1, &mask);
  }
}

Executed in a loop with timeout to trigger SIGTERM:
  while true; do timeout 1 /a.out ; done

This will hit the following BUG() in very few attempts.

BUG: kernel NULL pointer dereference, address: 00000000000007a8
PGD 800000010e949067 P4D 800000010e949067 PUD 10e46e067 PMD 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 0 PID: 15715 Comm: dead-sqpoll Not tainted 6.5.0-rc7-next-20230825-g193296236fa0-dirty #23
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:io_sqpoll_wq_cpu_affinity+0x27/0x70
Code: 90 90 90 0f 1f 44 00 00 55 53 48 8b 9f 98 03 00 00 48 85 db 74 4f
48 89 df 48 89 f5 e8 e2 f8 ff ff 48 8b 43 38 48 85 c0 74 22 <48> 8b b8
a8 07 00 00 48 89 ee e8 ba b1 00 00 48 89 df 89 c5 e8 70
RSP: 0018:ffffb04040ea7e70 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff93c010749e40 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffffa7653331 RDI: 00000000ffffffff
RBP: ffffb04040ea7eb8 R08: 0000000000000000 R09: c0000000ffffdfff
R10: ffff93c01141b600 R11: ffffb04040ea7d18 R12: ffff93c00ea74840
R13: 0000000000000011 R14: 0000000000000000 R15: ffff93c00ea74800
FS:  00007fb7c276ab80(0000) GS:ffff93c36f200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000007a8 CR3: 0000000111634003 CR4: 0000000000370ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ? __die_body+0x1a/0x60
 ? page_fault_oops+0x154/0x440
 ? do_user_addr_fault+0x174/0x7b0
 ? exc_page_fault+0x63/0x140
 ? asm_exc_page_fault+0x22/0x30
 ? io_sqpoll_wq_cpu_affinity+0x27/0x70
 __io_register_iowq_aff+0x2b/0x60
 __io_uring_register+0x614/0xa70
 __x64_sys_io_uring_register+0xaa/0x1a0
 do_syscall_64+0x3a/0x90
 entry_SYSCALL_64_after_hwframe+0x6e/0xd8
RIP: 0033:0x7fb7c226fec9
Code: 2e 00 b8 ca 00 00 00 0f 05 eb a5 66 0f 1f 44 00 00 48 89 f8 48 89
f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01
f0 ff ff 73 01 c3 48 8b 0d 97 7f 2d 00 f7 d8 64 89 01 48
RSP: 002b:00007ffe2c0674f8 EFLAGS: 00000246 ORIG_RAX: 00000000000001ab
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb7c226fec9
RDX: 00007ffe2c067530 RSI: 0000000000000011 RDI: 0000000000000003
RBP: 00007ffe2c0675d0 R08: 00007ffe2c067550 R09: 00007ffe2c067550
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe2c067750 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
Modules linked in:
CR2: 00000000000007a8
---[ end trace 0000000000000000 ]---

Reported-by: syzbot+c74fea926a78b8a91042@syzkaller.appspotmail.com
Fixes: ebdfefc09c ("io_uring/sqpoll: fix io-wq affinity when IORING_SETUP_SQPOLL is used")
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/87v8cybuo6.fsf@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-30 09:53:44 -06:00
Linus Torvalds
c1b7fcf3f6 for-6.6/io_uring-2023-08-28
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Merge tag 'for-6.6/io_uring-2023-08-28' of git://git.kernel.dk/linux

Pull io_uring updates from Jens Axboe:
 "Fairly quiet round in terms of features, mostly just improvements all
  over the map for existing code. In detail:

   - Initial support for socket operations through io_uring. Latter half
     of this will likely land with the 6.7 kernel, then allowing things
     like get/setsockopt (Breno)

   - Cleanup of the cancel code, and then adding support for canceling
     requests with the opcode as the key (me)

   - Improvements for the io-wq locking (me)

   - Fix affinity setting for SQPOLL based io-wq (me)

   - Remove the io_uring userspace code. These were added initially as
     copies from liburing, but all of them have since bitrotted and are
     way out of date at this point. Rather than attempt to keep them in
     sync, just get rid of them. People will have liburing available
     anyway for these examples. (Pavel)

   - Series improving the CQ/SQ ring caching (Pavel)

   - Misc fixes and cleanups (Pavel, Yue, me)"

* tag 'for-6.6/io_uring-2023-08-28' of git://git.kernel.dk/linux: (47 commits)
  io_uring: move iopoll ctx fields around
  io_uring: move multishot cqe cache in ctx
  io_uring: separate task_work/waiting cache line
  io_uring: banish non-hot data to end of io_ring_ctx
  io_uring: move non aligned field to the end
  io_uring: add option to remove SQ indirection
  io_uring: compact SQ/CQ heads/tails
  io_uring: force inline io_fill_cqe_req
  io_uring: merge iopoll and normal completion paths
  io_uring: reorder cqring_flush and wakeups
  io_uring: optimise extra io_get_cqe null check
  io_uring: refactor __io_get_cqe()
  io_uring: simplify big_cqe handling
  io_uring: cqe init hardening
  io_uring: improve cqe !tracing hot path
  io_uring/rsrc: Annotate struct io_mapped_ubuf with __counted_by
  io_uring/sqpoll: fix io-wq affinity when IORING_SETUP_SQPOLL is used
  io_uring: simplify io_run_task_work_sig return
  io_uring/rsrc: keep one global dummy_ubuf
  io_uring: never overflow io_aux_cqe
  ...
2023-08-29 20:11:33 -07:00
Linus Torvalds
b96a3e9142 - Some swap cleanups from Ma Wupeng ("fix WARN_ON in add_to_avail_list")
- Peter Xu has a series (mm/gup: Unify hugetlb, speed up thp") which
   reduces the special-case code for handling hugetlb pages in GUP.  It
   also speeds up GUP handling of transparent hugepages.
 
 - Peng Zhang provides some maple tree speedups ("Optimize the fast path
   of mas_store()").
 
 - Sergey Senozhatsky has improved te performance of zsmalloc during
   compaction (zsmalloc: small compaction improvements").
 
 - Domenico Cerasuolo has developed additional selftest code for zswap
   ("selftests: cgroup: add zswap test program").
 
 - xu xin has doe some work on KSM's handling of zero pages.  These
   changes are mainly to enable the user to better understand the
   effectiveness of KSM's treatment of zero pages ("ksm: support tracking
   KSM-placed zero-pages").
 
 - Jeff Xu has fixes the behaviour of memfd's
   MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED sysctl ("mm/memfd: fix sysctl
   MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED").
 
 - David Howells has fixed an fscache optimization ("mm, netfs, fscache:
   Stop read optimisation when folio removed from pagecache").
 
 - Axel Rasmussen has given userfaultfd the ability to simulate memory
   poisoning ("add UFFDIO_POISON to simulate memory poisoning with UFFD").
 
 - Miaohe Lin has contributed some routine maintenance work on the
   memory-failure code ("mm: memory-failure: remove unneeded PageHuge()
   check").
 
 - Peng Zhang has contributed some maintenance work on the maple tree
   code ("Improve the validation for maple tree and some cleanup").
 
 - Hugh Dickins has optimized the collapsing of shmem or file pages into
   THPs ("mm: free retracted page table by RCU").
 
 - Jiaqi Yan has a patch series which permits us to use the healthy
   subpages within a hardware poisoned huge page for general purposes
   ("Improve hugetlbfs read on HWPOISON hugepages").
 
 - Kemeng Shi has done some maintenance work on the pagetable-check code
   ("Remove unused parameters in page_table_check").
 
 - More folioification work from Matthew Wilcox ("More filesystem folio
   conversions for 6.6"), ("Followup folio conversions for zswap").  And
   from ZhangPeng ("Convert several functions in page_io.c to use a
   folio").
 
 - page_ext cleanups from Kemeng Shi ("minor cleanups for page_ext").
 
 - Baoquan He has converted some architectures to use the GENERIC_IOREMAP
   ioremap()/iounmap() code ("mm: ioremap: Convert architectures to take
   GENERIC_IOREMAP way").
 
 - Anshuman Khandual has optimized arm64 tlb shootdown ("arm64: support
   batched/deferred tlb shootdown during page reclamation/migration").
 
 - Better maple tree lockdep checking from Liam Howlett ("More strict
   maple tree lockdep").  Liam also developed some efficiency improvements
   ("Reduce preallocations for maple tree").
 
 - Cleanup and optimization to the secondary IOMMU TLB invalidation, from
   Alistair Popple ("Invalidate secondary IOMMU TLB on permission
   upgrade").
 
 - Ryan Roberts fixes some arm64 MM selftest issues ("selftests/mm fixes
   for arm64").
 
 - Kemeng Shi provides some maintenance work on the compaction code ("Two
   minor cleanups for compaction").
 
 - Some reduction in mmap_lock pressure from Matthew Wilcox ("Handle most
   file-backed faults under the VMA lock").
 
 - Aneesh Kumar contributes code to use the vmemmap optimization for DAX
   on ppc64, under some circumstances ("Add support for DAX vmemmap
   optimization for ppc64").
 
 - page-ext cleanups from Kemeng Shi ("add page_ext_data to get client
   data in page_ext"), ("minor cleanups to page_ext header").
 
 - Some zswap cleanups from Johannes Weiner ("mm: zswap: three
   cleanups").
 
 - kmsan cleanups from ZhangPeng ("minor cleanups for kmsan").
 
 - VMA handling cleanups from Kefeng Wang ("mm: convert to
   vma_is_initial_heap/stack()").
 
 - DAMON feature work from SeongJae Park ("mm/damon/sysfs-schemes:
   implement DAMOS tried total bytes file"), ("Extend DAMOS filters for
   address ranges and DAMON monitoring targets").
 
 - Compaction work from Kemeng Shi ("Fixes and cleanups to compaction").
 
 - Liam Howlett has improved the maple tree node replacement code
   ("maple_tree: Change replacement strategy").
 
 - ZhangPeng has a general code cleanup - use the K() macro more widely
   ("cleanup with helper macro K()").
 
 - Aneesh Kumar brings memmap-on-memory to ppc64 ("Add support for memmap
   on memory feature on ppc64").
 
 - pagealloc cleanups from Kemeng Shi ("Two minor cleanups for pcp list
   in page_alloc"), ("Two minor cleanups for get pageblock migratetype").
 
 - Vishal Moola introduces a memory descriptor for page table tracking,
   "struct ptdesc" ("Split ptdesc from struct page").
 
 - memfd selftest maintenance work from Aleksa Sarai ("memfd: cleanups
   for vm.memfd_noexec").
 
 - MM include file rationalization from Hugh Dickins ("arch: include
   asm/cacheflush.h in asm/hugetlb.h").
 
 - THP debug output fixes from Hugh Dickins ("mm,thp: fix sloppy text
   output").
 
 - kmemleak improvements from Xiaolei Wang ("mm/kmemleak: use
   object_cache instead of kmemleak_initialized").
 
 - More folio-related cleanups from Matthew Wilcox ("Remove _folio_dtor
   and _folio_order").
 
 - A VMA locking scalability improvement from Suren Baghdasaryan
   ("Per-VMA lock support for swap and userfaults").
 
 - pagetable handling cleanups from Matthew Wilcox ("New page table range
   API").
 
 - A batch of swap/thp cleanups from David Hildenbrand ("mm/swap: stop
   using page->private on tail pages for THP_SWAP + cleanups").
 
 - Cleanups and speedups to the hugetlb fault handling from Matthew
   Wilcox ("Change calling convention for ->huge_fault").
 
 - Matthew Wilcox has also done some maintenance work on the MM subsystem
   documentation ("Improve mm documentation").
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Merge tag 'mm-stable-2023-08-28-18-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Some swap cleanups from Ma Wupeng ("fix WARN_ON in
   add_to_avail_list")

 - Peter Xu has a series (mm/gup: Unify hugetlb, speed up thp") which
   reduces the special-case code for handling hugetlb pages in GUP. It
   also speeds up GUP handling of transparent hugepages.

 - Peng Zhang provides some maple tree speedups ("Optimize the fast path
   of mas_store()").

 - Sergey Senozhatsky has improved te performance of zsmalloc during
   compaction (zsmalloc: small compaction improvements").

 - Domenico Cerasuolo has developed additional selftest code for zswap
   ("selftests: cgroup: add zswap test program").

 - xu xin has doe some work on KSM's handling of zero pages. These
   changes are mainly to enable the user to better understand the
   effectiveness of KSM's treatment of zero pages ("ksm: support
   tracking KSM-placed zero-pages").

 - Jeff Xu has fixes the behaviour of memfd's
   MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED sysctl ("mm/memfd: fix sysctl
   MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED").

 - David Howells has fixed an fscache optimization ("mm, netfs, fscache:
   Stop read optimisation when folio removed from pagecache").

 - Axel Rasmussen has given userfaultfd the ability to simulate memory
   poisoning ("add UFFDIO_POISON to simulate memory poisoning with
   UFFD").

 - Miaohe Lin has contributed some routine maintenance work on the
   memory-failure code ("mm: memory-failure: remove unneeded PageHuge()
   check").

 - Peng Zhang has contributed some maintenance work on the maple tree
   code ("Improve the validation for maple tree and some cleanup").

 - Hugh Dickins has optimized the collapsing of shmem or file pages into
   THPs ("mm: free retracted page table by RCU").

 - Jiaqi Yan has a patch series which permits us to use the healthy
   subpages within a hardware poisoned huge page for general purposes
   ("Improve hugetlbfs read on HWPOISON hugepages").

 - Kemeng Shi has done some maintenance work on the pagetable-check code
   ("Remove unused parameters in page_table_check").

 - More folioification work from Matthew Wilcox ("More filesystem folio
   conversions for 6.6"), ("Followup folio conversions for zswap"). And
   from ZhangPeng ("Convert several functions in page_io.c to use a
   folio").

 - page_ext cleanups from Kemeng Shi ("minor cleanups for page_ext").

 - Baoquan He has converted some architectures to use the
   GENERIC_IOREMAP ioremap()/iounmap() code ("mm: ioremap: Convert
   architectures to take GENERIC_IOREMAP way").

 - Anshuman Khandual has optimized arm64 tlb shootdown ("arm64: support
   batched/deferred tlb shootdown during page reclamation/migration").

 - Better maple tree lockdep checking from Liam Howlett ("More strict
   maple tree lockdep"). Liam also developed some efficiency
   improvements ("Reduce preallocations for maple tree").

 - Cleanup and optimization to the secondary IOMMU TLB invalidation,
   from Alistair Popple ("Invalidate secondary IOMMU TLB on permission
   upgrade").

 - Ryan Roberts fixes some arm64 MM selftest issues ("selftests/mm fixes
   for arm64").

 - Kemeng Shi provides some maintenance work on the compaction code
   ("Two minor cleanups for compaction").

 - Some reduction in mmap_lock pressure from Matthew Wilcox ("Handle
   most file-backed faults under the VMA lock").

 - Aneesh Kumar contributes code to use the vmemmap optimization for DAX
   on ppc64, under some circumstances ("Add support for DAX vmemmap
   optimization for ppc64").

 - page-ext cleanups from Kemeng Shi ("add page_ext_data to get client
   data in page_ext"), ("minor cleanups to page_ext header").

 - Some zswap cleanups from Johannes Weiner ("mm: zswap: three
   cleanups").

 - kmsan cleanups from ZhangPeng ("minor cleanups for kmsan").

 - VMA handling cleanups from Kefeng Wang ("mm: convert to
   vma_is_initial_heap/stack()").

 - DAMON feature work from SeongJae Park ("mm/damon/sysfs-schemes:
   implement DAMOS tried total bytes file"), ("Extend DAMOS filters for
   address ranges and DAMON monitoring targets").

 - Compaction work from Kemeng Shi ("Fixes and cleanups to compaction").

 - Liam Howlett has improved the maple tree node replacement code
   ("maple_tree: Change replacement strategy").

 - ZhangPeng has a general code cleanup - use the K() macro more widely
   ("cleanup with helper macro K()").

 - Aneesh Kumar brings memmap-on-memory to ppc64 ("Add support for
   memmap on memory feature on ppc64").

 - pagealloc cleanups from Kemeng Shi ("Two minor cleanups for pcp list
   in page_alloc"), ("Two minor cleanups for get pageblock
   migratetype").

 - Vishal Moola introduces a memory descriptor for page table tracking,
   "struct ptdesc" ("Split ptdesc from struct page").

 - memfd selftest maintenance work from Aleksa Sarai ("memfd: cleanups
   for vm.memfd_noexec").

 - MM include file rationalization from Hugh Dickins ("arch: include
   asm/cacheflush.h in asm/hugetlb.h").

 - THP debug output fixes from Hugh Dickins ("mm,thp: fix sloppy text
   output").

 - kmemleak improvements from Xiaolei Wang ("mm/kmemleak: use
   object_cache instead of kmemleak_initialized").

 - More folio-related cleanups from Matthew Wilcox ("Remove _folio_dtor
   and _folio_order").

 - A VMA locking scalability improvement from Suren Baghdasaryan
   ("Per-VMA lock support for swap and userfaults").

 - pagetable handling cleanups from Matthew Wilcox ("New page table
   range API").

 - A batch of swap/thp cleanups from David Hildenbrand ("mm/swap: stop
   using page->private on tail pages for THP_SWAP + cleanups").

 - Cleanups and speedups to the hugetlb fault handling from Matthew
   Wilcox ("Change calling convention for ->huge_fault").

 - Matthew Wilcox has also done some maintenance work on the MM
   subsystem documentation ("Improve mm documentation").

* tag 'mm-stable-2023-08-28-18-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (489 commits)
  maple_tree: shrink struct maple_tree
  maple_tree: clean up mas_wr_append()
  secretmem: convert page_is_secretmem() to folio_is_secretmem()
  nios2: fix flush_dcache_page() for usage from irq context
  hugetlb: add documentation for vma_kernel_pagesize()
  mm: add orphaned kernel-doc to the rst files.
  mm: fix clean_record_shared_mapping_range kernel-doc
  mm: fix get_mctgt_type() kernel-doc
  mm: fix kernel-doc warning from tlb_flush_rmaps()
  mm: remove enum page_entry_size
  mm: allow ->huge_fault() to be called without the mmap_lock held
  mm: move PMD_ORDER to pgtable.h
  mm: remove checks for pte_index
  memcg: remove duplication detection for mem_cgroup_uncharge_swap
  mm/huge_memory: work on folio->swap instead of page->private when splitting folio
  mm/swap: inline folio_set_swap_entry() and folio_swap_entry()
  mm/swap: use dedicated entry for swap in folio
  mm/swap: stop using page->private on tail pages for THP_SWAP
  selftests/mm: fix WARNING comparing pointer to 0
  selftests: cgroup: fix test_kmem_memcg_deletion kernel mem check
  ...
2023-08-29 14:25:26 -07:00
Linus Torvalds
6016fc9162 New code for 6.6:
* Make large writes to the page cache fill sparse parts of the cache
    with large folios, then use large memcpy calls for the large folio.
  * Track the per-block dirty state of each large folio so that a
    buffered write to a single byte on a large folio does not result in a
    (potentially) multi-megabyte writeback IO.
  * Allow some directio completions to be performed in the initiating
    task's context instead of punting through a workqueue.  This will
    reduce latency for some io_uring requests.
 
 Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Merge tag 'iomap-6.6-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull iomap updates from Darrick Wong:
 "We've got some big changes for this release -- I'm very happy to be
  landing willy's work to enable large folios for the page cache for
  general read and write IOs when the fs can make contiguous space
  allocations, and Ritesh's work to track sub-folio dirty state to
  eliminate the write amplification problems inherent in using large
  folios.

  As a bonus, io_uring can now process write completions in the caller's
  context instead of bouncing through a workqueue, which should reduce
  io latency dramatically. IOWs, XFS should see a nice performance bump
  for both IO paths.

  Summary:

   - Make large writes to the page cache fill sparse parts of the cache
     with large folios, then use large memcpy calls for the large folio.

   - Track the per-block dirty state of each large folio so that a
     buffered write to a single byte on a large folio does not result in
     a (potentially) multi-megabyte writeback IO.

   - Allow some directio completions to be performed in the initiating
     task's context instead of punting through a workqueue. This will
     reduce latency for some io_uring requests"

* tag 'iomap-6.6-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (26 commits)
  iomap: support IOCB_DIO_CALLER_COMP
  io_uring/rw: add write support for IOCB_DIO_CALLER_COMP
  fs: add IOCB flags related to passing back dio completions
  iomap: add IOMAP_DIO_INLINE_COMP
  iomap: only set iocb->private for polled bio
  iomap: treat a write through cache the same as FUA
  iomap: use an unsigned type for IOMAP_DIO_* defines
  iomap: cleanup up iomap_dio_bio_end_io()
  iomap: Add per-block dirty state tracking to improve performance
  iomap: Allocate ifs in ->write_begin() early
  iomap: Refactor iomap_write_delalloc_punch() function out
  iomap: Use iomap_punch_t typedef
  iomap: Fix possible overflow condition in iomap_write_delalloc_scan
  iomap: Add some uptodate state handling helpers for ifs state bitmap
  iomap: Drop ifs argument from iomap_set_range_uptodate()
  iomap: Rename iomap_page to iomap_folio_state and others
  iomap: Copy larger chunks from userspace
  iomap: Create large folios in the buffered write path
  filemap: Allow __filemap_get_folio to allocate large folios
  filemap: Add fgf_t typedef
  ...
2023-08-28 11:59:52 -07:00
Linus Torvalds
de16588a77 v6.6-vfs.misc
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Merge tag 'v6.6-vfs.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 filesystems.

  Features:

   - Block mode changes on symlinks and rectify our broken semantics

   - Report file modifications via fsnotify() for splice

   - Allow specifying an explicit timeout for the "rootwait" kernel
     command line option. This allows to timeout and reboot instead of
     always waiting indefinitely for the root device to show up

   - Use synchronous fput for the close system call

  Cleanups:

   - Get rid of open-coded lockdep workarounds for async io submitters
     and replace it all with a single consolidated helper

   - Simplify epoll allocation helper

   - Convert simple_write_begin and simple_write_end to use a folio

   - Convert page_cache_pipe_buf_confirm() to use a folio

   - Simplify __range_close to avoid pointless locking

   - Disable per-cpu buffer head cache for isolated cpus

   - Port ecryptfs to kmap_local_page() api

   - Remove redundant initialization of pointer buf in pipe code

   - Unexport the d_genocide() function which is only used within core
     vfs

   - Replace printk(KERN_ERR) and WARN_ON() with WARN()

  Fixes:

   - Fix various kernel-doc issues

   - Fix refcount underflow for eventfds when used as EFD_SEMAPHORE

   - Fix a mainly theoretical issue in devpts

   - Check the return value of __getblk() in reiserfs

   - Fix a racy assert in i_readcount_dec

   - Fix integer conversion issues in various functions

   - Fix LSM security context handling during automounts that prevented
     NFS superblock sharing"

* tag 'v6.6-vfs.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (39 commits)
  cachefiles: use kiocb_{start,end}_write() helpers
  ovl: use kiocb_{start,end}_write() helpers
  aio: use kiocb_{start,end}_write() helpers
  io_uring: use kiocb_{start,end}_write() helpers
  fs: create kiocb_{start,end}_write() helpers
  fs: add kerneldoc to file_{start,end}_write() helpers
  io_uring: rename kiocb_end_write() local helper
  splice: Convert page_cache_pipe_buf_confirm() to use a folio
  libfs: Convert simple_write_begin and simple_write_end to use a folio
  fs/dcache: Replace printk and WARN_ON by WARN
  fs/pipe: remove redundant initialization of pointer buf
  fs: Fix kernel-doc warnings
  devpts: Fix kernel-doc warnings
  doc: idmappings: fix an error and rephrase a paragraph
  init: Add support for rootwait timeout parameter
  vfs: fix up the assert in i_readcount_dec
  fs: Fix one kernel-doc comment
  docs: filesystems: idmappings: clarify from where idmappings are taken
  fs/buffer.c: disable per-CPU buffer_head cache for isolated CPUs
  vfs, security: Fix automount superblock LSM init problem, preventing NFS sb sharing
  ...
2023-08-28 10:17:14 -07:00
Pavel Begunkov
0aa7aa5f76 io_uring: move multishot cqe cache in ctx
We cache multishot CQEs before flushing them to the CQ in
submit_state.cqe. It's a 16 entry cache totalling 256 bytes in the
middle of the io_submit_state structure. Move it out of there, it
should help with CPU caches for the submission state, and shouldn't
affect cached CQEs.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/dbe1f39c043ee23da918836be44fcec252ce6711.1692916914.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-24 17:16:20 -06:00
Pavel Begunkov
2af89abda7 io_uring: add option to remove SQ indirection
Not many aware, but io_uring submission queue has two levels. The first
level usually appears as sq_array and stores indexes into the actual SQ.

To my knowledge, no one has ever seriously used it, nor liburing exposes
it to users. Add IORING_SETUP_NO_SQARRAY, when set we don't bother
creating and using the sq_array and SQ heads/tails will be pointing
directly into the SQ. Improves memory footprint, in term of both
allocations as well as cache usage, and also should make io_get_sqe()
less branchy in the end.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/0ffa3268a5ef61d326201ff43a233315c96312e0.1692916914.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-24 17:16:19 -06:00
Pavel Begunkov
093a650b75 io_uring: force inline io_fill_cqe_req
There are only 2 callers of io_fill_cqe_req left, and one of them is
extremely hot. Force inline the function.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/ffce4fc5e3521966def848a4d930586dfe33ae11.1692916914.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-24 17:16:19 -06:00
Pavel Begunkov
ec26c225f0 io_uring: merge iopoll and normal completion paths
io_do_iopoll() and io_submit_flush_completions() are pretty similar,
both filling CQEs and then free a list of requests. Don't duplicate it
and make iopoll use __io_submit_flush_completions(), which also helps
with inlining and other optimisations.

For that, we need to first find all completed iopoll requests and splice
them from the iopoll list and then pass it down. This adds one extra
list traversal, which should be fine as requests will stay hot in cache.

CQ locking is already conditional, introduce ->lockless_cq and skip
locking for IOPOLL as it's protected by ->uring_lock.

We also add a wakeup optimisation for IOPOLL to __io_cq_unlock_post(),
so it works just like io_cqring_ev_posted_iopoll().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/3840473f5e8a960de35b77292026691880f6bdbc.1692916914.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-24 17:16:19 -06:00
Pavel Begunkov
54927baf6c io_uring: reorder cqring_flush and wakeups
Unlike in the past, io_commit_cqring_flush() doesn't do anything that
may need io_cqring_wake() to be issued after, all requests it completes
will go via task_work. Do io_commit_cqring_flush() after
io_cqring_wake() to clean up __io_cq_unlock_post().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/ed32dcfeec47e6c97bd6b18c152ddce5b218403f.1692916914.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-24 17:16:19 -06:00
Pavel Begunkov
59fbc409e7 io_uring: optimise extra io_get_cqe null check
If the cached cqe check passes in io_get_cqe*() it already means that
the cqe we return is valid and non-zero, however the compiler is unable
to optimise null checks like in io_fill_cqe_req().

Do a bit of trickery, return success/fail boolean from io_get_cqe*()
and store cqe in the cqe parameter. That makes it do the right thing,
erasing the check together with the introduced indirection.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/322ea4d3377d3d4efd8ae90ab8ed28a99f518210.1692916914.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-24 17:16:19 -06:00
Pavel Begunkov
20d6b63387 io_uring: refactor __io_get_cqe()
Make __io_get_cqe simpler by not grabbing the cqe from refilled cached,
but letting io_get_cqe() do it for us. That's cleaner and removes some
duplication.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/74dc8fdf2657e438b2e05e1d478a3596924604e9.1692916914.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-24 17:16:19 -06:00
Pavel Begunkov
b24c5d7529 io_uring: simplify big_cqe handling
Don't keep big_cqe bits of req in a union with hash_node, find a
separate space for it. It's bit safer, but also if we keep it always
initialised, we can get rid of ugly REQ_F_CQE32_INIT handling.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/447aa1b2968978c99e655ba88db536e903df0fe9.1692916914.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-24 17:16:19 -06:00
Pavel Begunkov
31d3ba924f io_uring: cqe init hardening
io_kiocb::cqe stores the completion info which we'll memcpy to
userspace, and we rely on callbacks and other later steps to populate
it with right values. We have never had problems with that, but it would
still be safer to zero it on allocation.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b16a3b64dde678686460d3c3792c3ba6d3d1bc7a.1692916914.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-24 17:16:19 -06:00
Pavel Begunkov
a0727c7383 io_uring: improve cqe !tracing hot path
While looking at io_fill_cqe_req()'s asm I stumbled on our trace points
turning into the chunk below:

trace_io_uring_complete(req->ctx, req, req->cqe.user_data,
			req->cqe.res, req->cqe.flags,
			req->extra1, req->extra2);

io_uring/io_uring.c:898: 	trace_io_uring_complete(req->ctx, req, req->cqe.user_data,
	movq	232(%rbx), %rdi	# req_44(D)->big_cqe.extra2, _5
	movq	224(%rbx), %rdx	# req_44(D)->big_cqe.extra1, _6
	movl	84(%rbx), %r9d	# req_44(D)->cqe.D.81184.flags, _7
	movl	80(%rbx), %r8d	# req_44(D)->cqe.res, _8
	movq	72(%rbx), %rcx	# req_44(D)->cqe.user_data, _9
	movq	88(%rbx), %rsi	# req_44(D)->ctx, _10
./arch/x86/include/asm/jump_label.h:27: 	asm_volatile_goto("1:"
	1:jmp .L1772 # objtool NOPs this 	#
	...

It does a jump_label for actual tracing, but those 6 moves will stay
there in the hottest io_uring path. As an optimisation, add a
trace_io_uring_complete_enabled() check, which is also uses jump_labels,
it tricks the compiler into behaving. It removes the junk without
changing anything else int the hot path.

Note: apparently, it's not only me noticing it, and people are also
working it around. We should remove the check when it's solved
generically or rework tracing.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/555d8312644b3776f4be7e23f9b92943875c4bc7.1692916914.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-24 17:16:19 -06:00
Matthew Wilcox (Oracle)
99a9e0b83a io_uring: stop calling free_compound_page()
Patch series "Remove _folio_dtor and _folio_order", v2.


This patch (of 13):

folio_put() is the standard way to write this, and it's not appreciably
slower.  This is an enabling patch for removing free_compound_page()
entirely.

Link: https://lkml.kernel.org/r/20230816151201.3655946-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20230816151201.3655946-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21 14:28:42 -07:00
Amir Goldstein
e484fd73f4 io_uring: use kiocb_{start,end}_write() helpers
Use helpers instead of the open coded dance to silence lockdep warnings.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Message-Id: <20230817141337.1025891-5-amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-21 17:27:26 +02:00
Amir Goldstein
a370167fe5 io_uring: rename kiocb_end_write() local helper
This helper does not take a kiocb as input and we want to create a
common helper by that name that takes a kiocb as input.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Message-Id: <20230817141337.1025891-2-amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-21 17:27:25 +02:00
Kees Cook
04d9244c94 io_uring/rsrc: Annotate struct io_mapped_ubuf with __counted_by
Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct io_mapped_ubuf.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: io-uring@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20230817212146.never.853-kees@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-17 19:14:47 -06:00
Jens Axboe
ebdfefc09c io_uring/sqpoll: fix io-wq affinity when IORING_SETUP_SQPOLL is used
If we setup the ring with SQPOLL, then that polling thread has its
own io-wq setup. This means that if the application uses
IORING_REGISTER_IOWQ_AFF to set the io-wq affinity, we should not be
setting it for the invoking task, but rather the sqpoll task.

Add an sqpoll helper that parks the thread and updates the affinity,
and use that one if we're using SQPOLL.

Fixes: fe76421d1d ("io_uring: allow user configurable IO thread CPU affinity")
Cc: stable@vger.kernel.org # 5.10+
Link: https://github.com/axboe/liburing/discussions/884
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-16 13:40:28 -06:00
Pavel Begunkov
d246c759c4 io_uring: simplify io_run_task_work_sig return
Nobody cares about io_run_task_work_sig returning 1, we only check for
negative errors. Simplify by keeping to 0/-error returns.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/3aec8a532c003d6e50739b969a82989402696170.1691757663.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-11 10:42:57 -06:00
Pavel Begunkov
19a63c4021 io_uring/rsrc: keep one global dummy_ubuf
We set empty registered buffers to dummy_ubuf as an optimisation.
Currently, we allocate the dummy entry for each ring, whenever we can
simply have one global instance.

We're casting out const on assignment, it's fine as we're not going to
change the content of the dummy, the constness gives us an extra layer
of protection if sth ever goes wrong.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e4a96dda35ab755914bc43f6781bba0df97ac489.1691757663.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-11 10:42:57 -06:00
Pavel Begunkov
b6b2bb58a7 io_uring: never overflow io_aux_cqe
Now all callers of io_aux_cqe() set allow_overflow to false, remove the
parameter and not allow overflowing auxilary multishot cqes.

When CQ is full the function callers and all multishot requests in
general are expected to complete the request. That prevents indefinite
in-background grows of the overflow list and let's the userspace to
handle the backlog at its own pace.

Resubmitting a request should also be faster than accounting a bunch of
overflows, so it should be better for perf when it happens, but a well
behaving userspace should be trying to avoid overflows in any case.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/bb20d14d708ea174721e58bb53786b0521e4dd6d.1691757663.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-11 10:42:57 -06:00
Pavel Begunkov
056695bffa io_uring: remove return from io_req_cqe_overflow()
Nobody checks io_req_cqe_overflow()'s return, make it return void.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/8f2029ad0c22f73451664172d834372608ee0a77.1691757663.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-11 10:42:57 -06:00
Pavel Begunkov
00b0db5624 io_uring: open code io_fill_cqe_req()
io_fill_cqe_req() is only called from one place, open code it, and
rename __io_fill_cqe_req().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f432ce75bb1c94cadf0bd2add4d6aa510bd1fb36.1691757663.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-11 10:42:57 -06:00
Pavel Begunkov
b2e74db55d io_uring/net: don't overflow multishot recv
Don't allow overflowing multishot recv CQEs, it might get out of
hand, hurt performance, and in the worst case scenario OOM the task.

Cc: stable@vger.kernel.org
Fixes: b3fdea6ecb ("io_uring: multishot recv")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/0b295634e8f1b71aa764c984608c22d85f88f75c.1691757663.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-11 10:42:51 -06:00
Pavel Begunkov
1bfed23349 io_uring/net: don't overflow multishot accept
Don't allow overflowing multishot accept CQEs, we want to limit
the grows of the overflow list.

Cc: stable@vger.kernel.org
Fixes: 4e86a2c980 ("io_uring: implement multishot mode for accept")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/7d0d749649244873772623dd7747966f516fe6e2.1691757663.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-11 10:42:34 -06:00
Jens Axboe
22f7fb80e6 io_uring/io-wq: don't gate worker wake up success on wake_up_process()
All we really care about is finding a free worker. If said worker is
already running, it's either starting new work already or it's just
finishing up existing work. For the latter, we'll be finding this work
item next anyway, and for the former, if the worker does go to sleep,
it'll create a new worker anyway as we have pending items.

This reduces try_to_wake_up() overhead considerably:

23.16%    -10.46%  [kernel.kallsyms]      [k] try_to_wake_up

Reviewed-by: Hao Xu <howeyxu@tencent.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-11 10:36:20 -06:00
Jens Axboe
de36a15f9a io_uring/io-wq: reduce frequency of acct->lock acquisitions
When we check if we have work to run, we grab the acct lock, check,
drop it, and then return the result. If we do have work to run, then
running the work will again grab acct->lock and get the work item.

This causes us to grab acct->lock more frequently than we need to.
If we have work to do, have io_acct_run_queue() return with the acct
lock still acquired. io_worker_handle_work() is then always invoked
with the acct lock already held.

In a simple test cases that stats files (IORING_OP_STATX always hits
io-wq), we see a nice reduction in locking overhead with this change:

19.32%   -12.55%  [kernel.kallsyms]      [k] __cmpwait_case_32
20.90%   -12.07%  [kernel.kallsyms]      [k] queued_spin_lock_slowpath

Reviewed-by: Hao Xu <howeyxu@tencent.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-11 10:36:17 -06:00
Jens Axboe
78848b9b05 io_uring/io-wq: don't grab wq->lock for worker activation
The worker free list is RCU protected, and checks for workers going away
when iterating it. There's no need to hold the wq->lock around the
lookup.

Reviewed-by: Hao Xu <howeyxu@tencent.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-11 10:36:12 -06:00
Jens Axboe
89226307b1 io_uring: remove unnecessary forward declaration
We never use io_move_task_work_from_local() before it's defined in the
file anyway, so kill the forward declaration.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-10 15:01:58 -06:00
Jens Axboe
17bc28374c io_uring: have io_file_put() take an io_kiocb rather than the file
No functional changes in this patch, just a prep patch for needing the
request in io_file_put().

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-10 10:27:46 -06:00
Jens Axboe
9f69a25957 io_uring/splice: use fput() directly
No point in using io_file_put() here, as we need to check if it's a
fixed file in the caller anyway.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-10 10:24:25 -06:00
Jens Axboe
3aaf22b62a io_uring/fdinfo: get rid of ref tryget
The caller holds a reference to the ring itself, so by definition
the ring cannot go away. There's no need to play games with tryget
for the reference, as we don't need an extra reference at all.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-10 10:24:19 -06:00
Jens Axboe
9e4bef2ba9 io_uring: cleanup 'ret' handling in io_iopoll_check()
We return 0 for success, or -error when there's an error. Move the 'ret'
variable into the loop where we are actually using it, to make it
clearer that we don't carry this variable forward for return outside of
the loop.

While at it, also move the need_resched() break condition out of the
while check itself, keeping it with the signal pending check.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-09 10:46:46 -06:00
Pavel Begunkov
dc314886cb io_uring: break iopolling on signal
Don't keep spinning iopoll with a signal set. It'll eventually return
back, e.g. by virtue of need_resched(), but it's not a nice user
experience.

Cc: stable@vger.kernel.org
Fixes: def596e955 ("io_uring: support for IO polling")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/eeba551e82cad12af30c3220125eb6cb244cc94c.1691594339.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-09 10:46:46 -06:00
Pavel Begunkov
569f5308e5 io_uring: fix false positive KASAN warnings
io_req_local_work_add() peeks into the work list, which can be executed
in the meanwhile. It's completely fine without KASAN as we're in an RCU
read section and it's SLAB_TYPESAFE_BY_RCU. With KASAN though it may
trigger a false positive warning because internal io_uring caches are
sanitised.

Remove sanitisation from the io_uring request cache for now.

Cc: stable@vger.kernel.org
Fixes: 8751d15426 ("io_uring: reduce scheduling due to tw")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/c6fbf7a82a341e66a0007c76eefd9d57f2d3ba51.1691541473.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-09 10:46:46 -06:00
Pavel Begunkov
cfdbaa3a29 io_uring: fix drain stalls by invalid SQE
cq_extra is protected by ->completion_lock, which io_get_sqe() misses.
The bug is harmless as it doesn't happen in real life, requires invalid
SQ index array and racing with submission, and only messes up the
userspace, i.e. stall requests execution but will be cleaned up on
ring destruction.

Fixes: 15641e4270 ("io_uring: don't cache number of dropped SQEs")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/66096d54651b1a60534bb2023f2947f09f50ef73.1691538547.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-09 10:46:46 -06:00
Yue Haibing
d4b30eed51 io_uring/rsrc: Remove unused declaration io_rsrc_put_tw()
Commit 36b9818a5a ("io_uring/rsrc: don't offload node free")
removed the implementation but leave declaration.

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20230808151058.4572-1-yuehaibing@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-09 10:46:46 -06:00
Jens Axboe
b97f96e22f io_uring: annotate the struct io_kiocb slab for appropriate user copy
When compiling the kernel with clang and having HARDENED_USERCOPY
enabled, the liburing openat2.t test case fails during request setup:

usercopy: Kernel memory overwrite attempt detected to SLUB object 'io_kiocb' (offset 24, size 24)!
------------[ cut here ]------------
kernel BUG at mm/usercopy.c:102!
invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
CPU: 3 PID: 413 Comm: openat2.t Tainted: G                 N 6.4.3-g6995e2de6891-dirty #19
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014
RIP: 0010:usercopy_abort+0x84/0x90
Code: ce 49 89 ce 48 c7 c3 68 48 98 82 48 0f 44 de 48 c7 c7 56 c6 94 82 4c 89 de 48 89 c1 41 52 41 56 53 e8 e0 51 c5 00 48 83 c4 18 <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 41 57 41 56
RSP: 0018:ffffc900016b3da0 EFLAGS: 00010296
RAX: 0000000000000062 RBX: ffffffff82984868 RCX: 4e9b661ac6275b00
RDX: ffff8881b90ec580 RSI: ffffffff82949a64 RDI: 00000000ffffffff
RBP: 0000000000000018 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc900016b3c88 R11: ffffc900016b3c30 R12: 00007ffe549659e0
R13: ffff888119014000 R14: 0000000000000018 R15: 0000000000000018
FS:  00007f862e3ca680(0000) GS:ffff8881b90c0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005571483542a8 CR3: 0000000118c11000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 ? __die_body+0x63/0xb0
 ? die+0x9d/0xc0
 ? do_trap+0xa7/0x180
 ? usercopy_abort+0x84/0x90
 ? do_error_trap+0xc6/0x110
 ? usercopy_abort+0x84/0x90
 ? handle_invalid_op+0x2c/0x40
 ? usercopy_abort+0x84/0x90
 ? exc_invalid_op+0x2f/0x40
 ? asm_exc_invalid_op+0x16/0x20
 ? usercopy_abort+0x84/0x90
 __check_heap_object+0xe2/0x110
 __check_object_size+0x142/0x3d0
 io_openat2_prep+0x68/0x140
 io_submit_sqes+0x28a/0x680
 __se_sys_io_uring_enter+0x120/0x580
 do_syscall_64+0x3d/0x80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x55714834de26
Code: ca 01 0f b6 82 d0 00 00 00 8b ba cc 00 00 00 45 31 c0 31 d2 41 b9 08 00 00 00 83 e0 01 c1 e0 04 41 09 c2 b8 aa 01 00 00 0f 05 <c3> 66 0f 1f 84 00 00 00 00 00 89 30 eb 89 0f 1f 40 00 8b 00 a8 06
RSP: 002b:00007ffe549659c8 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 00007ffe54965a50 RCX: 000055714834de26
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000008
R10: 0000000000000000 R11: 0000000000000246 R12: 000055714834f057
R13: 00007ffe54965a50 R14: 0000000000000001 R15: 0000557148351dd8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---

when it tries to copy struct open_how from userspace into the per-command
space in the io_kiocb. There's nothing wrong with the copy, but we're
missing the appropriate annotations for allowing user copies to/from the
io_kiocb slab.

Allow copies in the per-command area, which is from the 'file' pointer to
when 'opcode' starts. We do have existing user copies there, but they are
not all annotated like the one that openat2_prep() uses,
copy_struct_from_user(). But in practice opcodes should be allowed to
copy data into their per-command area in the io_kiocb.

Reported-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-09 10:46:44 -06:00
Breno Leitao
8e9fad0e70 io_uring: Add io_uring command support for sockets
Enable io_uring commands on network sockets. Create two new
SOCKET_URING_OP commands that will operate on sockets.

In order to call ioctl on sockets, use the file_operations->io_uring_cmd
callbacks, and map it to a uring socket function, which handles the
SOCKET_URING_OP accordingly, and calls socket ioctls.

This patches was tested by creating a new test case in liburing.
Link: https://github.com/leitao/liburing/tree/io_uring_cmd

Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20230627134424.2784797-1-leitao@debian.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-09 10:46:15 -06:00
Helge Deller
56675f8b9f io_uring/parisc: Adjust pgoff in io_uring mmap() for parisc
The changes from commit 32832a407a ("io_uring: Fix io_uring mmap() by
using architecture-provided get_unmapped_area()") to the parisc
implementation of get_unmapped_area() broke glibc's locale-gen
executable when running on parisc.

This patch reverts those architecture-specific changes, and instead
adjusts in io_uring_mmu_get_unmapped_area() the pgoff offset which is
then given to parisc's get_unmapped_area() function.  This is much
cleaner than the previous approach, and we still will get a coherent
addresss.

This patch has no effect on other architectures (SHM_COLOUR is only
defined on parisc), and the liburing testcase stil passes on parisc.

Cc: stable@vger.kernel.org # 6.4
Signed-off-by: Helge Deller <deller@gmx.de>
Reported-by: Christoph Biedl <linux-kernel.bfrz@manchmal.in-ulm.de>
Fixes: 32832a407a ("io_uring: Fix io_uring mmap() by using architecture-provided get_unmapped_area()")
Fixes: d808459b2e ("io_uring: Adjust mapping wrt architecture aliasing requirements")
Link: https://lore.kernel.org/r/ZNEyGV0jyI8kOOfz@p100
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-08 12:37:01 -06:00
Aleksa Sarai
72dbde0f2a io_uring: correct check for O_TMPFILE
O_TMPFILE is actually __O_TMPFILE|O_DIRECTORY. This means that the old
check for whether RESOLVE_CACHED can be used would incorrectly think
that O_DIRECTORY could not be used with RESOLVE_CACHED.

Cc: stable@vger.kernel.org # v5.12+
Fixes: 3a81fd0204 ("io_uring: enable LOOKUP_CACHED path resolution for filename lookups")
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Link: https://lore.kernel.org/r/20230807-resolve_cached-o_tmpfile-v3-1-e49323e1ef6f@cyphar.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-07 12:34:23 -06:00
Darrick J. Wong
377698d4ab Improve iomap/xfs async dio write performance
iomap always punts async dio write completions to a workqueue, which has
 a cost in terms of efficiency (now you need an unrelated worker to
 process it) and latency (now you're bouncing a completion through an
 async worker, which is a classic slowdown scenario).
 
 io_uring handles IRQ completions via task_work, and for writes that
 don't need to do extra IO at completion time, we can safely complete
 them inline from that. This patchset adds IOCB_DIO_CALLER_COMP, which an
 IO issuer can set to inform the completion side that any extra work that
 needs doing for that completion can be punted to a safe task context.
 
 The iomap dio completion will happen in hard/soft irq context, and we
 need a saner context to process these completions. IOCB_DIO_CALLER_COMP
 is added, which can be set in a struct kiocb->ki_flags by the issuer. If
 the completion side of the iocb handling understands this flag, it can
 choose to set a kiocb->dio_complete() handler and just call ki_complete
 from IRQ context. The issuer must then ensure that this callback is
 processed from a task. io_uring punts IRQ completions to task_work
 already, so it's trivial wire it up to run more of the completion before
 posting a CQE. This is good for up to a 37% improvement in
 throughput/latency for low queue depth IO, patch 5 has the details.
 
 If we need to do real work at completion time, iomap will clear the
 IOMAP_DIO_CALLER_COMP flag.
 
 This work came about when Andres tested low queue depth dio writes for
 postgres and compared it to doing sync dio writes, showing that the
 async processing slows us down a lot.
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Merge tag 'xfs-async-dio.6-2023-08-01' of git://git.kernel.dk/linux into iomap-6.6-mergeA

Improve iomap/xfs async dio write performance

iomap always punts async dio write completions to a workqueue, which has
a cost in terms of efficiency (now you need an unrelated worker to
process it) and latency (now you're bouncing a completion through an
async worker, which is a classic slowdown scenario).

io_uring handles IRQ completions via task_work, and for writes that
don't need to do extra IO at completion time, we can safely complete
them inline from that. This patchset adds IOCB_DIO_CALLER_COMP, which an
IO issuer can set to inform the completion side that any extra work that
needs doing for that completion can be punted to a safe task context.

The iomap dio completion will happen in hard/soft irq context, and we
need a saner context to process these completions. IOCB_DIO_CALLER_COMP
is added, which can be set in a struct kiocb->ki_flags by the issuer. If
the completion side of the iocb handling understands this flag, it can
choose to set a kiocb->dio_complete() handler and just call ki_complete
from IRQ context. The issuer must then ensure that this callback is
processed from a task. io_uring punts IRQ completions to task_work
already, so it's trivial wire it up to run more of the completion before
posting a CQE. This is good for up to a 37% improvement in
throughput/latency for low queue depth IO, patch 5 has the details.

If we need to do real work at completion time, iomap will clear the
IOMAP_DIO_CALLER_COMP flag.

This work came about when Andres tested low queue depth dio writes for
postgres and compared it to doing sync dio writes, showing that the
async processing slows us down a lot.

* tag 'xfs-async-dio.6-2023-08-01' of git://git.kernel.dk/linux:
  iomap: support IOCB_DIO_CALLER_COMP
  io_uring/rw: add write support for IOCB_DIO_CALLER_COMP
  fs: add IOCB flags related to passing back dio completions
  iomap: add IOMAP_DIO_INLINE_COMP
  iomap: only set iocb->private for polled bio
  iomap: treat a write through cache the same as FUA
  iomap: use an unsigned type for IOMAP_DIO_* defines
  iomap: cleanup up iomap_dio_bio_end_io()

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2023-08-01 16:41:49 -07:00