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>
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>
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>
-----BEGIN PGP SIGNATURE-----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=+97D
-----END PGP SIGNATURE-----
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
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>
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQQqUNBr3gm4hGXdBJlZ7Krx/gZQ6wUCZkzp/gAKCRBZ7Krx/gZQ
63KFAQCsKv3XdcF+2BO+QuwPvR6eAvDxFjrFEcQFyyOXgFVLaAD/UMM0HcEFWxBb
PCPvyKVP22wF9PbodkrKJn8DRdtRZwM=
=jvWv
-----END PGP SIGNATURE-----
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
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>
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".
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZkgQYwAKCRDdBJ7gKXxA
jrdKAP9WVJdpEcXxpoub/vVE0UWGtffr8foifi9bCwrQrGh5mgEAx7Yf0+d/oBZB
nvA4E0DcPrUAFy144FNM0NTCb7u9vAw=
=V3R/
-----END PGP SIGNATURE-----
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
...
-----BEGIN PGP SIGNATURE-----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=S6Xt
-----END PGP SIGNATURE-----
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
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>
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>
-----BEGIN PGP SIGNATURE-----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=DwAV
-----END PGP SIGNATURE-----
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
...
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZj3HuwAKCRCRxhvAZXjc
orYvAQCZOr68uJaEaXAArYTdnMdQ6HIzG+FVlwrqtrhz0BV07wEAqgmtSR9XKh+L
0+DNepg4R8PZOHH371eSSsLNRCUCkAs=
=SVsU
-----END PGP SIGNATURE-----
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
...
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
A previous consolidation cleanup missed handling the case where the ring
is dying, and __io_cqring_overflow_flush() doesn't flush entries if the
CQ ring is already full. This is fine for the normal CQE overflow
flushing, but if the ring is going away, we need to flush everything,
even if it means simply freeing the overflown entries.
Fixes: 6c948ec44b29 ("io_uring: consolidate overflow flushing")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In the __io_timeout_prep function, the io_timeout list is initialized
twice, removing the meaningless second initialization.
Signed-off-by: Ruyi Zhang <ruyi.zhang@samsung.com>
Link: https://lore.kernel.org/r/20240411055953.2029218-1-ruyi.zhang@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We're exporting some io_uring bits to networking, e.g. for implementing
a net callback for io_uring cmds, but we don't want to expose more than
needed. Add a separate header for networking.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: David Wei <dw@davidwei.uk>
Link: https://lore.kernel.org/r/20240409210554.1878789-1-dw@davidwei.uk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The only caller doesn't handle the return value of io_put_kbuf_comp(), so
change its return type into void.
Also follow Jens's suggestion to rename it as io_put_kbuf_drop().
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20240407132759.4056167-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_req_put_rsrc_locked() is a weird shim function around
io_req_put_rsrc(). All calls to io_req_put_rsrc() require holding
->uring_lock, so we can just use it directly.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a195bc78ac3d2c6fbaea72976e982fe51e50ecdd.1712331455.git.asml.silence@gmail.com
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_req_complete_post() was a sole user of ->locked_free_list, but
since we just gutted the function, the cache is not used anymore and
can be removed.
->locked_free_list served as an asynhronous counterpart of the main
request (i.e. struct io_kiocb) cache for all unlocked cases like io-wq.
Now they're all forced to be completed into the main cache directly,
off of the normal completion path or via io_free_req().
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/7bffccd213e370abd4de480e739d8b08ab6c1326.1712331455.git.asml.silence@gmail.com
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_req_complete_post() is now io-wq only and shouldn't be used outside
of it, i.e. it relies that io-wq holds a ref for the request as
explained in a comment below. Let's add a warning to enforce the
assumption and make sure nobody would try to do anything weird.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1013b60c35d431d0698cafbc53c06f5917348c20.1712331455.git.asml.silence@gmail.com
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Since commit 8f6c829491fe ("io_uring: remove struct io_tw_state::locked"),
io_req_complete_post() is only called from io-wq submit work, where the
request reference is guaranteed to be grabbed and won't drop to zero
in io_req_complete_post().
Kill the dead code, meantime add req_ref_put() to put the reference.
Cc: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1d8297e2046553153e763a52574f0e0f4d512f86.1712331455.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There are a few of those:
io_uring/fdinfo.c:170:16: warning: declaration shadows a local variable [-Wshadow]
170 | struct file *f = io_file_from_index(&ctx->file_table, i);
| ^
io_uring/fdinfo.c:53:67: note: previous declaration is here
53 | __cold void io_uring_show_fdinfo(struct seq_file *m, struct file *f)
| ^
io_uring/cancel.c:187:25: warning: declaration shadows a local variable [-Wshadow]
187 | struct io_uring_task *tctx = node->task->io_uring;
| ^
io_uring/cancel.c:166:31: note: previous declaration is here
166 | struct io_uring_task *tctx,
| ^
io_uring/register.c:371:25: warning: declaration shadows a local variable [-Wshadow]
371 | struct io_uring_task *tctx = node->task->io_uring;
| ^
io_uring/register.c:312:24: note: previous declaration is here
312 | struct io_uring_task *tctx = NULL;
| ^
and a simple cleanup gets rid of them. For the fdinfo case, make a
distinction between the file being passed in (for the ring), and the
registered files we iterate. For the other two cases, just get rid of
shadowed variable, there's no reason to have a new one.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the related code from io_uring.c into memmap.c. No functional
changes in this patch, just cleaning it up a bit now that the full
transition is done.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Rather than use remap_pfn_range() for this and manually free later,
switch to using vm_insert_page() and have it Just Work.
This requires a bit of effort on the mmap lookup side, as the ctx
uring_lock isn't held, which otherwise protects buffer_lists from being
torn down, and it's not safe to grab from mmap context that would
introduce an ABBA deadlock between the mmap lock and the ctx uring_lock.
Instead, lookup the buffer_list under RCU, as the the list is RCU freed
already. Use the existing reference count to determine whether it's
possible to safely grab a reference to it (eg if it's not zero already),
and drop that reference when done with the mapping. If the mmap
reference is the last one, the buffer_list and the associated memory can
go away, since the vma insertion has references to the inserted pages at
that point.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This avoids needing to care about HIGHMEM, and it makes the buffer
indexing easier as both ring provided buffer methods are now virtually
mapped in a contigious fashion.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move it into io_uring.c where it belongs, and use it in there as well
rather than have two implementations of this.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This is the last holdout which does odd page checking, convert it to
vmap just like what is done for the non-mmap path.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Rather than use remap_pfn_range() for this and manually free later,
switch to using vm_insert_pages() and have it Just Work.
If possible, allocate a single compound page that covers the range that
is needed. If that works, then we can just use page_address() on that
page. If we fail to get a compound page, allocate single pages and use
vmap() to map them into the kernel virtual address space.
This just covers the rings/sqes, the other remaining user of the mmap
remap_pfn_range() user will be converted separately. Once that is done,
we can kill the old alloc/free code.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_task_work_pending() uses wq_list_empty() on ctx->work_llist, but it's
not an io_wq_work_list, it's a struct llist_head. They both have
->first as head-of-list, and it turns out the checks are identical. But
be proper and use the right helper.
Fixes: dac6a0eae7 ("io_uring: ensure iopoll runs local task work as well")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The object list is a bit of a mess, with core and opcode files mixed in.
Re-arrange it so that we have the core bits first, and then opcode
specific files after that.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The allocator will generally return memory in order, but
__io_alloc_req_refill() then adds them to a stack and we'll extract them
in the opposite order. This obviously isn't a huge deal, but:
1) it makes debugging easier when they are in order
2) keeping them in-order is the right thing to do
3) reduces the code for adding them to the stack
Just add them in reverse to the stack.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This should be plenty, rather than the default of 128, and matches what
we have on the rsrc and futex side as well.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently lists are being used to manage this, but best practice is
usually to have these in an array instead as that it cheaper to manage.
Outside of that detail, games are also played with KASAN as the list
is inside the cached entry itself.
Finally, all users of this need a struct io_cache_entry embedded in
their struct, which is union'ized with something else in there that
isn't used across the free -> realloc cycle.
Get rid of all of that, and simply have it be an array. This will not
change the memory used, as we're just trading an 8-byte member entry
for the per-elem array size.
This reduces the overhead of the recycled allocations, and it reduces
the amount of code code needed to support recycling to about half of
what it currently is.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
It's now unused, drop the code related to it. This includes the
io_issue_defs->manual alloc field.
While in there, and since ->async_size is now being used a bit more
frequently and in the issue path, move it to io_issue_defs[].
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The previous commit turned on async data for uring_cmd, and did the
basic conversion of setting everything up on the prep side. However, for
a lot of use cases, -EIOCBQUEUED will get returned on issue, as the
operation got successfully queued. For that case, a persistent SQE isn't
needed, as it's just used for issue.
Unless execution goes async immediately, defer copying the double SQE
until it's necessary.
This greatly reduces the overhead of such commands, as evidenced by
a perf diff from before and after this change:
10.60% -8.58% [kernel.vmlinux] [k] io_uring_cmd_prep
where the prep side drops from 10.60% to ~2%, which is more expected.
Performance also rises from ~113M IOPS to ~122M IOPS, bringing us back
to where it was before the async command prep.
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Basic conversion ensuring async_data is allocated off the prep path. Adds
a basic alloc cache as well, as passthrough IO can be quite high in rate.
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
While doing that, get rid of io_async_connect and just use the generic
io_async_msghdr. Both of them have a struct sockaddr_storage in there,
and while io_async_msghdr is bigger, if the same type can be used then
the netmsg_cache can get reused for connect as well.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Let the io_async_rw hold on to the iovec and reuse it, rather than always
allocate and free them.
Also enables KASAN for the iovec entries, so that reuse can be detected
even while they are in the cache.
While doing so, shrink io_async_rw by getting rid of the bigger embedded
fast iovec. Since iovecs are being recycled now, shrink it from 8 to 1.
This reduces the io_async_rw size from 264 to 160 bytes, a 40% reduction.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We no longer need to gate a potential retry on whether or not the
context matches our original task, as all read/write operations have
been fully prepared upfront. This means there's never any re-import
needed, and hence we can always retry requests.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
read/write requests try to put everything on the stack, and then alloc
and copy if a retry is needed. This necessitates a bunch of nasty code
that deals with intermediate state.
Get rid of this, and have the prep side setup everything that is needed
upfront, which greatly simplifies the opcode handlers.
This includes adding an alloc cache for io_async_rw, to make it cheap
to handle.
In terms of cost, this should be basically free and transparent. For
the worst case of {READ,WRITE}_FIXED which didn't need it before,
performance is unaffected in the normal peak workload that is being
used to test that. Still runs at 122M IOPS.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Now that iovec recycling is being done, the iovec is no longer being
freed in there. Hence the kmsg parameter is now useless.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Right now the io_async_msghdr is recycled to avoid the overhead of
allocating+freeing it for every request. But the iovec is not included,
hence that will be allocated and freed for each transfer regardless.
This commit enables recyling of the iovec between io_async_msghdr
recycles. This avoids alloc+free for each one if an iovec is used, and
on top of that, it extends the cache hot nature of msg to the iovec as
well.
Also enables KASAN for the iovec entries, so that reuse can be detected
even while they are in the cache.
The io_async_msghdr also shrinks from 376 -> 288 bytes, an 88 byte
saving (or ~23% smaller), as the fast_iovec entry is dropped from 8
entries to a single entry. There's no point keeping a big fast iovec
entry, if iovecs aren't being allocated and freed continually.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We now ONLY call io_msg_alloc_async() from inside prep handling, which
is always locked. No need for this helper anymore, or the check in
io_msg_alloc_async() on whether the ring is locked or not.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the io_async_msghdr out of the issue path and into prep handling,
e it's now done unconditionally and hence does not need to be part
of the issue path. This means any usage of io_sendrecv_prep_async() and
io_sendmsg_prep_async(), and hence the forced async setup path is now
unified with the normal prep setup.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the io_async_msghdr out of the issue path and into prep handling,
since it's now done unconditionally and hence does not need to be part
of the issue path. This reduces the footprint of the multishot fast
path of multiple invocations of ->issue() per prep, and also means that
using ->prep_async() can be dropped for recvmsg asthis is now done via
setup on the prep side.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We currently set this separately for async/sync entry, but let's just
move it to a generic pre-issue spot and eliminate the difference
between the two.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Rather than use an on-stack one and then need to allocate and copy if
async execution is required, always grab one upfront. This should be
very cheap, and potentially even have cache hotness benefits for
back-to-back send/recv requests.
For any recv type of request, this is probably a good choice in general,
as it's expected that no data is available initially. For send this is
not necessarily the case, as space in the socket buffer is expected to
be available. However, getting a cached io_async_msghdr is very cheap,
and as it should be cache hot, probably the difference here is neglible,
if any.
A nice side benefit is that io_setup_async_msg can get killed
completely, which has some nasty iovec manipulation code.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
No functional changes in this patch, just in preparation for carrying
more state than what is available now, if necessary.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
No functional changes in this patch, just in preparation for carrying
more state then what is being done now, if necessary. While unifying
some of this code, add a generic send setup prep handler that they can
both use.
This gets rid of some manual msghdr and sockaddr on the stack, and makes
it look a bit more like the sendmsg/recvmsg variants. Going forward, more
can get unified on top.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In practice, we just need to recycle a few elements for (by far) most
use cases. Shrink the total size down from 512 to 128, which should be
more than plenty.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
For historical reasons these were special cased, as they were the only
ones that needed cancelation. But now we handle cancelations generally,
and hence there's no need to check for these in
io_ring_ctx_wait_and_kill() when io_uring_try_cancel_requests() handles
both these and the rest as well.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Make io_req_complete_post() to push all IORING_SETUP_IOPOLL requests
to task_work, it's much cleaner and should normally happen. We couldn't
do it before because there was a possibility of looping in
complete_post() -> tw -> complete_post() -> ...
Also, unexport the function and inline __io_req_complete_post().
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/ea19c032ace3e0dd96ac4d991a063b0188037014.1710799188.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
task_work execution is now always locked, and we shouldn't get into
io_req_complete_post() from them. That means that complete_post() is
always called out of the original task context and we don't even need to
check current.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/24ec27f27db0d8f58c974d8118dca1d345314ddc.1710799188.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_post_aux_cqe(), which is used for multishot requests, delays
completions by putting CQEs into a temporary array for the purpose
completion lock/flush batching.
DEFER_TASKRUN doesn't need any locking, so for it we can put completions
directly into the CQ and defer post completion handling with a flag.
That leaves !DEFER_TASKRUN, which is not that interesting / hot for
multishot requests, so have conditional locking with deferred flush
for them.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/b1d05a81fd27aaa2a07f9860af13059e7ad7a890.1710799188.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The restriction on multishot execution context disallowing io-wq is
driven by rules of io_fill_cqe_req_aux(), it should only be called in
the master task context, either from the syscall path or in task_work.
Since task_work now always takes the ctx lock implying
IO_URING_F_COMPLETE_DEFER, we can just assume that the function is
always called with its defer argument set to true.
Kill the argument. Also rename the function for more consistency as
"fill" in CQE related functions was usually meant for raw interfaces
only copying data into the CQ without any locking, waking the user
and other accounting "post" functions take care of.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/93423d106c33116c7d06bf277f651aa68b427328.1710799188.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
ctx is always locked for task_work now, so get rid of struct
io_tw_state::locked. Note I'm stopping one step before removing
io_tw_state altogether, which is not empty, because it still serves the
purpose of indicating which function is a tw callback and forcing users
not to invoke them carelessly out of a wrong context. The removal can
always be done later.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/e95e1ea116d0bfa54b656076e6a977bc221392a4.1710799188.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We can run normal task_work without locking the ctx, however we try to
lock anyway and most handlers prefer or require it locked. It might have
been interesting to multi-submitter ring with high contention completing
async read/write requests via task_work, however that will still need to
go through io_req_complete_post() and potentially take the lock for
rsrc node putting or some other case.
In other words, it's hard to care about it, so alawys force the locking.
The case described would also because of various io_uring caches.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/6ae858f2ef562e6ed9f13c60978c0d48926954ba.1710799188.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
kiocb_done() should care to specifically redirecting requests to io-wq.
Remove the hopping to tw to then queue an io-wq, return -EAGAIN and let
the core code io_uring handle offloading.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/413564e550fe23744a970e1783dfa566291b0e6f.1710799188.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
!IO_URING_F_UNLOCKED does not translate to availability of the deferred
completion infra, IO_URING_F_COMPLETE_DEFER does, that what we should
pass and look for to use io_req_complete_defer() and other variants.
Luckily, it's not a real problem as two wrongs actually made it right,
at least as far as io_uring_cmd_work() goes.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/aef76d34fe9410df8ecc42a14544fd76cd9d8b9e.1710799188.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_uring cmd converts struct io_tw_state to issue_flags and later back
to io_tw_state, it's awfully ill-fated, not to mention that intermediate
issue_flags state is not correct.
Get rid of the last conversion, drag through tw everything that came
with IO_URING_F_UNLOCKED, and replace io_req_complete_defer() with a
direct call to io_req_complete_defer(), at least for the time being.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/c53fa3df749752bd058cf6f824a90704822d6bcc.1710799188.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There's a bunch of flags that are purely based on what the file
operations support while also never being conditionally set or unset.
IOW, they're not subject to change for individual files. Imho, such
flags don't need to live in f_mode they might as well live in the fops
structs itself. And the fops struct already has that lonely
mmap_supported_flags member. We might as well turn that into a generic
fop_flags member and move a few flags from FMODE_* space into FOP_*
space. That gets us four FMODE_* bits back and the ability for new
static flags that are about file ops to not have to live in FMODE_*
space but in their own FOP_* space. It's not the most beautiful thing
ever but it gets the job done. Yes, there'll be an additional pointer
chase but hopefully that won't matter for these flags.
I suspect there's a few more we can move into there and that we can also
redirect a bunch of new flag suggestions that follow this pattern into
the fop_flags field instead of f_mode.
Link: https://lore.kernel.org/r/20240328-gewendet-spargel-aa60a030ef74@brauner
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This bug was introduced in commit 950e79dd73 ("io_uring: minor
io_cqring_wait() optimization"), which was made in preparation for
adc8682ec6 ("io_uring: Add support for napi_busy_poll"). The latter
got reverted in cb31821673 ("Revert "io_uring: Add support for
napi_busy_poll""), so simply undo the former as well.
Cc: stable@vger.kernel.org
Fixes: 950e79dd73 ("io_uring: minor io_cqring_wait() optimization")
Signed-off-by: Alexey Izbyshev <izbyshev@ispras.ru>
Link: https://lore.kernel.org/r/20240405125551.237142-1-izbyshev@ispras.ru
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If we look up the kbuf, ensure that it doesn't get unregistered until
after we're done with it. Since we're inside mmap, we cannot safely use
the io_uring lock. Rely on the fact that we can lookup the buffer list
under RCU now and grab a reference to it, preventing it from being
unregistered until we're done with it. The lookup returns the
io_buffer_list directly with it referenced.
Cc: stable@vger.kernel.org # v6.4+
Fixes: 5cf4f52e6d ("io_uring: free io_buffer_list entries via RCU")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
No functional changes in this patch, just in preparation for being able
to keep the buffer list alive outside of the ctx->uring_lock.
Cc: stable@vger.kernel.org # v6.4+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Now that xarray is being exclusively used for the buffer_list lookup,
this check is no longer needed. Get rid of it and the is_ready member.
Cc: stable@vger.kernel.org # v6.4+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Just rely on the xarray for any kind of bgid. This simplifies things, and
it really doesn't bring us much, if anything.
Cc: stable@vger.kernel.org # v6.4+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Rather than use the system unbound event workqueue, use an io_uring
specific one. This avoids dependencies with the tty, which also uses
the system_unbound_wq, and issues flushes of said workqueue from inside
its poll handling.
Cc: stable@vger.kernel.org
Reported-by: Rasmus Karlsson <rasmus.karlsson@pajlada.com>
Tested-by: Rasmus Karlsson <rasmus.karlsson@pajlada.com>
Tested-by: Iskren Chernev <me@iskren.info>
Link: https://github.com/axboe/liburing/issues/1113
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Do the same check for direct io-wq execution for multishot requests that
commit 2a975d426c did for the inline execution, and disable multishot
mode (and revert to single shot) if the file type doesn't support NOWAIT,
and isn't opened in O_NONBLOCK mode. For multishot to work properly, it's
a requirement that nonblocking read attempts can be done.
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Supporting multishot reads requires support for NOWAIT, as the
alternative would be always having io-wq execute the work item whenever
the poll readiness triggered. Any fast file type will have NOWAIT
support (eg it understands both O_NONBLOCK and IOCB_NOWAIT). If the
given file type does not, then simply resort to single shot execution.
Cc: stable@vger.kernel.org
Fixes: fc68fcda04 ("io_uring/rw: add support for IORING_OP_READ_MULTISHOT")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ideally we'd want to simply kill the task rather than wake it, but for
now let's just add a startup check that causes the thread to exit.
This can only happen if io_uring_alloc_task_context() fails, which
generally requires fault injection.
Reported-by: Ubisectech Sirius <bugreport@ubisectech.com>
Fixes: af5d68f889 ("io_uring/sqpoll: manage task_work privately")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If failure happens before the opcode prep handler is called, ensure that
we clear the opcode specific area of the request, which holds data
specific to that request type. This prevents errors where opcode
handlers either don't get to clear per-request private data since prep
isn't even called.
Reported-and-tested-by: syzbot+f8e9a371388aa62ecab4@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If we get a request with IOSQE_ASYNC set, then we first run the prep
async handlers. But if we then fail setting it up and want to post
a CQE with -EINVAL, we use ->done_io. This was previously guarded with
REQ_F_PARTIAL_IO, and the normal setup handlers do set it up before any
potential errors, but we need to cover the async setup too.
Fixes: 9817ad8589 ("io_uring/net: remove dependency on REQ_F_PARTIAL_IO for sr->done_io")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We know the request is either being removed, or already in the process of
being removed through task_work, so we can delete it from our waitid list
upfront. This is important for remove all conditions, as we otherwise
will find it multiple times and prevent cancelation progress.
Remove the dead check in cancelation as well for the hash_node being
empty or not. We already have a waitid reference check for ownership,
so we don't need to check the list too.
Cc: stable@vger.kernel.org
Fixes: f31ecf671d ("io_uring: add IORING_OP_WAITID support")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We know the request is either being removed, or already in the process of
being removed through task_work, so we can delete it from our futex list
upfront. This is important for remove all conditions, as we otherwise
will find it multiple times and prevent cancelation progress.
Cc: stable@vger.kernel.org
Fixes: 194bb58c60 ("io_uring: add support for futex wake and wait")
Fixes: 8f350194d5 ("io_uring: add support for vectored futex waits")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Taking the ctx lock is not enough to use the deferred request completion
infrastructure, it'll get queued into the list but no one would expect
it there, so it will sit there until next io_submit_flush_completions().
It's hard to care about the cancellation path, so complete it via tw.
Fixes: ef7dfac51d ("io_uring/poll: serialize poll linked timer start with poll removal")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/c446740bc16858f8a2a8dcdce899812f21d15f23.1710514702.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Looking at the error path of __io_uaddr_map, if we fail after pinning
the pages for any reasons, ret will be set to -EINVAL and the error
handler won't properly release the pinned pages.
I didn't manage to trigger it without forcing a failure, but it can
happen in real life when memory is heavily fragmented.
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Fixes: 223ef47431 ("io_uring: don't allow IORING_SETUP_NO_MMAP rings on highmem pages")
Link: https://lore.kernel.org/r/20240313213912.1920-1-krisman@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In buffer lists we have ->is_mapped as well as ->is_mmap, it's
pretty hard to stay sane double checking which one means what,
and in the long run there is a high chance of an eventual bug.
Rename ->is_mapped into ->is_buf_ring.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/c4838f4d8ad506ad6373f1c305aee2d2c1a89786.1710343154.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We make a few cancellation judgements based on ctx->rings, so let's
zero it afer deallocation for IORING_SETUP_NO_MMAP just like it's
done with the mmap case. Likely, it's not a real problem, but zeroing
is safer and better tested.
Cc: stable@vger.kernel.org
Fixes: 03d89a2de2 ("io_uring: support for user allocated memory for rings/sqes")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9ff6cdf91429b8a51699c210e1f6af6ea3f8bdcf.1710255382.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If read multishot is being invoked from the poll retry handler, then we
should return IOU_ISSUE_SKIP_COMPLETE rather than -EAGAIN. If not, then
a CQE will be posted with -EAGAIN rather than triggering the retry when
the file is flagged as readable again.
Cc: stable@vger.kernel.org
Reported-by: Sargun Dhillon <sargun@meta.com>
Fixes: fc68fcda04 ("io_uring/rw: add support for IORING_OP_READ_MULTISHOT")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This kind of state is per-syscall, and since we're doing the waiting off
entering the io_uring_enter(2) syscall, there's no way that iowait can
already be set for this case. Simplify it by setting it if we need to,
and always clearing it to 0 when done.
Fixes: 7b72d661f1 ("io_uring: gate iowait schedule on having pending requests")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
-----BEGIN PGP SIGNATURE-----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=Hy//
-----END PGP SIGNATURE-----
Merge tag 'for-6.9/io_uring-20240310' of git://git.kernel.dk/linux
Pull io_uring updates from Jens Axboe:
- Make running of task_work internal loops more fair, and unify how the
different methods deal with them (me)
- Support for per-ring NAPI. The two minor networking patches are in a
shared branch with netdev (Stefan)
- Add support for truncate (Tony)
- Export SQPOLL utilization stats (Xiaobing)
- Multishot fixes (Pavel)
- Fix for a race in manipulating the request flags via poll (Pavel)
- Cleanup the multishot checking by making it generic, moving it out of
opcode handlers (Pavel)
- Various tweaks and cleanups (me, Kunwu, Alexander)
* tag 'for-6.9/io_uring-20240310' of git://git.kernel.dk/linux: (53 commits)
io_uring: Fix sqpoll utilization check racing with dying sqpoll
io_uring/net: dedup io_recv_finish req completion
io_uring: refactor DEFER_TASKRUN multishot checks
io_uring: fix mshot io-wq checks
io_uring/net: add io_req_msg_cleanup() helper
io_uring/net: simplify msghd->msg_inq checking
io_uring/kbuf: rename REQ_F_PARTIAL_IO to REQ_F_BL_NO_RECYCLE
io_uring/net: remove dependency on REQ_F_PARTIAL_IO for sr->done_io
io_uring/net: correctly handle multishot recvmsg retry setup
io_uring/net: clear REQ_F_BL_EMPTY in the multishot retry handler
io_uring: fix io_queue_proc modifying req->flags
io_uring: fix mshot read defer taskrun cqe posting
io_uring/net: fix overflow check in io_recvmsg_mshot_prep()
io_uring/net: correct the type of variable
io_uring/sqpoll: statistics of the true utilization of sq threads
io_uring/net: move recv/recvmsg flags out of retry loop
io_uring/kbuf: flag request if buffer pool is empty after buffer pick
io_uring/net: improve the usercopy for sendmsg/recvmsg
io_uring/net: move receive multishot out of the generic msghdr path
io_uring/net: unify how recvmsg and sendmsg copy in the msghdr
...
We disallow DEFER_TASKRUN multishots from running by io-wq, which is
checked by individual opcodes in the issue path. We can consolidate all
it in io_wq_submit_work() at the same time moving the checks out of the
hot path.
Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e492f0f11588bb5aa11d7d24e6f53b7c7628afdb.1709905727.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When checking for concurrent CQE posting, we're not only interested in
requests running from the poll handler but also strayed requests ended
up in normal io-wq execution. We're disallowing multishots in general
from io-wq, not only when they came in a certain way.
Cc: stable@vger.kernel.org
Fixes: 17add5cea2 ("io_uring: force multishot CQEs into task context")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d8c5b36a39258036f93301cd60d3cd295e40653d.1709905727.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
For the fast inline path, we manually recycle the io_async_msghdr and
free the iovec, and then clear the REQ_F_NEED_CLEANUP flag to avoid
that needing doing in the slower path. We already do that in 2 spots, and
in preparation for adding more, add a helper and use it.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Just check for larger than zero rather than check for non-zero and
not -1. This is easier to read, and also protects against any errants
< 0 values that aren't -1.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We only use the flag for this purpose, so rename it accordingly. This
further prevents various other use cases of it, keeping it clean and
consistent. Then we can also check it in one spot, when it's being
attempted recycled, and remove some dead code in io_kbuf_recycle_ring().
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ensure that prep handlers always initialize sr->done_io before any
potential failure conditions, and with that, we now it's always been
set even for the failure case.
With that, we don't need to use the REQ_F_PARTIAL_IO flag to gate on that.
Additionally, we should not overwrite req->cqe.res unless sr->done_io is
actually positive.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If we loop for multishot receive on the initial attempt, and then abort
later on to wait for more, we miss a case where we should be copying the
io_async_msghdr from the stack to stable storage. This leads to the next
retry potentially failing, if the application had the msghdr on the
stack.
Cc: stable@vger.kernel.org
Fixes: 9bb66906f2 ("io_uring: support multishot in recvmsg")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This flag should not be persistent across retries, so ensure we clear
it before potentially attemting a retry.
Fixes: c3f9109dbc ("io_uring/kbuf: flag request if buffer pool is empty after buffer pick")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
With multiple poll entries __io_queue_proc() might be running in
parallel with poll handlers and possibly task_work, we should not be
carelessly modifying req->flags there. io_poll_double_prepare() handles
a similar case with locking but it's much easier to move it into
__io_arm_poll_handler().
Cc: stable@vger.kernel.org
Fixes: 595e52284d ("io_uring/poll: don't enable lazy wake for POLLEXCLUSIVE")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/455cc49e38cf32026fa1b49670be8c162c2cb583.1709834755.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The "controllen" variable is type size_t (unsigned long). Casting it
to int could lead to an integer underflow.
The check_add_overflow() function considers the type of the destination
which is type int. If we add two positive values and the result cannot
fit in an integer then that's counted as an overflow.
However, if we cast "controllen" to an int and it turns negative, then
negative values *can* fit into an int type so there is no overflow.
Good: 100 + (unsigned long)-4 = 96 <-- overflow
Bad: 100 + (int)-4 = 96 <-- no overflow
I deleted the cast of the sizeof() as well. That's not a bug but the
cast is unnecessary.
Fixes: 9b0fc3c054 ("io_uring: fix types in io_recvmsg_multishot_overflow")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/138bd2e2-ede8-4bcc-aa7b-f3d9de167a37@moroto.mountain
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The namelen is of type int. It shouldn't be made size_t which is
unsigned. The signed number is needed for error checking before use.
Fixes: c55978024d ("io_uring/net: move receive multishot out of the generic msghdr path")
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Link: https://lore.kernel.org/r/20240301144349.2807544-1-usama.anjum@collabora.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Count the running time and actual IO processing time of the sqpoll
thread, and output the statistical data to fdinfo.
Variable description:
"work_time" in the code represents the sum of the jiffies of the sq
thread actually processing IO, that is, how many milliseconds it
actually takes to process IO. "total_time" represents the total time
that the sq thread has elapsed from the beginning of the loop to the
current time point, that is, how many milliseconds it has spent in
total.
The test tool is fio, and its parameters are as follows:
[global]
ioengine=io_uring
direct=1
group_reporting
bs=128k
norandommap=1
randrepeat=0
refill_buffers
ramp_time=30s
time_based
runtime=1m
clocksource=clock_gettime
overwrite=1
log_avg_msec=1000
numjobs=1
[disk0]
filename=/dev/nvme0n1
rw=read
iodepth=16
hipri
sqthread_poll=1
The test results are as follows:
Every 2.0s: cat /proc/9230/fdinfo/6 | grep -E Sq
SqMask: 0x3
SqHead: 3197153
SqTail: 3197153
CachedSqHead: 3197153
SqThread: 9231
SqThreadCpu: 11
SqTotalTime: 18099614
SqWorkTime: 16748316
The test results corresponding to different iodepths are as follows:
|-----------|-------|-------|-------|------|-------|
| iodepth | 1 | 4 | 8 | 16 | 64 |
|-----------|-------|-------|-------|------|-------|
|utilization| 2.9% | 8.8% | 10.9% | 92.9%| 84.4% |
|-----------|-------|-------|-------|------|-------|
| idle | 97.1% | 91.2% | 89.1% | 7.1% | 15.6% |
|-----------|-------|-------|-------|------|-------|
Signed-off-by: Xiaobing Li <xiaobing.li@samsung.com>
Link: https://lore.kernel.org/r/20240228091251.543383-1-xiaobing.li@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Normally we do an extra roundtrip for retries even if the buffer pool has
depleted, as we don't check that upfront. Rather than add this check, have
the buffer selection methods mark the request with REQ_F_BL_EMPTY if the
used buffer group is out of buffers after this selection. This is very
cheap to do once we're all the way inside there anyway, and it gives the
caller a chance to make better decisions on how to proceed.
For example, recv/recvmsg multishot could check this flag when it
decides whether to keep receiving or not.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We're spending a considerable amount of the sendmsg/recvmsg time just
copying in the message header. And for provided buffers, the known
single entry iovec.
Be a bit smarter about it and enable/disable user access around our
copying. In a test case that does both sendmsg and recvmsg, the
runtime before this change (averaged over multiple runs, very stable
times however):
Kernel Time Diff
====================================
-git 4720 usec
-git+commit 4311 usec -8.7%
and looking at a profile diff, we see the following:
0.25% +9.33% [kernel.kallsyms] [k] _copy_from_user
4.47% -3.32% [kernel.kallsyms] [k] __io_msg_copy_hdr.constprop.0
where we drop more than 9% of _copy_from_user() time, and consequently
add time to __io_msg_copy_hdr() where the copies are now attributed to,
but with a net win of 6%.
In comparison, the same test case with send/recv runs in 3745 usec, which
is (expectedly) still quite a bit faster. But at least sendmsg/recvmsg is
now only ~13% slower, where it was ~21% slower before.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the actual user_msghdr / compat_msghdr into the send and receive
sides, respectively, so we can move the uaddr receive handling into its
own handler, and ditto the multishot with buffer selection logic.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
