Commit Graph

954 Commits

Author SHA1 Message Date
Linus Torvalds f01c30de86 More VFS fixes for 5.10-rc4:
- Minor cleanups of the sb_start_* fs freeze helpers.
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Merge tag 'vfs-5.10-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull fs freeze fix and cleanups from Darrick Wong:
 "A single vfs fix for 5.10, along with two subsequent cleanups.

  A very long time ago, a hack was added to the vfs fs freeze protection
  code to work around lockdep complaints about XFS, which would try to
  run a transaction (which requires intwrite protection) to finalize an
  xfs freeze (by which time the vfs had already taken intwrite).

  Fast forward a few years, and XFS fixed the recursive intwrite problem
  on its own, and the hack became unnecessary. Fast forward almost a
  decade, and latent bugs in the code converting this hack from freeze
  flags to freeze locks combine with lockdep bugs to make this reproduce
  frequently enough to notice page faults racing with freeze.

  Since the hack is unnecessary and causes thread race errors, just get
  rid of it completely. Making this kind of vfs change midway through a
  cycle makes me nervous, but a large enough number of the usual
  VFS/ext4/XFS/btrfs suspects have said this looks good and solves a
  real problem vector.

  And once that removal is done, __sb_start_write is now simple enough
  that it becomes possible to refactor the function into smaller,
  simpler static inline helpers in linux/fs.h. The cleanup is
  straightforward.

  Summary:

   - Finally remove the "convert to trylock" weirdness in the fs freezer
     code. It was necessary 10 years ago to deal with nested
     transactions in XFS, but we've long since removed that; and now
     this is causing subtle race conditions when lockdep goes offline
     and sb_start_* aren't prepared to retry a trylock failure.

   - Minor cleanups of the sb_start_* fs freeze helpers"

* tag 'vfs-5.10-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  vfs: move __sb_{start,end}_write* to fs.h
  vfs: separate __sb_start_write into blocking and non-blocking helpers
  vfs: remove lockdep bogosity in __sb_start_write
2020-11-13 16:07:53 -08:00
Jens Axboe 88ec3211e4 io_uring: round-up cq size before comparing with rounded sq size
If an application specifies IORING_SETUP_CQSIZE to set the CQ ring size
to a specific size, we ensure that the CQ size is at least that of the
SQ ring size. But in doing so, we compare the already rounded up to power
of two SQ size to the as-of yet unrounded CQ size. This means that if an
application passes in non power of two sizes, we can return -EINVAL when
the final value would've been fine. As an example, an application passing
in 100/100 for sq/cq size should end up with 128 for both. But since we
round the SQ size first, we compare the CQ size of 100 to 128, and return
-EINVAL as that is too small.

Cc: stable@vger.kernel.org
Fixes: 33a107f0a1 ("io_uring: allow application controlled CQ ring size")
Reported-by: Dan Melnic <dmm@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-11 10:42:41 -07:00
Darrick J. Wong 8a3c84b649 vfs: separate __sb_start_write into blocking and non-blocking helpers
Break this function into two helpers so that it's obvious that the
trylock versions return a value that must be checked, and the blocking
versions don't require that.  While we're at it, clean up the return
type mismatch.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-11-10 16:53:07 -08:00
Pavel Begunkov 9a472ef7a3 io_uring: fix link lookup racing with link timeout
We can't just go over linked requests because it may race with linked
timeouts. Take ctx->completion_lock in that case.

Cc: stable@vger.kernel.org # v5.7+
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-05 15:36:40 -07:00
Jens Axboe 6b47ab81c9 io_uring: use correct pointer for io_uring_show_cred()
Previous commit changed how we index the registered credentials, but
neglected to update one spot that is used when the personalities are
iterated through ->show_fdinfo(). Ensure we use the right struct type
for the iteration.

Reported-by: syzbot+a6d494688cdb797bdfce@syzkaller.appspotmail.com
Fixes: 1e6fa5216a ("io_uring: COW io_identity on mismatch")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-05 09:50:16 -07:00
Pavel Begunkov ef9865a442 io_uring: don't forget to task-cancel drained reqs
If there is a long-standing request of one task locking up execution of
deferred requests, and the defer list contains requests of another task
(all files-less), then a potential execution of __io_uring_task_cancel()
by that another task will sleep until that first long-standing request
completion, and that may take long.

E.g.
tsk1: req1/read(empty_pipe) -> tsk2: req(DRAIN)
Then __io_uring_task_cancel(tsk2) waits for req1 completion.

It seems we even can manufacture a complicated case with many tasks
sharing many rings that can lock them forever.

Cancel deferred requests for __io_uring_task_cancel() as well.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-05 09:15:24 -07:00
Pavel Begunkov 99b328084f io_uring: fix overflowed cancel w/ linked ->files
Current io_match_files() check in io_cqring_overflow_flush() is useless
because requests drop ->files before going to the overflow list, however
linked to it request do not, and we don't check them.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-04 10:22:57 -07:00
Jens Axboe cb8a8ae310 io_uring: drop req/tctx io_identity separately
We can't bundle this into one operation, as the identity may not have
originated from the tctx to begin with. Drop one ref for each of them
separately, if they don't match the static assignment. If we don't, then
if the identity is a lookup from registered credentials, we could be
freeing that identity as we're dropping a reference assuming it came from
the tctx. syzbot reports this as a use-after-free, as the identity is
still referencable from idr lookup:

==================================================================
BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
BUG: KASAN: use-after-free in atomic_fetch_add_relaxed include/asm-generic/atomic-instrumented.h:142 [inline]
BUG: KASAN: use-after-free in __refcount_add include/linux/refcount.h:193 [inline]
BUG: KASAN: use-after-free in __refcount_inc include/linux/refcount.h:250 [inline]
BUG: KASAN: use-after-free in refcount_inc include/linux/refcount.h:267 [inline]
BUG: KASAN: use-after-free in io_init_req fs/io_uring.c:6700 [inline]
BUG: KASAN: use-after-free in io_submit_sqes+0x15a9/0x25f0 fs/io_uring.c:6774
Write of size 4 at addr ffff888011e08e48 by task syz-executor165/8487

CPU: 1 PID: 8487 Comm: syz-executor165 Not tainted 5.10.0-rc1-next-20201102-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x4c8 mm/kasan/report.c:385
 __kasan_report mm/kasan/report.c:545 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562
 check_memory_region_inline mm/kasan/generic.c:186 [inline]
 check_memory_region+0x13d/0x180 mm/kasan/generic.c:192
 instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
 atomic_fetch_add_relaxed include/asm-generic/atomic-instrumented.h:142 [inline]
 __refcount_add include/linux/refcount.h:193 [inline]
 __refcount_inc include/linux/refcount.h:250 [inline]
 refcount_inc include/linux/refcount.h:267 [inline]
 io_init_req fs/io_uring.c:6700 [inline]
 io_submit_sqes+0x15a9/0x25f0 fs/io_uring.c:6774
 __do_sys_io_uring_enter+0xc8e/0x1b50 fs/io_uring.c:9159
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x440e19
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb 0f fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff644ff178 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000440e19
RDX: 0000000000000000 RSI: 000000000000450c RDI: 0000000000000003
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000022b4850
R13: 0000000000000010 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 8487:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:461
 kmalloc include/linux/slab.h:552 [inline]
 io_register_personality fs/io_uring.c:9638 [inline]
 __io_uring_register fs/io_uring.c:9874 [inline]
 __do_sys_io_uring_register+0x10f0/0x40a0 fs/io_uring.c:9924
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 8487:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56
 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355
 __kasan_slab_free+0x102/0x140 mm/kasan/common.c:422
 slab_free_hook mm/slub.c:1544 [inline]
 slab_free_freelist_hook+0x5d/0x150 mm/slub.c:1577
 slab_free mm/slub.c:3140 [inline]
 kfree+0xdb/0x360 mm/slub.c:4122
 io_identity_cow fs/io_uring.c:1380 [inline]
 io_prep_async_work+0x903/0xbc0 fs/io_uring.c:1492
 io_prep_async_link fs/io_uring.c:1505 [inline]
 io_req_defer fs/io_uring.c:5999 [inline]
 io_queue_sqe+0x212/0xed0 fs/io_uring.c:6448
 io_submit_sqe fs/io_uring.c:6542 [inline]
 io_submit_sqes+0x14f6/0x25f0 fs/io_uring.c:6784
 __do_sys_io_uring_enter+0xc8e/0x1b50 fs/io_uring.c:9159
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff888011e08e00
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 72 bytes inside of
 96-byte region [ffff888011e08e00, ffff888011e08e60)
The buggy address belongs to the page:
page:00000000a7104751 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11e08
flags: 0xfff00000000200(slab)
raw: 00fff00000000200 ffffea00004f8540 0000001f00000002 ffff888010041780
raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888011e08d00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
 ffff888011e08d80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
> ffff888011e08e00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                                              ^
 ffff888011e08e80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
 ffff888011e08f00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
==================================================================

Reported-by: syzbot+625ce3bb7835b63f7f3d@syzkaller.appspotmail.com
Fixes: 1e6fa5216a ("io_uring: COW io_identity on mismatch")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-04 10:22:57 -07:00
Jens Axboe 4b70cf9dea io_uring: ensure consistent view of original task ->mm from SQPOLL
Ensure we get a valid view of the task mm, by using task_lock() when
attempting to grab the original task mm.

Reported-by: syzbot+b57abf7ee60829090495@syzkaller.appspotmail.com
Fixes: 2aede0e417 ("io_uring: stash ctx task reference for SQPOLL")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-04 10:22:57 -07:00
Jens Axboe fdaf083cdf io_uring: properly handle SQPOLL request cancelations
Track if a given task io_uring context contains SQPOLL instances, so we
can iterate those for cancelation (and request counts). This ensures that
we properly wait on SQPOLL contexts, and find everything that needs
canceling.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-04 10:22:56 -07:00
Linus Torvalds cf9446cc8e io_uring-5.10-2020-10-30
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Merge tag 'io_uring-5.10-2020-10-30' of git://git.kernel.dk/linux-block

Pull io_uring fixes from Jens Axboe:

 - Fixes for linked timeouts (Pavel)

 - Set IO_WQ_WORK_CONCURRENT early for async offload (Pavel)

 - Two minor simplifications that make the code easier to read and
   follow (Pavel)

* tag 'io_uring-5.10-2020-10-30' of git://git.kernel.dk/linux-block:
  io_uring: use type appropriate io_kiocb handler for double poll
  io_uring: simplify __io_queue_sqe()
  io_uring: simplify nxt propagation in io_queue_sqe
  io_uring: don't miss setting IO_WQ_WORK_CONCURRENT
  io_uring: don't defer put of cancelled ltimeout
  io_uring: always clear LINK_TIMEOUT after cancel
  io_uring: don't adjust LINK_HEAD in cancel ltimeout
  io_uring: remove opcode check on ltimeout kill
2020-10-30 14:55:36 -07:00
Jens Axboe c8b5e2600a io_uring: use type appropriate io_kiocb handler for double poll
io_poll_double_wake() is called for both request types - both pure poll
requests, and internal polls. This means that we should be using the
right handler based on the request type. Use the one that the original
caller already assigned for the waitqueue handling, that will always
match the correct type.

Cc: stable@vger.kernel.org # v5.8+
Reported-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-25 13:53:26 -06:00
Linus Torvalds af0041875c io_uring-5.10-2020-10-24
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Merge tag 'io_uring-5.10-2020-10-24' of git://git.kernel.dk/linux-block

Pull io_uring fixes from Jens Axboe:

 - fsize was missed in previous unification of work flags

 - Few fixes cleaning up the flags unification creds cases (Pavel)

 - Fix NUMA affinities for completely unplugged/replugged node for io-wq

 - Two fallout fixes from the set_fs changes. One local to io_uring, one
   for the splice entry point that io_uring uses.

 - Linked timeout fixes (Pavel)

 - Removal of ->flush() ->files work-around that we don't need anymore
   with referenced files (Pavel)

 - Various cleanups (Pavel)

* tag 'io_uring-5.10-2020-10-24' of git://git.kernel.dk/linux-block:
  splice: change exported internal do_splice() helper to take kernel offset
  io_uring: make loop_rw_iter() use original user supplied pointers
  io_uring: remove req cancel in ->flush()
  io-wq: re-set NUMA node affinities if CPUs come online
  io_uring: don't reuse linked_timeout
  io_uring: unify fsize with def->work_flags
  io_uring: fix racy REQ_F_LINK_TIMEOUT clearing
  io_uring: do poll's hash_node init in common code
  io_uring: inline io_poll_task_handler()
  io_uring: remove extra ->file check in poll prep
  io_uring: make cached_cq_overflow non atomic_t
  io_uring: inline io_fail_links()
  io_uring: kill ref get/drop in personality init
  io_uring: flags-based creds init in queue
2020-10-24 12:40:18 -07:00
Pavel Begunkov 0d63c148d6 io_uring: simplify __io_queue_sqe()
Restructure __io_queue_sqe() so it follows simple if/else if/else
control flow. It's more readable and removes extra goto/labels.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-23 13:07:12 -06:00
Pavel Begunkov 9aaf354352 io_uring: simplify nxt propagation in io_queue_sqe
Don't overuse goto's, complex control flow doesn't make compilers happy
and makes code harder to read.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-23 13:07:12 -06:00
Pavel Begunkov feaadc4fc2 io_uring: don't miss setting IO_WQ_WORK_CONCURRENT
Set IO_WQ_WORK_CONCURRENT for all REQ_F_FORCE_ASYNC requests, do that in
that is also looks better.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-23 13:07:11 -06:00
Pavel Begunkov c9abd7ad83 io_uring: don't defer put of cancelled ltimeout
Inline io_link_cancel_timeout() and __io_kill_linked_timeout() into
io_kill_linked_timeout(). That allows to easily move a put of a cancelled
linked timeout out of completion_lock and to not deferring it. It is also
much more readable when not scattered across three different functions.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-23 13:07:11 -06:00
Pavel Begunkov cdfcc3ee04 io_uring: always clear LINK_TIMEOUT after cancel
Move REQ_F_LINK_TIMEOUT clearing out of __io_kill_linked_timeout()
because it might return early and leave the flag set. It's not a
problem, but may be confusing.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-23 13:07:11 -06:00
Pavel Begunkov ac877d2edd io_uring: don't adjust LINK_HEAD in cancel ltimeout
An armed linked timeout can never be a head of a link, so we don't need
to clear REQ_F_LINK_HEAD for it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-23 13:07:11 -06:00
Pavel Begunkov e08102d507 io_uring: remove opcode check on ltimeout kill
__io_kill_linked_timeout() already checks for REQ_F_LTIMEOUT_ACTIVE and
it's set only for linked timeouts. No need to verify next request's
opcode.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-23 13:07:11 -06:00
Linus Torvalds 4a22709e21 arch-cleanup-2020-10-22
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Merge tag 'arch-cleanup-2020-10-22' of git://git.kernel.dk/linux-block

Pull arch task_work cleanups from Jens Axboe:
 "Two cleanups that don't fit other categories:

   - Finally get the task_work_add() cleanup done properly, so we don't
     have random 0/1/false/true/TWA_SIGNAL confusing use cases. Updates
     all callers, and also fixes up the documentation for
     task_work_add().

   - While working on some TIF related changes for 5.11, this
     TIF_NOTIFY_RESUME cleanup fell out of that. Remove some arch
     duplication for how that is handled"

* tag 'arch-cleanup-2020-10-22' of git://git.kernel.dk/linux-block:
  task_work: cleanup notification modes
  tracehook: clear TIF_NOTIFY_RESUME in tracehook_notify_resume()
2020-10-23 10:06:38 -07:00
Jens Axboe 4017eb91a9 io_uring: make loop_rw_iter() use original user supplied pointers
We jump through a hoop for fixed buffers, where we first map these to
a bvec(), then kmap() the bvec to obtain the pointer we copy to/from.
This was always a bit ugly, and with the set_fs changes, it ends up
being practically problematic as well.

There's no need to jump through these hoops, just use the original user
pointers and length for the non iter based read/write.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-22 14:14:12 -06:00
Pavel Begunkov c8fb20b5b4 io_uring: remove req cancel in ->flush()
Every close(io_uring) causes cancellation of all inflight requests
carrying ->files. That's not nice but was neccessary up until recently.
Now task->files removal is handled in the core code, so that part of
flush can be removed.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-22 09:54:19 -06:00
Pavel Begunkov ff5771613c io_uring: don't reuse linked_timeout
Clear linked_timeout for next requests in __io_queue_sqe() so we won't
queue it up unnecessary when it's going to be punted.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Cc: stable@vger.kernel.org # v5.9
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-21 16:37:56 -06:00
Jens Axboe 69228338c9 io_uring: unify fsize with def->work_flags
This one was missed in the earlier conversion, should be included like
any of the other IO identity flags. Make sure we restore to RLIM_INIFITY
when dropping the personality again.

Fixes: 98447d65b4 ("io_uring: move io identity items into separate struct")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-20 16:03:13 -06:00
Linus Torvalds 4962a85696 io_uring-5.10-2020-10-20
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Merge tag 'io_uring-5.10-2020-10-20' of git://git.kernel.dk/linux-block

Pull io_uring updates from Jens Axboe:
 "A mix of fixes and a few stragglers. In detail:

   - Revert the bogus __read_mostly that we discussed for the initial
     pull request.

   - Fix a merge window regression with fixed file registration error
     path handling.

   - Fix io-wq numa node affinities.

   - Series abstracting out an io_identity struct, making it both easier
     to see what the personality items are, and also easier to to adopt
     more. Use this to cover audit logging.

   - Fix for read-ahead disabled block condition in async buffered
     reads, and using single page read-ahead to unify what
     generic_file_buffer_read() path is used.

   - Series for REQ_F_COMP_LOCKED fix and removal of it (Pavel)

   - Poll fix (Pavel)"

* tag 'io_uring-5.10-2020-10-20' of git://git.kernel.dk/linux-block: (21 commits)
  io_uring: use blk_queue_nowait() to check if NOWAIT supported
  mm: use limited read-ahead to satisfy read
  mm: mark async iocb read as NOWAIT once some data has been copied
  io_uring: fix double poll mask init
  io-wq: inherit audit loginuid and sessionid
  io_uring: use percpu counters to track inflight requests
  io_uring: assign new io_identity for task if members have changed
  io_uring: store io_identity in io_uring_task
  io_uring: COW io_identity on mismatch
  io_uring: move io identity items into separate struct
  io_uring: rely solely on work flags to determine personality.
  io_uring: pass required context in as flags
  io-wq: assign NUMA node locality if appropriate
  io_uring: fix error path cleanup in io_sqe_files_register()
  Revert "io_uring: mark io_uring_fops/io_op_defs as __read_mostly"
  io_uring: fix REQ_F_COMP_LOCKED by killing it
  io_uring: dig out COMP_LOCK from deep call chain
  io_uring: don't put a poll req under spinlock
  io_uring: don't unnecessarily clear F_LINK_TIMEOUT
  io_uring: don't set COMP_LOCKED if won't put
  ...
2020-10-20 13:19:30 -07:00
Pavel Begunkov 900fad45dc io_uring: fix racy REQ_F_LINK_TIMEOUT clearing
io_link_timeout_fn() removes REQ_F_LINK_TIMEOUT from the link head's
flags, it's not atomic and may race with what the head is doing.

If io_link_timeout_fn() doesn't clear the flag, as forced by this patch,
then it may happen that for "req -> link_timeout1 -> link_timeout2",
__io_kill_linked_timeout() would find link_timeout2 and try to cancel
it, so miscounting references. Teach it to ignore such double timeouts
by marking the active one with a new flag in io_prep_linked_timeout().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-19 13:29:51 -06:00
Pavel Begunkov 4d52f33899 io_uring: do poll's hash_node init in common code
Move INIT_HLIST_NODE(&req->hash_node) into __io_arm_poll_handler(), so
that it doesn't duplicated and common poll code would be responsible for
it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-19 13:29:29 -06:00
Pavel Begunkov dd221f46f6 io_uring: inline io_poll_task_handler()
io_poll_task_handler() doesn't add clarity, inline it in its only user.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-19 13:29:29 -06:00
Pavel Begunkov 069b89384d io_uring: remove extra ->file check in poll prep
io_poll_add_prep() doesn't need to verify ->file because it's already
done in io_init_req().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-19 13:29:29 -06:00
Pavel Begunkov 2c3bac6dd6 io_uring: make cached_cq_overflow non atomic_t
ctx->cached_cq_overflow is changed only under completion_lock. Convert
it from atomic_t to just int, and mark all places when it's read without
lock with READ_ONCE, which guarantees atomicity (relaxed ordering).

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-19 13:29:29 -06:00
Pavel Begunkov d148ca4b07 io_uring: inline io_fail_links()
Inline io_fail_links() and kill extra io_cqring_ev_posted().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-19 13:29:29 -06:00
Pavel Begunkov ec99ca6c47 io_uring: kill ref get/drop in personality init
Don't take an identity on personality/creds init only to drop it a few
lines after. Extract a function which prepares req->work but leaves it
without identity.

Note: it's safe to not check REQ_F_WORK_INITIALIZED there because it's
nobody had a chance to init it before io_init_req().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-19 13:29:29 -06:00
Pavel Begunkov 2e5aa6cb4d io_uring: flags-based creds init in queue
Use IO_WQ_WORK_CREDS to figure out if req has creds to be used.
Since recently it should rely only on flags, but not value of
work.creds.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-19 13:29:29 -06:00
Jeffle Xu 9ba0d0c812 io_uring: use blk_queue_nowait() to check if NOWAIT supported
commit 021a24460d ("block: add QUEUE_FLAG_NOWAIT") adds a new helper
function blk_queue_nowait() to check if the bdev supports handling of
REQ_NOWAIT or not. Since then bio-based dm device can also support
REQ_NOWAIT, and currently only dm-linear supports that since
commit 6abc49468e ("dm: add support for REQ_NOWAIT and enable it for
linear target").

Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-19 07:32:36 -06:00
Minchan Kim 0726b01e70 mm/madvise: pass mm to do_madvise
Patch series "introduce memory hinting API for external process", v9.

Now, we have MADV_PAGEOUT and MADV_COLD as madvise hinting API.  With
that, application could give hints to kernel what memory range are
preferred to be reclaimed.  However, in some platform(e.g., Android), the
information required to make the hinting decision is not known to the app.
Instead, it is known to a centralized userspace daemon(e.g.,
ActivityManagerService), and that daemon must be able to initiate reclaim
on its own without any app involvement.

To solve the concern, this patch introduces new syscall -
process_madvise(2).  Bascially, it's same with madvise(2) syscall but it
has some differences.

1. It needs pidfd of target process to provide the hint

2. It supports only MADV_{COLD|PAGEOUT|MERGEABLE|UNMEREABLE} at this
   moment.  Other hints in madvise will be opened when there are explicit
   requests from community to prevent unexpected bugs we couldn't support.

3. Only privileged processes can do something for other process's
   address space.

For more detail of the new API, please see "mm: introduce external memory
hinting API" description in this patchset.

This patch (of 3):

In upcoming patches, do_madvise will be called from external process
context so we shouldn't asssume "current" is always hinted process's
task_struct.

Furthermore, we must not access mm_struct via task->mm, but obtain it via
access_mm() once (in the following patch) and only use that pointer [1],
so pass it to do_madvise() as well.  Note the vma->vm_mm pointers are
safe, so we can use them further down the call stack.

And let's pass current->mm as arguments of do_madvise so it shouldn't
change existing behavior but prepare next patch to make review easy.

[vbabka@suse.cz: changelog tweak]
[minchan@kernel.org: use current->mm for io_uring]
  Link: http://lkml.kernel.org/r/20200423145215.72666-1-minchan@kernel.org
[akpm@linux-foundation.org: fix it for upstream changes]
[akpm@linux-foundation.org: whoops]
[rdunlap@infradead.org: add missing includes]

Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jann Horn <jannh@google.com>
Cc: Tim Murray <timmurray@google.com>
Cc: Daniel Colascione <dancol@google.com>
Cc: Sandeep Patil <sspatil@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: John Dias <joaodias@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: SeongJae Park <sj38.park@gmail.com>
Cc: Christian Brauner <christian@brauner.io>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: SeongJae Park <sjpark@amazon.de>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Florian Weimer <fw@deneb.enyo.de>
Cc: <linux-man@vger.kernel.org>
Link: https://lkml.kernel.org/r/20200901000633.1920247-1-minchan@kernel.org
Link: http://lkml.kernel.org/r/20200622192900.22757-1-minchan@kernel.org
Link: http://lkml.kernel.org/r/20200302193630.68771-2-minchan@kernel.org
Link: http://lkml.kernel.org/r/20200622192900.22757-2-minchan@kernel.org
Link: https://lkml.kernel.org/r/20200901000633.1920247-2-minchan@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-18 09:27:09 -07:00
Jens Axboe 91989c7078 task_work: cleanup notification modes
A previous commit changed the notification mode from true/false to an
int, allowing notify-no, notify-yes, or signal-notify. This was
backwards compatible in the sense that any existing true/false user
would translate to either 0 (on notification sent) or 1, the latter
which mapped to TWA_RESUME. TWA_SIGNAL was assigned a value of 2.

Clean this up properly, and define a proper enum for the notification
mode. Now we have:

- TWA_NONE. This is 0, same as before the original change, meaning no
  notification requested.
- TWA_RESUME. This is 1, same as before the original change, meaning
  that we use TIF_NOTIFY_RESUME.
- TWA_SIGNAL. This uses TIF_SIGPENDING/JOBCTL_TASK_WORK for the
  notification.

Clean up all the callers, switching their 0/1/false/true to using the
appropriate TWA_* mode for notifications.

Fixes: e91b481623 ("task_work: teach task_work_add() to do signal_wake_up()")
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17 15:05:30 -06:00
Pavel Begunkov 58852d4d67 io_uring: fix double poll mask init
__io_queue_proc() is used by both, poll reqs and apoll. Don't use
req->poll.events to copy poll mask because for apoll it aliases with
private data of the request.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17 09:25:47 -06:00
Jens Axboe 4ea33a976b io-wq: inherit audit loginuid and sessionid
Make sure the async io-wq workers inherit the loginuid and sessionid from
the original task, and restore them to unset once we're done with the
async work item.

While at it, disable the ability for kernel threads to write to their own
loginuid.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17 09:25:47 -06:00
Jens Axboe d8a6df10aa io_uring: use percpu counters to track inflight requests
Even though we place the req_issued and req_complete in separate
cachelines, there's considerable overhead in doing the atomics
particularly on the completion side.

Get rid of having the two counters, and just use a percpu_counter for
this. That's what it was made for, after all. This considerably
reduces the overhead in __io_free_req().

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17 09:25:47 -06:00
Jens Axboe 500a373d73 io_uring: assign new io_identity for task if members have changed
This avoids doing a copy for each new async IO, if some parts of the
io_identity has changed. We avoid reference counting for the normal
fast path of nothing ever changing.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17 09:25:46 -06:00
Jens Axboe 5c3462cfd1 io_uring: store io_identity in io_uring_task
This is, by definition, a per-task structure. So store it in the
task context, instead of doing carrying it in each io_kiocb. We're being
a bit inefficient if members have changed, as that requires an alloc and
copy of a new io_identity struct. The next patch will fix that up.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17 09:25:46 -06:00
Jens Axboe 1e6fa5216a io_uring: COW io_identity on mismatch
If the io_identity doesn't completely match the task, then create a
copy of it and use that. The existing copy remains valid until the last
user of it has gone away.

This also changes the personality lookup to be indexed by io_identity,
instead of creds directly.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17 09:25:46 -06:00
Jens Axboe 98447d65b4 io_uring: move io identity items into separate struct
io-wq contains a pointer to the identity, which we just hold in io_kiocb
for now. This is in preparation for putting this outside io_kiocb. The
only exception is struct files_struct, which we'll need different rules
for to avoid a circular dependency.

No functional changes in this patch.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17 09:25:45 -06:00
Jens Axboe dfead8a8e2 io_uring: rely solely on work flags to determine personality.
We solely rely on work->work_flags now, so use that for proper checking
and clearing/dropping of various identity items.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17 09:25:45 -06:00
Jens Axboe 0f20376588 io_uring: pass required context in as flags
We have a number of bits that decide what context to inherit. Set up
io-wq flags for these instead. This is in preparation for always having
the various members set, but not always needing them for all requests.

No intended functional changes in this patch.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17 09:25:45 -06:00
Jens Axboe 55cbc2564a io_uring: fix error path cleanup in io_sqe_files_register()
syzbot reports the following crash:

general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 8927 Comm: syz-executor.3 Not tainted 5.9.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:io_file_from_index fs/io_uring.c:5963 [inline]
RIP: 0010:io_sqe_files_register fs/io_uring.c:7369 [inline]
RIP: 0010:__io_uring_register fs/io_uring.c:9463 [inline]
RIP: 0010:__do_sys_io_uring_register+0x2fd2/0x3ee0 fs/io_uring.c:9553
Code: ec 03 49 c1 ee 03 49 01 ec 49 01 ee e8 57 61 9c ff 41 80 3c 24 00 0f 85 9b 09 00 00 4d 8b af b8 01 00 00 4c 89 e8 48 c1 e8 03 <80> 3c 28 00 0f 85 76 09 00 00 49 8b 55 00 89 d8 c1 f8 09 48 98 4c
RSP: 0018:ffffc90009137d68 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9000ef2a000
RDX: 0000000000040000 RSI: ffffffff81d81dd9 RDI: 0000000000000005
RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffed1012882a37
R13: 0000000000000000 R14: ffffed1012882a38 R15: ffff888094415000
FS:  00007f4266f3c700(0000) GS:ffff8880ae500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000118c000 CR3: 000000008e57d000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45de59
Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f4266f3bc78 EFLAGS: 00000246 ORIG_RAX: 00000000000001ab
RAX: ffffffffffffffda RBX: 00000000000083c0 RCX: 000000000045de59
RDX: 0000000020000280 RSI: 0000000000000002 RDI: 0000000000000005
RBP: 000000000118bf68 R08: 0000000000000000 R09: 0000000000000000
R10: 40000000000000a1 R11: 0000000000000246 R12: 000000000118bf2c
R13: 00007fff2fa4f12f R14: 00007f4266f3c9c0 R15: 000000000118bf2c
Modules linked in:
---[ end trace 2a40a195e2d5e6e6 ]---
RIP: 0010:io_file_from_index fs/io_uring.c:5963 [inline]
RIP: 0010:io_sqe_files_register fs/io_uring.c:7369 [inline]
RIP: 0010:__io_uring_register fs/io_uring.c:9463 [inline]
RIP: 0010:__do_sys_io_uring_register+0x2fd2/0x3ee0 fs/io_uring.c:9553
Code: ec 03 49 c1 ee 03 49 01 ec 49 01 ee e8 57 61 9c ff 41 80 3c 24 00 0f 85 9b 09 00 00 4d 8b af b8 01 00 00 4c 89 e8 48 c1 e8 03 <80> 3c 28 00 0f 85 76 09 00 00 49 8b 55 00 89 d8 c1 f8 09 48 98 4c
RSP: 0018:ffffc90009137d68 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9000ef2a000
RDX: 0000000000040000 RSI: ffffffff81d81dd9 RDI: 0000000000000005
RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffed1012882a37
R13: 0000000000000000 R14: ffffed1012882a38 R15: ffff888094415000
FS:  00007f4266f3c700(0000) GS:ffff8880ae400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000074a918 CR3: 000000008e57d000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

which is a copy of fget failure condition jumping to cleanup, but the
cleanup requires ctx->file_data to be assigned. Assign it when setup,
and ensure that we clear it again for the error path exit.

Fixes: 5398ae6985 ("io_uring: clean file_data access in files_register")
Reported-by: syzbot+f4ebcc98223dafd8991e@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17 09:25:44 -06:00
Jens Axboe 0918682be4 Revert "io_uring: mark io_uring_fops/io_op_defs as __read_mostly"
This reverts commit 738277adc8.

This change didn't make a lot of sense, and as Linus reports, it actually
fails on clang:

   /tmp/io_uring-dd40c4.s:26476: Warning: ignoring changed section
   attributes for .data..read_mostly

The arrays are already marked const so, by definition, they are not
just read-mostly, they are read-only.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17 09:25:43 -06:00
Pavel Begunkov 216578e55a io_uring: fix REQ_F_COMP_LOCKED by killing it
REQ_F_COMP_LOCKED is used and implemented in a buggy way. The problem is
that the flag is set before io_put_req() but not cleared after, and if
that wasn't the final reference, the request will be freed with the flag
set from some other context, which may not hold a spinlock. That means
possible races with removing linked timeouts and unsynchronised
completion (e.g. access to CQ).

Instead of fixing REQ_F_COMP_LOCKED, kill the flag and use
task_work_add() to move such requests to a fresh context to free from
it, as was done with __io_free_req_finish().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17 09:25:43 -06:00
Pavel Begunkov 4edf20f999 io_uring: dig out COMP_LOCK from deep call chain
io_req_clean_work() checks REQ_F_COMP_LOCK to pass this two layers up.
Move the check up into __io_free_req(), so at least it doesn't looks so
ugly and would facilitate further changes.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17 09:25:43 -06:00
Pavel Begunkov 6a0af224c2 io_uring: don't put a poll req under spinlock
Move io_put_req() in io_poll_task_handler() from under spinlock. This
eliminates the need to use REQ_F_COMP_LOCKED, at the expense of
potentially having to grab the lock again. That's still a better trade
off than relying on the locked flag.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17 09:25:42 -06:00
Pavel Begunkov b1b74cfc19 io_uring: don't unnecessarily clear F_LINK_TIMEOUT
If a request had REQ_F_LINK_TIMEOUT it would've been cleared in
__io_kill_linked_timeout() by the time of __io_fail_links(), so no need
to care about it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17 09:25:42 -06:00
Pavel Begunkov 368c5481ae io_uring: don't set COMP_LOCKED if won't put
__io_kill_linked_timeout() sets REQ_F_COMP_LOCKED for a linked timeout
even if it can't cancel it, e.g. it's already running. It not only races
with io_link_timeout_fn() for ->flags field, but also leaves the flag
set and so io_link_timeout_fn() may find it and decide that it holds the
lock. Hopefully, the second problem is potential.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17 09:25:42 -06:00
Colin Ian King 035fbafc7a io_uring: Fix sizeof() mismatch
An incorrect sizeof() is being used, sizeof(file_data->table) is not
correct, it should be sizeof(*file_data->table).

Fixes: 5398ae6985 ("io_uring: clean file_data access in files_register")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Addresses-Coverity: ("Sizeof not portable (SIZEOF_MISMATCH)")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17 09:25:41 -06:00
Linus Torvalds 9ff9b0d392 networking changes for the 5.10 merge window
Add redirect_neigh() BPF packet redirect helper, allowing to limit stack
 traversal in common container configs and improving TCP back-pressure.
 Daniel reports ~10Gbps => ~15Gbps single stream TCP performance gain.
 
 Expand netlink policy support and improve policy export to user space.
 (Ge)netlink core performs request validation according to declared
 policies. Expand the expressiveness of those policies (min/max length
 and bitmasks). Allow dumping policies for particular commands.
 This is used for feature discovery by user space (instead of kernel
 version parsing or trial and error).
 
 Support IGMPv3/MLDv2 multicast listener discovery protocols in bridge.
 
 Allow more than 255 IPv4 multicast interfaces.
 
 Add support for Type of Service (ToS) reflection in SYN/SYN-ACK
 packets of TCPv6.
 
 In Multi-patch TCP (MPTCP) support concurrent transmission of data
 on multiple subflows in a load balancing scenario. Enhance advertising
 addresses via the RM_ADDR/ADD_ADDR options.
 
 Support SMC-Dv2 version of SMC, which enables multi-subnet deployments.
 
 Allow more calls to same peer in RxRPC.
 
 Support two new Controller Area Network (CAN) protocols -
 CAN-FD and ISO 15765-2:2016.
 
 Add xfrm/IPsec compat layer, solving the 32bit user space on 64bit
 kernel problem.
 
 Add TC actions for implementing MPLS L2 VPNs.
 
 Improve nexthop code - e.g. handle various corner cases when nexthop
 objects are removed from groups better, skip unnecessary notifications
 and make it easier to offload nexthops into HW by converting
 to a blocking notifier.
 
 Support adding and consuming TCP header options by BPF programs,
 opening the doors for easy experimental and deployment-specific
 TCP option use.
 
 Reorganize TCP congestion control (CC) initialization to simplify life
 of TCP CC implemented in BPF.
 
 Add support for shipping BPF programs with the kernel and loading them
 early on boot via the User Mode Driver mechanism, hence reusing all the
 user space infra we have.
 
 Support sleepable BPF programs, initially targeting LSM and tracing.
 
 Add bpf_d_path() helper for returning full path for given 'struct path'.
 
 Make bpf_tail_call compatible with bpf-to-bpf calls.
 
 Allow BPF programs to call map_update_elem on sockmaps.
 
 Add BPF Type Format (BTF) support for type and enum discovery, as
 well as support for using BTF within the kernel itself (current use
 is for pretty printing structures).
 
 Support listing and getting information about bpf_links via the bpf
 syscall.
 
 Enhance kernel interfaces around NIC firmware update. Allow specifying
 overwrite mask to control if settings etc. are reset during update;
 report expected max time operation may take to users; support firmware
 activation without machine reboot incl. limits of how much impact
 reset may have (e.g. dropping link or not).
 
 Extend ethtool configuration interface to report IEEE-standard
 counters, to limit the need for per-vendor logic in user space.
 
 Adopt or extend devlink use for debug, monitoring, fw update
 in many drivers (dsa loop, ice, ionic, sja1105, qed, mlxsw,
 mv88e6xxx, dpaa2-eth).
 
 In mlxsw expose critical and emergency SFP module temperature alarms.
 Refactor port buffer handling to make the defaults more suitable and
 support setting these values explicitly via the DCBNL interface.
 
 Add XDP support for Intel's igb driver.
 
 Support offloading TC flower classification and filtering rules to
 mscc_ocelot switches.
 
 Add PTP support for Marvell Octeontx2 and PP2.2 hardware, as well as
 fixed interval period pulse generator and one-step timestamping in
 dpaa-eth.
 
 Add support for various auth offloads in WiFi APs, e.g. SAE (WPA3)
 offload.
 
 Add Lynx PHY/PCS MDIO module, and convert various drivers which have
 this HW to use it. Convert mvpp2 to split PCS.
 
 Support Marvell Prestera 98DX3255 24-port switch ASICs, as well as
 7-port Mediatek MT7531 IP.
 
 Add initial support for QCA6390 and IPQ6018 in ath11k WiFi driver,
 and wcn3680 support in wcn36xx.
 
 Improve performance for packets which don't require much offloads
 on recent Mellanox NICs by 20% by making multiple packets share
 a descriptor entry.
 
 Move chelsio inline crypto drivers (for TLS and IPsec) from the crypto
 subtree to drivers/net. Move MDIO drivers out of the phy directory.
 
 Clean up a lot of W=1 warnings, reportedly the actively developed
 subsections of networking drivers should now build W=1 warning free.
 
 Make sure drivers don't use in_interrupt() to dynamically adapt their
 code. Convert tasklets to use new tasklet_setup API (sadly this
 conversion is not yet complete).
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:

 - Add redirect_neigh() BPF packet redirect helper, allowing to limit
   stack traversal in common container configs and improving TCP
   back-pressure.

   Daniel reports ~10Gbps => ~15Gbps single stream TCP performance gain.

 - Expand netlink policy support and improve policy export to user
   space. (Ge)netlink core performs request validation according to
   declared policies. Expand the expressiveness of those policies
   (min/max length and bitmasks). Allow dumping policies for particular
   commands. This is used for feature discovery by user space (instead
   of kernel version parsing or trial and error).

 - Support IGMPv3/MLDv2 multicast listener discovery protocols in
   bridge.

 - Allow more than 255 IPv4 multicast interfaces.

 - Add support for Type of Service (ToS) reflection in SYN/SYN-ACK
   packets of TCPv6.

 - In Multi-patch TCP (MPTCP) support concurrent transmission of data on
   multiple subflows in a load balancing scenario. Enhance advertising
   addresses via the RM_ADDR/ADD_ADDR options.

 - Support SMC-Dv2 version of SMC, which enables multi-subnet
   deployments.

 - Allow more calls to same peer in RxRPC.

 - Support two new Controller Area Network (CAN) protocols - CAN-FD and
   ISO 15765-2:2016.

 - Add xfrm/IPsec compat layer, solving the 32bit user space on 64bit
   kernel problem.

 - Add TC actions for implementing MPLS L2 VPNs.

 - Improve nexthop code - e.g. handle various corner cases when nexthop
   objects are removed from groups better, skip unnecessary
   notifications and make it easier to offload nexthops into HW by
   converting to a blocking notifier.

 - Support adding and consuming TCP header options by BPF programs,
   opening the doors for easy experimental and deployment-specific TCP
   option use.

 - Reorganize TCP congestion control (CC) initialization to simplify
   life of TCP CC implemented in BPF.

 - Add support for shipping BPF programs with the kernel and loading
   them early on boot via the User Mode Driver mechanism, hence reusing
   all the user space infra we have.

 - Support sleepable BPF programs, initially targeting LSM and tracing.

 - Add bpf_d_path() helper for returning full path for given 'struct
   path'.

 - Make bpf_tail_call compatible with bpf-to-bpf calls.

 - Allow BPF programs to call map_update_elem on sockmaps.

 - Add BPF Type Format (BTF) support for type and enum discovery, as
   well as support for using BTF within the kernel itself (current use
   is for pretty printing structures).

 - Support listing and getting information about bpf_links via the bpf
   syscall.

 - Enhance kernel interfaces around NIC firmware update. Allow
   specifying overwrite mask to control if settings etc. are reset
   during update; report expected max time operation may take to users;
   support firmware activation without machine reboot incl. limits of
   how much impact reset may have (e.g. dropping link or not).

 - Extend ethtool configuration interface to report IEEE-standard
   counters, to limit the need for per-vendor logic in user space.

 - Adopt or extend devlink use for debug, monitoring, fw update in many
   drivers (dsa loop, ice, ionic, sja1105, qed, mlxsw, mv88e6xxx,
   dpaa2-eth).

 - In mlxsw expose critical and emergency SFP module temperature alarms.
   Refactor port buffer handling to make the defaults more suitable and
   support setting these values explicitly via the DCBNL interface.

 - Add XDP support for Intel's igb driver.

 - Support offloading TC flower classification and filtering rules to
   mscc_ocelot switches.

 - Add PTP support for Marvell Octeontx2 and PP2.2 hardware, as well as
   fixed interval period pulse generator and one-step timestamping in
   dpaa-eth.

 - Add support for various auth offloads in WiFi APs, e.g. SAE (WPA3)
   offload.

 - Add Lynx PHY/PCS MDIO module, and convert various drivers which have
   this HW to use it. Convert mvpp2 to split PCS.

 - Support Marvell Prestera 98DX3255 24-port switch ASICs, as well as
   7-port Mediatek MT7531 IP.

 - Add initial support for QCA6390 and IPQ6018 in ath11k WiFi driver,
   and wcn3680 support in wcn36xx.

 - Improve performance for packets which don't require much offloads on
   recent Mellanox NICs by 20% by making multiple packets share a
   descriptor entry.

 - Move chelsio inline crypto drivers (for TLS and IPsec) from the
   crypto subtree to drivers/net. Move MDIO drivers out of the phy
   directory.

 - Clean up a lot of W=1 warnings, reportedly the actively developed
   subsections of networking drivers should now build W=1 warning free.

 - Make sure drivers don't use in_interrupt() to dynamically adapt their
   code. Convert tasklets to use new tasklet_setup API (sadly this
   conversion is not yet complete).

* tag 'net-next-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2583 commits)
  Revert "bpfilter: Fix build error with CONFIG_BPFILTER_UMH"
  net, sockmap: Don't call bpf_prog_put() on NULL pointer
  bpf, selftest: Fix flaky tcp_hdr_options test when adding addr to lo
  bpf, sockmap: Add locking annotations to iterator
  netfilter: nftables: allow re-computing sctp CRC-32C in 'payload' statements
  net: fix pos incrementment in ipv6_route_seq_next
  net/smc: fix invalid return code in smcd_new_buf_create()
  net/smc: fix valid DMBE buffer sizes
  net/smc: fix use-after-free of delayed events
  bpfilter: Fix build error with CONFIG_BPFILTER_UMH
  cxgb4/ch_ipsec: Replace the module name to ch_ipsec from chcr
  net: sched: Fix suspicious RCU usage while accessing tcf_tunnel_info
  bpf: Fix register equivalence tracking.
  rxrpc: Fix loss of final ack on shutdown
  rxrpc: Fix bundle counting for exclusive connections
  netfilter: restore NF_INET_NUMHOOKS
  ibmveth: Identify ingress large send packets.
  ibmveth: Switch order of ibmveth_helper calls.
  cxgb4: handle 4-tuple PEDIT to NAT mode translation
  selftests: Add VRF route leaking tests
  ...
2020-10-15 18:42:13 -07:00
Linus Torvalds 6ad4bf6ea1 io_uring-5.10-2020-10-12
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Merge tag 'io_uring-5.10-2020-10-12' of git://git.kernel.dk/linux-block

Pull io_uring updates from Jens Axboe:

 - Add blkcg accounting for io-wq offload (Dennis)

 - A use-after-free fix for io-wq (Hillf)

 - Cancelation fixes and improvements

 - Use proper files_struct references for offload

 - Cleanup of io_uring_get_socket() since that can now go into our own
   header

 - SQPOLL fixes and cleanups, and support for sharing the thread

 - Improvement to how page accounting is done for registered buffers and
   huge pages, accounting the real pinned state

 - Series cleaning up the xarray code (Willy)

 - Various cleanups, refactoring, and improvements (Pavel)

 - Use raw spinlock for io-wq (Sebastian)

 - Add support for ring restrictions (Stefano)

* tag 'io_uring-5.10-2020-10-12' of git://git.kernel.dk/linux-block: (62 commits)
  io_uring: keep a pointer ref_node in file_data
  io_uring: refactor *files_register()'s error paths
  io_uring: clean file_data access in files_register
  io_uring: don't delay io_init_req() error check
  io_uring: clean leftovers after splitting issue
  io_uring: remove timeout.list after hrtimer cancel
  io_uring: use a separate struct for timeout_remove
  io_uring: improve submit_state.ios_left accounting
  io_uring: simplify io_file_get()
  io_uring: kill extra check in fixed io_file_get()
  io_uring: clean up ->files grabbing
  io_uring: don't io_prep_async_work() linked reqs
  io_uring: Convert advanced XArray uses to the normal API
  io_uring: Fix XArray usage in io_uring_add_task_file
  io_uring: Fix use of XArray in __io_uring_files_cancel
  io_uring: fix break condition for __io_uring_register() waiting
  io_uring: no need to call xa_destroy() on empty xarray
  io_uring: batch account ->req_issue and task struct references
  io_uring: kill callback_head argument for io_req_task_work_add()
  io_uring: move req preps out of io_issue_sqe()
  ...
2020-10-13 12:36:21 -07:00
Linus Torvalds 85ed13e78d Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull compat iovec cleanups from Al Viro:
 "Christoph's series around import_iovec() and compat variant thereof"

* 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  security/keys: remove compat_keyctl_instantiate_key_iov
  mm: remove compat_process_vm_{readv,writev}
  fs: remove compat_sys_vmsplice
  fs: remove the compat readv/writev syscalls
  fs: remove various compat readv/writev helpers
  iov_iter: transparently handle compat iovecs in import_iovec
  iov_iter: refactor rw_copy_check_uvector and import_iovec
  iov_iter: move rw_copy_check_uvector() into lib/iov_iter.c
  compat.h: fix a spelling error in <linux/compat.h>
2020-10-12 16:35:51 -07:00
Pavel Begunkov b2e9685283 io_uring: keep a pointer ref_node in file_data
->cur_refs of struct fixed_file_data always points to percpu_ref
embedded into struct fixed_file_ref_node. Don't overuse container_of()
and offsetting, and point directly to fixed_file_ref_node.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-10 12:49:25 -06:00
Pavel Begunkov 600cf3f8b3 io_uring: refactor *files_register()'s error paths
Don't keep repeating cleaning sequences in error paths, write it once
in the and use labels. It's less error prone and looks cleaner.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-10 12:49:25 -06:00
Pavel Begunkov 5398ae6985 io_uring: clean file_data access in files_register
Keep file_data in a local var and replace with it complex references
such as ctx->file_data.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-10 12:49:25 -06:00
Pavel Begunkov 692d836351 io_uring: don't delay io_init_req() error check
Don't postpone io_init_req() error checks and do that right after
calling it. There is no control-flow statements or dependencies with
sqe/submitted accounting, so do those earlier, that makes the code flow
a bit more natural.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-10 12:49:25 -06:00
Pavel Begunkov 062d04d731 io_uring: clean leftovers after splitting issue
Kill extra if in io_issue_sqe() and place send/recv[msg] calls
appropriately under switch's cases.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-10 12:49:25 -06:00
Pavel Begunkov a71976f3fa io_uring: remove timeout.list after hrtimer cancel
Remove timeouts from ctx->timeout_list after hrtimer_try_to_cancel()
successfully cancels it. With this we don't need to care whether there
was a race and it was removed in io_timeout_fn(), and that will be handy
for following patches.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-10 12:49:25 -06:00
Pavel Begunkov 0bdf7a2ddb io_uring: use a separate struct for timeout_remove
Don't use struct io_timeout for both IORING_OP_TIMEOUT and
IORING_OP_TIMEOUT_REMOVE, they're quite different. Split them in two,
that allows to remove an unused field in struct io_timeout, and btw kill
->flags not used by either. This also easier to follow, especially for
timeout remove.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-10 12:49:25 -06:00
Pavel Begunkov 71b547c048 io_uring: improve submit_state.ios_left accounting
state->ios_left isn't decremented for requests that don't need a file,
so it might be larger than number of SQEs left. That in some
circumstances makes us to grab more files that is needed so imposing
extra put.
Deaccount one ios_left for each request.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-10 12:49:25 -06:00
Pavel Begunkov 8371adf53c io_uring: simplify io_file_get()
Keep ->needs_file_no_error check out of io_file_get(), and let callers
handle it. It makes it more straightforward. Also, as the only error it
can hand back -EBADF, make it return a file or NULL.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-10 12:49:24 -06:00
Pavel Begunkov 479f517be5 io_uring: kill extra check in fixed io_file_get()
ctx->nr_user_files == 0 IFF ctx->file_data == NULL and there fixed files
are not used. Hence, verifying fds only against ctx->nr_user_files is
enough. Remove the other check from hot path.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-10 12:49:24 -06:00
Pavel Begunkov 233295130e io_uring: clean up ->files grabbing
Move work.files grabbing into io_prep_async_work() to all other work
resources initialisation. We don't need to keep it separately now, as
->ring_fd/file are gone. It also allows to not grab it when a request
is not going to io-wq.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-10 12:49:24 -06:00
Pavel Begunkov 5bf5e464f1 io_uring: don't io_prep_async_work() linked reqs
There is no real reason left for preparing io-wq work context for linked
requests in advance, remove it as this might become a bottleneck in some
cases.

Reported-by: Roman Gershman <romger@amazon.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-10 12:49:20 -06:00
Matthew Wilcox (Oracle) 5e2ed8c4f4 io_uring: Convert advanced XArray uses to the normal API
There are no bugs here that I've spotted, it's just easier to use the
normal API and there are no performance advantages to using the more
verbose advanced API.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-09 09:00:05 -06:00
Matthew Wilcox (Oracle) 236434c343 io_uring: Fix XArray usage in io_uring_add_task_file
The xas_store() wasn't paired with an xas_nomem() loop, so if it couldn't
allocate memory using GFP_NOWAIT, it would leak the reference to the file
descriptor.  Also the node pointed to by the xas could be freed between
the call to xas_load() under the rcu_read_lock() and the acquisition of
the xa_lock.

It's easier to just use the normal xa_load/xa_store interface here.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
[axboe: fix missing assign after alloc, cur_uring -> tctx rename]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-09 08:59:40 -06:00
Matthew Wilcox (Oracle) ce765372bc io_uring: Fix use of XArray in __io_uring_files_cancel
We have to drop the lock during each iteration, so there's no advantage
to using the advanced API.  Convert this to a standard xa_for_each() loop.

Reported-by: syzbot+27c12725d8ff0bfe1a13@syzkaller.appspotmail.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-09 08:52:26 -06:00
Jens Axboe ed6930c920 io_uring: fix break condition for __io_uring_register() waiting
Colin reports that there's unreachable code, since we only ever break
if ret == 0. This is correct, and is due to a reversed logic condition
in when to break or not.

Break out of the loop if we don't process any task work, in that case
we do want to return -EINTR.

Fixes: af9c1a44f8 ("io_uring: process task work in io_uring_register()")
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-08 20:37:45 -06:00
Jens Axboe ca6484cd30 io_uring: no need to call xa_destroy() on empty xarray
The kernel test robot reports this lockdep issue:

[child1:659] mbind (274) returned ENOSYS, marking as inactive.
[child1:659] mq_timedsend (279) returned ENOSYS, marking as inactive.
[main] 10175 iterations. [F:7781 S:2344 HI:2397]
[   24.610601]
[   24.610743] ================================
[   24.611083] WARNING: inconsistent lock state
[   24.611437] 5.9.0-rc7-00017-g0f2122045b9462 #5 Not tainted
[   24.611861] --------------------------------
[   24.612193] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
[   24.612660] ksoftirqd/0/7 [HC0[0]:SC1[3]:HE0:SE0] takes:
[   24.613086] f00ed998 (&xa->xa_lock#4){+.?.}-{2:2}, at: xa_destroy+0x43/0xc1
[   24.613642] {SOFTIRQ-ON-W} state was registered at:
[   24.614024]   lock_acquire+0x20c/0x29b
[   24.614341]   _raw_spin_lock+0x21/0x30
[   24.614636]   io_uring_add_task_file+0xe8/0x13a
[   24.614987]   io_uring_create+0x535/0x6bd
[   24.615297]   io_uring_setup+0x11d/0x136
[   24.615606]   __ia32_sys_io_uring_setup+0xd/0xf
[   24.615977]   do_int80_syscall_32+0x53/0x6c
[   24.616306]   restore_all_switch_stack+0x0/0xb1
[   24.616677] irq event stamp: 939881
[   24.616968] hardirqs last  enabled at (939880): [<8105592d>] __local_bh_enable_ip+0x13c/0x145
[   24.617642] hardirqs last disabled at (939881): [<81b6ace3>] _raw_spin_lock_irqsave+0x1b/0x4e
[   24.618321] softirqs last  enabled at (939738): [<81b6c7c8>] __do_softirq+0x3f0/0x45a
[   24.618924] softirqs last disabled at (939743): [<81055741>] run_ksoftirqd+0x35/0x61
[   24.619521]
[   24.619521] other info that might help us debug this:
[   24.620028]  Possible unsafe locking scenario:
[   24.620028]
[   24.620492]        CPU0
[   24.620685]        ----
[   24.620894]   lock(&xa->xa_lock#4);
[   24.621168]   <Interrupt>
[   24.621381]     lock(&xa->xa_lock#4);
[   24.621695]
[   24.621695]  *** DEADLOCK ***
[   24.621695]
[   24.622154] 1 lock held by ksoftirqd/0/7:
[   24.622468]  #0: 823bfb94 (rcu_callback){....}-{0:0}, at: rcu_process_callbacks+0xc0/0x155
[   24.623106]
[   24.623106] stack backtrace:
[   24.623454] CPU: 0 PID: 7 Comm: ksoftirqd/0 Not tainted 5.9.0-rc7-00017-g0f2122045b9462 #5
[   24.624090] Call Trace:
[   24.624284]  ? show_stack+0x40/0x46
[   24.624551]  dump_stack+0x1b/0x1d
[   24.624809]  print_usage_bug+0x17a/0x185
[   24.625142]  mark_lock+0x11d/0x1db
[   24.625474]  ? print_shortest_lock_dependencies+0x121/0x121
[   24.625905]  __lock_acquire+0x41e/0x7bf
[   24.626206]  lock_acquire+0x20c/0x29b
[   24.626517]  ? xa_destroy+0x43/0xc1
[   24.626810]  ? lock_acquire+0x20c/0x29b
[   24.627110]  _raw_spin_lock_irqsave+0x3e/0x4e
[   24.627450]  ? xa_destroy+0x43/0xc1
[   24.627725]  xa_destroy+0x43/0xc1
[   24.627989]  __io_uring_free+0x57/0x71
[   24.628286]  ? get_pid+0x22/0x22
[   24.628544]  __put_task_struct+0xf2/0x163
[   24.628865]  put_task_struct+0x1f/0x2a
[   24.629161]  delayed_put_task_struct+0xe2/0xe9
[   24.629509]  rcu_process_callbacks+0x128/0x155
[   24.629860]  __do_softirq+0x1a3/0x45a
[   24.630151]  run_ksoftirqd+0x35/0x61
[   24.630443]  smpboot_thread_fn+0x304/0x31a
[   24.630763]  kthread+0x124/0x139
[   24.631016]  ? sort_range+0x18/0x18
[   24.631290]  ? kthread_create_worker_on_cpu+0x17/0x17
[   24.631682]  ret_from_fork+0x1c/0x28

which is complaining about xa_destroy() grabbing the xa lock in an
IRQ disabling fashion, whereas the io_uring uses cases aren't interrupt
safe. This is really an xarray issue, since it should not assume the
lock type. But for our use case, since we know the xarray is empty at
this point, there's no need to actually call xa_destroy(). So just get
rid of it.

Fixes: 0f2122045b ("io_uring: don't rely on weak ->files references")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-08 07:46:52 -06:00
Jens Axboe faf7b51c06 io_uring: batch account ->req_issue and task struct references
Identical to how we handle the ctx reference counts, increase by the
batch we're expecting to submit, and handle any slow path residual,
if any. The request alloc-and-issue path is very hot, and this makes
a noticeable difference by avoiding an two atomic incs for each
individual request.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-07 12:55:42 -06:00
David S. Miller 8b0308fe31 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Rejecting non-native endian BTF overlapped with the addition
of support for it.

The rest were more simple overlapping changes, except the
renesas ravb binding update, which had to follow a file
move as well as a YAML conversion.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-05 18:40:01 -07:00
Christoph Hellwig 89cd35c58b iov_iter: transparently handle compat iovecs in import_iovec
Use in compat_syscall to import either native or the compat iovecs, and
remove the now superflous compat_import_iovec.

This removes the need for special compat logic in most callers, and
the remaining ones can still be simplified by using __import_iovec
with a bool compat parameter.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-10-03 00:02:13 -04:00
Linus Torvalds 702bfc891d io_uring-5.9-2020-10-02
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Merge tag 'io_uring-5.9-2020-10-02' of git://git.kernel.dk/linux-block

Pull io_uring fixes from Jens Axboe:

 - fix for async buffered reads if read-ahead is fully disabled (Hao)

 - double poll match fix

 - ->show_fdinfo() potential ABBA deadlock complaint fix

* tag 'io_uring-5.9-2020-10-02' of git://git.kernel.dk/linux-block:
  io_uring: fix async buffered reads when readahead is disabled
  io_uring: fix potential ABBA deadlock in ->show_fdinfo()
  io_uring: always delete double poll wait entry on match
2020-10-02 14:38:10 -07:00
Jens Axboe 87c4311fd2 io_uring: kill callback_head argument for io_req_task_work_add()
We always use &req->task_work anyway, no point in passing it in.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 21:00:16 -06:00
Pavel Begunkov c1379e247a io_uring: move req preps out of io_issue_sqe()
All request preparations are done only during submission, reflect it in
the code by moving io_req_prep() much earlier into io_queue_sqe().

That's much cleaner, because it doen't expose bits to async code which
it won't ever use. Also it makes the interface harder to misuse, and
there are potential places for bugs.

For instance, __io_queue() doesn't clear @sqe before proceeding to a
next linked request, that could have been disastrous, but hopefully
there are linked requests IFF sqe==NULL, so not actually a bug.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:38:46 -06:00
Pavel Begunkov bfe7655983 io_uring: decouple issuing and req preparation
io_issue_sqe() does two things at once, trying to prepare request and
issuing them. Split it in two and deduplicate with io_defer_prep().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:38:46 -06:00
Pavel Begunkov 73debe68b3 io_uring: remove nonblock arg from io_{rw}_prep()
All io_*_prep() functions including io_{read,write}_prep() are called
only during submission where @force_nonblock is always true. Don't keep
propagating it and instead remove the @force_nonblock argument
from prep() altogether.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:38:46 -06:00
Pavel Begunkov a88fc40021 io_uring: set/clear IOCB_NOWAIT into io_read/write
Move setting IOCB_NOWAIT from io_prep_rw() into io_read()/io_write(), so
it's set/cleared in a single place. Also remove @force_nonblock
parameter from io_prep_rw().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:38:46 -06:00
Pavel Begunkov 2d199895d2 io_uring: remove F_NEED_CLEANUP check in *prep()
REQ_F_NEED_CLEANUP is set only by io_*_prep() and they're guaranteed to
be called only once, so there is no one who may have set the flag
before. Kill REQ_F_NEED_CLEANUP check in these *prep() handlers.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:38:46 -06:00
Pavel Begunkov 5b09e37e27 io_uring: io_kiocb_ppos() style change
Put brackets around bitwise ops in a complex expression

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:38:45 -06:00
Pavel Begunkov 291b2821e0 io_uring: simplify io_alloc_req()
Extract common code from if/else branches. That is cleaner and optimised
even better.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:38:45 -06:00
Joseph Qi dbbe9c6424 io_uring: show sqthread pid and cpu in fdinfo
In most cases we'll specify IORING_SETUP_SQPOLL and run multiple
io_uring instances in a host. Since all sqthreads are named
"io_uring-sq", it's hard to distinguish the relations between
application process and its io_uring sqthread.
With this patch, application can get its corresponding sqthread pid
and cpu through show_fdinfo.
Steps:
1. Get io_uring fd first.
$ ls -l /proc/<pid>/fd | grep -w io_uring
2. Then get io_uring instance related info, including corresponding
sqthread pid and cpu.
$ cat /proc/<pid>/fdinfo/<io_uring_fd>

pos:	0
flags:	02000002
mnt_id:	13
SqThread:	6929
SqThreadCpu:	2
UserFiles:	1
    0: testfile
UserBufs:	0
PollList:

Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
[axboe: fixed for new shared SQPOLL]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:34 -06:00
Jens Axboe af9c1a44f8 io_uring: process task work in io_uring_register()
We do this for CQ ring wait, in case task_work completions come in. We
should do the same in io_uring_register(), to avoid spurious -EINTR
if the ring quiescing ends up having to process task_work to complete
the operation

Reported-by: Dan Melnic <dmm@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:34 -06:00
Dennis Zhou 91d8f5191e io_uring: add blkcg accounting to offloaded operations
There are a few operations that are offloaded to the worker threads. In
this case, we lose process context and end up in kthread context. This
results in ios to be not accounted to the issuing cgroup and
consequently end up as issued by root. Just like others, adopt the
personality of the blkcg too when issuing via the workqueues.

For the SQPOLL thread, it will live and attach in the inited cgroup's
context.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:34 -06:00
Jens Axboe de2939388b io_uring: improve registered buffer accounting for huge pages
io_uring does account any registered buffer as pinned/locked memory, and
checks limit and fails if the given user doesn't have a big enough limit
to register the ranges specified. However, if huge pages are used, we
are potentially under-accounting the memory in terms of what gets pinned
on the vm side.

This patch rectifies that, by ensuring that we account the full size of
a compound page, regardless of how much of it is being registered. Huge
pages are not accounted mulitple times - if multiple sections of a huge
page is registered, then the page is only accounted once.

Reported-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:34 -06:00
Zheng Bin 14db84110d io_uring: remove unneeded semicolon
Fixes coccicheck warning:

fs/io_uring.c:4242:13-14: Unneeded semicolon

Signed-off-by: Zheng Bin <zhengbin13@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:34 -06:00
Jens Axboe e95eee2dee io_uring: cap SQ submit size for SQPOLL with multiple rings
In the spirit of fairness, cap the max number of SQ entries we'll submit
for SQPOLL if we have multiple rings. If we don't do that, we could be
submitting tons of entries for one ring, while others are waiting to get
service.

The value of 8 is somewhat arbitrarily chosen as something that allows
a fair bit of batching, without using an excessive time per ring.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:34 -06:00
Jens Axboe e8c2bc1fb6 io_uring: get rid of req->io/io_async_ctx union
There's really no point in having this union, it just means that we're
always allocating enough room to cater to any command. But that's
pointless, as the ->io field is request type private anyway.

This gets rid of the io_async_ctx structure, and fills in the required
size in the io_op_defs[] instead.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:34 -06:00
Pavel Begunkov 4be1c61512 io_uring: kill extra user_bufs check
Testing ctx->user_bufs for NULL in io_import_fixed() is not neccessary,
because in that case ctx->nr_user_bufs would be zero, and the following
check would fail.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:34 -06:00
Pavel Begunkov ab0b196ce5 io_uring: fix overlapped memcpy in io_req_map_rw()
When io_req_map_rw() is called from io_rw_prep_async(), it memcpy()
iorw->iter into itself. Even though it doesn't lead to an error, such a
memcpy()'s aliasing rules violation is considered to be a bad practise.

Inline io_req_map_rw() into io_rw_prep_async(). We don't really need any
remapping there, so it's much simpler than the generic implementation.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:33 -06:00
Pavel Begunkov afb87658f8 io_uring: refactor io_req_map_rw()
Set rw->free_iovec to @iovec, that gives an identical result and stresses
that @iovec param rw->free_iovec play the same role.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:33 -06:00
Pavel Begunkov f4bff104ff io_uring: simplify io_rw_prep_async()
Don't touch iter->iov and iov in between __io_import_iovec() and
io_req_map_rw(), the former function aleady sets it correctly, because it
creates one more case with NULL'ed iov to consider in io_req_map_rw().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:33 -06:00
Jens Axboe 9055420072 io_uring: provide IORING_ENTER_SQ_WAIT for SQPOLL SQ ring waits
When using SQPOLL, applications can run into the issue of running out of
SQ ring entries because the thread hasn't consumed them yet. The only
option for dealing with that is checking later, or busy checking for the
condition.

Provide IORING_ENTER_SQ_WAIT if applications want to wait on this
condition.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:33 -06:00
Jens Axboe 738277adc8 io_uring: mark io_uring_fops/io_op_defs as __read_mostly
These structures are never written, move them appropriately.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:33 -06:00
Jens Axboe aa06165de8 io_uring: enable IORING_SETUP_ATTACH_WQ to attach to SQPOLL thread too
We support using IORING_SETUP_ATTACH_WQ to share async backends between
rings created by the same process, this now also allows the same to
happen with SQPOLL. The setup procedure remains the same, the caller
sets io_uring_params->wq_fd to the 'parent' context, and then the newly
created ring will attach to that async backend.

This means that multiple rings can share the same SQPOLL thread, saving
resources.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:33 -06:00
Jens Axboe 69fb21310f io_uring: base SQPOLL handling off io_sq_data
Remove the SQPOLL thread from the ctx, and use the io_sq_data as the
data structure we pass in. io_sq_data has a list of ctx's that we can
then iterate over and handle.

As of now we're ready to handle multiple ctx's, though we're still just
handling a single one after this patch.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:33 -06:00
Jens Axboe 534ca6d684 io_uring: split SQPOLL data into separate structure
Move all the necessary state out of io_ring_ctx, and into a new
structure, io_sq_data. The latter now deals with any state or
variables associated with the SQPOLL thread itself.

In preparation for supporting more than one io_ring_ctx per SQPOLL
thread.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:33 -06:00
Jens Axboe c8d1ba583f io_uring: split work handling part of SQPOLL into helper
This is done in preparation for handling more than one ctx, but it also
cleans up the code a bit since io_sq_thread() was a bit too unwieldy to
get a get overview on.

__io_sq_thread() is now the main handler, and it returns an enum sq_ret
that tells io_sq_thread() what it ended up doing. The parent then makes
a decision on idle, spinning, or work handling based on that.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:33 -06:00
Jens Axboe 3f0e64d054 io_uring: move SQPOLL post-wakeup ring need wakeup flag into wake handler
We need to decouple the clearing on wakeup from the the inline schedule,
as that is going to be required for handling multiple rings in one
thread.

Wrap our wakeup handler so we can clear it when we get the wakeup, by
definition that is when we no longer need the flag set.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:33 -06:00
Jens Axboe 6a7793828f io_uring: use private ctx wait queue entries for SQPOLL
This is in preparation to sharing the poller thread between rings. For
that we need per-ring wait_queue_entry storage, and we can't easily put
that on the stack if one thread is managing multiple rings.

We'll also be sharing the wait_queue_head across rings for the purposes
of wakeups, provide the usual private ring wait_queue_head for now but
make it a pointer so we can easily override it when sharing.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:33 -06:00
Jens Axboe e35afcf912 io_uring: io_sq_thread() doesn't need to flush signals
We're not handling signals by default in kernel threads, and we never
use TWA_SIGNAL for the SQPOLL thread internally. Hence we can never
have a signal pending, and we don't need to check for it (nor flush it).

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:33 -06:00
Stefano Garzarella 7e84e1c756 io_uring: allow disabling rings during the creation
This patch adds a new IORING_SETUP_R_DISABLED flag to start the
rings disabled, allowing the user to register restrictions,
buffers, files, before to start processing SQEs.

When IORING_SETUP_R_DISABLED is set, SQE are not processed and
SQPOLL kthread is not started.

The restrictions registration are allowed only when the rings
are disable to prevent concurrency issue while processing SQEs.

The rings can be enabled using IORING_REGISTER_ENABLE_RINGS
opcode with io_uring_register(2).

Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:33 -06:00
Stefano Garzarella 21b55dbc06 io_uring: add IOURING_REGISTER_RESTRICTIONS opcode
The new io_uring_register(2) IOURING_REGISTER_RESTRICTIONS opcode
permanently installs a feature allowlist on an io_ring_ctx.
The io_ring_ctx can then be passed to untrusted code with the
knowledge that only operations present in the allowlist can be
executed.

The allowlist approach ensures that new features added to io_uring
do not accidentally become available when an existing application
is launched on a newer kernel version.

Currently is it possible to restrict sqe opcodes, sqe flags, and
register opcodes.

IOURING_REGISTER_RESTRICTIONS can only be made once. Afterwards
it is not possible to change restrictions anymore.
This prevents untrusted code from removing restrictions.

Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:33 -06:00
Jens Axboe 9b82849215 io_uring: reference ->nsproxy for file table commands
If we don't get and assign the namespace for the async work, then certain
paths just don't work properly (like /dev/stdin, /proc/mounts, etc).
Anything that references the current namespace of the given task should
be assigned for async work on behalf of that task.

Cc: stable@vger.kernel.org # v5.5+
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:32 -06:00
Jens Axboe 0f2122045b io_uring: don't rely on weak ->files references
Grab actual references to the files_struct. To avoid circular references
issues due to this, we add a per-task note that keeps track of what
io_uring contexts a task has used. When the tasks execs or exits its
assigned files, we cancel requests based on this tracking.

With that, we can grab proper references to the files table, and no
longer need to rely on stashing away ring_fd and ring_file to check
if the ring_fd may have been closed.

Cc: stable@vger.kernel.org # v5.5+
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:32 -06:00
Jens Axboe e6c8aa9ac3 io_uring: enable task/files specific overflow flushing
This allows us to selectively flush out pending overflows, depending on
the task and/or files_struct being passed in.

No intended functional changes in this patch.

Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:32 -06:00
Jens Axboe 76e1b6427f io_uring: return cancelation status from poll/timeout/files handlers
Return whether we found and canceled requests or not. This is in
preparation for using this information, no functional changes in this
patch.

Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:32 -06:00
Jens Axboe e3bc8e9dad io_uring: unconditionally grab req->task
Sometimes we assign a weak reference to it, sometimes we grab a
reference to it. Clean this up and make it unconditional, and drop the
flag related to tracking this state.

Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:32 -06:00
Jens Axboe 2aede0e417 io_uring: stash ctx task reference for SQPOLL
We can grab a reference to the task instead of stashing away the task
files_struct. This is doable without creating a circular reference
between the ring fd and the task itself.

Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:32 -06:00
Jens Axboe f573d38445 io_uring: move dropping of files into separate helper
No functional changes in this patch, prep patch for grabbing references
to the files_struct.

Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:32 -06:00
Jens Axboe f3606e3a92 io_uring: allow timeout/poll/files killing to take task into account
We currently cancel these when the ring exits, and we cancel all of
them. This is in preparation for killing only the ones associated
with a given task.

Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-30 20:32:32 -06:00
Jens Axboe 0f07889691 Merge branch 'io_uring-5.9' into for-5.10/io_uring
* io_uring-5.9:
  io_uring: fix async buffered reads when readahead is disabled
  io_uring: fix potential ABBA deadlock in ->show_fdinfo()
  io_uring: always delete double poll wait entry on match
2020-09-30 20:32:25 -06:00
Hao Xu c8d317aa18 io_uring: fix async buffered reads when readahead is disabled
The async buffered reads feature is not working when readahead is
turned off. There are two things to concern:

- when doing retry in io_read, not only the IOCB_WAITQ flag but also
  the IOCB_NOWAIT flag is still set, which makes it goes to would_block
  phase in generic_file_buffered_read() and then return -EAGAIN. After
  that, the io-wq thread work is queued, and later doing the async
  reads in the old way.

- even if we remove IOCB_NOWAIT when doing retry, the feature is still
  not running properly, since in generic_file_buffered_read() it goes to
  lock_page_killable() after calling mapping->a_ops->readpage() to do
  IO, and thus causing process to sleep.

Fixes: 1a0a7853b9 ("mm: support async buffered reads in generic_file_buffered_read()")
Fixes: 3b2a4439e0 ("io_uring: get rid of kiocb_wait_page_queue_init()")
Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-29 07:54:00 -06:00
Jens Axboe fad8e0de44 io_uring: fix potential ABBA deadlock in ->show_fdinfo()
syzbot reports a potential lock deadlock between the normal IO path and
->show_fdinfo():

======================================================
WARNING: possible circular locking dependency detected
5.9.0-rc6-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.2/19710 is trying to acquire lock:
ffff888098ddc450 (sb_writers#4){.+.+}-{0:0}, at: io_write+0x6b5/0xb30 fs/io_uring.c:3296

but task is already holding lock:
ffff8880a11b8428 (&ctx->uring_lock){+.+.}-{3:3}, at: __do_sys_io_uring_enter+0xe9a/0x1bd0 fs/io_uring.c:8348

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (&ctx->uring_lock){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:956 [inline]
       __mutex_lock+0x134/0x10e0 kernel/locking/mutex.c:1103
       __io_uring_show_fdinfo fs/io_uring.c:8417 [inline]
       io_uring_show_fdinfo+0x194/0xc70 fs/io_uring.c:8460
       seq_show+0x4a8/0x700 fs/proc/fd.c:65
       seq_read+0x432/0x1070 fs/seq_file.c:208
       do_loop_readv_writev fs/read_write.c:734 [inline]
       do_loop_readv_writev fs/read_write.c:721 [inline]
       do_iter_read+0x48e/0x6e0 fs/read_write.c:955
       vfs_readv+0xe5/0x150 fs/read_write.c:1073
       kernel_readv fs/splice.c:355 [inline]
       default_file_splice_read.constprop.0+0x4e6/0x9e0 fs/splice.c:412
       do_splice_to+0x137/0x170 fs/splice.c:871
       splice_direct_to_actor+0x307/0x980 fs/splice.c:950
       do_splice_direct+0x1b3/0x280 fs/splice.c:1059
       do_sendfile+0x55f/0xd40 fs/read_write.c:1540
       __do_sys_sendfile64 fs/read_write.c:1601 [inline]
       __se_sys_sendfile64 fs/read_write.c:1587 [inline]
       __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1587
       do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

-> #1 (&p->lock){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:956 [inline]
       __mutex_lock+0x134/0x10e0 kernel/locking/mutex.c:1103
       seq_read+0x61/0x1070 fs/seq_file.c:155
       pde_read fs/proc/inode.c:306 [inline]
       proc_reg_read+0x221/0x300 fs/proc/inode.c:318
       do_loop_readv_writev fs/read_write.c:734 [inline]
       do_loop_readv_writev fs/read_write.c:721 [inline]
       do_iter_read+0x48e/0x6e0 fs/read_write.c:955
       vfs_readv+0xe5/0x150 fs/read_write.c:1073
       kernel_readv fs/splice.c:355 [inline]
       default_file_splice_read.constprop.0+0x4e6/0x9e0 fs/splice.c:412
       do_splice_to+0x137/0x170 fs/splice.c:871
       splice_direct_to_actor+0x307/0x980 fs/splice.c:950
       do_splice_direct+0x1b3/0x280 fs/splice.c:1059
       do_sendfile+0x55f/0xd40 fs/read_write.c:1540
       __do_sys_sendfile64 fs/read_write.c:1601 [inline]
       __se_sys_sendfile64 fs/read_write.c:1587 [inline]
       __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1587
       do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

-> #0 (sb_writers#4){.+.+}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:2496 [inline]
       check_prevs_add kernel/locking/lockdep.c:2601 [inline]
       validate_chain kernel/locking/lockdep.c:3218 [inline]
       __lock_acquire+0x2a96/0x5780 kernel/locking/lockdep.c:4441
       lock_acquire+0x1f3/0xaf0 kernel/locking/lockdep.c:5029
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write+0x228/0x450 fs/super.c:1672
       io_write+0x6b5/0xb30 fs/io_uring.c:3296
       io_issue_sqe+0x18f/0x5c50 fs/io_uring.c:5719
       __io_queue_sqe+0x280/0x1160 fs/io_uring.c:6175
       io_queue_sqe+0x692/0xfa0 fs/io_uring.c:6254
       io_submit_sqe fs/io_uring.c:6324 [inline]
       io_submit_sqes+0x1761/0x2400 fs/io_uring.c:6521
       __do_sys_io_uring_enter+0xeac/0x1bd0 fs/io_uring.c:8349
       do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

other info that might help us debug this:

Chain exists of:
  sb_writers#4 --> &p->lock --> &ctx->uring_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ctx->uring_lock);
                               lock(&p->lock);
                               lock(&ctx->uring_lock);
  lock(sb_writers#4);

 *** DEADLOCK ***

1 lock held by syz-executor.2/19710:
 #0: ffff8880a11b8428 (&ctx->uring_lock){+.+.}-{3:3}, at: __do_sys_io_uring_enter+0xe9a/0x1bd0 fs/io_uring.c:8348

stack backtrace:
CPU: 0 PID: 19710 Comm: syz-executor.2 Not tainted 5.9.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x198/0x1fd lib/dump_stack.c:118
 check_noncircular+0x324/0x3e0 kernel/locking/lockdep.c:1827
 check_prev_add kernel/locking/lockdep.c:2496 [inline]
 check_prevs_add kernel/locking/lockdep.c:2601 [inline]
 validate_chain kernel/locking/lockdep.c:3218 [inline]
 __lock_acquire+0x2a96/0x5780 kernel/locking/lockdep.c:4441
 lock_acquire+0x1f3/0xaf0 kernel/locking/lockdep.c:5029
 percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
 __sb_start_write+0x228/0x450 fs/super.c:1672
 io_write+0x6b5/0xb30 fs/io_uring.c:3296
 io_issue_sqe+0x18f/0x5c50 fs/io_uring.c:5719
 __io_queue_sqe+0x280/0x1160 fs/io_uring.c:6175
 io_queue_sqe+0x692/0xfa0 fs/io_uring.c:6254
 io_submit_sqe fs/io_uring.c:6324 [inline]
 io_submit_sqes+0x1761/0x2400 fs/io_uring.c:6521
 __do_sys_io_uring_enter+0xeac/0x1bd0 fs/io_uring.c:8349
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45e179
Code: 3d b2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 0b b2 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f1194e74c78 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 00000000000082c0 RCX: 000000000045e179
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000004
RBP: 000000000118cf98 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c
R13: 00007ffd1aa5756f R14: 00007f1194e759c0 R15: 000000000118cf4c

Fix this by just not diving into details if we fail to trylock the
io_uring mutex. We know the ctx isn't going away during this operation,
but we cannot safely iterate buffers/files/personalities if we don't
hold the io_uring mutex.

Reported-by: syzbot+2f8fa4e860edc3066aba@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-28 09:06:08 -06:00
Jens Axboe 8706e04ed7 io_uring: always delete double poll wait entry on match
syzbot reports a crash with tty polling, which is using the double poll
handling:

general protection fault, probably for non-canonical address 0xdffffc0000000009: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000048-0x000000000000004f]
CPU: 0 PID: 6874 Comm: syz-executor749 Not tainted 5.9.0-rc6-next-20200924-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:io_poll_get_single fs/io_uring.c:4778 [inline]
RIP: 0010:io_poll_double_wake+0x51/0x510 fs/io_uring.c:4845
Code: fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 9e 03 00 00 48 b8 00 00 00 00 00 fc ff df 49 8b 5d 08 48 8d 7b 48 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 06 0f 8e 63 03 00 00 0f b6 6b 48 bf 06 00 00
RSP: 0018:ffffc90001c1fb70 EFLAGS: 00010006
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000004
RDX: 0000000000000009 RSI: ffffffff81d9b3ad RDI: 0000000000000048
RBP: dffffc0000000000 R08: ffff8880a3cac798 R09: ffffc90001c1fc60
R10: fffff52000383f73 R11: 0000000000000000 R12: 0000000000000004
R13: ffff8880a3cac798 R14: ffff8880a3cac7a0 R15: 0000000000000004
FS:  0000000001f98880(0000) GS:ffff8880ae400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f18886916c0 CR3: 0000000094c5a000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __wake_up_common+0x147/0x650 kernel/sched/wait.c:93
 __wake_up_common_lock+0xd0/0x130 kernel/sched/wait.c:123
 tty_ldisc_hangup+0x1cf/0x680 drivers/tty/tty_ldisc.c:735
 __tty_hangup.part.0+0x403/0x870 drivers/tty/tty_io.c:625
 __tty_hangup drivers/tty/tty_io.c:575 [inline]
 tty_vhangup+0x1d/0x30 drivers/tty/tty_io.c:698
 pty_close+0x3f5/0x550 drivers/tty/pty.c:79
 tty_release+0x455/0xf60 drivers/tty/tty_io.c:1679
 __fput+0x285/0x920 fs/file_table.c:281
 task_work_run+0xdd/0x190 kernel/task_work.c:141
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:165 [inline]
 exit_to_user_mode_prepare+0x1e2/0x1f0 kernel/entry/common.c:192
 syscall_exit_to_user_mode+0x7a/0x2c0 kernel/entry/common.c:267
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x401210

which is due to a failure in removing the double poll wait entry if we
hit a wakeup match. This can cause multiple invocations of the wakeup,
which isn't safe.

Cc: stable@vger.kernel.org # v5.8
Reported-by: syzbot+81b3883093f772addf6d@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-28 08:38:54 -06:00
Linus Torvalds 692495baa3 io_uring-5.9-2020-09-25
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Merge tag 'io_uring-5.9-2020-09-25' of git://git.kernel.dk/linux-block

Pull io_uring fixes from Jens Axboe:
 "Two fixes for regressions in this cycle, and one that goes to 5.8
  stable:

   - fix leak of getname() retrieved filename

   - remove plug->nowait assignment, fixing a regression with btrfs

   - fix for async buffered retry"

* tag 'io_uring-5.9-2020-09-25' of git://git.kernel.dk/linux-block:
  io_uring: ensure async buffered read-retry is setup properly
  io_uring: don't unconditionally set plug->nowait = true
  io_uring: ensure open/openat2 name is cleaned on cancelation
2020-09-26 11:13:51 -07:00
Jens Axboe f38c7e3abf io_uring: ensure async buffered read-retry is setup properly
A previous commit for fixing up short reads botched the async retry
path, so we ended up going to worker threads more often than we should.
Fix this up, so retries work the way they originally were intended to.

Fixes: 227c0c9673 ("io_uring: internally retry short reads")
Reported-by: Hao_Xu <haoxu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-25 15:39:13 -06:00
Jens Axboe 62c774ed48 io_uring: don't unconditionally set plug->nowait = true
This causes all the bios to be submitted with REQ_NOWAIT, which can be
problematic on either btrfs or on file systems that otherwise use a mix
of block devices where only some of them support it.

For now, just remove the setting of plug->nowait = true.

Reported-by: Dan Melnic <dmm@fb.com>
Reported-by: Brian Foster <bfoster@redhat.com>
Fixes: b63534c41e ("io_uring: re-issue block requests that failed because of resources")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-25 09:01:53 -06:00
Jens Axboe f3cd485050 io_uring: ensure open/openat2 name is cleaned on cancelation
If we cancel these requests, we'll leak the memory associated with the
filename. Add them to the table of ops that need cleaning, if
REQ_F_NEED_CLEANUP is set.

Cc: stable@vger.kernel.org
Fixes: e62753e4e2 ("io_uring: call statx directly")
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-25 07:41:46 -06:00
David S. Miller 3ab0a7a0c3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Two minor conflicts:

1) net/ipv4/route.c, adding a new local variable while
   moving another local variable and removing it's
   initial assignment.

2) drivers/net/dsa/microchip/ksz9477.c, overlapping changes.
   One pretty prints the port mode differently, whilst another
   changes the driver to try and obtain the port mode from
   the port node rather than the switch node.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-22 16:45:34 -07:00
Linus Torvalds 0baca07006 io_uring-5.9-2020-09-22
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Merge tag 'io_uring-5.9-2020-09-22' of git://git.kernel.dk/linux-block

Pull io_uring fixes from Jens Axboe:
 "A few fixes - most of them regression fixes from this cycle, but also
  a few stable heading fixes, and a build fix for the included demo tool
  since some systems now actually have gettid() available"

* tag 'io_uring-5.9-2020-09-22' of git://git.kernel.dk/linux-block:
  io_uring: fix openat/openat2 unified prep handling
  io_uring: mark statx/files_update/epoll_ctl as non-SQPOLL
  tools/io_uring: fix compile breakage
  io_uring: don't use retry based buffered reads for non-async bdev
  io_uring: don't re-setup vecs/iter in io_resumit_prep() is already there
  io_uring: don't run task work on an exiting task
  io_uring: drop 'ctx' ref on task work cancelation
  io_uring: grab any needed state during defer prep
2020-09-22 14:36:50 -07:00
Jens Axboe 4eb8dded6b io_uring: fix openat/openat2 unified prep handling
A previous commit unified how we handle prep for these two functions,
but this means that we check the allowed context (SQPOLL, specifically)
later than we should. Move the ring type checking into the two parent
functions, instead of doing it after we've done some setup work.

Fixes: ec65fea5a8 ("io_uring: deduplicate io_openat{,2}_prep()")
Reported-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-21 07:51:03 -06:00
Jens Axboe 6ca56f8459 io_uring: mark statx/files_update/epoll_ctl as non-SQPOLL
These will naturally fail when attempted through SQPOLL, but either
with -EFAULT or -EBADF. Make it explicit that these are not workable
through SQPOLL and return -EINVAL, just like other ops that need to
use ->files.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-21 07:51:00 -06:00
Jens Axboe f5cac8b156 io_uring: don't use retry based buffered reads for non-async bdev
Some block devices, like dm, bubble back -EAGAIN through the completion
handler. We check for this in io_read(), but don't honor it for when
we have copied the iov. Return -EAGAIN for this case before retrying,
to force punt to io-wq.

Fixes: bcf5a06304 ("io_uring: support true async buffered reads, if file provides it")
Reported-by: Zorro Lang <zlang@redhat.com>
Tested-by: Zorro Lang <zlang@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-21 07:50:56 -06:00
Jens Axboe 8f3d749685 io_uring: don't re-setup vecs/iter in io_resumit_prep() is already there
If we already have mapped the necessary data for retry, then don't set
it up again. It's a pointless operation, and we leak the iovec if it's
a large (non-stack) vec.

Fixes: b63534c41e ("io_uring: re-issue block requests that failed because of resources")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-21 07:50:54 -06:00
Jens Axboe 6200b0ae4e io_uring: don't run task work on an exiting task
This isn't safe, and isn't needed either. We are guaranteed that any
work we queue is on a live task (and will be run), or it goes to
our backup io-wq threads if the task is exiting.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-14 10:22:15 -06:00
Jens Axboe 87ceb6a6b8 io_uring: drop 'ctx' ref on task work cancelation
If task_work ends up being marked for cancelation, we go through a
cancelation helper instead of the queue path. In converting task_work to
always hold a ctx reference, this path was missed. Make sure that
io_req_task_cancel() puts the reference that is being held against the
ctx.

Fixes: 6d816e088c ("io_uring: hold 'ctx' reference around task_work queue + execute")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-14 10:22:14 -06:00
Jens Axboe 202700e18a io_uring: grab any needed state during defer prep
Always grab work environment for deferred links. The assumption that we
will be running it always from the task in question is false, as exiting
tasks may mean that we're deferring this one to a thread helper. And at
that point it's too late to grab the work environment.

Fixes: debb85f496 ("io_uring: factor out grab_env() from defer_prep()")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-13 14:47:06 -06:00
Linus Torvalds a8205e3100 io_uring-5.9-2020-09-06
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Merge tag 'io_uring-5.9-2020-09-06' of git://git.kernel.dk/linux-block

Pull more io_uring fixes from Jens Axboe:
 "Two followup fixes. One is fixing a regression from this merge window,
  the other is two commits fixing cancelation of deferred requests.

  Both have gone through full testing, and both spawned a few new
  regression test additions to liburing.

   - Don't play games with const, properly store the output iovec and
     assign it as needed.

   - Deferred request cancelation fix (Pavel)"

* tag 'io_uring-5.9-2020-09-06' of git://git.kernel.dk/linux-block:
  io_uring: fix linked deferred ->files cancellation
  io_uring: fix cancel of deferred reqs with ->files
  io_uring: fix explicit async read/write mapping for large segments
2020-09-06 12:10:27 -07:00
Pavel Begunkov c127a2a1b7 io_uring: fix linked deferred ->files cancellation
While looking for ->files in ->defer_list, consider that requests there
may actually be links.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-05 16:02:42 -06:00
Pavel Begunkov b7ddce3cbf io_uring: fix cancel of deferred reqs with ->files
While trying to cancel requests with ->files, it also should look for
requests in ->defer_list, otherwise it might end up hanging a thread.

Cancel all requests in ->defer_list up to the last request there with
matching ->files, that's needed to follow drain ordering semantics.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-05 15:59:51 -06:00
Jens Axboe c183edff33 io_uring: fix explicit async read/write mapping for large segments
If we exceed UIO_FASTIOV, we don't handle the transition correctly
between an allocated vec for requests that are queued with IOSQE_ASYNC.
Store the iovec appropriately and re-set it in the iter iov in case
it changed.

Fixes: ff6165b2d7 ("io_uring: retain iov_iter state over io_read/io_write calls")
Reported-by: Nick Hill <nick@nickhill.org>
Tested-by: Norman Maurer <norman.maurer@googlemail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-05 09:02:47 -06:00
Jakub Kicinski 44a8c4f33c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
We got slightly different patches removing a double word
in a comment in net/ipv4/raw.c - picked the version from net.

Simple conflict in drivers/net/ethernet/ibm/ibmvnic.c. Use cached
values instead of VNIC login response buffer (following what
commit 507ebe6444 ("ibmvnic: Fix use-after-free of VNIC login
response buffer") did).

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-09-04 21:28:59 -07:00
Linus Torvalds d849ca483d io_uring-5.9-2020-09-04
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Merge tag 'io_uring-5.9-2020-09-04' of git://git.kernel.dk/linux-block

Pull io_uring fixes from Jens Axboe:

 - EAGAIN with O_NONBLOCK retry fix

 - Two small fixes for registered files (Jiufei)

* tag 'io_uring-5.9-2020-09-04' of git://git.kernel.dk/linux-block:
  io_uring: no read/write-retry on -EAGAIN error and O_NONBLOCK marked file
  io_uring: set table->files[i] to NULL when io_sqe_file_register failed
  io_uring: fix removing the wrong file in __io_sqe_files_update()
2020-09-04 12:55:22 -07:00
Jens Axboe 355afaeb57 io_uring: no read/write-retry on -EAGAIN error and O_NONBLOCK marked file
Actually two things that need fixing up here:

- The io_rw_reissue() -EAGAIN retry is explicit to block devices and
  regular files, so don't ever attempt to do that on other types of
  files.

- If we hit -EAGAIN on a nonblock marked file, don't arm poll handler for
  it. It should just complete with -EAGAIN.

Cc: stable@vger.kernel.org
Reported-by: Norman Maurer <norman.maurer@googlemail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-02 10:20:41 -06:00
Jiufei Xue 95d1c8e5f8 io_uring: set table->files[i] to NULL when io_sqe_file_register failed
While io_sqe_file_register() failed in __io_sqe_files_update(),
table->files[i] still point to the original file which may freed
soon, and that will trigger use-after-free problems.

Cc: stable@vger.kernel.org
Fixes: f3bd9dae37 ("io_uring: fix memleak in __io_sqe_files_update()")
Signed-off-by: Jiufei Xue <jiufei.xue@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-02 09:11:59 -06:00
Jiufei Xue 98dfd5024a io_uring: fix removing the wrong file in __io_sqe_files_update()
Index here is already the position of the file in fixed_file_table, we
should not use io_file_from_index() again to get it. Otherwise, the
wrong file which still in use may be released unexpectedly.

Cc: stable@vger.kernel.org # v5.6
Fixes: 05f3fb3c53 ("io_uring: avoid ring quiesce for fixed file set unregister and update")
Signed-off-by: Jiufei Xue <jiufei.xue@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 08:04:58 -06:00
Linus Torvalds 24148d8648 io_uring-5.9-2020-08-28
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Merge tag 'io_uring-5.9-2020-08-28' of git://git.kernel.dk/linux-block

Pull io_uring fixes from Jens Axboe:
 "A few fixes in here, all based on reports and test cases from folks
  using it. Most of it is stable material as well:

   - Hashed work cancelation fix (Pavel)

   - poll wakeup signalfd fix

   - memlock accounting fix

   - nonblocking poll retry fix

   - ensure we never return -ERESTARTSYS for reads

   - ensure offset == -1 is consistent with preadv2() as documented

   - IOPOLL -EAGAIN handling fixes

   - remove useless task_work bounce for block based -EAGAIN retry"

* tag 'io_uring-5.9-2020-08-28' of git://git.kernel.dk/linux-block:
  io_uring: don't bounce block based -EAGAIN retry off task_work
  io_uring: fix IOPOLL -EAGAIN retries
  io_uring: clear req->result on IOPOLL re-issue
  io_uring: make offset == -1 consistent with preadv2/pwritev2
  io_uring: ensure read requests go through -ERESTART* transformation
  io_uring: don't use poll handler if file can't be nonblocking read/written
  io_uring: fix imbalanced sqo_mm accounting
  io_uring: revert consumed iov_iter bytes on error
  io-wq: fix hang after cancelling pending hashed work
  io_uring: don't recurse on tsk->sighand->siglock with signalfd
2020-08-28 16:23:16 -07:00
Jens Axboe fdee946d09 io_uring: don't bounce block based -EAGAIN retry off task_work
These events happen inline from submission, so there's no need to
bounce them through the original task. Just set them up for retry
and issue retry directly instead of going over task_work.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-27 16:48:34 -06:00
Jens Axboe eefdf30f3d io_uring: fix IOPOLL -EAGAIN retries
This normally isn't hit, as polling is mostly done on NVMe with deep
queue depths. But if we do run into request starvation, we need to
ensure that retries are properly serialized.

Reported-by: Andres Freund <andres@anarazel.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-27 16:40:29 -06:00
Jens Axboe 56450c20fe io_uring: clear req->result on IOPOLL re-issue
Make sure we clear req->result, which was set to -EAGAIN for retry
purposes, when moving it to the reissue list. Otherwise we can end up
retrying a request more than once, which leads to weird results in
the io-wq handling (and other spots).

Cc: stable@vger.kernel.org
Reported-by: Andres Freund <andres@anarazel.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-26 18:58:26 -06:00
Jens Axboe 0fef948363 io_uring: make offset == -1 consistent with preadv2/pwritev2
The man page for io_uring generally claims were consistent with what
preadv2 and pwritev2 accept, but turns out there's a slight discrepancy
in how offset == -1 is handled for pipes/streams. preadv doesn't allow
it, but preadv2 does. This currently causes io_uring to return -EINVAL
if that is attempted, but we should allow that as documented.

This change makes us consistent with preadv2/pwritev2 for just passing
in a NULL ppos for streams if the offset is -1.

Cc: stable@vger.kernel.org # v5.7+
Reported-by: Benedikt Ames <wisp3rwind@posteo.eu>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-26 10:36:20 -06:00
Jens Axboe 00d23d516e io_uring: ensure read requests go through -ERESTART* transformation
We need to call kiocb_done() for any ret < 0 to ensure that we always
get the proper -ERESTARTSYS (and friends) transformation done.

At some point this should be tied into general error handling, so we
can get rid of the various (mostly network) related commands that check
and perform this substitution.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-25 12:59:22 -06:00
Jens Axboe 9dab14b818 io_uring: don't use poll handler if file can't be nonblocking read/written
There's no point in using the poll handler if we can't do a nonblocking
IO attempt of the operation, since we'll need to go async anyway. In
fact this is actively harmful, as reading from eg pipes won't return 0
to indicate EOF.

Cc: stable@vger.kernel.org # v5.7+
Reported-by: Benedikt Ames <wisp3rwind@posteo.eu>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-25 12:27:50 -06:00
Jens Axboe 6b7898eb18 io_uring: fix imbalanced sqo_mm accounting
We do the initial accounting of locked_vm and pinned_vm before we have
setup ctx->sqo_mm, which means we can end up having not accounted the
memory at setup time, but still decrement it when we exit. This causes
an imbalance in the accounting.

Setup ctx->sqo_mm earlier in io_uring_create(), before we do the first
accounting of mm->{locked,pinned}_vm. This also unifies the state
grabbing for the ctx, and eliminates a failure case in
io_sq_offload_start().

Fixes: f74441e631 ("io_uring: account locked memory before potential error case")
Reported-by: Robert M. Muncrief <rmuncrief@humanavance.com>
Reported-by: Niklas Schnelle <schnelle@linux.ibm.com>
Tested-by: Niklas Schnelle <schnelle@linux.ibm.com>
Tested-by: Robert M. Muncrief <rmuncrief@humanavance.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-25 12:05:57 -06:00