Move ctx pinning from io_req_local_work_add() to the caller, looks
better and makes working with the code a bit easier.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/49c0dbed390b0d6d04cb942dd3592879fd5bfb1b.1680782017.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Rather than check this in the fast path issue, it makes more sense to
just assign the copy of the data when we're setting it up anyway. This
makes the code a bit cleaner, and removes the need for this check in
the issue path.
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

The number of entries in the rsrc node cache is limited to 512, which
still seems unnecessarily large. Add per cache thresholds and set to
to 32 for the rsrc node cache.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d0cd538b944dac0bf878e276fc0199f21e6bccea.1680576071.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Every struct io_rsrc_node takes a struct io_rsrc_data reference, which
means all rsrc updates do 2 extra atomics. Replace atomics refcounting
with a int as it's all done under ->uring_lock.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e73c3d6820cf679532696d790b5b8fae23537213.1680576071.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

We should hold ->uring_lock while putting nodes with io_put_rsrc_node(),
add a lockdep check for that.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b50d5f156ac41450029796738c1dfd22a521df7a.1680576071.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Add allocation cache for struct io_rsrc_node, it's always allocated and
put under ->uring_lock, so it doesn't need any extra synchronisation
around caches.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/252a9d9ef9654e6467af30fdc02f57c0118fb76e.1680576071.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

struct delayed_work rsrc_put_work was previously used to offload node
freeing because io_rsrc_node_ref_zero() was previously called by RCU in
the IRQ context. Now, as percpu refcounting is gone, we can do it
eagerly at the spot without pushing it to a worker.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/13fb1aac1e8d068ad8fd4a0c6d0d157ab61b90c0.1680576071.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Every io_rsrc_node keeps a list of items to put, and all entries are
kmalloc()'ed. However, it's quite often to queue up only one entry per
node, so let's add an inline entry there to avoid extra allocations.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/c482c1c652c45c85ac52e67c974bc758a50fed5f.1680576071.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

We have too many "rsrc" around which makes the name of struct
io_rsrc_node::rsrc_list confusing. The field is responsible for keeping
a list of files or buffers, so call it item_list and add comments
around.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/3e34d4dfc1fdbb6b520f904ee6187c2ccf680efe.1680576071.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

We use ->rsrc_ref_lock spinlock to protect ->rsrc_ref_list in
io_rsrc_node_ref_zero(). Now we removed pcpu refcounting, which means
io_rsrc_node_ref_zero() is not executed from the irq context as an RCU
callback anymore, and we also put it under ->uring_lock.
io_rsrc_node_switch(), which queues up nodes into the list, is also
protected by ->uring_lock, so we can safely get rid of ->rsrc_ref_lock.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6b60af883c263551190b526a55ff2c9d5ae07141.1680576071.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Currently, for nodes we have an atomic counter and some cached
(non-atomic) refs protected by uring_lock. Let's put all ref
manipulations under uring_lock and get rid of the atomic part.
It's free as in all cases we care about we already hold the lock.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/25b142feed7d831008257d90c8b17c0115d4fc15.1680576071.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

io_free_req() is not often used but nevertheless problematic as there is
no way to know the current context, it may be used from the submission
path or even by an irq handler. Push it to a fresh context using
task_work.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/3a92fe80bb068757e51aaa0b105cfbe8f5dfee9e.1680576071.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

io_req_put_rsrc() doesn't need any locking, so move it out of
a spinlock section in __io_req_complete_post() and adjust helpers.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d5b87a5f31270dade6805f7acafc4cc34b84b241.1680576071.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

We cache refs of the current node (i.e. ctx->rsrc_node) in
ctx->rsrc_cached_refs. We'll be moving away from atomics, so move the
cached refs in struct io_rsrc_node for now. It's a prep patch and
shouldn't change anything in practise.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9edc3669c1d71b06c2dca78b2b2b8bb9292738b9.1680576071.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

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

Replace pcpu refs with normal refcounting. There is already a hot path
avoiding atomics / refs, but following patches will further improve it.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e9ed8a9457b331a26555ff9443afc64cdaab7247.1680576071.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

We already do this manually for the !SQPOLL case, do it in general and
we can also dump the ugly min3() in io_submit_sqes().
Signed-off-by: Jens Axboe <axboe@kernel.dk>

It has nothing to do with the SQE at this point, it's a request
submission. While in there, get rid of the 'force_nonblock' argument
which is also dead, as we only pass in true.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

For task works we're passing around a bool pointer for whether the
current ring is locked or not, let's wrap it in a structure, that
will make it more opaque preventing abuse and will also help us
to pass more info in the future if needed.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1ecec9483d58696e248d1bfd52cf62b04442df1d.1679931367.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Before cond_resched()'ing in handle_tw_list() we also drop the current
ring context, and so the next loop iteration will need to pick/pin a new
context and do trylock.

The chunk removed by this patch was intended to be an optimisation
covering exactly this case, i.e. retaking the lock after reschedule, but
in reality it's skipped for the first iteration after resched as
described and will keep hammering the lock if it's contended.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1ecec9483d58696e248d1bfd52cf62b04442df1d.1679931367.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Since the move to PF_IO_WORKER, we don't juggle memory context manually
anymore. Remove that outdated part of the comment for __io_worker_idle().
Signed-off-by: Jens Axboe <axboe@kernel.dk>

There are two leftover structures from the notification registration
mechanism that has never been released, kill them.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f05f65aebaf8b1b5bf28519a8fdb350e3e7c9ad0.1679924536.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Since commit 0654b05e7e65 ("io_uring: One wqe per wq"), we have just a
single io_wqe instance embedded per io_wq.  Drop the extra structure in
favor of accessing struct io_wq directly, cleaning up quite a bit of
dereferences and backpointers.

No functional changes intended.  Tested with liburing's testsuite
and mmtests performance microbenchmarks.  I didn't observe any
performance regressions.
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/20230322011628.23359-2-krisman@suse.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Since we now have a single io_wqe per io_wq instead of per-node, and in
preparation to its removal, move the accounting into the parent
structure.
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/20230322011628.23359-2-krisman@suse.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

On at least parisc, we have strict requirements on how we virtually map
an address that is shared between the application and the kernel. On
these platforms, IOU_PBUF_RING_MMAP should be used when setting up a
shared ring buffer for provided buffers. If the application is mapping
these pages and asking the kernel to pin+map them as well, then we have
no control over what virtual address we get in the kernel.

For that case, do a sanity check if SHM_COLOUR is defined, and disallow
the mapping request. The application must fall back to using
IOU_PBUF_RING_MMAP for this case, and liburing will do that transparently
with the set of helpers that it has.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Add support for KASAN in the alloc_caches (apoll and netmsg_cache).
Thus, if something touches the unused caches, it will raise a KASAN
warning/exception.

It poisons the object when the object is put to the cache, and unpoisons
it when the object is gotten or freed.
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/20230223164353.2839177-2-leitao@debian.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

Having cache entries linked using the hlist format brings no benefit, and
also requires an unnecessary extra pointer address per cache entry.

Use the internal io_wq_work_node single-linked list for the internal
alloc caches (async_msghdr and async_poll)

This is required to be able to use KASAN on cache entries, since we do
not need to touch unused (and poisoned) cache entries when adding more
entries to the list.
Suggested-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20230223164353.2839177-2-leitao@debian.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

Right now io_wq allocates one io_wqe per NUMA node.  As io_wq is now
bound to a task, the task basically uses only the NUMA local io_wqe, and
almost never changes NUMA nodes, thus, the other wqes are mostly
unused.

Allocate just one io_wqe embedded into io_wq, and uses all possible cpus
(cpu_possible_mask) in the io_wqe->cpumask.
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20230310201107.4020580-1-leitao@debian.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

The ring mapped provided buffer rings rely on the application allocating
the memory for the ring, and then the kernel will map it. This generally
works fine, but runs into issues on some architectures where we need
to be able to ensure that the kernel and application virtual address for
the ring play nicely together. This at least impacts architectures that
set SHM_COLOUR, but potentially also anyone setting SHMLBA.

To use this variant of ring provided buffers, the application need not
allocate any memory for the ring. Instead the kernel will do so, and
the allocation must subsequently call mmap(2) on the ring with the
offset set to:

	IORING_OFF_PBUF_RING | (bgid << IORING_OFF_PBUF_SHIFT)

to get a virtual address for the buffer ring. Normally the application
would allocate a suitable piece of memory (and correctly aligned) and
simply pass that in via io_uring_buf_reg.ring_addr and the kernel would
map it.

Outside of the setup differences, the kernel allocate + user mapped
provided buffer ring works exactly the same.
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

In preparation for allowing flags to be set for registration, rename
the padding and use it for that.
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Rather than rely on checking buffer_list->buf_pages or ->buf_nr_pages,
add a separate member that tracks if this is a ring mapped provided
buffer list or not.
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

In preparation for allowing the kernel to allocate the provided buffer
rings and have the application mmap it instead, abstract out the
current method of pinning and mapping the user allocated ring.

No functional changes intended in this patch.
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Some architectures have memory cache aliasing requirements (e.g. parisc)
if memory is shared between userspace and kernel. This patch fixes the
kernel to return an aliased address when asked by userspace via mmap().
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

io_uring hashes writes to a given file/inode so that it can serialize
them. This is useful if the file system needs exclusive access to the
file to perform the write, as otherwise we end up with a ton of io-wq
threads trying to lock the inode at the same time. This can cause
excessive system time.

But if the file system has flagged that it supports parallel O_DIRECT
writes, then there's no need to serialize the writes. Check for that
through FMODE_DIO_PARALLEL_WRITE and don't hash it if we don't need to.

In a basic test of 8 threads writing to a file on XFS on a gen2 Optane,
with each thread writing in 4k chunks, it improves performance from
~1350K IOPS (or ~5290MiB/sec) to ~1410K IOPS (or ~5500MiB/sec).
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Some filesystems support multiple threads writing to the same file with
O_DIRECT without requiring exclusive access to it. io_uring can use this
hint to avoid serializing dio writes to this inode, instead allowing them
to run in parallel.

XFS and ext4 both fall into this category, so set the flag for both of
them.
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull btrfs fixes from David Sterba:

 - scan block devices in non-exclusive mode to avoid temporary mkfs
   failures

 - fix race between quota disable and quota assign ioctls

 - fix deadlock when aborting transaction during relocation with scrub

 - ignore fiemap path cache when there are multiple paths for a node

* tag 'for-6.3-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: ignore fiemap path cache when there are multiple paths for a node
  btrfs: fix deadlock when aborting transaction during relocation with scrub
  btrfs: scan device in non-exclusive mode
  btrfs: fix race between quota disable and quota assign ioctls

This reverts commit a837e516, which broke probing of the venus
driver, at least on the SC7180 SoC HP X2 Chromebook:

  qcom-venus aa00000.video-codec: Adding to iommu group 11
  qcom-venus aa00000.video-codec: non legacy binding
  qcom-venus aa00000.video-codec: failed to reset venus core
  qcom-venus: probe of aa00000.video-codec failed with error -110

Matthias Kaehlcke also reported that the same change caused a regression
in SC7180 and sc7280, that prevents AOSS from entering sleep mode during
system suspend.  So let's revert this commit for now to fix both issues.

Fixes: a837e516 ("venus: firmware: Correct non-pix start and end addresses")
Reported-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull driver core fixes from Greg KH:
 "Here are three small changes for 6.3-rc5 semi-related to driver core
  stuff:

   - documentation update where we move the security_bugs file to a more
     relevant location.

   - mdt/spi-nor debugfs memory leak fix that's been floating around for
     a long time and acked by the maintainer

   - cacheinfo bugfix for a regression in 6.3-rc1

  All have been in linux-next with no reported problems"

* tag 'driver-core-6.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  cacheinfo: Fix LLC is not exported through sysfs
  Documentation/security-bugs: move from admin-guide/ to process/
  mtd: spi-nor: fix memory leak when using debugfs_lookup()

Pull powerpc fixes from Michael Ellerman:

 - Fix a false positive warning in __pte_needs_flush() (with DEBUG_VM=y)

 - Fix oops when a PF_IO_WORKER thread tries to core dump

 - Don't try to reconfigure VAS when it's disabled

Thanks to Benjamin Gray, Haren Myneni, Jens Axboe, Nathan Lynch, and
Russell Currey.

* tag 'powerpc-6.3-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/pseries/vas: Ignore VAS update for DLPAR if copy/paste is not enabled
  powerpc: Don't try to copy PPR for task with NULL pt_regs
  powerpc/64s: Fix __pte_needs_flush() false positive warning

Pull cifs client fixes from Steve French:
 "Four cifs/smb3 client (reconnect and DFS related) fixes, including two
  for stable:

   - DFS oops fix

   - DFS reconnect recursion fix

   - An SMB1 parallel reconnect fix

   - Trivial dead code removal in smb2_reconnect"

* tag '6.3-rc4-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: get rid of dead check in smb2_reconnect()
  cifs: prevent infinite recursion in CIFSGetDFSRefer()
  cifs: avoid races in parallel reconnects in smb1
  cifs: fix DFS traversal oops without CONFIG_CIFS_DFS_UPCALL