Pull btrfs fixes from David Sterba:
 "A few more fixes.

  Besides the one-liners in Btrfs there's fix to the io_uring and
  encoded read integration (added in this development cycle). The update
  to io_uring provides more space for the ongoing command that is then
  used in Btrfs to handle some cases.

   - io_uring and encoded read:
       - provide stable storage for io_uring command data
       - make a copy of encoded read ioctl call, reuse that in case the
         call would block and will be called again

   - properly initialize zlib context for hardware compression on s390

   - fix max extent size calculation on filesystems with non-zoned
     devices

   - fix crash in scrub on crafted image due to invalid extent tree"

* tag 'for-6.13-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: zlib: fix avail_in bytes for s390 zlib HW compression path
  btrfs: zoned: calculate max_extent_size properly on non-zoned setup
  btrfs: avoid NULL pointer dereference if no valid extent tree
  btrfs: don't read from userspace twice in btrfs_uring_encoded_read()
  io_uring: add io_uring_cmd_get_async_data helper
  io_uring/cmd: add per-op data to struct io_uring_cmd_data
  io_uring/cmd: rename struct uring_cache to io_uring_cmd_data

In case an op handler for ->uring_cmd() needs stable storage for user
data, it can allocate io_uring_cmd_data->op_data and use it for the
duration of the request. When the request gets cleaned up, uring_cmd
will free it automatically.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: David Sterba <dsterba@suse.com>

In preparation for making this more generically available for
->uring_cmd() usage that needs stable command data, rename it and move
it to io_uring/cmd.h instead.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: David Sterba <dsterba@suse.com>

Change the type of the res2 parameter in io_uring_cmd_done from ssize_t
to u64. This aligns the parameter type with io_req_set_cqe32_extra,
which expects u64 arguments.
The change eliminates potential issues on 32-bit architectures where
ssize_t might be 32-bit.

Only user of passing res2 is drivers/nvme/host/ioctl.c and it actually
passes u64.

Fixes: ee692a21e9bf ("fs,io_uring: add infrastructure for uring-cmd")
Cc: stable@vger.kernel.org
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Tested-by: Li Zetao <lizetao1@huawei.com>
Reviewed-by: Li Zetao <lizetao1@huawei.com>
Signed-off-by: Bernd Schubert <bschubert@ddn.com>
Link: https://lore.kernel.org/r/20241203-io_uring_cmd_done-res2-as-u64-v2-1-5e59ae617151@ddn.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull io_uring updates from Jens Axboe:

 - Cleanups of the eventfd handling code, making it fully private.

 - Support for sending a sync message to another ring, without having a
   ring available to send a normal async message.

 - Get rid of the separate unlocked hash table, unify everything around
   the single locked one.

 - Add support for ring resizing. It can be hard to appropriately size
   the CQ ring upfront, if the application doesn't know how busy it will
   be. This results in applications sizing rings for the most busy case,
   which can be wasteful. With ring resizing, they can start small and
   grow the ring, if needed.

 - Add support for fixed wait regions, rather than needing to copy the
   same wait data tons of times for each wait operation.

 - Rewrite the resource node handling, which before was serialized per
   ring. This caused issues with particularly fixed files, where one
   file waiting on IO could hold up putting and freeing of other
   unrelated files. Now each node is handled separately. New code is
   much simpler too, and was a net 250 line reduction in code.

 - Add support for just doing partial buffer clones, rather than always
   cloning the entire buffer table.

 - Series adding static NAPI support, where a specific NAPI instance is
   used rather than having a list of them available that need lookup.

 - Add support for mapped regions, and also convert the fixed wait
   support mentioned above to that concept. This avoids doing special
   mappings for various planned features, and folds the existing
   registered wait into that too.

 - Add support for hybrid IO polling, which is a variant of strict
   IOPOLL but with an initial sleep delay to avoid spinning too early
   and wasting resources on devices that aren't necessarily in the < 5
   usec category wrt latencies.

 - Various cleanups and little fixes.

* tag 'for-6.13/io_uring-20241118' of git://git.kernel.dk/linux: (79 commits)
  io_uring/region: fix error codes after failed vmap
  io_uring: restore back registered wait arguments
  io_uring: add memory region registration
  io_uring: introduce concept of memory regions
  io_uring: temporarily disable registered waits
  io_uring: disable ENTER_EXT_ARG_REG for IOPOLL
  io_uring: fortify io_pin_pages with a warning
  switch io_msg_ring() to CLASS(fd)
  io_uring: fix invalid hybrid polling ctx leaks
  io_uring/uring_cmd: fix buffer index retrieval
  io_uring/rsrc: add & apply io_req_assign_buf_node()
  io_uring/rsrc: remove '->ctx_ptr' of 'struct io_rsrc_node'
  io_uring/rsrc: pass 'struct io_ring_ctx' reference to rsrc helpers
  io_uring: avoid normal tw intermediate fallback
  io_uring/napi: add static napi tracking strategy
  io_uring/napi: clean up __io_napi_do_busy_loop
  io_uring/napi: Use lock guards
  io_uring/napi: improve __io_napi_add
  io_uring/napi: fix io_napi_entry RCU accesses
  io_uring/napi: protect concurrent io_napi_entry timeout accesses
  ...

Add back buffer index retrieval for IORING_URING_CMD_FIXED.

Reported-by: Guangwu Zhang <guazhang@redhat.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Fixes: b54a14041ee6 ("io_uring/rsrc: add io_rsrc_node_lookup() helper")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Tested-by: Guangwu Zhang <guazhang@redhat.com>
Link: https://lore.kernel.org/r/20241111101318.1387557-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

When the taks that submitted a request is dying, a task work for that
request might get run by a kernel thread or even worse by a half
dismantled task. We can't just cancel the task work without running the
callback as the cmd might need to do some clean up, so pass a flag
instead. If set, it's not safe to access any task resources and the
callback is expected to cancel the cmd ASAP.

Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>

The following pattern becomes more and more:

+       io_req_assign_rsrc_node(&req->buf_node, node);
+       req->flags |= REQ_F_BUF_NODE;

so make it a helper, which is less fragile to use than above code, for
example, the BUF_NODE flag is even missed in current io_uring_cmd_prep().

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241107110149.890530-4-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Rather than store the task_struct itself in struct io_kiocb, store
the io_uring specific task_struct. The life times are the same in terms
of io_uring, and this avoids doing some dereferences through the
task_struct. For the hot path of putting local task references, we can
deref req->tctx instead, which we'll need anyway in that function
regardless of whether it's local or remote references.

This is mostly straight forward, except the original task PF_EXITING
check needs a bit of tweaking. task_work is _always_ run from the
originating task, except in the fallback case, where it's run from a
kernel thread. Replace the potentially racy (in case of fallback work)
checks for req->task->flags with current->flags. It's either the still
the original task, in which case PF_EXITING will be sane, or it has
PF_KTHREAD set, in which case it's fallback work. Both cases should
prevent moving forward with the given request.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

Right now the task_struct pointer is used as the key to match a task,
but in preparation for some io_kiocb changes, move it to using struct
io_uring_task instead. No functional changes intended in this patch.

Signed-off-by: Jens Axboe <axboe@kernel.dk>