`rustfmt`, by default, formats imports in a way that is prone to conflicts
while merging and rebasing, since in some cases it condenses several
items into the same line.

For instance, Linus mentioned [1] that the following case:

use crate::{
fmt,
page::AsPageIter,
};

is compressed by `rustfmt` into:

use crate::{fmt, page::AsPageIter};

which is undesirable.

Similarly, `rustfmt` may put several items in the same line even if the
braces span already multiple lines, e.g.:

use kernel::{
acpi, c_str,
device::{property, Core},
of, platform,
};

The options that control the formatting behavior around imports are
generally unstable, and `rustfmt` releases do not allow to use nightly
features, unlike the compiler and other Rust tooling [2].

For the moment, we can introduce a workaround to prevent `rustfmt`
from compressing the example above -- the "trailing empty comment":

use crate::{
fmt,
page::AsPageIter, //
};

which is reminiscent of the trailing comma behavior in other formatters.
We already used empty comments for formatting purposes in the past,
e.g. in commit b9b701fce49a ("rust: clarify the language unstable features
in use").

In addition, `rustfmt` actually reformats with a vertical layout (i.e. it
does not put two items in the same line) when seeing such a comment,
i.e. it doesn't just preserve the formatting, which is good in the sense
that we can use it to easily reformat some imports, since it matches
the style we generally want to have.

A Git merge driver would help (suggested by Gary and Wedson), though
maintainers would need to set it up, the diffs would still be larger
and the formatting rules for imports would remain hard to predict.

Thus document the style that we will follow in the coding guidelines
by introducing a new section and explain how the trailing empty comment
works there too.

We discussed the issue with upstream Rust in our usual Rust <-> Rust
for Linux meeting [3], and there have also been a few other discussions
in parallel in issues [4][5] and Zulip [6]. We will see what happens,
but upstream Rust has already created a subteam of `rustfmt` to try
to overcome the bandwidth issue [7], which is a good signal, and some
organization work has already started (e.g. tracking issues). We will
continue our discussions with them about it.

Cc: Caleb Cartwright <caleb.cartwright@outlook.com>
Cc: Yacin Tmimi <yacintmimi@gmail.com>
Cc: Manish Goregaokar <manishsmail@gmail.com>
Cc: Deadbeef <ent3rm4n@gmail.com>
Cc: Cameron Steffen <cam.steffen94@gmail.com>
Cc: Jieyou Xu <jieyouxu@outlook.com>
Link: https://lore.kernel.org/all/CAHk-=wgO7S_FZUSBbngG5vtejWOpzDfTTBkVvP3_yjJmFddbzA@mail.gmail.com/ [1]
Link: https://github.com/rust-lang/rustfmt/issues/4884 [2]
Link: https://hackmd.io/iSCyY3JTTz-g8YM-nnzTTA [3]
Link: https://github.com/rust-lang/rustfmt/issues/4991 [4]
Link: https://github.com/rust-lang/rustfmt/issues/3361 [5]
Link: https://rust-lang.zulipchat.com/#narrow/channel/392734-council/topic/rustfmt.20maintenance/near/543815381 [6]
Link: https://github.com/rust-lang/team/pull/2017 [7]
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Pull f2fs fixes from Jaegeuk Kim:

- fix soft lockupg caused by iput() added in bc986b1d756482a ("fs: stop
accessing ->i_count directly in f2fs and gfs2")

- fix a wrong block address map on multiple devices

Link: https://lore.kernel.org/oe-lkp/202509301450.138b448f-lkp@intel.com [1]

* tag 'f2fs-fix-6.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs:
f2fs: fix wrong block mapping for multi-devices
f2fs: don't call iput() from f2fs_drop_inode()

Pull btrfs fixes from David Sterba:

- in tree-checker fix extref bounds check

- reorder send context structure to avoid
-Wflex-array-member-not-at-end warning

- fix extent readahead length for compressed extents

- fix memory leaks on error paths (qgroup assign ioctl, zone loading
with raid stripe tree enabled)

- fix how device specific mount options are applied, in particular the
'ssd' option will be set unexpectedly

- fix tracking of relocation state when tasks are running and
cancellation is attempted

- adjust assertion condition for folios allocated for scrub

- remove incorrect assertion checking for block group when populating
free space tree

* tag 'for-6.18-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: send: fix -Wflex-array-member-not-at-end warning in struct send_ctx
btrfs: tree-checker: fix bounds check in check_inode_extref()
btrfs: fix memory leaks when rejecting a non SINGLE data profile without an RST
btrfs: fix incorrect readahead expansion length
btrfs: do not assert we found block group item when creating free space tree
btrfs: do not use folio_test_partial_kmap() in ASSERT()s
btrfs: only set the device specific options after devices are opened
btrfs: fix memory leak on duplicated memory in the qgroup assign ioctl
btrfs: fix clearing of BTRFS_FS_RELOC_RUNNING if relocation already running

Assuming the disk layout as below,

disk0: 0 --- 0x00035abfff
disk1: 0x00035ac000 --- 0x00037abfff
disk2: 0x00037ac000 --- 0x00037ebfff

and we want to read data from offset=13568 having len=128 across the block
devices, we can illustrate the block addresses like below.

0 .. 0x00037ac000 ------------------- 0x00037ebfff, 0x00037ec000 -------
| ^ ^ ^
| fofs 0 13568 13568+128
| ------------------------------------------------------
| LBA 0x37e8aa9 0x37ebfa9 0x37ec029
--- map 0x3caa9 0x3ffa9

In this example, we should give the relative map of the target block device
ranging from 0x3caa9 to 0x3ffa9 where the length should be calculated by
0x37ebfff + 1 - 0x37ebfa9.

In the below equation, however, map->m_pblk was supposed to be the original
address instead of the one from the target block address.

- map->m_len = min(map->m_len, dev->end_blk + 1 - map->m_pblk);

Cc: stable@vger.kernel.org
Fixes: 71f2c8206202 ("f2fs: multidevice: support direct IO")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Pull smb server fixes from Steve French:

- Fix RPC hang due to locking bug

- Fix for memory leak in read and refcount leak (in session setup)

- Minor cleanup

* tag 'v6.18-rc1-smb-server-fixes' of git://git.samba.org/ksmbd:
ksmbd: fix recursive locking in RPC handle list access
smb/server: fix possible refcount leak in smb2_sess_setup()
smb/server: fix possible memory leak in smb2_read()
smb: server: Use common error handling code in smb_direct_rdma_xmit()

The warning -Wflex-array-member-not-at-end was introduced in GCC-14, and
we are getting ready to enable it, globally.

Fix the following warning:

fs/btrfs/send.c:181:24: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]

and move the declaration of send_ctx::cur_inode_path to the end.

Notice that struct fs_path contains a flexible array member inline_buf,
but also a padding array and a limit calculated for the usable space of
inline_buf (FS_PATH_INLINE_SIZE). It is not the pattern where flexible
array is in the middle of a structure and could potentially overwrite
other members.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

iput() calls the problematic routine, which does a ->i_count inc/dec
cycle. Undoing it with iput() recurses into the problem.

Note f2fs should not be playing games with the refcount to begin with,
but that will be handled later. Right now solve the immediate
regression.

Fixes: bc986b1d756482a ("fs: stop accessing ->i_count directly in f2fs and gfs2")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202509301450.138b448f-lkp@intel.com
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Pull networking fixes from Paolo Abeni:
"Including fixes from CAN

Current release - regressions:

- udp: do not use skb_release_head_state() before
skb_attempt_defer_free()

- gro_cells: use nested-BH locking for gro_cell

- dpll: zl3073x: increase maximum size of flash utility

Previous releases - regressions:

- core: fix lockdep splat on device unregister

- tcp: fix tcp_tso_should_defer() vs large RTT

- tls:
- don't rely on tx_work during send()
- wait for pending async decryptions if tls_strp_msg_hold fails

- can: j1939: add missing calls in NETDEV_UNREGISTER notification
handler

- eth: lan78xx: fix lost EEPROM write timeout in
lan78xx_write_raw_eeprom

Previous releases - always broken:

- ip6_tunnel: prevent perpetual tunnel growth

- dpll: zl3073x: handle missing or corrupted flash configuration

- can: m_can: fix pm_runtime and CAN state handling

- eth:
- ixgbe: fix too early devlink_free() in ixgbe_remove()
- ixgbevf: fix mailbox API compatibility
- gve: Check valid ts bit on RX descriptor before hw timestamping
- idpf: cleanup remaining SKBs in PTP flows
- r8169: fix packet truncation after S4 resume on RTL8168H/RTL8111H"

* tag 'net-6.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (50 commits)
udp: do not use skb_release_head_state() before skb_attempt_defer_free()
net: usb: lan78xx: fix use of improperly initialized dev->chipid in lan78xx_reset
netdevsim: set the carrier when the device goes up
selftests: tls: add test for short splice due to full skmsg
selftests: net: tls: add tests for cmsg vs MSG_MORE
tls: don't rely on tx_work during send()
tls: wait for pending async decryptions if tls_strp_msg_hold fails
tls: always set record_type in tls_process_cmsg
tls: wait for async encrypt in case of error during latter iterations of sendmsg
tls: trim encrypted message to match the plaintext on short splice
tg3: prevent use of uninitialized remote_adv and local_adv variables
MAINTAINERS: new entry for IPv6 IOAM
gve: Check valid ts bit on RX descriptor before hw timestamping
net: core: fix lockdep splat on device unregister
MAINTAINERS: add myself as maintainer for b53
selftests: net: check jq command is supported
net: airoha: Take into account out-of-order tx completions in airoha_dev_xmit()
tcp: fix tcp_tso_should_defer() vs large RTT
r8152: add error handling in rtl8152_driver_init
usbnet: Fix using smp_processor_id() in preemptible code warnings
...

Since commit 305853cce3794 ("ksmbd: Fix race condition in RPC handle list
access"), ksmbd_session_rpc_method() attempts to lock sess->rpc_lock.

This causes hung connections / tasks when a client attempts to open
a named pipe. Using Samba's rpcclient tool:

$ rpcclient //192.168.1.254 -U user%password
$ rpcclient $> srvinfo
<connection hung here>

Kernel side:
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:0 state:D stack:0 pid:5021 tgid:5021 ppid:2 flags:0x00200000
Workqueue: ksmbd-io handle_ksmbd_work
Call trace:
__schedule from schedule+0x3c/0x58
schedule from schedule_preempt_disabled+0xc/0x10
schedule_preempt_disabled from rwsem_down_read_slowpath+0x1b0/0x1d8
rwsem_down_read_slowpath from down_read+0x28/0x30
down_read from ksmbd_session_rpc_method+0x18/0x3c
ksmbd_session_rpc_method from ksmbd_rpc_open+0x34/0x68
ksmbd_rpc_open from ksmbd_session_rpc_open+0x194/0x228
ksmbd_session_rpc_open from create_smb2_pipe+0x8c/0x2c8
create_smb2_pipe from smb2_open+0x10c/0x27ac
smb2_open from handle_ksmbd_work+0x238/0x3dc
handle_ksmbd_work from process_scheduled_works+0x160/0x25c
process_scheduled_works from worker_thread+0x16c/0x1e8
worker_thread from kthread+0xa8/0xb8
kthread from ret_from_fork+0x14/0x38
Exception stack(0x8529ffb0 to 0x8529fff8)

The task deadlocks because the lock is already held:
ksmbd_session_rpc_open
down_write(&sess->rpc_lock)
ksmbd_rpc_open
ksmbd_session_rpc_method
down_read(&sess->rpc_lock) <-- deadlock

Adjust ksmbd_session_rpc_method() callers to take the lock when necessary.

Fixes: 305853cce3794 ("ksmbd: Fix race condition in RPC handle list access")
Signed-off-by: Marios Makassikis <mmakassikis@freebox.fr>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

The parentheses for the unlikely() annotation were put in the wrong
place so it means that the condition is basically never true and the
bounds checking is skipped.

Fixes: aab9458b9f00 ("btrfs: tree-checker: add inode extref checks")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Pull ata fix from Niklas Cassel:

- Do not print an error message (and assume that the General Purpose
Log Directory log page is not supported) for a device that reports a
bogus General Purpose Logging Version.

Unsurprisingly, many vendors fail to report the only valid General
Purpose Logging Version (Damien)

* tag 'ata-6.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/libata/linux:
ata: libata-core: relax checks in ata_read_log_directory()

Michal reported and bisected an issue after recent adoption
of skb_attempt_defer_free() in UDP.

The issue here is that skb_release_head_state() is called twice per skb,
one time from skb_consume_udp(), then a second time from skb_defer_free_flush()
and napi_consume_skb().

As Sabrina suggested, remove skb_release_head_state() call from
skb_consume_udp().

Add a DEBUG_NET_WARN_ON_ONCE(skb_nfct(skb)) in skb_attempt_defer_free()

Many thanks to Michal, Sabrina, Paolo and Florian for their help.

Fixes: 6471658dc66c ("udp: use skb_attempt_defer_free()")
Reported-and-bisected-by: Michal Kubecek <mkubecek@suse.cz>
Closes: https://lore.kernel.org/netdev/gpjh4lrotyephiqpuldtxxizrsg6job7cvhiqrw72saz2ubs3h@g6fgbvexgl3r/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Michal Kubecek <mkubecek@suse.cz>
Cc: Sabrina Dubroca <sd@queasysnail.net>
Cc: Florian Westphal <fw@strlen.de>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://patch.msgid.link/20251015052715.4140493-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Reference count of ksmbd_session will leak when session need reconnect.
Fix this by adding the missing ksmbd_user_session_put().

Co-developed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: ZhangGuoDong <zhangguodong@kylinos.cn>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

At the end of btrfs_load_block_group_zone_info() the first thing we do
is to ensure that if the mapping type is not a SINGLE one and there is
no RAID stripe tree, then we return early with an error.

Doing that, though, prevents the code from running the last calls from
this function which are about freeing memory allocated during its
run. Hence, in this case, instead of returning early, we set the ret
value and fall through the rest of the cleanup code.

Fixes: 5906333cc4af ("btrfs: zoned: don't skip block group profile checks on conventional zones")
CC: stable@vger.kernel.org # 6.8+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Pull i2c fix from Wolfram Sang:
"One revert because of a regression in the I2C core which has sadly not
showed up during its time in -next"

* tag 'i2c-for-6.18-rc1-hotfix' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
Revert "i2c: boardinfo: Annotate code used in init phase only"