md: factor out a helper to wake up md_thread directly

md_wakeup_thread() can't wakeup md_thread->tsk if md_thread->run is
still in progress, and in some cases md_thread->tsk need to be woke up
directly, like md_set_readonly() and do_md_stop().

Commit 9dfbdafda3b3 ("md: unlock mddev before reap sync_thread in
action_store") introduce a new scenario where unregister sync_thread is
not protected by 'reconfig_mutex', this can cause null-ptr-deference in
theroy:

t1: md_set_readonly t2: action_store
md_unregister_thread
// 'reconfig_mutex' is not held
// 'reconfig_mutex' is held by caller
if (mddev->sync_thread)
 thread = *threadp
 *threadp = NULL
 wake_up_process(mddev->sync_thread->tsk)
 // null-ptr-deference

Fix this problem by factoring out a helper to wake up md_thread directly,
so that 'sync_thread' won't be accessed multiple times from the reader
side. This helper also prepare to protect md_thread with rcu.

Noted that later patches is going to fix that unregister sync_thread is
not protected by 'reconfig_mutex' from action_store().

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230523021017.3048783-2-yukuai1@huaweicloud.com

md: fix duplicate filename for rdev

Commit 5792a2856a63 ("[PATCH] md: avoid a deadlock when removing a device
from an md array via sysfs") delays the deletion of rdev, however, this
introduces a window that rdev can be added again while the deletion is
not done yet, and sysfs will complain about duplicate filename.

Follow up patches try to fix this problem by flushing workqueue, however,
flush_rdev_wq() is just dead code, the progress in
md_kick_rdev_from_array():

1) list_del_rcu(&rdev->same_set);
2) synchronize_rcu();
3) queue_work(md_rdev_misc_wq, &rdev->del_work);

So in flush_rdev_wq(), if rdev is found in the list, work_pending() can
never pass, in the meantime, if work is queued, then rdev can never be
found in the list.

flush_rdev_wq() can be replaced by flush_workqueue() directly, however,
this approach is not good:
- the workqueue is global, this synchronization for all raid disks is
  not necessary.
- flush_workqueue can't be called under 'reconfig_mutex', there is still
  a small window between flush_workqueue() and mddev_lock() that other
  contexts can queue new work, hence the problem is not solved completely.

sysfs already has apis to support delete itself through writer, and
these apis, specifically sysfs_break/unbreak_active_protection(), is used
to support deleting rdev synchronously. Therefore, the above commit can be
reverted, and sysfs duplicate filename can be avoided.

A new mdadm regression test is proposed as well([1]).

[1] https://lore.kernel.org/linux-raid/20230428062845.1975462-1-yukuai1@huaweicloud.com/

Fixes: 5792a2856a63 ("[PATCH] md: avoid a deadlock when removing a device from an md array via sysfs")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230523012727.3042247-1-yukuai1@huaweicloud.com

md/raid10: fix wrong setting of max_corr_read_errors

There is no input check when echo md/max_read_errors and overflow might
occur. Add check of input number.

Fixes: 1e50915fe0bb ("raid: improve MD/raid10 handling of correctable read errors.")
Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230522072535.1523740-3-linan666@huaweicloud.com

md/raid10: fix overflow of md/safe_mode_delay

There is no input check when echo md/safe_mode_delay in safe_delay_store().
And msec might also overflow when HZ < 1000 in safe_delay_show(), Fix it by
checking overflow in safe_delay_store() and use unsigned long conversion in
safe_delay_show().

Fixes: 72e02075a33f ("md: factor out parsing of fixed-point numbers")
Signed-off-by: Li Nan <linan122@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230522072535.1523740-2-linan666@huaweicloud.com

md/raid5: fix a deadlock in the case that reshape is interrupted

If reshape is in progress and io across reshape_position is issued, such
io will wait for reshape to make progress(see details in the case that
make_stripe_request() return STRIPE_SCHEDULE_AND_RETRY).

It has been reported several times that if system reboot while growing
raid5 to raid6, array assemble will hang infinitely([1, 2]). This is
because following deadlock is triggered:

1) a normal io is waiting for reshape to progress, this io can be from
   system-udevd or mdadm.
2) while assemble, mdadm tries to suspend the array, hence
   'reconfig_mutex' is held and mddev_suspend() must wait for normal io
   to be done.
3) daemon thread can't start reshape because 'reconfig_mutex' can't be
   held.

1) and 3) is unbreakable because they're foundation design. In order to
break 2), following is possible solutions that I can think of:

a) Let mddev_suspend() fail is not a good option, because this will
   break many scenarios since mddev_suspend() doesn't fail before.
b) Fail the io that is waiting for reshape to make progress from
   mddev_suspend().
c) Return false for the io that is waiting for reshape to make
   progress from raid5_make_request(), and these io will wait for
   suspend to be done in md_handle_request(), where 'active_io' is
   not grabbed.

c) sounds better than b), however, b) is used because it's easy and
straightforward, and it's verified that mdadm can assemble in this case.
On the other hand, c) breaks the logic that mddev_suspend() will wait
for submitted io to be completely handled.

Fix the problem by checking reshape in mddev_suspend(), if reshape can't
make progress and there are still some io waiting for reshape, fail
those io.

[1] https://lore.kernel.org/all/CAFig2csUV2QiomUhj_t3dPOgV300dbQ6XtM9ygKPdXJFSH__Nw@mail.gmail.com/
[2] https://lore.kernel.org/all/CAO2ABipzbw6QL5eNa44CQHjiVa-LTvS696Mh9QaTw+qsUKFUCw@mail.gmail.com/

Reported-by: Jove <jovetoo@gmail.com>
Reported-by: David Gilmour <dgilmour76@gmail.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230512015610.821290-6-yukuai1@huaweicloud.com

md: add a new api prepare_suspend() in md_personality

There are no functional changes, the new api will be used later to do
special handling for raid456 in md_suspend().

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230512015610.821290-5-yukuai1@huaweicloud.com

md: export md_is_rdwr() and is_md_suspended()

The two apis will be used later to fix a deadlock in raid456, there are
no functional changes.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230512015610.821290-4-yukuai1@huaweicloud.com

md: fix data corruption for raid456 when reshape restart while grow up

Currently, if reshape is interrupted, echo "reshape" to sync_action will
restart reshape from scratch, for example:

echo frozen > sync_action
echo reshape > sync_action

This will corrupt data before reshape_position if the array is growing,
fix the problem by continue reshape from reshape_position.

Reported-by: Peter Neuwirth <reddunur@online.de>
Link: https://lore.kernel.org/linux-raid/e2f96772-bfbc-f43b-6da1-f520e5164536@online.de/
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230512015610.821290-3-yukuai1@huaweicloud.com

md/raid5: don't allow replacement while reshape is in progress

If reshape is interrupted(for example, echo frozen to sync_action), then
rdev replacement can be set. It's safe because reshape is always prior to
resync in md_check_recovery(). However, if system reboots, then kernel will
complain cannot handle concurrent replacement and reshape and this array
is not able to assemble anymore.

Fix this problem by don't allow replacement until reshape is done.

Reported-by: Peter Neuwirth <reddunur@online.de>
Link: https://lore.kernel.org/linux-raid/e2f96772-bfbc-f43b-6da1-f520e5164536@online.de/
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230512015610.821290-2-yukuai1@huaweicloud.com

md/raid10: check slab-out-of-bounds in md_bitmap_get_counter

If we write a large number to md/bitmap_set_bits, md_bitmap_checkpage()
will return -EINVAL because 'page >= bitmap->pages', but the return value
was not checked immediately in md_bitmap_get_counter() in order to set
*blocks value and slab-out-of-bounds occurs.

Move check of 'page >= bitmap->pages' to md_bitmap_get_counter() and
return directly if true.

Fixes: ef4256733506 ("md/bitmap: optimise scanning of empty bitmaps.")
Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230515134808.3936750-2-linan666@huaweicloud.com

raid6: neon: add missing prototypes

The raid6 syndrome functions are generated for different sizes and have
no generic prototype, while in the inner functions have a prototype
in a header that cannot be included from the correct file. In both
cases, the compiler warns about missing prototypes:

lib/raid6/recov_neon_inner.c:27:6: warning: no previous prototype for '__raid6_2data_recov_neon' [-Wmissing-prototypes]
lib/raid6/recov_neon_inner.c:77:6: warning: no previous prototype for '__raid6_datap_recov_neon' [-Wmissing-prototypes]
lib/raid6/neon1.c:56:6: warning: no previous prototype for 'raid6_neon1_gen_syndrome_real' [-Wmissing-prototypes]
lib/raid6/neon1.c:86:6: warning: no previous prototype for 'raid6_neon1_xor_syndrome_real' [-Wmissing-prototypes]
lib/raid6/neon2.c:56:6: warning: no previous prototype for 'raid6_neon2_gen_syndrome_real' [-Wmissing-prototypes]
lib/raid6/neon2.c:97:6: warning: no previous prototype for 'raid6_neon2_xor_syndrome_real' [-Wmissing-prototypes]
lib/raid6/neon4.c:56:6: warning: no previous prototype for 'raid6_neon4_gen_syndrome_real' [-Wmissing-prototypes]
lib/raid6/neon4.c:119:6: warning: no previous prototype for 'raid6_neon4_xor_syndrome_real' [-Wmissing-prototypes]
lib/raid6/neon8.c:56:6: warning: no previous prototype for 'raid6_neon8_gen_syndrome_real' [-Wmissing-prototypes]
lib/raid6/neon8.c:163:6: warning: no previous prototype for 'raid6_neon8_xor_syndrome_real' [-Wmissing-prototypes]

Add a new header file that contains the prototypes for both to avoid
the warnings.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230517132220.937200-1-arnd@kernel.org

swim3: fix the floppy_locked_ioctl prototype

Add back the accidentally dropped mode parameter.

Fixes: b60f7635788a ("swim3: fix the floppy_locked_ioctl prototype")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230613154309.327557-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

blk-mq: fix potential io hang by wrong 'wake_batch'

In __blk_mq_tag_busy/idle(), updating 'active_queues' and calculating
'wake_batch' is not atomic:

t1: t2:
_blk_mq_tag_busy blk_mq_tag_busy
inc active_queues
// assume 1->2
inc active_queues
// 2 -> 3
blk_mq_update_wake_batch
// calculate based on 3
blk_mq_update_wake_batch
/* calculate based on 2, while active_queues is actually 3. */

Fix this problem by protecting them wih 'tags->lock', this is not a hot
path, so performance should not be concerned. And now that all writers
are inside the lock, switch 'actives_queues' from atomic to unsigned
int.

Fixes: 180dccb0dba4 ("blk-mq: fix tag_get wait task can't be awakened")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230610023043.2559121-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs: remove the now unused FMODE_* flags

FMODE_NDELAY, FMODE_EXCL and FMODE_WRITE_IOCTL were only used for
block internal purposed and are now entirely unused, so remove them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-31-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: store the holder in file->private_data

Store the file struct used as the holder in file->private_data as an
indicator that this file descriptor was opened exclusively to  remove
the last use of FMODE_EXCL.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20230608110258.189493-30-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: always use I_BDEV on file->f_mapping->host to find the bdev

Always use I_BDEV(file->f_mapping->host) to find the bdev for a file to
free up file->private_data for other uses.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-29-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: replace fmode_t with a block-specific type for block open flags

The only overlap between the block open flags mapped into the fmode_t and
other uses of fmode_t are FMODE_READ and FMODE_WRITE.  Define a new
blk_mode_t instead for use in blkdev_get_by_{dev,path}, ->open and
->ioctl and stop abusing fmode_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jack Wang <jinpu.wang@ionos.com> [rnbd]
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-28-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: remove unused fmode_t arguments from ioctl handlers

A few ioctl handlers have fmode_t arguments that are entirely unused,
remove them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20230608110258.189493-27-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: move a few internal definitions out of blkdev.h

All these helpers are only used in core block code, so move them out of
the public header.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-26-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

ubd: remove commented out code in ubd_open

This code has been dead forever, make sure it doesn't show up in code
searches.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: Richard Weinberger <richard@nod.at>
Link: https://lore.kernel.org/r/20230608110258.189493-25-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

rnbd-srv: replace sess->open_flags with a "bool readonly"

Stop passing the fmode_t around and just use a simple bool to track if
an export is read-only.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Link: https://lore.kernel.org/r/20230608110258.189493-24-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

mtd: block: use a simple bool to track open for write

Instead of propagating the fmode_t, just use a bool to track if a mtd
block device was opened for writing.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: Richard Weinberger <richard@nod.at>
Link: https://lore.kernel.org/r/20230608110258.189493-23-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nvme: replace the fmode_t argument to the nvme ioctl handlers with a simple bool

Instead of passing a fmode_t and only checking it fo0r FMODE_WRITE, pass
a bool open_for_write to prepare for callers that won't have the fmode_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-22-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: replace the fmode_t argument to ->sg_io_fn with a simple bool

Instead of passing a fmode_t and only checking it for FMODE_WRITE, pass
a bool open_for_write to prepare for callers that won't have the fmode_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-21-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: replace the fmode_t argument to scsi_ioctl with a simple bool

Instead of passing a fmode_t and only checking it for FMODE_WRITE, pass
a bool open_for_write to prepare for callers that won't have the fmode_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-20-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: replace the fmode_t argument to scsi_cmd_allowed with a simple bool

Instead of passing a fmode_t and only checking it for FMODE_WRITE, pass
a bool open_for_write to prepare for callers that won't have the fmode_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-19-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs: remove sb->s_mode

There is no real need to store the open mode in the super_block now.
It is only used by f2fs, which can easily recalculate it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-18-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: add a sb_open_mode helper

Add a helper to return the open flags for blkdev_get_by* for passed in
super block flags instead of open coding the logic in many places.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-17-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: use the holder as indication for exclusive opens

The current interface for exclusive opens is rather confusing as it
requires both the FMODE_EXCL flag and a holder.  Remove the need to pass
FMODE_EXCL and just key off the exclusive open off a non-NULL holder.

For blkdev_put this requires adding the holder argument, which provides
better debug checking that only the holder actually releases the hold,
but at the same time allows removing the now superfluous mode argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
Acked-by: Jack Wang <jinpu.wang@ionos.com> [rnbd]
Link: https://lore.kernel.org/r/20230608110258.189493-16-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

btrfs: don't pass a holder for non-exclusive blkdev_get_by_path

Passing a holder to blkdev_get_by_path when FMODE_EXCL isn't set doesn't
make sense, so pass NULL instead and remove the holder argument from the
call chains the only end up in non-FMODE_EXCL blkdev_get_by_path calls.

Exclusive mode for device scanning is not used since commit 50d281fc434c
("btrfs: scan device in non-exclusive mode")".

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: David Sterba <dsterba@suse.com>
Link: https://lore.kernel.org/r/20230608110258.189493-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

rnbd-srv: don't pass a holder for non-exclusive blkdev_get_by_path

Passing a holder to blkdev_get_by_path when FMODE_EXCL isn't set doesn't
make sense, so pass NULL instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Link: https://lore.kernel.org/r/20230608110258.189493-14-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

bcache: don't pass a stack address to blkdev_get_by_path

sb is just an on-stack pointer that can easily be reused by other calls.
Switch to use the bcache-wide bcache_kobj instead as there is no need to
claim per-bcache device anyway.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20230608110258.189493-13-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

swsusp: don't pass a stack address to blkdev_get_by_path

holder is just an on-stack pointer that can easily be reused by other calls,
replace it with a static variable that doesn't change.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-12-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: rename blkdev_close to blkdev_release

Make the function name match the method name.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-11-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: remove the unused mode argument to ->release

The mode argument to the ->release block_device_operation is never used,
so remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: Jack Wang <jinpu.wang@ionos.com> [rnbd]
Link: https://lore.kernel.org/r/20230608110258.189493-10-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: pass a gendisk to ->open

->open is only called on the whole device.  Make that explicit by
passing a gendisk instead of the block_device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: Jack Wang <jinpu.wang@ionos.com> [rnbd]
Link: https://lore.kernel.org/r/20230608110258.189493-9-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: pass a gendisk on bdev_check_media_change

bdev_check_media_change should only ever be called for the whole device.
Pass a gendisk to make that explicit and rename the function to
disk_check_media_change.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

cdrom: remove the unused mode argument to cdrom_release

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Phillip Potter <phil@philpotter.co.uk>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

cdrom: track if a cdrom_device_info was opened for data

Set a flag when a cdrom_device_info is opened for writing, instead of
trying to figure out this at release time.  This will allow to eventually
remove the mode argument to the ->release block_device_operation as
nothing but the CDROM drivers uses that argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Phillip Potter <phil@philpotter.co.uk>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20230608110258.189493-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

cdrom: remove the unused cdrom_close_write release code

cdrom_close_write is empty, and the for_data flag it is keyed off is
never set.  Remove all this clutter.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Phillip Potter <phil@philpotter.co.uk>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

cdrom: remove the unused mode argument to cdrom_ioctl

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Phillip Potter <phil@philpotter.co.uk>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

cdrom: remove the unused bdev argument to cdrom_open

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Phillip Potter <phil@philpotter.co.uk>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: also call ->open for incremental partition opens

For whole devices ->open is called for each open, but for partitions it
is only called on the first open of a partition, e.g.:

  open("/dev/vdb", ...)
  open("/dev/vdb", ...)
    - 2 call to ->open

  open("/dev/vdb1", ...)
  open("/dev/vdb", ...)
    - 2 call to ->open

  open("/dev/vdb", ...)
  open("/dev/vdb", ...)
    - just open call to ->open

This is problematic as various block drivers look at open flags and
might not do all the required setup if the earlier open was with an
odd flag like O_NDELAY or the magic 3 ioctl-only open mode.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Phillip Potter <phil@philpotter.co.uk>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/rnbd-srv: make process_msg_sess_info returns void

Change the return type to void given it always returns 0.

Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20230524070026.2932-9-guoqing.jiang@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/rnbd-srv: init err earlier in rnbd_srv_init_module

With this, we can remove several lines of code.

Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20230524070026.2932-8-guoqing.jiang@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/rnbd-srv: init ret with 0 instead of -EPERM

Let's always set errno after pr_err which is consistent with
default case.

Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20230524070026.2932-7-guoqing.jiang@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/rnbd-srv: rename one member in rnbd_srv_dev

It actually represents the name of rnbd_srv_dev.

Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20230524070026.2932-6-guoqing.jiang@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/rnbd-srv: no need to check sess_dev

Check ret is enough since if sess_dev is NULL which also
implies ret should be 0.

Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20230524070026.2932-5-guoqing.jiang@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/rnbd: introduce rnbd_access_modes

Add one new array (marked with __maybe_unused to prevent gcc warning about
"defined but not used" with W=1), then we can remove rnbd_access_mode_str
and rnbd-common.c accordingly.

Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Link: https://lore.kernel.org/r/20230524070026.2932-4-guoqing.jiang@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/rnbd-srv: remove unused header

No need to include it since none of macros in limits.h are
used by rnbd-srv.

Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20230524070026.2932-3-guoqing.jiang@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/rnbd: kill rnbd_flags_supported

This routine is not called since added. Then the two flags
(RNBD_OP_LAST and RNBD_F_ALL) can be removed too after kill
rnbd_flags_supported.

Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20230524070026.2932-2-guoqing.jiang@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: fix rootwait= again

The previous rootwait fix added an -EINVAL return to a completely
bogus superflous branch, fix this.

Fixes: 1341c7d2ccf4 ("block: fix rootwait=")
Reported-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Fabio Estevam <festevam@gmail.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230609051737.328930-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

pktcdvd: Sort headers

Sort the headers in alphabetic order in order to ease
the maintenance for this part.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20230310164549.22133-10-andriy.shevchenko@linux.intel.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

pktcdvd: Get rid of redundant 'else'

In the snippets like the following

if (...)
return / goto / break / continue ...;
else
...

the 'else' is redundant. Get rid of it.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20230310164549.22133-9-andriy.shevchenko@linux.intel.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

pktcdvd: Use put_unaligned_be16() and get_unaligned_be16()

This makes the driver code slightly better to understand.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230310164549.22133-8-andriy.shevchenko@linux.intel.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

pktcdvd: Use DEFINE_SHOW_ATTRIBUTE() to simplify code

Use DEFINE_SHOW_ATTRIBUTE() helper macro to simplify the code.
No functional change.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20230310164549.22133-7-andriy.shevchenko@linux.intel.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

pktcdvd: Drop redundant castings for sector_t

Since the commit 72deb455b5ec ("block: remove CONFIG_LBDAF")
the sector_t is always 64-bit type, no need to cast anymore.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20230310164549.22133-6-andriy.shevchenko@linux.intel.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

pktcdvd: Get rid of pkt_seq_show() forward declaration

The code can be neater without forward declarations.
Get rid of pkt_seq_show() forward declaration. This
will also allow futher cleanups to be cleaner.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20230310164549.22133-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

pktcdvd: use sysfs_emit() to instead of scnprintf()

Follow the advice of the Documentation/filesystems/sysfs.rst and show()
should only use sysfs_emit() or sysfs_emit_at() when formatting the
value to be returned to user space.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20230310164549.22133-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

pktcdvd: replace sscanf() by kstrtoul()

The checkpatch.pl warns: "Prefer kstrto<type> to single variable sscanf".
Fix the code accordingly.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230310164549.22133-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

pktcdvd: Get rid of custom printing macros

We may use traditional dev_*() macros instead of custom ones
provided by the driver.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20230310164549.22133-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: fix rootwait=

Failures to look up the gendisk must return -ENODEV so that rootwait
retries the lookup instead of -EINVAL which exits early.

Fixes: cf056a431215 ("init: improve the name_to_dev_t interface")
Reported-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Fabio Estevam <festevam@gmail.com>
Link: https://lore.kernel.org/r/20230607135746.92995-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

blk-cgroup: Reinit blkg_iostat_set after clearing in blkcg_reset_stats()

When blkg_alloc() is called to allocate a blkcg_gq structure
with the associated blkg_iostat_set's, there are 2 fields within
blkg_iostat_set that requires proper initialization - blkg & sync.
The former field was introduced by commit 3b8cc6298724 ("blk-cgroup:
Optimize blkcg_rstat_flush()") while the later one was introduced by
commit f73316482977 ("blk-cgroup: reimplement basic IO stats using
cgroup rstat").

Unfortunately those fields in the blkg_iostat_set's are not properly
re-initialized when they are cleared in v1's blkcg_reset_stats(). This
can lead to a kernel panic due to NULL pointer access of the blkg
pointer. The missing initialization of sync is less problematic and
can be a problem in a debug kernel due to missing lockdep initialization.

Fix these problems by re-initializing them after memory clearing.

Fixes: 3b8cc6298724 ("blk-cgroup: Optimize blkcg_rstat_flush()")
Fixes: f73316482977 ("blk-cgroup: reimplement basic IO stats using cgroup rstat")
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230606180724.2455066-1-longman@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

blk-ioc: fix recursive spin_lock/unlock_irq() in ioc_clear_queue()

Recursive spin_lock/unlock_irq() is not safe, because spin_unlock_irq()
will enable irq unconditionally:

spin_lock_irq queue_lock -> disable irq
spin_lock_irq ioc->lock
spin_unlock_irq ioc->lock -> enable irq
/*
 * AA dead lock will be triggered if current context is preempted by irq,
 * and irq try to hold queue_lock again.
 */
spin_unlock_irq queue_lock

Fix this problem by using spin_lock/unlock() directly for 'ioc->lock'.

Fixes: 5a0ac57c48aa ("blk-ioc: protect ioc_destroy_icq() by 'queue_lock'")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230606011438.3743440-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

nbd: Add the maximum limit of allocated index in nbd_dev_add

If the index allocated by idr_alloc greater than MINORMASK >> part_shift,
the device number will overflow, resulting in failure to create a block
device.

Fix it by imiting the size of the max allocation.

Signed-off-by: Zhong Jinghua <zhongjinghua@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230605122159.2134384-1-zhongjinghua@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

blk-ioprio: Introduce promote-to-rt policy

Since commit a78418e6a04c ("block: Always initialize bio IO priority on
submit"), bio->bi_ioprio will never be IOPRIO_CLASS_NONE when calling
blkcg_set_ioprio(), so there will be no way to promote the io-priority
of one cgroup to IOPRIO_CLASS_RT, because bi_ioprio will always be
greater than or equals to IOPRIO_CLASS_RT.

It seems possible to call blkcg_set_ioprio() first then try to
initialize bi_ioprio later in bio_set_ioprio(), but this doesn't work
for bio in which bi_ioprio is already initialized (e.g., direct-io), so
introduce a new promote-to-rt policy to promote the iopriority of bio to
IOPRIO_CLASS_RT if the ioprio is not already RT.

For none-to-rt policy, although it doesn't work now, but considering
that its purpose was also to override the io-priority to RT and allowing
for a smoother transition, just keep it and treat it as an alias of
the promote-to-rt policy.

Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Link: https://lore.kernel.org/r/20230428074404.280532-1-houtao@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

blk-iocost: use spin_lock_irqsave in adjust_inuse_and_calc_cost

adjust_inuse_and_calc_cost() use spin_lock_irq() and IRQ will be enabled
when unlock. DEADLOCK might happen if we have held other locks and disabled
IRQ before invoking it.

Fix it by using spin_lock_irqsave() instead, which can keep IRQ state
consistent with before when unlock.

  ================================
  WARNING: inconsistent lock state
  5.10.0-02758-g8e5f91fd772f #26 Not tainted
  --------------------------------
  inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
  kworker/2:3/388 [HC0[0]:SC0[0]:HE0:SE1] takes:
  ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: spin_lock_irq
  ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: bfq_bio_merge+0x141/0x390
  {IN-HARDIRQ-W} state was registered at:
    __lock_acquire+0x3d7/0x1070
    lock_acquire+0x197/0x4a0
    __raw_spin_lock_irqsave
    _raw_spin_lock_irqsave+0x3b/0x60
    bfq_idle_slice_timer_body
    bfq_idle_slice_timer+0x53/0x1d0
    __run_hrtimer+0x477/0xa70
    __hrtimer_run_queues+0x1c6/0x2d0
    hrtimer_interrupt+0x302/0x9e0
    local_apic_timer_interrupt
    __sysvec_apic_timer_interrupt+0xfd/0x420
    run_sysvec_on_irqstack_cond
    sysvec_apic_timer_interrupt+0x46/0xa0
    asm_sysvec_apic_timer_interrupt+0x12/0x20
  irq event stamp: 837522
  hardirqs last  enabled at (837521): [<ffffffff84b9419d>] __raw_spin_unlock_irqrestore
  hardirqs last  enabled at (837521): [<ffffffff84b9419d>] _raw_spin_unlock_irqrestore+0x3d/0x40
  hardirqs last disabled at (837522): [<ffffffff84b93fa3>] __raw_spin_lock_irq
  hardirqs last disabled at (837522): [<ffffffff84b93fa3>] _raw_spin_lock_irq+0x43/0x50
  softirqs last  enabled at (835852): [<ffffffff84e00558>] __do_softirq+0x558/0x8ec
  softirqs last disabled at (835845): [<ffffffff84c010ff>] asm_call_irq_on_stack+0xf/0x20

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(&bfqd->lock);
    <Interrupt>
      lock(&bfqd->lock);

   *** DEADLOCK ***

  3 locks held by kworker/2:3/388:
   #0: ffff888107af0f38 ((wq_completion)kthrotld){+.+.}-{0:0}, at: process_one_work+0x742/0x13f0
   #1: ffff8881176bfdd8 ((work_completion)(&td->dispatch_work)){+.+.}-{0:0}, at: process_one_work+0x777/0x13f0
   #2: ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: spin_lock_irq
   #2: ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: bfq_bio_merge+0x141/0x390

  stack backtrace:
  CPU: 2 PID: 388 Comm: kworker/2:3 Not tainted 5.10.0-02758-g8e5f91fd772f #26
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
  Workqueue: kthrotld blk_throtl_dispatch_work_fn
  Call Trace:
   __dump_stack lib/dump_stack.c:77 [inline]
   dump_stack+0x107/0x167
   print_usage_bug
   valid_state
   mark_lock_irq.cold+0x32/0x3a
   mark_lock+0x693/0xbc0
   mark_held_locks+0x9e/0xe0
   __trace_hardirqs_on_caller
   lockdep_hardirqs_on_prepare.part.0+0x151/0x360
   trace_hardirqs_on+0x5b/0x180
   __raw_spin_unlock_irq
   _raw_spin_unlock_irq+0x24/0x40
   spin_unlock_irq
   adjust_inuse_and_calc_cost+0x4fb/0x970
   ioc_rqos_merge+0x277/0x740
   __rq_qos_merge+0x62/0xb0
   rq_qos_merge
   bio_attempt_back_merge+0x12c/0x4a0
   blk_mq_sched_try_merge+0x1b6/0x4d0
   bfq_bio_merge+0x24a/0x390
   __blk_mq_sched_bio_merge+0xa6/0x460
   blk_mq_sched_bio_merge
   blk_mq_submit_bio+0x2e7/0x1ee0
   __submit_bio_noacct_mq+0x175/0x3b0
   submit_bio_noacct+0x1fb/0x270
   blk_throtl_dispatch_work_fn+0x1ef/0x2b0
   process_one_work+0x83e/0x13f0
   process_scheduled_works
   worker_thread+0x7e3/0xd80
   kthread+0x353/0x470
   ret_from_fork+0x1f/0x30

Fixes: b0853ab4a238 ("blk-iocost: revamp in-period donation snapbacks")
Signed-off-by: Li Nan <linan122@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20230527091904.3001833-1-linan666@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: mark early_lookup_bdev as __init

early_lookup_bdev is now only used during the early boot code as it
should, so mark it __init to not waste run time memory on it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230531125535.676098-25-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

mtd: block2mtd: don't call early_lookup_bdev after the system is running

early_lookup_bdev is supposed to only be called from the early boot
code, but mdtblock_early_get_bdev is called as a general fallback when
lookup_bdev fails, which is problematic because early_lookup_bdev
bypasses all normal path based permission checking, and might cause
problems with certain container environments renaming devices.

Switch to only call early_lookup_bdev when block2mtd is built-in and the
system state in not running yet.

Note that this strictly speaking changes the kernel ABI as the PARTUUID=
and PARTLABEL= style syntax is now not available during a running
systems.  They never were intended for that, but this breaks things
we'll have to figure out a way to make them available again.  But if
avoidable in any way I'd rather avoid that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20230531125535.676098-24-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

mtd: block2mtd: factor the early block device open logic into a helper

Simplify add_device a bit by splitting out the cumbersome early boot logic
into a separate helper.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20230531125535.676098-23-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

PM: hibernate: don't use early_lookup_bdev in resume_store

resume_store is a sysfs attribute written during normal kernel runtime,
and it should not use the early_lookup_bdev API that bypasses all normal
path based permission checking, and might cause problems with certain
container environments renaming devices.

Switch to lookup_bdev, which does a normal path lookup instead, and fall
back to trying to parse a numeric dev_t just like early_lookup_bdev did.

Note that this strictly speaking changes the kernel ABI as the PARTUUID=
and PARTLABEL= style syntax is now not available during a running
systems.  They never were intended for that, but this breaks things
we'll have to figure out a way to make them available again.  But if
avoidable in any way I'd rather avoid that.

Fixes: 421a5fa1a6cf ("PM / hibernate: use name_to_dev_t to parse resume")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230531125535.676098-22-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

dm: only call early_lookup_bdev from early boot context

early_lookup_bdev is supposed to only be called from the early boot
code, but dm_get_device calls it as a general fallback when lookup_bdev
fails, which is problematic because early_lookup_bdev bypasses all normal
path based permission checking, and might cause problems with certain
container environments renaming devices.

Switch to only call early_lookup_bdev when dm is built-in and the system
state in not running yet.  This means it is still available when tables
are constructed by dm-init.c from the kernel command line, but not
otherwise.

Note that this strictly speaking changes the kernel ABI as the PARTUUID=
and PARTLABEL= style syntax is now not available during a running
systems.  They never were intended for that, but this breaks things
we'll have to figure out a way to make them available again.  But if
avoidable in any way I'd rather avoid that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Link: https://lore.kernel.org/r/20230531125535.676098-21-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

dm: remove dm_get_dev_t

Open code dm_get_dev_t in the only remaining caller, and propagate the
exact error code from lookup_bdev and early_lookup_bdev.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230531125535.676098-20-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

dm: open code dm_get_dev_t in dm_init_init

dm_init_init is called from early boot code, and thus lookup_bdev
will never succeed.  Just open code that call to early_lookup_bdev
instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Link: https://lore.kernel.org/r/20230531125535.676098-19-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

dm-snap: simplify the origin_dev == cow_dev check in snapshot_ctr

Use the block_device acquired in dm_get_device for the check instead
of doing an extra lookup.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Link: https://lore.kernel.org/r/20230531125535.676098-18-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: move more code to early-lookup.c

blk_lookup_devt is only used by code in early-lookup.c, so move it
there.

printk_all_partitions and it's helper bdevt_str are only used by the
early init code in init/do_mounts.c, so they should go there as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230531125535.676098-17-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: move the code to do early boot lookup of block devices to block/

Create a new block/early-lookup.c to keep the early block device lookup
code instead of having this code sit with the early mount code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230531125535.676098-16-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

init: clear root_wait on all invalid root= strings

Instead of only clearing root_wait in devt_from_partuuid when the UUID
format was invalid, do that in parse_root_device for all strings that
failed to parse.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230531125535.676098-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

init: improve the name_to_dev_t interface

name_to_dev_t has a very misleading name, that doesn't make clear
it should only be used by the early init code, and also has a bad
calling convention that doesn't allow returning different kinds of
errors.  Rename it to early_lookup_bdev to make the use case clear,
and return an errno, where -EINVAL means the string could not be
parsed, and -ENODEV means it the string was valid, but there was
no device found for it.

Also stub out the whole call for !CONFIG_BLOCK as all the non-block
root cases are always covered in the caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230531125535.676098-14-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

init: move the nfs/cifs/ram special cases out of name_to_dev_t

The nfs/cifs/ram special case only needs to be parsed once, and only in
the boot code.  Move them out of name_to_dev_t and into
prepare_namespace.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230531125535.676098-13-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

init: factor the root_wait logic in prepare_namespace into a helper

The root_wait logic is a bit obsfucated right now.  Expand it and move it
into a helper.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230531125535.676098-12-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

init: handle ubi/mtd root mounting like all other root types

Assign a Root_Generic magic value for UBI/MTD root and handle the root
mounting in mount_root like all other root types.  Besides making the
code more clear this also means that UBI/MTD root can be used together
with an initrd (not that anyone should care).

Also factor parsing of the root name into a helper now that it can
be easily done and will get more complicated with subsequent patches.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230531125535.676098-11-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

init: don't remove the /dev/ prefix from error messages

Remove the code that drops the /dev/ prefix from root_device_name, which
is only used for error messages when mounting the root device fails.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230531125535.676098-10-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

init: pass root_device_name explicitly

Instead of declaring root_device_name as a global variable pass it as an
argument to the functions using it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230531125535.676098-9-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

init: refactor mount_root

Provide stubs for all the lower level mount helpers, and just switch
on ROOT_DEV in the main function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230531125535.676098-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

init: rename mount_block_root to mount_root_generic

mount_block_root is also used to mount non-block file systems, so give
it a better name.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230531125535.676098-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

init: remove pointless Root_* values

Remove all unused defines, and just use the expanded versions for
the SCSI disk majors.

I've decided to keep Root_RAM0 even if it could be expanded as there
is a lot of special casing for it in the init code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230531125535.676098-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

PM: hibernate: move finding the resume device out of software_resume

software_resume can be called either from an init call in the boot code,
or from sysfs once the system has finished booting, and the two
invocation methods this can't race with each other.

For the latter case we did just parse the suspend device manually, while
the former might not have one.  Split software_resume so that the search
only happens for the boot case, which also means the special lockdep
nesting annotation can go away as the system transition mutex can be
taken a little later and doesn't have the sysfs locking nest inside it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230531125535.676098-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

PM: hibernate: remove the global snapshot_test variable

Passing call dependent variable in global variables is a huge
antipattern.  Fix it up.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230531125535.676098-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

PM: hibernate: factor out a helper to find the resume device

Split the logic to find the resume device out software_resume and into
a separate helper to start unwindig the convoluted goto logic.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230531125535.676098-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

driver core: return bool from driver_probe_done

bool is the most sensible return value for a yes/no return.  Also
add __init as this funtion is only called from the early boot code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20230531125535.676098-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

ext4: wire up the ->mark_dead holder operation for log devices

Implement a set of holder_ops that shut down the file system when the
block device used as log device is removed undeneath the file system.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Link: https://lore.kernel.org/r/20230601094459.1350643-17-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

ext4: wire up sops->shutdown

Wire up the shutdown method to shut down the file system when the
underlying block device is marked dead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Link: https://lore.kernel.org/r/20230601094459.1350643-16-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

ext4: split ext4_shutdown

Split ext4_shutdown into a low-level helper that will be reused for
implementing the shutdown super operation and a wrapper for the ioctl
handling.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Link: https://lore.kernel.org/r/20230601094459.1350643-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

xfs: wire up the ->mark_dead holder operation for log and RT devices

Implement a set of holder_ops that shut down the file system when the
block device used as log or RT device is removed undeneath the file
system.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Link: https://lore.kernel.org/r/20230601094459.1350643-14-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

xfs: wire up sops->shutdown

Wire up the shutdown method to shut down the file system when the
underlying block device is marked dead.  Add a new message to
clearly distinguish this shutdown reason from other shutdowns.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Link: https://lore.kernel.org/r/20230601094459.1350643-13-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs: add a method to shut down the file system

Add a new ->shutdown super operation that can be used to tell the file
system to shut down, and call it from newly created holder ops when the
block device under a file system shuts down.

This only covers the main block device for "simple" file systems using
get_tree_bdev / mount_bdev.  File systems their own get_tree method
or opening additional devices will need to set up their own
blk_holder_ops.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Link: https://lore.kernel.org/r/20230601094459.1350643-12-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: add a mark_dead holder operation

Add a mark_dead method to blk_holder_ops that is called from blk_mark_disk_dead
to notify the holder that the block device it is using has been marked dead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Link: https://lore.kernel.org/r/20230601094459.1350643-11-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: introduce holder ops

Add a new blk_holder_ops structure, which is passed to blkdev_get_by_* and
installed in the block_device for exclusive claims.  It will be used to
allow the block layer to call back into the user of the block device for
thing like notification of a removed device or a device resize.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Link: https://lore.kernel.org/r/20230601094459.1350643-10-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: remove blk_drop_partitions

There is only a single caller left, so fold the loop into that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Link: https://lore.kernel.org/r/20230601094459.1350643-9-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>