Commit graph

1030501 commits

Author SHA1 Message Date
Christoph Hellwig
3d2e79894b block: pass a gendisk to bdev_resize_partition
bdev_resize_partition can only operate on the whole device.  Make that clear
by passing a gendisk instead of a block_device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210810154512.1809898-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12 10:31:36 -06:00
Christoph Hellwig
926fbb1677 block: pass a gendisk to bdev_del_partition
bdev_del_partition can only operate on the whole device.  Make that clear
by passing a gendisk instead of a block_device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210810154512.1809898-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12 10:31:35 -06:00
Christoph Hellwig
7f6be3765e block: pass a gendisk to bdev_add_partition
bdev_add_partition can only operate on the whole device.  Make that clear
by passing a gendisk instead of a block_device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210810154512.1809898-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12 10:31:35 -06:00
Christoph Hellwig
a08aa9bccd block: store a gendisk in struct parsed_partitions
Partition scanning only happens on the whole device, so pass a
struct gendisk instead of the whole device block_device to the scanners.
This allows to simplify printing the device name in various places as the
disk name is available in disk->name.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Stefan Haberland <sth@linux.ibm.com>
Link: https://lore.kernel.org/r/20210810154512.1809898-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12 10:31:35 -06:00
Christoph Hellwig
50b4aecfbb block: remove GENHD_FL_UP
Just check inode_unhashed on the whole device bdev inode instead,
and provide a helper to check for that information.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210809064028.1198327-9-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12 10:29:36 -06:00
Christoph Hellwig
b75f4aed88 bcache: move the del_gendisk call out of bcache_device_free
Let the callers call del_gendisk so that we can check if add_disk
has been called properly for the cached device case instead of relying
on the block layer internal GENHD_FL_UP flag.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20210809064028.1198327-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12 10:29:36 -06:00
Christoph Hellwig
224b068322 bcache: add proper error unwinding in bcache_device_init
Except for the IDA none of the allocations in bcache_device_init is
unwound on error, fix that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20210809064028.1198327-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12 10:29:36 -06:00
Christoph Hellwig
4f9e14aecf sx8: use the internal state machine to check if del_gendisk needs to be called
Remove usage of the block layer internal GENHD_FL_UP by just looking
at the host state.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210809064028.1198327-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12 10:29:36 -06:00
Christoph Hellwig
916a470da0 nvme: replace the GENHD_FL_UP check in nvme_mpath_shutdown_disk
Use the nvme-internal NVME_NSHEAD_DISK_LIVE flag instead of abusing
the block layer state.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210809064028.1198327-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12 10:29:36 -06:00
Christoph Hellwig
5eba200526 nvme: remove the GENHD_FL_UP check in nvme_ns_remove
Early probe failure never reaches nvme_ns_remove, so GENHD_FL_UP must
be set at this point.  Remove the check.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210809064028.1198327-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12 10:29:36 -06:00
Christoph Hellwig
a94dcfce70 mmc: block: cleanup gendisk creation
Restructure mmc_blk_probe to avoid a failure path with a half created
disk.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20210809064028.1198327-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12 10:29:35 -06:00
Christoph Hellwig
29e6a5e01d mmc: block: let device_add_disk create disk attributes
Pass the attribute group for the attributes on the gendisk to
device_add_disk so that they are created atomically with the
disk creation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20210809064028.1198327-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-12 10:29:35 -06:00
Guoqing Jiang
018eca456c block: move some macros to blkdev.h
Move them (PAGE_SECTORS_SHIFT, PAGE_SECTORS and SECTOR_MASK) to the
generic header file to remove redundancy.

Signed-off-by: Guoqing Jiang <jiangguoqing@kylinos.cn>
Link: https://lore.kernel.org/r/20210721025315.1729118-1-guoqing.jiang@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-11 19:40:28 -06:00
Christoph Hellwig
99d26de2f6 writeback: make the laptop_mode prototypes available unconditionally
Fix the !CONFIG_BLOCK build after the recent cleanup.

Fixes: 5ed964f8e5 ("mm: hide laptop_mode_wb_timer entirely behind the BDI API")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-10 07:00:50 -06:00
Ming Lei
866663b7b5 block: return ELEVATOR_DISCARD_MERGE if possible
When merging one bio to request, if they are discard IO and the queue
supports multi-range discard, we need to return ELEVATOR_DISCARD_MERGE
because both block core and related drivers(nvme, virtio-blk) doesn't
handle mixed discard io merge(traditional IO merge together with
discard merge) well.

Fix the issue by returning ELEVATOR_DISCARD_MERGE in this situation,
so both blk-mq and drivers just need to handle multi-range discard.

Reported-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Fixes: 2705dfb209 ("block: fix discard request merge")
Link: https://lore.kernel.org/r/20210729034226.1591070-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09 14:37:47 -06:00
Christoph Hellwig
a11d7fc2d0 block: remove the bd_bdi in struct block_device
Just retrieve the bdi from the disk.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210809141744.1203023-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09 11:53:26 -06:00
Christoph Hellwig
edb0872f44 block: move the bdi from the request_queue to the gendisk
The backing device information only makes sense for file system I/O,
and thus belongs into the gendisk and not the lower level request_queue
structure.  Move it there.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210809141744.1203023-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09 11:53:23 -06:00
Christoph Hellwig
1008162b27 block: add a queue_has_disk helper
Add a helper to check if a gendisk is associated with a request_queue.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210809141744.1203023-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09 11:52:28 -06:00
Christoph Hellwig
471aa704db block: pass a gendisk to blk_queue_update_readahead
.. and rename the function to disk_update_readahead.  This is in
preparation for moving the BDI from the request_queue to the gendisk.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210809141744.1203023-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09 11:52:28 -06:00
Christoph Hellwig
5ed964f8e5 mm: hide laptop_mode_wb_timer entirely behind the BDI API
Don't leak the detaіls of the timer into the block layer, instead
initialize the timer in bdi_alloc and delete it in bdi_unregister.
Note that this means the timer is initialized (but not armed) for
non-block queues as well now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210809141744.1203023-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09 11:52:28 -06:00
Christoph Hellwig
d1254a8749 block: remove support for delayed queue registrations
Now that device mapper has been changed to register the disk once
it is fully ready all this code is unused.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20210804094147.459763-9-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09 11:50:43 -06:00
Christoph Hellwig
89f871af1b dm: delay registering the gendisk
device mapper is currently the only outlier that tries to call
register_disk after add_disk, leading to fairly inconsistent state
of these block layer data structures.  Instead change device-mapper
to just register the gendisk later now that the holder mechanism
can cope with that.

Note that this introduces a user visible change: the dm kobject is
now only visible after the initial table has been loaded.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20210804094147.459763-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09 11:50:43 -06:00
Christoph Hellwig
ba30585936 dm: move setting md->type into dm_setup_md_queue
Move setting md->type from both callers into dm_setup_md_queue.
This ensures that md->type is only set to a valid value after the queue
has been fully setup, something we'll rely on future changes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20210804094147.459763-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09 11:50:43 -06:00
Christoph Hellwig
74a2b6ec93 dm: cleanup cleanup_mapped_device
md->queue is now always set when md->disk is set, so simplify the
conditionals a bit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20210804094147.459763-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09 11:50:43 -06:00
Christoph Hellwig
d626338735 block: support delayed holder registration
device mapper needs to register holders before it is ready to do I/O.
Currently it does so by registering the disk early, which can leave
the disk and queue in a weird half state where the queue is registered
with the disk, except for sysfs and the elevator.  And this state has
been a bit promlematic before, and will get more so when sorting out
the responsibilities between the queue and the disk.

Support registering holders on an initialized but not registered disk
instead by delaying the sysfs registration until the disk is registered.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20210804094147.459763-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09 11:50:42 -06:00
Christoph Hellwig
0dbcfe247f block: look up holders by bdev
Invert they way the holder relations are tracked.  This very
slightly reduces the memory overhead for partitioned devices.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210804094147.459763-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09 11:50:42 -06:00
Christoph Hellwig
fbd9a39542 block: remove the extra kobject reference in bd_link_disk_holder
Since commit 0d02129e76 ("block: merge struct block_device and struct
hd_struct") there is no way for the bdev to go away as long as there is
a holder, so remove the extra references.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20210804094147.459763-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09 11:50:42 -06:00
Christoph Hellwig
c66fd01971 block: make the block holder code optional
Move the block holder code into a separate file as it is not in any way
related to the other block_dev.c code, and add a new selectable config
option for it so that we don't have to build it without any remapped
drivers selected.

The Kconfig symbol contains a _DEPRECATED suffix to match the comments
added in commit 49731baa41
("block: restore multiple bd_link_disk_holder() support").

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20210804094147.459763-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09 11:50:42 -06:00
Bart Van Assche
2112f5c133 loop: Select I/O scheduler 'none' from inside add_disk()
We noticed that the user interface of Android devices becomes very slow
under memory pressure. This is because Android uses the zram driver on top
of the loop driver for swapping, because under memory pressure the swap
code alternates reads and writes quickly, because mq-deadline is the
default scheduler for loop devices and because mq-deadline delays writes by
five seconds for such a workload with default settings. Fix this by making
the kernel select I/O scheduler 'none' from inside add_disk() for loop
devices. This default can be overridden at any time from user space,
e.g. via a udev rule. This approach has an advantage compared to changing
the I/O scheduler from userspace from 'mq-deadline' into 'none', namely
that synchronize_rcu() does not get called.

This patch changes the default I/O scheduler for loop devices from
'mq-deadline' into 'none'.

Additionally, this patch reduces the Android boot time on my test setup
with 0.5 seconds compared to configuring the loop I/O scheduler from user
space.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Martijn Coenen <maco@android.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20210805174200.3250718-3-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-05 11:49:21 -06:00
Bart Van Assche
90b7198001 blk-mq: Introduce the BLK_MQ_F_NO_SCHED_BY_DEFAULT flag
elevator_get_default() uses the following algorithm to select an I/O
scheduler from inside add_disk():
- In case of a single hardware queue or if sharing hardware queues across
  multiple request queues (BLK_MQ_F_TAG_HCTX_SHARED), use mq-deadline.
- Otherwise, use 'none'.

This is a good choice for most but not for all block drivers. Make it
possible to override the selection of mq-deadline with a new flag,
namely BLK_MQ_F_NO_SCHED_BY_DEFAULT.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Martijn Coenen <maco@android.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20210805174200.3250718-2-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-05 11:49:21 -06:00
Damien Le Moal
2bc1f6e442 block: remove blk-mq-sysfs dead code
In block/blk-mq-sysfs.c, struct blk_mq_ctx_sysfs_entry is not used to
define any attribute since the "mq" sysfs directory contains only
sub-directories (no attribute files). As a result, blk_mq_sysfs_show(),
blk_mq_sysfs_store(), and struct sysfs_ops blk_mq_sysfs_ops are all
unused and unnecessary. Remove all this unused code.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Link: https://lore.kernel.org/r/20210713081837.524422-1-damien.lemoal@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02 13:37:29 -06:00
Matteo Croce
9f65c489b6 loop: raise media_change event
Make the loop device raise a DISK_MEDIA_CHANGE event on attach or detach.

	# udevadm monitor -up |grep -e DISK_MEDIA_CHANGE -e DEVNAME &

	# losetup -f zero
	[    7.454235] loop0: detected capacity change from 0 to 16384
	DISK_MEDIA_CHANGE=1
	DEVNAME=/dev/loop0
	DEVNAME=/dev/loop0
	DEVNAME=/dev/loop0

	# losetup -f zero
	[   10.205245] loop1: detected capacity change from 0 to 16384
	DISK_MEDIA_CHANGE=1
	DEVNAME=/dev/loop1
	DEVNAME=/dev/loop1
	DEVNAME=/dev/loop1

	# losetup -f zero2
	[   13.532368] loop2: detected capacity change from 0 to 40960
	DISK_MEDIA_CHANGE=1
	DEVNAME=/dev/loop2
	DEVNAME=/dev/loop2

	# losetup -D
	DEVNAME=/dev/loop1
	DISK_MEDIA_CHANGE=1
	DEVNAME=/dev/loop1
	DEVNAME=/dev/loop2
	DISK_MEDIA_CHANGE=1
	DEVNAME=/dev/loop2
	DEVNAME=/dev/loop0
	DISK_MEDIA_CHANGE=1
	DEVNAME=/dev/loop0

Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Luca Boccassi <bluca@debian.org>
Link: https://lore.kernel.org/r/20210712230530.29323-7-mcroce@linux.microsoft.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02 13:37:29 -06:00
Matteo Croce
e6138dc12d block: add a helper to raise a media changed event
Refactor disk_check_events() and move some code into disk_event_uevent().
Then add disk_force_media_change(), a helper which will be used by
devices to force issuing a DISK_EVENT_MEDIA_CHANGE event.

Co-developed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Tested-by: Luca Boccassi <bluca@debian.org>
Link: https://lore.kernel.org/r/20210712230530.29323-6-mcroce@linux.microsoft.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02 13:37:28 -06:00
Matteo Croce
13927b31b1 block: export diskseq in sysfs
Add a new sysfs handle to export the new diskseq value.
Place it in <sysfs>/block/<disk>/diskseq and document it.

    $ grep . /sys/class/block/*/diskseq
    /sys/class/block/loop0/diskseq:13
    /sys/class/block/loop1/diskseq:14
    /sys/class/block/loop2/diskseq:5
    /sys/class/block/loop3/diskseq:6
    /sys/class/block/ram0/diskseq:1
    /sys/class/block/ram1/diskseq:2
    /sys/class/block/vda/diskseq:7

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Tested-by: Luca Boccassi <bluca@debian.org>
Link: https://lore.kernel.org/r/20210712230530.29323-5-mcroce@linux.microsoft.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02 13:37:28 -06:00
Matteo Croce
7957d93bf3 block: add ioctl to read the disk sequence number
Add a new BLKGETDISKSEQ ioctl which retrieves the disk sequence number
from the genhd structure.

    # ./getdiskseq /dev/loop*
    /dev/loop0:     13
    /dev/loop0p1:   13
    /dev/loop0p2:   13
    /dev/loop0p3:   13
    /dev/loop1:     14
    /dev/loop1p1:   14
    /dev/loop1p2:   14
    /dev/loop2:     5
    /dev/loop3:     6

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Tested-by: Luca Boccassi <bluca@debian.org>
Link: https://lore.kernel.org/r/20210712230530.29323-4-mcroce@linux.microsoft.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02 13:37:28 -06:00
Matteo Croce
87eb710747 block: export the diskseq in uevents
Export the newly introduced diskseq in uevents:

    $ udevadm info /sys/class/block/* |grep -e DEVNAME -e DISKSEQ
    E: DEVNAME=/dev/loop0
    E: DISKSEQ=1
    E: DEVNAME=/dev/loop1
    E: DISKSEQ=2
    E: DEVNAME=/dev/loop2
    E: DISKSEQ=3
    E: DEVNAME=/dev/loop3
    E: DISKSEQ=4
    E: DEVNAME=/dev/loop4
    E: DISKSEQ=5
    E: DEVNAME=/dev/loop5
    E: DISKSEQ=6
    E: DEVNAME=/dev/loop6
    E: DISKSEQ=7
    E: DEVNAME=/dev/loop7
    E: DISKSEQ=8
    E: DEVNAME=/dev/nvme0n1
    E: DISKSEQ=9
    E: DEVNAME=/dev/nvme0n1p1
    E: DISKSEQ=9
    E: DEVNAME=/dev/nvme0n1p2
    E: DISKSEQ=9
    E: DEVNAME=/dev/nvme0n1p3
    E: DISKSEQ=9
    E: DEVNAME=/dev/nvme0n1p4
    E: DISKSEQ=9
    E: DEVNAME=/dev/nvme0n1p5
    E: DISKSEQ=9
    E: DEVNAME=/dev/sda
    E: DISKSEQ=10
    E: DEVNAME=/dev/sda1
    E: DISKSEQ=10
    E: DEVNAME=/dev/sda2
    E: DISKSEQ=10

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Tested-by: Luca Boccassi <bluca@debian.org>
Link: https://lore.kernel.org/r/20210712230530.29323-3-mcroce@linux.microsoft.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02 13:37:28 -06:00
Matteo Croce
cf17994855 block: add disk sequence number
Associating uevents with block devices in userspace is difficult and racy:
the uevent netlink socket is lossy, and on slow and overloaded systems
has a very high latency.
Block devices do not have exclusive owners in userspace, any process can
set one up (e.g. loop devices). Moreover, device names can be reused
(e.g. loop0 can be reused again and again). A userspace process setting
up a block device and watching for its events cannot thus reliably tell
whether an event relates to the device it just set up or another earlier
instance with the same name.

Being able to set a UUID on a loop device would solve the race conditions.
But it does not allow to derive orderings from uevents: if you see a
uevent with a UUID that does not match the device you are waiting for,
you cannot tell whether it's because the right uevent has not arrived yet,
or it was already sent and you missed it. So you cannot tell whether you
should wait for it or not.

Associating a unique, monotonically increasing sequential number to the
lifetime of each block device, which can be retrieved with an ioctl
immediately upon setting it up, allows to solve the race conditions with
uevents, and also allows userspace processes to know whether they should
wait for the uevent they need or if it was dropped and thus they should
move on.

Additionally, increment the disk sequence number when the media change,
i.e. on DISK_EVENT_MEDIA_CHANGE event.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Tested-by: Luca Boccassi <bluca@debian.org>
Link: https://lore.kernel.org/r/20210712230530.29323-2-mcroce@linux.microsoft.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02 13:37:28 -06:00
Christoph Hellwig
2164877c7f block: remove cmdline-parser.c
cmdline-parser.c is only used by the cmdline faux partition format,
so merge the code into that and avoid an indirect call.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210728053756.409654-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02 13:37:28 -06:00
Christoph Hellwig
abd2864a3e block: remove disk_name()
Remove the disk_name function now that all users are gone.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20210727062518.122108-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02 13:37:28 -06:00
Christoph Hellwig
1d7035478f block: simplify disk name formatting in check_partition
disk_name for partition 0 just copies out the disk_name field.  Replace
the call to disk_name with a %s format specifier.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20210727062518.122108-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02 13:37:28 -06:00
Christoph Hellwig
453b8ab696 block: simplify printing the device names disk_stack_limits
Printk ->disk_name directly for the disk and use the %pg format specifier
for the block device, which is equivalent to a bdevname call.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20210727062518.122108-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02 13:37:28 -06:00
Christoph Hellwig
a291bb43e5 block: use the %pg format specifier in show_partition
Simplify printing the partition name by using the %pg format specifier
that is equivalent to a bdevname call.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20210727062518.122108-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02 13:37:28 -06:00
Christoph Hellwig
a9e7bc3de4 block: use the %pg format specifier in printk_all_partitions
Simplify printing the partition name by using the %pg format specifier
that is equivalent to a bdevname call.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20210727062518.122108-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02 13:37:28 -06:00
Abd-Alrhman Masalkhi
26e2d7a362 block: reduce stack usage in diskstats_show
I have compiled the kernel with a cross compiler "hppa-linux-gnu-" v9.3.0
on x86-64 host machine. I got the following warning:

block/genhd.c: In function ‘diskstats_show’:
block/genhd.c:1227:1: warning: the frame size of 1688 bytes is larger
than 1280 bytes [-Wframe-larger-than=]
 1227  |  }

By Reduced the stack footprint by using the %pg printk specifier instead
of disk_name to remove the need for the on-stack buffer.

Signed-off-by: Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20210727062518.122108-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02 13:37:28 -06:00
Christoph Hellwig
2f4731dcd0 block: remove bdput
Now that we've stopped using inode references for anything meaninful
in the block layer get rid of the helper to put it and just open code
the call to iput on the block_device inode.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Chaitanya Kulkarni <ckulkarnilinux@gmail.com>
Link: https://lore.kernel.org/r/20210722075402.983367-10-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02 13:37:28 -06:00
Christoph Hellwig
14cf1dbb55 block: remove bdgrab
All callers are gone, and no one should grab a pure inode reference to
a block device anymore.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20210722075402.983367-9-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02 13:37:28 -06:00
Christoph Hellwig
4b2731226d loop: don't grab a reference to the block device
The whole device block device won't be removed while the disk is still
alive, so don't bother to grab a reference to it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Ming Lei <ming.lei@rehat.com>
Reviewed-by: Chaitanya Kulkarni <ckulkarnilinux@gmail.com>
Link: https://lore.kernel.org/r/20210722075402.983367-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02 13:37:28 -06:00
Christoph Hellwig
9d3b881389 block: change the refcounting for partitions
Instead of acquiring an inode reference on open make sure partitions
always hold device model references to the disk while alive, and switch
open to grab only a device model reference to the opened block device.
If that is a partition the disk reference is transitively held by the
partition already.

Link: https://lore.kernel.org/r/20210722075402.983367-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02 13:37:28 -06:00
Christoph Hellwig
0468c53234 block: allocate bd_meta_info later in add_partitions
Move the allocation of bd_meta_info after initializing the struct device
to avoid the special bdput error handling path.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210722075402.983367-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02 13:37:28 -06:00
Christoph Hellwig
d7a66574b3 block: unhash the whole device inode earlier
Unhash the whole device inode early in del_gendisk.  This allows to
remove the first GENHD_FL_UP check in the open path as we simply
won't find a just removed inode.  The second non-racy check after
taking open_mutex is still kept.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210722075402.983367-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02 13:37:28 -06:00