Commit Graph

527 Commits

Author SHA1 Message Date
Christoph Hellwig
4a1fa41d30 block: pass a request_queue to __blk_alloc_disk
Pass in a request_queue and assign disk->queue in __blk_alloc_disk to
ensure struct gendisk always has a valid ->queue pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210816131910.615153-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 12:54:30 -06:00
Christoph Hellwig
a58bd7683f block: remove the minors argument to __alloc_disk_node
This was a leftover from the legacy alloc_disk interface.  Switch
the scsi ULPs and dasd to set ->minors directly like all other
drivers and remove the argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Stefan Haberland <sth@linux.ibm.com>	[dasd]
Link: https://lore.kernel.org/r/20210816131910.615153-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 12:54:30 -06:00
Christoph Hellwig
4dcc4874de block: cleanup the lockdep handling in *alloc_disk
Pass the lockdep name to the low-level __blk_alloc_disk helper and
hardcode the name for it given that the number of minors or node_id
are not very useful information.  While this passes a pointless
argument for non-lockdep builds that is not really an issue as
disk allocation is a probe time only slow path.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210816131910.615153-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23 12:54:30 -06:00
Christoph Hellwig
889c05cc58 block: ensure the bdi is freed after inode_detach_wb
inode_detach_wb references the "main" bdi of the inode.  With the
recent change to move the bdi from the request_queue to the gendisk
this causes a guaranteed use after free when using certain cgroup
configurations.  The big itself is older through as any non-default
inode reference (e.g. an open file descriptor) could have injected
this use after free even before that.

Fixes: 52ebea749a ("writeback: make backing_dev_info host cgroup-specific bdi_writebacks")
Reported-by: Qian Cai <quic_qiancai@quicinc.com>
Reported-by: syzbot <syzbot+1fb38bb7d3ce0fa3e1c4@syzkaller.appspotmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210816122614.601358-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-16 10:49:11 -06:00
Christoph Hellwig
9451aa0aac block: free the extended dev_t minor later
The dev_t is used as the inode hash, so we should only released it
once then block device inode is gone from the inode cache.  Move it
to bdev_free_inode to ensure that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210816122614.601358-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-16 10:49:11 -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
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
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
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
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
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
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
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
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
Christoph Hellwig
340e845738 block: delay freeing the gendisk
blkdev_get_no_open acquires a reference to the block_device through
the block device inode and then tries to acquire a device model
reference to the gendisk.  But at this point the disk migh already
be freed (although the race is free).  Fix this by only freeing the
gendisk from the whole device bdevs ->free_inode callback as well.

Fixes: 22ae8ce8b8 ("block: simplify bdev/disk lookup in blkdev_get")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210722075402.983367-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-07-27 19:35:47 -06:00
Christoph Hellwig
498dcc13fd block: grab a device refcount in disk_uevent
Sending uevents requires the struct device to be alive.  To
ensure that grab the device refcount instead of just an inode
reference.

Fixes: bc359d03c7 ("block: add a disk_uevent helper")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210701081638.246552-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-07-01 10:21:24 -06:00
Christoph Hellwig
2bc8cda5ea block: add the events* attributes to disk_attrs
Add the events attributes to the disk_attrs array, which ensures they are
added by the driver core when the device is created rather than adding
them after the device has been added, which is racy versus uevents and
requires more boilerplate code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20210624073843.251178-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-24 12:00:22 -06:00
Christoph Hellwig
d5870edfa3 block: move the disk events code to a separate file
Move the code for handling disk events from genhd.c into a new file
as it isn't very related to the rest of the file while at the same
time requiring lots of forward declarations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20210624073843.251178-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-24 12:00:22 -06:00
Christoph Hellwig
0e0ccdecb3 block: remove bdget_disk
Just opencode the xa_load in the callers, as none of them actually
needs a reference to the bdev.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210525061301.2242282-9-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-01 07:47:14 -06:00
Christoph Hellwig
c97d93c31e block: factor out a part_devt helper
Add a helper to find the dev_t for a disk + partno tuple.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210525061301.2242282-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-01 07:45:49 -06:00
Christoph Hellwig
a8698707a1 block: move bd_mutex to struct gendisk
Replace the per-block device bd_mutex with a per-gendisk open_mutex,
thus simplifying locking wherever we deal with partitions.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Link: https://lore.kernel.org/r/20210525061301.2242282-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-01 07:44:32 -06:00
Christoph Hellwig
f525464a80 block: add blk_alloc_disk and blk_cleanup_disk APIs
Add two new APIs to allocate and free a gendisk including the
request_queue for use with BIO based drivers.  This is to avoid
boilerplate code in drivers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20210521055116.1053587-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-01 07:42:23 -06:00
Christoph Hellwig
958229a7c5 block: add a flag to make put_disk on partially initalized disks safer
Add a flag to indicate that __device_add_disk did grab a queue reference
so that disk_release only drops it if we actually had it.  This sort
out one of the major pitfals with partially initialized gendisk that
a lot of drivers did get wrong or still do.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20210521055116.1053587-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-01 07:42:23 -06:00
Christoph Hellwig
0d1feb72ff block: automatically enable GENHD_FL_EXT_DEVT
Automatically set the GENHD_FL_EXT_DEVT flag for all disks allocated
without an explicit number of minors.  This is what all new block
drivers should do, so make sure it is the default without boilerplate
code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20210521055116.1053587-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-01 07:42:23 -06:00
Christoph Hellwig
2e3c73fa0c block: move the DISK_MAX_PARTS sanity check into __device_add_disk
Keep this together with the first place that actually looks at
->minors and prepare for not passing a minors argument to
alloc_disk.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20210521055116.1053587-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-01 07:42:23 -06:00
Christoph Hellwig
7c3f828b52 block: refactor device number setup in __device_add_disk
Untangle the mess around blk_alloc_devt by moving the check for
the used allocation scheme into the callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20210521055116.1053587-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-01 07:42:22 -06:00
Christoph Hellwig
6c60ff048c block: prevent block device lookups at the beginning of del_gendisk
As an artifact of how gendisk lookup used to work in earlier kernels,
GENHD_FL_UP is only cleared very late in del_gendisk, and a global lock
is used to prevent opens from succeeding while del_gendisk is tearing
down the gendisk.  Switch to clearing the flag early and under bd_mutex
so that callers can use bd_mutex to stabilize the flag, which removes
the need for the global mutex.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210514131842.1600568-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-05-20 07:59:35 -06:00
Christoph Hellwig
3212135a71 block: remove disk_part_iter
Just open code the xa_for_each in the remaining user.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210406062303.811835-12-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-08 10:24:36 -06:00
Christoph Hellwig
7fae67cc9c block: simplify diskstats_show
Just use xa_for_each to iterate over the partitions as there is no need
to grab a reference to each partition.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210406062303.811835-11-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-08 10:24:36 -06:00
Christoph Hellwig
ecc75a98b8 block: simplify show_partition
Just use xa_for_each to iterate over the partitions as there is no need
to grab a reference to each partition.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210406062303.811835-10-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-08 10:24:36 -06:00
Christoph Hellwig
e559f58d20 block: simplify printk_all_partitions
Just use xa_for_each to iterate over the partitions as there is no need
to grab a reference to each partition.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210406062303.811835-9-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-08 10:24:36 -06:00
Christoph Hellwig
c76f48eb5c block: take bd_mutex around delete_partitions in del_gendisk
There is nothing preventing an ioctl from trying do delete partition
concurrenly with del_gendisk, so take open_mutex to serialize against
that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210406062303.811835-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-08 10:24:36 -06:00
Christoph Hellwig
d3c4a43d92 block: refactor blk_drop_partitions
Move the busy check and disk-wide sync into the only caller, so that
the remainder can be shared with del_gendisk.  Also pass the gendisk
instead of the bdev as that is all that is needed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210406062303.811835-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-08 10:24:36 -06:00
Christoph Hellwig
473338be3a block: move more syncing and invalidation to delete_partition
Move the calls to fsync_bdev and __invalidate_device from del_gendisk to
delete_partition.  For the other two callers that check that there are
no openers for the delete partitions(s) the callouts are a no-op as no
file system can be mounted, but this keeps all the cleanup in one
place.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210406062303.811835-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-08 10:24:36 -06:00
Christoph Hellwig
45611837bb block: remove invalidate_partition
invalidate_partition has two callers, one of which already performs
the remove_inode_hash just after the call.  Just open code the
function in the two callsites.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210406062303.811835-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-08 10:24:36 -06:00
Daniel Wagner
9ec491447b block: Suppress uevent for hidden device when removed
register_disk() suppress uevents for devices with the GENHD_FL_HIDDEN
but enables uevents at the end again in order to announce disk after
possible partitions are created.

When the device is removed the uevents are still on and user land sees
'remove' messages for devices which were never 'add'ed to the system.

  KERNEL[95481.571887] remove   /devices/virtual/nvme-fabrics/ctl/nvme5/nvme0c5n1 (block)

Let's suppress the uevents for GENHD_FL_HIDDEN by not enabling the
uevents at all.

Signed-off-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Link: https://lore.kernel.org/r/20210311151917.136091-1-dwagner@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-11 11:48:25 -07:00
Damien Le Moal
0f47227705 block: revert "block: fix bd_size_lock use"
With the removal of the skd driver, using IRQ safe locking of a bdev
bd_size_lock spinlock to protect the bdev inode size is not necessary
anymore as there is no other known driver using this lock under an IRQ
disabled context (e.g. calling set_capacity() with IRQ disabled).
Revert commit 0fe37724f8 ("block: fix bd_size_lock use") which
introduced the IRQ safe change.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-02-28 20:12:02 -07:00
Ming Lei
452c0bf875 block: fix logging on capacity change
Local variable of 'capacity' stores the previous disk capacity, and
'size' variable records the latest disk capacity, so swap them for
fixing logging on capacity change.

Cc: Christoph Hellwig <hch@lst.de>
Fixes: a782483cc1 ("block: remove the nr_sects field in struct hd_struct")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-02-23 19:28:51 -07:00
Christoph Hellwig
75ab6afacd block: don't skip empty device in in disk_uevent
Restore the previous behavior by using the correct flag for the whole device
("part0").

Fixes: 99dfc43ecb ("block: use ->bi_bdev for bio based I/O accounting")
Reported-by: John Stultz <john.stultz@linaro.org>
Tested-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-02-23 15:41:25 -07:00
Linus Torvalds
582cd91f69 for-5.12/block-2021-02-17
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Merge tag 'for-5.12/block-2021-02-17' of git://git.kernel.dk/linux-block

Pull core block updates from Jens Axboe:
 "Another nice round of removing more code than what is added, mostly
  due to Christoph's relentless pursuit of tech debt removal/cleanups.
  This pull request contains:

   - Two series of BFQ improvements (Paolo, Jan, Jia)

   - Block iov_iter improvements (Pavel)

   - bsg error path fix (Pan)

   - blk-mq scheduler improvements (Jan)

   - -EBUSY discard fix (Jan)

   - bvec allocation improvements (Ming, Christoph)

   - bio allocation and init improvements (Christoph)

   - Store bdev pointer in bio instead of gendisk + partno (Christoph)

   - Block trace point cleanups (Christoph)

   - hard read-only vs read-only split (Christoph)

   - Block based swap cleanups (Christoph)

   - Zoned write granularity support (Damien)

   - Various fixes/tweaks (Chunguang, Guoqing, Lei, Lukas, Huhai)"

* tag 'for-5.12/block-2021-02-17' of git://git.kernel.dk/linux-block: (104 commits)
  mm: simplify swapdev_block
  sd_zbc: clear zone resources for non-zoned case
  block: introduce blk_queue_clear_zone_settings()
  zonefs: use zone write granularity as block size
  block: introduce zone_write_granularity limit
  block: use blk_queue_set_zoned in add_partition()
  nullb: use blk_queue_set_zoned() to setup zoned devices
  nvme: cleanup zone information initialization
  block: document zone_append_max_bytes attribute
  block: use bi_max_vecs to find the bvec pool
  md/raid10: remove dead code in reshape_request
  block: mark the bio as cloned in bio_iov_bvec_set
  block: set BIO_NO_PAGE_REF in bio_iov_bvec_set
  block: remove a layer of indentation in bio_iov_iter_get_pages
  block: turn the nr_iovecs argument to bio_alloc* into an unsigned short
  block: remove the 1 and 4 vec bvec_slabs entries
  block: streamline bvec_alloc
  block: factor out a bvec_alloc_gfp helper
  block: move struct biovec_slab to bio.c
  block: reuse BIO_INLINE_VECS for integrity bvecs
  ...
2021-02-21 11:02:48 -08:00
Lukas Bulwahn
7f31bee360 block: remove typo in kernel-doc of set_disk_ro()
Commit 52f019d43c ("block: add a hard-readonly flag to struct gendisk")
provides some kernel-doc for set_disk_ro(), but introduces a small typo.

Hence, make htmldocs warns on ./block/genhd.c:1441:

  warning: Function parameter or member 'read_only' not described in 'set_disk_ro'
  warning: Excess function parameter 'ready_only' description in 'set_disk_ro'

Remove that typo in the kernel-doc for set_disk_ro().

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-01-29 07:15:50 -07:00
Damien Le Moal
0fe37724f8 block: fix bd_size_lock use
Some block device drivers, e.g. the skd driver, call set_capacity() with
IRQ disabled. This results in lockdep ito complain about inconsistent
lock states ("inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage")
because set_capacity takes a block device bd_size_lock using the
functions spin_lock() and spin_unlock(). Ensure a consistent locking
state by replacing these calls with spin_lock_irqsave() and
spin_lock_irqrestore(). The same applies to bdev_set_nr_sectors().
With this fix, all lockdep complaints are resolved.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-01-28 07:31:50 -07:00
Christoph Hellwig
a33df75c63 block: use an xarray for disk->part_tbl
Now that no fast path lookups in the partition table are left, there is
no point in micro-optimizing the data structure for it.  Just use a bog
standard xarray.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-01-24 18:17:20 -07:00
Christoph Hellwig
0470dd9d5f block: remove DISK_PITER_REVERSE
There is good reason to iterate backwards when deleting all partitions in
del_gendisk, just like we don't in blk_drop_partitions.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-01-24 18:17:20 -07:00
Christoph Hellwig
bc359d03c7 block: add a disk_uevent helper
Add a helper to call kobject_uevent for the disk and all partitions, and
unexport the disk_part_iter_* helpers that are now only used in the core
block code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-01-24 18:17:20 -07:00
Christoph Hellwig
0b6e522cdc blk-mq: use ->bi_bdev for I/O accounting
Remove the reverse map from a sector to a partition for I/O accounting by
simply using ->bi_bdev.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-01-24 18:17:20 -07:00
Christoph Hellwig
309dca309f block: store a block_device pointer in struct bio
Replace the gendisk pointer in struct bio with a pointer to the newly
improved struct block device.  From that the gendisk can be trivially
accessed with an extra indirection, but it also allows to directly
look up all information related to partition remapping.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-01-24 18:17:20 -07:00
Christoph Hellwig
947139bf3c block: propagate BLKROSET on the whole device to all partitions
Change the policy so that a BLKROSET on the whole device also affects
partitions.  To quote Martin K. Petersen:

It's very common for database folks to twiddle the read-only state of
block devices and partitions. I know that our users will find it very
counter-intuitive that setting /dev/sda read-only won't prevent writes
to /dev/sda1.

The existing behavior is inconsistent in the sense that doing:

  # blockdev --setro /dev/sda
  # echo foo > /dev/sda1

permits writes. But:

  # blockdev --setro /dev/sda
  <something triggers revalidate>
  # echo foo > /dev/sda1

doesn't.

And a subsequent:

  # blockdev --setrw /dev/sda
  # echo foo > /dev/sda1

doesn't work either since sda1's read-only policy has been inherited
from the whole-disk device.

You need to do:

  # blockdev --rereadpt

after setting the whole-disk device rw to effectuate the same change on
the partitions, otherwise they are stuck being read-only indefinitely.

However, setting the read-only policy on a partition does *not* require
the revalidate step. As a matter of fact, doing the revalidate will blow
away the policy setting you just made.

So the user needs to take different actions depending on whether they
are trying to read-protect a whole-disk device or a partition. Despite
using the same ioctl. That is really confusing.

I have lost count how many times our customers have had data clobbered
because of ambiguity of the existing whole-disk device policy. The
current behavior violates the principle of least surprise by letting the
user think they write protected the whole disk when they actually
didn't.

Suggested-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-01-24 18:15:57 -07:00
Christoph Hellwig
52f019d43c block: add a hard-readonly flag to struct gendisk
Commit 20bd1d026a ("scsi: sd: Keep disk read-only when re-reading
partition") addressed a long-standing problem with user read-only
policy being overridden as a result of a device-initiated revalidate.
The commit has since been reverted due to a regression that left some
USB devices read-only indefinitely.

To fix the underlying problems with revalidate we need to keep track
of hardware state and user policy separately.

The gendisk has been updated to reflect the current hardware state set
by the device driver. This is done to allow returning the device to
the hardware state once the user clears the BLKROSET flag.

The resulting semantics are as follows:

 - If BLKROSET sets a given partition read-only, that partition will
   remain read-only even if the underlying storage stack initiates a
   revalidate. However, the BLKRRPART ioctl will cause the partition
   table to be dropped and any user policy on partitions will be lost.

 - If BLKROSET has not been set, both the whole disk device and any
   partitions will reflect the current write-protect state of the
   underlying device.

Based on a patch from Martin K. Petersen <martin.petersen@oracle.com>.

Reported-by: Oleksii Kurochko <olkuroch@cisco.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201221
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-01-24 18:15:57 -07:00
Christoph Hellwig
6f0d9689b6 block: remove the NULL bdev check in bdev_read_only
Only a single caller can end up in bdev_read_only, so move the check
there.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-01-24 18:15:57 -07:00
Ming Lei
aebf5db917 block: fix use-after-free in disk_part_iter_next
Make sure that bdgrab() is done on the 'block_device' instance before
referring to it for avoiding use-after-free.

Cc: <stable@vger.kernel.org>
Reported-by: syzbot+825f0f9657d4e528046e@syzkaller.appspotmail.com
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-01-05 11:35:17 -07:00
Christoph Hellwig
7b51e703a8 block: update some copyrights
Update copyrights for files that have gotten some major rewrites lately.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-22 08:43:06 -07:00
Christoph Hellwig
977115c0f6 block: stop using bdget_disk for partition 0
We can just dereference the point in struct gendisk instead.  Also
remove the now unused export.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00
Christoph Hellwig
0d02129e76 block: merge struct block_device and struct hd_struct
Instead of having two structures that represent each block device with
different life time rules, merge them into a single one.  This also
greatly simplifies the reference counting rules, as we can use the inode
reference count as the main reference count for the new struct
block_device, with the device model reference front ending it for device
model interaction.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00
Christoph Hellwig
ad1eaa5344 block: switch disk_part_iter_* to use a struct block_device
Switch the partition iter infrastructure to iterate over block_device
references instead of hd_struct ones mostly used to get at the
block_device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00
Christoph Hellwig
71773cf797 block: pass a block_device to invalidate_partition
Pass the block_device actually needed instead of looking it up using
bdget_disk.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00
Christoph Hellwig
9fc995a6e0 block: pass a block_device to blk_alloc_devt
Pass the block_device actually needed instead of the hd_struct.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00
Christoph Hellwig
41e5c81984 block: remove the partno field from struct hd_struct
Just use the bd_partno field in struct block_device everywhere.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00
Christoph Hellwig
8446fe9255 block: switch partition lookup to use struct block_device
Use struct block_device to lookup partitions on a disk.  This removes
all usage of struct hd_struct from the I/O path.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Coly Li <colyli@suse.de>			[bcache]
Acked-by: Chao Yu <yuchao0@huawei.com>			[f2fs]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00
Christoph Hellwig
cb8432d650 block: allocate struct hd_struct as part of struct bdev_inode
Allocate hd_struct together with struct block_device to pre-load
the lifetime rule changes in preparation of merging the two structures.

Note that part0 was previously embedded into struct gendisk, but is
a separate allocation now, and already points to the block_device instead
of the hd_struct.  The lifetime of struct gendisk is still controlled by
the struct device embedded in the part0 hd_struct.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00
Christoph Hellwig
83950d3590 block: move the policy field to struct block_device
Move the policy field to struct block_device and rename it to the
more descriptive bd_read_only.  Also turn the field into a bool as it
is used as such.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00
Christoph Hellwig
b309e99363 block: move make_it_fail to struct block_device
Move the make_it_fail flag to struct block_device an turn it into a bool
in preparation of killing struct hd_struct.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00
Christoph Hellwig
1bdd5ae025 block: move holder_dir to struct block_device
Move the holder_dir field to struct block_device in preparation for
kill struct hd_struct.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00
Christoph Hellwig
231926dbf0 block: move the partition_meta_info to struct block_device
Move the partition_meta_info to struct block_device in preparation for
killing struct hd_struct.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00
Christoph Hellwig
29ff57c610 block: move the start_sect field to struct block_device
Move the start_sect field to struct block_device in preparation
of killing struct hd_struct.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00
Christoph Hellwig
15e3d2c5cd block: move disk stat accounting to struct block_device
Move the dkstats and stamp field to struct block_device in preparation
of killing struct hd_struct.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00
Christoph Hellwig
a782483cc1 block: remove the nr_sects field in struct hd_struct
Now that the hd_struct always has a block device attached to it, there is
no need for having two size field that just get out of sync.

Additionally the field in hd_struct did not use proper serialization,
possibly allowing for torn writes.  By only using the block_device field
this problem also gets fixed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Coly Li <colyli@suse.de>			[bcache]
Acked-by: Chao Yu <yuchao0@huawei.com>			[f2fs]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00
Christoph Hellwig
22ae8ce8b8 block: simplify bdev/disk lookup in blkdev_get
To simplify block device lookup and a few other upcoming areas, make sure
that we always have a struct block_device available for each disk and
each partition, and only find existing block devices in bdget.  The only
downside of this is that each device and partition uses a little more
memory.  The upside will be that a lot of code can be simplified.

With that all we need to look up the block device is to lookup the inode
and do a few sanity checks on the gendisk, instead of the separate lookup
for the gendisk.  For blk-cgroup which wants to access a gendisk without
opening it, a new blkdev_{get,put}_no_open low-level interface is added
to replace the previous get_gendisk use.

Note that the change to look up block device directly instead of the two
step lookup using struct gendisk causes a subtile change in behavior:
accessing a non-existing partition on an existing block device can now
cause a call to request_module.  That call is harmless, and in practice
no recent system will access these nodes as they aren't created by udev
and static /dev/ setups are unusual.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:39 -07:00
Christoph Hellwig
efdc41c8d4 block: use put_device in put_disk
Use put_device to put the device instead of poking into the internals
and using kobject_put.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:39 -07:00
Christoph Hellwig
e79319af6d block: use disk_part_iter_exit in disk_part_iter_next
Call disk_part_iter_exit in disk_part_iter_next instead of duplicating
the functionality.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:39 -07:00
Christoph Hellwig
449f4ec989 block: remove the update_bdev parameter to set_capacity_revalidate_and_notify
The update_bdev argument is always set to true, so remove it.  Also
rename the function to the slighly less verbose set_capacity_and_notify,
as propagating the disk size to the block device isn't really
revalidation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-16 08:34:14 -07:00
Christoph Hellwig
e2b6b30187 block: fix the kerneldoc comment for __register_blkdev
Switch the comment to talk about __register_blkdev instead of
register_blkdev and document the new probe parameter.

Fixes: 3da1a61e7046 ("block: add an optional probe callback to major_names")
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>
2020-11-16 08:14:31 -07:00
Christoph Hellwig
e418de3abc block: switch gendisk lookup to a simple xarray
Now that bdev_map is only used for finding gendisks, we can use
a simple xarray instead of the regions tracking structure for it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-16 08:14:31 -07:00
Christoph Hellwig
a160c6159d block: add an optional probe callback to major_names
Add a callback to the major_names array that allows a driver to override
how to probe for dev_t that doesn't currently have a gendisk registered.
This will help separating the lookup of the gendisk by dev_t vs probe
action for a not currently registered dev_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-16 08:14:30 -07:00
Christoph Hellwig
bd8eff3ba2 block: rework requesting modules for unclaimed devices
Instead of reusing the ranges in bdev_map, add a new helper that is
called if no ranges was found.  This is a first step to unpeel and
eventually remove the complex ranges structure.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-16 08:14:30 -07:00
Christoph Hellwig
e49fbbbf0a block: split block_class_lock
Split the block_class_lock mutex into one each to protect bdev_map
and major_names.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-16 08:14:30 -07:00
Christoph Hellwig
62b508f8b6 block: open code kobj_map into in block/genhd.c
Copy and paste the kobj_map functionality in the block code in preparation
for completely rewriting it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-16 08:14:30 -07:00
Christoph Hellwig
6b3ba9762f block: cleanup del_gendisk a bit
Merge three hidden gendisk checks into one.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-16 08:14:29 -07:00
Christoph Hellwig
98f49b63e8 block: remove set_device_ro
Fold set_device_ro into its only remaining caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-16 08:14:29 -07:00
Christoph Hellwig
7e890c37c2 block: add a return value to set_capacity_revalidate_and_notify
Return if the function ended up sending an uevent or not.

Cc: stable@vger.kernel.org # v5.9
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-12 13:59:04 -07:00
Christoph Hellwig
10ed16662d block: add a bdget_part helper
All remaining callers of bdget() outside of fs/block_dev.c want to get a
reference to the struct block_device for a given struct hd_struct.  Add
a helper just for that and then mark bdget static.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-05 10:38:33 -06:00
Christoph Hellwig
8a63a86e1f block: use bd_partno in bdevname
No need to go through the hd_struct to find the partition number.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-25 08:18:58 -06:00
Christoph Hellwig
9301fe7343 block: cleanup partition scanning in register_disk
Use blkdev_get_by_dev instead of open coding it using bdget_disk +
blkdev_get, and split the code to read the partition table into a
separate helper to make it a little more obvious.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-23 10:43:19 -06:00
Christoph Hellwig
38430f0876 block: move the NEED_PART_SCAN flag to struct gendisk
We can only scan for partitions on the whole disk, so move the flag
from struct block_device to struct gendisk.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-23 10:43:18 -06:00
Christoph Hellwig
95f6f3a46f block: add a bdev_check_media_change helper
Like check_disk_changed, except that it does not call ->revalidate_disk
but leaves that to the caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-10 09:32:30 -06:00
Christoph Hellwig
b8086d3f5a block: use revalidate_disk_size in set_capacity_revalidate_and_notify
Only virtio_blk and xen-blkfront set the revalidate argument to true,
and both do not implement the ->revalidate_disk method.  So switch
to the helper that just updates the size instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-02 08:00:07 -06:00
Christoph Hellwig
f4ad06f2bb block: rename bd_invalidated
Replace bd_invalidate with a new BDEV_NEED_PART_SCAN flag in a bd_flags
variable to better describe the condition.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-02 08:00:02 -06:00
Christoph Hellwig
1f06959bd2 block: remove the unused q argument to part_in_flight and part_in_flight_rw
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:31 -06:00
Christoph Hellwig
8328eb2836 block: remove the disk argument to delete_partition
We can trivially derive the gendisk from the hd_struct.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 19:38:25 -06:00
Christoph Hellwig
f93af2a494 block: cleanup __alloc_disk_node
Use early returns and goto-based unwinding to simplify the flow a bit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-01 16:49:26 -06:00
Randy Dunlap
0d20dcc277 block: genhd: delete duplicated words
Drop the repeated word "to" in multiple places.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-31 16:29:47 -06:00
Boris Burkov
ef45fe470e blk-cgroup: show global disk stats in root cgroup io.stat
In order to improve consistency and usability in cgroup stat accounting,
we would like to support the root cgroup's io.stat.

Since the root cgroup has processes doing io even if the system has no
explicitly created cgroups, we need to be careful to avoid overhead in
that case.  For that reason, the rstat algorithms don't handle the root
cgroup, so just turning the file on wouldn't give correct statistics.

To get around this, we simulate flushing the iostat struct by filling it
out directly from global disk stats. The result is a root cgroup io.stat
file consistent with both /proc/diskstats and io.stat.

Note that in order to collect the disk stats, we needed to iterate over
devices. To facilitate that, we had to change the linkage of a disk_type
to external so that it can be used from blk-cgroup.c to iterate over
disks.

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Boris Burkov <boris@bur.io>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-17 20:18:00 -06:00
Christoph Hellwig
a564e23f0f md: switch to ->check_events for media change notifications
md is the last driver using the legacy media_changed method.  Switch
it over to (not so) new ->clear_events approach, which also removes the
need for the ->revalidate_disk method.

Signed-off-by: Christoph Hellwig <hch@lst.de>
[axboe: remove unused 'bdops' variable in disk_clear_events()]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-08 16:19:47 -06:00
Luis Chamberlain
e8c7d14ac6 block: revert back to synchronous request_queue removal
Commit dc9edc44de ("block: Fix a blk_exit_rl() regression") merged on
v4.12 moved the work behind blk_release_queue() into a workqueue after a
splat floated around which indicated some work on blk_release_queue()
could sleep in blk_exit_rl(). This splat would be possible when a driver
called blk_put_queue() or blk_cleanup_queue() (which calls blk_put_queue()
as its final call) from an atomic context.

blk_put_queue() decrements the refcount for the request_queue kobject, and
upon reaching 0 blk_release_queue() is called. Although blk_exit_rl() is
now removed through commit db6d995235 ("block: remove request_list code")
on v5.0, we reserve the right to be able to sleep within
blk_release_queue() context.

The last reference for the request_queue must not be called from atomic
context. *When* the last reference to the request_queue reaches 0 varies,
and so let's take the opportunity to document when that is expected to
happen and also document the context of the related calls as best as
possible so we can avoid future issues, and with the hopes that the
synchronous request_queue removal sticks.

We revert back to synchronous request_queue removal because asynchronous
removal creates a regression with expected userspace interaction with
several drivers. An example is when removing the loopback driver, one
uses ioctls from userspace to do so, but upon return and if successful,
one expects the device to be removed. Likewise if one races to add another
device the new one may not be added as it is still being removed. This was
expected behavior before and it now fails as the device is still present
and busy still. Moving to asynchronous request_queue removal could have
broken many scripts which relied on the removal to have been completed if
there was no error. Document this expectation as well so that this
doesn't regress userspace again.

Using asynchronous request_queue removal however has helped us find
other bugs. In the future we can test what could break with this
arrangement by enabling CONFIG_DEBUG_KOBJECT_RELEASE.

While at it, update the docs with the context expectations for the
request_queue / gendisk refcount decrement, and make these
expectations explicit by using might_sleep().

Fixes: dc9edc44de ("block: Fix a blk_exit_rl() regression")
Suggested-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: yu kuai <yukuai3@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:58 -06:00
Luis Chamberlain
763b58923a block: clarify context for refcount increment helpers
Let us clarify the context under which the helpers to increment the
refcount for the gendisk and request_queue can be called under. We
make this explicit on the places where we may sleep with might_sleep().

We don't address the decrement context yet, as that needs some extra
work and fixes, but will be addressed in the next patch.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:58 -06:00
Luis Chamberlain
b5bd357cf8 block: add docs for gendisk / request_queue refcount helpers
This adds documentation for the gendisk / request_queue refcount
helpers.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:57 -06:00
Konstantin Khlebnikov
8ab1d40a64 block: remove rcu_read_lock() from part_stat_lock()
The RCU lock is required only in disk_map_sector_rcu() to lookup the
partition.  After that request holds reference to related hd_struct.

Replace get_cpu() with preempt_disable() - returned cpu index is unused.

[hch: rebased]

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27 05:21:23 -06:00
Christoph Hellwig
58d4f14fc3 block: always use a percpu variable for disk stats
percpu variables have a perfectly fine working stub implementation
for UP kernels, so use that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27 05:21:23 -06:00
Christoph Hellwig
10ec5e86f9 block: merge part_{inc,dev}_in_flight into their only callers
part_inc_in_flight and part_dec_in_flight only have one caller each, and
those callers are purely for bio based drivers.  Merge each function into
the only caller, and remove the superflous blk-mq checks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19 09:35:24 -06:00
Christoph Hellwig
b2f609e191 block: move the blk-mq calls out of part_in_flight{,_rw}
Don't bother to call part_in_flight / part_in_flight_rw on blk-mq
devices, just call the blk-mq versions directly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19 09:35:24 -06:00
Ming Lei
27eb3af9a3 block: don't hold part0's refcount in IO path
gendisk can't be gone when there is IO activity, so not hold
part0's refcount in IO path.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Cc: Yufen Yu <yuyufen@huawei.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12 20:31:40 -06:00
Ming Lei
07c4e1e834 block: only define 'nr_sects_seq' in hd_part for 32bit SMP
The seqcount of 'nr_sects_seq' is only needed in case of 32bit SMP,
so define it just for 32bit SMP.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Cc: Yufen Yu <yuyufen@huawei.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12 20:31:39 -06:00
Ming Lei
b7d6c30333 block: fix use-after-free on cached last_lookup partition
delete_partition() clears the cached last_lookup partition. However the
.last_lookup cache may be overwritten by one IO path after it is cleared
from delete_partition(). Then another IO path may use the cached deleting
partition after hd_struct_free() is called, then use-after-free is triggered
on the cached partition.

Fixes the issue by the following approach:

1) always get the partition's refcount via hd_struct_try_get() before
setting .last_lookup

2) move clearing .last_lookup from delete_partition() to hd_struct_free()
which is the release handle of the partition's percpu-refcount, so that no
IO path can cache deleteing partition via .last_lookup.

It is one candidate approach of Yufen's patch[1] which adds overhead
in fast path by indirect lookup which may introduce one extra cacheline
in IO path. Also this patch relies on percpu-refcount's protection, and
it is easier to understand and verify.

[1] https://lore.kernel.org/linux-block/20200109013551.GB9655@ming.t460p/T/#t

Reported-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12 20:31:39 -06:00
Christoph Hellwig
3c5d202b55 bdi: remove bdi_register_owner
Split out a new bdi_set_owner helper to set the owner, and move the policy
for creating the bdi name back into genhd.c, where it belongs.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-09 16:15:13 -06:00
Christoph Hellwig
9bc5c397d8 block: fold bdev_unhash_inode into invalidate_partition
invalidate_partition and bdev_unhash_inode are always paired, and
invalidate_partition already does an icache lookup for the block device
inode.  Piggy back on that to remove the inode from the hash.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-20 11:33:00 -06:00
Christoph Hellwig
02d33b6771 block: mark invalidate_partition static
invalidate_partition is only used in genhd.c, so mark it static.  Also
drop the return value given that is is always ignored.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-20 11:32:59 -06:00
Christoph Hellwig
cddae808ae block: pass a hd_struct to delete_partition
All callers have the hd_struct at hand, so pass it instead of performing
another lookup.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-20 11:32:59 -06:00
Linus Torvalds
10f36b1e80 for-5.7/block-2020-03-29
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Merge tag 'for-5.7/block-2020-03-29' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:

 - Online capacity resizing (Balbir)

 - Number of hardware queue change fixes (Bart)

 - null_blk fault injection addition (Bart)

 - Cleanup of queue allocation, unifying the node/no-node API
   (Christoph)

 - Cleanup of genhd, moving code to where it makes sense (Christoph)

 - Cleanup of the partition handling code (Christoph)

 - disk stat fixes/improvements (Konstantin)

 - BFQ improvements (Paolo)

 - Various fixes and improvements

* tag 'for-5.7/block-2020-03-29' of git://git.kernel.dk/linux-block: (72 commits)
  block: return NULL in blk_alloc_queue() on error
  block: move bio_map_* to blk-map.c
  Revert "blkdev: check for valid request queue before issuing flush"
  block: simplify queue allocation
  bcache: pass the make_request methods to blk_queue_make_request
  null_blk: use blk_mq_init_queue_data
  block: add a blk_mq_init_queue_data helper
  block: move the ->devnode callback to struct block_device_operations
  block: move the part_stat* helpers from genhd.h to a new header
  block: move block layer internals out of include/linux/genhd.h
  block: move guard_bio_eod to bio.c
  block: unexport get_gendisk
  block: unexport disk_map_sector_rcu
  block: unexport disk_get_part
  block: mark part_in_flight and part_in_flight_rw static
  block: mark block_depr static
  block: factor out requeue handling from dispatch code
  block/diskstats: replace time_in_queue with sum of request times
  block/diskstats: accumulate all per-cpu counters in one pass
  block/diskstats: more accurate approximation of io_ticks for slow disks
  ...
2020-03-30 11:20:13 -07:00
Christoph Hellwig
348e114bbd block: move the ->devnode callback to struct block_device_operations
There really isn't any good reason to stash a method directly into
struct gendisk.  Move it together with the other block device
operations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-27 09:50:05 -06:00
Christoph Hellwig
1b4d4dbdae block: unexport get_gendisk
get_gendisk is not used by any modular code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 09:50:08 -06:00
Christoph Hellwig
a7818aedda block: unexport disk_map_sector_rcu
disk_map_sector_rcu is not used by any modular code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 09:50:08 -06:00
Christoph Hellwig
572e7fc85b block: unexport disk_get_part
disk_get_part is not used by any modular code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 09:50:08 -06:00
Christoph Hellwig
6005771c17 block: mark part_in_flight and part_in_flight_rw static
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 09:50:08 -06:00
Christoph Hellwig
31eb618679 block: mark block_depr static
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 09:50:08 -06:00
Konstantin Khlebnikov
8cd5b8fc00 block/diskstats: replace time_in_queue with sum of request times
Column "time_in_queue" in diskstats is supposed to show total waiting time
of all requests. I.e. value should be equal to the sum of times from other
columns. But this is not true, because column "time_in_queue" is counted
separately in jiffies rather than in nanoseconds as other times.

This patch removes redundant counter for "time_in_queue" and shows total
time of read, write, discard and flush requests.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 08:49:12 -06:00
Konstantin Khlebnikov
ea18e0f0a6 block/diskstats: accumulate all per-cpu counters in one pass
Reading /proc/diskstats iterates over all cpus for summing each field.
It's faster to sum all fields in one pass.

Hammering /proc/diskstats with fio shows 2x performance improvement:

fio --name=test --numjobs=$JOBS --filename=/proc/diskstats \
    --size=1k --bs=1k --fallocate=none --create_on_open=1 \
    --time_based=1 --runtime=10 --invalidate=0 --group_report

	  JOBS=1	JOBS=10
Before:	  7k iops	64k iops
After:	 18k iops      120k iops

Also this way code is more compact:

add/remove: 1/0 grow/shrink: 0/2 up/down: 194/-1540 (-1346)
Function                                     old     new   delta
part_stat_read_all                             -     194    +194
diskstats_show                              1344     631    -713
part_stat_show                              1219     392    -827
Total: Before=14966947, After=14965601, chg -0.01%

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 08:49:10 -06:00
Christoph Hellwig
3ad5cee5cd block: move sysfs methods shared by disks and partitions to genhd.c
Move the sysfs _show methods that are used both on the full disk and
partition nodes to genhd.c instead of hiding them in the partitioning
code.  Also move the declaration for these methods to block/blk.h so
that we don't expose them to drivers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 07:57:07 -06:00
Christoph Hellwig
5cbd28e3ce block: move disk_name and related helpers out of partition-generic.c
Thes functions aren't really related to partition support, so move them
to a more suitable place.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 07:57:07 -06:00
Christoph Hellwig
d2332c5c04 block: remove the blk_lookup_devt export
This function is only used by init/do_mounts.c, which can't be modular.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 07:57:07 -06:00
Balbir Singh
e598a72fae block/genhd: Notify udev about capacity change
Allow block/genhd to notify user space (via udev) about disk size changes
using a new helper set_capacity_revalidate_and_notify(), which is a wrapper
on top of set_capacity(). set_capacity_revalidate_and_notify() will only
notify via udev if the current capacity or the target capacity is not zero
and iff the capacity changes.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Someswarudu Sangaraju <ssomesh@amazon.com>
Signed-off-by: Balbir Singh <sblbir@amazon.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-18 15:13:21 -06:00
Shin'ichiro Kawasaki
b53df2e744 block: Fix partition support for host aware zoned block devices
Commit b72053072c ("block: allow partitions on host aware zone
devices") introduced the helper function disk_has_partitions() to check
if a given disk has valid partitions. However, since this function result
directly depends on the disk partition table length rather than the
actual existence of valid partitions in the table, it returns true even
after all partitions are removed from the disk. For host aware zoned
block devices, this results in zone management support to be kept
disabled even after removing all partitions.

Fix this by changing disk_has_partitions() to walk through the partition
table entries and return true if and only if a valid non-zero size
partition is found.

Fixes: b72053072c ("block: allow partitions on host aware zone devices")
Cc: stable@vger.kernel.org # 5.5
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-12 07:54:39 -06:00
Konstantin Khlebnikov
b686631865 block: add iostat counters for flush requests
Requests that triggers flushing volatile writeback cache to disk (barriers)
have significant effect to overall performance.

Block layer has sophisticated engine for combining several flush requests
into one. But there is no statistics for actual flushes executed by disk.
Requests which trigger flushes usually are barriers - zero-size writes.

This patch adds two iostat counters into /sys/class/block/$dev/stat and
/proc/diskstats - count of completed flush requests and their total time.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-21 09:06:47 -07:00
Damien Le Moal
737eb78e82 block: Delay default elevator initialization
When elevator_init_mq() is called from blk_mq_init_allocated_queue(),
the only information known about the device is the number of hardware
queues as the block device scan by the device driver is not completed
yet for most drivers. The device type and elevator required features
are not set yet, preventing to correctly select the default elevator
most suitable for the device.

This currently affects all multi-queue zoned block devices which default
to the "none" elevator instead of the required "mq-deadline" elevator.
These drives currently include host-managed SMR disks connected to a
smartpqi HBA and null_blk block devices with zoned mode enabled.
Upcoming NVMe Zoned Namespace devices will also be affected.

Fix this by adding the boolean elevator_init argument to
blk_mq_init_allocated_queue() to control the execution of
elevator_init_mq(). Two cases exist:
1) elevator_init = false is used for calls to
   blk_mq_init_allocated_queue() within blk_mq_init_queue(). In this
   case, a call to elevator_init_mq() is added to __device_add_disk(),
   resulting in the delayed initialization of the queue elevator
   after the device driver finished probing the device information. This
   effectively allows elevator_init_mq() access to more information
   about the device.
2) elevator_init = true preserves the current behavior of initializing
   the elevator directly from blk_mq_init_allocated_queue(). This case
   is used for the special request based DM devices where the device
   gendisk is created before the queue initialization and device
   information (e.g. queue limits) is already known when the queue
   initialization is executed.

Additionally, to make sure that the elevator initialization is never
done while requests are in-flight (there should be none when the device
driver calls device_add_disk()), freeze and quiesce the device request
queue before calling blk_mq_init_sched() in elevator_init_mq().

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-05 19:52:34 -06:00
Akinobu Mita
1624b0b200 block: fix sysfs module parameters directory path in comment
The runtime configurable module parameter files are located under
/sys/module/MODULENAME/parameters, not /sys/module/MODULENAME.

Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-07-16 10:16:33 -06:00
Gustavo A. R. Silva
78b90a2ce8 block: genhd: Use struct_size() helper
Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes, in particular in the
context in which this code is being used.

So, replace the following form:

sizeof(*new_ptbl) + target * sizeof(new_ptbl->part[0])

with:

struct_size(new_ptbl, part, target)

Also, notice that variable size is unnecessary, hence it is removed.

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-15 01:46:09 -06:00
Bart Van Assche
33c826ef19 block: Convert blk_invalidate_devt() header into a non-kernel-doc header
This patch avoids that the kernel-doc tool warns about this function
header when building with W=1.

Reviewed-by: Chaitanya Kulkarni <chiatanya.kulkarni@wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-31 15:12:34 -06:00
Christoph Hellwig
3dcf60bcb6 block: add SPDX tags to block layer files missing licensing information
Various block layer files do not have any licensing information at all.
Add SPDX tags for the default kernel GPLv2 license to those.

Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-30 16:12:03 -06:00
Yufen Yu
6fcc44d1d7 block: fix use-after-free on gendisk
commit 2da78092dd "block: Fix dev_t minor allocation lifetime"
specifically moved blk_free_devt(dev->devt) call to part_release()
to avoid reallocating device number before the device is fully
shutdown.

However, it can cause use-after-free on gendisk in get_gendisk().
We use md device as example to show the race scenes:

Process1		Worker			Process2
md_free
						blkdev_open
del_gendisk
  add delete_partition_work_fn() to wq
  						__blkdev_get
						get_gendisk
put_disk
  disk_release
    kfree(disk)
    						find part from ext_devt_idr
						get_disk_and_module(disk)
    					  	cause use after free

    			delete_partition_work_fn
			put_device(part)
    		  	part_release
		    	remove part from ext_devt_idr

Before <devt, hd_struct pointer> is removed from ext_devt_idr by
delete_partition_work_fn(), we can find the devt and then access
gendisk by hd_struct pointer. But, if we access the gendisk after
it have been freed, it can cause in use-after-freeon gendisk in
get_gendisk().

We fix this by adding a new helper blk_invalidate_devt() in
delete_partition() and del_gendisk(). It replaces hd_struct
pointer in idr with value 'NULL', and deletes the entry from
idr in part_release() as we do now.

Thanks to Jan Kara for providing the solution and more clear comments
for the code.

Fixes: 2da78092dd ("block: Fix dev_t minor allocation lifetime")
Cc: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-22 09:48:12 -06:00
Martin Wilck
cdf3e3deb7 block: check_events: don't bother with events if unsupported
Drivers now report to the block layer if they support media change
events. If this is not the case, there's no need to allocate the event
structure, and all event handling code can effectively be skipped. This
simplifies code flow in particular for non-removable sd devices.

This effectively reverts commit 75e3f3ee3c ("block: always allocate
genhd->ev if check_events is implemented").

The sysfs files for the events are kept in place even if no events are
supported, as user space may rely on them being present. The only
difference is that an error code is now returned if the user tries to
set poll_msecs.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-12 13:35:28 -06:00
Martin Wilck
c92e2f04b3 block: disk_events: introduce event flags
Currently, an empty disk->events field tells the block layer not to
forward media change events to user space. This was done in commit
7c88a168da ("block: don't propagate unlisted DISK_EVENTs to userland")
in order to avoid events from "fringe" drivers to be forwarded to user
space. By doing so, the block layer lost the information which events
were supported by a particular block device, and most importantly,
whether or not a given device supports media change events at all.

Prepare for not interpreting the "events" field this way in the future
any more. This is done by adding an additional field "event_flags" to
struct gendisk, and two flag bits that can be set to have the device
treated like one that had the "events" field set to a non-zero value
before. This applies only to the sd and sr drivers, which are changed to
set the new flags.

The new flags are DISK_EVENT_FLAG_POLL to enforce polling of the device
for synchronous events, and DISK_EVENT_FLAG_UEVENT to tell the
blocklayer to generate udev events from kernel events.

In order to add the event_flags field to struct gendisk, the events
field is converted to an "unsigned short"; it doesn't need to hold
values bigger than 2 anyway.

This patch doesn't change behavior.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-12 13:35:24 -06:00
Martin Wilck
673387a930 block: genhd: remove async_events field
The async_events field, intended to be used for drivers that support
asynchronous notifications about disk events (aka media change events),
isn't currently used by any driver, and apparently that has been that
way for a long time (if not forever). Remove it.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-12 13:35:22 -06:00
Keyur Patel
dfc76d11dd block: Replace function name in string with __func__
Replace hard coded function name register_blkdev with __func__, to
improve robustness and to conform to the Linux kernel coding
style. Issue found using checkpatch.

Signed-off-by: Keyur Patel <iamkeyur96@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-28 14:09:08 -07:00
zhengbin
4d7c1d3fd7 block: fix NULL pointer dereference in register_disk
If __device_add_disk-->bdi_register_owner-->bdi_register-->
bdi_register_va-->device_create_vargs fails, bdi->dev is still
NULL, __device_add_disk-->register_disk will visit bdi->dev->kobj.
This patch fixes that.

Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-28 14:01:36 -07:00
Mikulas Patocka
e016b78201 block: return just one value from part_in_flight
The previous patches deleted all the code that needed the second value
returned from part_in_flight - now the kernel only uses the first value.

Consequently, part_in_flight (and blk_mq_in_flight) may be changed so that
it only returns one value.

This patch just refactors the code, there's no functional change.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-10 08:30:38 -07:00
Mikulas Patocka
1226b8dd0e block: switch to per-cpu in-flight counters
Now when part_round_stats is gone, we can switch to per-cpu in-flight
counters.

We use the local-atomic type local_t, so that if part_inc_in_flight or
part_dec_in_flight is reentrantly called from an interrupt, the value will
be correct.

The other counters could be corrupted due to reentrant interrupt, but the
corruption only results in slight counter skew - the in_flight counter
must be exact, so it needs local_t.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-10 08:30:37 -07:00
Mikulas Patocka
5b18b5a737 block: delete part_round_stats and switch to less precise counting
We want to convert to per-cpu in_flight counters.

The function part_round_stats needs the in_flight counter every jiffy, it
would be too costly to sum all the percpu variables every jiffy, so it
must be deleted. part_round_stats is used to calculate two counters -
time_in_queue and io_ticks.

time_in_queue can be calculated without part_round_stats, by adding the
duration of the I/O when the I/O ends (the value is almost as exact as the
previously calculated value, except that time for in-progress I/Os is not
counted).

io_ticks can be approximated by increasing the value when I/O is started
or ended and the jiffies value has changed. If the I/Os take less than a
jiffy, the value is as exact as the previously calculated value. If the
I/Os take more than a jiffy, io_ticks can drift behind the previously
calculated value.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-10 08:30:37 -07:00
Mike Snitzer
112f158f66 block: stop passing 'cpu' to all percpu stats methods
All of part_stat_* and related methods are used with preempt disabled,
so there is no need to pass cpu around to allow of them.  Just call
smp_processor_id() as needed.

Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-10 08:30:37 -07:00
Jens Axboe
344e9ffcbd block: add queue_is_mq() helper
Various spots check for q->mq_ops being non-NULL, but provide
a helper to do this instead.

Where the ->mq_ops != NULL check is redundant, remove it.

Since mq == rq-based now that legacy is gone, get rid of the
queue_is_rq_based() and just use queue_is_mq() everywhere.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-16 08:34:06 -07:00
Jens Axboe
c0aac682fa This is the 4.19-rc6 release
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Merge tag 'v4.19-rc6' into for-4.20/block

Merge -rc6 in, for two reasons:

1) Resolve a trivial conflict in the blk-mq-tag.c documentation
2) A few important regression fixes went into upstream directly, so
   they aren't in the 4.20 branch.

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

* tag 'v4.19-rc6': (780 commits)
  Linux 4.19-rc6
  MAINTAINERS: fix reference to moved drivers/{misc => auxdisplay}/panel.c
  cpufreq: qcom-kryo: Fix section annotations
  perf/core: Add sanity check to deal with pinned event failure
  xen/blkfront: correct purging of persistent grants
  Revert "xen/blkfront: When purging persistent grants, keep them in the buffer"
  selftests/powerpc: Fix Makefiles for headers_install change
  blk-mq: I/O and timer unplugs are inverted in blktrace
  dax: Fix deadlock in dax_lock_mapping_entry()
  x86/boot: Fix kexec booting failure in the SEV bit detection code
  bcache: add separate workqueue for journal_write to avoid deadlock
  drm/amd/display: Fix Edid emulation for linux
  drm/amd/display: Fix Vega10 lightup on S3 resume
  drm/amdgpu: Fix vce work queue was not cancelled when suspend
  Revert "drm/panel: Add device_link from panel device to DRM device"
  xen/blkfront: When purging persistent grants, keep them in the buffer
  clocksource/drivers/timer-atmel-pit: Properly handle error cases
  block: fix deadline elevator drain for zoned block devices
  ACPI / hotplug / PCI: Don't scan for non-hotplug bridges if slot is not bridge
  drm/syncobj: Don't leak fences when WAIT_FOR_SUBMIT is set
  ...

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-01 08:58:57 -06:00
Hannes Reinecke
fef912bf86 block: genhd: add 'groups' argument to device_add_disk
Update device_add_disk() to take an 'groups' argument so that
individual drivers can register a device with additional sysfs
attributes.
This avoids race condition the driver would otherwise have if these
groups were to be created with sysfs_add_groups().

Signed-off-by: Martin Wilck <martin.wilck@suse.com>
Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-28 08:30:28 -06:00
Omar Sandoval
b57e99b4b8 block: use nanosecond resolution for iostat
Klaus Kusche reported that the I/O busy time in /proc/diskstats was not
updating properly on 4.18. This is because we started using ktime to
track elapsed time, and we convert nanoseconds to jiffies when we update
the partition counter. However, this gets rounded down, so any I/Os that
take less than a jiffy are not accounted for. Previously in this case,
the value of jiffies would sometimes increment while we were doing I/O,
so at least some I/Os were accounted for.

Let's convert the stats to use nanoseconds internally. We still report
milliseconds as before, now more accurately than ever. The value is
still truncated to 32 bits for backwards compatibility.

Fixes: 522a777566 ("block: consolidate struct request timestamp fields")
Cc: stable@vger.kernel.org
Reported-by: Klaus Kusche <klaus.kusche@computerix.info>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-21 20:26:59 -06:00
Michael Callahan
bdca3c87fb block: Track DISCARD statistics and output them in stat and diskstat
Add tracking of REQ_OP_DISCARD ios to the partition statistics and
append them to the various stat files in /sys as well as
/proc/diskstats.  These are tracked with the same four stats as reads
and writes:

Number of discard ios completed.
Number of discard ios merged
Number of discard sectors completed
Milliseconds spent on discard requests

This is done via adding a new STAT_DISCARD define to genhd.h and then
using it to index that stat field for discard requests.

tj: Refreshed on top of v4.17 and other previous updates.

Signed-off-by: Michael Callahan <michaelcallahan@fb.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andy Newell <newella@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-18 08:44:22 -06:00
Michael Callahan
dbae2c5513 block: Define and use STAT_READ and STAT_WRITE
Add defines for STAT_READ and STAT_WRITE for indexing the partition
stat entries. This clarifies some fs/ code which has hardcoded 1 for
STAT_WRITE and will make it easier to extend the stats with additional
fields.

tj: Refreshed on top of v4.17.

Signed-off-by: Michael Callahan <michaelcallahan@fb.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-18 08:44:18 -06:00
Linus Torvalds
cf626b0da7 Merge branch 'hch.procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull procfs updates from Al Viro:
 "Christoph's proc_create_... cleanups series"

* 'hch.procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (44 commits)
  xfs, proc: hide unused xfs procfs helpers
  isdn/gigaset: add back gigaset_procinfo assignment
  proc: update SIZEOF_PDE_INLINE_NAME for the new pde fields
  tty: replace ->proc_fops with ->proc_show
  ide: replace ->proc_fops with ->proc_show
  ide: remove ide_driver_proc_write
  isdn: replace ->proc_fops with ->proc_show
  atm: switch to proc_create_seq_private
  atm: simplify procfs code
  bluetooth: switch to proc_create_seq_data
  netfilter/x_tables: switch to proc_create_seq_private
  netfilter/xt_hashlimit: switch to proc_create_{seq,single}_data
  neigh: switch to proc_create_seq_data
  hostap: switch to proc_create_{seq,single}_data
  bonding: switch to proc_create_seq_data
  rtc/proc: switch to proc_create_single_data
  drbd: switch to proc_create_single
  resource: switch to proc_create_seq_data
  staging/rtl8192u: simplify procfs code
  jfs: simplify procfs code
  ...
2018-06-04 10:00:01 -07:00
Joe Perches
5657a819a8 block drivers/block: Use octal not symbolic permissions
Convert the S_<FOO> symbolic permissions to their octal equivalents as
using octal and not symbolic permissions is preferred by many as more
readable.

see: https://lkml.org/lkml/2016/8/2/1945

Done with automated conversion via:
$ ./scripts/checkpatch.pl -f --types=SYMBOLIC_PERMS --fix-inplace <files...>

Miscellanea:

o Wrapped modified multi-line calls to a single line where appropriate
o Realign modified multi-line calls to open parenthesis

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-05-24 13:38:59 -06:00
Christoph Hellwig
fddda2b7b5 proc: introduce proc_create_seq{,_data}
Variants of proc_create{,_data} that directly take a struct seq_operations
argument and drastically reduces the boilerplate code in the callers.

All trivial callers converted over.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-05-16 07:23:35 +02:00
Omar Sandoval
bf0ddaba65 blk-mq: fix sysfs inflight counter
When the blk-mq inflight implementation was added, /proc/diskstats was
converted to use it, but /sys/block/$dev/inflight was not. Fix it by
adding another helper to count in-flight requests by data direction.

Fixes: f299b7c7a9 ("blk-mq: provide internal in-flight variant")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-04-26 09:02:01 -06:00
Srivatsa S. Bhat
f33ff110ef block, char_dev: Use correct format specifier for unsigned ints
register_blkdev() and __register_chrdev_region() treat the major
number as an unsigned int. So print it the same way to avoid
absurd error statements such as:
"... major requested (-1) is greater than the maximum (511) ..."
(and also fix off-by-one bugs in the error prints).

While at it, also update the comment describing register_blkdev().

Signed-off-by: Srivatsa S. Bhat <srivatsa@csail.mit.edu>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-15 17:59:24 +01:00
Jan Kara
56c0908c85 genhd: Fix BUG in blkdev_open()
When two blkdev_open() calls for a partition race with device removal
and recreation, we can hit BUG_ON(!bd_may_claim(bdev, whole, holder)) in
blkdev_open(). The race can happen as follows:

CPU0				CPU1			CPU2
							del_gendisk()
							  bdev_unhash_inode(part1);

blkdev_open(part1, O_EXCL)	blkdev_open(part1, O_EXCL)
  bdev = bd_acquire()		  bdev = bd_acquire()
  blkdev_get(bdev)
    bd_start_claiming(bdev)
      - finds old inode 'whole'
      bd_prepare_to_claim() -> 0
							  bdev_unhash_inode(whole);
							<device removed>
							<new device under same
							 number created>
				  blkdev_get(bdev);
				    bd_start_claiming(bdev)
				      - finds new inode 'whole'
				      bd_prepare_to_claim()
					- this also succeeds as we have
					  different 'whole' here...
					- bad things happen now as we
					  have two exclusive openers of
					  the same bdev

The problem here is that block device opens can see various intermediate
states while gendisk is shutting down and then being recreated.

We fix the problem by introducing new lookup_sem in gendisk that
synchronizes gendisk deletion with get_gendisk() and furthermore by
making sure that get_gendisk() does not return gendisk that is being (or
has been) deleted. This makes sure that once we ever manage to look up
newly created bdev inode, we are also guaranteed that following
get_gendisk() will either return failure (and we fail open) or it
returns gendisk for the new device and following bdget_disk() will
return new bdev inode (i.e., blkdev_open() follows the path as if it is
completely run after new device is created).

Reported-and-analyzed-by: Hou Tao <houtao1@huawei.com>
Tested-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-02-26 09:48:42 -07:00
Jan Kara
9df6c29912 genhd: Add helper put_disk_and_module()
Add a proper counterpart to get_disk_and_module() -
put_disk_and_module(). Currently it is opencoded in several places.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-02-26 09:48:42 -07:00
Jan Kara
3079c22ea8 genhd: Rename get_disk() to get_disk_and_module()
Rename get_disk() to get_disk_and_module() to make sure what the
function does. It's not a great name but at least it is now clear that
put_disk() is not it's counterpart.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-02-26 09:48:42 -07:00
Jan Kara
d52987b524 genhd: Fix leaked module reference for NVME devices
Commit 8ddcd65325 "block: introduce GENHD_FL_HIDDEN" added handling of
hidden devices to get_gendisk() but forgot to drop module reference
which is also acquired by get_disk(). Drop the reference as necessary.

Arguably the function naming here is misleading as put_disk() is *not*
the counterpart of get_disk() but let's fix that in the follow up
commit since that will be more intrusive.

Fixes: 8ddcd65325
CC: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-02-26 09:48:42 -07:00
Mike Snitzer
fa70d2e2c4 block: allow gendisk's request_queue registration to be deferred
Since I can remember DM has forced the block layer to allow the
allocation and initialization of the request_queue to be distinct
operations.  Reason for this is block/genhd.c:add_disk() has requires
that the request_queue (and associated bdi) be tied to the gendisk
before add_disk() is called -- because add_disk() also deals with
exposing the request_queue via blk_register_queue().

DM's dynamic creation of arbitrary device types (and associated
request_queue types) requires the DM device's gendisk be available so
that DM table loads can establish a master/slave relationship with
subordinate devices that are referenced by loaded DM tables -- using
bd_link_disk_holder().  But until these DM tables, and their associated
subordinate devices, are known DM cannot know what type of request_queue
it needs -- nor what its queue_limits should be.

This chicken and egg scenario has created all manner of problems for DM
and, at times, the block layer.

Summary of changes:

- Add device_add_disk_no_queue_reg() and add_disk_no_queue_reg() variant
  that drivers may use to add a disk without also calling
  blk_register_queue().  Driver must call blk_register_queue() once its
  request_queue is fully initialized.

- Return early from blk_unregister_queue() if QUEUE_FLAG_REGISTERED
  is not set.  It won't be set if driver used add_disk_no_queue_reg()
  but driver encounters an error and must del_gendisk() before calling
  blk_register_queue().

- Export blk_register_queue().

These changes allow DM to use add_disk_no_queue_reg() to anchor its
gendisk as the "master" for master/slave relationships DM must establish
with subordinate devices referenced in DM tables that get loaded.  Once
all "slave" devices for a DM device are known its request_queue can be
properly initialized and then advertised via sysfs -- important
improvement being that no request_queue resource initialization
performed by blk_register_queue() is missed for DM devices anymore.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-15 08:41:38 -07:00
Mike Snitzer
bc8d062c36 block: only bdi_unregister() in del_gendisk() if !GENHD_FL_HIDDEN
device_add_disk() will only call bdi_register_owner() if
!GENHD_FL_HIDDEN, so it follows that del_gendisk() should only call
bdi_unregister() if !GENHD_FL_HIDDEN.

Found with code inspection.  bdi_unregister() won't do any harm if
bdi_register_owner() wasn't used but best to avoid the unnecessary
call to bdi_unregister().

Fixes: 8ddcd65325 ("block: introduce GENHD_FL_HIDDEN")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-15 08:41:38 -07:00
Randy Dunlap
7fb526212f block: genhd.c: fix message typo
Fix typo in error message.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-19 11:02:19 -07:00
weiping zhang
3a92168bc8 block: add WARN_ON if bdi register fail
device_add_disk need do more safety error handle, so this patch just
add WARN_ON.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: weiping zhang <zhangweiping@didichuxing.com>

Adapted for current series by me.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-19 11:02:13 -07:00
Linus Torvalds
e2c5923c34 Merge branch 'for-4.15/block' of git://git.kernel.dk/linux-block
Pull core block layer updates from Jens Axboe:
 "This is the main pull request for block storage for 4.15-rc1.

  Nothing out of the ordinary in here, and no API changes or anything
  like that. Just various new features for drivers, core changes, etc.
  In particular, this pull request contains:

   - A patch series from Bart, closing the whole on blk/scsi-mq queue
     quescing.

   - A series from Christoph, building towards hidden gendisks (for
     multipath) and ability to move bio chains around.

   - NVMe
        - Support for native multipath for NVMe (Christoph).
        - Userspace notifications for AENs (Keith).
        - Command side-effects support (Keith).
        - SGL support (Chaitanya Kulkarni)
        - FC fixes and improvements (James Smart)
        - Lots of fixes and tweaks (Various)

   - bcache
        - New maintainer (Michael Lyle)
        - Writeback control improvements (Michael)
        - Various fixes (Coly, Elena, Eric, Liang, et al)

   - lightnvm updates, mostly centered around the pblk interface
     (Javier, Hans, and Rakesh).

   - Removal of unused bio/bvec kmap atomic interfaces (me, Christoph)

   - Writeback series that fix the much discussed hundreds of millions
     of sync-all units. This goes all the way, as discussed previously
     (me).

   - Fix for missing wakeup on writeback timer adjustments (Yafang
     Shao).

   - Fix laptop mode on blk-mq (me).

   - {mq,name} tupple lookup for IO schedulers, allowing us to have
     alias names. This means you can use 'deadline' on both !mq and on
     mq (where it's called mq-deadline). (me).

   - blktrace race fix, oopsing on sg load (me).

   - blk-mq optimizations (me).

   - Obscure waitqueue race fix for kyber (Omar).

   - NBD fixes (Josef).

   - Disable writeback throttling by default on bfq, like we do on cfq
     (Luca Miccio).

   - Series from Ming that enable us to treat flush requests on blk-mq
     like any other request. This is a really nice cleanup.

   - Series from Ming that improves merging on blk-mq with schedulers,
     getting us closer to flipping the switch on scsi-mq again.

   - BFQ updates (Paolo).

   - blk-mq atomic flags memory ordering fixes (Peter Z).

   - Loop cgroup support (Shaohua).

   - Lots of minor fixes from lots of different folks, both for core and
     driver code"

* 'for-4.15/block' of git://git.kernel.dk/linux-block: (294 commits)
  nvme: fix visibility of "uuid" ns attribute
  blk-mq: fixup some comment typos and lengths
  ide: ide-atapi: fix compile error with defining macro DEBUG
  blk-mq: improve tag waiting setup for non-shared tags
  brd: remove unused brd_mutex
  blk-mq: only run the hardware queue if IO is pending
  block: avoid null pointer dereference on null disk
  fs: guard_bio_eod() needs to consider partitions
  xtensa/simdisk: fix compile error
  nvme: expose subsys attribute to sysfs
  nvme: create 'slaves' and 'holders' entries for hidden controllers
  block: create 'slaves' and 'holders' entries for hidden gendisks
  nvme: also expose the namespace identification sysfs files for mpath nodes
  nvme: implement multipath access to nvme subsystems
  nvme: track shared namespaces
  nvme: introduce a nvme_ns_ids structure
  nvme: track subsystems
  block, nvme: Introduce blk_mq_req_flags_t
  block, scsi: Make SCSI quiesce and resume work reliably
  block: Add the QUEUE_FLAG_PREEMPT_ONLY request queue flag
  ...
2017-11-14 15:32:19 -08:00
Colin Ian King
f0fba398fe block: avoid null pointer dereference on null disk
It is possible that the pointer disk can be null and hence
we can get a null pointer deference when accessing disk->flags.
Add a null pointer check to avoid the dereference.

Detected by CoverityScan, CID#1461133 ("Explicit null dereferenced")

Fixes: 8ddcd65325 ("block: introduce GENHD_FL_HIDDEN")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-10 19:55:57 -07:00
Hannes Reinecke
17eac09963 block: create 'slaves' and 'holders' entries for hidden gendisks
When creating nvme multipath devices we should populate the 'slaves' and
'holders' directorys properly to aid userspace topology detection.

Signed-off-by: Hannes Reinecke <hare@suse.com>
[hch: split from a larger patch]
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-10 19:53:25 -07:00
Christoph Hellwig
8ddcd65325 block: introduce GENHD_FL_HIDDEN
With this flag a driver can create a gendisk that can be used for I/O
submission inside the kernel, but which is not registered as user
facing block device.  This will be useful for the NVMe multipath
implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-03 10:31:48 -06:00
Christoph Hellwig
517bf3c306 block: don't look at the struct device dev_t in disk_devt
The hidden gendisks introduced in the next patch need to keep the dev
field in their struct device empty so that udev won't try to create
block device nodes for them.  To support that rewrite disk_devt to
look at the major and first_minor fields in the gendisk itself instead
of looking into the struct device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-03 10:31:48 -06:00
Byungchul Park
e319e1fbd9 block, locking/lockdep: Assign a lock_class per gendisk used for wait_for_completion()
Darrick posted the following warning and Dave Chinner analyzed it:

> ======================================================
> WARNING: possible circular locking dependency detected
> 4.14.0-rc1-fixes #1 Tainted: G        W
> ------------------------------------------------------
> loop0/31693 is trying to acquire lock:
>  (&(&ip->i_mmaplock)->mr_lock){++++}, at: [<ffffffffa00f1b0c>] xfs_ilock+0x23c/0x330 [xfs]
>
> but now in release context of a crosslock acquired at the following:
>  ((complete)&ret.event){+.+.}, at: [<ffffffff81326c1f>] submit_bio_wait+0x7f/0xb0
>
> which lock already depends on the new lock.
>
> the existing dependency chain (in reverse order) is:
>
> -> #2 ((complete)&ret.event){+.+.}:
>        lock_acquire+0xab/0x200
>        wait_for_completion_io+0x4e/0x1a0
>        submit_bio_wait+0x7f/0xb0
>        blkdev_issue_zeroout+0x71/0xa0
>        xfs_bmapi_convert_unwritten+0x11f/0x1d0 [xfs]
>        xfs_bmapi_write+0x374/0x11f0 [xfs]
>        xfs_iomap_write_direct+0x2ac/0x430 [xfs]
>        xfs_file_iomap_begin+0x20d/0xd50 [xfs]
>        iomap_apply+0x43/0xe0
>        dax_iomap_rw+0x89/0xf0
>        xfs_file_dax_write+0xcc/0x220 [xfs]
>        xfs_file_write_iter+0xf0/0x130 [xfs]
>        __vfs_write+0xd9/0x150
>        vfs_write+0xc8/0x1c0
>        SyS_write+0x45/0xa0
>        entry_SYSCALL_64_fastpath+0x1f/0xbe
>
> -> #1 (&xfs_nondir_ilock_class){++++}:
>        lock_acquire+0xab/0x200
>        down_write_nested+0x4a/0xb0
>        xfs_ilock+0x263/0x330 [xfs]
>        xfs_setattr_size+0x152/0x370 [xfs]
>        xfs_vn_setattr+0x6b/0x90 [xfs]
>        notify_change+0x27d/0x3f0
>        do_truncate+0x5b/0x90
>        path_openat+0x237/0xa90
>        do_filp_open+0x8a/0xf0
>        do_sys_open+0x11c/0x1f0
>        entry_SYSCALL_64_fastpath+0x1f/0xbe
>
> -> #0 (&(&ip->i_mmaplock)->mr_lock){++++}:
>        up_write+0x1c/0x40
>        xfs_iunlock+0x1d0/0x310 [xfs]
>        xfs_file_fallocate+0x8a/0x310 [xfs]
>        loop_queue_work+0xb7/0x8d0
>        kthread_worker_fn+0xb9/0x1f0
>
> Chain exists of:
>   &(&ip->i_mmaplock)->mr_lock --> &xfs_nondir_ilock_class --> (complete)&ret.event
>
>  Possible unsafe locking scenario by crosslock:
>
>        CPU0                    CPU1
>        ----                    ----
>   lock(&xfs_nondir_ilock_class);
>   lock((complete)&ret.event);
>                                lock(&(&ip->i_mmaplock)->mr_lock);
>                                unlock((complete)&ret.event);
>
>                *** DEADLOCK ***

The warning is a false positive, caused by the fact that all
wait_for_completion()s in submit_bio_wait() are waiting with the same
lock class.

However, some bios have nothing to do with others, for example in the case
of loop devices, there's no direct connection between the bios of an upper
device and the bios of a lower device(=loop device).

The safest way to assign different lock classes to different devices is
to do it for each gendisk. In other words, this patch assigns a
lockdep_map per gendisk and uses it when initializing completion in
submit_bio_wait().

Analyzed-by: Dave Chinner <david@fromorbit.com>
Reported-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: amir73il@gmail.com
Cc: axboe@kernel.dk
Cc: david@fromorbit.com
Cc: hch@infradead.org
Cc: idryomov@gmail.com
Cc: johan@kernel.org
Cc: johannes.berg@intel.com
Cc: kernel-team@lge.com
Cc: linux-block@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-xfs@vger.kernel.org
Cc: oleg@redhat.com
Cc: tj@kernel.org
Link: http://lkml.kernel.org/r/1508921765-15396-10-git-send-email-byungchul.park@lge.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-26 07:54:17 +02:00
Linus Torvalds
a0725ab0c7 Merge branch 'for-4.14/block' of git://git.kernel.dk/linux-block
Pull block layer updates from Jens Axboe:
 "This is the first pull request for 4.14, containing most of the code
  changes. It's a quiet series this round, which I think we needed after
  the churn of the last few series. This contains:

   - Fix for a registration race in loop, from Anton Volkov.

   - Overflow complaint fix from Arnd for DAC960.

   - Series of drbd changes from the usual suspects.

   - Conversion of the stec/skd driver to blk-mq. From Bart.

   - A few BFQ improvements/fixes from Paolo.

   - CFQ improvement from Ritesh, allowing idling for group idle.

   - A few fixes found by Dan's smatch, courtesy of Dan.

   - A warning fixup for a race between changing the IO scheduler and
     device remova. From David Jeffery.

   - A few nbd fixes from Josef.

   - Support for cgroup info in blktrace, from Shaohua.

   - Also from Shaohua, new features in the null_blk driver to allow it
     to actually hold data, among other things.

   - Various corner cases and error handling fixes from Weiping Zhang.

   - Improvements to the IO stats tracking for blk-mq from me. Can
     drastically improve performance for fast devices and/or big
     machines.

   - Series from Christoph removing bi_bdev as being needed for IO
     submission, in preparation for nvme multipathing code.

   - Series from Bart, including various cleanups and fixes for switch
     fall through case complaints"

* 'for-4.14/block' of git://git.kernel.dk/linux-block: (162 commits)
  kernfs: checking for IS_ERR() instead of NULL
  drbd: remove BIOSET_NEED_RESCUER flag from drbd_{md_,}io_bio_set
  drbd: Fix allyesconfig build, fix recent commit
  drbd: switch from kmalloc() to kmalloc_array()
  drbd: abort drbd_start_resync if there is no connection
  drbd: move global variables to drbd namespace and make some static
  drbd: rename "usermode_helper" to "drbd_usermode_helper"
  drbd: fix race between handshake and admin disconnect/down
  drbd: fix potential deadlock when trying to detach during handshake
  drbd: A single dot should be put into a sequence.
  drbd: fix rmmod cleanup, remove _all_ debugfs entries
  drbd: Use setup_timer() instead of init_timer() to simplify the code.
  drbd: fix potential get_ldev/put_ldev refcount imbalance during attach
  drbd: new disk-option disable-write-same
  drbd: Fix resource role for newly created resources in events2
  drbd: mark symbols static where possible
  drbd: Send P_NEG_ACK upon write error in protocol != C
  drbd: add explicit plugging when submitting batches
  drbd: change list_for_each_safe to while(list_first_entry_or_null)
  drbd: introduce drbd_recv_header_maybe_unplug
  ...
2017-09-07 11:59:42 -07:00
Christoph Hellwig
807d4af2f6 block: add a __disk_get_part helper
This helper allows looking up a partion under RCU protection without
grabbing a reference to it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-23 12:49:52 -06:00
Christoph Hellwig
de65b01232 block: reject attempts to allocate more than DISK_MAX_PARTS partitions
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-23 12:49:50 -06:00
Bart Van Assche
6d2cf6f2b4 genhd: Annotate all part and part_tbl pointer dereferences
Annotate gendisk.part_tbl and disk_part_tbl.part dereferences with
rcu_dereference_protected(). This patch does not change the behavior
of the modified code but ensures that sparse does not complain about
disk->part_tbl manipulations nor about part_tbl->part accesses.
Additionally, improve documentation of the locking requirements of
the modified functions.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-18 08:36:58 -06:00
Jens Axboe
f299b7c7a9 blk-mq: provide internal in-flight variant
We don't have to inc/dec some counter, since we can just
iterate the tags. That makes inc/dec a noop, but means we
have to iterate busy tags to get an in-flight count.

Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-09 13:09:28 -06:00
Jens Axboe
0609e0efc5 block: make part_in_flight() take an array of two ints
Instead of returning the count that matches the partition, pass
in an array of two ints. Index 0 will be filled with the inflight
count for the partition in question, and index 1 will filled
with the root inflight count, if the partition passed in is not the
root.

This is in preparation for being able to calculate both in one
go.

Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-09 13:09:20 -06:00
Jens Axboe
d62e26b3ff block: pass in queue to inflight accounting
No functional change in this patch, just in preparation for
basing the inflight mechanism on the queue in question.

Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-09 13:09:16 -06:00
Logan Gunthorpe
133d55cdb2 block: order /proc/devices by major number
Presently, the order of the block devices listed in /proc/devices is not
entirely sequential. If a block device has a major number greater than
BLKDEV_MAJOR_HASH_SIZE (255), it will be ordered as if its major were
module 255. For example, 511 appears after 1.

This patch cleans that up and prints each major number in the correct
order, regardless of where they are stored in the hash table.

In order to do this, we introduce BLKDEV_MAJOR_MAX as an artificial
limit (chosen to be 512). It will then print all devices in major
order number from 0 to the maximum.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jeff Layton <jlayton@poochiereds.net>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-17 15:42:20 +02:00
Bart Van Assche
edf8ff5588 block: Constify disk_type
The variable 'disk_type' is never modified so constify it.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-20 19:27:14 -06:00
Linus Torvalds
c58d4055c0 A reasonably busy cycle for documentation this time around. There is a new
guide for user-space API documents, rather sparsely populated at the
 moment, but it's a start.  Markus improved the infrastructure for
 converting diagrams.  Mauro has converted much of the USB documentation
 over to RST.  Plus the usual set of fixes, improvements, and tweaks.
 
 There's a bit more than the usual amount of reaching out of Documentation/
 to fix comments elsewhere in the tree; I have acks for those where I could
 get them.
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Merge tag 'docs-4.12' of git://git.lwn.net/linux

Pull documentation update from Jonathan Corbet:
 "A reasonably busy cycle for documentation this time around. There is a
  new guide for user-space API documents, rather sparsely populated at
  the moment, but it's a start. Markus improved the infrastructure for
  converting diagrams. Mauro has converted much of the USB documentation
  over to RST. Plus the usual set of fixes, improvements, and tweaks.

  There's a bit more than the usual amount of reaching out of
  Documentation/ to fix comments elsewhere in the tree; I have acks for
  those where I could get them"

* tag 'docs-4.12' of git://git.lwn.net/linux: (74 commits)
  docs: Fix a couple typos
  docs: Fix a spelling error in vfio-mediated-device.txt
  docs: Fix a spelling error in ioctl-number.txt
  MAINTAINERS: update file entry for HSI subsystem
  Documentation: allow installing man pages to a user defined directory
  Doc/PM: Sync with intel_powerclamp code behavior
  zr364xx.rst: usb/devices is now at /sys/kernel/debug/
  usb.rst: move documentation from proc_usb_info.txt to USB ReST book
  convert philips.txt to ReST and add to media docs
  docs-rst: usb: update old usbfs-related documentation
  arm: Documentation: update a path name
  docs: process/4.Coding.rst: Fix a couple of document refs
  docs-rst: fix usb cross-references
  usb: gadget.h: be consistent at kernel doc macros
  usb: composite.h: fix two warnings when building docs
  usb: get rid of some ReST doc build errors
  usb.rst: get rid of some Sphinx errors
  usb/URB.txt: convert to ReST and update it
  usb/persist.txt: convert to ReST and add to driver-api book
  usb/hotplug.txt: convert to ReST and add to driver-api book
  ...
2017-05-02 10:21:17 -07:00
Dan Williams
9438b3e080 block: hide badblocks attribute by default
Commit 99e6608c9e "block: Add badblock management for gendisks"
allowed for drivers like pmem and software-raid to advertise a list of
bad media areas. However, it inadvertently added a 'badblocks' to all
block devices. Lets clean this up by having the 'badblocks' attribute
not be visible when the driver has not populated a 'struct badblocks'
instance in the gendisk.

Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-28 08:26:42 -06:00
mchehab@s-opensource.com
0e056eb553 kernel-api.rst: fix a series of errors when parsing C files
./lib/string.c:134: WARNING: Inline emphasis start-string without end-string.
./mm/filemap.c:522: WARNING: Inline interpreted text or phrase reference start-string without end-string.
./mm/filemap.c:1283: ERROR: Unexpected indentation.
./mm/filemap.c:3003: WARNING: Inline interpreted text or phrase reference start-string without end-string.
./mm/vmalloc.c:1544: WARNING: Inline emphasis start-string without end-string.
./mm/page_alloc.c:4245: ERROR: Unexpected indentation.
./ipc/util.c:676: ERROR: Unexpected indentation.
./drivers/pci/irq.c:35: WARNING: Block quote ends without a blank line; unexpected unindent.
./security/security.c:109: ERROR: Unexpected indentation.
./security/security.c:110: WARNING: Definition list ends without a blank line; unexpected unindent.
./block/genhd.c:275: WARNING: Inline strong start-string without end-string.
./block/genhd.c:283: WARNING: Inline strong start-string without end-string.
./include/linux/clk.h:134: WARNING: Inline emphasis start-string without end-string.
./include/linux/clk.h:134: WARNING: Inline emphasis start-string without end-string.
./ipc/util.c:477: ERROR: Unknown target name: "s".

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-04-02 14:31:49 -06:00
Jan Kara
d01b2dcb44 block: Fix oops scsi_disk_get()
When device open races with device shutdown, we can get the following
oops in scsi_disk_get():

[11863.044351] general protection fault: 0000 [#1] SMP
[11863.045561] Modules linked in: scsi_debug xfs libcrc32c netconsole btrfs raid6_pq zlib_deflate lzo_compress xor [last unloaded: loop]
[11863.047853] CPU: 3 PID: 13042 Comm: hald-probe-stor Tainted: G W      4.10.0-rc2-xen+ #35
[11863.048030] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[11863.048030] task: ffff88007f438200 task.stack: ffffc90000fd0000
[11863.048030] RIP: 0010:scsi_disk_get+0x43/0x70
[11863.048030] RSP: 0018:ffffc90000fd3a08 EFLAGS: 00010202
[11863.048030] RAX: 6b6b6b6b6b6b6b6b RBX: ffff88007f56d000 RCX: 0000000000000000
[11863.048030] RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff81a8d880
[11863.048030] RBP: ffffc90000fd3a18 R08: 0000000000000000 R09: 0000000000000001
[11863.059217] R10: 0000000000000000 R11: 0000000000000000 R12: 00000000fffffffa
[11863.059217] R13: ffff880078872800 R14: ffff880070915540 R15: 000000000000001d
[11863.059217] FS:  00007f2611f71800(0000) GS:ffff88007f0c0000(0000) knlGS:0000000000000000
[11863.059217] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[11863.059217] CR2: 000000000060e048 CR3: 00000000778d4000 CR4: 00000000000006e0
[11863.059217] Call Trace:
[11863.059217]  ? disk_get_part+0x22/0x1f0
[11863.059217]  sd_open+0x39/0x130
[11863.059217]  __blkdev_get+0x69/0x430
[11863.059217]  ? bd_acquire+0x7f/0xc0
[11863.059217]  ? bd_acquire+0x96/0xc0
[11863.059217]  ? blkdev_get+0x350/0x350
[11863.059217]  blkdev_get+0x126/0x350
[11863.059217]  ? _raw_spin_unlock+0x2b/0x40
[11863.059217]  ? bd_acquire+0x7f/0xc0
[11863.059217]  ? blkdev_get+0x350/0x350
[11863.059217]  blkdev_open+0x65/0x80
...

As you can see RAX value is already poisoned showing that gendisk we got
is already freed. The problem is that get_gendisk() looks up device
number in ext_devt_idr and then does get_disk() which does kobject_get()
on the disks kobject. However the disk gets removed from ext_devt_idr
only in disk_release() (through blk_free_devt()) at which moment it has
already 0 refcount and is already on its way to be freed. Indeed we've
got a warning from kobject_get() about 0 refcount shortly before the
oops.

We fix the problem by using kobject_get_unless_zero() in get_disk() so
that get_disk() cannot get reference on a disk that is already being
freed.

Tested-by: Lekshmi Pillai <lekshmicpillai@in.ibm.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-22 20:11:37 -06:00
Jan Kara
c01228db4b Revert "scsi, block: fix duplicate bdi name registration crashes"
This reverts commit 0dba1314d4. It causes
leaking of device numbers for SCSI when SCSI registers multiple gendisks
for one request_queue in succession. It can be easily reproduced using
Omar's script [1] on kernel with CONFIG_DEBUG_TEST_DRIVER_REMOVE.
Furthermore the protection provided by this commit is not needed anymore
as the problem it was fixing got also fixed by commit 165a5e22fa
"block: Move bdi_unregister() to del_gendisk()".

[1]: http://marc.info/?l=linux-block&m=148554717109098&w=2

Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-08 10:55:17 -07:00
Jan Kara
90f16fddcc block: Make del_gendisk() safer for disks without queues
Commit 165a5e22fa "block: Move bdi_unregister() to del_gendisk()"
added disk->queue dereference to del_gendisk(). Although del_gendisk()
is not supposed to be called without disk->queue valid and
blk_unregister_queue() warns in that case, this change will make it oops
instead. Return to the old more robust behavior of just warning when
del_gendisk() gets called for gendisk with disk->queue being NULL.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Tested-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-08 10:55:17 -07:00
Jan Kara
165a5e22fa block: Move bdi_unregister() to del_gendisk()
Commit 6cd18e711d "block: destroy bdi before blockdev is
unregistered." moved bdi unregistration (at that time through
bdi_destroy()) from blk_release_queue() to blk_cleanup_queue() because
it needs to happen before blk_unregister_region() call in del_gendisk()
for MD. SCSI though will free up the device number from sd_remove()
called through a maze of callbacks from device_del() in
__scsi_remove_device() before blk_cleanup_queue() and thus similar races
as described in 6cd18e711d can happen for SCSI as well as reported by
Omar [1].

Moving bdi_unregister() to del_gendisk() works for MD and fixes the
problem for SCSI since del_gendisk() gets called from sd_remove() before
freeing the device number.

This also makes device_add_disk() (calling bdi_register_owner()) more
symmetric with del_gendisk().

[1] http://marc.info/?l=linux-block&m=148554717109098&w=2

Tested-by: Lekshmi Pillai <lekshmicpillai@in.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Tested-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-02 16:08:35 -07:00
Jan Kara
d06e05c026 block: Unhash also block device inode for the whole device
Iteration over partitions in del_gendisk() omits part0. Add
bdev_unhash_inode() call for the whole device. Otherwise if the device
number gets reused, bdev inode will be still associated with the old
(stale) bdi.

Tested-by: Lekshmi Pillai <lekshmicpillai@in.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-21 12:51:54 -07:00
Jan Kara
4b8c861a7c block: Move bdev_unhash_inode() after invalidate_partition()
Move bdev_unhash_inode() after invalidate_partition() as
invalidate_partition() looks up bdev and it cannot find the right bdev
inode after bdev_unhash_inode() is called. Thus invalidate_partition()
would not invalidate page cache of the previously used bdev. Also use
part_devt() when calling bdev_unhash_inode() instead of manually
creating the device number.

Tested-by: Lekshmi Pillai <lekshmicpillai@in.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-21 12:51:54 -07:00
Dan Williams
0dba1314d4 scsi, block: fix duplicate bdi name registration crashes
Warnings of the following form occur because scsi reuses a devt number
while the block layer still has it referenced as the name of the bdi
[1]:

 WARNING: CPU: 1 PID: 93 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x62/0x80
 sysfs: cannot create duplicate filename '/devices/virtual/bdi/8:192'
 [..]
 Call Trace:
  dump_stack+0x86/0xc3
  __warn+0xcb/0xf0
  warn_slowpath_fmt+0x5f/0x80
  ? kernfs_path_from_node+0x4f/0x60
  sysfs_warn_dup+0x62/0x80
  sysfs_create_dir_ns+0x77/0x90
  kobject_add_internal+0xb2/0x350
  kobject_add+0x75/0xd0
  device_add+0x15a/0x650
  device_create_groups_vargs+0xe0/0xf0
  device_create_vargs+0x1c/0x20
  bdi_register+0x90/0x240
  ? lockdep_init_map+0x57/0x200
  bdi_register_owner+0x36/0x60
  device_add_disk+0x1bb/0x4e0
  ? __pm_runtime_use_autosuspend+0x5c/0x70
  sd_probe_async+0x10d/0x1c0
  async_run_entry_fn+0x39/0x170

This is a brute-force fix to pass the devt release information from
sd_probe() to the locations where we register the bdi,
device_add_disk(), and unregister the bdi, blk_cleanup_queue().

Thanks to Omar for the quick reproducer script [2]. This patch survives
where an unmodified kernel fails in a few seconds.

[1]: https://marc.info/?l=linux-scsi&m=147116857810716&w=4
[2]: http://marc.info/?l=linux-block&m=148554717109098&w=2

Cc: James Bottomley <James.Bottomley@hansenpartnership.com>
Cc: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Jan Kara <jack@suse.cz>
Reported-by: Omar Sandoval <osandov@osandov.com>
Tested-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-02 08:23:19 -07:00
Jan Kara
dc3b17cc8b block: Use pointer to backing_dev_info from request_queue
We will want to have struct backing_dev_info allocated separately from
struct request_queue. As the first step add pointer to backing_dev_info
to request_queue and convert all users touching it. No functional
changes in this patch.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-02 08:20:48 -07:00
Jan Kara
f44f1ab5a2 block: Unhash block device inodes on gendisk destruction
Currently, block device inodes stay around after corresponding gendisk
hash died until memory reclaim finds them and frees them. Since we will
make block device inode pin the bdi, we want to free the block device
inode as soon as the device goes away so that bdi does not stay around
unnecessarily. Furthermore we need to avoid issues when new device with
the same major,minor pair gets created since reusing the bdi structure
would be rather difficult in this case.

Unhashing block device inode on gendisk destruction nicely deals with
these problems. Once last block device inode reference is dropped (which
may be directly in del_gendisk()), the inode gets evicted. Furthermore if
the major,minor pair gets reallocated, we are guaranteed to get new
block device inode even if old block device inode is not yet evicted and
thus we avoid issues with possible reuse of bdi.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-02 08:18:41 -07:00
Dan Williams
df08c32ce3 block: fix bdi vs gendisk lifetime mismatch
The name for a bdi of a gendisk is derived from the gendisk's devt.
However, since the gendisk is destroyed before the bdi it leaves a
window where a new gendisk could dynamically reuse the same devt while a
bdi with the same name is still live.  Arrange for the bdi to hold a
reference against its "owner" disk device while it is registered.
Otherwise we can hit sysfs duplicate name collisions like the following:

 WARNING: CPU: 10 PID: 2078 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x64/0x80
 sysfs: cannot create duplicate filename '/devices/virtual/bdi/259:1'

 Hardware name: HP ProLiant DL580 Gen8, BIOS P79 05/06/2015
  0000000000000286 0000000002c04ad5 ffff88006f24f970 ffffffff8134caec
  ffff88006f24f9c0 0000000000000000 ffff88006f24f9b0 ffffffff8108c351
  0000001f0000000c ffff88105d236000 ffff88105d1031e0 ffff8800357427f8
 Call Trace:
  [<ffffffff8134caec>] dump_stack+0x63/0x87
  [<ffffffff8108c351>] __warn+0xd1/0xf0
  [<ffffffff8108c3cf>] warn_slowpath_fmt+0x5f/0x80
  [<ffffffff812a0d34>] sysfs_warn_dup+0x64/0x80
  [<ffffffff812a0e1e>] sysfs_create_dir_ns+0x7e/0x90
  [<ffffffff8134faaa>] kobject_add_internal+0xaa/0x320
  [<ffffffff81358d4e>] ? vsnprintf+0x34e/0x4d0
  [<ffffffff8134ff55>] kobject_add+0x75/0xd0
  [<ffffffff816e66b2>] ? mutex_lock+0x12/0x2f
  [<ffffffff8148b0a5>] device_add+0x125/0x610
  [<ffffffff8148b788>] device_create_groups_vargs+0xd8/0x100
  [<ffffffff8148b7cc>] device_create_vargs+0x1c/0x20
  [<ffffffff811b775c>] bdi_register+0x8c/0x180
  [<ffffffff811b7877>] bdi_register_dev+0x27/0x30
  [<ffffffff813317f5>] add_disk+0x175/0x4a0

Cc: <stable@vger.kernel.org>
Reported-by: Yi Zhang <yizhan@redhat.com>
Tested-by: Yi Zhang <yizhan@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Fixed up missing 0 return in bdi_register_owner().

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-04 14:19:16 -06:00
Vegard Nossum
77da160530 block: fix use-after-free in seq file
I got a KASAN report of use-after-free:

    ==================================================================
    BUG: KASAN: use-after-free in klist_iter_exit+0x61/0x70 at addr ffff8800b6581508
    Read of size 8 by task trinity-c1/315
    =============================================================================
    BUG kmalloc-32 (Not tainted): kasan: bad access detected
    -----------------------------------------------------------------------------

    Disabling lock debugging due to kernel taint
    INFO: Allocated in disk_seqf_start+0x66/0x110 age=144 cpu=1 pid=315
            ___slab_alloc+0x4f1/0x520
            __slab_alloc.isra.58+0x56/0x80
            kmem_cache_alloc_trace+0x260/0x2a0
            disk_seqf_start+0x66/0x110
            traverse+0x176/0x860
            seq_read+0x7e3/0x11a0
            proc_reg_read+0xbc/0x180
            do_loop_readv_writev+0x134/0x210
            do_readv_writev+0x565/0x660
            vfs_readv+0x67/0xa0
            do_preadv+0x126/0x170
            SyS_preadv+0xc/0x10
            do_syscall_64+0x1a1/0x460
            return_from_SYSCALL_64+0x0/0x6a
    INFO: Freed in disk_seqf_stop+0x42/0x50 age=160 cpu=1 pid=315
            __slab_free+0x17a/0x2c0
            kfree+0x20a/0x220
            disk_seqf_stop+0x42/0x50
            traverse+0x3b5/0x860
            seq_read+0x7e3/0x11a0
            proc_reg_read+0xbc/0x180
            do_loop_readv_writev+0x134/0x210
            do_readv_writev+0x565/0x660
            vfs_readv+0x67/0xa0
            do_preadv+0x126/0x170
            SyS_preadv+0xc/0x10
            do_syscall_64+0x1a1/0x460
            return_from_SYSCALL_64+0x0/0x6a

    CPU: 1 PID: 315 Comm: trinity-c1 Tainted: G    B           4.7.0+ #62
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
     ffffea0002d96000 ffff880119b9f918 ffffffff81d6ce81 ffff88011a804480
     ffff8800b6581500 ffff880119b9f948 ffffffff8146c7bd ffff88011a804480
     ffffea0002d96000 ffff8800b6581500 fffffffffffffff4 ffff880119b9f970
    Call Trace:
     [<ffffffff81d6ce81>] dump_stack+0x65/0x84
     [<ffffffff8146c7bd>] print_trailer+0x10d/0x1a0
     [<ffffffff814704ff>] object_err+0x2f/0x40
     [<ffffffff814754d1>] kasan_report_error+0x221/0x520
     [<ffffffff8147590e>] __asan_report_load8_noabort+0x3e/0x40
     [<ffffffff83888161>] klist_iter_exit+0x61/0x70
     [<ffffffff82404389>] class_dev_iter_exit+0x9/0x10
     [<ffffffff81d2e8ea>] disk_seqf_stop+0x3a/0x50
     [<ffffffff8151f812>] seq_read+0x4b2/0x11a0
     [<ffffffff815f8fdc>] proc_reg_read+0xbc/0x180
     [<ffffffff814b24e4>] do_loop_readv_writev+0x134/0x210
     [<ffffffff814b4c45>] do_readv_writev+0x565/0x660
     [<ffffffff814b8a17>] vfs_readv+0x67/0xa0
     [<ffffffff814b8de6>] do_preadv+0x126/0x170
     [<ffffffff814b92ec>] SyS_preadv+0xc/0x10

This problem can occur in the following situation:

open()
 - pread()
    - .seq_start()
       - iter = kmalloc() // succeeds
       - seqf->private = iter
    - .seq_stop()
       - kfree(seqf->private)
 - pread()
    - .seq_start()
       - iter = kmalloc() // fails
    - .seq_stop()
       - class_dev_iter_exit(seqf->private) // boom! old pointer

As the comment in disk_seqf_stop() says, stop is called even if start
failed, so we need to reinitialise the private pointer to NULL when seq
iteration stops.

An alternative would be to set the private pointer to NULL when the
kmalloc() in disk_seqf_start() fails.

Cc: stable@vger.kernel.org
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-04 14:19:16 -06:00
Linus Torvalds
3fc9d69093 Merge branch 'for-4.8/drivers' of git://git.kernel.dk/linux-block
Pull block driver updates from Jens Axboe:
 "This branch also contains core changes.  I've come to the conclusion
  that from 4.9 and forward, I'll be doing just a single branch.  We
  often have dependencies between core and drivers, and it's hard to
  always split them up appropriately without pulling core into drivers
  when that happens.

  That said, this contains:

   - separate secure erase type for the core block layer, from
     Christoph.

   - set of discard fixes, from Christoph.

   - bio shrinking fixes from Christoph, as a followup up to the
     op/flags change in the core branch.

   - map and append request fixes from Christoph.

   - NVMeF (NVMe over Fabrics) code from Christoph.  This is pretty
     exciting!

   - nvme-loop fixes from Arnd.

   - removal of ->driverfs_dev from Dan, after providing a
     device_add_disk() helper.

   - bcache fixes from Bhaktipriya and Yijing.

   - cdrom subchannel read fix from Vchannaiah.

   - set of lightnvm updates from Wenwei, Matias, Johannes, and Javier.

   - set of drbd updates and fixes from Fabian, Lars, and Philipp.

   - mg_disk error path fix from Bart.

   - user notification for failed device add for loop, from Minfei.

   - NVMe in general:
        + NVMe delay quirk from Guilherme.
        + SR-IOV support and command retry limits from Keith.
        + fix for memory-less NUMA node from Masayoshi.
        + use UINT_MAX for discard sectors, from Minfei.
        + cancel IO fixes from Ming.
        + don't allocate unused major, from Neil.
        + error code fixup from Dan.
        + use constants for PSDT/FUSE from James.
        + variable init fix from Jay.
        + fabrics fixes from Ming, Sagi, and Wei.
        + various fixes"

* 'for-4.8/drivers' of git://git.kernel.dk/linux-block: (115 commits)
  nvme/pci: Provide SR-IOV support
  nvme: initialize variable before logical OR'ing it
  block: unexport various bio mapping helpers
  scsi/osd: open code blk_make_request
  target: stop using blk_make_request
  block: simplify and export blk_rq_append_bio
  block: ensure bios return from blk_get_request are properly initialized
  virtio_blk: use blk_rq_map_kern
  memstick: don't allow REQ_TYPE_BLOCK_PC requests
  block: shrink bio size again
  block: simplify and cleanup bvec pool handling
  block: get rid of bio_rw and READA
  block: don't ignore -EOPNOTSUPP blkdev_issue_write_same
  block: introduce BLKDEV_DISCARD_ZERO to fix zeroout
  NVMe: don't allocate unused nvme_major
  nvme: avoid crashes when node 0 is memoryless node.
  nvme: Limit command retries
  loop: Make user notify for adding loop device failed
  nvme-loop: fix nvme-loop Kconfig dependencies
  nvmet: fix return value check in nvmet_subsys_alloc()
  ...
2016-07-26 15:37:51 -07:00
Thomas Gleixner
53bf837b78 timers: Remove set_timer_slack() leftovers
We now have implicit batching in the timer wheel. The slack API is no longer
used, so remove it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Andrew F. Davis <afd@ti.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Chris Mason <clm@fb.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: George Spelvin <linux@sciencehorizons.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathias Nyman <mathias.nyman@intel.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: linux-block@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mmc@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160704094342.189813118@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-07 10:35:09 +02:00
Dan Williams
52c44d93c2 block: remove ->driverfs_dev
Now that all drivers that specify a ->driverfs_dev have been converted
to device_add_disk(), the pointer can be removed from struct gendisk.

Cc: Jens Axboe <axboe@fb.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-06-27 12:26:08 -07:00
Dan Williams
e63a46bef0 block: introduce device_add_disk()
In preparation for removing the ->driverfs_dev member of a gendisk, add
an api that takes the parent device as a parameter to add_disk().  For
now this maintains the status quo of WARN()ing on failure, but not
return a error code.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-06-15 19:53:06 -07:00
Linus Torvalds
7c24d9f3b2 Merge branch 'for-4.5/core' of git://git.kernel.dk/linux-block
Pull core block updates from Jens Axboe:
 "We don't have a lot of core changes this time around, it's mostly in
  drivers, which will come in a subsequent pull.

  The cores changes include:

   - blk-mq
        - Prep patch from Christoph, changing blk_mq_alloc_request() to
          take flags instead of just using gfp_t for sleep/nosleep.
        - Doc patch from me, clarifying the difference between legacy
          and blk-mq for timer usage.
        - Fixes from Raghavendra for memory-less numa nodes, and a reuse
          of CPU masks.

   - Cleanup from Geliang Tang, using offset_in_page() instead of open
     coding it.

   - From Ilya, rename request_queue slab to it reflects what it holds,
     and a fix for proper use of bdgrab/put.

   - A real fix for the split across stripe boundaries from Keith.  We
     yanked a broken version of this from 4.4-rc final, this one works.

   - From Mike Krinkin, emit a trace message when we split.

   - From Wei Tang, two small cleanups, not explicitly clearing memory
     that is already cleared"

* 'for-4.5/core' of git://git.kernel.dk/linux-block:
  block: use bd{grab,put}() instead of open-coding
  block: split bios to max possible length
  block: add call to split trace point
  blk-mq: Avoid memoryless numa node encoded in hctx numa_node
  blk-mq: Reuse hardware context cpumask for tags
  blk-mq: add a flags parameter to blk_mq_alloc_request
  Revert "blk-flush: Queue through IO scheduler when flush not required"
  block: clarify blk_add_timer() use case for blk-mq
  bio: use offset_in_page macro
  block: do not initialise statics to 0 or NULL
  block: do not initialise globals to 0 or NULL
  block: rename request_queue slab cache
2016-01-19 15:03:34 -08:00
Dan Williams
55f5560d8c block: kill disk_{check|set|clear|alloc}_badblocks
These actions are completely managed by a block driver or can use the
badblocks api directly.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09 22:42:31 -08:00
Dan Williams
20a308f09e block: clarify badblocks lifetime
The badblocks list attached to a gendisk is allocated by the driver
which equates to the driver owning the lifetime of the object.  Do not
automatically free it in del_gendisk(). This is in preparation for
expanding the use of badblocks in libnvdimm drivers and introducing
devm_init_badblocks().

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09 08:39:04 -08:00
Dan Williams
d3b407fb3f badblocks: rename badblocks_free to badblocks_exit
For symmetry with badblocks_init() make it clear that this path only
destroys incremental allocations of a badblocks instance, and does not
free the badblocks instance itself.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09 08:39:04 -08:00
Vishal Verma
99e6608c9e block: Add badblock management for gendisks
NVDIMM devices, which can behave more like DRAM rather than block
devices, may develop bad cache lines, or 'poison'. A block device
exposed by the pmem driver can then consume poison via a read (or
write), and cause a machine check. On platforms without machine
check recovery features, this would mean a crash.

The block device maintaining a runtime list of all known sectors that
have poison can directly avoid this, and also provide a path forward
to enable proper handling/recovery for DAX faults on such a device.

Use the new badblock management interfaces to add a badblocks list to
gendisks.

Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09 08:36:51 -08:00
Dan Williams
ac34f15e0c block: fix del_gendisk() vs blkdev_ioctl crash
When tearing down a block device early in its lifetime, userspace may
still be performing discovery actions like blkdev_ioctl() to re-read
partitions.

The nvdimm_revalidate_disk() implementation depends on
disk->driverfs_dev to be valid at entry.  However, it is set to NULL in
del_gendisk() and fatally this is happening *before* the disk device is
deleted from userspace view.

There's no reason for del_gendisk() to clear ->driverfs_dev.  That
device is the parent of the disk.  It is guaranteed to not be freed
until the disk, as a child, drops its ->parent reference.

We could also fix this issue locally in nvdimm_revalidate_disk() by
using disk_to_dev(disk)->parent, but lets fix it globally since
->driverfs_dev follows the lifetime of the parent.  Longer term we
should probably just add a @parent parameter to add_disk(), and stop
carrying this pointer in the gendisk.

 BUG: unable to handle kernel NULL pointer dereference at           (null)
 IP: [<ffffffffa00340a8>] nvdimm_revalidate_disk+0x18/0x90 [libnvdimm]
 CPU: 2 PID: 538 Comm: systemd-udevd Tainted: G           O    4.4.0-rc5 #2257
 [..]
 Call Trace:
  [<ffffffff8143e5c7>] rescan_partitions+0x87/0x2c0
  [<ffffffff810f37f9>] ? __lock_is_held+0x49/0x70
  [<ffffffff81438c62>] __blkdev_reread_part+0x72/0xb0
  [<ffffffff81438cc5>] blkdev_reread_part+0x25/0x40
  [<ffffffff8143982d>] blkdev_ioctl+0x4fd/0x9c0
  [<ffffffff811246c9>] ? current_kernel_time64+0x69/0xd0
  [<ffffffff812916dd>] block_ioctl+0x3d/0x50
  [<ffffffff81264c38>] do_vfs_ioctl+0x308/0x560
  [<ffffffff8115dbd1>] ? __audit_syscall_entry+0xb1/0x100
  [<ffffffff810031d6>] ? do_audit_syscall_entry+0x66/0x70
  [<ffffffff81264f09>] SyS_ioctl+0x79/0x90
  [<ffffffff81902672>] entry_SYSCALL_64_fastpath+0x12/0x76

Reported-by: Robert Hu <robert.hu@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09 06:35:12 -08:00