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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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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
...
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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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
...
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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
...
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>
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>
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>
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>
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>
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
...
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>
