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author | Christoph Hellwig <hch@lst.de> | 2020-11-26 11:23:26 +0300 |
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committer | Jens Axboe <axboe@kernel.dk> | 2020-12-02 00:53:39 +0300 |
commit | 22ae8ce8b89241c94ac00c237752c0ffa37ba5ae (patch) | |
tree | af6d4dfd72e76789c25c64cd1765f037d91f6b72 /drivers/block/loop.c | |
parent | 4e7b5671c6a883d94b5428e1a9c141bbd56cb2a6 (diff) | |
download | linux-22ae8ce8b89241c94ac00c237752c0ffa37ba5ae.tar.xz |
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>
Diffstat (limited to 'drivers/block/loop.c')
0 files changed, 0 insertions, 0 deletions