Hello,

this patch series implements the idea of blkdev_get_by_*() calls returning
bdev_handle which is then passed to blkdev_put() [1]. This makes the get
and put calls for bdevs more obviously matching and allows us to propagate
context from get to put without having to modify all the users (again!).
In particular I need to propagate used open flags to blkdev_put() to be able
count writeable opens and add support for blocking writes to mounted block
devices. I'll send that series separately.

The series is based on Linus' tree as of yesterday + two bcache fixes which are
in the block tree. Patches have passed some basic testing, I plan to test more
users once we agree this is the right way to go.

								Honza

[1] https://lore.kernel.org/all/ZJGNsVDhZx0Xgs2H@infradead.org

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