On Thu, Sep 20, 2012 at 05:25:55PM -0700, Tejun Heo wrote:
Hello, Kent.
On Mon, Sep 10, 2012 at 05:22:30PM -0700, Kent Overstreet wrote:
quoted
A bunch of what __blk_queue_bounce() was doing was problematic for the
immutable bvec work; this cleans that up and the code is quite a bit
smaller, too.
The __bio_for_each_segment() in copy_to_high_bio_irq() was changed
because that one's looping over the original bio, not the bounce bio -
since the bounce code doesn't own that bio the __ version wasn't
correct.
I do like the new implementation. I think the function is broken
before and after tho. Allocating from fs_bio_set from block layer is
never safe and nothing seems to prevent multiple allocators compete in
the bounce page mempool. This will need a separate bioset and the
multiple mempool allocation would have to be put inside a mutex.
Yeah, I should've at least made a note of that.
I should really add "audit all uses of fs_bio_set" to my todo list.
Also, how was this tested?
Changed queue_bounce_pfn() to return 0, forcing all io to be bounced.