Buncha changes in this version. I came up with a new, much better solution to the "bio allocation from bio sets under generic_make_request()" problem. Previously, I was working around this in all of my code that allocated bios; it'd mask out GFP_WAIT if current->bio_list != NULL, then punt to workqueue if the allocation failed - so as to avoid the deadlock from allocating multiple bios from the same bio set.
This approach worked, but it required it to be explicitly handled in any stacking driver that might split a bio an arbitrary number of times - less than ideal. My new patch inverts this - when we go to allocate a bio and we're blocking another bio from being submitted, we punt the bio(s) that are being blocked off to a workqueue to be submitted. This means we only have to handle it in one place, in bio_alloc_bioset() - stack block drivers no longer have to do anything special (I got to delete some code from bcache, and dm wasn't handling this at all before). Other big change - I consolidated bio allocation. Now bio_alloc(), bio_kmalloc(), bio_clone(), and bio_clone_kmalloc() are all one line wrappers. Incorporated a bunch of review feedback, most of which I hopefully remembered to note in the patch descriptions this time. Kent Overstreet (13): block: Generalized bio pool freeing dm: Use bioset's front_pad for dm_rq_clone_bio_info block: Add bio_reset() pktcdvd: Switch to bio_kmalloc() block: Kill bi_destructor block: Consolidate bio_alloc_bioset(), bio_kmalloc() block: Avoid deadlocks with bio allocation by stacking drivers block: Add an explicit bio flag for bios that own their bvec block: Rename bio_split() -> bio_pair_split() block: Introduce new bio_split() block: Rework bio_pair_split() block: Add bio_clone_bioset(), bio_clone_kmalloc() block: Only clone bio vecs that are in use Documentation/block/biodoc.txt | 5 - block/blk-core.c | 10 +- drivers/block/drbd/drbd_main.c | 13 +- drivers/block/drbd/drbd_req.c | 18 +- drivers/block/osdblk.c | 3 +- drivers/block/pktcdvd.c | 73 ++----- drivers/block/rbd.c | 8 +- drivers/md/dm-crypt.c | 9 - drivers/md/dm-io.c | 11 - drivers/md/dm.c | 68 ++---- drivers/md/linear.c | 6 +- drivers/md/md.c | 44 +--- drivers/md/raid0.c | 8 +- drivers/md/raid10.c | 23 +- drivers/target/target_core_iblock.c | 9 - fs/bio-integrity.c | 45 ---- fs/bio.c | 419 +++++++++++++++++++++++------------- fs/exofs/ore.c | 5 +- include/linux/bio.h | 155 +++++++------ include/linux/blk_types.h | 16 +- 20 files changed, 434 insertions(+), 514 deletions(-) -- 1.7.12 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
