Some of bcache's utility code has made it into the rest of the kernel,
so drop the bcache versions.
Bcache used to have a workaround for allocating from a bio set under
generic_make_request() (if you allocated more than once, the bios you
already allocated would get stuck on current->bio_list when you
submitted, and you'd risk deadlock) - bcache would mask out __GFP_WAIT
when allocating bios under generic_make_request() so that allocation
could fail and it could retry from workqueue. But bio_alloc_bioset() has
a workaround now, so we can drop this hack and the associated error
handling.
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Now that we're tracking dirty data per stripe, we can add two
optimizations for raid5/6:
* If a stripe is already dirty, force writes to that stripe to
writeback mode - to help build up full stripes of dirty data
* When flushing dirty data, preferentially write out full stripes first
if there are any.
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Old gcc doesnt like the struct hack, and it is kind of ugly. So finish
off the work to convert pr_debug() statements to tracepoints, and delete
pkey()/pbtree().
Signed-off-by: Kent Overstreet <koverstreet@google.com>
The most significant change is that btree reads are now done
synchronously, instead of asynchronously and doing the post read stuff
from a workqueue.
This was originally done because we can't block on IO under
generic_make_request(). But - we already have a mechanism to punt cache
lookups to workqueue if needed, so if we just use that we don't have to
deal with the complexity of doing things asynchronously.
The main benefit is this makes the locking situation saner; we can hold
our write lock on the btree node until we're finished reading it, and we
don't need that btree_node_read_done() flag anymore.
Also, for writes, btree_write() was broken out into btree_node_write()
and btree_leaf_dirty() - the old code with the boolean argument was dumb
and confusing.
The prio_blocked mechanism was improved a bit too, now the only counter
is in struct btree_write, we don't mess with transfering a count from
struct btree anymore.
This required changing garbage collection to block prios at the start
and unblock when it finishes, which is cleaner than what it was doing
anyways (the old code had mostly the same effect, but was doing it in a
convoluted way)
And the btree iter btree_node_read_done() uses was converted to a real
mempool.
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Took out some nested functions, and fixed some more checkpatch
complaints.
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: linux-bcache@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Does writethrough and writeback caching, handles unclean shutdown, and
has a bunch of other nifty features motivated by real world usage.
See the wiki at http://bcache.evilpiepirate.org for more.
Signed-off-by: Kent Overstreet <koverstreet@google.com>
