Add a new blk_mq_tag_set structure that gets set up before we initialize
the queue. A single blk_mq_tag_set structure can be shared by multiple
queues.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Modular export of blk_mq_{alloc,free}_tagset added by me.
Signed-off-by: Jens Axboe <axboe@fb.com>
Drivers can reach their private data easily using the blk_mq_rq_to_pdu
helper and don't need req->special. By not initializing it code can
be simplified nicely, and we also shave off a few more instructions from
the I/O path.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Use the block layer helpers for CPU-local completions instead of
reimplementing them locally.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
The completion queue is implemented using lockless list.
The llist_add is adds the events to the list head which is a push operation.
The processing of the completion elements is done by disconnecting all the
pushed elements and iterating over the disconnected list. The problem is
that the processing is done in reverse order w.r.t order of the insertion
i.e. LIFO processing. By reversing the disconnected list which is done in
linear time the desired FIFO processing is achieved.
Signed-off-by: Shlomo Pongratz <shlomop@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull block IO driver changes from Jens Axboe:
- bcache update from Kent Overstreet.
- two bcache fixes from Nicholas Swenson.
- cciss pci init error fix from Andrew.
- underflow fix in the parallel IDE pg_write code from Dan Carpenter.
I'm sure the 1 (or 0) users of that are now happy.
- two PCI related fixes for sx8 from Jingoo Han.
- floppy init fix for first block read from Jiri Kosina.
- pktcdvd error return miss fix from Julia Lawall.
- removal of IRQF_SHARED from the SEGA Dreamcast CD-ROM code from
Michael Opdenacker.
- comment typo fix for the loop driver from Olaf Hering.
- potential oops fix for null_blk from Raghavendra K T.
- two fixes from Sam Bradshaw (Micron) for the mtip32xx driver, fixing
an OOM problem and a problem with handling security locked conditions
* 'for-3.14/drivers' of git://git.kernel.dk/linux-block: (47 commits)
mg_disk: Spelling s/finised/finished/
null_blk: Null pointer deference problem in alloc_page_buffers
mtip32xx: Correctly handle security locked condition
mtip32xx: Make SGL container per-command to eliminate high order dma allocation
drivers/block/loop.c: fix comment typo in loop_config_discard
drivers/block/cciss.c:cciss_init_one(): use proper errnos
drivers/block/paride/pg.c: underflow bug in pg_write()
drivers/block/sx8.c: remove unnecessary pci_set_drvdata()
drivers/block/sx8.c: use module_pci_driver()
floppy: bail out in open() if drive is not responding to block0 read
bcache: Fix auxiliary search trees for key size > cacheline size
bcache: Don't return -EINTR when insert finished
bcache: Improve bucket_prio() calculation
bcache: Add bch_bkey_equal_header()
bcache: update bch_bkey_try_merge
bcache: Move insert_fixup() to btree_keys_ops
bcache: Convert sorting to btree_keys
bcache: Convert debug code to btree_keys
bcache: Convert btree_iter to struct btree_keys
bcache: Refactor bset_tree sysfs stats
...
If we load the null_blk module with bs=8k we get following oops:
[ 3819.812190] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[ 3819.812387] IP: [<ffffffff81170aa5>] create_empty_buffers+0x28/0xaf
[ 3819.812527] PGD 219244067 PUD 215a06067 PMD 0
[ 3819.812640] Oops: 0000 [#1] SMP
[ 3819.812772] Modules linked in: null_blk(+)
Fix that by resetting block size to PAGE_SIZE if it is greater than PAGE_SIZE
Reported-by: Sumanth <sumantk2@linux.vnet.ibm.com>
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Reviewed-by: Matias Bjorling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When queue_mode is NULL_Q_MQ and null_blk is being removed,
blk_cleanup_queue() isn't called to cleanup queue, so the queue
allocated won't be freed.
This patch calls blk_cleanup_queue() for MQ to drain all pending
requests first and release the reference counter of queue kobject, then
blk_mq_free_queue() will be called in queue kobject's release handler
when queue kobject's reference counter drops to zero.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull block fixes from Jens Axboe:
- fix for a memory leak on certain unplug events
- a collection of bcache fixes from Kent and Nicolas
- a few null_blk fixes and updates form Matias
- a marking of static of functions in the stec pci-e driver
* 'for-linus' of git://git.kernel.dk/linux-block:
null_blk: support submit_queues on use_per_node_hctx
null_blk: set use_per_node_hctx param to false
null_blk: corrections to documentation
null_blk: warning on ignored submit_queues param
null_blk: refactor init and init errors code paths
null_blk: documentation
null_blk: mem garbage on NUMA systems during init
drivers: block: Mark the functions as static in skd_main.c
bcache: New writeback PD controller
bcache: bugfix for race between moving_gc and bucket_invalidate
bcache: fix for gc and writeback race
bcache: bugfix - moving_gc now moves only correct buckets
bcache: fix for gc crashing when no sectors are used
bcache: Fix heap_peek() macro
bcache: Fix for can_attach_cache()
bcache: Fix dirty_data accounting
bcache: Use uninterruptible sleep in writeback
bcache: kthread don't set writeback task to INTERUPTIBLE
block: fix memory leaks on unplugging block device
bcache: fix sparse non static symbol warning
In the case of both the submit_queues param and use_per_node_hctx param
are used. We limit the number af submit_queues to the number of online
nodes.
If the submit_queues is a multiple of nr_online_nodes, its trivial. Simply map
them to the nodes. For example: 8 submit queues are mapped as node0[0,1],
node1[2,3], ...
If uneven, we are left with an uneven number of submit_queues that must be
mapped. These are mapped toward the first node and onward. E.g. 5
submit queues mapped onto 4 nodes are mapped as node0[0,1], node1[2], ...
Signed-off-by: Matias Bjorling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The defaults for the module is to instantiate itself with blk-mq and a
submit queue for each CPU node in the system.
To save resources, initialize instead with a single submit queue.
Signed-off-by: Matias Bjorling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Let the user know when the number of submission queues are being
ignored.
Signed-off-by: Matias Bjorling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Simplify the initialization logic of the three block-layers.
- The queue initialization is split into two parts. This allows reuse of
code when initializing the sq-, bio- and mq-based layers.
- Set submit_queues default value to 0 and always set it at init time.
- Simplify the init error code paths.
Signed-off-by: Matias Bjorling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
For NUMA systems, initializing the blk-mq layer and using per node hctx.
We initialize submit queues to 1, while blk-mq nr_hw_queues is
initialized to the number of NUMA nodes.
This makes the null_init_hctx function overwrite memory outside of what
it allocated. In my case it lead to writing garbage into struct
request_queue's mq_map.
Signed-off-by: Matias Bjorling <m@bjorling.me>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For NUMA systems, initializing the blk-mq layer and using per node hctx.
We initialize submit queues to 1, while blk-mq nr_hw_queues is
initialized to the number of NUMA nodes.
This makes the null_init_hctx function overwrite memory outside of what
it allocated. In my case it lead to writing garbage into struct
request_queue's mq_map.
Signed-off-by: Matias Bjorling <m@bjorling.me>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove CONFIG_USE_GENERIC_SMP_HELPERS left by commit 0a06ff068f
("kernel: remove CONFIG_USE_GENERIC_SMP_HELPERS").
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A driver that simply completes IO it receives, it does no
transfers. Written to fascilitate testing of the blk-mq code.
It supports various module options to use either bio queueing,
rq queueing, or mq mode.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
