commit 220bb38c ("bcache: Break up struct search") introduced
changes to struct search and s->iop. bypass/bio are fields of struct
data_insert_op now. Update the comment.
Signed-off-by: NShenghui Wang <shhuiw@foxmail.com>
Signed-off-by: NColy Li <colyli@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

debugfs_remove and debugfs_remove_recursive will check if the dentry
pointer is NULL or ERR, and will do nothing in that case.

Remove the check in cache_set_free and bch_debug_init.
Signed-off-by: NShenghui Wang <shhuiw@foxmail.com>
Signed-off-by: NColy Li <colyli@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

We have the following define for btree iterator:
	struct btree_iter {
		size_t size, used;
	#ifdef CONFIG_BCACHE_DEBUG
		struct btree_keys *b;
	#endif
		struct btree_iter_set {
			struct bkey *k, *end;
		} data[MAX_BSETS];
	};

We can see that the length of data[] field is static MAX_BSETS, which is
defined as 4 currently.

But a btree node on disk could have too many bsets for an iterator to fit
on the stack - maybe far more that MAX_BSETS. Have to dynamically allocate
space to host more btree_iter_sets.

bch_cache_set_alloc() will make sure the pool cache_set->fill_iter can
allocate an iterator equipped with enough room that can host
	(sb.bucket_size / sb.block_size)
btree_iter_sets, which is more than static MAX_BSETS.

bch_btree_node_read_done() will use that pool to allocate one iterator, to
host many bsets in one btree node.

Add more comment around cache_set->fill_iter to make code less confusing.
Signed-off-by: NShenghui Wang <shhuiw@foxmail.com>
Signed-off-by: NColy Li <colyli@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Between v3 [1] and v4 [2] of the blkg association series, the
association point moved from generic_make_request_checks(), which is
called after the request enters the queue, to bio_set_dev(), which is when
the bio is formed before submit_bio(). When the request_queue goes away,
the blkgs supporting the request_queue are destroyed and then the
q->root_blkg is set to %NULL.

This patch adds a %NULL check to blkg_tryget_closest() to prevent the
NPE caused by the above. It also adds a guard to see if the
request_queue is dying when creating a blkg to prevent creating a blkg
for a dead request_queue.

[1] https://lore.kernel.org/lkml/20180911184137.35897-1-dennisszhou@gmail.com/
[2] https://lore.kernel.org/lkml/20181126211946.77067-1-dennis@kernel.org/

Fixes: 5cdf2e3f ("blkcg: associate blkg when associating a device")
Reported-and-tested-by: NMing Lei <ming.lei@redhat.com>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NDennis Zhou <dennis@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

rwb_enabled() can't be changed when there is any inflight IO.

wbt_disable_default() may set rwb->wb_normal as zero, however the
blk_stat timer may still be pending, and the timer function will update
wrb->wb_normal again.

This patch introduces blk_stat_deactivate() and applies it in
wbt_disable_default(), then the following IO hang triggered when running
parted & switching io scheduler can be fixed:

[  369.937806] INFO: task parted:3645 blocked for more than 120 seconds.
[  369.938941]       Not tainted 4.20.0-rc6-00284-g906c801e5248 #498
[  369.939797] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  369.940768] parted          D    0  3645   3239 0x00000000
[  369.941500] Call Trace:
[  369.941874]  ? __schedule+0x6d9/0x74c
[  369.942392]  ? wbt_done+0x5e/0x5e
[  369.942864]  ? wbt_cleanup_cb+0x16/0x16
[  369.943404]  ? wbt_done+0x5e/0x5e
[  369.943874]  schedule+0x67/0x78
[  369.944298]  io_schedule+0x12/0x33
[  369.944771]  rq_qos_wait+0xb5/0x119
[  369.945193]  ? karma_partition+0x1c2/0x1c2
[  369.945691]  ? wbt_cleanup_cb+0x16/0x16
[  369.946151]  wbt_wait+0x85/0xb6
[  369.946540]  __rq_qos_throttle+0x23/0x2f
[  369.947014]  blk_mq_make_request+0xe6/0x40a
[  369.947518]  generic_make_request+0x192/0x2fe
[  369.948042]  ? submit_bio+0x103/0x11f
[  369.948486]  ? __radix_tree_lookup+0x35/0xb5
[  369.949011]  submit_bio+0x103/0x11f
[  369.949436]  ? blkg_lookup_slowpath+0x25/0x44
[  369.949962]  submit_bio_wait+0x53/0x7f
[  369.950469]  blkdev_issue_flush+0x8a/0xae
[  369.951032]  blkdev_fsync+0x2f/0x3a
[  369.951502]  do_fsync+0x2e/0x47
[  369.951887]  __x64_sys_fsync+0x10/0x13
[  369.952374]  do_syscall_64+0x89/0x149
[  369.952819]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  369.953492] RIP: 0033:0x7f95a1e729d4
[  369.953996] Code: Bad RIP value.
[  369.954456] RSP: 002b:00007ffdb570dd48 EFLAGS: 00000246 ORIG_RAX: 000000000000004a
[  369.955506] RAX: ffffffffffffffda RBX: 000055c2139c6be0 RCX: 00007f95a1e729d4
[  369.956389] RDX: 0000000000000001 RSI: 0000000000001261 RDI: 0000000000000004
[  369.957325] RBP: 0000000000000002 R08: 0000000000000000 R09: 000055c2139c6ce0
[  369.958199] R10: 0000000000000000 R11: 0000000000000246 R12: 000055c2139c0380
[  369.959143] R13: 0000000000000004 R14: 0000000000000100 R15: 0000000000000008

Cc: stable@vger.kernel.org
Cc: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

We're missing a deferred clear off the shallow get, which can cause
a hang. Additionally, when we resize the sbitmap, we should also
flush deferred clears for good measure.

Ensure we have full coverage on batch clears, even for paths where
we would not be doing deferred clear. This makes it less error
prone for future additions.
Reported-by: NBart Van Assche <bvanassche@acm.org>
Tested-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Ehen using pblk with 0 sized metadata both ppa list and meta list
points to the same memory since pblk_dma_meta_size() returns 0 in
that case.

This patch fix that issue by ensuring that pblk_dma_meta_size()
always returns space equal to sizeof(struct pblk_sec_meta) and thus
ppa list and meta list points to different memory address.

Even that in that case drive does not really care about meta_list
pointer, this is the easiest way to fix that issue without introducing
changes in many places in the code just for 0 sized metadata case.

The same approach needs to be also done for pblk_get_sec_meta()
since we also cannot point to the same memory address in meta buffer
when we are using it for pblk recovery process
Reported-by: NHans Holmberg <hans.holmberg@cnexlabs.com>
Tested-by: NHans Holmberg <hans.holmberg@cnexlabs.com>
Signed-off-by: NIgor Konopko <igor.j.konopko@intel.com>
Signed-off-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

pblk performs recovery of open lines by storing the LBA in the per LBA
metadata field. Recovery therefore only works for drives that has this
field.

This patch adds support for packed metadata, which store l2p mapping
for open lines in last sector of every write unit and enables drives
without per IO metadata to recover open lines.

After this patch, drives with OOB size <16B will use packed metadata
and metadata size larger than16B will continue to use the device per
IO metadata.
Reviewed-by: NJavier González <javier@cnexlabs.com>
Signed-off-by: NIgor Konopko <igor.j.konopko@intel.com>
Signed-off-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Currently pblk only check the size of I/O metadata and does not take
into account if this metadata is in a separate buffer or interleaved
in a single metadata buffer.

In reality only the first scenario is supported, where second mode will
break pblk functionality during any IO operation.

This patch prevents pblk to be instantiated in case device only
supports interleaved metadata.
Reviewed-by: NJavier González <javier@cnexlabs.com>
Signed-off-by: NIgor Konopko <igor.j.konopko@intel.com>
Signed-off-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Currently lightnvm and pblk uses single DMA pool, for which the entry
size always is equal to PAGE_SIZE. The contents of each entry allocated
from the DMA pool consists of a PPA list (8bytes * 64), leaving
56bytes * 64 space for metadata. Since the metadata field can be bigger,
such as 128 bytes, the static size does not cover this use-case.

This patch adds support for I/O metadata above 56 bytes by changing DMA
pool size based on device meta size and allows pblk to use OOB metadata
>=16B.
Reviewed-by: NJavier González <javier@cnexlabs.com>
Signed-off-by: NIgor Konopko <igor.j.konopko@intel.com>
Signed-off-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

pblk currently assumes that size of OOB metadata on drive is always
equal to size of pblk_sec_meta struct. This commit add helpers which will
allow to handle different sizes of OOB metadata on drive in the future.

After this patch only OOB metadata equal to 16 bytes is supported.
Reviewed-by: NJavier González <javier@cnexlabs.com>
Signed-off-by: NIgor Konopko <igor.j.konopko@intel.com>
Signed-off-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Currently DMA allocated memory is reused on partial read
for lba_list_mem and lba_list_media arrays. In preparation
for dynamic DMA pool sizes we need to move this arrays
into pblk_pr_ctx structures.
Reviewed-by: NJavier González <javier@cnexlabs.com>
Signed-off-by: NIgor Konopko <igor.j.konopko@intel.com>
Signed-off-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The current kref implementation around pblk global caches triggers a
false positive on refcount_inc_checked() (when called) as the kref is
initialized to 0. Instead of usint kref_inc() on a 0 reference, which is
in principle correct, use kref_init() to avoid the check. This is also
more explicit about what actually happens on cache creation.

In the process, do a small refactoring to use kref helpers.

Fixes: 1864de94 "lightnvm: pblk: stop recreating global caches"
Signed-off-by: NJavier González <javier@cnexlabs.com>
Reviewed-by: NHans Holmberg <hans.holmberg@cnexlabs.com>
Signed-off-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Currently the geometry of an OCSSD is enumerated using a two step
approach:

First, nvm_register is called, the OCSSD identify command is issued,
and second the geometry sos and csecs values are read either from the
OCSSD identify if it is a 1.2 drive, or from the NVMe namespace data
structure if it is a 2.0 device.

This patch recombines it into a single step, such that nvm_register can
use the csecs and sos fields independent of which version is used. This
enables one to dynamically size the lightnvm subsystem dma pool.
Reviewed-by: NIgor Konopko <igor.j.konopko@intel.com>
Reviewed-by: NJavier González <javier@cnexlabs.com>
Signed-off-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

pblk's recovery path is single threaded and therefore a number of
assumptions regarding concurrency can be made. To avoid confusion, make
this explicit with a couple of comments in the code.
Signed-off-by: NJavier González <javier@cnexlabs.com>
Signed-off-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Protect the list_add on the pblk_line_init_bb() error
path in case this code is used for some other purpose
in the future.
Signed-off-by: NHua Su <suhua.tanke@gmail.com>
Reviewed-by: NJavier González <javier@cnexlabs.com>
Signed-off-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Signed-off-by: NHua Su <suhua.tanke@gmail.com>
Updated description.
Signed-off-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Remove the call to pblk_line_replace_data as it returns
directly because we have not set l_mg->data_next yet.
Signed-off-by: NHans Holmberg <hans.holmberg@cnexlabs.com>
Reviewed-by: NJavier González <javier@javigon.com>
Signed-off-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The chunk metadata is allocated with vmalloc, so we need to use
vfree to free it.

Fixes: 090ee26f ("lightnvm: use internal allocation for chunk log page")
Signed-off-by: NHans Holmberg <hans.holmberg@cnexlabs.com>
Reviewed-by: NJavier González <javier@javigon.com>
Signed-off-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

ADDR_POOL_SIZE is not used anymore, so remove the macro.
Signed-off-by: NHans Holmberg <hans.holmberg@cnexlabs.com>
Reviewed-by: NJavier González <javier@javigon.com>
Signed-off-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

In a worst-case scenario (random writes), OP% of sectors
in each line will be invalid, and we will then need
to move data out of 100/OP% lines to free a single line.

So, to prevent the possibility of running out of lines,
temporarily block user writes when there is less than
100/OP% free lines.

Also ensure that pblk creation does not produce instances
with insufficient over provisioning.

Insufficient over-provising is not a problem on real hardware,
but often an issue when running QEMU simulations (with few lines).
100 lines is enough to create a sane instance with the standard
(11%) over provisioning.
Signed-off-by: NHans Holmberg <hans.holmberg@cnexlabs.com>
Reviewed-by: NJavier González <javier@javigon.com>
Signed-off-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

If mapping fails (i.e. when running out of lines), handle the error
and stop writing.
Signed-off-by: NHans Holmberg <hans.holmberg@cnexlabs.com>
Reviewed-by: NJavier González <javier@javigon.com>
Signed-off-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Lines inflicted with write errors lines might be recovered
if they have not been recycled after write error garbage collection.

Ensure that the emeta accounting of valid lbas is correct
for such lines to avoid recovery inconsistencies.
Signed-off-by: NHans Holmberg <hans.holmberg@cnexlabs.com>
Reviewed-by: NJavier González <javier@javigon.com>
Signed-off-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Make sure we only look up valid lba addresses on the resubmission path.

If an lba is invalidated in the write buffer, that sector will be
submitted to disk (as it is already mapped to a ppa), and that write
might fail, resulting in a crash when trying to look up the lba in the
mapping table (as the lba is marked as invalid).
Signed-off-by: NHans Holmberg <hans.holmberg@cnexlabs.com>
Reviewed-by: NJavier González <javier@javigon.com>
Signed-off-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The check for chunk closes suffers from an off-by-one issue, leading
to chunk close events not being traced.

Fixes: 4c44abf4 ("lightnvm: pblk: add trace events for chunk states")
Signed-off-by: NHans Holmberg <hans.holmberg@cnexlabs.com>
Signed-off-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

With gcc 4.1:

    drivers/lightnvm/core.c: In function ‘nvm_get_bb_meta’:
    drivers/lightnvm/core.c:977: warning: ‘ret’ may be used uninitialized in this function

and

    drivers/nvme/host/lightnvm.c: In function ‘nvme_nvm_get_chk_meta’:
    drivers/nvme/host/lightnvm.c:580: warning: ‘ret’ may be used uninitialized in this function

Indeed, if (for the former) the number of channels or LUNs is zero, or
(for both) the passed number of chunks is zero, ret will be returned
uninitialized.

Fix this by preinitializing ret to zero.

Fixes: aff3fb18 ("lightnvm: move bad block and chunk state logic to core")
Fixes: a294c199 ("lightnvm: implement get log report chunk helpers")
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The smeta area l2p mapping is empty, and actually the
recovery procedure only need to restore data sector's l2p
mapping. So ignore the smeta oob scan.
Signed-off-by: NZhoujie Wu <zjwu@marvell.com>
Reviewed-by: NJavier González <javier@javigon.com>
Reviewed-by: NHans Holmberg <hans.holmberg@cnexlabs.com>
Signed-off-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The md->wait waitqueue is used by both bio-based and request-based DM.
Commit dbd3bbd2 ("dm rq: leverage blk_mq_queue_busy() to check for
outstanding IO") lost sight of the requirement that
dm_wait_for_completion() must work with all types of DM devices.

Fix md_in_flight() to call the blk-mq or bio-based method accordingly.

Fixes: dbd3bbd2 ("dm rq: leverage blk_mq_queue_busy() to check for outstanding IO")
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Guenter reported an boot hang issue on HPPA after we default to 0 poll
queues. We have two issues in the queue count calculations:

1) We don't separate the poll queues from the read/write queues. This is
   important, since the former doesn't need interrupts.
2) The adjust logic is broken.

Adjust the poll queue count before doing nvme_calc_io_queues(). The poll
queue count is only limited by the IO queue count we were able to get
from the controller, not failures in the IRQ allocation loop. This
leaves nvme_calc_io_queues() just adjusting the read/write queue map.
Reported-by: NReported-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

After switching to percpu inflight counters, the inflight check
is totally buggy. It's perfectly valid for some counters to be
non-zero while having a total inflight IO count of 0, that's how
these kinds of counters work (inc on one CPU, dec on another).
Fix the md_in_flight() check to sum all counters before returning
a false positive, potentially.

While at it, remove the inflight read for IO completion. We don't
need it, just wake anyone that's waiting for the IO count to drop
to zero. The caller needs to re-check that value anyway when woken,
which it does.

Fixes: 6f757231 ("dm: remove the pending IO accounting")
Acked-by: NMike Snitzer <snitzer@redhat.com>
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

For cases where we can only fail with IO in-flight, we should be using
BLK_STS_DEV_RESOURCE instead of BLK_STS_RESOURCE. The latter refers to
system wide resource constraints.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The "cmd_slot_unal" semaphore is never used in a blocking way
but only as an atomic counter. Change the code to using
atomic_dec_if_positive() as a better API.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Remove the "pending" atomic counters, that duplicate block-core's
in_flight counters, and update md_in_flight() to look at percpu
in_flight counters.
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The previous patches deleted all the code that needed the second value
returned from part_in_flight - now the kernel only uses the first value.

Consequently, part_in_flight (and blk_mq_in_flight) may be changed so that
it only returns one value.

This patch just refactors the code, there's no functional change.
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Now when part_round_stats is gone, we can switch to per-cpu in-flight
counters.

We use the local-atomic type local_t, so that if part_inc_in_flight or
part_dec_in_flight is reentrantly called from an interrupt, the value will
be correct.

The other counters could be corrupted due to reentrant interrupt, but the
corruption only results in slight counter skew - the in_flight counter
must be exact, so it needs local_t.
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

We want to convert to per-cpu in_flight counters.

The function part_round_stats needs the in_flight counter every jiffy, it
would be too costly to sum all the percpu variables every jiffy, so it
must be deleted. part_round_stats is used to calculate two counters -
time_in_queue and io_ticks.

time_in_queue can be calculated without part_round_stats, by adding the
duration of the I/O when the I/O ends (the value is almost as exact as the
previously calculated value, except that time for in-progress I/Os is not
counted).

io_ticks can be approximated by increasing the value when I/O is started
or ended and the jiffies value has changed. If the I/Os take less than a
jiffy, the value is as exact as the previously calculated value. If the
I/Os take more than a jiffy, io_ticks can drift behind the previously
calculated value.
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

All of part_stat_* and related methods are used with preempt disabled,
so there is no need to pass cpu around to allow of them.  Just call
smp_processor_id() as needed.
Suggested-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Now that request-based dm-multipath only supports blk-mq, make use of
the newly introduced blk_mq_queue_busy() to check for outstanding IO --
rather than (ab)using the block core's in_flight counters.
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

generic_start_io_acct and generic_end_io_acct already update the variable
in_flight using atomic operations, so we don't have to overwrite them
again.
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Pull in v4.20-rc6 to resolve the conflict in NVMe, but also to get the
two corruption fixes. We're going to be overhauling the direct dispatch
path, and we need to do that on top of the changes we made for that
in mainline.
Signed-off-by: NJens Axboe <axboe@kernel.dk>