This reverts a series committed earlier due to null pointer exception
bug report in [1]. It seems there are edge case interactions that I did
not consider and will need some time to understand what causes the
adverse interactions.

The original series can be found in [2] with a follow up series in [3].

[1] https://www.spinics.net/lists/cgroups/msg20719.html
[2] https://lore.kernel.org/lkml/20180911184137.35897-1-dennisszhou@gmail.com/
[3] https://lore.kernel.org/lkml/20181020185612.51587-1-dennis@kernel.org/

This reverts the following commits:
d459d853, b2c3fa54, 101246ec, b3b9f24f, e2b09899,
f0fcb3ec, c839e7a0, bdc24917, 74b7c02a, 5bf9a1f3,
a7b39b4e, 07b05bcc, 49f4c2dc, 27e6fa99Signed-off-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Drivers exposing zoned block devices have to initialize and maintain
correctness (i.e. revalidate) of the device zone bitmaps attached to
the device request queue (seq_zones_bitmap and seq_zones_wlock).

To simplify coding this, introduce a generic helper function
blk_revalidate_disk_zones() suitable for most (and likely all) cases.
This new function always update the seq_zones_bitmap and seq_zones_wlock
bitmaps as well as the queue nr_zones field when called for a disk
using a request based queue. For a disk using a BIO based queue, only
the number of zones is updated since these queues do not have
schedulers and so do not need the zone bitmaps.

With this change, the zone bitmap initialization code in sd_zbc.c can be
replaced with a call to this function in sd_zbc_read_zones(), which is
called from the disk revalidate block operation method.

A call to blk_revalidate_disk_zones() is also added to the null_blk
driver for devices created with the zoned mode enabled.

Finally, to ensure that zoned devices created with dm-linear or
dm-flakey expose the correct number of zones through sysfs, a call to
blk_revalidate_disk_zones() is added to dm_table_set_restrictions().

The zone bitmaps allocated and initialized with
blk_revalidate_disk_zones() are freed automatically from
__blk_release_queue() using the block internal function
blk_queue_free_zone_bitmaps().
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Dispatching a report zones command through the request queue is a major
pain due to the command reply payload rewriting necessary. Given that
blkdev_report_zones() is executing everything synchronously, implement
report zones as a block device file operation instead, allowing major
simplification of the code in many places.

sd, null-blk, dm-linear and dm-flakey being the only block device
drivers supporting exposing zoned block devices, these drivers are
modified to provide the device side implementation of the
report_zones() block device file operation.

For device mappers, a new report_zones() target type operation is
defined so that the upper block layer calls blkdev_report_zones() can
be propagated down to the underlying devices of the dm targets.
Implementation for this new operation is added to the dm-linear and
dm-flakey targets.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
[Damien]
* Changed method block_device argument to gendisk
* Various bug fixes and improvements
* Added support for null_blk, dm-linear and dm-flakey.
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Introduce the blkdev_nr_zones() helper function to get the total
number of zones of a zoned block device. This number is always 0 for a
regular block device (q->limits.zoned == BLK_ZONED_NONE case).

Replace hard-coded number of zones calculation in dmz_get_zoned_device()
with a call to this helper.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

flush_pool is leaked when flush bio size is zero

Fixes: 5a409b4f ("MD: fix lock contention for flush bios")
Signed-off-by: David Jeffery <djeffery@redhat.com>
Signed-off-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>

I noticed kmemleak report memory leak when run create/stop
md in a loop, backtrace:
[<000000001ca975e7>] mempool_create_node+0x86/0xd0
[<0000000095576bcd>] md_run+0x1057/0x1410 [md_mod]
[<000000007b45c5fc>] do_md_run+0x15/0x130 [md_mod]
[<000000001ede9ec0>] md_ioctl+0x1f49/0x25d0 [md_mod]
[<000000004142cacf>] blkdev_ioctl+0x680/0xd00

The root cause is we alloc mddev->flush_pool and
mddev->flush_bio_pool in md_run, but from do_md_stop
will not call into md_stop but __md_stop, move the
mempool_destroy to __md_stop fixes the problem for me.

The bug was introduced in 5a409b4f, the fixes should go to
4.18+

Fixes: 5a409b4f ("MD: fix lock contention for flush bios")
Signed-off-by: Jack Wang <jinpu.wang@profitbricks.com>
Reviewed-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>

This dead branch was missed during review.  It only makes memory_entry()
more inefficient due to needless call to is_power_of_2(), etc.
Reported-by: shenghui <shhuiw@foxmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

dmz_fetch_mblock() called from dmz_get_mblock() has a race since the
allocation of the new metadata block descriptor and its insertion in
the cache rbtree with the READING state is not atomic. Two different
contexts requesting the same block may end up each adding two different
descriptors of the same block to the cache.

Another problem for this function is that the BIO for processing the
block read is allocated after the metadata block descriptor is inserted
in the cache rbtree. If the BIO allocation fails, the metadata block
descriptor is freed without first being removed from the rbtree.

Fix the first problem by checking again if the requested block is not in
the cache right before inserting the newly allocated descriptor,
atomically under the mblk_lock spinlock. The second problem is fixed by
simply allocating the BIO before inserting the new block in the cache.

Finally, since dmz_fetch_mblock() also increments a block reference
counter, rename the function to dmz_get_mblock_slow(). To be symmetric
and clear, also rename dmz_lookup_mblock() to dmz_get_mblock_fast() and
increment the block reference counter directly in that function rather
than in dmz_get_mblock().

Fixes: 3b1a94c8 ("dm zoned: drive-managed zoned block device target")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Since the ref field of struct dmz_mblock is always used with the
spinlock of struct dmz_metadata locked, there is no need to use an
atomic_t type. Change the type of the ref field to an unsigne
integer.

Fixes: 3b1a94c8 ("dm zoned: drive-managed zoned block device target")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

With raid4/5/6, journal device and write intent bitmap are mutually exclusive.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Previously, we allow multiple nodes can resync device, but we
had changed it to only support one node can do resync at one
time, but suspend_info is still used.

Now, let's remove the structure and use suspend_lo/hi to record
the range.
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

We need to continue the reshaping if it was interrupted in
original node. So original node should call resync_bitmap
in case reshaping is aborted.

Then BITMAP_NEEDS_SYNC message is broadcasted to other nodes,
node which continues the reshaping should restart reshape from
mddev->reshape_position instead of from the first beginning.
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

When reshape is happening in one node, other nodes could receive
lots of RESYNCING messages, so md_bitmap_sync_with_cluster is called.

Since the resyncing window is typically small in these RESYNCING
messages, so WARN is always triggered, so we should not call the
func when reshape is happening.
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

remove_and_add_spares is not needed if reshape is
happening in another node, because raid10_add_disk
called inside raid10_start_reshape would handle the
role changes of disk. Plus, remove_and_add_spares
can't deal with the role change due to reshape.
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

We need to change the capacity in all nodes after one node
finishs reshape. And as we did before, we can't change the
capacity directly in md_do_sync, instead, the capacity should
be only changed in update_size or received CHANGE_CAPACITY
msg.

So master node calls update_size after completes reshape in
md_reap_sync_thread, but we need to skip ops->update_size if
MD_CLOSING is set since reshaping could not be finish.
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

Since the resync region from suspend_info means one node
is reshaping this area, so the position of reshape_progress
should be included in the area.
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

For clustered raid10 scenario, we need to let all the nodes
know about that a new disk is added to the array, and the
reshape caused by add new member just need to be happened in
one node, but other nodes should know about the change.

Since reshape means read data from somewhere (which is already
used by array) and write data to unused region. Obviously, it
is awful if one node is reading data from address while another
node is writing to the same address. Considering we have
implemented suspend writes in the resyncing area, so we can
just broadcast the reading address to other nodes to avoid the
trouble.

For master node, it would call reshape_request then update sb
during the reshape period. To avoid above trouble, we call
resync_info_update to send RESYNC message in reshape_request.

Then from slave node's view, it receives two type messages:
1. RESYNCING message
Slave node add the address (where master node reading data from)
to suspend list.

2. METADATA_UPDATED message
Once slave nodes know the reshaping is started in master node,
it is time to update reshape position and call start_reshape to
follow master node's step. After reshape is done, only reshape
position is need to be updated, so the majority task of reshaping
is happened on the master node.
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

To support add disk under grow mode, we need to resize
all the bitmaps of each node before reshape, so that we
can ensure all nodes have the same view of the bitmap of
the clustered raid.

So after the master node resized the bitmap, it broadcast
a message to other slave nodes, and it checks the size of
each bitmap are same or not by compare pages. We can only
continue the reshaping after all nodes update the bitmap
to the same size (by checking the pages), otherwise revert
bitmap size to previous value.

The resize_bitmaps interface and BITMAP_RESIZE message are
introduced in md-cluster.c for the purpose.
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

Make cpu-usage debugging easier by naming workqueues per device.

Example ps output:

root       413  0.0  0.0      0     0 ?        I<   paź02   0:00  [kcryptd_io/253:0]
root       414  0.0  0.0      0     0 ?        I<   paź02   0:00  [kcryptd/253:0]
root       415  0.0  0.0      0     0 ?        S    paź02   1:10  [dmcrypt_write/253:0]
root       465  0.0  0.0      0     0 ?        I<   paź02   0:00  [kcryptd_io/253:2]
root       466  0.0  0.0      0     0 ?        I<   paź02   0:00  [kcryptd/253:2]
root       467  0.0  0.0      0     0 ?        S    paź02   2:06  [dmcrypt_write/253:2]
root     15359  0.2  0.0      0     0 ?        I<   19:43   0:25  [kworker/u17:8-kcryptd/253:0]
root     16563  0.2  0.0      0     0 ?        I<   20:10   0:18  [kworker/u17:0-kcryptd/253:2]
root     23205  0.1  0.0      0     0 ?        I<   21:21   0:04  [kworker/u17:4-kcryptd/253:0]
root     13383  0.1  0.0      0     0 ?        I<   21:32   0:02  [kworker/u17:2-kcryptd/253:2]
root      2610  0.1  0.0      0     0 ?        I<   21:42   0:01  [kworker/u17:12-kcryptd/253:2]
root     20124  0.1  0.0      0     0 ?        I<   21:56   0:01  [kworker/u17:1-kcryptd/253:2]
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Add a shortcut for dm_device_name(dm_table_get_md(t)).
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

In copy_params(), the struct 'dm_ioctl' is first copied from the user
space buffer 'user' to 'param_kernel' and the field 'data_size' is
checked against 'minimum_data_size' (size of 'struct dm_ioctl' payload
up to its 'data' member).  If the check fails, an error code EINVAL will be
returned.  Otherwise, param_kernel->data_size is used to do a second copy,
which copies from the same user-space buffer to 'dmi'.  After the second
copy, only 'dmi->data_size' is checked against 'param_kernel->data_size'.
Given that the buffer 'user' resides in the user space, a malicious
user-space process can race to change the content in the buffer between
the two copies.  This way, the attacker can inject inconsistent data
into 'dmi' (versus previously validated 'param_kernel').

Fix redundant copying of 'minimum_data_size' from user-space buffer by
using the first copy stored in 'param_kernel'.  Also remove the
'data_size' check after the second copy because it is now unnecessary.

Cc: stable@vger.kernel.org
Signed-off-by: Wenwen Wang <wang6495@umn.edu>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

WARN_ON() already contains an unlikely(), so it's not necessary to
wrap it into another.
Signed-off-by: Igor Stoppa <igor.stoppa@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

The API surrounding refcount_t should be used in place of atomic_t
when variables are being used as reference counters.  This API can
prevent issues such as counter overflows and use-after-free
conditions.  Within the dm zoned target stack, the atomic_t API is
used for bioctx->ref and cw->refcount.  Change these to use
refcount_t, avoiding the issues mentioned.
Signed-off-by: John Pittman <jpittman@redhat.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Tested-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

The API surrounding refcount_t should be used in place of atomic_t
when variables are being used as reference counters.  It can
potentially prevent reference counter overflows and use-after-free
conditions.  In the dm thin layer, one such example is tc->refcount.
Change this from the atomic_t API to the refcount_t API to prevent
mentioned conditions.
Signed-off-by: John Pittman <jpittman@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Commit d595567d (MD: fix invalid stored role for a disk) broke linear
hotadd. Let's only fix the role for disks in raid1/10.
Based on Guoqing's original patch.
Reported-by: kernel test robot <rong.a.chen@intel.com>
Cc: Gioh Kim <gi-oh.kim@profitbricks.com>
Cc: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

Now that request-based DM (multipath) is blk-mq only: this restriction
is required while the legacy request-based IO path still exists.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Now that request-based DM is only using blk-mq, there is no need to
differentiate between legacy "rq" and new "mq".  We're back to a single
request-based DM -- and there was much rejoicing!
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

dm supports both, and since we're killing off the legacy path in
general, get rid of it in dm.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

The dm-linear target is independent of the dm-zoned target. For code
requiring support for zoned block devices, use CONFIG_BLK_DEV_ZONED
instead of CONFIG_DM_ZONED.

While at it, similarly to dm linear, also enable the DM_TARGET_ZONED_HM
feature in dm-flakey only if CONFIG_BLK_DEV_ZONED is defined.

Fixes: beb9caac ("dm linear: eliminate linear_end_io call if CONFIG_DM_ZONED disabled")
Fixes: 0be12c1c ("dm linear: add support for zoned block devices")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

After 9e1cc0a5 ("md: use mddev_suspend/resume instead of ->quiesce()")
We still have similar left in bitmap functions.

Replace quiesce() with mddev_suspend/resume.

Also move md_bitmap_create out of mddev_suspend. and move mddev_resume
after md_bitmap_destroy. as we did in set_bitmap_file.
Signed-off-by: Jack Wang <jinpu.wang@profitbricks.com>
Reviewed-by: Gioh Kim <gi-oh.kim@profitbricks.com>
Signed-off-by: Shaohua Li <shli@fb.com>

And earlier commit removed the error label to two statements that
are now never reachable.  Since this code is now dead code, remove it.

Detected by CoverityScan, CID#1462409 ("Structurally dead code")

Fixes: d5d885fd ("md: introduce new personality funciton start()")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Shaohua Li <shli@fb.com>

It is best to avoid any extra overhead associated with bio completion.
DM core will indirectly call a DM target's .end_io if it is defined.
In the case of DM linear, there is no need to do so (for every bio that
completes) if CONFIG_DM_ZONED is not enabled.

Avoiding an extra indirect call for every bio completion is very
important for ensuring DM linear doesn't incur more overhead that
further widens the performance gap between dm-linear and raw block
devices.

Fixes: 0be12c1c ("dm linear: add support for zoned block devices")
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

If dm-linear or dm-flakey are layered on top of a partition of a zoned
block device, remapping of the start sector and write pointer position
of the zones reported by a report zones BIO must be modified to account
for the target table entry mapping (start offset within the device and
entry mapping with the dm device).  If the target's backing device is a
partition of a whole disk, the start sector on the physical device of
the partition must also be accounted for when modifying the zone
information.  However, dm_remap_zone_report() was not considering this
last case, resulting in incorrect zone information remapping with
targets using disk partitions.

Fix this by calculating the target backing device start sector using
the position of the completed report zones BIO and the unchanged
position and size of the original report zone BIO. With this value
calculated, the start sector and write pointer position of the target
zones can be correctly remapped.

Fixes: 10999307 ("dm: introduce dm_remap_zone_report()")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Commit 7e6358d2 ("dm: fix various targets to dm_register_target
after module __init resources created") inadvertently introduced this
bug when it moved dm_register_target() after the call to KMEM_CACHE().

Fixes: 7e6358d2 ("dm: fix various targets to dm_register_target after module __init resources created")
Cc: stable@vger.kernel.org
Signed-off-by: Shenghui Wang <shhuiw@foxmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

when the nbuckets of cache device is smaller than 1024, making cache
device will trigger BUG_ON in kernel, add a condition to avoid this.
Reported-by: nitroxis <n@nxs.re>
Signed-off-by: Dongbo Cao <cdbdyx@163.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Split the combined '||' statements in if() check, to make the code easier
for debug.
Signed-off-by: Dongbo Cao <cdbdyx@163.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Current cache_set has MAX_CACHES_PER_SET caches most, and the macro
is used for
"
	struct cache *cache_by_alloc[MAX_CACHES_PER_SET];
"
in the define of struct cache_set.

Use MAX_CACHES_PER_SET instead of magic number 8 in
__bch_bucket_alloc_set.
Signed-off-by: Shenghui Wang <shhuiw@foxmail.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

In extents.c:bch_extent_bad(), number 96 is used as parameter to call
btree_bug_on(). The purpose is to check whether stale gen value exceeds
BUCKET_GC_GEN_MAX, so it is better to use macro BUCKET_GC_GEN_MAX to
make the code more understandable.
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Parameter "struct kobject *kobj" in bch_debug_init() is useless,
remove it in this patch.
Signed-off-by: Dongbo Cao <cdbdyx@163.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

struct kmem_cache *bch_passthrough_cache is not used in
bcache code. Remove it.
Signed-off-by: Shenghui Wang <shhuiw@foxmail.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>