Rename _nvme_revalidate_disk to nvme_validate_ns to better describe
what the function does, and pass the struct nvme_ns instead of the
gendisk to better match the call chain.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@wdc.com>

Use a slightly more descriptive name to enable reusing nvme_validate_ns
in the next patch for a lower level function.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@wdc.com>

The queue can trivially be derived from the nvme_ns structure.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@wdc.com>

The removal of the ->revalidate_disk method broke the initialization of
the zone bitmaps, as nvme_revalidate_disk now never gets called during
initialization.

Move the zone related code from nvme_revalidate_disk into a new helper in
zns.c, and call it from nvme_alloc_ns in addition to nvme_validate_ns to
ensure the zone bitmaps are initialized during probe.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NDamien Le Moal <damien.lemoal@wdc.com>

Always return BLK_ZONED_NONE if zoned device support is not enabled.
This allows various compiler optimizations including the dead code
elimination that we so like for avoiding ifdefs.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@wdc.com>

The function nvme_init_ctrl() gets the ctrl reference & when it fails it
does put the ctrl reference in the error unwind code.

When creating loop ctrl in nvme_loop_create_ctrl() if nvme_init_ctrl()
returns non zero (i.e. error) value it jumps to the "out_put_ctrl" label
which calls nvme_put_ctrl(), that will lead to douple ctrl put in error
unwind path.

Update nvme_loop_create_ctrl() such that this patch removes the
"out_put_ctrl" label, add a new "out" label after nvme_put_ctrl() in
error unwind path and jump to newly added label when nvme_init_ctrl()
call retuns an error.
Signed-off-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Fusion adapters can steer completions to individual queues, and
we now have support for shared host-wide tags.
So we can enable multiqueue support for fusion adapters.

Once driver enable shared host-wide tags, cpu hotplug feature is also
supported as it was enabled using below patchsets -
commit bf0beec0 ("blk-mq: drain I/O when all CPUs in a hctx are
offline")

Currently driver has provision to disable host-wide tags using
"host_tagset_enable" module parameter.

Once we do not have any major performance regression using host-wide
tags, we will drop the hand-crafted interrupt affinity settings.

Performance is also meeting the expecatation - (used both none and
mq-deadline scheduler)
24 Drive SSD on Aero with/without this patch can get 3.1M IOPs
3 VDs consist of 8 SAS SSD on Aero with/without this patch can get 3.1M
IOPs.
Signed-off-by: NKashyap Desai <kashyap.desai@broadcom.com>
Signed-off-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Tested-by: NDouglas Gilbert <dgilbert@interlog.com>
Acked-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

When host_max_queue is set (> 0), set the Scsi_Host.host_tagset such that
blk-mq will use a hostwide tagset over all SCSI host submission queues.

This means that we may expose all submission queues and always use the hwq
chosen by blk-mq.

And since if sdebug_host_max_queue is set, sdebug_max_queue is fixed to the
same value, we can simplify how sdebug_driver_template.can_queue is set.
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Tested-by: NDouglas Gilbert <dgilbert@interlog.com>
Acked-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Now that the block layer provides a shared tag, we can switch the driver
to expose all HW queues.
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Tested-by: NDouglas Gilbert <dgilbert@interlog.com>
Acked-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

So that we don't use a value of 0 for when Scsi_Host.nr_hw_queues is unset,
use the tag_set->nr_hw_queues (which holds 1 for this case).
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Tested-by: NDouglas Gilbert <dgilbert@interlog.com>
Acked-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Add Host and host template flag 'host_tagset' so hostwide tagset can be
shared on multiple reply queues after the SCSI device's reply queue is
converted to blk-mq hw queue.

[jpg: Update comment on .can_queue and add Scsi_Host.host_tagset]
Signed-off-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Tested-by: Don Brace<don.brace@microsemi.com> #SCSI resv cmds patches used
Tested-by: NDouglas Gilbert <dgilbert@interlog.com>
Acked-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

One-element arrays are being deprecated[1]. Replace the one-element array
with a simple object of type compat_caddr_t: 'compat_caddr_t unused'[2],
once it seems this field is actually never used.

Also, update struct cdrom_generic_command in UAPI by adding an
anonimous union to avoid using the one-element array _reserved_.

[1] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays
[2] https://github.com/KSPP/linux/issues/86Signed-off-by: NGustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/lkml/5f76f5d0.qJ4t%2FHWuRzSW7bTa%25lkp@intel.com/Build-tested-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Replace /* Fall through. */ comment with the new pseudo-keyword macro
fallthrough[1].

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-throughSigned-off-by: NGustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Since bcache code was merged into mainline kerrnel, each cache set only
as one single cache in it. The multiple caches framework is here but the
code is far from completed. Considering the multiple copies of cached
data can also be stored on e.g. md raid1 devices, it is unnecessary to
support multiple caches in one cache set indeed.

The previous preparation patches fix the dependencies of explicitly
making a cache set only have single cache. Now we don't have to maintain
an embedded partial super block in struct cache_set, the in-memory super
block can be directly referenced from struct cache.

This patch removes the embedded struct cache_sb from struct cache_set,
and fixes all locations where the superb lock was referenced from this
removed super block by referencing the in-memory super block of struct
cache.
Signed-off-by: NColy Li <colyli@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Currently the cache's sync status is checked and set on cache set's in-
memory partial super block. After removing the embedded struct cache_sb
from cache set and reference cache's in-memory super block from struct
cache_set, the sync status can set and check directly on cache's super
block.

This patch checks and sets the cache sync status directly on cache's
in-memory super block. This is a preparation for later removing embedded
struct cache_sb from struct cache_set.
Signed-off-by: NColy Li <colyli@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

After removing the embedded struct cache_sb from struct cache_set, cache
set will directly reference the in-memory super block of struct cache.
It is unnecessary to compare block_size, bucket_size and nr_in_set from
the identical in-memory super block in can_attach_cache().

This is a preparation patch for latter removing cache_set->sb from
struct cache_set.
Signed-off-by: NColy Li <colyli@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

In order to update the partial super block of cache set, the seq numbers
of cache and cache set are checked in register_cache_set(). If cache's
seq number is larger than cache set's seq number, cache set must update
its partial super block from cache's super block. It is unncessary when
the embedded struct cache_sb is removed from struct cache set.

This patch removed the seq numbers checking from register_cache_set(),
because later there will be no such partial super block in struct cache
set, the cache set will directly reference in-memory super block from
struct cache. This is a preparation patch for removing embedded struct
cache_sb from struct cache_set.
Signed-off-by: NColy Li <colyli@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Because struct cache_set and struct cache both have struct cache_sb,
macro bucket_bytes() currently are used on both of them. When removing
the embedded struct cache_sb from struct cache_set, this macro won't be
used on struct cache_set anymore.

This patch unifies all bucket_bytes() usage only on struct cache, this is
one of the preparation to remove the embedded struct cache_sb from
struct cache_set.
Signed-off-by: NColy Li <colyli@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

It seems alloc_bucket_pages() is the only user of bucket_pages().
Considering alloc_bucket_pages() is removed from bcache code, it is safe
to remove the useless macro bucket_pages() now.
Signed-off-by: NColy Li <colyli@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Now no one uses alloc_bucket_pages() anymore, remove it from bcache.h.
Signed-off-by: NColy Li <colyli@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Because struct cache_set and struct cache both have struct cache_sb,
therefore macro block_bytes() can be used on both of them. When removing
the embedded struct cache_sb from struct cache_set, this macro won't be
used on struct cache_set anymore.

This patch unifies all block_bytes() usage only on struct cache, this is
one of the preparation to remove the embedded struct cache_sb from
struct cache_set.
Signed-off-by: NColy Li <colyli@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

This patch adds a separated set_uuid[16] in struct cache_set, to store
the uuid of the cache set. This is the preparation to remove the
embedded struct cache_sb from struct cache_set.
Signed-off-by: NColy Li <colyli@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Since now each cache_set explicitly has single cache, for_each_cache()
is unnecessary. This patch removes this macro, and update all locations
where it is used, and makes sure all code logic still being consistent.
Signed-off-by: NColy Li <colyli@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Currently although the bcache code has a framework for multiple caches
in a cache set, but indeed the multiple caches never completed and users
use md raid1 for multiple copies of the cached data.

This patch does the following change in struct cache_set, to explicitly
make a cache_set only have single cache,
- Change pointer array "*cache[MAX_CACHES_PER_SET]" to a single pointer
  "*cache".
- Remove pointer array "*cache_by_alloc[MAX_CACHES_PER_SET]".
- Remove "caches_loaded".

Now the code looks as exactly what it does in practic: only one cache is
used in the cache set.
Signed-off-by: NColy Li <colyli@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The parameter 'int n' from bch_bucket_alloc_set() is not cleared
defined. From the code comments n is the number of buckets to alloc, but
from the code itself 'n' is the maximum cache to iterate. Indeed all the
locations where bch_bucket_alloc_set() is called, 'n' is alwasy 1.

This patch removes the confused and unnecessary 'int n' from parameter
list of  bch_bucket_alloc_set(), and explicitly allocates only 1 bucket
for its caller.
Signed-off-by: NColy Li <colyli@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code.

As inode->iprivate equals to third parameter of
debugfs_create_file() which is NULL. So it's equivalent
to original code logic.
Signed-off-by: NQinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: NColy Li <colyli@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

In mca_reserve(c) macro, we are checking root whether is NULL or not.
But that's not enough, when we read the root node in run_cache_set(),
if we got an error in bch_btree_node_read_done(), we will return
ERR_PTR(-EIO) to c->root.

And then we will go continue to unregister, but before calling
unregister_shrinker(&c->shrink), there is a possibility to call
bch_mca_count(), and we would get a crash with call trace like that:

[ 2149.876008] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000b5
... ...
[ 2150.598931] Call trace:
[ 2150.606439]  bch_mca_count+0x58/0x98 [escache]
[ 2150.615866]  do_shrink_slab+0x54/0x310
[ 2150.624429]  shrink_slab+0x248/0x2d0
[ 2150.632633]  drop_slab_node+0x54/0x88
[ 2150.640746]  drop_slab+0x50/0x88
[ 2150.648228]  drop_caches_sysctl_handler+0xf0/0x118
[ 2150.657219]  proc_sys_call_handler.isra.18+0xb8/0x110
[ 2150.666342]  proc_sys_write+0x40/0x50
[ 2150.673889]  __vfs_write+0x48/0x90
[ 2150.681095]  vfs_write+0xac/0x1b8
[ 2150.688145]  ksys_write+0x6c/0xd0
[ 2150.695127]  __arm64_sys_write+0x24/0x30
[ 2150.702749]  el0_svc_handler+0xa0/0x128
[ 2150.710296]  el0_svc+0x8/0xc
Signed-off-by: NDongsheng Yang <dongsheng.yang@easystack.cn>
Signed-off-by: NColy Li <colyli@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Previously the experimental async registration uses a separate sysfs
file register_async. Now the async registration code seems working well
for a while, we can do furtuher testing with it now.

This patch changes the async bcache registration shares the same sysfs
file /sys/fs/bcache/register (and register_quiet). Async registration
will be default behavior if BCACHE_ASYNC_REGISTRATION is set in kernel
configure. By default, BCACHE_ASYNC_REGISTRATION is not configured yet.
Signed-off-by: NColy Li <colyli@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Add support for user space to set a max open zone and a max active zone
limit via configfs. By default, the default values are 0 == no limit.

Call the block layer API functions used for exposing the configured
limits to sysfs.

Add accounting in null_blk_zoned so that these new limits are respected.
Performing an operation that would exceed these limits results in a
standard I/O error.

A max open zone limit exists in the ZBC standard.
While null_blk_zoned is used to test the Zoned Block Device model in
Linux, when it comes to differences between ZBC and ZNS, null_blk_zoned
mostly follows ZBC.

Therefore, implement the manage open zone resources function from ZBC,
but additionally add support for max active zones.
This enables user space not only to test against a device with an open
zone limit, but also to test against a device with an active zone limit.
Signed-off-by: NNiklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Pull NVMe updates from Christoph:

"nvme updates for 5.10

 - fix keep alive timer modification (Amit Engel)
 - order the PCI ID list more sensibly (Andy Shevchenko)
 - cleanup the open by controller helper (Chaitanya Kulkarni)
 - use an xarray for th CSE log lookup (Chaitanya Kulkarni)
 - support ZNS in nvmet passthrough mode (Chaitanya Kulkarni)
 - fix nvme_ns_report_zones (me)
 - add a sanity check to nvmet-fc (James Smart)
 - fix interrupt allocation when too many polled queues are specified
   (Jeffle Xu)
 - small nvmet-tcp optimization (Mark Wunderlich)"

* tag 'nvme-5.10-2020-09-27' of git://git.infradead.org/nvme:
  nvme-pci: allocate separate interrupt for the reserved non-polled I/O queue
  nvme: fix error handling in nvme_ns_report_zones
  nvmet-fc: fix missing check for no hostport struct
  nvmet: add passthru ZNS support
  nvmet: handle keep-alive timer when kato is modified by a set features cmd
  nvmet-tcp: have queue io_work context run on sock incoming cpu
  nvme-pci: Move enumeration by class to be last in the table
  nvme: use an xarray to lookup the Commands Supported and Effects log
  nvme: lift the file open code from nvme_ctrl_get_by_path

One queue will be reserved for non-polled IO when nvme.poll_queues is
greater or equal than the number of IO queues that the nvme controller
can provide. Currently the reserved queue for non-polled IO will reuse
the interrupt used by admin queue in this case, e.g, vector 0.

This can work and the performance may not be an issue since the admin
queue is used unfrequently. However this behaviour may be inconsistent
with that when nvme.poll_queues is smaller than the number of IO
queues available.

Thus allocate separate interrupt for this reserved queue, and thus make
the behaviour consistent.
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
[hch: minor cleanups, mostly to the pre-existing surrounding code]
Signed-off-by: NChristoph Hellwig <hch@lst.de>

nvme_submit_sync_cmd can return positive NVMe error codes in addition to
the negative Linux error code, which are currently ignored.  Fix this
by removing __nvme_ns_report_zones and handling the errors from
nvme_submit_sync_cmd in the caller instead of multiplexing the return
value and the number of zones reported into a single return value.

Fixes: 240e6ee2 ("nvme: support for zoned namespaces")
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDamien Le Moal <damien.lemoal@wdc.com>

A hostport port pointer is allowed to be NULL as it is not allocated if
the lldd does not support the new interfaces for NVME LS request support.
The hostport free routine validates the handle but forgot to validate the
hostport pointer.

Validate the hostport pointer before using it to validate the handle.
Signed-off-by: NJames Smart <james.smart@broadcom.com>
Reviewed-by: NHimanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

In the default passthru implementation NVMeOF target passthru ctrl is
not capable of handling Zoned Namespaces (ZNS).

Update the nvmet_parse_pasthru_admin_cmd() to allow
NVME_ID_CNS_CS_CTRL/NVME_CIS_ZNS and NVME_ID_CNS_CS_NS/NVME_CIS_ZNS.

With this addition NVMeOF Passthru allows Zoned Namespaces.
Signed-off-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

A user may modify the kato by a set features cmd.  To properly deal
with races or a kato value of 0 (no keep alive enabled) change
nvmet_set_feat_kato to first disable the timer, then set the value
and then re-enable the timer.
Signed-off-by: NAmit Engel <amit.engel@dell.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

No real good need to spread queues artificially. Usually the
target will serve multiple hosts, and it's better to run on the socket
incoming cpu for better affinitization rather than spread queues on all
online cpus.

We rely on RSS to spread the work around sufficiently.
Signed-off-by: NMark Wunderlich <mark.wunderlich@intel.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

It's unusual that we have enumeration by class in the middle of the table.
It might potentially be problematic in the future if we add another entry
after it.

So, move class matching entry to be the last in the ID table.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

When using linked list we have to open code the locking, search, and
destroy operations with the loops even if data structure doesn't fall
into the fast path.

One of the main advantage of having XArray to store, search, and remove
items is that it handles all the locking by itself, avoids the loops
when using linked lists, provides clear API to replace the linked list's
search and destroy loops.

This patch replaces the ctrl->cel list with XArray and removes :-

a. Extra code needed for the linked list for ctrl->cel item management
   such as nvme_find_cel().
b. Destroy loop in the nvme_free_ctrl().
c. Explicit insertion locking in the nvme_get_effects_log().
Signed-off-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Lift opening the file open/close code from nvme_ctrl_get_by_path into
the caller, just keeping a simple nvme_ctrl_from_file() helper.
Signed-off-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
[hch: refactored a bit, split the bug fixes into a separate prep patch]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NLogan Gunthorpe <logang@deltatee.com>

Merge branch 'md-next' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md into for-5.10/drivers

Pull MD updates from Song.

* 'md-next' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md:
  md/raid10: improve discard request for far layout
  md/raid10: improve raid10 discard request
  md/raid10: pull codes that wait for blocked dev into one function
  md/raid10: extend r10bio devs to raid disks
  md: add md_submit_discard_bio() for submitting discard bio
  md: Simplify code with existing definition RESYNC_SECTORS in raid10.c
  md/raid5: reallocate page array after setting new stripe_size
  md/raid5: resize stripe_head when reshape array
  md/raid5: let multiple devices of stripe_head share page
  md/raid6: let async recovery function support different page offset
  md/raid6: let syndrome computor support different page offset
  md/raid5: convert to new xor compution interface
  md/raid5: add new xor function to support different page offset
  md/raid5: make async_copy_data() to support different page offset
  md/raid5: add a new member of offset into r5dev
  md: only calculate blocksize once and use i_blocksize()