Commit 3b99107f authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'for-5.3/block-20190708' of git://git.kernel.dk/linux-block 

Pull block updates from Jens Axboe:
 "This is the main block updates for 5.3. Nothing earth shattering or
  major in here, just fixes, additions, and improvements all over the
  map. This contains:

   - Series of documentation fixes (Bart)

   - Optimization of the blk-mq ctx get/put (Bart)

   - null_blk removal race condition fix (Bob)

   - req/bio_op() cleanups (Chaitanya)

   - Series cleaning up the segment accounting, and request/bio mapping
     (Christoph)

   - Series cleaning up the page getting/putting for bios (Christoph)

   - block cgroup cleanups and moving it to where it is used (Christoph)

   - block cgroup fixes (Tejun)

   - Series of fixes and improvements to bcache, most notably a write
     deadlock fix (Coly)

   - blk-iolatency STS_AGAIN and accounting fixes (Dennis)

   - Series of improvements and fixes to BFQ (Douglas, Paolo)

   - debugfs_create() return value check removal for drbd (Greg)

   - Use struct_size(), where appropriate (Gustavo)

   - Two lighnvm fixes (Heiner, Geert)

   - MD fixes, including a read balance and corruption fix (Guoqing,
     Marcos, Xiao, Yufen)

   - block opal shadow mbr additions (Jonas, Revanth)

   - sbitmap compare-and-exhange improvemnts (Pavel)

   - Fix for potential bio->bi_size overflow (Ming)

   - NVMe pull requests:
       - improved PCIe suspent support (Keith Busch)
       - error injection support for the admin queue (Akinobu Mita)
       - Fibre Channel discovery improvements (James Smart)
       - tracing improvements including nvmetc tracing support (Minwoo Im)
       - misc fixes and cleanups (Anton Eidelman, Minwoo Im, Chaitanya
         Kulkarni)"

   - Various little fixes and improvements to drivers and core"

* tag 'for-5.3/block-20190708' of git://git.kernel.dk/linux-block: (153 commits)
  blk-iolatency: fix STS_AGAIN handling
  block: nr_phys_segments needs to be zero for REQ_OP_WRITE_ZEROES
  blk-mq: simplify blk_mq_make_request()
  blk-mq: remove blk_mq_put_ctx()
  sbitmap: Replace cmpxchg with xchg
  block: fix .bi_size overflow
  block: sed-opal: check size of shadow mbr
  block: sed-opal: ioctl for writing to shadow mbr
  block: sed-opal: add ioctl for done-mark of shadow mbr
  block: never take page references for ITER_BVEC
  direct-io: use bio_release_pages in dio_bio_complete
  block_dev: use bio_release_pages in bio_unmap_user
  block_dev: use bio_release_pages in blkdev_bio_end_io
  iomap: use bio_release_pages in iomap_dio_bio_end_io
  block: use bio_release_pages in bio_map_user_iov
  block: use bio_release_pages in bio_unmap_user
  block: optionally mark pages dirty in bio_release_pages
  block: move the BIO_NO_PAGE_REF check into bio_release_pages
  block: skd_main.c: Remove call to memset after dma_alloc_coherent
  block: mtip32xx: Remove call to memset after dma_alloc_coherent
  ...
parents 0415052d c9b3007f

Documentation/block/bfq-iosched.txt

+6 −6
Original line number Diff line number Diff line
@@ -38,13 +38,13 @@ stack). To give an idea of the limits with BFQ, on slow or average 
CPUs, here are, first, the limits of BFQ for three different CPUs, on,

respectively, an average laptop, an old desktop, and a cheap embedded

system, in case full hierarchical support is enabled (i.e.,

CONFIG_BFQ_GROUP_IOSCHED is set), but CONFIG_DEBUG_BLK_CGROUP is not

CONFIG_BFQ_GROUP_IOSCHED is set), but CONFIG_BFQ_CGROUP_DEBUG is not

set (Section 4-2):

- Intel i7-4850HQ: 400 KIOPS

- AMD A8-3850: 250 KIOPS

- ARM CortexTM-A53 Octa-core: 80 KIOPS



If CONFIG_DEBUG_BLK_CGROUP is set (and of course full hierarchical

If CONFIG_BFQ_CGROUP_DEBUG is set (and of course full hierarchical

support is enabled), then the sustainable throughput with BFQ

decreases, because all blkio.bfq* statistics are created and updated

(Section 4-2). For BFQ, this leads to the following maximum
@@ -537,19 +537,19 @@ or io.bfq.weight. 


As for cgroups-v1 (blkio controller), the exact set of stat files

created, and kept up-to-date by bfq, depends on whether

CONFIG_DEBUG_BLK_CGROUP is set. If it is set, then bfq creates all

CONFIG_BFQ_CGROUP_DEBUG is set. If it is set, then bfq creates all

the stat files documented in

Documentation/cgroup-v1/blkio-controller.rst. If, instead,

CONFIG_DEBUG_BLK_CGROUP is not set, then bfq creates only the files

CONFIG_BFQ_CGROUP_DEBUG is not set, then bfq creates only the files

blkio.bfq.io_service_bytes

blkio.bfq.io_service_bytes_recursive

blkio.bfq.io_serviced

blkio.bfq.io_serviced_recursive



The value of CONFIG_DEBUG_BLK_CGROUP greatly influences the maximum

The value of CONFIG_BFQ_CGROUP_DEBUG greatly influences the maximum

throughput sustainable with bfq, because updating the blkio.bfq.*

stats is rather costly, especially for some of the stats enabled by

CONFIG_DEBUG_BLK_CGROUP.

CONFIG_BFQ_CGROUP_DEBUG.



Parameters to set

-----------------

Documentation/block/biodoc.txt

+0 −1
Original line number Diff line number Diff line
@@ -436,7 +436,6 @@ struct bio { 
       struct bvec_iter	bi_iter;	/* current index into bio_vec array */



       unsigned int	bi_size;     /* total size in bytes */

       unsigned short 	bi_phys_segments; /* segments after physaddr coalesce*/

       unsigned short	bi_hw_segments; /* segments after DMA remapping */

       unsigned int	bi_max;	     /* max bio_vecs we can hold

                                        used as index into pool */

Documentation/block/queue-sysfs.txt

+43 −21
Original line number Diff line number Diff line
@@ -14,6 +14,15 @@ add_random (RW) 
This file allows to turn off the disk entropy contribution. Default

value of this file is '1'(on).



chunk_sectors (RO)

------------------

This has different meaning depending on the type of the block device.

For a RAID device (dm-raid), chunk_sectors indicates the size in 512B sectors

of the RAID volume stripe segment. For a zoned block device, either host-aware

or host-managed, chunk_sectors indicates the size in 512B sectors of the zones

of the device, with the eventual exception of the last zone of the device which

may be smaller.



dax (RO)

--------

This file indicates whether the device supports Direct Access (DAX),
@@ -43,6 +52,16 @@ large discards are issued, setting this value lower will make Linux issue 
smaller discards and potentially help reduce latencies induced by large

discard operations.



discard_zeroes_data (RO)

------------------------

Obsolete. Always zero.



fua (RO)

--------

Whether or not the block driver supports the FUA flag for write requests.

FUA stands for Force Unit Access. If the FUA flag is set that means that

write requests must bypass the volatile cache of the storage device.



hw_sector_size (RO)

-------------------

This is the hardware sector size of the device, in bytes.
@@ -83,14 +102,19 @@ logical_block_size (RO) 
-----------------------

This is the logical block size of the device, in bytes.



max_discard_segments (RO)

-------------------------

The maximum number of DMA scatter/gather entries in a discard request.



max_hw_sectors_kb (RO)

----------------------

This is the maximum number of kilobytes supported in a single data transfer.



max_integrity_segments (RO)

---------------------------

When read, this file shows the max limit of integrity segments as

set by block layer which a hardware controller can handle.

Maximum number of elements in a DMA scatter/gather list with integrity

data that will be submitted by the block layer core to the associated

block driver.



max_sectors_kb (RW)

-------------------
@@ -100,11 +124,12 @@ size allowed by the hardware. 


max_segments (RO)

-----------------

Maximum number of segments of the device.

Maximum number of elements in a DMA scatter/gather list that is submitted

to the associated block driver.



max_segment_size (RO)

---------------------

Maximum segment size of the device.

Maximum size in bytes of a single element in a DMA scatter/gather list.



minimum_io_size (RO)

--------------------
@@ -132,6 +157,12 @@ per-block-cgroup request pool. IOW, if there are N block cgroups, 
each request queue may have up to N request pools, each independently

regulated by nr_requests.



nr_zones (RO)

-------------

For zoned block devices (zoned attribute indicating "host-managed" or

"host-aware"), this indicates the total number of zones of the device.

This is always 0 for regular block devices.



optimal_io_size (RO)

--------------------

This is the optimal IO size reported by the device.
@@ -185,8 +216,8 @@ This is the number of bytes the device can write in a single write-same 
command.  A value of '0' means write-same is not supported by this

device.



wb_lat_usec (RW)

----------------

wbt_lat_usec (RW)

-----------------

If the device is registered for writeback throttling, then this file shows

the target minimum read latency. If this latency is exceeded in a given

window of time (see wb_window_usec), then the writeback throttling will start
@@ -201,6 +232,12 @@ blk-throttle makes decision based on the samplings. Lower time means cgroups 
have more smooth throughput, but higher CPU overhead. This exists only when

CONFIG_BLK_DEV_THROTTLING_LOW is enabled.



write_zeroes_max_bytes (RO)

---------------------------

For block drivers that support REQ_OP_WRITE_ZEROES, the maximum number of

bytes that can be zeroed at once. The value 0 means that REQ_OP_WRITE_ZEROES

is not supported.



zoned (RO)

----------

This indicates if the device is a zoned block device and the zone model of the
@@ -213,19 +250,4 @@ devices are described in the ZBC (Zoned Block Commands) and ZAC 
do not support zone commands, they will be treated as regular block devices

and zoned will report "none".



nr_zones (RO)

-------------

For zoned block devices (zoned attribute indicating "host-managed" or

"host-aware"), this indicates the total number of zones of the device.

This is always 0 for regular block devices.



chunk_sectors (RO)

------------------

This has different meaning depending on the type of the block device.

For a RAID device (dm-raid), chunk_sectors indicates the size in 512B sectors

of the RAID volume stripe segment. For a zoned block device, either host-aware

or host-managed, chunk_sectors indicates the size in 512B sectors of the zones

of the device, with the eventual exception of the last zone of the device which

may be smaller.



Jens Axboe <jens.axboe@oracle.com>, February 2009

Documentation/cgroup-v1/blkio-controller.rst

+6 −6
Original line number Diff line number Diff line
@@ -82,7 +82,7 @@ Various user visible config options 
CONFIG_BLK_CGROUP

	- Block IO controller.



CONFIG_DEBUG_BLK_CGROUP

CONFIG_BFQ_CGROUP_DEBUG

	- Debug help. Right now some additional stats file show up in cgroup

	  if this option is enabled.
@@ -202,13 +202,13 @@ Proportional weight policy files 
	  write, sync or async.



- blkio.avg_queue_size

	- Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y.

	- Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y.

	  The average queue size for this cgroup over the entire time of this

	  cgroup's existence. Queue size samples are taken each time one of the

	  queues of this cgroup gets a timeslice.



- blkio.group_wait_time

	- Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y.

	- Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y.

	  This is the amount of time the cgroup had to wait since it became busy

	  (i.e., went from 0 to 1 request queued) to get a timeslice for one of

	  its queues. This is different from the io_wait_time which is the
@@ -219,7 +219,7 @@ Proportional weight policy files 
	  got a timeslice and will not include the current delta.



- blkio.empty_time

	- Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y.

	- Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y.

	  This is the amount of time a cgroup spends without any pending

	  requests when not being served, i.e., it does not include any time

	  spent idling for one of the queues of the cgroup. This is in
@@ -228,7 +228,7 @@ Proportional weight policy files 
	  time it had a pending request and will not include the current delta.



- blkio.idle_time

	- Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y.

	- Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y.

	  This is the amount of time spent by the IO scheduler idling for a

	  given cgroup in anticipation of a better request than the existing ones

	  from other queues/cgroups. This is in nanoseconds. If this is read
@@ -237,7 +237,7 @@ Proportional weight policy files 
	  the current delta.



- blkio.dequeue

	- Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y. This

	- Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y. This

	  gives the statistics about how many a times a group was dequeued

	  from service tree of the device. First two fields specify the major

	  and minor number of the device and third field specifies the number

Documentation/fault-injection/nvme-fault-injection.txt

+56 −0
Original line number Diff line number Diff line
@@ -114,3 +114,59 @@ R13: ffff88011a3c9680 R14: 0000000000000000 R15: 0000000000000000 
  cpu_startup_entry+0x6f/0x80

  start_secondary+0x187/0x1e0

  secondary_startup_64+0xa5/0xb0



Example 3: Inject an error into the 10th admin command

------------------------------------------------------



echo 100 > /sys/kernel/debug/nvme0/fault_inject/probability

echo 10 > /sys/kernel/debug/nvme0/fault_inject/space

echo 1 > /sys/kernel/debug/nvme0/fault_inject/times

nvme reset /dev/nvme0



Expected Result:



After NVMe controller reset, the reinitialization may or may not succeed.

It depends on which admin command is actually forced to fail.



Message from dmesg:



nvme nvme0: resetting controller

FAULT_INJECTION: forcing a failure.

name fault_inject, interval 1, probability 100, space 1, times 1

CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.2.0-rc2+ #2

Hardware name: MSI MS-7A45/B150M MORTAR ARCTIC (MS-7A45), BIOS 1.50 04/25/2017

Call Trace:

 <IRQ>

 dump_stack+0x63/0x85

 should_fail+0x14a/0x170

 nvme_should_fail+0x38/0x80 [nvme_core]

 nvme_irq+0x129/0x280 [nvme]

 ? blk_mq_end_request+0xb3/0x120

 __handle_irq_event_percpu+0x84/0x1a0

 handle_irq_event_percpu+0x32/0x80

 handle_irq_event+0x3b/0x60

 handle_edge_irq+0x7f/0x1a0

 handle_irq+0x20/0x30

 do_IRQ+0x4e/0xe0

 common_interrupt+0xf/0xf

 </IRQ>

RIP: 0010:cpuidle_enter_state+0xc5/0x460

Code: ff e8 8f 5f 86 ff 80 7d c7 00 74 17 9c 58 0f 1f 44 00 00 f6 c4 02 0f 85 69 03 00 00 31 ff e8 62 aa 8c ff fb 66 0f 1f 44 00 00 <45> 85 ed 0f 88 37 03 00 00 4c 8b 45 d0 4c 2b 45 b8 48 ba cf f7 53

RSP: 0018:ffffffff88c03dd0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffdc

RAX: ffff9dac25a2ac80 RBX: ffffffff88d53760 RCX: 000000000000001f

RDX: 0000000000000000 RSI: 000000002d958403 RDI: 0000000000000000

RBP: ffffffff88c03e18 R08: fffffff75e35ffb7 R09: 00000a49a56c0b48

R10: ffffffff88c03da0 R11: 0000000000001b0c R12: ffff9dac25a34d00

R13: 0000000000000006 R14: 0000000000000006 R15: ffffffff88d53760

 cpuidle_enter+0x2e/0x40

 call_cpuidle+0x23/0x40

 do_idle+0x201/0x280

 cpu_startup_entry+0x1d/0x20

 rest_init+0xaa/0xb0

 arch_call_rest_init+0xe/0x1b

 start_kernel+0x51c/0x53b

 x86_64_start_reservations+0x24/0x26

 x86_64_start_kernel+0x74/0x77

 secondary_startup_64+0xa4/0xb0

nvme nvme0: Could not set queue count (16385)

nvme nvme0: IO queues not created

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