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
  ...

Author: torvalds

Documentation/block/bfq-iosched.txt

@@ -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

@@ -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

@@ -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 <[email protected]>, February 2009

Documentation/cgroup-v1/blkio-controller.rst

@@ -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

@@ -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

block/Kconfig.iosched

@@ -36,6 +36,13 @@ config BFQ_GROUP_IOSCHED
        Enable hierarchical scheduling in BFQ, using the blkio
        (cgroups-v1) or io (cgroups-v2) controller.
 
+config BFQ_CGROUP_DEBUG
+	bool "BFQ IO controller debugging"
+	depends on BFQ_GROUP_IOSCHED
+	---help---
+	Enable some debugging help. Currently it exports additional stat
+	files in a cgroup which can be useful for debugging.
+
 endmenu
 
 endif