linux/block
Linus Torvalds 97d052ea3f A set of locking fixes and updates:
- Untangle the header spaghetti which causes build failures in various
     situations caused by the lockdep additions to seqcount to validate that
     the write side critical sections are non-preemptible.
 
   - The seqcount associated lock debug addons which were blocked by the
     above fallout.
 
     seqcount writers contrary to seqlock writers must be externally
     serialized, which usually happens via locking - except for strict per
     CPU seqcounts. As the lock is not part of the seqcount, lockdep cannot
     validate that the lock is held.
 
     This new debug mechanism adds the concept of associated locks.
     sequence count has now lock type variants and corresponding
     initializers which take a pointer to the associated lock used for
     writer serialization. If lockdep is enabled the pointer is stored and
     write_seqcount_begin() has a lockdep assertion to validate that the
     lock is held.
 
     Aside of the type and the initializer no other code changes are
     required at the seqcount usage sites. The rest of the seqcount API is
     unchanged and determines the type at compile time with the help of
     _Generic which is possible now that the minimal GCC version has been
     moved up.
 
     Adding this lockdep coverage unearthed a handful of seqcount bugs which
     have been addressed already independent of this.
 
     While generaly useful this comes with a Trojan Horse twist: On RT
     kernels the write side critical section can become preemtible if the
     writers are serialized by an associated lock, which leads to the well
     known reader preempts writer livelock. RT prevents this by storing the
     associated lock pointer independent of lockdep in the seqcount and
     changing the reader side to block on the lock when a reader detects
     that a writer is in the write side critical section.
 
  - Conversion of seqcount usage sites to associated types and initializers.
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Merge tag 'locking-urgent-2020-08-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking updates from Thomas Gleixner:
 "A set of locking fixes and updates:

   - Untangle the header spaghetti which causes build failures in
     various situations caused by the lockdep additions to seqcount to
     validate that the write side critical sections are non-preemptible.

   - The seqcount associated lock debug addons which were blocked by the
     above fallout.

     seqcount writers contrary to seqlock writers must be externally
     serialized, which usually happens via locking - except for strict
     per CPU seqcounts. As the lock is not part of the seqcount, lockdep
     cannot validate that the lock is held.

     This new debug mechanism adds the concept of associated locks.
     sequence count has now lock type variants and corresponding
     initializers which take a pointer to the associated lock used for
     writer serialization. If lockdep is enabled the pointer is stored
     and write_seqcount_begin() has a lockdep assertion to validate that
     the lock is held.

     Aside of the type and the initializer no other code changes are
     required at the seqcount usage sites. The rest of the seqcount API
     is unchanged and determines the type at compile time with the help
     of _Generic which is possible now that the minimal GCC version has
     been moved up.

     Adding this lockdep coverage unearthed a handful of seqcount bugs
     which have been addressed already independent of this.

     While generally useful this comes with a Trojan Horse twist: On RT
     kernels the write side critical section can become preemtible if
     the writers are serialized by an associated lock, which leads to
     the well known reader preempts writer livelock. RT prevents this by
     storing the associated lock pointer independent of lockdep in the
     seqcount and changing the reader side to block on the lock when a
     reader detects that a writer is in the write side critical section.

   - Conversion of seqcount usage sites to associated types and
     initializers"

* tag 'locking-urgent-2020-08-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits)
  locking/seqlock, headers: Untangle the spaghetti monster
  locking, arch/ia64: Reduce <asm/smp.h> header dependencies by moving XTP bits into the new <asm/xtp.h> header
  x86/headers: Remove APIC headers from <asm/smp.h>
  seqcount: More consistent seqprop names
  seqcount: Compress SEQCNT_LOCKNAME_ZERO()
  seqlock: Fold seqcount_LOCKNAME_init() definition
  seqlock: Fold seqcount_LOCKNAME_t definition
  seqlock: s/__SEQ_LOCKDEP/__SEQ_LOCK/g
  hrtimer: Use sequence counter with associated raw spinlock
  kvm/eventfd: Use sequence counter with associated spinlock
  userfaultfd: Use sequence counter with associated spinlock
  NFSv4: Use sequence counter with associated spinlock
  iocost: Use sequence counter with associated spinlock
  raid5: Use sequence counter with associated spinlock
  vfs: Use sequence counter with associated spinlock
  timekeeping: Use sequence counter with associated raw spinlock
  xfrm: policy: Use sequence counters with associated lock
  netfilter: nft_set_rbtree: Use sequence counter with associated rwlock
  netfilter: conntrack: Use sequence counter with associated spinlock
  sched: tasks: Use sequence counter with associated spinlock
  ...
2020-08-10 19:07:44 -07:00
..
partitions block: always remove partitions from blk_drop_partitions() 2020-07-15 09:23:42 -06:00
badblocks.c block: switch all files cleared marked as GPLv2 to SPDX tags 2019-04-30 16:11:57 -06:00
bfq-cgroup.c block, bfq: invoke flush_idle_tree after reparent_active_queues in pd_offline 2020-03-21 14:31:03 -06:00
bfq-iosched.c block: bfq-iosched: fix duplicated word 2020-07-31 16:29:47 -06:00
bfq-iosched.h block, bfq: turn put_queue into release_process_ref in __bfq_bic_change_cgroup 2020-03-21 14:31:00 -06:00
bfq-wf2q.c block, bfq: get a ref to a group when adding it to a service tree 2020-02-03 06:58:15 -07:00
bio-integrity.c block: make function __bio_integrity_free() static 2020-07-02 12:38:18 -06:00
bio.c block: bio: delete duplicated words 2020-07-31 16:29:47 -06:00
blk-cgroup-rwstat.c blk-cgroup: separate out blkg_rwstat under CONFIG_BLK_CGROUP_RWSTAT 2019-11-07 12:28:13 -07:00
blk-cgroup-rwstat.h blk-cgroup: separate out blkg_rwstat under CONFIG_BLK_CGROUP_RWSTAT 2019-11-07 12:28:13 -07:00
blk-cgroup.c blk-cgroup: show global disk stats in root cgroup io.stat 2020-07-17 20:18:00 -06:00
blk-core.c for-5.9/io_uring-20200802 2020-08-03 13:01:22 -07:00
blk-crypto-fallback.c block: rename generic_make_request to submit_bio_noacct 2020-07-01 07:27:24 -06:00
blk-crypto-internal.h block: blk-crypto-fallback for Inline Encryption 2020-05-14 09:48:03 -06:00
blk-crypto.c block: rename generic_make_request to submit_bio_noacct 2020-07-01 07:27:24 -06:00
blk-exec.c block: add a blk_account_io_merge_bio helper 2020-05-27 05:21:23 -06:00
blk-flush.c block: defer flush request no matter whether we have elevator 2020-07-17 07:14:28 -06:00
blk-integrity.c block: Make blk-integrity preclude hardware inline encryption 2020-05-14 09:48:03 -06:00
blk-ioc.c block: remove retry loop in ioc_release_fn() 2020-07-16 10:22:15 -06:00
blk-iocost.c A set of locking fixes and updates: 2020-08-10 19:07:44 -07:00
blk-iolatency.c blk-iolatency: only call ktime_get() if needed 2020-07-01 08:02:38 -06:00
blk-lib.c block: improve discard bio alignment in __blkdev_issue_discard() 2020-07-17 07:15:10 -06:00
blk-map.c block: Inline encryption support for blk-mq 2020-05-14 09:47:53 -06:00
blk-merge.c Remove uninitialized_var() macro for v5.9-rc1 2020-08-04 13:49:43 -07:00
blk-mq-cpumap.c blk-mq: balance mapping between present CPUs and queues 2019-08-04 21:43:12 -06:00
blk-mq-debugfs-zoned.c block: Cleanup license notice 2019-01-17 21:21:40 -07:00
blk-mq-debugfs.c for-5.9/block-20200802 2020-08-03 11:57:03 -07:00
blk-mq-debugfs.h blk-mq: no need to check return value of debugfs_create functions 2019-06-13 03:00:30 -06:00
blk-mq-pci.c block: Fix blk_mq_*_map_queues() kernel-doc headers 2019-05-31 15:12:34 -06:00
blk-mq-rdma.c block: Fix blk_mq_*_map_queues() kernel-doc headers 2019-05-31 15:12:34 -06:00
blk-mq-sched.c block: blk-mq-sched: delete duplicated word 2020-07-31 16:29:47 -06:00
blk-mq-sched.h block: blk-mq: Remove blk_mq_sched_started_request and started_request 2019-07-23 07:25:09 -06:00
blk-mq-sysfs.c blk-mq: make sure that line break can be printed 2019-11-04 07:14:10 -07:00
blk-mq-tag.c blk-mq: move blk_mq_get_driver_tag into blk-mq.c 2020-06-30 12:57:59 -06:00
blk-mq-tag.h blk-mq: centralise related handling into blk_mq_get_driver_tag 2020-07-08 16:06:42 -06:00
blk-mq-virtio.c blk-mq: Fix typo in comment 2020-03-17 20:55:21 +01:00
blk-mq.c for-5.9/block-20200802 2020-08-03 11:57:03 -07:00
blk-mq.h Revert "blk-mq: put driver tag when this request is completed" 2020-07-01 22:58:32 -06:00
blk-pm.c scsi: block: pm: Simplify resume handling 2020-07-24 22:09:55 -04:00
blk-pm.h block: remove the queue_lock indirection 2018-11-15 12:17:28 -07:00
blk-rq-qos.c Revert "blk-rq-qos: remove redundant finish_wait to rq_qos_wait." 2020-07-15 09:33:37 -06:00
blk-rq-qos.h blk-rq-qos: fix first node deletion of rq_qos_del() 2019-10-15 10:13:13 -06:00
blk-settings.c block: remove blk_queue_stack_limits 2020-07-20 15:38:52 -06:00
blk-stat.c blk-stat: Optimise blk_stat_add() 2019-10-07 21:19:10 -06:00
blk-stat.h block: deactivate blk_stat timer in wbt_disable_default() 2018-12-12 06:47:51 -07:00
blk-sysfs.c block: add max_active_zones to blk-sysfs 2020-07-15 14:26:11 -06:00
blk-throttle.c block: rename generic_make_request to submit_bio_noacct 2020-07-01 07:27:24 -06:00
blk-timeout.c block: blk-timeout: delete duplicated word 2020-07-31 16:29:47 -06:00
blk-wbt.c blk-wbt: rename __wbt_update_limits to wbt_update_limits 2020-05-29 16:30:39 -06:00
blk-wbt.h blk-wbt: remove wbt_update_limits 2020-05-29 16:30:39 -06:00
blk-zoned.c block: don't do revalidate zones on invalid devices 2020-08-03 09:24:04 -06:00
blk.h block: improve discard bio alignment in __blkdev_issue_discard() 2020-07-17 07:15:10 -06:00
bounce.c block: rename generic_make_request to submit_bio_noacct 2020-07-01 07:27:24 -06:00
bsg-lib.c blk-mq: move failure injection out of blk_mq_complete_request 2020-06-24 09:15:57 -06:00
bsg.c compat_ioctl: bsg: add handler 2020-01-03 09:33:21 +01:00
cmdline-parser.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
elevator.c block: elevator: delete duplicated word and fix typos 2020-07-31 16:29:47 -06:00
genhd.c block: genhd: delete duplicated words 2020-07-31 16:29:47 -06:00
ioctl.c block: Fix type of first compat_put_{,u}long() argument 2020-05-19 09:40:29 -06:00
ioprio.c docs: block: convert to ReST 2019-07-15 09:20:27 -03:00
Kconfig nvme: support for zoned namespaces 2020-07-08 16:16:20 +02:00
Kconfig.iosched treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
keyslot-manager.c block/keyslot-manager: use kvfree_sensitive() 2020-06-29 13:24:05 -06:00
kyber-iosched.c blk-mq: remove the bio argument to ->prepare_request 2020-05-29 10:23:24 -06:00
Makefile blk-mq: merge blk-softirq.c into blk-mq.c 2020-06-24 09:15:56 -06:00
mq-deadline.c blk-mq: remove the bio argument to ->prepare_request 2020-05-29 10:23:24 -06:00
opal_proto.h block: sed-opal: Change the check condition for regular session validity 2020-03-12 08:00:10 -06:00
scsi_ioctl.c scsi: core: Allow non-root users to perform ZBC commands 2020-03-16 18:26:31 -04:00
sed-opal.c block: sed-opal: Change the check condition for regular session validity 2020-03-12 08:00:10 -06:00
t10-pi.c block: Allow t10-pi to be modular 2020-01-06 20:59:04 -07:00