linux.git/fs/notify, branch v6.3

Merge tag 'rcu.2023.02.10a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

2023-02-21T18:45:51+00:00

Pull RCU updates from Paul McKenney:

 - Documentation updates

 - Miscellaneous fixes, perhaps most notably:

      - Throttling callback invocation based on the number of callbacks
        that are now ready to invoke instead of on the total number of
        callbacks

      - Several patches that suppress false-positive boot-time
        diagnostics, for example, due to lockdep not yet being
        initialized

      - Make expedited RCU CPU stall warnings dump stacks of any tasks
        that are blocking the stalled grace period. (Normal RCU CPU
        stall warnings have done this for many years)

      - Lazy-callback fixes to avoid delays during boot, suspend, and
        resume. (Note that lazy callbacks must be explicitly enabled, so
        this should not (yet) affect production use cases)

 - Make kfree_rcu() and friends take advantage of polled grace periods,
   thus reducing memory footprint by almost two orders of magnitude,
   admittedly on a microbenchmark

   This also begins the transition from kfree_rcu(p) to
   kfree_rcu_mightsleep(p). This transition was motivated by bugs where
   kfree_rcu(p), which can block, was typed instead of the intended
   kfree_rcu(p, rh)

 - SRCU updates, perhaps most notably fixing a bug that causes SRCU to
   fail when booted on a system with a non-zero boot CPU. This
   surprising situation actually happens for kdump kernels on the
   powerpc architecture

   This also adds an srcu_down_read() and srcu_up_read(), which act like
   srcu_read_lock() and srcu_read_unlock(), but allow an SRCU read-side
   critical section to be handed off from one task to another

 - Clean up the now-useless SRCU Kconfig option

   There are a few more commits that are not yet acked or pulled into
   maintainer trees, and these will be in a pull request for a later
   merge window

 - RCU-tasks updates, perhaps most notably these fixes:

      - A strange interaction between PID-namespace unshare and the
        RCU-tasks grace period that results in a low-probability but
        very real hang

      - A race between an RCU tasks rude grace period on a single-CPU
        system and CPU-hotplug addition of the second CPU that can
        result in a too-short grace period

      - A race between shrinking RCU tasks down to a single callback
        list and queuing a new callback to some other CPU, but where
        that queuing is delayed for more than an RCU grace period. This
        can result in that callback being stranded on the non-boot CPU

 - Torture-test updates and fixes

 - Torture-test scripting updates and fixes

 - Provide additional RCU CPU stall-warning information in kernels built
   with CONFIG_RCU_CPU_STALL_CPUTIME=y, and restore the full five-minute
   timeout limit for expedited RCU CPU stall warnings

* tag 'rcu.2023.02.10a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (80 commits)
  rcu/kvfree: Add kvfree_rcu_mightsleep() and kfree_rcu_mightsleep()
  kernel/notifier: Remove CONFIG_SRCU
  init: Remove "select SRCU"
  fs/quota: Remove "select SRCU"
  fs/notify: Remove "select SRCU"
  fs/btrfs: Remove "select SRCU"
  fs: Remove CONFIG_SRCU
  drivers/pci/controller: Remove "select SRCU"
  drivers/net: Remove "select SRCU"
  drivers/md: Remove "select SRCU"
  drivers/hwtracing/stm: Remove "select SRCU"
  drivers/dax: Remove "select SRCU"
  drivers/base: Remove CONFIG_SRCU
  rcu: Disable laziness if lazy-tracking says so
  rcu: Track laziness during boot and suspend
  rcu: Remove redundant call to rcu_boost_kthread_setaffinity()
  rcu: Allow up to five minutes expedited RCU CPU stall-warning timeouts
  rcu: Align the output of RCU CPU stall warning messages
  rcu: Add RCU stall diagnosis information
  sched: Add helper nr_context_switches_cpu()
  ...

fanotify,audit: Allow audit to use the full permission event response

2023-02-07T11:53:53+00:00

This patch passes the full response so that the audit function can use all
of it. The audit function was updated to log the additional information in
the AUDIT_FANOTIFY record.

Currently the only type of fanotify info that is defined is an audit
rule number, but convert it to hex encoding to future-proof the field.
Hex encoding suggested by Paul Moore .

The {subj,obj}_trust values are {0,1,2}, corresponding to no, yes, unknown.

Sample records:
  type=FANOTIFY msg=audit(1600385147.372:590): resp=2 fan_type=1 fan_info=3137 subj_trust=3 obj_trust=5
  type=FANOTIFY msg=audit(1659730979.839:284): resp=1 fan_type=0 fan_info=0 subj_trust=2 obj_trust=2

Suggested-by: Steve Grubb 
Link: https://lore.kernel.org/r/3075502.aeNJFYEL58@x2
Tested-by: Steve Grubb 
Acked-by: Steve Grubb 
Signed-off-by: Richard Guy Briggs 
Signed-off-by: Jan Kara 
Message-Id:

fanotify: define struct members to hold response decision context

2023-02-07T11:53:53+00:00

This patch adds a flag, FAN_INFO and an extensible buffer to provide
additional information about response decisions.  The buffer contains
one or more headers defining the information type and the length of the
following information.  The patch defines one additional information
type, FAN_RESPONSE_INFO_AUDIT_RULE, to audit a rule number.  This will
allow for the creation of other information types in the future if other
users of the API identify different needs.

The kernel can be tested if it supports a given info type by supplying
the complete info extension but setting fd to FAN_NOFD.  It will return
the expected size but not issue an audit record.

Suggested-by: Steve Grubb 
Link: https://lore.kernel.org/r/2745105.e9J7NaK4W3@x2
Suggested-by: Jan Kara 
Link: https://lore.kernel.org/r/20201001101219.GE17860@quack2.suse.cz
Tested-by: Steve Grubb 
Acked-by: Steve Grubb 
Signed-off-by: Richard Guy Briggs 
Signed-off-by: Jan Kara 
Message-Id: <10177cfcae5480926b7176321a28d9da6835b667.1675373475.git.rgb@redhat.com>

fanotify: Ensure consistent variable type for response

2023-02-07T11:53:32+00:00

The user space API for the response variable is __u32. This patch makes
sure that the whole path through the kernel uses u32 so that there is
no sign extension or truncation of the user space response.

Suggested-by: Steve Grubb 
Link: https://lore.kernel.org/r/12617626.uLZWGnKmhe@x2
Signed-off-by: Richard Guy Briggs 
Acked-by: Paul Moore 
Tested-by: Steve Grubb 
Acked-by: Steve Grubb 
Signed-off-by: Jan Kara 
Message-Id: <3778cb0b3501bc4e686ba7770b20eb9ab0506cf4.1675373475.git.rgb@redhat.com>

fs/notify: Remove "select SRCU"

2023-02-03T00:26:06+00:00

Now that the SRCU Kconfig option is unconditionally selected, there is
no longer any point in selecting it.  Therefore, remove the "select SRCU"
Kconfig statements.

Signed-off-by: Paul E. McKenney 
Cc: Jan Kara 
Cc: Amir Goldstein 
Cc: 
Acked-by: Jan Kara 
Reviewed-by: John Ogness

Merge tag 'fsnotify-for_v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

2022-10-07T15:28:50+00:00

Pull fsnotify updates from Jan Kara:
 "Two cleanups for fsnotify code"

* tag 'fsnotify-for_v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  fanotify: Remove obsoleted fanotify_event_has_path()
  fsnotify: remove unused declaration

fanotify: Remove obsoleted fanotify_event_has_path()

2022-09-26T09:28:40+00:00

All uses of fanotify_event_has_path() have
been removed since commit 9c61f3b560f5 ("fanotify: break up
fanotify_alloc_event()"), now it is useless, so remove it.

Link: https://lore.kernel.org/r/20220926023018.1505270-1-cuigaosheng1@huawei.com
Signed-off-by: Gaosheng Cui 
Signed-off-by: Jan Kara

fsnotify: remove unused declaration

2022-09-09T09:40:03+00:00

fsnotify_alloc_event_holder() and fsnotify_destroy_event_holder()
has been removed since commit 7053aee26a35 ("fsnotify: do not share
events between notification groups"), so remove it.

Reviewed-by: Ritesh Harjani (IBM) 
Signed-off-by: Gaosheng Cui 
Signed-off-by: Jan Kara

fs/notify: constify path

2022-09-01T21:37:29+00:00

Reviewed-by: Matthew Bobrowski 
Reviewed-by: Christian Brauner (Microsoft) 
Signed-off-by: Al Viro

fsnotify: Fix comment typo

2022-07-26T11:38:47+00:00

The double `if' is duplicated in line 104, remove one.

Signed-off-by: Xin Gao 
Signed-off-by: Jan Kara 
Link: https://lore.kernel.org/r/20220722194639.18545-1-gaoxin@cdjrlc.com