spl-patches/0005-Add-cv_timedwait_io.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Brian Behlendorf <behlendorf1@llnl.gov>
   3 Date: Wed, 24 Jan 2018 11:33:47 -0800
   4 Subject: [PATCH] Add cv_timedwait_io()
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 Add missing helper function cv_timedwait_io(), it should be used
  10 when waiting on IO with a specified timeout.
  11
  12 Reviewed-by: Tim Chase <tim@chase2k.com>
  13 Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
  14 Closes #674
  15 (cherry picked from commit ba003d46e3269ead9128b537f8f31c44bc3a974f)
  16 Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
  17 ---
  18  include/sys/condvar.h    |  2 ++
  19  module/spl/spl-condvar.c | 58 +++++++++++++++++++++++++++++++++++++++++-------
  20  config/spl-build.m4      | 21 ++++++++++++++++++
  21  3 files changed, 73 insertions(+), 8 deletions(-)
  22
  23 diff --git a/include/sys/condvar.h b/include/sys/condvar.h
  24 index 5479e75..5fcc906 100644
  25 --- a/include/sys/condvar.h
  26 +++ b/include/sys/condvar.h
  27 @@ -56,6 +56,7 @@ extern void __cv_wait(kcondvar_t *, kmutex_t *);
  28  extern void __cv_wait_io(kcondvar_t *, kmutex_t *);
  29  extern void __cv_wait_sig(kcondvar_t *, kmutex_t *);
  30  extern clock_t __cv_timedwait(kcondvar_t *, kmutex_t *, clock_t);
  31 +extern clock_t __cv_timedwait_io(kcondvar_t *, kmutex_t *, clock_t);
  32  extern clock_t __cv_timedwait_sig(kcondvar_t *, kmutex_t *, clock_t);
  33  extern clock_t cv_timedwait_hires(kcondvar_t *, kmutex_t *, hrtime_t,
  34      hrtime_t res, int flag);
  35 @@ -71,6 +72,7 @@ extern void __cv_broadcast(kcondvar_t *c);
  36  #define        cv_wait_sig(cvp, mp)                    __cv_wait_sig(cvp, mp)
  37  #define        cv_wait_interruptible(cvp, mp)          cv_wait_sig(cvp, mp)
  38  #define        cv_timedwait(cvp, mp, t)                __cv_timedwait(cvp, mp, t)
  39 +#define        cv_timedwait_io(cvp, mp, t)             __cv_timedwait_io(cvp, mp, t)
  40  #define        cv_timedwait_sig(cvp, mp, t)            __cv_timedwait_sig(cvp, mp, t)
  41  #define        cv_timedwait_interruptible(cvp, mp, t)  cv_timedwait_sig(cvp, mp, t)
  42  #define        cv_signal(cvp)                          __cv_signal(cvp)
  43 diff --git a/module/spl/spl-condvar.c b/module/spl/spl-condvar.c
  44 index 80c2ef0..4778fb2 100644
  45 --- a/module/spl/spl-condvar.c
  46 +++ b/module/spl/spl-condvar.c
  47 @@ -136,6 +136,13 @@ __cv_wait(kcondvar_t *cvp, kmutex_t *mp)
  48  }
  49  EXPORT_SYMBOL(__cv_wait);
  50
  51 +void
  52 +__cv_wait_io(kcondvar_t *cvp, kmutex_t *mp)
  53 +{
  54 +       cv_wait_common(cvp, mp, TASK_UNINTERRUPTIBLE, 1);
  55 +}
  56 +EXPORT_SYMBOL(__cv_wait_io);
  57 +
  58  void
  59  __cv_wait_sig(kcondvar_t *cvp, kmutex_t *mp)
  60  {
  61 @@ -143,12 +150,34 @@ __cv_wait_sig(kcondvar_t *cvp, kmutex_t *mp)
  62  }
  63  EXPORT_SYMBOL(__cv_wait_sig);
  64
  65 -void
  66 -__cv_wait_io(kcondvar_t *cvp, kmutex_t *mp)
  67 +#if defined(HAVE_IO_SCHEDULE_TIMEOUT)
  68 +#define        spl_io_schedule_timeout(t)      io_schedule_timeout(t)
  69 +#else
  70 +static void
  71 +__cv_wakeup(unsigned long data)
  72  {
  73 -       cv_wait_common(cvp, mp, TASK_UNINTERRUPTIBLE, 1);
  74 +       wake_up_process((struct task_struct *)data);
  75  }
  76 -EXPORT_SYMBOL(__cv_wait_io);
  77 +
  78 +static long
  79 +spl_io_schedule_timeout(long time_left)
  80 +{
  81 +       long expire_time = jiffies + time_left;
  82 +       struct timer_list timer;
  83 +
  84 +       init_timer(&timer);
  85 +       setup_timer(&timer, __cv_wakeup, (unsigned long)current);
  86 +       timer.expires = expire_time;
  87 +       add_timer(&timer);
  88 +
  89 +       io_schedule();
  90 +
  91 +       del_timer_sync(&timer);
  92 +       time_left = expire_time - jiffies;
  93 +
  94 +       return (time_left < 0 ? 0 : time_left);
  95 +}
  96 +#endif
  97
  98  /*
  99   * 'expire_time' argument is an absolute wall clock time in jiffies.
 100 @@ -156,7 +185,7 @@ EXPORT_SYMBOL(__cv_wait_io);
 101   */
 102  static clock_t
 103  __cv_timedwait_common(kcondvar_t *cvp, kmutex_t *mp, clock_t expire_time,
 104 -    int state)
 105 +    int state, int io)
 106  {
 107         DEFINE_WAIT(wait);
 108         kmutex_t *m;
 109 @@ -188,7 +217,10 @@ __cv_timedwait_common(kcondvar_t *cvp, kmutex_t *mp, clock_t expire_time,
 110          * race where 'cvp->cv_waiters > 0' but the list is empty.
 111          */
 112         mutex_exit(mp);
 113 -       time_left = schedule_timeout(time_left);
 114 +       if (io)
 115 +               time_left = spl_io_schedule_timeout(time_left);
 116 +       else
 117 +               time_left = schedule_timeout(time_left);
 118
 119         /* No more waiters a different mutex could be used */
 120         if (atomic_dec_and_test(&cvp->cv_waiters)) {
 121 @@ -214,14 +246,24 @@ __cv_timedwait_common(kcondvar_t *cvp, kmutex_t *mp, clock_t expire_time,
 122  clock_t
 123  __cv_timedwait(kcondvar_t *cvp, kmutex_t *mp, clock_t exp_time)
 124  {
 125 -       return (__cv_timedwait_common(cvp, mp, exp_time, TASK_UNINTERRUPTIBLE));
 126 +       return (__cv_timedwait_common(cvp, mp, exp_time,
 127 +           TASK_UNINTERRUPTIBLE, 0));
 128  }
 129  EXPORT_SYMBOL(__cv_timedwait);
 130
 131 +clock_t
 132 +__cv_timedwait_io(kcondvar_t *cvp, kmutex_t *mp, clock_t exp_time)
 133 +{
 134 +       return (__cv_timedwait_common(cvp, mp, exp_time,
 135 +           TASK_UNINTERRUPTIBLE, 1));
 136 +}
 137 +EXPORT_SYMBOL(__cv_timedwait_io);
 138 +
 139  clock_t
 140  __cv_timedwait_sig(kcondvar_t *cvp, kmutex_t *mp, clock_t exp_time)
 141  {
 142 -       return (__cv_timedwait_common(cvp, mp, exp_time, TASK_INTERRUPTIBLE));
 143 +       return (__cv_timedwait_common(cvp, mp, exp_time,
 144 +           TASK_INTERRUPTIBLE, 0));
 145  }
 146  EXPORT_SYMBOL(__cv_timedwait_sig);
 147
 148 diff --git a/config/spl-build.m4 b/config/spl-build.m4
 149 index 926abd5..afc8de6 100644
 150 --- a/config/spl-build.m4
 151 +++ b/config/spl-build.m4
 152 @@ -52,6 +52,7 @@ AC_DEFUN([SPL_AC_CONFIG_KERNEL], [
 153         SPL_AC_KMEM_CACHE_CREATE_USERCOPY
 154         SPL_AC_WAIT_QUEUE_ENTRY_T
 155         SPL_AC_WAIT_QUEUE_HEAD_ENTRY
 156 +       SPL_AC_IO_SCHEDULE_TIMEOUT
 157         SPL_AC_KERNEL_WRITE
 158         SPL_AC_KERNEL_READ
 159         SPL_AC_KERNEL_TIMER_FUNCTION_TIMER_LIST
 160 @@ -1598,6 +1599,26 @@ AC_DEFUN([SPL_AC_WAIT_QUEUE_HEAD_ENTRY], [
 161         ])
 162  ])
 163
 164 +dnl #
 165 +dnl # 3.19 API change
 166 +dnl # The io_schedule_timeout() function is present in all 2.6.32 kernels
 167 +dnl # but it was not exported until Linux 3.19.  The RHEL 7.x kernels which
 168 +dnl # are based on a 3.10 kernel do export this symbol.
 169 +dnl #
 170 +AC_DEFUN([SPL_AC_IO_SCHEDULE_TIMEOUT], [
 171 +       AC_MSG_CHECKING([whether io_schedule_timeout() is available])
 172 +       SPL_LINUX_TRY_COMPILE_SYMBOL([
 173 +               #include <linux/sched.h>
 174 +       ], [
 175 +               (void) io_schedule_timeout(1);
 176 +       ], [io_schedule_timeout], [], [
 177 +               AC_MSG_RESULT(yes)
 178 +               AC_DEFINE(HAVE_IO_SCHEDULE_TIMEOUT, 1, [yes])
 179 +       ],[
 180 +               AC_MSG_RESULT(no)
 181 +       ])
 182 +])
 183 +
 184  dnl #
 185  dnl # 4.14 API change
 186  dnl # kernel_write() which was introduced in 3.9 was updated to take
 187 --
 188 2.14.2
 189