zfs-patches/0011-Trim-new-line-from-zfs_vdev_scheduler.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Brian Behlendorf <behlendorf1@llnl.gov>
   3 Date: Tue, 5 Sep 2017 13:41:32 -0700
   4 Subject: [PATCH] Trim new line from zfs_vdev_scheduler
   5
   6 Add a helper function to trim the tailing new line.  While we're
   7 here use this new hook to immediately apply the new scheduler.
   8
   9 Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
  10 Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
  11 Closes #3356
  12 Closes #6573
  13
  14 Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
  15 ---
  16  module/zfs/vdev_disk.c | 71 +++++++++++++++++++++++++++++++++++++-------------
  17  1 file changed, 53 insertions(+), 18 deletions(-)
  18
  19 diff --git a/module/zfs/vdev_disk.c b/module/zfs/vdev_disk.c
  20 index 5ae50a31..d6212835 100644
  21 --- a/module/zfs/vdev_disk.c
  22 +++ b/module/zfs/vdev_disk.c
  23 @@ -27,13 +27,14 @@
  24   */
  25
  26  #include <sys/zfs_context.h>
  27 -#include <sys/spa.h>
  28 +#include <sys/spa_impl.h>
  29  #include <sys/vdev_disk.h>
  30  #include <sys/vdev_impl.h>
  31  #include <sys/abd.h>
  32  #include <sys/fs/zfs.h>
  33  #include <sys/zio.h>
  34  #include <sys/sunldi.h>
  35 +#include <linux/mod_compat.h>
  36
  37  char *zfs_vdev_scheduler = VDEV_SCHEDULER;
  38  static void *zfs_vdev_holder = VDEV_HOLDER;
  39 @@ -113,15 +114,23 @@ vdev_disk_error(zio_t *zio)
  40   * physical device.  This yields the largest possible requests for
  41   * the device with the lowest total overhead.
  42   */
  43 -static int
  44 +static void
  45  vdev_elevator_switch(vdev_t *v, char *elevator)
  46  {
  47         vdev_disk_t *vd = v->vdev_tsd;
  48 -       struct block_device *bdev = vd->vd_bdev;
  49 -       struct request_queue *q = bdev_get_queue(bdev);
  50 -       char *device = bdev->bd_disk->disk_name;
  51 +       struct request_queue *q;
  52 +       char *device;
  53         int error;
  54
  55 +       for (int c = 0; c < v->vdev_children; c++)
  56 +               vdev_elevator_switch(v->vdev_child[c], elevator);
  57 +
  58 +       if (!v->vdev_ops->vdev_op_leaf || vd->vd_bdev == NULL)
  59 +               return;
  60 +
  61 +       q = bdev_get_queue(vd->vd_bdev);
  62 +       device = vd->vd_bdev->bd_disk->disk_name;
  63 +
  64         /*
  65          * Skip devices which are not whole disks (partitions).
  66          * Device-mapper devices are excepted since they may be whole
  67 @@ -131,15 +140,15 @@ vdev_elevator_switch(vdev_t *v, char *elevator)
  68          * "Skip devices without schedulers" check below will fail.
  69          */
  70         if (!v->vdev_wholedisk && strncmp(device, "dm-", 3) != 0)
  71 -               return (0);
  72 +               return;
  73
  74         /* Skip devices without schedulers (loop, ram, dm, etc) */
  75         if (!q->elevator || !blk_queue_stackable(q))
  76 -               return (0);
  77 +               return;
  78
  79         /* Leave existing scheduler when set to "none" */
  80         if ((strncmp(elevator, "none", 4) == 0) && (strlen(elevator) == 4))
  81 -               return (0);
  82 +               return;
  83
  84  #ifdef HAVE_ELEVATOR_CHANGE
  85         error = elevator_change(q, elevator);
  86 @@ -156,20 +165,16 @@ vdev_elevator_switch(vdev_t *v, char *elevator)
  87         "     2>/dev/null; " \
  88         "echo %s"
  89
  90 -       {
  91 -               char *argv[] = { "/bin/sh", "-c", NULL, NULL };
  92 -               char *envp[] = { NULL };
  93 +       char *argv[] = { "/bin/sh", "-c", NULL, NULL };
  94 +       char *envp[] = { NULL };
  95
  96 -               argv[2] = kmem_asprintf(SET_SCHEDULER_CMD, device, elevator);
  97 -               error = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
  98 -               strfree(argv[2]);
  99 -       }
 100 +       argv[2] = kmem_asprintf(SET_SCHEDULER_CMD, device, elevator);
 101 +       error = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
 102 +       strfree(argv[2]);
 103  #endif /* HAVE_ELEVATOR_CHANGE */
 104         if (error)
 105                 printk("ZFS: Unable to set \"%s\" scheduler for %s (%s): %d\n",
 106                     elevator, v->vdev_path, device, error);
 107 -
 108 -       return (error);
 109  }
 110
 111  /*
 112 @@ -798,6 +803,35 @@ vdev_disk_rele(vdev_t *vd)
 113         /* XXX: Implement me as a vnode rele for the device */
 114  }
 115
 116 +static int
 117 +param_set_vdev_scheduler(const char *val, zfs_kernel_param_t *kp)
 118 +{
 119 +       spa_t *spa = NULL;
 120 +       char *p;
 121 +
 122 +       if (val == NULL)
 123 +               return (SET_ERROR(-EINVAL));
 124 +
 125 +       if ((p = strchr(val, '\n')) != NULL)
 126 +               *p = '\0';
 127 +
 128 +       mutex_enter(&spa_namespace_lock);
 129 +       while ((spa = spa_next(spa)) != NULL) {
 130 +               if (spa_state(spa) != POOL_STATE_ACTIVE ||
 131 +                   !spa_writeable(spa) || spa_suspended(spa))
 132 +                       continue;
 133 +
 134 +               spa_open_ref(spa, FTAG);
 135 +               mutex_exit(&spa_namespace_lock);
 136 +               vdev_elevator_switch(spa->spa_root_vdev, (char *)val);
 137 +               mutex_enter(&spa_namespace_lock);
 138 +               spa_close(spa, FTAG);
 139 +       }
 140 +       mutex_exit(&spa_namespace_lock);
 141 +
 142 +       return (param_set_charp(val, kp));
 143 +}
 144 +
 145  vdev_ops_t vdev_disk_ops = {
 146         vdev_disk_open,
 147         vdev_disk_close,
 148 @@ -812,5 +846,6 @@ vdev_ops_t vdev_disk_ops = {
 149         B_TRUE                  /* leaf vdev */
 150  };
 151
 152 -module_param(zfs_vdev_scheduler, charp, 0644);
 153 +module_param_call(zfs_vdev_scheduler, param_set_vdev_scheduler,
 154 +    param_get_charp, &zfs_vdev_scheduler, 0644);
 155  MODULE_PARM_DESC(zfs_vdev_scheduler, "I/O scheduler");