src/patches/suse-2.6.27.25/patches.suse/dlm-detect-available-userspace-daemon.patch

   1 From: David Teigland <teigland@redhat.com>
   2 commit dc68c7ed362a00a48290252573a8eb9f74463c3a
   3 Author: David Teigland <teigland@redhat.com>
   4 Date:   Mon Aug 18 11:43:30 2008 -0500
   5 Subject: dlm: detect available userspace daemon
   6
   7     If dlm_controld (the userspace daemon that controls the setup and
   8     recovery of the dlm) fails, the kernel should shut down the lockspaces
   9     in the kernel rather than leaving them running.  This is detected by
  10     having dlm_controld hold a misc device open while running, and if
  11     the kernel detects a close while the daemon is still needed, it stops
  12     the lockspaces in the kernel.
  13
  14     Knowing that the userspace daemon isn't running also allows the
  15     lockspace create/remove routines to avoid waiting on the daemon
  16     for join/leave operations.
  17
  18 Signed-off-by: David Teigland <teigland@redhat.com>
  19 Signed-off-by: Coly Li <coly.li@suse.de>
  20
  21 diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c
  22 index 56eae4e..ba672fe 100644
  23 --- a/fs/dlm/lockspace.c
  24 +++ b/fs/dlm/lockspace.c
  25 @@ -378,6 +378,11 @@ static int new_lockspace(char *name, int namelen, void **lockspace,
  26         if (!try_module_get(THIS_MODULE))
  27                 return -EINVAL;
  28
  29 +       if (!dlm_user_daemon_available()) {
  30 +               module_put(THIS_MODULE);
  31 +               return -EUNATCH;
  32 +       }
  33 +
  34         error = 0;
  35
  36         spin_lock(&lslist_lock);
  37 @@ -669,7 +674,7 @@ static int release_lockspace(struct dlm_ls *ls, int force)
  38
  39         dlm_device_deregister(ls);
  40
  41 -       if (force < 3)
  42 +       if (force < 3 && dlm_user_daemon_available())
  43                 do_uevent(ls, 0);
  44
  45         dlm_recoverd_stop(ls);
  46 @@ -791,3 +796,20 @@ int dlm_release_lockspace(void *lockspace, int force)
  47         return error;
  48  }
  49
  50 +void dlm_stop_lockspaces(void)
  51 +{
  52 +       struct dlm_ls *ls;
  53 +
  54 + restart:
  55 +       spin_lock(&lslist_lock);
  56 +       list_for_each_entry(ls, &lslist, ls_list) {
  57 +               if (!test_bit(LSFL_RUNNING, &ls->ls_flags))
  58 +                       continue;
  59 +               spin_unlock(&lslist_lock);
  60 +               log_error(ls, "no userland control daemon, stopping lockspace");
  61 +               dlm_ls_stop(ls);
  62 +               goto restart;
  63 +       }
  64 +       spin_unlock(&lslist_lock);
  65 +}
  66 +
  67 diff --git a/fs/dlm/lockspace.h b/fs/dlm/lockspace.h
  68 index 891eabb..f879f87 100644
  69 --- a/fs/dlm/lockspace.h
  70 +++ b/fs/dlm/lockspace.h
  71 @@ -20,6 +20,7 @@ struct dlm_ls *dlm_find_lockspace_global(uint32_t id);
  72  struct dlm_ls *dlm_find_lockspace_local(void *id);
  73  struct dlm_ls *dlm_find_lockspace_device(int minor);
  74  void dlm_put_lockspace(struct dlm_ls *ls);
  75 +void dlm_stop_lockspaces(void);
  76
  77  #endif                         /* __LOCKSPACE_DOT_H__ */
  78
  79 diff --git a/fs/dlm/user.c b/fs/dlm/user.c
  80 index 6542110..81627b5 100644
  81 --- a/fs/dlm/user.c
  82 +++ b/fs/dlm/user.c
  83 @@ -27,6 +27,8 @@
  84
  85  static const char name_prefix[] = "dlm";
  86  static const struct file_operations device_fops;
  87 +static atomic_t dlm_monitor_opened;
  88 +static int dlm_monitor_unused = 1;
  89
  90  #ifdef CONFIG_COMPAT
  91
  92 @@ -890,6 +892,26 @@ static unsigned int device_poll(struct file *file, poll_table *wait)
  93         return 0;
  94  }
  95
  96 +int dlm_user_daemon_available(void)
  97 +{
  98 +       /* dlm_controld hasn't started (or, has started, but not
  99 +          properly populated configfs) */
 100 +
 101 +       if (!dlm_our_nodeid())
 102 +               return 0;
 103 +
 104 +       /* This is to deal with versions of dlm_controld that don't
 105 +          know about the monitor device.  We assume that if the
 106 +          dlm_controld was started (above), but the monitor device
 107 +          was never opened, that it's an old version.  dlm_controld
 108 +          should open the monitor device before populating configfs. */
 109 +
 110 +       if (dlm_monitor_unused)
 111 +               return 1;
 112 +
 113 +       return atomic_read(&dlm_monitor_opened) ? 1 : 0;
 114 +}
 115 +
 116  static int ctl_device_open(struct inode *inode, struct file *file)
 117  {
 118         cycle_kernel_lock();
 119 @@ -902,6 +924,20 @@ static int ctl_device_close(struct inode *inode, struct file *file)
 120         return 0;
 121  }
 122
 123 +static int monitor_device_open(struct inode *inode, struct file *file)
 124 +{
 125 +       atomic_inc(&dlm_monitor_opened);
 126 +       dlm_monitor_unused = 0;
 127 +       return 0;
 128 +}
 129 +
 130 +static int monitor_device_close(struct inode *inode, struct file *file)
 131 +{
 132 +       if (atomic_dec_and_test(&dlm_monitor_opened))
 133 +               dlm_stop_lockspaces();
 134 +       return 0;
 135 +}
 136 +
 137  static const struct file_operations device_fops = {
 138         .open    = device_open,
 139         .release = device_close,
 140 @@ -925,19 +961,42 @@ static struct miscdevice ctl_device = {
 141         .minor = MISC_DYNAMIC_MINOR,
 142  };
 143
 144 +static const struct file_operations monitor_device_fops = {
 145 +       .open    = monitor_device_open,
 146 +       .release = monitor_device_close,
 147 +       .owner   = THIS_MODULE,
 148 +};
 149 +
 150 +static struct miscdevice monitor_device = {
 151 +       .name  = "dlm-monitor",
 152 +       .fops  = &monitor_device_fops,
 153 +       .minor = MISC_DYNAMIC_MINOR,
 154 +};
 155 +
 156  int __init dlm_user_init(void)
 157  {
 158         int error;
 159
 160 +       atomic_set(&dlm_monitor_opened, 0);
 161 +
 162         error = misc_register(&ctl_device);
 163 -       if (error)
 164 +       if (error) {
 165                 log_print("misc_register failed for control device");
 166 +               goto out;
 167 +       }
 168
 169 +       error = misc_register(&monitor_device);
 170 +       if (error) {
 171 +               log_print("misc_register failed for monitor device");
 172 +               misc_deregister(&ctl_device);
 173 +       }
 174 + out:
 175         return error;
 176  }
 177
 178  void dlm_user_exit(void)
 179  {
 180         misc_deregister(&ctl_device);
 181 +       misc_deregister(&monitor_device);
 182  }
 183
 184 diff --git a/fs/dlm/user.h b/fs/dlm/user.h
 185 index c528b6b..35eb6a1 100644
 186 --- a/fs/dlm/user.h
 187 +++ b/fs/dlm/user.h
 188 @@ -13,5 +13,6 @@ void dlm_user_add_ast(struct dlm_lkb *lkb, int type);
 189  int dlm_user_init(void);
 190  void dlm_user_exit(void);
 191  int dlm_device_deregister(struct dlm_ls *ls);
 192 +int dlm_user_daemon_available(void);
 193
 194  #endif