src/patches/suse-2.6.27.31/patches.suse/dlm-fix-locking-of-lockspace-list-in-dlm_scand.patch

   1 From: David Teigland <teigland@redhat.com>
   2 commit c1dcf65ffc5796bf4ff75c13f448e63b3a416fd6
   3 Author: David Teigland <teigland@redhat.com>
   4 Date:   Mon Aug 18 14:03:25 2008 -0500
   5 Subject: dlm: fix locking of lockspace list in dlm_scand
   6
   7     The dlm_scand thread needs to lock the list of lockspaces
   8     when going through it.
   9
  10 Signed-off-by: David Teigland <teigland@redhat.com>
  11 Signed-off-by: Coly Li <coly.li@suse.de>
  12
  13 diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h
  14 index 9e0622a..868e4c9 100644
  15 --- a/fs/dlm/dlm_internal.h
  16 +++ b/fs/dlm/dlm_internal.h
  17 @@ -445,6 +445,7 @@ struct dlm_ls {
  18                                                    the dlm using this ls */
  19         int                     ls_create_count; /* create/release refcount */
  20         unsigned long           ls_flags;       /* LSFL_ */
  21 +       unsigned long           ls_scan_time;
  22         struct kobject          ls_kobj;
  23
  24         struct dlm_rsbtable     *ls_rsbtbl;
  25 diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c
  26 index ba672fe..d910501 100644
  27 --- a/fs/dlm/lockspace.c
  28 +++ b/fs/dlm/lockspace.c
  29 @@ -212,19 +212,41 @@ void dlm_lockspace_exit(void)
  30         kset_unregister(dlm_kset);
  31  }
  32
  33 +static struct dlm_ls *find_ls_to_scan(void)
  34 +{
  35 +       struct dlm_ls *ls;
  36 +
  37 +       spin_lock(&lslist_lock);
  38 +       list_for_each_entry(ls, &lslist, ls_list) {
  39 +               if (time_after_eq(jiffies, ls->ls_scan_time +
  40 +                                           dlm_config.ci_scan_secs * HZ)) {
  41 +                       spin_unlock(&lslist_lock);
  42 +                       return ls;
  43 +               }
  44 +       }
  45 +       spin_unlock(&lslist_lock);
  46 +       return NULL;
  47 +}
  48 +
  49  static int dlm_scand(void *data)
  50  {
  51         struct dlm_ls *ls;
  52 +       int timeout_jiffies = dlm_config.ci_scan_secs * HZ;
  53
  54         while (!kthread_should_stop()) {
  55 -               list_for_each_entry(ls, &lslist, ls_list) {
  56 +               ls = find_ls_to_scan();
  57 +               if (ls) {
  58                         if (dlm_lock_recovery_try(ls)) {
  59 +                               ls->ls_scan_time = jiffies;
  60                                 dlm_scan_rsbs(ls);
  61                                 dlm_scan_timeout(ls);
  62                                 dlm_unlock_recovery(ls);
  63 +                       } else {
  64 +                               ls->ls_scan_time += HZ;
  65                         }
  66 +               } else {
  67 +                       schedule_timeout_interruptible(timeout_jiffies);
  68                 }
  69 -               schedule_timeout_interruptible(dlm_config.ci_scan_secs * HZ);
  70         }
  71         return 0;
  72  }
  73 @@ -418,6 +440,7 @@ static int new_lockspace(char *name, int namelen, void **lockspace,
  74         ls->ls_lvblen = lvblen;
  75         ls->ls_count = 0;
  76         ls->ls_flags = 0;
  77 +       ls->ls_scan_time = jiffies;
  78
  79         if (flags & DLM_LSFL_TIMEWARN)
  80                 set_bit(LSFL_TIMEWARN, &ls->ls_flags);