src/patches/suse-2.6.27.39/patches.suse/dlm-Change-rwlock-which-is-only-used-in-write-mode-to-a-spinlock.patch

   1 From: Steven Whitehouse <swhiteho@redhat.com>
   2 commit 305a47b17c6efcc0e7b67b0bd41e2c12b7af758b
   3 Author: Steven Whitehouse <swhiteho@redhat.com>
   4 Date:   Fri Jan 16 16:21:12 2009 +0000
   5 Subject: dlm: Change rwlock which is only used in write mode to a spinlock
   6
   7     The ls_dirtbl[].lock was an rwlock, but since it was only used in write
   8     mode a spinlock will suffice.
   9
  10 Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
  11 Signed-off-by: David Teigland <teigland@redhat.com>
  12 Signed-off-by: Coly Li <coly.li@suse.de>
  13
  14 diff --git a/fs/dlm/dir.c b/fs/dlm/dir.c
  15 index 92969f8..858fba1 100644
  16 --- a/fs/dlm/dir.c
  17 +++ b/fs/dlm/dir.c
  18 @@ -156,7 +156,7 @@ void dlm_dir_remove_entry(struct dlm_ls *ls, int nodeid, char *name, int namelen
  19
  20         bucket = dir_hash(ls, name, namelen);
  21
  22 -       write_lock(&ls->ls_dirtbl[bucket].lock);
  23 +       spin_lock(&ls->ls_dirtbl[bucket].lock);
  24
  25         de = search_bucket(ls, name, namelen, bucket);
  26
  27 @@ -173,7 +173,7 @@ void dlm_dir_remove_entry(struct dlm_ls *ls, int nodeid, char *name, int namelen
  28         list_del(&de->list);
  29         kfree(de);
  30   out:
  31 -       write_unlock(&ls->ls_dirtbl[bucket].lock);
  32 +       spin_unlock(&ls->ls_dirtbl[bucket].lock);
  33  }
  34
  35  void dlm_dir_clear(struct dlm_ls *ls)
  36 @@ -185,14 +185,14 @@ void dlm_dir_clear(struct dlm_ls *ls)
  37         DLM_ASSERT(list_empty(&ls->ls_recover_list), );
  38
  39         for (i = 0; i < ls->ls_dirtbl_size; i++) {
  40 -               write_lock(&ls->ls_dirtbl[i].lock);
  41 +               spin_lock(&ls->ls_dirtbl[i].lock);
  42                 head = &ls->ls_dirtbl[i].list;
  43                 while (!list_empty(head)) {
  44                         de = list_entry(head->next, struct dlm_direntry, list);
  45                         list_del(&de->list);
  46                         put_free_de(ls, de);
  47                 }
  48 -               write_unlock(&ls->ls_dirtbl[i].lock);
  49 +               spin_unlock(&ls->ls_dirtbl[i].lock);
  50         }
  51  }
  52
  53 @@ -307,17 +307,17 @@ static int get_entry(struct dlm_ls *ls, int nodeid, char *name,
  54
  55         bucket = dir_hash(ls, name, namelen);
  56
  57 -       write_lock(&ls->ls_dirtbl[bucket].lock);
  58 +       spin_lock(&ls->ls_dirtbl[bucket].lock);
  59         de = search_bucket(ls, name, namelen, bucket);
  60         if (de) {
  61                 *r_nodeid = de->master_nodeid;
  62 -               write_unlock(&ls->ls_dirtbl[bucket].lock);
  63 +               spin_unlock(&ls->ls_dirtbl[bucket].lock);
  64                 if (*r_nodeid == nodeid)
  65                         return -EEXIST;
  66                 return 0;
  67         }
  68
  69 -       write_unlock(&ls->ls_dirtbl[bucket].lock);
  70 +       spin_unlock(&ls->ls_dirtbl[bucket].lock);
  71
  72         if (namelen > DLM_RESNAME_MAXLEN)
  73                 return -EINVAL;
  74 @@ -330,7 +330,7 @@ static int get_entry(struct dlm_ls *ls, int nodeid, char *name,
  75         de->length = namelen;
  76         memcpy(de->name, name, namelen);
  77
  78 -       write_lock(&ls->ls_dirtbl[bucket].lock);
  79 +       spin_lock(&ls->ls_dirtbl[bucket].lock);
  80         tmp = search_bucket(ls, name, namelen, bucket);
  81         if (tmp) {
  82                 kfree(de);
  83 @@ -339,7 +339,7 @@ static int get_entry(struct dlm_ls *ls, int nodeid, char *name,
  84                 list_add_tail(&de->list, &ls->ls_dirtbl[bucket].list);
  85         }
  86         *r_nodeid = de->master_nodeid;
  87 -       write_unlock(&ls->ls_dirtbl[bucket].lock);
  88 +       spin_unlock(&ls->ls_dirtbl[bucket].lock);
  89         return 0;
  90  }
  91
  92 diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h
  93 index 076e86f..d01ca0a 100644
  94 --- a/fs/dlm/dlm_internal.h
  95 +++ b/fs/dlm/dlm_internal.h
  96 @@ -99,7 +99,7 @@ struct dlm_direntry {
  97
  98  struct dlm_dirtable {
  99         struct list_head        list;
 100 -       rwlock_t                lock;
 101 +       spinlock_t              lock;
 102  };
 103
 104  struct dlm_rsbtable {
 105 diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c
 106 index aa32e5f..cd8e2df 100644
 107 --- a/fs/dlm/lockspace.c
 108 +++ b/fs/dlm/lockspace.c
 109 @@ -487,7 +487,7 @@ static int new_lockspace(char *name, int namelen, void **lockspace,
 110                 goto out_lkbfree;
 111         for (i = 0; i < size; i++) {
 112                 INIT_LIST_HEAD(&ls->ls_dirtbl[i].list);
 113 -               rwlock_init(&ls->ls_dirtbl[i].lock);
 114 +               spin_lock_init(&ls->ls_dirtbl[i].lock);
 115         }
 116
 117         INIT_LIST_HEAD(&ls->ls_waiters);