lustre/kernel_patches/patches/quota-avoid-dqget-calls.patch

   1 Index: linux-2.6.32-358.0.1.el6/fs/quota/dquot.c
   2 ===================================================================
   3 --- linux-2.6.32-358.0.1.el6.orig/fs/quota/dquot.c
   4 +++ linux-2.6.32-358.0.1.el6/fs/quota/dquot.c
   5 @@ -1230,7 +1230,7 @@ static int info_bdq_free(struct dquot *d
   6  int dquot_initialize(struct inode *inode, int type)
   7  {
   8         unsigned int id = 0;
   9 -       int cnt, ret = 0;
  10 +       int cnt, ret = 0, dq_get = 0;
  11         struct dquot *got[MAXQUOTAS] = { NULL, NULL };
  12         struct super_block *sb = inode->i_sb;
  13         qsize_t rsv;
  14 @@ -1240,7 +1240,14 @@ int dquot_initialize(struct inode *inode
  15         if (IS_NOQUOTA(inode))
  16                 return 0;
  17
  18 -       /* First get references to structures we might need. */
  19 +       /* In most case, the i_dquot should have been initialized, except
  20 +        * the newly allocated one. We'd always try to skip the dqget() and
  21 +        * dqput() calls to avoid unnecessary global lock contention. */
  22 +       if (!(inode->i_state & I_NEW))
  23 +               goto init_idquot;
  24 +
  25 +get_dquots:
  26 +       dq_get = 1;
  27         for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
  28                 if (type != -1 && cnt != type)
  29                         continue;
  30 @@ -1254,7 +1261,7 @@ int dquot_initialize(struct inode *inode
  31                 }
  32                 got[cnt] = dqget(sb, id, cnt);
  33         }
  34 -
  35 +init_idquot:
  36         spin_lock(&inode->i_lock);
  37         if (IS_NOQUOTA(inode))
  38                 goto out_err;
  39 @@ -1265,6 +1272,10 @@ int dquot_initialize(struct inode *inode
  40                 if (!sb_has_quota_active(sb, cnt))
  41                         continue;
  42                 if (!inode->i_dquot[cnt]) {
  43 +                       if (dq_get == 0) {
  44 +                               spin_unlock(&inode->i_lock);
  45 +                               goto get_dquots;
  46 +                       }
  47                         inode->i_dquot[cnt] = got[cnt];
  48                         got[cnt] = NULL;
  49                         /*
  50 @@ -1272,7 +1283,7 @@ int dquot_initialize(struct inode *inode
  51                          * did a write before quota was turned on
  52                          */
  53                         rsv = inode_get_rsv_space(inode);
  54 -                       if (unlikely(rsv)) {
  55 +                       if (unlikely(rsv) && likely(inode->i_dquot[cnt])) {
  56                                 spin_lock(&dq_data_lock);
  57                                 dquot_resv_space(inode->i_dquot[cnt], rsv);
  58                                 spin_unlock(&dq_data_lock);