patches/zap-cursor-move-to-key.patch

   1 Add a ZAP API to move a ZAP cursor to a given key.
   2
   3 Index: zfs+chaos4/lib/libzfscommon/include/sys/zap.h
   4 ===================================================================
   5 --- zfs+chaos4.orig/lib/libzfscommon/include/sys/zap.h
   6 +++ zfs+chaos4/lib/libzfscommon/include/sys/zap.h
   7 @@ -302,6 +302,11 @@ void zap_cursor_advance(zap_cursor_t *zc
   8  uint64_t zap_cursor_serialize(zap_cursor_t *zc);
   9
  10  /*
  11 + * Advance the cursor to the attribute having the key.
  12 + */
  13 +int zap_cursor_move_to_key(zap_cursor_t *zc, const char *name, matchtype_t mt);
  14 +
  15 +/*
  16   * Initialize a zap cursor pointing to the position recorded by
  17   * zap_cursor_serialize (in the "serialized" argument).  You can also
  18   * use a "serialized" argument of 0 to start at the beginning of the
  19 Index: zfs+chaos4/lib/libzfscommon/include/sys/zap_impl.h
  20 ===================================================================
  21 --- zfs+chaos4.orig/lib/libzfscommon/include/sys/zap_impl.h
  22 +++ zfs+chaos4/lib/libzfscommon/include/sys/zap_impl.h
  23 @@ -210,6 +210,7 @@ int fzap_add_cd(zap_name_t *zn,
  24      uint64_t integer_size, uint64_t num_integers,
  25      const void *val, uint32_t cd, dmu_tx_t *tx);
  26  void fzap_upgrade(zap_t *zap, dmu_tx_t *tx);
  27 +int fzap_cursor_move_to_key(zap_cursor_t *zc, zap_name_t *zn);
  28
  29  #ifdef __cplusplus
  30  }
  31 Index: zfs+chaos4/lib/libzpool/zap.c
  32 ===================================================================
  33 --- zfs+chaos4.orig/lib/libzpool/zap.c
  34 +++ zfs+chaos4/lib/libzpool/zap.c
  35 @@ -1029,6 +1029,30 @@ zap_stats_ptrtbl(zap_t *zap, uint64_t *t
  36         }
  37  }
  38
  39 +int fzap_cursor_move_to_key(zap_cursor_t *zc, zap_name_t *zn)
  40 +{
  41 +       int err;
  42 +       zap_leaf_t *l;
  43 +       zap_entry_handle_t zeh;
  44 +       uint64_t hash;
  45 +
  46 +       if (zn->zn_name_orij && strlen(zn->zn_name_orij) > ZAP_MAXNAMELEN)
  47 +               return (E2BIG);
  48 +
  49 +       err = zap_deref_leaf(zc->zc_zap, zn->zn_hash, NULL, RW_READER, &l);
  50 +       if (err != 0)
  51 +               return (err);
  52 +
  53 +       err = zap_leaf_lookup(l, zn, &zeh);
  54 +       if (err != 0)
  55 +               return (err);
  56 +
  57 +       zc->zc_leaf = l;
  58 +       zc->zc_hash = zeh.zeh_hash;
  59 +       zc->zc_cd = zeh.zeh_cd;
  60 +       return 0;
  61 +}
  62 +
  63  void
  64  fzap_get_stats(zap_t *zap, zap_stats_t *zs)
  65  {
  66 Index: zfs+chaos4/lib/libzpool/zap_micro.c
  67 ===================================================================
  68 --- zfs+chaos4.orig/lib/libzpool/zap_micro.c
  69 +++ zfs+chaos4/lib/libzpool/zap_micro.c
  70 @@ -1045,6 +1045,45 @@ zap_cursor_advance(zap_cursor_t *zc)
  71         }
  72  }
  73
  74 +int zap_cursor_move_to_key(zap_cursor_t *zc, const char *name, matchtype_t mt)
  75 +{
  76 +       int err = 0;
  77 +       mzap_ent_t *mze;
  78 +       zap_name_t *zn;
  79 +
  80 +       if (zc->zc_zap == NULL) {
  81 +               err = zap_lockdir(zc->zc_objset, zc->zc_zapobj, NULL,
  82 +                               RW_READER, TRUE, FALSE, &zc->zc_zap);
  83 +               if (err)
  84 +                       return (err);
  85 +       } else {
  86 +               rw_enter(&zc->zc_zap->zap_rwlock, RW_READER);
  87 +       }
  88 +
  89 +       zn = zap_name_alloc(zc->zc_zap, name, mt);
  90 +       if (zn == NULL) {
  91 +               rw_exit(&zc->zc_zap->zap_rwlock);
  92 +               return (ENOTSUP);
  93 +       }
  94 +
  95 +       if (!zc->zc_zap->zap_ismicro) {
  96 +               err = fzap_cursor_move_to_key(zc, zn);
  97 +       } else {
  98 +               mze = mze_find(zn);
  99 +               if (mze == NULL) {
 100 +                       err = (ENOENT);
 101 +                       goto out;
 102 +               }
 103 +               zc->zc_hash = mze->mze_hash;
 104 +               zc->zc_cd = mze->mze_phys.mze_cd;
 105 +       }
 106 +
 107 +out:
 108 +       zap_name_free(zn);
 109 +       rw_exit(&zc->zc_zap->zap_rwlock);
 110 +       return (err);
 111 +}
 112 +
 113  int
 114  zap_get_stats(objset_t *os, uint64_t zapobj, zap_stats_t *zs)
 115  {