bcachefs: Kill btree_iter->journal_pos

For BTREE_ITER_WITH_JOURNAL, we memoize lookups in the journal keys, to
avoid the binary search overhead.

Previously we stashed the pos of the last key returned from the journal,
in order to force the lookup to be redone when rewinding.

Now bch2_journal_keys_peek_upto() handles rewinding itself when
necessary - so we can slim down btree_iter.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c
index f58e03e3e038712ad4f490145177907ef66903fc..89592a4f356304de57324079943c4223a072b619 100644 (file)
--- a/fs/bcachefs/btree_iter.c
+++ b/fs/bcachefs/btree_iter.c
@@ -1854,19 +1854,11 @@ static struct bkey_i *bch2_btree_journal_peek(struct btree_trans *trans,
                                              struct btree_iter *iter,
                                              struct bpos end_pos)
 {
-       struct bkey_i *k;
-
-       if (bpos_lt(iter->path->pos, iter->journal_pos))
-               iter->journal_idx = 0;
-
-       k = bch2_journal_keys_peek_upto(trans->c, iter->btree_id,
-                                       iter->path->level,
-                                       iter->path->pos,
-                                       end_pos,
-                                       &iter->journal_idx);
-
-       iter->journal_pos = k ? k->k.p : end_pos;
-       return k;
+       return bch2_journal_keys_peek_upto(trans->c, iter->btree_id,
+                                          iter->path->level,
+                                          iter->path->pos,
+                                          end_pos,
+                                          &iter->journal_idx);
 }
 
 static noinline

diff --git a/fs/bcachefs/btree_iter.h b/fs/bcachefs/btree_iter.h
index 064720171551bdacf2916759aaaa3cbc396a7f5b..9ef5021a6d37ce3c3457a652a1418e92cae1b7e5 100644 (file)
--- a/fs/bcachefs/btree_iter.h
+++ b/fs/bcachefs/btree_iter.h
@@ -455,7 +455,6 @@ static inline void bch2_trans_iter_init_common(struct btree_trans *trans,
        iter->pos               = pos;
        iter->k                 = POS_KEY(pos);
        iter->journal_idx       = 0;
-       iter->journal_pos       = POS_MIN;
 #ifdef CONFIG_BCACHEFS_DEBUG
        iter->ip_allocated = ip;
 #endif

diff --git a/fs/bcachefs/btree_journal_iter.c b/fs/bcachefs/btree_journal_iter.c
index ec52f50d249d075f4fae6ad60976c330ba7e46f0..7a5e0a893df924b35a6126829111c3240c847d1f 100644 (file)
--- a/fs/bcachefs/btree_journal_iter.c
+++ b/fs/bcachefs/btree_journal_iter.c
@@ -73,6 +73,7 @@ static size_t bch2_journal_key_search(struct journal_keys *keys,
        return idx_to_pos(keys, __bch2_journal_key_search(keys, id, level, pos));
 }
 
+/* Returns first non-overwritten key >= search key: */
 struct bkey_i *bch2_journal_keys_peek_upto(struct bch_fs *c, enum btree_id btree_id,
                                           unsigned level, struct bpos pos,
                                           struct bpos end_pos, size_t *idx)
@@ -86,12 +87,26 @@ search:
        if (!*idx)
                *idx = __bch2_journal_key_search(keys, btree_id, level, pos);
 
+       while (*idx &&
+              __journal_key_cmp(btree_id, level, end_pos, idx_to_key(keys, *idx - 1)) <= 0) {
+               --(*idx);
+               iters++;
+               if (iters == 10) {
+                       *idx = 0;
+                       goto search;
+               }
+       }
+
        while ((k = *idx < keys->nr ? idx_to_key(keys, *idx) : NULL)) {
                if (__journal_key_cmp(btree_id, level, end_pos, k) < 0)
                        return NULL;
 
-               if (__journal_key_cmp(btree_id, level, pos, k) <= 0 &&
-                   !k->overwritten)
+               if (k->overwritten) {
+                       (*idx)++;
+                       continue;
+               }
+
+               if (__journal_key_cmp(btree_id, level, pos, k) <= 0)
                        return k->k;
 
                (*idx)++;

diff --git a/fs/bcachefs/btree_types.h b/fs/bcachefs/btree_types.h
index 662852b1e12fbad57a66b8331f6e0051339c923c..ca7526603d0693fd02a7fa18682354bb67e09221 100644 (file)
--- a/fs/bcachefs/btree_types.h
+++ b/fs/bcachefs/btree_types.h
@@ -304,7 +304,6 @@ struct btree_iter {
 
        /* BTREE_ITER_WITH_JOURNAL: */
        size_t                  journal_idx;
-       struct bpos             journal_pos;
 #ifdef TRACK_PATH_ALLOCATED
        unsigned long           ip_allocated;
 #endif