bcachefs: Convert alloc code to for_each_btree_key_commit()

The new for_each_btree_key2() macro handles transaction retries,
allowing us to avoid nested transactions - which we want to avoid since
they're tricky to do completely correctly and upcoming assertions are
going to be checking for that.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

diff --git a/fs/bcachefs/alloc_background.c b/fs/bcachefs/alloc_background.c
index 99b3f35c42d7aff60f8a711893c3070677765a09..baefd12a3fe8166b3df03e116229fa8fdedfbe3e 100644 (file)
--- a/fs/bcachefs/alloc_background.c
+++ b/fs/bcachefs/alloc_background.c
@@ -715,7 +715,7 @@ static int bch2_check_discard_freespace_key(struct btree_trans *trans,
 {
        struct bch_fs *c = trans->c;
        struct btree_iter alloc_iter;
-       struct bkey_s_c k, freespace_k;
+       struct bkey_s_c alloc_k;
        struct bch_alloc_v4 a;
        u64 genbits;
        struct bpos pos;
@@ -725,14 +725,6 @@ static int bch2_check_discard_freespace_key(struct btree_trans *trans,
        struct printbuf buf = PRINTBUF;
        int ret;
 
-       freespace_k = bch2_btree_iter_peek(iter);
-       if (!freespace_k.k)
-               return 1;
-
-       ret = bkey_err(freespace_k);
-       if (ret)
-               return ret;
-
        pos = iter->pos;
        pos.offset &= ~(~0ULL << 56);
        genbits = iter->pos.offset & (~0ULL << 56);
@@ -744,18 +736,18 @@ static int bch2_check_discard_freespace_key(struct btree_trans *trans,
                        bch2_btree_ids[iter->btree_id], pos.inode, pos.offset))
                goto delete;
 
-       k = bch2_btree_iter_peek_slot(&alloc_iter);
-       ret = bkey_err(k);
+       alloc_k = bch2_btree_iter_peek_slot(&alloc_iter);
+       ret = bkey_err(alloc_k);
        if (ret)
                goto err;
 
-       bch2_alloc_to_v4(k, &a);
+       bch2_alloc_to_v4(alloc_k, &a);
 
        if (fsck_err_on(a.data_type != state ||
                        (state == BCH_DATA_free &&
                         genbits != alloc_freespace_genbits(a)), c,
                        "%s\n  incorrectly set in %s index (free %u, genbits %llu should be %llu)",
-                       (bch2_bkey_val_to_text(&buf, c, k), buf.buf),
+                       (bch2_bkey_val_to_text(&buf, c, alloc_k), buf.buf),
                        bch2_btree_ids[iter->btree_id],
                        a.data_type == state,
                        genbits >> 56, alloc_freespace_genbits(a) >> 56))
@@ -776,6 +768,7 @@ int bch2_check_alloc_info(struct bch_fs *c)
 {
        struct btree_trans trans;
        struct btree_iter iter, discard_iter, freespace_iter;
+       struct bkey_s_c k;
        int ret = 0;
 
        bch2_trans_init(&trans, c, 0, 0);
@@ -805,36 +798,16 @@ int bch2_check_alloc_info(struct bch_fs *c)
        if (ret < 0)
                goto err;
 
-       bch2_trans_iter_init(&trans, &iter, BTREE_ID_need_discard, POS_MIN,
-                            BTREE_ITER_PREFETCH);
-       while (1) {
-               ret = commit_do(&trans, NULL, NULL,
-                                     BTREE_INSERT_NOFAIL|
-                                     BTREE_INSERT_LAZY_RW,
-                       bch2_check_discard_freespace_key(&trans, &iter));
-               if (ret)
-                       break;
-
-               bch2_btree_iter_advance(&iter);
-       }
-       bch2_trans_iter_exit(&trans, &iter);
-
-       if (ret < 0)
-               goto err;
-
-       bch2_trans_iter_init(&trans, &iter, BTREE_ID_freespace, POS_MIN,
-                            BTREE_ITER_PREFETCH);
-       while (1) {
-               ret = commit_do(&trans, NULL, NULL,
-                                     BTREE_INSERT_NOFAIL|
-                                     BTREE_INSERT_LAZY_RW,
-                       bch2_check_discard_freespace_key(&trans, &iter));
-               if (ret)
-                       break;
-
-               bch2_btree_iter_advance(&iter);
-       }
-       bch2_trans_iter_exit(&trans, &iter);
+       ret = for_each_btree_key_commit(&trans, iter,
+                       BTREE_ID_need_discard, POS_MIN,
+                       BTREE_ITER_PREFETCH, k,
+                       NULL, NULL, BTREE_INSERT_NOFAIL|BTREE_INSERT_LAZY_RW,
+               bch2_check_discard_freespace_key(&trans, &iter)) ?:
+             for_each_btree_key_commit(&trans, iter,
+                       BTREE_ID_freespace, POS_MIN,
+                       BTREE_ITER_PREFETCH, k,
+                       NULL, NULL, BTREE_INSERT_NOFAIL|BTREE_INSERT_LAZY_RW,
+               bch2_check_discard_freespace_key(&trans, &iter));
 err:
        bch2_trans_exit(&trans);
        return ret < 0 ? ret : 0;