bcachefs: Convert bch2_do_invalidates_work() to for_each_btree_key2()

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 69cfc73..99b3f35 100644 (file)
--- a/fs/bcachefs/alloc_background.c
+++ b/fs/bcachefs/alloc_background.c
@@ -1088,29 +1088,20 @@ void bch2_do_discards(struct bch_fs *c)
                percpu_ref_put(&c->writes);
 }
 
-static int invalidate_one_bucket(struct btree_trans *trans, struct bch_dev *ca,
-                                struct bpos *bucket_pos, unsigned *cached_sectors)
+static int invalidate_one_bucket(struct btree_trans *trans,
+                                struct btree_iter *lru_iter, struct bkey_s_c k,
+                                unsigned dev_idx, s64 *nr_to_invalidate)
 {
        struct bch_fs *c = trans->c;
-       struct btree_iter lru_iter, alloc_iter = { NULL };
-       struct bkey_s_c k;
+       struct btree_iter alloc_iter = { NULL };
        struct bkey_i_alloc_v4 *a;
-       u64 bucket, idx;
+       struct bpos bucket;
        struct printbuf buf = PRINTBUF;
-       int ret;
-
-       bch2_trans_iter_init(trans, &lru_iter, BTREE_ID_lru,
-                            POS(ca->dev_idx, 0), 0);
-next_lru:
-       k = bch2_btree_iter_peek(&lru_iter);
-       ret = bkey_err(k);
-       if (ret)
-               goto out;
+       unsigned cached_sectors;
+       int ret = 0;
 
-       if (!k.k || k.k->p.inode != ca->dev_idx) {
-               ret = 1;
-               goto out;
-       }
+       if (*nr_to_invalidate <= 0 || k.k->p.inode != dev_idx)
+               return 1;
 
        if (k.k->type != KEY_TYPE_lru) {
                prt_printf(&buf, "non lru key in lru btree:\n  ");
@@ -1118,26 +1109,22 @@ next_lru:
 
                if (!test_bit(BCH_FS_CHECK_LRUS_DONE, &c->flags)) {
                        bch_err(c, "%s", buf.buf);
-                       bch2_btree_iter_advance(&lru_iter);
-                       goto next_lru;
                } else {
                        bch2_trans_inconsistent(trans, "%s", buf.buf);
                        ret = -EINVAL;
-                       goto out;
                }
-       }
 
-       idx     = k.k->p.offset;
-       bucket  = le64_to_cpu(bkey_s_c_to_lru(k).v->idx);
+               goto out;
+       }
 
-       *bucket_pos = POS(ca->dev_idx, bucket);
+       bucket = POS(dev_idx, le64_to_cpu(bkey_s_c_to_lru(k).v->idx));
 
-       a = bch2_trans_start_alloc_update(trans, &alloc_iter, *bucket_pos);
+       a = bch2_trans_start_alloc_update(trans, &alloc_iter, bucket);
        ret = PTR_ERR_OR_ZERO(a);
        if (ret)
                goto out;
 
-       if (idx != alloc_lru_idx(a->v)) {
+       if (k.k->p.offset != alloc_lru_idx(a->v)) {
                prt_printf(&buf, "alloc key does not point back to lru entry when invalidating bucket:\n  ");
                bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(&a->k_i));
                prt_printf(&buf, "\n  ");
@@ -1145,19 +1132,18 @@ next_lru:
 
                if (!test_bit(BCH_FS_CHECK_LRUS_DONE, &c->flags)) {
                        bch_err(c, "%s", buf.buf);
-                       bch2_btree_iter_advance(&lru_iter);
-                       goto next_lru;
                } else {
                        bch2_trans_inconsistent(trans, "%s", buf.buf);
                        ret = -EINVAL;
-                       goto out;
                }
+
+               goto out;
        }
 
        if (!a->v.cached_sectors)
                bch_err(c, "invalidating empty bucket, confused");
 
-       *cached_sectors = a->v.cached_sectors;
+       cached_sectors = a->v.cached_sectors;
 
        SET_BCH_ALLOC_V4_NEED_INC_GEN(&a->v, false);
        a->v.gen++;
@@ -1167,13 +1153,18 @@ next_lru:
        a->v.io_time[READ]      = atomic64_read(&c->io_clock[READ].now);
        a->v.io_time[WRITE]     = atomic64_read(&c->io_clock[WRITE].now);
 
-       ret = bch2_trans_update(trans, &alloc_iter, &a->k_i,
-                               BTREE_TRIGGER_BUCKET_INVALIDATE);
+       ret =   bch2_trans_update(trans, &alloc_iter, &a->k_i,
+                               BTREE_TRIGGER_BUCKET_INVALIDATE) ?:
+               bch2_trans_commit(trans, NULL, NULL,
+                                 BTREE_INSERT_USE_RESERVE|BTREE_INSERT_NOFAIL);
        if (ret)
                goto out;
+
+       trace_invalidate_bucket(c, bucket.inode, bucket.offset, cached_sectors);
+       this_cpu_inc(c->counters[BCH_COUNTER_bucket_invalidate]);
+       --*nr_to_invalidate;
 out:
        bch2_trans_iter_exit(trans, &alloc_iter);
-       bch2_trans_iter_exit(trans, &lru_iter);
        printbuf_exit(&buf);
        return ret;
 }
@@ -1183,8 +1174,9 @@ static void bch2_do_invalidates_work(struct work_struct *work)
        struct bch_fs *c = container_of(work, struct bch_fs, invalidate_work);
        struct bch_dev *ca;
        struct btree_trans trans;
-       struct bpos bucket;
-       unsigned i, sectors;
+       struct btree_iter iter;
+       struct bkey_s_c k;
+       unsigned i;
        int ret = 0;
 
        bch2_trans_init(&trans, c, 0, 0);
@@ -1193,17 +1185,13 @@ static void bch2_do_invalidates_work(struct work_struct *work)
                s64 nr_to_invalidate =
                        should_invalidate_buckets(ca, bch2_dev_usage_read(ca));
 
-               while (nr_to_invalidate-- >= 0) {
-                       ret = commit_do(&trans, NULL, NULL,
-                                             BTREE_INSERT_USE_RESERVE|
-                                             BTREE_INSERT_NOFAIL,
-                                       invalidate_one_bucket(&trans, ca, &bucket,
-                                                             &sectors));
-                       if (ret)
-                               break;
+               ret = for_each_btree_key2(&trans, iter, BTREE_ID_lru,
+                               POS(ca->dev_idx, 0), BTREE_ITER_INTENT, k,
+                       invalidate_one_bucket(&trans, &iter, k, ca->dev_idx, &nr_to_invalidate));
 
-                       trace_invalidate_bucket(c, bucket.inode, bucket.offset, sectors);
-                       this_cpu_inc(c->counters[BCH_COUNTER_bucket_invalidate]);
+               if (ret < 0) {
+                       percpu_ref_put(&ca->ref);
+                       break;
                }
        }