]> git.sesse.net Git - bcachefs-tools-debian/blobdiff - libbcachefs/alloc_background.c
Move c_src dirs back to toplevel
[bcachefs-tools-debian] / libbcachefs / alloc_background.c
index c59629bbbccec570cc6559825a4c29852d3bc81a..a09b9d00226a4e1dd510c0c097ac59e7cb7d3c77 100644 (file)
@@ -79,36 +79,6 @@ static inline u64 alloc_field_v1_get(const struct bch_alloc *a,
        return v;
 }
 
-static inline void alloc_field_v1_put(struct bkey_i_alloc *a, void **p,
-                                     unsigned field, u64 v)
-{
-       unsigned bytes = BCH_ALLOC_V1_FIELD_BYTES[field];
-
-       if (!v)
-               return;
-
-       a->v.fields |= 1 << field;
-
-       switch (bytes) {
-       case 1:
-               *((u8 *) *p) = v;
-               break;
-       case 2:
-               *((__le16 *) *p) = cpu_to_le16(v);
-               break;
-       case 4:
-               *((__le32 *) *p) = cpu_to_le32(v);
-               break;
-       case 8:
-               *((__le64 *) *p) = cpu_to_le64(v);
-               break;
-       default:
-               BUG();
-       }
-
-       *p += bytes;
-}
-
 static void bch2_alloc_unpack_v1(struct bkey_alloc_unpacked *out,
                                 struct bkey_s_c k)
 {
@@ -222,145 +192,106 @@ static unsigned bch_alloc_v1_val_u64s(const struct bch_alloc *a)
        return DIV_ROUND_UP(bytes, sizeof(u64));
 }
 
-int bch2_alloc_v1_invalid(const struct bch_fs *c, struct bkey_s_c k,
+int bch2_alloc_v1_invalid(struct bch_fs *c, struct bkey_s_c k,
                          enum bkey_invalid_flags flags,
                          struct printbuf *err)
 {
        struct bkey_s_c_alloc a = bkey_s_c_to_alloc(k);
+       int ret = 0;
 
        /* allow for unknown fields */
-       if (bkey_val_u64s(a.k) < bch_alloc_v1_val_u64s(a.v)) {
-               prt_printf(err, "incorrect value size (%zu < %u)",
-                      bkey_val_u64s(a.k), bch_alloc_v1_val_u64s(a.v));
-               return -BCH_ERR_invalid_bkey;
-       }
-
-       return 0;
+       bkey_fsck_err_on(bkey_val_u64s(a.k) < bch_alloc_v1_val_u64s(a.v), c, err,
+                        alloc_v1_val_size_bad,
+                        "incorrect value size (%zu < %u)",
+                        bkey_val_u64s(a.k), bch_alloc_v1_val_u64s(a.v));
+fsck_err:
+       return ret;
 }
 
-int bch2_alloc_v2_invalid(const struct bch_fs *c, struct bkey_s_c k,
+int bch2_alloc_v2_invalid(struct bch_fs *c, struct bkey_s_c k,
                          enum bkey_invalid_flags flags,
                          struct printbuf *err)
 {
        struct bkey_alloc_unpacked u;
+       int ret = 0;
 
-       if (bch2_alloc_unpack_v2(&u, k)) {
-               prt_printf(err, "unpack error");
-               return -BCH_ERR_invalid_bkey;
-       }
-
-       return 0;
+       bkey_fsck_err_on(bch2_alloc_unpack_v2(&u, k), c, err,
+                        alloc_v2_unpack_error,
+                        "unpack error");
+fsck_err:
+       return ret;
 }
 
-int bch2_alloc_v3_invalid(const struct bch_fs *c, struct bkey_s_c k,
+int bch2_alloc_v3_invalid(struct bch_fs *c, struct bkey_s_c k,
                          enum bkey_invalid_flags flags,
                          struct printbuf *err)
 {
        struct bkey_alloc_unpacked u;
+       int ret = 0;
 
-       if (bch2_alloc_unpack_v3(&u, k)) {
-               prt_printf(err, "unpack error");
-               return -BCH_ERR_invalid_bkey;
-       }
-
-       return 0;
+       bkey_fsck_err_on(bch2_alloc_unpack_v3(&u, k), c, err,
+                        alloc_v2_unpack_error,
+                        "unpack error");
+fsck_err:
+       return ret;
 }
 
-int bch2_alloc_v4_invalid(const struct bch_fs *c, struct bkey_s_c k,
-                         unsigned flags, struct printbuf *err)
+int bch2_alloc_v4_invalid(struct bch_fs *c, struct bkey_s_c k,
+                         enum bkey_invalid_flags flags, struct printbuf *err)
 {
        struct bkey_s_c_alloc_v4 a = bkey_s_c_to_alloc_v4(k);
-       int rw = flags & WRITE;
-
-       if (alloc_v4_u64s(a.v) > bkey_val_u64s(k.k)) {
-               prt_printf(err, "bad val size (%u > %lu)",
-                      alloc_v4_u64s(a.v), bkey_val_u64s(k.k));
-               return -BCH_ERR_invalid_bkey;
-       }
-
-       if (!BCH_ALLOC_V4_BACKPOINTERS_START(a.v) &&
-           BCH_ALLOC_V4_NR_BACKPOINTERS(a.v)) {
-               prt_printf(err, "invalid backpointers_start");
-               return -BCH_ERR_invalid_bkey;
-       }
-
-       if (rw == WRITE &&
-           !(flags & BKEY_INVALID_JOURNAL) &&
-           test_bit(BCH_FS_CHECK_BACKPOINTERS_DONE, &c->flags)) {
-               unsigned i, bp_len = 0;
+       int ret = 0;
 
-               for (i = 0; i < BCH_ALLOC_V4_NR_BACKPOINTERS(a.v); i++)
-                       bp_len += alloc_v4_backpointers_c(a.v)[i].bucket_len;
+       bkey_fsck_err_on(alloc_v4_u64s(a.v) > bkey_val_u64s(k.k), c, err,
+                        alloc_v4_val_size_bad,
+                        "bad val size (%u > %zu)",
+                        alloc_v4_u64s(a.v), bkey_val_u64s(k.k));
 
-               if (bp_len > a.v->dirty_sectors) {
-                       prt_printf(err, "too many backpointers");
-                       return -BCH_ERR_invalid_bkey;
-               }
-       }
+       bkey_fsck_err_on(!BCH_ALLOC_V4_BACKPOINTERS_START(a.v) &&
+                        BCH_ALLOC_V4_NR_BACKPOINTERS(a.v), c, err,
+                        alloc_v4_backpointers_start_bad,
+                        "invalid backpointers_start");
 
-       if (rw == WRITE) {
-               if (alloc_data_type(*a.v, a.v->data_type) != a.v->data_type) {
-                       prt_printf(err, "invalid data type (got %u should be %u)",
-                              a.v->data_type, alloc_data_type(*a.v, a.v->data_type));
-                       return -BCH_ERR_invalid_bkey;
-               }
+       bkey_fsck_err_on(alloc_data_type(*a.v, a.v->data_type) != a.v->data_type, c, err,
+                        alloc_key_data_type_bad,
+                        "invalid data type (got %u should be %u)",
+                        a.v->data_type, alloc_data_type(*a.v, a.v->data_type));
 
-               switch (a.v->data_type) {
-               case BCH_DATA_free:
-               case BCH_DATA_need_gc_gens:
-               case BCH_DATA_need_discard:
-                       if (a.v->dirty_sectors ||
-                           a.v->cached_sectors ||
-                           a.v->stripe) {
-                               prt_printf(err, "empty data type free but have data");
-                               return -BCH_ERR_invalid_bkey;
-                       }
-                       break;
-               case BCH_DATA_sb:
-               case BCH_DATA_journal:
-               case BCH_DATA_btree:
-               case BCH_DATA_user:
-               case BCH_DATA_parity:
-                       if (!a.v->dirty_sectors) {
-                               prt_printf(err, "data_type %s but dirty_sectors==0",
-                                      bch2_data_types[a.v->data_type]);
-                               return -BCH_ERR_invalid_bkey;
-                       }
-                       break;
-               case BCH_DATA_cached:
-                       if (!a.v->cached_sectors ||
-                           a.v->dirty_sectors ||
-                           a.v->stripe) {
-                               prt_printf(err, "data type inconsistency");
-                               return -BCH_ERR_invalid_bkey;
-                       }
-
-                       if (!a.v->io_time[READ] &&
-                           test_bit(BCH_FS_CHECK_ALLOC_TO_LRU_REFS_DONE, &c->flags)) {
-                               prt_printf(err, "cached bucket with read_time == 0");
-                               return -BCH_ERR_invalid_bkey;
-                       }
-                       break;
-               case BCH_DATA_stripe:
-                       if (!a.v->stripe) {
-                               prt_printf(err, "data_type %s but stripe==0",
-                                      bch2_data_types[a.v->data_type]);
-                               return -BCH_ERR_invalid_bkey;
-                       }
-                       break;
-               }
+       switch (a.v->data_type) {
+       case BCH_DATA_free:
+       case BCH_DATA_need_gc_gens:
+       case BCH_DATA_need_discard:
+               bkey_fsck_err_on(bch2_bucket_sectors(*a.v) || a.v->stripe,
+                                c, err, alloc_key_empty_but_have_data,
+                                "empty data type free but have data");
+               break;
+       case BCH_DATA_sb:
+       case BCH_DATA_journal:
+       case BCH_DATA_btree:
+       case BCH_DATA_user:
+       case BCH_DATA_parity:
+               bkey_fsck_err_on(!bch2_bucket_sectors_dirty(*a.v),
+                                c, err, alloc_key_dirty_sectors_0,
+                                "data_type %s but dirty_sectors==0",
+                                bch2_data_types[a.v->data_type]);
+               break;
+       case BCH_DATA_cached:
+               bkey_fsck_err_on(!a.v->cached_sectors ||
+                                bch2_bucket_sectors_dirty(*a.v) ||
+                                a.v->stripe,
+                                c, err, alloc_key_cached_inconsistency,
+                                "data type inconsistency");
+
+               bkey_fsck_err_on(!a.v->io_time[READ] &&
+                                c->curr_recovery_pass > BCH_RECOVERY_PASS_check_alloc_to_lru_refs,
+                                c, err, alloc_key_cached_but_read_time_zero,
+                                "cached bucket with read_time == 0");
+               break;
+       case BCH_DATA_stripe:
+               break;
        }
-
-       return 0;
-}
-
-static inline u64 swab40(u64 x)
-{
-       return (((x & 0x00000000ffULL) << 32)|
-               ((x & 0x000000ff00ULL) << 16)|
-               ((x & 0x0000ff0000ULL) >>  0)|
-               ((x & 0x00ff000000ULL) >> 16)|
-               ((x & 0xff00000000ULL) >> 32));
+fsck_err:
+       return ret;
 }
 
 void bch2_alloc_v4_swab(struct bkey_s k)
@@ -376,6 +307,7 @@ void bch2_alloc_v4_swab(struct bkey_s k)
        a->io_time[1]           = swab64(a->io_time[1]);
        a->stripe               = swab32(a->stripe);
        a->nr_external_backpointers = swab32(a->nr_external_backpointers);
+       a->fragmentation_lru    = swab64(a->fragmentation_lru);
 
        bps = alloc_v4_backpointers(a);
        for (bp = bps; bp < bps + BCH_ALLOC_V4_NR_BACKPOINTERS(a); bp++) {
@@ -551,40 +483,6 @@ err:
        return ERR_PTR(ret);
 }
 
-int bch2_alloc_read(struct bch_fs *c)
-{
-       struct btree_trans trans;
-       struct btree_iter iter;
-       struct bkey_s_c k;
-       struct bch_alloc_v4 a;
-       struct bch_dev *ca;
-       int ret;
-
-       bch2_trans_init(&trans, c, 0, 0);
-
-       for_each_btree_key(&trans, iter, BTREE_ID_alloc, POS_MIN,
-                          BTREE_ITER_PREFETCH, k, ret) {
-               /*
-                * Not a fsck error because this is checked/repaired by
-                * bch2_check_alloc_key() which runs later:
-                */
-               if (!bch2_dev_bucket_exists(c, k.k->p))
-                       continue;
-
-               ca = bch_dev_bkey_exists(c, k.k->p.inode);
-
-               *bucket_gen(ca, k.k->p.offset) = bch2_alloc_to_v4(k, &a)->gen;
-       }
-       bch2_trans_iter_exit(&trans, &iter);
-
-       bch2_trans_exit(&trans);
-
-       if (ret)
-               bch_err_fn(c, ret);
-
-       return ret;
-}
-
 static struct bpos alloc_gens_pos(struct bpos pos, unsigned *offset)
 {
        *offset = pos.offset & KEY_TYPE_BUCKET_GENS_MASK;
@@ -607,17 +505,18 @@ static unsigned alloc_gen(struct bkey_s_c k, unsigned offset)
                : 0;
 }
 
-int bch2_bucket_gens_invalid(const struct bch_fs *c, struct bkey_s_c k,
+int bch2_bucket_gens_invalid(struct bch_fs *c, struct bkey_s_c k,
                             enum bkey_invalid_flags flags,
                             struct printbuf *err)
 {
-       if (bkey_val_bytes(k.k) != sizeof(struct bch_bucket_gens)) {
-               prt_printf(err, "bad val size (%lu != %zu)",
-                      bkey_val_bytes(k.k), sizeof(struct bch_bucket_gens));
-               return -BCH_ERR_invalid_bkey;
-       }
+       int ret = 0;
 
-       return 0;
+       bkey_fsck_err_on(bkey_val_bytes(k.k) != sizeof(struct bch_bucket_gens), c, err,
+                        bucket_gens_val_size_bad,
+                        "bad val size (%zu != %zu)",
+                        bkey_val_bytes(k.k), sizeof(struct bch_bucket_gens));
+fsck_err:
+       return ret;
 }
 
 void bch2_bucket_gens_to_text(struct printbuf *out, struct bch_fs *c, struct bkey_s_c k)
@@ -634,21 +533,13 @@ void bch2_bucket_gens_to_text(struct printbuf *out, struct bch_fs *c, struct bke
 
 int bch2_bucket_gens_init(struct bch_fs *c)
 {
-       struct btree_trans trans;
-       struct btree_iter iter;
-       struct bkey_s_c k;
-       struct bch_alloc_v4 a;
+       struct btree_trans *trans = bch2_trans_get(c);
        struct bkey_i_bucket_gens g;
        bool have_bucket_gens_key = false;
-       unsigned offset;
-       struct bpos pos;
-       u8 gen;
        int ret;
 
-       bch2_trans_init(&trans, c, 0, 0);
-
-       for_each_btree_key(&trans, iter, BTREE_ID_alloc, POS_MIN,
-                          BTREE_ITER_PREFETCH, k, ret) {
+       ret = for_each_btree_key(trans, iter, BTREE_ID_alloc, POS_MIN,
+                                BTREE_ITER_PREFETCH, k, ({
                /*
                 * Not a fsck error because this is checked/repaired by
                 * bch2_check_alloc_key() which runs later:
@@ -656,14 +547,15 @@ int bch2_bucket_gens_init(struct bch_fs *c)
                if (!bch2_dev_bucket_exists(c, k.k->p))
                        continue;
 
-               gen = bch2_alloc_to_v4(k, &a)->gen;
-               pos = alloc_gens_pos(iter.pos, &offset);
+               struct bch_alloc_v4 a;
+               u8 gen = bch2_alloc_to_v4(k, &a)->gen;
+               unsigned offset;
+               struct bpos pos = alloc_gens_pos(iter.pos, &offset);
 
                if (have_bucket_gens_key && bkey_cmp(iter.pos, pos)) {
-                       ret = commit_do(&trans, NULL, NULL,
-                                       BTREE_INSERT_NOFAIL|
-                                       BTREE_INSERT_LAZY_RW,
-                               __bch2_btree_insert(&trans, BTREE_ID_bucket_gens, &g.k_i, 0));
+                       ret = commit_do(trans, NULL, NULL,
+                                       BCH_TRANS_COMMIT_no_enospc,
+                               bch2_btree_insert_trans(trans, BTREE_ID_bucket_gens, &g.k_i, 0));
                        if (ret)
                                break;
                        have_bucket_gens_key = false;
@@ -676,65 +568,75 @@ int bch2_bucket_gens_init(struct bch_fs *c)
                }
 
                g.v.gens[offset] = gen;
-       }
-       bch2_trans_iter_exit(&trans, &iter);
+               0;
+       }));
 
        if (have_bucket_gens_key && !ret)
-               ret = commit_do(&trans, NULL, NULL,
-                               BTREE_INSERT_NOFAIL|
-                               BTREE_INSERT_LAZY_RW,
-                       __bch2_btree_insert(&trans, BTREE_ID_bucket_gens, &g.k_i, 0));
+               ret = commit_do(trans, NULL, NULL,
+                               BCH_TRANS_COMMIT_no_enospc,
+                       bch2_btree_insert_trans(trans, BTREE_ID_bucket_gens, &g.k_i, 0));
 
-       bch2_trans_exit(&trans);
+       bch2_trans_put(trans);
 
-       if (ret)
-               bch_err_fn(c, ret);
+       bch_err_fn(c, ret);
        return ret;
 }
 
-int bch2_bucket_gens_read(struct bch_fs *c)
+int bch2_alloc_read(struct bch_fs *c)
 {
-       struct btree_trans trans;
-       struct btree_iter iter;
-       struct bkey_s_c k;
-       const struct bch_bucket_gens *g;
-       struct bch_dev *ca;
-       u64 b;
+       struct btree_trans *trans = bch2_trans_get(c);
        int ret;
 
-       bch2_trans_init(&trans, c, 0, 0);
+       down_read(&c->gc_lock);
 
-       for_each_btree_key(&trans, iter, BTREE_ID_bucket_gens, POS_MIN,
-                          BTREE_ITER_PREFETCH, k, ret) {
-               u64 start = bucket_gens_pos_to_alloc(k.k->p, 0).offset;
-               u64 end = bucket_gens_pos_to_alloc(bpos_nosnap_successor(k.k->p), 0).offset;
+       if (c->sb.version_upgrade_complete >= bcachefs_metadata_version_bucket_gens) {
+               ret = for_each_btree_key(trans, iter, BTREE_ID_bucket_gens, POS_MIN,
+                                        BTREE_ITER_PREFETCH, k, ({
+                       u64 start = bucket_gens_pos_to_alloc(k.k->p, 0).offset;
+                       u64 end = bucket_gens_pos_to_alloc(bpos_nosnap_successor(k.k->p), 0).offset;
 
-               if (k.k->type != KEY_TYPE_bucket_gens)
-                       continue;
+                       if (k.k->type != KEY_TYPE_bucket_gens)
+                               continue;
 
-               g = bkey_s_c_to_bucket_gens(k).v;
+                       const struct bch_bucket_gens *g = bkey_s_c_to_bucket_gens(k).v;
 
-               /*
-                * Not a fsck error because this is checked/repaired by
-                * bch2_check_alloc_key() which runs later:
-                */
-               if (!bch2_dev_exists2(c, k.k->p.inode))
-                       continue;
+                       /*
+                        * Not a fsck error because this is checked/repaired by
+                        * bch2_check_alloc_key() which runs later:
+                        */
+                       if (!bch2_dev_exists2(c, k.k->p.inode))
+                               continue;
 
-               ca = bch_dev_bkey_exists(c, k.k->p.inode);
+                       struct bch_dev *ca = bch_dev_bkey_exists(c, k.k->p.inode);
 
-               for (b = max_t(u64, ca->mi.first_bucket, start);
-                    b < min_t(u64, ca->mi.nbuckets, end);
-                    b++)
-                       *bucket_gen(ca, b) = g->gens[b & KEY_TYPE_BUCKET_GENS_MASK];
-       }
-       bch2_trans_iter_exit(&trans, &iter);
+                       for (u64 b = max_t(u64, ca->mi.first_bucket, start);
+                            b < min_t(u64, ca->mi.nbuckets, end);
+                            b++)
+                               *bucket_gen(ca, b) = g->gens[b & KEY_TYPE_BUCKET_GENS_MASK];
+                       0;
+               }));
+       } else {
+               ret = for_each_btree_key(trans, iter, BTREE_ID_alloc, POS_MIN,
+                                        BTREE_ITER_PREFETCH, k, ({
+                       /*
+                        * Not a fsck error because this is checked/repaired by
+                        * bch2_check_alloc_key() which runs later:
+                        */
+                       if (!bch2_dev_bucket_exists(c, k.k->p))
+                               continue;
 
-       bch2_trans_exit(&trans);
+                       struct bch_dev *ca = bch_dev_bkey_exists(c, k.k->p.inode);
 
-       if (ret)
-               bch_err_fn(c, ret);
+                       struct bch_alloc_v4 a;
+                       *bucket_gen(ca, k.k->p.offset) = bch2_alloc_to_v4(k, &a)->gen;
+                       0;
+               }));
+       }
 
+       bch2_trans_put(trans);
+       up_read(&c->gc_lock);
+
+       bch_err_fn(c, ret);
        return ret;
 }
 
@@ -789,12 +691,12 @@ static int bch2_bucket_do_index(struct btree_trans *trans,
                return ret;
 
        if (ca->mi.freespace_initialized &&
-           test_bit(BCH_FS_CHECK_ALLOC_DONE, &c->flags) &&
+           c->curr_recovery_pass > BCH_RECOVERY_PASS_check_alloc_info &&
            bch2_trans_inconsistent_on(old.k->type != old_type, trans,
                        "incorrect key when %s %s:%llu:%llu:0 (got %s should be %s)\n"
                        "  for %s",
                        set ? "setting" : "clearing",
-                       bch2_btree_ids[btree],
+                       bch2_btree_id_str(btree),
                        iter.pos.inode,
                        iter.pos.offset,
                        bch2_bkey_types[old.k->type],
@@ -847,83 +749,177 @@ static noinline int bch2_bucket_gen_update(struct btree_trans *trans,
        return ret;
 }
 
-int bch2_trans_mark_alloc(struct btree_trans *trans,
-                         enum btree_id btree_id, unsigned level,
-                         struct bkey_s_c old, struct bkey_i *new,
-                         unsigned flags)
+int bch2_trigger_alloc(struct btree_trans *trans,
+                      enum btree_id btree, unsigned level,
+                      struct bkey_s_c old, struct bkey_s new,
+                      unsigned flags)
 {
        struct bch_fs *c = trans->c;
-       struct bch_alloc_v4 old_a_convert, *new_a;
-       const struct bch_alloc_v4 *old_a;
-       u64 old_lru, new_lru;
        int ret = 0;
 
-       /*
-        * Deletion only happens in the device removal path, with
-        * BTREE_TRIGGER_NORUN:
-        */
-       BUG_ON(new->k.type != KEY_TYPE_alloc_v4);
+       if (bch2_trans_inconsistent_on(!bch2_dev_bucket_exists(c, new.k->p), trans,
+                                      "alloc key for invalid device or bucket"))
+               return -EIO;
 
-       old_a = bch2_alloc_to_v4(old, &old_a_convert);
-       new_a = &bkey_i_to_alloc_v4(new)->v;
+       struct bch_dev *ca = bch_dev_bkey_exists(c, new.k->p.inode);
 
-       new_a->data_type = alloc_data_type(*new_a, new_a->data_type);
+       struct bch_alloc_v4 old_a_convert;
+       const struct bch_alloc_v4 *old_a = bch2_alloc_to_v4(old, &old_a_convert);
 
-       if (new_a->dirty_sectors > old_a->dirty_sectors ||
-           new_a->cached_sectors > old_a->cached_sectors) {
-               new_a->io_time[READ] = max_t(u64, 1, atomic64_read(&c->io_clock[READ].now));
-               new_a->io_time[WRITE]= max_t(u64, 1, atomic64_read(&c->io_clock[WRITE].now));
-               SET_BCH_ALLOC_V4_NEED_INC_GEN(new_a, true);
-               SET_BCH_ALLOC_V4_NEED_DISCARD(new_a, true);
-       }
+       if (flags & BTREE_TRIGGER_TRANSACTIONAL) {
+               struct bch_alloc_v4 *new_a = bkey_s_to_alloc_v4(new).v;
 
-       if (data_type_is_empty(new_a->data_type) &&
-           BCH_ALLOC_V4_NEED_INC_GEN(new_a) &&
-           !bch2_bucket_is_open_safe(c, new->k.p.inode, new->k.p.offset)) {
-               new_a->gen++;
-               SET_BCH_ALLOC_V4_NEED_INC_GEN(new_a, false);
-       }
+               new_a->data_type = alloc_data_type(*new_a, new_a->data_type);
 
-       if (old_a->data_type != new_a->data_type ||
-           (new_a->data_type == BCH_DATA_free &&
-            alloc_freespace_genbits(*old_a) != alloc_freespace_genbits(*new_a))) {
-               ret =   bch2_bucket_do_index(trans, old, old_a, false) ?:
-                       bch2_bucket_do_index(trans, bkey_i_to_s_c(new), new_a, true);
-               if (ret)
-                       return ret;
-       }
+               if (bch2_bucket_sectors(*new_a) > bch2_bucket_sectors(*old_a)) {
+                       new_a->io_time[READ] = max_t(u64, 1, atomic64_read(&c->io_clock[READ].now));
+                       new_a->io_time[WRITE]= max_t(u64, 1, atomic64_read(&c->io_clock[WRITE].now));
+                       SET_BCH_ALLOC_V4_NEED_INC_GEN(new_a, true);
+                       SET_BCH_ALLOC_V4_NEED_DISCARD(new_a, true);
+               }
 
-       if (new_a->data_type == BCH_DATA_cached &&
-           !new_a->io_time[READ])
-               new_a->io_time[READ] = max_t(u64, 1, atomic64_read(&c->io_clock[READ].now));
+               if (data_type_is_empty(new_a->data_type) &&
+                   BCH_ALLOC_V4_NEED_INC_GEN(new_a) &&
+                   !bch2_bucket_is_open_safe(c, new.k->p.inode, new.k->p.offset)) {
+                       new_a->gen++;
+                       SET_BCH_ALLOC_V4_NEED_INC_GEN(new_a, false);
+               }
 
-       old_lru = alloc_lru_idx_read(*old_a);
-       new_lru = alloc_lru_idx_read(*new_a);
+               if (old_a->data_type != new_a->data_type ||
+                   (new_a->data_type == BCH_DATA_free &&
+                    alloc_freespace_genbits(*old_a) != alloc_freespace_genbits(*new_a))) {
+                       ret =   bch2_bucket_do_index(trans, old, old_a, false) ?:
+                               bch2_bucket_do_index(trans, new.s_c, new_a, true);
+                       if (ret)
+                               return ret;
+               }
 
-       if (old_lru != new_lru) {
-               ret = bch2_lru_change(trans, new->k.p.inode,
-                                     bucket_to_u64(new->k.p),
-                                     old_lru, new_lru);
-               if (ret)
-                       return ret;
+               if (new_a->data_type == BCH_DATA_cached &&
+                   !new_a->io_time[READ])
+                       new_a->io_time[READ] = max_t(u64, 1, atomic64_read(&c->io_clock[READ].now));
+
+               u64 old_lru = alloc_lru_idx_read(*old_a);
+               u64 new_lru = alloc_lru_idx_read(*new_a);
+               if (old_lru != new_lru) {
+                       ret = bch2_lru_change(trans, new.k->p.inode,
+                                             bucket_to_u64(new.k->p),
+                                             old_lru, new_lru);
+                       if (ret)
+                               return ret;
+               }
+
+               new_a->fragmentation_lru = alloc_lru_idx_fragmentation(*new_a,
+                                               bch_dev_bkey_exists(c, new.k->p.inode));
+               if (old_a->fragmentation_lru != new_a->fragmentation_lru) {
+                       ret = bch2_lru_change(trans,
+                                       BCH_LRU_FRAGMENTATION_START,
+                                       bucket_to_u64(new.k->p),
+                                       old_a->fragmentation_lru, new_a->fragmentation_lru);
+                       if (ret)
+                               return ret;
+               }
+
+               if (old_a->gen != new_a->gen) {
+                       ret = bch2_bucket_gen_update(trans, new.k->p, new_a->gen);
+                       if (ret)
+                               return ret;
+               }
+
+               /*
+                * need to know if we're getting called from the invalidate path or
+                * not:
+                */
+
+               if ((flags & BTREE_TRIGGER_BUCKET_INVALIDATE) &&
+                   old_a->cached_sectors) {
+                       ret = bch2_update_cached_sectors_list(trans, new.k->p.inode,
+                                                             -((s64) old_a->cached_sectors));
+                       if (ret)
+                               return ret;
+               }
        }
 
-       new_a->fragmentation_lru = alloc_lru_idx_fragmentation(*new_a,
-                                       bch_dev_bkey_exists(c, new->k.p.inode));
+       if (!(flags & BTREE_TRIGGER_TRANSACTIONAL) && (flags & BTREE_TRIGGER_INSERT)) {
+               struct bch_alloc_v4 *new_a = bkey_s_to_alloc_v4(new).v;
+               u64 journal_seq = trans->journal_res.seq;
+               u64 bucket_journal_seq = new_a->journal_seq;
 
-       if (old_a->fragmentation_lru != new_a->fragmentation_lru) {
-               ret = bch2_lru_change(trans,
-                               BCH_LRU_FRAGMENTATION_START,
-                               bucket_to_u64(new->k.p),
-                               old_a->fragmentation_lru, new_a->fragmentation_lru);
-               if (ret)
-                       return ret;
+               if ((flags & BTREE_TRIGGER_INSERT) &&
+                   data_type_is_empty(old_a->data_type) !=
+                   data_type_is_empty(new_a->data_type) &&
+                   new.k->type == KEY_TYPE_alloc_v4) {
+                       struct bch_alloc_v4 *v = bkey_s_to_alloc_v4(new).v;
+
+                       /*
+                        * If the btree updates referring to a bucket weren't flushed
+                        * before the bucket became empty again, then the we don't have
+                        * to wait on a journal flush before we can reuse the bucket:
+                        */
+                       v->journal_seq = bucket_journal_seq =
+                               data_type_is_empty(new_a->data_type) &&
+                               (journal_seq == v->journal_seq ||
+                                bch2_journal_noflush_seq(&c->journal, v->journal_seq))
+                               ? 0 : journal_seq;
+               }
+
+               if (!data_type_is_empty(old_a->data_type) &&
+                   data_type_is_empty(new_a->data_type) &&
+                   bucket_journal_seq) {
+                       ret = bch2_set_bucket_needs_journal_commit(&c->buckets_waiting_for_journal,
+                                       c->journal.flushed_seq_ondisk,
+                                       new.k->p.inode, new.k->p.offset,
+                                       bucket_journal_seq);
+                       if (ret) {
+                               bch2_fs_fatal_error(c,
+                                       "error setting bucket_needs_journal_commit: %i", ret);
+                               return ret;
+                       }
+               }
+
+               percpu_down_read(&c->mark_lock);
+               if (new_a->gen != old_a->gen)
+                       *bucket_gen(ca, new.k->p.offset) = new_a->gen;
+
+               bch2_dev_usage_update(c, ca, old_a, new_a, journal_seq, false);
+
+               if (new_a->data_type == BCH_DATA_free &&
+                   (!new_a->journal_seq || new_a->journal_seq < c->journal.flushed_seq_ondisk))
+                       closure_wake_up(&c->freelist_wait);
+
+               if (new_a->data_type == BCH_DATA_need_discard &&
+                   (!bucket_journal_seq || bucket_journal_seq < c->journal.flushed_seq_ondisk))
+                       bch2_do_discards(c);
+
+               if (old_a->data_type != BCH_DATA_cached &&
+                   new_a->data_type == BCH_DATA_cached &&
+                   should_invalidate_buckets(ca, bch2_dev_usage_read(ca)))
+                       bch2_do_invalidates(c);
+
+               if (new_a->data_type == BCH_DATA_need_gc_gens)
+                       bch2_do_gc_gens(c);
+               percpu_up_read(&c->mark_lock);
        }
 
-       if (old_a->gen != new_a->gen) {
-               ret = bch2_bucket_gen_update(trans, new->k.p, new_a->gen);
-               if (ret)
-                       return ret;
+       if ((flags & BTREE_TRIGGER_GC) &&
+           (flags & BTREE_TRIGGER_BUCKET_INVALIDATE)) {
+               struct bch_alloc_v4 new_a_convert;
+               const struct bch_alloc_v4 *new_a = bch2_alloc_to_v4(new.s_c, &new_a_convert);
+
+               percpu_down_read(&c->mark_lock);
+               struct bucket *g = gc_bucket(ca, new.k->p.offset);
+
+               bucket_lock(g);
+
+               g->gen_valid            = 1;
+               g->gen                  = new_a->gen;
+               g->data_type            = new_a->data_type;
+               g->stripe               = new_a->stripe;
+               g->stripe_redundancy    = new_a->stripe_redundancy;
+               g->dirty_sectors        = new_a->dirty_sectors;
+               g->cached_sectors       = new_a->cached_sectors;
+
+               bucket_unlock(g);
+               percpu_up_read(&c->mark_lock);
        }
 
        return 0;
@@ -948,8 +944,9 @@ static struct bkey_s_c bch2_get_key_or_hole(struct btree_iter *iter, struct bpos
 
                bch2_trans_copy_iter(&iter2, iter);
 
-               if (!bpos_eq(iter->path->l[0].b->key.k.p, SPOS_MAX))
-                       end = bkey_min(end, bpos_nosnap_successor(iter->path->l[0].b->key.k.p));
+               struct btree_path *path = btree_iter_path(iter->trans, iter);
+               if (!bpos_eq(path->l[0].b->key.k.p, SPOS_MAX))
+                       end = bkey_min(end, bpos_nosnap_successor(path->l[0].b->key.k.p));
 
                end = bkey_min(end, POS(iter->pos.inode, iter->pos.offset + U32_MAX - 1));
 
@@ -977,7 +974,6 @@ static struct bkey_s_c bch2_get_key_or_hole(struct btree_iter *iter, struct bpos
 static bool next_bucket(struct bch_fs *c, struct bpos *bucket)
 {
        struct bch_dev *ca;
-       unsigned iter;
 
        if (bch2_dev_bucket_exists(c, *bucket))
                return true;
@@ -995,8 +991,7 @@ static bool next_bucket(struct bch_fs *c, struct bpos *bucket)
        }
 
        rcu_read_lock();
-       iter = bucket->inode;
-       ca = __bch2_next_dev(c, &iter, NULL);
+       ca = __bch2_next_dev_idx(c, bucket->inode, NULL);
        if (ca)
                *bucket = POS(ca->dev_idx, ca->mi.first_bucket);
        rcu_read_unlock();
@@ -1053,6 +1048,7 @@ int bch2_check_alloc_key(struct btree_trans *trans,
        int ret;
 
        if (fsck_err_on(!bch2_dev_bucket_exists(c, alloc_k.k->p), c,
+                       alloc_key_to_missing_dev_bucket,
                        "alloc key for invalid device:bucket %llu:%llu",
                        alloc_k.k->p.inode, alloc_k.k->p.offset))
                return bch2_btree_delete_at(trans, alloc_iter, 0);
@@ -1072,7 +1068,8 @@ int bch2_check_alloc_key(struct btree_trans *trans,
 
        if (k.k->type != discard_key_type &&
            (c->opts.reconstruct_alloc ||
-            fsck_err(c, "incorrect key in need_discard btree (got %s should be %s)\n"
+            fsck_err(c, need_discard_key_wrong,
+                     "incorrect key in need_discard btree (got %s should be %s)\n"
                      "  %s",
                      bch2_bkey_types[k.k->type],
                      bch2_bkey_types[discard_key_type],
@@ -1102,7 +1099,8 @@ int bch2_check_alloc_key(struct btree_trans *trans,
 
        if (k.k->type != freespace_key_type &&
            (c->opts.reconstruct_alloc ||
-            fsck_err(c, "incorrect key in freespace btree (got %s should be %s)\n"
+            fsck_err(c, freespace_key_wrong,
+                     "incorrect key in freespace btree (got %s should be %s)\n"
                      "  %s",
                      bch2_bkey_types[k.k->type],
                      bch2_bkey_types[freespace_key_type],
@@ -1133,7 +1131,8 @@ int bch2_check_alloc_key(struct btree_trans *trans,
 
        if (a->gen != alloc_gen(k, gens_offset) &&
            (c->opts.reconstruct_alloc ||
-            fsck_err(c, "incorrect gen in bucket_gens btree (got %u should be %u)\n"
+            fsck_err(c, bucket_gens_key_wrong,
+                     "incorrect gen in bucket_gens btree (got %u should be %u)\n"
                      "  %s",
                      alloc_gen(k, gens_offset), a->gen,
                      (printbuf_reset(&buf),
@@ -1191,7 +1190,8 @@ int bch2_check_alloc_hole_freespace(struct btree_trans *trans,
 
        if (k.k->type != KEY_TYPE_set &&
            (c->opts.reconstruct_alloc ||
-            fsck_err(c, "hole in alloc btree missing in freespace btree\n"
+            fsck_err(c, freespace_hole_missing,
+                     "hole in alloc btree missing in freespace btree\n"
                      "  device %llu buckets %llu-%llu",
                      freespace_iter->pos.inode,
                      freespace_iter->pos.offset,
@@ -1232,10 +1232,6 @@ int bch2_check_alloc_hole_bucket_gens(struct btree_trans *trans,
        unsigned i, gens_offset, gens_end_offset;
        int ret;
 
-       if (c->sb.version < bcachefs_metadata_version_bucket_gens &&
-           !c->opts.version_upgrade)
-               return 0;
-
        bch2_btree_iter_set_pos(bucket_gens_iter, alloc_gens_pos(start, &gens_offset));
 
        k = bch2_btree_iter_peek_slot(bucket_gens_iter);
@@ -1255,6 +1251,7 @@ int bch2_check_alloc_hole_bucket_gens(struct btree_trans *trans,
 
                for (i = gens_offset; i < gens_end_offset; i++) {
                        if (fsck_err_on(g.v.gens[i], c,
+                                       bucket_gens_hole_wrong,
                                        "hole in alloc btree at %llu:%llu with nonzero gen in bucket_gens btree (%u)",
                                        bucket_gens_pos_to_alloc(k.k->p, i).inode,
                                        bucket_gens_pos_to_alloc(k.k->p, i).offset,
@@ -1265,15 +1262,15 @@ int bch2_check_alloc_hole_bucket_gens(struct btree_trans *trans,
                }
 
                if (need_update) {
-                       struct bkey_i *k = bch2_trans_kmalloc(trans, sizeof(g));
+                       struct bkey_i *u = bch2_trans_kmalloc(trans, sizeof(g));
 
-                       ret = PTR_ERR_OR_ZERO(k);
+                       ret = PTR_ERR_OR_ZERO(u);
                        if (ret)
                                goto err;
 
-                       memcpy(k, &g, sizeof(g));
+                       memcpy(u, &g, sizeof(g));
 
-                       ret = bch2_trans_update(trans, bucket_gens_iter, k, 0);
+                       ret = bch2_trans_update(trans, bucket_gens_iter, u, 0);
                        if (ret)
                                goto err;
                }
@@ -1286,7 +1283,7 @@ fsck_err:
        return ret;
 }
 
-static noinline_for_stack int __bch2_check_discard_freespace_key(struct btree_trans *trans,
+static noinline_for_stack int bch2_check_discard_freespace_key(struct btree_trans *trans,
                                              struct btree_iter *iter)
 {
        struct bch_fs *c = trans->c;
@@ -1312,8 +1309,9 @@ static noinline_for_stack int __bch2_check_discard_freespace_key(struct btree_tr
                return ret;
 
        if (fsck_err_on(!bch2_dev_bucket_exists(c, pos), c,
+                       need_discard_freespace_key_to_invalid_dev_bucket,
                        "entry in %s btree for nonexistant dev:bucket %llu:%llu",
-                       bch2_btree_ids[iter->btree_id], pos.inode, pos.offset))
+                       bch2_btree_id_str(iter->btree_id), pos.inode, pos.offset))
                goto delete;
 
        a = bch2_alloc_to_v4(alloc_k, &a_convert);
@@ -1321,9 +1319,10 @@ static noinline_for_stack int __bch2_check_discard_freespace_key(struct btree_tr
        if (fsck_err_on(a->data_type != state ||
                        (state == BCH_DATA_free &&
                         genbits != alloc_freespace_genbits(*a)), c,
+                       need_discard_freespace_key_bad,
                        "%s\n  incorrectly set at %s:%llu:%llu:0 (free %u, genbits %llu should be %llu)",
                        (bch2_bkey_val_to_text(&buf, c, alloc_k), buf.buf),
-                       bch2_btree_ids[iter->btree_id],
+                       bch2_btree_id_str(iter->btree_id),
                        iter->pos.inode,
                        iter->pos.offset,
                        a->data_type == state,
@@ -1339,28 +1338,10 @@ delete:
        ret =   bch2_btree_delete_extent_at(trans, iter,
                        iter->btree_id == BTREE_ID_freespace ? 1 : 0, 0) ?:
                bch2_trans_commit(trans, NULL, NULL,
-                       BTREE_INSERT_NOFAIL|BTREE_INSERT_LAZY_RW);
+                       BCH_TRANS_COMMIT_no_enospc);
        goto out;
 }
 
-static int bch2_check_discard_freespace_key(struct btree_trans *trans,
-                                           struct btree_iter *iter,
-                                           struct bpos end)
-{
-       if (!btree_node_type_is_extents(iter->btree_id)) {
-               return __bch2_check_discard_freespace_key(trans, iter);
-       } else {
-               int ret;
-
-               while (!bkey_eq(iter->pos, end) &&
-                      !(ret = btree_trans_too_many_iters(trans) ?:
-                              __bch2_check_discard_freespace_key(trans, iter)))
-                       bch2_btree_iter_set_pos(iter, bpos_nosnap_successor(iter->pos));
-
-               return ret;
-       }
-}
-
 /*
  * We've already checked that generation numbers in the bucket_gens btree are
  * valid for buckets that exist; this just checks for keys for nonexistent
@@ -1388,6 +1369,7 @@ int bch2_check_bucket_gens_key(struct btree_trans *trans,
        dev_exists = bch2_dev_exists2(c, k.k->p.inode);
        if (!dev_exists) {
                if (fsck_err_on(!dev_exists, c,
+                               bucket_gens_to_invalid_dev,
                                "bucket_gens key for invalid device:\n  %s",
                                (bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
                        ret = bch2_btree_delete_at(trans, iter, 0);
@@ -1398,6 +1380,7 @@ int bch2_check_bucket_gens_key(struct btree_trans *trans,
        ca = bch_dev_bkey_exists(c, k.k->p.inode);
        if (fsck_err_on(end <= ca->mi.first_bucket ||
                        start >= ca->mi.nbuckets, c,
+                       bucket_gens_to_invalid_buckets,
                        "bucket_gens key for invalid buckets:\n  %s",
                        (bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
                ret = bch2_btree_delete_at(trans, iter, 0);
@@ -1406,6 +1389,7 @@ int bch2_check_bucket_gens_key(struct btree_trans *trans,
 
        for (b = start; b < ca->mi.first_bucket; b++)
                if (fsck_err_on(g.v.gens[b & KEY_TYPE_BUCKET_GENS_MASK], c,
+                               bucket_gens_nonzero_for_invalid_buckets,
                                "bucket_gens key has nonzero gen for invalid bucket")) {
                        g.v.gens[b & KEY_TYPE_BUCKET_GENS_MASK] = 0;
                        need_update = true;
@@ -1413,21 +1397,21 @@ int bch2_check_bucket_gens_key(struct btree_trans *trans,
 
        for (b = ca->mi.nbuckets; b < end; b++)
                if (fsck_err_on(g.v.gens[b & KEY_TYPE_BUCKET_GENS_MASK], c,
+                               bucket_gens_nonzero_for_invalid_buckets,
                                "bucket_gens key has nonzero gen for invalid bucket")) {
                        g.v.gens[b & KEY_TYPE_BUCKET_GENS_MASK] = 0;
                        need_update = true;
                }
 
        if (need_update) {
-               struct bkey_i *k;
+               struct bkey_i *u = bch2_trans_kmalloc(trans, sizeof(g));
 
-               k = bch2_trans_kmalloc(trans, sizeof(g));
-               ret = PTR_ERR_OR_ZERO(k);
+               ret = PTR_ERR_OR_ZERO(u);
                if (ret)
                        goto out;
 
-               memcpy(k, &g, sizeof(g));
-               ret = bch2_trans_update(trans, iter, k, 0);
+               memcpy(u, &g, sizeof(g));
+               ret = bch2_trans_update(trans, iter, u, 0);
        }
 out:
 fsck_err:
@@ -1437,27 +1421,25 @@ fsck_err:
 
 int bch2_check_alloc_info(struct bch_fs *c)
 {
-       struct btree_trans trans;
+       struct btree_trans *trans = bch2_trans_get(c);
        struct btree_iter iter, discard_iter, freespace_iter, bucket_gens_iter;
        struct bkey hole;
        struct bkey_s_c k;
        int ret = 0;
 
-       bch2_trans_init(&trans, c, 0, 0);
-
-       bch2_trans_iter_init(&trans, &iter, BTREE_ID_alloc, POS_MIN,
+       bch2_trans_iter_init(trans, &iter, BTREE_ID_alloc, POS_MIN,
                             BTREE_ITER_PREFETCH);
-       bch2_trans_iter_init(&trans, &discard_iter, BTREE_ID_need_discard, POS_MIN,
+       bch2_trans_iter_init(trans, &discard_iter, BTREE_ID_need_discard, POS_MIN,
                             BTREE_ITER_PREFETCH);
-       bch2_trans_iter_init(&trans, &freespace_iter, BTREE_ID_freespace, POS_MIN,
+       bch2_trans_iter_init(trans, &freespace_iter, BTREE_ID_freespace, POS_MIN,
                             BTREE_ITER_PREFETCH);
-       bch2_trans_iter_init(&trans, &bucket_gens_iter, BTREE_ID_bucket_gens, POS_MIN,
+       bch2_trans_iter_init(trans, &bucket_gens_iter, BTREE_ID_bucket_gens, POS_MIN,
                             BTREE_ITER_PREFETCH);
 
        while (1) {
                struct bpos next;
 
-               bch2_trans_begin(&trans);
+               bch2_trans_begin(trans);
 
                k = bch2_get_key_or_real_bucket_hole(&iter, &hole);
                ret = bkey_err(k);
@@ -1470,7 +1452,7 @@ int bch2_check_alloc_info(struct bch_fs *c)
                if (k.k->type) {
                        next = bpos_nosnap_successor(k.k->p);
 
-                       ret = bch2_check_alloc_key(&trans,
+                       ret = bch2_check_alloc_key(trans,
                                                   k, &iter,
                                                   &discard_iter,
                                                   &freespace_iter,
@@ -1480,11 +1462,11 @@ int bch2_check_alloc_info(struct bch_fs *c)
                } else {
                        next = k.k->p;
 
-                       ret = bch2_check_alloc_hole_freespace(&trans,
+                       ret = bch2_check_alloc_hole_freespace(trans,
                                                    bkey_start_pos(k.k),
                                                    &next,
                                                    &freespace_iter) ?:
-                               bch2_check_alloc_hole_bucket_gens(&trans,
+                               bch2_check_alloc_hole_bucket_gens(trans,
                                                    bkey_start_pos(k.k),
                                                    &next,
                                                    &bucket_gens_iter);
@@ -1492,9 +1474,8 @@ int bch2_check_alloc_info(struct bch_fs *c)
                                goto bkey_err;
                }
 
-               ret = bch2_trans_commit(&trans, NULL, NULL,
-                                       BTREE_INSERT_NOFAIL|
-                                       BTREE_INSERT_LAZY_RW);
+               ret = bch2_trans_commit(trans, NULL, NULL,
+                                       BCH_TRANS_COMMIT_no_enospc);
                if (ret)
                        goto bkey_err;
 
@@ -1505,31 +1486,58 @@ bkey_err:
                if (ret)
                        break;
        }
-       bch2_trans_iter_exit(&trans, &bucket_gens_iter);
-       bch2_trans_iter_exit(&trans, &freespace_iter);
-       bch2_trans_iter_exit(&trans, &discard_iter);
-       bch2_trans_iter_exit(&trans, &iter);
+       bch2_trans_iter_exit(trans, &bucket_gens_iter);
+       bch2_trans_iter_exit(trans, &freespace_iter);
+       bch2_trans_iter_exit(trans, &discard_iter);
+       bch2_trans_iter_exit(trans, &iter);
 
        if (ret < 0)
                goto err;
 
-       ret = for_each_btree_key2(&trans, iter,
+       ret = for_each_btree_key(trans, iter,
                        BTREE_ID_need_discard, POS_MIN,
                        BTREE_ITER_PREFETCH, k,
-               bch2_check_discard_freespace_key(&trans, &iter, k.k->p)) ?:
-             for_each_btree_key2(&trans, iter,
-                       BTREE_ID_freespace, POS_MIN,
-                       BTREE_ITER_PREFETCH, k,
-               bch2_check_discard_freespace_key(&trans, &iter, k.k->p)) ?:
-             for_each_btree_key_commit(&trans, iter,
+               bch2_check_discard_freespace_key(trans, &iter));
+       if (ret)
+               goto err;
+
+       bch2_trans_iter_init(trans, &iter, BTREE_ID_freespace, POS_MIN,
+                            BTREE_ITER_PREFETCH);
+       while (1) {
+               bch2_trans_begin(trans);
+               k = bch2_btree_iter_peek(&iter);
+               if (!k.k)
+                       break;
+
+               ret = bkey_err(k) ?:
+                       bch2_check_discard_freespace_key(trans, &iter);
+               if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) {
+                       ret = 0;
+                       continue;
+               }
+               if (ret) {
+                       struct printbuf buf = PRINTBUF;
+                       bch2_bkey_val_to_text(&buf, c, k);
+
+                       bch_err(c, "while checking %s", buf.buf);
+                       printbuf_exit(&buf);
+                       break;
+               }
+
+               bch2_btree_iter_set_pos(&iter, bpos_nosnap_successor(iter.pos));
+       }
+       bch2_trans_iter_exit(trans, &iter);
+       if (ret)
+               goto err;
+
+       ret = for_each_btree_key_commit(trans, iter,
                        BTREE_ID_bucket_gens, POS_MIN,
                        BTREE_ITER_PREFETCH, k,
-                       NULL, NULL, BTREE_INSERT_NOFAIL|BTREE_INSERT_LAZY_RW,
-               bch2_check_bucket_gens_key(&trans, &iter, k));
+                       NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
+               bch2_check_bucket_gens_key(trans, &iter, k));
 err:
-       bch2_trans_exit(&trans);
-       if (ret)
-               bch_err_fn(c, ret);
+       bch2_trans_put(trans);
+       bch_err_fn(c, ret);
        return ret;
 }
 
@@ -1557,6 +1565,27 @@ static int bch2_check_alloc_to_lru_ref(struct btree_trans *trans,
        if (a->data_type != BCH_DATA_cached)
                return 0;
 
+       if (fsck_err_on(!a->io_time[READ], c,
+                       alloc_key_cached_but_read_time_zero,
+                       "cached bucket with read_time 0\n"
+                       "  %s",
+               (printbuf_reset(&buf),
+                bch2_bkey_val_to_text(&buf, c, alloc_k), buf.buf))) {
+               struct bkey_i_alloc_v4 *a_mut =
+                       bch2_alloc_to_v4_mut(trans, alloc_k);
+               ret = PTR_ERR_OR_ZERO(a_mut);
+               if (ret)
+                       goto err;
+
+               a_mut->v.io_time[READ] = atomic64_read(&c->io_clock[READ].now);
+               ret = bch2_trans_update(trans, alloc_iter,
+                                       &a_mut->k_i, BTREE_TRIGGER_NORUN);
+               if (ret)
+                       goto err;
+
+               a = &a_mut->v;
+       }
+
        lru_k = bch2_bkey_get_iter(trans, &lru_iter, BTREE_ID_lru,
                             lru_pos(alloc_k.k->p.inode,
                                     bucket_to_u64(alloc_k.k->p),
@@ -1565,39 +1594,18 @@ static int bch2_check_alloc_to_lru_ref(struct btree_trans *trans,
        if (ret)
                return ret;
 
-       if (fsck_err_on(!a->io_time[READ], c,
-                       "cached bucket with read_time 0\n"
-                       "  %s",
-               (printbuf_reset(&buf),
-                bch2_bkey_val_to_text(&buf, c, alloc_k), buf.buf)) ||
-           fsck_err_on(lru_k.k->type != KEY_TYPE_set, c,
+       if (fsck_err_on(lru_k.k->type != KEY_TYPE_set, c,
+                       alloc_key_to_missing_lru_entry,
                        "missing lru entry\n"
                        "  %s",
                        (printbuf_reset(&buf),
                         bch2_bkey_val_to_text(&buf, c, alloc_k), buf.buf))) {
-               u64 read_time = a->io_time[READ] ?:
-                       atomic64_read(&c->io_clock[READ].now);
-
                ret = bch2_lru_set(trans,
                                   alloc_k.k->p.inode,
                                   bucket_to_u64(alloc_k.k->p),
-                                  read_time);
+                                  a->io_time[READ]);
                if (ret)
                        goto err;
-
-               if (a->io_time[READ] != read_time) {
-                       struct bkey_i_alloc_v4 *a_mut =
-                               bch2_alloc_to_v4_mut(trans, alloc_k);
-                       ret = PTR_ERR_OR_ZERO(a_mut);
-                       if (ret)
-                               goto err;
-
-                       a_mut->v.io_time[READ] = read_time;
-                       ret = bch2_trans_update(trans, alloc_iter,
-                                               &a_mut->k_i, BTREE_TRIGGER_NORUN);
-                       if (ret)
-                               goto err;
-               }
        }
 err:
 fsck_err:
@@ -1608,17 +1616,12 @@ fsck_err:
 
 int bch2_check_alloc_to_lru_refs(struct bch_fs *c)
 {
-       struct btree_iter iter;
-       struct bkey_s_c k;
-       int ret = 0;
-
-       ret = bch2_trans_run(c,
-               for_each_btree_key_commit(&trans, iter, BTREE_ID_alloc,
+       int ret = bch2_trans_run(c,
+               for_each_btree_key_commit(trans, iter, BTREE_ID_alloc,
                                POS_MIN, BTREE_ITER_PREFETCH, k,
-                               NULL, NULL, BTREE_INSERT_NOFAIL|BTREE_INSERT_LAZY_RW,
-                       bch2_check_alloc_to_lru_ref(&trans, &iter)));
-       if (ret)
-               bch_err_fn(c, ret);
+                               NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
+                       bch2_check_alloc_to_lru_ref(trans, &iter)));
+       bch_err_fn(c, ret);
        return ret;
 }
 
@@ -1676,7 +1679,7 @@ static int bch2_discard_one_bucket(struct btree_trans *trans,
        }
 
        if (a->v.journal_seq > c->journal.flushed_seq_ondisk) {
-               if (test_bit(BCH_FS_CHECK_ALLOC_DONE, &c->flags)) {
+               if (c->curr_recovery_pass > BCH_RECOVERY_PASS_check_alloc_info) {
                        bch2_trans_inconsistent(trans,
                                "clearing need_discard but journal_seq %llu > flushed_seq %llu\n"
                                "%s",
@@ -1689,7 +1692,7 @@ static int bch2_discard_one_bucket(struct btree_trans *trans,
        }
 
        if (a->v.data_type != BCH_DATA_need_discard) {
-               if (test_bit(BCH_FS_CHECK_ALLOC_DONE, &c->flags)) {
+               if (c->curr_recovery_pass > BCH_RECOVERY_PASS_check_alloc_info) {
                        bch2_trans_inconsistent(trans,
                                "bucket incorrectly set in need_discard btree\n"
                                "%s",
@@ -1724,11 +1727,11 @@ write:
        ret =   bch2_trans_update(trans, &iter, &a->k_i, 0) ?:
                bch2_trans_commit(trans, NULL, NULL,
                                  BCH_WATERMARK_btree|
-                                 BTREE_INSERT_NOFAIL);
+                                 BCH_TRANS_COMMIT_no_enospc);
        if (ret)
                goto out;
 
-       this_cpu_inc(c->counters[BCH_COUNTER_bucket_discard]);
+       count_event(c, bucket_discard);
        (*discarded)++;
 out:
        (*seen)++;
@@ -1741,29 +1744,23 @@ out:
 static void bch2_do_discards_work(struct work_struct *work)
 {
        struct bch_fs *c = container_of(work, struct bch_fs, discard_work);
-       struct btree_trans trans;
-       struct btree_iter iter;
-       struct bkey_s_c k;
        u64 seen = 0, open = 0, need_journal_commit = 0, discarded = 0;
        struct bpos discard_pos_done = POS_MAX;
        int ret;
 
-       bch2_trans_init(&trans, c, 0, 0);
-
        /*
         * We're doing the commit in bch2_discard_one_bucket instead of using
         * for_each_btree_key_commit() so that we can increment counters after
         * successful commit:
         */
-       ret = for_each_btree_key2(&trans, iter,
-                       BTREE_ID_need_discard, POS_MIN, 0, k,
-               bch2_discard_one_bucket(&trans, &iter, &discard_pos_done,
-                                       &seen,
-                                       &open,
-                                       &need_journal_commit,
-                                       &discarded));
-
-       bch2_trans_exit(&trans);
+       ret = bch2_trans_run(c,
+               for_each_btree_key(trans, iter,
+                                  BTREE_ID_need_discard, POS_MIN, 0, k,
+                       bch2_discard_one_bucket(trans, &iter, &discard_pos_done,
+                                               &seen,
+                                               &open,
+                                               &need_journal_commit,
+                                               &discarded)));
 
        if (need_journal_commit * 2 > seen)
                bch2_journal_flush_async(&c->journal, NULL);
@@ -1833,7 +1830,7 @@ static int invalidate_one_bucket(struct btree_trans *trans,
                                BTREE_TRIGGER_BUCKET_INVALIDATE) ?:
                bch2_trans_commit(trans, NULL, NULL,
                                  BCH_WATERMARK_btree|
-                                 BTREE_INSERT_NOFAIL);
+                                 BCH_TRANS_COMMIT_no_enospc);
        if (ret)
                goto out;
 
@@ -1857,7 +1854,7 @@ err:
                bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(&a->k_i));
 
        bch_err(c, "%s", buf.buf);
-       if (test_bit(BCH_FS_CHECK_LRUS_DONE, &c->flags)) {
+       if (c->curr_recovery_pass > BCH_RECOVERY_PASS_check_lrus) {
                bch2_inconsistent_error(c);
                ret = -EINVAL;
        }
@@ -1868,28 +1865,22 @@ err:
 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 btree_iter iter;
-       struct bkey_s_c k;
-       unsigned i;
+       struct btree_trans *trans = bch2_trans_get(c);
        int ret = 0;
 
-       bch2_trans_init(&trans, c, 0, 0);
-
-       ret = bch2_btree_write_buffer_flush(&trans);
+       ret = bch2_btree_write_buffer_tryflush(trans);
        if (ret)
                goto err;
 
-       for_each_member_device(ca, c, i) {
+       for_each_member_device(c, ca) {
                s64 nr_to_invalidate =
                        should_invalidate_buckets(ca, bch2_dev_usage_read(ca));
 
-               ret = for_each_btree_key2_upto(&trans, iter, BTREE_ID_lru,
+               ret = for_each_btree_key_upto(trans, iter, BTREE_ID_lru,
                                lru_pos(ca->dev_idx, 0, 0),
                                lru_pos(ca->dev_idx, U64_MAX, LRU_TIME_MAX),
                                BTREE_ITER_INTENT, k,
-                       invalidate_one_bucket(&trans, &iter, k, &nr_to_invalidate));
+                       invalidate_one_bucket(trans, &iter, k, &nr_to_invalidate));
 
                if (ret < 0) {
                        percpu_ref_put(&ca->ref);
@@ -1897,7 +1888,7 @@ static void bch2_do_invalidates_work(struct work_struct *work)
                }
        }
 err:
-       bch2_trans_exit(&trans);
+       bch2_trans_put(trans);
        bch2_write_ref_put(c, BCH_WRITE_REF_invalidate);
 }
 
@@ -1908,34 +1899,36 @@ void bch2_do_invalidates(struct bch_fs *c)
                bch2_write_ref_put(c, BCH_WRITE_REF_invalidate);
 }
 
-static int bch2_dev_freespace_init(struct bch_fs *c, struct bch_dev *ca,
-                                  unsigned long *last_updated)
+int bch2_dev_freespace_init(struct bch_fs *c, struct bch_dev *ca,
+                           u64 bucket_start, u64 bucket_end)
 {
-       struct btree_trans trans;
+       struct btree_trans *trans = bch2_trans_get(c);
        struct btree_iter iter;
        struct bkey_s_c k;
        struct bkey hole;
-       struct bpos end = POS(ca->dev_idx, ca->mi.nbuckets);
+       struct bpos end = POS(ca->dev_idx, bucket_end);
        struct bch_member *m;
+       unsigned long last_updated = jiffies;
        int ret;
 
-       bch2_trans_init(&trans, c, 0, 0);
+       BUG_ON(bucket_start > bucket_end);
+       BUG_ON(bucket_end > ca->mi.nbuckets);
 
-       bch2_trans_iter_init(&trans, &iter, BTREE_ID_alloc,
-                            POS(ca->dev_idx, ca->mi.first_bucket),
-                            BTREE_ITER_PREFETCH);
+       bch2_trans_iter_init(trans, &iter, BTREE_ID_alloc,
+               POS(ca->dev_idx, max_t(u64, ca->mi.first_bucket, bucket_start)),
+               BTREE_ITER_PREFETCH);
        /*
         * Scan the alloc btree for every bucket on @ca, and add buckets to the
         * freespace/need_discard/need_gc_gens btrees as needed:
         */
        while (1) {
-               if (*last_updated + HZ * 10 < jiffies) {
+               if (last_updated + HZ * 10 < jiffies) {
                        bch_info(ca, "%s: currently at %llu/%llu",
                                 __func__, iter.pos.offset, ca->mi.nbuckets);
-                       *last_updated = jiffies;
+                       last_updated = jiffies;
                }
 
-               bch2_trans_begin(&trans);
+               bch2_trans_begin(trans);
 
                if (bkey_ge(iter.pos, end)) {
                        ret = 0;
@@ -1955,10 +1948,9 @@ static int bch2_dev_freespace_init(struct bch_fs *c, struct bch_dev *ca,
                        struct bch_alloc_v4 a_convert;
                        const struct bch_alloc_v4 *a = bch2_alloc_to_v4(k, &a_convert);
 
-                       ret =   bch2_bucket_do_index(&trans, k, a, true) ?:
-                               bch2_trans_commit(&trans, NULL, NULL,
-                                                 BTREE_INSERT_LAZY_RW|
-                                                 BTREE_INSERT_NOFAIL);
+                       ret =   bch2_bucket_do_index(trans, k, a, true) ?:
+                               bch2_trans_commit(trans, NULL, NULL,
+                                                 BCH_TRANS_COMMIT_no_enospc);
                        if (ret)
                                goto bkey_err;
 
@@ -1966,7 +1958,7 @@ static int bch2_dev_freespace_init(struct bch_fs *c, struct bch_dev *ca,
                } else {
                        struct bkey_i *freespace;
 
-                       freespace = bch2_trans_kmalloc(&trans, sizeof(*freespace));
+                       freespace = bch2_trans_kmalloc(trans, sizeof(*freespace));
                        ret = PTR_ERR_OR_ZERO(freespace);
                        if (ret)
                                goto bkey_err;
@@ -1976,10 +1968,9 @@ static int bch2_dev_freespace_init(struct bch_fs *c, struct bch_dev *ca,
                        freespace->k.p          = k.k->p;
                        freespace->k.size       = k.k->size;
 
-                       ret = __bch2_btree_insert(&trans, BTREE_ID_freespace, freespace, 0) ?:
-                               bch2_trans_commit(&trans, NULL, NULL,
-                                                 BTREE_INSERT_LAZY_RW|
-                                                 BTREE_INSERT_NOFAIL);
+                       ret = bch2_btree_insert_trans(trans, BTREE_ID_freespace, freespace, 0) ?:
+                               bch2_trans_commit(trans, NULL, NULL,
+                                                 BCH_TRANS_COMMIT_no_enospc);
                        if (ret)
                                goto bkey_err;
 
@@ -1992,16 +1983,16 @@ bkey_err:
                        break;
        }
 
-       bch2_trans_iter_exit(&trans, &iter);
-       bch2_trans_exit(&trans);
+       bch2_trans_iter_exit(trans, &iter);
+       bch2_trans_put(trans);
 
        if (ret < 0) {
-               bch_err(ca, "error initializing free space: %s", bch2_err_str(ret));
+               bch_err_msg(ca, ret, "initializing free space");
                return ret;
        }
 
        mutex_lock(&c->sb_lock);
-       m = bch2_sb_get_members(c->disk_sb.sb)->members + ca->dev_idx;
+       m = bch2_members_v2_get_mut(c->disk_sb.sb, ca->dev_idx);
        SET_BCH_MEMBER_FREESPACE_INITIALIZED(m, true);
        mutex_unlock(&c->sb_lock);
 
@@ -2010,18 +2001,15 @@ bkey_err:
 
 int bch2_fs_freespace_init(struct bch_fs *c)
 {
-       struct bch_dev *ca;
-       unsigned i;
        int ret = 0;
        bool doing_init = false;
-       unsigned long last_updated = jiffies;
 
        /*
         * We can crash during the device add path, so we need to check this on
         * every mount:
         */
 
-       for_each_member_device(ca, c, i) {
+       for_each_member_device(c, ca) {
                if (ca->mi.freespace_initialized)
                        continue;
 
@@ -2030,7 +2018,7 @@ int bch2_fs_freespace_init(struct bch_fs *c)
                        doing_init = true;
                }
 
-               ret = bch2_dev_freespace_init(c, ca, &last_updated);
+               ret = bch2_dev_freespace_init(c, ca, 0, ca->mi.nbuckets);
                if (ret) {
                        percpu_ref_put(&ca->ref);
                        bch_err_fn(c, ret);
@@ -2081,15 +2069,13 @@ out:
 
 void bch2_recalc_capacity(struct bch_fs *c)
 {
-       struct bch_dev *ca;
        u64 capacity = 0, reserved_sectors = 0, gc_reserve;
        unsigned bucket_size_max = 0;
        unsigned long ra_pages = 0;
-       unsigned i;
 
        lockdep_assert_held(&c->state_lock);
 
-       for_each_online_member(ca, c, i) {
+       for_each_online_member(c, ca) {
                struct backing_dev_info *bdi = ca->disk_sb.bdev->bd_disk->bdi;
 
                ra_pages += bdi->ra_pages;
@@ -2097,7 +2083,7 @@ void bch2_recalc_capacity(struct bch_fs *c)
 
        bch2_set_ra_pages(c, ra_pages);
 
-       for_each_rw_member(ca, c, i) {
+       for_each_rw_member(c, ca) {
                u64 dev_reserve = 0;
 
                /*
@@ -2151,6 +2137,15 @@ void bch2_recalc_capacity(struct bch_fs *c)
        closure_wake_up(&c->freelist_wait);
 }
 
+u64 bch2_min_rw_member_capacity(struct bch_fs *c)
+{
+       u64 ret = U64_MAX;
+
+       for_each_rw_member(c, ca)
+               ret = min(ret, ca->mi.nbuckets * ca->mi.bucket_size);
+       return ret;
+}
+
 static bool bch2_dev_has_open_write_point(struct bch_fs *c, struct bch_dev *ca)
 {
        struct open_bucket *ob;