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-rw-r--r--fs/bcachefs/btree_gc.c2111
1 files changed, 2111 insertions, 0 deletions
diff --git a/fs/bcachefs/btree_gc.c b/fs/bcachefs/btree_gc.c
new file mode 100644
index 000000000000..693ed067b1a7
--- /dev/null
+++ b/fs/bcachefs/btree_gc.c
@@ -0,0 +1,2111 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2010 Kent Overstreet <kent.overstreet@gmail.com>
+ * Copyright (C) 2014 Datera Inc.
+ */
+
+#include "bcachefs.h"
+#include "alloc_background.h"
+#include "alloc_foreground.h"
+#include "bkey_methods.h"
+#include "bkey_buf.h"
+#include "btree_journal_iter.h"
+#include "btree_key_cache.h"
+#include "btree_locking.h"
+#include "btree_update_interior.h"
+#include "btree_io.h"
+#include "btree_gc.h"
+#include "buckets.h"
+#include "clock.h"
+#include "debug.h"
+#include "ec.h"
+#include "error.h"
+#include "extents.h"
+#include "journal.h"
+#include "keylist.h"
+#include "move.h"
+#include "recovery.h"
+#include "reflink.h"
+#include "replicas.h"
+#include "super-io.h"
+#include "trace.h"
+
+#include <linux/slab.h>
+#include <linux/bitops.h>
+#include <linux/freezer.h>
+#include <linux/kthread.h>
+#include <linux/preempt.h>
+#include <linux/rcupdate.h>
+#include <linux/sched/task.h>
+
+#define DROP_THIS_NODE 10
+#define DROP_PREV_NODE 11
+
+static bool should_restart_for_topology_repair(struct bch_fs *c)
+{
+ return c->opts.fix_errors != FSCK_FIX_no &&
+ !(c->recovery_passes_complete & BIT_ULL(BCH_RECOVERY_PASS_check_topology));
+}
+
+static inline void __gc_pos_set(struct bch_fs *c, struct gc_pos new_pos)
+{
+ preempt_disable();
+ write_seqcount_begin(&c->gc_pos_lock);
+ c->gc_pos = new_pos;
+ write_seqcount_end(&c->gc_pos_lock);
+ preempt_enable();
+}
+
+static inline void gc_pos_set(struct bch_fs *c, struct gc_pos new_pos)
+{
+ BUG_ON(gc_pos_cmp(new_pos, c->gc_pos) <= 0);
+ __gc_pos_set(c, new_pos);
+}
+
+/*
+ * Missing: if an interior btree node is empty, we need to do something -
+ * perhaps just kill it
+ */
+static int bch2_gc_check_topology(struct bch_fs *c,
+ struct btree *b,
+ struct bkey_buf *prev,
+ struct bkey_buf cur,
+ bool is_last)
+{
+ struct bpos node_start = b->data->min_key;
+ struct bpos node_end = b->data->max_key;
+ struct bpos expected_start = bkey_deleted(&prev->k->k)
+ ? node_start
+ : bpos_successor(prev->k->k.p);
+ struct printbuf buf1 = PRINTBUF, buf2 = PRINTBUF;
+ int ret = 0;
+
+ if (cur.k->k.type == KEY_TYPE_btree_ptr_v2) {
+ struct bkey_i_btree_ptr_v2 *bp = bkey_i_to_btree_ptr_v2(cur.k);
+
+ if (!bpos_eq(expected_start, bp->v.min_key)) {
+ bch2_topology_error(c);
+
+ if (bkey_deleted(&prev->k->k)) {
+ prt_printf(&buf1, "start of node: ");
+ bch2_bpos_to_text(&buf1, node_start);
+ } else {
+ bch2_bkey_val_to_text(&buf1, c, bkey_i_to_s_c(prev->k));
+ }
+ bch2_bkey_val_to_text(&buf2, c, bkey_i_to_s_c(cur.k));
+
+ if (__fsck_err(c,
+ FSCK_CAN_FIX|
+ FSCK_CAN_IGNORE|
+ FSCK_NO_RATELIMIT,
+ "btree node with incorrect min_key at btree %s level %u:\n"
+ " prev %s\n"
+ " cur %s",
+ bch2_btree_ids[b->c.btree_id], b->c.level,
+ buf1.buf, buf2.buf) &&
+ should_restart_for_topology_repair(c)) {
+ bch_info(c, "Halting mark and sweep to start topology repair pass");
+ ret = bch2_run_explicit_recovery_pass(c, BCH_RECOVERY_PASS_check_topology);
+ goto err;
+ } else {
+ set_bit(BCH_FS_INITIAL_GC_UNFIXED, &c->flags);
+ }
+ }
+ }
+
+ if (is_last && !bpos_eq(cur.k->k.p, node_end)) {
+ bch2_topology_error(c);
+
+ printbuf_reset(&buf1);
+ printbuf_reset(&buf2);
+
+ bch2_bkey_val_to_text(&buf1, c, bkey_i_to_s_c(cur.k));
+ bch2_bpos_to_text(&buf2, node_end);
+
+ if (__fsck_err(c,
+ FSCK_CAN_FIX|
+ FSCK_CAN_IGNORE|
+ FSCK_NO_RATELIMIT,
+ "btree node with incorrect max_key at btree %s level %u:\n"
+ " %s\n"
+ " expected %s",
+ bch2_btree_ids[b->c.btree_id], b->c.level,
+ buf1.buf, buf2.buf) &&
+ should_restart_for_topology_repair(c)) {
+ bch_info(c, "Halting mark and sweep to start topology repair pass");
+ ret = bch2_run_explicit_recovery_pass(c, BCH_RECOVERY_PASS_check_topology);
+ goto err;
+ } else {
+ set_bit(BCH_FS_INITIAL_GC_UNFIXED, &c->flags);
+ }
+ }
+
+ bch2_bkey_buf_copy(prev, c, cur.k);
+err:
+fsck_err:
+ printbuf_exit(&buf2);
+ printbuf_exit(&buf1);
+ return ret;
+}
+
+static void btree_ptr_to_v2(struct btree *b, struct bkey_i_btree_ptr_v2 *dst)
+{
+ switch (b->key.k.type) {
+ case KEY_TYPE_btree_ptr: {
+ struct bkey_i_btree_ptr *src = bkey_i_to_btree_ptr(&b->key);
+
+ dst->k.p = src->k.p;
+ dst->v.mem_ptr = 0;
+ dst->v.seq = b->data->keys.seq;
+ dst->v.sectors_written = 0;
+ dst->v.flags = 0;
+ dst->v.min_key = b->data->min_key;
+ set_bkey_val_bytes(&dst->k, sizeof(dst->v) + bkey_val_bytes(&src->k));
+ memcpy(dst->v.start, src->v.start, bkey_val_bytes(&src->k));
+ break;
+ }
+ case KEY_TYPE_btree_ptr_v2:
+ bkey_copy(&dst->k_i, &b->key);
+ break;
+ default:
+ BUG();
+ }
+}
+
+static void bch2_btree_node_update_key_early(struct btree_trans *trans,
+ enum btree_id btree, unsigned level,
+ struct bkey_s_c old, struct bkey_i *new)
+{
+ struct bch_fs *c = trans->c;
+ struct btree *b;
+ struct bkey_buf tmp;
+ int ret;
+
+ bch2_bkey_buf_init(&tmp);
+ bch2_bkey_buf_reassemble(&tmp, c, old);
+
+ b = bch2_btree_node_get_noiter(trans, tmp.k, btree, level, true);
+ if (!IS_ERR_OR_NULL(b)) {
+ mutex_lock(&c->btree_cache.lock);
+
+ bch2_btree_node_hash_remove(&c->btree_cache, b);
+
+ bkey_copy(&b->key, new);
+ ret = __bch2_btree_node_hash_insert(&c->btree_cache, b);
+ BUG_ON(ret);
+
+ mutex_unlock(&c->btree_cache.lock);
+ six_unlock_read(&b->c.lock);
+ }
+
+ bch2_bkey_buf_exit(&tmp, c);
+}
+
+static int set_node_min(struct bch_fs *c, struct btree *b, struct bpos new_min)
+{
+ struct bkey_i_btree_ptr_v2 *new;
+ int ret;
+
+ new = kmalloc_array(BKEY_BTREE_PTR_U64s_MAX, sizeof(u64), GFP_KERNEL);
+ if (!new)
+ return -BCH_ERR_ENOMEM_gc_repair_key;
+
+ btree_ptr_to_v2(b, new);
+ b->data->min_key = new_min;
+ new->v.min_key = new_min;
+ SET_BTREE_PTR_RANGE_UPDATED(&new->v, true);
+
+ ret = bch2_journal_key_insert_take(c, b->c.btree_id, b->c.level + 1, &new->k_i);
+ if (ret) {
+ kfree(new);
+ return ret;
+ }
+
+ bch2_btree_node_drop_keys_outside_node(b);
+ bkey_copy(&b->key, &new->k_i);
+ return 0;
+}
+
+static int set_node_max(struct bch_fs *c, struct btree *b, struct bpos new_max)
+{
+ struct bkey_i_btree_ptr_v2 *new;
+ int ret;
+
+ ret = bch2_journal_key_delete(c, b->c.btree_id, b->c.level + 1, b->key.k.p);
+ if (ret)
+ return ret;
+
+ new = kmalloc_array(BKEY_BTREE_PTR_U64s_MAX, sizeof(u64), GFP_KERNEL);
+ if (!new)
+ return -BCH_ERR_ENOMEM_gc_repair_key;
+
+ btree_ptr_to_v2(b, new);
+ b->data->max_key = new_max;
+ new->k.p = new_max;
+ SET_BTREE_PTR_RANGE_UPDATED(&new->v, true);
+
+ ret = bch2_journal_key_insert_take(c, b->c.btree_id, b->c.level + 1, &new->k_i);
+ if (ret) {
+ kfree(new);
+ return ret;
+ }
+
+ bch2_btree_node_drop_keys_outside_node(b);
+
+ mutex_lock(&c->btree_cache.lock);
+ bch2_btree_node_hash_remove(&c->btree_cache, b);
+
+ bkey_copy(&b->key, &new->k_i);
+ ret = __bch2_btree_node_hash_insert(&c->btree_cache, b);
+ BUG_ON(ret);
+ mutex_unlock(&c->btree_cache.lock);
+ return 0;
+}
+
+static int btree_repair_node_boundaries(struct bch_fs *c, struct btree *b,
+ struct btree *prev, struct btree *cur)
+{
+ struct bpos expected_start = !prev
+ ? b->data->min_key
+ : bpos_successor(prev->key.k.p);
+ struct printbuf buf1 = PRINTBUF, buf2 = PRINTBUF;
+ int ret = 0;
+
+ if (!prev) {
+ prt_printf(&buf1, "start of node: ");
+ bch2_bpos_to_text(&buf1, b->data->min_key);
+ } else {
+ bch2_bkey_val_to_text(&buf1, c, bkey_i_to_s_c(&prev->key));
+ }
+
+ bch2_bkey_val_to_text(&buf2, c, bkey_i_to_s_c(&cur->key));
+
+ if (prev &&
+ bpos_gt(expected_start, cur->data->min_key) &&
+ BTREE_NODE_SEQ(cur->data) > BTREE_NODE_SEQ(prev->data)) {
+ /* cur overwrites prev: */
+
+ if (mustfix_fsck_err_on(bpos_ge(prev->data->min_key,
+ cur->data->min_key), c,
+ "btree node overwritten by next node at btree %s level %u:\n"
+ " node %s\n"
+ " next %s",
+ bch2_btree_ids[b->c.btree_id], b->c.level,
+ buf1.buf, buf2.buf)) {
+ ret = DROP_PREV_NODE;
+ goto out;
+ }
+
+ if (mustfix_fsck_err_on(!bpos_eq(prev->key.k.p,
+ bpos_predecessor(cur->data->min_key)), c,
+ "btree node with incorrect max_key at btree %s level %u:\n"
+ " node %s\n"
+ " next %s",
+ bch2_btree_ids[b->c.btree_id], b->c.level,
+ buf1.buf, buf2.buf))
+ ret = set_node_max(c, prev,
+ bpos_predecessor(cur->data->min_key));
+ } else {
+ /* prev overwrites cur: */
+
+ if (mustfix_fsck_err_on(bpos_ge(expected_start,
+ cur->data->max_key), c,
+ "btree node overwritten by prev node at btree %s level %u:\n"
+ " prev %s\n"
+ " node %s",
+ bch2_btree_ids[b->c.btree_id], b->c.level,
+ buf1.buf, buf2.buf)) {
+ ret = DROP_THIS_NODE;
+ goto out;
+ }
+
+ if (mustfix_fsck_err_on(!bpos_eq(expected_start, cur->data->min_key), c,
+ "btree node with incorrect min_key at btree %s level %u:\n"
+ " prev %s\n"
+ " node %s",
+ bch2_btree_ids[b->c.btree_id], b->c.level,
+ buf1.buf, buf2.buf))
+ ret = set_node_min(c, cur, expected_start);
+ }
+out:
+fsck_err:
+ printbuf_exit(&buf2);
+ printbuf_exit(&buf1);
+ return ret;
+}
+
+static int btree_repair_node_end(struct bch_fs *c, struct btree *b,
+ struct btree *child)
+{
+ struct printbuf buf1 = PRINTBUF, buf2 = PRINTBUF;
+ int ret = 0;
+
+ bch2_bkey_val_to_text(&buf1, c, bkey_i_to_s_c(&child->key));
+ bch2_bpos_to_text(&buf2, b->key.k.p);
+
+ if (mustfix_fsck_err_on(!bpos_eq(child->key.k.p, b->key.k.p), c,
+ "btree node with incorrect max_key at btree %s level %u:\n"
+ " %s\n"
+ " expected %s",
+ bch2_btree_ids[b->c.btree_id], b->c.level,
+ buf1.buf, buf2.buf)) {
+ ret = set_node_max(c, child, b->key.k.p);
+ if (ret)
+ goto err;
+ }
+err:
+fsck_err:
+ printbuf_exit(&buf2);
+ printbuf_exit(&buf1);
+ return ret;
+}
+
+static int bch2_btree_repair_topology_recurse(struct btree_trans *trans, struct btree *b)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_and_journal_iter iter;
+ struct bkey_s_c k;
+ struct bkey_buf prev_k, cur_k;
+ struct btree *prev = NULL, *cur = NULL;
+ bool have_child, dropped_children = false;
+ struct printbuf buf = PRINTBUF;
+ int ret = 0;
+
+ if (!b->c.level)
+ return 0;
+again:
+ prev = NULL;
+ have_child = dropped_children = false;
+ bch2_bkey_buf_init(&prev_k);
+ bch2_bkey_buf_init(&cur_k);
+ bch2_btree_and_journal_iter_init_node_iter(&iter, c, b);
+
+ while ((k = bch2_btree_and_journal_iter_peek(&iter)).k) {
+ BUG_ON(bpos_lt(k.k->p, b->data->min_key));
+ BUG_ON(bpos_gt(k.k->p, b->data->max_key));
+
+ bch2_btree_and_journal_iter_advance(&iter);
+ bch2_bkey_buf_reassemble(&cur_k, c, k);
+
+ cur = bch2_btree_node_get_noiter(trans, cur_k.k,
+ b->c.btree_id, b->c.level - 1,
+ false);
+ ret = PTR_ERR_OR_ZERO(cur);
+
+ printbuf_reset(&buf);
+ bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(cur_k.k));
+
+ if (mustfix_fsck_err_on(ret == -EIO, c,
+ "Topology repair: unreadable btree node at btree %s level %u:\n"
+ " %s",
+ bch2_btree_ids[b->c.btree_id],
+ b->c.level - 1,
+ buf.buf)) {
+ bch2_btree_node_evict(trans, cur_k.k);
+ ret = bch2_journal_key_delete(c, b->c.btree_id,
+ b->c.level, cur_k.k->k.p);
+ cur = NULL;
+ if (ret)
+ break;
+ continue;
+ }
+
+ if (ret) {
+ bch_err_msg(c, ret, "getting btree node");
+ break;
+ }
+
+ ret = btree_repair_node_boundaries(c, b, prev, cur);
+
+ if (ret == DROP_THIS_NODE) {
+ six_unlock_read(&cur->c.lock);
+ bch2_btree_node_evict(trans, cur_k.k);
+ ret = bch2_journal_key_delete(c, b->c.btree_id,
+ b->c.level, cur_k.k->k.p);
+ cur = NULL;
+ if (ret)
+ break;
+ continue;
+ }
+
+ if (prev)
+ six_unlock_read(&prev->c.lock);
+ prev = NULL;
+
+ if (ret == DROP_PREV_NODE) {
+ bch2_btree_node_evict(trans, prev_k.k);
+ ret = bch2_journal_key_delete(c, b->c.btree_id,
+ b->c.level, prev_k.k->k.p);
+ if (ret)
+ break;
+
+ bch2_btree_and_journal_iter_exit(&iter);
+ bch2_bkey_buf_exit(&prev_k, c);
+ bch2_bkey_buf_exit(&cur_k, c);
+ goto again;
+ } else if (ret)
+ break;
+
+ prev = cur;
+ cur = NULL;
+ bch2_bkey_buf_copy(&prev_k, c, cur_k.k);
+ }
+
+ if (!ret && !IS_ERR_OR_NULL(prev)) {
+ BUG_ON(cur);
+ ret = btree_repair_node_end(c, b, prev);
+ }
+
+ if (!IS_ERR_OR_NULL(prev))
+ six_unlock_read(&prev->c.lock);
+ prev = NULL;
+ if (!IS_ERR_OR_NULL(cur))
+ six_unlock_read(&cur->c.lock);
+ cur = NULL;
+
+ if (ret)
+ goto err;
+
+ bch2_btree_and_journal_iter_exit(&iter);
+ bch2_btree_and_journal_iter_init_node_iter(&iter, c, b);
+
+ while ((k = bch2_btree_and_journal_iter_peek(&iter)).k) {
+ bch2_bkey_buf_reassemble(&cur_k, c, k);
+ bch2_btree_and_journal_iter_advance(&iter);
+
+ cur = bch2_btree_node_get_noiter(trans, cur_k.k,
+ b->c.btree_id, b->c.level - 1,
+ false);
+ ret = PTR_ERR_OR_ZERO(cur);
+
+ if (ret) {
+ bch_err_msg(c, ret, "getting btree node");
+ goto err;
+ }
+
+ ret = bch2_btree_repair_topology_recurse(trans, cur);
+ six_unlock_read(&cur->c.lock);
+ cur = NULL;
+
+ if (ret == DROP_THIS_NODE) {
+ bch2_btree_node_evict(trans, cur_k.k);
+ ret = bch2_journal_key_delete(c, b->c.btree_id,
+ b->c.level, cur_k.k->k.p);
+ dropped_children = true;
+ }
+
+ if (ret)
+ goto err;
+
+ have_child = true;
+ }
+
+ printbuf_reset(&buf);
+ bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(&b->key));
+
+ if (mustfix_fsck_err_on(!have_child, c,
+ "empty interior btree node at btree %s level %u\n"
+ " %s",
+ bch2_btree_ids[b->c.btree_id],
+ b->c.level, buf.buf))
+ ret = DROP_THIS_NODE;
+err:
+fsck_err:
+ if (!IS_ERR_OR_NULL(prev))
+ six_unlock_read(&prev->c.lock);
+ if (!IS_ERR_OR_NULL(cur))
+ six_unlock_read(&cur->c.lock);
+
+ bch2_btree_and_journal_iter_exit(&iter);
+ bch2_bkey_buf_exit(&prev_k, c);
+ bch2_bkey_buf_exit(&cur_k, c);
+
+ if (!ret && dropped_children)
+ goto again;
+
+ printbuf_exit(&buf);
+ return ret;
+}
+
+int bch2_check_topology(struct bch_fs *c)
+{
+ struct btree_trans *trans = bch2_trans_get(c);
+ struct btree *b;
+ unsigned i;
+ int ret = 0;
+
+ for (i = 0; i < btree_id_nr_alive(c) && !ret; i++) {
+ struct btree_root *r = bch2_btree_id_root(c, i);
+
+ if (!r->alive)
+ continue;
+
+ b = r->b;
+ if (btree_node_fake(b))
+ continue;
+
+ btree_node_lock_nopath_nofail(trans, &b->c, SIX_LOCK_read);
+ ret = bch2_btree_repair_topology_recurse(trans, b);
+ six_unlock_read(&b->c.lock);
+
+ if (ret == DROP_THIS_NODE) {
+ bch_err(c, "empty btree root - repair unimplemented");
+ ret = -BCH_ERR_fsck_repair_unimplemented;
+ }
+ }
+
+ bch2_trans_put(trans);
+
+ return ret;
+}
+
+static int bch2_check_fix_ptrs(struct btree_trans *trans, enum btree_id btree_id,
+ unsigned level, bool is_root,
+ struct bkey_s_c *k)
+{
+ struct bch_fs *c = trans->c;
+ struct bkey_ptrs_c ptrs_c = bch2_bkey_ptrs_c(*k);
+ const union bch_extent_entry *entry_c;
+ struct extent_ptr_decoded p = { 0 };
+ bool do_update = false;
+ struct printbuf buf = PRINTBUF;
+ int ret = 0;
+
+ /*
+ * XXX
+ * use check_bucket_ref here
+ */
+ bkey_for_each_ptr_decode(k->k, ptrs_c, p, entry_c) {
+ struct bch_dev *ca = bch_dev_bkey_exists(c, p.ptr.dev);
+ struct bucket *g = PTR_GC_BUCKET(ca, &p.ptr);
+ enum bch_data_type data_type = bch2_bkey_ptr_data_type(*k, &entry_c->ptr);
+
+ if (!g->gen_valid &&
+ (c->opts.reconstruct_alloc ||
+ fsck_err(c, "bucket %u:%zu data type %s ptr gen %u missing in alloc btree\n"
+ "while marking %s",
+ p.ptr.dev, PTR_BUCKET_NR(ca, &p.ptr),
+ bch2_data_types[ptr_data_type(k->k, &p.ptr)],
+ p.ptr.gen,
+ (printbuf_reset(&buf),
+ bch2_bkey_val_to_text(&buf, c, *k), buf.buf)))) {
+ if (!p.ptr.cached) {
+ g->gen_valid = true;
+ g->gen = p.ptr.gen;
+ } else {
+ do_update = true;
+ }
+ }
+
+ if (gen_cmp(p.ptr.gen, g->gen) > 0 &&
+ (c->opts.reconstruct_alloc ||
+ fsck_err(c, "bucket %u:%zu data type %s ptr gen in the future: %u > %u\n"
+ "while marking %s",
+ p.ptr.dev, PTR_BUCKET_NR(ca, &p.ptr),
+ bch2_data_types[ptr_data_type(k->k, &p.ptr)],
+ p.ptr.gen, g->gen,
+ (printbuf_reset(&buf),
+ bch2_bkey_val_to_text(&buf, c, *k), buf.buf)))) {
+ if (!p.ptr.cached) {
+ g->gen_valid = true;
+ g->gen = p.ptr.gen;
+ g->data_type = 0;
+ g->dirty_sectors = 0;
+ g->cached_sectors = 0;
+ set_bit(BCH_FS_NEED_ANOTHER_GC, &c->flags);
+ } else {
+ do_update = true;
+ }
+ }
+
+ if (gen_cmp(g->gen, p.ptr.gen) > BUCKET_GC_GEN_MAX &&
+ (c->opts.reconstruct_alloc ||
+ fsck_err(c, "bucket %u:%zu gen %u data type %s: ptr gen %u too stale\n"
+ "while marking %s",
+ p.ptr.dev, PTR_BUCKET_NR(ca, &p.ptr), g->gen,
+ bch2_data_types[ptr_data_type(k->k, &p.ptr)],
+ p.ptr.gen,
+ (printbuf_reset(&buf),
+ bch2_bkey_val_to_text(&buf, c, *k), buf.buf))))
+ do_update = true;
+
+ if (!p.ptr.cached && gen_cmp(p.ptr.gen, g->gen) < 0 &&
+ (c->opts.reconstruct_alloc ||
+ fsck_err(c, "bucket %u:%zu data type %s stale dirty ptr: %u < %u\n"
+ "while marking %s",
+ p.ptr.dev, PTR_BUCKET_NR(ca, &p.ptr),
+ bch2_data_types[ptr_data_type(k->k, &p.ptr)],
+ p.ptr.gen, g->gen,
+ (printbuf_reset(&buf),
+ bch2_bkey_val_to_text(&buf, c, *k), buf.buf))))
+ do_update = true;
+
+ if (data_type != BCH_DATA_btree && p.ptr.gen != g->gen)
+ continue;
+
+ if (fsck_err_on(bucket_data_type(g->data_type) &&
+ bucket_data_type(g->data_type) != data_type, c,
+ "bucket %u:%zu different types of data in same bucket: %s, %s\n"
+ "while marking %s",
+ p.ptr.dev, PTR_BUCKET_NR(ca, &p.ptr),
+ bch2_data_types[g->data_type],
+ bch2_data_types[data_type],
+ (printbuf_reset(&buf),
+ bch2_bkey_val_to_text(&buf, c, *k), buf.buf))) {
+ if (data_type == BCH_DATA_btree) {
+ g->data_type = data_type;
+ set_bit(BCH_FS_NEED_ANOTHER_GC, &c->flags);
+ } else {
+ do_update = true;
+ }
+ }
+
+ if (p.has_ec) {
+ struct gc_stripe *m = genradix_ptr(&c->gc_stripes, p.ec.idx);
+
+ if (fsck_err_on(!m || !m->alive, c,
+ "pointer to nonexistent stripe %llu\n"
+ "while marking %s",
+ (u64) p.ec.idx,
+ (printbuf_reset(&buf),
+ bch2_bkey_val_to_text(&buf, c, *k), buf.buf)))
+ do_update = true;
+
+ if (fsck_err_on(m && m->alive && !bch2_ptr_matches_stripe_m(m, p), c,
+ "pointer does not match stripe %llu\n"
+ "while marking %s",
+ (u64) p.ec.idx,
+ (printbuf_reset(&buf),
+ bch2_bkey_val_to_text(&buf, c, *k), buf.buf)))
+ do_update = true;
+ }
+ }
+
+ if (do_update) {
+ struct bkey_ptrs ptrs;
+ union bch_extent_entry *entry;
+ struct bch_extent_ptr *ptr;
+ struct bkey_i *new;
+
+ if (is_root) {
+ bch_err(c, "cannot update btree roots yet");
+ ret = -EINVAL;
+ goto err;
+ }
+
+ new = kmalloc(bkey_bytes(k->k), GFP_KERNEL);
+ if (!new) {
+ bch_err_msg(c, ret, "allocating new key");
+ ret = -BCH_ERR_ENOMEM_gc_repair_key;
+ goto err;
+ }
+
+ bkey_reassemble(new, *k);
+
+ if (level) {
+ /*
+ * We don't want to drop btree node pointers - if the
+ * btree node isn't there anymore, the read path will
+ * sort it out:
+ */
+ ptrs = bch2_bkey_ptrs(bkey_i_to_s(new));
+ bkey_for_each_ptr(ptrs, ptr) {
+ struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
+ struct bucket *g = PTR_GC_BUCKET(ca, ptr);
+
+ ptr->gen = g->gen;
+ }
+ } else {
+ bch2_bkey_drop_ptrs(bkey_i_to_s(new), ptr, ({
+ struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
+ struct bucket *g = PTR_GC_BUCKET(ca, ptr);
+ enum bch_data_type data_type = bch2_bkey_ptr_data_type(*k, ptr);
+
+ (ptr->cached &&
+ (!g->gen_valid || gen_cmp(ptr->gen, g->gen) > 0)) ||
+ (!ptr->cached &&
+ gen_cmp(ptr->gen, g->gen) < 0) ||
+ gen_cmp(g->gen, ptr->gen) > BUCKET_GC_GEN_MAX ||
+ (g->data_type &&
+ g->data_type != data_type);
+ }));
+again:
+ ptrs = bch2_bkey_ptrs(bkey_i_to_s(new));
+ bkey_extent_entry_for_each(ptrs, entry) {
+ if (extent_entry_type(entry) == BCH_EXTENT_ENTRY_stripe_ptr) {
+ struct gc_stripe *m = genradix_ptr(&c->gc_stripes,
+ entry->stripe_ptr.idx);
+ union bch_extent_entry *next_ptr;
+
+ bkey_extent_entry_for_each_from(ptrs, next_ptr, entry)
+ if (extent_entry_type(next_ptr) == BCH_EXTENT_ENTRY_ptr)
+ goto found;
+ next_ptr = NULL;
+found:
+ if (!next_ptr) {
+ bch_err(c, "aieee, found stripe ptr with no data ptr");
+ continue;
+ }
+
+ if (!m || !m->alive ||
+ !__bch2_ptr_matches_stripe(&m->ptrs[entry->stripe_ptr.block],
+ &next_ptr->ptr,
+ m->sectors)) {
+ bch2_bkey_extent_entry_drop(new, entry);
+ goto again;
+ }
+ }
+ }
+ }
+
+ ret = bch2_journal_key_insert_take(c, btree_id, level, new);
+ if (ret) {
+ kfree(new);
+ goto err;
+ }
+
+ if (level)
+ bch2_btree_node_update_key_early(trans, btree_id, level - 1, *k, new);
+
+ if (0) {
+ printbuf_reset(&buf);
+ bch2_bkey_val_to_text(&buf, c, *k);
+ bch_info(c, "updated %s", buf.buf);
+
+ printbuf_reset(&buf);
+ bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(new));
+ bch_info(c, "new key %s", buf.buf);
+ }
+
+ *k = bkey_i_to_s_c(new);
+ }
+err:
+fsck_err:
+ printbuf_exit(&buf);
+ return ret;
+}
+
+/* marking of btree keys/nodes: */
+
+static int bch2_gc_mark_key(struct btree_trans *trans, enum btree_id btree_id,
+ unsigned level, bool is_root,
+ struct bkey_s_c *k,
+ bool initial)
+{
+ struct bch_fs *c = trans->c;
+ struct bkey deleted = KEY(0, 0, 0);
+ struct bkey_s_c old = (struct bkey_s_c) { &deleted, NULL };
+ unsigned flags =
+ BTREE_TRIGGER_GC|
+ (initial ? BTREE_TRIGGER_NOATOMIC : 0);
+ int ret = 0;
+
+ deleted.p = k->k->p;
+
+ if (initial) {
+ BUG_ON(bch2_journal_seq_verify &&
+ k->k->version.lo > atomic64_read(&c->journal.seq));
+
+ ret = bch2_check_fix_ptrs(trans, btree_id, level, is_root, k);
+ if (ret)
+ goto err;
+
+ if (fsck_err_on(k->k->version.lo > atomic64_read(&c->key_version), c,
+ "key version number higher than recorded: %llu > %llu",
+ k->k->version.lo,
+ atomic64_read(&c->key_version)))
+ atomic64_set(&c->key_version, k->k->version.lo);
+ }
+
+ ret = commit_do(trans, NULL, NULL, 0,
+ bch2_mark_key(trans, btree_id, level, old, *k, flags));
+fsck_err:
+err:
+ if (ret)
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+static int btree_gc_mark_node(struct btree_trans *trans, struct btree *b, bool initial)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_node_iter iter;
+ struct bkey unpacked;
+ struct bkey_s_c k;
+ struct bkey_buf prev, cur;
+ int ret = 0;
+
+ if (!btree_node_type_needs_gc(btree_node_type(b)))
+ return 0;
+
+ bch2_btree_node_iter_init_from_start(&iter, b);
+ bch2_bkey_buf_init(&prev);
+ bch2_bkey_buf_init(&cur);
+ bkey_init(&prev.k->k);
+
+ while ((k = bch2_btree_node_iter_peek_unpack(&iter, b, &unpacked)).k) {
+ ret = bch2_gc_mark_key(trans, b->c.btree_id, b->c.level, false,
+ &k, initial);
+ if (ret)
+ break;
+
+ bch2_btree_node_iter_advance(&iter, b);
+
+ if (b->c.level) {
+ bch2_bkey_buf_reassemble(&cur, c, k);
+
+ ret = bch2_gc_check_topology(c, b, &prev, cur,
+ bch2_btree_node_iter_end(&iter));
+ if (ret)
+ break;
+ }
+ }
+
+ bch2_bkey_buf_exit(&cur, c);
+ bch2_bkey_buf_exit(&prev, c);
+ return ret;
+}
+
+static int bch2_gc_btree(struct btree_trans *trans, enum btree_id btree_id,
+ bool initial, bool metadata_only)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_iter iter;
+ struct btree *b;
+ unsigned depth = metadata_only ? 1 : 0;
+ int ret = 0;
+
+ gc_pos_set(c, gc_pos_btree(btree_id, POS_MIN, 0));
+
+ __for_each_btree_node(trans, iter, btree_id, POS_MIN,
+ 0, depth, BTREE_ITER_PREFETCH, b, ret) {
+ bch2_verify_btree_nr_keys(b);
+
+ gc_pos_set(c, gc_pos_btree_node(b));
+
+ ret = btree_gc_mark_node(trans, b, initial);
+ if (ret)
+ break;
+ }
+ bch2_trans_iter_exit(trans, &iter);
+
+ if (ret)
+ return ret;
+
+ mutex_lock(&c->btree_root_lock);
+ b = bch2_btree_id_root(c, btree_id)->b;
+ if (!btree_node_fake(b)) {
+ struct bkey_s_c k = bkey_i_to_s_c(&b->key);
+
+ ret = bch2_gc_mark_key(trans, b->c.btree_id, b->c.level + 1,
+ true, &k, initial);
+ }
+ gc_pos_set(c, gc_pos_btree_root(b->c.btree_id));
+ mutex_unlock(&c->btree_root_lock);
+
+ return ret;
+}
+
+static int bch2_gc_btree_init_recurse(struct btree_trans *trans, struct btree *b,
+ unsigned target_depth)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_and_journal_iter iter;
+ struct bkey_s_c k;
+ struct bkey_buf cur, prev;
+ struct printbuf buf = PRINTBUF;
+ int ret = 0;
+
+ bch2_btree_and_journal_iter_init_node_iter(&iter, c, b);
+ bch2_bkey_buf_init(&prev);
+ bch2_bkey_buf_init(&cur);
+ bkey_init(&prev.k->k);
+
+ while ((k = bch2_btree_and_journal_iter_peek(&iter)).k) {
+ BUG_ON(bpos_lt(k.k->p, b->data->min_key));
+ BUG_ON(bpos_gt(k.k->p, b->data->max_key));
+
+ ret = bch2_gc_mark_key(trans, b->c.btree_id, b->c.level,
+ false, &k, true);
+ if (ret)
+ goto fsck_err;
+
+ if (b->c.level) {
+ bch2_bkey_buf_reassemble(&cur, c, k);
+ k = bkey_i_to_s_c(cur.k);
+
+ bch2_btree_and_journal_iter_advance(&iter);
+
+ ret = bch2_gc_check_topology(c, b,
+ &prev, cur,
+ !bch2_btree_and_journal_iter_peek(&iter).k);
+ if (ret)
+ goto fsck_err;
+ } else {
+ bch2_btree_and_journal_iter_advance(&iter);
+ }
+ }
+
+ if (b->c.level > target_depth) {
+ bch2_btree_and_journal_iter_exit(&iter);
+ bch2_btree_and_journal_iter_init_node_iter(&iter, c, b);
+
+ while ((k = bch2_btree_and_journal_iter_peek(&iter)).k) {
+ struct btree *child;
+
+ bch2_bkey_buf_reassemble(&cur, c, k);
+ bch2_btree_and_journal_iter_advance(&iter);
+
+ child = bch2_btree_node_get_noiter(trans, cur.k,
+ b->c.btree_id, b->c.level - 1,
+ false);
+ ret = PTR_ERR_OR_ZERO(child);
+
+ if (ret == -EIO) {
+ bch2_topology_error(c);
+
+ if (__fsck_err(c,
+ FSCK_CAN_FIX|
+ FSCK_CAN_IGNORE|
+ FSCK_NO_RATELIMIT,
+ "Unreadable btree node at btree %s level %u:\n"
+ " %s",
+ bch2_btree_ids[b->c.btree_id],
+ b->c.level - 1,
+ (printbuf_reset(&buf),
+ bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(cur.k)), buf.buf)) &&
+ should_restart_for_topology_repair(c)) {
+ bch_info(c, "Halting mark and sweep to start topology repair pass");
+ ret = bch2_run_explicit_recovery_pass(c, BCH_RECOVERY_PASS_check_topology);
+ goto fsck_err;
+ } else {
+ /* Continue marking when opted to not
+ * fix the error: */
+ ret = 0;
+ set_bit(BCH_FS_INITIAL_GC_UNFIXED, &c->flags);
+ continue;
+ }
+ } else if (ret) {
+ bch_err_msg(c, ret, "getting btree node");
+ break;
+ }
+
+ ret = bch2_gc_btree_init_recurse(trans, child,
+ target_depth);
+ six_unlock_read(&child->c.lock);
+
+ if (ret)
+ break;
+ }
+ }
+fsck_err:
+ bch2_bkey_buf_exit(&cur, c);
+ bch2_bkey_buf_exit(&prev, c);
+ bch2_btree_and_journal_iter_exit(&iter);
+ printbuf_exit(&buf);
+ return ret;
+}
+
+static int bch2_gc_btree_init(struct btree_trans *trans,
+ enum btree_id btree_id,
+ bool metadata_only)
+{
+ struct bch_fs *c = trans->c;
+ struct btree *b;
+ unsigned target_depth = metadata_only ? 1 : 0;
+ struct printbuf buf = PRINTBUF;
+ int ret = 0;
+
+ b = bch2_btree_id_root(c, btree_id)->b;
+
+ if (btree_node_fake(b))
+ return 0;
+
+ six_lock_read(&b->c.lock, NULL, NULL);
+ printbuf_reset(&buf);
+ bch2_bpos_to_text(&buf, b->data->min_key);
+ if (mustfix_fsck_err_on(!bpos_eq(b->data->min_key, POS_MIN), c,
+ "btree root with incorrect min_key: %s", buf.buf)) {
+ bch_err(c, "repair unimplemented");
+ ret = -BCH_ERR_fsck_repair_unimplemented;
+ goto fsck_err;
+ }
+
+ printbuf_reset(&buf);
+ bch2_bpos_to_text(&buf, b->data->max_key);
+ if (mustfix_fsck_err_on(!bpos_eq(b->data->max_key, SPOS_MAX), c,
+ "btree root with incorrect max_key: %s", buf.buf)) {
+ bch_err(c, "repair unimplemented");
+ ret = -BCH_ERR_fsck_repair_unimplemented;
+ goto fsck_err;
+ }
+
+ if (b->c.level >= target_depth)
+ ret = bch2_gc_btree_init_recurse(trans, b, target_depth);
+
+ if (!ret) {
+ struct bkey_s_c k = bkey_i_to_s_c(&b->key);
+
+ ret = bch2_gc_mark_key(trans, b->c.btree_id, b->c.level + 1, true,
+ &k, true);
+ }
+fsck_err:
+ six_unlock_read(&b->c.lock);
+
+ if (ret < 0)
+ bch_err_fn(c, ret);
+ printbuf_exit(&buf);
+ return ret;
+}
+
+static inline int btree_id_gc_phase_cmp(enum btree_id l, enum btree_id r)
+{
+ return (int) btree_id_to_gc_phase(l) -
+ (int) btree_id_to_gc_phase(r);
+}
+
+static int bch2_gc_btrees(struct bch_fs *c, bool initial, bool metadata_only)
+{
+ struct btree_trans *trans = bch2_trans_get(c);
+ enum btree_id ids[BTREE_ID_NR];
+ unsigned i;
+ int ret = 0;
+
+ for (i = 0; i < BTREE_ID_NR; i++)
+ ids[i] = i;
+ bubble_sort(ids, BTREE_ID_NR, btree_id_gc_phase_cmp);
+
+ for (i = 0; i < BTREE_ID_NR && !ret; i++)
+ ret = initial
+ ? bch2_gc_btree_init(trans, ids[i], metadata_only)
+ : bch2_gc_btree(trans, ids[i], initial, metadata_only);
+
+ for (i = BTREE_ID_NR; i < btree_id_nr_alive(c) && !ret; i++) {
+ if (!bch2_btree_id_root(c, i)->alive)
+ continue;
+
+ ret = initial
+ ? bch2_gc_btree_init(trans, i, metadata_only)
+ : bch2_gc_btree(trans, i, initial, metadata_only);
+ }
+
+ if (ret < 0)
+ bch_err_fn(c, ret);
+
+ bch2_trans_put(trans);
+ return ret;
+}
+
+static void mark_metadata_sectors(struct bch_fs *c, struct bch_dev *ca,
+ u64 start, u64 end,
+ enum bch_data_type type,
+ unsigned flags)
+{
+ u64 b = sector_to_bucket(ca, start);
+
+ do {
+ unsigned sectors =
+ min_t(u64, bucket_to_sector(ca, b + 1), end) - start;
+
+ bch2_mark_metadata_bucket(c, ca, b, type, sectors,
+ gc_phase(GC_PHASE_SB), flags);
+ b++;
+ start += sectors;
+ } while (start < end);
+}
+
+static void bch2_mark_dev_superblock(struct bch_fs *c, struct bch_dev *ca,
+ unsigned flags)
+{
+ struct bch_sb_layout *layout = &ca->disk_sb.sb->layout;
+ unsigned i;
+ u64 b;
+
+ for (i = 0; i < layout->nr_superblocks; i++) {
+ u64 offset = le64_to_cpu(layout->sb_offset[i]);
+
+ if (offset == BCH_SB_SECTOR)
+ mark_metadata_sectors(c, ca, 0, BCH_SB_SECTOR,
+ BCH_DATA_sb, flags);
+
+ mark_metadata_sectors(c, ca, offset,
+ offset + (1 << layout->sb_max_size_bits),
+ BCH_DATA_sb, flags);
+ }
+
+ for (i = 0; i < ca->journal.nr; i++) {
+ b = ca->journal.buckets[i];
+ bch2_mark_metadata_bucket(c, ca, b, BCH_DATA_journal,
+ ca->mi.bucket_size,
+ gc_phase(GC_PHASE_SB), flags);
+ }
+}
+
+static void bch2_mark_superblocks(struct bch_fs *c)
+{
+ struct bch_dev *ca;
+ unsigned i;
+
+ mutex_lock(&c->sb_lock);
+ gc_pos_set(c, gc_phase(GC_PHASE_SB));
+
+ for_each_online_member(ca, c, i)
+ bch2_mark_dev_superblock(c, ca, BTREE_TRIGGER_GC);
+ mutex_unlock(&c->sb_lock);
+}
+
+#if 0
+/* Also see bch2_pending_btree_node_free_insert_done() */
+static void bch2_mark_pending_btree_node_frees(struct bch_fs *c)
+{
+ struct btree_update *as;
+ struct pending_btree_node_free *d;
+
+ mutex_lock(&c->btree_interior_update_lock);
+ gc_pos_set(c, gc_phase(GC_PHASE_PENDING_DELETE));
+
+ for_each_pending_btree_node_free(c, as, d)
+ if (d->index_update_done)
+ bch2_mark_key(c, bkey_i_to_s_c(&d->key), BTREE_TRIGGER_GC);
+
+ mutex_unlock(&c->btree_interior_update_lock);
+}
+#endif
+
+static void bch2_gc_free(struct bch_fs *c)
+{
+ struct bch_dev *ca;
+ unsigned i;
+
+ genradix_free(&c->reflink_gc_table);
+ genradix_free(&c->gc_stripes);
+
+ for_each_member_device(ca, c, i) {
+ kvpfree(rcu_dereference_protected(ca->buckets_gc, 1),
+ sizeof(struct bucket_array) +
+ ca->mi.nbuckets * sizeof(struct bucket));
+ ca->buckets_gc = NULL;
+
+ free_percpu(ca->usage_gc);
+ ca->usage_gc = NULL;
+ }
+
+ free_percpu(c->usage_gc);
+ c->usage_gc = NULL;
+}
+
+static int bch2_gc_done(struct bch_fs *c,
+ bool initial, bool metadata_only)
+{
+ struct bch_dev *ca = NULL;
+ struct printbuf buf = PRINTBUF;
+ bool verify = !metadata_only &&
+ !c->opts.reconstruct_alloc &&
+ (!initial || (c->sb.compat & (1ULL << BCH_COMPAT_alloc_info)));
+ unsigned i, dev;
+ int ret = 0;
+
+ percpu_down_write(&c->mark_lock);
+
+#define copy_field(_f, _msg, ...) \
+ if (dst->_f != src->_f && \
+ (!verify || \
+ fsck_err(c, _msg ": got %llu, should be %llu" \
+ , ##__VA_ARGS__, dst->_f, src->_f))) \
+ dst->_f = src->_f
+#define copy_dev_field(_f, _msg, ...) \
+ copy_field(_f, "dev %u has wrong " _msg, dev, ##__VA_ARGS__)
+#define copy_fs_field(_f, _msg, ...) \
+ copy_field(_f, "fs has wrong " _msg, ##__VA_ARGS__)
+
+ for (i = 0; i < ARRAY_SIZE(c->usage); i++)
+ bch2_fs_usage_acc_to_base(c, i);
+
+ for_each_member_device(ca, c, dev) {
+ struct bch_dev_usage *dst = ca->usage_base;
+ struct bch_dev_usage *src = (void *)
+ bch2_acc_percpu_u64s((u64 __percpu *) ca->usage_gc,
+ dev_usage_u64s());
+
+ copy_dev_field(buckets_ec, "buckets_ec");
+
+ for (i = 0; i < BCH_DATA_NR; i++) {
+ copy_dev_field(d[i].buckets, "%s buckets", bch2_data_types[i]);
+ copy_dev_field(d[i].sectors, "%s sectors", bch2_data_types[i]);
+ copy_dev_field(d[i].fragmented, "%s fragmented", bch2_data_types[i]);
+ }
+ }
+
+ {
+ unsigned nr = fs_usage_u64s(c);
+ struct bch_fs_usage *dst = c->usage_base;
+ struct bch_fs_usage *src = (void *)
+ bch2_acc_percpu_u64s((u64 __percpu *) c->usage_gc, nr);
+
+ copy_fs_field(hidden, "hidden");
+ copy_fs_field(btree, "btree");
+
+ if (!metadata_only) {
+ copy_fs_field(data, "data");
+ copy_fs_field(cached, "cached");
+ copy_fs_field(reserved, "reserved");
+ copy_fs_field(nr_inodes,"nr_inodes");
+
+ for (i = 0; i < BCH_REPLICAS_MAX; i++)
+ copy_fs_field(persistent_reserved[i],
+ "persistent_reserved[%i]", i);
+ }
+
+ for (i = 0; i < c->replicas.nr; i++) {
+ struct bch_replicas_entry *e =
+ cpu_replicas_entry(&c->replicas, i);
+
+ if (metadata_only &&
+ (e->data_type == BCH_DATA_user ||
+ e->data_type == BCH_DATA_cached))
+ continue;
+
+ printbuf_reset(&buf);
+ bch2_replicas_entry_to_text(&buf, e);
+
+ copy_fs_field(replicas[i], "%s", buf.buf);
+ }
+ }
+
+#undef copy_fs_field
+#undef copy_dev_field
+#undef copy_stripe_field
+#undef copy_field
+fsck_err:
+ if (ca)
+ percpu_ref_put(&ca->ref);
+ if (ret)
+ bch_err_fn(c, ret);
+
+ percpu_up_write(&c->mark_lock);
+ printbuf_exit(&buf);
+ return ret;
+}
+
+static int bch2_gc_start(struct bch_fs *c)
+{
+ struct bch_dev *ca = NULL;
+ unsigned i;
+
+ BUG_ON(c->usage_gc);
+
+ c->usage_gc = __alloc_percpu_gfp(fs_usage_u64s(c) * sizeof(u64),
+ sizeof(u64), GFP_KERNEL);
+ if (!c->usage_gc) {
+ bch_err(c, "error allocating c->usage_gc");
+ return -BCH_ERR_ENOMEM_gc_start;
+ }
+
+ for_each_member_device(ca, c, i) {
+ BUG_ON(ca->usage_gc);
+
+ ca->usage_gc = alloc_percpu(struct bch_dev_usage);
+ if (!ca->usage_gc) {
+ bch_err(c, "error allocating ca->usage_gc");
+ percpu_ref_put(&ca->ref);
+ return -BCH_ERR_ENOMEM_gc_start;
+ }
+
+ this_cpu_write(ca->usage_gc->d[BCH_DATA_free].buckets,
+ ca->mi.nbuckets - ca->mi.first_bucket);
+ }
+
+ return 0;
+}
+
+static int bch2_gc_reset(struct bch_fs *c)
+{
+ struct bch_dev *ca;
+ unsigned i;
+
+ for_each_member_device(ca, c, i) {
+ free_percpu(ca->usage_gc);
+ ca->usage_gc = NULL;
+ }
+
+ free_percpu(c->usage_gc);
+ c->usage_gc = NULL;
+
+ return bch2_gc_start(c);
+}
+
+/* returns true if not equal */
+static inline bool bch2_alloc_v4_cmp(struct bch_alloc_v4 l,
+ struct bch_alloc_v4 r)
+{
+ return l.gen != r.gen ||
+ l.oldest_gen != r.oldest_gen ||
+ l.data_type != r.data_type ||
+ l.dirty_sectors != r.dirty_sectors ||
+ l.cached_sectors != r.cached_sectors ||
+ l.stripe_redundancy != r.stripe_redundancy ||
+ l.stripe != r.stripe;
+}
+
+static int bch2_alloc_write_key(struct btree_trans *trans,
+ struct btree_iter *iter,
+ struct bkey_s_c k,
+ bool metadata_only)
+{
+ struct bch_fs *c = trans->c;
+ struct bch_dev *ca = bch_dev_bkey_exists(c, iter->pos.inode);
+ struct bucket gc, *b;
+ struct bkey_i_alloc_v4 *a;
+ struct bch_alloc_v4 old_convert, new;
+ const struct bch_alloc_v4 *old;
+ enum bch_data_type type;
+ int ret;
+
+ if (bkey_ge(iter->pos, POS(ca->dev_idx, ca->mi.nbuckets)))
+ return 1;
+
+ old = bch2_alloc_to_v4(k, &old_convert);
+ new = *old;
+
+ percpu_down_read(&c->mark_lock);
+ b = gc_bucket(ca, iter->pos.offset);
+
+ /*
+ * b->data_type doesn't yet include need_discard & need_gc_gen states -
+ * fix that here:
+ */
+ type = __alloc_data_type(b->dirty_sectors,
+ b->cached_sectors,
+ b->stripe,
+ *old,
+ b->data_type);
+ if (b->data_type != type) {
+ struct bch_dev_usage *u;
+
+ preempt_disable();
+ u = this_cpu_ptr(ca->usage_gc);
+ u->d[b->data_type].buckets--;
+ b->data_type = type;
+ u->d[b->data_type].buckets++;
+ preempt_enable();
+ }
+
+ gc = *b;
+ percpu_up_read(&c->mark_lock);
+
+ if (metadata_only &&
+ gc.data_type != BCH_DATA_sb &&
+ gc.data_type != BCH_DATA_journal &&
+ gc.data_type != BCH_DATA_btree)
+ return 0;
+
+ if (gen_after(old->gen, gc.gen))
+ return 0;
+
+ if (c->opts.reconstruct_alloc ||
+ fsck_err_on(new.data_type != gc.data_type, c,
+ "bucket %llu:%llu gen %u has wrong data_type"
+ ": got %s, should be %s",
+ iter->pos.inode, iter->pos.offset,
+ gc.gen,
+ bch2_data_types[new.data_type],
+ bch2_data_types[gc.data_type]))
+ new.data_type = gc.data_type;
+
+#define copy_bucket_field(_f) \
+ if (c->opts.reconstruct_alloc || \
+ fsck_err_on(new._f != gc._f, c, \
+ "bucket %llu:%llu gen %u data type %s has wrong " #_f \
+ ": got %u, should be %u", \
+ iter->pos.inode, iter->pos.offset, \
+ gc.gen, \
+ bch2_data_types[gc.data_type], \
+ new._f, gc._f)) \
+ new._f = gc._f; \
+
+ copy_bucket_field(gen);
+ copy_bucket_field(dirty_sectors);
+ copy_bucket_field(cached_sectors);
+ copy_bucket_field(stripe_redundancy);
+ copy_bucket_field(stripe);
+#undef copy_bucket_field
+
+ if (!bch2_alloc_v4_cmp(*old, new))
+ return 0;
+
+ a = bch2_alloc_to_v4_mut(trans, k);
+ ret = PTR_ERR_OR_ZERO(a);
+ if (ret)
+ return ret;
+
+ a->v = new;
+
+ /*
+ * The trigger normally makes sure this is set, but we're not running
+ * triggers:
+ */
+ if (a->v.data_type == BCH_DATA_cached && !a->v.io_time[READ])
+ a->v.io_time[READ] = max_t(u64, 1, atomic64_read(&c->io_clock[READ].now));
+
+ ret = bch2_trans_update(trans, iter, &a->k_i, BTREE_TRIGGER_NORUN);
+fsck_err:
+ return ret;
+}
+
+static int bch2_gc_alloc_done(struct bch_fs *c, bool metadata_only)
+{
+ struct btree_trans *trans = bch2_trans_get(c);
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ struct bch_dev *ca;
+ unsigned i;
+ int ret = 0;
+
+ for_each_member_device(ca, c, i) {
+ ret = for_each_btree_key_commit(trans, iter, BTREE_ID_alloc,
+ POS(ca->dev_idx, ca->mi.first_bucket),
+ BTREE_ITER_SLOTS|BTREE_ITER_PREFETCH, k,
+ NULL, NULL, BTREE_INSERT_LAZY_RW,
+ bch2_alloc_write_key(trans, &iter, k, metadata_only));
+
+ if (ret < 0) {
+ bch_err_fn(c, ret);
+ percpu_ref_put(&ca->ref);
+ break;
+ }
+ }
+
+ bch2_trans_put(trans);
+ return ret < 0 ? ret : 0;
+}
+
+static int bch2_gc_alloc_start(struct bch_fs *c, bool metadata_only)
+{
+ struct bch_dev *ca;
+ struct btree_trans *trans = bch2_trans_get(c);
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ struct bucket *g;
+ struct bch_alloc_v4 a_convert;
+ const struct bch_alloc_v4 *a;
+ unsigned i;
+ int ret;
+
+ for_each_member_device(ca, c, i) {
+ struct bucket_array *buckets = kvpmalloc(sizeof(struct bucket_array) +
+ ca->mi.nbuckets * sizeof(struct bucket),
+ GFP_KERNEL|__GFP_ZERO);
+ if (!buckets) {
+ percpu_ref_put(&ca->ref);
+ bch_err(c, "error allocating ca->buckets[gc]");
+ ret = -BCH_ERR_ENOMEM_gc_alloc_start;
+ goto err;
+ }
+
+ buckets->first_bucket = ca->mi.first_bucket;
+ buckets->nbuckets = ca->mi.nbuckets;
+ rcu_assign_pointer(ca->buckets_gc, buckets);
+ }
+
+ for_each_btree_key(trans, iter, BTREE_ID_alloc, POS_MIN,
+ BTREE_ITER_PREFETCH, k, ret) {
+ ca = bch_dev_bkey_exists(c, k.k->p.inode);
+ g = gc_bucket(ca, k.k->p.offset);
+
+ a = bch2_alloc_to_v4(k, &a_convert);
+
+ g->gen_valid = 1;
+ g->gen = a->gen;
+
+ if (metadata_only &&
+ (a->data_type == BCH_DATA_user ||
+ a->data_type == BCH_DATA_cached ||
+ a->data_type == BCH_DATA_parity)) {
+ g->data_type = a->data_type;
+ g->dirty_sectors = a->dirty_sectors;
+ g->cached_sectors = a->cached_sectors;
+ g->stripe = a->stripe;
+ g->stripe_redundancy = a->stripe_redundancy;
+ }
+ }
+ bch2_trans_iter_exit(trans, &iter);
+err:
+ bch2_trans_put(trans);
+ if (ret)
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+static void bch2_gc_alloc_reset(struct bch_fs *c, bool metadata_only)
+{
+ struct bch_dev *ca;
+ unsigned i;
+
+ for_each_member_device(ca, c, i) {
+ struct bucket_array *buckets = gc_bucket_array(ca);
+ struct bucket *g;
+
+ for_each_bucket(g, buckets) {
+ if (metadata_only &&
+ (g->data_type == BCH_DATA_user ||
+ g->data_type == BCH_DATA_cached ||
+ g->data_type == BCH_DATA_parity))
+ continue;
+ g->data_type = 0;
+ g->dirty_sectors = 0;
+ g->cached_sectors = 0;
+ }
+ }
+}
+
+static int bch2_gc_write_reflink_key(struct btree_trans *trans,
+ struct btree_iter *iter,
+ struct bkey_s_c k,
+ size_t *idx)
+{
+ struct bch_fs *c = trans->c;
+ const __le64 *refcount = bkey_refcount_c(k);
+ struct printbuf buf = PRINTBUF;
+ struct reflink_gc *r;
+ int ret = 0;
+
+ if (!refcount)
+ return 0;
+
+ while ((r = genradix_ptr(&c->reflink_gc_table, *idx)) &&
+ r->offset < k.k->p.offset)
+ ++*idx;
+
+ if (!r ||
+ r->offset != k.k->p.offset ||
+ r->size != k.k->size) {
+ bch_err(c, "unexpected inconsistency walking reflink table at gc finish");
+ return -EINVAL;
+ }
+
+ if (fsck_err_on(r->refcount != le64_to_cpu(*refcount), c,
+ "reflink key has wrong refcount:\n"
+ " %s\n"
+ " should be %u",
+ (bch2_bkey_val_to_text(&buf, c, k), buf.buf),
+ r->refcount)) {
+ struct bkey_i *new = bch2_bkey_make_mut(trans, iter, &k, 0);
+
+ ret = PTR_ERR_OR_ZERO(new);
+ if (ret)
+ return ret;
+
+ if (!r->refcount)
+ new->k.type = KEY_TYPE_deleted;
+ else
+ *bkey_refcount(new) = cpu_to_le64(r->refcount);
+ }
+fsck_err:
+ printbuf_exit(&buf);
+ return ret;
+}
+
+static int bch2_gc_reflink_done(struct bch_fs *c, bool metadata_only)
+{
+ struct btree_trans *trans;
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ size_t idx = 0;
+ int ret = 0;
+
+ if (metadata_only)
+ return 0;
+
+ trans = bch2_trans_get(c);
+
+ ret = for_each_btree_key_commit(trans, iter,
+ BTREE_ID_reflink, POS_MIN,
+ BTREE_ITER_PREFETCH, k,
+ NULL, NULL, BTREE_INSERT_NOFAIL,
+ bch2_gc_write_reflink_key(trans, &iter, k, &idx));
+
+ c->reflink_gc_nr = 0;
+ bch2_trans_put(trans);
+ return ret;
+}
+
+static int bch2_gc_reflink_start(struct bch_fs *c,
+ bool metadata_only)
+{
+ struct btree_trans *trans;
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ struct reflink_gc *r;
+ int ret = 0;
+
+ if (metadata_only)
+ return 0;
+
+ trans = bch2_trans_get(c);
+ c->reflink_gc_nr = 0;
+
+ for_each_btree_key(trans, iter, BTREE_ID_reflink, POS_MIN,
+ BTREE_ITER_PREFETCH, k, ret) {
+ const __le64 *refcount = bkey_refcount_c(k);
+
+ if (!refcount)
+ continue;
+
+ r = genradix_ptr_alloc(&c->reflink_gc_table, c->reflink_gc_nr++,
+ GFP_KERNEL);
+ if (!r) {
+ ret = -BCH_ERR_ENOMEM_gc_reflink_start;
+ break;
+ }
+
+ r->offset = k.k->p.offset;
+ r->size = k.k->size;
+ r->refcount = 0;
+ }
+ bch2_trans_iter_exit(trans, &iter);
+
+ bch2_trans_put(trans);
+ return ret;
+}
+
+static void bch2_gc_reflink_reset(struct bch_fs *c, bool metadata_only)
+{
+ struct genradix_iter iter;
+ struct reflink_gc *r;
+
+ genradix_for_each(&c->reflink_gc_table, iter, r)
+ r->refcount = 0;
+}
+
+static int bch2_gc_write_stripes_key(struct btree_trans *trans,
+ struct btree_iter *iter,
+ struct bkey_s_c k)
+{
+ struct bch_fs *c = trans->c;
+ struct printbuf buf = PRINTBUF;
+ const struct bch_stripe *s;
+ struct gc_stripe *m;
+ bool bad = false;
+ unsigned i;
+ int ret = 0;
+
+ if (k.k->type != KEY_TYPE_stripe)
+ return 0;
+
+ s = bkey_s_c_to_stripe(k).v;
+ m = genradix_ptr(&c->gc_stripes, k.k->p.offset);
+
+ for (i = 0; i < s->nr_blocks; i++) {
+ u32 old = stripe_blockcount_get(s, i);
+ u32 new = (m ? m->block_sectors[i] : 0);
+
+ if (old != new) {
+ prt_printf(&buf, "stripe block %u has wrong sector count: got %u, should be %u\n",
+ i, old, new);
+ bad = true;
+ }
+ }
+
+ if (bad)
+ bch2_bkey_val_to_text(&buf, c, k);
+
+ if (fsck_err_on(bad, c, "%s", buf.buf)) {
+ struct bkey_i_stripe *new;
+
+ new = bch2_trans_kmalloc(trans, bkey_bytes(k.k));
+ ret = PTR_ERR_OR_ZERO(new);
+ if (ret)
+ return ret;
+
+ bkey_reassemble(&new->k_i, k);
+
+ for (i = 0; i < new->v.nr_blocks; i++)
+ stripe_blockcount_set(&new->v, i, m ? m->block_sectors[i] : 0);
+
+ ret = bch2_trans_update(trans, iter, &new->k_i, 0);
+ }
+fsck_err:
+ printbuf_exit(&buf);
+ return ret;
+}
+
+static int bch2_gc_stripes_done(struct bch_fs *c, bool metadata_only)
+{
+ struct btree_trans *trans;
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ int ret = 0;
+
+ if (metadata_only)
+ return 0;
+
+ trans = bch2_trans_get(c);
+
+ ret = for_each_btree_key_commit(trans, iter,
+ BTREE_ID_stripes, POS_MIN,
+ BTREE_ITER_PREFETCH, k,
+ NULL, NULL, BTREE_INSERT_NOFAIL,
+ bch2_gc_write_stripes_key(trans, &iter, k));
+
+ bch2_trans_put(trans);
+ return ret;
+}
+
+static void bch2_gc_stripes_reset(struct bch_fs *c, bool metadata_only)
+{
+ genradix_free(&c->gc_stripes);
+}
+
+/**
+ * bch2_gc - walk _all_ references to buckets, and recompute them:
+ *
+ * @c: filesystem object
+ * @initial: are we in recovery?
+ * @metadata_only: are we just checking metadata references, or everything?
+ *
+ * Returns: 0 on success, or standard errcode on failure
+ *
+ * Order matters here:
+ * - Concurrent GC relies on the fact that we have a total ordering for
+ * everything that GC walks - see gc_will_visit_node(),
+ * gc_will_visit_root()
+ *
+ * - also, references move around in the course of index updates and
+ * various other crap: everything needs to agree on the ordering
+ * references are allowed to move around in - e.g., we're allowed to
+ * start with a reference owned by an open_bucket (the allocator) and
+ * move it to the btree, but not the reverse.
+ *
+ * This is necessary to ensure that gc doesn't miss references that
+ * move around - if references move backwards in the ordering GC
+ * uses, GC could skip past them
+ */
+int bch2_gc(struct bch_fs *c, bool initial, bool metadata_only)
+{
+ unsigned iter = 0;
+ int ret;
+
+ lockdep_assert_held(&c->state_lock);
+
+ down_write(&c->gc_lock);
+
+ bch2_btree_interior_updates_flush(c);
+
+ ret = bch2_gc_start(c) ?:
+ bch2_gc_alloc_start(c, metadata_only) ?:
+ bch2_gc_reflink_start(c, metadata_only);
+ if (ret)
+ goto out;
+again:
+ gc_pos_set(c, gc_phase(GC_PHASE_START));
+
+ bch2_mark_superblocks(c);
+
+ ret = bch2_gc_btrees(c, initial, metadata_only);
+
+ if (ret)
+ goto out;
+
+#if 0
+ bch2_mark_pending_btree_node_frees(c);
+#endif
+ c->gc_count++;
+
+ if (test_bit(BCH_FS_NEED_ANOTHER_GC, &c->flags) ||
+ (!iter && bch2_test_restart_gc)) {
+ if (iter++ > 2) {
+ bch_info(c, "Unable to fix bucket gens, looping");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /*
+ * XXX: make sure gens we fixed got saved
+ */
+ bch_info(c, "Second GC pass needed, restarting:");
+ clear_bit(BCH_FS_NEED_ANOTHER_GC, &c->flags);
+ __gc_pos_set(c, gc_phase(GC_PHASE_NOT_RUNNING));
+
+ bch2_gc_stripes_reset(c, metadata_only);
+ bch2_gc_alloc_reset(c, metadata_only);
+ bch2_gc_reflink_reset(c, metadata_only);
+ ret = bch2_gc_reset(c);
+ if (ret)
+ goto out;
+
+ /* flush fsck errors, reset counters */
+ bch2_flush_fsck_errs(c);
+ goto again;
+ }
+out:
+ if (!ret) {
+ bch2_journal_block(&c->journal);
+
+ ret = bch2_gc_stripes_done(c, metadata_only) ?:
+ bch2_gc_reflink_done(c, metadata_only) ?:
+ bch2_gc_alloc_done(c, metadata_only) ?:
+ bch2_gc_done(c, initial, metadata_only);
+
+ bch2_journal_unblock(&c->journal);
+ }
+
+ percpu_down_write(&c->mark_lock);
+ /* Indicates that gc is no longer in progress: */
+ __gc_pos_set(c, gc_phase(GC_PHASE_NOT_RUNNING));
+
+ bch2_gc_free(c);
+ percpu_up_write(&c->mark_lock);
+
+ up_write(&c->gc_lock);
+
+ /*
+ * At startup, allocations can happen directly instead of via the
+ * allocator thread - issue wakeup in case they blocked on gc_lock:
+ */
+ closure_wake_up(&c->freelist_wait);
+
+ if (ret)
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+static int gc_btree_gens_key(struct btree_trans *trans,
+ struct btree_iter *iter,
+ struct bkey_s_c k)
+{
+ struct bch_fs *c = trans->c;
+ struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
+ const struct bch_extent_ptr *ptr;
+ struct bkey_i *u;
+ int ret;
+
+ percpu_down_read(&c->mark_lock);
+ bkey_for_each_ptr(ptrs, ptr) {
+ struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
+
+ if (ptr_stale(ca, ptr) > 16) {
+ percpu_up_read(&c->mark_lock);
+ goto update;
+ }
+ }
+
+ bkey_for_each_ptr(ptrs, ptr) {
+ struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
+ u8 *gen = &ca->oldest_gen[PTR_BUCKET_NR(ca, ptr)];
+
+ if (gen_after(*gen, ptr->gen))
+ *gen = ptr->gen;
+ }
+ percpu_up_read(&c->mark_lock);
+ return 0;
+update:
+ u = bch2_bkey_make_mut(trans, iter, &k, 0);
+ ret = PTR_ERR_OR_ZERO(u);
+ if (ret)
+ return ret;
+
+ bch2_extent_normalize(c, bkey_i_to_s(u));
+ return 0;
+}
+
+static int bch2_alloc_write_oldest_gen(struct btree_trans *trans, struct btree_iter *iter,
+ struct bkey_s_c k)
+{
+ struct bch_dev *ca = bch_dev_bkey_exists(trans->c, iter->pos.inode);
+ struct bch_alloc_v4 a_convert;
+ const struct bch_alloc_v4 *a = bch2_alloc_to_v4(k, &a_convert);
+ struct bkey_i_alloc_v4 *a_mut;
+ int ret;
+
+ if (a->oldest_gen == ca->oldest_gen[iter->pos.offset])
+ return 0;
+
+ a_mut = bch2_alloc_to_v4_mut(trans, k);
+ ret = PTR_ERR_OR_ZERO(a_mut);
+ if (ret)
+ return ret;
+
+ a_mut->v.oldest_gen = ca->oldest_gen[iter->pos.offset];
+ a_mut->v.data_type = alloc_data_type(a_mut->v, a_mut->v.data_type);
+
+ return bch2_trans_update(trans, iter, &a_mut->k_i, 0);
+}
+
+int bch2_gc_gens(struct bch_fs *c)
+{
+ struct btree_trans *trans;
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ struct bch_dev *ca;
+ u64 b, start_time = local_clock();
+ unsigned i;
+ int ret;
+
+ /*
+ * Ideally we would be using state_lock and not gc_lock here, but that
+ * introduces a deadlock in the RO path - we currently take the state
+ * lock at the start of going RO, thus the gc thread may get stuck:
+ */
+ if (!mutex_trylock(&c->gc_gens_lock))
+ return 0;
+
+ trace_and_count(c, gc_gens_start, c);
+ down_read(&c->gc_lock);
+ trans = bch2_trans_get(c);
+
+ for_each_member_device(ca, c, i) {
+ struct bucket_gens *gens;
+
+ BUG_ON(ca->oldest_gen);
+
+ ca->oldest_gen = kvmalloc(ca->mi.nbuckets, GFP_KERNEL);
+ if (!ca->oldest_gen) {
+ percpu_ref_put(&ca->ref);
+ ret = -BCH_ERR_ENOMEM_gc_gens;
+ goto err;
+ }
+
+ gens = bucket_gens(ca);
+
+ for (b = gens->first_bucket;
+ b < gens->nbuckets; b++)
+ ca->oldest_gen[b] = gens->b[b];
+ }
+
+ for (i = 0; i < BTREE_ID_NR; i++)
+ if (btree_type_has_ptrs(i)) {
+ c->gc_gens_btree = i;
+ c->gc_gens_pos = POS_MIN;
+
+ ret = for_each_btree_key_commit(trans, iter, i,
+ POS_MIN,
+ BTREE_ITER_PREFETCH|BTREE_ITER_ALL_SNAPSHOTS,
+ k,
+ NULL, NULL,
+ BTREE_INSERT_NOFAIL,
+ gc_btree_gens_key(trans, &iter, k));
+ if (ret && !bch2_err_matches(ret, EROFS))
+ bch_err_fn(c, ret);
+ if (ret)
+ goto err;
+ }
+
+ ret = for_each_btree_key_commit(trans, iter, BTREE_ID_alloc,
+ POS_MIN,
+ BTREE_ITER_PREFETCH,
+ k,
+ NULL, NULL,
+ BTREE_INSERT_NOFAIL,
+ bch2_alloc_write_oldest_gen(trans, &iter, k));
+ if (ret && !bch2_err_matches(ret, EROFS))
+ bch_err_fn(c, ret);
+ if (ret)
+ goto err;
+
+ c->gc_gens_btree = 0;
+ c->gc_gens_pos = POS_MIN;
+
+ c->gc_count++;
+
+ bch2_time_stats_update(&c->times[BCH_TIME_btree_gc], start_time);
+ trace_and_count(c, gc_gens_end, c);
+err:
+ for_each_member_device(ca, c, i) {
+ kvfree(ca->oldest_gen);
+ ca->oldest_gen = NULL;
+ }
+
+ bch2_trans_put(trans);
+ up_read(&c->gc_lock);
+ mutex_unlock(&c->gc_gens_lock);
+ return ret;
+}
+
+static int bch2_gc_thread(void *arg)
+{
+ struct bch_fs *c = arg;
+ struct io_clock *clock = &c->io_clock[WRITE];
+ unsigned long last = atomic64_read(&clock->now);
+ unsigned last_kick = atomic_read(&c->kick_gc);
+ int ret;
+
+ set_freezable();
+
+ while (1) {
+ while (1) {
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ if (kthread_should_stop()) {
+ __set_current_state(TASK_RUNNING);
+ return 0;
+ }
+
+ if (atomic_read(&c->kick_gc) != last_kick)
+ break;
+
+ if (c->btree_gc_periodic) {
+ unsigned long next = last + c->capacity / 16;
+
+ if (atomic64_read(&clock->now) >= next)
+ break;
+
+ bch2_io_clock_schedule_timeout(clock, next);
+ } else {
+ schedule();
+ }
+
+ try_to_freeze();
+ }
+ __set_current_state(TASK_RUNNING);
+
+ last = atomic64_read(&clock->now);
+ last_kick = atomic_read(&c->kick_gc);
+
+ /*
+ * Full gc is currently incompatible with btree key cache:
+ */
+#if 0
+ ret = bch2_gc(c, false, false);
+#else
+ ret = bch2_gc_gens(c);
+#endif
+ if (ret < 0)
+ bch_err_fn(c, ret);
+
+ debug_check_no_locks_held();
+ }
+
+ return 0;
+}
+
+void bch2_gc_thread_stop(struct bch_fs *c)
+{
+ struct task_struct *p;
+
+ p = c->gc_thread;
+ c->gc_thread = NULL;
+
+ if (p) {
+ kthread_stop(p);
+ put_task_struct(p);
+ }
+}
+
+int bch2_gc_thread_start(struct bch_fs *c)
+{
+ struct task_struct *p;
+
+ if (c->gc_thread)
+ return 0;
+
+ p = kthread_create(bch2_gc_thread, c, "bch-gc/%s", c->name);
+ if (IS_ERR(p)) {
+ bch_err_fn(c, PTR_ERR(p));
+ return PTR_ERR(p);
+ }
+
+ get_task_struct(p);
+ c->gc_thread = p;
+ wake_up_process(p);
+ return 0;
+}