--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+
+#include "bcachefs.h"
+#include "alloc_background.h"
+#include "alloc_foreground.h"
+#include "btree_iter.h"
+#include "btree_update.h"
+#include "btree_write_buffer.h"
+#include "buckets.h"
+#include "clock.h"
+#include "compress.h"
+#include "disk_groups.h"
+#include "errcode.h"
+#include "error.h"
+#include "inode.h"
+#include "move.h"
+#include "rebalance.h"
+#include "subvolume.h"
+#include "super-io.h"
+#include "trace.h"
+
+#include <linux/freezer.h>
+#include <linux/kthread.h>
+#include <linux/sched/cputime.h>
+
+#define REBALANCE_WORK_SCAN_OFFSET (U64_MAX - 1)
+
+static const char * const bch2_rebalance_state_strs[] = {
+#define x(t) #t,
+ BCH_REBALANCE_STATES()
+ NULL
+#undef x
+};
+
+static int __bch2_set_rebalance_needs_scan(struct btree_trans *trans, u64 inum)
+{
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ struct bkey_i_cookie *cookie;
+ u64 v;
+ int ret;
+
+ bch2_trans_iter_init(trans, &iter, BTREE_ID_rebalance_work,
+ SPOS(inum, REBALANCE_WORK_SCAN_OFFSET, U32_MAX),
+ BTREE_ITER_INTENT);
+ k = bch2_btree_iter_peek_slot(&iter);
+ ret = bkey_err(k);
+ if (ret)
+ goto err;
+
+ v = k.k->type == KEY_TYPE_cookie
+ ? le64_to_cpu(bkey_s_c_to_cookie(k).v->cookie)
+ : 0;
+
+ cookie = bch2_trans_kmalloc(trans, sizeof(*cookie));
+ ret = PTR_ERR_OR_ZERO(cookie);
+ if (ret)
+ goto err;
+
+ bkey_cookie_init(&cookie->k_i);
+ cookie->k.p = iter.pos;
+ cookie->v.cookie = cpu_to_le64(v + 1);
+
+ ret = bch2_trans_update(trans, &iter, &cookie->k_i, 0);
+err:
+ bch2_trans_iter_exit(trans, &iter);
+ return ret;
+}
+
+int bch2_set_rebalance_needs_scan(struct bch_fs *c, u64 inum)
+{
+ int ret = bch2_trans_do(c, NULL, NULL, BCH_TRANS_COMMIT_no_enospc|BCH_TRANS_COMMIT_lazy_rw,
+ __bch2_set_rebalance_needs_scan(trans, inum));
+ rebalance_wakeup(c);
+ return ret;
+}
+
+int bch2_set_fs_needs_rebalance(struct bch_fs *c)
+{
+ return bch2_set_rebalance_needs_scan(c, 0);
+}
+
+static int bch2_clear_rebalance_needs_scan(struct btree_trans *trans, u64 inum, u64 cookie)
+{
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ u64 v;
+ int ret;
+
+ bch2_trans_iter_init(trans, &iter, BTREE_ID_rebalance_work,
+ SPOS(inum, REBALANCE_WORK_SCAN_OFFSET, U32_MAX),
+ BTREE_ITER_INTENT);
+ k = bch2_btree_iter_peek_slot(&iter);
+ ret = bkey_err(k);
+ if (ret)
+ goto err;
+
+ v = k.k->type == KEY_TYPE_cookie
+ ? le64_to_cpu(bkey_s_c_to_cookie(k).v->cookie)
+ : 0;
+
+ if (v == cookie)
+ ret = bch2_btree_delete_at(trans, &iter, 0);
+err:
+ bch2_trans_iter_exit(trans, &iter);
+ return ret;
+}
+
+static struct bkey_s_c next_rebalance_entry(struct btree_trans *trans,
+ struct btree_iter *work_iter)
+{
+ return !kthread_should_stop()
+ ? bch2_btree_iter_peek(work_iter)
+ : bkey_s_c_null;
+}
+
+static int bch2_bkey_clear_needs_rebalance(struct btree_trans *trans,
+ struct btree_iter *iter,
+ struct bkey_s_c k)
+{
+ struct bkey_i *n = bch2_bkey_make_mut(trans, iter, &k, 0);
+ int ret = PTR_ERR_OR_ZERO(n);
+ if (ret)
+ return ret;
+
+ extent_entry_drop(bkey_i_to_s(n),
+ (void *) bch2_bkey_rebalance_opts(bkey_i_to_s_c(n)));
+ return bch2_trans_commit(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc);
+}
+
+static struct bkey_s_c next_rebalance_extent(struct btree_trans *trans,
+ struct bpos work_pos,
+ struct btree_iter *extent_iter,
+ struct data_update_opts *data_opts)
+{
+ struct bch_fs *c = trans->c;
+ struct bkey_s_c k;
+
+ bch2_trans_iter_exit(trans, extent_iter);
+ bch2_trans_iter_init(trans, extent_iter,
+ work_pos.inode ? BTREE_ID_extents : BTREE_ID_reflink,
+ work_pos,
+ BTREE_ITER_ALL_SNAPSHOTS);
+ k = bch2_btree_iter_peek_slot(extent_iter);
+ if (bkey_err(k))
+ return k;
+
+ const struct bch_extent_rebalance *r = k.k ? bch2_bkey_rebalance_opts(k) : NULL;
+ if (!r) {
+ /* raced due to btree write buffer, nothing to do */
+ return bkey_s_c_null;
+ }
+
+ memset(data_opts, 0, sizeof(*data_opts));
+
+ data_opts->rewrite_ptrs =
+ bch2_bkey_ptrs_need_rebalance(c, k, r->target, r->compression);
+ data_opts->target = r->target;
+
+ if (!data_opts->rewrite_ptrs) {
+ /*
+ * device we would want to write to offline? devices in target
+ * changed?
+ *
+ * We'll now need a full scan before this extent is picked up
+ * again:
+ */
+ int ret = bch2_bkey_clear_needs_rebalance(trans, extent_iter, k);
+ if (ret)
+ return bkey_s_c_err(ret);
+ return bkey_s_c_null;
+ }
+
+ if (trace_rebalance_extent_enabled()) {
+ struct printbuf buf = PRINTBUF;
+
+ prt_str(&buf, "target=");
+ bch2_target_to_text(&buf, c, r->target);
+ prt_str(&buf, " compression=");
+ struct bch_compression_opt opt = __bch2_compression_decode(r->compression);
+ prt_str(&buf, bch2_compression_opts[opt.type]);
+ prt_str(&buf, " ");
+ bch2_bkey_val_to_text(&buf, c, k);
+
+ trace_rebalance_extent(c, buf.buf);
+ printbuf_exit(&buf);
+ }
+
+ return k;
+}
+
+noinline_for_stack
+static int do_rebalance_extent(struct moving_context *ctxt,
+ struct bpos work_pos,
+ struct btree_iter *extent_iter)
+{
+ struct btree_trans *trans = ctxt->trans;
+ struct bch_fs *c = trans->c;
+ struct bch_fs_rebalance *r = &trans->c->rebalance;
+ struct data_update_opts data_opts;
+ struct bch_io_opts io_opts;
+ struct bkey_s_c k;
+ struct bkey_buf sk;
+ int ret;
+
+ ctxt->stats = &r->work_stats;
+ r->state = BCH_REBALANCE_working;
+
+ bch2_bkey_buf_init(&sk);
+
+ ret = bkey_err(k = next_rebalance_extent(trans, work_pos,
+ extent_iter, &data_opts));
+ if (ret || !k.k)
+ goto out;
+
+ ret = bch2_move_get_io_opts_one(trans, &io_opts, k);
+ if (ret)
+ goto out;
+
+ atomic64_add(k.k->size, &ctxt->stats->sectors_seen);
+
+ /*
+ * The iterator gets unlocked by __bch2_read_extent - need to
+ * save a copy of @k elsewhere:
+ */
+ bch2_bkey_buf_reassemble(&sk, c, k);
+ k = bkey_i_to_s_c(sk.k);
+
+ ret = bch2_move_extent(ctxt, NULL, extent_iter, k, io_opts, data_opts);
+ if (ret) {
+ if (bch2_err_matches(ret, ENOMEM)) {
+ /* memory allocation failure, wait for some IO to finish */
+ bch2_move_ctxt_wait_for_io(ctxt);
+ ret = -BCH_ERR_transaction_restart_nested;
+ }
+
+ if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+ goto out;
+
+ /* skip it and continue, XXX signal failure */
+ ret = 0;
+ }
+out:
+ bch2_bkey_buf_exit(&sk, c);
+ return ret;
+}
+
+static bool rebalance_pred(struct bch_fs *c, void *arg,
+ struct bkey_s_c k,
+ struct bch_io_opts *io_opts,
+ struct data_update_opts *data_opts)
+{
+ unsigned target, compression;
+
+ if (k.k->p.inode) {
+ target = io_opts->background_target;
+ compression = io_opts->background_compression ?: io_opts->compression;
+ } else {
+ const struct bch_extent_rebalance *r = bch2_bkey_rebalance_opts(k);
+
+ target = r ? r->target : io_opts->background_target;
+ compression = r ? r->compression :
+ (io_opts->background_compression ?: io_opts->compression);
+ }
+
+ data_opts->rewrite_ptrs = bch2_bkey_ptrs_need_rebalance(c, k, target, compression);
+ data_opts->target = target;
+ return data_opts->rewrite_ptrs != 0;
+}
+
+static int do_rebalance_scan(struct moving_context *ctxt, u64 inum, u64 cookie)
+{
+ struct btree_trans *trans = ctxt->trans;
+ struct bch_fs_rebalance *r = &trans->c->rebalance;
+ int ret;
+
+ bch2_move_stats_init(&r->scan_stats, "rebalance_scan");
+ ctxt->stats = &r->scan_stats;
+
+ if (!inum) {
+ r->scan_start = BBPOS_MIN;
+ r->scan_end = BBPOS_MAX;
+ } else {
+ r->scan_start = BBPOS(BTREE_ID_extents, POS(inum, 0));
+ r->scan_end = BBPOS(BTREE_ID_extents, POS(inum, U64_MAX));
+ }
+
+ r->state = BCH_REBALANCE_scanning;
+
+ ret = __bch2_move_data(ctxt, r->scan_start, r->scan_end, rebalance_pred, NULL) ?:
+ commit_do(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
+ bch2_clear_rebalance_needs_scan(trans, inum, cookie));
+
+ bch2_move_stats_exit(&r->scan_stats, trans->c);
+ return ret;
+}
+
+static void rebalance_wait(struct bch_fs *c)
+{
+ struct bch_fs_rebalance *r = &c->rebalance;
+ struct io_clock *clock = &c->io_clock[WRITE];
+ u64 now = atomic64_read(&clock->now);
+ u64 min_member_capacity = bch2_min_rw_member_capacity(c);
+
+ if (min_member_capacity == U64_MAX)
+ min_member_capacity = 128 * 2048;
+
+ r->wait_iotime_end = now + (min_member_capacity >> 6);
+
+ if (r->state != BCH_REBALANCE_waiting) {
+ r->wait_iotime_start = now;
+ r->wait_wallclock_start = ktime_get_real_ns();
+ r->state = BCH_REBALANCE_waiting;
+ }
+
+ bch2_kthread_io_clock_wait(clock, r->wait_iotime_end, MAX_SCHEDULE_TIMEOUT);
+}
+
+static int do_rebalance(struct moving_context *ctxt)
+{
+ struct btree_trans *trans = ctxt->trans;
+ struct bch_fs *c = trans->c;
+ struct bch_fs_rebalance *r = &c->rebalance;
+ struct btree_iter rebalance_work_iter, extent_iter = { NULL };
+ struct bkey_s_c k;
+ int ret = 0;
+
+ bch2_move_stats_init(&r->work_stats, "rebalance_work");
+ bch2_move_stats_init(&r->scan_stats, "rebalance_scan");
+
+ bch2_trans_iter_init(trans, &rebalance_work_iter,
+ BTREE_ID_rebalance_work, POS_MIN,
+ BTREE_ITER_ALL_SNAPSHOTS);
+
+ while (!bch2_move_ratelimit(ctxt)) {
+ if (!r->enabled) {
+ bch2_moving_ctxt_flush_all(ctxt);
+ kthread_wait_freezable(r->enabled ||
+ kthread_should_stop());
+ }
+
+ if (kthread_should_stop())
+ break;
+
+ bch2_trans_begin(trans);
+
+ ret = bkey_err(k = next_rebalance_entry(trans, &rebalance_work_iter));
+ if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+ continue;
+ if (ret || !k.k)
+ break;
+
+ ret = k.k->type == KEY_TYPE_cookie
+ ? do_rebalance_scan(ctxt, k.k->p.inode,
+ le64_to_cpu(bkey_s_c_to_cookie(k).v->cookie))
+ : do_rebalance_extent(ctxt, k.k->p, &extent_iter);
+
+ if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+ continue;
+ if (ret)
+ break;
+
+ bch2_btree_iter_advance(&rebalance_work_iter);
+ }
+
+ bch2_trans_iter_exit(trans, &extent_iter);
+ bch2_trans_iter_exit(trans, &rebalance_work_iter);
+ bch2_move_stats_exit(&r->scan_stats, c);
+
+ if (!ret &&
+ !kthread_should_stop() &&
+ !atomic64_read(&r->work_stats.sectors_seen) &&
+ !atomic64_read(&r->scan_stats.sectors_seen)) {
+ bch2_trans_unlock_long(trans);
+ rebalance_wait(c);
+ }
+
+ if (!bch2_err_matches(ret, EROFS))
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+static int bch2_rebalance_thread(void *arg)
+{
+ struct bch_fs *c = arg;
+ struct bch_fs_rebalance *r = &c->rebalance;
+ struct moving_context ctxt;
+ int ret;
+
+ set_freezable();
+
+ bch2_moving_ctxt_init(&ctxt, c, NULL, &r->work_stats,
+ writepoint_ptr(&c->rebalance_write_point),
+ true);
+
+ while (!kthread_should_stop() &&
+ !(ret = do_rebalance(&ctxt)))
+ ;
+
+ bch2_moving_ctxt_exit(&ctxt);
+
+ return 0;
+}
+
+void bch2_rebalance_status_to_text(struct printbuf *out, struct bch_fs *c)
+{
+ struct bch_fs_rebalance *r = &c->rebalance;
+
+ prt_str(out, bch2_rebalance_state_strs[r->state]);
+ prt_newline(out);
+ printbuf_indent_add(out, 2);
+
+ switch (r->state) {
+ case BCH_REBALANCE_waiting: {
+ u64 now = atomic64_read(&c->io_clock[WRITE].now);
+
+ prt_str(out, "io wait duration: ");
+ bch2_prt_human_readable_s64(out, r->wait_iotime_end - r->wait_iotime_start);
+ prt_newline(out);
+
+ prt_str(out, "io wait remaining: ");
+ bch2_prt_human_readable_s64(out, r->wait_iotime_end - now);
+ prt_newline(out);
+
+ prt_str(out, "duration waited: ");
+ bch2_pr_time_units(out, ktime_get_real_ns() - r->wait_wallclock_start);
+ prt_newline(out);
+ break;
+ }
+ case BCH_REBALANCE_working:
+ bch2_move_stats_to_text(out, &r->work_stats);
+ break;
+ case BCH_REBALANCE_scanning:
+ bch2_move_stats_to_text(out, &r->scan_stats);
+ break;
+ }
+ prt_newline(out);
+ printbuf_indent_sub(out, 2);
+}
+
+void bch2_rebalance_stop(struct bch_fs *c)
+{
+ struct task_struct *p;
+
+ c->rebalance.pd.rate.rate = UINT_MAX;
+ bch2_ratelimit_reset(&c->rebalance.pd.rate);
+
+ p = rcu_dereference_protected(c->rebalance.thread, 1);
+ c->rebalance.thread = NULL;
+
+ if (p) {
+ /* for sychronizing with rebalance_wakeup() */
+ synchronize_rcu();
+
+ kthread_stop(p);
+ put_task_struct(p);
+ }
+}
+
+int bch2_rebalance_start(struct bch_fs *c)
+{
+ struct task_struct *p;
+ int ret;
+
+ if (c->rebalance.thread)
+ return 0;
+
+ if (c->opts.nochanges)
+ return 0;
+
+ p = kthread_create(bch2_rebalance_thread, c, "bch-rebalance/%s", c->name);
+ ret = PTR_ERR_OR_ZERO(p);
+ bch_err_msg(c, ret, "creating rebalance thread");
+ if (ret)
+ return ret;
+
+ get_task_struct(p);
+ rcu_assign_pointer(c->rebalance.thread, p);
+ wake_up_process(p);
+ return 0;
+}
+
+void bch2_fs_rebalance_init(struct bch_fs *c)
+{
+ bch2_pd_controller_init(&c->rebalance.pd);
+}
projects / bcachefs-tools-debian / blobdiff