From 01a69402cf9d38ff180345d55c2ee51c7e89fbc7 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 18 May 2024 20:50:03 +0200 Subject: Adding upstream version 6.8.9. Signed-off-by: Daniel Baumann --- fs/bcachefs/btree_locking.c | 149 +++++++++++++++++++++++++++++++++----------- 1 file changed, 113 insertions(+), 36 deletions(-) (limited to 'fs/bcachefs/btree_locking.c') diff --git a/fs/bcachefs/btree_locking.c b/fs/bcachefs/btree_locking.c index 3d48834d09..6843974423 100644 --- a/fs/bcachefs/btree_locking.c +++ b/fs/bcachefs/btree_locking.c @@ -32,13 +32,14 @@ struct six_lock_count bch2_btree_node_lock_counts(struct btree_trans *trans, { struct btree_path *path; struct six_lock_count ret; + unsigned i; memset(&ret, 0, sizeof(ret)); if (IS_ERR_OR_NULL(b)) return ret; - trans_for_each_path(trans, path) + trans_for_each_path(trans, path, i) if (path != skip && &path->l[level].b->c == b) { int t = btree_node_locked_type(path, level); @@ -85,8 +86,14 @@ static noinline void print_cycle(struct printbuf *out, struct lock_graph *g) prt_printf(out, "Found lock cycle (%u entries):", g->nr); prt_newline(out); - for (i = g->g; i < g->g + g->nr; i++) + for (i = g->g; i < g->g + g->nr; i++) { + struct task_struct *task = READ_ONCE(i->trans->locking_wait.task); + if (!task) + continue; + bch2_btree_trans_to_text(out, i->trans); + bch2_prt_task_backtrace(out, task, i == g->g ? 5 : 1, GFP_NOWAIT); + } } static noinline void print_chain(struct printbuf *out, struct lock_graph *g) @@ -94,9 +101,10 @@ static noinline void print_chain(struct printbuf *out, struct lock_graph *g) struct trans_waiting_for_lock *i; for (i = g->g; i != g->g + g->nr; i++) { + struct task_struct *task = i->trans->locking_wait.task; if (i != g->g) prt_str(out, "<- "); - prt_printf(out, "%u ", i->trans->locking_wait.task->pid); + prt_printf(out, "%u ", task ?task->pid : 0); } prt_newline(out); } @@ -142,10 +150,27 @@ static bool lock_graph_remove_non_waiters(struct lock_graph *g) return false; } +static void trace_would_deadlock(struct lock_graph *g, struct btree_trans *trans) +{ + struct bch_fs *c = trans->c; + + count_event(c, trans_restart_would_deadlock); + + if (trace_trans_restart_would_deadlock_enabled()) { + struct printbuf buf = PRINTBUF; + + buf.atomic++; + print_cycle(&buf, g); + + trace_trans_restart_would_deadlock(trans, buf.buf); + printbuf_exit(&buf); + } +} + static int abort_lock(struct lock_graph *g, struct trans_waiting_for_lock *i) { if (i == g->g) { - trace_and_count(i->trans->c, trans_restart_would_deadlock, i->trans, _RET_IP_); + trace_would_deadlock(g, i->trans); return btree_trans_restart(i->trans, BCH_ERR_transaction_restart_would_deadlock); } else { i->trans->lock_must_abort = true; @@ -202,7 +227,7 @@ static noinline int break_cycle(struct lock_graph *g, struct printbuf *cycle) prt_printf(&buf, "backtrace:"); prt_newline(&buf); printbuf_indent_add(&buf, 2); - bch2_prt_task_backtrace(&buf, trans->locking_wait.task); + bch2_prt_task_backtrace(&buf, trans->locking_wait.task, 2, GFP_NOWAIT); printbuf_indent_sub(&buf, 2); prt_newline(&buf); } @@ -262,27 +287,40 @@ int bch2_check_for_deadlock(struct btree_trans *trans, struct printbuf *cycle) struct lock_graph g; struct trans_waiting_for_lock *top; struct btree_bkey_cached_common *b; - struct btree_path *path; - unsigned path_idx; - int ret; + btree_path_idx_t path_idx; + int ret = 0; + + g.nr = 0; if (trans->lock_must_abort) { if (cycle) return -1; - trace_and_count(trans->c, trans_restart_would_deadlock, trans, _RET_IP_); + trace_would_deadlock(&g, trans); return btree_trans_restart(trans, BCH_ERR_transaction_restart_would_deadlock); } - g.nr = 0; lock_graph_down(&g, trans); + + /* trans->paths is rcu protected vs. freeing */ + rcu_read_lock(); + if (cycle) + cycle->atomic++; next: if (!g.nr) - return 0; + goto out; top = &g.g[g.nr - 1]; - trans_for_each_path_safe_from(top->trans, path, path_idx, top->path_idx) { + struct btree_path *paths = rcu_dereference(top->trans->paths); + if (!paths) + goto up; + + unsigned long *paths_allocated = trans_paths_allocated(paths); + + trans_for_each_path_idx_from(paths_allocated, *trans_paths_nr(paths), + path_idx, top->path_idx) { + struct btree_path *path = paths + path_idx; if (!path->nodes_locked) continue; @@ -348,18 +386,23 @@ next: ret = lock_graph_descend(&g, trans, cycle); if (ret) - return ret; + goto out; goto next; } raw_spin_unlock(&b->lock.wait_lock); } } - +up: if (g.nr > 1 && cycle) print_chain(cycle, &g); lock_graph_up(&g); goto next; +out: + if (cycle) + --cycle->atomic; + rcu_read_unlock(); + return ret; } int bch2_six_check_for_deadlock(struct six_lock *lock, void *p) @@ -398,7 +441,7 @@ void bch2_btree_node_lock_write_nofail(struct btree_trans *trans, struct btree_bkey_cached_common *b) { struct btree_path *linked; - unsigned i; + unsigned i, iter; int ret; /* @@ -412,7 +455,7 @@ void bch2_btree_node_lock_write_nofail(struct btree_trans *trans, * already taken are no longer needed: */ - trans_for_each_path(trans, linked) { + trans_for_each_path(trans, linked, iter) { if (!linked->nodes_locked) continue; @@ -588,8 +631,7 @@ int bch2_btree_path_relock_intent(struct btree_trans *trans, } __flatten -bool bch2_btree_path_relock_norestart(struct btree_trans *trans, - struct btree_path *path, unsigned long trace_ip) +bool bch2_btree_path_relock_norestart(struct btree_trans *trans, struct btree_path *path) { struct get_locks_fail f; @@ -599,7 +641,7 @@ bool bch2_btree_path_relock_norestart(struct btree_trans *trans, int __bch2_btree_path_relock(struct btree_trans *trans, struct btree_path *path, unsigned long trace_ip) { - if (!bch2_btree_path_relock_norestart(trans, path, trace_ip)) { + if (!bch2_btree_path_relock_norestart(trans, path)) { trace_and_count(trans->c, trans_restart_relock_path, trans, trace_ip, path); return btree_trans_restart(trans, BCH_ERR_transaction_restart_relock_path); } @@ -624,8 +666,6 @@ bool __bch2_btree_path_upgrade(struct btree_trans *trans, unsigned new_locks_want, struct get_locks_fail *f) { - struct btree_path *linked; - if (bch2_btree_path_upgrade_noupgrade_sibs(trans, path, new_locks_want, f)) return true; @@ -648,8 +688,11 @@ bool __bch2_btree_path_upgrade(struct btree_trans *trans, * before interior nodes - now that's handled by * bch2_btree_path_traverse_all(). */ - if (!path->cached && !trans->in_traverse_all) - trans_for_each_path(trans, linked) + if (!path->cached && !trans->in_traverse_all) { + struct btree_path *linked; + unsigned i; + + trans_for_each_path(trans, linked, i) if (linked != path && linked->cached == path->cached && linked->btree_id == path->btree_id && @@ -657,6 +700,7 @@ bool __bch2_btree_path_upgrade(struct btree_trans *trans, linked->locks_want = new_locks_want; btree_path_get_locks(trans, linked, true, NULL); } + } return false; } @@ -665,7 +709,7 @@ void __bch2_btree_path_downgrade(struct btree_trans *trans, struct btree_path *path, unsigned new_locks_want) { - unsigned l; + unsigned l, old_locks_want = path->locks_want; if (trans->restarted) return; @@ -689,8 +733,7 @@ void __bch2_btree_path_downgrade(struct btree_trans *trans, bch2_btree_path_verify_locks(path); - path->downgrade_seq++; - trace_path_downgrade(trans, _RET_IP_, path); + trace_path_downgrade(trans, _RET_IP_, path, old_locks_want); } /* Btree transaction locking: */ @@ -698,40 +741,70 @@ void __bch2_btree_path_downgrade(struct btree_trans *trans, void bch2_trans_downgrade(struct btree_trans *trans) { struct btree_path *path; + unsigned i; if (trans->restarted) return; - trans_for_each_path(trans, path) + trans_for_each_path(trans, path, i) bch2_btree_path_downgrade(trans, path); } int bch2_trans_relock(struct btree_trans *trans) { struct btree_path *path; + unsigned i; if (unlikely(trans->restarted)) return -((int) trans->restarted); - trans_for_each_path(trans, path) + trans_for_each_path(trans, path, i) { + struct get_locks_fail f; + if (path->should_be_locked && - !bch2_btree_path_relock_norestart(trans, path, _RET_IP_)) { - trace_and_count(trans->c, trans_restart_relock, trans, _RET_IP_, path); + !btree_path_get_locks(trans, path, false, &f)) { + if (trace_trans_restart_relock_enabled()) { + struct printbuf buf = PRINTBUF; + + bch2_bpos_to_text(&buf, path->pos); + prt_printf(&buf, " l=%u seq=%u node seq=", + f.l, path->l[f.l].lock_seq); + if (IS_ERR_OR_NULL(f.b)) { + prt_str(&buf, bch2_err_str(PTR_ERR(f.b))); + } else { + prt_printf(&buf, "%u", f.b->c.lock.seq); + + struct six_lock_count c = + bch2_btree_node_lock_counts(trans, NULL, &f.b->c, f.l); + prt_printf(&buf, " self locked %u.%u.%u", c.n[0], c.n[1], c.n[2]); + + c = six_lock_counts(&f.b->c.lock); + prt_printf(&buf, " total locked %u.%u.%u", c.n[0], c.n[1], c.n[2]); + } + + trace_trans_restart_relock(trans, _RET_IP_, buf.buf); + printbuf_exit(&buf); + } + + count_event(trans->c, trans_restart_relock); return btree_trans_restart(trans, BCH_ERR_transaction_restart_relock); } + } + return 0; } int bch2_trans_relock_notrace(struct btree_trans *trans) { struct btree_path *path; + unsigned i; if (unlikely(trans->restarted)) return -((int) trans->restarted); - trans_for_each_path(trans, path) + trans_for_each_path(trans, path, i) if (path->should_be_locked && - !bch2_btree_path_relock_norestart(trans, path, _RET_IP_)) { + !bch2_btree_path_relock_norestart(trans, path)) { return btree_trans_restart(trans, BCH_ERR_transaction_restart_relock); } return 0; @@ -740,16 +813,18 @@ int bch2_trans_relock_notrace(struct btree_trans *trans) void bch2_trans_unlock_noassert(struct btree_trans *trans) { struct btree_path *path; + unsigned i; - trans_for_each_path(trans, path) + trans_for_each_path(trans, path, i) __bch2_btree_path_unlock(trans, path); } void bch2_trans_unlock(struct btree_trans *trans) { struct btree_path *path; + unsigned i; - trans_for_each_path(trans, path) + trans_for_each_path(trans, path, i) __bch2_btree_path_unlock(trans, path); } @@ -762,8 +837,9 @@ void bch2_trans_unlock_long(struct btree_trans *trans) bool bch2_trans_locked(struct btree_trans *trans) { struct btree_path *path; + unsigned i; - trans_for_each_path(trans, path) + trans_for_each_path(trans, path, i) if (path->nodes_locked) return true; return false; @@ -809,8 +885,9 @@ void bch2_btree_path_verify_locks(struct btree_path *path) void bch2_trans_verify_locks(struct btree_trans *trans) { struct btree_path *path; + unsigned i; - trans_for_each_path(trans, path) + trans_for_each_path(trans, path, i) bch2_btree_path_verify_locks(path); } -- cgit v1.2.3