diff options
| -rw-r--r-- | fs/bcachefs/btree_iter.c | 2 | ||||
| -rw-r--r-- | fs/bcachefs/btree_locking.c | 44 | ||||
| -rw-r--r-- | fs/bcachefs/btree_locking.h | 1 | ||||
| -rw-r--r-- | fs/bcachefs/debug.c | 43 |
4 files changed, 69 insertions, 21 deletions
diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c index 5773b00e69ac..ece80d7914b2 100644 --- a/fs/bcachefs/btree_iter.c +++ b/fs/bcachefs/btree_iter.c @@ -2992,7 +2992,6 @@ bch2_btree_path_node_to_text(struct printbuf *out, c.n[0], c.n[1], c.n[2], pid); } -#ifdef CONFIG_BCACHEFS_DEBUG_TRANSACTIONS void bch2_btree_trans_to_text(struct printbuf *out, struct btree_trans *trans) { struct btree_path *path; @@ -3041,7 +3040,6 @@ void bch2_btree_trans_to_text(struct printbuf *out, struct btree_trans *trans) prt_printf(out, "\n"); } } -#endif void bch2_fs_btree_iter_exit(struct bch_fs *c) { diff --git a/fs/bcachefs/btree_locking.c b/fs/bcachefs/btree_locking.c index 869f4163a3c6..e270579d3622 100644 --- a/fs/bcachefs/btree_locking.c +++ b/fs/bcachefs/btree_locking.c @@ -76,6 +76,17 @@ static void lock_graph_pop(struct lock_graph *g) closure_put(&g->g[--g->nr].trans->ref); } +static noinline void print_cycle(struct printbuf *out, struct lock_graph *g) +{ + struct trans_waiting_for_lock *i; + + prt_printf(out, "Found lock cycle (%u entries):", g->nr); + prt_newline(out); + + for (i = g->g; i < g->g + g->nr; i++) + bch2_btree_trans_to_text(out, i->trans); +} + static int abort_lock(struct lock_graph *g, struct trans_waiting_for_lock *i) { int ret; @@ -122,7 +133,8 @@ static noinline int break_cycle(struct lock_graph *g) BUG(); } -static int lock_graph_descend(struct lock_graph *g, struct btree_trans *trans) +static int lock_graph_descend(struct lock_graph *g, struct btree_trans *trans, + struct printbuf *cycle) { struct btree_trans *orig_trans = g->g->trans; struct trans_waiting_for_lock *i; @@ -136,7 +148,14 @@ static int lock_graph_descend(struct lock_graph *g, struct btree_trans *trans) } if (i->trans == trans) { - ret = break_cycle(g); + if (cycle) { + /* Only checking: */ + print_cycle(cycle, g); + ret = -1; + } else { + ret = break_cycle(g); + } + if (ret) goto deadlock; /* @@ -170,19 +189,6 @@ deadlock: return ret; } -#if 0 -static void print_cycle(struct printbuf *out, struct lock_graph *g) -{ - struct trans_waiting_for_lock *i; - - prt_str(out, "Found lock cycle:"); - prt_newline(out); - - for (i = g->g; i < g->g + g->nr; i++) - bch2_btree_trans_to_text(out, i->trans); -} -#endif - static noinline void lock_graph_remove_non_waiters(struct lock_graph *g) { struct trans_waiting_for_lock *i; @@ -202,7 +208,7 @@ static bool lock_type_conflicts(enum six_lock_type t1, enum six_lock_type t2) return t1 + t2 > 1; } -static int check_for_deadlock(struct btree_trans *trans) +int bch2_check_for_deadlock(struct btree_trans *trans, struct printbuf *cycle) { struct lock_graph g; struct trans_waiting_for_lock *top; @@ -214,7 +220,7 @@ static int check_for_deadlock(struct btree_trans *trans) return btree_trans_restart(trans, BCH_ERR_transaction_restart_would_deadlock); g.nr = 0; - ret = lock_graph_descend(&g, trans); + ret = lock_graph_descend(&g, trans, cycle); BUG_ON(ret); next: if (!g.nr) @@ -265,7 +271,7 @@ next: !lock_type_conflicts(lock_held, trans->locking_wait.lock_want)) continue; - ret = lock_graph_descend(&g, trans); + ret = lock_graph_descend(&g, trans, cycle); raw_spin_unlock(&b->lock.wait_lock); if (ret) @@ -285,7 +291,7 @@ int bch2_six_check_for_deadlock(struct six_lock *lock, void *p) { struct btree_trans *trans = p; - return check_for_deadlock(trans); + return bch2_check_for_deadlock(trans, NULL); } int __bch2_btree_node_lock_write(struct btree_trans *trans, diff --git a/fs/bcachefs/btree_locking.h b/fs/bcachefs/btree_locking.h index 874dd4428b3a..86f68b26cc94 100644 --- a/fs/bcachefs/btree_locking.h +++ b/fs/bcachefs/btree_locking.h @@ -426,6 +426,7 @@ struct six_lock_count bch2_btree_node_lock_counts(struct btree_trans *, struct btree_bkey_cached_common *b, unsigned); +int bch2_check_for_deadlock(struct btree_trans *, struct printbuf *); #ifdef CONFIG_BCACHEFS_DEBUG void bch2_btree_path_verify_locks(struct btree_path *); diff --git a/fs/bcachefs/debug.c b/fs/bcachefs/debug.c index 6944dfef5bcb..41b2772afef9 100644 --- a/fs/bcachefs/debug.c +++ b/fs/bcachefs/debug.c @@ -11,6 +11,7 @@ #include "btree_cache.h" #include "btree_io.h" #include "btree_iter.h" +#include "btree_locking.h" #include "btree_update.h" #include "buckets.h" #include "debug.h" @@ -708,6 +709,45 @@ static const struct file_operations lock_held_stats_op = { .read = lock_held_stats_read, }; +static ssize_t bch2_btree_deadlock_read(struct file *file, char __user *buf, + size_t size, loff_t *ppos) +{ + struct dump_iter *i = file->private_data; + struct bch_fs *c = i->c; + struct btree_trans *trans; + ssize_t ret = 0; + + i->ubuf = buf; + i->size = size; + i->ret = 0; + + if (i->iter) + goto out; + + mutex_lock(&c->btree_trans_lock); + list_for_each_entry(trans, &c->btree_trans_list, list) + if (bch2_check_for_deadlock(trans, &i->buf)) { + i->iter = 1; + break; + } + mutex_unlock(&c->btree_trans_lock); +out: + if (i->buf.allocation_failure) + ret = -ENOMEM; + + if (!ret) + ret = flush_buf(i); + + return ret ?: i->ret; +} + +static const struct file_operations btree_deadlock_ops = { + .owner = THIS_MODULE, + .open = bch2_dump_open, + .release = bch2_dump_release, + .read = bch2_btree_deadlock_read, +}; + void bch2_fs_debug_exit(struct bch_fs *c) { if (!IS_ERR_OR_NULL(c->fs_debug_dir)) @@ -741,6 +781,9 @@ void bch2_fs_debug_init(struct bch_fs *c) debugfs_create_file("btree_transaction_stats", 0400, c->fs_debug_dir, c, &lock_held_stats_op); + debugfs_create_file("btree_deadlock", 0400, c->fs_debug_dir, + c->btree_debug, &btree_deadlock_ops); + c->btree_debug_dir = debugfs_create_dir("btrees", c->fs_debug_dir); if (IS_ERR_OR_NULL(c->btree_debug_dir)) return; |