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bcachefs: Shutdown path improvements

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We're seeing occasional firings of the assertion in the key cache
shutdown code that nr_dirty == 0, which means we must sometimes be doing
transaction commits after we've gone read only.

Cleanups & changes:
 - BCH_FS_ALLOC_CLEAN renamed to BCH_FS_CLEAN_SHUTDOWN
 - new helper bch2_btree_interior_updates_flush(), which returns true if
   it had to wait
 - bch2_btree_flush_writes() now also returns true if there were btree
   writes in flight
 - __bch2_fs_read_only now checks if btree writes were in flight in the
   shutdown loop: btree write completion does a transaction update, to
   update the pointer in the parent node
 - assert that !BCH_FS_CLEAN_SHUTDOWN in __bch2_trans_commit

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
This commit is contained in:
Kent Overstreet 2022-04-17 17:30:49 -04:00 committed by Kent Overstreet
parent d8f31407c8
commit c0960603e2
10 changed files with 43 additions and 60 deletions
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2
fs/bcachefs/bcachefs.h
View File

@ -494,7 +494,7 @@ struct bch_dev {
enum {
/* startup: */
BCH_FS_ALLOC_CLEAN,
BCH_FS_CLEAN_SHUTDOWN,
BCH_FS_INITIAL_GC_DONE,
BCH_FS_INITIAL_GC_UNFIXED,
BCH_FS_TOPOLOGY_REPAIR_DONE,

4
fs/bcachefs/btree_gc.c
View File

@ -1751,9 +1751,7 @@ int bch2_gc(struct bch_fs *c, bool initial, bool metadata_only)
down_write(&c->gc_lock);
/* flush interior btree updates: */
closure_wait_event(&c->btree_interior_update_wait,
!bch2_btree_interior_updates_nr_pending(c));
bch2_btree_interior_updates_flush(c);
ret = bch2_gc_start(c, metadata_only) ?:
bch2_gc_alloc_start(c, metadata_only) ?:

14
fs/bcachefs/btree_io.c
View File

@ -2099,29 +2099,33 @@ void bch2_btree_node_write(struct bch_fs *c, struct btree *b,
}
}
static void __bch2_btree_flush_all(struct bch_fs *c, unsigned flag)
static bool __bch2_btree_flush_all(struct bch_fs *c, unsigned flag)
{
struct bucket_table *tbl;
struct rhash_head *pos;
struct btree *b;
unsigned i;
bool ret = false;
restart:
rcu_read_lock();
for_each_cached_btree(b, c, tbl, i, pos)
if (test_bit(flag, &b->flags)) {
rcu_read_unlock();
wait_on_bit_io(&b->flags, flag, TASK_UNINTERRUPTIBLE);
ret = true;
goto restart;
}
rcu_read_unlock();
return ret;
}
void bch2_btree_flush_all_reads(struct bch_fs *c)
bool bch2_btree_flush_all_reads(struct bch_fs *c)
{
__bch2_btree_flush_all(c, BTREE_NODE_read_in_flight);
return __bch2_btree_flush_all(c, BTREE_NODE_read_in_flight);
}
void bch2_btree_flush_all_writes(struct bch_fs *c)
bool bch2_btree_flush_all_writes(struct bch_fs *c)
{
__bch2_btree_flush_all(c, BTREE_NODE_write_in_flight);
return __bch2_btree_flush_all(c, BTREE_NODE_write_in_flight);
}

4
fs/bcachefs/btree_io.h
View File

@ -152,8 +152,8 @@ static inline void btree_node_write_if_need(struct bch_fs *c, struct btree *b,
bch2_btree_node_write(c, b, lock_held, BTREE_WRITE_ONLY_IF_NEED);
}
void bch2_btree_flush_all_reads(struct bch_fs *);
void bch2_btree_flush_all_writes(struct bch_fs *);
bool bch2_btree_flush_all_reads(struct bch_fs *);
bool bch2_btree_flush_all_writes(struct bch_fs *);
static inline void compat_bformat(unsigned level, enum btree_id btree_id,
unsigned version, unsigned big_endian,

18
fs/bcachefs/btree_update_interior.c
View File

@ -2175,19 +2175,27 @@ void bch2_btree_updates_to_text(struct printbuf *out, struct bch_fs *c)
mutex_unlock(&c->btree_interior_update_lock);
}
size_t bch2_btree_interior_updates_nr_pending(struct bch_fs *c)
static bool bch2_btree_interior_updates_pending(struct bch_fs *c)
{
size_t ret = 0;
struct list_head *i;
bool ret;
mutex_lock(&c->btree_interior_update_lock);
list_for_each(i, &c->btree_interior_update_list)
ret++;
ret = !list_empty(&c->btree_interior_update_list);
mutex_unlock(&c->btree_interior_update_lock);
return ret;
}
bool bch2_btree_interior_updates_flush(struct bch_fs *c)
{
bool ret = bch2_btree_interior_updates_pending(c);
if (ret)
closure_wait_event(&c->btree_interior_update_wait,
!bch2_btree_interior_updates_pending(c));
return ret;
}
void bch2_journal_entries_to_btree_roots(struct bch_fs *c, struct jset *jset)
{
struct btree_root *r;

2
fs/bcachefs/btree_update_interior.h
View File

@ -309,7 +309,7 @@ static inline bool bch2_btree_node_insert_fits(struct bch_fs *c,
void bch2_btree_updates_to_text(struct printbuf *, struct bch_fs *);
size_t bch2_btree_interior_updates_nr_pending(struct bch_fs *);
bool bch2_btree_interior_updates_flush(struct bch_fs *);
void bch2_journal_entries_to_btree_roots(struct bch_fs *, struct jset *);
struct jset_entry *bch2_btree_roots_to_journal_entries(struct bch_fs *,

2
fs/bcachefs/btree_update_leaf.c
View File

@ -1117,6 +1117,8 @@ int __bch2_trans_commit(struct btree_trans *trans)
goto out_reset;
}
EBUG_ON(test_bit(BCH_FS_CLEAN_SHUTDOWN, &c->flags));
memset(&trans->journal_preres, 0, sizeof(trans->journal_preres));
trans->journal_u64s = trans->extra_journal_entries.nr;

5
fs/bcachefs/migrate.c
View File

@ -175,10 +175,7 @@ next:
goto err;
}
/* flush relevant btree updates */
closure_wait_event(&c->btree_interior_update_wait,
!bch2_btree_interior_updates_nr_pending(c));
bch2_btree_interior_updates_flush(c);
ret = 0;
err:
bch2_trans_exit(&trans);

4
fs/bcachefs/move.c
View File

@ -942,9 +942,7 @@ next:
if (ret)
bch_err(c, "error %i in bch2_move_btree", ret);
/* flush relevant btree updates */
closure_wait_event(&c->btree_interior_update_wait,
!bch2_btree_interior_updates_nr_pending(c));
bch2_btree_interior_updates_flush(c);
progress_list_del(c, stats);
return ret;

48
fs/bcachefs/super.c
View File

@ -195,57 +195,33 @@ static void __bch2_fs_read_only(struct bch_fs *c)
{
struct bch_dev *ca;
unsigned i, clean_passes = 0;
u64 seq = 0;
bch2_rebalance_stop(c);
bch2_copygc_stop(c);
bch2_gc_thread_stop(c);
/*
* Flush journal before stopping allocators, because flushing journal
* blacklist entries involves allocating new btree nodes:
*/
bch2_journal_flush_all_pins(&c->journal);
bch_verbose(c, "flushing journal and stopping allocators");
bch2_journal_flush_all_pins(&c->journal);
do {
clean_passes++;
if (bch2_journal_flush_all_pins(&c->journal))
clean_passes = 0;
/*
* In flight interior btree updates will generate more journal
* updates and btree updates (alloc btree):
*/
if (bch2_btree_interior_updates_nr_pending(c)) {
closure_wait_event(&c->btree_interior_update_wait,
!bch2_btree_interior_updates_nr_pending(c));
if (bch2_btree_interior_updates_flush(c) ||
bch2_journal_flush_all_pins(&c->journal) ||
bch2_btree_flush_all_writes(c) ||
seq != atomic64_read(&c->journal.seq)) {
seq = atomic64_read(&c->journal.seq);
clean_passes = 0;
}
flush_work(&c->btree_interior_update_work);
if (bch2_journal_flush_all_pins(&c->journal))
clean_passes = 0;
} while (clean_passes < 2);
bch_verbose(c, "flushing journal and stopping allocators complete");
set_bit(BCH_FS_ALLOC_CLEAN, &c->flags);
closure_wait_event(&c->btree_interior_update_wait,
!bch2_btree_interior_updates_nr_pending(c));
flush_work(&c->btree_interior_update_work);
if (test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags) &&
!test_bit(BCH_FS_EMERGENCY_RO, &c->flags))
set_bit(BCH_FS_CLEAN_SHUTDOWN, &c->flags);
bch2_fs_journal_stop(&c->journal);
/*
* the journal kicks off btree writes via reclaim - wait for in flight
* writes after stopping journal:
*/
bch2_btree_flush_all_writes(c);
/*
* After stopping journal:
*/
@ -304,7 +280,7 @@ void bch2_fs_read_only(struct bch_fs *c)
!test_bit(BCH_FS_ERROR, &c->flags) &&
!test_bit(BCH_FS_EMERGENCY_RO, &c->flags) &&
test_bit(BCH_FS_STARTED, &c->flags) &&
test_bit(BCH_FS_ALLOC_CLEAN, &c->flags) &&
test_bit(BCH_FS_CLEAN_SHUTDOWN, &c->flags) &&
!c->opts.norecovery) {
bch_verbose(c, "marking filesystem clean");
bch2_fs_mark_clean(c);
@ -395,7 +371,7 @@ static int __bch2_fs_read_write(struct bch_fs *c, bool early)
if (ret)
goto err;
clear_bit(BCH_FS_ALLOC_CLEAN, &c->flags);
clear_bit(BCH_FS_CLEAN_SHUTDOWN, &c->flags);
for_each_rw_member(ca, c, i)
bch2_dev_allocator_add(c, ca);