Commit 9e2c3c2e authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcachefs: Fix lost rebalance wakeups 



Fix a missing wakeup in

'bcachefs set-file-option' -> xattr option update -> inode_write

this was missing because the wakeup needs to happen after transaction
commit. Also, add a 'kick' counter, to make sure we don't miss a wakeup
that occured right after we finished checking the rebalance_work btree.

Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent dc37dcca

fs/bcachefs/fs.c

+5 −1
Original line number Diff line number Diff line
@@ -124,8 +124,9 @@ int __must_check bch2_write_inode(struct bch_fs *c, 
		goto err;



	struct bch_extent_rebalance new_r = bch2_inode_rebalance_opts_get(c, &inode_u);

	bool rebalance_changed = memcmp(&old_r, &new_r, sizeof(new_r));



	if (memcmp(&old_r, &new_r, sizeof(new_r))) {

	if (rebalance_changed) {

		ret = bch2_set_rebalance_needs_scan_trans(trans, inode_u.bi_inum);

		if (ret)

			goto err;
@@ -146,6 +147,9 @@ int __must_check bch2_write_inode(struct bch_fs *c, 
	if (bch2_err_matches(ret, BCH_ERR_transaction_restart))

		goto retry;



	if (rebalance_changed)

		bch2_rebalance_wakeup(c);



	bch2_fs_fatal_err_on(bch2_err_matches(ret, ENOENT), c,

			     "%s: inode %llu:%llu not found when updating",

			     bch2_err_str(ret),

fs/bcachefs/rebalance.c

+4 −2
Original line number Diff line number Diff line
@@ -527,7 +527,7 @@ static void rebalance_wait(struct bch_fs *c) 
		r->state		= BCH_REBALANCE_waiting;

	}



	bch2_kthread_io_clock_wait(clock, r->wait_iotime_end, MAX_SCHEDULE_TIMEOUT);

	bch2_kthread_io_clock_wait_once(clock, r->wait_iotime_end, MAX_SCHEDULE_TIMEOUT);

}



static bool bch2_rebalance_enabled(struct bch_fs *c)
@@ -544,6 +544,7 @@ static int do_rebalance(struct moving_context *ctxt) 
	struct bch_fs_rebalance *r = &c->rebalance;

	struct btree_iter rebalance_work_iter, extent_iter = {};

	struct bkey_s_c k;

	u32 kick = r->kick;

	int ret = 0;



	bch2_trans_begin(trans);
@@ -593,7 +594,8 @@ static int do_rebalance(struct moving_context *ctxt) 
	if (!ret &&

	    !kthread_should_stop() &&

	    !atomic64_read(&r->work_stats.sectors_seen) &&

	    !atomic64_read(&r->scan_stats.sectors_seen)) {

	    !atomic64_read(&r->scan_stats.sectors_seen) &&

	    kick == r->kick) {

		bch2_moving_ctxt_flush_all(ctxt);

		bch2_trans_unlock_long(trans);

		rebalance_wait(c);

fs/bcachefs/rebalance.h

+3 −5
Original line number Diff line number Diff line
@@ -39,13 +39,11 @@ int bch2_set_fs_needs_rebalance(struct bch_fs *); 


static inline void bch2_rebalance_wakeup(struct bch_fs *c)

{

	struct task_struct *p;



	rcu_read_lock();

	p = rcu_dereference(c->rebalance.thread);

	c->rebalance.kick++;

	guard(rcu)();

	struct task_struct *p = rcu_dereference(c->rebalance.thread);

	if (p)

		wake_up_process(p);

	rcu_read_unlock();

}



void bch2_rebalance_status_to_text(struct printbuf *, struct bch_fs *);

fs/bcachefs/rebalance_types.h

+1 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ enum bch_rebalance_states { 


struct bch_fs_rebalance {

	struct task_struct __rcu	*thread;

	u32				kick;

	struct bch_pd_controller pd;



	enum bch_rebalance_states	state;