Commit 2341ccd1 authored by Josef Bacik's avatar Josef Bacik Committed by David Sterba
Browse files

btrfs: rework wake_all_tickets 



Now that we no longer partially fill tickets we need to rework
wake_all_tickets to call btrfs_try_to_wakeup_tickets() in order to see
if any subsequent tickets are able to be satisfied.  If our tickets_id
changes we know something happened and we can keep flushing.

Also if we find a ticket that is smaller than the first ticket in our
queue then we want to retry the flushing loop again in case
may_commit_transaction() decides we could satisfy the ticket by
committing the transaction.

Rename this to maybe_fail_all_tickets() while we're at it, to better
reflect what the function is actually doing.

Signed-off-by: default avatarJosef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 18fa2284

fs/btrfs/space-info.c

+49 −7
Original line number Diff line number Diff line
@@ -679,19 +679,61 @@ static inline int need_do_async_reclaim(struct btrfs_fs_info *fs_info, 
		!test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state));

}



static bool wake_all_tickets(struct list_head *head)

/*

 * maybe_fail_all_tickets - we've exhausted our flushing, start failing tickets

 * @fs_info - fs_info for this fs

 * @space_info - the space info we were flushing

 *

 * We call this when we've exhausted our flushing ability and haven't made

 * progress in satisfying tickets.  The reservation code handles tickets in

 * order, so if there is a large ticket first and then smaller ones we could

 * very well satisfy the smaller tickets.  This will attempt to wake up any

 * tickets in the list to catch this case.

 *

 * This function returns true if it was able to make progress by clearing out

 * other tickets, or if it stumbles across a ticket that was smaller than the

 * first ticket.

 */

static bool maybe_fail_all_tickets(struct btrfs_fs_info *fs_info,

				   struct btrfs_space_info *space_info)

{

	struct reserve_ticket *ticket;

	u64 tickets_id = space_info->tickets_id;

	u64 first_ticket_bytes = 0;



	while (!list_empty(&space_info->tickets) &&

	       tickets_id == space_info->tickets_id) {

		ticket = list_first_entry(&space_info->tickets,

					  struct reserve_ticket, list);



		/*

		 * may_commit_transaction will avoid committing the transaction

		 * if it doesn't feel like the space reclaimed by the commit

		 * would result in the ticket succeeding.  However if we have a

		 * smaller ticket in the queue it may be small enough to be

		 * satisified by committing the transaction, so if any

		 * subsequent ticket is smaller than the first ticket go ahead

		 * and send us back for another loop through the enospc flushing

		 * code.

		 */

		if (first_ticket_bytes == 0)

			first_ticket_bytes = ticket->bytes;

		else if (first_ticket_bytes > ticket->bytes)

			return true;



	while (!list_empty(head)) {

		ticket = list_first_entry(head, struct reserve_ticket, list);

		list_del_init(&ticket->list);

		ticket->error = -ENOSPC;

		wake_up(&ticket->wait);

		if (ticket->bytes != ticket->orig_bytes)

			return true;



		/*

		 * We're just throwing tickets away, so more flushing may not

		 * trip over btrfs_try_granting_tickets, so we need to call it

		 * here to see if we can make progress with the next ticket in

		 * the list.

		 */

		btrfs_try_granting_tickets(fs_info, space_info);

	}

	return false;

	return (tickets_id != space_info->tickets_id);

}



/*
@@ -759,7 +801,7 @@ static void btrfs_async_reclaim_metadata_space(struct work_struct *work) 
		if (flush_state > COMMIT_TRANS) {

			commit_cycles++;

			if (commit_cycles > 2) {

				if (wake_all_tickets(&space_info->tickets)) {

				if (maybe_fail_all_tickets(fs_info, space_info)) {

					flush_state = FLUSH_DELAYED_ITEMS_NR;

					commit_cycles--;

				} else {

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