@@ -233,52 +233,41 @@ void btrfs_space_info_add_old_bytes(struct btrfs_fs_info *fs_info,
struct btrfs_space_info *space_info,
u64 num_bytes)
{
- struct reserve_ticket *ticket;
struct list_head *head;
- u64 used;
enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_NO_FLUSH;
- bool check_overcommit = false;
spin_lock(&space_info->lock);
head = &space_info->priority_tickets;
+ btrfs_space_info_update_bytes_may_use(fs_info, space_info, -num_bytes);
- /*
- * If we are over our limit then we need to check and see if we can
- * overcommit, and if we can't then we just need to free up our space
- * and not satisfy any requests.
- */
- used = btrfs_space_info_used(space_info, true);
- if (used - num_bytes >= space_info->total_bytes)
- check_overcommit = true;
again:
- while (!list_empty(head) && num_bytes) {
- ticket = list_first_entry(head, struct reserve_ticket,
- list);
- /*
- * We use 0 bytes because this space is already reserved, so
- * adding the ticket space would be a double count.
- */
- if (check_overcommit &&
- !can_overcommit(fs_info, space_info, 0, flush, false))
- break;
- if (num_bytes >= ticket->bytes) {
+ while (!list_empty(head)) {
+ struct reserve_ticket *ticket;
+ u64 used = btrfs_space_info_used(space_info, true);
+
+ ticket = list_first_entry(head, struct reserve_ticket, list);
+
+ /* Check and see if our ticket can be satisified now. */
+ if ((used + ticket->bytes <= space_info->total_bytes) ||
+ can_overcommit(fs_info, space_info, ticket->bytes, flush,
+ false)) {
+ btrfs_space_info_update_bytes_may_use(fs_info,
+ space_info,
+ ticket->bytes);
list_del_init(&ticket->list);
- num_bytes -= ticket->bytes;
ticket->bytes = 0;
space_info->tickets_id++;
wake_up(&ticket->wait);
} else {
- ticket->bytes -= num_bytes;
- num_bytes = 0;
+ break;
}
}
- if (num_bytes && head == &space_info->priority_tickets) {
+ if (head == &space_info->priority_tickets) {
head = &space_info->tickets;
flush = BTRFS_RESERVE_FLUSH_ALL;
goto again;
}
- btrfs_space_info_update_bytes_may_use(fs_info, space_info, -num_bytes);
spin_unlock(&space_info->lock);
}
If there are pending tickets and we are overcommitted we will simply return free'd reservations to space_info->bytes_may_use if we cannot overcommit any more. This is problematic because we assume any free space would have been added to the tickets, and so if we go from an overcommitted state to not overcommitted we could have plenty of space in our space_info but be unable to make progress on our tickets because we only refill tickets from previous reservations. Instead of doing this partial filling of tickets dance we need to simply add our space to the space_info, and then do the normal check to see if we can satisfy the whole reservation. If we can then we wake up the ticket and carry on. Signed-off-by: Josef Bacik <josef@toxicpanda.com> --- fs/btrfs/space-info.c | 43 ++++++++++++++++--------------------------- 1 file changed, 16 insertions(+), 27 deletions(-)