From 9f35f76d7df66507b698ac7298fb6c175a6aae7d Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Tue, 9 Nov 2021 10:12:01 -0500 Subject: [PATCH] btrfs: handle priority ticket failures in their respective helpers Currently the error case for the priority tickets is handled where we deal with all of the tickets, priority and non-priority. This is OK in general, but it makes for some awkward locking. We take and drop the space_info->lock back to back because of these different types of tickets. Rework the code to handle priority ticket failures in their respective helpers. This allows us to be less wonky with our space_info->lock usage, and means that the main handler simply has to check ticket->error, as the ticket is guaranteed to be off any list and completely handled by the time it exits one of the handlers. Reviewed-by: Nikolay Borisov Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/space-info.c | 46 ++++++++++++++++++++----------------------- 1 file changed, 21 insertions(+), 25 deletions(-) diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c index 48d77f360a24..9d6048f54097 100644 --- a/fs/btrfs/space-info.c +++ b/fs/btrfs/space-info.c @@ -1260,7 +1260,7 @@ static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info, int states_nr) { u64 to_reclaim; - int flush_state; + int flush_state = 0; spin_lock(&space_info->lock); to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info); @@ -1268,10 +1268,9 @@ static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info, spin_unlock(&space_info->lock); return; } - spin_unlock(&space_info->lock); - flush_state = 0; - do { + while (flush_state < states_nr) { + spin_unlock(&space_info->lock); flush_space(fs_info, space_info, to_reclaim, states[flush_state], false); flush_state++; @@ -1280,23 +1279,38 @@ static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info, spin_unlock(&space_info->lock); return; } - spin_unlock(&space_info->lock); - } while (flush_state < states_nr); + } + + /* + * We must run try_granting_tickets here because we could be a large + * ticket in front of a smaller ticket that can now be satisfied with + * the available space. + */ + ticket->error = -ENOSPC; + remove_ticket(space_info, ticket); + btrfs_try_granting_tickets(fs_info, space_info); + spin_unlock(&space_info->lock); } static void priority_reclaim_data_space(struct btrfs_fs_info *fs_info, struct btrfs_space_info *space_info, struct reserve_ticket *ticket) { + spin_lock(&space_info->lock); while (!space_info->full) { + spin_unlock(&space_info->lock); flush_space(fs_info, space_info, U64_MAX, ALLOC_CHUNK_FORCE, false); spin_lock(&space_info->lock); if (ticket->bytes == 0) { spin_unlock(&space_info->lock); return; } - spin_unlock(&space_info->lock); } + + ticket->error = -ENOSPC; + remove_ticket(space_info, ticket); + btrfs_try_granting_tickets(fs_info, space_info); + spin_unlock(&space_info->lock); } static void wait_reserve_ticket(struct btrfs_fs_info *fs_info, @@ -1378,25 +1392,7 @@ static int handle_reserve_ticket(struct btrfs_fs_info *fs_info, break; } - spin_lock(&space_info->lock); ret = ticket->error; - if (ticket->bytes || ticket->error) { - /* - * We were a priority ticket, so we need to delete ourselves - * from the list. Because we could have other priority tickets - * behind us that require less space, run - * btrfs_try_granting_tickets() to see if their reservations can - * now be made. - */ - if (!list_empty(&ticket->list)) { - remove_ticket(space_info, ticket); - btrfs_try_granting_tickets(fs_info, space_info); - } - - if (!ret) - ret = -ENOSPC; - } - spin_unlock(&space_info->lock); ASSERT(list_empty(&ticket->list)); /* * Check that we can't have an error set if the reservation succeeded,