From: Josef Bacik Date: Wed, 21 Nov 2018 19:03:12 +0000 (-0500) Subject: btrfs: be more explicit about allowed flush states X-Git-Tag: v5.1-rc1~47^2~29 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=8a1bbe1d5cba415c771fe5ff68b83b93701c1d7f;p=linux-2.6-block.git btrfs: be more explicit about allowed flush states For FLUSH_LIMIT flushers we really can only allocate chunks and flush delayed inode items, everything else is problematic. I added a bunch of new states and it lead to weirdness in the FLUSH_LIMIT case because I forgot about how it worked. So instead explicitly declare the states that are ok for flushing with FLUSH_LIMIT and use that for our state machine. Then as we add new things that are safe we can just add them to this list. Reviewed-by: Nikolay Borisov Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba --- diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index cb97ada7f410..3c9ae2a0c0be 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -5143,12 +5143,18 @@ void btrfs_init_async_reclaim_work(struct work_struct *work) INIT_WORK(work, btrfs_async_reclaim_metadata_space); } +static const enum btrfs_flush_state priority_flush_states[] = { + FLUSH_DELAYED_ITEMS_NR, + FLUSH_DELAYED_ITEMS, + ALLOC_CHUNK, +}; + static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info, struct btrfs_space_info *space_info, struct reserve_ticket *ticket) { u64 to_reclaim; - int flush_state = FLUSH_DELAYED_ITEMS_NR; + int flush_state; spin_lock(&space_info->lock); to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info, @@ -5159,8 +5165,10 @@ static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info, } spin_unlock(&space_info->lock); + flush_state = 0; do { - flush_space(fs_info, space_info, to_reclaim, flush_state); + flush_space(fs_info, space_info, to_reclaim, + priority_flush_states[flush_state]); flush_state++; spin_lock(&space_info->lock); if (ticket->bytes == 0) { @@ -5168,15 +5176,7 @@ static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info, return; } spin_unlock(&space_info->lock); - - /* - * Priority flushers can't wait on delalloc without - * deadlocking. - */ - if (flush_state == FLUSH_DELALLOC || - flush_state == FLUSH_DELALLOC_WAIT) - flush_state = ALLOC_CHUNK; - } while (flush_state < COMMIT_TRANS); + } while (flush_state < ARRAY_SIZE(priority_flush_states)); } static int wait_reserve_ticket(struct btrfs_fs_info *fs_info,