From: Josef Bacik <josef@toxicpanda.com>
Date: Wed, 21 Nov 2018 14:03:12 -0500
Subject: btrfs: be more explicit about allowed flush states
Git-commit: 8a1bbe1d5cba415c771fe5ff68b83b93701c1d7f
Patch-mainline: v5.1-rc1
References: bsc#1165949
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 <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Acked-by: Nikolay Borisov <nborisov@suse.com>
---
fs/btrfs/extent-tree.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -5264,12 +5264,18 @@ void btrfs_init_async_reclaim_work(struc
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,
@@ -5280,8 +5286,10 @@ static void priority_reclaim_metadata_sp
}
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) {
@@ -5289,15 +5297,7 @@ static void priority_reclaim_metadata_sp
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,