From: Josef Bacik <josef@toxicpanda.com>
Date: Thu, 1 Aug 2019 18:19:34 -0400
Subject: btrfs: unify error handling for ticket flushing
Git-commit: 374bf9c5cd7d0b5c270cb954aaf18d794d4b088c
Patch-mainline: v5.4-rc1
References: bsc#1165949

Currently we handle the cleanup of errored out tickets in both the
priority flush path and the normal flushing path.  This is the same code
in both places, so just refactor so we don't duplicate the cleanup work.

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/space-info.c | 32 +++++++++++---------------------
 1 file changed, 11 insertions(+), 21 deletions(-)

diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c
index 1f4e97070f33..bf2fde3fe782 100644
--- a/fs/btrfs/space-info.c
+++ b/fs/btrfs/space-info.c
@@ -878,20 +878,19 @@ static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info,
 	} while (flush_state < ARRAY_SIZE(priority_flush_states));
 }
 
-static int wait_reserve_ticket(struct btrfs_fs_info *fs_info,
-			       struct btrfs_space_info *space_info,
-			       struct reserve_ticket *ticket)
+static void wait_reserve_ticket(struct btrfs_fs_info *fs_info,
+				struct btrfs_space_info *space_info,
+				struct reserve_ticket *ticket)
 
 {
 	DEFINE_WAIT(wait);
-	u64 reclaim_bytes = 0;
 	int ret = 0;
 
 	spin_lock(&space_info->lock);
 	while (ticket->bytes > 0 && ticket->error == 0) {
 		ret = prepare_to_wait_event(&ticket->wait, &wait, TASK_KILLABLE);
 		if (ret) {
-			ret = -EINTR;
+			ticket->error = -EINTR;
 			break;
 		}
 		spin_unlock(&space_info->lock);
@@ -901,18 +900,7 @@ static int wait_reserve_ticket(struct btrfs_fs_info *fs_info,
 		finish_wait(&ticket->wait, &wait);
 		spin_lock(&space_info->lock);
 	}
-	if (!ret)
-		ret = ticket->error;
-	if (!list_empty(&ticket->list))
-		list_del_init(&ticket->list);
-	if (ticket->bytes && ticket->bytes < ticket->orig_bytes)
-		reclaim_bytes = ticket->orig_bytes - ticket->bytes;
 	spin_unlock(&space_info->lock);
-
-	if (reclaim_bytes)
-		btrfs_space_info_add_old_bytes(fs_info, space_info,
-					       reclaim_bytes);
-	return ret;
 }
 
 /**
@@ -1010,16 +998,18 @@ static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info,
 		return ret;
 
 	if (flush == BTRFS_RESERVE_FLUSH_ALL)
-		return wait_reserve_ticket(fs_info, space_info, &ticket);
+		wait_reserve_ticket(fs_info, space_info, &ticket);
+	else
+		priority_reclaim_metadata_space(fs_info, space_info, &ticket);
 
-	ret = 0;
-	priority_reclaim_metadata_space(fs_info, space_info, &ticket);
 	spin_lock(&space_info->lock);
-	if (ticket.bytes) {
+	ret = ticket.error;
+	if (ticket.bytes || ticket.error) {
 		if (ticket.bytes < orig_bytes)
 			reclaim_bytes = orig_bytes - ticket.bytes;
 		list_del_init(&ticket.list);
-		ret = -ENOSPC;
+		if (!ret)
+			ret = -ENOSPC;
 	}
 	spin_unlock(&space_info->lock);