From: Josef Bacik <josef@toxicpanda.com>
Date: Thu, 11 Oct 2018 15:54:31 -0400
Subject: btrfs: don't run delayed_iputs in commit
Git-commit: 30928e9baac238a7330085a1c5747f0b5df444b4
Patch-mainline: v4.20-rc1
References: bsc##1165949

This could result in a really bad case where we do something like

evict
  evict_refill_and_join
    btrfs_commit_transaction
      btrfs_run_delayed_iputs
        evict
          evict_refill_and_join
            btrfs_commit_transaction
... forever

We have plenty of other places where we run delayed iputs that are much
safer, let those do the work.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@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/transaction.c |   10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -542,7 +542,7 @@ again:
 	 * and then we deadlock with somebody doing a freeze.
 	 *
 	 * If we are ATTACH, it means we just want to catch the current
-	 * transaction and commit it, so we needn't do sb_start_intwrite(). 
+	 * transaction and commit it, so we needn't do sb_start_intwrite().
 	 */
 	if (type & __TRANS_FREEZABLE)
 		sb_start_intwrite(fs_info->sb);
@@ -2315,14 +2315,6 @@ int btrfs_commit_transaction(struct btrf
 
 	kmem_cache_free(btrfs_trans_handle_cachep, trans);
 
-	/*
-	 * If fs has been frozen, we can not handle delayed iputs, otherwise
-	 * it'll result in deadlock about SB_FREEZE_FS.
-	 */
-	if (current != fs_info->transaction_kthread &&
-	    current != fs_info->cleaner_kthread && !fs_info->fs_frozen)
-		btrfs_run_delayed_iputs(fs_info);
-
 	return ret;
 
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