FAILED: patch "[PATCH] btrfs: don't run delayed_iputs in commit" failed to apply to 4.9-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From 30928e9baac238a7330085a1c5747f0b5df444b4 Mon Sep 17 00:00:00 2001
From: Josef Bacik <josef@toxicpanda.com>
Date: Thu, 11 Oct 2018 15:54:31 -0400
Subject: [PATCH] btrfs: don't run delayed_iputs in commit

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>

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 5686290a50e1..d1eeef9ec5da 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -2283,15 +2283,6 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
 
 	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 &&
-	    !test_bit(BTRFS_FS_FROZEN, &fs_info->flags))
-		btrfs_run_delayed_iputs(fs_info);
-
 	return ret;
 
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