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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Anand Jain <anand.jain@oracle.com>,
        David Sterba <dsterba@suse.com>
Subject: [PATCH 5.4 37/77] btrfs: replace: drop assert for suspended replace
Date:   Fri,  2 Sep 2022 14:18:46 +0200
Message-Id: <20220902121404.886346717@linuxfoundation.org>
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From: Anand Jain <anand.jain@oracle.com>

commit 59a3991984dbc1fc47e5651a265c5200bd85464e upstream.

If the filesystem mounts with the replace-operation in a suspended state
and try to cancel the suspended replace-operation, we hit the assert. The
assert came from the commit fe97e2e173af ("btrfs: dev-replace: replace's
scrub must not be running in suspended state") that was actually not
required. So just remove it.

 $ mount /dev/sda5 /btrfs

    BTRFS info (device sda5): cannot continue dev_replace, tgtdev is missing
    BTRFS info (device sda5): you may cancel the operation after 'mount -o degraded'

 $ mount -o degraded /dev/sda5 /btrfs <-- success.

 $ btrfs replace cancel /btrfs

    kernel: assertion failed: ret != -ENOTCONN, in fs/btrfs/dev-replace.c:1131
    kernel: ------------[ cut here ]------------
    kernel: kernel BUG at fs/btrfs/ctree.h:3750!

After the patch:

 $ btrfs replace cancel /btrfs

    BTRFS info (device sda5): suspended dev_replace from /dev/sda5 (devid 1) to <missing disk> canceled

Fixes: fe97e2e173af ("btrfs: dev-replace: replace's scrub must not be running in suspended state")
CC: stable@vger.kernel.org # 5.0+
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/btrfs/dev-replace.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -918,8 +918,7 @@ int btrfs_dev_replace_cancel(struct btrf
 		up_write(&dev_replace->rwsem);
 
 		/* Scrub for replace must not be running in suspended state */
-		ret = btrfs_scrub_cancel(fs_info);
-		ASSERT(ret != -ENOTCONN);
+		btrfs_scrub_cancel(fs_info);
 
 		trans = btrfs_start_transaction(root, 0);
 		if (IS_ERR(trans)) {