The patch below does not apply to the 6.1-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.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 35fec1089ebb5617f85884d3fa6a699ce6337a75 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025041732-purgatory-either-8bfc@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

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

From 35fec1089ebb5617f85884d3fa6a699ce6337a75 Mon Sep 17 00:00:00 2001 From: Johannes Thumshirn johannes.thumshirn@wdc.com Date: Mon, 17 Mar 2025 12:24:59 +0100 Subject: [PATCH] btrfs: zoned: fix zone finishing with missing devices

If do_zone_finish() is called with a filesystem that has missing devices (e.g. a RAID file system mounted in degraded mode) it is accessing the btrfs_device::zone_info pointer, which will not be set if the device in question is missing.

Check if the device is present (by checking if it has a valid block device pointer associated) and if not, skip zone finishing for it.

Fixes: 4dcbb8ab31c1 ("btrfs: zoned: make zone finishing multi stripe capable") CC: stable@vger.kernel.org # 6.1+ Reviewed-by: Naohiro Aota naohiro.aota@wdc.com Reviewed-by: Anand Jain anand.jain@oracle.com Signed-off-by: Johannes Thumshirn johannes.thumshirn@wdc.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com

diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c index 9faf1e097196..fb8b8b29c169 100644 --- a/fs/btrfs/zoned.c +++ b/fs/btrfs/zoned.c @@ -2275,6 +2275,9 @@ static int do_zone_finish(struct btrfs_block_group *block_group, bool fully_writ struct btrfs_zoned_device_info *zinfo = device->zone_info; unsigned int nofs_flags;

+ if (!device->bdev) + continue; + if (zinfo->max_active_zones == 0) continue;