This is a note to let you know that I've just added the patch titled btrfs: properly flag filesystem with BTRFS_FEATURE_INCOMPAT_BIG_METADATA to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: btrfs-properly-flag-filesystem-with-btrfs_feature_in.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 6b607f1c8790fef2b56dd25d1d5caaff57970c9f Author: Nikolay Borisov <nborisov@xxxxxxxx> Date: Thu Jun 23 10:55:47 2022 +0300 btrfs: properly flag filesystem with BTRFS_FEATURE_INCOMPAT_BIG_METADATA [ Upstream commit e26b04c4c91925dba57324db177a24e18e2d0013 ] Commit 6f93e834fa7c seemingly inadvertently moved the code responsible for flagging the filesystem as having BIG_METADATA to a place where setting the flag was essentially lost. This means that filesystems created with kernels containing this bug (starting with 5.15) can potentially be mounted by older (pre-3.4) kernels. In reality chances for this happening are low because there are other incompat flags introduced in the mean time. Still the correct behavior is to set INCOMPAT_BIG_METADATA flag and persist this in the superblock. Fixes: 6f93e834fa7c ("btrfs: fix upper limit for max_inline for page size 64K") CC: stable@xxxxxxxxxxxxxxx # 5.4+ Reviewed-by: Qu Wenruo <wqu@xxxxxxxx> Signed-off-by: Nikolay Borisov <nborisov@xxxxxxxx> Reviewed-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 383e9c861306..e65c3039caf1 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3337,16 +3337,6 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device */ fs_info->compress_type = BTRFS_COMPRESS_ZLIB; - /* - * Flag our filesystem as having big metadata blocks if they are bigger - * than the page size. - */ - if (btrfs_super_nodesize(disk_super) > PAGE_SIZE) { - if (!(features & BTRFS_FEATURE_INCOMPAT_BIG_METADATA)) - btrfs_info(fs_info, - "flagging fs with big metadata feature"); - features |= BTRFS_FEATURE_INCOMPAT_BIG_METADATA; - } /* Set up fs_info before parsing mount options */ nodesize = btrfs_super_nodesize(disk_super); @@ -3387,6 +3377,17 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device if (features & BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA) btrfs_info(fs_info, "has skinny extents"); + /* + * Flag our filesystem as having big metadata blocks if they are bigger + * than the page size. + */ + if (btrfs_super_nodesize(disk_super) > PAGE_SIZE) { + if (!(features & BTRFS_FEATURE_INCOMPAT_BIG_METADATA)) + btrfs_info(fs_info, + "flagging fs with big metadata feature"); + features |= BTRFS_FEATURE_INCOMPAT_BIG_METADATA; + } + /* * mixed block groups end up with duplicate but slightly offset * extent buffers for the same range. It leads to corruptions