The patch below does not apply to the 5.10-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 e26b04c4c91925dba57324db177a24e18e2d0013 Mon Sep 17 00:00:00 2001 From: Nikolay Borisov nborisov@suse.com Date: Thu, 23 Jun 2022 10:55:47 +0300 Subject: [PATCH] btrfs: properly flag filesystem with BTRFS_FEATURE_INCOMPAT_BIG_METADATA
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@vger.kernel.org # 5.4+ Reviewed-by: Qu Wenruo wqu@suse.com Signed-off-by: Nikolay Borisov nborisov@suse.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 243bd7bd79cd..e12fd3abd689 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3484,16 +3484,6 @@ 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); @@ -3534,6 +3524,17 @@ 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