From c3660423c7bdcf6a4011fd0dd7455cce1a4b0b5f Mon Sep 17 00:00:00 2001 From: Nikolay Borisov Date: Thu, 23 Jun 2022 10:55:47 +0300 Subject: [PATCH] btrfs: properly flag filesystem with BTRFS_FEATURE_INCOMPAT_BIG_METADATA Commit 066cad67b8db 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: 066cad67b8db ("btrfs: fix upper limit for max_inline for page size 64K") CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Qu Wenruo Signed-off-by: Nikolay Borisov Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/disk-io.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 243bd7bd79cd7..e12fd3abd689b 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 -- 2.39.5