From 461cc16b200710557a58e2a02755a01d6c461a37 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Mon, 13 Jun 2022 15:06:35 +0800 Subject: [PATCH] btrfs: warn about dev extents that are inside the reserved range Btrfs on-disk format has reserved the first 1MiB for the primary super block (at 64KiB offset) and bootloaders may also use this space. This behavior is only introduced since v4.1 btrfs-progs release, although kernel can ensure we never touch the reserved range of super blocks, it's better to inform the end users, and a balance will resolve the problem. Signed-off-by: Qu Wenruo [ update changelog and message ] Signed-off-by: David Sterba --- fs/btrfs/volumes.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index e6af960a69614..076040310f6fb 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -7996,6 +7996,16 @@ static int verify_one_dev_extent(struct btrfs_fs_info *fs_info, goto out; } + /* + * Very old mkfs.btrfs (before v4.1) will not respect the reserved + * space. Although kernel can handle it without problem, better to warn + * the users. + */ + if (physical_offset < BTRFS_DEVICE_RANGE_RESERVED) + btrfs_warn(fs_info, + "devid %llu physical %llu len %llu inside the reserved space", + devid, physical_offset, physical_len); + for (i = 0; i < map->num_stripes; i++) { if (map->stripes[i].dev->devid == devid && map->stripes[i].physical == physical_offset) { -- 2.39.5