From 19af63780c7b606ea995b98266d871dfe7b8d135 Mon Sep 17 00:00:00 2001
From: Qu Wenruo <wqu@suse.com>
Date: Mon, 13 Jun 2022 15:06:35 +0800
Subject: 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 <wqu@suse.com>
[ update changelog and message ]
Signed-off-by: David Sterba <dsterba@suse.com>
---
fs/btrfs/volumes.c | 10 ++++++++++
1 file changed, 10 insertions(+)
(limited to 'fs/btrfs')
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index e6af960a6961..076040310f6f 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) {
--
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