Commit 06e1e7f4 authored by Johannes Thumshirn's avatar Johannes Thumshirn Committed by David Sterba
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btrfs: zoned: bail out if we can't read a reliable write pointer 



If we can't read a reliable write pointer from a sequential zone fail
creating the block group with an I/O error.

Also if the read write pointer is beyond the end of the respective zone,
fail the creation of the block group on this zone with an I/O error.

While this could also happen in real world scenarios with misbehaving
drives, this issue addresses a problem uncovered by fstests' test case
generic/475.

CC: stable@vger.kernel.org # 5.12+
Signed-off-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 47cdfb5e

fs/btrfs/zoned.c

+14 −0
Original line number Diff line number Diff line
@@ -1204,6 +1204,13 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache, bool new) 


	switch (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {

	case 0: /* single */

		if (alloc_offsets[0] == WP_MISSING_DEV) {

			btrfs_err(fs_info,

			"zoned: cannot recover write pointer for zone %llu",

				physical);

			ret = -EIO;

			goto out;

		}

		cache->alloc_offset = alloc_offsets[0];

		break;

	case BTRFS_BLOCK_GROUP_DUP:
@@ -1221,6 +1228,13 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache, bool new) 
	}



out:

	if (cache->alloc_offset > fs_info->zone_size) {

		btrfs_err(fs_info,

			"zoned: invalid write pointer %llu in block group %llu",

			cache->alloc_offset, cache->start);

		ret = -EIO;

	}



	/* An extent is allocated after the write pointer */

	if (!ret && num_conventional && last_alloc > cache->alloc_offset) {

		btrfs_err(fs_info,