On 9/3/25 10:36 AM, Yi Zhang wrote: > The kernel BUG was triggered by blktests zbd/009 on v6.17-rc3, please > help check it and let me know if you need any infor/test for it, > thanks. [...] > [ 319.819821] assertion failed: bg->zone_unusable == 0 :: 0, in > fs/btrfs/zoned.c:2587 > [ 319.828449] ------------[ cut here ]------------ > [ 319.833618] kernel BUG at fs/btrfs/zoned.c:2587! > [ 319.838793] Oops: invalid opcode: 0000 [#1] SMP KASAN PTI > [ 319.844829] CPU: 3 UID: 0 PID: 1370 Comm: mount Tainted: G W > ------ --- > 6.17.0-0.rc3.250826gfab1beda7597.32.fc44.x86_64+debug #1 PREEMPT(lazy) > [ 319.860948] Tainted: [W]=WARN > [ 319.864259] Hardware name: Dell Inc. PowerEdge R730/0WCJNT, BIOS > 2.19.0 12/12/2023 > [ 319.872704] RIP: 0010:btrfs_zoned_reserve_data_reloc_bg.cold+0xb2/0xb4 > [ 319.880014] Code: ab e8 7e ab f7 ff 0f 0b 41 b8 1b 0a 00 00 48 c7 > c1 80 9f 59 ab 31 d2 48 c7 c6 20 b8 59 ab 48 c7 c7 20 a0 59 ab e8 5a > ab f7 ff <0f> 0b 41 b8 5f 0a 00 00 48 c7 c1 80 9f 59 ab 31 d2 48 c7 c6 > 00 b9 > [ 319.900977] RSP: 0018:ffffc9000c21f930 EFLAGS: 00010282 > [ 319.906816] RAX: 0000000000000047 RBX: ffff8888d1a54000 RCX: 0000000000000000 > [ 319.914783] RDX: 0000000000000047 RSI: 1ffffffff629cc84 RDI: fffff52001843f18 > [ 319.922742] RBP: ffff888121b7c000 R08: ffffffffa802cbb5 R09: fffff52001843edc > [ 319.930709] R10: 0000000000000003 R11: 0000000000000001 R12: 0000000000000000 > [ 319.938666] R13: 0000000000000001 R14: ffff888121b7c128 R15: ffff88810f379800 > [ 319.946625] FS: 00007fbd89e98840(0000) GS:ffff8890af8e8000(0000) > knlGS:0000000000000000 > [ 319.955661] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 319.962077] CR2: 0000559e0ad4b540 CR3: 00000008e14ce003 CR4: 00000000003726f0 > [ 319.970046] Call Trace: > [ 319.972767] <TASK> > [ 319.975102] ? create_space_info+0x155/0x390 > [ 319.979880] open_ctree+0x1874/0x2203 > [ 319.983977] btrfs_fill_super.cold+0x2c/0x16d > [ 319.988850] btrfs_get_tree_super+0x936/0xd60 > [ 319.993725] btrfs_get_tree_subvol+0x230/0x5f0 > OK the problem is, we're ASSERTing if zone_unusable is 0 and that obviously fails, because zbd/009 configures scsi_debug with a zone_size of 4MB and a zone_capacity of 3MB. This automatically leads to an assertion failure as bg->zone_unusable is 1MB. The test in there is to check if we have an empty block-group. @Naohiro what do you think of the following: diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c index 6e66ec491181..f897f914b78e 100644 --- a/fs/btrfs/zoned.c +++ b/fs/btrfs/zoned.c @@ -2590,7 +2590,8 @@ void btrfs_zoned_reserve_data_reloc_bg(struct btrfs_fs_info *fs_info) space_info->disk_total -= bg->length * factor; /* There is no allocation ever happened. */ ASSERT(bg->used == 0); - ASSERT(bg->zone_unusable == 0); + ASSERT(bg->zone_unusable == 0 || + bg->length - bg->zone_unusable == bg->zone_capacity); /* No super block in a block group on the zoned setup. */ ASSERT(bg->bytes_super == 0); spin_unlock(&space_info->lock);
