In Fedora CoreOS we have a test that tests kdump by forcing a kernel crash. We also have code that does an xfs_growfs on our root filesystem on instance bringup. Our CI recently exposed a race condition here where if you trigger the kernel crash in the right time window after growfs the kernel starts spitting out traces in the XFS stack. ``` [ 1.920053] systemd[1]: Mounting kdumproot-sysroot.mount - /kdumproot/sysroot... [ 2.194643] SGI XFS with ACLs, security attributes, scrub, quota, no debug enabled [ 2.199585] XFS: attr2 mount option is deprecated. [ 2.200537] XFS (vda4): Mounting V5 Filesystem [ 2.241396] XFS (vda4): Starting recovery (logdev: internal) [ 2.264029] XFS (vda4): xfs_buf_find: daddr 0x3b6001 out of range, EOFS 0x3b6000 [ 2.264921] ------------[ cut here ]------------ [ 2.265443] WARNING: CPU: 0 PID: 487 at fs/xfs/xfs_buf.c:556 xfs_buf_find+0x518/0x5f0 [xfs] [ 2.266645] Modules linked in: xfs crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel serio_raw virtio_net net_failover virtio_console failover virtio_blk ata_generic pata_acpi qemu_fw_cfg ip6_tables ip_tables ipmi_devintf ipmi_msghandler fuse overlay squashfs loop [ 2.269172] CPU: 0 PID: 487 Comm: mount Not tainted 5.17.6-300.fc36.x86_64 #1 [ 2.269920] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014 [ 2.270835] RIP: 0010:xfs_buf_find+0x518/0x5f0 [xfs] [ 2.271448] Code: e8 2d 4f f1 c0 e9 e5 fe ff ff 0f 1f 44 00 00 e9 b5 fe ff ff 48 89 c1 48 c7 c2 b0 bb 22 c0 48 c7 c6 e0 c6 23 c0 e8 65 28 05 00 <0f> 0b b8 8b ff ff ff e9 cd fe ff ff 0f 1f 44 00 00 e9 1a fd ff ff [ 2.273331] RSP: 0018:ffffc9000073f980 EFLAGS: 00010282 [ 2.273888] RAX: 00000000ffffffea RBX: 0000000000000001 RCX: 000000007fffffff [ 2.274642] RDX: 0000000000000021 RSI: 0000000000000000 RDI: ffffffffc02378fd [ 2.275423] RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000000a [ 2.276300] R10: 000000000000000a R11: 0fffffffffffffff R12: ffff8880bb1c5100 [ 2.277205] R13: ffffc9000073f9e8 R14: ffffc9000073fa98 R15: 0000000000000001 [ 2.278144] FS: 00007f815240f800(0000) GS:ffff8880b8a00000(0000) knlGS:0000000000000000 [ 2.279101] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 2.279807] CR2: 00007f4b81ba8c08 CR3: 00000000bb248000 CR4: 0000000000350eb0 [ 2.280829] Call Trace: [ 2.281176] <TASK> [ 2.281461] xfs_buf_get_map+0x35/0x390 [xfs] [ 2.282289] xfs_buf_read_map+0x39/0x270 [xfs] [ 2.282932] xfs_buf_readahead_map+0x40/0x50 [xfs] [ 2.283648] ? xfs_buf_readahead_map+0x22/0x50 [xfs] [ 2.284421] xlog_buf_readahead+0x52/0x60 [xfs] [ 2.285113] xlog_recover_commit_trans+0xcf/0x300 [xfs] [ 2.285879] xlog_recovery_process_trans+0xc0/0xf0 [xfs] [ 2.286685] xlog_recover_process_data+0xa0/0x120 [xfs] [ 2.287395] xlog_do_recovery_pass+0x3ae/0x5b0 [xfs] [ 2.288004] ? preempt_count_add+0x44/0x90 [ 2.288474] xlog_do_log_recovery+0x87/0xb0 [xfs] [ 2.289046] xlog_do_recover+0x34/0x1b0 [xfs] [ 2.289597] xlog_recover+0xb6/0x150 [xfs] [ 2.290113] xfs_log_mount+0x14a/0x280 [xfs] [ 2.290651] xfs_mountfs+0x3ce/0x840 [xfs] [ 2.291175] ? xfs_filestream_get_parent+0x70/0x70 [xfs] [ 2.291807] ? xfs_mru_cache_create+0x136/0x180 [xfs] [ 2.292469] xfs_fs_fill_super+0x466/0x810 [xfs] [ 2.293032] ? xfs_init_fs_context+0x170/0x170 [xfs] [ 2.293637] get_tree_bdev+0x16d/0x260 [ 2.294064] vfs_get_tree+0x25/0xb0 [ 2.294465] path_mount+0x431/0xa70 [ 2.294857] __x64_sys_mount+0xe2/0x120 [ 2.295290] do_syscall_64+0x3a/0x80 [ 2.295688] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 2.296241] RIP: 0033:0x7f81526002ae [ 2.296641] Code: 48 8b 0d 6d fb 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 3a fb 0d 00 f7 d8 64 89 01 48 [ 2.298518] RSP: 002b:00007ffdf1b0e548 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [ 2.299312] RAX: ffffffffffffffda RBX: 0000564ccec18bb0 RCX: 00007f81526002ae [ 2.300051] RDX: 0000564ccec18f20 RSI: 0000564ccec18f80 RDI: 0000564ccec19c50 [ 2.300801] RBP: 0000000000000000 R08: 0000564ccec18e80 R09: 0000000000000073 [ 2.301560] R10: 0000000000200000 R11: 0000000000000246 R12: 0000564ccec19c50 [ 2.302314] R13: 0000564ccec18f20 R14: 00000000ffffffff R15: 00007f815274e076 [ 2.303056] </TASK> [ 2.303329] ---[ end trace 0000000000000000 ]--- ``` The original bug with some more context is at https://github.com/coreos/fedora-coreos-tracker/issues/1195 This was originally seen with Fedora kernel 5.17.6-300.fc36.x86_64 Eric Sandeen created a small reproducer: ``` #!/bin/bash rm -f fsfile mkfs.xfs -b size=4096 -dfile,name=fsfile,size=486400b truncate --size=10199478272 fsfile mkdir -p mnt mount -o loop fsfile mnt xfs_growfs mnt for I in `seq 1 32`; do mkdir mnt/dir$I touch mnt/dir$I/file done sync -f mnt xfs_io -x -c "shutdown" mnt umount mnt mount -o loop fsfile mnt umount mnt ```