Hi Hellwig,

I bisected my boot problem down to this commit:

$ git bisect good
af2814149883e2c1851866ea2afcd8eadc040f79 is the first bad commit
commit af2814149883e2c1851866ea2afcd8eadc040f79
Author: Christoph Hellwig [off-list ref]
Date:   Mon Jun 17 08:04:38 2024 +0200

     block: freeze the queue in queue_attr_store

     queue_attr_store updates attributes used to control generating I/O, and
     can cause malformed bios if changed with I/O in flight.  Freeze the 
queue
     in common code instead of adding it to almost every attribute.

     Signed-off-by: Christoph Hellwig [off-list ref]
     Reviewed-by: Bart Van Assche [off-list ref]
     Reviewed-by: Damien Le Moal [off-list ref]
     Reviewed-by: Hannes Reinecke [off-list ref]
     Reviewed-by: Chaitanya Kulkarni [off-list ref]
     Link: https://lore.kernel.org/r/20240617060532.127975-12-hch@lst.de (local)
     Signed-off-by: Jens Axboe [off-list ref]

  block/blk-mq.c    | 5 +++--
  block/blk-sysfs.c | 9 ++-------
  2 files changed, 5 insertions(+), 9 deletions(-)

git describe --contains af2814149883e2c1851866ea2afcd8eadc040f79
v6.11-rc1~80^2~66^2~15


On 10/09/2024 16.49, Jesper Dangaard Brouer wrote:

On 10/09/2024 15.06, Damien Le Moal wrote:

quoted

On 2024/09/10 21:19, Jesper Dangaard Brouer wrote:

quoted

Hi Linus,

My testlab kernel devel server isn't booting correctly on v6.11 branches
(e.g. net-next at 6.11.0-rc5)
I just confirmed this also happens on your tree tag: v6.11-rc7.

The symptom/issue is that harddisk dev names (e.g /dev/sda, /dev/sdb,
/dev/sdc) gets reordered.  I switched /etc/fstab to use UUID's instead
(which boots on v6.10) but on 6.11 it still cannot mount harddisks and
doesn't fully boot.

Parallel SCSI device scanning has been around for a long time... This is
controlled with CONFIG_SCSI_SCAN_ASYNC. And yes, that can cause disk 
names to
change, which is why it is never a good idea to rely on them but 
instead use
/dev/disk/by-* names. Disabling CONFIG_SCSI_SCAN_ASYNC will likely not 
guarantee
that disk names will be constant, given that you seem to have 2 AHCI 
adapters on
your host and PCI device scanning is done in parallel.

quoted

E.g. errors:
    systemd[1]: Expecting device
dev-disk-by\x2duuid-0c2b348d\x2de013\x2d482b\x2da91c\x2d029640ec427a.device
- /dev/disk/by-uuid/0c2b348d-e013-482b-a91c-029640ec42
7a...
    [DEPEND] Dependency failed for var-lib.mount - /var/lib.
    [...]
    [ TIME ] Timed out waiting for device
dev-d…499e46-b40d-4067-afd4-5f6ad09fcff2.
    [DEPEND] Dependency failed for boot.mount - /boot.

That corresponds to fstab's:
   - UUID=8b499e46-b40d-4067-afd4-5f6ad09fcff2 /boot     xfs defaults 
0 0
   - UUID=0c2b348d-e013-482b-a91c-029640ec427a /var/lib/ xfs defaults 
0 0

It looks like disk controller initialization happens in *parallel* on
these newer kernels as dmesg shows init printk's overlapping:

   [    5.683393] scsi 5:0:0:0: Direct-Access     ATA      SAMSUNG
MZ7KM120 003Q PQ: 0 ANSI: 5
   [    5.683641] scsi 7:0:0:0: Direct-Access     ATA      SAMSUNG
MZ7KM120 003Q PQ: 0 ANSI: 5
   [    5.683797] scsi 8:0:0:0: Direct-Access     ATA      Samsung SSD
840  BB0Q PQ: 0 ANSI: 5
   [...]
   [    7.057376] sd 5:0:0:0: [sda] 234441648 512-byte logical blocks:
(120 GB/112 GiB)
   [    7.062279] sd 7:0:0:0: [sdb] 234441648 512-byte logical blocks:
(120 GB/112 GiB)
   [    7.070628] sd 5:0:0:0: [sda] Write Protect is off
   [    7.070701] sd 8:0:0:0: [sdc] 488397168 512-byte logical blocks:
(250 GB/233 GiB)

Perhaps this could be a hint to what changed?

See above. The disk /dev/sdX names not being reliable is rather normal.
Are you sure you have the correct UUIDs of your FSes on the disks ? 
You can
check them with "blkid /dev/sdX[n]"

I have checked that I use the correct UUIDs.

I checked my /etc/fstab have the UUID entries under /dev/disk/by-uuid/
via this oneliner, which needs to have a /etc/fstab entry under each
UUID. We can see I have one partition that I'm not using
(0fd3bc38-6496-401f-87f2-87e09532de53), which is expected.

$ for UUID in $(ls /dev/disk/by-uuid/); do echo $UUID; grep -H $UUID 
/etc/fstab; done
09e8c15f-80d2-47e3-8e73-d3fdfcf33eef
/etc/fstab:UUID=09e8c15f-80d2-47e3-8e73-d3fdfcf33eef /     xfs     
defaults        0 0
0c2b348d-e013-482b-a91c-029640ec427a
/etc/fstab:UUID=0c2b348d-e013-482b-a91c-029640ec427a    /var/lib/        
xfs defaults 0 0
0fd3bc38-6496-401f-87f2-87e09532de53
581920da-1ccb-4b25-856c-036310032a74
/etc/fstab:UUID=581920da-1ccb-4b25-856c-036310032a74    /nix            
xfs    defaults 0 0
8b499e46-b40d-4067-afd4-5f6ad09fcff2
/etc/fstab:UUID=8b499e46-b40d-4067-afd4-5f6ad09fcff2 /boot     xfs     
defaults        0 0
cd409a50-0371-47ca-9213-49a2bc7b9317
/etc/fstab:UUID=cd409a50-0371-47ca-9213-49a2bc7b9317 swap     swap    
defaults        0 0

quoted

quoted

Any hints what commit I should try to test revert?
Or good starting point for bisecting?

You said that 6.10 works, so maybe start from there ?

I tested I could boot tag v6.10, and have started bisection.

I've not tried to deselect CONFIG_SCSI_SCAN_ASYNC as the kernel that
worked on tag v6.10 also had this CONFIG_SCSI_SCAN_ASYNC enabled. So, it
is likely not related to the async controller init.

--Jesper