Re: 回复: 回复: [PATCH] btrfs: Fix missing close devices

[Johannes Thumshirn]

On 23/09/2020 08:03, Zhang, Qiang wrote:
> Hello Johannes Thumshirn
> 
> the crash happend in "snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev)" in btrfs_mount_root func,  the  "bdev" may be destroyed in btrfs_close_devices.
> I think add  btrfs_close_devices func before deactivate_locked_super is reasonable.
>  I'm not sure if that's another problem .
>  What's your point of view ？
> 

I think this is generally unneeded.
Think of this call chain:
deactivate_locked_super()
`-> fs->kill_sb()
    `-> btrfs_kill_super()
        `-> kill_anon_super()
            `-> generic_shutdown_super()
                `-> sop->put_super()
                    `-> btrfs_put_super()
                        `-> close_ctree()
                            `-> btrfs_close_devices()