Hi, guys! Recently, We have met a problem that systemd insides docker always hang at below stack, stays inside shrink_dcache_sb as long as hours. __dentry_kill+0x124/0x170 shrink_dentry_list+0x64/0xb0 shrink_dcache_sb+0xb2/0x140 reconfigure_super+0x85/0x220 do_mount+0x90e/0x980 ksys_mount+0xb6/0xd0 __x64_sys_mount+0x25/0x30 do_syscall_64+0x47/0x140 entry_SYSCALL_64_after_hwframe+0x44/0xa9 We run many containers onside /data which is a xfs file system. Directories on /data are bind mounted inside containers, sometimes, systemd inside containers may do remount operations with these bind directories. Each remount would cause a reconfigure on /data and shrink_dcache_sb is called to shrink the s_dentry_lru list, as data is shared by all containers, processes may still produce dentries on this list, which may cause a long time to wait shrinking ends. So, We mailed to wonder is it possible to skip this shrink operation for containers as lower xfs file system is still running, or is it possible to optimize shrink_dcache_sb function to scan only once of the dentry lru list, do not wait the list to become empty. We appreciate for a response, Thanks!
