Here is the output of `ls -latr /proc/<pid>/fd`


root      3377  0.0  0.0  11980  3352 ?        D    Jan24   0:00 blkid -c /dev/null -o export
root      6293  0.0  0.0  11980  3316 ?        D    Jan24   0:00 blkid -c /dev/null -o export
root     10422  0.0  0.0  11980  3556 ?        D    Jan26   0:00 blkid -c /dev/null -o export
root     13020  0.0  0.0  11980  3492 ?        D    Jan24   0:00 blkid -c /dev/null -o export
root     13192  0.0  0.0  11980  3752 ?        D    Jan26   0:00 blkid -c /dev/null -o export
root     15494  0.0  0.0  11980  3704 ?        D    Jan27   0:00 blkid -c /dev/null -o export
root     15506  0.0  0.0  11212  2532 ?        D    Jan23   0:00 blkid -c /dev/null -o export
root     15630  0.0  0.0  11980  3456 ?        D    Jan24   0:00 blkid -c /dev/null -o export
root     15768  0.0  0.0  11980  3700 ?        D    Jan26   0:00 blkid -c /dev/null -o export
root     16282  0.0  0.0  11980  3704 ?        D    Jan27   0:00 blkid -c /dev/null -o export
root     18328  0.0  0.0  11980  3616 ?        D    Jan27   0:00 blkid -c /dev/null -o export
root     18364  0.0  0.0  11980  3432 ?        D    Jan23   0:00 blkid -c /dev/null -o export
root     18549  0.0  0.0  11980  3324 ?        D    Jan24   0:00 blkid -c /dev/null -o export
root     18755  0.0  0.0  11980  3620 ?        D    Jan26   0:00 blkid -c /dev/null -o export
root     19266  0.0  0.0  11980  3556 ?        D    Jan27   0:00 blkid -c /dev/null -o export
root     20480  0.0  0.0  11980  3616 ?        D    Jan26   0:00 blkid -c /dev/null -o export
root     21131  0.0  0.0  11980  3504 ?        D    Jan23   0:00 blkid -c /dev/null -o export
root     21149  0.0  0.0  11980  3636 ?        D    Jan27   0:00 blkid -c /dev/null -o export
root     21378  0.0  0.0  11980  3180 ?        D    Jan24   0:00 blkid -c /dev/null -o export
root     21927  0.0  0.0  11980  3624 ?        D    Jan27   0:00 blkid -c /dev/null -o export
root     23165  0.0  0.0  11980  3704 ?        D    Jan26   0:00 blkid -c /dev/null -o export
root     23795  0.0  0.0  11980  3616 ?        D    Jan27   0:00 blkid -c /dev/null -o export
root     23911  0.0  0.0  11980  3456 ?        D    Jan23   0:00 blkid -c /dev/null -o export
root     24554  0.0  0.0  11980  3592 ?        D    Jan27   0:00 blkid -c /dev/null -o export
root     25672  0.0  0.0  11980  3752 ?        D    Jan26   0:00 blkid -c /dev/null -o export
root     28344  0.0  0.0  11980  3704 ?        D    Jan26   0:00 blkid -c /dev/null -o export
root     30382  0.0  0.0  11980  3216 ?        D    Jan24   0:00 blkid -c /dev/null -o export


dr-xr-xr-x 9 root root  0 Jan 30 06:29 ..
lr-x------ 1 root root 64 Jan 30 15:22 4 -> /proc/partitions
l-wx------ 1 root root 64 Jan 30 15:22 3 -> /run/cloud-init/ds-identify.log
lrwx------ 1 root root 64 Jan 30 15:22 2 -> /dev/null
l-wx------ 1 root root 64 Jan 30 15:22 1 -> 'pipe:[399588299]'
lrwx------ 1 root root 64 Jan 30 15:22 0 -> /dev/null
dr-x------ 2 root root  0 Jan 30 15:22 .


root@ubuntuapp02:/# ls -latr /proc/23795/fd
total 0
dr-xr-xr-x 9 root root  0 Jan 30 06:29 ..
lr-x------ 1 root root 64 Jan 30 15:23 4 -> /proc/partitions
l-wx------ 1 root root 64 Jan 30 15:23 3 -> /run/cloud-init/ds-identify.log
lrwx------ 1 root root 64 Jan 30 15:23 2 -> /dev/null
l-wx------ 1 root root 64 Jan 30 15:23 1 -> 'pipe:[415355377]'
lrwx------ 1 root root 64 Jan 30 15:23 0 -> /dev/null
dr-x------ 2 root root  0 Jan 30 15:23 .