tree 1878f49e8ab0d458113c2d6744f785b915eeaba9
parent 73953b8f8db9a8e8e35ea58f0b8312d823a4a65b
author Marri Devender Rao <devenrao@in.ibm.com> 1656475934 -0500
committer Marri Devender Rao <devenrao@in.ibm.com> 1679596231 -0500

sdevent:inode entry is not released after creating dump

For every dump generated an "anon_inode:[pidfd]" entry is
created for the associated process and the same is not
released.

When the number of inode entries reach the maximum count
dump request will fail and the dump service takes a reset
with a core dump.

When a dump is requested a child process is spawned to
perform dump collection, parent process waits on the
child process completion using sd-event-add-child
systemd call.

sd-event-add-child adds an inode entry which needs to
be released during the callback method called after
child process exit using unref but the same is not done.

Now switching to sdeventplus::source::Child wrapper class for
sd-event-add-child which takes care of releasing the inode fd.

Tested:
'''
Without the fix for the 3 dumps created noticed 3 anon_inode:[pidfd]
are added but not cleared
root@rain135bmc:/proc/2044/fd# ls -la
dr-x------    2 root     root             0 Jun 27 08:38 .
dr-xr-xr-x    8 root     root             0 Jun 27 08:38 ..
lr-x------    1 root     root            64 Jun 27 08:39 0 -> /dev/null
lrwx------    1 root     root            64 Jun 27 08:39 1 -> socket:[21586]
lrwx------    1 root     root            64 Jun 27 08:39 10 ->anon_inode:[timerfd]
lrwx------    1 root     root            64 Jun 27 08:47 11 ->anon_inode:[pidfd]
lrwx------    1 root     root            64 Jun 27 08:47 12 ->anon_inode:[pidfd]
lrwx------    1 root     root            64 Jun 27 08:47 13 ->anon_inode:[pidfd]

After the fix noticed all the anon_inode:[pidfd] are cleared
dr-x------    2 root     root             0 Jun 27 08:38 .
dr-xr-xr-x    8 root     root             0 Jun 27 08:38 ..
lr-x------    1 root     root            64 Jun 27 08:39 0 -> /dev/null
lrwx------    1 root     root            64 Jun 27 08:39 1 -> socket:[21586]
lrwx------    1 root     root            64 Jun 27 08:39 10 ->anon_inode:[timerfd]
'''

Signed-off-by: Marri Devender Rao <devenrao@in.ibm.com>
Change-Id: I9a2fec0a2287bfe978b811671c1cfeb1356e59d2