[Bugs] [Bug 1397052] OOM kill of nfs-ganesha on one node while fs-sanity test suite is executed.

[bugzilla at redhat.com]

https://bugzilla.redhat.com/show_bug.cgi?id=1397052

Jiffin <jthottan at redhat.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |POST



--- Comment #3 from Jiffin <jthottan at redhat.com> ---
The above issue happens when rename/00.t test executed on nfs-ganesha clients :
Steps executed in that script
 * create a file using root
 * rename the file using a non root user, it fails with EACESS
 * delete the file 
 * create directory directory using root
 * rename the directory using non root user, test hungs and slowly led to OOM
kill of ganesha 

RCA put forwarded by Du for OOM kill of ganesha
Note that when we hit this bug, we've a scenario of a dentry being present as:
 * a linkto file on one subvol 
 * a directory on rest of subvols

When a lookup happens on the dentry in such a scenario, the control flow goes
into an infinite loop of: 
dht_lookup_everywhere
dht_lookup_everywhere_cbk
dht_lookup_unlink_cbk
dht_lookup_everywhere_done
dht_lookup_directory (as local->dir_count > 0)
dht_lookup_dir_cbk (sets to local->need_selfheal = 1 as the entry is a linkto
file on one of the subvol)
dht_lookup_everywhere (as need_selfheal = 1).

This infinite loop can cause increased consumption of memory due to:
1) dht_lookup_directory assigns a new layout to local->layout unconditionally
2) Most of the functions in this loop do a stack_wind of various fops.

This results in growing of call stack (note that call-stack is destroyed only
after lookup response is received by fuse - which never happens in this case)

-- 
You are receiving this mail because:
You are on the CC list for the bug.
Unsubscribe from this bug https://bugzilla.redhat.com/token.cgi?t=JHJfBCLN6f&a=cc_unsubscribe