[Gluster-devel] regarding inode_link/unlink

[Raghavendra Gowdappa]

----- Original Message -----
> From: "Pranith Kumar Karampuri" <pkarampu at redhat.com>
> To: "Raghavendra Gowdappa" <rgowdapp at redhat.com>
> Cc: "Gluster Devel" <gluster-devel at gluster.org>, "Anand Avati" <avati at gluster.org>, "Brian Foster"
> <bfoster at redhat.com>, "Raghavendra Bhat" <rabhat at redhat.com>
> Sent: Friday, July 4, 2014 5:39:03 PM
> Subject: Re: regarding inode_link/unlink
> 
> 
> On 07/04/2014 04:28 PM, Raghavendra Gowdappa wrote:
> >
> > ----- Original Message -----
> >> From: "Pranith Kumar Karampuri" <pkarampu at redhat.com>
> >> To: "Gluster Devel" <gluster-devel at gluster.org>, "Anand Avati"
> >> <avati at gluster.org>, "Brian Foster"
> >> <bfoster at redhat.com>, "Raghavendra Gowdappa" <rgowdapp at redhat.com>,
> >> "Raghavendra Bhat" <rabhat at redhat.com>
> >> Sent: Friday, July 4, 2014 3:44:29 PM
> >> Subject: regarding inode_link/unlink
> >>
> >> hi,
> >>        I have a doubt about when a particular dentry_unset thus
> >> inode_unref on parent dir happens on fuse-bridge in gluster.
> >> When a file is looked up for the first time fuse_entry_cbk does
> >> 'inode_link' with parent-gfid/bname. Whenever an unlink/rmdir/(lookup
> >> gives ENOENT) happens then corresponding inode unlink happens. The
> >> question is, will the present set of operations lead to leaks:
> >> 1) Mount 'M0' creates a file 'a'
> >> 2) Mount 'M1' of same volume deletes file 'a'
> >>
> >> M0 never touches 'a' anymore. When will inode_unlink happen for such
> >> cases? Will it lead to memory leaks?
> > Kernel will eventually send forget (a) on M0 and that will cleanup the
> > dentries and inode. Its equivalent to a file being looked up and never
> > used again (deleting doesn't matter in this case).
> Do you know the trigger points for that? When I do 'touch a' on the
> mount point and leave the system like that, forget is not coming.
> If I do unlink on the file then forget is coming.

I am not very familiar with how kernel manages its inodes. However, as Avati has mentioned in another mail, you can force kernel to send forgets by invalidating the inode. I think he has given enough details in another mail.

> 
> Pranith
> >
> >
> >> Pranith
> >>
> 
>