Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

2018-03-12 Thread sriram patil
The other way is instead of removing the fs_locations callback from object
ops we can add attrlist as one more parameter to the function and pull the
attrs from mdcache and pass it down to fsal. Fsal can then parse the
strings and fill the fsroot and servers.

On Mon 12 Mar, 2018, 8:02 PM Sriram Patil, <srir...@vmware.com> wrote:

> Some questions about this implementation.
>
>
>
> We should be filling the fs_locations in attrs as part of getattrs now,
> this can be done by subfsal getattrs callback so that subfsals have control
> over the fs_locations. But, with this, we may not require the fs_locations
> callback in the obj_ops. Is ti okay to get rid of the fs_locations callback
> or should I just add a comment mentioning this will be deprecated? It will
> also require changes in the existing FSALs which use the fs_locations
> callback currently. What do you think?
>
>
>
> Thanks,
>
> Sriram
>
>
>
> *From: *Sriram Patil <srir...@vmware.com>
> *Date: *Saturday, March 10, 2018 at 8:30 PM
> *To: *Frank Filz <ffilz...@mindspring.com>, "
> nfs-ganesha-devel@lists.sourceforge.net" <
> nfs-ganesha-devel@lists.sourceforge.net>
> *Subject: *Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS
>
>
>
> Okay, sounds good. Will work towards getting this right.
>
>
>
> Thanks,
>
> Sriram
>
>
>
> *From: *Frank Filz <ffilz...@mindspring.com>
> *Date: *Friday, March 9, 2018 at 11:20 PM
> *To: *Sriram Patil <srir...@vmware.com>, "
> nfs-ganesha-devel@lists.sourceforge.net" <
> nfs-ganesha-devel@lists.sourceforge.net>
> *Subject: *RE: [Nfs-ganesha-devel] About referrals in FSAL_VFS
>
>
>
> Hmm, did I sow confusion about fs_locations in attrlist? I think that
> would be the best solution. We do need to work to be careful about tracking
> the validity of different parts of the attrlist, since we don’t necessarily
> want to fetch the fs_locations from the filesystem every time we refresh
> attributes.
>
>
>
> I think with fs_locations being in the attrlist, it becomes much easier to
> have a sub-fsal with different handling.
>
>
> Frank
>
>
>
> *From:* Sriram Patil [mailto:srir...@vmware.com]
> *Sent:* Friday, March 9, 2018 9:09 AM
> *To:* Frank Filz <ffilz...@mindspring.com>;
> nfs-ganesha-devel@lists.sourceforge.net
> *Subject:* Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS
>
>
>
> Hi Frank,
>
>
>
> Now that the referral fixes for pynfs are approved (not merged yet), I
> wanted to work on the subfsal layer to extend this to subfsal and allow
> having referral points as desired. As we had discussed before, it would be
> a good idea to store fs locations in the attrlist, but a few days back on
> IRC you mentioned that we do not want to jump onto that as yet. So, I was
> thinking of supporting referrals and fs_locations at subfsal layer a little
> differently which will not involve a lot of changes.
>
>
>
> Currently, the vfs_fsal_obj_handle stores fsroot and fslocations as part
> of directory (hdl->u.directory). I was thinking of moving these out of the
> union and make them first class variable in the structure or the union
> inside it. This way the fsroot and fslocations can be stored for any file
> type, for example a symlink. I will be adding some subfsal callbacks for
> populating and retrieving the fslocation details as discussed before.
>
>
>
> Let me know if this looks like a good thing to do or should we think about
> fslocations in attrlist?
>
>
>
> Thanks,
>
> Sriram
>
>
>
> *From: *Sriram Patil <srir...@vmware.com>
> *Date: *Friday, February 9, 2018 at 10:30 AM
> *To: *Frank Filz <ffilz...@mindspring.com>, "
> nfs-ganesha-devel@lists.sourceforge.net" <
> nfs-ganesha-devel@lists.sourceforge.net>
> *Subject: *Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS
>
>
>
> Okay, so there are a bunch of things that we need to do. I will just list
> them down here, let me know if I miss anything.
>
>1. Fs locations can be moved to attrlist and FSAL can fill it as part
>of getattr if required
>2. We need ref counting for fs locations for handling attr copy where
>multiple objects can hold reference to fs locations
>3. Have a validity bit for fs locations. Allow a dbus command to
>invalidate all fs_locations to be able to refresh the locations for dynamic
>    updates
>    4. Add methods/callbacks to subfsal mechanism to allow subfsals to
>choose how referrals work for them. This should also allow a way to follow
>the default VFS mechanism
>
>
>
> Thanks,
>
> Sriram
>
>
>
>

Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

2018-03-12 Thread Sriram Patil
Some questions about this implementation.

We should be filling the fs_locations in attrs as part of getattrs now, this 
can be done by subfsal getattrs callback so that subfsals have control over the 
fs_locations. But, with this, we may not require the fs_locations callback in 
the obj_ops. Is ti okay to get rid of the fs_locations callback or should I 
just add a comment mentioning this will be deprecated? It will also require 
changes in the existing FSALs which use the fs_locations callback currently. 
What do you think?

Thanks,
Sriram

From: Sriram Patil <srir...@vmware.com>
Date: Saturday, March 10, 2018 at 8:30 PM
To: Frank Filz <ffilz...@mindspring.com>, 
"nfs-ganesha-devel@lists.sourceforge.net" 
<nfs-ganesha-devel@lists.sourceforge.net>
Subject: Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

Okay, sounds good. Will work towards getting this right.

Thanks,
Sriram

From: Frank Filz <ffilz...@mindspring.com>
Date: Friday, March 9, 2018 at 11:20 PM
To: Sriram Patil <srir...@vmware.com>, 
"nfs-ganesha-devel@lists.sourceforge.net" 
<nfs-ganesha-devel@lists.sourceforge.net>
Subject: RE: [Nfs-ganesha-devel] About referrals in FSAL_VFS

Hmm, did I sow confusion about fs_locations in attrlist? I think that would be 
the best solution. We do need to work to be careful about tracking the validity 
of different parts of the attrlist, since we don’t necessarily want to fetch 
the fs_locations from the filesystem every time we refresh attributes.

I think with fs_locations being in the attrlist, it becomes much easier to have 
a sub-fsal with different handling.

Frank

From: Sriram Patil [mailto:srir...@vmware.com]
Sent: Friday, March 9, 2018 9:09 AM
To: Frank Filz <ffilz...@mindspring.com>; 
nfs-ganesha-devel@lists.sourceforge.net
Subject: Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

Hi Frank,

Now that the referral fixes for pynfs are approved (not merged yet), I wanted 
to work on the subfsal layer to extend this to subfsal and allow having 
referral points as desired. As we had discussed before, it would be a good idea 
to store fs locations in the attrlist, but a few days back on IRC you mentioned 
that we do not want to jump onto that as yet. So, I was thinking of supporting 
referrals and fs_locations at subfsal layer a little differently which will not 
involve a lot of changes.

Currently, the vfs_fsal_obj_handle stores fsroot and fslocations as part of 
directory (hdl->u.directory). I was thinking of moving these out of the union 
and make them first class variable in the structure or the union inside it. 
This way the fsroot and fslocations can be stored for any file type, for 
example a symlink. I will be adding some subfsal callbacks for populating and 
retrieving the fslocation details as discussed before.

Let me know if this looks like a good thing to do or should we think about 
fslocations in attrlist?

Thanks,
Sriram

From: Sriram Patil <srir...@vmware.com<mailto:srir...@vmware.com>>
Date: Friday, February 9, 2018 at 10:30 AM
To: Frank Filz <ffilz...@mindspring.com<mailto:ffilz...@mindspring.com>>, 
"nfs-ganesha-devel@lists.sourceforge.net<mailto:nfs-ganesha-devel@lists.sourceforge.net>"
 
<nfs-ganesha-devel@lists.sourceforge.net<mailto:nfs-ganesha-devel@lists.sourceforge.net>>
Subject: Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

Okay, so there are a bunch of things that we need to do. I will just list them 
down here, let me know if I miss anything.

  1.  Fs locations can be moved to attrlist and FSAL can fill it as part of 
getattr if required
  2.  We need ref counting for fs locations for handling attr copy where 
multiple objects can hold reference to fs locations
  3.  Have a validity bit for fs locations. Allow a dbus command to invalidate 
all fs_locations to be able to refresh the locations for dynamic updates
  4.  Add methods/callbacks to subfsal mechanism to allow subfsals to choose 
how referrals work for them. This should also allow a way to follow the default 
VFS mechanism

Thanks,
Sriram

From: Frank Filz <ffilz...@mindspring.com<mailto:ffilz...@mindspring.com>>
Date: Friday, February 9, 2018 at 12:05 AM
To: Sriram Patil <srir...@vmware.com<mailto:srir...@vmware.com>>, 
"nfs-ganesha-devel@lists.sourceforge.net<mailto:nfs-ganesha-devel@lists.sourceforge.net>"
 
<nfs-ganesha-devel@lists.sourceforge.net<mailto:nfs-ganesha-devel@lists.sourceforge.net>>
Subject: RE: [Nfs-ganesha-devel] About referrals in FSAL_VFS

There are places the struct attrlist gets copied, if so, either the referral 
needs to be duplicated in that copy, or it needs to be a single entity with a 
refcount.

One advantage of adding the referral to the struct attrlist is that MDCACHE 
will manage cache life of it.

It may or may not be worth having a separate cache validity bit for it 
(advantage of doing that is the

Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

2018-03-10 Thread Sriram Patil
Okay, sounds good. Will work towards getting this right.

Thanks,
Sriram

From: Frank Filz <ffilz...@mindspring.com>
Date: Friday, March 9, 2018 at 11:20 PM
To: Sriram Patil <srir...@vmware.com>, 
"nfs-ganesha-devel@lists.sourceforge.net" 
<nfs-ganesha-devel@lists.sourceforge.net>
Subject: RE: [Nfs-ganesha-devel] About referrals in FSAL_VFS

Hmm, did I sow confusion about fs_locations in attrlist? I think that would be 
the best solution. We do need to work to be careful about tracking the validity 
of different parts of the attrlist, since we don’t necessarily want to fetch 
the fs_locations from the filesystem every time we refresh attributes.

I think with fs_locations being in the attrlist, it becomes much easier to have 
a sub-fsal with different handling.

Frank

From: Sriram Patil [mailto:srir...@vmware.com]
Sent: Friday, March 9, 2018 9:09 AM
To: Frank Filz <ffilz...@mindspring.com>; 
nfs-ganesha-devel@lists.sourceforge.net
Subject: Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

Hi Frank,

Now that the referral fixes for pynfs are approved (not merged yet), I wanted 
to work on the subfsal layer to extend this to subfsal and allow having 
referral points as desired. As we had discussed before, it would be a good idea 
to store fs locations in the attrlist, but a few days back on IRC you mentioned 
that we do not want to jump onto that as yet. So, I was thinking of supporting 
referrals and fs_locations at subfsal layer a little differently which will not 
involve a lot of changes.

Currently, the vfs_fsal_obj_handle stores fsroot and fslocations as part of 
directory (hdl->u.directory). I was thinking of moving these out of the union 
and make them first class variable in the structure or the union inside it. 
This way the fsroot and fslocations can be stored for any file type, for 
example a symlink. I will be adding some subfsal callbacks for populating and 
retrieving the fslocation details as discussed before.

Let me know if this looks like a good thing to do or should we think about 
fslocations in attrlist?

Thanks,
Sriram

From: Sriram Patil <srir...@vmware.com<mailto:srir...@vmware.com>>
Date: Friday, February 9, 2018 at 10:30 AM
To: Frank Filz <ffilz...@mindspring.com<mailto:ffilz...@mindspring.com>>, 
"nfs-ganesha-devel@lists.sourceforge.net<mailto:nfs-ganesha-devel@lists.sourceforge.net>"
 
<nfs-ganesha-devel@lists.sourceforge.net<mailto:nfs-ganesha-devel@lists.sourceforge.net>>
Subject: Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

Okay, so there are a bunch of things that we need to do. I will just list them 
down here, let me know if I miss anything.

  1.  Fs locations can be moved to attrlist and FSAL can fill it as part of 
getattr if required
  2.  We need ref counting for fs locations for handling attr copy where 
multiple objects can hold reference to fs locations
  3.  Have a validity bit for fs locations. Allow a dbus command to invalidate 
all fs_locations to be able to refresh the locations for dynamic updates
  4.  Add methods/callbacks to subfsal mechanism to allow subfsals to choose 
how referrals work for them. This should also allow a way to follow the default 
VFS mechanism

Thanks,
Sriram

From: Frank Filz <ffilz...@mindspring.com<mailto:ffilz...@mindspring.com>>
Date: Friday, February 9, 2018 at 12:05 AM
To: Sriram Patil <srir...@vmware.com<mailto:srir...@vmware.com>>, 
"nfs-ganesha-devel@lists.sourceforge.net<mailto:nfs-ganesha-devel@lists.sourceforge.net>"
 
<nfs-ganesha-devel@lists.sourceforge.net<mailto:nfs-ganesha-devel@lists.sourceforge.net>>
Subject: RE: [Nfs-ganesha-devel] About referrals in FSAL_VFS

There are places the struct attrlist gets copied, if so, either the referral 
needs to be duplicated in that copy, or it needs to be a single entity with a 
refcount.

One advantage of adding the referral to the struct attrlist is that MDCACHE 
will manage cache life of it.

It may or may not be worth having a separate cache validity bit for it 
(advantage of doing that is then 9P and V3 GETATTR won’t need to fetch it. 
Also, conceivably we could have a dBUS trigger to invalidate all referral 
attributes (on the other hand, without a separate validity bit, that dBUS 
command could just invalidate the attributes of any object that had a non-empty 
referral, though that would delay when a fs_locations attribute becomes visible 
if added to an object that previously didn’t have one…) I think I just talked 
myself into a separate validity bit. We will want to be able to tell Ganesha to 
refresh fs_locations, it can march through all the cached inodes and invalidate 
the fs_locations attribute (whether it was empty or not) thus allowing 
dynamically moving a sub-tree.

Frank

From: Sriram Patil [mailto:srir...@vmware.com]
Sent: Thursday, February 8, 2018 9:33 AM
To: Frank Filz <ffilz...@mindspring.com<m

Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

2018-03-09 Thread Frank Filz
Hmm, did I sow confusion about fs_locations in attrlist? I think that would be 
the best solution. We do need to work to be careful about tracking the validity 
of different parts of the attrlist, since we don’t necessarily want to fetch 
the fs_locations from the filesystem every time we refresh attributes.

 

I think with fs_locations being in the attrlist, it becomes much easier to have 
a sub-fsal with different handling.


Frank

 

From: Sriram Patil [mailto:srir...@vmware.com] 
Sent: Friday, March 9, 2018 9:09 AM
To: Frank Filz <ffilz...@mindspring.com>; 
nfs-ganesha-devel@lists.sourceforge.net
Subject: Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

 

Hi Frank,

 

Now that the referral fixes for pynfs are approved (not merged yet), I wanted 
to work on the subfsal layer to extend this to subfsal and allow having 
referral points as desired. As we had discussed before, it would be a good idea 
to store fs locations in the attrlist, but a few days back on IRC you mentioned 
that we do not want to jump onto that as yet. So, I was thinking of supporting 
referrals and fs_locations at subfsal layer a little differently which will not 
involve a lot of changes.

 

Currently, the vfs_fsal_obj_handle stores fsroot and fslocations as part of 
directory (hdl->u.directory). I was thinking of moving these out of the union 
and make them first class variable in the structure or the union inside it. 
This way the fsroot and fslocations can be stored for any file type, for 
example a symlink. I will be adding some subfsal callbacks for populating and 
retrieving the fslocation details as discussed before.

 

Let me know if this looks like a good thing to do or should we think about 
fslocations in attrlist?

 

Thanks,

Sriram

 

From: Sriram Patil <srir...@vmware.com <mailto:srir...@vmware.com> >
Date: Friday, February 9, 2018 at 10:30 AM
To: Frank Filz <ffilz...@mindspring.com>, 
"nfs-ganesha-devel@lists.sourceforge.net 
<mailto:nfs-ganesha-devel@lists.sourceforge.net> " 
<nfs-ganesha-devel@lists.sourceforge.net 
<mailto:nfs-ganesha-devel@lists.sourceforge.net> >
Subject: Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

 

Okay, so there are a bunch of things that we need to do. I will just list them 
down here, let me know if I miss anything.

1.  Fs locations can be moved to attrlist and FSAL can fill it as part of 
getattr if required
2.  We need ref counting for fs locations for handling attr copy where 
multiple objects can hold reference to fs locations
3.  Have a validity bit for fs locations. Allow a dbus command to 
invalidate all fs_locations to be able to refresh the locations for dynamic 
updates
4.  Add methods/callbacks to subfsal mechanism to allow subfsals to choose 
how referrals work for them. This should also allow a way to follow the default 
VFS mechanism

 

Thanks,

Sriram

 

From: Frank Filz <ffilz...@mindspring.com <mailto:ffilz...@mindspring.com> >
Date: Friday, February 9, 2018 at 12:05 AM
To: Sriram Patil <srir...@vmware.com <mailto:srir...@vmware.com> >, 
"nfs-ganesha-devel@lists.sourceforge.net 
<mailto:nfs-ganesha-devel@lists.sourceforge.net> " 
<nfs-ganesha-devel@lists.sourceforge.net 
<mailto:nfs-ganesha-devel@lists.sourceforge.net> >
Subject: RE: [Nfs-ganesha-devel] About referrals in FSAL_VFS

 

There are places the struct attrlist gets copied, if so, either the referral 
needs to be duplicated in that copy, or it needs to be a single entity with a 
refcount.

 

One advantage of adding the referral to the struct attrlist is that MDCACHE 
will manage cache life of it.

 

It may or may not be worth having a separate cache validity bit for it 
(advantage of doing that is then 9P and V3 GETATTR won’t need to fetch it. 
Also, conceivably we could have a dBUS trigger to invalidate all referral 
attributes (on the other hand, without a separate validity bit, that dBUS 
command could just invalidate the attributes of any object that had a non-empty 
referral, though that would delay when a fs_locations attribute becomes visible 
if added to an object that previously didn’t have one…) I think I just talked 
myself into a separate validity bit. We will want to be able to tell Ganesha to 
refresh fs_locations, it can march through all the cached inodes and invalidate 
the fs_locations attribute (whether it was empty or not) thus allowing 
dynamically moving a sub-tree.

 

Frank

 

From: Sriram Patil [mailto:srir...@vmware.com] 
Sent: Thursday, February 8, 2018 9:33 AM
To: Frank Filz <ffilz...@mindspring.com <mailto:ffilz...@mindspring.com> >; 
nfs-ganesha-devel@lists.sourceforge.net 
<mailto:nfs-ganesha-devel@lists.sourceforge.net> 
Subject: Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

 

attrlist changes sound good. I am trying to figure out the necessity of a 
separate cache and ref counts. As far as I see, there will

Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

2018-03-09 Thread Sriram Patil
Hi Frank,

Now that the referral fixes for pynfs are approved (not merged yet), I wanted 
to work on the subfsal layer to extend this to subfsal and allow having 
referral points as desired. As we had discussed before, it would be a good idea 
to store fs locations in the attrlist, but a few days back on IRC you mentioned 
that we do not want to jump onto that as yet. So, I was thinking of supporting 
referrals and fs_locations at subfsal layer a little differently which will not 
involve a lot of changes.

Currently, the vfs_fsal_obj_handle stores fsroot and fslocations as part of 
directory (hdl->u.directory). I was thinking of moving these out of the union 
and make them first class variable in the structure or the union inside it. 
This way the fsroot and fslocations can be stored for any file type, for 
example a symlink. I will be adding some subfsal callbacks for populating and 
retrieving the fslocation details as discussed before.

Let me know if this looks like a good thing to do or should we think about 
fslocations in attrlist?

Thanks,
Sriram

From: Sriram Patil <srir...@vmware.com>
Date: Friday, February 9, 2018 at 10:30 AM
To: Frank Filz <ffilz...@mindspring.com>, 
"nfs-ganesha-devel@lists.sourceforge.net" 
<nfs-ganesha-devel@lists.sourceforge.net>
Subject: Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

Okay, so there are a bunch of things that we need to do. I will just list them 
down here, let me know if I miss anything.

  1.  Fs locations can be moved to attrlist and FSAL can fill it as part of 
getattr if required
  2.  We need ref counting for fs locations for handling attr copy where 
multiple objects can hold reference to fs locations
  3.  Have a validity bit for fs locations. Allow a dbus command to invalidate 
all fs_locations to be able to refresh the locations for dynamic updates
  4.  Add methods/callbacks to subfsal mechanism to allow subfsals to choose 
how referrals work for them. This should also allow a way to follow the default 
VFS mechanism

Thanks,
Sriram

From: Frank Filz <ffilz...@mindspring.com>
Date: Friday, February 9, 2018 at 12:05 AM
To: Sriram Patil <srir...@vmware.com>, 
"nfs-ganesha-devel@lists.sourceforge.net" 
<nfs-ganesha-devel@lists.sourceforge.net>
Subject: RE: [Nfs-ganesha-devel] About referrals in FSAL_VFS

There are places the struct attrlist gets copied, if so, either the referral 
needs to be duplicated in that copy, or it needs to be a single entity with a 
refcount.

One advantage of adding the referral to the struct attrlist is that MDCACHE 
will manage cache life of it.

It may or may not be worth having a separate cache validity bit for it 
(advantage of doing that is then 9P and V3 GETATTR won’t need to fetch it. 
Also, conceivably we could have a dBUS trigger to invalidate all referral 
attributes (on the other hand, without a separate validity bit, that dBUS 
command could just invalidate the attributes of any object that had a non-empty 
referral, though that would delay when a fs_locations attribute becomes visible 
if added to an object that previously didn’t have one…) I think I just talked 
myself into a separate validity bit. We will want to be able to tell Ganesha to 
refresh fs_locations, it can march through all the cached inodes and invalidate 
the fs_locations attribute (whether it was empty or not) thus allowing 
dynamically moving a sub-tree.

Frank

From: Sriram Patil [mailto:srir...@vmware.com]
Sent: Thursday, February 8, 2018 9:33 AM
To: Frank Filz <ffilz...@mindspring.com>; 
nfs-ganesha-devel@lists.sourceforge.net
Subject: Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

attrlist changes sound good. I am trying to figure out the necessity of a 
separate cache and ref counts. As far as I see, there will not be multiple 
references to fs_locations (which will be just a string in attrlist).

What do you mean by xattr utility is being added in nfs-utils? Is that 
nfs-utils package? Is it just a package dependency or something else?

Thanks,
Sriram

From: Frank Filz <ffilz...@mindspring.com<mailto:ffilz...@mindspring.com>>
Date: Thursday, February 8, 2018 at 8:34 PM
To: Sriram Patil <srir...@vmware.com<mailto:srir...@vmware.com>>, 
"nfs-ganesha-devel@lists.sourceforge.net<mailto:nfs-ganesha-devel@lists.sourceforge.net>"
 
<nfs-ganesha-devel@lists.sourceforge.net<mailto:nfs-ganesha-devel@lists.sourceforge.net>>
Subject: RE: [Nfs-ganesha-devel] About referrals in FSAL_VFS

Ok, the additional sub_fsal ops look workable.

For the protocol layer stuff, we need a quick way to check if an object is a 
junction. One option is to resurrect the fsal_obj_handle JUNCTION type. Another 
option is to add fs_locations to struct attrlist and then an FSAL supporting 
referral objects would just set that attribute (reading the xattr for those 
implementations). That would mean the fs_locations attribute is a

Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

2018-02-09 Thread Frank Filz
Yea, that looks right.



Frank



From: Sriram Patil [mailto:srir...@vmware.com]
Sent: Thursday, February 8, 2018 9:01 PM
To: Frank Filz <ffilz...@mindspring.com>; 
nfs-ganesha-devel@lists.sourceforge.net
Subject: Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS



Okay, so there are a bunch of things that we need to do. I will just list them 
down here, let me know if I miss anything.

1.  Fs locations can be moved to attrlist and FSAL can fill it as part of 
getattr if required
2.  We need ref counting for fs locations for handling attr copy where 
multiple objects can hold reference to fs locations
3.  Have a validity bit for fs locations. Allow a dbus command to 
invalidate all fs_locations to be able to refresh the locations for dynamic 
updates
4.  Add methods/callbacks to subfsal mechanism to allow subfsals to choose 
how referrals work for them. This should also allow a way to follow the default 
VFS mechanism



Thanks,

Sriram



From: Frank Filz <ffilz...@mindspring.com <mailto:ffilz...@mindspring.com> >
Date: Friday, February 9, 2018 at 12:05 AM
To: Sriram Patil <srir...@vmware.com <mailto:srir...@vmware.com> >, 
"nfs-ganesha-devel@lists.sourceforge.net 
<mailto:nfs-ganesha-devel@lists.sourceforge.net> " 
<nfs-ganesha-devel@lists.sourceforge.net 
<mailto:nfs-ganesha-devel@lists.sourceforge.net> >
Subject: RE: [Nfs-ganesha-devel] About referrals in FSAL_VFS



There are places the struct attrlist gets copied, if so, either the referral 
needs to be duplicated in that copy, or it needs to be a single entity with a 
refcount.



One advantage of adding the referral to the struct attrlist is that MDCACHE 
will manage cache life of it.



It may or may not be worth having a separate cache validity bit for it 
(advantage of doing that is then 9P and V3 GETATTR won’t need to fetch it. 
Also, conceivably we could have a dBUS trigger to invalidate all referral 
attributes (on the other hand, without a separate validity bit, that dBUS 
command could just invalidate the attributes of any object that had a non-empty 
referral, though that would delay when a fs_locations attribute becomes visible 
if added to an object that previously didn’t have one…) I think I just talked 
myself into a separate validity bit. We will want to be able to tell Ganesha to 
refresh fs_locations, it can march through all the cached inodes and invalidate 
the fs_locations attribute (whether it was empty or not) thus allowing 
dynamically moving a sub-tree.



Frank



From: Sriram Patil [mailto:srir...@vmware.com]
Sent: Thursday, February 8, 2018 9:33 AM
To: Frank Filz <ffilz...@mindspring.com <mailto:ffilz...@mindspring.com> >; 
nfs-ganesha-devel@lists.sourceforge.net 
<mailto:nfs-ganesha-devel@lists.sourceforge.net>
Subject: Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS



attrlist changes sound good. I am trying to figure out the necessity of a 
separate cache and ref counts. As far as I see, there will not be multiple 
references to fs_locations (which will be just a string in attrlist).



What do you mean by xattr utility is being added in nfs-utils? Is that 
nfs-utils package? Is it just a package dependency or something else?



Thanks,

Sriram



From: Frank Filz <ffilz...@mindspring.com <mailto:ffilz...@mindspring.com> >
Date: Thursday, February 8, 2018 at 8:34 PM
To: Sriram Patil <srir...@vmware.com <mailto:srir...@vmware.com> >, 
"nfs-ganesha-devel@lists.sourceforge.net 
<mailto:nfs-ganesha-devel@lists.sourceforge.net> " 
<nfs-ganesha-devel@lists.sourceforge.net 
<mailto:nfs-ganesha-devel@lists.sourceforge.net> >
Subject: RE: [Nfs-ganesha-devel] About referrals in FSAL_VFS



Ok, the additional sub_fsal ops look workable.



For the protocol layer stuff, we need a quick way to check if an object is a 
junction. One option is to resurrect the fsal_obj_handle JUNCTION type. Another 
option is to add fs_locations to struct attrlist and then an FSAL supporting 
referral objects would just set that attribute (reading the xattr for those 
implementations). That would mean the fs_locations attribute is always fetched, 
perhaps slowing down getattrs for all referral objects even if the caller isn’t 
going to trigger use of the referral, but one hopes there aren’t too many 
referrals (and most access, at least via NFS v4, will trigger the fs_locations 
anyway).



I think I actually like adding fs_locations to struct attrlist (note that it 
will add a 2nd attribute like ACL that probably should be refcounted etc.). The 
consequences of forgetting to check for fs_locations attribute somewhere in 
code will be less than not handling the JUNCTION type.



Interesting, a utility to manage the xattr is being added to nfs-utils…



Frank



From: Sriram Patil [mailto:srir...@vmware.com]
Sent: Wednesday, February 7, 2018 6:06 PM
To: Frank Filz <ffilz...@mindspring.com <mai

Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

2018-02-08 Thread Sriram Patil
Okay, so there are a bunch of things that we need to do. I will just list them 
down here, let me know if I miss anything.

  1.  Fs locations can be moved to attrlist and FSAL can fill it as part of 
getattr if required
  2.  We need ref counting for fs locations for handling attr copy where 
multiple objects can hold reference to fs locations
  3.  Have a validity bit for fs locations. Allow a dbus command to invalidate 
all fs_locations to be able to refresh the locations for dynamic updates
  4.  Add methods/callbacks to subfsal mechanism to allow subfsals to choose 
how referrals work for them. This should also allow a way to follow the default 
VFS mechanism

Thanks,
Sriram

From: Frank Filz <ffilz...@mindspring.com>
Date: Friday, February 9, 2018 at 12:05 AM
To: Sriram Patil <srir...@vmware.com>, 
"nfs-ganesha-devel@lists.sourceforge.net" 
<nfs-ganesha-devel@lists.sourceforge.net>
Subject: RE: [Nfs-ganesha-devel] About referrals in FSAL_VFS

There are places the struct attrlist gets copied, if so, either the referral 
needs to be duplicated in that copy, or it needs to be a single entity with a 
refcount.

One advantage of adding the referral to the struct attrlist is that MDCACHE 
will manage cache life of it.

It may or may not be worth having a separate cache validity bit for it 
(advantage of doing that is then 9P and V3 GETATTR won’t need to fetch it. 
Also, conceivably we could have a dBUS trigger to invalidate all referral 
attributes (on the other hand, without a separate validity bit, that dBUS 
command could just invalidate the attributes of any object that had a non-empty 
referral, though that would delay when a fs_locations attribute becomes visible 
if added to an object that previously didn’t have one…) I think I just talked 
myself into a separate validity bit. We will want to be able to tell Ganesha to 
refresh fs_locations, it can march through all the cached inodes and invalidate 
the fs_locations attribute (whether it was empty or not) thus allowing 
dynamically moving a sub-tree.

Frank

From: Sriram Patil [mailto:srir...@vmware.com]
Sent: Thursday, February 8, 2018 9:33 AM
To: Frank Filz <ffilz...@mindspring.com>; 
nfs-ganesha-devel@lists.sourceforge.net
Subject: Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

attrlist changes sound good. I am trying to figure out the necessity of a 
separate cache and ref counts. As far as I see, there will not be multiple 
references to fs_locations (which will be just a string in attrlist).

What do you mean by xattr utility is being added in nfs-utils? Is that 
nfs-utils package? Is it just a package dependency or something else?

Thanks,
Sriram

From: Frank Filz <ffilz...@mindspring.com<mailto:ffilz...@mindspring.com>>
Date: Thursday, February 8, 2018 at 8:34 PM
To: Sriram Patil <srir...@vmware.com<mailto:srir...@vmware.com>>, 
"nfs-ganesha-devel@lists.sourceforge.net<mailto:nfs-ganesha-devel@lists.sourceforge.net>"
 
<nfs-ganesha-devel@lists.sourceforge.net<mailto:nfs-ganesha-devel@lists.sourceforge.net>>
Subject: RE: [Nfs-ganesha-devel] About referrals in FSAL_VFS

Ok, the additional sub_fsal ops look workable.

For the protocol layer stuff, we need a quick way to check if an object is a 
junction. One option is to resurrect the fsal_obj_handle JUNCTION type. Another 
option is to add fs_locations to struct attrlist and then an FSAL supporting 
referral objects would just set that attribute (reading the xattr for those 
implementations). That would mean the fs_locations attribute is always fetched, 
perhaps slowing down getattrs for all referral objects even if the caller isn’t 
going to trigger use of the referral, but one hopes there aren’t too many 
referrals (and most access, at least via NFS v4, will trigger the fs_locations 
anyway).

I think I actually like adding fs_locations to struct attrlist (note that it 
will add a 2nd attribute like ACL that probably should be refcounted etc.). The 
consequences of forgetting to check for fs_locations attribute somewhere in 
code will be less than not handling the JUNCTION type.

Interesting, a utility to manage the xattr is being added to nfs-utils…

Frank

From: Sriram Patil [mailto:srir...@vmware.com]
Sent: Wednesday, February 7, 2018 6:06 PM
To: Frank Filz <ffilz...@mindspring.com<mailto:ffilz...@mindspring.com>>; 
nfs-ganesha-devel@lists.sourceforge.net<mailto:nfs-ganesha-devel@lists.sourceforge.net>
Subject: Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

So, any subfsal for a filesystem which does not support xattrs cannot work with 
the current FSAL_VFS referrals mechanism. Ideally, it would be good to have 
subfsal callbacks, the way we have it for other things in ganesha. It will look 
much better instead of overriding a set of functions declared in subfsal.h. 
But, let’s push this for some other day and keep it open for discussion. I was 
thinking of making this cha

Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

2018-02-08 Thread Frank Filz
There are places the struct attrlist gets copied, if so, either the referral 
needs to be duplicated in that copy, or it needs to be a single entity with a 
refcount.



One advantage of adding the referral to the struct attrlist is that MDCACHE 
will manage cache life of it.



It may or may not be worth having a separate cache validity bit for it 
(advantage of doing that is then 9P and V3 GETATTR won’t need to fetch it. 
Also, conceivably we could have a dBUS trigger to invalidate all referral 
attributes (on the other hand, without a separate validity bit, that dBUS 
command could just invalidate the attributes of any object that had a non-empty 
referral, though that would delay when a fs_locations attribute becomes visible 
if added to an object that previously didn’t have one…) I think I just talked 
myself into a separate validity bit. We will want to be able to tell Ganesha to 
refresh fs_locations, it can march through all the cached inodes and invalidate 
the fs_locations attribute (whether it was empty or not) thus allowing 
dynamically moving a sub-tree.



Frank



From: Sriram Patil [mailto:srir...@vmware.com]
Sent: Thursday, February 8, 2018 9:33 AM
To: Frank Filz <ffilz...@mindspring.com>; 
nfs-ganesha-devel@lists.sourceforge.net
Subject: Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS



attrlist changes sound good. I am trying to figure out the necessity of a 
separate cache and ref counts. As far as I see, there will not be multiple 
references to fs_locations (which will be just a string in attrlist).



What do you mean by xattr utility is being added in nfs-utils? Is that 
nfs-utils package? Is it just a package dependency or something else?



Thanks,

Sriram



From: Frank Filz <ffilz...@mindspring.com <mailto:ffilz...@mindspring.com> >
Date: Thursday, February 8, 2018 at 8:34 PM
To: Sriram Patil <srir...@vmware.com <mailto:srir...@vmware.com> >, 
"nfs-ganesha-devel@lists.sourceforge.net 
<mailto:nfs-ganesha-devel@lists.sourceforge.net> " 
<nfs-ganesha-devel@lists.sourceforge.net 
<mailto:nfs-ganesha-devel@lists.sourceforge.net> >
Subject: RE: [Nfs-ganesha-devel] About referrals in FSAL_VFS



Ok, the additional sub_fsal ops look workable.



For the protocol layer stuff, we need a quick way to check if an object is a 
junction. One option is to resurrect the fsal_obj_handle JUNCTION type. Another 
option is to add fs_locations to struct attrlist and then an FSAL supporting 
referral objects would just set that attribute (reading the xattr for those 
implementations). That would mean the fs_locations attribute is always fetched, 
perhaps slowing down getattrs for all referral objects even if the caller isn’t 
going to trigger use of the referral, but one hopes there aren’t too many 
referrals (and most access, at least via NFS v4, will trigger the fs_locations 
anyway).



I think I actually like adding fs_locations to struct attrlist (note that it 
will add a 2nd attribute like ACL that probably should be refcounted etc.). The 
consequences of forgetting to check for fs_locations attribute somewhere in 
code will be less than not handling the JUNCTION type.



Interesting, a utility to manage the xattr is being added to nfs-utils…



Frank



From: Sriram Patil [mailto:srir...@vmware.com]
Sent: Wednesday, February 7, 2018 6:06 PM
To: Frank Filz <ffilz...@mindspring.com <mailto:ffilz...@mindspring.com> >; 
nfs-ganesha-devel@lists.sourceforge.net 
<mailto:nfs-ganesha-devel@lists.sourceforge.net>
Subject: Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS



So, any subfsal for a filesystem which does not support xattrs cannot work with 
the current FSAL_VFS referrals mechanism. Ideally, it would be good to have 
subfsal callbacks, the way we have it for other things in ganesha. It will look 
much better instead of overriding a set of functions declared in subfsal.h. 
But, let’s push this for some other day and keep it open for discussion. I was 
thinking of making this change without doing much changes in the current 
framework. This is what I would like to do,



Add a couple of functions in subfsal.h for allowing subfsals to decide how 
referrals work. For example,



bool vfs_is_referral_handle(struct vfs_fsal_obj_handle *hdl, struct attrlist 
*atrs); - we check for the attributes and file types here to decide whether it 
is a referral



fsal_status_t vfs_fetch_referral_locations(struct vfs_fsal_obj_handle *hdl) – 
read the fs_locations (currently through xattrs) and store them where ever 
desired (currently stored in hdl->u.directory.fs_location)



Add fs_locations callback in vfs_subfsal_obj_ops, to allow subfsals manage the 
fs_locations on their own.



Both these methods will have a default implementation in FSAL_VFS. So, a 
subfsal can keep using the current mechanism.



However, this is not sufficient. The directory and sticky bit referral is also 
checked in nfs4_op_getattr and 

Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

2018-02-08 Thread Sriram Patil
attrlist changes sound good. I am trying to figure out the necessity of a 
separate cache and ref counts. As far as I see, there will not be multiple 
references to fs_locations (which will be just a string in attrlist).

What do you mean by xattr utility is being added in nfs-utils? Is that 
nfs-utils package? Is it just a package dependency or something else?

Thanks,
Sriram

From: Frank Filz <ffilz...@mindspring.com>
Date: Thursday, February 8, 2018 at 8:34 PM
To: Sriram Patil <srir...@vmware.com>, 
"nfs-ganesha-devel@lists.sourceforge.net" 
<nfs-ganesha-devel@lists.sourceforge.net>
Subject: RE: [Nfs-ganesha-devel] About referrals in FSAL_VFS

Ok, the additional sub_fsal ops look workable.

For the protocol layer stuff, we need a quick way to check if an object is a 
junction. One option is to resurrect the fsal_obj_handle JUNCTION type. Another 
option is to add fs_locations to struct attrlist and then an FSAL supporting 
referral objects would just set that attribute (reading the xattr for those 
implementations). That would mean the fs_locations attribute is always fetched, 
perhaps slowing down getattrs for all referral objects even if the caller isn’t 
going to trigger use of the referral, but one hopes there aren’t too many 
referrals (and most access, at least via NFS v4, will trigger the fs_locations 
anyway).

I think I actually like adding fs_locations to struct attrlist (note that it 
will add a 2nd attribute like ACL that probably should be refcounted etc.). The 
consequences of forgetting to check for fs_locations attribute somewhere in 
code will be less than not handling the JUNCTION type.

Interesting, a utility to manage the xattr is being added to nfs-utils…

Frank

From: Sriram Patil [mailto:srir...@vmware.com]
Sent: Wednesday, February 7, 2018 6:06 PM
To: Frank Filz <ffilz...@mindspring.com>; 
nfs-ganesha-devel@lists.sourceforge.net
Subject: Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

So, any subfsal for a filesystem which does not support xattrs cannot work with 
the current FSAL_VFS referrals mechanism. Ideally, it would be good to have 
subfsal callbacks, the way we have it for other things in ganesha. It will look 
much better instead of overriding a set of functions declared in subfsal.h. 
But, let’s push this for some other day and keep it open for discussion. I was 
thinking of making this change without doing much changes in the current 
framework. This is what I would like to do,

Add a couple of functions in subfsal.h for allowing subfsals to decide how 
referrals work. For example,

bool vfs_is_referral_handle(struct vfs_fsal_obj_handle *hdl, struct attrlist 
*atrs); - we check for the attributes and file types here to decide whether it 
is a referral

fsal_status_t vfs_fetch_referral_locations(struct vfs_fsal_obj_handle *hdl) – 
read the fs_locations (currently through xattrs) and store them where ever 
desired (currently stored in hdl->u.directory.fs_location)

Add fs_locations callback in vfs_subfsal_obj_ops, to allow subfsals manage the 
fs_locations on their own.

Both these methods will have a default implementation in FSAL_VFS. So, a 
subfsal can keep using the current mechanism.

However, this is not sufficient. The directory and sticky bit referral is also 
checked in nfs4_op_getattr and nfs4_op_readdir. Need to figure out how to get 
rid of that.

Thanks,
Sriram

From: Frank Filz <ffilz...@mindspring.com<mailto:ffilz...@mindspring.com>>
Date: Thursday, February 8, 2018 at 12:24 AM
To: Sriram Patil <srir...@vmware.com<mailto:srir...@vmware.com>>, 
"nfs-ganesha-devel@lists.sourceforge.net<mailto:nfs-ganesha-devel@lists.sourceforge.net>"
 
<nfs-ganesha-devel@lists.sourceforge.net<mailto:nfs-ganesha-devel@lists.sourceforge.net>>
Subject: RE: [Nfs-ganesha-devel] About referrals in FSAL_VFS

If you could share the details of what you want to do differently we can 
discuss the best way to accomplish that.

After the research on what it would take to eliminate sub-FSAL, it’s clear that 
is here to stay, and extending the sub-FSAL API could be the best solution.

Frank

From: Sriram Patil [mailto:srir...@vmware.com]
Sent: Wednesday, February 7, 2018 7:06 AM
To: 
nfs-ganesha-devel@lists.sourceforge.net<mailto:nfs-ganesha-devel@lists.sourceforge.net>
Subject: [Nfs-ganesha-devel] About referrals in FSAL_VFS

Hi,

I understand that we are not supposed to extend subfsals and should move to 
Stackable FSALs. But, since it is not possible in some cases (e.g. 
open_by_handle is not supported by the kernel), subfsal has to stay.

Currently, the referrals decision is made by FSAL_VFS depending on a specific 
set of attributes and user.fs_location xattr value. If a subfsal wants to 
achieve this with some other mechanism, there is no way to do that in the 
current code. So, I wanted to extend the referrals functionality in FSAL_VFS 
and make it more flexible by allowing subfsa

Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

2018-02-08 Thread Frank Filz
Ok, the additional sub_fsal ops look workable.



For the protocol layer stuff, we need a quick way to check if an object is a 
junction. One option is to resurrect the fsal_obj_handle JUNCTION type. Another 
option is to add fs_locations to struct attrlist and then an FSAL supporting 
referral objects would just set that attribute (reading the xattr for those 
implementations). That would mean the fs_locations attribute is always fetched, 
perhaps slowing down getattrs for all referral objects even if the caller isn’t 
going to trigger use of the referral, but one hopes there aren’t too many 
referrals (and most access, at least via NFS v4, will trigger the fs_locations 
anyway).



I think I actually like adding fs_locations to struct attrlist (note that it 
will add a 2nd attribute like ACL that probably should be refcounted etc.). The 
consequences of forgetting to check for fs_locations attribute somewhere in 
code will be less than not handling the JUNCTION type.



Interesting, a utility to manage the xattr is being added to nfs-utils…



Frank



From: Sriram Patil [mailto:srir...@vmware.com]
Sent: Wednesday, February 7, 2018 6:06 PM
To: Frank Filz <ffilz...@mindspring.com>; 
nfs-ganesha-devel@lists.sourceforge.net
Subject: Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS



So, any subfsal for a filesystem which does not support xattrs cannot work with 
the current FSAL_VFS referrals mechanism. Ideally, it would be good to have 
subfsal callbacks, the way we have it for other things in ganesha. It will look 
much better instead of overriding a set of functions declared in subfsal.h. 
But, let’s push this for some other day and keep it open for discussion. I was 
thinking of making this change without doing much changes in the current 
framework. This is what I would like to do,



Add a couple of functions in subfsal.h for allowing subfsals to decide how 
referrals work. For example,



bool vfs_is_referral_handle(struct vfs_fsal_obj_handle *hdl, struct attrlist 
*atrs); - we check for the attributes and file types here to decide whether it 
is a referral



fsal_status_t vfs_fetch_referral_locations(struct vfs_fsal_obj_handle *hdl) – 
read the fs_locations (currently through xattrs) and store them where ever 
desired (currently stored in hdl->u.directory.fs_location)



Add fs_locations callback in vfs_subfsal_obj_ops, to allow subfsals manage the 
fs_locations on their own.



Both these methods will have a default implementation in FSAL_VFS. So, a 
subfsal can keep using the current mechanism.



However, this is not sufficient. The directory and sticky bit referral is also 
checked in nfs4_op_getattr and nfs4_op_readdir. Need to figure out how to get 
rid of that.



Thanks,

Sriram



From: Frank Filz <ffilz...@mindspring.com <mailto:ffilz...@mindspring.com> >
Date: Thursday, February 8, 2018 at 12:24 AM
To: Sriram Patil <srir...@vmware.com <mailto:srir...@vmware.com> >, 
"nfs-ganesha-devel@lists.sourceforge.net 
<mailto:nfs-ganesha-devel@lists.sourceforge.net> " 
<nfs-ganesha-devel@lists.sourceforge.net 
<mailto:nfs-ganesha-devel@lists.sourceforge.net> >
Subject: RE: [Nfs-ganesha-devel] About referrals in FSAL_VFS



If you could share the details of what you want to do differently we can 
discuss the best way to accomplish that.



After the research on what it would take to eliminate sub-FSAL, it’s clear that 
is here to stay, and extending the sub-FSAL API could be the best solution.



Frank



From: Sriram Patil [mailto:srir...@vmware.com]
Sent: Wednesday, February 7, 2018 7:06 AM
To: nfs-ganesha-devel@lists.sourceforge.net 
<mailto:nfs-ganesha-devel@lists.sourceforge.net>
Subject: [Nfs-ganesha-devel] About referrals in FSAL_VFS



Hi,



I understand that we are not supposed to extend subfsals and should move to 
Stackable FSALs. But, since it is not possible in some cases (e.g. 
open_by_handle is not supported by the kernel), subfsal has to stay.



Currently, the referrals decision is made by FSAL_VFS depending on a specific 
set of attributes and user.fs_location xattr value. If a subfsal wants to 
achieve this with some other mechanism, there is no way to do that in the 
current code. So, I wanted to extend the referrals functionality in FSAL_VFS 
and make it more flexible by allowing subfsal to change the behavior or not 
support referrals at all.



Any thoughts?



Thanks,

Sriram




 
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Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

2018-02-07 Thread Sriram Patil
So, any subfsal for a filesystem which does not support xattrs cannot work with 
the current FSAL_VFS referrals mechanism. Ideally, it would be good to have 
subfsal callbacks, the way we have it for other things in ganesha. It will look 
much better instead of overriding a set of functions declared in subfsal.h. 
But, let’s push this for some other day and keep it open for discussion. I was 
thinking of making this change without doing much changes in the current 
framework. This is what I would like to do,

Add a couple of functions in subfsal.h for allowing subfsals to decide how 
referrals work. For example,

bool vfs_is_referral_handle(struct vfs_fsal_obj_handle *hdl, struct attrlist 
*atrs); - we check for the attributes and file types here to decide whether it 
is a referral

fsal_status_t vfs_fetch_referral_locations(struct vfs_fsal_obj_handle *hdl) – 
read the fs_locations (currently through xattrs) and store them where ever 
desired (currently stored in hdl->u.directory.fs_location)

Add fs_locations callback in vfs_subfsal_obj_ops, to allow subfsals manage the 
fs_locations on their own.

Both these methods will have a default implementation in FSAL_VFS. So, a 
subfsal can keep using the current mechanism.

However, this is not sufficient. The directory and sticky bit referral is also 
checked in nfs4_op_getattr and nfs4_op_readdir. Need to figure out how to get 
rid of that.

Thanks,
Sriram

From: Frank Filz <ffilz...@mindspring.com>
Date: Thursday, February 8, 2018 at 12:24 AM
To: Sriram Patil <srir...@vmware.com>, 
"nfs-ganesha-devel@lists.sourceforge.net" 
<nfs-ganesha-devel@lists.sourceforge.net>
Subject: RE: [Nfs-ganesha-devel] About referrals in FSAL_VFS

If you could share the details of what you want to do differently we can 
discuss the best way to accomplish that.

After the research on what it would take to eliminate sub-FSAL, it’s clear that 
is here to stay, and extending the sub-FSAL API could be the best solution.

Frank

From: Sriram Patil [mailto:srir...@vmware.com]
Sent: Wednesday, February 7, 2018 7:06 AM
To: nfs-ganesha-devel@lists.sourceforge.net
Subject: [Nfs-ganesha-devel] About referrals in FSAL_VFS

Hi,

I understand that we are not supposed to extend subfsals and should move to 
Stackable FSALs. But, since it is not possible in some cases (e.g. 
open_by_handle is not supported by the kernel), subfsal has to stay.

Currently, the referrals decision is made by FSAL_VFS depending on a specific 
set of attributes and user.fs_location xattr value. If a subfsal wants to 
achieve this with some other mechanism, there is no way to do that in the 
current code. So, I wanted to extend the referrals functionality in FSAL_VFS 
and make it more flexible by allowing subfsal to change the behavior or not 
support referrals at all.

Any thoughts?

Thanks,
Sriram

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Re: [Nfs-ganesha-devel] About referrals in FSAL_VFS

2018-02-07 Thread Frank Filz
If you could share the details of what you want to do differently we can 
discuss the best way to accomplish that.



After the research on what it would take to eliminate sub-FSAL, it’s clear that 
is here to stay, and extending the sub-FSAL API could be the best solution.



Frank



From: Sriram Patil [mailto:srir...@vmware.com]
Sent: Wednesday, February 7, 2018 7:06 AM
To: nfs-ganesha-devel@lists.sourceforge.net
Subject: [Nfs-ganesha-devel] About referrals in FSAL_VFS



Hi,



I understand that we are not supposed to extend subfsals and should move to 
Stackable FSALs. But, since it is not possible in some cases (e.g. 
open_by_handle is not supported by the kernel), subfsal has to stay.



Currently, the referrals decision is made by FSAL_VFS depending on a specific 
set of attributes and user.fs_location xattr value. If a subfsal wants to 
achieve this with some other mechanism, there is no way to do that in the 
current code. So, I wanted to extend the referrals functionality in FSAL_VFS 
and make it more flexible by allowing subfsal to change the behavior or not 
support referrals at all.



Any thoughts?



Thanks,

Sriram



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