Re: [Acl-devel] setfacl is not atomic?

[K, Dinesh (Nokia - IN/Bangalore)]

Hi Andreas,
Thanks for the reply. 
We have multiple VM having shared mount point. ACL's are being set from 
different VMs by different services. 
setfacl at least should block till permissions are set right?
Or what could be the better approach for us in this case?

Regards,
Dinesh.

-----Original Message-----
From: Andreas Grünbacher <address@hidden> 
Sent: Wednesday, February 27, 2019 4:05 PM
To: K, Dinesh (Nokia - IN/Bangalore) <address@hidden>
Cc: address@hidden
Subject: Re: [Acl-devel] setfacl is not atomic?

Hi,

Am Mi., 27. Feb. 2019 um 08:29 Uhr schrieb K, Dinesh (Nokia -
IN/Bangalore) <address@hidden>:
> When I try to set the acl for a single path from two different services at 
> the same time, it is failing.
> Though the return code is success, acl’s set by the second service is 
> overwriting the acl’s set by the first service.

when setting an acl, the previous value is overwritten, and the file mode is 
updated as well. This is the defined behavior, not a bug.
There is no compare-and-exchange like operation for acls, or even for xattrs.

Andreas