Extended Attributes Support (SetXAttr, GetXAttr, ListXAttr)

[bhawesh-khandelwal]

Describe the issue
GCSFuse does not support set and get extend attributes posix operations (SetXAttr, GetXAttr, ListXAttr) and throws operation not supported error for these. This can be very useful for many use cases such as storing filesystem metadata, custom application data etc.

There had been another request raised for similar but slightly different use case where the ask was to copy the metadata in case it is available in the object to local.

The request here is to at least support the operations on extended attributes for the session. These attributes can be stored in the iNode and can be served from the iNode as well. This can be the starting point and later this functionality can be extended to pushing these attributes to the cloud as well.

System & Version (please complete the following information):

• Ubuntu 20.04
• GKE
• Gcsfuse version: 2.4.2

Steps to reproduce the behavior with following information:

1. Mount a gcs bucket using gcsfuse.
2. Create a file in the mounted directory
3. Perform SetXAttr operation on the created file.

Additional context
Attaching the error screenshot for reference:

SLO:
We strive to respond to all bug reports within 24 business hours provided the information mentioned above is included.

[bhawesh-khandelwal]

As mentioned in the description, the request here is to support basic set, get, list operations on extended attributes and the starting can be done with storing them in iNode and later the functionality can be extended to populating them to the storage layer if required. I can work on supporting these operations once the feature request is accepted.

[raj-prince]

Thanks @bhawesh-khandelwal for the suggestion, I will discuss with the team and get back to you.

CC: @mustvicky @marcoa6 @charith87

[bhawesh-khandelwal]

Thanks @raj-prince for the response.
This is sort of a pre-req for my project. When can I expect an update on feature acceptance? I can take up the implementation once the feature is accepted.

[bhawesh-khandelwal]

@raj-prince A gentle reminder on this. Were you able to discuss it with the team?

[sethiay]

@bhawesh-khandelwal While we are discussing this internally, it would be really helpful if you can elaborate a bit more on your use-case for extended attributes.

[bhawesh-khandelwal]

@sethiay Sure. Our usecase is basically that we would want to store some extended attributes of the file for the mount session.
One process sets these extended attributes on the gcsfuse mounted file and other process poll for these attributes.

Please let me know in case any other information is required.

[marcoa6]

@bhawesh-khandelwal can you please provide more details on this usecase/project from a workload perspective (ex: AI/ML training, backup, home share, analytical workload, etc)? Also, do you work with a GCP account team you can also pass this request to?

[bhawesh-khandelwal]

@marcoa6 Our usecase involves writing to gcs using gcsfuse and then we do backups. From a workload perspective, it is a backup project.