On 8/8/2025 3:04 AM, Ackerley Tng wrote:
David Hildenbrand david@redhat.com writes:
On 13.07.25 19:43, Shivank Garg wrote:
From: Ackerley Tng ackerleytng@google.com
- ctx->ops = &kvm_gmem_super_operations;
Curious, why is that required? (secretmem doesn't have it, so I wonder)
Good point! pseudo_fs_fill_super() fills in a struct super_operations which already does simple_statfs, so guest_memfd doesn't need this.
Right, simple_statfs isn't strictly needed in this patch, but the super_operations is required for the subsequent patches in the series which add custom alloc_inode, destroy_inode, and free_inode callback.
- if (!try_module_get(kvm_gmem_fops.owner))
goto err;Curious, shouldn't there be a module_put() somewhere after this function returned a file?
This was interesting indeed, but IIUC this is correct.
I think this flow was basically copied from __anon_inode_getfile(), which does this try_module_get().
The corresponding module_put() is in __fput(), which calls fops_put() and calls module_put() on the owner.
Nothing else jumped at me.
Thanks for the review!
Since we're going to submit this patch through Shivank's mempolicy support series, I'll follow up soon by sending a replacement patch in reply to this series so Shivank could build on top of that?
yes, I'll post the V10 soon.
Thanks, Shivank