Re: [RFC PATCH v11 12/29] KVM: Add KVM_CREATE_GUEST_MEMFD ioctl() for guest-specific backing memory

Binbin Wu [off-list ref] writes:

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quoted

I'm not sure whose refcount the folio_put() in kvm_gmem_allocate() is
dropping though:

+ The refcount for the filemap depends on whether this is a hugepage or
   not, but folio_put() strictly drops a refcount of 1.
+ The refcount for the lru list is just 1, but doesn't the page still
   remain in the lru list?

I guess the refcount drop here is the one get on the fresh allocation.
Now the filemap has grabbed the folio, so the lifecycle of the folio now 
is decided by the filemap/inode?

This makes sense! So folio_put() here is saying, I'm not using this
folio anymore, but the filemap and the lru list are stil using the
folio.

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