linux-kernel - [PATCH 02/13] KVM: Actually truncate the inode when doing PUNCH_HOLE for guest

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Date:   Thu, 21 Sep 2023 13:33:19 -0700
From:   Sean Christopherson <seanjc@...gle.com>
To:     Sean Christopherson <seanjc@...gle.com>,
        Paolo Bonzini <pbonzini@...hat.com>
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        Michael Roth <michael.roth@....com>,
        Binbin Wu <binbin.wu@...ux.intel.com>
Subject: [PATCH 02/13] KVM: Actually truncate the inode when doing PUNCH_HOLE
 for guest_memfd

Restore the call to truncate_inode_pages_range() in guest_memfd's handling
of PUNCH_HOLE that was unintentionally removed in a rebase gone bad.

Reported-by: Michael Roth <michael.roth@....com>
Fixes: 1d46f95498c5 ("KVM: Add KVM_CREATE_GUEST_MEMFD ioctl() for guest-specific backing memory")
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 virt/kvm/guest_mem.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/virt/kvm/guest_mem.c b/virt/kvm/guest_mem.c
index a819367434e9..3c9e83a596fe 100644
--- a/virt/kvm/guest_mem.c
+++ b/virt/kvm/guest_mem.c
@@ -140,10 +140,13 @@ static long kvm_gmem_punch_hole(struct inode *inode, loff_t offset, loff_t len)
 	 */
 	filemap_invalidate_lock(inode->i_mapping);
 
-	list_for_each_entry(gmem, gmem_list, entry) {
+	list_for_each_entry(gmem, gmem_list, entry)
 		kvm_gmem_invalidate_begin(gmem, start, end);
+
+	truncate_inode_pages_range(inode->i_mapping, offset, offset + len - 1);
+
+	list_for_each_entry(gmem, gmem_list, entry)
 		kvm_gmem_invalidate_end(gmem, start, end);
-	}
 
 	filemap_invalidate_unlock(inode->i_mapping);
 
-- 
2.42.0.515.g380fc7ccd1-goog