[v3] memory-backend-file related improvements and VM templating support

[PATCH v3 05/11] softmmu/physmem: Bail out early in ram_block_discard_range() with readonly files

David Hildenbrand posted 11 patches 1 year, 3 months ago

Diff against v2 v4
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Maintainers: David Hildenbrand <david@redhat.com>, Igor Mammedov <imammedo@redhat.com>, Elena Ufimtseva <elena.ufimtseva@oracle.com>, Jagannathan Raman <jag.raman@oracle.com>, "Michael S. Tsirkin" <mst@redhat.com>, Ani Sinha <anisinha@redhat.com>, Eduardo Habkost <eduardo@habkost.net>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Yanan Wang <wangyanan55@huawei.com>, Xiao Guangrong <xiaoguangrong.eric@gmail.com>, Daniel Henrique Barboza <danielhb413@gmail.com>, "Cédric Le Goater" <clg@kaod.org>, David Gibson <david@gibson.dropbear.id.au>, Greg Kurz <groug@kaod.org>, Harsh Prateek Bora <harshpb@linux.ibm.com>, Paolo Bonzini <pbonzini@redhat.com>, Peter Xu <peterx@redhat.com>, "Daniel P. Berrangé" <berrange@redhat.com>, Eric Blake <eblake@redhat.com>, Markus Armbruster <armbru@redhat.com>

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[PATCH v3 05/11] softmmu/physmem: Bail out early in ram_block_discard_range() with readonly files

Posted by David Hildenbrand 1 year, 3 months ago

fallocate() will fail, let's print a nicer error message.

Suggested-by: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 softmmu/physmem.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/softmmu/physmem.c b/softmmu/physmem.c
index c09eda6303..32d641754b 100644
--- a/softmmu/physmem.c
+++ b/softmmu/physmem.c
@@ -3457,6 +3457,16 @@ int ram_block_discard_range(RAMBlock *rb, uint64_t start, size_t length)
              * so a userfault will trigger.
              */
 #ifdef CONFIG_FALLOCATE_PUNCH_HOLE
+            /*
+             * fallocate() will fail with readonly files. Let's print a
+             * proper error message.
+             */
+            if (rb->flags & RAM_READONLY_FD) {
+                error_report("ram_block_discard_range: Discarding RAM"
+                             " with readonly files is not supported");
+                goto err;
+
+            }
             /*
              * We'll discard data from the actual file, even though we only
              * have a MAP_PRIVATE mapping, possibly messing with other
-- 
2.41.0

Re: [PATCH v3 05/11] softmmu/physmem: Bail out early in ram_block_discard_range() with readonly files

Posted by Peter Xu 1 year, 3 months ago

On Wed, Aug 23, 2023 at 05:34:05PM +0200, David Hildenbrand wrote:
> fallocate() will fail, let's print a nicer error message.
> 
> Suggested-by: Peter Xu <peterx@redhat.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>

Reviewed-by: Peter Xu <peterx@redhat.com>

-- 
Peter Xu