From c28455a0bac4bbf171d1f19e162557377a85e96c Mon Sep 17 00:00:00 2001
From: Ming Yang <yangming73@huawei.com>
Date: Sat, 23 Mar 2024 16:32:46 +0800
Subject: [PATCH] [backup] memory: bakcup hugepages: hugepages files maybe
 leftover

old info:
commit id:
3cb1b0ce091998532a30793e3272925da4e6f3aa
old messages:
hugepages: hugepages files maybe leftover

Before qemu uses the hugepage memory directory /dev/hugepages/libvirt/qemu/xxx,
The directory may be deleted because of the destroy virtual machine.
Cause qemu to create files directly under /dev/hugepages/libvirt/qemu/.
After the file is created, the file is not cleaned up by unlink,
and when the virtual machine is destroyed, libvirt will only clean up
/dev/hugepages/libvirt/qemu/xxx directory. After creating the hugepage file,
execute unlink to clean up the file to fix the problem.

Signed-off-by: Jinhua Cao <caojinhua1@huawei.com>
Signed-off-by: Jiajie Li <lijiajie11@huawei.com>

Signed-off-by: Ming Yang <yangming73@huawei.com>
---
 include/qemu/mmap-alloc.h |  4 ++++
 system/physmem.c          |  9 ++++++++-
 util/mmap-alloc.c         | 22 ++++++++++++++++++++++
 3 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/include/qemu/mmap-alloc.h b/include/qemu/mmap-alloc.h
index 8344daaa03..63e4edfd2f 100644
--- a/include/qemu/mmap-alloc.h
+++ b/include/qemu/mmap-alloc.h
@@ -1,6 +1,10 @@
 #ifndef QEMU_MMAP_ALLOC_H
 #define QEMU_MMAP_ALLOC_H
 
+#define HUGETLBFS_MAGIC       0x958458f6
+
+size_t qemu_fd_getfiletype(int fd);
+
 typedef enum {
     QEMU_FS_TYPE_UNKNOWN = 0,
     QEMU_FS_TYPE_TMPFS,
diff --git a/system/physmem.c b/system/physmem.c
index a63853a7bc..f14d64819b 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -1329,7 +1329,14 @@ static int file_ram_open(const char *path,
             /* @path names a file that doesn't exist, create it */
             fd = open(path, O_RDWR | O_CREAT | O_EXCL, 0644);
             if (fd >= 0) {
-                *created = true;
+                info_report("open %s success \n", path);
+                /* if fd file type is HUGETLBFS_MAGIC, unlink it, */
+                /* in case to prevent residue after qemu killed */
+                if (qemu_fd_getfiletype(fd) == HUGETLBFS_MAGIC) {
+                    unlink(path);
+                } else {
+                    *created = true;
+                }
                 break;
             }
         } else if (errno == EISDIR) {
diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c
index ed14f9c64d..6890ad676c 100644
--- a/util/mmap-alloc.c
+++ b/util/mmap-alloc.c
@@ -30,6 +30,28 @@
 #include <linux/magic.h>
 #endif
 
+size_t qemu_fd_getfiletype(int fd)
+{
+    struct statfs fs;
+    int ret;
+
+    if (fd != -1) {
+        do {
+            ret = fstatfs(fd, &fs);
+        } while (ret != 0 && errno == EINTR);
+
+        if (ret != 0) {
+            fprintf(stderr, "Couldn't fstatfs() fd: %s\n",
+                    strerror(errno));
+            return -1;
+        }
+        return fs.f_type;
+    } else {
+        fprintf(stderr, "fd is invalid \n");
+        return -1;
+    }
+}
+
 QemuFsType qemu_fd_getfs(int fd)
 {
 #ifdef CONFIG_LINUX
-- 
2.27.0