qemu/hugepages-hugepages-files-maybe-leftover.patch

From 3cb1b0ce091998532a30793e3272925da4e6f3aa Mon Sep 17 00:00:00 2001
From: Jiajie Li <lijiajie11@huawei.com>
Date: Mon, 7 Feb 2022 14:31:34 +0800
Subject: [PATCH 1/2] 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>
---
 include/qemu/mmap-alloc.h |  3 +++
 softmmu/physmem.c         | 10 +++++++++-
 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 90d0eee705..707202e5be 100644
--- a/include/qemu/mmap-alloc.h
+++ b/include/qemu/mmap-alloc.h
@@ -1,6 +1,9 @@
 #ifndef QEMU_MMAP_ALLOC_H
 #define QEMU_MMAP_ALLOC_H
 
+#define HUGETLBFS_MAGIC       0x958458f6
+
+size_t qemu_fd_getfiletype(int fd);
 
 size_t qemu_fd_getpagesize(int fd);
 
diff --git a/softmmu/physmem.c b/softmmu/physmem.c
index 3524c04c2a..3b9a61448c 100644
--- a/softmmu/physmem.c
+++ b/softmmu/physmem.c
@@ -1496,7 +1496,14 @@ 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) {
@@ -1515,6 +1522,7 @@ static int file_ram_open(const char *path,
 
             fd = mkstemp(filename);
             if (fd >= 0) {
+                info_report("mkstemp %s success \n", filename);
                 unlink(filename);
                 g_free(filename);
                 break;
diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c
index 893d864354..4993dd5bfa 100644
--- a/util/mmap-alloc.c
+++ b/util/mmap-alloc.c
@@ -29,6 +29,28 @@
 #include <sys/vfs.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;
+    }
+}
+
 size_t qemu_fd_getpagesize(int fd)
 {
 #ifdef CONFIG_LINUX
-- 
2.27.0