fix #4710: vma create: don't use O_DIRECT for tmpfs

The implementation of the helper is_path_tmpfs() is similar to the
existing qemu_fd_getfs() function in util/mmap-alloc.c, which
unfortunately only takes an existing fd.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
master
Fiona Ebner 2023-11-07 15:28:24 +01:00 committed by Thomas Lamprecht
parent 1807330a6f
commit 763949965f
1 changed files with 31 additions and 6 deletions

View File

@ -16,10 +16,10 @@ Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
block/meson.build | 2 + block/meson.build | 2 +
meson.build | 5 + meson.build | 5 +
vma-reader.c | 867 ++++++++++++++++++++++++++++++++++++++++++++ vma-reader.c | 867 ++++++++++++++++++++++++++++++++++++++++++++
vma-writer.c | 793 ++++++++++++++++++++++++++++++++++++++++ vma-writer.c | 818 +++++++++++++++++++++++++++++++++++++++++
vma.c | 900 ++++++++++++++++++++++++++++++++++++++++++++++ vma.c | 900 ++++++++++++++++++++++++++++++++++++++++++++++
vma.h | 150 ++++++++ vma.h | 150 ++++++++
6 files changed, 2717 insertions(+) 6 files changed, 2742 insertions(+)
create mode 100644 vma-reader.c create mode 100644 vma-reader.c
create mode 100644 vma-writer.c create mode 100644 vma-writer.c
create mode 100644 vma.c create mode 100644 vma.c
@ -936,10 +936,10 @@ index 0000000000..81a891c6b1
+ +
diff --git a/vma-writer.c b/vma-writer.c diff --git a/vma-writer.c b/vma-writer.c
new file mode 100644 new file mode 100644
index 0000000000..6b7af81cae index 0000000000..126b296647
--- /dev/null --- /dev/null
+++ b/vma-writer.c +++ b/vma-writer.c
@@ -0,0 +1,793 @@ @@ -0,0 +1,818 @@
+/* +/*
+ * VMA: Virtual Machine Archive + * VMA: Virtual Machine Archive
+ * + *
@ -955,6 +955,8 @@ index 0000000000..6b7af81cae
+ +
+#include "qemu/osdep.h" +#include "qemu/osdep.h"
+#include <glib.h> +#include <glib.h>
+#include <linux/magic.h>
+#include <sys/vfs.h>
+#include <uuid/uuid.h> +#include <uuid/uuid.h>
+ +
+#include "vma.h" +#include "vma.h"
@ -963,6 +965,7 @@ index 0000000000..6b7af81cae
+#include "qemu/main-loop.h" +#include "qemu/main-loop.h"
+#include "qemu/coroutine.h" +#include "qemu/coroutine.h"
+#include "qemu/cutils.h" +#include "qemu/cutils.h"
+#include "qemu/error-report.h"
+#include "qemu/memalign.h" +#include "qemu/memalign.h"
+ +
+#define DEBUG_VMA 0 +#define DEBUG_VMA 0
@ -1198,6 +1201,23 @@ index 0000000000..6b7af81cae
+ return (done == bytes) ? bytes : -1; + return (done == bytes) ? bytes : -1;
+} +}
+ +
+static bool is_path_tmpfs(const char *path) {
+ struct statfs fs;
+ int ret;
+
+ do {
+ ret = statfs(path, &fs);
+ } while (ret != 0 && errno == EINTR);
+
+ if (ret != 0) {
+ warn_report("statfs call for %s failed, assuming not tmpfs - %s\n",
+ path, strerror(errno));
+ return false;
+ }
+
+ return fs.f_type == TMPFS_MAGIC;
+}
+
+VmaWriter *vma_writer_create(const char *filename, uuid_t uuid, Error **errp) +VmaWriter *vma_writer_create(const char *filename, uuid_t uuid, Error **errp)
+{ +{
+ const char *p; + const char *p;
@ -1247,8 +1267,13 @@ index 0000000000..6b7af81cae
+ } + }
+ /* try to use O_NONBLOCK */ + /* try to use O_NONBLOCK */
+ fcntl(vmaw->fd, F_SETFL, fcntl(vmaw->fd, F_GETFL)|O_NONBLOCK); + fcntl(vmaw->fd, F_SETFL, fcntl(vmaw->fd, F_GETFL)|O_NONBLOCK);
+ } else { + } else {
+ oflags = O_NONBLOCK|O_DIRECT|O_WRONLY|O_EXCL; + gchar *dirname = g_path_get_dirname(filename);
+ oflags = O_NONBLOCK|O_WRONLY|O_EXCL;
+ if (!is_path_tmpfs(dirname)) {
+ oflags |= O_DIRECT;
+ }
+ g_free(dirname);
+ vmaw->fd = qemu_create(filename, oflags, 0644, errp); + vmaw->fd = qemu_create(filename, oflags, 0644, errp);
+ } + }
+ +