@@ -14,6 +14,7 @@
#include "qemu/osdep.h"
#include "9p.h"
#include "9p-xattr.h"
+#include "9p-util.h"
#include "fsdev/qemu-fsdev.h" /* local_ops */
#include <arpa/inet.h>
#include <pwd.h>
@@ -43,6 +44,10 @@
#define BTRFS_SUPER_MAGIC 0x9123683E
#endif
+struct local_data {
+ int mountfd;
+};
+
#define VIRTFS_META_DIR ".virtfs_metadata"
static char *local_mapped_attr_path(FsContext *ctx, const char *path)
@@ -1573,13 +1578,28 @@ static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
static int local_init(FsContext *ctx)
{
struct statfs stbuf;
+ struct local_data *data = g_malloc(sizeof(*data));
+ int rootfd;
+
+ rootfd = open("/", O_DIRECTORY | O_RDONLY);
+ if (rootfd == -1) {
+ goto err;
+ }
+
+ data->mountfd = openat_nofollow(rootfd, ctx->fs_root,
+ O_DIRECTORY | O_RDONLY, 0);
+ close_preserve_errno(rootfd);
+ if (data->mountfd == -1) {
+ goto err;
+ }
#ifdef FS_IOC_GETVERSION
/*
* use ioc_getversion only if the iocl is definied
*/
- if (statfs(ctx->fs_root, &stbuf) < 0) {
- return -1;
+ if (fstatfs(data->mountfd, &stbuf) < 0) {
+ close_preserve_errno(data->mountfd);
+ goto err;
}
switch (stbuf.f_type) {
case EXT2_SUPER_MAGIC:
@@ -1606,7 +1626,20 @@ static int local_init(FsContext *ctx)
}
ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT;
+ ctx->private = data;
return 0;
+
+err:
+ g_free(data);
+ return -1;
+}
+
+static void local_cleanup(FsContext *ctx)
+{
+ struct local_data *data = ctx->private;
+
+ close(data->mountfd);
+ g_free(data);
}
static int local_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse)
@@ -1649,6 +1682,7 @@ static int local_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse)
FileOperations local_ops = {
.parse_opts = local_parse_opts,
.init = local_init,
+ .cleanup = local_cleanup,
.lstat = local_lstat,
.readlink = local_readlink,
.close = local_close,
This patch opens the shared folder and caches the file descriptor, so that it can be used to do symlink-safe path walk. Since nothing prevents several QEMU instances to pass overlapping export paths to -fsdev, we also make sure that the export path doesn't traverse a symlink either. Signed-off-by: Greg Kurz <groug@kaod.org> --- hw/9pfs/9p-local.c | 38 ++++++++++++++++++++++++++++++++++++-- 1 file changed, 36 insertions(+), 2 deletions(-)