@@ -60,6 +60,8 @@ typedef struct extended_ops {
#define V9FS_SEC_MASK 0x0000001C
+#define V9FS_RDONLY 0x00000020
+
typedef struct FsContext
{
uid_t uid;
@@ -36,7 +36,7 @@ int qemu_fsdev_add(QemuOpts *opts)
const char *path = qemu_opt_get(opts, "path");
const char *sec_model = qemu_opt_get(opts, "security_model");
const char *writeout = qemu_opt_get(opts, "writeout");
-
+ bool ro = qemu_opt_get_bool(opts, "readonly", 0);
if (!fsdev_id) {
fprintf(stderr, "fsdev: No id specified\n");
@@ -87,6 +87,11 @@ int qemu_fsdev_add(QemuOpts *opts)
fsle->fse.export_flags |= V9FS_IMMEDIATE_WRITEOUT;
}
}
+ if (ro) {
+ fsle->fse.export_flags |= V9FS_RDONLY;
+ } else {
+ fsle->fse.export_flags &= ~V9FS_RDONLY;
+ }
if (strcmp(fsdriver, "local")) {
goto done;
@@ -1271,6 +1271,11 @@ static void v9fs_fix_path(V9fsPath *dst, V9fsPath *src, int len)
dst->size++;
}
+static inline bool is_ro_export(int export_flags)
+{
+ return export_flags & V9FS_RDONLY;
+}
+
static void v9fs_version(void *opaque)
{
V9fsPDU *pdu = opaque;
@@ -1692,6 +1697,15 @@ static void v9fs_open(void *opaque)
} else {
flags = omode_to_uflags(mode);
}
+ if (is_ro_export(s->ctx.export_flags)) {
+ if (mode & O_WRONLY || mode & O_RDWR ||
+ mode & O_APPEND || mode & O_TRUNC) {
+ err = -EROFS;
+ goto out;
+ } else {
+ flags |= O_NOATIME;
+ }
+ }
err = v9fs_co_open(pdu, fidp, flags);
if (err < 0) {
goto out;
@@ -3311,6 +3325,39 @@ static void v9fs_op_not_supp(void *opaque)
complete_pdu(pdu->s, pdu, -EOPNOTSUPP);
}
+static void v9fs_fs_ro(void *opaque)
+{
+ V9fsPDU *pdu = opaque;
+ complete_pdu(pdu->s, pdu, -EROFS);
+}
+
+static inline bool is_read_only_op(int id)
+{
+ switch (id) {
+ case P9_TREADDIR:
+ case P9_TSTATFS:
+ case P9_TGETATTR:
+ case P9_TXATTRWALK:
+ case P9_TLOCK:
+ case P9_TGETLOCK:
+ case P9_TREADLINK:
+ case P9_TVERSION:
+ case P9_TLOPEN:
+ case P9_TATTACH:
+ case P9_TSTAT:
+ case P9_TWALK:
+ case P9_TCLUNK:
+ case P9_TFSYNC:
+ case P9_TOPEN:
+ case P9_TREAD:
+ case P9_TAUTH:
+ case P9_TFLUSH:
+ return 1;
+ default:
+ return 0;
+ }
+}
+
static void submit_pdu(V9fsState *s, V9fsPDU *pdu)
{
Coroutine *co;
@@ -3322,6 +3369,10 @@ static void submit_pdu(V9fsState *s, V9fsPDU *pdu)
} else {
handler = pdu_co_handlers[pdu->id];
}
+
+ if (is_ro_export(s->ctx.export_flags) && !is_read_only_op(pdu->id)) {
+ handler = v9fs_fs_ro;
+ }
co = qemu_coroutine_create(handler);
qemu_coroutine_enter(co, pdu);
}
@@ -180,7 +180,11 @@ QemuOptsList qemu_fsdev_opts = {
}, {
.name = "writeout",
.type = QEMU_OPT_STRING,
+ }, {
+ .name = "readonly",
+ .type = QEMU_OPT_BOOL,
},
+
{ /*End of list */ }
},
};
@@ -205,6 +209,9 @@ QemuOptsList qemu_virtfs_opts = {
}, {
.name = "writeout",
.type = QEMU_OPT_STRING,
+ }, {
+ .name = "readonly",
+ .type = QEMU_OPT_BOOL,
},
{ /*End of list */ }
@@ -2823,6 +2823,8 @@ int main(int argc, char **argv, char **envp)
qemu_opt_set(fsdev, "security_model",
qemu_opt_get(opts, "security_model"));
+ qemu_opt_set_bool(fsdev, "readonly",
+ qemu_opt_get_bool(opts, "readonly", 0));
device = qemu_opts_create(qemu_find_opts("device"), NULL, 0);
qemu_opt_set(device, "driver", "virtio-9p-pci");
qemu_opt_set(device, "fsdev",