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[Qemu-devel] [PATCH V4 2/2] hw/9pfs: Add readonly support for 9p export
|
From: |
M. Mohan Kumar |
|
Subject: |
[Qemu-devel] [PATCH V4 2/2] hw/9pfs: Add readonly support for 9p export |
|
Date: |
Wed, 12 Oct 2011 13:23:34 +0530 |
A new fsdev parameter "readonly" is introduced to control accessing 9p export.
readonly=on|off can be used to specify the access type. By default rw
access is given.
Signed-off-by: M. Mohan Kumar <address@hidden>
---
Changes from previous version V3:
* Use opt_set_bool function to set readonly option
* Change the flag from MS_READONLY to 9p specific
Change from previous version V2:
* QEMU_OPT_BOOL is used for readdonly parameter
Changes from previous version:
* Use "readonly" option instead of "access"
* Change function return type to boolean where its needed
fsdev/file-op-9p.h | 3 +-
fsdev/qemu-fsdev.c | 12 +++++++++-
fsdev/qemu-fsdev.h | 1 +
hw/9pfs/virtio-9p-device.c | 3 ++
hw/9pfs/virtio-9p.c | 46 ++++++++++++++++++++++++++++++++++++++++++++
qemu-config.c | 7 ++++++
vl.c | 2 +
7 files changed, 71 insertions(+), 3 deletions(-)
diff --git a/fsdev/file-op-9p.h b/fsdev/file-op-9p.h
index 33fb07f..b75290d 100644
--- a/fsdev/file-op-9p.h
+++ b/fsdev/file-op-9p.h
@@ -58,7 +58,8 @@ typedef struct extended_ops {
} extended_ops;
/* FsContext flag values */
-#define PATHNAME_FSCONTEXT 0x1
+#define PATHNAME_FSCONTEXT 0x1
+#define P9_RDONLY_EXPORT 0x2
/* cache flags */
#define V9FS_WRITETHROUGH_CACHE 0x1
diff --git a/fsdev/qemu-fsdev.c b/fsdev/qemu-fsdev.c
index d08ba9c..f8a8227 100644
--- a/fsdev/qemu-fsdev.c
+++ b/fsdev/qemu-fsdev.c
@@ -29,13 +29,13 @@ static FsTypeTable FsTypes[] = {
int qemu_fsdev_add(QemuOpts *opts)
{
struct FsTypeListEntry *fsle;
- int i;
+ int i, flags = 0;
const char *fsdev_id = qemu_opts_id(opts);
const char *fstype = qemu_opt_get(opts, "fstype");
const char *path = qemu_opt_get(opts, "path");
const char *sec_model = qemu_opt_get(opts, "security_model");
const char *cache = qemu_opt_get(opts, "cache");
-
+ int rdonly = qemu_opt_get_bool(opts, "readonly", 0);
if (!fsdev_id) {
fprintf(stderr, "fsdev: No id specified\n");
@@ -76,6 +76,14 @@ int qemu_fsdev_add(QemuOpts *opts)
fsle->fse.cache_flags = V9FS_WRITETHROUGH_CACHE;
}
}
+ if (rdonly) {
+ flags |= P9_RDONLY_EXPORT;
+ } else {
+ flags &= ~P9_RDONLY_EXPORT;
+ }
+
+ fsle->fse.flags = flags;
+
QTAILQ_INSERT_TAIL(&fstype_entries, fsle, next);
return 0;
}
diff --git a/fsdev/qemu-fsdev.h b/fsdev/qemu-fsdev.h
index 0f67880..2938eaf 100644
--- a/fsdev/qemu-fsdev.h
+++ b/fsdev/qemu-fsdev.h
@@ -44,6 +44,7 @@ typedef struct FsTypeEntry {
char *security_model;
int cache_flags;
FileOperations *ops;
+ int flags;
} FsTypeEntry;
typedef struct FsTypeListEntry {
diff --git a/hw/9pfs/virtio-9p-device.c b/hw/9pfs/virtio-9p-device.c
index 1846e36..336292c 100644
--- a/hw/9pfs/virtio-9p-device.c
+++ b/hw/9pfs/virtio-9p-device.c
@@ -125,6 +125,9 @@ VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf
*conf)
s->tag_len = len;
s->ctx.uid = -1;
s->ctx.flags = 0;
+ if (fse->flags & P9_RDONLY_EXPORT) {
+ s->ctx.flags |= P9_RDONLY_EXPORT;
+ }
s->ops = fse->ops;
s->vdev.get_features = virtio_9p_get_features;
diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
index 47ed2f1..9f15787 100644
--- a/hw/9pfs/virtio-9p.c
+++ b/hw/9pfs/virtio-9p.c
@@ -1271,6 +1271,11 @@ static void v9fs_fix_path(V9fsPath *dst, V9fsPath *src,
int len)
dst->size++;
}
+static inline bool is_ro_export(FsContext *fs_ctx)
+{
+ return fs_ctx->flags & P9_RDONLY_EXPORT;
+}
+
static void v9fs_version(void *opaque)
{
V9fsPDU *pdu = opaque;
@@ -1690,6 +1695,14 @@ static void v9fs_open(void *opaque)
} else {
flags = omode_to_uflags(mode);
}
+ if (is_ro_export(&s->ctx)) {
+ if (mode & O_WRONLY || mode & O_RDWR || mode & O_APPEND) {
+ err = -EROFS;
+ goto out;
+ } else {
+ flags |= O_NOATIME;
+ }
+ }
err = v9fs_co_open(pdu, fidp, flags);
if (err < 0) {
goto out;
@@ -3301,6 +3314,33 @@ static void v9fs_op_not_supp(void *opaque)
complete_pdu(pdu->s, pdu, -EOPNOTSUPP);
}
+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;
@@ -3312,6 +3352,12 @@ static void submit_pdu(V9fsState *s, V9fsPDU *pdu)
} else {
handler = pdu_co_handlers[pdu->id];
}
+
+ if (is_ro_export(&s->ctx) && !is_read_only_op(pdu->id)) {
+ complete_pdu(s, pdu, -EROFS);
+ return;
+ }
+
co = qemu_coroutine_create(handler);
qemu_coroutine_enter(co, pdu);
}
diff --git a/qemu-config.c b/qemu-config.c
index b2ab0b2..5cad718 100644
--- a/qemu-config.c
+++ b/qemu-config.c
@@ -180,7 +180,11 @@ QemuOptsList qemu_fsdev_opts = {
}, {
.name = "cache",
.type = QEMU_OPT_STRING,
+ }, {
+ .name = "readonly",
+ .type = QEMU_OPT_BOOL,
},
+
{ /*End of list */ }
},
};
@@ -205,6 +209,9 @@ QemuOptsList qemu_virtfs_opts = {
}, {
.name = "cache",
.type = QEMU_OPT_STRING,
+ }, {
+ .name = "readonly",
+ .type = QEMU_OPT_BOOL,
},
{ /*End of list */ }
diff --git a/vl.c b/vl.c
index cab4002..04ffb26 100644
--- a/vl.c
+++ b/vl.c
@@ -2848,6 +2848,8 @@ 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",
--
1.7.6