[Qemu-devel] [PATCH v3 0/4] 9pfs: add cleanup operation in handle/proxy backend

[Qemu-devel] [PATCH v3 0/4] 9pfs: add cleanup operation in handle/proxy backend

[Li Qiang]

Currently, the backend of VirtFS doesn't have a cleanup
function. This will leak some resources in handle and proxy
backend driver. This patchset addresses this issue.

Li Qiang (4):
  9pfs: adjust the order of resource cleanup in device unrealize
  9pfs: add cleanup operation in FileOperations
  9pfs: add cleanup operation for handle backend driver
  9pfs: add cleanup operation for proxy backend driver

 fsdev/file-op-9p.h  |  1 +
 hw/9pfs/9p-handle.c |  9 +++++++++
 hw/9pfs/9p-proxy.c  | 13 +++++++++++++
 hw/9pfs/9p.c        | 10 ++++++++--
 4 files changed, 31 insertions(+), 2 deletions(-)

-- 
1.8.3.1

[Qemu-devel] [PATCH v3 1/4] 9pfs: adjust the order of resource cleanup in device unrealize

[Li Qiang]

Unrealize should undo things that were set during realize in
reverse order. So should do in the error path in realize.

Signed-off-by: Li Qiang <liq3ea@gmail.com>
---

Changes since the v2:
-adjust the order in the error path in realize

 hw/9pfs/9p.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
index aea7e9d..087b5c9 100644
--- a/hw/9pfs/9p.c
+++ b/hw/9pfs/9p.c
@@ -3521,8 +3521,8 @@ int v9fs_device_realize_common(V9fsState *s, Error **errp)
     rc = 0;
 out:
     if (rc) {
-        g_free(s->ctx.fs_root);
         g_free(s->tag);
+        g_free(s->ctx.fs_root);
         v9fs_path_free(&path);
     }
     return rc;
@@ -3530,8 +3530,8 @@ out:
 
 void v9fs_device_unrealize_common(V9fsState *s, Error **errp)
 {
-    g_free(s->ctx.fs_root);
     g_free(s->tag);
+    g_free(s->ctx.fs_root);
 }
 
 typedef struct VirtfsCoResetData {
-- 
1.8.3.1

[Qemu-devel] [PATCH v3 2/4] 9pfs: add cleanup operation in FileOperations

[Li Qiang]

Currently, the backend of VirtFS doesn't have a cleanup
function. This will lead resource leak issues if the backed
driver allocates resources. This patch addresses this issue.

Signed-off-by: Li Qiang <liq3ea@gmail.com>
---

Changes since the v1:
-move the cleanup stuff above calls to g_free
-add cleanup call in the error path of realize if init was called

 fsdev/file-op-9p.h | 1 +
 hw/9pfs/9p.c       | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/fsdev/file-op-9p.h b/fsdev/file-op-9p.h
index 6db9fea..a56dc84 100644
--- a/fsdev/file-op-9p.h
+++ b/fsdev/file-op-9p.h
@@ -100,6 +100,7 @@ struct FileOperations
 {
     int (*parse_opts)(QemuOpts *, struct FsDriverEntry *);
     int (*init)(struct FsContext *);
+    void (*cleanup)(struct FsContext *);
     int (*lstat)(FsContext *, V9fsPath *, struct stat *);
     ssize_t (*readlink)(FsContext *, V9fsPath *, char *, size_t);
     int (*chmod)(FsContext *, V9fsPath *, FsCred *);
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
index 087b5c9..faebd91 100644
--- a/hw/9pfs/9p.c
+++ b/hw/9pfs/9p.c
@@ -3521,6 +3521,9 @@ int v9fs_device_realize_common(V9fsState *s, Error **errp)
     rc = 0;
 out:
     if (rc) {
+        if (s->ops->cleanup && s->ctx.private) {
+            s->ops->cleanup(&s->ctx);
+        }
         g_free(s->tag);
         g_free(s->ctx.fs_root);
         v9fs_path_free(&path);
@@ -3530,6 +3533,9 @@ out:
 
 void v9fs_device_unrealize_common(V9fsState *s, Error **errp)
 {
+    if (s->ops->cleanup) {
+        s->ops->cleanup(&s->ctx);
+    }
     g_free(s->tag);
     g_free(s->ctx.fs_root);
 }
-- 
1.8.3.1

[Qemu-devel] [PATCH v3 3/4] 9pfs: add cleanup operation for handle backend driver

[Li Qiang]

In the init operation of handle backend dirver, it allocates a
handle_data struct and opens a mount file. We should free these
resources when the 9pfs device is unrealized. This is what this
patch does.

Signed-off-by: Li Qiang <liq3ea@gmail.com>
---
 hw/9pfs/9p-handle.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/hw/9pfs/9p-handle.c b/hw/9pfs/9p-handle.c
index 3d77594..1687661 100644
--- a/hw/9pfs/9p-handle.c
+++ b/hw/9pfs/9p-handle.c
@@ -649,6 +649,14 @@ out:
     return ret;
 }
 
+static void handle_cleanup(FsContext *ctx)
+{
+    struct handle_data *data = ctx->private;
+
+    close(data->mountfd);
+    g_free(data);
+}
+
 static int handle_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse)
 {
     const char *sec_model = qemu_opt_get(opts, "security_model");
@@ -671,6 +679,7 @@ static int handle_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse)
 FileOperations handle_ops = {
     .parse_opts   = handle_parse_opts,
     .init         = handle_init,
+    .cleanup      = handle_cleanup,
     .lstat        = handle_lstat,
     .readlink     = handle_readlink,
     .close        = handle_close,
-- 
1.8.3.1

[Qemu-devel] [PATCH v3 4/4] 9pfs: add cleanup operation for proxy backend driver

[Li Qiang]

In the init operation of proxy backend dirver, it allocates a
V9fsProxy struct and some other resources. We should free these
resources when the 9pfs device is unrealized. This is what this
patch does.

Signed-off-by: Li Qiang <liq3ea@gmail.com>
---

Changes since the v2:
-only close proxy->sockfd if QEMU opened the fd
-do the cleanup work in reverse order

 hw/9pfs/9p-proxy.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/hw/9pfs/9p-proxy.c b/hw/9pfs/9p-proxy.c
index f2417b7..f4aa7a9 100644
--- a/hw/9pfs/9p-proxy.c
+++ b/hw/9pfs/9p-proxy.c
@@ -1168,9 +1168,22 @@ static int proxy_init(FsContext *ctx)
     return 0;
 }
 
+static void proxy_cleanup(FsContext *ctx)
+{
+    V9fsProxy *proxy = ctx->private;
+
+    g_free(proxy->out_iovec.iov_base);
+    g_free(proxy->in_iovec.iov_base);
+    if (ctx->export_flags & V9FS_PROXY_SOCK_NAME) {
+        close(proxy->sockfd);
+    }
+    g_free(proxy);
+}
+
 FileOperations proxy_ops = {
     .parse_opts   = proxy_parse_opts,
     .init         = proxy_init,
+    .cleanup      = proxy_cleanup,
     .lstat        = proxy_lstat,
     .readlink     = proxy_readlink,
     .close        = proxy_close,
-- 
1.8.3.1

Re: [Qemu-devel] [PATCH v3 0/4] 9pfs: add cleanup operation in handle/proxy backend

[Greg Kurz]

On Wed, 16 Nov 2016 22:16:52 -0500
Li Qiang <liq3ea@gmail.com> wrote:

> Currently, the backend of VirtFS doesn't have a cleanup
> function. This will leak some resources in handle and proxy
> backend driver. This patchset addresses this issue.
> 
> Li Qiang (4):
>   9pfs: adjust the order of resource cleanup in device unrealize
>   9pfs: add cleanup operation in FileOperations
>   9pfs: add cleanup operation for handle backend driver
>   9pfs: add cleanup operation for proxy backend driver
> 
>  fsdev/file-op-9p.h  |  1 +
>  hw/9pfs/9p-handle.c |  9 +++++++++
>  hw/9pfs/9p-proxy.c  | 13 +++++++++++++
>  hw/9pfs/9p.c        | 10 ++++++++--
>  4 files changed, 31 insertions(+), 2 deletions(-)
> 

Hi Li,

This looks good. I'll send a pull request shortly.

Thanks for your help in fixing all these leaks.

--
Greg