[Qemu-devel] [PATCH 0/4] 9pfs: various cleanups

[Qemu-devel] [PATCH 0/4] 9pfs: various cleanups

[Greg Kurz]

These are nearly trivial class code changes. They don't fix any bug, nor change
functionality.

---

Greg Kurz (4):
      9pfs: drop unused fmt strings in the proxy backend
      9pfs: drop duplicate line in proxy backend
      9pfs: drop useless v9fs_string_null() function
      9pfs: introduce v9fs_path_sprintf() helper


 fsdev/9p-marshal.c |    5 ---
 fsdev/9p-marshal.h |    1 -
 hw/9pfs/9p-local.c |    7 +----
 hw/9pfs/9p-proxy.c |   75 ++++++++++++++++++++++------------------------------
 hw/9pfs/9p.c       |   27 ++++++++++++++-----
 hw/9pfs/9p.h       |    1 +
 6 files changed, 55 insertions(+), 61 deletions(-)

--
Greg

[Qemu-devel] [PATCH 1/4] 9pfs: drop unused fmt strings in the proxy backend

[Greg Kurz]

The v9fs_request() function doesn't use its fmt argument: it passes literal
format strings to proxy_marshal() for all commands.

This patch simply drops the unused fmt argument and updates all callers
accordingly.

Signed-off-by: Greg Kurz <groug@kaod.org>
---
 hw/9pfs/9p-proxy.c |   67 +++++++++++++++++++++++-----------------------------
 1 file changed, 30 insertions(+), 37 deletions(-)

diff --git a/hw/9pfs/9p-proxy.c b/hw/9pfs/9p-proxy.c
index f265501eac1d..52bbf4f1b37c 100644
--- a/hw/9pfs/9p-proxy.c
+++ b/hw/9pfs/9p-proxy.c
@@ -292,12 +292,11 @@ static int v9fs_receive_status(V9fsProxy *proxy,
 /*
  * Proxy->header and proxy->request written to socket by QEMU process.
  * This request read by proxy helper process
  * returns 0 on success and -errno on error
  */
-static int v9fs_request(V9fsProxy *proxy, int type,
-                        void *response, const char *fmt, ...)
+static int v9fs_request(V9fsProxy *proxy, int type, void *response, ...)
 {
     dev_t rdev;
     va_list ap;
     int size = 0;
     int retval = 0;
@@ -315,11 +314,11 @@ static int v9fs_request(V9fsProxy *proxy, int type,
         retval = -EIO;
         goto err_out;
     }
     iovec = &proxy->out_iovec;
     reply = &proxy->in_iovec;
-    va_start(ap, fmt);
+    va_start(ap, response);
     switch (type) {
     case T_OPEN:
         path = va_arg(ap, V9fsString *);
         flags = va_arg(ap, int);
         retval = proxy_marshal(iovec, PROXY_HDR_SZ, "sd", path, flags);
@@ -603,11 +602,11 @@ close_error:
 }
 
 static int proxy_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
 {
     int retval;
-    retval = v9fs_request(fs_ctx->private, T_LSTAT, stbuf, "s", fs_path);
+    retval = v9fs_request(fs_ctx->private, T_LSTAT, stbuf, fs_path);
     if (retval < 0) {
         errno = -retval;
         return -1;
     }
     return retval;
@@ -615,12 +614,11 @@ static int proxy_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
 
 static ssize_t proxy_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
                               char *buf, size_t bufsz)
 {
     int retval;
-    retval = v9fs_request(fs_ctx->private, T_READLINK, buf, "sd",
-                          fs_path, bufsz);
+    retval = v9fs_request(fs_ctx->private, T_READLINK, buf, fs_path, bufsz);
     if (retval < 0) {
         errno = -retval;
         return -1;
     }
     return strlen(buf);
@@ -637,11 +635,11 @@ static int proxy_closedir(FsContext *ctx, V9fsFidOpenState *fs)
 }
 
 static int proxy_open(FsContext *ctx, V9fsPath *fs_path,
                       int flags, V9fsFidOpenState *fs)
 {
-    fs->fd = v9fs_request(ctx->private, T_OPEN, NULL, "sd", fs_path, flags);
+    fs->fd = v9fs_request(ctx->private, T_OPEN, NULL, fs_path, flags);
     if (fs->fd < 0) {
         errno = -fs->fd;
         fs->fd = -1;
     }
     return fs->fd;
@@ -651,11 +649,11 @@ static int proxy_opendir(FsContext *ctx,
                          V9fsPath *fs_path, V9fsFidOpenState *fs)
 {
     int serrno, fd;
 
     fs->dir.stream = NULL;
-    fd = v9fs_request(ctx->private, T_OPEN, NULL, "sd", fs_path, O_DIRECTORY);
+    fd = v9fs_request(ctx->private, T_OPEN, NULL, fs_path, O_DIRECTORY);
     if (fd < 0) {
         errno = -fd;
         return -1;
     }
     fs->dir.stream = fdopendir(fd);
@@ -733,12 +731,12 @@ static ssize_t proxy_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
 }
 
 static int proxy_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
 {
     int retval;
-    retval = v9fs_request(fs_ctx->private, T_CHMOD, NULL, "sd",
-                          fs_path, credp->fc_mode);
+    retval = v9fs_request(fs_ctx->private, T_CHMOD, NULL, fs_path,
+                          credp->fc_mode);
     if (retval < 0) {
         errno = -retval;
     }
     return retval;
 }
@@ -750,12 +748,12 @@ static int proxy_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
     V9fsString fullname;
 
     v9fs_string_init(&fullname);
     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
 
-    retval = v9fs_request(fs_ctx->private, T_MKNOD, NULL, "sdqdd",
-                          &fullname, credp->fc_mode, credp->fc_rdev,
+    retval = v9fs_request(fs_ctx->private, T_MKNOD, NULL, &fullname,
+                          credp->fc_mode, credp->fc_rdev,
                           credp->fc_uid, credp->fc_gid);
     v9fs_string_free(&fullname);
     if (retval < 0) {
         errno = -retval;
         retval = -1;
@@ -770,11 +768,11 @@ static int proxy_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
     V9fsString fullname;
 
     v9fs_string_init(&fullname);
     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
 
-    retval = v9fs_request(fs_ctx->private, T_MKDIR, NULL, "sddd", &fullname,
+    retval = v9fs_request(fs_ctx->private, T_MKDIR, NULL, &fullname,
                           credp->fc_mode, credp->fc_uid, credp->fc_gid);
     v9fs_string_free(&fullname);
     if (retval < 0) {
         errno = -retval;
         retval = -1;
@@ -802,13 +800,12 @@ static int proxy_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
     V9fsString fullname;
 
     v9fs_string_init(&fullname);
     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
 
-    fs->fd = v9fs_request(fs_ctx->private, T_CREATE, NULL, "sdddd",
-                          &fullname, flags, credp->fc_mode,
-                          credp->fc_uid, credp->fc_gid);
+    fs->fd = v9fs_request(fs_ctx->private, T_CREATE, NULL, &fullname, flags,
+                          credp->fc_mode, credp->fc_uid, credp->fc_gid);
     v9fs_string_free(&fullname);
     if (fs->fd < 0) {
         errno = -fs->fd;
         fs->fd = -1;
     }
@@ -825,12 +822,12 @@ static int proxy_symlink(FsContext *fs_ctx, const char *oldpath,
     v9fs_string_init(&target);
 
     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
     v9fs_string_sprintf(&target, "%s", oldpath);
 
-    retval = v9fs_request(fs_ctx->private, T_SYMLINK, NULL, "ssdd",
-                          &target, &fullname, credp->fc_uid, credp->fc_gid);
+    retval = v9fs_request(fs_ctx->private, T_SYMLINK, NULL, &target, &fullname,
+                          credp->fc_uid, credp->fc_gid);
     v9fs_string_free(&fullname);
     v9fs_string_free(&target);
     if (retval < 0) {
         errno = -retval;
         retval = -1;
@@ -845,11 +842,11 @@ static int proxy_link(FsContext *ctx, V9fsPath *oldpath,
     V9fsString newpath;
 
     v9fs_string_init(&newpath);
     v9fs_string_sprintf(&newpath, "%s/%s", dirpath->data, name);
 
-    retval = v9fs_request(ctx->private, T_LINK, NULL, "ss", oldpath, &newpath);
+    retval = v9fs_request(ctx->private, T_LINK, NULL, oldpath, &newpath);
     v9fs_string_free(&newpath);
     if (retval < 0) {
         errno = -retval;
         retval = -1;
     }
@@ -858,11 +855,11 @@ static int proxy_link(FsContext *ctx, V9fsPath *oldpath,
 
 static int proxy_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
 {
     int retval;
 
-    retval = v9fs_request(ctx->private, T_TRUNCATE, NULL, "sq", fs_path, size);
+    retval = v9fs_request(ctx->private, T_TRUNCATE, NULL, fs_path, size);
     if (retval < 0) {
         errno = -retval;
         return -1;
     }
     return 0;
@@ -877,12 +874,11 @@ static int proxy_rename(FsContext *ctx, const char *oldpath,
     v9fs_string_init(&oldname);
     v9fs_string_init(&newname);
 
     v9fs_string_sprintf(&oldname, "%s", oldpath);
     v9fs_string_sprintf(&newname, "%s", newpath);
-    retval = v9fs_request(ctx->private, T_RENAME, NULL, "ss",
-                          &oldname, &newname);
+    retval = v9fs_request(ctx->private, T_RENAME, NULL, &oldname, &newname);
     v9fs_string_free(&oldname);
     v9fs_string_free(&newname);
     if (retval < 0) {
         errno = -retval;
     }
@@ -890,24 +886,23 @@ static int proxy_rename(FsContext *ctx, const char *oldpath,
 }
 
 static int proxy_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
 {
     int retval;
-    retval = v9fs_request(fs_ctx->private, T_CHOWN, NULL, "sdd",
-                          fs_path, credp->fc_uid, credp->fc_gid);
+    retval = v9fs_request(fs_ctx->private, T_CHOWN, NULL, fs_path,
+                          credp->fc_uid, credp->fc_gid);
     if (retval < 0) {
         errno = -retval;
     }
     return retval;
 }
 
 static int proxy_utimensat(FsContext *s, V9fsPath *fs_path,
                            const struct timespec *buf)
 {
     int retval;
-    retval = v9fs_request(s->private, T_UTIME, NULL, "sqqqq",
-                          fs_path,
+    retval = v9fs_request(s->private, T_UTIME, NULL, fs_path,
                           buf[0].tv_sec, buf[0].tv_nsec,
                           buf[1].tv_sec, buf[1].tv_nsec);
     if (retval < 0) {
         errno = -retval;
     }
@@ -918,11 +913,11 @@ static int proxy_remove(FsContext *ctx, const char *path)
 {
     int retval;
     V9fsString name;
     v9fs_string_init(&name);
     v9fs_string_sprintf(&name, "%s", path);
-    retval = v9fs_request(ctx->private, T_REMOVE, NULL, "s", &name);
+    retval = v9fs_request(ctx->private, T_REMOVE, NULL, &name);
     v9fs_string_free(&name);
     if (retval < 0) {
         errno = -retval;
     }
     return retval;
@@ -947,11 +942,11 @@ static int proxy_fsync(FsContext *ctx, int fid_type,
 }
 
 static int proxy_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf)
 {
     int retval;
-    retval = v9fs_request(s->private, T_STATFS, stbuf, "s", fs_path);
+    retval = v9fs_request(s->private, T_STATFS, stbuf, fs_path);
     if (retval < 0) {
         errno = -retval;
         return -1;
     }
     return retval;
@@ -963,12 +958,12 @@ static ssize_t proxy_lgetxattr(FsContext *ctx, V9fsPath *fs_path,
     int retval;
     V9fsString xname;
 
     v9fs_string_init(&xname);
     v9fs_string_sprintf(&xname, "%s", name);
-    retval = v9fs_request(ctx->private, T_LGETXATTR, value, "dss", size,
-                          fs_path, &xname);
+    retval = v9fs_request(ctx->private, T_LGETXATTR, value, size, fs_path,
+                          &xname);
     v9fs_string_free(&xname);
     if (retval < 0) {
         errno = -retval;
     }
     return retval;
@@ -976,12 +971,11 @@ static ssize_t proxy_lgetxattr(FsContext *ctx, V9fsPath *fs_path,
 
 static ssize_t proxy_llistxattr(FsContext *ctx, V9fsPath *fs_path,
                                 void *value, size_t size)
 {
     int retval;
-    retval = v9fs_request(ctx->private, T_LLISTXATTR, value, "ds", size,
-                        fs_path);
+    retval = v9fs_request(ctx->private, T_LLISTXATTR, value, size, fs_path);
     if (retval < 0) {
         errno = -retval;
     }
     return retval;
 }
@@ -998,12 +992,12 @@ static int proxy_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name,
     v9fs_string_init(&xvalue);
     xvalue.size = size;
     xvalue.data = g_malloc(size);
     memcpy(xvalue.data, value, size);
 
-    retval = v9fs_request(ctx->private, T_LSETXATTR, value, "sssdd",
-                          fs_path, &xname, &xvalue, size, flags);
+    retval = v9fs_request(ctx->private, T_LSETXATTR, value, fs_path, &xname,
+                          &xvalue, size, flags);
     v9fs_string_free(&xname);
     v9fs_string_free(&xvalue);
     if (retval < 0) {
         errno = -retval;
     }
@@ -1016,12 +1010,11 @@ static int proxy_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
     int retval;
     V9fsString xname;
 
     v9fs_string_init(&xname);
     v9fs_string_sprintf(&xname, "%s", name);
-    retval = v9fs_request(ctx->private, T_LREMOVEXATTR, NULL, "ss",
-                          fs_path, &xname);
+    retval = v9fs_request(ctx->private, T_LREMOVEXATTR, NULL, fs_path, &xname);
     v9fs_string_free(&xname);
     if (retval < 0) {
         errno = -retval;
     }
     return retval;
@@ -1084,11 +1077,11 @@ static int proxy_ioc_getversion(FsContext *fs_ctx, V9fsPath *path,
      */
     if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
         errno = ENOTTY;
         return -1;
     }
-    err = v9fs_request(fs_ctx->private, T_GETVERSION, st_gen, "s", path);
+    err = v9fs_request(fs_ctx->private, T_GETVERSION, st_gen, path);
     if (err < 0) {
         errno = -err;
         err = -1;
     }
     return err;

Re: [Qemu-devel] [PATCH 1/4] 9pfs: drop unused fmt strings in the proxy backend

[Cédric Le Goater]

On 09/15/2016 04:24 PM, Greg Kurz wrote:
> The v9fs_request() function doesn't use its fmt argument: it passes literal
> format strings to proxy_marshal() for all commands.
> 
> This patch simply drops the unused fmt argument and updates all callers
> accordingly.

Reviewed-by: Cédric Le Goater <clg@kaod.org>

> Signed-off-by: Greg Kurz <groug@kaod.org>
> ---
>  hw/9pfs/9p-proxy.c |   67 +++++++++++++++++++++++-----------------------------
>  1 file changed, 30 insertions(+), 37 deletions(-)
> 
> diff --git a/hw/9pfs/9p-proxy.c b/hw/9pfs/9p-proxy.c
> index f265501eac1d..52bbf4f1b37c 100644
> --- a/hw/9pfs/9p-proxy.c
> +++ b/hw/9pfs/9p-proxy.c
> @@ -292,12 +292,11 @@ static int v9fs_receive_status(V9fsProxy *proxy,
>  /*
>   * Proxy->header and proxy->request written to socket by QEMU process.
>   * This request read by proxy helper process
>   * returns 0 on success and -errno on error
>   */
> -static int v9fs_request(V9fsProxy *proxy, int type,
> -                        void *response, const char *fmt, ...)
> +static int v9fs_request(V9fsProxy *proxy, int type, void *response, ...)
>  {
>      dev_t rdev;
>      va_list ap;
>      int size = 0;
>      int retval = 0;
> @@ -315,11 +314,11 @@ static int v9fs_request(V9fsProxy *proxy, int type,
>          retval = -EIO;
>          goto err_out;
>      }
>      iovec = &proxy->out_iovec;
>      reply = &proxy->in_iovec;
> -    va_start(ap, fmt);
> +    va_start(ap, response);
>      switch (type) {
>      case T_OPEN:
>          path = va_arg(ap, V9fsString *);
>          flags = va_arg(ap, int);
>          retval = proxy_marshal(iovec, PROXY_HDR_SZ, "sd", path, flags);
> @@ -603,11 +602,11 @@ close_error:
>  }
>  
>  static int proxy_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
>  {
>      int retval;
> -    retval = v9fs_request(fs_ctx->private, T_LSTAT, stbuf, "s", fs_path);
> +    retval = v9fs_request(fs_ctx->private, T_LSTAT, stbuf, fs_path);
>      if (retval < 0) {
>          errno = -retval;
>          return -1;
>      }
>      return retval;
> @@ -615,12 +614,11 @@ static int proxy_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
>  
>  static ssize_t proxy_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
>                                char *buf, size_t bufsz)
>  {
>      int retval;
> -    retval = v9fs_request(fs_ctx->private, T_READLINK, buf, "sd",
> -                          fs_path, bufsz);
> +    retval = v9fs_request(fs_ctx->private, T_READLINK, buf, fs_path, bufsz);
>      if (retval < 0) {
>          errno = -retval;
>          return -1;
>      }
>      return strlen(buf);
> @@ -637,11 +635,11 @@ static int proxy_closedir(FsContext *ctx, V9fsFidOpenState *fs)
>  }
>  
>  static int proxy_open(FsContext *ctx, V9fsPath *fs_path,
>                        int flags, V9fsFidOpenState *fs)
>  {
> -    fs->fd = v9fs_request(ctx->private, T_OPEN, NULL, "sd", fs_path, flags);
> +    fs->fd = v9fs_request(ctx->private, T_OPEN, NULL, fs_path, flags);
>      if (fs->fd < 0) {
>          errno = -fs->fd;
>          fs->fd = -1;
>      }
>      return fs->fd;
> @@ -651,11 +649,11 @@ static int proxy_opendir(FsContext *ctx,
>                           V9fsPath *fs_path, V9fsFidOpenState *fs)
>  {
>      int serrno, fd;
>  
>      fs->dir.stream = NULL;
> -    fd = v9fs_request(ctx->private, T_OPEN, NULL, "sd", fs_path, O_DIRECTORY);
> +    fd = v9fs_request(ctx->private, T_OPEN, NULL, fs_path, O_DIRECTORY);
>      if (fd < 0) {
>          errno = -fd;
>          return -1;
>      }
>      fs->dir.stream = fdopendir(fd);
> @@ -733,12 +731,12 @@ static ssize_t proxy_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
>  }
>  
>  static int proxy_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
>  {
>      int retval;
> -    retval = v9fs_request(fs_ctx->private, T_CHMOD, NULL, "sd",
> -                          fs_path, credp->fc_mode);
> +    retval = v9fs_request(fs_ctx->private, T_CHMOD, NULL, fs_path,
> +                          credp->fc_mode);
>      if (retval < 0) {
>          errno = -retval;
>      }
>      return retval;
>  }
> @@ -750,12 +748,12 @@ static int proxy_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
>      V9fsString fullname;
>  
>      v9fs_string_init(&fullname);
>      v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
>  
> -    retval = v9fs_request(fs_ctx->private, T_MKNOD, NULL, "sdqdd",
> -                          &fullname, credp->fc_mode, credp->fc_rdev,
> +    retval = v9fs_request(fs_ctx->private, T_MKNOD, NULL, &fullname,
> +                          credp->fc_mode, credp->fc_rdev,
>                            credp->fc_uid, credp->fc_gid);
>      v9fs_string_free(&fullname);
>      if (retval < 0) {
>          errno = -retval;
>          retval = -1;
> @@ -770,11 +768,11 @@ static int proxy_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
>      V9fsString fullname;
>  
>      v9fs_string_init(&fullname);
>      v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
>  
> -    retval = v9fs_request(fs_ctx->private, T_MKDIR, NULL, "sddd", &fullname,
> +    retval = v9fs_request(fs_ctx->private, T_MKDIR, NULL, &fullname,
>                            credp->fc_mode, credp->fc_uid, credp->fc_gid);
>      v9fs_string_free(&fullname);
>      if (retval < 0) {
>          errno = -retval;
>          retval = -1;
> @@ -802,13 +800,12 @@ static int proxy_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
>      V9fsString fullname;
>  
>      v9fs_string_init(&fullname);
>      v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
>  
> -    fs->fd = v9fs_request(fs_ctx->private, T_CREATE, NULL, "sdddd",
> -                          &fullname, flags, credp->fc_mode,
> -                          credp->fc_uid, credp->fc_gid);
> +    fs->fd = v9fs_request(fs_ctx->private, T_CREATE, NULL, &fullname, flags,
> +                          credp->fc_mode, credp->fc_uid, credp->fc_gid);
>      v9fs_string_free(&fullname);
>      if (fs->fd < 0) {
>          errno = -fs->fd;
>          fs->fd = -1;
>      }
> @@ -825,12 +822,12 @@ static int proxy_symlink(FsContext *fs_ctx, const char *oldpath,
>      v9fs_string_init(&target);
>  
>      v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
>      v9fs_string_sprintf(&target, "%s", oldpath);
>  
> -    retval = v9fs_request(fs_ctx->private, T_SYMLINK, NULL, "ssdd",
> -                          &target, &fullname, credp->fc_uid, credp->fc_gid);
> +    retval = v9fs_request(fs_ctx->private, T_SYMLINK, NULL, &target, &fullname,
> +                          credp->fc_uid, credp->fc_gid);
>      v9fs_string_free(&fullname);
>      v9fs_string_free(&target);
>      if (retval < 0) {
>          errno = -retval;
>          retval = -1;
> @@ -845,11 +842,11 @@ static int proxy_link(FsContext *ctx, V9fsPath *oldpath,
>      V9fsString newpath;
>  
>      v9fs_string_init(&newpath);
>      v9fs_string_sprintf(&newpath, "%s/%s", dirpath->data, name);
>  
> -    retval = v9fs_request(ctx->private, T_LINK, NULL, "ss", oldpath, &newpath);
> +    retval = v9fs_request(ctx->private, T_LINK, NULL, oldpath, &newpath);
>      v9fs_string_free(&newpath);
>      if (retval < 0) {
>          errno = -retval;
>          retval = -1;
>      }
> @@ -858,11 +855,11 @@ static int proxy_link(FsContext *ctx, V9fsPath *oldpath,
>  
>  static int proxy_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
>  {
>      int retval;
>  
> -    retval = v9fs_request(ctx->private, T_TRUNCATE, NULL, "sq", fs_path, size);
> +    retval = v9fs_request(ctx->private, T_TRUNCATE, NULL, fs_path, size);
>      if (retval < 0) {
>          errno = -retval;
>          return -1;
>      }
>      return 0;
> @@ -877,12 +874,11 @@ static int proxy_rename(FsContext *ctx, const char *oldpath,
>      v9fs_string_init(&oldname);
>      v9fs_string_init(&newname);
>  
>      v9fs_string_sprintf(&oldname, "%s", oldpath);
>      v9fs_string_sprintf(&newname, "%s", newpath);
> -    retval = v9fs_request(ctx->private, T_RENAME, NULL, "ss",
> -                          &oldname, &newname);
> +    retval = v9fs_request(ctx->private, T_RENAME, NULL, &oldname, &newname);
>      v9fs_string_free(&oldname);
>      v9fs_string_free(&newname);
>      if (retval < 0) {
>          errno = -retval;
>      }
> @@ -890,24 +886,23 @@ static int proxy_rename(FsContext *ctx, const char *oldpath,
>  }
>  
>  static int proxy_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
>  {
>      int retval;
> -    retval = v9fs_request(fs_ctx->private, T_CHOWN, NULL, "sdd",
> -                          fs_path, credp->fc_uid, credp->fc_gid);
> +    retval = v9fs_request(fs_ctx->private, T_CHOWN, NULL, fs_path,
> +                          credp->fc_uid, credp->fc_gid);
>      if (retval < 0) {
>          errno = -retval;
>      }
>      return retval;
>  }
>  
>  static int proxy_utimensat(FsContext *s, V9fsPath *fs_path,
>                             const struct timespec *buf)
>  {
>      int retval;
> -    retval = v9fs_request(s->private, T_UTIME, NULL, "sqqqq",
> -                          fs_path,
> +    retval = v9fs_request(s->private, T_UTIME, NULL, fs_path,
>                            buf[0].tv_sec, buf[0].tv_nsec,
>                            buf[1].tv_sec, buf[1].tv_nsec);
>      if (retval < 0) {
>          errno = -retval;
>      }
> @@ -918,11 +913,11 @@ static int proxy_remove(FsContext *ctx, const char *path)
>  {
>      int retval;
>      V9fsString name;
>      v9fs_string_init(&name);
>      v9fs_string_sprintf(&name, "%s", path);
> -    retval = v9fs_request(ctx->private, T_REMOVE, NULL, "s", &name);
> +    retval = v9fs_request(ctx->private, T_REMOVE, NULL, &name);
>      v9fs_string_free(&name);
>      if (retval < 0) {
>          errno = -retval;
>      }
>      return retval;
> @@ -947,11 +942,11 @@ static int proxy_fsync(FsContext *ctx, int fid_type,
>  }
>  
>  static int proxy_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf)
>  {
>      int retval;
> -    retval = v9fs_request(s->private, T_STATFS, stbuf, "s", fs_path);
> +    retval = v9fs_request(s->private, T_STATFS, stbuf, fs_path);
>      if (retval < 0) {
>          errno = -retval;
>          return -1;
>      }
>      return retval;
> @@ -963,12 +958,12 @@ static ssize_t proxy_lgetxattr(FsContext *ctx, V9fsPath *fs_path,
>      int retval;
>      V9fsString xname;
>  
>      v9fs_string_init(&xname);
>      v9fs_string_sprintf(&xname, "%s", name);
> -    retval = v9fs_request(ctx->private, T_LGETXATTR, value, "dss", size,
> -                          fs_path, &xname);
> +    retval = v9fs_request(ctx->private, T_LGETXATTR, value, size, fs_path,
> +                          &xname);
>      v9fs_string_free(&xname);
>      if (retval < 0) {
>          errno = -retval;
>      }
>      return retval;
> @@ -976,12 +971,11 @@ static ssize_t proxy_lgetxattr(FsContext *ctx, V9fsPath *fs_path,
>  
>  static ssize_t proxy_llistxattr(FsContext *ctx, V9fsPath *fs_path,
>                                  void *value, size_t size)
>  {
>      int retval;
> -    retval = v9fs_request(ctx->private, T_LLISTXATTR, value, "ds", size,
> -                        fs_path);
> +    retval = v9fs_request(ctx->private, T_LLISTXATTR, value, size, fs_path);
>      if (retval < 0) {
>          errno = -retval;
>      }
>      return retval;
>  }
> @@ -998,12 +992,12 @@ static int proxy_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name,
>      v9fs_string_init(&xvalue);
>      xvalue.size = size;
>      xvalue.data = g_malloc(size);
>      memcpy(xvalue.data, value, size);
>  
> -    retval = v9fs_request(ctx->private, T_LSETXATTR, value, "sssdd",
> -                          fs_path, &xname, &xvalue, size, flags);
> +    retval = v9fs_request(ctx->private, T_LSETXATTR, value, fs_path, &xname,
> +                          &xvalue, size, flags);
>      v9fs_string_free(&xname);
>      v9fs_string_free(&xvalue);
>      if (retval < 0) {
>          errno = -retval;
>      }
> @@ -1016,12 +1010,11 @@ static int proxy_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
>      int retval;
>      V9fsString xname;
>  
>      v9fs_string_init(&xname);
>      v9fs_string_sprintf(&xname, "%s", name);
> -    retval = v9fs_request(ctx->private, T_LREMOVEXATTR, NULL, "ss",
> -                          fs_path, &xname);
> +    retval = v9fs_request(ctx->private, T_LREMOVEXATTR, NULL, fs_path, &xname);
>      v9fs_string_free(&xname);
>      if (retval < 0) {
>          errno = -retval;
>      }
>      return retval;
> @@ -1084,11 +1077,11 @@ static int proxy_ioc_getversion(FsContext *fs_ctx, V9fsPath *path,
>       */
>      if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
>          errno = ENOTTY;
>          return -1;
>      }
> -    err = v9fs_request(fs_ctx->private, T_GETVERSION, st_gen, "s", path);
> +    err = v9fs_request(fs_ctx->private, T_GETVERSION, st_gen, path);
>      if (err < 0) {
>          errno = -err;
>          err = -1;
>      }
>      return err;
> 
> 

[Qemu-devel] [PATCH 2/4] 9pfs: drop duplicate line in proxy backend

[Greg Kurz]

This double free did not cause harm because v9fs_string_free() sets
str->data to NULL and g_free(NULL) is valid.

Signed-off-by: Greg Kurz <groug@kaod.org>
---
 hw/9pfs/9p-proxy.c |    1 -
 1 file changed, 1 deletion(-)

diff --git a/hw/9pfs/9p-proxy.c b/hw/9pfs/9p-proxy.c
index 52bbf4f1b37c..d091564b6fd2 100644
--- a/hw/9pfs/9p-proxy.c
+++ b/hw/9pfs/9p-proxy.c
@@ -775,11 +775,10 @@ static int proxy_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
     v9fs_string_free(&fullname);
     if (retval < 0) {
         errno = -retval;
         retval = -1;
     }
-    v9fs_string_free(&fullname);
     return retval;
 }
 
 static int proxy_fstat(FsContext *fs_ctx, int fid_type,
                        V9fsFidOpenState *fs, struct stat *stbuf)

Re: [Qemu-devel] [PATCH 2/4] 9pfs: drop duplicate line in proxy backend

[Cédric Le Goater]

On 09/15/2016 04:24 PM, Greg Kurz wrote:
> This double free did not cause harm because v9fs_string_free() sets
> str->data to NULL and g_free(NULL) is valid.
> 
> Signed-off-by: Greg Kurz <groug@kaod.org>


Reviewed-by: Cédric Le Goater <clg@kaod.org>

> ---
>  hw/9pfs/9p-proxy.c |    1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/hw/9pfs/9p-proxy.c b/hw/9pfs/9p-proxy.c
> index 52bbf4f1b37c..d091564b6fd2 100644
> --- a/hw/9pfs/9p-proxy.c
> +++ b/hw/9pfs/9p-proxy.c
> @@ -775,11 +775,10 @@ static int proxy_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
>      v9fs_string_free(&fullname);
>      if (retval < 0) {
>          errno = -retval;
>          retval = -1;
>      }
> -    v9fs_string_free(&fullname);
>      return retval;
>  }
>  
>  static int proxy_fstat(FsContext *fs_ctx, int fid_type,
>                         V9fsFidOpenState *fs, struct stat *stbuf)
> 
> 

[Qemu-devel] [PATCH 3/4] 9pfs: drop useless v9fs_string_null() function

[Greg Kurz]

The v9fs_string_null() function just calls v9fs_string_free(). Also it
only has 4 users, whereas v9fs_string_free() has 87.

This patch converts users to call directly v9fs_string_free() and drops
the useless function.

Signed-off-by: Greg Kurz <groug@kaod.org>
---
 fsdev/9p-marshal.c |    5 -----
 fsdev/9p-marshal.h |    1 -
 hw/9pfs/9p.c       |    8 ++++----
 3 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/fsdev/9p-marshal.c b/fsdev/9p-marshal.c
index 238dbf21b1d5..a01bba6908a8 100644
--- a/fsdev/9p-marshal.c
+++ b/fsdev/9p-marshal.c
@@ -23,15 +23,10 @@ void v9fs_string_free(V9fsString *str)
     g_free(str->data);
     str->data = NULL;
     str->size = 0;
 }
 
-void v9fs_string_null(V9fsString *str)
-{
-    v9fs_string_free(str);
-}
-
 void GCC_FMT_ATTR(2, 3)
 v9fs_string_sprintf(V9fsString *str, const char *fmt, ...)
 {
     va_list ap;
 
diff --git a/fsdev/9p-marshal.h b/fsdev/9p-marshal.h
index 140db6d99f9c..77f7fef326ee 100644
--- a/fsdev/9p-marshal.h
+++ b/fsdev/9p-marshal.h
@@ -75,10 +75,9 @@ static inline void v9fs_string_init(V9fsString *str)
 {
     str->data = NULL;
     str->size = 0;
 }
 extern void v9fs_string_free(V9fsString *str);
-extern void v9fs_string_null(V9fsString *str);
 extern void v9fs_string_sprintf(V9fsString *str, const char *fmt, ...);
 extern void v9fs_string_copy(V9fsString *lhs, V9fsString *rhs);
 
 #endif
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
index dfe293d11d1c..d8f48ca76c47 100644
--- a/hw/9pfs/9p.c
+++ b/hw/9pfs/9p.c
@@ -808,19 +808,19 @@ static int stat_to_v9stat(V9fsPDU *pdu, V9fsPath *name,
     v9stat->mode = stat_to_v9mode(stbuf);
     v9stat->atime = stbuf->st_atime;
     v9stat->mtime = stbuf->st_mtime;
     v9stat->length = stbuf->st_size;
 
-    v9fs_string_null(&v9stat->uid);
-    v9fs_string_null(&v9stat->gid);
-    v9fs_string_null(&v9stat->muid);
+    v9fs_string_free(&v9stat->uid);
+    v9fs_string_free(&v9stat->gid);
+    v9fs_string_free(&v9stat->muid);
 
     v9stat->n_uid = stbuf->st_uid;
     v9stat->n_gid = stbuf->st_gid;
     v9stat->n_muid = 0;
 
-    v9fs_string_null(&v9stat->extension);
+    v9fs_string_free(&v9stat->extension);
 
     if (v9stat->mode & P9_STAT_MODE_SYMLINK) {
         err = v9fs_co_readlink(pdu, name, &v9stat->extension);
         if (err < 0) {
             return err;

Re: [Qemu-devel] [PATCH 3/4] 9pfs: drop useless v9fs_string_null() function

[Cédric Le Goater]

On 09/15/2016 04:24 PM, Greg Kurz wrote:
> The v9fs_string_null() function just calls v9fs_string_free(). Also it
> only has 4 users, whereas v9fs_string_free() has 87.
> 
> This patch converts users to call directly v9fs_string_free() and drops
> the useless function.

Reviewed-by: Cédric Le Goater <clg@kaod.org>

> Signed-off-by: Greg Kurz <groug@kaod.org>
> ---
>  fsdev/9p-marshal.c |    5 -----
>  fsdev/9p-marshal.h |    1 -
>  hw/9pfs/9p.c       |    8 ++++----
>  3 files changed, 4 insertions(+), 10 deletions(-)
> 
> diff --git a/fsdev/9p-marshal.c b/fsdev/9p-marshal.c
> index 238dbf21b1d5..a01bba6908a8 100644
> --- a/fsdev/9p-marshal.c
> +++ b/fsdev/9p-marshal.c
> @@ -23,15 +23,10 @@ void v9fs_string_free(V9fsString *str)
>      g_free(str->data);
>      str->data = NULL;
>      str->size = 0;
>  }
>  
> -void v9fs_string_null(V9fsString *str)
> -{
> -    v9fs_string_free(str);
> -}
> -
>  void GCC_FMT_ATTR(2, 3)
>  v9fs_string_sprintf(V9fsString *str, const char *fmt, ...)
>  {
>      va_list ap;
>  
> diff --git a/fsdev/9p-marshal.h b/fsdev/9p-marshal.h
> index 140db6d99f9c..77f7fef326ee 100644
> --- a/fsdev/9p-marshal.h
> +++ b/fsdev/9p-marshal.h
> @@ -75,10 +75,9 @@ static inline void v9fs_string_init(V9fsString *str)
>  {
>      str->data = NULL;
>      str->size = 0;
>  }
>  extern void v9fs_string_free(V9fsString *str);
> -extern void v9fs_string_null(V9fsString *str);
>  extern void v9fs_string_sprintf(V9fsString *str, const char *fmt, ...);
>  extern void v9fs_string_copy(V9fsString *lhs, V9fsString *rhs);
>  
>  #endif
> diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
> index dfe293d11d1c..d8f48ca76c47 100644
> --- a/hw/9pfs/9p.c
> +++ b/hw/9pfs/9p.c
> @@ -808,19 +808,19 @@ static int stat_to_v9stat(V9fsPDU *pdu, V9fsPath *name,
>      v9stat->mode = stat_to_v9mode(stbuf);
>      v9stat->atime = stbuf->st_atime;
>      v9stat->mtime = stbuf->st_mtime;
>      v9stat->length = stbuf->st_size;
>  
> -    v9fs_string_null(&v9stat->uid);
> -    v9fs_string_null(&v9stat->gid);
> -    v9fs_string_null(&v9stat->muid);
> +    v9fs_string_free(&v9stat->uid);
> +    v9fs_string_free(&v9stat->gid);
> +    v9fs_string_free(&v9stat->muid);
>  
>      v9stat->n_uid = stbuf->st_uid;
>      v9stat->n_gid = stbuf->st_gid;
>      v9stat->n_muid = 0;
>  
> -    v9fs_string_null(&v9stat->extension);
> +    v9fs_string_free(&v9stat->extension);
>  
>      if (v9stat->mode & P9_STAT_MODE_SYMLINK) {
>          err = v9fs_co_readlink(pdu, name, &v9stat->extension);
>          if (err < 0) {
>              return err;
> 
> 

[Qemu-devel] [PATCH 4/4] 9pfs: introduce v9fs_path_sprintf() helper

[Greg Kurz]

This helper is similar to v9fs_string_sprintf(), but it includes the
terminating NUL character in the size field.

This is to avoid doing v9fs_string_sprintf((V9fsString *) &path) and
then bumping the size.

Affected users are changed to use this new helper.

Signed-off-by: Greg Kurz <groug@kaod.org>
---
 hw/9pfs/9p-local.c |    7 ++-----
 hw/9pfs/9p-proxy.c |    7 ++-----
 hw/9pfs/9p.c       |   19 ++++++++++++++++---
 hw/9pfs/9p.h       |    1 +
 4 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c
index 3f271fcbd2c5..845675e7a1bb 100644
--- a/hw/9pfs/9p-local.c
+++ b/hw/9pfs/9p-local.c
@@ -1058,17 +1058,14 @@ static int local_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
 
 static int local_name_to_path(FsContext *ctx, V9fsPath *dir_path,
                               const char *name, V9fsPath *target)
 {
     if (dir_path) {
-        v9fs_string_sprintf((V9fsString *)target, "%s/%s",
-                            dir_path->data, name);
+        v9fs_path_sprintf(target, "%s/%s", dir_path->data, name);
     } else {
-        v9fs_string_sprintf((V9fsString *)target, "%s", name);
+        v9fs_path_sprintf(target, "%s", name);
     }
-    /* Bump the size for including terminating NULL */
-    target->size++;
     return 0;
 }
 
 static int local_renameat(FsContext *ctx, V9fsPath *olddir,
                           const char *old_name, V9fsPath *newdir,
diff --git a/hw/9pfs/9p-proxy.c b/hw/9pfs/9p-proxy.c
index d091564b6fd2..f2417b7fd73d 100644
--- a/hw/9pfs/9p-proxy.c
+++ b/hw/9pfs/9p-proxy.c
@@ -1021,17 +1021,14 @@ static int proxy_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
 
 static int proxy_name_to_path(FsContext *ctx, V9fsPath *dir_path,
                               const char *name, V9fsPath *target)
 {
     if (dir_path) {
-        v9fs_string_sprintf((V9fsString *)target, "%s/%s",
-                            dir_path->data, name);
+        v9fs_path_sprintf(target, "%s/%s", dir_path->data, name);
     } else {
-        v9fs_string_sprintf((V9fsString *)target, "%s", name);
+        v9fs_path_sprintf(target, "%s", name);
     }
-    /* Bump the size for including terminating NULL */
-    target->size++;
     return 0;
 }
 
 static int proxy_renameat(FsContext *ctx, V9fsPath *olddir,
                           const char *old_name, V9fsPath *newdir,
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
index d8f48ca76c47..639f93930285 100644
--- a/hw/9pfs/9p.c
+++ b/hw/9pfs/9p.c
@@ -10,10 +10,11 @@
  * the COPYING file in the top-level directory.
  *
  */
 
 #include "qemu/osdep.h"
+#include <glib/gprintf.h>
 #include "hw/virtio/virtio.h"
 #include "qapi/error.h"
 #include "qemu/error-report.h"
 #include "qemu/iov.h"
 #include "qemu/sockets.h"
@@ -177,10 +178,24 @@ void v9fs_path_free(V9fsPath *path)
     g_free(path->data);
     path->data = NULL;
     path->size = 0;
 }
 
+
+void GCC_FMT_ATTR(2, 3)
+v9fs_path_sprintf(V9fsPath *path, const char *fmt, ...)
+{
+    va_list ap;
+
+    v9fs_path_free(path);
+
+    va_start(ap, fmt);
+    /* Bump the size for including terminating NULL */
+    path->size = g_vasprintf(&path->data, fmt, ap) + 1;
+    va_end(ap);
+}
+
 void v9fs_path_copy(V9fsPath *lhs, V9fsPath *rhs)
 {
     v9fs_path_free(lhs);
     lhs->data = g_malloc(rhs->size);
     memcpy(lhs->data, rhs->data, rhs->size);
@@ -915,14 +930,12 @@ static void print_sg(struct iovec *sg, int cnt)
 static void v9fs_fix_path(V9fsPath *dst, V9fsPath *src, int len)
 {
     V9fsPath str;
     v9fs_path_init(&str);
     v9fs_path_copy(&str, dst);
-    v9fs_string_sprintf((V9fsString *)dst, "%s%s", src->data, str.data+len);
+    v9fs_path_sprintf(dst, "%s%s", src->data, str.data + len);
     v9fs_path_free(&str);
-    /* +1 to include terminating NULL */
-    dst->size++;
 }
 
 static inline bool is_ro_export(FsContext *ctx)
 {
     return ctx->export_flags & V9FS_RDONLY;
diff --git a/hw/9pfs/9p.h b/hw/9pfs/9p.h
index a38603398ef5..d539d2ebe9c0 100644
--- a/hw/9pfs/9p.h
+++ b/hw/9pfs/9p.h
@@ -325,10 +325,11 @@ static inline uint8_t v9fs_request_cancelled(V9fsPDU *pdu)
 }
 
 extern void v9fs_reclaim_fd(V9fsPDU *pdu);
 extern void v9fs_path_init(V9fsPath *path);
 extern void v9fs_path_free(V9fsPath *path);
+extern void v9fs_path_sprintf(V9fsPath *path, const char *fmt, ...);
 extern void v9fs_path_copy(V9fsPath *lhs, V9fsPath *rhs);
 extern int v9fs_name_to_path(V9fsState *s, V9fsPath *dirpath,
                              const char *name, V9fsPath *path);
 extern int v9fs_device_realize_common(V9fsState *s, Error **errp);
 extern void v9fs_device_unrealize_common(V9fsState *s, Error **errp);

Re: [Qemu-devel] [PATCH 4/4] 9pfs: introduce v9fs_path_sprintf() helper

[Cédric Le Goater]

On 09/15/2016 04:24 PM, Greg Kurz wrote:
> This helper is similar to v9fs_string_sprintf(), but it includes the
> terminating NUL character in the size field.

NULL

> This is to avoid doing v9fs_string_sprintf((V9fsString *) &path) and
> then bumping the size.
> 
> Affected users are changed to use this new helper.



Reviewed-by: Cédric Le Goater <clg@kaod.org>

 
> Signed-off-by: Greg Kurz <groug@kaod.org>
> ---
>  hw/9pfs/9p-local.c |    7 ++-----
>  hw/9pfs/9p-proxy.c |    7 ++-----
>  hw/9pfs/9p.c       |   19 ++++++++++++++++---
>  hw/9pfs/9p.h       |    1 +
>  4 files changed, 21 insertions(+), 13 deletions(-)
> 
> diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c
> index 3f271fcbd2c5..845675e7a1bb 100644
> --- a/hw/9pfs/9p-local.c
> +++ b/hw/9pfs/9p-local.c
> @@ -1058,17 +1058,14 @@ static int local_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
>  
>  static int local_name_to_path(FsContext *ctx, V9fsPath *dir_path,
>                                const char *name, V9fsPath *target)
>  {
>      if (dir_path) {
> -        v9fs_string_sprintf((V9fsString *)target, "%s/%s",
> -                            dir_path->data, name);
> +        v9fs_path_sprintf(target, "%s/%s", dir_path->data, name);
>      } else {
> -        v9fs_string_sprintf((V9fsString *)target, "%s", name);
> +        v9fs_path_sprintf(target, "%s", name);
>      }
> -    /* Bump the size for including terminating NULL */
> -    target->size++;
>      return 0;
>  }
>  
>  static int local_renameat(FsContext *ctx, V9fsPath *olddir,
>                            const char *old_name, V9fsPath *newdir,
> diff --git a/hw/9pfs/9p-proxy.c b/hw/9pfs/9p-proxy.c
> index d091564b6fd2..f2417b7fd73d 100644
> --- a/hw/9pfs/9p-proxy.c
> +++ b/hw/9pfs/9p-proxy.c
> @@ -1021,17 +1021,14 @@ static int proxy_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
>  
>  static int proxy_name_to_path(FsContext *ctx, V9fsPath *dir_path,
>                                const char *name, V9fsPath *target)
>  {
>      if (dir_path) {
> -        v9fs_string_sprintf((V9fsString *)target, "%s/%s",
> -                            dir_path->data, name);
> +        v9fs_path_sprintf(target, "%s/%s", dir_path->data, name);
>      } else {
> -        v9fs_string_sprintf((V9fsString *)target, "%s", name);
> +        v9fs_path_sprintf(target, "%s", name);
>      }
> -    /* Bump the size for including terminating NULL */
> -    target->size++;
>      return 0;
>  }
>  
>  static int proxy_renameat(FsContext *ctx, V9fsPath *olddir,
>                            const char *old_name, V9fsPath *newdir,
> diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
> index d8f48ca76c47..639f93930285 100644
> --- a/hw/9pfs/9p.c
> +++ b/hw/9pfs/9p.c
> @@ -10,10 +10,11 @@
>   * the COPYING file in the top-level directory.
>   *
>   */
>  
>  #include "qemu/osdep.h"
> +#include <glib/gprintf.h>
>  #include "hw/virtio/virtio.h"
>  #include "qapi/error.h"
>  #include "qemu/error-report.h"
>  #include "qemu/iov.h"
>  #include "qemu/sockets.h"
> @@ -177,10 +178,24 @@ void v9fs_path_free(V9fsPath *path)
>      g_free(path->data);
>      path->data = NULL;
>      path->size = 0;
>  }
>  
> +
> +void GCC_FMT_ATTR(2, 3)
> +v9fs_path_sprintf(V9fsPath *path, const char *fmt, ...)
> +{
> +    va_list ap;
> +
> +    v9fs_path_free(path);
> +
> +    va_start(ap, fmt);
> +    /* Bump the size for including terminating NULL */
> +    path->size = g_vasprintf(&path->data, fmt, ap) + 1;
> +    va_end(ap);
> +}
> +
>  void v9fs_path_copy(V9fsPath *lhs, V9fsPath *rhs)
>  {
>      v9fs_path_free(lhs);
>      lhs->data = g_malloc(rhs->size);
>      memcpy(lhs->data, rhs->data, rhs->size);
> @@ -915,14 +930,12 @@ static void print_sg(struct iovec *sg, int cnt)
>  static void v9fs_fix_path(V9fsPath *dst, V9fsPath *src, int len)
>  {
>      V9fsPath str;
>      v9fs_path_init(&str);
>      v9fs_path_copy(&str, dst);
> -    v9fs_string_sprintf((V9fsString *)dst, "%s%s", src->data, str.data+len);
> +    v9fs_path_sprintf(dst, "%s%s", src->data, str.data + len);
>      v9fs_path_free(&str);
> -    /* +1 to include terminating NULL */
> -    dst->size++;
>  }
>  
>  static inline bool is_ro_export(FsContext *ctx)
>  {
>      return ctx->export_flags & V9FS_RDONLY;
> diff --git a/hw/9pfs/9p.h b/hw/9pfs/9p.h
> index a38603398ef5..d539d2ebe9c0 100644
> --- a/hw/9pfs/9p.h
> +++ b/hw/9pfs/9p.h
> @@ -325,10 +325,11 @@ static inline uint8_t v9fs_request_cancelled(V9fsPDU *pdu)
>  }
>  
>  extern void v9fs_reclaim_fd(V9fsPDU *pdu);
>  extern void v9fs_path_init(V9fsPath *path);
>  extern void v9fs_path_free(V9fsPath *path);
> +extern void v9fs_path_sprintf(V9fsPath *path, const char *fmt, ...);
>  extern void v9fs_path_copy(V9fsPath *lhs, V9fsPath *rhs);
>  extern int v9fs_name_to_path(V9fsState *s, V9fsPath *dirpath,
>                               const char *name, V9fsPath *path);
>  extern int v9fs_device_realize_common(V9fsState *s, Error **errp);
>  extern void v9fs_device_unrealize_common(V9fsState *s, Error **errp);
> 
> 

Re: [Qemu-devel] [PATCH 4/4] 9pfs: introduce v9fs_path_sprintf() helper

[Greg Kurz]

On Thu, 15 Sep 2016 17:09:08 +0200
Cédric Le Goater <clg@kaod.org> wrote:

> On 09/15/2016 04:24 PM, Greg Kurz wrote:
> > This helper is similar to v9fs_string_sprintf(), but it includes the
> > terminating NUL character in the size field.  
> 
> NULL
> 

The null character is often abbreviated NUL.

https://en.wikipedia.org/wiki/Null_character

> > This is to avoid doing v9fs_string_sprintf((V9fsString *) &path) and
> > then bumping the size.
> > 
> > Affected users are changed to use this new helper.  
> 
> 
> 
> Reviewed-by: Cédric Le Goater <clg@kaod.org>
> 
>  
> > Signed-off-by: Greg Kurz <groug@kaod.org>
> > ---
> >  hw/9pfs/9p-local.c |    7 ++-----
> >  hw/9pfs/9p-proxy.c |    7 ++-----
> >  hw/9pfs/9p.c       |   19 ++++++++++++++++---
> >  hw/9pfs/9p.h       |    1 +
> >  4 files changed, 21 insertions(+), 13 deletions(-)
> > 
> > diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c
> > index 3f271fcbd2c5..845675e7a1bb 100644
> > --- a/hw/9pfs/9p-local.c
> > +++ b/hw/9pfs/9p-local.c
> > @@ -1058,17 +1058,14 @@ static int local_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
> >  
> >  static int local_name_to_path(FsContext *ctx, V9fsPath *dir_path,
> >                                const char *name, V9fsPath *target)
> >  {
> >      if (dir_path) {
> > -        v9fs_string_sprintf((V9fsString *)target, "%s/%s",
> > -                            dir_path->data, name);
> > +        v9fs_path_sprintf(target, "%s/%s", dir_path->data, name);
> >      } else {
> > -        v9fs_string_sprintf((V9fsString *)target, "%s", name);
> > +        v9fs_path_sprintf(target, "%s", name);
> >      }
> > -    /* Bump the size for including terminating NULL */
> > -    target->size++;
> >      return 0;
> >  }
> >  
> >  static int local_renameat(FsContext *ctx, V9fsPath *olddir,
> >                            const char *old_name, V9fsPath *newdir,
> > diff --git a/hw/9pfs/9p-proxy.c b/hw/9pfs/9p-proxy.c
> > index d091564b6fd2..f2417b7fd73d 100644
> > --- a/hw/9pfs/9p-proxy.c
> > +++ b/hw/9pfs/9p-proxy.c
> > @@ -1021,17 +1021,14 @@ static int proxy_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
> >  
> >  static int proxy_name_to_path(FsContext *ctx, V9fsPath *dir_path,
> >                                const char *name, V9fsPath *target)
> >  {
> >      if (dir_path) {
> > -        v9fs_string_sprintf((V9fsString *)target, "%s/%s",
> > -                            dir_path->data, name);
> > +        v9fs_path_sprintf(target, "%s/%s", dir_path->data, name);
> >      } else {
> > -        v9fs_string_sprintf((V9fsString *)target, "%s", name);
> > +        v9fs_path_sprintf(target, "%s", name);
> >      }
> > -    /* Bump the size for including terminating NULL */
> > -    target->size++;
> >      return 0;
> >  }
> >  
> >  static int proxy_renameat(FsContext *ctx, V9fsPath *olddir,
> >                            const char *old_name, V9fsPath *newdir,
> > diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
> > index d8f48ca76c47..639f93930285 100644
> > --- a/hw/9pfs/9p.c
> > +++ b/hw/9pfs/9p.c
> > @@ -10,10 +10,11 @@
> >   * the COPYING file in the top-level directory.
> >   *
> >   */
> >  
> >  #include "qemu/osdep.h"
> > +#include <glib/gprintf.h>
> >  #include "hw/virtio/virtio.h"
> >  #include "qapi/error.h"
> >  #include "qemu/error-report.h"
> >  #include "qemu/iov.h"
> >  #include "qemu/sockets.h"
> > @@ -177,10 +178,24 @@ void v9fs_path_free(V9fsPath *path)
> >      g_free(path->data);
> >      path->data = NULL;
> >      path->size = 0;
> >  }
> >  
> > +
> > +void GCC_FMT_ATTR(2, 3)
> > +v9fs_path_sprintf(V9fsPath *path, const char *fmt, ...)
> > +{
> > +    va_list ap;
> > +
> > +    v9fs_path_free(path);
> > +
> > +    va_start(ap, fmt);
> > +    /* Bump the size for including terminating NULL */
> > +    path->size = g_vasprintf(&path->data, fmt, ap) + 1;
> > +    va_end(ap);
> > +}
> > +
> >  void v9fs_path_copy(V9fsPath *lhs, V9fsPath *rhs)
> >  {
> >      v9fs_path_free(lhs);
> >      lhs->data = g_malloc(rhs->size);
> >      memcpy(lhs->data, rhs->data, rhs->size);
> > @@ -915,14 +930,12 @@ static void print_sg(struct iovec *sg, int cnt)
> >  static void v9fs_fix_path(V9fsPath *dst, V9fsPath *src, int len)
> >  {
> >      V9fsPath str;
> >      v9fs_path_init(&str);
> >      v9fs_path_copy(&str, dst);
> > -    v9fs_string_sprintf((V9fsString *)dst, "%s%s", src->data, str.data+len);
> > +    v9fs_path_sprintf(dst, "%s%s", src->data, str.data + len);
> >      v9fs_path_free(&str);
> > -    /* +1 to include terminating NULL */
> > -    dst->size++;
> >  }
> >  
> >  static inline bool is_ro_export(FsContext *ctx)
> >  {
> >      return ctx->export_flags & V9FS_RDONLY;
> > diff --git a/hw/9pfs/9p.h b/hw/9pfs/9p.h
> > index a38603398ef5..d539d2ebe9c0 100644
> > --- a/hw/9pfs/9p.h
> > +++ b/hw/9pfs/9p.h
> > @@ -325,10 +325,11 @@ static inline uint8_t v9fs_request_cancelled(V9fsPDU *pdu)
> >  }
> >  
> >  extern void v9fs_reclaim_fd(V9fsPDU *pdu);
> >  extern void v9fs_path_init(V9fsPath *path);
> >  extern void v9fs_path_free(V9fsPath *path);
> > +extern void v9fs_path_sprintf(V9fsPath *path, const char *fmt, ...);
> >  extern void v9fs_path_copy(V9fsPath *lhs, V9fsPath *rhs);
> >  extern int v9fs_name_to_path(V9fsState *s, V9fsPath *dirpath,
> >                               const char *name, V9fsPath *path);
> >  extern int v9fs_device_realize_common(V9fsState *s, Error **errp);
> >  extern void v9fs_device_unrealize_common(V9fsState *s, Error **errp);
> > 
> >   
>