Merge remote-tracking branch 'remotes/gkurz/tags/for-upstream' into staging

This pull request contains:
- a fix for a regression introduced in 2.7
- basic functional testing for virtio-9p
- some code cleanups for 9pfs

# gpg: Signature made Mon 19 Sep 2016 10:40:17 BST
# gpg:                using DSA key 0x02FC3AEB0101DBC2
# gpg: Good signature from "Greg Kurz <groug@kaod.org>"
# gpg:                 aka "Greg Kurz <groug@free.fr>"
# gpg:                 aka "Greg Kurz <gkurz@fr.ibm.com>"
# gpg:                 aka "Greg Kurz <gkurz@linux.vnet.ibm.com>"
# gpg:                 aka "Gregory Kurz (Groug) <groug@free.fr>"
# gpg:                 aka "Gregory Kurz (Cimai Technology) <gkurz@cimai.com>"
# gpg:                 aka "Gregory Kurz (Meiosys Technology) <gkurz@meiosys.com>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 2BD4 3B44 535E C0A7 9894  DBA2 02FC 3AEB 0101 DBC2

* remotes/gkurz/tags/for-upstream:
  9pfs: fix potential segfault during walk
  tests: virtio-9p: add basic configuration test
  tests: virtio-9p: introduce start/stop functions
  9pfs: introduce v9fs_path_sprintf() helper
  9pfs: drop useless v9fs_string_null() function
  9pfs: drop duplicate line in proxy backend
  9pfs: drop unused fmt strings in the proxy backend

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

4 files changed, 58 insertions, 57 deletions

diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c
index 3f271fcbd2..845675e7a1 100644
--- a/hw/9pfs/9p-local.c
+++ b/hw/9pfs/9p-local.c
@@ -1060,13 +1060,10 @@ 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;
 }
 
diff --git a/hw/9pfs/9p-proxy.c b/hw/9pfs/9p-proxy.c
index f265501eac..f2417b7fd7 100644
--- a/hw/9pfs/9p-proxy.c
+++ b/hw/9pfs/9p-proxy.c
@@ -294,8 +294,7 @@ static int v9fs_receive_status(V9fsProxy *proxy,
  * 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;
@@ -317,7 +316,7 @@ static int v9fs_request(V9fsProxy *proxy, int type,
     }
     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 *);
@@ -605,7 +604,7 @@ 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;
@@ -617,8 +616,7 @@ 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;
@@ -639,7 +637,7 @@ 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;
@@ -653,7 +651,7 @@ static int proxy_opendir(FsContext *ctx,
     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;
@@ -735,8 +733,8 @@ 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;
     }
@@ -752,8 +750,8 @@ static int proxy_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
     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) {
@@ -772,14 +770,13 @@ static int proxy_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
     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;
     }
-    v9fs_string_free(&fullname);
     return retval;
 }
 
@@ -804,9 +801,8 @@ static int proxy_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
     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;
@@ -827,8 +823,8 @@ static int proxy_symlink(FsContext *fs_ctx, const char *oldpath,
     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) {
@@ -847,7 +843,7 @@ static int proxy_link(FsContext *ctx, V9fsPath *oldpath,
     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;
@@ -860,7 +856,7 @@ 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;
@@ -879,8 +875,7 @@ static int proxy_rename(FsContext *ctx, const char *oldpath,
 
     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) {
@@ -892,8 +887,8 @@ 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;
     }
@@ -904,8 +899,7 @@ 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) {
@@ -920,7 +914,7 @@ static int proxy_remove(FsContext *ctx, const char *path)
     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;
@@ -949,7 +943,7 @@ 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;
@@ -965,8 +959,8 @@ static ssize_t proxy_lgetxattr(FsContext *ctx, V9fsPath *fs_path,
 
     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;
@@ -978,8 +972,7 @@ 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;
     }
@@ -1000,8 +993,8 @@ static int proxy_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name,
     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) {
@@ -1018,8 +1011,7 @@ static int proxy_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
 
     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;
@@ -1031,13 +1023,10 @@ 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;
 }
 
@@ -1086,7 +1075,7 @@ static int proxy_ioc_getversion(FsContext *fs_ctx, V9fsPath *path,
         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;
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
index dfe293d11d..119ee58496 100644
--- a/hw/9pfs/9p.c
+++ b/hw/9pfs/9p.c
@@ -12,6 +12,7 @@
  */
 
 #include "qemu/osdep.h"
+#include <glib/gprintf.h>
 #include "hw/virtio/virtio.h"
 #include "qapi/error.h"
 #include "qemu/error-report.h"
@@ -179,6 +180,20 @@ void v9fs_path_free(V9fsPath *path)
     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);
@@ -810,15 +825,15 @@ static int stat_to_v9stat(V9fsPDU *pdu, V9fsPath *name,
     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);
@@ -917,10 +932,8 @@ 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)
@@ -1320,13 +1333,14 @@ static void v9fs_walk(void *opaque)
         goto out_nofid;
     }
 
+    v9fs_path_init(&dpath);
+    v9fs_path_init(&path);
+
     err = fid_to_qid(pdu, fidp, &qid);
     if (err < 0) {
         goto out;
     }
 
-    v9fs_path_init(&dpath);
-    v9fs_path_init(&path);
     /*
      * Both dpath and path initially poin to fidp.
      * Needed to handle request with nwnames == 0
diff --git a/hw/9pfs/9p.h b/hw/9pfs/9p.h
index a38603398e..d539d2ebe9 100644
--- a/hw/9pfs/9p.h
+++ b/hw/9pfs/9p.h
@@ -327,6 +327,7 @@ 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);