qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Qemu-devel] [PATCH 1/3] 9pfs-proxy: simplify error handling


From: Michael Tokarev
Subject: [Qemu-devel] [PATCH 1/3] 9pfs-proxy: simplify error handling
Date: Sat, 7 Mar 2015 00:43:02 +0300

All filesystem methods that call common v9fs_request() function
also convert return value to errno.  Move this conversion to the
common function and remove redundand error handling in methods.

I didn't remove local `retval' variable in simple functions to
keep the code consistent.

Also, proxy_truncate() seem to prefer zero successful return
instead of returning whatever the helper returned, maybe this
should be changed.

This also removes (harmless) double call to v9fs_string_free()
in proxy_mkdir(), and renames local variables in some functions
for consistency.

Signed-off-by: Michael Tokarev <address@hidden>
---
 hw/9pfs/virtio-9p-proxy.c | 142 ++++++++++++----------------------------------
 1 file changed, 35 insertions(+), 107 deletions(-)

diff --git a/hw/9pfs/virtio-9p-proxy.c b/hw/9pfs/virtio-9p-proxy.c
index 0904130..13064b6 100644
--- a/hw/9pfs/virtio-9p-proxy.c
+++ b/hw/9pfs/virtio-9p-proxy.c
@@ -291,7 +291,7 @@ 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
+ * returns 0 on success and -1 (setting errno) on error
  */
 static int v9fs_request(V9fsProxy *proxy, int type,
                         void *response, const char *fmt, ...)
@@ -299,7 +299,7 @@ static int v9fs_request(V9fsProxy *proxy, int type,
     dev_t rdev;
     va_list ap;
     int size = 0;
-    int retval = 0;
+    int retval, err;
     uint64_t offset;
     ProxyHeader header = { 0, 0};
     struct timespec spec[2];
@@ -310,10 +310,11 @@ static int v9fs_request(V9fsProxy *proxy, int type,
 
     qemu_mutex_lock(&proxy->mutex);
 
-    if (proxy->sockfd == -1) {
+    if (proxy->sockfd < 0) {
         retval = -EIO;
-        goto err_out;
+        goto out;
     }
+
     iovec = &proxy->out_iovec;
     reply = &proxy->in_iovec;
     va_start(ap, fmt);
@@ -529,15 +530,15 @@ static int v9fs_request(V9fsProxy *proxy, int type,
     va_end(ap);
 
     if (retval < 0) {
-        goto err_out;
+        goto out;
     }
 
     /* marshal the header details */
     proxy_marshal(iovec, 0, "dd", header.type, header.size);
     header.size += PROXY_HDR_SZ;
 
-    retval = qemu_write_full(proxy->sockfd, iovec->iov_base, header.size);
-    if (retval != header.size) {
+    err = qemu_write_full(proxy->sockfd, iovec->iov_base, header.size);
+    if (err != header.size) {
         goto close_error;
     }
 
@@ -548,9 +549,7 @@ static int v9fs_request(V9fsProxy *proxy, int type,
          * A file descriptor is returned as response for
          * T_OPEN,T_CREATE on success
          */
-        if (v9fs_receivefd(proxy->sockfd, &retval) < 0) {
-            goto close_error;
-        }
+        err = v9fs_receivefd(proxy->sockfd, &retval);
         break;
     case T_MKNOD:
     case T_MKDIR:
@@ -564,51 +563,44 @@ static int v9fs_request(V9fsProxy *proxy, int type,
     case T_REMOVE:
     case T_LSETXATTR:
     case T_LREMOVEXATTR:
-        if (v9fs_receive_status(proxy, reply, &retval) < 0) {
-            goto close_error;
-        }
+        err = v9fs_receive_status(proxy, reply, &retval);
         break;
     case T_LSTAT:
     case T_READLINK:
     case T_STATFS:
     case T_GETVERSION:
-        if (v9fs_receive_response(proxy, type, &retval, response) < 0) {
-            goto close_error;
-        }
+        err = v9fs_receive_response(proxy, type, &retval, response);
         break;
     case T_LGETXATTR:
     case T_LLISTXATTR:
         if (!size) {
-            if (v9fs_receive_status(proxy, reply, &retval) < 0) {
-                goto close_error;
-            }
+            err = v9fs_receive_status(proxy, reply, &retval);
         } else {
-            if (v9fs_receive_response(proxy, type, &retval, response) < 0) {
-                goto close_error;
-            }
+            err = v9fs_receive_response(proxy, type, &retval, response);
         }
         break;
     }
 
-err_out:
-    qemu_mutex_unlock(&proxy->mutex);
-    return retval;
-
+    if (err < 0) {
 close_error:
-    close(proxy->sockfd);
-    proxy->sockfd = -1;
+        close(proxy->sockfd);
+        proxy->sockfd = -1;
+        retval = -EIO;
+    }
+
+out:
+    if (retval < 0) {
+        errno = -retval;
+        retval = -1;
+    }
     qemu_mutex_unlock(&proxy->mutex);
-    return -EIO;
+    return retval;
 }
 
 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);
-    if (retval < 0) {
-        errno = -retval;
-        return -1;
-    }
     return retval;
 }
 
@@ -619,7 +611,6 @@ static ssize_t proxy_readlink(FsContext *fs_ctx, V9fsPath 
*fs_path,
     retval = v9fs_request(fs_ctx->private, T_READLINK, buf, "sd",
                           fs_path, bufsz);
     if (retval < 0) {
-        errno = -retval;
         return -1;
     }
     return strlen(buf);
@@ -639,10 +630,6 @@ 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);
-    if (fs->fd < 0) {
-        errno = -fs->fd;
-        fs->fd = -1;
-    }
     return fs->fd;
 }
 
@@ -654,7 +641,6 @@ static int proxy_opendir(FsContext *ctx,
     fs->dir = NULL;
     fd = v9fs_request(ctx->private, T_OPEN, NULL, "sd", fs_path, O_DIRECTORY);
     if (fd < 0) {
-        errno = -fd;
         return -1;
     }
     fs->dir = fdopendir(fd);
@@ -738,9 +724,6 @@ 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);
-    if (retval < 0) {
-        errno = -retval;
-    }
     return retval;
 }
 
@@ -757,10 +740,6 @@ static int proxy_mknod(FsContext *fs_ctx, V9fsPath 
*dir_path,
                           &fullname, credp->fc_mode, credp->fc_rdev,
                           credp->fc_uid, credp->fc_gid);
     v9fs_string_free(&fullname);
-    if (retval < 0) {
-        errno = -retval;
-        retval = -1;
-    }
     return retval;
 }
 
@@ -776,11 +755,6 @@ static int proxy_mkdir(FsContext *fs_ctx, V9fsPath 
*dir_path,
     retval = v9fs_request(fs_ctx->private, T_MKDIR, NULL, "sddd", &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;
 }
 
@@ -809,10 +783,6 @@ static int proxy_open2(FsContext *fs_ctx, V9fsPath 
*dir_path, const char *name,
                           &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;
-    }
     return fs->fd;
 }
 
@@ -832,10 +802,6 @@ static int proxy_symlink(FsContext *fs_ctx, const char 
*oldpath,
                           &target, &fullname, credp->fc_uid, credp->fc_gid);
     v9fs_string_free(&fullname);
     v9fs_string_free(&target);
-    if (retval < 0) {
-        errno = -retval;
-        retval = -1;
-    }
     return retval;
 }
 
@@ -850,20 +816,14 @@ static int proxy_link(FsContext *ctx, V9fsPath *oldpath,
 
     retval = v9fs_request(ctx->private, T_LINK, NULL, "ss", oldpath, &newpath);
     v9fs_string_free(&newpath);
-    if (retval < 0) {
-        errno = -retval;
-        retval = -1;
-    }
     return retval;
 }
 
 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);
     if (retval < 0) {
-        errno = -retval;
         return -1;
     }
     return 0;
@@ -884,9 +844,6 @@ static int proxy_rename(FsContext *ctx, const char *oldpath,
                           &oldname, &newname);
     v9fs_string_free(&oldname);
     v9fs_string_free(&newname);
-    if (retval < 0) {
-        errno = -retval;
-    }
     return retval;
 }
 
@@ -895,9 +852,6 @@ 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);
-    if (retval < 0) {
-        errno = -retval;
-    }
     return retval;
 }
 
@@ -909,9 +863,6 @@ static int proxy_utimensat(FsContext *s, V9fsPath *fs_path,
                           fs_path,
                           buf[0].tv_sec, buf[0].tv_nsec,
                           buf[1].tv_sec, buf[1].tv_nsec);
-    if (retval < 0) {
-        errno = -retval;
-    }
     return retval;
 }
 
@@ -923,9 +874,6 @@ static int proxy_remove(FsContext *ctx, const char *path)
     v9fs_string_sprintf(&name, "%s", path);
     retval = v9fs_request(ctx->private, T_REMOVE, NULL, "s", &name);
     v9fs_string_free(&name);
-    if (retval < 0) {
-        errno = -retval;
-    }
     return retval;
 }
 
@@ -951,10 +899,6 @@ 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);
-    if (retval < 0) {
-        errno = -retval;
-        return -1;
-    }
     return retval;
 }
 
@@ -969,9 +913,6 @@ static ssize_t proxy_lgetxattr(FsContext *ctx, V9fsPath 
*fs_path,
     retval = v9fs_request(ctx->private, T_LGETXATTR, value, "dss", size,
                           fs_path, &xname);
     v9fs_string_free(&xname);
-    if (retval < 0) {
-        errno = -retval;
-    }
     return retval;
 }
 
@@ -980,10 +921,7 @@ static ssize_t proxy_llistxattr(FsContext *ctx, V9fsPath 
*fs_path,
 {
     int retval;
     retval = v9fs_request(ctx->private, T_LLISTXATTR, value, "ds", size,
-                        fs_path);
-    if (retval < 0) {
-        errno = -retval;
-    }
+                          fs_path);
     return retval;
 }
 
@@ -1005,9 +943,6 @@ static int proxy_lsetxattr(FsContext *ctx, V9fsPath 
*fs_path, const char *name,
                           fs_path, &xname, &xvalue, size, flags);
     v9fs_string_free(&xname);
     v9fs_string_free(&xvalue);
-    if (retval < 0) {
-        errno = -retval;
-    }
     return retval;
 }
 
@@ -1022,9 +957,6 @@ static int proxy_lremovexattr(FsContext *ctx, V9fsPath 
*fs_path,
     retval = v9fs_request(ctx->private, T_LREMOVEXATTR, NULL, "ss",
                           fs_path, &xname);
     v9fs_string_free(&xname);
-    if (retval < 0) {
-        errno = -retval;
-    }
     return retval;
 }
 
@@ -1046,7 +978,7 @@ static int proxy_renameat(FsContext *ctx, V9fsPath *olddir,
                           const char *old_name, V9fsPath *newdir,
                           const char *new_name)
 {
-    int ret;
+    int retval;
     V9fsString old_full_name, new_full_name;
 
     v9fs_string_init(&old_full_name);
@@ -1055,30 +987,30 @@ static int proxy_renameat(FsContext *ctx, V9fsPath 
*olddir,
     v9fs_string_sprintf(&old_full_name, "%s/%s", olddir->data, old_name);
     v9fs_string_sprintf(&new_full_name, "%s/%s", newdir->data, new_name);
 
-    ret = proxy_rename(ctx, old_full_name.data, new_full_name.data);
+    retval = proxy_rename(ctx, old_full_name.data, new_full_name.data);
     v9fs_string_free(&old_full_name);
     v9fs_string_free(&new_full_name);
-    return ret;
+    return retval;
 }
 
 static int proxy_unlinkat(FsContext *ctx, V9fsPath *dir,
                           const char *name, int flags)
 {
-    int ret;
+    int retval;
     V9fsString fullname;
     v9fs_string_init(&fullname);
 
     v9fs_string_sprintf(&fullname, "%s/%s", dir->data, name);
-    ret = proxy_remove(ctx, fullname.data);
+    retval = proxy_remove(ctx, fullname.data);
     v9fs_string_free(&fullname);
 
-    return ret;
+    return retval;
 }
 
 static int proxy_ioc_getversion(FsContext *fs_ctx, V9fsPath *path,
                                 mode_t st_mode, uint64_t *st_gen)
 {
-    int err;
+    int retval;
 
     /* Do not try to open special files like device nodes, fifos etc
      * we can get fd for regular files and directories only
@@ -1087,12 +1019,8 @@ 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);
-    if (err < 0) {
-        errno = -err;
-        err = -1;
-    }
-    return err;
+    retval = v9fs_request(fs_ctx->private, T_GETVERSION, st_gen, "s", path);
+    return retval;
 }
 
 static int connect_namedsocket(const char *path)
-- 
2.1.4




reply via email to

[Prev in Thread] Current Thread [Next in Thread]