From 4bb0afef46409583c737044437565e6886017376 Mon Sep 17 00:00:00 2001
From: code <code@T410.(none)>
Date: Thu, 1 Sep 2011 13:01:11 +0800
Subject: [PATCH] do not use fd

---
 block/add-cow.c | 74 ++++++++++++++++++++++++++++-----------------------------
 1 file changed, 37 insertions(+), 37 deletions(-)

diff --git a/block/add-cow.c b/block/add-cow.c
index 06c22441b5..2c12e6c52c 100644
--- a/block/add-cow.c
+++ b/block/add-cow.c
@@ -15,7 +15,7 @@ struct add_cow_header {
     char image_file[1024];
     uint64_t size;
     uint32_t sectorsize;
-};
+}add_cow_header;
 
 typedef struct BDRVAddCowState {
     CoMutex lock;
@@ -159,14 +159,13 @@ static void add_cow_close(BlockDriverState *bs)
 
 static int add_cow_create(const char *filename, QEMUOptionParameter *options)
 {
-    int fd, cow_fd;
     struct add_cow_header add_cow_header;
     int64_t image_sectors = 0;
     const char *backing_filename = NULL;
     const char *image_filename = NULL;
     int ret;
+    BlockDriverState* bs;
 
-    /* Read out options */
     while (options && options->name) {
         if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
             image_sectors = options->value.n / 512;
@@ -178,54 +177,44 @@ static int add_cow_create(const char *filename, QEMUOptionParameter *options)
         options++;
     }
 
-    cow_fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
-              0644);
-    if (cow_fd < 0) {
-        return -errno;
+    ret = bdrv_create_file(filename, NULL);
+    if (ret < 0) {
+        return ret;
     }
 
-    if (!backing_filename || !image_filename) {
-        fprintf(stderr, " backing_file and image_file can not be empty!\n");
-        ret = -EINVAL;
-        goto exit;
+    ret = bdrv_file_open(&bs, filename, BDRV_O_RDWR);
+    if (ret < 0) {
+        return ret;
     }
 
-
     memset(&add_cow_header, 0, sizeof(add_cow_header));
     add_cow_header.magic = cpu_to_be64(ADD_COW_MAGIC);
     add_cow_header.version = cpu_to_be32(ADD_COW_VERSION);
-    /* Make sure backing_file exists*/
-    if (backing_filename) {
-        fd = open(backing_filename, O_RDONLY | O_BINARY);
-        if (fd < 0) {
-            close(cow_fd);
-            goto open_fail;
-        }
-        close(fd);
-open_fail:
-        pstrcpy(add_cow_header.backing_file, \
+    pstrcpy(add_cow_header.backing_file, \
                 sizeof(add_cow_header.backing_file), backing_filename);
-        pstrcpy(add_cow_header.image_file, sizeof(add_cow_header.image_file),
+    pstrcpy(add_cow_header.image_file, sizeof(add_cow_header.image_file),
                 image_filename);
-    }
-
+    
     add_cow_header.sectorsize = cpu_to_be32(512);
     add_cow_header.size = cpu_to_be64(image_sectors * 512);
-    ret = qemu_write_full(cow_fd, &add_cow_header, sizeof(add_cow_header));
-    if (ret != sizeof(add_cow_header)) {
-        ret = -errno;
-        goto exit;
+
+    ret = bdrv_pwrite(bs, 0, &add_cow_header, sizeof(add_cow_header));
+    if (ret < 0) {
+        return ret;
     }
+    bdrv_close(bs);
 
-    ret = ftruncate(cow_fd, sizeof(add_cow_header) + \
-             ((image_sectors + 7) >> 3));
-    if (ret) {
-        ret = -errno;
-        goto exit;
+    BlockDriver* drv = bdrv_find_format("add-cow");
+    assert(drv != NULL);
+    ret = bdrv_open(bs, filename, BDRV_O_RDWR | BDRV_O_NO_FLUSH, drv);
+    if (ret < 0) {
+        return ret;
     }
 
-exit:
-    close(cow_fd);
+    ret = bdrv_truncate(bs, ((image_sectors + 7) >> 3));
+    if (ret < 0) {
+        return ret;
+    }
     return ret;
 }
 
@@ -359,7 +348,6 @@ static int add_cow_co_readv(BlockDriverState *bs, int64_t sector_num,
     int ret;
   
     acb = add_cow_aio_setup(bs, sector_num, qiov, nb_sectors, 0);
-
     qemu_co_mutex_lock(&s->lock);
     do {
         ret = add_cow_aio_read_cb(acb);
@@ -401,6 +389,17 @@ static int add_cow_co_writev(BlockDriverState *bs, int64_t sector_num,
     return ret;
 }
 
+static int bdrv_add_cow_truncate(BlockDriverState *bs, int64_t offset)
+{
+    int ret;
+    ret = bdrv_truncate(bs->file,offset + sizeof(add_cow_header));
+    if (ret < 0) {
+        return ret;
+    }
+
+    return 0;
+}
+
 static QEMUOptionParameter add_cow_create_options[] = {
     {
         .name = BLOCK_OPT_SIZE,
@@ -431,6 +430,7 @@ static BlockDriver bdrv_add_cow = {
 
     .bdrv_co_readv      = add_cow_co_readv,
     .bdrv_co_writev     = add_cow_co_writev,
+    .bdrv_truncate      = bdrv_add_cow_truncate,
 
     .create_options = add_cow_create_options,
 };
-- 
2.11.4.GIT