[Qemu-devel] [PATCH 3/7] block/vpc: Replace HEADER_SIZE by FOOTER_SIZE

[Stefan Weil]

HEADER_SIZE is the size of the footer (the last sector of the VHD image),
so its correct name is FOOTER_SIZE.

For the same reason, we have a footer checksum instead of a header checksum.

Signed-off-by: Stefan Weil <address@hidden>
---
 block/vpc.c |   32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/block/vpc.c b/block/vpc.c
index 4565723..bcc2ace 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -35,7 +35,7 @@
 
 /**************************************************************/
 
-#define HEADER_SIZE 512
+#define FOOTER_SIZE 512
 
 //#define CACHE
 
@@ -118,7 +118,7 @@ struct vhd_dyndisk_header {
 
 typedef struct BDRVVPCState {
     CoMutex lock;
-    uint8_t footer_buf[HEADER_SIZE];
+    uint8_t footer_buf[FOOTER_SIZE];
     uint64_t free_data_block_offset;
     int max_table_entries;
     uint32_t *pagetable;
@@ -166,24 +166,24 @@ static int vpc_open(BlockDriverState *bs, int flags)
     int i;
     struct vhd_footer *footer;
     struct vhd_dyndisk_header *dyndisk_header;
-    uint8_t buf[HEADER_SIZE];
+    uint8_t buf[FOOTER_SIZE];
     uint32_t checksum;
     int err = -1;
     int disk_type = VHD_DYNAMIC;
 
-    if (bdrv_pread(bs->file, 0, s->footer_buf, HEADER_SIZE) != HEADER_SIZE) {
+    if (bdrv_pread(bs->file, 0, s->footer_buf, FOOTER_SIZE) != FOOTER_SIZE) {
         goto fail;
     }
 
     footer = (struct vhd_footer *)s->footer_buf;
     if (strncmp(footer->creator, "conectix", 8)) {
         int64_t offset = bdrv_getlength(bs->file);
-        if (offset < HEADER_SIZE) {
+        if (offset < FOOTER_SIZE) {
             goto fail;
         }
         /* If a fixed disk, the footer is found only at the end of the file */
-        if (bdrv_pread(bs->file, offset-HEADER_SIZE, s->footer_buf, 
HEADER_SIZE)
-                != HEADER_SIZE) {
+        if (bdrv_pread(bs->file, offset-FOOTER_SIZE, s->footer_buf, 
FOOTER_SIZE)
+                != FOOTER_SIZE) {
             goto fail;
         }
         if (strncmp(footer->creator, "conectix", 8)) {
@@ -194,8 +194,8 @@ static int vpc_open(BlockDriverState *bs, int flags)
 
     checksum = be32_to_cpu(footer->checksum);
     footer->checksum = 0;
-    if (vpc_checksum(s->footer_buf, HEADER_SIZE) != checksum) {
-        fprintf(stderr, "block-vpc: The header checksum of '%s' is "
+    if (vpc_checksum(s->footer_buf, FOOTER_SIZE) != checksum) {
+        fprintf(stderr, "block-vpc: The footer checksum of '%s' is "
             "incorrect.\n", bs->filename);
     }
 
@@ -216,7 +216,7 @@ static int vpc_open(BlockDriverState *bs, int flags)
 
     if (disk_type == VHD_DYNAMIC) {
         if (bdrv_pread(bs->file, be64_to_cpu(footer->data_offset), buf,
-                HEADER_SIZE) != HEADER_SIZE) {
+                FOOTER_SIZE) != FOOTER_SIZE) {
             goto fail;
         }
 
@@ -366,7 +366,7 @@ static int rewrite_footer(BlockDriverState *bs)
     BDRVVPCState *s = bs->opaque;
     int64_t offset = s->free_data_block_offset;
 
-    ret = bdrv_pwrite_sync(bs->file, offset, s->footer_buf, HEADER_SIZE);
+    ret = bdrv_pwrite_sync(bs->file, offset, s->footer_buf, FOOTER_SIZE);
     if (ret < 0) {
         return ret;
     }
@@ -602,14 +602,14 @@ static int create_dynamic_disk(int fd, uint8_t *buf, 
int64_t total_sectors)
     block_size = 0x200000;
     num_bat_entries = (total_sectors + block_size / 512) / (block_size / 512);
 
-    if (write(fd, buf, HEADER_SIZE) != HEADER_SIZE) {
+    if (write(fd, buf, FOOTER_SIZE) != FOOTER_SIZE) {
         goto fail;
     }
 
     if (lseek(fd, 1536 + ((num_bat_entries * 4 + 511) & ~511), SEEK_SET) < 0) {
         goto fail;
     }
-    if (write(fd, buf, HEADER_SIZE) != HEADER_SIZE) {
+    if (write(fd, buf, FOOTER_SIZE) != FOOTER_SIZE) {
         goto fail;
     }
 
@@ -669,7 +669,7 @@ static int create_fixed_disk(int fd, uint8_t *buf, int64_t 
total_size)
     if (lseek(fd, -512, SEEK_END) < 0) {
         goto fail;
     }
-    if (write(fd, buf, HEADER_SIZE) != HEADER_SIZE) {
+    if (write(fd, buf, FOOTER_SIZE) != FOOTER_SIZE) {
         goto fail;
     }
 
@@ -742,7 +742,7 @@ static int vpc_create(const char *filename, 
QEMUOptionParameter *options)
     footer->features = be32_to_cpu(0x02);
     footer->version = be32_to_cpu(0x00010000);
     if (disk_type == VHD_DYNAMIC) {
-        footer->data_offset = be64_to_cpu(HEADER_SIZE);
+        footer->data_offset = be64_to_cpu(FOOTER_SIZE);
     } else {
         footer->data_offset = be64_to_cpu(0xFFFFFFFFFFFFFFFFULL);
     }
@@ -768,7 +768,7 @@ static int vpc_create(const char *filename, 
QEMUOptionParameter *options)
     uuid_generate(footer->uuid);
 #endif
 
-    footer->checksum = be32_to_cpu(vpc_checksum(buf, HEADER_SIZE));
+    footer->checksum = be32_to_cpu(vpc_checksum(buf, FOOTER_SIZE));
 
     if (disk_type == VHD_DYNAMIC) {
         ret = create_dynamic_disk(fd, buf, total_sectors);
-- 
1.7.10.4