block: Open the underlying image file in generic code

Format drivers shouldn't need to bother with things like file names, but rather
just get an open BlockDriverState for the underlying protocol. This patch
introduces this behaviour for bdrv_open implementation. For protocols which
need to access the filename to open their file/device/connection/... a new
callback bdrv_file_open is introduced which doesn't get an underlying file
opened.

For now, also some of the more obscure formats use bdrv_file_open because they
open() the file themselves instead of using the block.c functions. They need to
be fixed in later patches.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 12 insertions, 20 deletions

diff --git a/block/vpc.c b/block/vpc.c
index 950ad58..f94e469 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -150,20 +150,16 @@ static int vpc_probe(const uint8_t *buf, int buf_size, const char *filename)
     return 0;
 }
 
-static int vpc_open(BlockDriverState *bs, const char *filename, int flags)
+static int vpc_open(BlockDriverState *bs, int flags)
 {
     BDRVVPCState *s = bs->opaque;
-    int ret, i;
+    int i;
     struct vhd_footer* footer;
     struct vhd_dyndisk_header* dyndisk_header;
     uint8_t buf[HEADER_SIZE];
     uint32_t checksum;
 
-    ret = bdrv_file_open(&s->hd, filename, flags);
-    if (ret < 0)
-        return ret;
-
-    if (bdrv_pread(s->hd, 0, s->footer_buf, HEADER_SIZE) != HEADER_SIZE)
+    if (bdrv_pread(bs->file, 0, s->footer_buf, HEADER_SIZE) != HEADER_SIZE)
         goto fail;
 
     footer = (struct vhd_footer*) s->footer_buf;
@@ -174,7 +170,7 @@ static int vpc_open(BlockDriverState *bs, const char *filename, int flags)
     footer->checksum = 0;
     if (vpc_checksum(s->footer_buf, HEADER_SIZE) != checksum)
         fprintf(stderr, "block-vpc: The header checksum of '%s' is "
-            "incorrect.\n", filename);
+            "incorrect.\n", bs->filename);
 
     // The visible size of a image in Virtual PC depends on the geometry
     // rather than on the size stored in the footer (the size in the footer
@@ -182,7 +178,7 @@ static int vpc_open(BlockDriverState *bs, const char *filename, int flags)
     bs->total_sectors = (int64_t)
         be16_to_cpu(footer->cyls) * footer->heads * footer->secs_per_cyl;
 
-    if (bdrv_pread(s->hd, be64_to_cpu(footer->data_offset), buf, HEADER_SIZE)
+    if (bdrv_pread(bs->file, be64_to_cpu(footer->data_offset), buf, HEADER_SIZE)
             != HEADER_SIZE)
         goto fail;
 
@@ -199,7 +195,7 @@ static int vpc_open(BlockDriverState *bs, const char *filename, int flags)
     s->pagetable = qemu_malloc(s->max_table_entries * 4);
 
     s->bat_offset = be64_to_cpu(dyndisk_header->table_offset);
-    if (bdrv_pread(s->hd, s->bat_offset, s->pagetable,
+    if (bdrv_pread(bs->file, s->bat_offset, s->pagetable,
             s->max_table_entries * 4) != s->max_table_entries * 4)
 	    goto fail;
 
@@ -228,7 +224,6 @@ static int vpc_open(BlockDriverState *bs, const char *filename, int flags)
 
     return 0;
  fail:
-    bdrv_delete(s->hd);
     return -1;
 }
 
@@ -266,7 +261,7 @@ static inline int64_t get_sector_offset(BlockDriverState *bs,
 
         s->last_bitmap_offset = bitmap_offset;
         memset(bitmap, 0xff, s->bitmap_size);
-        bdrv_pwrite(s->hd, bitmap_offset, bitmap, s->bitmap_size);
+        bdrv_pwrite(bs->file, bitmap_offset, bitmap, s->bitmap_size);
     }
 
 //    printf("sector: %" PRIx64 ", index: %x, offset: %x, bioff: %" PRIx64 ", bloff: %" PRIx64 "\n",
@@ -316,7 +311,7 @@ static int rewrite_footer(BlockDriverState* bs)
     BDRVVPCState *s = bs->opaque;
     int64_t offset = s->free_data_block_offset;
 
-    ret = bdrv_pwrite(s->hd, offset, s->footer_buf, HEADER_SIZE);
+    ret = bdrv_pwrite(bs->file, offset, s->footer_buf, HEADER_SIZE);
     if (ret < 0)
         return ret;
 
@@ -351,7 +346,7 @@ static int64_t alloc_block(BlockDriverState* bs, int64_t sector_num)
 
     // Initialize the block's bitmap
     memset(bitmap, 0xff, s->bitmap_size);
-    bdrv_pwrite(s->hd, s->free_data_block_offset, bitmap, s->bitmap_size);
+    bdrv_pwrite(bs->file, s->free_data_block_offset, bitmap, s->bitmap_size);
 
     // Write new footer (the old one will be overwritten)
     s->free_data_block_offset += s->block_size + s->bitmap_size;
@@ -362,7 +357,7 @@ static int64_t alloc_block(BlockDriverState* bs, int64_t sector_num)
     // Write BAT entry to disk
     bat_offset = s->bat_offset + (4 * index);
     bat_value = be32_to_cpu(s->pagetable[index]);
-    ret = bdrv_pwrite(s->hd, bat_offset, &bat_value, 4);
+    ret = bdrv_pwrite(bs->file, bat_offset, &bat_value, 4);
     if (ret < 0)
         goto fail;
 
@@ -376,7 +371,6 @@ fail:
 static int vpc_read(BlockDriverState *bs, int64_t sector_num,
                     uint8_t *buf, int nb_sectors)
 {
-    BDRVVPCState *s = bs->opaque;
     int ret;
     int64_t offset;
 
@@ -386,7 +380,7 @@ static int vpc_read(BlockDriverState *bs, int64_t sector_num,
         if (offset == -1) {
             memset(buf, 0, 512);
         } else {
-            ret = bdrv_pread(s->hd, offset, buf, 512);
+            ret = bdrv_pread(bs->file, offset, buf, 512);
             if (ret != 512)
                 return -1;
         }
@@ -401,7 +395,6 @@ static int vpc_read(BlockDriverState *bs, int64_t sector_num,
 static int vpc_write(BlockDriverState *bs, int64_t sector_num,
     const uint8_t *buf, int nb_sectors)
 {
-    BDRVVPCState *s = bs->opaque;
     int64_t offset;
     int ret;
 
@@ -414,7 +407,7 @@ static int vpc_write(BlockDriverState *bs, int64_t sector_num,
                 return -1;
         }
 
-        ret = bdrv_pwrite(s->hd, offset, buf, 512);
+        ret = bdrv_pwrite(bs->file, offset, buf, 512);
         if (ret != 512)
             return -1;
 
@@ -590,7 +583,6 @@ static void vpc_close(BlockDriverState *bs)
 #ifdef CACHE
     qemu_free(s->pageentry_u8);
 #endif
-    bdrv_delete(s->hd);
 }
 
 static QEMUOptionParameter vpc_create_options[] = {