aboutsummaryrefslogtreecommitdiff
path: root/block-cow.c
diff options
context:
space:
mode:
Diffstat (limited to 'block-cow.c')
-rw-r--r--block-cow.c38
1 files changed, 17 insertions, 21 deletions
diff --git a/block-cow.c b/block-cow.c
index 6af8b74975..07c8a7bf16 100644
--- a/block-cow.c
+++ b/block-cow.c
@@ -62,7 +62,7 @@ static int cow_probe(const uint8_t *buf, int buf_size, const char *filename)
return 0;
}
-static int cow_open(BlockDriverState *bs, const char *filename)
+static int cow_open(BlockDriverState *bs, const char *filename, int flags)
{
BDRVCowState *s = bs->opaque;
int fd;
@@ -93,22 +93,6 @@ static int cow_open(BlockDriverState *bs, const char *filename)
pstrcpy(bs->backing_file, sizeof(bs->backing_file),
cow_header.backing_file);
-#if 0
- if (cow_header.backing_file[0] != '\0') {
- if (stat(cow_header.backing_file, &st) != 0) {
- fprintf(stderr, "%s: could not find original disk image '%s'\n", filename, cow_header.backing_file);
- goto fail;
- }
- if (st.st_mtime != be32_to_cpu(cow_header.mtime)) {
- fprintf(stderr, "%s: original raw disk image '%s' does not match saved timestamp\n", filename, cow_header.backing_file);
- goto fail;
- }
- fd = open(cow_header.backing_file, O_RDONLY | O_LARGEFILE);
- if (fd < 0)
- goto fail;
- bs->fd = fd;
- }
-#endif
/* mmap the bitmap */
s->cow_bitmap_size = ((bs->total_sectors + 7) >> 3) + sizeof(cow_header);
s->cow_bitmap_addr = mmap(get_mmap_addr(s->cow_bitmap_size),
@@ -179,8 +163,15 @@ static int cow_read(BlockDriverState *bs, int64_t sector_num,
if (ret != n * 512)
return -1;
} else {
+ if (bs->backing_hd) {
+ /* read from the base image */
+ ret = bdrv_read(bs->backing_hd, sector_num, buf, n);
+ if (ret < 0)
+ return -1;
+ } else {
memset(buf, 0, n * 512);
}
+ }
nb_sectors -= n;
sector_num += n;
buf += n * 512;
@@ -220,7 +211,7 @@ static int cow_create(const char *filename, int64_t image_sectors,
if (flags)
return -ENOTSUP;
- cow_fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
+ cow_fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
0644);
if (cow_fd < 0)
return -1;
@@ -228,18 +219,23 @@ static int cow_create(const char *filename, int64_t image_sectors,
cow_header.magic = cpu_to_be32(COW_MAGIC);
cow_header.version = cpu_to_be32(COW_VERSION);
if (image_filename) {
+ /* Note: if no file, we put a dummy mtime */
+ cow_header.mtime = cpu_to_be32(0);
+
fd = open(image_filename, O_RDONLY | O_BINARY);
if (fd < 0) {
close(cow_fd);
- return -1;
+ goto mtime_fail;
}
if (fstat(fd, &st) != 0) {
close(fd);
- return -1;
+ goto mtime_fail;
}
close(fd);
cow_header.mtime = cpu_to_be32(st.st_mtime);
- realpath(image_filename, cow_header.backing_file);
+ mtime_fail:
+ pstrcpy(cow_header.backing_file, sizeof(cow_header.backing_file),
+ image_filename);
}
cow_header.sectorsize = cpu_to_be32(512);
cow_header.size = cpu_to_be64(image_sectors * 512);