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async file I/O API

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git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@2075 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
bellard 2006-08-01 16:21:11 +00:00
parent 7954c73498
commit 83f6409109
16 changed files with 1914 additions and 472 deletions
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38
block-cow.c
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@ -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);