Commit 95389c86 authored by bellard's avatar bellard
Browse files

qcow_make_empty() support (Johannes Schindelin)


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@1716 c046a42c-6fe2-441c-8c8c-71466251a162
parent 1658b44b
......@@ -552,25 +552,28 @@ static int qcow_create(const char *filename, int64_t total_size,
header_size = sizeof(header);
backing_filename_len = 0;
if (backing_file) {
const char *p;
/* XXX: this is a hack: we do not attempt to check for URL
like syntax */
p = strchr(backing_file, ':');
if (p && (p - backing_file) >= 2) {
/* URL like but exclude "c:" like filenames */
pstrcpy(backing_filename, sizeof(backing_filename),
backing_file);
} else {
realpath(backing_file, backing_filename);
if (stat(backing_filename, &st) != 0) {
return -1;
}
}
if (strcmp(backing_file, "fat:")) {
const char *p;
/* XXX: this is a hack: we do not attempt to check for URL
like syntax */
p = strchr(backing_file, ':');
if (p && (p - backing_file) >= 2) {
/* URL like but exclude "c:" like filenames */
pstrcpy(backing_filename, sizeof(backing_filename),
backing_file);
} else {
realpath(backing_file, backing_filename);
if (stat(backing_filename, &st) != 0) {
return -1;
}
}
header.backing_file_offset = cpu_to_be64(header_size);
backing_filename_len = strlen(backing_filename);
header.backing_file_size = cpu_to_be32(backing_filename_len);
header_size += backing_filename_len;
} else
backing_file = NULL;
header.mtime = cpu_to_be32(st.st_mtime);
header.backing_file_offset = cpu_to_be64(header_size);
backing_filename_len = strlen(backing_filename);
header.backing_file_size = cpu_to_be32(backing_filename_len);
header_size += backing_filename_len;
header.cluster_bits = 9; /* 512 byte cluster to avoid copying
unmodifyed sectors */
header.l2_bits = 12; /* 32 KB L2 tables */
......@@ -603,6 +606,24 @@ static int qcow_create(const char *filename, int64_t total_size,
return 0;
}
int qcow_make_empty(BlockDriverState *bs)
{
BDRVQcowState *s = bs->opaque;
uint32_t l1_length = s->l1_size * sizeof(uint64_t);
memset(s->l1_table, 0, l1_length);
lseek(s->fd, s->l1_table_offset, SEEK_SET);
if (write(s->fd, s->l1_table, l1_length) < 0)
return -1;
ftruncate(s->fd, s->l1_table_offset + l1_length);
memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t));
memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t));
return 0;
}
int qcow_get_cluster_size(BlockDriverState *bs)
{
BDRVQcowState *s = bs->opaque;
......@@ -683,6 +704,7 @@ BlockDriver bdrv_qcow = {
qcow_create,
qcow_is_allocated,
qcow_set_key,
qcow_make_empty
};
......@@ -150,13 +150,19 @@ int bdrv_create(BlockDriver *drv,
}
#ifdef _WIN32
static void get_tmp_filename(char *filename, int size)
void get_tmp_filename(char *filename, int size)
{
char* p = strrchr(filename, '/');
if (p == NULL)
return;
/* XXX: find a better function */
tmpnam(filename);
tmpnam(p);
*p = '/';
}
#else
static void get_tmp_filename(char *filename, int size)
void get_tmp_filename(char *filename, int size)
{
int fd;
/* XXX: race condition possible */
......@@ -394,6 +400,10 @@ int bdrv_commit(BlockDriverState *bs)
i += n;
}
}
if (bs->drv->bdrv_make_empty)
return bs->drv->bdrv_make_empty(bs);
return 0;
}
......
......@@ -39,6 +39,7 @@ struct BlockDriver {
int (*bdrv_is_allocated)(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, int *pnum);
int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
int (*bdrv_make_empty)(BlockDriverState *bs);
struct BlockDriver *next;
};
......@@ -74,4 +75,6 @@ struct BlockDriverState {
BlockDriverState *next;
};
void get_tmp_filename(char *filename, int size);
#endif /* BLOCK_INT_H */
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