Commit 95389c86 authored by Fabrice Bellard's avatar Fabrice 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

block-qcow.c

+40 −18
Original line number Diff line number Diff line
@@ -552,6 +552,7 @@ static int qcow_create(const char *filename, int64_t total_size, 
    header_size = sizeof(header);

    backing_filename_len = 0;

    if (backing_file) {

	if (strcmp(backing_file, "fat:")) {

	    const char *p;

	    /* XXX: this is a hack: we do not attempt to check for URL

	       like syntax */
@@ -566,11 +567,13 @@ static int qcow_create(const char *filename, int64_t total_size, 
		    return -1;

		}

	    }

        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;

	} else

	    backing_file = NULL;

        header.mtime = cpu_to_be32(st.st_mtime);

        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

};

block.c

+13 −3
Original line number Diff line number Diff line
@@ -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;

}

block_int.h

+3 −0
Original line number Diff line number Diff line
@@ -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 */