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Re: [Qemu-devel] [PATCH] [RFC] libqblock draft code v1
From: |
Blue Swirl |
Subject: |
Re: [Qemu-devel] [PATCH] [RFC] libqblock draft code v1 |
Date: |
Wed, 1 Aug 2012 18:04:36 +0000 |
On Wed, Aug 1, 2012 at 9:09 AM, Wenchao Xia <address@hidden> wrote:
> This patch encapsulate qemu general block layer to provide block
> services. API are declared in libqblock.h. libqblock-test.c
> simulate library consumer's behaviors. Make libqblock-test could
> build the code.
> For easy this patch does not form a dynamic libarary yet.
>
> Signed-off-by: Wenchao Xia <address@hidden>
> ---
> Makefile | 4 +-
> libqblock-test.c | 56 +++++++++++++++
> libqblock.c | 199
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++
> libqblock.h | 72 ++++++++++++++++++++
> 4 files changed, 330 insertions(+), 1 deletions(-)
> create mode 100644 libqblock-test.c
> create mode 100644 libqblock.c
> create mode 100644 libqblock.h
>
> diff --git a/Makefile b/Makefile
> index 621cb86..6a34be6 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -152,7 +152,6 @@ vscclient$(EXESUF): $(libcacard-y) $(oslib-obj-y)
> $(trace-obj-y) qemu-timer-comm
> $(call quiet-command,$(CC) $(LDFLAGS) -o $@ $^ $(libcacard_libs)
> $(LIBS)," LINK $@")
>
> ######################################################################
> -
> qemu-img.o: qemu-img-cmds.h
>
> tools-obj-y = $(oslib-obj-y) $(trace-obj-y) qemu-tool.o qemu-timer.o \
> @@ -160,6 +159,9 @@ tools-obj-y = $(oslib-obj-y) $(trace-obj-y) qemu-tool.o
> qemu-timer.o \
> iohandler.o cutils.o iov.o async.o
> tools-obj-$(CONFIG_POSIX) += compatfd.o
>
> +libqblock-test$(EXESUF): libqblock.o libqblock-test.o $(tools-obj-y)
> $(block-obj-y)
> + $(call quiet-command,$(CC) $(LDFLAGS) -o $@ $^ $(LIBS)," LINK $@")
> +
> qemu-img$(EXESUF): qemu-img.o $(tools-obj-y) $(block-obj-y)
> qemu-nbd$(EXESUF): qemu-nbd.o $(tools-obj-y) $(block-obj-y)
> qemu-io$(EXESUF): qemu-io.o cmd.o $(tools-obj-y) $(block-obj-y)
> diff --git a/libqblock-test.c b/libqblock-test.c
> new file mode 100644
> index 0000000..663111e
> --- /dev/null
> +++ b/libqblock-test.c
> @@ -0,0 +1,56 @@
> +#include "libqblock.h"
> +
> +#include <stdarg.h>
> +#include <stdio.h>
> +
> +
> +unsigned char buf0[1024];
> +unsigned char buf1[1024] = {4, 0, 0, 2};
'static' for the above, 'const' for buf1. I'd use uint8_t instead of
'unsigned char'.
> +int main(int argc, char **argv)
> +{
> + struct QBlockState i_qbs;
> + struct QBlockOpenOption i_qboo;
> + struct QBlockCreateOption i_qbco;
> + struct QBlockInfo i_qbi;
The variable names are cryptic.
> + char *filename;
> +
> + int i;
> + unsigned long op_size = 512;
> + unsigned long op_start = 1024;
size_t
> +
> + filename = argv[1];
> + printf("qemu test, file name is %s.\n", filename);
> +
> + libqblock_init();
> +
> + qbs_init(&i_qbs);
> + memset(&i_qbco, 0, sizeof(struct QBlockCreateOption));
> +
> + i_qbco.filename = filename;
> + i_qbco.fmt = (char *)"qcow2";
Add 'const' to fmt field and remove cast.
> + i_qbco.flag = BDRV_O_NOCACHE;
> + i_qbco.size = 512 * 1024 * 1024;
> + qb_create(&i_qbs, &i_qbco);
> +
> + i_qboo.filename = filename;
> + i_qboo.flag = BDRV_O_RDWR;
> + qb_open(&i_qbs, &i_qboo);
> +
> + qb_write(&i_qbs, op_start, op_size, buf1);
> + qb_read(&i_qbs, op_start, op_size, buf0);
> + for (i = 0; i < op_size; i++) {
> + if (buf0[i] != buf1[i]) {
> + printf("unmatch found at %d.\n", i);
mismatch
> + break;
> + }
> + }
> + qbi_init(&i_qbi);
> + qb_getinfo(&i_qbs, &i_qbi);
> + qbi_print_test(&i_qbi);
> + qbi_uninit(&i_qbi);
> +
> + qb_close(&i_qbs);
> + qb_delete(&i_qbs, filename);
> + qbs_uninit(&i_qbs);
> + return 0;
> +}
> diff --git a/libqblock.c b/libqblock.c
> new file mode 100644
> index 0000000..00b6649
> --- /dev/null
> +++ b/libqblock.c
> @@ -0,0 +1,199 @@
> +#include "libqblock.h"
> +
> +#include <unistd.h>
> +
> +#define QB_ERR_MEM_ERR (-1)
> +#define QB_ERR_INTERNAL_ERR (-2)
> +#define QB_ERR_INVALID_PARAM (-3)
> +
> +#define FUNC_FREE g_free
Useless.
> +
> +#define CLEAN_FREE(p) { \
> + FUNC_FREE(p); \
> + (p) = NULL; \
> +}
> +
> +/* try string dup and check if it succeed, dest would be freed before dup */
> +#define SAFE_STRDUP(dest, src, ret, err_v) { \
> + if ((ret) != (err_v)) { \
> + if ((dest) != NULL) { \
> + FUNC_FREE(dest); \
> + } \
> + (dest) = strdup(src); \
> + if ((dest) == NULL) { \
> + (ret) = (err_v); \
> + } \
> + } \
> +}
Just use g_strdup().
> +
> +int libqblock_init(void)
> +{
> + bdrv_init();
> + return 0;
> +}
> +
> +int qbs_init(struct QBlockState *qbs)
> +{
> + memset(qbs, 0, sizeof(struct QBlockState));
> + qbs->bdrvs = bdrv_new("hda");
> + if (qbs->bdrvs == NULL) {
> + return QB_ERR_INTERNAL_ERR;
> + }
> + return 0;
> +}
> +
> +int qbs_uninit(struct QBlockState *qbs)
> +{
> + CLEAN_FREE(qbs->filename);
> + if (qbs->bdrvs == NULL) {
> + return QB_ERR_INVALID_PARAM;
> + }
> + bdrv_delete(qbs->bdrvs);
> + return 0;
> +}
> +
> +int qb_create(struct QBlockState *qbs, struct QBlockCreateOption *op)
> +{
> + int ret;
> + BlockDriverState *bs;
> +
> + bs = (BlockDriverState *)qbs->bdrvs;
> +
> + ret = bdrv_img_create(op->filename, op->fmt, op->base_filename,
> + op->base_fmt, op->options, op->size, op->flag);
> + return 0;
> +}
> +
> +int qb_open(struct QBlockState *qbs, struct QBlockOpenOption *op)
const struct QBlockOpenOption *op
> +{
> + int ret;
> + BlockDriverState *bs;
> +
> + bs = (BlockDriverState *)qbs->bdrvs;
> + ret = bdrv_open(bs, op->filename, op->flag, NULL);
> + if (ret < 0) {
> + return ret;
> + }
> +
> + SAFE_STRDUP(qbs->filename, op->filename, ret, QB_ERR_MEM_ERR);
> + return ret;
> +}
> +
> +int qb_close(struct QBlockState *qbs)
> +{
> + int ret = 0;
> + BlockDriverState *bs;
> +
> + bs = (BlockDriverState *)qbs->bdrvs;
> + bdrv_close(bs);
> + return ret;
> +}
> +
> +int qb_delete(struct QBlockState *qbs, const char *filename)
> +{
> + return unlink(filename);
> +}
> +
> +/* ignore case that len is not alligned to 512 now. */
aligned
> +int qb_read(struct QBlockState *qbs, unsigned long start, unsigned long len,
> + unsigned char *buf)
I'd make this closer to pread() interface:
ssize_t qb_read(struct QBlockState *qbs, void *buf, size_t len, off_t offset)
> +{
> + int ret;
> + BlockDriverState *bs;
> +
> + bs = (BlockDriverState *)qbs->bdrvs;
> +
> + ret = bdrv_read(bs, start / 512,
> + buf, len / 512);
IIRC there is a constant for 512 somewhere.
> + return ret;
> +}
> +
> +/* ignore case that len is not alligned to 512 now. */
aligned
> +int qb_write(struct QBlockState *qbs, unsigned long start, unsigned long len,
> + unsigned char
> *buf)
Also here match pwrite:
ssize_t qb_write(struct QBlockState *qbs, const void *buf, size_t len,
off_t offset)
> +{
> + int ret;
> + BlockDriverState *bs;
> +
> + bs = (BlockDriverState *)qbs->bdrvs;
> + ret = bdrv_write(bs, start / 512,
> + buf, len / 512);
> + return ret;
> +}
> +
> +int qb_flush(struct QBlockState *qbs)
> +{
> + int ret = 0;
> + BlockDriverState *bs;
> +
> + bs = (BlockDriverState *)qbs->bdrvs;
> + ret = bdrv_flush(bs);
> + return ret;
> +}
> +
> +int qbi_init(struct QBlockInfo *info)
> +{
> + memset(info, 0, sizeof(struct QBlockInfo));
> + return 0;
> +}
> +
> +int qbi_uninit(struct QBlockInfo *info)
> +{
> + CLEAN_FREE(info->filename);
> + CLEAN_FREE(info->fmt);
> + CLEAN_FREE(info->backing_filename);
> + CLEAN_FREE(info->sn_tab);
> + return 0;
> +}
> +
> +int qbi_print_test(struct QBlockInfo *info)
> +{
> + printf("name:%s, fmt %s, virt_size %ld, allocated_size %ld, encryt %d, "
> + "back_file %s, sn_tab %p, sn_num %d, cluster size %d, "
> + "vm_state_offset %ld, dirty %d.\n",
> + info->filename, info->fmt, info->virt_size, info->allocated_size,
> + info->encrypt_flag,
> + info->backing_filename, info->sn_tab, info->sn_tab_num,
> + info->cluster_size,
> + info->vm_state_offset, info->is_dirty);
> + return 0;
> +}
This does not belong to the library.
> +
> +int qb_getinfo(struct QBlockState *qbs, struct QBlockInfo *info)
> +{
> + int ret = 0;
> + BlockDriverState *bs;
> + const char *tmp;
> + BlockDriverInfo bdi;
> + uint64_t total_sectors;
> + char backing_filename[1024];
> +
> + bs = (BlockDriverState *)qbs->bdrvs;
> + SAFE_STRDUP(info->filename, qbs->filename, ret, QB_ERR_MEM_ERR);
> + tmp = bdrv_get_format_name(bs);
> + SAFE_STRDUP(info->fmt, tmp, ret, QB_ERR_MEM_ERR);
> + bdrv_get_geometry(bs, &total_sectors);
> + info->virt_size = total_sectors * 512;
> + info->allocated_size = bdrv_get_allocated_file_size(bs);
> + info->encrypt_flag = bdrv_is_encrypted(bs);
> + bdrv_get_full_backing_filename(bs, backing_filename,
> + sizeof(backing_filename));
> + if (backing_filename[0] != '\0') {
> + SAFE_STRDUP(info->backing_filename, backing_filename, ret,
> + QB_ERR_MEM_ERR);
> + }
> + info->sn_tab_num = bdrv_snapshot_list(bs, &(info->sn_tab));
> + if (info->sn_tab_num < 0) {
> + info->sn_tab_num = 0;
> + }
> + if (bdrv_get_info(bs, &bdi) >= 0) {
> + info->cluster_size = bdi.cluster_size;
> + info->vm_state_offset = bdi.vm_state_offset;
> + info->is_dirty = bdi.is_dirty;
> + } else {
> + info->cluster_size = -1;
> + info->vm_state_offset = -1;
> + info->is_dirty = -1;
> + }
> + return ret;
> +}
> diff --git a/libqblock.h b/libqblock.h
> new file mode 100644
> index 0000000..64a8b96
> --- /dev/null
> +++ b/libqblock.h
> @@ -0,0 +1,72 @@
> +#ifndef LIBQBLOCK_H
> +#define LIBQBLOCK_H
> +
> +#include "block.h"
> +
> +/* details should be hidden to user */
> +struct QBlockState {
> + void *bdrvs;
> + char *filename;
> +};
> +
> +/* libarary init or uninit */
> +int libqblock_init(void);
> +
> +/* qbs init and uninit */
> +int qbs_init(struct QBlockState *qbs);
> +int qbs_uninit(struct QBlockState *qbs);
> +
> +/* file open and close */
> +struct QBlockOpenOption {
> + char *filename;
> + int flag;
Possible flags should be listed as enums.
> +};
> +
> +struct QBlockCreateOption {
> + char *filename;
> + char *fmt;
> + char *base_filename;
> + char *base_fmt;
> + char *options;
What would these be?
> + unsigned long size;
uint64_t
> + int flag;
Possible flags should be listed as enums.
> +};
> +
> +int qb_open(struct QBlockState *qbs, struct QBlockOpenOption *op);
> +int qb_close(struct QBlockState *qbs);
> +
> +int qb_create(struct QBlockState *qbs, struct QBlockCreateOption *op);
> +int qb_delete(struct QBlockState *qbs, const char *filename);
> +
> +/* information */
> +struct QBlockInfo {
> + /* basic info */
> + char *filename;
> + char *fmt;
> + /* advance info */
> + unsigned long virt_size;
> + unsigned long allocated_size;
uint64_t for both above.
> + int encrypt_flag;
bool is_encrypted;
> + char *backing_filename;
> + QEMUSnapshotInfo *sn_tab;
Nack, don't export QEMU types directly.
> + int sn_tab_num;
I'm not sure this is needed.
> +
> + /* in bytes, 0 if irrelevant */
> + int cluster_size;
> + int64_t vm_state_offset;
Nack, not part of block interface.
> + int is_dirty;
bool
> +};
> +
> +/* sync access */
> +int qb_read(struct QBlockState *qbs, unsigned long start, unsigned long len,
> + unsigned char
> *buf);
> +int qb_write(struct QBlockState *qbs, unsigned long start, unsigned long len,
> + unsigned char
> *buf);
> +int qb_flush(struct QBlockState *qbs);
> +
> +/* get info */
Comment is misplaced.
> +int qbi_init(struct QBlockInfo *info);
> +int qbi_uninit(struct QBlockInfo *info);
> +int qbi_print_test(struct QBlockInfo *info);
> +int qb_getinfo(struct QBlockState *qbs, struct QBlockInfo *info);
> +#endif
> --
> 1.7.1
>
>
>
Re: [Qemu-devel] [PATCH] [RFC] libqblock draft code v1,
Blue Swirl <=