Am 28.05.2013 04:50, schrieb qiaonuo...@cn.fujitsu.com:
> From: Qiao Nuohan <qiaonuo...@cn.fujitsu.com>
>
> Struct cache_data is associated with a tmp file which is used to store page
> desc and page data in kdump-compressed format temporarily.
CacheData please - but I do find the English term "cache data"
irritating as it sounds like data about a cache when instead it is about
cached data. DataCache? CachedData? Maybe a native English speaker can
advise?
> The following patch
> will use these function to gather data of page and cache them in tmp files.
>
> Signed-off-by: Qiao Nuohan <qiaonuo...@cn.fujitsu.com>
> Reviewed-by: Zhang Xiaohe <zhan...@cn.fujitsu.com>
> ---
> Makefile.target | 2 +-
> cache_data.c | 121
> ++++++++++++++++++++++++++++++++++++++++++++++++++
> include/cache_data.h | 56 +++++++++++++++++++++++
> 3 files changed, 178 insertions(+), 1 deletions(-)
> create mode 100644 cache_data.c
> create mode 100644 include/cache_data.h
>
> diff --git a/Makefile.target b/Makefile.target
> index 8e557f9..298ec84 100644
> --- a/Makefile.target
> +++ b/Makefile.target
> @@ -110,7 +110,7 @@ obj-y += qtest.o
> obj-y += hw/
> obj-$(CONFIG_FDT) += device_tree.o
> obj-$(CONFIG_KVM) += kvm-all.o
> -obj-y += dump_bitmap.o
> +obj-y += dump_bitmap.o cache_data.o
Same comment as for dump_bitmap.o: Can we build this only once, please?
> obj-y += memory.o savevm.o cputlb.o
> obj-$(CONFIG_HAVE_GET_MEMORY_MAPPING) += memory_mapping.o
> obj-$(CONFIG_HAVE_CORE_DUMP) += dump.o
> diff --git a/cache_data.c b/cache_data.c
> new file mode 100644
> index 0000000..6e91538
> --- /dev/null
> +++ b/cache_data.c
> @@ -0,0 +1,121 @@
> +/*
> + * QEMU cache data
> + *
> + * Copyright (C) 2013 FUJITSU LIMITED
> + *
> + * Authors:
> + * Qiao Nuohan <qiaonuo...@cn.fujitsu.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + *
> + */
> +
> +#include "qemu-common.h"
> +#include "cache_data.h"
> +
> +int init_cache_data(struct cache_data *cd, const char *filename)
> +{
> + int fd;
> + char *tmpname;
> +
> + /* init the tmp file */
> + tmpname = getenv("TMPDIR");
> + if (!tmpname) {
> + tmpname = (char *)P_tmpdir;
P_tmpdir is marked obsolescent in Open Group spec 7. Maybe Erik can
comment some more? Did you verify it builds with mingw32/64?
(I stumbled over it because I found the variable name odd and didn't see
it defined anywhere.)
> + }
> +
> + cd->file_name = (char *)g_strdup_printf("%s/%s", tmpname, filename);
> +
> + fd = mkstemp(cd->file_name);
> + if (fd < 0) {
> + return -1;
Error **errp? Same below.
> + }
> +
> + cd->fd = fd;
> + unlink(cd->file_name);
> +
> + /* init buf */
> + cd->buf_size = BUFSIZE_CACHE_DATA;
> + cd->cache_size = 0;
> + cd->buf = g_malloc0(BUFSIZE_CACHE_DATA);
> +
> + cd->offset = 0;
> +
> + return 0;
> +}
I wonder if it makes sense to introduce this interface instead of going
through the block layer, which would offer a number of different
backends at least. CC'ing the experts.
> +
> +int write_cache(struct cache_data *cd, void *buf, size_t size)
> +{
> + /*
> + * check if the space is enough to cache data, if not write cached
> + * data to the tmp file
> + */
> + if (cd->cache_size + size > cd->buf_size) {
> + if (lseek(cd->fd, cd->offset, SEEK_SET) < 0) {
> + return -1;
> + }
> +
> + if (write(cd->fd, cd->buf, cd->cache_size) != cd->cache_size) {
> + return -1;
> + }
> +
> + cd->offset += cd->cache_size;
> + cd->cache_size = 0;
> + }
> +
> + memcpy(cd->buf + cd->cache_size, buf, size);
> + cd->cache_size += size;
> +
> + return 0;
> +}
> +
> +int sync_cache(struct cache_data *cd)
> +{
> + /* no data is cached in cache_data */
> + if (cd->cache_size == 0) {
> + return 0;
> + }
> +
> + if (lseek(cd->fd, cd->offset, SEEK_SET) < 0) {
> + return -1;
> + }
> +
> + if (write(cd->fd, cd->buf, cd->cache_size) != cd->cache_size) {
> + return -1;
> + }
> +
> + cd->offset += cd->cache_size;
> +
> + return 0;
> +}
> +
> +int read_cache(struct cache_data *cd)
> +{
> + if (lseek(cd->fd, cd->offset, SEEK_SET) < 0) {
> + return -1;
> + }
> +
> + if (read(cd->fd, cd->buf, cd->cache_size) != cd->cache_size) {
> + return -1;
> + }
> +
> + cd->offset += cd->cache_size;
> +
> + return 0;
> +}
> +
> +void free_cache_data(struct cache_data *cd)
> +{
> + if (cd) {
> + if (cd->file_name) {
> + g_free(cd->file_name);
> + }
> +
> + if (cd->buf) {
> + g_free(cd->buf);
> + }
> +
> + g_free(cd);
> + }
> +}
> diff --git a/include/cache_data.h b/include/cache_data.h
> new file mode 100644
> index 0000000..18e8680
> --- /dev/null
> +++ b/include/cache_data.h
> @@ -0,0 +1,56 @@
> +/*
> + * QEMU cache data
> + *
> + * Copyright (C) 2013 FUJITSU LIMITED
> + *
> + * Authors:
> + * Qiao Nuohan <qiaonuo...@cn.fujitsu.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + *
> + */
> +
> +#ifndef CACHE_DATA_H
> +#define CACHE_DATA_H
> +
> +#define BUFSIZE_CACHE_DATA (4096 * 4)
> +
> +struct cache_data {
> + int fd; /* fd of the tmp file used to store cache data */
> + char *file_name; /* name of the tmp file */
> + char *buf; /* used to cache data */
> + size_t buf_size; /* size of the buf */
> + size_t cache_size; /* size of cached data in buf */
> + off_t offset; /* offset of the tmp file */
> +};
CamelCase and typedef please.
Regards,
Andreas
> +
> +/*
> + * create a tmp file used to store cache data, then init the buf
> + */
> +int init_cache_data(struct cache_data *cd, const char *filename);
> +
> +/*
> + * write data to the tmp file, the data may first be cached in the buf of
> + * cache_data
> + */
> +int write_cache(struct cache_data *cd, void *buf, size_t size);
> +
> +/*
> + * when cache_data is caching data in the buf, sync_cache is needed to write
> the
> + * data back to tmp file
> + */
> +int sync_cache(struct cache_data *cd);
> +
> +/* read data from the tmp file to the buf of 'cd', the start place is set by
> + * cd->offset, and the size is set by cd->cache_size. cd->offset is changed
> + * automaticlly according to the size of data read this time.
> + */
> +int read_cache(struct cache_data *cd);
> +
> +/*
> + * free the space used by cache_data
> + */
> +void free_cache_data(struct cache_data *cd);
> +
> +#endif
>
--
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg
