Function dfs_aspace_write

components/dfs/dfs_v2/src/dfs_pcache.c:1632–1706

* @brief Write data to file through address space page cache * * This function writes data to a file using its address space page cache. It handles * page lookup, data copying, dirty page marking, and synchronization operations. * * @param[in] file Pointer to the file structure containing vnode and aspace * @param[in] buf Buffer containing data to write * @param[in] count Number of bytes

 * @return Number of bytes successfully written, or negative error code
 */
int dfs_aspace_write(struct dfs_file *file, const void *buf, size_t count, off_t *pos)
{
    int ret = -EINVAL;

    if (file && file->vnode && file->vnode->aspace)
    {
        struct dfs_vnode *vnode = file->vnode;
        struct dfs_aspace *aspace = vnode->aspace;

        struct dfs_page *page;
        char *ptr = (char *)buf;

        if (!(aspace->ops->write))
        {
            return ret;
        }
        else if (aspace->mnt && (aspace->mnt->flags & MNT_RDONLY))
        {
            return -EROFS;
        }

        ret = 0;

        while (count)
        {
            page = dfs_page_lookup(file, *pos);
            if (page)
            {
                off_t len;

                dfs_aspace_lock(aspace);
                len = page->fpos + ARCH_PAGE_SIZE - *pos;
                len = count > len ? len : count;
                rt_memcpy(page->page + *pos - page->fpos, ptr, len);
                ptr += len;
                *pos += len;
                count -= len;
                ret += len;

                if (*pos > aspace->vnode->size)
                {
                    aspace->vnode->size = *pos;
                }

                if (file->flags & O_SYNC)
                {
                    if (aspace->vnode->size < page->fpos + page->size)
                    {
                        page->len = aspace->vnode->size - page->fpos;
                    }
                    else
                    {
                        page->len = page->size;
                    }

                    aspace->ops->write(page);
                    page->is_dirty = 0;
                }