__sg_alloc_table_from

函数名称：__sg_alloc_table_from_pages - Allocate and initialize an sg table from* an array of pages*@sgt: The sg table header to use*@pages: Pointer to an array of page pointers*@n_pages: Number of pages in the pages array*@offset: Offset from start of the first

函数原型：int __sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages, unsigned int n_pages, unsigned int offset, unsigned long size, unsigned int max_segment, gfp_t gfp_mask)

返回类型：int

参数：

类型	参数	名称
struct sg_table *	sgt
struct page **	pages
unsigned int	n_pages
unsigned int	offset
unsigned long	size
unsigned int	max_segment
gfp_t	gfp_mask

398

如果WARN_ON(!max_segment || offset_in_page(max_segment))则返回:负EINVAL

402

chunks等于1

403

seg_len等于0

404

以i小于n_pages 循环

405

seg_len加等于PAGE_SIZE

406

如果seg_len大于等于max_segment或page_to_pfn(pages[i])不等于page_to_pfn(pages[i - 1])加1则

408

chunks自加

409

seg_len等于0

413

ret等于sg_alloc_table - Allocate and initialize an sg table*@table: The sg table header to use*@nents: Number of entries in sg list*@gfp_mask: GFP allocation mask* Description:* Allocate and initialize an sg table. If @nents@ is larger than

414

如果此条件成立可能性小(为编译器优化)(ret)则返回:ret

418

cur_page等于0

423

seg_len等于0

424

以j小于n_pages 循环

425

seg_len加等于PAGE_SIZE

426

如果seg_len大于等于max_segment或page_to_pfn(pages[j])不等于page_to_pfn(pages[j - 1])加1则退出

432

chunk_size等于j减cur_page左移PAGE_SHIFT determines the page size 位的值减offset

433

sg_set_page - Set sg entry to point at given page*@sg: SG entry*@page: The page*@len: Length of data*@offset: Offset into page* Description:* Use this function to set an sg entry pointing at a page, never assign* the page directly

435

size减等于chunk_size

436

offset等于0

437

cur_page等于j

440

返回:0

**调用者**
名称	描述
sg_alloc_table_from_pages	sg_alloc_table_from_pages - Allocate and initialize an sg table from* an array of pages@sgt: The sg table header to use@pages: Pointer to an array of page pointers@n_pages: Number of pages in the pages array@offset: Offset from start of the first page

源代码转换工具开放的插件接口	X
支持：c/c++/esqlc/java Oracle/Informix/Mysql 插件可实现：逻辑报告代码生成和批量转换代码

函数逻辑报告