__blkdev_issue_write

函数名称：__blkdev_issue_write_same - generate number of bios with same page*@bdev: target blockdev*@sector: start sector*@nr_sects: number of sectors to write*@gfp_mask: memory allocation flags (for bio_alloc)*@page: page containing data to write*@biop: pointer to

函数原型：static int __blkdev_issue_write_same(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask, struct page *page, struct bio **biop)

返回类型：int

参数：

类型	参数	名称
struct block_device *	bdev
sector_t	sector
sector_t	nr_sects
gfp_t	gfp_mask
struct page *	page
struct bio **	biop

135

q等于bdev_get_queue(bdev)

137

bio等于biop

140

如果非q则返回:负ENXIO

143

如果bdev_read_only(bdev)则返回:负EPERM

146

bs_mask等于bdev_logical_block_size(bdev)右移9位的值减1

147

如果sector按位或nr_sects的值按位与bs_mask则返回:负EINVAL

150

如果非bdev_write_same(bdev)则返回:负EOPNOTSUPP

154

max_write_same_sectors等于The max size one bio can handle is UINT_MAX becasue bvec_iter.bi_size* is defined as 'unsigned int', meantime it has to aligned to with logical* block size which is the minimum accepted unit by hardware.

156

当nr_sects 循环

157

bio等于blk_next_bio(bio, 1, gfp_mask)

158

device address in 512 byte sectors 等于sector

159

bio_set_dev(bio, bdev)

160

how many bio_vec's 等于1

161

bv_page等于page

162

bv_offset等于0

163

bv_len等于bdev_logical_block_size(bdev)

164

bsolete, don't use in new code

166

如果nr_sects大于max_write_same_sectors则

167

residual I/O count 等于max_write_same_sectors左移9位

168

nr_sects减等于max_write_same_sectors

169

sector加等于max_write_same_sectors

170

否则

171

residual I/O count 等于nr_sects左移9位

172

nr_sects等于0

174

cond_resched()

177

biop等于bio

178

返回:0

**调用者**
名称	描述
blkdev_issue_write_same	lkdev_issue_write_same - queue a write same operation@bdev: target blockdev@sector: start sector@nr_sects: number of sectors to write@gfp_mask: memory allocation flags (for bio_alloc)@page: page containing data Description:

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