ioctl_preallocate

函数名称：This provides compatibility with legacy XFS pre-allocation ioctls* which predate the fallocate syscall.* Only the l_start, l_len and l_whence fields of the 'struct space_resv'* are used here, rest are ignored.

函数原型：int ioctl_preallocate(struct file *filp, int mode, void __user *argp)

返回类型：int

参数：

类型	参数	名称
struct file *	filp
int	mode
void __user *	argp

472

inode等于file_inode(filp)

475

如果copy_from_user( & sr, argp, sr的长度)则返回:负EFAULT

479

当:l_whence恒等于seek relative to beginning of file

480

退出

481

当:l_whence恒等于seek relative to current file position

482

l_start加等于f_pos

483

退出

484

当:l_whence恒等于seek relative to end of file

485

l_start加等于NOTE: in a 32bit arch with a preemptable kernel and* an UP compile the i_size_read/write must be atomic* with respect to the local cpu (unlike with preempt disabled),* but they don't need to be atomic with respect to other cpus like in* true SMP (so they

486

退出

487

默认

488

返回:负EINVAL

491

返回:vfs_fallocate(filp, mode | default is extend size , l_start, len == 0 means until end of file )

**调用者**
名称	描述
file_ioctl

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