ioctl_preallocate

Name: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.

Proto:int ioctl_preallocate(struct file *filp, int mode, void __user *argp)

Type:int

Parameter:

Type	Parameter	Name
struct file *	filp
int	mode
void __user *	argp

472

inode = file_inode(filp)

475

If copy_from_user( & sr, argp, size of sr ) Then Return -EFAULT

479

Case l_whence == seek relative to beginning of file

480

Break

481

Case l_whence == seek relative to current file position

482

l_start += f_pos

483

Break

484

Case l_whence == seek relative to end of file

485

l_start += 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

Break

487

Default

488

Return -EINVAL

491

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

**Caller**
Name	Describe
file_ioctl

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Function report