copy_page_to_iter

Name:copy_page_to_iter

Proto:size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i)

Type:size_t

Parameter:

Type	Parameter	Name
struct page *	page
size_t	offset
size_t	bytes
struct iov_iter *	i

910

If Value for the false possibility is greater at compile time(!page_copy_sane(page, offset, bytes)) Then Return 0

912

If * Bit 0 is the read/write bit, set if we're writing. * Bit 1 is the BVEC_FLAG_NO_REF bit, set if type is a bvec and * the caller isn't expecting to drop a page reference when done. & (ITER_BVEC | ITER_KVEC) Then

913

kaddr = kmap_atomic(page)

914

wanted = copy_to_iter(kaddr + offset, bytes, i)

915

Prevent people trying to call kunmap_atomic() as if it were kunmap()* kunmap_atomic() should get the return value of kmap_atomic, not the page.(kaddr)

916

Return wanted

917

Else if Value for the false possibility is greater at compile time(iov_iter_is_discard(i)) Then Return bytes

919

Else if Value is more likely to compile time(!iov_iter_is_pipe(i)) Then Return copy_page_to_iter_iovec(page, offset, bytes, i)

921

Else Return copy_page_to_iter_pipe(page, offset, bytes, i)

**Caller**
Name	Describe
process_vm_rw_pages	process_vm_rw_pages - read/write pages from task specified@pages: array of pointers to pages we want to copy@offset: offset in page to start copying from/to@len: number of bytes to copy@iter: where to copy to/from locally*@vm_write: 0 means copy from,
pipe_to_user

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