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2014-05-06bio_vec-backed iov_iterAl Viro
New variant of iov_iter - ITER_BVEC in iter->type, backed with bio_vec array instead of iovec one. Primitives taught to deal with such beasts, __swap_write() switched to using that kind of iov_iter. Note that bio_vec is just a <page, offset, length> triple - there's nothing block-specific about it. I've left the definition where it was, but took it from under ifdef CONFIG_BLOCK. Next target: ->splice_write()... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06optimize copy_page_{to,from}_iter()Al Viro
if we'd ended up in the end of a segment, jump to the beginning of the next one (iov_offset = 0, iov++), rather than having the next primitive deal with that. Ought to be folded back... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06new helper: copy_page_from_iter()Al Viro
parallel to copy_page_to_iter(). pipe_write() switched to it (and became ->write_iter()). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06new helper: iov_iter_get_pages_alloc()Al Viro
same as iov_iter_get_pages(), except that pages array is allocated (kmalloc if possible, vmalloc if that fails) and left for caller to free. Lustre and NFS ->direct_IO() switched to it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06new helper: iov_iter_npages()Al Viro
counts the pages covered by iov_iter, up to given limit. do_block_direct_io() and fuse_iter_npages() switched to it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06new helper: iov_iter_get_pages()Al Viro
iov_iter_get_pages(iter, pages, maxsize, &start) grabs references pinning the pages of up to maxsize of (contiguous) data from iter. Returns the amount of memory grabbed or -error. In case of success, the requested area begins at offset start in pages[0] and runs through pages[1], etc. Less than requested amount might be returned - either because the contiguous area in the beginning of iterator is smaller than requested, or because the kernel failed to pin that many pages. direct-io.c switched to using iov_iter_get_pages() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06start adding the tag to iov_iterAl Viro
For now, just use the same thing we pass to ->direct_IO() - it's all iovec-based at the moment. Pass it explicitly to iov_iter_init() and account for kvec vs. iovec in there, by the same kludge NFS ->direct_IO() uses. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06new primitive: iov_iter_alignment()Al Viro
returns the value aligned as badly as the worst remaining segment in iov_iter is. Use instead of open-coded equivalents. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06kill iov_iter_copy_from_user()Al Viro
all callers can use copy_page_from_iter() and it actually simplifies them. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01take iov_iter stuff to mm/iov_iter.cAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>