> On Dec 8, 2020, at 4:11 PM, Anna Schumaker <schumaker.anna@xxxxxxxxx> wrote: > > On Tue, Dec 8, 2020 at 3:56 PM Chuck Lever <chuck.lever@xxxxxxxxxx> wrote: >> >> >> >>> On Dec 8, 2020, at 3:29 PM, schumaker.anna@xxxxxxxxx wrote: >>> >>> From: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx> >>> >>> Otherwise we could end up placing data a few bytes off from where we >>> actually want to put it. >>> >>> Fixes: 84ce182ab85b "SUNRPC: Add the ability to expand holes in data pages" >>> Signed-off-by: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx> >>> --- >>> net/sunrpc/xdr.c | 3 ++- >>> 1 file changed, 2 insertions(+), 1 deletion(-) >>> >>> diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c >>> index 71e03b930b70..5b848fe65c81 100644 >>> --- a/net/sunrpc/xdr.c >>> +++ b/net/sunrpc/xdr.c >>> @@ -1314,6 +1314,7 @@ uint64_t xdr_expand_hole(struct xdr_stream *xdr, uint64_t offset, uint64_t lengt >>> unsigned int res = _shift_data_right_tail(buf, from + bytes - shift, shift); >>> truncated = shift - res; >>> xdr->nwords -= XDR_QUADLEN(truncated); >>> + buf->len -= 4 * XDR_QUADLEN(truncated); >> >> If I understand what you're doing here correctly, the usual idiom >> is "XDR_QUADLEN(truncated) << 2" . > > Oh, that works too. I'll adjust the patch. Thanks for letting me know! > Urp, sorry. These days, the preferred mechanism is xdr_align_size(). Old habits die hard, I guess. > Anna > >> >> >>> bytes -= shift; >>> } >>> >>> @@ -1325,7 +1326,7 @@ uint64_t xdr_expand_hole(struct xdr_stream *xdr, uint64_t offset, uint64_t lengt >>> bytes); >>> _zero_pages(buf->pages, buf->page_base + offset, length); >>> >>> - buf->len += length - (from - offset) - truncated; >>> + buf->len += length - (from - offset); >>> xdr_set_page(xdr, offset + length, PAGE_SIZE); >>> return length; >>> } >>> -- >>> 2.29.2 >>> >> >> -- >> Chuck Lever -- Chuck Lever
