From 610c7a71543df32fcecf64004f974905f5881fb3 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 25 Apr 2021 01:03:16 -0400 Subject: [PATCH] iov_iter_gap_alignment(): get rid of iterate_all_kinds() For one thing, it's only used for iovec (and makes sense only for those). For another, here we don't care about iov_offset, since the beginning of the first segment and the end of the last one are ignored. So it makes a lot more sense to just walk through the iovec array... We need to deal with the case of truncated iov_iter, but unlike the situation with iov_iter_alignment() we don't care where the last segment ends - just which segment is the last one. [fixed a braino spotted by Qian Cai ] Signed-off-by: Al Viro --- lib/iov_iter.c | 27 ++++++++++++++------------- 1 file changed, 14 insertions(+), 13 deletions(-) diff --git a/lib/iov_iter.c b/lib/iov_iter.c index ed9318358b68..6569e3f5d01d 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1398,23 +1398,24 @@ EXPORT_SYMBOL(iov_iter_alignment); unsigned long iov_iter_gap_alignment(const struct iov_iter *i) { unsigned long res = 0; + unsigned long v = 0; size_t size = i->count; + unsigned k; - if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { - WARN_ON(1); + if (WARN_ON(!iter_is_iovec(i))) return ~0U; - } - iterate_all_kinds(i, size, v, - (res |= (!res ? 0 : (unsigned long)v.iov_base) | - (size != v.iov_len ? size : 0), 0), - (res |= (!res ? 0 : (unsigned long)v.bv_offset) | - (size != v.bv_len ? size : 0)), - (res |= (!res ? 0 : (unsigned long)v.iov_base) | - (size != v.iov_len ? size : 0)), - (res |= (!res ? 0 : (unsigned long)v.bv_offset) | - (size != v.bv_len ? size : 0)) - ); + for (k = 0; k < i->nr_segs; k++) { + if (i->iov[k].iov_len) { + unsigned long base = (unsigned long)i->iov[k].iov_base; + if (v) // if not the first one + res |= base | v; // this start | previous end + v = base + i->iov[k].iov_len; + if (size <= i->iov[k].iov_len) + break; + size -= i->iov[k].iov_len; + } + } return res; } EXPORT_SYMBOL(iov_iter_gap_alignment);