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authorAl Viro <viro@zeniv.linux.org.uk>2021-04-25 01:03:16 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2021-06-10 11:45:11 -0400
commit610c7a71543df32fcecf64004f974905f5881fb3 (patch)
tree7811b3b50723fe322b5c60c79fb3d8d38e5edd0b /lib/iov_iter.c
parent9221d2e37b729077797e6d02012289892dbdb859 (diff)
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 <quic_qiancai@quicinc.com>] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'lib/iov_iter.c')
-rw-r--r--lib/iov_iter.c27
1 files 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);