From 2112ff5ce0c1128fe7b4d19cfe7f2b8ce5b595fa Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Mon, 23 Aug 2021 11:18:44 +0100 Subject: iov_iter: track truncated size Remember how many bytes were truncated and reverted back. Because not reexpanded iterators don't always work well with reverting, we may need to know that to reexpand ourselves when needed. Signed-off-by: Pavel Begunkov Signed-off-by: Al Viro --- include/linux/uio.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'include/linux/uio.h') diff --git a/include/linux/uio.h b/include/linux/uio.h index 82c3c3e819e0..5265024e8b90 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -47,6 +47,7 @@ struct iov_iter { }; loff_t xarray_start; }; + size_t truncated; }; static inline enum iter_type iov_iter_type(const struct iov_iter *i) @@ -254,8 +255,10 @@ static inline void iov_iter_truncate(struct iov_iter *i, u64 count) * conversion in assignement is by definition greater than all * values of size_t, including old i->count. */ - if (i->count > count) + if (i->count > count) { + i->truncated += i->count - count; i->count = count; + } } /* @@ -264,6 +267,7 @@ static inline void iov_iter_truncate(struct iov_iter *i, u64 count) */ static inline void iov_iter_reexpand(struct iov_iter *i, size_t count) { + i->truncated -= count - i->count; i->count = count; } -- cgit