Messages in this thread Patch in this message | | | From | Al Viro <> | Subject | [RFC PATCH 06/37] copy_page_to_iter(): fix ITER_DISCARD case | Date | Sun, 6 Jun 2021 19:10:20 +0000 |
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we need to advance the iterator...
Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> --- lib/iov_iter.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 12fb04b23143..c8877cffb7bc 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -965,9 +965,12 @@ static size_t __copy_page_to_iter(struct page *page, size_t offset, size_t bytes size_t wanted = copy_to_iter(kaddr + offset, bytes, i); kunmap_atomic(kaddr); return wanted; - } else if (unlikely(iov_iter_is_discard(i))) + } else if (unlikely(iov_iter_is_discard(i))) { + if (unlikely(i->count < bytes)) + bytes = i->count; + i->count -= bytes; return bytes; - else if (likely(!iov_iter_is_pipe(i))) + } else if (likely(!iov_iter_is_pipe(i))) return copy_page_to_iter_iovec(page, offset, bytes, i); else return copy_page_to_iter_pipe(page, offset, bytes, i); -- 2.11.0
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