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ITER_PIPE: clean pipe_advance() up
instead of setting ->iov_offset for new position and calling pipe_truncate() to adjust ->len of the last buffer and discard everything after it, adjust ->len at the same time we set ->iov_offset and use pipe_discard_from() to deal with buffers past that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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@ -845,27 +845,27 @@ static inline void pipe_truncate(struct iov_iter *i)
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static void pipe_advance(struct iov_iter *i, size_t size)
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{
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struct pipe_inode_info *pipe = i->pipe;
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if (size) {
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struct pipe_buffer *buf;
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unsigned int p_mask = pipe->ring_size - 1;
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unsigned int i_head = i->head;
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size_t off = i->iov_offset, left = size;
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unsigned int off = i->iov_offset;
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if (off) /* make it relative to the beginning of buffer */
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left += off - pipe->bufs[i_head & p_mask].offset;
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while (1) {
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buf = &pipe->bufs[i_head & p_mask];
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if (left <= buf->len)
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break;
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left -= buf->len;
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i_head++;
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}
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i->head = i_head;
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i->iov_offset = buf->offset + left;
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if (!off && !size) {
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pipe_discard_from(pipe, i->start_head); // discard everything
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return;
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}
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i->count -= size;
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/* ... and discard everything past that point */
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pipe_truncate(i);
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while (1) {
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struct pipe_buffer *buf = pipe_buf(pipe, i->head);
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if (off) /* make it relative to the beginning of buffer */
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size += off - buf->offset;
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if (size <= buf->len) {
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buf->len = size;
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i->iov_offset = buf->offset + size;
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break;
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}
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size -= buf->len;
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i->head++;
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off = 0;
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}
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pipe_discard_from(pipe, i->head + 1); // discard everything past this one
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}
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static void iov_iter_bvec_advance(struct iov_iter *i, size_t size)
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