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See http://www.infradead.org/rpr.html X-Stat-Signature: n9far1nkh9iyuhjow4zsxsmsjkq98b35 X-Rspamd-Queue-Id: 990C3160011 X-Rspam-User: X-Rspamd-Server: rspam02 X-HE-Tag: 1748955872-198565 X-HE-Meta: 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 QdtsOhSe 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Jun 03, 2025 at 05:52:43PM +0800, wangtao wrote: > +static ssize_t dma_buf_rw_file(struct dma_buf *dmabuf, loff_t my_pos, > + struct file *file, loff_t pos, size_t count, bool is_write) > +{ > + if (!dmabuf->ops->rw_file) > + return -EINVAL; > + > + if (my_pos >= dmabuf->size) > + count = 0; > + else > + count = min_t(size_t, count, dmabuf->size - my_pos); > + if (!count) > + return 0; > + > + return dmabuf->ops->rw_file(dmabuf, my_pos, file, pos, count, is_write); So despite claiming in the cover letter that dmabufs can't support direct I/O you are just reimplementing it badly here using a side interface.