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See http://www.infradead.org/rpr.html X-Rspamd-Queue-Id: E2BD4A0008 X-Rspam-User: X-Rspamd-Server: rspam05 X-Stat-Signature: h6a1chtki7tfxa35neoxihsind86q875 X-HE-Tag: 1684554926-850008 X-HE-Meta: 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 78O6+mX3 H8OnSFNhbzNIiLnlQQrSLJGOIT2zzvZXqpTPPeY4LHNV6wqSCbqCT7wuapO5m8o3BDgf/XAkfRWKSkBRcE1YSNsFXn4Je5seZbhQkyBk1O0Vlr8Ez7ABO6FIfw/GB4UdzqnIbYC656xk04/9Gv3B/EzYrwVhjappf0bH4JafbFH85lZqxLNceopuBv6bHiha6WoqA7cLs7RN3I8Zx7ueVI7y+UTQruwk7VACbRkQldUXHadpf+fsdlmQakoMjQxL38di27GcqdYod9mZuRiZPRhEPOjq+83V58L4Z3+x8q5WrJH0xIb24BaGbQ0apSQzuuVIZnRRyXPSF26GUXLAQjg8ibnkyaIbLk89s4FmptFt1wSPAFvPOTl/1Q+532ClveRyubtJYNHQ+RzUkHmZs+DaiYKoWJW5N2YAkY1IJWkoaE0560Zj0B5ggEg== 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: On Fri, May 19, 2023 at 11:27:51PM +0100, David Howells wrote: > ssize_t generic_file_splice_read(struct file *in, loff_t *ppos, > struct pipe_inode_info *pipe, size_t len, > unsigned int flags) > { > if (unlikely(*ppos >= in->f_mapping->host->i_sb->s_maxbytes)) > return 0; > if (unlikely(!len)) > return 0; > return filemap_splice_read(in, ppos, pipe, len, flags); > } > > so I wonder if the tests in generic_file_splice_read() can be folded into > vfs_splice_read(), pointers to generic_file_splice_read() be replaced with > pointers to filemap_splice_read() and generic_file_splice_read() just be > removed. > > I suspect we can't quite do this because of the *ppos check - but I wonder if > that's actually necessary since filemap_splice_read() checks against > i_size... or if the check can be moved there if we definitely want to do it. > > Certainly, the zero-length check can be done in vfs_splice_read(). The zero length check makes sense in vfs_splice_read. The ppos check I think makes sense for filemap_splice_read - after all we're dealing with the page cache here, and the page cache needs a working maxbytes and i_size. What callers of filemap_splice_read that don't have the checks do you have in your tree right now and how did you end up with them?