From patchwork Tue Nov 7 21:26:41 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 13449305 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 579FF2C860 for ; Tue, 7 Nov 2023 21:26:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="NXRUiGQ1" Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A1FE610E4; Tue, 7 Nov 2023 13:26:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=YwVh6l/W1yK7KiZyEJlfwu5hHInPV2A4ijrPzoQDwKI=; b=NXRUiGQ1reyOncWjpC1pyDdJ+t Goyz1m7qTUWS0PRa/Dqn9ZSWvv43hjble24CYNoFlr32oR55XcZH/Jj7lZQw8H4+QtgUfaFWb6Bg1 lpy32NyNeBhJIQLv69u6pNYFuraoYFPTBVud2E0OB81JpP2aCBnk5F2SXfKYn/TYkAPXbX45LWjEv YCQF5Jur5FhRtADhxyVqfdjtTQx6DYyn2v2lOleAdnTl5BIhR+cLF3aK8GnlceSt41tUQrOjOw4lI ZvudLz1DMbRYtjOxKV1MhQMqsYpI2wVlhYaf8W7OMT9qySFBUL0TJZCGfq07whhAZ9PNya5D8c2Z7 QNM1r6Iw==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1r0Tav-00Ee0X-6a; Tue, 07 Nov 2023 21:26:45 +0000 From: "Matthew Wilcox (Oracle)" To: Andrew Morton Cc: "Matthew Wilcox (Oracle)" , linux-ext4@vger.kernel.org, gfs2@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, "Darrick J . Wong" , linux-erofs@lists.ozlabs.org, "Theodore Ts'o" , Andreas Dilger , Andreas Gruenbacher Subject: [PATCH 2/3] mm: Add folio_fill_tail() and use it in iomap Date: Tue, 7 Nov 2023 21:26:41 +0000 Message-Id: <20231107212643.3490372-3-willy@infradead.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20231107212643.3490372-1-willy@infradead.org> References: <20231107212643.3490372-1-willy@infradead.org> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The iomap code was limited to PAGE_SIZE bytes; generalise it to cover an arbitrary-sized folio, and move it to be a common helper. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Andreas Gruenbacher --- fs/iomap/buffered-io.c | 14 ++------------ include/linux/highmem.h | 38 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+), 12 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index f72df2babe56..093c4515b22a 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -305,28 +305,18 @@ static int iomap_read_inline_data(const struct iomap_iter *iter, { const struct iomap *iomap = iomap_iter_srcmap(iter); size_t size = i_size_read(iter->inode) - iomap->offset; - size_t poff = offset_in_page(iomap->offset); size_t offset = offset_in_folio(folio, iomap->offset); - void *addr; if (folio_test_uptodate(folio)) return 0; - if (WARN_ON_ONCE(size > PAGE_SIZE - poff)) - return -EIO; - if (WARN_ON_ONCE(size > PAGE_SIZE - - offset_in_page(iomap->inline_data))) - return -EIO; if (WARN_ON_ONCE(size > iomap->length)) return -EIO; if (offset > 0) ifs_alloc(iter->inode, folio, iter->flags); - addr = kmap_local_folio(folio, offset); - memcpy(addr, iomap->inline_data, size); - memset(addr + size, 0, PAGE_SIZE - poff - size); - kunmap_local(addr); - iomap_set_range_uptodate(folio, offset, PAGE_SIZE - poff); + folio_fill_tail(folio, offset, iomap->inline_data, size); + iomap_set_range_uptodate(folio, offset, folio_size(folio) - offset); return 0; } diff --git a/include/linux/highmem.h b/include/linux/highmem.h index 1b81416196dd..0fbb60ffefc9 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -521,6 +521,44 @@ static inline __must_check void *folio_zero_tail(struct folio *folio, return kaddr; } +/** + * folio_fill_tail - Copy some data to a folio and pad with zeroes. + * @folio: The destination folio. + * @offset: The offset into @folio at which to start copying. + * @from: The data to copy. + * @len: How many bytes of data to copy. + * + * This function is most useful for filesystems which support inline data. + * When they want to copy data from the inode into the page cache, this + * function does everything for them. It supports large folios even on + * HIGHMEM configurations. + */ +static inline void folio_fill_tail(struct folio *folio, size_t offset, + const char *from, size_t len) +{ + char *to = kmap_local_folio(folio, offset); + + VM_BUG_ON(offset + len > folio_size(folio)); + + if (folio_test_highmem(folio)) { + size_t max = PAGE_SIZE - offset_in_page(offset); + + while (len > max) { + memcpy(to, from, max); + kunmap_local(to); + len -= max; + from += max; + offset += max; + max = PAGE_SIZE; + to = kmap_local_folio(folio, offset); + } + } + + memcpy(to, from, len); + to = folio_zero_tail(folio, offset, to); + kunmap_local(to); +} + /** * memcpy_from_file_folio - Copy some bytes from a file folio. * @to: The destination buffer.