From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Vishal Moola (Oracle)" Subject: [PATCH v2 6/7] ramfs: Convert ramfs_nommu_get_unmapped_area() to use filemap_get_folios_contig() Date: Tue, 16 Aug 2022 10:52:45 -0700 Message-ID: <20220816175246.42401-7-vishal.moola@gmail.com> References: <20220816175246.42401-1-vishal.moola@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc; bh=JxYlL9B7PcenLE4u6mpHNMIpwNwBfeAtvgsgZnBC2EQ=; b=Nq+9QouXGb9OtKzDYs9F8DUKfb+2kMYjnY9YqSGh58CPfgXesRfH7AB/vwHuUCUeTZ tR5fd1Z2FcQIXpTnaS7MCNHzac6DLnCEZwhEMGe6RP3BtPbE1bgUNGTES/uo1EkkwKA4 bBPp/B8YXeI20uy2wEPAWp1LrQxh8Pj1Wjzcw3yEXBHfZmbT9IimlafYhclU6FVRnA27 SrfhSvtNeFiu2pcXT6TLj+fhB1ru65S1RG3ATIcgDiaboBDt96lWqU/L1zom/ilGXrHG BBVjwFombZRkSMnrrilxsNTVOFiXeVHFScQYjkPHdUmeuEUHxcBxW2aJm87IVi5lU+Cu fGFg== In-Reply-To: <20220816175246.42401-1-vishal.moola@gmail.com> List-ID: Content-Type: text/plain; charset="us-ascii" To: linux-fsdevel@vger.kernel.org Cc: linux-btrfs@vger.kernel.org, linux-nilfs@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Vishal Moola (Oracle)" Converted to use folios throughout. This is in preparation for the removal for find_get_pages_contig(). Now also supports large folios. The initial version of this function set the page_address to be returned after finishing all the checks. Since folio_batches have a maximum of 15 folios, the function had to be modified to support getting and checking up to lpages, 15 pages at a time while still returning the initial page address. Now the function sets ret as soon as the first batch arrives, and updates it only if a check fails. The physical adjacency check utilizes the page frame numbers. The page frame number of each folio must be nr_pages away from the first folio. Signed-off-by: Vishal Moola (Oracle) --- fs/ramfs/file-nommu.c | 50 +++++++++++++++++++++++++------------------ 1 file changed, 29 insertions(+), 21 deletions(-) diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c index ba3525ccc27e..81817f301e17 100644 --- a/fs/ramfs/file-nommu.c +++ b/fs/ramfs/file-nommu.c @@ -203,9 +203,9 @@ static unsigned long ramfs_nommu_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags) { - unsigned long maxpages, lpages, nr, loop, ret; + unsigned long maxpages, lpages, nr, loop, ret, nr_pages, pfn; struct inode *inode = file_inode(file); - struct page **pages = NULL, **ptr, *page; + struct folio_batch fbatch; loff_t isize; /* the mapping mustn't extend beyond the EOF */ @@ -221,31 +221,39 @@ static unsigned long ramfs_nommu_get_unmapped_area(struct file *file, goto out; /* gang-find the pages */ - pages = kcalloc(lpages, sizeof(struct page *), GFP_KERNEL); - if (!pages) - goto out_free; - - nr = find_get_pages_contig(inode->i_mapping, pgoff, lpages, pages); - if (nr != lpages) - goto out_free_pages; /* leave if some pages were missing */ + folio_batch_init(&fbatch); + nr_pages = 0; +repeat: + nr = filemap_get_folios_contig(inode->i_mapping, &pgoff, + ULONG_MAX, &fbatch); + if (!nr) { + ret = -ENOSYS; + return ret; + } + if (ret == -ENOSYS) { + ret = (unsigned long) folio_address(fbatch.folios[0]); + pfn = folio_pfn(fbatch.folios[0]); + } /* check the pages for physical adjacency */ - ptr = pages; - page = *ptr++; - page++; - for (loop = lpages; loop > 1; loop--) - if (*ptr++ != page++) - goto out_free_pages; + for (loop = 0; loop < nr; loop++) { + if (pfn + nr_pages != folio_pfn(fbatch.folios[loop])) { + ret = -ENOSYS; + goto out_free; /* leave if not physical adjacent */ + } + nr_pages += folio_nr_pages(fbatch.folios[loop]); + if (nr_pages >= lpages) + goto out_free; /* successfully found desired pages*/ + } + if (nr_pages < lpages) { + folio_batch_release(&fbatch); + goto repeat; /* loop if pages are missing */ + } /* okay - all conditions fulfilled */ - ret = (unsigned long) page_address(pages[0]); -out_free_pages: - ptr = pages; - for (loop = nr; loop > 0; loop--) - put_page(*ptr++); out_free: - kfree(pages); + folio_batch_release(&fbatch); out: return ret; } -- 2.36.1