From patchwork Fri Dec 30 22:12:35 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Darrick J. Wong" X-Patchwork-Id: 13084856 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 13349C53210 for ; Fri, 30 Dec 2022 23:26:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235764AbiL3XZu (ORCPT ); Fri, 30 Dec 2022 18:25:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36672 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235943AbiL3XZM (ORCPT ); Fri, 30 Dec 2022 18:25:12 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7E22E1E3DE; Fri, 30 Dec 2022 15:25:00 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0FC4361C2C; Fri, 30 Dec 2022 23:25:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 68B7CC433D2; Fri, 30 Dec 2022 23:24:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1672442699; bh=5z3fd5l8ZAbcNUR/2OKoxyGqTHfDkVHL0P5ZYH67JjI=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=diMSvwtyvEJ/4W8FN9hromo1Gx08e3L+Zb/9hIbDZ0uSxBaQGVW/TvSgXAWaTxkVg ZtY0HV1HVbKsaTKvhzP2x8eDAchk+BOm26HV//LoQHuh4g6pTQKCGdNW1VfmZ0mDdY 2FEVP1aVqQOnF1SULv0WcraqFxCIsgGAl0zrl88rD6VyFUJUqWDHNCnqJu6U33Pipf pPor9F0rGJ6pQmgX8AyyxKzq+15WW13VDMukTet85241dnuW01ob93CthDuborrVxQ LpLV4np1tYE/lDGDNSILaCtpex76kIoLOl9d9ahwd58rx6ogLWiKc04JAgCyAoFYNS nC5QCfFrHMMGQ== Subject: [PATCH 4/7] xfs: teach xfile to pass back direct-map pages to caller From: "Darrick J. Wong" To: djwong@kernel.org Cc: linux-xfs@vger.kernel.org, willy@infradead.org, linux-fsdevel@vger.kernel.org Date: Fri, 30 Dec 2022 14:12:35 -0800 Message-ID: <167243835545.692498.13924192102230205821.stgit@magnolia> In-Reply-To: <167243835481.692498.14657125042725378987.stgit@magnolia> References: <167243835481.692498.14657125042725378987.stgit@magnolia> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Darrick J. Wong Certain xfile array operations (such as sorting) can be sped up quite a bit by allowing xfile users to grab a page to bulk-read the records contained within it. Create helper methods to facilitate this. Signed-off-by: Darrick J. Wong --- fs/xfs/scrub/trace.h | 2 + fs/xfs/scrub/xfile.c | 108 ++++++++++++++++++++++++++++++++++++++++++++++++++ fs/xfs/scrub/xfile.h | 10 +++++ 3 files changed, 120 insertions(+) diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h index 9de9d4f795e8..79b844c969df 100644 --- a/fs/xfs/scrub/trace.h +++ b/fs/xfs/scrub/trace.h @@ -824,6 +824,8 @@ DEFINE_EVENT(xfile_class, name, \ DEFINE_XFILE_EVENT(xfile_pread); DEFINE_XFILE_EVENT(xfile_pwrite); DEFINE_XFILE_EVENT(xfile_seek_data); +DEFINE_XFILE_EVENT(xfile_get_page); +DEFINE_XFILE_EVENT(xfile_put_page); TRACE_EVENT(xfarray_create, TP_PROTO(struct xfarray *xfa, unsigned long long required_capacity), diff --git a/fs/xfs/scrub/xfile.c b/fs/xfs/scrub/xfile.c index 43455aa78243..7090a8e12b60 100644 --- a/fs/xfs/scrub/xfile.c +++ b/fs/xfs/scrub/xfile.c @@ -316,3 +316,111 @@ xfile_stat( statbuf->bytes = ks.blocks << SECTOR_SHIFT; return 0; } + +/* + * Grab the (locked) page for a memory object. The object cannot span a page + * boundary. Returns 0 (and a locked page) if successful, -ENOTBLK if we + * cannot grab the page, or the usual negative errno. + */ +int +xfile_get_page( + struct xfile *xf, + loff_t pos, + unsigned int len, + struct xfile_page *xfpage) +{ + struct inode *inode = file_inode(xf->file); + struct address_space *mapping = inode->i_mapping; + const struct address_space_operations *aops = mapping->a_ops; + struct page *page = NULL; + void *fsdata = NULL; + loff_t key = round_down(pos, PAGE_SIZE); + unsigned int pflags; + int error; + + if (inode->i_sb->s_maxbytes - pos < len) + return -ENOMEM; + if (len > PAGE_SIZE - offset_in_page(pos)) + return -ENOTBLK; + + trace_xfile_get_page(xf, pos, len); + + pflags = memalloc_nofs_save(); + + /* + * We call write_begin directly here to avoid all the freezer + * protection lock-taking that happens in the normal path. shmem + * doesn't support fs freeze, but lockdep doesn't know that and will + * trip over that. + */ + error = aops->write_begin(NULL, mapping, key, PAGE_SIZE, &page, + &fsdata); + if (error) + goto out_pflags; + + /* We got the page, so make sure we push out EOF. */ + if (i_size_read(inode) < pos + len) + i_size_write(inode, pos + len); + + /* + * If the page isn't up to date, fill it with zeroes before we hand it + * to the caller and make sure the backing store will hold on to them. + */ + if (!PageUptodate(page)) { + void *kaddr; + + kaddr = kmap_local_page(page); + memset(kaddr, 0, PAGE_SIZE); + kunmap_local(kaddr); + SetPageUptodate(page); + } + + /* + * Mark each page dirty so that the contents are written to some + * backing store when we drop this buffer, and take an extra reference + * to prevent the xfile page from being swapped or removed from the + * page cache by reclaim if the caller unlocks the page. + */ + set_page_dirty(page); + get_page(page); + + xfpage->page = page; + xfpage->fsdata = fsdata; + xfpage->pos = key; +out_pflags: + memalloc_nofs_restore(pflags); + return error; +} + +/* + * Release the (locked) page for a memory object. Returns 0 or a negative + * errno. + */ +int +xfile_put_page( + struct xfile *xf, + struct xfile_page *xfpage) +{ + struct inode *inode = file_inode(xf->file); + struct address_space *mapping = inode->i_mapping; + const struct address_space_operations *aops = mapping->a_ops; + unsigned int pflags; + int ret; + + trace_xfile_put_page(xf, xfpage->pos, PAGE_SIZE); + + /* Give back the reference that we took in xfile_get_page. */ + put_page(xfpage->page); + + pflags = memalloc_nofs_save(); + ret = aops->write_end(NULL, mapping, xfpage->pos, PAGE_SIZE, PAGE_SIZE, + xfpage->page, xfpage->fsdata); + memalloc_nofs_restore(pflags); + memset(xfpage, 0, sizeof(struct xfile_page)); + + if (ret < 0) + return ret; + if (ret != PAGE_SIZE) + return -EIO; + return 0; +} diff --git a/fs/xfs/scrub/xfile.h b/fs/xfs/scrub/xfile.h index b37dba1961d8..e34ab9c4aad9 100644 --- a/fs/xfs/scrub/xfile.h +++ b/fs/xfs/scrub/xfile.h @@ -6,6 +6,12 @@ #ifndef __XFS_SCRUB_XFILE_H__ #define __XFS_SCRUB_XFILE_H__ +struct xfile_page { + struct page *page; + void *fsdata; + loff_t pos; +}; + struct xfile { struct file *file; }; @@ -55,4 +61,8 @@ struct xfile_stat { int xfile_stat(struct xfile *xf, struct xfile_stat *statbuf); +int xfile_get_page(struct xfile *xf, loff_t offset, unsigned int len, + struct xfile_page *xbuf); +int xfile_put_page(struct xfile *xf, struct xfile_page *xbuf); + #endif /* __XFS_SCRUB_XFILE_H__ */