Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-pz0-f46.google.com ([209.85.210.46]:43629 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752910Ab2HWQ2r (ORCPT ); Thu, 23 Aug 2012 12:28:47 -0400 Received: by mail-pz0-f46.google.com with SMTP id y13so493174dad.19 for ; Thu, 23 Aug 2012 09:28:46 -0700 (PDT) From: Peng Tao To: Trond.Myklebust@netapp.com Cc: linux-nfs@vger.kernel.org Subject: [PATCH-resend 5/6] pnfsblock: fix non-aligned DIO read Date: Fri, 24 Aug 2012 00:27:52 +0800 Message-Id: <1345739273-2241-6-git-send-email-bergwolf@gmail.com> In-Reply-To: <1345739273-2241-1-git-send-email-bergwolf@gmail.com> References: <1345739273-2241-1-git-send-email-bergwolf@gmail.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: For DIO read, if it is not sector aligned, we should reject it and resend via MDS. Otherwise there might be data corruption. Also teach bl_read_pagelist to handle partial page reads for DIO. Cc: stable [since v3.4] Signed-off-by: Peng Tao --- fs/nfs/blocklayout/blocklayout.c | 64 +++++++++++++++++++++++++++++++++----- 1 files changed, 56 insertions(+), 8 deletions(-) diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c index 39fa002..e5dfef5 100644 --- a/fs/nfs/blocklayout/blocklayout.c +++ b/fs/nfs/blocklayout/blocklayout.c @@ -252,8 +252,11 @@ bl_read_pagelist(struct nfs_read_data *rdata) sector_t isect, extent_length = 0; struct parallel_io *par; loff_t f_offset = rdata->args.offset; + size_t bytes_left = rdata->args.count; + unsigned int pg_offset, pg_len; struct page **pages = rdata->args.pages; int pg_index = rdata->args.pgbase >> PAGE_CACHE_SHIFT; + const bool is_dio = (header->dreq != NULL); dprintk("%s enter nr_pages %u offset %lld count %u\n", __func__, rdata->pages.npages, f_offset, (unsigned int)rdata->args.count); @@ -287,36 +290,53 @@ bl_read_pagelist(struct nfs_read_data *rdata) extent_length = min(extent_length, cow_length); } } + + if (is_dio) { + pg_offset = f_offset & ~PAGE_CACHE_MASK; + if (pg_offset + bytes_left > PAGE_CACHE_SIZE) + pg_len = PAGE_CACHE_SIZE - pg_offset; + else + pg_len = bytes_left; + + f_offset += pg_len; + bytes_left -= pg_len; + isect += (pg_offset >> SECTOR_SHIFT); + } else { + pg_offset = 0; + pg_len = PAGE_CACHE_SIZE; + } + hole = is_hole(be, isect); if (hole && !cow_read) { bio = bl_submit_bio(READ, bio); /* Fill hole w/ zeroes w/o accessing device */ dprintk("%s Zeroing page for hole\n", __func__); - zero_user_segment(pages[i], 0, PAGE_CACHE_SIZE); + zero_user_segment(pages[i], pg_offset, pg_len); print_page(pages[i]); SetPageUptodate(pages[i]); } else { struct pnfs_block_extent *be_read; be_read = (hole && cow_read) ? cow_read : be; - bio = bl_add_page_to_bio(bio, rdata->pages.npages - i, + bio = do_add_page_to_bio(bio, rdata->pages.npages - i, READ, isect, pages[i], be_read, - bl_end_io_read, par); + bl_end_io_read, par, + pg_offset, pg_len); if (IS_ERR(bio)) { header->pnfs_error = PTR_ERR(bio); bio = NULL; goto out; } } - isect += PAGE_CACHE_SECTORS; + isect += (pg_len >> SECTOR_SHIFT); extent_length -= PAGE_CACHE_SECTORS; } if ((isect << SECTOR_SHIFT) >= header->inode->i_size) { rdata->res.eof = 1; - rdata->res.count = header->inode->i_size - f_offset; + rdata->res.count = header->inode->i_size - rdata->args.offset; } else { - rdata->res.count = (isect << SECTOR_SHIFT) - f_offset; + rdata->res.count = (isect << SECTOR_SHIFT) - rdata->args.offset; } out: bl_put_extent(be); @@ -1149,9 +1169,37 @@ bl_clear_layoutdriver(struct nfs_server *server) return 0; } +static bool +is_aligned_req(struct nfs_page *req, unsigned int alignment) +{ + return IS_ALIGNED(req->wb_offset, alignment) && + IS_ALIGNED(req->wb_bytes, alignment); +} + +static void +bl_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req) +{ + if (pgio->pg_dreq != NULL && + !is_aligned_req(req, SECTOR_SIZE)) + nfs_pageio_reset_read_mds(pgio); + else + pnfs_generic_pg_init_read(pgio, req); +} + +static bool +bl_pg_test_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev, + struct nfs_page *req) +{ + if (pgio->pg_dreq != NULL && + !is_aligned_req(req, SECTOR_SIZE)) + return false; + + return pnfs_generic_pg_test(pgio, prev, req); +} + static const struct nfs_pageio_ops bl_pg_read_ops = { - .pg_init = pnfs_generic_pg_init_read, - .pg_test = pnfs_generic_pg_test, + .pg_init = bl_pg_init_read, + .pg_test = bl_pg_test_read, .pg_doio = pnfs_generic_pg_readpages, }; -- 1.7.1.262.g5ef3d