Hi Greg, Bellow is backport of upstream commit f742dc4a32587bff50b13dde9d8894b96851951a, to the 3.6.y branch.
Thanks, Tao From f7ff690e8121d5142129d4a7854205287d17f92a Mon Sep 17 00:00:00 2001 From: Peng Tao <[email protected]> Date: Fri, 24 Aug 2012 00:27:52 +0800 Subject: [PATCH 1/2] pnfsblock: fix non-aligned DIO read 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. Signed-off-by: Peng Tao <[email protected]> Signed-off-by: Trond Myklebust <[email protected]> --- fs/nfs/blocklayout/blocklayout.c | 77 ++++++++++++++++++++++--------------- 1 files changed, 46 insertions(+), 31 deletions(-) diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c index f3d16ad..e5dfef5 100644 --- a/fs/nfs/blocklayout/blocklayout.c +++ b/fs/nfs/blocklayout/blocklayout.c @@ -242,14 +242,6 @@ bl_end_par_io_read(void *data, int unused) schedule_work(&rdata->task.u.tk_work); } -static bool -bl_check_alignment(u64 offset, u32 len, unsigned long blkmask) -{ - if ((offset & blkmask) || (len & blkmask)) - return false; - return true; -} - static enum pnfs_try_status bl_read_pagelist(struct nfs_read_data *rdata) { @@ -260,15 +252,15 @@ 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); - if (!bl_check_alignment(f_offset, rdata->args.count, PAGE_CACHE_MASK)) - goto use_mds; - par = alloc_parallel(rdata); if (!par) goto use_mds; @@ -298,36 +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); @@ -676,7 +685,7 @@ bl_write_pagelist(struct nfs_write_data *wdata, int sync) struct bio *bio = NULL; struct pnfs_block_extent *be = NULL, *cow_read = NULL; sector_t isect, last_isect = 0, extent_length = 0; - struct parallel_io *par = NULL; + struct parallel_io *par; loff_t offset = wdata->args.offset; size_t count = wdata->args.count; unsigned int pg_offset, pg_len, saved_len; @@ -688,10 +697,6 @@ bl_write_pagelist(struct nfs_write_data *wdata, int sync) NFS_SERVER(header->inode)->pnfs_blksize >> PAGE_CACHE_SHIFT; dprintk("%s enter, %Zu@%lld\n", __func__, count, offset); - /* Check for alignment first */ - if (!bl_check_alignment(offset, count, PAGE_CACHE_MASK)) - goto out_mds; - /* At this point, wdata->pages is a (sequential) list of nfs_pages. * We want to write each, and if there is an error set pnfs_error * to have it redone using nfs. @@ -1164,32 +1169,42 @@ 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 (!bl_check_alignment(req->wb_offset, req->wb_bytes, PAGE_CACHE_MASK)) + 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 void -bl_pg_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *req) +static bool +bl_pg_test_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev, + struct nfs_page *req) { - if (!bl_check_alignment(req->wb_offset, req->wb_bytes, PAGE_CACHE_MASK)) - nfs_pageio_reset_write_mds(pgio); - else - pnfs_generic_pg_init_write(pgio, 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 = bl_pg_init_read, - .pg_test = pnfs_generic_pg_test, + .pg_test = bl_pg_test_read, .pg_doio = pnfs_generic_pg_readpages, }; static const struct nfs_pageio_ops bl_pg_write_ops = { - .pg_init = bl_pg_init_write, + .pg_init = pnfs_generic_pg_init_write, .pg_test = pnfs_generic_pg_test, .pg_doio = pnfs_generic_pg_writepages, }; -- 1.7.1 > -----Original Message----- > From: [email protected] [mailto:[email protected]] > Sent: Sunday, October 14, 2012 6:29 PM > To: [email protected]; [email protected]; Peng, Tao; > [email protected] > Cc: [email protected] > Subject: FAILED: patch "[PATCH] pnfsblock: fix non-aligned DIO read" failed > to apply to 3.6-stable > tree > > > The patch below does not apply to the 3.6-stable tree. > If someone wants it applied there, or to any other stable or longterm > tree, then please email the backport, including the original git commit > id to <[email protected]>. > > thanks, > > greg k-h > > ------------------ original commit in Linus's tree ------------------ > > From f742dc4a32587bff50b13dde9d8894b96851951a Mon Sep 17 00:00:00 2001 > From: Peng Tao <[email protected]> > Date: Fri, 24 Aug 2012 00:27:52 +0800 > Subject: [PATCH] pnfsblock: fix non-aligned DIO read > > 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 <[email protected]> [since v3.4] > Signed-off-by: Peng Tao <[email protected]> > Signed-off-by: Trond Myklebust <[email protected]> > > diff --git a/fs/nfs/blocklayout/blocklayout.c > b/fs/nfs/blocklayout/blocklayout.c > index a9fe644..61e04fb 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, > }; > >
