From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([66.187.233.31]:51116 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756323AbXI1IBy (ORCPT ); Fri, 28 Sep 2007 04:01:54 -0400 Message-Id: <20070928080042.527431000@chello.nl> References: <20070928074200.436463000@chello.nl> Date: Fri, 28 Sep 2007 09:42:10 +0200 From: Peter Zijlstra Subject: [PATCH 10/12] lockdep: lock_page: handle IO-completions Content-Disposition: inline; filename=lockdep-page-async.patch Sender: linux-arch-owner@vger.kernel.org To: lkml , linux-arch@vger.kernel.org Cc: Zach Brown , Ingo Molnar , akpm@linux-foundation.org, Peter Zijlstra List-ID: IO-completions unlock the page in interrupt context, which is not the same context as that locked the page. Avoid this problem by doing the unlock tracking when submitting the page for IO. Signed-off-by: Peter Zijlstra --- fs/buffer.c | 4 +++- fs/mpage.c | 19 +++++++++++++++---- fs/nfs/read.c | 4 +++- include/linux/pagemap.h | 5 +++++ mm/page_io.c | 3 ++- 5 files changed, 28 insertions(+), 7 deletions(-) Index: linux-2.6/fs/buffer.c =================================================================== --- linux-2.6.orig/fs/buffer.c +++ linux-2.6/fs/buffer.c @@ -413,7 +413,7 @@ static void end_buffer_async_read(struct */ if (page_uptodate && !PageError(page)) SetPageUptodate(page); - unlock_page(page); + unlock_page_nocheck(page); return; still_busy: @@ -1988,6 +1988,8 @@ int block_read_full_page(struct page *pa mark_buffer_async_read(bh); } + unlock_page_check(page); + /* * Stage 3: start the IO. Check for uptodateness * inside the buffer lock in case another process reading Index: linux-2.6/fs/mpage.c =================================================================== --- linux-2.6.orig/fs/mpage.c +++ linux-2.6/fs/mpage.c @@ -59,7 +59,7 @@ static int mpage_end_io_read(struct bio ClearPageUptodate(page); SetPageError(page); } - unlock_page(page); + unlock_page_nocheck(page); } while (bvec >= bio->bi_io_vec); bio_put(bio); return 0; @@ -92,9 +92,20 @@ static int mpage_end_io_write(struct bio static struct bio *mpage_bio_submit(int rw, struct bio *bio) { - bio->bi_end_io = mpage_end_io_read; - if (rw == WRITE) - bio->bi_end_io = mpage_end_io_write; + bio->bi_end_io = mpage_end_io_write; + if (rw == READ) { + struct bio_vec *bvec = bio->bi_io_vec; + int i; + + bio->bi_end_io = mpage_end_io_read; + + for (i = 0; i < bio->bi_vcnt; i++) { + struct page *page = bvec[i].bv_page; + + if (page) + unlock_page_check(page); + } + } submit_bio(rw, bio); return NULL; } Index: linux-2.6/fs/nfs/read.c =================================================================== --- linux-2.6.orig/fs/nfs/read.c +++ linux-2.6/fs/nfs/read.c @@ -137,12 +137,13 @@ static int nfs_readpage_async(struct nfs nfs_pagein_multi(inode, &one_request, 1, len, 0); else nfs_pagein_one(inode, &one_request, 1, len, 0); + unlock_page_check(page); return 0; } static void nfs_readpage_release(struct nfs_page *req) { - unlock_page(req->wb_page); + unlock_page_nocheck(req->wb_page); dprintk("NFS: read done (%s/%Ld %d@%Ld)\n", req->wb_context->path.dentry->d_inode->i_sb->s_id, @@ -540,6 +541,7 @@ readpage_async_filler(void *data, struct if (len < PAGE_CACHE_SIZE) zero_user_page(page, len, PAGE_CACHE_SIZE - len, KM_USER0); nfs_pageio_add_request(desc->pgio, new); + unlock_page_check(page); return 0; out_error: error = PTR_ERR(new); Index: linux-2.6/mm/page_io.c =================================================================== --- linux-2.6.orig/mm/page_io.c +++ linux-2.6/mm/page_io.c @@ -92,7 +92,7 @@ int end_swap_bio_read(struct bio *bio, u } else { SetPageUptodate(page); } - unlock_page(page); + unlock_page_nocheck(page); bio_put(bio); return 0; } @@ -144,6 +144,7 @@ int swap_readpage(struct file *file, str } count_vm_event(PSWPIN); submit_bio(READ, bio); + unlock_page_check(page); out: return ret; } Index: linux-2.6/include/linux/pagemap.h =================================================================== --- linux-2.6.orig/include/linux/pagemap.h +++ linux-2.6/include/linux/pagemap.h @@ -189,6 +189,11 @@ static inline void unlock_page(struct pa unlock_page_nocheck(page); } +static inline void unlock_page_check(struct page *page) +{ + __unlock_page_check(page, _RET_IP_); +} + /* * lock_page_nosync should only be used if we can't pin the page's inode. * Doesn't play quite so well with block device plugging. --