From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chao Yu Subject: [f2fs-dev][PATCH] f2fs: avoid crash when trace f2fs_submit_page_mbio event in ra_sum_pages Date: Fri, 16 May 2014 17:14:47 +0800 Message-ID: <005801cf70e7$66cb0090$346101b0$@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: linux-f2fs-devel@lists.sourceforge.net, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org To: Jaegeuk Kim Return-path: Received: from mailout3.samsung.com ([203.254.224.33]:44211 "EHLO mailout3.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755529AbaEPJPk (ORCPT ); Fri, 16 May 2014 05:15:40 -0400 Content-language: zh-cn Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Previously we allocate pages with no mapping in ra_sum_pages(), so we may encounter a crash in event trace of f2fs_submit_page_mbio where we access mapping data of the page. We'd better allocate pages in bd_inode mapping and invalidate these pages after we restore data from pages. It could avoid crash in above scenario. Call Trace: [] ? ftrace_raw_event_f2fs_write_checkpoint+0x80/0x80 [f2fs] [] f2fs_submit_page_mbio+0x1cb/0x200 [f2fs] [] restore_node_summary+0x13a/0x280 [f2fs] [] build_curseg+0x2bd/0x620 [f2fs] [] build_segment_manager+0x1cb/0x920 [f2fs] [] f2fs_fill_super+0x535/0x8e0 [f2fs] [] mount_bdev+0x16a/0x1a0 [] f2fs_mount+0x1f/0x30 [f2fs] [] mount_fs+0x36/0x170 [] vfs_kern_mount+0x55/0xe0 [] do_mount+0x1e8/0x900 [] SyS_mount+0x82/0xc0 [] sysenter_do_call+0x12/0x22 Signed-off-by: Chao Yu --- fs/f2fs/node.c | 49 ++++++++++++++++++++++++++++--------------------- 1 file changed, 28 insertions(+), 21 deletions(-) diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 3d60d3d..b5cd814 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -1658,13 +1658,16 @@ int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page) /* * ra_sum_pages() merge contiguous pages into one bio and submit. - * these pre-readed pages are linked in pages list. + * these pre-readed pages are alloced in bd_inode's mapping tree. */ -static int ra_sum_pages(struct f2fs_sb_info *sbi, struct list_head *pages, +static int ra_sum_pages(struct f2fs_sb_info *sbi, struct page **pages, int start, int nrpages) { struct page *page; + struct inode *inode = sbi->sb->s_bdev->bd_inode; + struct address_space *mapping = inode->i_mapping; int page_idx = start; + int alloced, readed; struct f2fs_io_info fio = { .type = META, .rw = READ_SYNC | REQ_META | REQ_PRIO @@ -1672,21 +1675,23 @@ static int ra_sum_pages(struct f2fs_sb_info *sbi, struct list_head *pages, for (; page_idx < start + nrpages; page_idx++) { /* alloc temporal page for read node summary info*/ - page = alloc_page(GFP_F2FS_ZERO); + page = grab_cache_page(mapping, page_idx); if (!page) break; - - lock_page(page); - page->index = page_idx; - list_add_tail(&page->lru, pages); + page_cache_release(page); } - list_for_each_entry(page, pages, lru) - f2fs_submit_page_mbio(sbi, page, page->index, &fio); + alloced = page_idx - start; + readed = find_get_pages_contig(mapping, start, alloced, pages); + BUG_ON(alloced != readed); + + for (page_idx = 0; page_idx < readed; page_idx++) + f2fs_submit_page_mbio(sbi, pages[page_idx], + pages[page_idx]->index, &fio); f2fs_submit_merged_bio(sbi, META, READ); - return page_idx - start; + return readed; } int restore_node_summary(struct f2fs_sb_info *sbi, @@ -1694,11 +1699,11 @@ int restore_node_summary(struct f2fs_sb_info *sbi, { struct f2fs_node *rn; struct f2fs_summary *sum_entry; - struct page *page, *tmp; + struct inode *inode = sbi->sb->s_bdev->bd_inode; block_t addr; int bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi)); - int i, last_offset, nrpages, err = 0; - LIST_HEAD(page_list); + struct page *pages[bio_blocks]; + int i, index, last_offset, nrpages, err = 0; /* scan the node segment */ last_offset = sbi->blocks_per_seg; @@ -1709,29 +1714,31 @@ int restore_node_summary(struct f2fs_sb_info *sbi, nrpages = min(last_offset - i, bio_blocks); /* read ahead node pages */ - nrpages = ra_sum_pages(sbi, &page_list, addr, nrpages); + nrpages = ra_sum_pages(sbi, pages, addr, nrpages); if (!nrpages) return -ENOMEM; - list_for_each_entry_safe(page, tmp, &page_list, lru) { + for (index = 0; index < nrpages; index++) { if (err) goto skip; - lock_page(page); - if (unlikely(!PageUptodate(page))) { + lock_page(pages[index]); + if (unlikely(!PageUptodate(pages[index]))) { err = -EIO; } else { - rn = F2FS_NODE(page); + rn = F2FS_NODE(pages[index]); sum_entry->nid = rn->footer.nid; sum_entry->version = 0; sum_entry->ofs_in_node = 0; sum_entry++; } - unlock_page(page); + unlock_page(pages[index]); skip: - list_del(&page->lru); - __free_pages(page, 0); + page_cache_release(pages[index]); } + + invalidate_mapping_pages(inode->i_mapping, addr, + addr + nrpages); } return err; } -- 1.7.10.4