From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751992AbaEWFPs (ORCPT ); Fri, 23 May 2014 01:15:48 -0400 Received: from mailout1.samsung.com ([203.254.224.24]:15348 "EHLO mailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750961AbaEWFPq (ORCPT ); Fri, 23 May 2014 01:15:46 -0400 MIME-version: 1.0 Content-disposition: inline Content-type: text/plain; charset=utf-8 X-AuditID: cbfee68f-b7fef6d000003970-bd-537ed97bd071 Content-transfer-encoding: 8BIT Date: Fri, 23 May 2014 14:14:13 +0900 From: Changman Lee To: Jaegeuk Kim Cc: Chao Yu , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Subject: Re: [f2fs-dev] [PATCH] f2fs: avoid crash when trace f2fs_submit_page_mbio event in ra_sum_pages Message-id: <20140523051413.GB26933@cm224.lee> References: <005801cf70e7$66cb0090$346101b0$@samsung.com> <1400643406.12240.6.camel@kjgkr> In-reply-to: <1400643406.12240.6.camel@kjgkr> User-Agent: Mutt/1.5.21 (2010-09-15) X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrAIsWRmVeSWpSXmKPExsVy+t8zI93qm3XBBpd/mVn8b/rIZvFk/Sxm i0uL3C327D3JYnF51xw2B1aPTas62Tx2L/jM5NG3ZRWjx+dNcgEsUVw2Kak5mWWpRfp2CVwZ R2a/ZS5YYFSxed58lgbGfepdjJwcEgImEsv6fzFD2GISF+6tZ+ti5OIQEljGKLHwwT/WLkYO sKIPM7JAaoQEFjFK9F9WA7F5BQQlfky+xwJSwiwgL3HkUjZImFlAWuLR3xnsEGF1iSlTciE6 fzJKXFnpBWKzCKhKrFl1igXEZhPQkmg/vRbMFhFQkTi06DI7xJhORomGj3ogtrBAlsT+RY8Y IbbqSew+8Z8JYmaMxL8/V8Gu5xTQlfh/fRdYryjQnCknt4F9IiFwiF3iRetEJojFAhLfJh9i gfhKVmLTAajPJSUOrrjBMoFRfBaSx2YhPDYLyWOzEB5bwMiyilE0tSC5oDgpvchYrzgxt7g0 L10vOT93EyMk9vp3MN49YH2IMRlo+URmKdHkfGDs5pXEGxqbGVmYmpgaG5lbmpEmrCTOe/9h UpCQQHpiSWp2ampBalF8UWlOavEhRiYOTqkGxlXhzBm90VEKqy5WKids6FZdtP/Bq1ktLlHx f4W0f3+ZuOF42qu4FbcMnVb6nlLimfertbYhct7+E07/d3r965ayDmN9m7zqwhf9f28nXI8o us/2Iv7+oUavC1frzts++PvkyBPzhjsKZfwzOy0u2/tfjwyoYfaZ+DC7zH6ncV3GtJXLpTJ/ VCuxFGckGmoxFxUnAgCJtcrw0wIAAA== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprLKsWRmVeSWpSXmKPExsVy+t9jAd3qm3XBBh+nGln8b/rIZvFk/Sxm i0uL3C327D3JYnF51xw2B1aPTas62Tx2L/jM5NG3ZRWjx+dNcgEsUQ2MNhmpiSmpRQqpecn5 KZl56bZK3sHxzvGmZgaGuoaWFuZKCnmJuam2Si4+AbpumTlAe5UUyhJzSoFCAYnFxUr6dpgm hIa46VrANEbo+oYEwfUYGaCBhHWMGUdmv2UuWGBUsXnefJYGxn3qXYwcHBICJhIfZmR1MXIC mWISF+6tZwOxhQQWMUr0X1YDsXkFBCV+TL7HAlLOLCAvceRSNkiYWUBa4tHfGewQYXWJKVNy ITp/MkpcWekFYrMIqEqsWXWKBcRmE9CSaD+9FswWEVCROLToMjvEmE5GiYaPeiC2sECWxP5F jxghtupJ7D7xnwliZozEvz9XmUFsTgFdif/Xd4H1igLNmXJyG9sERsFZSA6dhXDoLCSHzkI4 dAEjyypG0dSC5ILipPRcI73ixNzi0rx0veT83E2M4Mh+Jr2DcVWDxSFGAQ5GJR7eB0x1wUKs iWXFlbmHGCU4mJVEeG9cAQrxpiRWVqUW5ccXleakFh9iTAb6eSKzlGhyPjDp5JXEGxqbmBlZ GplZGJmYm5MmrCTOe7DVOlBIID2xJDU7NbUgtQhmCxMHp1QDY7nAxO1iD4s8rRawPFp0w176 dsbcizP8lrd+fPt/y6M7swrvJTyu2hEgHu5eECDS8DGibe6uDAYZV57WzfLNuavm8zQ4TTlr vH3zZg426wedQl91dI89ve7+IeznE8V9m8vlvdjEA69aGHCXBTZM1OlI2PHbxNdJiMOcPbZF 6PKtdP/L+9TeKbEUZyQaajEXFScCAJbcoVAwAwAA DLP-Filter: Pass X-MTR: 20000000000000000@CPGS X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 21, 2014 at 12:36:46PM +0900, Jaegeuk Kim wrote: > Hi Chao, > > 2014-05-16 (금), 17:14 +0800, Chao Yu: > > 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; How about use sbi->meta_inode instead of bd_inode, then we can do caching summary pages for further i/o. > > + 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); > > IMO, we don't need to do like this. > Instead, > for() { > page = grab_cache_page(); > if (!page) > break; > page[page_idx] = page; > f2fs_submit_page_mbio(sbi, page, &fio); > } > f2fs_submit_merged_bio(sbi, META, READ); > return page_idx - start; > > Afterwards, in restore_node_summry(), > lock_page() will wait the end_io for read. > ... > f2fs_put_page(pages[index], 1); > > Thanks, > > > } > > > > - 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; > > } > > -- > Jaegeuk Kim > ------------------------------------------------------------------------------ > "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE > Instantly run your Selenium tests across 300+ browser/OS combos. > Get unparalleled scalability from the best Selenium testing platform available > Simple to use. Nothing to install. Get started now for free." > http://p.sf.net/sfu/SauceLabs > _______________________________________________ > Linux-f2fs-devel mailing list > Linux-f2fs-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel