From bac4eef6537a663585f3fb3d633a629c72e3b73d Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Tue, 27 May 2014 08:41:07 +0800 Subject: [PATCH] f2fs: avoid crash when trace f2fs_submit_page_mbio event in ra_sum_pages 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. Changes from V1 o remove redundant code in ra_sum_pages() suggested by Jaegeuk Kim. 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 Suggested-by: Jaegeuk Kim Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/node.c | 52 +++++++++++++++++++++++--------------------------- 1 file changed, 24 insertions(+), 28 deletions(-) diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 3d60d3d34ed2..02a59e9027b1 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -1658,35 +1658,29 @@ 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; - int page_idx = start; + struct inode *inode = sbi->sb->s_bdev->bd_inode; + struct address_space *mapping = inode->i_mapping; + int i, page_idx = start; struct f2fs_io_info fio = { .type = META, .rw = READ_SYNC | REQ_META | REQ_PRIO }; - for (; page_idx < start + nrpages; page_idx++) { - /* alloc temporal page for read node summary info*/ - page = alloc_page(GFP_F2FS_ZERO); - if (!page) + for (i = 0; page_idx < start + nrpages; page_idx++, i++) { + /* alloc page in bd_inode for reading node summary info */ + pages[i] = grab_cache_page(mapping, page_idx); + if (!pages[i]) break; - - lock_page(page); - page->index = page_idx; - list_add_tail(&page->lru, pages); + f2fs_submit_page_mbio(sbi, pages[i], page_idx, &fio); } - list_for_each_entry(page, pages, lru) - f2fs_submit_page_mbio(sbi, page, page->index, &fio); - f2fs_submit_merged_bio(sbi, META, READ); - - return page_idx - start; + return i; } int restore_node_summary(struct f2fs_sb_info *sbi, @@ -1694,11 +1688,11 @@ 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, idx, last_offset, nrpages, err = 0; /* scan the node segment */ last_offset = sbi->blocks_per_seg; @@ -1709,29 +1703,31 @@ 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 (idx = 0; idx < nrpages; idx++) { if (err) goto skip; - lock_page(page); - if (unlikely(!PageUptodate(page))) { + lock_page(pages[idx]); + if (unlikely(!PageUptodate(pages[idx]))) { err = -EIO; } else { - rn = F2FS_NODE(page); + rn = F2FS_NODE(pages[idx]); sum_entry->nid = rn->footer.nid; sum_entry->version = 0; sum_entry->ofs_in_node = 0; sum_entry++; } - unlock_page(page); + unlock_page(pages[idx]); skip: - list_del(&page->lru); - __free_pages(page, 0); + page_cache_release(pages[idx]); } + + invalidate_mapping_pages(inode->i_mapping, addr, + addr + nrpages); } return err; } -- 2.20.1