From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chao Yu Subject: [f2fs-dev][PATCH] f2fs: fix to release count of meta page in ->invalidatepage Date: Mon, 19 Jan 2015 20:12:26 +0800 Message-ID: <007601d033e1$653f74a0$2fbe5de0$@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Content-language: zh-cn Sender: linux-kernel-owner@vger.kernel.org To: Jaegeuk Kim , Changman Lee Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org List-Id: linux-f2fs-devel.lists.sourceforge.net We will encounter deadloop in below scenario: 1. increase page count for F2FS_DIRTY_META type in following path: ->recover_fsync_data ->recover_data ->do_recover_data ->recover_data_page ->change_curseg ->write_sum_page ->set_page_dirty 2. fail in recover_data() 3. invalidate meta pages in truncate_inode_pages_final without decreasing page count. 4. deadloop when sync_meta_pages as page count will always be non-zero. message: NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [] pagevec_lookup_tag+0x27/0x30 [] sync_meta_pages+0x87/0x160 [f2fs] [] recover_fsync_data+0xeb9/0xf10 [f2fs] [] f2fs_fill_super+0x888/0x980 [f2fs] [] mount_bdev+0x16a/0x1a0 [] f2fs_mount+0x1f/0x30 [f2fs] [] mount_fs+0x36/0x170 [] vfs_kern_mount+0x55/0xe0 [] do_mount+0x1df/0x9f0 [] SyS_mount+0x70/0xb0 [] sysenter_do_call+0x12/0x12 To avoid page count leak, let's add ->invalidatepage and ->releasepage in f2fs_meta_aops as f2fs_node_aops to release meta page count correctly. Signed-off-by: Chao Yu --- fs/f2fs/checkpoint.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c index 9f5317c..51ec97c 100644 --- a/fs/f2fs/checkpoint.c +++ b/fs/f2fs/checkpoint.c @@ -302,16 +302,35 @@ static int f2fs_set_meta_page_dirty(struct page *page) if (!PageDirty(page)) { __set_page_dirty_nobuffers(page); inc_page_count(F2FS_P_SB(page), F2FS_DIRTY_META); + SetPagePrivate(page); f2fs_trace_pid(page); return 1; } return 0; } +static void f2fs_invalidate_meta_page(struct page *page, unsigned int offset, + unsigned int length) +{ + struct inode *inode = page->mapping->host; + get_pages(F2FS_I_SB(inode), F2FS_DIRTY_META)); + if (PageDirty(page)) + dec_page_count(F2FS_I_SB(inode), F2FS_DIRTY_META); + ClearPagePrivate(page); +} + +static int f2fs_release_meta_page(struct page *page, gfp_t wait) +{ + ClearPagePrivate(page); + return 1; +} + const struct address_space_operations f2fs_meta_aops = { .writepage = f2fs_write_meta_page, .writepages = f2fs_write_meta_pages, .set_page_dirty = f2fs_set_meta_page_dirty, + .invalidatepage = f2fs_invalidate_meta_page, + .releasepage = f2fs_release_meta_page, }; static void __add_ino_entry(struct f2fs_sb_info *sbi, nid_t ino, int type) -- 2.2.1