From: Chao Yu <yuchao0@xxxxxxxxxx> [ Upstream commit fe1897eaa6646f5a64a4cee0e6473ed9887d324b ] generic/018 reports an inconsistent status of atime, the testcase is as below: - open file with O_SYNC - write file to construct fraged space - calc md5 of file - record {a,c,m}time - defrag file --- do nothing - umount & mount - check {a,c,m}time The root cause is, as f2fs enables lazytime by default, atime update will dirty vfs inode, rather than dirtying f2fs inode (by set with FI_DIRTY_INODE), so later f2fs_write_inode() called from VFS will fail to update inode page due to our skip: f2fs_write_inode() if (is_inode_flag_set(inode, FI_DIRTY_INODE)) return 0; So eventually, after evict(), we lose last atime for ever. To fix this issue, we need to check whether {a,c,m,cr}time is consistent in between inode cache and inode page, and only skip f2fs_update_inode() if f2fs inode is not dirty and time is consistent as well. Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- fs/f2fs/f2fs.h | 23 +++++++++++++++-------- fs/f2fs/inode.c | 6 +++++- 2 files changed, 20 insertions(+), 9 deletions(-) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 34e48bcf5087..72d154e71bb5 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -2578,6 +2578,20 @@ static inline void clear_file(struct inode *inode, int type) f2fs_mark_inode_dirty_sync(inode, true); } +static inline bool f2fs_is_time_consistent(struct inode *inode) +{ + if (!timespec64_equal(F2FS_I(inode)->i_disk_time, &inode->i_atime)) + return false; + if (!timespec64_equal(F2FS_I(inode)->i_disk_time + 1, &inode->i_ctime)) + return false; + if (!timespec64_equal(F2FS_I(inode)->i_disk_time + 2, &inode->i_mtime)) + return false; + if (!timespec64_equal(F2FS_I(inode)->i_disk_time + 3, + &F2FS_I(inode)->i_crtime)) + return false; + return true; +} + static inline bool f2fs_skip_inode_update(struct inode *inode, int dsync) { bool ret; @@ -2595,14 +2609,7 @@ static inline bool f2fs_skip_inode_update(struct inode *inode, int dsync) i_size_read(inode) & ~PAGE_MASK) return false; - if (!timespec64_equal(F2FS_I(inode)->i_disk_time, &inode->i_atime)) - return false; - if (!timespec64_equal(F2FS_I(inode)->i_disk_time + 1, &inode->i_ctime)) - return false; - if (!timespec64_equal(F2FS_I(inode)->i_disk_time + 2, &inode->i_mtime)) - return false; - if (!timespec64_equal(F2FS_I(inode)->i_disk_time + 3, - &F2FS_I(inode)->i_crtime)) + if (!f2fs_is_time_consistent(inode)) return false; down_read(&F2FS_I(inode)->i_sem); diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c index 540d45759621..a01be7d8db86 100644 --- a/fs/f2fs/inode.c +++ b/fs/f2fs/inode.c @@ -614,7 +614,11 @@ int f2fs_write_inode(struct inode *inode, struct writeback_control *wbc) inode->i_ino == F2FS_META_INO(sbi)) return 0; - if (!is_inode_flag_set(inode, FI_DIRTY_INODE)) + /* + * atime could be updated without dirtying f2fs inode in lazytime mode + */ + if (f2fs_is_time_consistent(inode) && + !is_inode_flag_set(inode, FI_DIRTY_INODE)) return 0; /* -- 2.20.1