On Fri, Mar 06, 2020 at 09:00:43PM -0500, Theodore Ts'o wrote: > In the case that an inode has dirty timestamp for longer than the > lazytime expiration timeout (or if all such inodes are being flushed > out due to a sync or syncfs system call), we need to inform the file > system that the inode is dirty so that the inode's timestamps can be > copied out to the on-disk data structures. That's because if the file > system supports lazytime, it will have ignored the dirty_inode(inode, > I_DIRTY_TIME) notification when the timestamp was modified in memory.q > > Previously, this was accomplished by calling mark_inode_dirty_sync(), > but that has the unfortunate side effect of also putting the inode the > writeback list, and that's not necessary in this case, since we will > immediately call write_inode() afterwards. > > Eric Biggers noticed that this was causing problems for fscrypt after > the key was removed[1]. > > [1] https://lore.kernel.org/r/20200306004555.GB225345@xxxxxxxxx > > Reported-by: Eric Biggers <ebiggers@xxxxxxxxxx> > Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> > --- > fs/fs-writeback.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c > index 76ac9c7d32ec..32101349ba97 100644 > --- a/fs/fs-writeback.c > +++ b/fs/fs-writeback.c > @@ -1504,8 +1504,9 @@ __writeback_single_inode(struct inode *inode, struct writeback_control *wbc) > > spin_unlock(&inode->i_lock); > > - if (dirty & I_DIRTY_TIME) > - mark_inode_dirty_sync(inode); > + /* This was a lazytime expiration; we need to tell the file system */ > + if (dirty & I_DIRTY_TIME_EXPIRED && inode->i_sb->s_op->dirty_inode) > + inode->i_sb->s_op->dirty_inode(inode, I_DIRTY_TIME_EXPIRED); > /* Don't write the inode if only I_DIRTY_PAGES was set */ > if (dirty & ~I_DIRTY_PAGES) { > int err = write_inode(inode, wbc); > -- Thanks Ted! This fixes the fscrypt test failure. However, are you sure this works correctly on all filesystems? I'm not sure about XFS. XFS only implements ->dirty_inode(), not ->write_inode(), and in its ->dirty_inode() it does: static void xfs_fs_dirty_inode( struct inode *inode, int flag) { struct xfs_inode *ip = XFS_I(inode); struct xfs_mount *mp = ip->i_mount; struct xfs_trans *tp; if (!(inode->i_sb->s_flags & SB_LAZYTIME)) return; if (flag != I_DIRTY_SYNC || !(inode->i_state & I_DIRTY_TIME)) return; if (xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, 0, &tp)) return; xfs_ilock(ip, XFS_ILOCK_EXCL); xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL); xfs_trans_log_inode(tp, ip, XFS_ILOG_TIMESTAMP); xfs_trans_commit(tp); } So flag=I_DIRTY_TIME_EXPIRED will be a no-op. Maybe you should be using I_DIRTY_SYNC instead? Or perhaps XFS should be checking for either I_DIRTY_TIME_EXPIRED or I_DIRTY_SYNC? - Eric
