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); -- 2.24.1
