This is a note to let you know that I've just added the patch titled fs: record I_DIRTY_TIME even if inode already has I_DIRTY_INODE to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: fs-record-i_dirty_time-even-if-inode-already-has-i_d.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 8139a7d3a79e5c63d33a578821e0cc2785e0d377 Author: Lukas Czerner <lczerner@xxxxxxxxxx> Date: Thu Aug 25 12:06:57 2022 +0200 fs: record I_DIRTY_TIME even if inode already has I_DIRTY_INODE [ Upstream commit cbfecb927f429a6fa613d74b998496bd71e4438a ] Currently the I_DIRTY_TIME will never get set if the inode already has I_DIRTY_INODE with assumption that it supersedes I_DIRTY_TIME. That's true, however ext4 will only update the on-disk inode in ->dirty_inode(), not on actual writeback. As a result if the inode already has I_DIRTY_INODE state by the time we get to __mark_inode_dirty() only with I_DIRTY_TIME, the time was already filled into on-disk inode and will not get updated until the next I_DIRTY_INODE update, which might never come if we crash or get a power failure. The problem can be reproduced on ext4 by running xfstest generic/622 with -o iversion mount option. Fix it by allowing I_DIRTY_TIME to be set even if the inode already has I_DIRTY_INODE. Also make sure that the case is properly handled in writeback_single_inode() as well. Additionally changes in xfs_fs_dirty_inode() was made to accommodate for I_DIRTY_TIME in flag. Thanks Jan Kara for suggestions on how to make this work properly. Cc: Dave Chinner <david@xxxxxxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx> Cc: stable@xxxxxxxxxx Signed-off-by: Lukas Czerner <lczerner@xxxxxxxxxx> Suggested-by: Jan Kara <jack@xxxxxxx> Reviewed-by: Jan Kara <jack@xxxxxxx> Link: https://lore.kernel.org/r/20220825100657.44217-1-lczerner@xxxxxxxxxx Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/Documentation/filesystems/vfs.rst b/Documentation/filesystems/vfs.rst index 287b80948a40..ee69d60818b5 100644 --- a/Documentation/filesystems/vfs.rst +++ b/Documentation/filesystems/vfs.rst @@ -274,6 +274,9 @@ or bottom half). This is specifically for the inode itself being marked dirty, not its data. If the update needs to be persisted by fdatasync(), then I_DIRTY_DATASYNC will be set in the flags argument. + I_DIRTY_TIME will be set in the flags in case lazytime is enabled + and struct inode has times updated since the last ->dirty_inode + call. ``write_inode`` this method is called when the VFS needs to write an inode to diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 4c667662a4d9..f47797e15685 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -1618,9 +1618,14 @@ static int writeback_single_inode(struct inode *inode, */ if (!(inode->i_state & I_DIRTY_ALL)) inode_cgwb_move_to_attached(inode, wb); - else if (!(inode->i_state & I_SYNC_QUEUED) && - (inode->i_state & I_DIRTY)) - redirty_tail_locked(inode, wb); + else if (!(inode->i_state & I_SYNC_QUEUED)) { + if ((inode->i_state & I_DIRTY)) + redirty_tail_locked(inode, wb); + else if (inode->i_state & I_DIRTY_TIME) { + inode->dirtied_when = jiffies; + inode_io_list_move_locked(inode, wb, &wb->b_dirty_time); + } + } spin_unlock(&wb->list_lock); inode_sync_complete(inode); @@ -2276,6 +2281,20 @@ void __mark_inode_dirty(struct inode *inode, int flags) trace_writeback_mark_inode_dirty(inode, flags); if (flags & I_DIRTY_INODE) { + /* + * Inode timestamp update will piggback on this dirtying. + * We tell ->dirty_inode callback that timestamps need to + * be updated by setting I_DIRTY_TIME in flags. + */ + if (inode->i_state & I_DIRTY_TIME) { + spin_lock(&inode->i_lock); + if (inode->i_state & I_DIRTY_TIME) { + inode->i_state &= ~I_DIRTY_TIME; + flags |= I_DIRTY_TIME; + } + spin_unlock(&inode->i_lock); + } + /* * Notify the filesystem about the inode being dirtied, so that * (if needed) it can update on-disk fields and journal the @@ -2285,7 +2304,8 @@ void __mark_inode_dirty(struct inode *inode, int flags) */ trace_writeback_dirty_inode_start(inode, flags); if (sb->s_op->dirty_inode) - sb->s_op->dirty_inode(inode, flags & I_DIRTY_INODE); + sb->s_op->dirty_inode(inode, + flags & (I_DIRTY_INODE | I_DIRTY_TIME)); trace_writeback_dirty_inode(inode, flags); /* I_DIRTY_INODE supersedes I_DIRTY_TIME. */ @@ -2306,21 +2326,15 @@ void __mark_inode_dirty(struct inode *inode, int flags) */ smp_mb(); - if (((inode->i_state & flags) == flags) || - (dirtytime && (inode->i_state & I_DIRTY_INODE))) + if ((inode->i_state & flags) == flags) return; spin_lock(&inode->i_lock); - if (dirtytime && (inode->i_state & I_DIRTY_INODE)) - goto out_unlock_inode; if ((inode->i_state & flags) != flags) { const int was_dirty = inode->i_state & I_DIRTY; inode_attach_wb(inode, NULL); - /* I_DIRTY_INODE supersedes I_DIRTY_TIME. */ - if (flags & I_DIRTY_INODE) - inode->i_state &= ~I_DIRTY_TIME; inode->i_state |= flags; /* @@ -2393,7 +2407,6 @@ void __mark_inode_dirty(struct inode *inode, int flags) out_unlock: if (wb) spin_unlock(&wb->list_lock); -out_unlock_inode: spin_unlock(&inode->i_lock); } EXPORT_SYMBOL(__mark_inode_dirty); diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index 434c87cc9fbf..3cc20640b3da 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -668,7 +668,7 @@ xfs_fs_destroy_inode( static void xfs_fs_dirty_inode( struct inode *inode, - int flag) + int flags) { struct xfs_inode *ip = XFS_I(inode); struct xfs_mount *mp = ip->i_mount; @@ -676,7 +676,13 @@ xfs_fs_dirty_inode( if (!(inode->i_sb->s_flags & SB_LAZYTIME)) return; - if (flag != I_DIRTY_SYNC || !(inode->i_state & I_DIRTY_TIME)) + + /* + * Only do the timestamp update if the inode is dirty (I_DIRTY_SYNC) + * and has dirty timestamp (I_DIRTY_TIME). I_DIRTY_TIME can be passed + * in flags possibly together with I_DIRTY_SYNC. + */ + if ((flags & ~I_DIRTY_TIME) != I_DIRTY_SYNC || !(flags & I_DIRTY_TIME)) return; if (xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, 0, &tp)) diff --git a/include/linux/fs.h b/include/linux/fs.h index 8ee26322a527..ae7cd6ee1142 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2104,13 +2104,14 @@ static inline void kiocb_clone(struct kiocb *kiocb, struct kiocb *kiocb_src, * don't have to write inode on fdatasync() when only * e.g. the timestamps have changed. * I_DIRTY_PAGES Inode has dirty pages. Inode itself may be clean. - * I_DIRTY_TIME The inode itself only has dirty timestamps, and the + * I_DIRTY_TIME The inode itself has dirty timestamps, and the * lazytime mount option is enabled. We keep track of this * separately from I_DIRTY_SYNC in order to implement * lazytime. This gets cleared if I_DIRTY_INODE - * (I_DIRTY_SYNC and/or I_DIRTY_DATASYNC) gets set. I.e. - * either I_DIRTY_TIME *or* I_DIRTY_INODE can be set in - * i_state, but not both. I_DIRTY_PAGES may still be set. + * (I_DIRTY_SYNC and/or I_DIRTY_DATASYNC) gets set. But + * I_DIRTY_TIME can still be set if I_DIRTY_SYNC is already + * in place because writeback might already be in progress + * and we don't want to lose the time update * I_NEW Serves as both a mutex and completion notification. * New inodes set I_NEW. If two processes both create * the same inode, one of them will release its inode and