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
