Re: Increase in XFS journal flushes with (direct_write;fdatasync)+

[Pankaj Raghav <pankaj.raghav@linux.dev>]

On 5/8/26 10:10, Christoph Hellwig wrote:
> On Thu, May 07, 2026 at 10:34:43PM +0200, Pankaj Raghav (Samsung) wrote:
>> This fix seems to reduce the number flush calls and fix the regression.
>> @carlos and @hch let me know if this is the correct fix or I am just
>> suppressing the symptom and not fixing the root cause.
> 
> This looks good from a very quick look.  It'll need testing, a line
> length fix and preferably a comment as a reminder and should be good
> to go.
> 

What about this:

diff --git a/fs/inode.c b/fs/inode.c
index 6a3cbc7dcd28..1b373fe1100d 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -2124,7 +2124,12 @@ static int inode_update_cmtime(struct inode *inode, unsigned int flags)
                            inode_iversion_need_inc(inode))
                                return -EAGAIN;
                } else {
-                       if (inode_maybe_inc_iversion(inode, !!dirty))
+                       /*
+                        * Don't force iversion increment for pure lazytime
+                        * updates (when dirty is set to I_DIRTY_TIME only).
+                        */
+                       if (inode_maybe_inc_iversion(inode,
+                                                    dirty != I_DIRTY_TIME))
                                dirty |= I_DIRTY_SYNC;
                }
        }

If you are tests are passing, then I can send a fix as a separate patch.

--
Pankaj