Re: [PATCH v2 16/16] xfs: add pre-content fsnotify hook for write faults

Josef Bacik
2024-08-09T14:15:50Z

On Fri, Aug 09, 2024 at 08:03:41AM +1000, Dave Chinner wrote:
> On Thu, Aug 08, 2024 at 03:27:18PM -0400, Josef Bacik wrote:
> > xfs has it's own handling for write faults, so we need to add the
> > pre-content fsnotify hook for this case. Reads go through filemap_fault
> > so they're handled properly there.
> >
> > Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> > ---
> > fs/xfs/xfs_file.c | 20 +++++++++++++++++---
> > 1 file changed, 17 insertions(+), 3 deletions(-)
> >
> > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> > index 4cdc54dc9686..585a8c2eea0f 100644
> > --- a/fs/xfs/xfs_file.c
> > +++ b/fs/xfs/xfs_file.c
> > @@ -1325,14 +1325,28 @@ __xfs_filemap_fault(
> > bool write_fault)
> > {
> > struct inode *inode = file_inode(vmf->vma->vm_file);
> > + struct file *fpin = NULL;
> > + vm_fault_t ret;
> >
> > trace_xfs_filemap_fault(XFS_I(inode), order, write_fault);
> >
> > - if (write_fault)
> > - return xfs_write_fault(vmf, order);
> > if (IS_DAX(inode))
> > return xfs_dax_read_fault(vmf, order);
> > - return filemap_fault(vmf);
> > +
> > + if (!write_fault)
> > + return filemap_fault(vmf);
>
> Doesn't this break DAX read faults? i.e. they have to go through
> xfs_dax_read_fault(), not filemap_fault().

Oops my bad, I had it right before then decided to make it cleaner and forgot
what the original code was doing, I'll fix it up, thanks!

Josef