Re: [PATCH v4 16/16] xfs: add pre-content fsnotify hook for write faults

Darrick J. Wong
2024-08-30T23:28:34Z

On Thu, Aug 29, 2024 at 01:17:53PM +0200, Jan Kara wrote:
> On Wed 14-08-24 17:25:34, 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>
>
> Looks good to me but it would be great to get explicit ack from some XFS
> guy... Some selection CCed :)

Looks decent to me, but I wonder why xfs_write_fault has to invoke
filemap_maybe_emit_fsnotify_event itself? Can that be done from
whatever calls ->page_mkwrite and friends?

--D

>
> Honza
>
> > ---
> > fs/xfs/xfs_file.c | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> > index 4cdc54dc9686..e61c4c389d7d 100644
> > --- a/fs/xfs/xfs_file.c
> > +++ b/fs/xfs/xfs_file.c
> > @@ -1283,6 +1283,10 @@ xfs_write_fault(
> > unsigned int lock_mode = XFS_MMAPLOCK_SHARED;
> > vm_fault_t ret;
> >
> > + ret = filemap_maybe_emit_fsnotify_event(vmf);
> > + if (unlikely(ret))
> > + return ret;
> > +
> > sb_start_pagefault(inode->i_sb);
> > file_update_time(vmf->vma->vm_file);
> >
> > --
> > 2.43.0
> >
> --
> Jan Kara <jack@suse.com>
> SUSE Labs, CR
>