Re: [PATCH v2 3/5] fs: change write_begin/write_end interface to take struct kiocb *

[Chen Taotao]

在 2025/6/25 16:04, Christian Brauner 写道:
> On Tue, Jun 24, 2025 at 01:51:51PM +0100, Matthew Wilcox wrote:
> > On Tue, Jun 24, 2025 at 12:12:08PM +0000, 陈涛涛 Taotao Chen wrote:
> > > -static int blkdev_write_end(struct file *file, struct address_space *mapping,
> > > +static int blkdev_write_end(struct kiocb *iocb, struct address_space *mapping,
> > >   		loff_t pos, unsigned len, unsigned copied, struct folio *folio,
> > >   		void *fsdata)
> > >   {
> > >   	int ret;
> > > -	ret = block_write_end(file, mapping, pos, len, copied, folio, fsdata);
> > > +	ret = block_write_end(iocb->ki_filp, mapping, pos, len, copied, folio, fsdata);
> > ... huh.  I thought block_write_end() had to have the same prototype as
> > ->write_end because it was used by some filesystems as the ->write_end.
> > I see that's not true (any more?).  Maybe I was confused with
> > generic_write_end().  Anyway, block_write_end() doesn't use it's file
> > argument, and never will, so we can just remove it.
> >
> > > +++ b/include/linux/fs.h
> > > @@ -446,10 +446,10 @@ struct address_space_operations {
> > >   
> > >   	void (*readahead)(struct readahead_control *);
> > >   
> > > -	int (*write_begin)(struct file *, struct address_space *mapping,
> > > +	int (*write_begin)(struct kiocb *, struct address_space *mapping,
> > >   				loff_t pos, unsigned len,
> > >   				struct folio **foliop, void **fsdata);
> > > -	int (*write_end)(struct file *, struct address_space *mapping,
> > > +	int (*write_end)(struct kiocb *, struct address_space *mapping,
> > >   				loff_t pos, unsigned len, unsigned copied,
> > >   				struct folio *folio, void *fsdata);
> > Should we make this a 'const struct kiocb *'?  I don't see a need for
> > filesystems to be allowed to modify the kiocb in future, but perhaps
> > other people have different opinions.
> Given I picked up Willy's change I'll wait for a resubmit of this series
> on top of vfs-6.17.misc unless I hear otherwise?
Sure, I’ll update the series on top of vfs-6.17.misc and resend it as 
soon as possible.

Best regards,
Taotao Chen