Re: [PATCH] ext2: Update also inode on disk when dir is IS_DIRSYNC

From: Jan Kara
Date: Wed Jan 14 2009 - 10:13:33 EST


On Tue 13-01-09 15:17:16, Andrew Morton wrote:
> On Tue, 13 Jan 2009 13:42:02 +0100
> Jan Kara <jack@xxxxxxx> wrote:
>
> > We used to just write changed page for IS_DIRSYNC inodes. But we also have to
> > update directory inode itself just for the case that we've allocated a new
> > block and changed i_size.
> >
> > Signed-off-by: Jan Kara <jack@xxxxxxx>
> > CC: Pavel Machek <pavel@xxxxxxx>
> > ---
> > fs/ext2/dir.c | 5 ++---
> > 1 files changed, 2 insertions(+), 3 deletions(-)
> >
> > Andrew, would you please merge the patch? Ext3 and ext4 don't have this
> > problem BTW.
> >
> > diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
> > index 9a0fc40..7fba549 100644
> > --- a/fs/ext2/dir.c
> > +++ b/fs/ext2/dir.c
> > @@ -94,11 +94,10 @@ static int ext2_commit_chunk(struct page *page, loff_t pos, unsigned len)
> > i_size_write(dir, pos+len);
> > mark_inode_dirty(dir);
> > }
> > + unlock_page(page);
> >
> > if (IS_DIRSYNC(dir))
> > - err = write_one_page(page, 1);
> > - else
> > - unlock_page(page);
> > + err = ext2_sync_inode(dir);
> >
>
> But with this change we no longer sync the data page? Don't we need
> something like this:
Oh, correct, we do. I was confused by sync_inode() calling fdatawrite()
but did not realize that the way ext2_sync_inode() calls it has start ==
end == 0. Thanks for spotting this.

> static int ext2_commit_chunk(struct page *page, loff_t pos, unsigned len)
> {
> struct address_space *mapping = page->mapping;
> struct inode *dir = mapping->host;
> int err = 0;
>
> dir->i_version++;
> block_write_end(NULL, mapping, pos, len, len, page, NULL);
>
> if (pos+len > dir->i_size) {
> i_size_write(dir, pos+len);
> mark_inode_dirty(dir);
> }
>
> if (IS_DIRSYNC(dir)) {
> err = write_one_page(page, 1);
> if (err == 0)
> err = ext2_sync_inode(dir);
> } else {
> unlock_page(page);
> }
>
> return err;
> }
>
> ?
Yes, I'll send you a new version of the patch and also send refreshed
second patch with blkdev_issue_flush() calls.

Honza
--
Jan Kara <jack@xxxxxxx>
SUSE Labs, CR
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