Re: [PATCH 3/3] reiser4: in our own sync writes, mark pages dirty before marking them writeback.

[Ivan Shapovalov <intelfx100@gmail.com>]

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On 2015-10-14 at 13:55 +0300, Ivan Shapovalov wrote:
> On 2015-10-14 at 13:05 +0300, Ivan Shapovalov wrote:
> > On 2015-10-12 at 11:07 +0200, Edward Shishkin wrote:
> > > [...]
> > 
> > So, I've added three non-fatal checks right before
> > set_page_writeback():
> > - PageDirty(pg)
> > - JF_ISSET(cur, JNODE_DIRTY)
> > - pg->mapping->host->i_wb != NULL
> > 
> > In almost all times when either of the checks is triggered,
> > the first two checks are triggered at once (i. e. neither page nor
> > jnode is dirty, but i_wb is not NULL). This happens with both
> > formatted
> > nodes (jnode_is_znode), unformatted nodes (jnode_is_unformatted)
> > and
> > other nodes.
> > 
> > And, finally, there are very few warnings where jnode _is_ dirty,
> > but
> > the page _isn't_. On the first such warning i_wb is also NULL. And,
> > just as you've suspected, this happens with an unformatted node.
> > 
> > I'll try to add a backtrace buffer into struct jnode and generate a
> > backtrace there on each jnode dirtying attempt... and then print it
> > for
> > the problematic jnode.
> > 
> 
> So, here it is. On all occurrences the backtrace is the same.
>
> [...]


Hmm. This obvious fix "works",  but causes an assertion on rootfs unmount:

"list_empty(&get_super_private(super)->all_jnodes)" in init_super.c:55 (no maintainer-id).

Why?

---
 fs/reiser4/plugin/file/tail_conversion.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/reiser4/plugin/file/tail_conversion.c b/fs/reiser4/plugin/file/tail_conversion.c
index 6ffa900..3b4e77d 100644
--- a/fs/reiser4/plugin/file/tail_conversion.c
+++ b/fs/reiser4/plugin/file/tail_conversion.c
@@ -175,6 +175,7 @@ static int replace(struct inode *inode, struct page **pages, unsigned nr_pages,
 								i_mapping));
 		if (result)
 			break;
+		set_page_dirty_notag(pages[i]);
 		unlock_page(pages[i]);
 		result = find_or_create_extent(pages[i]);
 		if (result) {
-- 
2.6.1

-- 
Ivan Shapovalov / intelfx /


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