Re: The bug of iput() removal from flusher thread?

From: OGAWA Hirofumi
Date: Mon Nov 19 2012 - 03:56:21 EST


OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx> writes:

> Hi,
>
> In 169ebd90131b2ffca74bb2dbe7eeacd39fb83714 commit, writeback doesn't
> __iget()/iput() anymore.
>
> This means nobody moves the inode to lru list. I.e.
>
> new_inode()
> dirty_inode()
> iput_final()
> /* keep inode without adding lru */
> flush indoes
> /* clean inode is not on lru */
>
> I noticed this situation in my FS though, I think the same bug is on all
> FSes of linus tree too, after this commit.
>
> Am I missing the something?

This seems to be reproducible by the following,

#!/bin/sh

for i in $(seq -w 1000); do
for j in $(seq -w 1000); do
for k in $(seq -w 1000); do
mkdir -p $i/$j
echo $i/$j/$k > $i/$j/$k
echo 2 > /proc/sys/vm/drop_caches
done
done
done

Some inodes never be reclaimed, and ls -l frees those inodes (stat(2)
does iget/iput).
--
OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/