Re: UBIFS assert failed in ubifs_dirty_inode

Matt Mackall
2010-01-27T02:14:08Z

On Tue, 2010-01-26 at 20:44 -0500, Jeff Angielski wrote:
> Artem Bityutskiy wrote:
> > On Mon, 2010-01-25 at 23:48 -0600, Matt Mackall wrote:
> >> Hmm. I'd just as soon drop it entirely. Here's a patch. Herbert, you
> >> want to send this through your crypto tree?
> >>
> >>
> >> random: drop weird m_time/a_time manipulation
> >>
> >> No other driver does anything remotely like this that I know of except
> >> for the tty drivers, and I can't see any reason for random/urandom to do
> >> it. In fact, it's a (trivial, harmless) timing information leak. And
> >> obviously, it generates power- and flash-cycle wasting I/O, especially
> >> if combined with something like hwrngd. Also, it breaks ubifs's
> >> expectations.
> >>
> >> Signed-off-by: Matt Mackall <mpm@selenic.com>
> >>
> >> diff -r 29db0c391ce8 drivers/char/random.c
> >> --- a/drivers/char/random.c Sun Jan 17 11:01:16 2010 -0800
> >> +++ b/drivers/char/random.c Mon Jan 25 23:32:00 2010 -0600
> >> @@ -1051,12 +1051,6 @@
> >> /* like a named pipe */
> >> }
> >>
> >> - /*
> >> - * If we gave the user some bytes, update the access time.
> >> - */
> >> - if (count)
> >> - file_accessed(file);
> >> -
> >> return (count ? count : retval);
> >> }
> >>
> >> @@ -1116,8 +1110,6 @@
> >> if (ret)
> >> return ret;
> >>
> >> - inode->i_mtime = current_fs_time(inode->i_sb);
> >> - mark_inode_dirty(inode);
> >> return (ssize_t)count;
> >> }
> >
> > It may brake other FSes expectations, theoretically, as well.
> >
> > Anyway, I'm perfectly fine if this is removed.
> >
> > Jeff, could you please try Matt's patch and report back if you still
> > have issues or not. If no, you can use this as a temporary work-around
> > until a proper fix hits upstream or ubifs-2.6.git.
>
> Matt's patch did not compile as written. I tried to implement what I
> think he was trying to do and created this patch (it seems to match the
> guts of what inode_setattr() was looking for):
>
>
> diff --git a/drivers/char/random.c b/drivers/char/random.c
> index 8258982..70f16c7 100644
> --- a/drivers/char/random.c
> +++ b/drivers/char/random.c
> @@ -1108,6 +1108,7 @@ static ssize_t random_write(struct file *file,
> const char __user *buffer,
> {
> size_t ret;
> struct inode *inode = file->f_path.dentry->d_inode;
> + struct iattr attr;
>
> ret = write_pool(&blocking_pool, buffer, count);
> if (ret)
> @@ -1116,8 +1117,12 @@ static ssize_t random_write(struct file *file,
> const char __user *buffer,
> if (ret)
> return ret;
>
> - inode->i_mtime = current_fs_time(inode->i_sb);
> - mark_inode_dirty(inode);
> + attr.ia_mtime = current_fs_time(inode->i_sb);
> + attr.ia_valid = ATTR_MTIME;
> + ret = inode_setattr(inode, &attr);
> + if (ret)
> + return ret;
> +
> return (ssize_t)count;
> }
>
> However, this patch does not fix the problem. I still see the same
> errors. Matt, is this what you were trying to do?

That doesn't look anything like my patch? And mine was test compiled.

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