Re: [-mm patch] do_revoke error handling (was Re: 2.6.21-mm1)

Frederik Deweerdt
2007-05-05T21:48:57Z

On Sun, May 06, 2007 at 12:23:15AM +0300, Pekka J Enberg wrote:
> On Sat, May 05, 2007 at 01:49:55AM -0700, Andrew Morton wrote:
> > >
> > > ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.21/2.6.21-mm1/
> > >
> > fs/revoke.c: In function 'do_revoke':
> > fs/revoke.c:563: warning: 'details.fset' may be used uninitialized in this function
> > fs/revoke.c:563: warning: 'details.restore_start' may be used uninitialized in this function
>
> On Sat, 5 May 2007, Frederik Deweerdt wrote:
> > It seems that we should goto 'out_free_table' if an error happens in
> > the mainloop. Otherwise 'details' is passed to restore_files() without
> > being initialized.
>
> Good catch. The patch is wrong, though. Wwe must restore the file
> descriptors in case revoke fails; otherwise we'll leave non-revoked files
> hanging. The proper fix is to move initialization before the
> do_each_thread() bit. Care to make a new patch, Frederik?
>
OK, thanks for the explanation. Here it is.
Frederik

Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com>

diff --git a/fs/revoke.c b/fs/revoke.c
index 1f2e3ef..86a2842 100644
--- a/fs/revoke.c
+++ b/fs/revoke.c
@@ -597,6 +597,9 @@ static int do_revoke(struct inode *inode, struct file *to_exclude)
goto retry;
}

+ details.fset = fset;
+ details.restore_start = 0;
+
/*
* First revoke the descriptors. After we are done, no one can start
* new operations on them.
@@ -625,9 +628,6 @@ static int do_revoke(struct inode *inode, struct file *to_exclude)
if (err)
goto out_restore;

- details.fset = fset;
- details.restore_start = 0;
-
/*
* Now, revoke the files for good.
*/