[PATCH] ext4: change variable "count" to signed integer

[PATCH] ext4: change variable "count" to signed integer

[Ding Xiang]

Since dx_make_map() may return -EFSCORRUPTED now,
so change "count" to signed integer.

Signed-off-by: Ding Xiang <dingxiang@cmss.chinamobile.com>
---
 fs/ext4/namei.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 47d0ca4c795b..db4ba99d1ceb 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1929,7 +1929,8 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
 			struct dx_hash_info *hinfo)
 {
 	unsigned blocksize = dir->i_sb->s_blocksize;
-	unsigned count, continued;
+	unsigned continued;
+	int count;
 	struct buffer_head *bh2;
 	ext4_lblk_t newblock;
 	u32 hash2;
-- 
2.31.1

Re: [PATCH] ext4: change variable "count" to signed integer

[Theodore Ts'o]

On Mon, 30 May 2022 18:00:47 +0800, Ding Xiang wrote:
> Since dx_make_map() may return -EFSCORRUPTED now,
> so change "count" to signed integer.
> 
> 

Applied, thanks!

[1/1] ext4: change variable "count" to signed integer
      commit: fefb759df063599ad483422eb07ef8e14c612cc2

Best regards,
-- 
Theodore Ts'o <tytso@mit.edu>

Re: [PATCH] ext4: change variable "count" to signed integer

[Dan Carpenter]

On Fri, Jun 17, 2022 at 10:59:01PM -0400, Theodore Ts'o wrote:
> On Mon, 30 May 2022 18:00:47 +0800, Ding Xiang wrote:
> > Since dx_make_map() may return -EFSCORRUPTED now,
> > so change "count" to signed integer.
> > 
> > 
> 
> Applied, thanks!
> 
> [1/1] ext4: change variable "count" to signed integer
>       commit: fefb759df063599ad483422eb07ef8e14c612cc2
> 

There was some kind of process error here...

1) That commit somehow never made it to linux-next.

2) No Fixes tag.  Presumably Greg searches for Fixes tags before he back
ports patches.  The original commit 46c116b920eb ("ext4: verify dir
block before splitting it") has been back ported to stable already.

3) I don't know why I didn't send a patch for this bug.  I looked at it
on May 23 but never sent a patch.  Sorry?

4) There are a dozen other static checkers which are supposed to have
warned about this.  I search lore.kernel.org for 46c116b920eb
and 46c116b920ebec58031f0a78c5ea9599b0d2a371 but I couldn't find any
static checker warnings.

regards,
dan carpenter

Re: [PATCH] ext4: change variable "count" to signed integer

[Theodore Ts'o]

On Sat, Jun 18, 2022 at 12:33:01PM +0300, Dan Carpenter wrote:
> On Fri, Jun 17, 2022 at 10:59:01PM -0400, Theodore Ts'o wrote:
> > On Mon, 30 May 2022 18:00:47 +0800, Ding Xiang wrote:
> > > Since dx_make_map() may return -EFSCORRUPTED now,
> > > so change "count" to signed integer.
> > > 
> > > 
> > 
> > Applied, thanks!
> > 
> > [1/1] ext4: change variable "count" to signed integer
> >       commit: fefb759df063599ad483422eb07ef8e14c612cc2
> > 
> 
> There was some kind of process error here...
> 
> 1) That commit somehow never made it to linux-next.

That's I only pushed it out Friday night (US/Eastern), and Stephen
Rothwell creates new linux-next release based on snapshots taken
Monday through Friday in the Morning (AU/Canberra time).

Things have been crazy busy, so a last set of ext4 backports only
happened Friday starting around 10pm localtime.  (Yes, I have no
life.)


> 2) No Fixes tag.  Presumably Greg searches for Fixes tags before he back
> ports patches.  The original commit 46c116b920eb ("ext4: verify dir
> block before splitting it") has been back ported to stable already.

I did add a Fixes tag in what is in the ext4 tree.  I don't always
mention when I've rewritten since that requries manual editing of the
"b4 ty" generated acknowledgement.

In the ideal world when I rewrite the one-line snapshot, at the *very*
least it should show up in the Applied/thanks.  Maybe something like
this:

[1/1] ext4: change variable "count" to signed integer
      commit: fefb759df063599ad483422eb07ef8e14c612cc2
      rewritten summary: ext4: make variable "count" signed

... and if the commit description is rewritten, maybe the "b4 ty"
e-mail should mention it.  (Very often I end up rewriting commit
descriptions, especially when the original poster's first language is
not English.)

For the record, this is what is in the ext4 tree that I plan to push
to Linus is:

commit fefb759df063599ad483422eb07ef8e14c612cc2
Author: Ding Xiang <dingxiang@cmss.chinamobile.com>
Date:   Mon May 30 18:00:47 2022 +0800

    ext4: make variable "count" signed
    
    Since dx_make_map() may return -EFSCORRUPTED now, so change "count" to
    be a signed integer so we can correct check for an error code returned
    by dx_make_map().
    
    Fixes: 46c116b920eb ("ext4: verify dir block before splitting it")
    Signed-off-by: Ding Xiang <dingxiang@cmss.chinamobile.com>
    Link: https://lore.kernel.org/r/20220530100047.537598-1-dingxiang@cmss.chinamobile.com
    Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Cheers,

					- Ted

Re: [PATCH] ext4: change variable "count" to signed integer

[Dan Carpenter]

On Sat, Jun 18, 2022 at 06:22:00PM -0400, Theodore Ts'o wrote:
> On Sat, Jun 18, 2022 at 12:33:01PM +0300, Dan Carpenter wrote:
> > On Fri, Jun 17, 2022 at 10:59:01PM -0400, Theodore Ts'o wrote:
> > > On Mon, 30 May 2022 18:00:47 +0800, Ding Xiang wrote:
> > > > Since dx_make_map() may return -EFSCORRUPTED now,
> > > > so change "count" to signed integer.
> > > > 
> > > > 
> > > 
> > > Applied, thanks!
> > > 
> > > [1/1] ext4: change variable "count" to signed integer
> > >       commit: fefb759df063599ad483422eb07ef8e14c612cc2
> > > 
> > 
> > There was some kind of process error here...
> > 
> > 1) That commit somehow never made it to linux-next.
> 
> That's I only pushed it out Friday night (US/Eastern), and Stephen
> Rothwell creates new linux-next release based on snapshots taken
> Monday through Friday in the Morning (AU/Canberra time).
> 
> Things have been crazy busy, so a last set of ext4 backports only
> happened Friday starting around 10pm localtime.  (Yes, I have no
> life.)

Ah, sorry.  I didn't look at the dates carefully.  Thanks for taking
care of this.

It's so weird that kbuild and I didn't send this bug report.  I can't
figure that bit out at all.  It's not super common though and other
people are looking at static analysis so it worked out in the end.

regards,
dan carpenter