Re: 2.4.28-pre2 and ntfs-2.1.6b ?

["O.Sezer" <sezeroz@ttnet.net.tr>]

Willy Tarreau wrote:
> Hi,
> 
> On Thu, Aug 26, 2004 at 11:59:47PM +0300, O.Sezer wrote:
> 
>>Hi all:
>>
>>With 2.4.28-pre2, ntfs-2.1.6b from linux-ntfs site
>>started failing to compile at aops.c:
>>
>>aops.c: In function `ntfs_read_block':
>>aops.c:315: parse error before "else"
>>-- or in case of gcc3.4 --
>>aops.c:315: error: syntax error before "else"
>>
>>This happens with gcc-3.2.2 and gcc-3.4.0
>>and can be fixed by:
>>
>>--- aops.c.BAK	2004-08-26 19:35:11.000000000 +0300
>>+++ aops.c	2004-08-26 21:41:53.000000000 +0300
>>@@ -310,10 +310,11 @@
>> 		return 0;
>> 	}
>> 	/* No i/o was scheduled on any of the buffers. */
>>-	if (likely(!PageError(page)))
>>+	if (likely(!PageError(page))) {
>> 		SetPageUptodate(page);
>>-	else /* Signal synchronous i/o error. */
>>+	} else { /* Signal synchronous i/o error. */
>> 		nr = -EIO;
>>+	}
>> 	unlock_page(page);
>> 	return nr;
>> }
> 
> 
> No !
> Please don't fix it this way ! The problem lies within the declaration of
> SetPageUptodate() which it seems is a macro which lacks some braces somewhere.
> You were very lucky that there was an 'else' to point it out, but imagine
> what it would do in the following case :
> 
> 	if (likely(!PageError(page))) {
>  		SetPageUptodate(page);
> 	blah();
> 
> It would always execute the second half of SetPageUptodate(), whatever
> the condition, and nothing will alert you.
> 
> What does SetPageUptodate() look like ?
> 
> 
>>The very same code used to compile fine with
>>2.4.27 without any changes to it.
> 
> 
> I think that the gcc-3.4 fixes might have hit some sensible parts...
> 
> 
>>I can't see
>>where the problem is (it's 23:57 here ;)).
>>Can anyone tell, please?
> 
> 
> It's even later now, good night :-)
> 
> Regards,
> Willy
> 
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> 

Hi Willy, and thanks, you're a lifesaver! All the evidence points
to the s390 changes in -pre2, specificly cset-1.1514 by schwidefsky
which touches include/linux/mm.h this way:

--- 1.44/include/linux/mm.h	2004-08-26 15:51:04 -07:00
+++ 1.45/include/linux/mm.h	2004-08-26 15:51:04 -07:00
@@ -308,11 +308,9 @@
/* Make it prettier to test the above... */
#define UnlockPage(page)	unlock_page(page)
#define Page_Uptodate(page)	test_bit(PG_uptodate, &(page)->flags)
-#define SetPageUptodate(page) \
-	do {								\
-		arch_set_page_uptodate(page);				\
-		set_bit(PG_uptodate, &(page)->flags);			\
-	} while (0)
+#ifndef SetPageUptodate
+#define SetPageUptodate(page)	set_bit(PG_uptodate, &(page)->flags);
+#endif
#define ClearPageUptodate(page)	clear_bit(PG_uptodate, &(page)->flags)
#define PageDirty(page)		test_bit(PG_dirty, &(page)->flags)
#define SetPageDirty(page)	set_bit(PG_dirty, &(page)->flags)

Marcelo, you maybe interested in this.

Cheers,
Ozkan Sezer