Re: [patch] f2fs: dereferencing an ERR_PTR

[Jaegeuk Kim <jaegeuk.kim@samsung.com>]

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2013-05-23 (목), 13:12 +0300, Dan Carpenter:
> Btw, Linus's new Sparse changes don't like the f2fs's NEW_ADDR
> macro.
> 
> #define NEW_ADDR                -1U
> 
> We use it like this:
> 
> 	block_t src, dest;
> 
> 	if (src != dest && dest != NEW_ADDR && dest != NULL_ADDR) {
> 
> block_t is 64 bits so probably the macro should probably be:
> 
> #define NEW_ADDR               ((block_t)-1)

Hi,
Agreed that it needs to synchronize on-disk and in-memory block address
types, __le32 and u64.
How about the below patch?

> 
> I'm not able to test this so there may be some reason why changing
> this breaks something.  In that case we could do:
> 
> #define NEW_ADDR               ((u32)(block_t)-1) /* explanation */
> 
> regards,
> dan carpenter
> 

From ded3c78fcb6dd8c39a8664471544942e51ff9faf Mon Sep 17 00:00:00 2001
From: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Date: Fri, 24 May 2013 12:41:04 +0900
Subject: [PATCH] f2fs: align data types between on-disk and in-memory
block
 addresses
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-f2fs-devel@lists.sourceforge.net

The on-disk block address is defined as __le32, but in-memory block
address,
block_t, does as u64.

Let's synchronize them to 32 bits.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
---
 fs/f2fs/f2fs.h          | 5 ++++-
 include/linux/f2fs_fs.h | 4 ++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 7b05029..92fd4e9 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -37,7 +37,10 @@
 		typecheck(unsigned long long, b) &&			\
 		((long long)((a) - (b)) > 0))
 
-typedef u64 block_t;
+typedef u32 block_t;	/*
+			 * should not change u32, since it is the on-disk block
+			 * address format, __le32.
+			 */
 typedef u32 nid_t;
 
 struct f2fs_mount_info {
diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
index df6fab8..383d5e3 100644
--- a/include/linux/f2fs_fs.h
+++ b/include/linux/f2fs_fs.h
@@ -20,8 +20,8 @@
 #define F2FS_BLKSIZE			4096	/* support only 4KB block */
 #define F2FS_MAX_EXTENSION		64	/* # of extension entries */
 
-#define NULL_ADDR		0x0U
-#define NEW_ADDR		-1U
+#define NULL_ADDR		((block_t)0)	/* used as block_t addresses */
+#define NEW_ADDR		((block_t)-1)	/* used as block_t addresses */
 
 #define F2FS_ROOT_INO(sbi)	(sbi->root_ino_num)
 #define F2FS_NODE_INO(sbi)	(sbi->node_ino_num)
-- 
1.8.1.3.566.gaa39828



-- 
Jaegeuk Kim
Samsung

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