Re: [patch] f2fs: dereferencing an ERR_PTR

Jaegeuk Kim
2013-05-24T03:46:08Z

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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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