buffer_head.b_bsize type

From: Stewart Smith (stewartsmith@mac.com)
Date: Thu May 29 2003 - 05:32:25 EST


The buffer_head structure (include/linux/buffer_head.h) uses a u32 type while everywhere else (e.g. bread) the size parameter is of type int.

Currently on all architectures u32 is defined as unsigned int. We should probably not be doing unsigned and signed swaps. And you should never really have a negative size of a buffer.

So, there are two solutions: either change the buffer_head struct to be int so it matches everywhere else, or change everywhere else.

The attached patch does the change in one place. Although perhaps changing everywhere else would be better. Thoughts? I'm happy to make up the patch if needed.


Applies cleanly to 2.5.69 and 2.5.70 and has been tested on i386 without causing any further problems (that I can see at least).

diff -ur linux-2.5.69-orig/include/linux/buffer_head.h linux-2.5.69/include/linux/buffer_head.h
--- linux-2.5.69-orig/include/linux/buffer_head.h Mon May 5 09:52:49 2003
+++ linux-2.5.69/include/linux/buffer_head.h Fri May 16 12:05:16 2003
@@ -51,7 +51,7 @@
struct page *b_page; /* the page this bh is mapped to */

sector_t b_blocknr; /* block number */
- u32 b_size; /* block size */
+ int b_size; /* block size */
char *b_data; /* pointer to data block */

struct block_device *b_bdev;


Attachment: patch-buffer_head-u32toint.diff
Description: Binary data


------------------------------
Stewart Smith
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