[BK-PATCH-2.5] Fix debugging check in async i/o completion handlers

From: Anton Altaparmakov <aia21@cantab.net>
To: torvalds@transmeta.com (Linus Torvalds)
Cc: linux-kernel@vger.kernel.org (Linux Kernel)
Subject: [BK-PATCH-2.5] Fix debugging check in async i/o completion handlers
Date: Mon, 15 Jul 2002 04:08:05 +0100 (BST)	[thread overview]
Message-ID: <E17TwDV-0001Zr-00@storm.christs.cam.ac.uk> (raw)

Linus,

The buffer_mapped(bh) checks in the async io completion handlers should
actually be buffer_mapped(tmp).

However, since buffers marked async_read or async_write must be locked,
execution should always "goto still_busy;" and hence why the conditional
BUG() can and should be made uncoditional.

Andrew Morton acked that the change for the async_read case makes sense.

I later noticed the async_write case is identical hence why I change both
here.

Patch is both compile, boot, and run tested. As expected, no problems.

Please apply.

Best regards,

	Anton
-- 
Anton Altaparmakov <aia21 at cantab.net> (replace at with @)
Linux NTFS maintainer / IRC: #ntfs on irc.openprojects.net
WWW: http://linux-ntfs.sf.net/, http://www-stu.christs.cam.ac.uk/~aia21/

===================================================================

This will update the following files:

 fs/buffer.c |    6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)

through these ChangeSets:

<aia21@cantab.net> (02/07/15 1.632)
   Fix&improve debugging checks in async io completion handlers.
   Beffers marked for async io must be locked!


diff -Nru a/fs/buffer.c b/fs/buffer.c

--- a/fs/buffer.c	Mon Jul 15 03:58:04 2002
+++ b/fs/buffer.c	Mon Jul 15 03:58:04 2002
@@ -519,8 +519,7 @@
 		if (buffer_async_read(tmp)) {
 			if (buffer_locked(tmp))
 				goto still_busy;
-			if (!buffer_mapped(bh))
-				BUG();
+			BUG();
 		}
 		tmp = tmp->b_this_page;
 	} while (tmp != bh);
@@ -570,8 +569,7 @@
 		if (buffer_async_write(tmp)) {
 			if (buffer_locked(tmp))
 				goto still_busy;
-			if (!buffer_mapped(bh))
-				BUG();
+			BUG();
 		}
 		tmp = tmp->b_this_page;
 	}

===================================================================

This BitKeeper patch contains the following changesets:
aia21@cantab.net|ChangeSet|20020715025751|04609
## Wrapped with gzip_uu ##


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