From: NeilBrown <neilb@cse.unsw.edu.au>
Date: Fri, 9 Sep 2005 23:23:52 +0000 (-0700)
Subject: [PATCH] md: fix bitmap/read_sb_page so that it handles errors properly.
X-Git-Tag: v2.6.14-rc1~241
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ab904d634625ef8dc590240b7ee06c7b724e636b;p=linux-2.6

[PATCH] md: fix bitmap/read_sb_page so that it handles errors properly.

read_sb_page() assumed that if sync_page_io fails, the device would be marked
faultly.  However it isn't.  So in the face of error, read_sb_page would loop
forever.

Redo the logic so that this cannot happen.

Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index c971d38f3a..90fe70d76a 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -270,19 +270,20 @@ static struct page *read_sb_page(mddev_t *mddev, long offset, unsigned long inde
 
 	if (!page)
 		return ERR_PTR(-ENOMEM);
-	do {
-		ITERATE_RDEV(mddev, rdev, tmp)
-			if (rdev->in_sync && !rdev->faulty)
-				goto found;
-		return ERR_PTR(-EIO);
 
-	found:
+	ITERATE_RDEV(mddev, rdev, tmp) {
+		if (! rdev->in_sync || rdev->faulty)
+			continue;
+
 		target = (rdev->sb_offset << 1) + offset + index * (PAGE_SIZE/512);
 
-	} while (!sync_page_io(rdev->bdev, target, PAGE_SIZE, page, READ));
+		if (sync_page_io(rdev->bdev, target, PAGE_SIZE, page, READ)) {
+			page->index = index;
+			return page;
+		}
+	}
+	return ERR_PTR(-EIO);
 
-	page->index = index;
-	return page;
 }
 
 static int write_sb_page(mddev_t *mddev, long offset, struct page *page, int wait)