From: NeilBrown <neilb@cse.unsw.edu.au>
mddev->bitmap gets clearred before the writeback daemon is stopped. So the
write_back daemon needs to be careful not to dereference the 'bitmap' if it is
NULL.
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
drivers/md/bitmap.c | 3 +++
1 files changed, 3 insertions(+)
diff -puN drivers/md/bitmap.c~md-ensure-bitmap_writeback_daemon-handles-shutdown-properly drivers/md/bitmap.c
--- devel/drivers/md/bitmap.c~md-ensure-bitmap_writeback_daemon-handles-shutdown-properly 2005-08-29 23:44:34.000000000 -0700
+++ devel-akpm/drivers/md/bitmap.c 2005-08-29 23:44:34.000000000 -0700
@@ -1156,6 +1156,9 @@ static void bitmap_writeback_daemon(mdde
err = -EINTR;
goto out;
}
+ if (bitmap == NULL)
+ /* about to be stopped. */
+ return;
PRINTK("%s: bitmap writeback daemon woke up...\n", bmname(bitmap));
/* wait on bitmap page writebacks */
_