From 063d006fa06fbf73fab370921120380333a33e85 Mon Sep 17 00:00:00 2001
From: Eric Sandeen <sandeen@redhat.com>
Date: Thu, 31 Jan 2013 00:55:01 +0000
Subject: [PATCH] btrfs: ensure we don't overrun devices_info[] in
__btrfs_alloc_chunk
WARN_ON isn't enough, we need to stop the loop if for any reason
we would overrun the devices_info array.
I tried to track down the connection between the length of
the alloc_devices list and the rw_devices counter but
it wasn't immediately obvious, so be defensive about it.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
---
fs/btrfs/volumes.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index c7843349c795..305b6a63ab1f 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3734,12 +3734,16 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
continue;
+ if (ndevs == fs_devices->rw_devices) {
+ WARN(1, "%s: found more than %llu devices\n",
+ __func__, fs_devices->rw_devices);
+ break;
+ }
devices_info[ndevs].dev_offset = dev_offset;
devices_info[ndevs].max_avail = max_avail;
devices_info[ndevs].total_avail = total_avail;
devices_info[ndevs].dev = device;
++ndevs;
- WARN_ON(ndevs > fs_devices->rw_devices);
}
/*