Revert "net: ifb error path loop fix"

This reverts commit 0c0b3ae68ec93b1db5c637d294647d1cca0df763.

Quoth David:

  "Jeff, please revert

   It's wrong.  We had a lengthy analysis of this piece of code
   several months ago, and it is correct.

   Consider, if we run the loop and we get an error
   the following happens:

   1) attempt of ifb_init_one(i) fails, therefore we should
      not try to "ifb_free_one()" on "i" since it failed
   2) the loop iteration first increments "i", then it
      check for error

   Therefore we must decrement "i" twice before the first
   free during the cleanup.  One to "undo" the for() loop
   increment, and one to "skip" the ifb_init_one() case which
   failed."

Reported-by: David Miller <davem@davemloft.net>
Acked-by: Jeff Garzik <jgarzik@pobox.com>
Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/net/ifb.c b/drivers/net/ifb.c
index c4ca7c930a46cec4fdcb6187407958224fbf77d4..ca2b21f9d44489f4008761764f520f90a8956053 100644 (file)
--- a/drivers/net/ifb.c
+++ b/drivers/net/ifb.c
@@ -271,7 +271,8 @@ static int __init ifb_init_module(void)
        for (i = 0; i < numifbs && !err; i++)
                err = ifb_init_one(i);
        if (err) {
-               while (i--)
+               i--;
+               while (--i >= 0)
                        ifb_free_one(i);
        }