From: Rob Landley Date: Fri, 23 Sep 2005 04:44:27 +0000 (-0700) Subject: [PATCH] Fix bd_claim() error code. X-Git-Tag: v2.6.14-rc3~51^2~27 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f7b3a4359b25311fb5894c8809478a2df6bed480;p=linux-2.6 [PATCH] Fix bd_claim() error code. Problem: In some circumstances, bd_claim() is returning the wrong error code. If we try to swapon an unused block device that isn't swap formatted, we get -EINVAL. But if that same block device is already mounted, we instead get -EBUSY, even though it still isn't a valid swap device. This issue came up on the busybox list trying to get the error message from "swapon -a" right. If a swap device is already enabled, we get -EBUSY, and we shouldn't report this as an error. But we can't distinguish the two -EBUSY conditions, which are very different errors. In the code, bd_claim() returns either 0 or -EBUSY, but in this case busy means "somebody other than sys_swapon has already claimed this", and _that_ means this block device can't be a valid swap device. So return -EINVAL there. Signed-off-by: Rob Landley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/mm/swapfile.c b/mm/swapfile.c index 0184f510aa..1dcaeda039 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1381,6 +1381,7 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags) error = bd_claim(bdev, sys_swapon); if (error < 0) { bdev = NULL; + error = -EINVAL; goto bad_swap; } p->old_block_size = block_size(bdev);