From: Cesar Eduardo Barros Date: Wed, 23 Mar 2011 02:03:13 +0000 (-0300) Subject: sys_swapon: fix inode locking X-Git-Tag: v2.6.39-rc1~201 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2130781e2aaab66e5a9f2fdc8af35da0153f405c;p=pandora-kernel.git sys_swapon: fix inode locking A conflict between 52c50567d8ab ("mm: swap: unlock swapfile inode mutex before closing file on bad swapfiles") and 83ef99befc32 ("sys_swapon: remove did_down variable") caused a double unlock of the inode mutex (once in bad_swap: before the filp_close, once at the end just before returning). The patch which added the extra unlock cleared did_down to avoid unlocking twice, but the other patch removed the did_down variable. To fix, set inode to NULL after the first unlock, since it will be used after that point only for the final unlock. While checking this patch, I found a path which could unlock without locking, in case the same inode was added as a swapfile twice. To fix, move the setting of the inode variable further down, to just before claim_swapfile, which will lock the inode before doing anything else. Cc: Mel Gorman Cc: Hugh Dickins Cc: Eric B Munson Cc: KAMEZAWA Hiroyuki Cc: Andrew Morton Signed-off-by: Cesar Eduardo Barros Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed