commit 3bd0f0c763e497c8674b28e3df2732f48683dabd
author Suresh Jayaraman <sjayaraman@suse.de> Wed Sep 30 10:53:48 2009 +0200
committer Jens Axboe <jens.axboe@oracle.com> Thu Oct 01 21:15:46 2009 +0200
tree fd3bb8635291ad8c0b4e302e40cc776fd1644ada
parent a112a71d45b5e40c3cf07371d20a4a5079a72610

swapfile: avoid NULL pointer dereference in swapon when s_bdev is NULL

While testing Swap over NFS patchset, I noticed an oops that was triggered
during swapon. Investigating further, the NULL pointer deference is due to the
SSD device check/optimization in the swapon code that assumes s_bdev could never
be NULL.

inode->i_sb->s_bdev could be NULL in a few cases. For e.g. one such case is
loopback NFS mount, there could be others as well. Fix this by ensuring s_bdev
is not NULL before we try to deference s_bdev.

Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>