Re: [PATCH] block, writeback: wait for writeback to finish before detaching wb

2017-03-09 Thread Jan Kara
On Thu 09-03-17 13:26:45, Tejun Heo wrote: > (cc'ing Jan and quoting the whole message) > > On Wed, Mar 08, 2017 at 06:19:37PM -0800, Tahsin Erdogan wrote: > > __blkdev_put() could surprise writeback thread by detaching the > > wb object from an inode that hasn't cleared the I_SYNC flag yet. > > T

Re: [PATCH] block, writeback: wait for writeback to finish before detaching wb

2017-03-09 Thread Tejun Heo
(cc'ing Jan and quoting the whole message) On Wed, Mar 08, 2017 at 06:19:37PM -0800, Tahsin Erdogan wrote: > __blkdev_put() could surprise writeback thread by detaching the > wb object from an inode that hasn't cleared the I_SYNC flag yet. > This causes a NULL pointer dereference as seen below: >

[PATCH] block, writeback: wait for writeback to finish before detaching wb

2017-03-08 Thread Tahsin Erdogan
__blkdev_put() could surprise writeback thread by detaching the wb object from an inode that hasn't cleared the I_SYNC flag yet. This causes a NULL pointer dereference as seen below: BUG: unable to handle kernel NULL pointer dereference at (null) IP: locked_inode_to_wb_and_lock_list+0x38/0x440