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| author | Jiufei Xue <jiufei.xue@linux.alibaba.com> | 2019-05-17 23:31:44 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-19 00:52:26 +0200 |
| commit | ec084de929e419e51bcdafaafe567d9e7d0273b7 (patch) | |
| tree | 8c9694cdd7e5e90ec859d746a42a43ca7d142d0d /init | |
| parent | mm/compaction.c: correct zone boundary handling when isolating pages from a p... (diff) | |
| download | linux-ec084de929e419e51bcdafaafe567d9e7d0273b7.tar.xz linux-ec084de929e419e51bcdafaafe567d9e7d0273b7.zip | |
fs/writeback.c: use rcu_barrier() to wait for inflight wb switches going into workqueue when umount
synchronize_rcu() didn't wait for call_rcu() callbacks, so inode wb
switch may not go to the workqueue after synchronize_rcu(). Thus
previous scheduled switches was not finished even flushing the
workqueue, which will cause a NULL pointer dereferenced followed below.
VFS: Busy inodes after unmount of vdd. Self-destruct in 5 seconds. Have a nice day...
BUG: unable to handle kernel NULL pointer dereference at 0000000000000278
evict+0xb3/0x180
iput+0x1b0/0x230
inode_switch_wbs_work_fn+0x3c0/0x6a0
worker_thread+0x4e/0x490
? process_one_work+0x410/0x410
kthread+0xe6/0x100
ret_from_fork+0x39/0x50
Replace the synchronize_rcu() call with a rcu_barrier() to wait for all
pending callbacks to finish. And inc isw_nr_in_flight after call_rcu()
in inode_switch_wbs() to make more sense.
Link: http://lkml.kernel.org/r/20190429024108.54150-1-jiufei.xue@linux.alibaba.com
Signed-off-by: Jiufei Xue <jiufei.xue@linux.alibaba.com>
Acked-by: Tejun Heo <tj@kernel.org>
Suggested-by: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'init')
0 files changed, 0 insertions, 0 deletions