| Message ID | befb45da-2a7b-8dff-30e7-59b441f604fe@maciej.szmigiero.name (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [RESEND,v2] cfq: clear queue pointers from cfqg after unpinning them in cfq_pd_offline | expand |
On 10/10/18 3:16 PM, Maciej S. Szmigiero wrote: > BFQ is already doing a similar thing in its .pd_offline_fn() method > implementation. > > While it seems that after commit 4c6994806f70 > ("blk-throttle: fix race between blkcg_bio_issue_check() and cgroup_rmdir()") > was reverted leaving these pointers intact no longer causes crashes > clearing them is still a sensible thing to do to make the code more robust. Applied, thanks.
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index d219e9a1af65..6a3d87dd3c1a 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -1644,14 +1644,20 @@ static void cfq_pd_offline(struct blkg_policy_data *pd) int i; for (i = 0; i < IOPRIO_BE_NR; i++) { - if (cfqg->async_cfqq[0][i]) + if (cfqg->async_cfqq[0][i]) { cfq_put_queue(cfqg->async_cfqq[0][i]); - if (cfqg->async_cfqq[1][i]) + cfqg->async_cfqq[0][i] = NULL; + } + if (cfqg->async_cfqq[1][i]) { cfq_put_queue(cfqg->async_cfqq[1][i]); + cfqg->async_cfqq[1][i] = NULL; + } } - if (cfqg->async_idle_cfqq) + if (cfqg->async_idle_cfqq) { cfq_put_queue(cfqg->async_idle_cfqq); + cfqg->async_idle_cfqq = NULL; + } /* * @blkg is going offline and will be ignored by
BFQ is already doing a similar thing in its .pd_offline_fn() method implementation. While it seems that after commit 4c6994806f70 ("blk-throttle: fix race between blkcg_bio_issue_check() and cgroup_rmdir()") was reverted leaving these pointers intact no longer causes crashes clearing them is still a sensible thing to do to make the code more robust. Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name> --- Changes from v1: Drop stable and fixes tags, rewrite the commit message as after commit 4c6994806f70 was reverted this change is no longer required to fix a crash. block/cfq-iosched.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)