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| author | Josef Bacik <josef@toxicpanda.com> | 2026-10-28 10:41:37 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2026-10-28 15:40:34 -0600 |
| commit | 045cbfc369f5929ed473f7c200dc2e8146569ce5 (patch) | |
| tree | 02bd31d46a85428a7a28dfb5172dccf7ebfe07ad /tools/lib/python/kdoc | |
| parent | ac81a07a0bd5e75e8edc0eb5be563be1b2d56554 (diff) | |
block: don't enter reclaim under rq_qos_mutex
ioc_qos_write() and the wbt_lat_usec writers take rq_qos_mutex with the
queue frozen, blkcg_deactivate_policy() does the same with blkcg_mutex,
so nothing holding either may wait for IO. blkg_conf_prep() got
GFP_NOIO for the blkg in commit 5d726c4dbeed, but the
radix_tree_preload() right after it, the policy init functions and the
GFP_KERNEL fallback in blkcg_activate_policy() can still enter reclaim
there. lockdep reports the cycle on the first write to io.max.
Use GFP_NOIO for all of them.
Fixes: 9730763f4756 ("block: correct locking order for protecting blk-wbt parameters")
Fixes: 5d726c4dbeed ("blk-cgroup: fix possible deadlock while configuring policy")
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://patch.msgid.link/20261028164415.1262013-35-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'tools/lib/python/kdoc')
0 files changed, 0 insertions, 0 deletions