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| author | Jens Axboe <axboe@kernel.dk> | 2019-09-06 07:02:31 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-09-06 07:02:31 -0600 |
| commit | a26142559c2be8c0975b941e3110d23a9e552ce5 (patch) | |
| tree | 013121f3e988d1787cb5956701ff407bffbb1124 | |
| parent | ebddd2a15323856d82d22b49236604c2e0d23ab9 (diff) | |
| download | linux-stable-a26142559c2be8c0975b941e3110d23a9e552ce5.tar.gz linux-stable-a26142559c2be8c0975b941e3110d23a9e552ce5.tar.bz2 linux-stable-a26142559c2be8c0975b941e3110d23a9e552ce5.zip | |
block: fix elevator_get_by_features()
The lookup logic is broken - 'e' will never be NULL, even if the
list is empty. Maintain lookup hit in a separate variable instead.
Fixes: a0958ba7fcdc ("block: Improve default elevator selection")
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/elevator.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/block/elevator.c b/block/elevator.c index 096a670d22d7..bba10e83478a 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -668,22 +668,23 @@ static struct elevator_type *elevator_get_default(struct request_queue *q) */ static struct elevator_type *elevator_get_by_features(struct request_queue *q) { - struct elevator_type *e; + struct elevator_type *e, *found = NULL; spin_lock(&elv_list_lock); list_for_each_entry(e, &elv_list, list) { if (elv_support_features(e->elevator_features, - q->required_elevator_features)) + q->required_elevator_features)) { + found = e; break; + } } - if (e && !try_module_get(e->elevator_owner)) - e = NULL; + if (found && !try_module_get(found->elevator_owner)) + found = NULL; spin_unlock(&elv_list_lock); - - return e; + return found; } /* |