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Groups > linux.kernel > #1580074
| From | Paolo Valente <paolo.valente@linaro.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH BUGFIX] block: make elevator_get robust against cross blk/blk-mq choice |
| Date | 2017-02-13 22:10 +0100 |
| Message-ID | <taw2K-Bl-19@gated-at.bofh.it> (permalink) |
| References | <taw2J-Bl-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
If, at boot, a legacy I/O scheduler is chosen for a device using blk-mq,
or, viceversa, a blk-mq scheduler is chosen for a device using blk, then
that scheduler is set and initialized without any check, driving the
system into an inconsistent state. This commit addresses this issue by
letting elevator_get fail for these wrong cross choices.
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
---
block/elevator.c | 26 ++++++++++++++++++--------
1 file changed, 18 insertions(+), 8 deletions(-)
diff --git a/block/elevator.c b/block/elevator.c
index 27ff1ed..a25bdd9 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -99,7 +99,8 @@ static void elevator_put(struct elevator_type *e)
module_put(e->elevator_owner);
}
-static struct elevator_type *elevator_get(const char *name, bool try_loading)
+static struct elevator_type *elevator_get(const char *name, bool try_loading,
+ bool mq_ops)
{
struct elevator_type *e;
@@ -113,6 +114,12 @@ static struct elevator_type *elevator_get(const char *name, bool try_loading)
e = elevator_find(name);
}
+ if (e && (e->uses_mq != mq_ops)) {
+ pr_err("ERROR: attempted to choose %s %s I/O scheduler in blk%s",
+ name, e->uses_mq ? "blk-mq" : "legacy", mq_ops ? "-mq" : "");
+ e = NULL;
+ }
+
if (e && !try_module_get(e->elevator_owner))
e = NULL;
@@ -201,7 +208,7 @@ int elevator_init(struct request_queue *q, char *name)
q->boundary_rq = NULL;
if (name) {
- e = elevator_get(name, true);
+ e = elevator_get(name, true, q->mq_ops);
if (!e)
return -EINVAL;
}
@@ -212,7 +219,7 @@ int elevator_init(struct request_queue *q, char *name)
* off async and request_module() isn't allowed from async.
*/
if (!e && *chosen_elevator) {
- e = elevator_get(chosen_elevator, false);
+ e = elevator_get(chosen_elevator, false, q->mq_ops);
if (!e)
printk(KERN_ERR "I/O scheduler %s not found\n",
chosen_elevator);
@@ -220,17 +227,20 @@ int elevator_init(struct request_queue *q, char *name)
if (!e) {
if (q->mq_ops && q->nr_hw_queues == 1)
- e = elevator_get(CONFIG_DEFAULT_SQ_IOSCHED, false);
+ e = elevator_get(CONFIG_DEFAULT_SQ_IOSCHED, false,
+ q->mq_ops);
else if (q->mq_ops)
- e = elevator_get(CONFIG_DEFAULT_MQ_IOSCHED, false);
+ e = elevator_get(CONFIG_DEFAULT_MQ_IOSCHED, false,
+ q->mq_ops);
else
- e = elevator_get(CONFIG_DEFAULT_IOSCHED, false);
+ e = elevator_get(CONFIG_DEFAULT_IOSCHED, false,
+ q->mq_ops);
if (!e) {
printk(KERN_ERR
"Default I/O scheduler not found. " \
"Using noop/none.\n");
- e = elevator_get("noop", false);
+ e = elevator_get("noop", false, q->mq_ops);
}
}
@@ -1051,7 +1061,7 @@ static int __elevator_change(struct request_queue *q, const char *name)
return elevator_switch(q, NULL);
strlcpy(elevator_name, name, sizeof(elevator_name));
- e = elevator_get(strstrip(elevator_name), true);
+ e = elevator_get(strstrip(elevator_name), true, q->mq_ops);
if (!e) {
printk(KERN_ERR "elevator: type %s not found\n", elevator_name);
return -EINVAL;
--
2.10.0
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH BUGFIX] attempt to fix wrong scheduler selection Paolo Valente <paolo.valente@linaro.org> - 2017-02-13 22:10 +0100
[PATCH BUGFIX] block: make elevator_get robust against cross blk/blk-mq choice Paolo Valente <paolo.valente@linaro.org> - 2017-02-13 22:10 +0100
Re: [PATCH BUGFIX] block: make elevator_get robust against cross blk/blk-mq choice Bart Van Assche <Bart.VanAssche@sandisk.com> - 2017-02-13 22:20 +0100
Re: [PATCH BUGFIX] block: make elevator_get robust against cross blk/blk-mq choice Omar Sandoval <osandov@osandov.com> - 2017-02-13 23:10 +0100
Re: [PATCH BUGFIX] block: make elevator_get robust against cross blk/blk-mq choice Jens Axboe <axboe@kernel.dk> - 2017-02-13 23:30 +0100
Re: [PATCH BUGFIX] block: make elevator_get robust against cross blk/blk-mq choice Jens Axboe <axboe@kernel.dk> - 2017-02-14 00:20 +0100
Re: [PATCH BUGFIX] block: make elevator_get robust against cross blk/blk-mq choice Paolo Valente <paolo.valente@linaro.org> - 2017-02-14 09:20 +0100
Re: [PATCH BUGFIX] block: make elevator_get robust against cross blk/blk-mq choice Jens Axboe <axboe@kernel.dk> - 2017-02-14 16:20 +0100
Re: [PATCH BUGFIX] block: make elevator_get robust against cross blk/blk-mq choice Paolo Valente <paolo.valente@linaro.org> - 2017-02-14 16:50 +0100
Re: [PATCH BUGFIX] block: make elevator_get robust against cross blk/blk-mq choice Hannes Reinecke <hare@suse.de> - 2017-02-14 08:00 +0100
Re: [PATCH BUGFIX] block: make elevator_get robust against cross blk/blk-mq choice Omar Sandoval <osandov@osandov.com> - 2017-02-14 08:10 +0100
Re: [PATCH BUGFIX] block: make elevator_get robust against cross blk/blk-mq choice Hannes Reinecke <hare@suse.de> - 2017-02-14 08:20 +0100
Re: [PATCH BUGFIX] block: make elevator_get robust against cross blk/blk-mq choice Jens Axboe <axboe@kernel.dk> - 2017-02-14 16:20 +0100
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