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| author | Damien Le Moal <dlemoal@kernel.org> | 2024-09-17 22:32:31 +0900 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2024-09-17 08:34:00 -0600 |
| commit | e3accac1a976e65491a9b9fba82ce8ddbd3d2389 (patch) | |
| tree | c71c9eef7ee3b820bbf6950620e0a9c32a596455 | |
| parent | 42b16d3ac371a2fac9b6f08fd75f23f34ba3955a (diff) | |
| download | linux-e3accac1a976e65491a9b9fba82ce8ddbd3d2389.tar.gz linux-e3accac1a976e65491a9b9fba82ce8ddbd3d2389.tar.bz2 linux-e3accac1a976e65491a9b9fba82ce8ddbd3d2389.zip | |
block: Fix elv_iosched_local_module handling of "none" scheduler
Commit 734e1a860312 ("block: Prevent deadlocks when switching
elevators") introduced the function elv_iosched_load_module() to allow
loading an elevator module outside of elv_iosched_store() with the
target device queue not frozen, to avoid deadlocks. However, the "none"
scheduler does not have a module and as a result,
elv_iosched_load_module() always returns an error when trying to switch
to this valid scheduler.
Fix this by ignoring the return value of the request_module() call
done by elv_iosched_load_module(). This restores the behavior before
commit 734e1a860312, which was to ignore the request_module() result and
instead rely on elevator_change() to handle the "none" scheduler case.
Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Fixes: 734e1a860312 ("block: Prevent deadlocks when switching elevators")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240917133231.134806-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/elevator.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/block/elevator.c b/block/elevator.c index c355b55d0107..4122026b11f1 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -715,7 +715,9 @@ int elv_iosched_load_module(struct gendisk *disk, const char *buf, strscpy(elevator_name, buf, sizeof(elevator_name)); - return request_module("%s-iosched", strstrip(elevator_name)); + request_module("%s-iosched", strstrip(elevator_name)); + + return 0; } ssize_t elv_iosched_store(struct gendisk *disk, const char *buf, |