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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-12-15 17:25:20 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-12-15 17:25:20 -0800 |
| commit | 9b8ec916df67ba31614796037caf606b763e2e79 (patch) | |
| tree | 686e3d85b8c5af57d54265354ffab61f4803856e | |
| parent | 27cb8823e26cecd03c00d82dfb501f6c144b3445 (diff) | |
| parent | 35d37c66356eed46700e0d5db87211844d43a241 (diff) | |
| download | linux-9b8ec916df67ba31614796037caf606b763e2e79.tar.bz2 | |
Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull core block fix from Jens Axboe:
"Jan reported a problem this morning with a crash in blk-mq, and after
looking over the recent changes, it's obvious that the blk-mq-tag
waitqueue handling change is buggy. We could end up _not_ doing
finish_wait() before switching to a new waitqueue, thus corrupting the
wait task list"
* 'for-linus' of git://git.kernel.dk/linux-block:
Revert "blk-mq: Micro-optimize bt_get()"
| -rw-r--r-- | block/blk-mq-tag.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index e3d4e4043b49..32e8dbb9ad1c 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -248,8 +248,8 @@ static int bt_get(struct blk_mq_alloc_data *data, if (!(data->gfp & __GFP_WAIT)) return -1; + bs = bt_wait_ptr(bt, hctx); do { - bs = bt_wait_ptr(bt, hctx); prepare_to_wait(&bs->wait, &wait, TASK_UNINTERRUPTIBLE); tag = __bt_get(hctx, bt, last_tag); @@ -285,6 +285,8 @@ static int bt_get(struct blk_mq_alloc_data *data, hctx = data->hctx; bt = &hctx->tags->bitmap_tags; } + finish_wait(&bs->wait, &wait); + bs = bt_wait_ptr(bt, hctx); } while (1); finish_wait(&bs->wait, &wait); |