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| author | Jens Axboe <axboe@kernel.dk> | 2021-09-01 14:15:59 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-09-03 06:16:11 -0600 |
| commit | fa84693b3c896460831fe0750554121121a23da8 (patch) | |
| tree | 5fe8b342f8c256587f47e3de11ebb4c89b9e78b0 /fs/io_uring.c | |
| parent | 3146cba99aa284b1d4a10fbd923df953f1d18035 (diff) | |
| download | lwn-fa84693b3c896460831fe0750554121121a23da8.tar.gz lwn-fa84693b3c896460831fe0750554121121a23da8.zip | |
io_uring: ensure IORING_REGISTER_IOWQ_MAX_WORKERS works with SQPOLL
SQPOLL has a different thread doing submissions, we need to check for
that and use the right task context when updating the worker values.
Just hold the sqd->lock across the operation, this ensures that the
thread cannot go away while we poke at ->io_uring.
Link: https://github.com/axboe/liburing/issues/420
Fixes: 2e480058ddc2 ("io-wq: provide a way to limit max number of workers")
Reported-by: Johannes Lundberg <johalun0@gmail.com>
Tested-by: Johannes Lundberg <johalun0@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs/io_uring.c')
| -rw-r--r-- | fs/io_uring.c | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 4a5eb9e856f0..4ad0d17dc92d 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -10323,26 +10323,46 @@ static int io_unregister_iowq_aff(struct io_ring_ctx *ctx) static int io_register_iowq_max_workers(struct io_ring_ctx *ctx, void __user *arg) { - struct io_uring_task *tctx = current->io_uring; + struct io_uring_task *tctx = NULL; + struct io_sq_data *sqd = NULL; __u32 new_count[2]; int i, ret; - if (!tctx || !tctx->io_wq) - return -EINVAL; if (copy_from_user(new_count, arg, sizeof(new_count))) return -EFAULT; for (i = 0; i < ARRAY_SIZE(new_count); i++) if (new_count[i] > INT_MAX) return -EINVAL; + if (ctx->flags & IORING_SETUP_SQPOLL) { + sqd = ctx->sq_data; + if (sqd) { + mutex_lock(&sqd->lock); + tctx = sqd->thread->io_uring; + } + } else { + tctx = current->io_uring; + } + + ret = -EINVAL; + if (!tctx || !tctx->io_wq) + goto err; + ret = io_wq_max_workers(tctx->io_wq, new_count); if (ret) - return ret; + goto err; + + if (sqd) + mutex_unlock(&sqd->lock); if (copy_to_user(arg, new_count, sizeof(new_count))) return -EFAULT; return 0; +err: + if (sqd) + mutex_unlock(&sqd->lock); + return ret; } static bool io_register_op_must_quiesce(int op) |