[PATCH 01/14] ubd: refactor the interrupt handler
- To: Jens Axboe <axboe@kernel.dk>, "Martin K. Petersen" <martin.petersen@oracle.com>
- Cc: Richard Weinberger <richard@nod.at>, Anton Ivanov <anton.ivanov@cambridgegreys.com>, Johannes Berg <johannes@sipsolutions.net>, Josef Bacik <josef@toxicpanda.com>, Ilya Dryomov <idryomov@gmail.com>, Dongsheng Yang <dongsheng.yang@easystack.cn>, Roger Pau Monné <roger.pau@citrix.com>, linux-um@lists.infradead.org, linux-block@vger.kernel.org, nbd@other.debian.org, ceph-devel@vger.kernel.org, xen-devel@lists.xenproject.org, linux-scsi@vger.kernel.org
- Subject: [PATCH 01/14] ubd: refactor the interrupt handler
- From: Christoph Hellwig <hch@lst.de>
- Date: Fri, 31 May 2024 09:47:56 +0200
- Message-id: <[🔎] 20240531074837.1648501-2-hch@lst.de>
- In-reply-to: <[🔎] 20240531074837.1648501-1-hch@lst.de>
- References: <[🔎] 20240531074837.1648501-1-hch@lst.de>
Instead of a separate handler function that leaves no work in the
interrupt hanler itself, split out a per-request end I/O helper and
clean up the coding style and variable naming while we're at it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
arch/um/drivers/ubd_kern.c | 49 ++++++++++++++------------------------
1 file changed, 18 insertions(+), 31 deletions(-)
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index ef805eaa9e013d..0c9542d58c01b7 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -447,43 +447,30 @@ static int bulk_req_safe_read(
return n;
}
-/* Called without dev->lock held, and only in interrupt context. */
-static void ubd_handler(void)
+static void ubd_end_request(struct io_thread_req *io_req)
{
- int n;
- int count;
-
- while(1){
- n = bulk_req_safe_read(
- thread_fd,
- irq_req_buffer,
- &irq_remainder,
- &irq_remainder_size,
- UBD_REQ_BUFFER_SIZE
- );
- if (n < 0) {
- if(n == -EAGAIN)
- break;
- printk(KERN_ERR "spurious interrupt in ubd_handler, "
- "err = %d\n", -n);
- return;
- }
- for (count = 0; count < n/sizeof(struct io_thread_req *); count++) {
- struct io_thread_req *io_req = (*irq_req_buffer)[count];
-
- if ((io_req->error == BLK_STS_NOTSUPP) && (req_op(io_req->req) == REQ_OP_DISCARD)) {
- blk_queue_max_discard_sectors(io_req->req->q, 0);
- blk_queue_max_write_zeroes_sectors(io_req->req->q, 0);
- }
- blk_mq_end_request(io_req->req, io_req->error);
- kfree(io_req);
- }
+ if (io_req->error == BLK_STS_NOTSUPP &&
+ req_op(io_req->req) == REQ_OP_DISCARD) {
+ blk_queue_max_discard_sectors(io_req->req->q, 0);
+ blk_queue_max_write_zeroes_sectors(io_req->req->q, 0);
}
+ blk_mq_end_request(io_req->req, io_req->error);
+ kfree(io_req);
}
static irqreturn_t ubd_intr(int irq, void *dev)
{
- ubd_handler();
+ int len, i;
+
+ while ((len = bulk_req_safe_read(thread_fd, irq_req_buffer,
+ &irq_remainder, &irq_remainder_size,
+ UBD_REQ_BUFFER_SIZE)) >= 0) {
+ for (i = 0; i < len / sizeof(struct io_thread_req *); i++)
+ ubd_end_request((*irq_req_buffer)[i]);
+ }
+
+ if (len < 0 && len != -EAGAIN)
+ pr_err("spurious interrupt in %s, err = %d\n", __func__, len);
return IRQ_HANDLED;
}
--
2.43.0
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