From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/block/blk-timeout.c | 146 +++++++++++-------------------------------------
1 files changed, 34 insertions(+), 112 deletions(-)
diff --git a/kernel/block/blk-timeout.c b/kernel/block/blk-timeout.c
index f2cfd56..1b8de04 100644
--- a/kernel/block/blk-timeout.c
+++ b/kernel/block/blk-timeout.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* Functions related to generic timeout handling of requests.
*/
@@ -19,13 +20,11 @@
}
__setup("fail_io_timeout=", setup_fail_io_timeout);
-int blk_should_fake_timeout(struct request_queue *q)
+bool __blk_should_fake_timeout(struct request_queue *q)
{
- if (!test_bit(QUEUE_FLAG_FAIL_IO, &q->queue_flags))
- return 0;
-
return should_fail(&fail_io_timeout, 1);
}
+EXPORT_SYMBOL_GPL(__blk_should_fake_timeout);
static int __init fail_io_timeout_debugfs(void)
{
@@ -68,113 +67,50 @@
#endif /* CONFIG_FAIL_IO_TIMEOUT */
-/*
- * blk_delete_timer - Delete/cancel timer for a given function.
- * @req: request that we are canceling timer for
- *
- */
-void blk_delete_timer(struct request *req)
-{
- list_del_init(&req->timeout_list);
-}
-
-static void blk_rq_timed_out(struct request *req)
-{
- struct request_queue *q = req->q;
- enum blk_eh_timer_return ret = BLK_EH_RESET_TIMER;
-
- if (q->rq_timed_out_fn)
- ret = q->rq_timed_out_fn(req);
- switch (ret) {
- case BLK_EH_RESET_TIMER:
- blk_add_timer(req);
- blk_clear_rq_complete(req);
- break;
- case BLK_EH_DONE:
- /*
- * LLD handles this for now but in the future
- * we can send a request msg to abort the command
- * and we can move more of the generic scsi eh code to
- * the blk layer.
- */
- break;
- default:
- printk(KERN_ERR "block: bad eh return: %d\n", ret);
- break;
- }
-}
-
-static void blk_rq_check_expired(struct request *rq, unsigned long *next_timeout,
- unsigned int *next_set)
-{
- const unsigned long deadline = blk_rq_deadline(rq);
-
- if (time_after_eq(jiffies, deadline)) {
- list_del_init(&rq->timeout_list);
-
- /*
- * Check if we raced with end io completion
- */
- if (!blk_mark_rq_complete(rq))
- blk_rq_timed_out(rq);
- } else if (!*next_set || time_after(*next_timeout, deadline)) {
- *next_timeout = deadline;
- *next_set = 1;
- }
-}
-
-void blk_timeout_work(struct work_struct *work)
-{
- struct request_queue *q =
- container_of(work, struct request_queue, timeout_work);
- unsigned long flags, next = 0;
- struct request *rq, *tmp;
- int next_set = 0;
-
- spin_lock_irqsave(q->queue_lock, flags);
-
- list_for_each_entry_safe(rq, tmp, &q->timeout_list, timeout_list)
- blk_rq_check_expired(rq, &next, &next_set);
-
- if (next_set)
- mod_timer(&q->timeout, round_jiffies_up(next));
-
- spin_unlock_irqrestore(q->queue_lock, flags);
-}
-
/**
- * blk_abort_request -- Request request recovery for the specified command
+ * blk_abort_request - Request recovery for the specified command
* @req: pointer to the request of interest
*
* This function requests that the block layer start recovery for the
* request by deleting the timer and calling the q's timeout function.
* LLDDs who implement their own error recovery MAY ignore the timeout
- * event if they generated blk_abort_req. Must hold queue lock.
+ * event if they generated blk_abort_request.
*/
void blk_abort_request(struct request *req)
{
- if (req->q->mq_ops) {
- /*
- * All we need to ensure is that timeout scan takes place
- * immediately and that scan sees the new timeout value.
- * No need for fancy synchronizations.
- */
- blk_rq_set_deadline(req, jiffies);
- kblockd_schedule_work(&req->q->timeout_work);
- } else {
- if (blk_mark_rq_complete(req))
- return;
- blk_delete_timer(req);
- blk_rq_timed_out(req);
- }
+ /*
+ * All we need to ensure is that timeout scan takes place
+ * immediately and that scan sees the new timeout value.
+ * No need for fancy synchronizations.
+ */
+ WRITE_ONCE(req->deadline, jiffies);
+ kblockd_schedule_work(&req->q->timeout_work);
}
EXPORT_SYMBOL_GPL(blk_abort_request);
+
+static unsigned long blk_timeout_mask __read_mostly;
+
+static int __init blk_timeout_init(void)
+{
+ blk_timeout_mask = roundup_pow_of_two(HZ) - 1;
+ return 0;
+}
+
+late_initcall(blk_timeout_init);
+
+/*
+ * Just a rough estimate, we don't care about specific values for timeouts.
+ */
+static inline unsigned long blk_round_jiffies(unsigned long j)
+{
+ return (j + blk_timeout_mask) + 1;
+}
unsigned long blk_rq_timeout(unsigned long timeout)
{
unsigned long maxt;
- maxt = round_jiffies_up(jiffies + BLK_MAX_TIMEOUT);
+ maxt = blk_round_jiffies(jiffies + BLK_MAX_TIMEOUT);
if (time_after(timeout, maxt))
timeout = maxt;
@@ -194,15 +130,6 @@
struct request_queue *q = req->q;
unsigned long expiry;
- if (!q->mq_ops)
- lockdep_assert_held(q->queue_lock);
-
- /* blk-mq has its own handler, so we don't need ->rq_timed_out_fn */
- if (!q->mq_ops && !q->rq_timed_out_fn)
- return;
-
- BUG_ON(!list_empty(&req->timeout_list));
-
/*
* Some LLDs, like scsi, peek at the timeout to prevent a
* command from being retried forever.
@@ -211,21 +138,16 @@
req->timeout = q->rq_timeout;
req->rq_flags &= ~RQF_TIMED_OUT;
- blk_rq_set_deadline(req, jiffies + req->timeout);
- /*
- * Only the non-mq case needs to add the request to a protected list.
- * For the mq case we simply scan the tag map.
- */
- if (!q->mq_ops)
- list_add_tail(&req->timeout_list, &req->q->timeout_list);
+ expiry = jiffies + req->timeout;
+ WRITE_ONCE(req->deadline, expiry);
/*
* If the timer isn't already pending or this timeout is earlier
* than an existing one, modify the timer. Round up to next nearest
* second.
*/
- expiry = blk_rq_timeout(round_jiffies_up(blk_rq_deadline(req)));
+ expiry = blk_rq_timeout(blk_round_jiffies(expiry));
if (!timer_pending(&q->timeout) ||
time_before(expiry, q->timeout.expires)) {
--
Gitblit v1.6.2