#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/blkdev.h>
+#include <linux/fault-inject.h>
#include "blk.h"
+#ifdef CONFIG_FAIL_IO_TIMEOUT
+
+static DECLARE_FAULT_ATTR(fail_io_timeout);
+
+static int __init setup_fail_io_timeout(char *str)
+{
+ return setup_fault_attr(&fail_io_timeout, str);
+}
+__setup("fail_io_timeout=", setup_fail_io_timeout);
+
+int 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);
+}
+
+static int __init fail_io_timeout_debugfs(void)
+{
+ return init_fault_attr_dentries(&fail_io_timeout, "fail_io_timeout");
+}
+
+late_initcall(fail_io_timeout_debugfs);
+
+ssize_t part_timeout_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+ int set = test_bit(QUEUE_FLAG_FAIL_IO, &disk->queue->queue_flags);
+
+ return sprintf(buf, "%d\n", set != 0);
+}
+
+ssize_t part_timeout_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+ int val;
+
+ if (count) {
+ struct request_queue *q = disk->queue;
+ char *p = (char *) buf;
+
+ val = simple_strtoul(p, &p, 10);
+ spin_lock_irq(q->queue_lock);
+ if (val)
+ queue_flag_set(QUEUE_FLAG_FAIL_IO, q);
+ else
+ queue_flag_clear(QUEUE_FLAG_FAIL_IO, q);
+ spin_unlock_irq(q->queue_lock);
+ }
+
+ return count;
+}
+
+#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)
{
- struct request_queue *q = req->q;
-
- /*
- * Nothing to detach
- */
- if (!q->rq_timed_out_fn || !req->deadline)
- return;
-
list_del_init(&req->timeout_list);
-
- if (list_empty(&q->timeout_list))
- del_timer(&q->timeout);
}
static void blk_rq_timed_out(struct request *req)
void blk_rq_timed_out_timer(unsigned long data)
{
struct request_queue *q = (struct request_queue *) data;
- unsigned long flags, uninitialized_var(next), next_set = 0;
+ unsigned long flags, next = 0;
struct request *rq, *tmp;
spin_lock_irqsave(q->queue_lock, flags);
if (blk_mark_rq_complete(rq))
continue;
blk_rq_timed_out(rq);
- }
- if (!next_set) {
- next = rq->deadline;
- next_set = 1;
- } else if (time_after(next, rq->deadline))
+ } else if (!next || time_after(next, rq->deadline))
next = rq->deadline;
}
- if (next_set && !list_empty(&q->timeout_list))
- mod_timer(&q->timeout, round_jiffies(next));
+ /*
+ * next can never be 0 here with the list non-empty, since we always
+ * bump ->deadline to 1 so we can detect if the timer was ever added
+ * or not. See comment in blk_add_timer()
+ */
+ if (next)
+ mod_timer(&q->timeout, round_jiffies_up(next));
spin_unlock_irqrestore(q->queue_lock, flags);
}
*/
void blk_abort_request(struct request *req)
{
+ if (blk_mark_rq_complete(req))
+ return;
blk_delete_timer(req);
blk_rq_timed_out(req);
}
BUG_ON(!list_empty(&req->timeout_list));
BUG_ON(test_bit(REQ_ATOM_COMPLETE, &req->atomic_flags));
- if (req->timeout)
- req->deadline = jiffies + req->timeout;
- else {
- req->deadline = jiffies + q->rq_timeout;
- /*
- * Some LLDs, like scsi, peek at the timeout to prevent
- * a command from being retried forever.
- */
+ /*
+ * Some LLDs, like scsi, peek at the timeout to prevent a
+ * command from being retried forever.
+ */
+ if (!req->timeout)
req->timeout = q->rq_timeout;
- }
+
+ req->deadline = jiffies + req->timeout;
list_add_tail(&req->timeout_list, &q->timeout_list);
/*
* If the timer isn't already pending or this timeout is earlier
- * than an existing one, modify the timer. Round to next nearest
+ * than an existing one, modify the timer. Round up to next nearest
* second.
*/
- expiry = round_jiffies(req->deadline);
-
- /*
- * We use ->deadline == 0 to detect whether a timer was added or
- * not, so just increase to next jiffy for that specific case
- */
- if (unlikely(!req->deadline))
- req->deadline = 1;
+ expiry = round_jiffies_up(req->deadline);
if (!timer_pending(&q->timeout) ||
time_before(expiry, q->timeout.expires))
{
unsigned long flags;
struct request *rq, *tmp;
+ LIST_HEAD(list);
+
+ /*
+ * Not a request based block device, nothing to abort
+ */
+ if (!q->request_fn)
+ return;
spin_lock_irqsave(q->queue_lock, flags);
elv_abort_queue(q);
- list_for_each_entry_safe(rq, tmp, &q->timeout_list, timeout_list)
+ /*
+ * Splice entries to local list, to avoid deadlocking if entries
+ * get readded to the timeout list by error handling
+ */
+ list_splice_init(&q->timeout_list, &list);
+
+ list_for_each_entry_safe(rq, tmp, &list, timeout_list)
blk_abort_request(rq);
+ /*
+ * Occasionally, blk_abort_request() will return without
+ * deleting the element from the list. Make sure we add those back
+ * instead of leaving them on the local stack list.
+ */
+ list_splice(&list, &q->timeout_list);
+
spin_unlock_irqrestore(q->queue_lock, flags);
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff