[PATCH] fault-injection capability for disk IO

[cascardo/linux.git] / block / ll_rw_blk.c

diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 0f82e12..4f83fd9 100644 (file)
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -28,13 +28,14 @@
 #include <linux/interrupt.h>
 #include <linux/cpu.h>
 #include <linux/blktrace_api.h>
+#include <linux/fault-inject.h>
 
 /*
  * for max sense size
  */
 #include <scsi/scsi_cmnd.h>
 
-static void blk_unplug_work(void *data);
+static void blk_unplug_work(struct work_struct *work);
 static void blk_unplug_timeout(unsigned long data);
 static void drive_stat_acct(struct request *rq, int nr_sectors, int new_io);
 static void init_request_from_bio(struct request *req, struct bio *bio);
@@ -44,17 +45,17 @@ static struct io_context *current_io_context(gfp_t gfp_flags, int node);
 /*
  * For the allocated request tables
  */
-static kmem_cache_t *request_cachep;
+static struct kmem_cache *request_cachep;
 
 /*
  * For queue allocation
  */
-static kmem_cache_t *requestq_cachep;
+static struct kmem_cache *requestq_cachep;
 
 /*
  * For io context allocations
  */
-static kmem_cache_t *iocontext_cachep;
+static struct kmem_cache *iocontext_cachep;
 
 /*
  * Controlling structure to kblockd
@@ -227,7 +228,7 @@ void blk_queue_make_request(request_queue_t * q, make_request_fn * mfn)
        if (q->unplug_delay == 0)
                q->unplug_delay = 1;
 
-       INIT_WORK(&q->unplug_work, blk_unplug_work, q);
+       INIT_WORK(&q->unplug_work, blk_unplug_work);
 
        q->unplug_timer.function = blk_unplug_timeout;
        q->unplug_timer.data = (unsigned long)q;
@@ -1631,9 +1632,9 @@ static void blk_backing_dev_unplug(struct backing_dev_info *bdi,
        }
 }
 
-static void blk_unplug_work(void *data)
+static void blk_unplug_work(struct work_struct *work)
 {
-       request_queue_t *q = data;
+       request_queue_t *q = container_of(work, request_queue_t, unplug_work);
 
        blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_IO, NULL,
                                q->rq.count[READ] + q->rq.count[WRITE]);
@@ -3056,6 +3057,42 @@ static void handle_bad_sector(struct bio *bio)
        set_bit(BIO_EOF, &bio->bi_flags);
 }
 
+#ifdef CONFIG_FAIL_MAKE_REQUEST
+
+static DECLARE_FAULT_ATTR(fail_make_request);
+
+static int __init setup_fail_make_request(char *str)
+{
+       return setup_fault_attr(&fail_make_request, str);
+}
+__setup("fail_make_request=", setup_fail_make_request);
+
+static int should_fail_request(struct bio *bio)
+{
+       if ((bio->bi_bdev->bd_disk->flags & GENHD_FL_FAIL) ||
+           (bio->bi_bdev->bd_part && bio->bi_bdev->bd_part->make_it_fail))
+               return should_fail(&fail_make_request, bio->bi_size);
+
+       return 0;
+}
+
+static int __init fail_make_request_debugfs(void)
+{
+       return init_fault_attr_dentries(&fail_make_request,
+                                       "fail_make_request");
+}
+
+late_initcall(fail_make_request_debugfs);
+
+#else /* CONFIG_FAIL_MAKE_REQUEST */
+
+static inline int should_fail_request(struct bio *bio)
+{
+       return 0;
+}
+
+#endif /* CONFIG_FAIL_MAKE_REQUEST */
+
 /**
  * generic_make_request: hand a buffer to its device driver for I/O
  * @bio:  The bio describing the location in memory and on the device.
@@ -3141,6 +3178,9 @@ end_io:
                if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)))
                        goto end_io;
 
+               if (should_fail_request(bio))
+                       goto end_io;
+
                /*
                 * If this device has partitions, remap block n
                 * of partition p to block n+start(p) of the disk.
@@ -3459,8 +3499,6 @@ static void blk_done_softirq(struct softirq_action *h)
        }
 }
 
-#ifdef CONFIG_HOTPLUG_CPU
-
 static int blk_cpu_notify(struct notifier_block *self, unsigned long action,
                          void *hcpu)
 {
@@ -3486,8 +3524,6 @@ static struct notifier_block __devinitdata blk_cpu_notifier = {
        .notifier_call  = blk_cpu_notify,
 };
 
-#endif /* CONFIG_HOTPLUG_CPU */
-
 /**
  * blk_complete_request - end I/O on a request
  * @req:      the request being processed