block: fix oops in blk_queue_io_stat()

[safe/jmp/linux-2.6] / block / blk-sysfs.c

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 21e275d..e29ddfc 100644 (file)
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -88,9 +88,7 @@ queue_ra_store(struct request_queue *q, const char *page, size_t count)
        unsigned long ra_kb;
        ssize_t ret = queue_var_store(&ra_kb, page, count);
 
-       spin_lock_irq(q->queue_lock);
        q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10);
-       spin_unlock_irq(q->queue_lock);
 
        return ret;
 }
@@ -117,10 +115,7 @@ queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
 
        if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
                return -EINVAL;
-       /*
-        * Take the queue lock to update the readahead and max_sectors
-        * values synchronously:
-        */
+
        spin_lock_irq(q->queue_lock);
        q->max_sectors = max_sectors_kb << 1;
        spin_unlock_irq(q->queue_lock);
@@ -135,6 +130,27 @@ static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
        return queue_var_show(max_hw_sectors_kb, (page));
 }
 
+static ssize_t queue_nonrot_show(struct request_queue *q, char *page)
+{
+       return queue_var_show(!blk_queue_nonrot(q), page);
+}
+
+static ssize_t queue_nonrot_store(struct request_queue *q, const char *page,
+                                 size_t count)
+{
+       unsigned long nm;
+       ssize_t ret = queue_var_store(&nm, page, count);
+
+       spin_lock_irq(q->queue_lock);
+       if (nm)
+               queue_flag_clear(QUEUE_FLAG_NONROT, q);
+       else
+               queue_flag_set(QUEUE_FLAG_NONROT, q);
+       spin_unlock_irq(q->queue_lock);
+
+       return ret;
+}
+
 static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
 {
        return queue_var_show(blk_queue_nomerges(q), page);
@@ -151,8 +167,8 @@ static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
                queue_flag_set(QUEUE_FLAG_NOMERGES, q);
        else
                queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
-
        spin_unlock_irq(q->queue_lock);
+
        return ret;
 }
 
@@ -181,6 +197,27 @@ queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
        return ret;
 }
 
+static ssize_t queue_iostats_show(struct request_queue *q, char *page)
+{
+       return queue_var_show(blk_queue_io_stat(q), page);
+}
+
+static ssize_t queue_iostats_store(struct request_queue *q, const char *page,
+                                  size_t count)
+{
+       unsigned long stats;
+       ssize_t ret = queue_var_store(&stats, page, count);
+
+       spin_lock_irq(q->queue_lock);
+       if (stats)
+               queue_flag_set(QUEUE_FLAG_IO_STAT, q);
+       else
+               queue_flag_clear(QUEUE_FLAG_IO_STAT, q);
+       spin_unlock_irq(q->queue_lock);
+
+       return ret;
+}
+
 static struct queue_sysfs_entry queue_requests_entry = {
        .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
        .show = queue_requests_show,
@@ -215,6 +252,12 @@ static struct queue_sysfs_entry queue_hw_sector_size_entry = {
        .show = queue_hw_sector_size_show,
 };
 
+static struct queue_sysfs_entry queue_nonrot_entry = {
+       .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
+       .show = queue_nonrot_show,
+       .store = queue_nonrot_store,
+};
+
 static struct queue_sysfs_entry queue_nomerges_entry = {
        .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
        .show = queue_nomerges_show,
@@ -227,6 +270,12 @@ static struct queue_sysfs_entry queue_rq_affinity_entry = {
        .store = queue_rq_affinity_store,
 };
 
+static struct queue_sysfs_entry queue_iostats_entry = {
+       .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR },
+       .show = queue_iostats_show,
+       .store = queue_iostats_store,
+};
+
 static struct attribute *default_attrs[] = {
        &queue_requests_entry.attr,
        &queue_ra_entry.attr,
@@ -234,8 +283,10 @@ static struct attribute *default_attrs[] = {
        &queue_max_sectors_entry.attr,
        &queue_iosched_entry.attr,
        &queue_hw_sector_size_entry.attr,
+       &queue_nonrot_entry.attr,
        &queue_nomerges_entry.attr,
        &queue_rq_affinity_entry.attr,
+       &queue_iostats_entry.attr,
        NULL,
 };