bt->pid = buts->pid;
bt->trace_state = Blktrace_setup;
- if (atomic_add_return(1, &blk_probes_ref) == 1)
- blk_register_tracepoints();
-
ret = -EBUSY;
old_bt = xchg(&q->blk_trace, bt);
if (old_bt) {
goto err;
}
+ if (atomic_add_return(1, &blk_probes_ref) == 1)
+ blk_register_tracepoints();
+
return 0;
err:
if (bt) {
static int blk_trace_setup_queue(struct request_queue *q, dev_t dev)
{
struct blk_trace *old_bt, *bt = NULL;
- int ret;
- ret = -ENOMEM;
bt = kzalloc(sizeof(*bt), GFP_KERNEL);
if (!bt)
- goto err;
+ return -ENOMEM;
bt->dev = dev;
bt->act_mask = (u16)-1;
if (old_bt != NULL) {
(void)xchg(&q->blk_trace, old_bt);
kfree(bt);
- ret = -EBUSY;
+ return -EBUSY;
}
+
return 0;
-err:
- return ret;
}
/*
* sysfs interface to enable and configure tracing
*/
-static ssize_t sysfs_blk_trace_enable_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
-{
- struct hd_struct *p = dev_to_part(dev);
- struct block_device *bdev;
- ssize_t ret = -ENXIO;
-
- lock_kernel();
- bdev = bdget(part_devt(p));
- if (bdev != NULL) {
- struct request_queue *q = bdev_get_queue(bdev);
-
- if (q != NULL) {
- mutex_lock(&bdev->bd_mutex);
- ret = sprintf(buf, "%u\n", !!q->blk_trace);
- mutex_unlock(&bdev->bd_mutex);
- }
-
- bdput(bdev);
- }
-
- unlock_kernel();
- return ret;
-}
-
-static ssize_t sysfs_blk_trace_enable_store(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t count)
-{
- struct block_device *bdev;
- struct request_queue *q;
- struct hd_struct *p;
- int value;
- ssize_t ret = -ENXIO;
-
- if (count == 0 || sscanf(buf, "%d", &value) != 1)
- goto out;
-
- lock_kernel();
- p = dev_to_part(dev);
- bdev = bdget(part_devt(p));
- if (bdev == NULL)
- goto out_unlock_kernel;
-
- q = bdev_get_queue(bdev);
- if (q == NULL)
- goto out_bdput;
-
- mutex_lock(&bdev->bd_mutex);
- if (value)
- ret = blk_trace_setup_queue(q, bdev->bd_dev);
- else
- ret = blk_trace_remove_queue(q);
- mutex_unlock(&bdev->bd_mutex);
-
- if (ret == 0)
- ret = count;
-out_bdput:
- bdput(bdev);
-out_unlock_kernel:
- unlock_kernel();
-out:
- return ret;
-}
-
static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
struct device_attribute *attr,
char *buf);
sysfs_blk_trace_attr_show, \
sysfs_blk_trace_attr_store)
-static DEVICE_ATTR(enable, S_IRUGO | S_IWUSR,
- sysfs_blk_trace_enable_show, sysfs_blk_trace_enable_store);
+static BLK_TRACE_DEVICE_ATTR(enable);
static BLK_TRACE_DEVICE_ATTR(act_mask);
static BLK_TRACE_DEVICE_ATTR(pid);
static BLK_TRACE_DEVICE_ATTR(start_lba);
if (q == NULL)
goto out_bdput;
mutex_lock(&bdev->bd_mutex);
+
+ if (attr == &dev_attr_enable) {
+ ret = sprintf(buf, "%u\n", !!q->blk_trace);
+ goto out_unlock_bdev;
+ }
+
if (q->blk_trace == NULL)
ret = sprintf(buf, "disabled\n");
else if (attr == &dev_attr_act_mask)
ret = sprintf(buf, "%llu\n", q->blk_trace->start_lba);
else if (attr == &dev_attr_end_lba)
ret = sprintf(buf, "%llu\n", q->blk_trace->end_lba);
+
+out_unlock_bdev:
mutex_unlock(&bdev->bd_mutex);
out_bdput:
bdput(bdev);
goto out_bdput;
mutex_lock(&bdev->bd_mutex);
+
+ if (attr == &dev_attr_enable) {
+ if (value)
+ ret = blk_trace_setup_queue(q, bdev->bd_dev);
+ else
+ ret = blk_trace_remove_queue(q);
+ goto out_unlock_bdev;
+ }
+
ret = 0;
if (q->blk_trace == NULL)
ret = blk_trace_setup_queue(q, bdev->bd_dev);
q->blk_trace->start_lba = value;
else if (attr == &dev_attr_end_lba)
q->blk_trace->end_lba = value;
- ret = count;
}
+
+out_unlock_bdev:
mutex_unlock(&bdev->bd_mutex);
out_bdput:
bdput(bdev);
out_unlock_kernel:
unlock_kernel();
out:
- return ret;
+ return ret ? ret : count;
}
+