/*
* Setup everything required to start tracing
*/
static int blk_trace_setup(request_queue_t *q, struct block_device *bdev,
char __user *arg)
{
struct blk_user_trace_setup buts;
struct blk_trace *old_bt, *bt = NULL;
struct dentry *dir = NULL;
char b[BDEVNAME_SIZE];
int ret, i;
if (copy_from_user(&buts, arg, sizeof(buts)))
return -EFAULT;
if (!buts.buf_size || !buts.buf_nr)
return -EINVAL;
strcpy(buts.name, bdevname(bdev, b));
/*
* some device names have larger paths - convert the slashes
* to underscores for this to work as expected
*/
for (i = 0; i < strlen(buts.name); i++)
if (buts.name[i] == '/')
buts.name[i] = '_';
if (copy_to_user(arg, &buts, sizeof(buts)))
return -EFAULT;
ret = -ENOMEM;
bt = kzalloc(sizeof(*bt), GFP_KERNEL);
if (!bt)
goto err;
bt->sequence = alloc_percpu(unsigned long);
if (!bt->sequence)
goto err;
ret = -ENOENT;
dir = blk_create_tree(buts.name);
if (!dir)
goto err;
bt->dir = dir;
bt->dev = bdev->bd_dev;
atomic_set(&bt->dropped, 0);
ret = -EIO;
bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt, &blk_dropped_fops);
if (!bt->dropped_file)
goto err;
bt->rchan = relay_open("trace", dir, buts.buf_size, buts.buf_nr, &blk_relay_callbacks);
if (!bt->rchan)
goto err;
bt->rchan->private_data = bt;
bt->act_mask = buts.act_mask;
if (!bt->act_mask)
bt->act_mask = (u16) -1;
bt->start_lba = buts.start_lba;
bt->end_lba = buts.end_lba;
if (!bt->end_lba)
bt->end_lba = -1ULL;
bt->pid = buts.pid;
bt->trace_state = Blktrace_setup;
ret = -EBUSY;
old_bt = xchg(&q->blk_trace, bt);
if (old_bt) {
(void) xchg(&q->blk_trace, old_bt);
goto err;
}
return 0;
err:
if (dir)
blk_remove_tree(dir);
if (bt) {
if (bt->dropped_file)
debugfs_remove(bt->dropped_file);
if (bt->sequence)
free_percpu(bt->sequence);
if (bt->rchan)
relay_close(bt->rchan);
kfree(bt);
}
return ret;
}
/*
* Setup everything required to start tracing
*/
int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
struct blk_user_trace_setup *buts)
{
struct blk_trace *old_bt, *bt = NULL;
struct dentry *dir = NULL;
int ret, i;
if (!buts->buf_size || !buts->buf_nr)
return -EINVAL;
strcpy(buts->name, name);
/*
* some device names have larger paths - convert the slashes
* to underscores for this to work as expected
*/
for (i = 0; i < strlen(buts->name); i++)
if (buts->name[i] == '/')
buts->name[i] = '_';
ret = -ENOMEM;
bt = kzalloc(sizeof(*bt), GFP_KERNEL);
if (!bt)
goto err;
bt->sequence = alloc_percpu(unsigned long);
if (!bt->sequence)
goto err;
ret = -ENOENT;
dir = blk_create_tree(buts->name);
if (!dir)
goto err;
bt->dir = dir;
bt->dev = dev;
atomic_set(&bt->dropped, 0);
ret = -EIO;
bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt, &blk_dropped_fops);
if (!bt->dropped_file)
goto err;
bt->rchan = relay_open("trace", dir, buts->buf_size,
buts->buf_nr, &blk_relay_callbacks, bt);
if (!bt->rchan)
goto err;
bt->act_mask = buts->act_mask;
if (!bt->act_mask)
bt->act_mask = (u16) -1;
bt->start_lba = buts->start_lba;
bt->end_lba = buts->end_lba;
if (!bt->end_lba)
bt->end_lba = -1ULL;
bt->pid = buts->pid;
bt->trace_state = Blktrace_setup;
ret = -EBUSY;
old_bt = xchg(&q->blk_trace, bt);
if (old_bt) {
(void) xchg(&q->blk_trace, old_bt);
goto err;
}
return 0;
err:
if (dir)
blk_remove_tree(dir);
if (bt) {
if (bt->dropped_file)
debugfs_remove(bt->dropped_file);
free_percpu(bt->sequence);
if (bt->rchan)
relay_close(bt->rchan);
kfree(bt);
}
return ret;
}