local_irq_restore(flags);
}
+void __trace_note_message(struct blk_trace *bt, const char *fmt, ...)
+{
+ int n;
+ va_list args;
+ unsigned long flags;
+ char *buf;
+
+ local_irq_save(flags);
+ buf = per_cpu_ptr(bt->msg_data, smp_processor_id());
+ va_start(args, fmt);
+ n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args);
+ va_end(args);
+
+ trace_note(bt, 0, BLK_TN_MESSAGE, buf, n);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL_GPL(__trace_note_message);
+
static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector,
pid_t pid)
{
/*
* A word about the locking here - we disable interrupts to reserve
* some space in the relay per-cpu buffer, to prevent an irq
- * from coming in and stepping on our toes. Once reserved, it's
- * enough to get preemption disabled to prevent read of this data
- * before we are through filling it. get_cpu()/put_cpu() does this
- * for us
+ * from coming in and stepping on our toes.
*/
local_irq_save(flags);
static void blk_trace_cleanup(struct blk_trace *bt)
{
relay_close(bt->rchan);
+ debugfs_remove(bt->msg_file);
debugfs_remove(bt->dropped_file);
blk_remove_tree(bt->dir);
free_percpu(bt->sequence);
+ free_percpu(bt->msg_data);
kfree(bt);
}
-static int blk_trace_remove(struct request_queue *q)
+int blk_trace_remove(struct request_queue *q)
{
struct blk_trace *bt;
return 0;
}
+EXPORT_SYMBOL_GPL(blk_trace_remove);
static int blk_dropped_open(struct inode *inode, struct file *filp)
{
.read = blk_dropped_read,
};
+static int blk_msg_open(struct inode *inode, struct file *filp)
+{
+ filp->private_data = inode->i_private;
+
+ return 0;
+}
+
+static ssize_t blk_msg_write(struct file *filp, const char __user *buffer,
+ size_t count, loff_t *ppos)
+{
+ char *msg;
+ struct blk_trace *bt;
+
+ if (count > BLK_TN_MAX_MSG)
+ return -EINVAL;
+
+ msg = kmalloc(count, GFP_KERNEL);
+ if (msg == NULL)
+ return -ENOMEM;
+
+ if (copy_from_user(msg, buffer, count)) {
+ kfree(msg);
+ return -EFAULT;
+ }
+
+ bt = filp->private_data;
+ __trace_note_message(bt, "%s", msg);
+ kfree(msg);
+
+ return count;
+}
+
+static const struct file_operations blk_msg_fops = {
+ .owner = THIS_MODULE,
+ .open = blk_msg_open,
+ .write = blk_msg_write,
+};
+
/*
* Keep track of how many times we encountered a full subbuffer, to aid
* the user space app in telling how many lost events there were.
/*
* Setup everything required to start tracing
*/
-int do_blk_trace_setup(struct request_queue *q, struct block_device *bdev,
+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;
- char b[BDEVNAME_SIZE];
int ret, i;
if (!buts->buf_size || !buts->buf_nr)
return -EINVAL;
- strcpy(buts->name, bdevname(bdev, b));
+ strcpy(buts->name, name);
/*
* some device names have larger paths - convert the slashes
if (!bt->sequence)
goto err;
+ bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG);
+ if (!bt->msg_data)
+ goto err;
+
ret = -ENOENT;
dir = blk_create_tree(buts->name);
if (!dir)
goto err;
bt->dir = dir;
- bt->dev = bdev->bd_dev;
+ bt->dev = dev;
atomic_set(&bt->dropped, 0);
ret = -EIO;
if (!bt->dropped_file)
goto err;
+ bt->msg_file = debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops);
+ if (!bt->msg_file)
+ goto err;
+
bt->rchan = relay_open("trace", dir, buts->buf_size,
buts->buf_nr, &blk_relay_callbacks, bt);
if (!bt->rchan)
if (dir)
blk_remove_tree(dir);
if (bt) {
+ if (bt->msg_file)
+ debugfs_remove(bt->msg_file);
if (bt->dropped_file)
debugfs_remove(bt->dropped_file);
free_percpu(bt->sequence);
+ free_percpu(bt->msg_data);
if (bt->rchan)
relay_close(bt->rchan);
kfree(bt);
return ret;
}
-static int blk_trace_setup(struct request_queue *q, struct block_device *bdev,
- char __user *arg)
+int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
+ char __user *arg)
{
struct blk_user_trace_setup buts;
int ret;
if (ret)
return -EFAULT;
- ret = do_blk_trace_setup(q, bdev, &buts);
+ ret = do_blk_trace_setup(q, name, dev, &buts);
if (ret)
return ret;
return 0;
}
+EXPORT_SYMBOL_GPL(blk_trace_setup);
-static int blk_trace_startstop(struct request_queue *q, int start)
+int blk_trace_startstop(struct request_queue *q, int start)
{
struct blk_trace *bt;
int ret;
return ret;
}
+EXPORT_SYMBOL_GPL(blk_trace_startstop);
/**
* blk_trace_ioctl: - handle the ioctls associated with tracing
{
struct request_queue *q;
int ret, start = 0;
+ char b[BDEVNAME_SIZE];
q = bdev_get_queue(bdev);
if (!q)
switch (cmd) {
case BLKTRACESETUP:
- ret = blk_trace_setup(q, bdev, arg);
+ bdevname(bdev, b);
+ ret = blk_trace_setup(q, b, bdev->bd_dev, arg);
break;
case BLKTRACESTART:
start = 1;