diff --git a/block/blktrace.c b/block/blktrace.c index 8d3a277802603dd89c252784ea94f8dcc2d4b6d1..eb9651ccb241c28ce666300c02830ffea65df691 100644 --- a/block/blktrace.c +++ b/block/blktrace.c @@ -244,6 +244,7 @@ static struct dentry *blk_create_tree(const char *blk_name) 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); @@ -291,6 +292,44 @@ static const struct file_operations blk_dropped_fops = { .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. @@ -380,6 +419,10 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, 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) @@ -409,6 +452,8 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, 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); diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h index e3ef903aae88224fef2f43fa96b0e0f199baa09b..d084b8d227a52fb978c02a4f07d98e08b653502b 100644 --- a/include/linux/blktrace_api.h +++ b/include/linux/blktrace_api.h @@ -129,6 +129,7 @@ struct blk_trace { u32 dev; struct dentry *dir; struct dentry *dropped_file; + struct dentry *msg_file; atomic_t dropped; };