From 30d53d9c11b6c2f71253a2be582969d7e6fa7f10 Mon Sep 17 00:00:00 2001 From: Markus Pargmann Date: Mon, 17 Aug 2015 08:20:06 +0200 Subject: nbd: Add debugfs entries Add some debugfs files that help to understand the internal state of NBD. This exports the different sizes, flags, tasks and so on. Signed-off-by: Markus Pargmann Signed-off-by: Jens Axboe --- drivers/block/nbd.c | 178 +++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 177 insertions(+), 1 deletion(-) (limited to 'drivers/block/nbd.c') diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index eeefa5cac520..6dd8305840bb 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include @@ -61,8 +62,18 @@ struct nbd_device { struct timer_list timeout_timer; struct task_struct *task_recv; struct task_struct *task_send; + +#if IS_ENABLED(CONFIG_DEBUG_FS) + struct dentry *dbg_dir; +#endif }; +#if IS_ENABLED(CONFIG_DEBUG_FS) +static struct dentry *nbd_dbg_dir; +#endif + +#define nbd_name(nbd) ((nbd)->disk->disk_name) + #define NBD_MAGIC 0x68797548 static unsigned int nbds_max = 16; @@ -609,6 +620,9 @@ static void do_nbd_request(struct request_queue *q) } } +static int nbd_dev_dbg_init(struct nbd_device *nbd); +static void nbd_dev_dbg_close(struct nbd_device *nbd); + /* Must be called with tx_lock held */ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, @@ -725,13 +739,15 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, blk_queue_flush(nbd->disk->queue, 0); thread = kthread_run(nbd_thread, nbd, "%s", - nbd->disk->disk_name); + nbd_name(nbd)); if (IS_ERR(thread)) { mutex_lock(&nbd->tx_lock); return PTR_ERR(thread); } + nbd_dev_dbg_init(nbd); error = nbd_do_it(nbd); + nbd_dev_dbg_close(nbd); kthread_stop(thread); mutex_lock(&nbd->tx_lock); @@ -797,6 +813,161 @@ static const struct block_device_operations nbd_fops = .ioctl = nbd_ioctl, }; +#if IS_ENABLED(CONFIG_DEBUG_FS) + +static int nbd_dbg_tasks_show(struct seq_file *s, void *unused) +{ + struct nbd_device *nbd = s->private; + + if (nbd->task_recv) + seq_printf(s, "recv: %d\n", task_pid_nr(nbd->task_recv)); + if (nbd->task_send) + seq_printf(s, "send: %d\n", task_pid_nr(nbd->task_send)); + + return 0; +} + +static int nbd_dbg_tasks_open(struct inode *inode, struct file *file) +{ + return single_open(file, nbd_dbg_tasks_show, inode->i_private); +} + +static const struct file_operations nbd_dbg_tasks_ops = { + .open = nbd_dbg_tasks_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static int nbd_dbg_flags_show(struct seq_file *s, void *unused) +{ + struct nbd_device *nbd = s->private; + u32 flags = nbd->flags; + + seq_printf(s, "Hex: 0x%08x\n\n", flags); + + seq_puts(s, "Known flags:\n"); + + if (flags & NBD_FLAG_HAS_FLAGS) + seq_puts(s, "NBD_FLAG_HAS_FLAGS\n"); + if (flags & NBD_FLAG_READ_ONLY) + seq_puts(s, "NBD_FLAG_READ_ONLY\n"); + if (flags & NBD_FLAG_SEND_FLUSH) + seq_puts(s, "NBD_FLAG_SEND_FLUSH\n"); + if (flags & NBD_FLAG_SEND_TRIM) + seq_puts(s, "NBD_FLAG_SEND_TRIM\n"); + + return 0; +} + +static int nbd_dbg_flags_open(struct inode *inode, struct file *file) +{ + return single_open(file, nbd_dbg_flags_show, inode->i_private); +} + +static const struct file_operations nbd_dbg_flags_ops = { + .open = nbd_dbg_flags_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static int nbd_dev_dbg_init(struct nbd_device *nbd) +{ + struct dentry *dir; + struct dentry *f; + + dir = debugfs_create_dir(nbd_name(nbd), nbd_dbg_dir); + if (IS_ERR_OR_NULL(dir)) { + dev_err(nbd_to_dev(nbd), "Failed to create debugfs dir for '%s' (%ld)\n", + nbd_name(nbd), PTR_ERR(dir)); + return PTR_ERR(dir); + } + nbd->dbg_dir = dir; + + f = debugfs_create_file("tasks", 0444, dir, nbd, &nbd_dbg_tasks_ops); + if (IS_ERR_OR_NULL(f)) { + dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'tasks', %ld\n", + PTR_ERR(f)); + return PTR_ERR(f); + } + + f = debugfs_create_u64("size_bytes", 0444, dir, &nbd->bytesize); + if (IS_ERR_OR_NULL(f)) { + dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'size_bytes', %ld\n", + PTR_ERR(f)); + return PTR_ERR(f); + } + + f = debugfs_create_u32("timeout", 0444, dir, &nbd->xmit_timeout); + if (IS_ERR_OR_NULL(f)) { + dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'timeout', %ld\n", + PTR_ERR(f)); + return PTR_ERR(f); + } + + f = debugfs_create_u32("blocksize", 0444, dir, &nbd->blksize); + if (IS_ERR_OR_NULL(f)) { + dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'blocksize', %ld\n", + PTR_ERR(f)); + return PTR_ERR(f); + } + + f = debugfs_create_file("flags", 0444, dir, &nbd, &nbd_dbg_flags_ops); + if (IS_ERR_OR_NULL(f)) { + dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'flags', %ld\n", + PTR_ERR(f)); + return PTR_ERR(f); + } + + return 0; +} + +static void nbd_dev_dbg_close(struct nbd_device *nbd) +{ + debugfs_remove_recursive(nbd->dbg_dir); +} + +static int nbd_dbg_init(void) +{ + struct dentry *dbg_dir; + + dbg_dir = debugfs_create_dir("nbd", NULL); + if (IS_ERR(dbg_dir)) + return PTR_ERR(dbg_dir); + + nbd_dbg_dir = dbg_dir; + + return 0; +} + +static void nbd_dbg_close(void) +{ + debugfs_remove_recursive(nbd_dbg_dir); +} + +#else /* IS_ENABLED(CONFIG_DEBUG_FS) */ + +static int nbd_dev_dbg_init(struct nbd_device *nbd) +{ + return 0; +} + +static void nbd_dev_dbg_close(struct nbd_device *nbd) +{ +} + +static int nbd_dbg_init(void) +{ + return 0; +} + +static void nbd_dbg_close(void) +{ +} + +#endif + /* * And here should be modules and kernel interface * (Just smiley confuses emacs :-) @@ -874,6 +1045,8 @@ static int __init nbd_init(void) printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR); + nbd_dbg_init(); + for (i = 0; i < nbds_max; i++) { struct gendisk *disk = nbd_dev[i].disk; nbd_dev[i].magic = NBD_MAGIC; @@ -910,6 +1083,9 @@ out: static void __exit nbd_cleanup(void) { int i; + + nbd_dbg_close(); + for (i = 0; i < nbds_max; i++) { struct gendisk *disk = nbd_dev[i].disk; nbd_dev[i].magic = 0; -- cgit v1.2.3