From 6b39bb6548d60b9a18826134b5ccd5c3cef85fe2 Mon Sep 17 00:00:00 2001 From: Paul Clements Date: Wed, 6 Dec 2006 20:40:53 -0800 Subject: [PATCH] nbd: show nbd client pid in sysfs Allow nbd to expose the nbd-client daemon's PID in /sys/block/nbd/pid. This is helpful for tracking connection status of a device and for determining which nbd devices are currently in use. Signed-off-by: Paul Clements Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/block/nbd.c | 16 ++++++++++++++++ include/linux/nbd.h | 1 + 2 files changed, 17 insertions(+) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 9d1035e8d9d..7bf2cfbd628 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -355,14 +355,30 @@ harderror: return NULL; } +static ssize_t pid_show(struct gendisk *disk, char *page) +{ + return sprintf(page, "%ld\n", + (long) ((struct nbd_device *)disk->private_data)->pid); +} + +static struct disk_attribute pid_attr = { + .attr = { .name = "pid", .mode = S_IRUGO }, + .show = pid_show, +}; + static void nbd_do_it(struct nbd_device *lo) { struct request *req; BUG_ON(lo->magic != LO_MAGIC); + lo->pid = current->pid; + sysfs_create_file(&lo->disk->kobj, &pid_attr.attr); + while ((req = nbd_read_stat(lo)) != NULL) nbd_end_request(req); + + sysfs_remove_file(&lo->disk->kobj, &pid_attr.attr); return; } diff --git a/include/linux/nbd.h b/include/linux/nbd.h index d6b6dc09ad9..0f3e6930254 100644 --- a/include/linux/nbd.h +++ b/include/linux/nbd.h @@ -64,6 +64,7 @@ struct nbd_device { struct gendisk *disk; int blksize; u64 bytesize; + pid_t pid; /* pid of nbd-client, if attached */ }; #endif -- cgit v1.2.3