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Commit 6b39bb65 authored by Paul Clements's avatar Paul Clements Committed by Linus Torvalds
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[PATCH] nbd: show nbd client pid in sysfs 



Allow nbd to expose the nbd-client daemon's PID in /sys/block/nbd<x>/pid.

This is helpful for tracking connection status of a device and for
determining which nbd devices are currently in use.

Signed-off-by: default avatarPaul Clements <paul.clements@steeleye.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 79290822

drivers/block/nbd.c

+16 −0
Original line number Diff line number Diff line
@@ -355,14 +355,30 @@ static struct request *nbd_read_stat(struct nbd_device *lo) 
	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;

}

include/linux/nbd.h

+1 −0
Original line number Diff line number Diff line
@@ -64,6 +64,7 @@ struct nbd_device { 
	struct gendisk *disk;

	int blksize;

	u64 bytesize;

	pid_t pid; /* pid of nbd-client, if attached */

};



#endif