Commit 6b39bb65 authored by Paul Clements's avatar Paul Clements Committed by Linus Torvalds

[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
......@@ -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;
}
......
......@@ -64,6 +64,7 @@ struct nbd_device {
struct gendisk *disk;
int blksize;
u64 bytesize;
pid_t pid; /* pid of nbd-client, if attached */
};
#endif
......
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