6b39bb6548
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: Paul Clements <paul.clements@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
104 lines
2.5 KiB
C
104 lines
2.5 KiB
C
/*
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* 1999 Copyright (C) Pavel Machek, pavel@ucw.cz. This code is GPL.
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* 1999/11/04 Copyright (C) 1999 VMware, Inc. (Regis "HPReg" Duchesne)
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* Made nbd_end_request() use the io_request_lock
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* 2001 Copyright (C) Steven Whitehouse
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* New nbd_end_request() for compatibility with new linux block
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* layer code.
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* 2003/06/24 Louis D. Langholtz <ldl@aros.net>
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* Removed unneeded blksize_bits field from nbd_device struct.
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* Cleanup PARANOIA usage & code.
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* 2004/02/19 Paul Clements
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* Removed PARANOIA, plus various cleanup and comments
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*/
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#ifndef LINUX_NBD_H
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#define LINUX_NBD_H
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#include <linux/types.h>
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#define NBD_SET_SOCK _IO( 0xab, 0 )
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#define NBD_SET_BLKSIZE _IO( 0xab, 1 )
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#define NBD_SET_SIZE _IO( 0xab, 2 )
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#define NBD_DO_IT _IO( 0xab, 3 )
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#define NBD_CLEAR_SOCK _IO( 0xab, 4 )
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#define NBD_CLEAR_QUE _IO( 0xab, 5 )
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#define NBD_PRINT_DEBUG _IO( 0xab, 6 )
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#define NBD_SET_SIZE_BLOCKS _IO( 0xab, 7 )
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#define NBD_DISCONNECT _IO( 0xab, 8 )
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enum {
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NBD_CMD_READ = 0,
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NBD_CMD_WRITE = 1,
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NBD_CMD_DISC = 2
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};
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#define nbd_cmd(req) ((req)->cmd[0])
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#define MAX_NBD 128
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/* userspace doesn't need the nbd_device structure */
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#ifdef __KERNEL__
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#include <linux/wait.h>
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#include <linux/mutex.h>
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/* values for flags field */
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#define NBD_READ_ONLY 0x0001
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#define NBD_WRITE_NOCHK 0x0002
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struct request;
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struct nbd_device {
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int flags;
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int harderror; /* Code of hard error */
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struct socket * sock;
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struct file * file; /* If == NULL, device is not ready, yet */
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int magic;
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spinlock_t queue_lock;
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struct list_head queue_head;/* Requests are added here... */
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struct request *active_req;
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wait_queue_head_t active_wq;
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struct mutex tx_lock;
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struct gendisk *disk;
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int blksize;
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u64 bytesize;
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pid_t pid; /* pid of nbd-client, if attached */
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};
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#endif
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/* These are sent over the network in the request/reply magic fields */
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#define NBD_REQUEST_MAGIC 0x25609513
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#define NBD_REPLY_MAGIC 0x67446698
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/* Do *not* use magics: 0x12560953 0x96744668. */
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/*
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* This is the packet used for communication between client and
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* server. All data are in network byte order.
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*/
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struct nbd_request {
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__be32 magic;
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__be32 type; /* == READ || == WRITE */
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char handle[8];
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__be64 from;
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__be32 len;
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}
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#ifdef __GNUC__
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__attribute__ ((packed))
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#endif
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;
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/*
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* This is the reply packet that nbd-server sends back to the client after
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* it has completed an I/O request (or an error occurs).
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*/
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struct nbd_reply {
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__be32 magic;
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__be32 error; /* 0 = ok, else error */
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char handle[8]; /* handle you got from request */
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};
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#endif
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