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-rw-r--r--include/linux/nbd.h102
1 files changed, 102 insertions, 0 deletions
diff --git a/include/linux/nbd.h b/include/linux/nbd.h
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+/*
+ * 1999 Copyright (C) Pavel Machek, pavel@ucw.cz. This code is GPL.
+ * 1999/11/04 Copyright (C) 1999 VMware, Inc. (Regis "HPReg" Duchesne)
+ * Made nbd_end_request() use the io_request_lock
+ * 2001 Copyright (C) Steven Whitehouse
+ * New nbd_end_request() for compatibility with new linux block
+ * layer code.
+ * 2003/06/24 Louis D. Langholtz <ldl@aros.net>
+ * Removed unneeded blksize_bits field from nbd_device struct.
+ * Cleanup PARANOIA usage & code.
+ * 2004/02/19 Paul Clements
+ * Removed PARANOIA, plus various cleanup and comments
+ */
+
+#ifndef LINUX_NBD_H
+#define LINUX_NBD_H
+
+#include <linux/types.h>
+
+#define NBD_SET_SOCK _IO( 0xab, 0 )
+#define NBD_SET_BLKSIZE _IO( 0xab, 1 )
+#define NBD_SET_SIZE _IO( 0xab, 2 )
+#define NBD_DO_IT _IO( 0xab, 3 )
+#define NBD_CLEAR_SOCK _IO( 0xab, 4 )
+#define NBD_CLEAR_QUE _IO( 0xab, 5 )
+#define NBD_PRINT_DEBUG _IO( 0xab, 6 )
+#define NBD_SET_SIZE_BLOCKS _IO( 0xab, 7 )
+#define NBD_DISCONNECT _IO( 0xab, 8 )
+#define NBD_SET_TIMEOUT _IO( 0xab, 9 )
+
+enum {
+ NBD_CMD_READ = 0,
+ NBD_CMD_WRITE = 1,
+ NBD_CMD_DISC = 2
+};
+
+#define nbd_cmd(req) ((req)->cmd[0])
+
+/* userspace doesn't need the nbd_device structure */
+#ifdef __KERNEL__
+
+#include <linux/wait.h>
+#include <linux/mutex.h>
+
+/* values for flags field */
+#define NBD_READ_ONLY 0x0001
+#define NBD_WRITE_NOCHK 0x0002
+
+struct request;
+
+struct nbd_device {
+ int flags;
+ int harderror; /* Code of hard error */
+ struct socket * sock;
+ struct file * file; /* If == NULL, device is not ready, yet */
+ int magic;
+
+ spinlock_t queue_lock;
+ struct list_head queue_head; /* Requests waiting result */
+ struct request *active_req;
+ wait_queue_head_t active_wq;
+ struct list_head waiting_queue; /* Requests to be sent */
+ wait_queue_head_t waiting_wq;
+
+ struct mutex tx_lock;
+ struct gendisk *disk;
+ int blksize;
+ u64 bytesize;
+ pid_t pid; /* pid of nbd-client, if attached */
+ int xmit_timeout;
+};
+
+#endif
+
+/* These are sent over the network in the request/reply magic fields */
+
+#define NBD_REQUEST_MAGIC 0x25609513
+#define NBD_REPLY_MAGIC 0x67446698
+/* Do *not* use magics: 0x12560953 0x96744668. */
+
+/*
+ * This is the packet used for communication between client and
+ * server. All data are in network byte order.
+ */
+struct nbd_request {
+ __be32 magic;
+ __be32 type; /* == READ || == WRITE */
+ char handle[8];
+ __be64 from;
+ __be32 len;
+} __attribute__((packed));
+
+/*
+ * This is the reply packet that nbd-server sends back to the client after
+ * it has completed an I/O request (or an error occurs).
+ */
+struct nbd_reply {
+ __be32 magic;
+ __be32 error; /* 0 = ok, else error */
+ char handle[8]; /* handle you got from request */
+};
+#endif