nbd.h 2.3 KB

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  1. /*
  2. * 1999 Copyright (C) Pavel Machek, pavel@ucw.cz. This code is GPL.
  3. * 1999/11/04 Copyright (C) 1999 VMware, Inc. (Regis "HPReg" Duchesne)
  4. * Made nbd_end_request() use the io_request_lock
  5. * 2001 Copyright (C) Steven Whitehouse
  6. * New nbd_end_request() for compatibility with new linux block
  7. * layer code.
  8. * 2003/06/24 Louis D. Langholtz <ldl@aros.net>
  9. * Removed unneeded blksize_bits field from nbd_device struct.
  10. * Cleanup PARANOIA usage & code.
  11. * 2004/02/19 Paul Clements
  12. * Removed PARANOIA, plus various cleanup and comments
  13. */
  14. #ifndef LINUX_NBD_H
  15. #define LINUX_NBD_H
  16. #include <linux/types.h>
  17. #define NBD_SET_SOCK _IO( 0xab, 0 )
  18. #define NBD_SET_BLKSIZE _IO( 0xab, 1 )
  19. #define NBD_SET_SIZE _IO( 0xab, 2 )
  20. #define NBD_DO_IT _IO( 0xab, 3 )
  21. #define NBD_CLEAR_SOCK _IO( 0xab, 4 )
  22. #define NBD_CLEAR_QUE _IO( 0xab, 5 )
  23. #define NBD_PRINT_DEBUG _IO( 0xab, 6 )
  24. #define NBD_SET_SIZE_BLOCKS _IO( 0xab, 7 )
  25. #define NBD_DISCONNECT _IO( 0xab, 8 )
  26. #define NBD_SET_TIMEOUT _IO( 0xab, 9 )
  27. #define NBD_SET_FLAGS _IO( 0xab, 10)
  28. enum {
  29. NBD_CMD_READ = 0,
  30. NBD_CMD_WRITE = 1,
  31. NBD_CMD_DISC = 2,
  32. NBD_CMD_FLUSH = 3,
  33. NBD_CMD_TRIM = 4
  34. };
  35. /* values for flags field */
  36. #define NBD_FLAG_HAS_FLAGS (1 << 0) /* nbd-server supports flags */
  37. #define NBD_FLAG_READ_ONLY (1 << 1) /* device is read-only */
  38. #define NBD_FLAG_SEND_FLUSH (1 << 2) /* can flush writeback cache */
  39. /* there is a gap here to match userspace */
  40. #define NBD_FLAG_SEND_TRIM (1 << 5) /* send trim/discard */
  41. /* userspace doesn't need the nbd_device structure */
  42. /* These are sent over the network in the request/reply magic fields */
  43. #define NBD_REQUEST_MAGIC 0x25609513
  44. #define NBD_REPLY_MAGIC 0x67446698
  45. /* Do *not* use magics: 0x12560953 0x96744668. */
  46. /*
  47. * This is the packet used for communication between client and
  48. * server. All data are in network byte order.
  49. */
  50. struct nbd_request {
  51. __be32 magic;
  52. __be32 type; /* == READ || == WRITE */
  53. char handle[8];
  54. __be64 from;
  55. __be32 len;
  56. } __attribute__((packed));
  57. /*
  58. * This is the reply packet that nbd-server sends back to the client after
  59. * it has completed an I/O request (or an error occurs).
  60. */
  61. struct nbd_reply {
  62. __be32 magic;
  63. __be32 error; /* 0 = ok, else error */
  64. char handle[8]; /* handle you got from request */
  65. };
  66. #endif /* LINUX_NBD_H */