ioctl.h 3.6 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. #ifndef FS_CEPH_IOCTL_H
  3. #define FS_CEPH_IOCTL_H
  4. #include <linux/ioctl.h>
  5. #include <linux/types.h>
  6. #define CEPH_IOCTL_MAGIC 0x97
  7. /*
  8. * CEPH_IOC_GET_LAYOUT - get file layout or dir layout policy
  9. * CEPH_IOC_SET_LAYOUT - set file layout
  10. * CEPH_IOC_SET_LAYOUT_POLICY - set dir layout policy
  11. *
  12. * The file layout specifies how file data is striped over objects in
  13. * the distributed object store, which object pool they belong to (if
  14. * it differs from the default), and an optional 'preferred osd' to
  15. * store them on.
  16. *
  17. * Files get a new layout based on the policy set on the containing
  18. * directory or one of its ancestors. The GET_LAYOUT ioctl will let
  19. * you examine the layout for a file or the policy on a directory.
  20. *
  21. * SET_LAYOUT will let you set a layout on a newly created file. This
  22. * only works immediately after the file is created and before any
  23. * data is written to it.
  24. *
  25. * SET_LAYOUT_POLICY will let you set a layout policy (default layout)
  26. * on a directory that will apply to any new files created in that
  27. * directory (or any child directory that doesn't specify a layout of
  28. * its own).
  29. */
  30. /* use u64 to align sanely on all archs */
  31. struct ceph_ioctl_layout {
  32. __u64 stripe_unit, stripe_count, object_size;
  33. __u64 data_pool;
  34. /* obsolete. new values ignored, always return -1 */
  35. __s64 preferred_osd;
  36. };
  37. #define CEPH_IOC_GET_LAYOUT _IOR(CEPH_IOCTL_MAGIC, 1, \
  38. struct ceph_ioctl_layout)
  39. #define CEPH_IOC_SET_LAYOUT _IOW(CEPH_IOCTL_MAGIC, 2, \
  40. struct ceph_ioctl_layout)
  41. #define CEPH_IOC_SET_LAYOUT_POLICY _IOW(CEPH_IOCTL_MAGIC, 5, \
  42. struct ceph_ioctl_layout)
  43. /*
  44. * CEPH_IOC_GET_DATALOC - get location of file data in the cluster
  45. *
  46. * Extract identity, address of the OSD and object storing a given
  47. * file offset.
  48. */
  49. struct ceph_ioctl_dataloc {
  50. __u64 file_offset; /* in+out: file offset */
  51. __u64 object_offset; /* out: offset in object */
  52. __u64 object_no; /* out: object # */
  53. __u64 object_size; /* out: object size */
  54. char object_name[64]; /* out: object name */
  55. __u64 block_offset; /* out: offset in block */
  56. __u64 block_size; /* out: block length */
  57. __s64 osd; /* out: osd # */
  58. struct sockaddr_storage osd_addr; /* out: osd address */
  59. };
  60. #define CEPH_IOC_GET_DATALOC _IOWR(CEPH_IOCTL_MAGIC, 3, \
  61. struct ceph_ioctl_dataloc)
  62. /*
  63. * CEPH_IOC_LAZYIO - relax consistency
  64. *
  65. * Normally Ceph switches to synchronous IO when multiple clients have
  66. * the file open (and or more for write). Reads and writes bypass the
  67. * page cache and go directly to the OSD. Setting this flag on a file
  68. * descriptor will allow buffered IO for this file in cases where the
  69. * application knows it won't interfere with other nodes (or doesn't
  70. * care).
  71. */
  72. #define CEPH_IOC_LAZYIO _IO(CEPH_IOCTL_MAGIC, 4)
  73. /*
  74. * CEPH_IOC_SYNCIO - force synchronous IO
  75. *
  76. * This ioctl sets a file flag that forces the synchronous IO that
  77. * bypasses the page cache, even if it is not necessary. This is
  78. * essentially the opposite behavior of IOC_LAZYIO. This forces the
  79. * same read/write path as a file opened by multiple clients when one
  80. * or more of those clients is opened for write.
  81. *
  82. * Note that this type of sync IO takes a different path than a file
  83. * opened with O_SYNC/D_SYNC (writes hit the page cache and are
  84. * immediately flushed on page boundaries). It is very similar to
  85. * O_DIRECT (writes bypass the page cache) excep that O_DIRECT writes
  86. * are not copied (user page must remain stable) and O_DIRECT writes
  87. * have alignment restrictions (on the buffer and file offset).
  88. */
  89. #define CEPH_IOC_SYNCIO _IO(CEPH_IOCTL_MAGIC, 5)
  90. #endif