1#ifndef FS_CEPH_IOCTL_H
2#define FS_CEPH_IOCTL_H
3
4#include <linux/ioctl.h>
5#include <linux/types.h>
6
7#define CEPH_IOCTL_MAGIC 0x97
8
9/*
10 * CEPH_IOC_GET_LAYOUT - get file layout or dir layout policy
11 * CEPH_IOC_SET_LAYOUT - set file layout
12 * CEPH_IOC_SET_LAYOUT_POLICY - set dir layout policy
13 *
14 * The file layout specifies how file data is striped over objects in
15 * the distributed object store, which object pool they belong to (if
16 * it differs from the default), and an optional 'preferred osd' to
17 * store them on.
18 *
19 * Files get a new layout based on the policy set on the containing
20 * directory or one of its ancestors.  The GET_LAYOUT ioctl will let
21 * you examine the layout for a file or the policy on a directory.
22 *
23 * SET_LAYOUT will let you set a layout on a newly created file.  This
24 * only works immediately after the file is created and before any
25 * data is written to it.
26 *
27 * SET_LAYOUT_POLICY will let you set a layout policy (default layout)
28 * on a directory that will apply to any new files created in that
29 * directory (or any child directory that doesn't specify a layout of
30 * its own).
31 */
32
33/* use u64 to align sanely on all archs */
34struct ceph_ioctl_layout {
35	__u64 stripe_unit, stripe_count, object_size;
36	__u64 data_pool;
37
38	/* obsolete.  new values ignored, always return -1 */
39	__s64 preferred_osd;
40};
41
42#define CEPH_IOC_GET_LAYOUT _IOR(CEPH_IOCTL_MAGIC, 1,		\
43				   struct ceph_ioctl_layout)
44#define CEPH_IOC_SET_LAYOUT _IOW(CEPH_IOCTL_MAGIC, 2,		\
45				   struct ceph_ioctl_layout)
46#define CEPH_IOC_SET_LAYOUT_POLICY _IOW(CEPH_IOCTL_MAGIC, 5,	\
47				   struct ceph_ioctl_layout)
48
49/*
50 * CEPH_IOC_GET_DATALOC - get location of file data in the cluster
51 *
52 * Extract identity, address of the OSD and object storing a given
53 * file offset.
54 */
55struct ceph_ioctl_dataloc {
56	__u64 file_offset;           /* in+out: file offset */
57	__u64 object_offset;         /* out: offset in object */
58	__u64 object_no;             /* out: object # */
59	__u64 object_size;           /* out: object size */
60	char object_name[64];        /* out: object name */
61	__u64 block_offset;          /* out: offset in block */
62	__u64 block_size;            /* out: block length */
63	__s64 osd;                   /* out: osd # */
64	struct sockaddr_storage osd_addr; /* out: osd address */
65};
66
67#define CEPH_IOC_GET_DATALOC _IOWR(CEPH_IOCTL_MAGIC, 3,	\
68				   struct ceph_ioctl_dataloc)
69
70/*
71 * CEPH_IOC_LAZYIO - relax consistency
72 *
73 * Normally Ceph switches to synchronous IO when multiple clients have
74 * the file open (and or more for write).  Reads and writes bypass the
75 * page cache and go directly to the OSD.  Setting this flag on a file
76 * descriptor will allow buffered IO for this file in cases where the
77 * application knows it won't interfere with other nodes (or doesn't
78 * care).
79 */
80#define CEPH_IOC_LAZYIO _IO(CEPH_IOCTL_MAGIC, 4)
81
82/*
83 * CEPH_IOC_SYNCIO - force synchronous IO
84 *
85 * This ioctl sets a file flag that forces the synchronous IO that
86 * bypasses the page cache, even if it is not necessary.  This is
87 * essentially the opposite behavior of IOC_LAZYIO.  This forces the
88 * same read/write path as a file opened by multiple clients when one
89 * or more of those clients is opened for write.
90 *
91 * Note that this type of sync IO takes a different path than a file
92 * opened with O_SYNC/D_SYNC (writes hit the page cache and are
93 * immediately flushed on page boundaries).  It is very similar to
94 * O_DIRECT (writes bypass the page cache) excep that O_DIRECT writes
95 * are not copied (user page must remain stable) and O_DIRECT writes
96 * have alignment restrictions (on the buffer and file offset).
97 */
98#define CEPH_IOC_SYNCIO _IO(CEPH_IOCTL_MAGIC, 5)
99
100#endif
101