1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef FS_CEPH_IOCTL_H
3#define FS_CEPH_IOCTL_H
4
5#include <linux/ioctl.h>
6#include <linux/types.h>
7
8#define CEPH_IOCTL_MAGIC 0x97
9
10/*
11 * CEPH_IOC_GET_LAYOUT - get file layout or dir layout policy
12 * CEPH_IOC_SET_LAYOUT - set file layout
13 * CEPH_IOC_SET_LAYOUT_POLICY - set dir layout policy
14 *
15 * The file layout specifies how file data is striped over objects in
16 * the distributed object store, which object pool they belong to (if
17 * it differs from the default), and an optional 'preferred osd' to
18 * store them on.
19 *
20 * Files get a new layout based on the policy set on the containing
21 * directory or one of its ancestors.  The GET_LAYOUT ioctl will let
22 * you examine the layout for a file or the policy on a directory.
23 *
24 * SET_LAYOUT will let you set a layout on a newly created file.  This
25 * only works immediately after the file is created and before any
26 * data is written to it.
27 *
28 * SET_LAYOUT_POLICY will let you set a layout policy (default layout)
29 * on a directory that will apply to any new files created in that
30 * directory (or any child directory that doesn't specify a layout of
31 * its own).
32 */
33
34/* use u64 to align sanely on all archs */
35struct ceph_ioctl_layout {
36	__u64 stripe_unit, stripe_count, object_size;
37	__u64 data_pool;
38
39	/* obsolete.  new values ignored, always return -1 */
40	__s64 preferred_osd;
41};
42
43#define CEPH_IOC_GET_LAYOUT _IOR(CEPH_IOCTL_MAGIC, 1,		\
44				   struct ceph_ioctl_layout)
45#define CEPH_IOC_SET_LAYOUT _IOW(CEPH_IOCTL_MAGIC, 2,		\
46				   struct ceph_ioctl_layout)
47#define CEPH_IOC_SET_LAYOUT_POLICY _IOW(CEPH_IOCTL_MAGIC, 5,	\
48				   struct ceph_ioctl_layout)
49
50/*
51 * CEPH_IOC_GET_DATALOC - get location of file data in the cluster
52 *
53 * Extract identity, address of the OSD and object storing a given
54 * file offset.
55 */
56struct ceph_ioctl_dataloc {
57	__u64 file_offset;           /* in+out: file offset */
58	__u64 object_offset;         /* out: offset in object */
59	__u64 object_no;             /* out: object # */
60	__u64 object_size;           /* out: object size */
61	char object_name[64];        /* out: object name */
62	__u64 block_offset;          /* out: offset in block */
63	__u64 block_size;            /* out: block length */
64	__s64 osd;                   /* out: osd # */
65	struct sockaddr_storage osd_addr; /* out: osd address */
66};
67
68#define CEPH_IOC_GET_DATALOC _IOWR(CEPH_IOCTL_MAGIC, 3,	\
69				   struct ceph_ioctl_dataloc)
70
71/*
72 * CEPH_IOC_LAZYIO - relax consistency
73 *
74 * Normally Ceph switches to synchronous IO when multiple clients have
75 * the file open (and or more for write).  Reads and writes bypass the
76 * page cache and go directly to the OSD.  Setting this flag on a file
77 * descriptor will allow buffered IO for this file in cases where the
78 * application knows it won't interfere with other nodes (or doesn't
79 * care).
80 */
81#define CEPH_IOC_LAZYIO _IO(CEPH_IOCTL_MAGIC, 4)
82
83/*
84 * CEPH_IOC_SYNCIO - force synchronous IO
85 *
86 * This ioctl sets a file flag that forces the synchronous IO that
87 * bypasses the page cache, even if it is not necessary.  This is
88 * essentially the opposite behavior of IOC_LAZYIO.  This forces the
89 * same read/write path as a file opened by multiple clients when one
90 * or more of those clients is opened for write.
91 *
92 * Note that this type of sync IO takes a different path than a file
93 * opened with O_SYNC/D_SYNC (writes hit the page cache and are
94 * immediately flushed on page boundaries).  It is very similar to
95 * O_DIRECT (writes bypass the page cache) excep that O_DIRECT writes
96 * are not copied (user page must remain stable) and O_DIRECT writes
97 * have alignment restrictions (on the buffer and file offset).
98 */
99#define CEPH_IOC_SYNCIO _IO(CEPH_IOCTL_MAGIC, 5)
100
101#endif
102