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 */
35 struct 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 */
56 struct 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
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