1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef FS_CEPH_IOCTL_H
3 #define FS_CEPH_IOCTL_H
5 #include <linux/ioctl.h>
6 #include <linux/types.h>
8 #define CEPH_IOCTL_MAGIC 0x97
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
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
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.
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.
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
34 /* use u64 to align sanely on all archs */
35 struct ceph_ioctl_layout
{
36 __u64 stripe_unit
, stripe_count
, object_size
;
39 /* obsolete. new values ignored, always return -1 */
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)
51 * CEPH_IOC_GET_DATALOC - get location of file data in the cluster
53 * Extract identity, address of the OSD and object storing a given
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 */
68 #define CEPH_IOC_GET_DATALOC _IOWR(CEPH_IOCTL_MAGIC, 3, \
69 struct ceph_ioctl_dataloc)
72 * CEPH_IOC_LAZYIO - relax consistency
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
81 #define CEPH_IOC_LAZYIO _IO(CEPH_IOCTL_MAGIC, 4)
84 * CEPH_IOC_SYNCIO - force synchronous IO
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.
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).
99 #define CEPH_IOC_SYNCIO _IO(CEPH_IOCTL_MAGIC, 5)