ioctl.h (3724B)
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