blob: 51f7f1d39a94c54b2b6c17bd83833be017edf38b [file] [log] [blame]
/* SPDX-License-Identifier: GPL-2.0 */
#include <linux/ioctl.h>
#include <linux/types.h>
#define CEPH_IOCTL_MAGIC 0x97
* CEPH_IOC_GET_LAYOUT - get file layout or dir layout policy
* CEPH_IOC_SET_LAYOUT - set file layout
* CEPH_IOC_SET_LAYOUT_POLICY - set dir layout policy
* The file layout specifies how file data is striped over objects in
* the distributed object store, which object pool they belong to (if
* it differs from the default), and an optional 'preferred osd' to
* store them on.
* Files get a new layout based on the policy set on the containing
* directory or one of its ancestors. The GET_LAYOUT ioctl will let
* you examine the layout for a file or the policy on a directory.
* SET_LAYOUT will let you set a layout on a newly created file. This
* only works immediately after the file is created and before any
* data is written to it.
* SET_LAYOUT_POLICY will let you set a layout policy (default layout)
* on a directory that will apply to any new files created in that
* directory (or any child directory that doesn't specify a layout of
* its own).
/* use u64 to align sanely on all archs */
struct ceph_ioctl_layout {
__u64 stripe_unit, stripe_count, object_size;
__u64 data_pool;
/* obsolete. new values ignored, always return -1 */
__s64 preferred_osd;
struct ceph_ioctl_layout)
struct ceph_ioctl_layout)
struct ceph_ioctl_layout)
* CEPH_IOC_GET_DATALOC - get location of file data in the cluster
* Extract identity, address of the OSD and object storing a given
* file offset.
struct ceph_ioctl_dataloc {
__u64 file_offset; /* in+out: file offset */
__u64 object_offset; /* out: offset in object */
__u64 object_no; /* out: object # */
__u64 object_size; /* out: object size */
char object_name[64]; /* out: object name */
__u64 block_offset; /* out: offset in block */
__u64 block_size; /* out: block length */
__s64 osd; /* out: osd # */
struct sockaddr_storage osd_addr; /* out: osd address */
struct ceph_ioctl_dataloc)
* CEPH_IOC_LAZYIO - relax consistency
* Normally Ceph switches to synchronous IO when multiple clients have
* the file open (and or more for write). Reads and writes bypass the
* page cache and go directly to the OSD. Setting this flag on a file
* descriptor will allow buffered IO for this file in cases where the
* application knows it won't interfere with other nodes (or doesn't
* care).
* CEPH_IOC_SYNCIO - force synchronous IO
* This ioctl sets a file flag that forces the synchronous IO that
* bypasses the page cache, even if it is not necessary. This is
* essentially the opposite behavior of IOC_LAZYIO. This forces the
* same read/write path as a file opened by multiple clients when one
* or more of those clients is opened for write.
* Note that this type of sync IO takes a different path than a file
* opened with O_SYNC/D_SYNC (writes hit the page cache and are
* immediately flushed on page boundaries). It is very similar to
* O_DIRECT (writes bypass the page cache) excep that O_DIRECT writes
* are not copied (user page must remain stable) and O_DIRECT writes
* have alignment restrictions (on the buffer and file offset).