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Diffstat (limited to 'fs/ceph/ioctl.h')
-rw-r--r-- | fs/ceph/ioctl.h | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/fs/ceph/ioctl.h b/fs/ceph/ioctl.h new file mode 100644 index 000000000..51f7f1d39 --- /dev/null +++ b/fs/ceph/ioctl.h @@ -0,0 +1,101 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef FS_CEPH_IOCTL_H +#define FS_CEPH_IOCTL_H + +#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; +}; + +#define CEPH_IOC_GET_LAYOUT _IOR(CEPH_IOCTL_MAGIC, 1, \ + struct ceph_ioctl_layout) +#define CEPH_IOC_SET_LAYOUT _IOW(CEPH_IOCTL_MAGIC, 2, \ + struct ceph_ioctl_layout) +#define CEPH_IOC_SET_LAYOUT_POLICY _IOW(CEPH_IOCTL_MAGIC, 5, \ + 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 */ +}; + +#define CEPH_IOC_GET_DATALOC _IOWR(CEPH_IOCTL_MAGIC, 3, \ + 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). + */ +#define CEPH_IOC_LAZYIO _IO(CEPH_IOCTL_MAGIC, 4) + +/* + * 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). + */ +#define CEPH_IOC_SYNCIO _IO(CEPH_IOCTL_MAGIC, 5) + +#endif |