[linux.git] / fs / ceph / ioctl.h

#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
Commit	Line	Data
8f4e91de SW	1	#ifndef FS_CEPH_IOCTL_H
	2	#define FS_CEPH_IOCTL_H
	3
	4	#include <linux/ioctl.h>
	5	#include <linux/types.h>
	6
1cd275f6	7	#define CEPH_IOCTL_MAGIC 0x97
8f4e91de	8
6a8ea470 SW	9	/*
	10	* CEPH_IOC_GET_LAYOUT - get file layout or dir layout policy
	11	* CEPH_IOC_SET_LAYOUT - set file layout
	12	* CEPH_IOC_SET_LAYOUT_POLICY - set dir layout policy
	13	*
	14	* The file layout specifies how file data is striped over objects in
	15	* the distributed object store, which object pool they belong to (if
	16	* it differs from the default), and an optional 'preferred osd' to
	17	* store them on.
	18	*
	19	* Files get a new layout based on the policy set on the containing
	20	* directory or one of its ancestors. The GET_LAYOUT ioctl will let
	21	* you examine the layout for a file or the policy on a directory.
	22	*
	23	* SET_LAYOUT will let you set a layout on a newly created file. This
	24	* only works immediately after the file is created and before any
	25	* data is written to it.
	26	*
	27	* SET_LAYOUT_POLICY will let you set a layout policy (default layout)
	28	* on a directory that will apply to any new files created in that
	29	* directory (or any child directory that doesn't specify a layout of
	30	* its own).
	31	*/
	32
	33	/* use u64 to align sanely on all archs */
8f4e91de SW	34	struct ceph_ioctl_layout {
	35	__u64 stripe_unit, stripe_count, object_size;
	36	__u64 data_pool;
702aeb1f SW	37
702aeb1f SW	38	/* obsolete. new values ignored, always return -1 */
33d4909c	39	__s64 preferred_osd;
8f4e91de SW	40	};
	41
	42	#define CEPH_IOC_GET_LAYOUT _IOR(CEPH_IOCTL_MAGIC, 1, \
	43	struct ceph_ioctl_layout)
	44	#define CEPH_IOC_SET_LAYOUT _IOW(CEPH_IOCTL_MAGIC, 2, \
	45	struct ceph_ioctl_layout)
571dba52 GF	46	#define CEPH_IOC_SET_LAYOUT_POLICY _IOW(CEPH_IOCTL_MAGIC, 5, \
571dba52 GF	47	struct ceph_ioctl_layout)
8f4e91de SW	48
8f4e91de SW	49	/*
6a8ea470 SW	50	* CEPH_IOC_GET_DATALOC - get location of file data in the cluster
6a8ea470 SW	51	*
8f4e91de SW	52	* Extract identity, address of the OSD and object storing a given
	53	* file offset.
	54	*/
	55	struct ceph_ioctl_dataloc {
	56	__u64 file_offset; /* in+out: file offset */
	57	__u64 object_offset; /* out: offset in object */
	58	__u64 object_no; /* out: object # */
	59	__u64 object_size; /* out: object size */
	60	char object_name[64]; /* out: object name */
	61	__u64 block_offset; /* out: offset in block */
	62	__u64 block_size; /* out: block length */
	63	__s64 osd; /* out: osd # */
	64	struct sockaddr_storage osd_addr; /* out: osd address */
	65	};
	66
	67	#define CEPH_IOC_GET_DATALOC _IOWR(CEPH_IOCTL_MAGIC, 3, \
	68	struct ceph_ioctl_dataloc)
	69
6a8ea470 SW	70	/*
	71	* CEPH_IOC_LAZYIO - relax consistency
	72	*
	73	* Normally Ceph switches to synchronous IO when multiple clients have
	74	* the file open (and or more for write). Reads and writes bypass the
	75	* page cache and go directly to the OSD. Setting this flag on a file
	76	* descriptor will allow buffered IO for this file in cases where the
	77	* application knows it won't interfere with other nodes (or doesn't
	78	* care).
	79	*/
8c6e9229	80	#define CEPH_IOC_LAZYIO _IO(CEPH_IOCTL_MAGIC, 4)
6a8ea470 SW	81
	82	/*
	83	* CEPH_IOC_SYNCIO - force synchronous IO
	84	*
	85	* This ioctl sets a file flag that forces the synchronous IO that
	86	* bypasses the page cache, even if it is not necessary. This is
	87	* essentially the opposite behavior of IOC_LAZYIO. This forces the
	88	* same read/write path as a file opened by multiple clients when one
	89	* or more of those clients is opened for write.
	90	*
	91	* Note that this type of sync IO takes a different path than a file
	92	* opened with O_SYNC/D_SYNC (writes hit the page cache and are
	93	* immediately flushed on page boundaries). It is very similar to
	94	* O_DIRECT (writes bypass the page cache) excep that O_DIRECT writes
	95	* are not copied (user page must remain stable) and O_DIRECT writes
	96	* have alignment restrictions (on the buffer and file offset).
	97	*/
4918b6d1	98	#define CEPH_IOC_SYNCIO _IO(CEPH_IOCTL_MAGIC, 5)
8c6e9229	99
8f4e91de	100	#endif