xref: /linux/fs/ceph/ioctl.h (revision 498495dba268b20e8eadd7fe93c140c68b6cc9d2)
1*b2441318SGreg Kroah-Hartman /* SPDX-License-Identifier: GPL-2.0 */
28f4e91deSSage Weil #ifndef FS_CEPH_IOCTL_H
38f4e91deSSage Weil #define FS_CEPH_IOCTL_H
48f4e91deSSage Weil 
58f4e91deSSage Weil #include <linux/ioctl.h>
68f4e91deSSage Weil #include <linux/types.h>
78f4e91deSSage Weil 
81cd275f6SSage Weil #define CEPH_IOCTL_MAGIC 0x97
98f4e91deSSage Weil 
106a8ea470SSage Weil /*
116a8ea470SSage Weil  * CEPH_IOC_GET_LAYOUT - get file layout or dir layout policy
126a8ea470SSage Weil  * CEPH_IOC_SET_LAYOUT - set file layout
136a8ea470SSage Weil  * CEPH_IOC_SET_LAYOUT_POLICY - set dir layout policy
146a8ea470SSage Weil  *
156a8ea470SSage Weil  * The file layout specifies how file data is striped over objects in
166a8ea470SSage Weil  * the distributed object store, which object pool they belong to (if
176a8ea470SSage Weil  * it differs from the default), and an optional 'preferred osd' to
186a8ea470SSage Weil  * store them on.
196a8ea470SSage Weil  *
206a8ea470SSage Weil  * Files get a new layout based on the policy set on the containing
216a8ea470SSage Weil  * directory or one of its ancestors.  The GET_LAYOUT ioctl will let
226a8ea470SSage Weil  * you examine the layout for a file or the policy on a directory.
236a8ea470SSage Weil  *
246a8ea470SSage Weil  * SET_LAYOUT will let you set a layout on a newly created file.  This
256a8ea470SSage Weil  * only works immediately after the file is created and before any
266a8ea470SSage Weil  * data is written to it.
276a8ea470SSage Weil  *
286a8ea470SSage Weil  * SET_LAYOUT_POLICY will let you set a layout policy (default layout)
296a8ea470SSage Weil  * on a directory that will apply to any new files created in that
306a8ea470SSage Weil  * directory (or any child directory that doesn't specify a layout of
316a8ea470SSage Weil  * its own).
326a8ea470SSage Weil  */
336a8ea470SSage Weil 
346a8ea470SSage Weil /* use u64 to align sanely on all archs */
358f4e91deSSage Weil struct ceph_ioctl_layout {
368f4e91deSSage Weil 	__u64 stripe_unit, stripe_count, object_size;
378f4e91deSSage Weil 	__u64 data_pool;
38702aeb1fSSage Weil 
39702aeb1fSSage Weil 	/* obsolete.  new values ignored, always return -1 */
4033d4909cSSage Weil 	__s64 preferred_osd;
418f4e91deSSage Weil };
428f4e91deSSage Weil 
438f4e91deSSage Weil #define CEPH_IOC_GET_LAYOUT _IOR(CEPH_IOCTL_MAGIC, 1,		\
448f4e91deSSage Weil 				   struct ceph_ioctl_layout)
458f4e91deSSage Weil #define CEPH_IOC_SET_LAYOUT _IOW(CEPH_IOCTL_MAGIC, 2,		\
468f4e91deSSage Weil 				   struct ceph_ioctl_layout)
47571dba52SGreg Farnum #define CEPH_IOC_SET_LAYOUT_POLICY _IOW(CEPH_IOCTL_MAGIC, 5,	\
48571dba52SGreg Farnum 				   struct ceph_ioctl_layout)
498f4e91deSSage Weil 
508f4e91deSSage Weil /*
516a8ea470SSage Weil  * CEPH_IOC_GET_DATALOC - get location of file data in the cluster
526a8ea470SSage Weil  *
538f4e91deSSage Weil  * Extract identity, address of the OSD and object storing a given
548f4e91deSSage Weil  * file offset.
558f4e91deSSage Weil  */
568f4e91deSSage Weil struct ceph_ioctl_dataloc {
578f4e91deSSage Weil 	__u64 file_offset;           /* in+out: file offset */
588f4e91deSSage Weil 	__u64 object_offset;         /* out: offset in object */
598f4e91deSSage Weil 	__u64 object_no;             /* out: object # */
608f4e91deSSage Weil 	__u64 object_size;           /* out: object size */
618f4e91deSSage Weil 	char object_name[64];        /* out: object name */
628f4e91deSSage Weil 	__u64 block_offset;          /* out: offset in block */
638f4e91deSSage Weil 	__u64 block_size;            /* out: block length */
648f4e91deSSage Weil 	__s64 osd;                   /* out: osd # */
658f4e91deSSage Weil 	struct sockaddr_storage osd_addr; /* out: osd address */
668f4e91deSSage Weil };
678f4e91deSSage Weil 
688f4e91deSSage Weil #define CEPH_IOC_GET_DATALOC _IOWR(CEPH_IOCTL_MAGIC, 3,	\
698f4e91deSSage Weil 				   struct ceph_ioctl_dataloc)
708f4e91deSSage Weil 
716a8ea470SSage Weil /*
726a8ea470SSage Weil  * CEPH_IOC_LAZYIO - relax consistency
736a8ea470SSage Weil  *
746a8ea470SSage Weil  * Normally Ceph switches to synchronous IO when multiple clients have
756a8ea470SSage Weil  * the file open (and or more for write).  Reads and writes bypass the
766a8ea470SSage Weil  * page cache and go directly to the OSD.  Setting this flag on a file
776a8ea470SSage Weil  * descriptor will allow buffered IO for this file in cases where the
786a8ea470SSage Weil  * application knows it won't interfere with other nodes (or doesn't
796a8ea470SSage Weil  * care).
806a8ea470SSage Weil  */
818c6e9229SSage Weil #define CEPH_IOC_LAZYIO _IO(CEPH_IOCTL_MAGIC, 4)
826a8ea470SSage Weil 
836a8ea470SSage Weil /*
846a8ea470SSage Weil  * CEPH_IOC_SYNCIO - force synchronous IO
856a8ea470SSage Weil  *
866a8ea470SSage Weil  * This ioctl sets a file flag that forces the synchronous IO that
876a8ea470SSage Weil  * bypasses the page cache, even if it is not necessary.  This is
886a8ea470SSage Weil  * essentially the opposite behavior of IOC_LAZYIO.  This forces the
896a8ea470SSage Weil  * same read/write path as a file opened by multiple clients when one
906a8ea470SSage Weil  * or more of those clients is opened for write.
916a8ea470SSage Weil  *
926a8ea470SSage Weil  * Note that this type of sync IO takes a different path than a file
936a8ea470SSage Weil  * opened with O_SYNC/D_SYNC (writes hit the page cache and are
946a8ea470SSage Weil  * immediately flushed on page boundaries).  It is very similar to
956a8ea470SSage Weil  * O_DIRECT (writes bypass the page cache) excep that O_DIRECT writes
966a8ea470SSage Weil  * are not copied (user page must remain stable) and O_DIRECT writes
976a8ea470SSage Weil  * have alignment restrictions (on the buffer and file offset).
986a8ea470SSage Weil  */
994918b6d1SSage Weil #define CEPH_IOC_SYNCIO _IO(CEPH_IOCTL_MAGIC, 5)
1008c6e9229SSage Weil 
1018f4e91deSSage Weil #endif
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