[linux.git] / fs / afs / xdr_fs.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
/* AFS fileserver XDR types
 *
 * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 */

#ifndef XDR_FS_H
#define XDR_FS_H

struct afs_xdr_AFSFetchStatus {
	__be32	if_version;
#define AFS_FSTATUS_VERSION	1
	__be32	type;
	__be32	nlink;
	__be32	size_lo;
	__be32	data_version_lo;
	__be32	author;
	__be32	owner;
	__be32	caller_access;
	__be32	anon_access;
	__be32	mode;
	__be32	parent_vnode;
	__be32	parent_unique;
	__be32	seg_size;
	__be32	mtime_client;
	__be32	mtime_server;
	__be32	group;
	__be32	sync_counter;
	__be32	data_version_hi;
	__be32	lock_count;
	__be32	size_hi;
	__be32	abort_code;
} __packed;

#define AFS_DIR_HASHTBL_SIZE	128
#define AFS_DIR_DIRENT_SIZE	32
#define AFS_DIR_SLOTS_PER_BLOCK	64
#define AFS_DIR_BLOCK_SIZE	2048
#define AFS_DIR_BLOCKS_PER_PAGE	(PAGE_SIZE / AFS_DIR_BLOCK_SIZE)
#define AFS_DIR_MAX_SLOTS	65536
#define AFS_DIR_BLOCKS_WITH_CTR	128
#define AFS_DIR_MAX_BLOCKS	1023
#define AFS_DIR_RESV_BLOCKS	1
#define AFS_DIR_RESV_BLOCKS0	13

/*
 * Directory entry structure.
 */
union afs_xdr_dirent {
	struct {
		u8		valid;
		u8		unused[1];
		__be16		hash_next;
		__be32		vnode;
		__be32		unique;
		u8		name[];
		/* When determining the number of dirent slots needed to
		 * represent a directory entry, name should be assumed to be 16
		 * bytes, due to a now-standardised (mis)calculation, but it is
		 * in fact 20 bytes in size.  afs_dir_calc_slots() should be
		 * used for this.
		 *
		 * For names longer than (16 or) 20 bytes, extra slots should
		 * be annexed to this one using the extended_name format.
		 */
	} u;
	u8			extended_name[32];
} __packed;

/*
 * Directory block header (one at the beginning of every 2048-byte block).
 */
struct afs_xdr_dir_hdr {
	__be16		npages;
	__be16		magic;
#define AFS_DIR_MAGIC htons(1234)
	u8		reserved;
	u8		bitmap[8];
	u8		pad[19];
} __packed;

/*
 * Directory block layout
 */
union afs_xdr_dir_block {
	struct afs_xdr_dir_hdr		hdr;

	struct {
		struct afs_xdr_dir_hdr	hdr;
		u8			alloc_ctrs[AFS_DIR_MAX_BLOCKS];
		__be16			hashtable[AFS_DIR_HASHTBL_SIZE];
	} meta;

	union afs_xdr_dirent	dirents[AFS_DIR_SLOTS_PER_BLOCK];
} __packed;

/*
 * Directory layout on a linux VM page.
 */
struct afs_xdr_dir_page {
	union afs_xdr_dir_block	blocks[AFS_DIR_BLOCKS_PER_PAGE];
};

/*
 * Calculate the number of dirent slots required for any given name length.
 * The calculation is made assuming the part of the name in the first slot is
 * 16 bytes, rather than 20, but this miscalculation is now standardised.
 */
static inline unsigned int afs_dir_calc_slots(size_t name_len)
{
	name_len++; /* NUL-terminated */
	return 1 + ((name_len + 15) / AFS_DIR_DIRENT_SIZE);
}

#endif /* XDR_FS_H */
Commit	Line	Data
b4d0d230	1	/* SPDX-License-Identifier: GPL-2.0-or-later */
dd9fbcb8 DH	2	/* AFS fileserver XDR types
	3	*
	4	* Copyright (C) 2018 Red Hat, Inc. All Rights Reserved.
	5	* Written by David Howells ([email protected])
dd9fbcb8 DH	6	*/
	7
	8	#ifndef XDR_FS_H
	9	#define XDR_FS_H
	10
	11	struct afs_xdr_AFSFetchStatus {
	12	__be32 if_version;
	13	#define AFS_FSTATUS_VERSION 1
	14	__be32 type;
	15	__be32 nlink;
	16	__be32 size_lo;
	17	__be32 data_version_lo;
	18	__be32 author;
	19	__be32 owner;
	20	__be32 caller_access;
	21	__be32 anon_access;
	22	__be32 mode;
	23	__be32 parent_vnode;
	24	__be32 parent_unique;
	25	__be32 seg_size;
	26	__be32 mtime_client;
	27	__be32 mtime_server;
	28	__be32 group;
	29	__be32 sync_counter;
	30	__be32 data_version_hi;
	31	__be32 lock_count;
	32	__be32 size_hi;
	33	__be32 abort_code;
	34	} __packed;
	35
4ea219a8 DH	36	#define AFS_DIR_HASHTBL_SIZE 128
	37	#define AFS_DIR_DIRENT_SIZE 32
	38	#define AFS_DIR_SLOTS_PER_BLOCK 64
	39	#define AFS_DIR_BLOCK_SIZE 2048
	40	#define AFS_DIR_BLOCKS_PER_PAGE (PAGE_SIZE / AFS_DIR_BLOCK_SIZE)
	41	#define AFS_DIR_MAX_SLOTS 65536
	42	#define AFS_DIR_BLOCKS_WITH_CTR 128
	43	#define AFS_DIR_MAX_BLOCKS 1023
	44	#define AFS_DIR_RESV_BLOCKS 1
	45	#define AFS_DIR_RESV_BLOCKS0 13
	46
	47	/*
	48	* Directory entry structure.
	49	*/
00317636	50	union afs_xdr_dirent {
4ea219a8	51	struct {
00317636 DH	52	u8 valid;
00317636 DH	53	u8 unused[1];
4ea219a8 DH	54	__be16 hash_next;
	55	__be32 vnode;
	56	__be32 unique;
26982a89 DH	57	u8 name[];
	58	/* When determining the number of dirent slots needed to
	59	* represent a directory entry, name should be assumed to be 16
	60	* bytes, due to a now-standardised (mis)calculation, but it is
366911cd DH	61	* in fact 20 bytes in size. afs_dir_calc_slots() should be
366911cd DH	62	* used for this.
26982a89 DH	63	*
	64	* For names longer than (16 or) 20 bytes, extra slots should
	65	* be annexed to this one using the extended_name format.
	66	*/
4ea219a8	67	} u;
00317636 DH	68	u8 extended_name[32];
00317636 DH	69	} __packed;
4ea219a8 DH	70
4ea219a8 DH	71	/*
00317636	72	* Directory block header (one at the beginning of every 2048-byte block).
4ea219a8	73	*/
00317636	74	struct afs_xdr_dir_hdr {
4ea219a8 DH	75	__be16 npages;
	76	__be16 magic;
	77	#define AFS_DIR_MAGIC htons(1234)
00317636 DH	78	u8 reserved;
	79	u8 bitmap[8];
	80	u8 pad[19];
	81	} __packed;
4ea219a8 DH	82
	83	/*
	84	* Directory block layout
	85	*/
00317636 DH	86	union afs_xdr_dir_block {
00317636 DH	87	struct afs_xdr_dir_hdr hdr;
4ea219a8 DH	88
4ea219a8 DH	89	struct {
00317636 DH	90	struct afs_xdr_dir_hdr hdr;
00317636 DH	91	u8 alloc_ctrs[AFS_DIR_MAX_BLOCKS];
4ea219a8	92	__be16 hashtable[AFS_DIR_HASHTBL_SIZE];
00317636	93	} meta;
4ea219a8	94
00317636 DH	95	union afs_xdr_dirent dirents[AFS_DIR_SLOTS_PER_BLOCK];
00317636 DH	96	} __packed;
4ea219a8 DH	97
	98	/*
	99	* Directory layout on a linux VM page.
	100	*/
00317636 DH	101	struct afs_xdr_dir_page {
00317636 DH	102	union afs_xdr_dir_block blocks[AFS_DIR_BLOCKS_PER_PAGE];
4ea219a8 DH	103	};
4ea219a8 DH	104
366911cd DH	105	/*
	106	* Calculate the number of dirent slots required for any given name length.
	107	* The calculation is made assuming the part of the name in the first slot is
	108	* 16 bytes, rather than 20, but this miscalculation is now standardised.
	109	*/
	110	static inline unsigned int afs_dir_calc_slots(size_t name_len)
	111	{
	112	name_len++; /* NUL-terminated */
	113	return 1 + ((name_len + 15) / AFS_DIR_DIRENT_SIZE);
	114	}
	115
dd9fbcb8	116	#endif /* XDR_FS_H */