xref: /linux/fs/jfs/jfs_dtree.h (revision 0c078e310b6d16b9b9489bbc7bc1476430d19a7c)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  *   Copyright (C) International Business Machines Corp., 2000-2002
4  */
5 #ifndef _H_JFS_DTREE
6 #define	_H_JFS_DTREE
7 
8 /*
9  *	jfs_dtree.h: directory B+-tree manager
10  */
11 
12 #include "jfs_btree.h"
13 
14 typedef union {
15 	struct {
16 		tid_t tid;
17 		struct inode *ip;
18 		u32 ino;
19 	} leaf;
20 	pxd_t xd;
21 } ddata_t;
22 
23 
24 /*
25  *	entry segment/slot
26  *
27  * an entry consists of type dependent head/only segment/slot and
28  * additional segments/slots linked vi next field;
29  * N.B. last/only segment of entry is terminated by next = -1;
30  */
31 /*
32  *	directory page slot
33  */
34 struct dtslot {
35 	s8 next;		/* 1: */
36 	s8 cnt;			/* 1: */
37 	__le16 name[15];	/* 30: */
38 };				/* (32) */
39 
40 
41 #define DATASLOTSIZE	16
42 #define L2DATASLOTSIZE	4
43 #define	DTSLOTSIZE	32
44 #define	L2DTSLOTSIZE	5
45 #define DTSLOTHDRSIZE	2
46 #define DTSLOTDATASIZE	30
47 #define DTSLOTDATALEN	15
48 
49 /*
50  *	 internal node entry head/only segment
51  */
52 struct idtentry {
53 	pxd_t xd;		/* 8: child extent descriptor */
54 
55 	s8 next;		/* 1: */
56 	u8 namlen;		/* 1: */
57 	__le16 name[11];	/* 22: 2-byte aligned */
58 };				/* (32) */
59 
60 #define DTIHDRSIZE	10
61 #define DTIHDRDATALEN	11
62 
63 /* compute number of slots for entry */
64 #define	NDTINTERNAL(klen) (DIV_ROUND_UP((4 + (klen)), 15))
65 
66 
67 /*
68  *	leaf node entry head/only segment
69  *
70  *	For legacy filesystems, name contains 13 wchars -- no index field
71  */
72 struct ldtentry {
73 	__le32 inumber;		/* 4: 4-byte aligned */
74 	s8 next;		/* 1: */
75 	u8 namlen;		/* 1: */
76 	__le16 name[11];	/* 22: 2-byte aligned */
77 	__le32 index;		/* 4: index into dir_table */
78 };				/* (32) */
79 
80 #define DTLHDRSIZE	6
81 #define DTLHDRDATALEN_LEGACY	13	/* Old (OS/2) format */
82 #define DTLHDRDATALEN	11
83 
84 /*
85  * dir_table used for directory traversal during readdir
86  */
87 
88 /*
89  * Keep persistent index for directory entries
90  */
91 #define DO_INDEX(INODE) (JFS_SBI((INODE)->i_sb)->mntflag & JFS_DIR_INDEX)
92 
93 /*
94  * Maximum entry in inline directory table
95  */
96 #define MAX_INLINE_DIRTABLE_ENTRY 13
97 
98 struct dir_table_slot {
99 	u8 rsrvd;		/* 1: */
100 	u8 flag;		/* 1: 0 if free */
101 	u8 slot;		/* 1: slot within leaf page of entry */
102 	u8 addr1;		/* 1: upper 8 bits of leaf page address */
103 	__le32 addr2;		/* 4: lower 32 bits of leaf page address -OR-
104 				   index of next entry when this entry was deleted */
105 };				/* (8) */
106 
107 /*
108  * flag values
109  */
110 #define DIR_INDEX_VALID 1
111 #define DIR_INDEX_FREE 0
112 
113 #define DTSaddress(dir_table_slot, address64)\
114 {\
115 	(dir_table_slot)->addr1 = ((u64)address64) >> 32;\
116 	(dir_table_slot)->addr2 = __cpu_to_le32((address64) & 0xffffffff);\
117 }
118 
119 #define addressDTS(dts)\
120 	( ((s64)((dts)->addr1)) << 32 | __le32_to_cpu((dts)->addr2) )
121 
122 /* compute number of slots for entry */
123 #define	NDTLEAF_LEGACY(klen)	(DIV_ROUND_UP((2 + (klen)), 15))
124 #define	NDTLEAF	NDTINTERNAL
125 
126 
127 /*
128  *	directory root page (in-line in on-disk inode):
129  *
130  * cf. dtpage_t below.
131  */
132 typedef union {
133 	struct {
134 		struct dasd DASD; /* 16: DASD limit/usage info */
135 
136 		u8 flag;	/* 1: */
137 		u8 nextindex;	/* 1: next free entry in stbl */
138 		s8 freecnt;	/* 1: free count */
139 		s8 freelist;	/* 1: freelist header */
140 
141 		__le32 idotdot;	/* 4: parent inode number */
142 
143 		s8 stbl[8];	/* 8: sorted entry index table */
144 	} header;		/* (32) */
145 
146 	struct dtslot slot[9];
147 } dtroot_t;
148 
149 #define PARENT(IP) \
150 	(le32_to_cpu(JFS_IP(IP)->i_dtroot.header.idotdot))
151 
152 #define DTROOTMAXSLOT	9
153 
154 #define	dtEmpty(IP) (JFS_IP(IP)->i_dtroot.header.nextindex == 0)
155 
156 
157 /*
158  *	directory regular page:
159  *
160  *	entry slot array of 32 byte slot
161  *
162  * sorted entry slot index table (stbl):
163  * contiguous slots at slot specified by stblindex,
164  * 1-byte per entry
165  *   512 byte block:  16 entry tbl (1 slot)
166  *  1024 byte block:  32 entry tbl (1 slot)
167  *  2048 byte block:  64 entry tbl (2 slot)
168  *  4096 byte block: 128 entry tbl (4 slot)
169  *
170  * data area:
171  *   512 byte block:  16 - 2 =  14 slot
172  *  1024 byte block:  32 - 2 =  30 slot
173  *  2048 byte block:  64 - 3 =  61 slot
174  *  4096 byte block: 128 - 5 = 123 slot
175  *
176  * N.B. index is 0-based; index fields refer to slot index
177  * except nextindex which refers to entry index in stbl;
178  * end of entry stot list or freelist is marked with -1.
179  */
180 typedef union {
181 	struct {
182 		__le64 next;	/* 8: next sibling */
183 		__le64 prev;	/* 8: previous sibling */
184 
185 		u8 flag;	/* 1: */
186 		u8 nextindex;	/* 1: next entry index in stbl */
187 		s8 freecnt;	/* 1: */
188 		s8 freelist;	/* 1: slot index of head of freelist */
189 
190 		u8 maxslot;	/* 1: number of slots in page slot[] */
191 		u8 stblindex;	/* 1: slot index of start of stbl */
192 		u8 rsrvd[2];	/* 2: */
193 
194 		pxd_t self;	/* 8: self pxd */
195 	} header;		/* (32) */
196 
197 	struct dtslot slot[128];
198 } dtpage_t;
199 
200 #define DTPAGEMAXSLOT        128
201 
202 #define DT8THPGNODEBYTES     512
203 #define DT8THPGNODETSLOTS      1
204 #define DT8THPGNODESLOTS      16
205 
206 #define DTQTRPGNODEBYTES    1024
207 #define DTQTRPGNODETSLOTS      1
208 #define DTQTRPGNODESLOTS      32
209 
210 #define DTHALFPGNODEBYTES   2048
211 #define DTHALFPGNODETSLOTS     2
212 #define DTHALFPGNODESLOTS     64
213 
214 #define DTFULLPGNODEBYTES   4096
215 #define DTFULLPGNODETSLOTS     4
216 #define DTFULLPGNODESLOTS    128
217 
218 #define DTENTRYSTART	1
219 
220 /* get sorted entry table of the page */
221 #define DT_GETSTBL(p) ( ((p)->header.flag & BT_ROOT) ?\
222 	((dtroot_t *)(p))->header.stbl : \
223 	(s8 *)&(p)->slot[(p)->header.stblindex] )
224 
225 /*
226  * Flags for dtSearch
227  */
228 #define JFS_CREATE 1
229 #define JFS_LOOKUP 2
230 #define JFS_REMOVE 3
231 #define JFS_RENAME 4
232 
233 /*
234  * Maximum file offset for directories.
235  */
236 #define DIREND	INT_MAX
237 
238 /*
239  *	external declarations
240  */
241 extern void dtInitRoot(tid_t tid, struct inode *ip, u32 idotdot);
242 
243 extern int dtSearch(struct inode *ip, struct component_name * key,
244 		    ino_t * data, struct btstack * btstack, int flag);
245 
246 extern int dtInsert(tid_t tid, struct inode *ip, struct component_name * key,
247 		    ino_t * ino, struct btstack * btstack);
248 
249 extern int dtDelete(tid_t tid, struct inode *ip, struct component_name * key,
250 		    ino_t * data, int flag);
251 
252 extern int dtModify(tid_t tid, struct inode *ip, struct component_name * key,
253 		    ino_t * orig_ino, ino_t new_ino, int flag);
254 
255 extern int jfs_readdir(struct file *file, struct dir_context *ctx);
256 #endif				/* !_H_JFS_DTREE */
257