1 /*
2  *   Copyright (C) International Business Machines Corp., 2000-2002
3  *
4  *   This program is free software;  you can redistribute it and/or modify
5  *   it under the terms of the GNU General Public License as published by
6  *   the Free Software Foundation; either version 2 of the License, or
7  *   (at your option) any later version.
8  *
9  *   This program is distributed in the hope that it will be useful,
10  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
12  *   the GNU General Public License for more details.
13  *
14  *   You should have received a copy of the GNU General Public License
15  *   along with this program;  if not, write to the Free Software
16  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17  */
18 #ifndef _H_JFS_DTREE
19 #define	_H_JFS_DTREE
20 
21 /*
22  *	jfs_dtree.h: directory B+-tree manager
23  */
24 
25 #include "jfs_btree.h"
26 
27 typedef union {
28 	struct {
29 		tid_t tid;
30 		struct inode *ip;
31 		u32 ino;
32 	} leaf;
33 	pxd_t xd;
34 } ddata_t;
35 
36 
37 /*
38  *	entry segment/slot
39  *
40  * an entry consists of type dependent head/only segment/slot and
41  * additional segments/slots linked vi next field;
42  * N.B. last/only segment of entry is terminated by next = -1;
43  */
44 /*
45  *	directory page slot
46  */
47 struct dtslot {
48 	s8 next;		/* 1: */
49 	s8 cnt;			/* 1: */
50 	__le16 name[15];	/* 30: */
51 };				/* (32) */
52 
53 
54 #define DATASLOTSIZE	16
55 #define L2DATASLOTSIZE	4
56 #define	DTSLOTSIZE	32
57 #define	L2DTSLOTSIZE	5
58 #define DTSLOTHDRSIZE	2
59 #define DTSLOTDATASIZE	30
60 #define DTSLOTDATALEN	15
61 
62 /*
63  *	 internal node entry head/only segment
64  */
65 struct idtentry {
66 	pxd_t xd;		/* 8: child extent descriptor */
67 
68 	s8 next;		/* 1: */
69 	u8 namlen;		/* 1: */
70 	__le16 name[11];	/* 22: 2-byte aligned */
71 };				/* (32) */
72 
73 #define DTIHDRSIZE	10
74 #define DTIHDRDATALEN	11
75 
76 /* compute number of slots for entry */
77 #define	NDTINTERNAL(klen) (DIV_ROUND_UP((4 + (klen)), 15))
78 
79 
80 /*
81  *	leaf node entry head/only segment
82  *
83  *	For legacy filesystems, name contains 13 wchars -- no index field
84  */
85 struct ldtentry {
86 	__le32 inumber;		/* 4: 4-byte aligned */
87 	s8 next;		/* 1: */
88 	u8 namlen;		/* 1: */
89 	__le16 name[11];	/* 22: 2-byte aligned */
90 	__le32 index;		/* 4: index into dir_table */
91 };				/* (32) */
92 
93 #define DTLHDRSIZE	6
94 #define DTLHDRDATALEN_LEGACY	13	/* Old (OS/2) format */
95 #define DTLHDRDATALEN	11
96 
97 /*
98  * dir_table used for directory traversal during readdir
99  */
100 
101 /*
102  * Keep persistent index for directory entries
103  */
104 #define DO_INDEX(INODE) (JFS_SBI((INODE)->i_sb)->mntflag & JFS_DIR_INDEX)
105 
106 /*
107  * Maximum entry in inline directory table
108  */
109 #define MAX_INLINE_DIRTABLE_ENTRY 13
110 
111 struct dir_table_slot {
112 	u8 rsrvd;		/* 1: */
113 	u8 flag;		/* 1: 0 if free */
114 	u8 slot;		/* 1: slot within leaf page of entry */
115 	u8 addr1;		/* 1: upper 8 bits of leaf page address */
116 	__le32 addr2;		/* 4: lower 32 bits of leaf page address -OR-
117 				   index of next entry when this entry was deleted */
118 };				/* (8) */
119 
120 /*
121  * flag values
122  */
123 #define DIR_INDEX_VALID 1
124 #define DIR_INDEX_FREE 0
125 
126 #define DTSaddress(dir_table_slot, address64)\
127 {\
128 	(dir_table_slot)->addr1 = ((u64)address64) >> 32;\
129 	(dir_table_slot)->addr2 = __cpu_to_le32((address64) & 0xffffffff);\
130 }
131 
132 #define addressDTS(dts)\
133 	( ((s64)((dts)->addr1)) << 32 | __le32_to_cpu((dts)->addr2) )
134 
135 /* compute number of slots for entry */
136 #define	NDTLEAF_LEGACY(klen)	(DIV_ROUND_UP((2 + (klen)), 15))
137 #define	NDTLEAF	NDTINTERNAL
138 
139 
140 /*
141  *	directory root page (in-line in on-disk inode):
142  *
143  * cf. dtpage_t below.
144  */
145 typedef union {
146 	struct {
147 		struct dasd DASD; /* 16: DASD limit/usage info */
148 
149 		u8 flag;	/* 1: */
150 		u8 nextindex;	/* 1: next free entry in stbl */
151 		s8 freecnt;	/* 1: free count */
152 		s8 freelist;	/* 1: freelist header */
153 
154 		__le32 idotdot;	/* 4: parent inode number */
155 
156 		s8 stbl[8];	/* 8: sorted entry index table */
157 	} header;		/* (32) */
158 
159 	struct dtslot slot[9];
160 } dtroot_t;
161 
162 #define PARENT(IP) \
163 	(le32_to_cpu(JFS_IP(IP)->i_dtroot.header.idotdot))
164 
165 #define DTROOTMAXSLOT	9
166 
167 #define	dtEmpty(IP) (JFS_IP(IP)->i_dtroot.header.nextindex == 0)
168 
169 
170 /*
171  *	directory regular page:
172  *
173  *	entry slot array of 32 byte slot
174  *
175  * sorted entry slot index table (stbl):
176  * contiguous slots at slot specified by stblindex,
177  * 1-byte per entry
178  *   512 byte block:  16 entry tbl (1 slot)
179  *  1024 byte block:  32 entry tbl (1 slot)
180  *  2048 byte block:  64 entry tbl (2 slot)
181  *  4096 byte block: 128 entry tbl (4 slot)
182  *
183  * data area:
184  *   512 byte block:  16 - 2 =  14 slot
185  *  1024 byte block:  32 - 2 =  30 slot
186  *  2048 byte block:  64 - 3 =  61 slot
187  *  4096 byte block: 128 - 5 = 123 slot
188  *
189  * N.B. index is 0-based; index fields refer to slot index
190  * except nextindex which refers to entry index in stbl;
191  * end of entry stot list or freelist is marked with -1.
192  */
193 typedef union {
194 	struct {
195 		__le64 next;	/* 8: next sibling */
196 		__le64 prev;	/* 8: previous sibling */
197 
198 		u8 flag;	/* 1: */
199 		u8 nextindex;	/* 1: next entry index in stbl */
200 		s8 freecnt;	/* 1: */
201 		s8 freelist;	/* 1: slot index of head of freelist */
202 
203 		u8 maxslot;	/* 1: number of slots in page slot[] */
204 		u8 stblindex;	/* 1: slot index of start of stbl */
205 		u8 rsrvd[2];	/* 2: */
206 
207 		pxd_t self;	/* 8: self pxd */
208 	} header;		/* (32) */
209 
210 	struct dtslot slot[128];
211 } dtpage_t;
212 
213 #define DTPAGEMAXSLOT        128
214 
215 #define DT8THPGNODEBYTES     512
216 #define DT8THPGNODETSLOTS      1
217 #define DT8THPGNODESLOTS      16
218 
219 #define DTQTRPGNODEBYTES    1024
220 #define DTQTRPGNODETSLOTS      1
221 #define DTQTRPGNODESLOTS      32
222 
223 #define DTHALFPGNODEBYTES   2048
224 #define DTHALFPGNODETSLOTS     2
225 #define DTHALFPGNODESLOTS     64
226 
227 #define DTFULLPGNODEBYTES   4096
228 #define DTFULLPGNODETSLOTS     4
229 #define DTFULLPGNODESLOTS    128
230 
231 #define DTENTRYSTART	1
232 
233 /* get sorted entry table of the page */
234 #define DT_GETSTBL(p) ( ((p)->header.flag & BT_ROOT) ?\
235 	((dtroot_t *)(p))->header.stbl : \
236 	(s8 *)&(p)->slot[(p)->header.stblindex] )
237 
238 /*
239  * Flags for dtSearch
240  */
241 #define JFS_CREATE 1
242 #define JFS_LOOKUP 2
243 #define JFS_REMOVE 3
244 #define JFS_RENAME 4
245 
246 /*
247  * Maximum file offset for directories.
248  */
249 #define DIREND	INT_MAX
250 
251 /*
252  *	external declarations
253  */
254 extern void dtInitRoot(tid_t tid, struct inode *ip, u32 idotdot);
255 
256 extern int dtSearch(struct inode *ip, struct component_name * key,
257 		    ino_t * data, struct btstack * btstack, int flag);
258 
259 extern int dtInsert(tid_t tid, struct inode *ip, struct component_name * key,
260 		    ino_t * ino, struct btstack * btstack);
261 
262 extern int dtDelete(tid_t tid, struct inode *ip, struct component_name * key,
263 		    ino_t * data, int flag);
264 
265 extern int dtModify(tid_t tid, struct inode *ip, struct component_name * key,
266 		    ino_t * orig_ino, ino_t new_ino, int flag);
267 
268 extern int jfs_readdir(struct file *file, struct dir_context *ctx);
269 #endif				/* !_H_JFS_DTREE */
270