tjh.dev
Linux kernel mirror (for testing)
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linux
1/*
2 * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * 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 the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18#ifndef __XFS_AG_H__
19#define __XFS_AG_H__
20
21/*
22 * Allocation group header
23 * This is divided into three structures, placed in sequential 512-byte
24 * buffers after a copy of the superblock (also in a 512-byte buffer).
25 */
26
27struct xfs_buf;
28struct xfs_mount;
29struct xfs_trans;
30
31#define XFS_AGF_MAGIC 0x58414746 /* 'XAGF' */
32#define XFS_AGI_MAGIC 0x58414749 /* 'XAGI' */
33#define XFS_AGFL_MAGIC 0x5841464c /* 'XAFL' */
34#define XFS_AGF_VERSION 1
35#define XFS_AGI_VERSION 1
36
37#define XFS_AGF_GOOD_VERSION(v) ((v) == XFS_AGF_VERSION)
38#define XFS_AGI_GOOD_VERSION(v) ((v) == XFS_AGI_VERSION)
39
40/*
41 * Btree number 0 is bno, 1 is cnt. This value gives the size of the
42 * arrays below.
43 */
44#define XFS_BTNUM_AGF ((int)XFS_BTNUM_CNTi + 1)
45
46/*
47 * The second word of agf_levels in the first a.g. overlaps the EFS
48 * superblock's magic number. Since the magic numbers valid for EFS
49 * are > 64k, our value cannot be confused for an EFS superblock's.
50 */
51
52typedef struct xfs_agf {
53 /*
54 * Common allocation group header information
55 */
56 __be32 agf_magicnum; /* magic number == XFS_AGF_MAGIC */
57 __be32 agf_versionnum; /* header version == XFS_AGF_VERSION */
58 __be32 agf_seqno; /* sequence # starting from 0 */
59 __be32 agf_length; /* size in blocks of a.g. */
60 /*
61 * Freespace information
62 */
63 __be32 agf_roots[XFS_BTNUM_AGF]; /* root blocks */
64 __be32 agf_spare0; /* spare field */
65 __be32 agf_levels[XFS_BTNUM_AGF]; /* btree levels */
66 __be32 agf_spare1; /* spare field */
67
68 __be32 agf_flfirst; /* first freelist block's index */
69 __be32 agf_fllast; /* last freelist block's index */
70 __be32 agf_flcount; /* count of blocks in freelist */
71 __be32 agf_freeblks; /* total free blocks */
72
73 __be32 agf_longest; /* longest free space */
74 __be32 agf_btreeblks; /* # of blocks held in AGF btrees */
75 uuid_t agf_uuid; /* uuid of filesystem */
76
77 /*
78 * reserve some contiguous space for future logged fields before we add
79 * the unlogged fields. This makes the range logging via flags and
80 * structure offsets much simpler.
81 */
82 __be64 agf_spare64[16];
83
84 /* unlogged fields, written during buffer writeback. */
85 __be64 agf_lsn; /* last write sequence */
86 __be32 agf_crc; /* crc of agf sector */
87 __be32 agf_spare2;
88
89 /* structure must be padded to 64 bit alignment */
90} xfs_agf_t;
91
92#define XFS_AGF_MAGICNUM 0x00000001
93#define XFS_AGF_VERSIONNUM 0x00000002
94#define XFS_AGF_SEQNO 0x00000004
95#define XFS_AGF_LENGTH 0x00000008
96#define XFS_AGF_ROOTS 0x00000010
97#define XFS_AGF_LEVELS 0x00000020
98#define XFS_AGF_FLFIRST 0x00000040
99#define XFS_AGF_FLLAST 0x00000080
100#define XFS_AGF_FLCOUNT 0x00000100
101#define XFS_AGF_FREEBLKS 0x00000200
102#define XFS_AGF_LONGEST 0x00000400
103#define XFS_AGF_BTREEBLKS 0x00000800
104#define XFS_AGF_UUID 0x00001000
105#define XFS_AGF_NUM_BITS 13
106#define XFS_AGF_ALL_BITS ((1 << XFS_AGF_NUM_BITS) - 1)
107
108#define XFS_AGF_FLAGS \
109 { XFS_AGF_MAGICNUM, "MAGICNUM" }, \
110 { XFS_AGF_VERSIONNUM, "VERSIONNUM" }, \
111 { XFS_AGF_SEQNO, "SEQNO" }, \
112 { XFS_AGF_LENGTH, "LENGTH" }, \
113 { XFS_AGF_ROOTS, "ROOTS" }, \
114 { XFS_AGF_LEVELS, "LEVELS" }, \
115 { XFS_AGF_FLFIRST, "FLFIRST" }, \
116 { XFS_AGF_FLLAST, "FLLAST" }, \
117 { XFS_AGF_FLCOUNT, "FLCOUNT" }, \
118 { XFS_AGF_FREEBLKS, "FREEBLKS" }, \
119 { XFS_AGF_LONGEST, "LONGEST" }, \
120 { XFS_AGF_BTREEBLKS, "BTREEBLKS" }, \
121 { XFS_AGF_UUID, "UUID" }
122
123/* disk block (xfs_daddr_t) in the AG */
124#define XFS_AGF_DADDR(mp) ((xfs_daddr_t)(1 << (mp)->m_sectbb_log))
125#define XFS_AGF_BLOCK(mp) XFS_HDR_BLOCK(mp, XFS_AGF_DADDR(mp))
126#define XFS_BUF_TO_AGF(bp) ((xfs_agf_t *)((bp)->b_addr))
127
128extern int xfs_read_agf(struct xfs_mount *mp, struct xfs_trans *tp,
129 xfs_agnumber_t agno, int flags, struct xfs_buf **bpp);
130
131/*
132 * Size of the unlinked inode hash table in the agi.
133 */
134#define XFS_AGI_UNLINKED_BUCKETS 64
135
136typedef struct xfs_agi {
137 /*
138 * Common allocation group header information
139 */
140 __be32 agi_magicnum; /* magic number == XFS_AGI_MAGIC */
141 __be32 agi_versionnum; /* header version == XFS_AGI_VERSION */
142 __be32 agi_seqno; /* sequence # starting from 0 */
143 __be32 agi_length; /* size in blocks of a.g. */
144 /*
145 * Inode information
146 * Inodes are mapped by interpreting the inode number, so no
147 * mapping data is needed here.
148 */
149 __be32 agi_count; /* count of allocated inodes */
150 __be32 agi_root; /* root of inode btree */
151 __be32 agi_level; /* levels in inode btree */
152 __be32 agi_freecount; /* number of free inodes */
153
154 __be32 agi_newino; /* new inode just allocated */
155 __be32 agi_dirino; /* last directory inode chunk */
156 /*
157 * Hash table of inodes which have been unlinked but are
158 * still being referenced.
159 */
160 __be32 agi_unlinked[XFS_AGI_UNLINKED_BUCKETS];
161
162 uuid_t agi_uuid; /* uuid of filesystem */
163 __be32 agi_crc; /* crc of agi sector */
164 __be32 agi_pad32;
165 __be64 agi_lsn; /* last write sequence */
166
167 /* structure must be padded to 64 bit alignment */
168} xfs_agi_t;
169
170#define XFS_AGI_MAGICNUM 0x00000001
171#define XFS_AGI_VERSIONNUM 0x00000002
172#define XFS_AGI_SEQNO 0x00000004
173#define XFS_AGI_LENGTH 0x00000008
174#define XFS_AGI_COUNT 0x00000010
175#define XFS_AGI_ROOT 0x00000020
176#define XFS_AGI_LEVEL 0x00000040
177#define XFS_AGI_FREECOUNT 0x00000080
178#define XFS_AGI_NEWINO 0x00000100
179#define XFS_AGI_DIRINO 0x00000200
180#define XFS_AGI_UNLINKED 0x00000400
181#define XFS_AGI_NUM_BITS 11
182#define XFS_AGI_ALL_BITS ((1 << XFS_AGI_NUM_BITS) - 1)
183
184/* disk block (xfs_daddr_t) in the AG */
185#define XFS_AGI_DADDR(mp) ((xfs_daddr_t)(2 << (mp)->m_sectbb_log))
186#define XFS_AGI_BLOCK(mp) XFS_HDR_BLOCK(mp, XFS_AGI_DADDR(mp))
187#define XFS_BUF_TO_AGI(bp) ((xfs_agi_t *)((bp)->b_addr))
188
189extern int xfs_read_agi(struct xfs_mount *mp, struct xfs_trans *tp,
190 xfs_agnumber_t agno, struct xfs_buf **bpp);
191
192/*
193 * The third a.g. block contains the a.g. freelist, an array
194 * of block pointers to blocks owned by the allocation btree code.
195 */
196#define XFS_AGFL_DADDR(mp) ((xfs_daddr_t)(3 << (mp)->m_sectbb_log))
197#define XFS_AGFL_BLOCK(mp) XFS_HDR_BLOCK(mp, XFS_AGFL_DADDR(mp))
198#define XFS_BUF_TO_AGFL(bp) ((xfs_agfl_t *)((bp)->b_addr))
199
200#define XFS_BUF_TO_AGFL_BNO(mp, bp) \
201 (xfs_sb_version_hascrc(&((mp)->m_sb)) ? \
202 &(XFS_BUF_TO_AGFL(bp)->agfl_bno[0]) : \
203 (__be32 *)(bp)->b_addr)
204
205/*
206 * Size of the AGFL. For CRC-enabled filesystes we steal a couple of
207 * slots in the beginning of the block for a proper header with the
208 * location information and CRC.
209 */
210#define XFS_AGFL_SIZE(mp) \
211 (((mp)->m_sb.sb_sectsize - \
212 (xfs_sb_version_hascrc(&((mp)->m_sb)) ? \
213 sizeof(struct xfs_agfl) : 0)) / \
214 sizeof(xfs_agblock_t))
215
216typedef struct xfs_agfl {
217 __be32 agfl_magicnum;
218 __be32 agfl_seqno;
219 uuid_t agfl_uuid;
220 __be64 agfl_lsn;
221 __be32 agfl_crc;
222 __be32 agfl_bno[]; /* actually XFS_AGFL_SIZE(mp) */
223} xfs_agfl_t;
224
225/*
226 * tags for inode radix tree
227 */
228#define XFS_ICI_NO_TAG (-1) /* special flag for an untagged lookup
229 in xfs_inode_ag_iterator */
230#define XFS_ICI_RECLAIM_TAG 0 /* inode is to be reclaimed */
231#define XFS_ICI_EOFBLOCKS_TAG 1 /* inode has blocks beyond EOF */
232
233#define XFS_AG_MAXLEVELS(mp) ((mp)->m_ag_maxlevels)
234#define XFS_MIN_FREELIST_RAW(bl,cl,mp) \
235 (MIN(bl + 1, XFS_AG_MAXLEVELS(mp)) + MIN(cl + 1, XFS_AG_MAXLEVELS(mp)))
236#define XFS_MIN_FREELIST(a,mp) \
237 (XFS_MIN_FREELIST_RAW( \
238 be32_to_cpu((a)->agf_levels[XFS_BTNUM_BNOi]), \
239 be32_to_cpu((a)->agf_levels[XFS_BTNUM_CNTi]), mp))
240#define XFS_MIN_FREELIST_PAG(pag,mp) \
241 (XFS_MIN_FREELIST_RAW( \
242 (unsigned int)(pag)->pagf_levels[XFS_BTNUM_BNOi], \
243 (unsigned int)(pag)->pagf_levels[XFS_BTNUM_CNTi], mp))
244
245#define XFS_AGB_TO_FSB(mp,agno,agbno) \
246 (((xfs_fsblock_t)(agno) << (mp)->m_sb.sb_agblklog) | (agbno))
247#define XFS_FSB_TO_AGNO(mp,fsbno) \
248 ((xfs_agnumber_t)((fsbno) >> (mp)->m_sb.sb_agblklog))
249#define XFS_FSB_TO_AGBNO(mp,fsbno) \
250 ((xfs_agblock_t)((fsbno) & xfs_mask32lo((mp)->m_sb.sb_agblklog)))
251#define XFS_AGB_TO_DADDR(mp,agno,agbno) \
252 ((xfs_daddr_t)XFS_FSB_TO_BB(mp, \
253 (xfs_fsblock_t)(agno) * (mp)->m_sb.sb_agblocks + (agbno)))
254#define XFS_AG_DADDR(mp,agno,d) (XFS_AGB_TO_DADDR(mp, agno, 0) + (d))
255
256/*
257 * For checking for bad ranges of xfs_daddr_t's, covering multiple
258 * allocation groups or a single xfs_daddr_t that's a superblock copy.
259 */
260#define XFS_AG_CHECK_DADDR(mp,d,len) \
261 ((len) == 1 ? \
262 ASSERT((d) == XFS_SB_DADDR || \
263 xfs_daddr_to_agbno(mp, d) != XFS_SB_DADDR) : \
264 ASSERT(xfs_daddr_to_agno(mp, d) == \
265 xfs_daddr_to_agno(mp, (d) + (len) - 1)))
266
267#endif /* __XFS_AG_H__ */