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xfs_ag.h
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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 
27 struct xfs_buf;
28 struct xfs_mount;
29 struct xfs_trans;
30 
31 #define XFS_AGF_MAGIC 0x58414746 /* 'XAGF' */
32 #define XFS_AGI_MAGIC 0x58414749 /* 'XAGI' */
33 #define XFS_AGF_VERSION 1
34 #define XFS_AGI_VERSION 1
35 
36 #define XFS_AGF_GOOD_VERSION(v) ((v) == XFS_AGF_VERSION)
37 #define XFS_AGI_GOOD_VERSION(v) ((v) == XFS_AGI_VERSION)
38 
39 /*
40  * Btree number 0 is bno, 1 is cnt. This value gives the size of the
41  * arrays below.
42  */
43 #define XFS_BTNUM_AGF ((int)XFS_BTNUM_CNTi + 1)
44 
45 /*
46  * The second word of agf_levels in the first a.g. overlaps the EFS
47  * superblock's magic number. Since the magic numbers valid for EFS
48  * are > 64k, our value cannot be confused for an EFS superblock's.
49  */
50 
51 typedef struct xfs_agf {
52  /*
53  * Common allocation group header information
54  */
55  __be32 agf_magicnum; /* magic number == XFS_AGF_MAGIC */
56  __be32 agf_versionnum; /* header version == XFS_AGF_VERSION */
57  __be32 agf_seqno; /* sequence # starting from 0 */
58  __be32 agf_length; /* size in blocks of a.g. */
59  /*
60  * Freespace information
61  */
62  __be32 agf_roots[XFS_BTNUM_AGF]; /* root blocks */
63  __be32 agf_spare0; /* spare field */
64  __be32 agf_levels[XFS_BTNUM_AGF]; /* btree levels */
65  __be32 agf_spare1; /* spare field */
66  __be32 agf_flfirst; /* first freelist block's index */
67  __be32 agf_fllast; /* last freelist block's index */
68  __be32 agf_flcount; /* count of blocks in freelist */
69  __be32 agf_freeblks; /* total free blocks */
70  __be32 agf_longest; /* longest free space */
71  __be32 agf_btreeblks; /* # of blocks held in AGF btrees */
72 } xfs_agf_t;
73 
74 #define XFS_AGF_MAGICNUM 0x00000001
75 #define XFS_AGF_VERSIONNUM 0x00000002
76 #define XFS_AGF_SEQNO 0x00000004
77 #define XFS_AGF_LENGTH 0x00000008
78 #define XFS_AGF_ROOTS 0x00000010
79 #define XFS_AGF_LEVELS 0x00000020
80 #define XFS_AGF_FLFIRST 0x00000040
81 #define XFS_AGF_FLLAST 0x00000080
82 #define XFS_AGF_FLCOUNT 0x00000100
83 #define XFS_AGF_FREEBLKS 0x00000200
84 #define XFS_AGF_LONGEST 0x00000400
85 #define XFS_AGF_BTREEBLKS 0x00000800
86 #define XFS_AGF_NUM_BITS 12
87 #define XFS_AGF_ALL_BITS ((1 << XFS_AGF_NUM_BITS) - 1)
88 
89 #define XFS_AGF_FLAGS \
90  { XFS_AGF_MAGICNUM, "MAGICNUM" }, \
91  { XFS_AGF_VERSIONNUM, "VERSIONNUM" }, \
92  { XFS_AGF_SEQNO, "SEQNO" }, \
93  { XFS_AGF_LENGTH, "LENGTH" }, \
94  { XFS_AGF_ROOTS, "ROOTS" }, \
95  { XFS_AGF_LEVELS, "LEVELS" }, \
96  { XFS_AGF_FLFIRST, "FLFIRST" }, \
97  { XFS_AGF_FLLAST, "FLLAST" }, \
98  { XFS_AGF_FLCOUNT, "FLCOUNT" }, \
99  { XFS_AGF_FREEBLKS, "FREEBLKS" }, \
100  { XFS_AGF_LONGEST, "LONGEST" }, \
101  { XFS_AGF_BTREEBLKS, "BTREEBLKS" }
102 
103 /* disk block (xfs_daddr_t) in the AG */
104 #define XFS_AGF_DADDR(mp) ((xfs_daddr_t)(1 << (mp)->m_sectbb_log))
105 #define XFS_AGF_BLOCK(mp) XFS_HDR_BLOCK(mp, XFS_AGF_DADDR(mp))
106 #define XFS_BUF_TO_AGF(bp) ((xfs_agf_t *)((bp)->b_addr))
107 
108 extern int xfs_read_agf(struct xfs_mount *mp, struct xfs_trans *tp,
109  xfs_agnumber_t agno, int flags, struct xfs_buf **bpp);
110 
111 /*
112  * Size of the unlinked inode hash table in the agi.
113  */
114 #define XFS_AGI_UNLINKED_BUCKETS 64
115 
116 typedef struct xfs_agi {
117  /*
118  * Common allocation group header information
119  */
120  __be32 agi_magicnum; /* magic number == XFS_AGI_MAGIC */
121  __be32 agi_versionnum; /* header version == XFS_AGI_VERSION */
122  __be32 agi_seqno; /* sequence # starting from 0 */
123  __be32 agi_length; /* size in blocks of a.g. */
124  /*
125  * Inode information
126  * Inodes are mapped by interpreting the inode number, so no
127  * mapping data is needed here.
128  */
129  __be32 agi_count; /* count of allocated inodes */
130  __be32 agi_root; /* root of inode btree */
131  __be32 agi_level; /* levels in inode btree */
132  __be32 agi_freecount; /* number of free inodes */
133  __be32 agi_newino; /* new inode just allocated */
134  __be32 agi_dirino; /* last directory inode chunk */
135  /*
136  * Hash table of inodes which have been unlinked but are
137  * still being referenced.
138  */
140 } xfs_agi_t;
141 
142 #define XFS_AGI_MAGICNUM 0x00000001
143 #define XFS_AGI_VERSIONNUM 0x00000002
144 #define XFS_AGI_SEQNO 0x00000004
145 #define XFS_AGI_LENGTH 0x00000008
146 #define XFS_AGI_COUNT 0x00000010
147 #define XFS_AGI_ROOT 0x00000020
148 #define XFS_AGI_LEVEL 0x00000040
149 #define XFS_AGI_FREECOUNT 0x00000080
150 #define XFS_AGI_NEWINO 0x00000100
151 #define XFS_AGI_DIRINO 0x00000200
152 #define XFS_AGI_UNLINKED 0x00000400
153 #define XFS_AGI_NUM_BITS 11
154 #define XFS_AGI_ALL_BITS ((1 << XFS_AGI_NUM_BITS) - 1)
155 
156 /* disk block (xfs_daddr_t) in the AG */
157 #define XFS_AGI_DADDR(mp) ((xfs_daddr_t)(2 << (mp)->m_sectbb_log))
158 #define XFS_AGI_BLOCK(mp) XFS_HDR_BLOCK(mp, XFS_AGI_DADDR(mp))
159 #define XFS_BUF_TO_AGI(bp) ((xfs_agi_t *)((bp)->b_addr))
160 
161 extern int xfs_read_agi(struct xfs_mount *mp, struct xfs_trans *tp,
162  xfs_agnumber_t agno, struct xfs_buf **bpp);
163 
164 /*
165  * The third a.g. block contains the a.g. freelist, an array
166  * of block pointers to blocks owned by the allocation btree code.
167  */
168 #define XFS_AGFL_DADDR(mp) ((xfs_daddr_t)(3 << (mp)->m_sectbb_log))
169 #define XFS_AGFL_BLOCK(mp) XFS_HDR_BLOCK(mp, XFS_AGFL_DADDR(mp))
170 #define XFS_AGFL_SIZE(mp) ((mp)->m_sb.sb_sectsize / sizeof(xfs_agblock_t))
171 #define XFS_BUF_TO_AGFL(bp) ((xfs_agfl_t *)((bp)->b_addr))
172 
173 typedef struct xfs_agfl {
174  __be32 agfl_bno[1]; /* actually XFS_AGFL_SIZE(mp) */
175 } xfs_agfl_t;
176 
177 /*
178  * Per-ag incore structure, copies of information in agf and agi,
179  * to improve the performance of allocation group selection.
180  */
181 #define XFS_PAGB_NUM_SLOTS 128
182 
183 typedef struct xfs_perag {
184  struct xfs_mount *pag_mount; /* owner filesystem */
185  xfs_agnumber_t pag_agno; /* AG this structure belongs to */
186  atomic_t pag_ref; /* perag reference count */
187  char pagf_init; /* this agf's entry is initialized */
188  char pagi_init; /* this agi's entry is initialized */
189  char pagf_metadata; /* the agf is preferred to be metadata */
190  char pagi_inodeok; /* The agi is ok for inodes */
192  /* # of levels in bno & cnt btree */
193  __uint32_t pagf_flcount; /* count of blocks in freelist */
194  xfs_extlen_t pagf_freeblks; /* total free blocks */
195  xfs_extlen_t pagf_longest; /* longest free space */
196  __uint32_t pagf_btreeblks; /* # of blocks held in AGF btrees */
197  xfs_agino_t pagi_freecount; /* number of free inodes */
198  xfs_agino_t pagi_count; /* number of allocated inodes */
199 
200  /*
201  * Inode allocation search lookup optimisation.
202  * If the pagino matches, the search for new inodes
203  * doesn't need to search the near ones again straight away
204  */
208 #ifdef __KERNEL__
209  spinlock_t pagb_lock; /* lock for pagb_tree */
210  struct rb_root pagb_tree; /* ordered tree of busy extents */
211 
212  atomic_t pagf_fstrms; /* # of filestreams active in this AG */
213 
214  spinlock_t pag_ici_lock; /* incore inode cache lock */
215  struct radix_tree_root pag_ici_root; /* incore inode cache root */
216  int pag_ici_reclaimable; /* reclaimable inodes */
217  struct mutex pag_ici_reclaim_lock; /* serialisation point */
218  unsigned long pag_ici_reclaim_cursor; /* reclaim restart point */
219 
220  /* buffer cache index */
221  spinlock_t pag_buf_lock; /* lock for pag_buf_tree */
222  struct rb_root pag_buf_tree; /* ordered tree of active buffers */
223 
224  /* for rcu-safe freeing */
225  struct rcu_head rcu_head;
226 #endif
227  int pagb_count; /* pagb slots in use */
228 } xfs_perag_t;
229 
230 /*
231  * tags for inode radix tree
232  */
233 #define XFS_ICI_NO_TAG (-1) /* special flag for an untagged lookup
234  in xfs_inode_ag_iterator */
235 #define XFS_ICI_RECLAIM_TAG 0 /* inode is to be reclaimed */
237 #define XFS_AG_MAXLEVELS(mp) ((mp)->m_ag_maxlevels)
238 #define XFS_MIN_FREELIST_RAW(bl,cl,mp) \
239  (MIN(bl + 1, XFS_AG_MAXLEVELS(mp)) + MIN(cl + 1, XFS_AG_MAXLEVELS(mp)))
240 #define XFS_MIN_FREELIST(a,mp) \
241  (XFS_MIN_FREELIST_RAW( \
242  be32_to_cpu((a)->agf_levels[XFS_BTNUM_BNOi]), \
243  be32_to_cpu((a)->agf_levels[XFS_BTNUM_CNTi]), mp))
244 #define XFS_MIN_FREELIST_PAG(pag,mp) \
245  (XFS_MIN_FREELIST_RAW( \
246  (unsigned int)(pag)->pagf_levels[XFS_BTNUM_BNOi], \
247  (unsigned int)(pag)->pagf_levels[XFS_BTNUM_CNTi], mp))
249 #define XFS_AGB_TO_FSB(mp,agno,agbno) \
250  (((xfs_fsblock_t)(agno) << (mp)->m_sb.sb_agblklog) | (agbno))
251 #define XFS_FSB_TO_AGNO(mp,fsbno) \
252  ((xfs_agnumber_t)((fsbno) >> (mp)->m_sb.sb_agblklog))
253 #define XFS_FSB_TO_AGBNO(mp,fsbno) \
254  ((xfs_agblock_t)((fsbno) & xfs_mask32lo((mp)->m_sb.sb_agblklog)))
255 #define XFS_AGB_TO_DADDR(mp,agno,agbno) \
256  ((xfs_daddr_t)XFS_FSB_TO_BB(mp, \
257  (xfs_fsblock_t)(agno) * (mp)->m_sb.sb_agblocks + (agbno)))
258 #define XFS_AG_DADDR(mp,agno,d) (XFS_AGB_TO_DADDR(mp, agno, 0) + (d))
259 
260 /*
261  * For checking for bad ranges of xfs_daddr_t's, covering multiple
262  * allocation groups or a single xfs_daddr_t that's a superblock copy.
263  */
264 #define XFS_AG_CHECK_DADDR(mp,d,len) \
265  ((len) == 1 ? \
266  ASSERT((d) == XFS_SB_DADDR || \
267  xfs_daddr_to_agbno(mp, d) != XFS_SB_DADDR) : \
268  ASSERT(xfs_daddr_to_agno(mp, d) == \
269  xfs_daddr_to_agno(mp, (d) + (len) - 1)))
270 
271 #endif /* __XFS_AG_H__ */