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1/*
2 * Copyright (c) 2000-2002,2005 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_ALLOC_H__
19#define __XFS_ALLOC_H__
20
21struct xfs_buf;
22struct xfs_btree_cur;
23struct xfs_mount;
24struct xfs_perag;
25struct xfs_trans;
26
27extern struct workqueue_struct *xfs_alloc_wq;
28
29/*
30 * Freespace allocation types. Argument to xfs_alloc_[v]extent.
31 */
32#define XFS_ALLOCTYPE_ANY_AG 0x01 /* allocate anywhere, use rotor */
33#define XFS_ALLOCTYPE_FIRST_AG 0x02 /* ... start at ag 0 */
34#define XFS_ALLOCTYPE_START_AG 0x04 /* anywhere, start in this a.g. */
35#define XFS_ALLOCTYPE_THIS_AG 0x08 /* anywhere in this a.g. */
36#define XFS_ALLOCTYPE_START_BNO 0x10 /* near this block else anywhere */
37#define XFS_ALLOCTYPE_NEAR_BNO 0x20 /* in this a.g. and near this block */
38#define XFS_ALLOCTYPE_THIS_BNO 0x40 /* at exactly this block */
39
40/* this should become an enum again when the tracing code is fixed */
41typedef unsigned int xfs_alloctype_t;
42
43#define XFS_ALLOC_TYPES \
44 { XFS_ALLOCTYPE_ANY_AG, "ANY_AG" }, \
45 { XFS_ALLOCTYPE_FIRST_AG, "FIRST_AG" }, \
46 { XFS_ALLOCTYPE_START_AG, "START_AG" }, \
47 { XFS_ALLOCTYPE_THIS_AG, "THIS_AG" }, \
48 { XFS_ALLOCTYPE_START_BNO, "START_BNO" }, \
49 { XFS_ALLOCTYPE_NEAR_BNO, "NEAR_BNO" }, \
50 { XFS_ALLOCTYPE_THIS_BNO, "THIS_BNO" }
51
52/*
53 * Flags for xfs_alloc_fix_freelist.
54 */
55#define XFS_ALLOC_FLAG_TRYLOCK 0x00000001 /* use trylock for buffer locking */
56#define XFS_ALLOC_FLAG_FREEING 0x00000002 /* indicate caller is freeing extents*/
57
58/*
59 * In order to avoid ENOSPC-related deadlock caused by
60 * out-of-order locking of AGF buffer (PV 947395), we place
61 * constraints on the relationship among actual allocations for
62 * data blocks, freelist blocks, and potential file data bmap
63 * btree blocks. However, these restrictions may result in no
64 * actual space allocated for a delayed extent, for example, a data
65 * block in a certain AG is allocated but there is no additional
66 * block for the additional bmap btree block due to a split of the
67 * bmap btree of the file. The result of this may lead to an
68 * infinite loop in xfssyncd when the file gets flushed to disk and
69 * all delayed extents need to be actually allocated. To get around
70 * this, we explicitly set aside a few blocks which will not be
71 * reserved in delayed allocation. Considering the minimum number of
72 * needed freelist blocks is 4 fsbs _per AG_, a potential split of file's bmap
73 * btree requires 1 fsb, so we set the number of set-aside blocks
74 * to 4 + 4*agcount.
75 */
76#define XFS_ALLOC_SET_ASIDE(mp) (4 + ((mp)->m_sb.sb_agcount * 4))
77
78/*
79 * When deciding how much space to allocate out of an AG, we limit the
80 * allocation maximum size to the size the AG. However, we cannot use all the
81 * blocks in the AG - some are permanently used by metadata. These
82 * blocks are generally:
83 * - the AG superblock, AGF, AGI and AGFL
84 * - the AGF (bno and cnt) and AGI btree root blocks
85 * - 4 blocks on the AGFL according to XFS_ALLOC_SET_ASIDE() limits
86 *
87 * The AG headers are sector sized, so the amount of space they take up is
88 * dependent on filesystem geometry. The others are all single blocks.
89 */
90#define XFS_ALLOC_AG_MAX_USABLE(mp) \
91 ((mp)->m_sb.sb_agblocks - XFS_BB_TO_FSB(mp, XFS_FSS_TO_BB(mp, 4)) - 7)
92
93
94/*
95 * Argument structure for xfs_alloc routines.
96 * This is turned into a structure to avoid having 20 arguments passed
97 * down several levels of the stack.
98 */
99typedef struct xfs_alloc_arg {
100 struct xfs_trans *tp; /* transaction pointer */
101 struct xfs_mount *mp; /* file system mount point */
102 struct xfs_buf *agbp; /* buffer for a.g. freelist header */
103 struct xfs_perag *pag; /* per-ag struct for this agno */
104 xfs_fsblock_t fsbno; /* file system block number */
105 xfs_agnumber_t agno; /* allocation group number */
106 xfs_agblock_t agbno; /* allocation group-relative block # */
107 xfs_extlen_t minlen; /* minimum size of extent */
108 xfs_extlen_t maxlen; /* maximum size of extent */
109 xfs_extlen_t mod; /* mod value for extent size */
110 xfs_extlen_t prod; /* prod value for extent size */
111 xfs_extlen_t minleft; /* min blocks must be left after us */
112 xfs_extlen_t total; /* total blocks needed in xaction */
113 xfs_extlen_t alignment; /* align answer to multiple of this */
114 xfs_extlen_t minalignslop; /* slop for minlen+alignment calcs */
115 xfs_extlen_t len; /* output: actual size of extent */
116 xfs_alloctype_t type; /* allocation type XFS_ALLOCTYPE_... */
117 xfs_alloctype_t otype; /* original allocation type */
118 char wasdel; /* set if allocation was prev delayed */
119 char wasfromfl; /* set if allocation is from freelist */
120 char isfl; /* set if is freelist blocks - !acctg */
121 char userdata; /* set if this is user data */
122 xfs_fsblock_t firstblock; /* io first block allocated */
123} xfs_alloc_arg_t;
124
125/*
126 * Defines for userdata
127 */
128#define XFS_ALLOC_USERDATA 1 /* allocation is for user data*/
129#define XFS_ALLOC_INITIAL_USER_DATA 2 /* special case start of file */
130
131/*
132 * Find the length of the longest extent in an AG.
133 */
134xfs_extlen_t
135xfs_alloc_longest_free_extent(struct xfs_mount *mp,
136 struct xfs_perag *pag);
137
138/*
139 * Compute and fill in value of m_ag_maxlevels.
140 */
141void
142xfs_alloc_compute_maxlevels(
143 struct xfs_mount *mp); /* file system mount structure */
144
145/*
146 * Get a block from the freelist.
147 * Returns with the buffer for the block gotten.
148 */
149int /* error */
150xfs_alloc_get_freelist(
151 struct xfs_trans *tp, /* transaction pointer */
152 struct xfs_buf *agbp, /* buffer containing the agf structure */
153 xfs_agblock_t *bnop, /* block address retrieved from freelist */
154 int btreeblk); /* destination is a AGF btree */
155
156/*
157 * Log the given fields from the agf structure.
158 */
159void
160xfs_alloc_log_agf(
161 struct xfs_trans *tp, /* transaction pointer */
162 struct xfs_buf *bp, /* buffer for a.g. freelist header */
163 int fields);/* mask of fields to be logged (XFS_AGF_...) */
164
165/*
166 * Interface for inode allocation to force the pag data to be initialized.
167 */
168int /* error */
169xfs_alloc_pagf_init(
170 struct xfs_mount *mp, /* file system mount structure */
171 struct xfs_trans *tp, /* transaction pointer */
172 xfs_agnumber_t agno, /* allocation group number */
173 int flags); /* XFS_ALLOC_FLAGS_... */
174
175/*
176 * Put the block on the freelist for the allocation group.
177 */
178int /* error */
179xfs_alloc_put_freelist(
180 struct xfs_trans *tp, /* transaction pointer */
181 struct xfs_buf *agbp, /* buffer for a.g. freelist header */
182 struct xfs_buf *agflbp,/* buffer for a.g. free block array */
183 xfs_agblock_t bno, /* block being freed */
184 int btreeblk); /* owner was a AGF btree */
185
186/*
187 * Read in the allocation group header (free/alloc section).
188 */
189int /* error */
190xfs_alloc_read_agf(
191 struct xfs_mount *mp, /* mount point structure */
192 struct xfs_trans *tp, /* transaction pointer */
193 xfs_agnumber_t agno, /* allocation group number */
194 int flags, /* XFS_ALLOC_FLAG_... */
195 struct xfs_buf **bpp); /* buffer for the ag freelist header */
196
197/*
198 * Allocate an extent (variable-size).
199 */
200int /* error */
201xfs_alloc_vextent(
202 xfs_alloc_arg_t *args); /* allocation argument structure */
203
204/*
205 * Free an extent.
206 */
207int /* error */
208xfs_free_extent(
209 struct xfs_trans *tp, /* transaction pointer */
210 xfs_fsblock_t bno, /* starting block number of extent */
211 xfs_extlen_t len); /* length of extent */
212
213int /* error */
214xfs_alloc_lookup_le(
215 struct xfs_btree_cur *cur, /* btree cursor */
216 xfs_agblock_t bno, /* starting block of extent */
217 xfs_extlen_t len, /* length of extent */
218 int *stat); /* success/failure */
219
220int /* error */
221xfs_alloc_lookup_ge(
222 struct xfs_btree_cur *cur, /* btree cursor */
223 xfs_agblock_t bno, /* starting block of extent */
224 xfs_extlen_t len, /* length of extent */
225 int *stat); /* success/failure */
226
227int /* error */
228xfs_alloc_get_rec(
229 struct xfs_btree_cur *cur, /* btree cursor */
230 xfs_agblock_t *bno, /* output: starting block of extent */
231 xfs_extlen_t *len, /* output: length of extent */
232 int *stat); /* output: success/failure */
233
234#endif /* __XFS_ALLOC_H__ */