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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 struct xfs_inode *ip; /* for userdata zeroing method */
105 xfs_fsblock_t fsbno; /* file system block number */
106 xfs_agnumber_t agno; /* allocation group number */
107 xfs_agblock_t agbno; /* allocation group-relative block # */
108 xfs_extlen_t minlen; /* minimum size of extent */
109 xfs_extlen_t maxlen; /* maximum size of extent */
110 xfs_extlen_t mod; /* mod value for extent size */
111 xfs_extlen_t prod; /* prod value for extent size */
112 xfs_extlen_t minleft; /* min blocks must be left after us */
113 xfs_extlen_t total; /* total blocks needed in xaction */
114 xfs_extlen_t alignment; /* align answer to multiple of this */
115 xfs_extlen_t minalignslop; /* slop for minlen+alignment calcs */
116 xfs_agblock_t min_agbno; /* set an agbno range for NEAR allocs */
117 xfs_agblock_t max_agbno; /* ... */
118 xfs_extlen_t len; /* output: actual size of extent */
119 xfs_alloctype_t type; /* allocation type XFS_ALLOCTYPE_... */
120 xfs_alloctype_t otype; /* original allocation type */
121 char wasdel; /* set if allocation was prev delayed */
122 char wasfromfl; /* set if allocation is from freelist */
123 char isfl; /* set if is freelist blocks - !acctg */
124 char userdata; /* mask defining userdata treatment */
125 xfs_fsblock_t firstblock; /* io first block allocated */
126} xfs_alloc_arg_t;
127
128/*
129 * Defines for userdata
130 */
131#define XFS_ALLOC_USERDATA (1 << 0)/* allocation is for user data*/
132#define XFS_ALLOC_INITIAL_USER_DATA (1 << 1)/* special case start of file */
133#define XFS_ALLOC_USERDATA_ZERO (1 << 2)/* zero extent on allocation */
134
135xfs_extlen_t xfs_alloc_longest_free_extent(struct xfs_mount *mp,
136 struct xfs_perag *pag, xfs_extlen_t need);
137unsigned int xfs_alloc_min_freelist(struct xfs_mount *mp,
138 struct xfs_perag *pag);
139
140/*
141 * Compute and fill in value of m_ag_maxlevels.
142 */
143void
144xfs_alloc_compute_maxlevels(
145 struct xfs_mount *mp); /* file system mount structure */
146
147/*
148 * Get a block from the freelist.
149 * Returns with the buffer for the block gotten.
150 */
151int /* error */
152xfs_alloc_get_freelist(
153 struct xfs_trans *tp, /* transaction pointer */
154 struct xfs_buf *agbp, /* buffer containing the agf structure */
155 xfs_agblock_t *bnop, /* block address retrieved from freelist */
156 int btreeblk); /* destination is a AGF btree */
157
158/*
159 * Log the given fields from the agf structure.
160 */
161void
162xfs_alloc_log_agf(
163 struct xfs_trans *tp, /* transaction pointer */
164 struct xfs_buf *bp, /* buffer for a.g. freelist header */
165 int fields);/* mask of fields to be logged (XFS_AGF_...) */
166
167/*
168 * Interface for inode allocation to force the pag data to be initialized.
169 */
170int /* error */
171xfs_alloc_pagf_init(
172 struct xfs_mount *mp, /* file system mount structure */
173 struct xfs_trans *tp, /* transaction pointer */
174 xfs_agnumber_t agno, /* allocation group number */
175 int flags); /* XFS_ALLOC_FLAGS_... */
176
177/*
178 * Put the block on the freelist for the allocation group.
179 */
180int /* error */
181xfs_alloc_put_freelist(
182 struct xfs_trans *tp, /* transaction pointer */
183 struct xfs_buf *agbp, /* buffer for a.g. freelist header */
184 struct xfs_buf *agflbp,/* buffer for a.g. free block array */
185 xfs_agblock_t bno, /* block being freed */
186 int btreeblk); /* owner was a AGF btree */
187
188/*
189 * Read in the allocation group header (free/alloc section).
190 */
191int /* error */
192xfs_alloc_read_agf(
193 struct xfs_mount *mp, /* mount point structure */
194 struct xfs_trans *tp, /* transaction pointer */
195 xfs_agnumber_t agno, /* allocation group number */
196 int flags, /* XFS_ALLOC_FLAG_... */
197 struct xfs_buf **bpp); /* buffer for the ag freelist header */
198
199/*
200 * Allocate an extent (variable-size).
201 */
202int /* error */
203xfs_alloc_vextent(
204 xfs_alloc_arg_t *args); /* allocation argument structure */
205
206/*
207 * Free an extent.
208 */
209int /* error */
210xfs_free_extent(
211 struct xfs_trans *tp, /* transaction pointer */
212 xfs_fsblock_t bno, /* starting block number of extent */
213 xfs_extlen_t len); /* length of extent */
214
215int /* error */
216xfs_alloc_lookup_le(
217 struct xfs_btree_cur *cur, /* btree cursor */
218 xfs_agblock_t bno, /* starting block of extent */
219 xfs_extlen_t len, /* length of extent */
220 int *stat); /* success/failure */
221
222int /* error */
223xfs_alloc_lookup_ge(
224 struct xfs_btree_cur *cur, /* btree cursor */
225 xfs_agblock_t bno, /* starting block of extent */
226 xfs_extlen_t len, /* length of extent */
227 int *stat); /* success/failure */
228
229int /* error */
230xfs_alloc_get_rec(
231 struct xfs_btree_cur *cur, /* btree cursor */
232 xfs_agblock_t *bno, /* output: starting block of extent */
233 xfs_extlen_t *len, /* output: length of extent */
234 int *stat); /* output: success/failure */
235
236int xfs_read_agf(struct xfs_mount *mp, struct xfs_trans *tp,
237 xfs_agnumber_t agno, int flags, struct xfs_buf **bpp);
238int xfs_alloc_fix_freelist(struct xfs_alloc_arg *args, int flags);
239
240#endif /* __XFS_ALLOC_H__ */