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
21 struct xfs_buf;
22 struct xfs_btree_cur;
23 struct xfs_mount;
24 struct xfs_perag;
25 struct xfs_trans;
26 struct xfs_busy_extent;
27
28 extern struct workqueue_struct *xfs_alloc_wq;
29
30 /*
31 * Freespace allocation types. Argument to xfs_alloc_[v]extent.
32 */
33 #define XFS_ALLOCTYPE_ANY_AG 0x01 /* allocate anywhere, use rotor */
34 #define XFS_ALLOCTYPE_FIRST_AG 0x02 /* ... start at ag 0 */
35 #define XFS_ALLOCTYPE_START_AG 0x04 /* anywhere, start in this a.g. */
36 #define XFS_ALLOCTYPE_THIS_AG 0x08 /* anywhere in this a.g. */
37 #define XFS_ALLOCTYPE_START_BNO 0x10 /* near this block else anywhere */
38 #define XFS_ALLOCTYPE_NEAR_BNO 0x20 /* in this a.g. and near this block */
39 #define XFS_ALLOCTYPE_THIS_BNO 0x40 /* at exactly this block */
40
41 /* this should become an enum again when the tracing code is fixed */
42 typedef unsigned int xfs_alloctype_t;
43
44 #define XFS_ALLOC_TYPES \
45 { XFS_ALLOCTYPE_ANY_AG, "ANY_AG" }, \
46 { XFS_ALLOCTYPE_FIRST_AG, "FIRST_AG" }, \
47 { XFS_ALLOCTYPE_START_AG, "START_AG" }, \
48 { XFS_ALLOCTYPE_THIS_AG, "THIS_AG" }, \
49 { XFS_ALLOCTYPE_START_BNO, "START_BNO" }, \
50 { XFS_ALLOCTYPE_NEAR_BNO, "NEAR_BNO" }, \
51 { XFS_ALLOCTYPE_THIS_BNO, "THIS_BNO" }
52
53 /*
54 * Flags for xfs_alloc_fix_freelist.
55 */
56 #define XFS_ALLOC_FLAG_TRYLOCK 0x00000001 /* use trylock for buffer locking */
57 #define XFS_ALLOC_FLAG_FREEING 0x00000002 /* indicate caller is freeing extents*/
58
59 /*
60 * In order to avoid ENOSPC-related deadlock caused by
61 * out-of-order locking of AGF buffer (PV 947395), we place
62 * constraints on the relationship among actual allocations for
63 * data blocks, freelist blocks, and potential file data bmap
64 * btree blocks. However, these restrictions may result in no
65 * actual space allocated for a delayed extent, for example, a data
66 * block in a certain AG is allocated but there is no additional
67 * block for the additional bmap btree block due to a split of the
68 * bmap btree of the file. The result of this may lead to an
69 * infinite loop in xfssyncd when the file gets flushed to disk and
70 * all delayed extents need to be actually allocated. To get around
71 * this, we explicitly set aside a few blocks which will not be
72 * reserved in delayed allocation. Considering the minimum number of
73 * needed freelist blocks is 4 fsbs _per AG_, a potential split of file's bmap
74 * btree requires 1 fsb, so we set the number of set-aside blocks
75 * to 4 + 4*agcount.
76 */
77 #define XFS_ALLOC_SET_ASIDE(mp) (4 + ((mp)->m_sb.sb_agcount * 4))
78
79 /*
80 * When deciding how much space to allocate out of an AG, we limit the
81 * allocation maximum size to the size the AG. However, we cannot use all the
82 * blocks in the AG - some are permanently used by metadata. These
83 * blocks are generally:
84 * - the AG superblock, AGF, AGI and AGFL
85 * - the AGF (bno and cnt) and AGI btree root blocks
86 * - 4 blocks on the AGFL according to XFS_ALLOC_SET_ASIDE() limits
87 *
88 * The AG headers are sector sized, so the amount of space they take up is
89 * dependent on filesystem geometry. The others are all single blocks.
90 */
91 #define XFS_ALLOC_AG_MAX_USABLE(mp) \
92 ((mp)->m_sb.sb_agblocks - XFS_BB_TO_FSB(mp, XFS_FSS_TO_BB(mp, 4)) - 7)
93
94
95 /*
96 * Argument structure for xfs_alloc routines.
97 * This is turned into a structure to avoid having 20 arguments passed
98 * down several levels of the stack.
99 */
100 typedef struct xfs_alloc_arg {
101 struct xfs_trans *tp; /* transaction pointer */
102 struct xfs_mount *mp; /* file system mount point */
103 struct xfs_buf *agbp; /* buffer for a.g. freelist header */
104 struct xfs_perag *pag; /* per-ag struct for this agno */
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_extlen_t len; /* output: actual size of extent */
117 xfs_alloctype_t type; /* allocation type XFS_ALLOCTYPE_... */
118 xfs_alloctype_t otype; /* original allocation type */
119 char wasdel; /* set if allocation was prev delayed */
120 char wasfromfl; /* set if allocation is from freelist */
121 char isfl; /* set if is freelist blocks - !acctg */
122 char userdata; /* set if this is user data */
123 xfs_fsblock_t firstblock; /* io first block allocated */
124 struct completion *done;
125 struct work_struct work;
126 int result;
127 } xfs_alloc_arg_t;
128
129 /*
130 * Defines for userdata
131 */
132 #define XFS_ALLOC_USERDATA 1 /* allocation is for user data*/
133 #define XFS_ALLOC_INITIAL_USER_DATA 2 /* special case start of file */
134
135 /*
136 * Find the length of the longest extent in an AG.
137 */
138 xfs_extlen_t
139 xfs_alloc_longest_free_extent(struct xfs_mount *mp,
140 struct xfs_perag *pag);
141
142 #ifdef __KERNEL__
143 void
144 xfs_alloc_busy_insert(struct xfs_trans *tp, xfs_agnumber_t agno,
145 xfs_agblock_t bno, xfs_extlen_t len, unsigned int flags);
146
147 void
148 xfs_alloc_busy_clear(struct xfs_mount *mp, struct list_head *list,
149 bool do_discard);
150
151 int
152 xfs_alloc_busy_search(struct xfs_mount *mp, xfs_agnumber_t agno,
153 xfs_agblock_t bno, xfs_extlen_t len);
154
155 void
156 xfs_alloc_busy_reuse(struct xfs_mount *mp, xfs_agnumber_t agno,
157 xfs_agblock_t fbno, xfs_extlen_t flen, bool userdata);
158
159 int
160 xfs_busy_extent_ag_cmp(void *priv, struct list_head *a, struct list_head *b);
161
xfs_alloc_busy_sort(struct list_head * list)162 static inline void xfs_alloc_busy_sort(struct list_head *list)
163 {
164 list_sort(NULL, list, xfs_busy_extent_ag_cmp);
165 }
166
167 #endif /* __KERNEL__ */
168
169 /*
170 * Compute and fill in value of m_ag_maxlevels.
171 */
172 void
173 xfs_alloc_compute_maxlevels(
174 struct xfs_mount *mp); /* file system mount structure */
175
176 /*
177 * Get a block from the freelist.
178 * Returns with the buffer for the block gotten.
179 */
180 int /* error */
181 xfs_alloc_get_freelist(
182 struct xfs_trans *tp, /* transaction pointer */
183 struct xfs_buf *agbp, /* buffer containing the agf structure */
184 xfs_agblock_t *bnop, /* block address retrieved from freelist */
185 int btreeblk); /* destination is a AGF btree */
186
187 /*
188 * Log the given fields from the agf structure.
189 */
190 void
191 xfs_alloc_log_agf(
192 struct xfs_trans *tp, /* transaction pointer */
193 struct xfs_buf *bp, /* buffer for a.g. freelist header */
194 int fields);/* mask of fields to be logged (XFS_AGF_...) */
195
196 /*
197 * Interface for inode allocation to force the pag data to be initialized.
198 */
199 int /* error */
200 xfs_alloc_pagf_init(
201 struct xfs_mount *mp, /* file system mount structure */
202 struct xfs_trans *tp, /* transaction pointer */
203 xfs_agnumber_t agno, /* allocation group number */
204 int flags); /* XFS_ALLOC_FLAGS_... */
205
206 /*
207 * Put the block on the freelist for the allocation group.
208 */
209 int /* error */
210 xfs_alloc_put_freelist(
211 struct xfs_trans *tp, /* transaction pointer */
212 struct xfs_buf *agbp, /* buffer for a.g. freelist header */
213 struct xfs_buf *agflbp,/* buffer for a.g. free block array */
214 xfs_agblock_t bno, /* block being freed */
215 int btreeblk); /* owner was a AGF btree */
216
217 /*
218 * Read in the allocation group header (free/alloc section).
219 */
220 int /* error */
221 xfs_alloc_read_agf(
222 struct xfs_mount *mp, /* mount point structure */
223 struct xfs_trans *tp, /* transaction pointer */
224 xfs_agnumber_t agno, /* allocation group number */
225 int flags, /* XFS_ALLOC_FLAG_... */
226 struct xfs_buf **bpp); /* buffer for the ag freelist header */
227
228 /*
229 * Allocate an extent (variable-size).
230 */
231 int /* error */
232 xfs_alloc_vextent(
233 xfs_alloc_arg_t *args); /* allocation argument structure */
234
235 /*
236 * Free an extent.
237 */
238 int /* error */
239 xfs_free_extent(
240 struct xfs_trans *tp, /* transaction pointer */
241 xfs_fsblock_t bno, /* starting block number of extent */
242 xfs_extlen_t len); /* length of extent */
243
244 int /* error */
245 xfs_alloc_lookup_le(
246 struct xfs_btree_cur *cur, /* btree cursor */
247 xfs_agblock_t bno, /* starting block of extent */
248 xfs_extlen_t len, /* length of extent */
249 int *stat); /* success/failure */
250
251 int /* error */
252 xfs_alloc_lookup_ge(
253 struct xfs_btree_cur *cur, /* btree cursor */
254 xfs_agblock_t bno, /* starting block of extent */
255 xfs_extlen_t len, /* length of extent */
256 int *stat); /* success/failure */
257
258 int /* error */
259 xfs_alloc_get_rec(
260 struct xfs_btree_cur *cur, /* btree cursor */
261 xfs_agblock_t *bno, /* output: starting block of extent */
262 xfs_extlen_t *len, /* output: length of extent */
263 int *stat); /* output: success/failure */
264
265 #endif /* __XFS_ALLOC_H__ */
266