2 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
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.
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.
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
18 #ifndef __XFS_ALLOC_H__
19 #define __XFS_ALLOC_H__
26 struct xfs_busy_extent
;
28 extern struct workqueue_struct
*xfs_alloc_wq
;
31 * Freespace allocation types. Argument to xfs_alloc_[v]extent.
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 */
41 /* this should become an enum again when the tracing code is fixed */
42 typedef unsigned int xfs_alloctype_t
;
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" }
54 * Flags for xfs_alloc_fix_freelist.
56 #define XFS_ALLOC_FLAG_TRYLOCK 0x00000001 /* use trylock for buffer locking */
57 #define XFS_ALLOC_FLAG_FREEING 0x00000002 /* indicate caller is freeing extents*/
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
77 #define XFS_ALLOC_SET_ASIDE(mp) (4 + ((mp)->m_sb.sb_agcount * 4))
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
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.
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)
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.
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
;
130 * Defines for userdata
132 #define XFS_ALLOC_USERDATA 1 /* allocation is for user data*/
133 #define XFS_ALLOC_INITIAL_USER_DATA 2 /* special case start of file */
136 * Find the length of the longest extent in an AG.
139 xfs_alloc_longest_free_extent(struct xfs_mount
*mp
,
140 struct xfs_perag
*pag
);
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
);
148 xfs_alloc_busy_clear(struct xfs_mount
*mp
, struct list_head
*list
,
152 xfs_alloc_busy_search(struct xfs_mount
*mp
, xfs_agnumber_t agno
,
153 xfs_agblock_t bno
, xfs_extlen_t len
);
156 xfs_alloc_busy_reuse(struct xfs_mount
*mp
, xfs_agnumber_t agno
,
157 xfs_agblock_t fbno
, xfs_extlen_t flen
, bool userdata
);
160 xfs_busy_extent_ag_cmp(void *priv
, struct list_head
*a
, struct list_head
*b
);
162 static inline void xfs_alloc_busy_sort(struct list_head
*list
)
164 list_sort(NULL
, list
, xfs_busy_extent_ag_cmp
);
167 #endif /* __KERNEL__ */
170 * Compute and fill in value of m_ag_maxlevels.
173 xfs_alloc_compute_maxlevels(
174 struct xfs_mount
*mp
); /* file system mount structure */
177 * Get a block from the freelist.
178 * Returns with the buffer for the block gotten.
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 */
188 * Log the given fields from the agf structure.
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_...) */
197 * Interface for inode allocation to force the pag data to be initialized.
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_... */
207 * Put the block on the freelist for the allocation group.
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 */
218 * Read in the allocation group header (free/alloc section).
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 */
229 * Allocate an extent (variable-size).
233 xfs_alloc_arg_t
*args
); /* allocation argument structure */
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 */
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 */
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 */
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 */
265 #endif /* __XFS_ALLOC_H__ */