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 struct completion *done; 124 struct work_struct work; 125 int result; 126} xfs_alloc_arg_t; 127 128/* 129 * Defines for userdata 130 */ 131#define XFS_ALLOC_USERDATA 1 /* allocation is for user data*/ 132#define XFS_ALLOC_INITIAL_USER_DATA 2 /* special case start of file */ 133 134/* 135 * Find the length of the longest extent in an AG. 136 */ 137xfs_extlen_t 138xfs_alloc_longest_free_extent(struct xfs_mount *mp, 139 struct xfs_perag *pag); 140 141/* 142 * Compute and fill in value of m_ag_maxlevels. 143 */ 144void 145xfs_alloc_compute_maxlevels( 146 struct xfs_mount *mp); /* file system mount structure */ 147 148/* 149 * Get a block from the freelist. 150 * Returns with the buffer for the block gotten. 151 */ 152int /* error */ 153xfs_alloc_get_freelist( 154 struct xfs_trans *tp, /* transaction pointer */ 155 struct xfs_buf *agbp, /* buffer containing the agf structure */ 156 xfs_agblock_t *bnop, /* block address retrieved from freelist */ 157 int btreeblk); /* destination is a AGF btree */ 158 159/* 160 * Log the given fields from the agf structure. 161 */ 162void 163xfs_alloc_log_agf( 164 struct xfs_trans *tp, /* transaction pointer */ 165 struct xfs_buf *bp, /* buffer for a.g. freelist header */ 166 int fields);/* mask of fields to be logged (XFS_AGF_...) */ 167 168/* 169 * Interface for inode allocation to force the pag data to be initialized. 170 */ 171int /* error */ 172xfs_alloc_pagf_init( 173 struct xfs_mount *mp, /* file system mount structure */ 174 struct xfs_trans *tp, /* transaction pointer */ 175 xfs_agnumber_t agno, /* allocation group number */ 176 int flags); /* XFS_ALLOC_FLAGS_... */ 177 178/* 179 * Put the block on the freelist for the allocation group. 180 */ 181int /* error */ 182xfs_alloc_put_freelist( 183 struct xfs_trans *tp, /* transaction pointer */ 184 struct xfs_buf *agbp, /* buffer for a.g. freelist header */ 185 struct xfs_buf *agflbp,/* buffer for a.g. free block array */ 186 xfs_agblock_t bno, /* block being freed */ 187 int btreeblk); /* owner was a AGF btree */ 188 189/* 190 * Read in the allocation group header (free/alloc section). 191 */ 192int /* error */ 193xfs_alloc_read_agf( 194 struct xfs_mount *mp, /* mount point structure */ 195 struct xfs_trans *tp, /* transaction pointer */ 196 xfs_agnumber_t agno, /* allocation group number */ 197 int flags, /* XFS_ALLOC_FLAG_... */ 198 struct xfs_buf **bpp); /* buffer for the ag freelist header */ 199 200/* 201 * Allocate an extent (variable-size). 202 */ 203int /* error */ 204xfs_alloc_vextent( 205 xfs_alloc_arg_t *args); /* allocation argument structure */ 206 207/* 208 * Free an extent. 209 */ 210int /* error */ 211xfs_free_extent( 212 struct xfs_trans *tp, /* transaction pointer */ 213 xfs_fsblock_t bno, /* starting block number of extent */ 214 xfs_extlen_t len); /* length of extent */ 215 216int /* error */ 217xfs_alloc_lookup_le( 218 struct xfs_btree_cur *cur, /* btree cursor */ 219 xfs_agblock_t bno, /* starting block of extent */ 220 xfs_extlen_t len, /* length of extent */ 221 int *stat); /* success/failure */ 222 223int /* error */ 224xfs_alloc_lookup_ge( 225 struct xfs_btree_cur *cur, /* btree cursor */ 226 xfs_agblock_t bno, /* starting block of extent */ 227 xfs_extlen_t len, /* length of extent */ 228 int *stat); /* success/failure */ 229 230int /* error */ 231xfs_alloc_get_rec( 232 struct xfs_btree_cur *cur, /* btree cursor */ 233 xfs_agblock_t *bno, /* output: starting block of extent */ 234 xfs_extlen_t *len, /* output: length of extent */ 235 int *stat); /* output: success/failure */ 236 237#endif /* __XFS_ALLOC_H__ */ 238