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; 26struct xfs_busy_extent; 27 28/* 29 * Freespace allocation types. Argument to xfs_alloc_[v]extent. 30 */ 31#define XFS_ALLOCTYPE_ANY_AG 0x01 /* allocate anywhere, use rotor */ 32#define XFS_ALLOCTYPE_FIRST_AG 0x02 /* ... start at ag 0 */ 33#define XFS_ALLOCTYPE_START_AG 0x04 /* anywhere, start in this a.g. */ 34#define XFS_ALLOCTYPE_THIS_AG 0x08 /* anywhere in this a.g. */ 35#define XFS_ALLOCTYPE_START_BNO 0x10 /* near this block else anywhere */ 36#define XFS_ALLOCTYPE_NEAR_BNO 0x20 /* in this a.g. and near this block */ 37#define XFS_ALLOCTYPE_THIS_BNO 0x40 /* at exactly this block */ 38 39/* this should become an enum again when the tracing code is fixed */ 40typedef unsigned int xfs_alloctype_t; 41 42#define XFS_ALLOC_TYPES \ 43 { XFS_ALLOCTYPE_ANY_AG, "ANY_AG" }, \ 44 { XFS_ALLOCTYPE_FIRST_AG, "FIRST_AG" }, \ 45 { XFS_ALLOCTYPE_START_AG, "START_AG" }, \ 46 { XFS_ALLOCTYPE_THIS_AG, "THIS_AG" }, \ 47 { XFS_ALLOCTYPE_START_BNO, "START_BNO" }, \ 48 { XFS_ALLOCTYPE_NEAR_BNO, "NEAR_BNO" }, \ 49 { XFS_ALLOCTYPE_THIS_BNO, "THIS_BNO" } 50 51/* 52 * Flags for xfs_alloc_fix_freelist. 53 */ 54#define XFS_ALLOC_FLAG_TRYLOCK 0x00000001 /* use trylock for buffer locking */ 55#define XFS_ALLOC_FLAG_FREEING 0x00000002 /* indicate caller is freeing extents*/ 56 57/* 58 * In order to avoid ENOSPC-related deadlock caused by 59 * out-of-order locking of AGF buffer (PV 947395), we place 60 * constraints on the relationship among actual allocations for 61 * data blocks, freelist blocks, and potential file data bmap 62 * btree blocks. However, these restrictions may result in no 63 * actual space allocated for a delayed extent, for example, a data 64 * block in a certain AG is allocated but there is no additional 65 * block for the additional bmap btree block due to a split of the 66 * bmap btree of the file. The result of this may lead to an 67 * infinite loop in xfssyncd when the file gets flushed to disk and 68 * all delayed extents need to be actually allocated. To get around 69 * this, we explicitly set aside a few blocks which will not be 70 * reserved in delayed allocation. Considering the minimum number of 71 * needed freelist blocks is 4 fsbs _per AG_, a potential split of file's bmap 72 * btree requires 1 fsb, so we set the number of set-aside blocks 73 * to 4 + 4*agcount. 74 */ 75#define XFS_ALLOC_SET_ASIDE(mp) (4 + ((mp)->m_sb.sb_agcount * 4)) 76 77/* 78 * When deciding how much space to allocate out of an AG, we limit the 79 * allocation maximum size to the size the AG. However, we cannot use all the 80 * blocks in the AG - some are permanently used by metadata. These 81 * blocks are generally: 82 * - the AG superblock, AGF, AGI and AGFL 83 * - the AGF (bno and cnt) and AGI btree root blocks 84 * - 4 blocks on the AGFL according to XFS_ALLOC_SET_ASIDE() limits 85 * 86 * The AG headers are sector sized, so the amount of space they take up is 87 * dependent on filesystem geometry. The others are all single blocks. 88 */ 89#define XFS_ALLOC_AG_MAX_USABLE(mp) \ 90 ((mp)->m_sb.sb_agblocks - XFS_BB_TO_FSB(mp, XFS_FSS_TO_BB(mp, 4)) - 7) 91 92 93/* 94 * Argument structure for xfs_alloc routines. 95 * This is turned into a structure to avoid having 20 arguments passed 96 * down several levels of the stack. 97 */ 98typedef struct xfs_alloc_arg { 99 struct xfs_trans *tp; /* transaction pointer */ 100 struct xfs_mount *mp; /* file system mount point */ 101 struct xfs_buf *agbp; /* buffer for a.g. freelist header */ 102 struct xfs_perag *pag; /* per-ag struct for this agno */ 103 xfs_fsblock_t fsbno; /* file system block number */ 104 xfs_agnumber_t agno; /* allocation group number */ 105 xfs_agblock_t agbno; /* allocation group-relative block # */ 106 xfs_extlen_t minlen; /* minimum size of extent */ 107 xfs_extlen_t maxlen; /* maximum size of extent */ 108 xfs_extlen_t mod; /* mod value for extent size */ 109 xfs_extlen_t prod; /* prod value for extent size */ 110 xfs_extlen_t minleft; /* min blocks must be left after us */ 111 xfs_extlen_t total; /* total blocks needed in xaction */ 112 xfs_extlen_t alignment; /* align answer to multiple of this */ 113 xfs_extlen_t minalignslop; /* slop for minlen+alignment calcs */ 114 xfs_extlen_t len; /* output: actual size of extent */ 115 xfs_alloctype_t type; /* allocation type XFS_ALLOCTYPE_... */ 116 xfs_alloctype_t otype; /* original allocation type */ 117 char wasdel; /* set if allocation was prev delayed */ 118 char wasfromfl; /* set if allocation is from freelist */ 119 char isfl; /* set if is freelist blocks - !acctg */ 120 char userdata; /* set if this is user data */ 121 xfs_fsblock_t firstblock; /* io first block allocated */ 122} xfs_alloc_arg_t; 123 124/* 125 * Defines for userdata 126 */ 127#define XFS_ALLOC_USERDATA 1 /* allocation is for user data*/ 128#define XFS_ALLOC_INITIAL_USER_DATA 2 /* special case start of file */ 129 130/* 131 * Find the length of the longest extent in an AG. 132 */ 133xfs_extlen_t 134xfs_alloc_longest_free_extent(struct xfs_mount *mp, 135 struct xfs_perag *pag); 136 137#ifdef __KERNEL__ 138void 139xfs_alloc_busy_insert(struct xfs_trans *tp, xfs_agnumber_t agno, 140 xfs_agblock_t bno, xfs_extlen_t len, unsigned int flags); 141 142void 143xfs_alloc_busy_clear(struct xfs_mount *mp, struct list_head *list, 144 bool do_discard); 145 146int 147xfs_alloc_busy_search(struct xfs_mount *mp, xfs_agnumber_t agno, 148 xfs_agblock_t bno, xfs_extlen_t len); 149 150void 151xfs_alloc_busy_reuse(struct xfs_mount *mp, xfs_agnumber_t agno, 152 xfs_agblock_t fbno, xfs_extlen_t flen, bool userdata); 153 154int 155xfs_busy_extent_ag_cmp(void *priv, struct list_head *a, struct list_head *b); 156 157static inline void xfs_alloc_busy_sort(struct list_head *list) 158{ 159 list_sort(NULL, list, xfs_busy_extent_ag_cmp); 160} 161 162#endif /* __KERNEL__ */ 163 164/* 165 * Compute and fill in value of m_ag_maxlevels. 166 */ 167void 168xfs_alloc_compute_maxlevels( 169 struct xfs_mount *mp); /* file system mount structure */ 170 171/* 172 * Get a block from the freelist. 173 * Returns with the buffer for the block gotten. 174 */ 175int /* error */ 176xfs_alloc_get_freelist( 177 struct xfs_trans *tp, /* transaction pointer */ 178 struct xfs_buf *agbp, /* buffer containing the agf structure */ 179 xfs_agblock_t *bnop, /* block address retrieved from freelist */ 180 int btreeblk); /* destination is a AGF btree */ 181 182/* 183 * Log the given fields from the agf structure. 184 */ 185void 186xfs_alloc_log_agf( 187 struct xfs_trans *tp, /* transaction pointer */ 188 struct xfs_buf *bp, /* buffer for a.g. freelist header */ 189 int fields);/* mask of fields to be logged (XFS_AGF_...) */ 190 191/* 192 * Interface for inode allocation to force the pag data to be initialized. 193 */ 194int /* error */ 195xfs_alloc_pagf_init( 196 struct xfs_mount *mp, /* file system mount structure */ 197 struct xfs_trans *tp, /* transaction pointer */ 198 xfs_agnumber_t agno, /* allocation group number */ 199 int flags); /* XFS_ALLOC_FLAGS_... */ 200 201/* 202 * Put the block on the freelist for the allocation group. 203 */ 204int /* error */ 205xfs_alloc_put_freelist( 206 struct xfs_trans *tp, /* transaction pointer */ 207 struct xfs_buf *agbp, /* buffer for a.g. freelist header */ 208 struct xfs_buf *agflbp,/* buffer for a.g. free block array */ 209 xfs_agblock_t bno, /* block being freed */ 210 int btreeblk); /* owner was a AGF btree */ 211 212/* 213 * Read in the allocation group header (free/alloc section). 214 */ 215int /* error */ 216xfs_alloc_read_agf( 217 struct xfs_mount *mp, /* mount point structure */ 218 struct xfs_trans *tp, /* transaction pointer */ 219 xfs_agnumber_t agno, /* allocation group number */ 220 int flags, /* XFS_ALLOC_FLAG_... */ 221 struct xfs_buf **bpp); /* buffer for the ag freelist header */ 222 223/* 224 * Allocate an extent (variable-size). 225 */ 226int /* error */ 227xfs_alloc_vextent( 228 xfs_alloc_arg_t *args); /* allocation argument structure */ 229 230/* 231 * Free an extent. 232 */ 233int /* error */ 234xfs_free_extent( 235 struct xfs_trans *tp, /* transaction pointer */ 236 xfs_fsblock_t bno, /* starting block number of extent */ 237 xfs_extlen_t len); /* length of extent */ 238 239int /* error */ 240xfs_alloc_lookup_le( 241 struct xfs_btree_cur *cur, /* btree cursor */ 242 xfs_agblock_t bno, /* starting block of extent */ 243 xfs_extlen_t len, /* length of extent */ 244 int *stat); /* success/failure */ 245 246int /* error */ 247xfs_alloc_get_rec( 248 struct xfs_btree_cur *cur, /* btree cursor */ 249 xfs_agblock_t *bno, /* output: starting block of extent */ 250 xfs_extlen_t *len, /* output: length of extent */ 251 int *stat); /* output: success/failure */ 252 253#endif /* __XFS_ALLOC_H__ */ 254