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 28extern 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 */ 42typedef 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 */ 100typedef 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 */ 138xfs_extlen_t 139xfs_alloc_longest_free_extent(struct xfs_mount *mp, 140 struct xfs_perag *pag); 141 142#ifdef __KERNEL__ 143void 144xfs_alloc_busy_insert(struct xfs_trans *tp, xfs_agnumber_t agno, 145 xfs_agblock_t bno, xfs_extlen_t len, unsigned int flags); 146 147void 148xfs_alloc_busy_clear(struct xfs_mount *mp, struct list_head *list, 149 bool do_discard); 150 151int 152xfs_alloc_busy_search(struct xfs_mount *mp, xfs_agnumber_t agno, 153 xfs_agblock_t bno, xfs_extlen_t len); 154 155void 156xfs_alloc_busy_reuse(struct xfs_mount *mp, xfs_agnumber_t agno, 157 xfs_agblock_t fbno, xfs_extlen_t flen, bool userdata); 158 159int 160xfs_busy_extent_ag_cmp(void *priv, struct list_head *a, struct list_head *b); 161 162static 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 */ 172void 173xfs_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 */ 180int /* error */ 181xfs_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 */ 190void 191xfs_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 */ 199int /* error */ 200xfs_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 */ 209int /* error */ 210xfs_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 */ 220int /* error */ 221xfs_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 */ 231int /* error */ 232xfs_alloc_vextent( 233 xfs_alloc_arg_t *args); /* allocation argument structure */ 234 235/* 236 * Free an extent. 237 */ 238int /* error */ 239xfs_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 244int /* error */ 245xfs_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 251int /* error */ 252xfs_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 258int /* error */ 259xfs_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