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 27 extern 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 */ 41 typedef 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 */ 99 typedef 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 struct xfs_inode *ip; /* for userdata zeroing method */ 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_agblock_t min_agbno; /* set an agbno range for NEAR allocs */ 117 xfs_agblock_t max_agbno; /* ... */ 118 xfs_extlen_t len; /* output: actual size of extent */ 119 xfs_alloctype_t type; /* allocation type XFS_ALLOCTYPE_... */ 120 xfs_alloctype_t otype; /* original allocation type */ 121 char wasdel; /* set if allocation was prev delayed */ 122 char wasfromfl; /* set if allocation is from freelist */ 123 char isfl; /* set if is freelist blocks - !acctg */ 124 char userdata; /* mask defining userdata treatment */ 125 xfs_fsblock_t firstblock; /* io first block allocated */ 126 } xfs_alloc_arg_t; 127 128 /* 129 * Defines for userdata 130 */ 131 #define XFS_ALLOC_USERDATA (1 << 0)/* allocation is for user data*/ 132 #define XFS_ALLOC_INITIAL_USER_DATA (1 << 1)/* special case start of file */ 133 #define XFS_ALLOC_USERDATA_ZERO (1 << 2)/* zero extent on allocation */ 134 135 xfs_extlen_t xfs_alloc_longest_free_extent(struct xfs_mount *mp, 136 struct xfs_perag *pag, xfs_extlen_t need); 137 unsigned int xfs_alloc_min_freelist(struct xfs_mount *mp, 138 struct xfs_perag *pag); 139 140 /* 141 * Compute and fill in value of m_ag_maxlevels. 142 */ 143 void 144 xfs_alloc_compute_maxlevels( 145 struct xfs_mount *mp); /* file system mount structure */ 146 147 /* 148 * Get a block from the freelist. 149 * Returns with the buffer for the block gotten. 150 */ 151 int /* error */ 152 xfs_alloc_get_freelist( 153 struct xfs_trans *tp, /* transaction pointer */ 154 struct xfs_buf *agbp, /* buffer containing the agf structure */ 155 xfs_agblock_t *bnop, /* block address retrieved from freelist */ 156 int btreeblk); /* destination is a AGF btree */ 157 158 /* 159 * Log the given fields from the agf structure. 160 */ 161 void 162 xfs_alloc_log_agf( 163 struct xfs_trans *tp, /* transaction pointer */ 164 struct xfs_buf *bp, /* buffer for a.g. freelist header */ 165 int fields);/* mask of fields to be logged (XFS_AGF_...) */ 166 167 /* 168 * Interface for inode allocation to force the pag data to be initialized. 169 */ 170 int /* error */ 171 xfs_alloc_pagf_init( 172 struct xfs_mount *mp, /* file system mount structure */ 173 struct xfs_trans *tp, /* transaction pointer */ 174 xfs_agnumber_t agno, /* allocation group number */ 175 int flags); /* XFS_ALLOC_FLAGS_... */ 176 177 /* 178 * Put the block on the freelist for the allocation group. 179 */ 180 int /* error */ 181 xfs_alloc_put_freelist( 182 struct xfs_trans *tp, /* transaction pointer */ 183 struct xfs_buf *agbp, /* buffer for a.g. freelist header */ 184 struct xfs_buf *agflbp,/* buffer for a.g. free block array */ 185 xfs_agblock_t bno, /* block being freed */ 186 int btreeblk); /* owner was a AGF btree */ 187 188 /* 189 * Read in the allocation group header (free/alloc section). 190 */ 191 int /* error */ 192 xfs_alloc_read_agf( 193 struct xfs_mount *mp, /* mount point structure */ 194 struct xfs_trans *tp, /* transaction pointer */ 195 xfs_agnumber_t agno, /* allocation group number */ 196 int flags, /* XFS_ALLOC_FLAG_... */ 197 struct xfs_buf **bpp); /* buffer for the ag freelist header */ 198 199 /* 200 * Allocate an extent (variable-size). 201 */ 202 int /* error */ 203 xfs_alloc_vextent( 204 xfs_alloc_arg_t *args); /* allocation argument structure */ 205 206 /* 207 * Free an extent. 208 */ 209 int /* error */ 210 xfs_free_extent( 211 struct xfs_trans *tp, /* transaction pointer */ 212 xfs_fsblock_t bno, /* starting block number of extent */ 213 xfs_extlen_t len); /* length of extent */ 214 215 int /* error */ 216 xfs_alloc_lookup_le( 217 struct xfs_btree_cur *cur, /* btree cursor */ 218 xfs_agblock_t bno, /* starting block of extent */ 219 xfs_extlen_t len, /* length of extent */ 220 int *stat); /* success/failure */ 221 222 int /* error */ 223 xfs_alloc_lookup_ge( 224 struct xfs_btree_cur *cur, /* btree cursor */ 225 xfs_agblock_t bno, /* starting block of extent */ 226 xfs_extlen_t len, /* length of extent */ 227 int *stat); /* success/failure */ 228 229 int /* error */ 230 xfs_alloc_get_rec( 231 struct xfs_btree_cur *cur, /* btree cursor */ 232 xfs_agblock_t *bno, /* output: starting block of extent */ 233 xfs_extlen_t *len, /* output: length of extent */ 234 int *stat); /* output: success/failure */ 235 236 int xfs_read_agf(struct xfs_mount *mp, struct xfs_trans *tp, 237 xfs_agnumber_t agno, int flags, struct xfs_buf **bpp); 238 int xfs_alloc_fix_freelist(struct xfs_alloc_arg *args, int flags); 239 240 #endif /* __XFS_ALLOC_H__ */ 241