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Diffstat (limited to 'fs/xfs/libxfs/xfs_alloc.h')
| -rw-r--r-- | fs/xfs/libxfs/xfs_alloc.h | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_alloc.h b/fs/xfs/libxfs/xfs_alloc.h new file mode 100644 index 000000000000..feacb061bab7 --- /dev/null +++ b/fs/xfs/libxfs/xfs_alloc.h @@ -0,0 +1,234 @@ +/* + * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc. + * All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it would be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ +#ifndef __XFS_ALLOC_H__ +#define __XFS_ALLOC_H__ + +struct xfs_buf; +struct xfs_btree_cur; +struct xfs_mount; +struct xfs_perag; +struct xfs_trans; + +extern struct workqueue_struct *xfs_alloc_wq; + +/* + * Freespace allocation types. Argument to xfs_alloc_[v]extent. + */ +#define XFS_ALLOCTYPE_ANY_AG 0x01 /* allocate anywhere, use rotor */ +#define XFS_ALLOCTYPE_FIRST_AG 0x02 /* ... start at ag 0 */ +#define XFS_ALLOCTYPE_START_AG 0x04 /* anywhere, start in this a.g. */ +#define XFS_ALLOCTYPE_THIS_AG 0x08 /* anywhere in this a.g. */ +#define XFS_ALLOCTYPE_START_BNO 0x10 /* near this block else anywhere */ +#define XFS_ALLOCTYPE_NEAR_BNO 0x20 /* in this a.g. and near this block */ +#define XFS_ALLOCTYPE_THIS_BNO 0x40 /* at exactly this block */ + +/* this should become an enum again when the tracing code is fixed */ +typedef unsigned int xfs_alloctype_t; + +#define XFS_ALLOC_TYPES \ + { XFS_ALLOCTYPE_ANY_AG, "ANY_AG" }, \ + { XFS_ALLOCTYPE_FIRST_AG, "FIRST_AG" }, \ + { XFS_ALLOCTYPE_START_AG, "START_AG" }, \ + { XFS_ALLOCTYPE_THIS_AG, "THIS_AG" }, \ + { XFS_ALLOCTYPE_START_BNO, "START_BNO" }, \ + { XFS_ALLOCTYPE_NEAR_BNO, "NEAR_BNO" }, \ + { XFS_ALLOCTYPE_THIS_BNO, "THIS_BNO" } + +/* + * Flags for xfs_alloc_fix_freelist. + */ +#define XFS_ALLOC_FLAG_TRYLOCK 0x00000001 /* use trylock for buffer locking */ +#define XFS_ALLOC_FLAG_FREEING 0x00000002 /* indicate caller is freeing extents*/ + +/* + * In order to avoid ENOSPC-related deadlock caused by + * out-of-order locking of AGF buffer (PV 947395), we place + * constraints on the relationship among actual allocations for + * data blocks, freelist blocks, and potential file data bmap + * btree blocks. However, these restrictions may result in no + * actual space allocated for a delayed extent, for example, a data + * block in a certain AG is allocated but there is no additional + * block for the additional bmap btree block due to a split of the + * bmap btree of the file. The result of this may lead to an + * infinite loop in xfssyncd when the file gets flushed to disk and + * all delayed extents need to be actually allocated. To get around + * this, we explicitly set aside a few blocks which will not be + * reserved in delayed allocation. Considering the minimum number of + * needed freelist blocks is 4 fsbs _per AG_, a potential split of file's bmap + * btree requires 1 fsb, so we set the number of set-aside blocks + * to 4 + 4*agcount. + */ +#define XFS_ALLOC_SET_ASIDE(mp) (4 + ((mp)->m_sb.sb_agcount * 4)) + +/* + * When deciding how much space to allocate out of an AG, we limit the + * allocation maximum size to the size the AG. However, we cannot use all the + * blocks in the AG - some are permanently used by metadata. These + * blocks are generally: + * - the AG superblock, AGF, AGI and AGFL + * - the AGF (bno and cnt) and AGI btree root blocks + * - 4 blocks on the AGFL according to XFS_ALLOC_SET_ASIDE() limits + * + * The AG headers are sector sized, so the amount of space they take up is + * dependent on filesystem geometry. The others are all single blocks. + */ +#define XFS_ALLOC_AG_MAX_USABLE(mp) \ + ((mp)->m_sb.sb_agblocks - XFS_BB_TO_FSB(mp, XFS_FSS_TO_BB(mp, 4)) - 7) + + +/* + * Argument structure for xfs_alloc routines. + * This is turned into a structure to avoid having 20 arguments passed + * down several levels of the stack. + */ +typedef struct xfs_alloc_arg { + struct xfs_trans *tp; /* transaction pointer */ + struct xfs_mount *mp; /* file system mount point */ + struct xfs_buf *agbp; /* buffer for a.g. freelist header */ + struct xfs_perag *pag; /* per-ag struct for this agno */ + xfs_fsblock_t fsbno; /* file system block number */ + xfs_agnumber_t agno; /* allocation group number */ + xfs_agblock_t agbno; /* allocation group-relative block # */ + xfs_extlen_t minlen; /* minimum size of extent */ + xfs_extlen_t maxlen; /* maximum size of extent */ + xfs_extlen_t mod; /* mod value for extent size */ + xfs_extlen_t prod; /* prod value for extent size */ + xfs_extlen_t minleft; /* min blocks must be left after us */ + xfs_extlen_t total; /* total blocks needed in xaction */ + xfs_extlen_t alignment; /* align answer to multiple of this */ + xfs_extlen_t minalignslop; /* slop for minlen+alignment calcs */ + xfs_extlen_t len; /* output: actual size of extent */ + xfs_alloctype_t type; /* allocation type XFS_ALLOCTYPE_... */ + xfs_alloctype_t otype; /* original allocation type */ + char wasdel; /* set if allocation was prev delayed */ + char wasfromfl; /* set if allocation is from freelist */ + char isfl; /* set if is freelist blocks - !acctg */ + char userdata; /* set if this is user data */ + xfs_fsblock_t firstblock; /* io first block allocated */ +} xfs_alloc_arg_t; + +/* + * Defines for userdata + */ +#define XFS_ALLOC_USERDATA 1 /* allocation is for user data*/ +#define XFS_ALLOC_INITIAL_USER_DATA 2 /* special case start of file */ + +/* + * Find the length of the longest extent in an AG. + */ +xfs_extlen_t +xfs_alloc_longest_free_extent(struct xfs_mount *mp, + struct xfs_perag *pag); + +/* + * Compute and fill in value of m_ag_maxlevels. + */ +void +xfs_alloc_compute_maxlevels( + struct xfs_mount *mp); /* file system mount structure */ + +/* + * Get a block from the freelist. + * Returns with the buffer for the block gotten. + */ +int /* error */ +xfs_alloc_get_freelist( + struct xfs_trans *tp, /* transaction pointer */ + struct xfs_buf *agbp, /* buffer containing the agf structure */ + xfs_agblock_t *bnop, /* block address retrieved from freelist */ + int btreeblk); /* destination is a AGF btree */ + +/* + * Log the given fields from the agf structure. + */ +void +xfs_alloc_log_agf( + struct xfs_trans *tp, /* transaction pointer */ + struct xfs_buf *bp, /* buffer for a.g. freelist header */ + int fields);/* mask of fields to be logged (XFS_AGF_...) */ + +/* + * Interface for inode allocation to force the pag data to be initialized. + */ +int /* error */ +xfs_alloc_pagf_init( + struct xfs_mount *mp, /* file system mount structure */ + struct xfs_trans *tp, /* transaction pointer */ + xfs_agnumber_t agno, /* allocation group number */ + int flags); /* XFS_ALLOC_FLAGS_... */ + +/* + * Put the block on the freelist for the allocation group. + */ +int /* error */ +xfs_alloc_put_freelist( + struct xfs_trans *tp, /* transaction pointer */ + struct xfs_buf *agbp, /* buffer for a.g. freelist header */ + struct xfs_buf *agflbp,/* buffer for a.g. free block array */ + xfs_agblock_t bno, /* block being freed */ + int btreeblk); /* owner was a AGF btree */ + +/* + * Read in the allocation group header (free/alloc section). + */ +int /* error */ +xfs_alloc_read_agf( + struct xfs_mount *mp, /* mount point structure */ + struct xfs_trans *tp, /* transaction pointer */ + xfs_agnumber_t agno, /* allocation group number */ + int flags, /* XFS_ALLOC_FLAG_... */ + struct xfs_buf **bpp); /* buffer for the ag freelist header */ + +/* + * Allocate an extent (variable-size). + */ +int /* error */ +xfs_alloc_vextent( + xfs_alloc_arg_t *args); /* allocation argument structure */ + +/* + * Free an extent. + */ +int /* error */ +xfs_free_extent( + struct xfs_trans *tp, /* transaction pointer */ + xfs_fsblock_t bno, /* starting block number of extent */ + xfs_extlen_t len); /* length of extent */ + +int /* error */ +xfs_alloc_lookup_le( + struct xfs_btree_cur *cur, /* btree cursor */ + xfs_agblock_t bno, /* starting block of extent */ + xfs_extlen_t len, /* length of extent */ + int *stat); /* success/failure */ + +int /* error */ +xfs_alloc_lookup_ge( + struct xfs_btree_cur *cur, /* btree cursor */ + xfs_agblock_t bno, /* starting block of extent */ + xfs_extlen_t len, /* length of extent */ + int *stat); /* success/failure */ + +int /* error */ +xfs_alloc_get_rec( + struct xfs_btree_cur *cur, /* btree cursor */ + xfs_agblock_t *bno, /* output: starting block of extent */ + xfs_extlen_t *len, /* output: length of extent */ + int *stat); /* output: success/failure */ + +#endif /* __XFS_ALLOC_H__ */ |