[linux.git] / fs / xfs / xfs_alloc.h

/*
 * 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_mount;
struct xfs_perag;
struct xfs_trans;

/*
 * Freespace allocation types.  Argument to xfs_alloc_[v]extent.
 */
typedef enum xfs_alloctype
{
	XFS_ALLOCTYPE_ANY_AG,		/* allocate anywhere, use rotor */
	XFS_ALLOCTYPE_FIRST_AG,		/* ... start at ag 0 */
	XFS_ALLOCTYPE_START_AG,		/* anywhere, start in this a.g. */
	XFS_ALLOCTYPE_THIS_AG,		/* anywhere in this a.g. */
	XFS_ALLOCTYPE_START_BNO,	/* near this block else anywhere */
	XFS_ALLOCTYPE_NEAR_BNO,		/* in this a.g. and near this block */
	XFS_ALLOCTYPE_THIS_BNO		/* at exactly this block */
} xfs_alloctype_t;

/*
 * 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))

/*
 * 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 */


#ifdef __KERNEL__

#if defined(XFS_ALLOC_TRACE)
/*
 * Allocation tracing buffer size.
 */
#define	XFS_ALLOC_TRACE_SIZE	4096
extern ktrace_t *xfs_alloc_trace_buf;

/*
 * Types for alloc tracing.
 */
#define	XFS_ALLOC_KTRACE_ALLOC	1
#define	XFS_ALLOC_KTRACE_FREE	2
#define	XFS_ALLOC_KTRACE_MODAGF	3
#define	XFS_ALLOC_KTRACE_BUSY	4
#define	XFS_ALLOC_KTRACE_UNBUSY	5
#define	XFS_ALLOC_KTRACE_BUSYSEARCH	6
#endif

/*
 * 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 */

void
xfs_alloc_mark_busy(xfs_trans_t *tp,
		xfs_agnumber_t agno,
		xfs_agblock_t bno,
		xfs_extlen_t len);

void
xfs_alloc_clear_busy(xfs_trans_t *tp,
		xfs_agnumber_t ag,
		int idx);


#endif	/* __KERNEL__ */

#endif	/* __XFS_ALLOC_H__ */
Commit	Line	Data
1da177e4	1	/*
7b718769 NS	2	* Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
7b718769 NS	3	* All Rights Reserved.
1da177e4	4	*
7b718769 NS	5	* This program is free software; you can redistribute it and/or
7b718769 NS	6	* modify it under the terms of the GNU General Public License as
1da177e4 LT	7	* published by the Free Software Foundation.
1da177e4 LT	8	*
7b718769 NS	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.
1da177e4	13	*
7b718769 NS	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
1da177e4 LT	17	*/
	18	#ifndef __XFS_ALLOC_H__
	19	#define __XFS_ALLOC_H__
	20
	21	struct xfs_buf;
	22	struct xfs_mount;
	23	struct xfs_perag;
	24	struct xfs_trans;
	25
	26	/*
	27	* Freespace allocation types. Argument to xfs_alloc_[v]extent.
	28	*/
	29	typedef enum xfs_alloctype
	30	{
	31	XFS_ALLOCTYPE_ANY_AG, /* allocate anywhere, use rotor */
	32	XFS_ALLOCTYPE_FIRST_AG, /* ... start at ag 0 */
	33	XFS_ALLOCTYPE_START_AG, /* anywhere, start in this a.g. */
	34	XFS_ALLOCTYPE_THIS_AG, /* anywhere in this a.g. */
	35	XFS_ALLOCTYPE_START_BNO, /* near this block else anywhere */
	36	XFS_ALLOCTYPE_NEAR_BNO, /* in this a.g. and near this block */
	37	XFS_ALLOCTYPE_THIS_BNO /* at exactly this block */
	38	} xfs_alloctype_t;
	39
	40	/*
	41	* Flags for xfs_alloc_fix_freelist.
	42	*/
	43	#define XFS_ALLOC_FLAG_TRYLOCK 0x00000001 /* use trylock for buffer locking */
d210a28c	44	#define XFS_ALLOC_FLAG_FREEING 0x00000002 /* indicate caller is freeing extents*/
1da177e4	45
4be536de DC	46	/*
	47	* In order to avoid ENOSPC-related deadlock caused by
	48	* out-of-order locking of AGF buffer (PV 947395), we place
	49	* constraints on the relationship among actual allocations for
	50	* data blocks, freelist blocks, and potential file data bmap
	51	* btree blocks. However, these restrictions may result in no
	52	* actual space allocated for a delayed extent, for example, a data
	53	* block in a certain AG is allocated but there is no additional
	54	* block for the additional bmap btree block due to a split of the
	55	* bmap btree of the file. The result of this may lead to an
	56	* infinite loop in xfssyncd when the file gets flushed to disk and
	57	* all delayed extents need to be actually allocated. To get around
	58	* this, we explicitly set aside a few blocks which will not be
	59	* reserved in delayed allocation. Considering the minimum number of
	60	* needed freelist blocks is 4 fsbs _per AG_, a potential split of file's bmap
	61	* btree requires 1 fsb, so we set the number of set-aside blocks
	62	* to 4 + 4*agcount.
	63	*/
	64	#define XFS_ALLOC_SET_ASIDE(mp) (4 + ((mp)->m_sb.sb_agcount * 4))
	65
1da177e4 LT	66	/*
	67	* Argument structure for xfs_alloc routines.
	68	* This is turned into a structure to avoid having 20 arguments passed
	69	* down several levels of the stack.
	70	*/
	71	typedef struct xfs_alloc_arg {
	72	struct xfs_trans tp; / transaction pointer */
	73	struct xfs_mount mp; / file system mount point */
	74	struct xfs_buf agbp; / buffer for a.g. freelist header */
	75	struct xfs_perag pag; / per-ag struct for this agno */
	76	xfs_fsblock_t fsbno; /* file system block number */
	77	xfs_agnumber_t agno; /* allocation group number */
	78	xfs_agblock_t agbno; /* allocation group-relative block # */
	79	xfs_extlen_t minlen; /* minimum size of extent */
	80	xfs_extlen_t maxlen; /* maximum size of extent */
	81	xfs_extlen_t mod; /* mod value for extent size */
	82	xfs_extlen_t prod; /* prod value for extent size */
	83	xfs_extlen_t minleft; /* min blocks must be left after us */
	84	xfs_extlen_t total; /* total blocks needed in xaction */
	85	xfs_extlen_t alignment; /* align answer to multiple of this */
	86	xfs_extlen_t minalignslop; /* slop for minlen+alignment calcs */
	87	xfs_extlen_t len; /* output: actual size of extent */
	88	xfs_alloctype_t type; /* allocation type XFS_ALLOCTYPE_... */
	89	xfs_alloctype_t otype; /* original allocation type */
	90	char wasdel; /* set if allocation was prev delayed */
	91	char wasfromfl; /* set if allocation is from freelist */
c41564b5	92	char isfl; /* set if is freelist blocks - !acctg */
1da177e4	93	char userdata; /* set if this is user data */
d210a28c	94	xfs_fsblock_t firstblock; /* io first block allocated */
1da177e4 LT	95	} xfs_alloc_arg_t;
	96
	97	/*
	98	* Defines for userdata
	99	*/
	100	#define XFS_ALLOC_USERDATA 1 /* allocation is for user data*/
	101	#define XFS_ALLOC_INITIAL_USER_DATA 2 /* special case start of file */
	102
	103
	104	#ifdef __KERNEL__
	105
	106	#if defined(XFS_ALLOC_TRACE)
	107	/*
	108	* Allocation tracing buffer size.
	109	*/
	110	#define XFS_ALLOC_TRACE_SIZE 4096
	111	extern ktrace_t *xfs_alloc_trace_buf;
	112
	113	/*
	114	* Types for alloc tracing.
	115	*/
	116	#define XFS_ALLOC_KTRACE_ALLOC 1
	117	#define XFS_ALLOC_KTRACE_FREE 2
	118	#define XFS_ALLOC_KTRACE_MODAGF 3
	119	#define XFS_ALLOC_KTRACE_BUSY 4
	120	#define XFS_ALLOC_KTRACE_UNBUSY 5
	121	#define XFS_ALLOC_KTRACE_BUSYSEARCH 6
	122	#endif
	123
	124	/*
	125	* Compute and fill in value of m_ag_maxlevels.
	126	*/
	127	void
	128	xfs_alloc_compute_maxlevels(
	129	struct xfs_mount mp); / file system mount structure */
	130
	131	/*
	132	* Get a block from the freelist.
	133	* Returns with the buffer for the block gotten.
	134	*/
	135	int /* error */
	136	xfs_alloc_get_freelist(
	137	struct xfs_trans tp, / transaction pointer */
	138	struct xfs_buf agbp, / buffer containing the agf structure */
92821e2b DC	139	xfs_agblock_t bnop, / block address retrieved from freelist */
92821e2b DC	140	int btreeblk); /* destination is a AGF btree */
1da177e4 LT	141
	142	/*
	143	* Log the given fields from the agf structure.
	144	*/
	145	void
	146	xfs_alloc_log_agf(
	147	struct xfs_trans tp, / transaction pointer */
	148	struct xfs_buf bp, / buffer for a.g. freelist header */
	149	int fields);/* mask of fields to be logged (XFS_AGF_...) */
	150
	151	/*
	152	* Interface for inode allocation to force the pag data to be initialized.
	153	*/
	154	int /* error */
	155	xfs_alloc_pagf_init(
	156	struct xfs_mount mp, / file system mount structure */
	157	struct xfs_trans tp, / transaction pointer */
	158	xfs_agnumber_t agno, /* allocation group number */
	159	int flags); /* XFS_ALLOC_FLAGS_... */
	160
	161	/*
	162	* Put the block on the freelist for the allocation group.
	163	*/
	164	int /* error */
	165	xfs_alloc_put_freelist(
	166	struct xfs_trans tp, / transaction pointer */
	167	struct xfs_buf agbp, / buffer for a.g. freelist header */
	168	struct xfs_buf agflbp,/ buffer for a.g. free block array */
92821e2b DC	169	xfs_agblock_t bno, /* block being freed */
92821e2b DC	170	int btreeblk); /* owner was a AGF btree */
1da177e4 LT	171
	172	/*
	173	* Read in the allocation group header (free/alloc section).
	174	*/
	175	int /* error */
	176	xfs_alloc_read_agf(
	177	struct xfs_mount mp, / mount point structure */
	178	struct xfs_trans tp, / transaction pointer */
	179	xfs_agnumber_t agno, /* allocation group number */
	180	int flags, /* XFS_ALLOC_FLAG_... */
	181	struct xfs_buf *bpp); / buffer for the ag freelist header */
	182
	183	/*
	184	* Allocate an extent (variable-size).
	185	*/
	186	int /* error */
	187	xfs_alloc_vextent(
	188	xfs_alloc_arg_t args); / allocation argument structure */
	189
	190	/*
	191	* Free an extent.
	192	*/
	193	int /* error */
	194	xfs_free_extent(
	195	struct xfs_trans tp, / transaction pointer */
	196	xfs_fsblock_t bno, /* starting block number of extent */
	197	xfs_extlen_t len); /* length of extent */
	198
	199	void
	200	xfs_alloc_mark_busy(xfs_trans_t *tp,
	201	xfs_agnumber_t agno,
	202	xfs_agblock_t bno,
	203	xfs_extlen_t len);
	204
	205	void
	206	xfs_alloc_clear_busy(xfs_trans_t *tp,
	207	xfs_agnumber_t ag,
	208	int idx);
	209
	210
	211	#endif /* __KERNEL__ */
	212
	213	#endif /* __XFS_ALLOC_H__ */