xref: /openbmc/linux/fs/xfs/xfs_rtalloc.h (revision 384740dc)
1 /*
2  * Copyright (c) 2000-2003,2005 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_RTALLOC_H__
19 #define	__XFS_RTALLOC_H__
20 
21 struct xfs_mount;
22 struct xfs_trans;
23 
24 /* Min and max rt extent sizes, specified in bytes */
25 #define	XFS_MAX_RTEXTSIZE	(1024 * 1024 * 1024)	/* 1GB */
26 #define	XFS_DFL_RTEXTSIZE	(64 * 1024)	        /* 64KB */
27 #define	XFS_MIN_RTEXTSIZE	(4 * 1024)		/* 4KB */
28 
29 /*
30  * Constants for bit manipulations.
31  */
32 #define	XFS_NBBYLOG	3		/* log2(NBBY) */
33 #define	XFS_WORDLOG	2		/* log2(sizeof(xfs_rtword_t)) */
34 #define	XFS_NBWORDLOG	(XFS_NBBYLOG + XFS_WORDLOG)
35 #define	XFS_NBWORD	(1 << XFS_NBWORDLOG)
36 #define	XFS_WORDMASK	((1 << XFS_WORDLOG) - 1)
37 
38 #define	XFS_BLOCKSIZE(mp)	((mp)->m_sb.sb_blocksize)
39 #define	XFS_BLOCKMASK(mp)	((mp)->m_blockmask)
40 #define	XFS_BLOCKWSIZE(mp)	((mp)->m_blockwsize)
41 #define	XFS_BLOCKWMASK(mp)	((mp)->m_blockwmask)
42 
43 /*
44  * Summary and bit manipulation macros.
45  */
46 #define	XFS_SUMOFFS(mp,ls,bb)	((int)((ls) * (mp)->m_sb.sb_rbmblocks + (bb)))
47 #define	XFS_SUMOFFSTOBLOCK(mp,s)	\
48 	(((s) * (uint)sizeof(xfs_suminfo_t)) >> (mp)->m_sb.sb_blocklog)
49 #define	XFS_SUMPTR(mp,bp,so)	\
50 	((xfs_suminfo_t *)((char *)XFS_BUF_PTR(bp) + \
51 		(((so) * (uint)sizeof(xfs_suminfo_t)) & XFS_BLOCKMASK(mp))))
52 
53 #define	XFS_BITTOBLOCK(mp,bi)	((bi) >> (mp)->m_blkbit_log)
54 #define	XFS_BLOCKTOBIT(mp,bb)	((bb) << (mp)->m_blkbit_log)
55 #define	XFS_BITTOWORD(mp,bi)	\
56 	((int)(((bi) >> XFS_NBWORDLOG) & XFS_BLOCKWMASK(mp)))
57 
58 #define	XFS_RTMIN(a,b)	((a) < (b) ? (a) : (b))
59 #define	XFS_RTMAX(a,b)	((a) > (b) ? (a) : (b))
60 
61 #define	XFS_RTLOBIT(w)	xfs_lowbit32(w)
62 #define	XFS_RTHIBIT(w)	xfs_highbit32(w)
63 
64 #if XFS_BIG_BLKNOS
65 #define	XFS_RTBLOCKLOG(b)	xfs_highbit64(b)
66 #else
67 #define	XFS_RTBLOCKLOG(b)	xfs_highbit32(b)
68 #endif
69 
70 
71 #ifdef __KERNEL__
72 
73 #ifdef CONFIG_XFS_RT
74 /*
75  * Function prototypes for exported functions.
76  */
77 
78 /*
79  * Allocate an extent in the realtime subvolume, with the usual allocation
80  * parameters.  The length units are all in realtime extents, as is the
81  * result block number.
82  */
83 int					/* error */
84 xfs_rtallocate_extent(
85 	struct xfs_trans	*tp,	/* transaction pointer */
86 	xfs_rtblock_t		bno,	/* starting block number to allocate */
87 	xfs_extlen_t		minlen,	/* minimum length to allocate */
88 	xfs_extlen_t		maxlen,	/* maximum length to allocate */
89 	xfs_extlen_t		*len,	/* out: actual length allocated */
90 	xfs_alloctype_t		type,	/* allocation type XFS_ALLOCTYPE... */
91 	int			wasdel,	/* was a delayed allocation extent */
92 	xfs_extlen_t		prod,	/* extent product factor */
93 	xfs_rtblock_t		*rtblock); /* out: start block allocated */
94 
95 /*
96  * Free an extent in the realtime subvolume.  Length is expressed in
97  * realtime extents, as is the block number.
98  */
99 int					/* error */
100 xfs_rtfree_extent(
101 	struct xfs_trans	*tp,	/* transaction pointer */
102 	xfs_rtblock_t		bno,	/* starting block number to free */
103 	xfs_extlen_t		len);	/* length of extent freed */
104 
105 /*
106  * Initialize realtime fields in the mount structure.
107  */
108 int					/* error */
109 xfs_rtmount_init(
110 	struct xfs_mount	*mp);	/* file system mount structure */
111 
112 /*
113  * Get the bitmap and summary inodes into the mount structure
114  * at mount time.
115  */
116 int					/* error */
117 xfs_rtmount_inodes(
118 	struct xfs_mount	*mp);	/* file system mount structure */
119 
120 /*
121  * Pick an extent for allocation at the start of a new realtime file.
122  * Use the sequence number stored in the atime field of the bitmap inode.
123  * Translate this to a fraction of the rtextents, and return the product
124  * of rtextents and the fraction.
125  * The fraction sequence is 0, 1/2, 1/4, 3/4, 1/8, ..., 7/8, 1/16, ...
126  */
127 int					/* error */
128 xfs_rtpick_extent(
129 	struct xfs_mount	*mp,	/* file system mount point */
130 	struct xfs_trans	*tp,	/* transaction pointer */
131 	xfs_extlen_t		len,	/* allocation length (rtextents) */
132 	xfs_rtblock_t		*pick);	/* result rt extent */
133 
134 /*
135  * Grow the realtime area of the filesystem.
136  */
137 int
138 xfs_growfs_rt(
139 	struct xfs_mount	*mp,	/* file system mount structure */
140 	xfs_growfs_rt_t		*in);	/* user supplied growfs struct */
141 
142 #else
143 # define xfs_rtallocate_extent(t,b,min,max,l,a,f,p,rb)  (ENOSYS)
144 # define xfs_rtfree_extent(t,b,l)                       (ENOSYS)
145 # define xfs_rtpick_extent(m,t,l,rb)                    (ENOSYS)
146 # define xfs_growfs_rt(mp,in)                           (ENOSYS)
147 # define xfs_rtmount_init(m)    (((mp)->m_sb.sb_rblocks == 0)? 0 : (ENOSYS))
148 # define xfs_rtmount_inodes(m)  (((mp)->m_sb.sb_rblocks == 0)? 0 : (ENOSYS))
149 #endif	/* CONFIG_XFS_RT */
150 
151 #endif	/* __KERNEL__ */
152 
153 #endif	/* __XFS_RTALLOC_H__ */
154