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xfs_rtalloc.h
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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 *)((bp)->b_addr + \
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 */
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 */
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 */
110  struct xfs_mount *mp); /* file system mount structure */
111 void
113  struct xfs_mount *mp);
114 
115 /*
116  * Get the bitmap and summary inodes into the mount structure
117  * at mount time.
118  */
119 int /* error */
121  struct xfs_mount *mp); /* file system mount structure */
122 
123 /*
124  * Pick an extent for allocation at the start of a new realtime file.
125  * Use the sequence number stored in the atime field of the bitmap inode.
126  * Translate this to a fraction of the rtextents, and return the product
127  * of rtextents and the fraction.
128  * The fraction sequence is 0, 1/2, 1/4, 3/4, 1/8, ..., 7/8, 1/16, ...
129  */
130 int /* error */
132  struct xfs_mount *mp, /* file system mount point */
133  struct xfs_trans *tp, /* transaction pointer */
134  xfs_extlen_t len, /* allocation length (rtextents) */
135  xfs_rtblock_t *pick); /* result rt extent */
136 
137 /*
138  * Grow the realtime area of the filesystem.
139  */
140 int
142  struct xfs_mount *mp, /* file system mount structure */
143  xfs_growfs_rt_t *in); /* user supplied growfs struct */
144 
145 #else
146 # define xfs_rtallocate_extent(t,b,min,max,l,a,f,p,rb) (ENOSYS)
147 # define xfs_rtfree_extent(t,b,l) (ENOSYS)
148 # define xfs_rtpick_extent(m,t,l,rb) (ENOSYS)
149 # define xfs_growfs_rt(mp,in) (ENOSYS)
150 static inline int /* error */
152  xfs_mount_t *mp) /* file system mount structure */
153 {
154  if (mp->m_sb.sb_rblocks == 0)
155  return 0;
156 
157  xfs_warn(mp, "Not built with CONFIG_XFS_RT");
158  return ENOSYS;
159 }
160 # define xfs_rtmount_inodes(m) (((mp)->m_sb.sb_rblocks == 0)? 0 : (ENOSYS))
161 # define xfs_rtunmount_inodes(m)
162 #endif /* CONFIG_XFS_RT */
163 
164 #endif /* __KERNEL__ */
165 
166 #endif /* __XFS_RTALLOC_H__ */