1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1982, 1986, 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36 #ifndef FAT_BUF_H
37 #define FAT_BUF_H
38
39
40 // Modified to support the Haiku FAT driver.
41
42 #include <sys/queue.h>
43
44 #ifdef FS_SHELL
45 #include "fssh_fs_cache.h"
46 #else
47 #include <fs_cache.h>
48 #endif // FS_SHELL
49
50 #include "fs/msdosfs/bpb.h"
51 #include "fs/msdosfs/msdosfsmount.h"
52 #include "sys/mount.h"
53 #include "sys/pcpu.h"
54 #include "sys/ucred.h"
55
56 #include "dosfs.h"
57
58
59 /*
60 * The buffer header describes an I/O operation in the kernel.
61 *
62 * NOTES:
63 * b_bufsize, b_bcount. b_bufsize is the allocation size of the
64 * buffer, either DEV_BSIZE or PAGE_SIZE aligned. b_bcount is the
65 * originally requested buffer size and can serve as a bounds check
66 * against EOF. For most, but not all uses, b_bcount == b_bufsize.
67 *
68 * b_resid. Number of bytes remaining in I/O. After an I/O operation
69 * completes, b_resid is usually 0 indicating 100% success.
70 */
71 struct buf {
72 long b_bcount;
73 caddr_t b_data;
74 long b_resid;
75 daddr_t b_blkno; /* Underlying physical block number. */
76 uint32_t b_flags; /* B_* flags. */
77 long b_bufsize; /* Allocated buffer size. */
78 // In the Haiku port, if b_data is a pointer to a block cache block,
79 // this is still populated even though b_data is not owned by the driver.
80 daddr_t b_lblkno; /* Logical block number. */
81 struct vnode* b_vp; /* Device vnode. */
82
83 // Members added for Haiku port
84 bool b_owned;
85 // false if b_data is a pointer to a block cache block
86 struct vnode* b_vreg;
87 // the node that was passed to bread, if it was of type VREG; otherwise, NULL
88 void* b_bcpointers[128];
89 // If b_data is assembled from multiple block cache blocks, this holds pointers to
90 // each source block. The FAT specification allows up to 128 sectors per cluster.
91 SLIST_ENTRY(buf) link;
92 // for the list members of struct bufobj
93 };
94
95 // In the Haiku port, these FreeBSD flags are referenced but do not have any effect
96 #define B_DELWRI 0x00000080 /* Delay I/O until buffer reused. */
97 #define B_CLUSTEROK 0x00020000 /* Pagein op, so swap() can count it. */
98 #define B_INVALONERR 0x00040000 /* Invalidate on write error. */
99
100 // In FreeBSD, struct vn_clusterw stores the state of an optimized routine for writing multiple
101 // bufs. In the Haiku port, it is not used for anything meaningful.
102 struct vn_clusterw {
103 daddr_t v_cstart; /* v start block of cluster */
104 daddr_t v_lasta; /* v last allocation */
105 daddr_t v_lastw; /* v last write */
106 int v_clen; /* v length of cur. cluster */
107 };
108
109 // Zero out the data member of a struct buf.
110 // Port version is tolerant of a buf that holds less than the client-requested size in b_data.
111 #define clrbuf(bp) \
112 { \
113 bzero((bp)->b_data, (u_int)(bp)->b_bufsize); \
114 (bp)->b_resid = 0; \
115 }
116
117
118 int bwrite(struct buf* bp);
119 int buf_dirty_count_severe(void);
120 int bread(struct vnode* vp, daddr_t blkno, int size, struct ucred* cred, struct buf** bpp);
121 void bdwrite(struct buf* bp);
122 void bawrite(struct buf* bp);
123 void brelse(struct buf* bp);
124 struct buf* getblk(struct vnode* vp, daddr_t blkno, int size, int slpflag, int slptimeo, int flags);
125
126
127 static inline void
cluster_init_vn(struct vn_clusterw * vnc)128 cluster_init_vn(struct vn_clusterw* vnc)
129 {
130 return;
131 }
132
133
134 void vfs_bio_bzero_buf(struct buf* bp, int base, int size);
135 void vfs_bio_clrbuf(struct buf* bp);
136
137
138 #endif // FAT_BUF_H
139