File: /usr/src/linux/fs/qnx4/fsync.c
1 /*
2 * QNX4 file system, Linux implementation.
3 *
4 * Version : 0.1
5 *
6 * Using parts of the xiafs filesystem.
7 *
8 * History :
9 *
10 * 24-03-1998 by Richard Frowijn : first release.
11 */
12
13 #include <linux/config.h>
14 #include <linux/errno.h>
15 #include <linux/sched.h>
16 #include <linux/stat.h>
17 #include <linux/fcntl.h>
18 #include <linux/locks.h>
19 #include <linux/smp_lock.h>
20
21 #include <linux/fs.h>
22 #include <linux/qnx4_fs.h>
23
24 #include <asm/segment.h>
25 #include <asm/system.h>
26
27 #define blocksize QNX4_BLOCK_SIZE
28
29 /*
30 * The functions for qnx4 fs file synchronization.
31 */
32
33 #ifdef CONFIG_QNX4FS_RW
34
35 static int sync_block(struct inode *inode, unsigned short *block, int wait)
36 {
37 struct buffer_head *bh;
38 unsigned short tmp;
39
40 if (!*block)
41 return 0;
42 tmp = *block;
43 bh = get_hash_table(inode->i_dev, *block, blocksize);
44 if (!bh)
45 return 0;
46 if (*block != tmp) {
47 brelse(bh);
48 return 1;
49 }
50 if (wait && buffer_req(bh) && !buffer_uptodate(bh)) {
51 brelse(bh);
52 return -1;
53 }
54 if (wait || !buffer_uptodate(bh) || !buffer_dirty(bh)) {
55 brelse(bh);
56 return 0;
57 }
58 ll_rw_block(WRITE, 1, &bh);
59 atomic_dec(&bh->b_count);
60 return 0;
61 }
62
63 #ifdef WTF
64 static int sync_iblock(struct inode *inode, unsigned short *iblock,
65 struct buffer_head **bh, int wait)
66 {
67 int rc;
68 unsigned short tmp;
69
70 *bh = NULL;
71 tmp = *iblock;
72 if (!tmp)
73 return 0;
74 rc = sync_block(inode, iblock, wait);
75 if (rc)
76 return rc;
77 *bh = bread(inode->i_dev, tmp, blocksize);
78 if (tmp != *iblock) {
79 brelse(*bh);
80 *bh = NULL;
81 return 1;
82 }
83 if (!*bh)
84 return -1;
85 return 0;
86 }
87 #endif
88
89 static int sync_direct(struct inode *inode, int wait)
90 {
91 int i;
92 int rc, err = 0;
93
94 for (i = 0; i < 7; i++) {
95 rc = sync_block(inode,
96 (unsigned short *) inode->u.qnx4_i.i_first_xtnt.xtnt_blk + i, wait);
97 if (rc > 0)
98 break;
99 if (rc)
100 err = rc;
101 }
102 return err;
103 }
104
105 #ifdef WTF
106 static int sync_indirect(struct inode *inode, unsigned short *iblock, int wait)
107 {
108 int i;
109 struct buffer_head *ind_bh;
110 int rc, err = 0;
111
112 rc = sync_iblock(inode, iblock, &ind_bh, wait);
113 if (rc || !ind_bh)
114 return rc;
115
116 for (i = 0; i < 512; i++) {
117 rc = sync_block(inode,
118 ((unsigned short *) ind_bh->b_data) + i,
119 wait);
120 if (rc > 0)
121 break;
122 if (rc)
123 err = rc;
124 }
125 brelse(ind_bh);
126 return err;
127 }
128
129 static int sync_dindirect(struct inode *inode, unsigned short *diblock,
130 int wait)
131 {
132 int i;
133 struct buffer_head *dind_bh;
134 int rc, err = 0;
135
136 rc = sync_iblock(inode, diblock, &dind_bh, wait);
137 if (rc || !dind_bh)
138 return rc;
139
140 for (i = 0; i < 512; i++) {
141 rc = sync_indirect(inode,
142 ((unsigned short *) dind_bh->b_data) + i,
143 wait);
144 if (rc > 0)
145 break;
146 if (rc)
147 err = rc;
148 }
149 brelse(dind_bh);
150 return err;
151 }
152 #endif
153
154 int qnx4_sync_file(struct file *file, struct dentry *dentry, int unused)
155 {
156 struct inode *inode = dentry->d_inode;
157 int wait, err = 0;
158
159 (void) file;
160 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
161 S_ISLNK(inode->i_mode)))
162 return -EINVAL;
163
164 lock_kernel();
165 for (wait = 0; wait <= 1; wait++) {
166 err |= sync_direct(inode, wait);
167 }
168 err |= qnx4_sync_inode(inode);
169 unlock_kernel();
170 return (err < 0) ? -EIO : 0;
171 }
172
173 #endif
174