This source file includes following definitions.
- xiafs_file_read
- xiafs_file_write
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12 #include <asm/segment.h>
13 #include <asm/system.h>
14
15 #include <linux/sched.h>
16 #include <linux/fs.h>
17 #include <linux/xia_fs.h>
18 #include <linux/kernel.h>
19 #include <linux/errno.h>
20 #include <linux/fcntl.h>
21 #include <linux/stat.h>
22 #include <linux/locks.h>
23
24 #include "xiafs_mac.h"
25
26 #define NBUF 16
27
28 #define MIN(a,b) (((a)<(b))?(a):(b))
29 #define MAX(a,b) (((a)>(b))?(a):(b))
30
31 static int xiafs_file_read(struct inode *, struct file *, char *, int);
32 static int xiafs_file_write(struct inode *, struct file *, char *, int);
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38 static struct file_operations xiafs_file_operations = {
39 NULL,
40 xiafs_file_read,
41 xiafs_file_write,
42 NULL,
43 NULL,
44 NULL,
45 generic_mmap,
46 NULL,
47 NULL,
48 xiafs_sync_file
49 };
50
51 struct inode_operations xiafs_file_inode_operations = {
52 &xiafs_file_operations,
53 NULL,
54 NULL,
55 NULL,
56 NULL,
57 NULL,
58 NULL,
59 NULL,
60 NULL,
61 NULL,
62 NULL,
63 NULL,
64 xiafs_bmap,
65 xiafs_truncate,
66 NULL
67 };
68
69 static int
70 xiafs_file_read(struct inode * inode, struct file * filp, char * buf, int count)
71 {
72 int read, left, chars;
73 int zone_nr, zones, f_zones, offset;
74 int bhrequest, uptodate;
75 struct buffer_head ** bhb, ** bhe;
76 struct buffer_head * bhreq[NBUF];
77 struct buffer_head * buflist[NBUF];
78
79 if (!inode) {
80 printk("XIA-FS: inode = NULL (%s %d)\n", WHERE_ERR);
81 return -EINVAL;
82 }
83 if (!S_ISREG(inode->i_mode)) {
84 printk("XIA-FS: mode != regular (%s %d)\n", WHERE_ERR);
85 return -EINVAL;
86 }
87 offset = filp->f_pos;
88 left = inode->i_size - offset;
89 if (left > count)
90 left = count;
91 if (left <= 0)
92 return 0;
93 read = 0;
94 zone_nr = offset >> XIAFS_ZSIZE_BITS(inode->i_sb);
95 offset &= XIAFS_ZSIZE(inode->i_sb) -1 ;
96 f_zones =(inode->i_size+XIAFS_ZSIZE(inode->i_sb)-1)>>XIAFS_ZSIZE_BITS(inode->i_sb);
97 zones = (left+offset+XIAFS_ZSIZE(inode->i_sb)-1) >> XIAFS_ZSIZE_BITS(inode->i_sb);
98 bhb = bhe = buflist;
99 if (filp->f_reada) {
100 zones += read_ahead[MAJOR(inode->i_dev)] >> (1+XIAFS_ZSHIFT(inode->i_sb));
101 if (zone_nr + zones > f_zones)
102 zones = f_zones - zone_nr;
103 }
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114
115 do {
116 bhrequest = 0;
117 uptodate = 1;
118 while (zones--) {
119 *bhb = xiafs_getblk(inode, zone_nr++, 0);
120 if (*bhb && !(*bhb)->b_uptodate) {
121 uptodate = 0;
122 bhreq[bhrequest++] = *bhb;
123 }
124
125 if (++bhb == &buflist[NBUF])
126 bhb = buflist;
127
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129
130 if (uptodate)
131 break;
132 if (bhb == bhe)
133 break;
134 }
135
136
137 if (bhrequest)
138 ll_rw_block(READ, bhrequest, bhreq);
139
140 do {
141 if (*bhe) {
142 wait_on_buffer(*bhe);
143 if (!(*bhe)->b_uptodate) {
144 left = 0;
145 break;
146 }
147 }
148 if (left < XIAFS_ZSIZE(inode->i_sb) - offset)
149 chars = left;
150 else
151 chars = XIAFS_ZSIZE(inode->i_sb) - offset;
152 filp->f_pos += chars;
153 left -= chars;
154 read += chars;
155 if (*bhe) {
156 memcpy_tofs(buf,offset+(*bhe)->b_data,chars);
157 brelse(*bhe);
158 buf += chars;
159 } else {
160 while (chars-->0)
161 put_fs_byte(0,buf++);
162 }
163 offset = 0;
164 if (++bhe == &buflist[NBUF])
165 bhe = buflist;
166 } while (left > 0 && bhe != bhb && (!*bhe || !(*bhe)->b_lock));
167 } while (left > 0);
168
169
170 while (bhe != bhb) {
171 brelse(*bhe);
172 if (++bhe == &buflist[NBUF])
173 bhe = buflist;
174 };
175 if (!read)
176 return -EIO;
177 filp->f_reada = 1;
178 if (!IS_RDONLY (inode)) {
179 inode->i_atime = CURRENT_TIME;
180 inode->i_dirt = 1;
181 }
182 return read;
183 }
184
185 static int
186 xiafs_file_write(struct inode * inode, struct file * filp, char * buf, int count)
187 {
188 off_t pos;
189 int written, c;
190 struct buffer_head * bh;
191 char * cp;
192
193 if (!inode) {
194 printk("XIA-FS: inode = NULL (%s %d)\n", WHERE_ERR);
195 return -EINVAL;
196 }
197 if (!S_ISREG(inode->i_mode)) {
198 printk("XIA-FS: mode != regular (%s %d)\n", WHERE_ERR);
199 return -EINVAL;
200 }
201
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204
205 if (filp->f_flags & O_APPEND)
206 pos = inode->i_size;
207 else
208 pos = filp->f_pos;
209 written = 0;
210 while (written < count) {
211 bh = xiafs_getblk(inode, pos >> XIAFS_ZSIZE_BITS(inode->i_sb), 1);
212 if (!bh) {
213 if (!written)
214 written = -ENOSPC;
215 break;
216 }
217 c = XIAFS_ZSIZE(inode->i_sb) - (pos & (XIAFS_ZSIZE(inode->i_sb) - 1));
218 if (c > count-written)
219 c = count-written;
220 if (c != XIAFS_ZSIZE(inode->i_sb) && !bh->b_uptodate) {
221 ll_rw_block(READ, 1, &bh);
222 wait_on_buffer(bh);
223 if (!bh->b_uptodate) {
224 brelse(bh);
225 if (!written)
226 written = -EIO;
227 break;
228 }
229 }
230 cp = (pos & (XIAFS_ZSIZE(inode->i_sb)-1)) + bh->b_data;
231 pos += c;
232 if (pos > inode->i_size) {
233 inode->i_size = pos;
234 inode->i_dirt = 1;
235 }
236 written += c;
237 memcpy_fromfs(cp,buf,c);
238 buf += c;
239 bh->b_uptodate = 1;
240 bh->b_dirt = 1;
241 brelse(bh);
242 }
243 inode->i_atime = inode->i_ctime = inode->i_mtime = CURRENT_TIME;
244 filp->f_pos = pos;
245 inode->i_dirt = 1;
246
247 return written;
248 }
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