This source file includes following definitions.
- xiafs_file_read
- xiafs_file_write
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12 #ifdef MODULE
13 #include <linux/module.h>
14 #endif
15
16 #include <asm/segment.h>
17 #include <asm/system.h>
18
19 #include <linux/sched.h>
20 #include <linux/fs.h>
21 #include <linux/xia_fs.h>
22 #include <linux/kernel.h>
23 #include <linux/errno.h>
24 #include <linux/fcntl.h>
25 #include <linux/stat.h>
26 #include <linux/locks.h>
27
28 #include "xiafs_mac.h"
29
30 #define NBUF 32
31
32 #define MIN(a,b) (((a)<(b))?(a):(b))
33 #define MAX(a,b) (((a)>(b))?(a):(b))
34
35 static int xiafs_file_read(struct inode *, struct file *, char *, int);
36 static int xiafs_file_write(struct inode *, struct file *, char *, int);
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38
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40
41
42 static struct file_operations xiafs_file_operations = {
43 NULL,
44 xiafs_file_read,
45 xiafs_file_write,
46 NULL,
47 NULL,
48 NULL,
49 generic_mmap,
50 NULL,
51 NULL,
52 xiafs_sync_file
53 };
54
55 struct inode_operations xiafs_file_inode_operations = {
56 &xiafs_file_operations,
57 NULL,
58 NULL,
59 NULL,
60 NULL,
61 NULL,
62 NULL,
63 NULL,
64 NULL,
65 NULL,
66 NULL,
67 NULL,
68 xiafs_bmap,
69 xiafs_truncate,
70 NULL
71 };
72
73 static int
74 xiafs_file_read(struct inode * inode, struct file * filp, char * buf, int count)
75 {
76 int read, left, chars;
77 int zone_nr, zones, f_zones, offset;
78 int bhrequest, uptodate;
79 struct buffer_head ** bhb, ** bhe;
80 struct buffer_head * bhreq[NBUF];
81 struct buffer_head * buflist[NBUF];
82
83 if (!inode) {
84 printk("XIA-FS: inode = NULL (%s %d)\n", WHERE_ERR);
85 return -EINVAL;
86 }
87 if (!S_ISREG(inode->i_mode)) {
88 printk("XIA-FS: mode != regular (%s %d)\n", WHERE_ERR);
89 return -EINVAL;
90 }
91 offset = filp->f_pos;
92 left = inode->i_size - offset;
93 if (left > count)
94 left = count;
95 if (left <= 0)
96 return 0;
97 read = 0;
98 zone_nr = offset >> XIAFS_ZSIZE_BITS(inode->i_sb);
99 offset &= XIAFS_ZSIZE(inode->i_sb) -1 ;
100 f_zones =(inode->i_size+XIAFS_ZSIZE(inode->i_sb)-1)>>XIAFS_ZSIZE_BITS(inode->i_sb);
101 zones = (left+offset+XIAFS_ZSIZE(inode->i_sb)-1) >> XIAFS_ZSIZE_BITS(inode->i_sb);
102 bhb = bhe = buflist;
103 if (filp->f_reada) {
104 if(zones < read_ahead[MAJOR(inode->i_dev)] >> (1+XIAFS_ZSHIFT(inode->i_sb)))
105 zones = read_ahead[MAJOR(inode->i_dev)] >> (1+XIAFS_ZSHIFT(inode->i_sb));
106 if (zone_nr + zones > f_zones)
107 zones = f_zones - zone_nr;
108 }
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118
119
120 do {
121 bhrequest = 0;
122 uptodate = 1;
123 while (zones--) {
124 *bhb = xiafs_getblk(inode, zone_nr++, 0);
125 if (*bhb && !(*bhb)->b_uptodate) {
126 uptodate = 0;
127 bhreq[bhrequest++] = *bhb;
128 }
129
130 if (++bhb == &buflist[NBUF])
131 bhb = buflist;
132
133
134
135 if (uptodate)
136 break;
137 if (bhb == bhe)
138 break;
139 }
140
141
142 if (bhrequest)
143 ll_rw_block(READ, bhrequest, bhreq);
144
145 do {
146 if (*bhe) {
147 wait_on_buffer(*bhe);
148 if (!(*bhe)->b_uptodate) {
149 brelse(*bhe);
150 if (++bhe == &buflist[NBUF])
151 bhe = buflist;
152 left = 0;
153 break;
154 }
155 }
156 if (left < XIAFS_ZSIZE(inode->i_sb) - offset)
157 chars = left;
158 else
159 chars = XIAFS_ZSIZE(inode->i_sb) - offset;
160 filp->f_pos += chars;
161 left -= chars;
162 read += chars;
163 if (*bhe) {
164 memcpy_tofs(buf,offset+(*bhe)->b_data,chars);
165 brelse(*bhe);
166 buf += chars;
167 } else {
168 while (chars-->0)
169 put_user(0,buf++);
170 }
171 offset = 0;
172 if (++bhe == &buflist[NBUF])
173 bhe = buflist;
174 } while (left > 0 && bhe != bhb && (!*bhe || !(*bhe)->b_lock));
175 } while (left > 0);
176
177
178 while (bhe != bhb) {
179 brelse(*bhe);
180 if (++bhe == &buflist[NBUF])
181 bhe = buflist;
182 };
183 if (!read)
184 return -EIO;
185 filp->f_reada = 1;
186 if (!IS_RDONLY (inode)) {
187 inode->i_atime = CURRENT_TIME;
188 inode->i_dirt = 1;
189 }
190 return read;
191 }
192
193 static int
194 xiafs_file_write(struct inode * inode, struct file * filp, char * buf, int count)
195 {
196 off_t pos;
197 int written, c;
198 struct buffer_head * bh;
199 char * cp;
200
201 if (!inode) {
202 printk("XIA-FS: inode = NULL (%s %d)\n", WHERE_ERR);
203 return -EINVAL;
204 }
205 if (!S_ISREG(inode->i_mode)) {
206 printk("XIA-FS: mode != regular (%s %d)\n", WHERE_ERR);
207 return -EINVAL;
208 }
209
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211
212
213 if (filp->f_flags & O_APPEND)
214 pos = inode->i_size;
215 else
216 pos = filp->f_pos;
217 written = 0;
218 while (written < count) {
219 bh = xiafs_getblk(inode, pos >> XIAFS_ZSIZE_BITS(inode->i_sb), 1);
220 if (!bh) {
221 if (!written)
222 written = -ENOSPC;
223 break;
224 }
225 c = XIAFS_ZSIZE(inode->i_sb) - (pos & (XIAFS_ZSIZE(inode->i_sb) - 1));
226 if (c > count-written)
227 c = count-written;
228 if (c != XIAFS_ZSIZE(inode->i_sb) && !bh->b_uptodate) {
229 ll_rw_block(READ, 1, &bh);
230 wait_on_buffer(bh);
231 if (!bh->b_uptodate) {
232 brelse(bh);
233 if (!written)
234 written = -EIO;
235 break;
236 }
237 }
238 cp = (pos & (XIAFS_ZSIZE(inode->i_sb)-1)) + bh->b_data;
239 pos += c;
240 if (pos > inode->i_size) {
241 inode->i_size = pos;
242 inode->i_dirt = 1;
243 }
244 written += c;
245 memcpy_fromfs(cp,buf,c);
246 buf += c;
247 bh->b_uptodate = 1;
248 mark_buffer_dirty(bh, 0);
249 brelse(bh);
250 }
251 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
252 filp->f_pos = pos;
253 inode->i_dirt = 1;
254
255 return written;
256 }