nilfs2: add truncation routine of segment usage file
[linux-2.6.git] / fs / ncpfs / file.c
1 /*
2  *  file.c
3  *
4  *  Copyright (C) 1995, 1996 by Volker Lendecke
5  *  Modified 1997 Peter Waltenberg, Bill Hawes, David Woodhouse for 2.1 dcache
6  *
7  */
8
9 #include <asm/uaccess.h>
10 #include <asm/system.h>
11
12 #include <linux/time.h>
13 #include <linux/kernel.h>
14 #include <linux/errno.h>
15 #include <linux/fcntl.h>
16 #include <linux/stat.h>
17 #include <linux/mm.h>
18 #include <linux/vmalloc.h>
19 #include <linux/sched.h>
20
21 #include "ncp_fs.h"
22
23 static int ncp_fsync(struct file *file, int datasync)
24 {
25         return 0;
26 }
27
28 /*
29  * Open a file with the specified read/write mode.
30  */
31 int ncp_make_open(struct inode *inode, int right)
32 {
33         int error;
34         int access;
35
36         error = -EINVAL;
37         if (!inode) {
38                 printk(KERN_ERR "ncp_make_open: got NULL inode\n");
39                 goto out;
40         }
41
42         DPRINTK("ncp_make_open: opened=%d, volume # %u, dir entry # %u\n",
43                 atomic_read(&NCP_FINFO(inode)->opened), 
44                 NCP_FINFO(inode)->volNumber, 
45                 NCP_FINFO(inode)->dirEntNum);
46         error = -EACCES;
47         mutex_lock(&NCP_FINFO(inode)->open_mutex);
48         if (!atomic_read(&NCP_FINFO(inode)->opened)) {
49                 struct ncp_entry_info finfo;
50                 int result;
51
52                 /* tries max. rights */
53                 finfo.access = O_RDWR;
54                 result = ncp_open_create_file_or_subdir(NCP_SERVER(inode),
55                                         inode, NULL, OC_MODE_OPEN,
56                                         0, AR_READ | AR_WRITE, &finfo);
57                 if (!result)
58                         goto update;
59                 /* RDWR did not succeeded, try readonly or writeonly as requested */
60                 switch (right) {
61                         case O_RDONLY:
62                                 finfo.access = O_RDONLY;
63                                 result = ncp_open_create_file_or_subdir(NCP_SERVER(inode),
64                                         inode, NULL, OC_MODE_OPEN,
65                                         0, AR_READ, &finfo);
66                                 break;
67                         case O_WRONLY:
68                                 finfo.access = O_WRONLY;
69                                 result = ncp_open_create_file_or_subdir(NCP_SERVER(inode),
70                                         inode, NULL, OC_MODE_OPEN,
71                                         0, AR_WRITE, &finfo);
72                                 break;
73                 }
74                 if (result) {
75                         PPRINTK("ncp_make_open: failed, result=%d\n", result);
76                         goto out_unlock;
77                 }
78                 /*
79                  * Update the inode information.
80                  */
81         update:
82                 ncp_update_inode(inode, &finfo);
83                 atomic_set(&NCP_FINFO(inode)->opened, 1);
84         }
85
86         access = NCP_FINFO(inode)->access;
87         PPRINTK("ncp_make_open: file open, access=%x\n", access);
88         if (access == right || access == O_RDWR) {
89                 atomic_inc(&NCP_FINFO(inode)->opened);
90                 error = 0;
91         }
92
93 out_unlock:
94         mutex_unlock(&NCP_FINFO(inode)->open_mutex);
95 out:
96         return error;
97 }
98
99 static ssize_t
100 ncp_file_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
101 {
102         struct dentry *dentry = file->f_path.dentry;
103         struct inode *inode = dentry->d_inode;
104         size_t already_read = 0;
105         off_t pos;
106         size_t bufsize;
107         int error;
108         void* freepage;
109         size_t freelen;
110
111         DPRINTK("ncp_file_read: enter %s/%s\n",
112                 dentry->d_parent->d_name.name, dentry->d_name.name);
113
114         pos = *ppos;
115
116         if ((ssize_t) count < 0) {
117                 return -EINVAL;
118         }
119         if (!count)
120                 return 0;
121         if (pos > inode->i_sb->s_maxbytes)
122                 return 0;
123         if (pos + count > inode->i_sb->s_maxbytes) {
124                 count = inode->i_sb->s_maxbytes - pos;
125         }
126
127         error = ncp_make_open(inode, O_RDONLY);
128         if (error) {
129                 DPRINTK(KERN_ERR "ncp_file_read: open failed, error=%d\n", error);
130                 return error;
131         }
132
133         bufsize = NCP_SERVER(inode)->buffer_size;
134
135         error = -EIO;
136         freelen = ncp_read_bounce_size(bufsize);
137         freepage = vmalloc(freelen);
138         if (!freepage)
139                 goto outrel;
140         error = 0;
141         /* First read in as much as possible for each bufsize. */
142         while (already_read < count) {
143                 int read_this_time;
144                 size_t to_read = min_t(unsigned int,
145                                      bufsize - (pos % bufsize),
146                                      count - already_read);
147
148                 error = ncp_read_bounce(NCP_SERVER(inode),
149                                 NCP_FINFO(inode)->file_handle,
150                                 pos, to_read, buf, &read_this_time, 
151                                 freepage, freelen);
152                 if (error) {
153                         error = -EIO;   /* NW errno -> Linux errno */
154                         break;
155                 }
156                 pos += read_this_time;
157                 buf += read_this_time;
158                 already_read += read_this_time;
159
160                 if (read_this_time != to_read) {
161                         break;
162                 }
163         }
164         vfree(freepage);
165
166         *ppos = pos;
167
168         file_accessed(file);
169
170         DPRINTK("ncp_file_read: exit %s/%s\n",
171                 dentry->d_parent->d_name.name, dentry->d_name.name);
172 outrel:
173         ncp_inode_close(inode);         
174         return already_read ? already_read : error;
175 }
176
177 static ssize_t
178 ncp_file_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
179 {
180         struct dentry *dentry = file->f_path.dentry;
181         struct inode *inode = dentry->d_inode;
182         size_t already_written = 0;
183         off_t pos;
184         size_t bufsize;
185         int errno;
186         void* bouncebuffer;
187
188         DPRINTK("ncp_file_write: enter %s/%s\n",
189                 dentry->d_parent->d_name.name, dentry->d_name.name);
190         if ((ssize_t) count < 0)
191                 return -EINVAL;
192         pos = *ppos;
193         if (file->f_flags & O_APPEND) {
194                 pos = i_size_read(inode);
195         }
196
197         if (pos + count > MAX_NON_LFS && !(file->f_flags&O_LARGEFILE)) {
198                 if (pos >= MAX_NON_LFS) {
199                         return -EFBIG;
200                 }
201                 if (count > MAX_NON_LFS - (u32)pos) {
202                         count = MAX_NON_LFS - (u32)pos;
203                 }
204         }
205         if (pos >= inode->i_sb->s_maxbytes) {
206                 if (count || pos > inode->i_sb->s_maxbytes) {
207                         return -EFBIG;
208                 }
209         }
210         if (pos + count > inode->i_sb->s_maxbytes) {
211                 count = inode->i_sb->s_maxbytes - pos;
212         }
213         
214         if (!count)
215                 return 0;
216         errno = ncp_make_open(inode, O_WRONLY);
217         if (errno) {
218                 DPRINTK(KERN_ERR "ncp_file_write: open failed, error=%d\n", errno);
219                 return errno;
220         }
221         bufsize = NCP_SERVER(inode)->buffer_size;
222
223         already_written = 0;
224
225         bouncebuffer = vmalloc(bufsize);
226         if (!bouncebuffer) {
227                 errno = -EIO;   /* -ENOMEM */
228                 goto outrel;
229         }
230         while (already_written < count) {
231                 int written_this_time;
232                 size_t to_write = min_t(unsigned int,
233                                       bufsize - (pos % bufsize),
234                                       count - already_written);
235
236                 if (copy_from_user(bouncebuffer, buf, to_write)) {
237                         errno = -EFAULT;
238                         break;
239                 }
240                 if (ncp_write_kernel(NCP_SERVER(inode), 
241                     NCP_FINFO(inode)->file_handle,
242                     pos, to_write, bouncebuffer, &written_this_time) != 0) {
243                         errno = -EIO;
244                         break;
245                 }
246                 pos += written_this_time;
247                 buf += written_this_time;
248                 already_written += written_this_time;
249
250                 if (written_this_time != to_write) {
251                         break;
252                 }
253         }
254         vfree(bouncebuffer);
255
256         file_update_time(file);
257
258         *ppos = pos;
259
260         if (pos > i_size_read(inode)) {
261                 mutex_lock(&inode->i_mutex);
262                 if (pos > i_size_read(inode))
263                         i_size_write(inode, pos);
264                 mutex_unlock(&inode->i_mutex);
265         }
266         DPRINTK("ncp_file_write: exit %s/%s\n",
267                 dentry->d_parent->d_name.name, dentry->d_name.name);
268 outrel:
269         ncp_inode_close(inode);         
270         return already_written ? already_written : errno;
271 }
272
273 static int ncp_release(struct inode *inode, struct file *file) {
274         if (ncp_make_closed(inode)) {
275                 DPRINTK("ncp_release: failed to close\n");
276         }
277         return 0;
278 }
279
280 const struct file_operations ncp_file_operations =
281 {
282         .llseek         = generic_file_llseek,
283         .read           = ncp_file_read,
284         .write          = ncp_file_write,
285         .unlocked_ioctl = ncp_ioctl,
286 #ifdef CONFIG_COMPAT
287         .compat_ioctl   = ncp_compat_ioctl,
288 #endif
289         .mmap           = ncp_mmap,
290         .release        = ncp_release,
291         .fsync          = ncp_fsync,
292 };
293
294 const struct inode_operations ncp_file_inode_operations =
295 {
296         .setattr        = ncp_notify_change,
297 };