OMAP3: SR: Fix init voltage on OPP change
[linux-ginger.git] / fs / 9p / vfs_file.c
blob3902bf43a0883bfe4b92d384170362e53c910e0d
1 /*
2 * linux/fs/9p/vfs_file.c
4 * This file contians vfs file ops for 9P2000.
6 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
7 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2
11 * as published by the Free Software Foundation.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to:
20 * Free Software Foundation
21 * 51 Franklin Street, Fifth Floor
22 * Boston, MA 02111-1301 USA
26 #include <linux/module.h>
27 #include <linux/errno.h>
28 #include <linux/fs.h>
29 #include <linux/sched.h>
30 #include <linux/file.h>
31 #include <linux/stat.h>
32 #include <linux/string.h>
33 #include <linux/inet.h>
34 #include <linux/list.h>
35 #include <linux/pagemap.h>
36 #include <asm/uaccess.h>
37 #include <linux/idr.h>
38 #include <net/9p/9p.h>
39 #include <net/9p/client.h>
41 #include "v9fs.h"
42 #include "v9fs_vfs.h"
43 #include "fid.h"
44 #include "cache.h"
46 static const struct file_operations v9fs_cached_file_operations;
48 /**
49 * v9fs_file_open - open a file (or directory)
50 * @inode: inode to be opened
51 * @file: file being opened
55 int v9fs_file_open(struct inode *inode, struct file *file)
57 int err;
58 struct v9fs_session_info *v9ses;
59 struct p9_fid *fid;
60 int omode;
62 P9_DPRINTK(P9_DEBUG_VFS, "inode: %p file: %p \n", inode, file);
63 v9ses = v9fs_inode2v9ses(inode);
64 omode = v9fs_uflags2omode(file->f_flags, v9fs_extended(v9ses));
65 fid = file->private_data;
66 if (!fid) {
67 fid = v9fs_fid_clone(file->f_path.dentry);
68 if (IS_ERR(fid))
69 return PTR_ERR(fid);
71 err = p9_client_open(fid, omode);
72 if (err < 0) {
73 p9_client_clunk(fid);
74 return err;
76 if (omode & P9_OTRUNC) {
77 i_size_write(inode, 0);
78 inode->i_blocks = 0;
80 if ((file->f_flags & O_APPEND) && (!v9fs_extended(v9ses)))
81 generic_file_llseek(file, 0, SEEK_END);
84 file->private_data = fid;
85 if ((fid->qid.version) && (v9ses->cache)) {
86 P9_DPRINTK(P9_DEBUG_VFS, "cached");
87 /* enable cached file options */
88 if(file->f_op == &v9fs_file_operations)
89 file->f_op = &v9fs_cached_file_operations;
91 #ifdef CONFIG_9P_FSCACHE
92 v9fs_cache_inode_set_cookie(inode, file);
93 #endif
96 return 0;
99 /**
100 * v9fs_file_lock - lock a file (or directory)
101 * @filp: file to be locked
102 * @cmd: lock command
103 * @fl: file lock structure
105 * Bugs: this looks like a local only lock, we should extend into 9P
106 * by using open exclusive
109 static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
111 int res = 0;
112 struct inode *inode = filp->f_path.dentry->d_inode;
114 P9_DPRINTK(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
116 /* No mandatory locks */
117 if (__mandatory_lock(inode))
118 return -ENOLCK;
120 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
121 filemap_write_and_wait(inode->i_mapping);
122 invalidate_mapping_pages(&inode->i_data, 0, -1);
125 return res;
129 * v9fs_file_readn - read from a file
130 * @filp: file pointer to read
131 * @data: data buffer to read data into
132 * @udata: user data buffer to read data into
133 * @count: size of buffer
134 * @offset: offset at which to read data
138 ssize_t
139 v9fs_file_readn(struct file *filp, char *data, char __user *udata, u32 count,
140 u64 offset)
142 int n, total;
143 struct p9_fid *fid = filp->private_data;
145 P9_DPRINTK(P9_DEBUG_VFS, "fid %d offset %llu count %d\n", fid->fid,
146 (long long unsigned) offset, count);
148 n = 0;
149 total = 0;
150 do {
151 n = p9_client_read(fid, data, udata, offset, count);
152 if (n <= 0)
153 break;
155 if (data)
156 data += n;
157 if (udata)
158 udata += n;
160 offset += n;
161 count -= n;
162 total += n;
163 } while (count > 0 && n == (fid->clnt->msize - P9_IOHDRSZ));
165 if (n < 0)
166 total = n;
168 return total;
172 * v9fs_file_read - read from a file
173 * @filp: file pointer to read
174 * @udata: user data buffer to read data into
175 * @count: size of buffer
176 * @offset: offset at which to read data
180 static ssize_t
181 v9fs_file_read(struct file *filp, char __user *udata, size_t count,
182 loff_t * offset)
184 int ret;
185 struct p9_fid *fid;
187 P9_DPRINTK(P9_DEBUG_VFS, "count %zu offset %lld\n", count, *offset);
188 fid = filp->private_data;
190 if (count > (fid->clnt->msize - P9_IOHDRSZ))
191 ret = v9fs_file_readn(filp, NULL, udata, count, *offset);
192 else
193 ret = p9_client_read(fid, NULL, udata, *offset, count);
195 if (ret > 0)
196 *offset += ret;
198 return ret;
202 * v9fs_file_write - write to a file
203 * @filp: file pointer to write
204 * @data: data buffer to write data from
205 * @count: size of buffer
206 * @offset: offset at which to write data
210 static ssize_t
211 v9fs_file_write(struct file *filp, const char __user * data,
212 size_t count, loff_t * offset)
214 int n, rsize, total = 0;
215 struct p9_fid *fid;
216 struct p9_client *clnt;
217 struct inode *inode = filp->f_path.dentry->d_inode;
218 int origin = *offset;
219 unsigned long pg_start, pg_end;
221 P9_DPRINTK(P9_DEBUG_VFS, "data %p count %d offset %x\n", data,
222 (int)count, (int)*offset);
224 fid = filp->private_data;
225 clnt = fid->clnt;
227 rsize = fid->iounit;
228 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
229 rsize = clnt->msize - P9_IOHDRSZ;
231 do {
232 if (count < rsize)
233 rsize = count;
235 n = p9_client_write(fid, NULL, data+total, origin+total,
236 rsize);
237 if (n <= 0)
238 break;
239 count -= n;
240 total += n;
241 } while (count > 0);
243 if (total > 0) {
244 pg_start = origin >> PAGE_CACHE_SHIFT;
245 pg_end = (origin + total - 1) >> PAGE_CACHE_SHIFT;
246 if (inode->i_mapping && inode->i_mapping->nrpages)
247 invalidate_inode_pages2_range(inode->i_mapping,
248 pg_start, pg_end);
249 *offset += total;
250 i_size_write(inode, i_size_read(inode) + total);
251 inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
254 if (n < 0)
255 return n;
257 return total;
260 static const struct file_operations v9fs_cached_file_operations = {
261 .llseek = generic_file_llseek,
262 .read = do_sync_read,
263 .aio_read = generic_file_aio_read,
264 .write = v9fs_file_write,
265 .open = v9fs_file_open,
266 .release = v9fs_dir_release,
267 .lock = v9fs_file_lock,
268 .mmap = generic_file_readonly_mmap,
271 const struct file_operations v9fs_file_operations = {
272 .llseek = generic_file_llseek,
273 .read = v9fs_file_read,
274 .write = v9fs_file_write,
275 .open = v9fs_file_open,
276 .release = v9fs_dir_release,
277 .lock = v9fs_file_lock,
278 .mmap = generic_file_readonly_mmap,