Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke...
[linux-2.6] / drivers / infiniband / hw / ipath / ipath_fs.c
1 /*
2  * Copyright (c) 2006, 2007 QLogic Corporation. All rights reserved.
3  * Copyright (c) 2006 PathScale, Inc. All rights reserved.
4  *
5  * This software is available to you under a choice of one of two
6  * licenses.  You may choose to be licensed under the terms of the GNU
7  * General Public License (GPL) Version 2, available from the file
8  * COPYING in the main directory of this source tree, or the
9  * OpenIB.org BSD license below:
10  *
11  *     Redistribution and use in source and binary forms, with or
12  *     without modification, are permitted provided that the following
13  *     conditions are met:
14  *
15  *      - Redistributions of source code must retain the above
16  *        copyright notice, this list of conditions and the following
17  *        disclaimer.
18  *
19  *      - Redistributions in binary form must reproduce the above
20  *        copyright notice, this list of conditions and the following
21  *        disclaimer in the documentation and/or other materials
22  *        provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  */
33
34 #include <linux/module.h>
35 #include <linux/fs.h>
36 #include <linux/mount.h>
37 #include <linux/pagemap.h>
38 #include <linux/init.h>
39 #include <linux/namei.h>
40
41 #include "ipath_kernel.h"
42
43 #define IPATHFS_MAGIC 0x726a77
44
45 static struct super_block *ipath_super;
46
47 static int ipathfs_mknod(struct inode *dir, struct dentry *dentry,
48                          int mode, const struct file_operations *fops,
49                          void *data)
50 {
51         int error;
52         struct inode *inode = new_inode(dir->i_sb);
53
54         if (!inode) {
55                 error = -EPERM;
56                 goto bail;
57         }
58
59         inode->i_mode = mode;
60         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
61         inode->i_private = data;
62         if ((mode & S_IFMT) == S_IFDIR) {
63                 inode->i_op = &simple_dir_inode_operations;
64                 inc_nlink(inode);
65                 inc_nlink(dir);
66         }
67
68         inode->i_fop = fops;
69
70         d_instantiate(dentry, inode);
71         error = 0;
72
73 bail:
74         return error;
75 }
76
77 static int create_file(const char *name, mode_t mode,
78                        struct dentry *parent, struct dentry **dentry,
79                        const struct file_operations *fops, void *data)
80 {
81         int error;
82
83         *dentry = NULL;
84         mutex_lock(&parent->d_inode->i_mutex);
85         *dentry = lookup_one_len(name, parent, strlen(name));
86         if (!IS_ERR(*dentry))
87                 error = ipathfs_mknod(parent->d_inode, *dentry,
88                                       mode, fops, data);
89         else
90                 error = PTR_ERR(dentry);
91         mutex_unlock(&parent->d_inode->i_mutex);
92
93         return error;
94 }
95
96 static ssize_t atomic_stats_read(struct file *file, char __user *buf,
97                                  size_t count, loff_t *ppos)
98 {
99         return simple_read_from_buffer(buf, count, ppos, &ipath_stats,
100                                        sizeof ipath_stats);
101 }
102
103 static const struct file_operations atomic_stats_ops = {
104         .read = atomic_stats_read,
105 };
106
107 static ssize_t atomic_counters_read(struct file *file, char __user *buf,
108                                     size_t count, loff_t *ppos)
109 {
110         struct infinipath_counters counters;
111         struct ipath_devdata *dd;
112
113         dd = file->f_path.dentry->d_inode->i_private;
114         dd->ipath_f_read_counters(dd, &counters);
115
116         return simple_read_from_buffer(buf, count, ppos, &counters,
117                                        sizeof counters);
118 }
119
120 static const struct file_operations atomic_counters_ops = {
121         .read = atomic_counters_read,
122 };
123
124 static ssize_t flash_read(struct file *file, char __user *buf,
125                           size_t count, loff_t *ppos)
126 {
127         struct ipath_devdata *dd;
128         ssize_t ret;
129         loff_t pos;
130         char *tmp;
131
132         pos = *ppos;
133
134         if ( pos < 0) {
135                 ret = -EINVAL;
136                 goto bail;
137         }
138
139         if (pos >= sizeof(struct ipath_flash)) {
140                 ret = 0;
141                 goto bail;
142         }
143
144         if (count > sizeof(struct ipath_flash) - pos)
145                 count = sizeof(struct ipath_flash) - pos;
146
147         tmp = kmalloc(count, GFP_KERNEL);
148         if (!tmp) {
149                 ret = -ENOMEM;
150                 goto bail;
151         }
152
153         dd = file->f_path.dentry->d_inode->i_private;
154         if (ipath_eeprom_read(dd, pos, tmp, count)) {
155                 ipath_dev_err(dd, "failed to read from flash\n");
156                 ret = -ENXIO;
157                 goto bail_tmp;
158         }
159
160         if (copy_to_user(buf, tmp, count)) {
161                 ret = -EFAULT;
162                 goto bail_tmp;
163         }
164
165         *ppos = pos + count;
166         ret = count;
167
168 bail_tmp:
169         kfree(tmp);
170
171 bail:
172         return ret;
173 }
174
175 static ssize_t flash_write(struct file *file, const char __user *buf,
176                            size_t count, loff_t *ppos)
177 {
178         struct ipath_devdata *dd;
179         ssize_t ret;
180         loff_t pos;
181         char *tmp;
182
183         pos = *ppos;
184
185         if (pos != 0) {
186                 ret = -EINVAL;
187                 goto bail;
188         }
189
190         if (count != sizeof(struct ipath_flash)) {
191                 ret = -EINVAL;
192                 goto bail;
193         }
194
195         tmp = kmalloc(count, GFP_KERNEL);
196         if (!tmp) {
197                 ret = -ENOMEM;
198                 goto bail;
199         }
200
201         if (copy_from_user(tmp, buf, count)) {
202                 ret = -EFAULT;
203                 goto bail_tmp;
204         }
205
206         dd = file->f_path.dentry->d_inode->i_private;
207         if (ipath_eeprom_write(dd, pos, tmp, count)) {
208                 ret = -ENXIO;
209                 ipath_dev_err(dd, "failed to write to flash\n");
210                 goto bail_tmp;
211         }
212
213         *ppos = pos + count;
214         ret = count;
215
216 bail_tmp:
217         kfree(tmp);
218
219 bail:
220         return ret;
221 }
222
223 static const struct file_operations flash_ops = {
224         .read = flash_read,
225         .write = flash_write,
226 };
227
228 static int create_device_files(struct super_block *sb,
229                                struct ipath_devdata *dd)
230 {
231         struct dentry *dir, *tmp;
232         char unit[10];
233         int ret;
234
235         snprintf(unit, sizeof unit, "%02d", dd->ipath_unit);
236         ret = create_file(unit, S_IFDIR|S_IRUGO|S_IXUGO, sb->s_root, &dir,
237                           &simple_dir_operations, dd);
238         if (ret) {
239                 printk(KERN_ERR "create_file(%s) failed: %d\n", unit, ret);
240                 goto bail;
241         }
242
243         ret = create_file("atomic_counters", S_IFREG|S_IRUGO, dir, &tmp,
244                           &atomic_counters_ops, dd);
245         if (ret) {
246                 printk(KERN_ERR "create_file(%s/atomic_counters) "
247                        "failed: %d\n", unit, ret);
248                 goto bail;
249         }
250
251         ret = create_file("flash", S_IFREG|S_IWUSR|S_IRUGO, dir, &tmp,
252                           &flash_ops, dd);
253         if (ret) {
254                 printk(KERN_ERR "create_file(%s/flash) "
255                        "failed: %d\n", unit, ret);
256                 goto bail;
257         }
258
259 bail:
260         return ret;
261 }
262
263 static int remove_file(struct dentry *parent, char *name)
264 {
265         struct dentry *tmp;
266         int ret;
267
268         tmp = lookup_one_len(name, parent, strlen(name));
269
270         if (IS_ERR(tmp)) {
271                 ret = PTR_ERR(tmp);
272                 goto bail;
273         }
274
275         spin_lock(&dcache_lock);
276         spin_lock(&tmp->d_lock);
277         if (!(d_unhashed(tmp) && tmp->d_inode)) {
278                 dget_locked(tmp);
279                 __d_drop(tmp);
280                 spin_unlock(&tmp->d_lock);
281                 spin_unlock(&dcache_lock);
282                 simple_unlink(parent->d_inode, tmp);
283         } else {
284                 spin_unlock(&tmp->d_lock);
285                 spin_unlock(&dcache_lock);
286         }
287
288         ret = 0;
289 bail:
290         /*
291          * We don't expect clients to care about the return value, but
292          * it's there if they need it.
293          */
294         return ret;
295 }
296
297 static int remove_device_files(struct super_block *sb,
298                                struct ipath_devdata *dd)
299 {
300         struct dentry *dir, *root;
301         char unit[10];
302         int ret;
303
304         root = dget(sb->s_root);
305         mutex_lock(&root->d_inode->i_mutex);
306         snprintf(unit, sizeof unit, "%02d", dd->ipath_unit);
307         dir = lookup_one_len(unit, root, strlen(unit));
308
309         if (IS_ERR(dir)) {
310                 ret = PTR_ERR(dir);
311                 printk(KERN_ERR "Lookup of %s failed\n", unit);
312                 goto bail;
313         }
314
315         remove_file(dir, "flash");
316         remove_file(dir, "atomic_counters");
317         d_delete(dir);
318         ret = simple_rmdir(root->d_inode, dir);
319
320 bail:
321         mutex_unlock(&root->d_inode->i_mutex);
322         dput(root);
323         return ret;
324 }
325
326 static int ipathfs_fill_super(struct super_block *sb, void *data,
327                               int silent)
328 {
329         struct ipath_devdata *dd, *tmp;
330         unsigned long flags;
331         int ret;
332
333         static struct tree_descr files[] = {
334                 [2] = {"atomic_stats", &atomic_stats_ops, S_IRUGO},
335                 {""},
336         };
337
338         ret = simple_fill_super(sb, IPATHFS_MAGIC, files);
339         if (ret) {
340                 printk(KERN_ERR "simple_fill_super failed: %d\n", ret);
341                 goto bail;
342         }
343
344         spin_lock_irqsave(&ipath_devs_lock, flags);
345
346         list_for_each_entry_safe(dd, tmp, &ipath_dev_list, ipath_list) {
347                 spin_unlock_irqrestore(&ipath_devs_lock, flags);
348                 ret = create_device_files(sb, dd);
349                 if (ret) {
350                         deactivate_locked_super(sb);
351                         goto bail;
352                 }
353                 spin_lock_irqsave(&ipath_devs_lock, flags);
354         }
355
356         spin_unlock_irqrestore(&ipath_devs_lock, flags);
357
358 bail:
359         return ret;
360 }
361
362 static int ipathfs_get_sb(struct file_system_type *fs_type, int flags,
363                         const char *dev_name, void *data, struct vfsmount *mnt)
364 {
365         int ret = get_sb_single(fs_type, flags, data,
366                                     ipathfs_fill_super, mnt);
367         if (ret >= 0)
368                 ipath_super = mnt->mnt_sb;
369         return ret;
370 }
371
372 static void ipathfs_kill_super(struct super_block *s)
373 {
374         kill_litter_super(s);
375         ipath_super = NULL;
376 }
377
378 int ipathfs_add_device(struct ipath_devdata *dd)
379 {
380         int ret;
381
382         if (ipath_super == NULL) {
383                 ret = 0;
384                 goto bail;
385         }
386
387         ret = create_device_files(ipath_super, dd);
388
389 bail:
390         return ret;
391 }
392
393 int ipathfs_remove_device(struct ipath_devdata *dd)
394 {
395         int ret;
396
397         if (ipath_super == NULL) {
398                 ret = 0;
399                 goto bail;
400         }
401
402         ret = remove_device_files(ipath_super, dd);
403
404 bail:
405         return ret;
406 }
407
408 static struct file_system_type ipathfs_fs_type = {
409         .owner =        THIS_MODULE,
410         .name =         "ipathfs",
411         .get_sb =       ipathfs_get_sb,
412         .kill_sb =      ipathfs_kill_super,
413 };
414
415 int __init ipath_init_ipathfs(void)
416 {
417         return register_filesystem(&ipathfs_fs_type);
418 }
419
420 void __exit ipath_exit_ipathfs(void)
421 {
422         unregister_filesystem(&ipathfs_fs_type);
423 }