SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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/version.h>
  35 #include <linux/module.h>
  36 #include <linux/fs.h>
  37 #include <linux/mount.h>
  38 #include <linux/pagemap.h>
  39 #include <linux/init.h>
  40 #include <linux/namei.h>
  41
  42 #include "ipath_kernel.h"
  43
  44 #define IPATHFS_MAGIC 0x726a77
  45
  46 static struct super_block *ipath_super;
  47
  48 static int ipathfs_mknod(struct inode *dir, struct dentry *dentry,
  49                          int mode, const struct file_operations *fops,
  50                          void *data)
  51 {
  52         int error;
  53         struct inode *inode = new_inode(dir->i_sb);
  54
  55         if (!inode) {
  56                 error = -EPERM;
  57                 goto bail;
  58         }
  59
  60         inode->i_mode = mode;
  61         inode->i_uid = 0;
  62         inode->i_gid = 0;
  63         inode->i_blocks = 0;
  64         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
  65         inode->i_private = data;
  66         if ((mode & S_IFMT) == S_IFDIR) {
  67                 inode->i_op = &simple_dir_inode_operations;
  68                 inc_nlink(inode);
  69                 inc_nlink(dir);
  70         }
  71
  72         inode->i_fop = fops;
  73
  74         d_instantiate(dentry, inode);
  75         error = 0;
  76
  77 bail:
  78         return error;
  79 }
  80
  81 static int create_file(const char *name, mode_t mode,
  82                        struct dentry *parent, struct dentry **dentry,
  83                        const struct file_operations *fops, void *data)
  84 {
  85         int error;
  86
  87         *dentry = NULL;
  88         mutex_lock(&parent->d_inode->i_mutex);
  89         *dentry = lookup_one_len(name, parent, strlen(name));
  90         if (!IS_ERR(dentry))
  91                 error = ipathfs_mknod(parent->d_inode, *dentry,
  92                                       mode, fops, data);
  93         else
  94                 error = PTR_ERR(dentry);
  95         mutex_unlock(&parent->d_inode->i_mutex);
  96
  97         return error;
  98 }
  99
 100 static ssize_t atomic_stats_read(struct file *file, char __user *buf,
 101                                  size_t count, loff_t *ppos)
 102 {
 103         return simple_read_from_buffer(buf, count, ppos, &ipath_stats,
 104                                        sizeof ipath_stats);
 105 }
 106
 107 static const struct file_operations atomic_stats_ops = {
 108         .read = atomic_stats_read,
 109 };
 110
 111 #define NUM_COUNTERS sizeof(struct infinipath_counters) / sizeof(u64)
 112
 113 static ssize_t atomic_counters_read(struct file *file, char __user *buf,
 114                                     size_t count, loff_t *ppos)
 115 {
 116         u64 counters[NUM_COUNTERS];
 117         u16 i;
 118         struct ipath_devdata *dd;
 119
 120         dd = file->f_path.dentry->d_inode->i_private;
 121
 122         for (i = 0; i < NUM_COUNTERS; i++)
 123                 counters[i] = ipath_snap_cntr(dd, i);
 124
 125         return simple_read_from_buffer(buf, count, ppos, counters,
 126                                        sizeof counters);
 127 }
 128
 129 static const struct file_operations atomic_counters_ops = {
 130         .read = atomic_counters_read,
 131 };
 132
 133 static ssize_t flash_read(struct file *file, char __user *buf,
 134                           size_t count, loff_t *ppos)
 135 {
 136         struct ipath_devdata *dd;
 137         ssize_t ret;
 138         loff_t pos;
 139         char *tmp;
 140
 141         pos = *ppos;
 142
 143         if ( pos < 0) {
 144                 ret = -EINVAL;
 145                 goto bail;
 146         }
 147
 148         if (pos >= sizeof(struct ipath_flash)) {
 149                 ret = 0;
 150                 goto bail;
 151         }
 152
 153         if (count > sizeof(struct ipath_flash) - pos)
 154                 count = sizeof(struct ipath_flash) - pos;
 155
 156         tmp = kmalloc(count, GFP_KERNEL);
 157         if (!tmp) {
 158                 ret = -ENOMEM;
 159                 goto bail;
 160         }
 161
 162         dd = file->f_path.dentry->d_inode->i_private;
 163         if (ipath_eeprom_read(dd, pos, tmp, count)) {
 164                 ipath_dev_err(dd, "failed to read from flash\n");
 165                 ret = -ENXIO;
 166                 goto bail_tmp;
 167         }
 168
 169         if (copy_to_user(buf, tmp, count)) {
 170                 ret = -EFAULT;
 171                 goto bail_tmp;
 172         }
 173
 174         *ppos = pos + count;
 175         ret = count;
 176
 177 bail_tmp:
 178         kfree(tmp);
 179
 180 bail:
 181         return ret;
 182 }
 183
 184 static ssize_t flash_write(struct file *file, const char __user *buf,
 185                            size_t count, loff_t *ppos)
 186 {
 187         struct ipath_devdata *dd;
 188         ssize_t ret;
 189         loff_t pos;
 190         char *tmp;
 191
 192         pos = *ppos;
 193
 194         if (pos != 0) {
 195                 ret = -EINVAL;
 196                 goto bail;
 197         }
 198
 199         if (count != sizeof(struct ipath_flash)) {
 200                 ret = -EINVAL;
 201                 goto bail;
 202         }
 203
 204         tmp = kmalloc(count, GFP_KERNEL);
 205         if (!tmp) {
 206                 ret = -ENOMEM;
 207                 goto bail;
 208         }
 209
 210         if (copy_from_user(tmp, buf, count)) {
 211                 ret = -EFAULT;
 212                 goto bail_tmp;
 213         }
 214
 215         dd = file->f_path.dentry->d_inode->i_private;
 216         if (ipath_eeprom_write(dd, pos, tmp, count)) {
 217                 ret = -ENXIO;
 218                 ipath_dev_err(dd, "failed to write to flash\n");
 219                 goto bail_tmp;
 220         }
 221
 222         *ppos = pos + count;
 223         ret = count;
 224
 225 bail_tmp:
 226         kfree(tmp);
 227
 228 bail:
 229         return ret;
 230 }
 231
 232 static const struct file_operations flash_ops = {
 233         .read = flash_read,
 234         .write = flash_write,
 235 };
 236
 237 static int create_device_files(struct super_block *sb,
 238                                struct ipath_devdata *dd)
 239 {
 240         struct dentry *dir, *tmp;
 241         char unit[10];
 242         int ret;
 243
 244         snprintf(unit, sizeof unit, "%02d", dd->ipath_unit);
 245         ret = create_file(unit, S_IFDIR|S_IRUGO|S_IXUGO, sb->s_root, &dir,
 246                           (struct file_operations *) &simple_dir_operations,
 247                           dd);
 248         if (ret) {
 249                 printk(KERN_ERR "create_file(%s) failed: %d\n", unit, ret);
 250                 goto bail;
 251         }
 252
 253         ret = create_file("atomic_counters", S_IFREG|S_IRUGO, dir, &tmp,
 254                           &atomic_counters_ops, dd);
 255         if (ret) {
 256                 printk(KERN_ERR "create_file(%s/atomic_counters) "
 257                        "failed: %d\n", unit, ret);
 258                 goto bail;
 259         }
 260
 261         ret = create_file("flash", S_IFREG|S_IWUSR|S_IRUGO, dir, &tmp,
 262                           &flash_ops, dd);
 263         if (ret) {
 264                 printk(KERN_ERR "create_file(%s/flash) "
 265                        "failed: %d\n", unit, ret);
 266                 goto bail;
 267         }
 268
 269 bail:
 270         return ret;
 271 }
 272
 273 static int remove_file(struct dentry *parent, char *name)
 274 {
 275         struct dentry *tmp;
 276         int ret;
 277
 278         tmp = lookup_one_len(name, parent, strlen(name));
 279
 280         if (IS_ERR(tmp)) {
 281                 ret = PTR_ERR(tmp);
 282                 goto bail;
 283         }
 284
 285         spin_lock(&dcache_lock);
 286         spin_lock(&tmp->d_lock);
 287         if (!(d_unhashed(tmp) && tmp->d_inode)) {
 288                 dget_locked(tmp);
 289                 __d_drop(tmp);
 290                 spin_unlock(&tmp->d_lock);
 291                 spin_unlock(&dcache_lock);
 292                 simple_unlink(parent->d_inode, tmp);
 293         } else {
 294                 spin_unlock(&tmp->d_lock);
 295                 spin_unlock(&dcache_lock);
 296         }
 297
 298         ret = 0;
 299 bail:
 300         /*
 301          * We don't expect clients to care about the return value, but
 302          * it's there if they need it.
 303          */
 304         return ret;
 305 }
 306
 307 static int remove_device_files(struct super_block *sb,
 308                                struct ipath_devdata *dd)
 309 {
 310         struct dentry *dir, *root;
 311         char unit[10];
 312         int ret;
 313
 314         root = dget(sb->s_root);
 315         mutex_lock(&root->d_inode->i_mutex);
 316         snprintf(unit, sizeof unit, "%02d", dd->ipath_unit);
 317         dir = lookup_one_len(unit, root, strlen(unit));
 318
 319         if (IS_ERR(dir)) {
 320                 ret = PTR_ERR(dir);
 321                 printk(KERN_ERR "Lookup of %s failed\n", unit);
 322                 goto bail;
 323         }
 324
 325         remove_file(dir, "flash");
 326         remove_file(dir, "atomic_counters");
 327         d_delete(dir);
 328         ret = simple_rmdir(root->d_inode, dir);
 329
 330 bail:
 331         mutex_unlock(&root->d_inode->i_mutex);
 332         dput(root);
 333         return ret;
 334 }
 335
 336 static int ipathfs_fill_super(struct super_block *sb, void *data,
 337                               int silent)
 338 {
 339         struct ipath_devdata *dd, *tmp;
 340         unsigned long flags;
 341         int ret;
 342
 343         static struct tree_descr files[] = {
 344                 [2] = {"atomic_stats", &atomic_stats_ops, S_IRUGO},
 345                 {""},
 346         };
 347
 348         ret = simple_fill_super(sb, IPATHFS_MAGIC, files);
 349         if (ret) {
 350                 printk(KERN_ERR "simple_fill_super failed: %d\n", ret);
 351                 goto bail;
 352         }
 353
 354         spin_lock_irqsave(&ipath_devs_lock, flags);
 355
 356         list_for_each_entry_safe(dd, tmp, &ipath_dev_list, ipath_list) {
 357                 spin_unlock_irqrestore(&ipath_devs_lock, flags);
 358                 ret = create_device_files(sb, dd);
 359                 if (ret) {
 360                         deactivate_super(sb);
 361                         goto bail;
 362                 }
 363                 spin_lock_irqsave(&ipath_devs_lock, flags);
 364         }
 365
 366         spin_unlock_irqrestore(&ipath_devs_lock, flags);
 367
 368 bail:
 369         return ret;
 370 }
 371
 372 static int ipathfs_get_sb(struct file_system_type *fs_type, int flags,
 373                         const char *dev_name, void *data, struct vfsmount *mnt)
 374 {
 375         int ret = get_sb_single(fs_type, flags, data,
 376                                     ipathfs_fill_super, mnt);
 377         if (ret >= 0)
 378                 ipath_super = mnt->mnt_sb;
 379         return ret;
 380 }
 381
 382 static void ipathfs_kill_super(struct super_block *s)
 383 {
 384         kill_litter_super(s);
 385         ipath_super = NULL;
 386 }
 387
 388 int ipathfs_add_device(struct ipath_devdata *dd)
 389 {
 390         int ret;
 391
 392         if (ipath_super == NULL) {
 393                 ret = 0;
 394                 goto bail;
 395         }
 396
 397         ret = create_device_files(ipath_super, dd);
 398
 399 bail:
 400         return ret;
 401 }
 402
 403 int ipathfs_remove_device(struct ipath_devdata *dd)
 404 {
 405         int ret;
 406
 407         if (ipath_super == NULL) {
 408                 ret = 0;
 409                 goto bail;
 410         }
 411
 412         ret = remove_device_files(ipath_super, dd);
 413
 414 bail:
 415         return ret;
 416 }
 417
 418 static struct file_system_type ipathfs_fs_type = {
 419         .owner =        THIS_MODULE,
 420         .name =         "ipathfs",
 421         .get_sb =       ipathfs_get_sb,
 422         .kill_sb =      ipathfs_kill_super,
 423 };
 424
 425 int __init ipath_init_ipathfs(void)
 426 {
 427         return register_filesystem(&ipathfs_fs_type);
 428 }
 429
 430 void __exit ipath_exit_ipathfs(void)
 431 {
 432         unregister_filesystem(&ipathfs_fs_type);
 433 }