drivers/char/ftape/zftape/zftape-init.c

   1 /*
   2  *      Copyright (C) 1996, 1997 Claus-Justus Heine.
   3
   4  This program is free software; you can redistribute it and/or modify
   5  it under the terms of the GNU General Public License as published by
   6  the Free Software Foundation; either version 2, or (at your option)
   7  any later version.
   8
   9  This program is distributed in the hope that it will be useful,
  10  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  GNU General Public License for more details.
  13
  14  You should have received a copy of the GNU General Public License
  15  along with this program; see the file COPYING.  If not, write to
  16  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18  *
  19  *      This file contains the code that registers the zftape frontend
  20  *      to the ftape floppy tape driver for Linux
  21  */
  22
  23 #include <linux/config.h>
  24 #include <linux/module.h>
  25 #include <linux/errno.h>
  26 #include <linux/version.h>
  27 #include <linux/fs.h>
  28 #include <asm/segment.h>
  29 #include <linux/kernel.h>
  30 #include <linux/signal.h>
  31 #include <linux/major.h>
  32 #include <linux/malloc.h>
  33 #ifdef CONFIG_KMOD
  34 #include <linux/kmod.h>
  35 #endif
  36 #include <linux/fcntl.h>
  37 #include <linux/wrapper.h>
  38
  39 #include <linux/zftape.h>
  40 #if LINUX_VERSION_CODE >=KERNEL_VER(2,1,16)
  41 #include <linux/init.h>
  42 #else
  43 #define __initdata
  44 #define __initfunc(__arg) __arg
  45 #endif
  46
  47 #include "../zftape/zftape-init.h"
  48 #include "../zftape/zftape-read.h"
  49 #include "../zftape/zftape-write.h"
  50 #include "../zftape/zftape-ctl.h"
  51 #include "../zftape/zftape-buffers.h"
  52 #include "../zftape/zftape_syms.h"
  53
  54 char zft_src[] __initdata = "$Source: /homes/cvs/ftape-stacked/ftape/zftape/zftape-init.c,v $";
  55 char zft_rev[] __initdata = "$Revision: 1.8 $";
  56 char zft_dat[] __initdata = "$Date: 1997/11/06 00:48:56 $";
  57
  58 #if LINUX_VERSION_CODE >= KERNEL_VER(2,1,18)
  59 MODULE_AUTHOR("(c) 1996, 1997 Claus-Justus Heine "
  60               "(claus@momo.math.rwth-aachen.de)");
  61 MODULE_DESCRIPTION(ZFTAPE_VERSION " - "
  62                    "VFS interface for the Linux floppy tape driver. "
  63                    "Support for QIC-113 compatible volume table "
  64                    "and builtin compression (lzrw3 algorithm)");
  65 MODULE_SUPPORTED_DEVICE("char-major-27");
  66 #endif
  67
  68 /*      Global vars.
  69  */
  70 struct zft_cmpr_ops *zft_cmpr_ops = NULL;
  71 const ftape_info *zft_status;
  72
  73 /*      Local vars.
  74  */
  75 static int busy_flag = 0;
  76 static sigset_t orig_sigmask;
  77
  78 /*  the interface to the kernel vfs layer
  79  */
  80
  81 /* Note about llseek():
  82  *
  83  * st.c and tpqic.c update fp->f_pos but don't implment llseek() and
  84  * initialize the llseek component of the file_ops struct with NULL.
  85  * This means that the user will get the default seek, but the tape
  86  * device will not respect the new position, but happily read from the
  87  * old position. Think a zftape specific llseek() function would be
  88  * better, returning -ESPIPE. TODO.
  89  */
  90
  91 static int  zft_open (struct inode *ino, struct file *filep);
  92 #if LINUX_VERSION_CODE >= KERNEL_VER(2,1,31)
  93 static int zft_close(struct inode *ino, struct file *filep);
  94 #else
  95 static void zft_close(struct inode *ino, struct file *filep);
  96 #endif
  97 static int  zft_ioctl(struct inode *ino, struct file *filep,
  98                       unsigned int command, unsigned long arg);
  99 #if LINUX_VERSION_CODE >= KERNEL_VER(2,1,56)
 100 static int  zft_mmap(struct file *filep, struct vm_area_struct *vma);
 101 #else
 102 static int  zft_mmap(struct inode *ino, struct file *filep,
 103                      struct vm_area_struct *vma);
 104 #endif
 105 #if LINUX_VERSION_CODE >= KERNEL_VER(2,1,60)
 106 static ssize_t zft_read (struct file *fp, char *buff,
 107                          size_t req_len, loff_t *ppos);
 108 static ssize_t zft_write(struct file *fp, const char *buff,
 109                          size_t req_len, loff_t *ppos);
 110 #elif LINUX_VERSION_CODE >= KERNEL_VER(2,1,0)
 111 static long zft_read (struct inode *ino, struct file *fp, char *buff,
 112                       unsigned long req_len);
 113 static long zft_write(struct inode *ino, struct file *fp, const char *buff,
 114                       unsigned long req_len);
 115 #else
 116 static int  zft_read (struct inode *ino, struct file *fp, char *buff,
 117                       int req_len);
 118 #if LINUX_VERSION_CODE >= KERNEL_VER(1,3,0)
 119 static int  zft_write(struct inode *ino, struct file *fp, const char *buff,
 120                       int req_len);
 121 #else
 122 static int  zft_write(struct inode *ino, struct file *fp, char *buff,
 123                       int req_len);
 124 #endif
 125 #endif
 126
 127 static struct file_operations zft_cdev =
 128 {
 129         NULL,                   /* llseek */
 130         zft_read,               /* read */
 131         zft_write,              /* write */
 132         NULL,                   /* readdir */
 133         NULL,                   /* select */
 134         zft_ioctl,              /* ioctl */
 135         zft_mmap,               /* mmap */
 136         zft_open,               /* open */
 137         NULL,                   /* flush */
 138         zft_close,              /* release */
 139         NULL,                   /* fsync */
 140 };
 141
 142 /*      Open floppy tape device
 143  */
 144 static int zft_open(struct inode *ino, struct file *filep)
 145 {
 146         int result;
 147         TRACE_FUN(ft_t_flow);
 148
 149 #if LINUX_VERSION_CODE < KERNEL_VER(2,1,18)
 150         if (!MOD_IN_USE) {
 151                 MOD_INC_USE_COUNT; /* lock module in memory */
 152         }
 153 #else
 154         MOD_INC_USE_COUNT; /*  sets MOD_VISITED and MOD_USED_ONCE,
 155                             *  locking is done with can_unload()
 156                             */
 157 #endif
 158         TRACE(ft_t_flow, "called for minor %d", MINOR(ino->i_rdev));
 159         if (busy_flag) {
 160                 TRACE_ABORT(-EBUSY, ft_t_warn, "failed: already busy");
 161         }
 162         busy_flag = 1;
 163         if ((MINOR(ino->i_rdev) & ~(ZFT_MINOR_OP_MASK | FTAPE_NO_REWIND))
 164              >
 165             FTAPE_SEL_D) {
 166                 busy_flag = 0;
 167 #if defined(MODULE) && LINUX_VERSION_CODE < KERNEL_VER(2,1,18)
 168                 if (!zft_dirty()) {
 169                         MOD_DEC_USE_COUNT; /* unlock module in memory */
 170                 }
 171 #endif
 172                 TRACE_ABORT(-ENXIO, ft_t_err, "failed: illegal unit nr");
 173         }
 174         orig_sigmask = current->blocked;
 175         sigfillset(&current->blocked);
 176         result = _zft_open(MINOR(ino->i_rdev), filep->f_flags & O_ACCMODE);
 177         if (result < 0) {
 178                 current->blocked = orig_sigmask; /* restore mask */
 179                 busy_flag = 0;
 180 #if defined(MODULE) && LINUX_VERSION_CODE < KERNEL_VER(2,1,18)
 181                 if (!zft_dirty()) {
 182                         MOD_DEC_USE_COUNT; /* unlock module in memory */
 183                 }
 184 #endif
 185                 TRACE_ABORT(result, ft_t_err, "_ftape_open failed");
 186         } else {
 187                 /* Mask signals that will disturb proper operation of the
 188                  * program that is calling.
 189                  */
 190                 current->blocked = orig_sigmask;
 191                 sigaddsetmask (&current->blocked, _DO_BLOCK);
 192                 TRACE_EXIT 0;
 193         }
 194 }
 195
 196 /*      Close floppy tape device
 197  */
 198 static int zft_close(struct inode *ino, struct file *filep)
 199 {
 200         int result;
 201         TRACE_FUN(ft_t_flow);
 202
 203         if (!busy_flag || MINOR(ino->i_rdev) != zft_unit) {
 204                 TRACE(ft_t_err, "failed: not busy or wrong unit");
 205 #if LINUX_VERSION_CODE >= KERNEL_VER(2,1,31)
 206                 TRACE_EXIT 0;
 207 #else
 208                 TRACE_EXIT; /* keep busy_flag !(?) */
 209 #endif
 210         }
 211         sigfillset(&current->blocked);
 212         result = _zft_close();
 213         if (result < 0) {
 214                 TRACE(ft_t_err, "_zft_close failed");
 215         }
 216         current->blocked = orig_sigmask; /* restore before open state */
 217         busy_flag = 0;
 218 #if defined(MODULE) && LINUX_VERSION_CODE < KERNEL_VER(2,1,18)
 219         if (!zft_dirty()) {
 220                 MOD_DEC_USE_COUNT; /* unlock module in memory */
 221         }
 222 #endif
 223 #if LINUX_VERSION_CODE >= KERNEL_VER(2,1,31)
 224         TRACE_EXIT 0;
 225 #else
 226         TRACE_EXIT;
 227 #endif
 228 }
 229
 230 /*      Ioctl for floppy tape device
 231  */
 232 static int zft_ioctl(struct inode *ino, struct file *filep,
 233                      unsigned int command, unsigned long arg)
 234 {
 235         int result = -EIO;
 236         sigset_t old_sigmask;
 237         TRACE_FUN(ft_t_flow);
 238
 239         if (!busy_flag || MINOR(ino->i_rdev) != zft_unit || ft_failure) {
 240                 TRACE_ABORT(-EIO, ft_t_err,
 241                             "failed: not busy, failure or wrong unit");
 242         }
 243         old_sigmask = current->blocked; /* save mask */
 244         sigfillset(&current->blocked);
 245         /* This will work as long as sizeof(void *) == sizeof(long) */
 246         result = _zft_ioctl(command, (void *) arg);
 247         current->blocked = old_sigmask; /* restore mask */
 248         TRACE_EXIT result;
 249 }
 250
 251 /*      Ioctl for floppy tape device
 252  */
 253 #if LINUX_VERSION_CODE >= KERNEL_VER(2,1,56)
 254 static int  zft_mmap(struct file *filep, struct vm_area_struct *vma)
 255 #else
 256 static int zft_mmap(struct inode *ino,
 257                     struct file *filep,
 258                     struct vm_area_struct *vma)
 259 #endif
 260 {
 261         int result = -EIO;
 262         sigset_t old_sigmask;
 263         TRACE_FUN(ft_t_flow);
 264
 265         if (!busy_flag ||
 266 #if LINUX_VERSION_CODE >= KERNEL_VER(2,1,56)
 267             MINOR(filep->f_dentry->d_inode->i_rdev) != zft_unit ||
 268 #else
 269             MINOR(ino->i_rdev) != zft_unit ||
 270 #endif
 271             ft_failure)
 272         {
 273                 TRACE_ABORT(-EIO, ft_t_err,
 274                             "failed: not busy, failure or wrong unit");
 275         }
 276         old_sigmask = current->blocked; /* save mask */
 277         sigfillset(&current->blocked);
 278         if ((result = ftape_mmap(vma)) >= 0) {
 279 #ifndef MSYNC_BUG_WAS_FIXED
 280                 static struct vm_operations_struct dummy = { NULL, };
 281                 vma->vm_ops = &dummy;
 282 #endif
 283         }
 284         current->blocked = old_sigmask; /* restore mask */
 285         TRACE_EXIT result;
 286 }
 287
 288 /*      Read from floppy tape device
 289  */
 290 #if LINUX_VERSION_CODE >= KERNEL_VER(2,1,60)
 291 static ssize_t zft_read(struct file *fp, char *buff,
 292                         size_t req_len, loff_t *ppos)
 293 #elif LINUX_VERSION_CODE >= KERNEL_VER(2,1,0)
 294 static long zft_read(struct inode *ino, struct file *fp, char *buff,
 295                      unsigned long req_len)
 296 #else
 297 static int  zft_read(struct inode *ino, struct file *fp, char *buff,
 298                      int req_len)
 299 #endif
 300 {
 301         int result = -EIO;
 302         sigset_t old_sigmask;
 303 #if LINUX_VERSION_CODE >= KERNEL_VER(2,1,60)
 304         struct inode *ino = fp->f_dentry->d_inode;
 305 #endif
 306         TRACE_FUN(ft_t_flow);
 307
 308         TRACE(ft_t_data_flow, "called with count: %ld", (unsigned long)req_len);
 309         if (!busy_flag || MINOR(ino->i_rdev) != zft_unit || ft_failure) {
 310                 TRACE_ABORT(-EIO, ft_t_err,
 311                             "failed: not busy, failure or wrong unit");
 312         }
 313         old_sigmask = current->blocked; /* save mask */
 314         sigfillset(&current->blocked);
 315         result = _zft_read(buff, req_len);
 316         current->blocked = old_sigmask; /* restore mask */
 317         TRACE(ft_t_data_flow, "return with count: %d", result);
 318         TRACE_EXIT result;
 319 }
 320
 321 /*      Write to tape device
 322  */
 323 #if LINUX_VERSION_CODE >= KERNEL_VER(2,1,60)
 324 static ssize_t zft_write(struct file *fp, const char *buff,
 325                          size_t req_len, loff_t *ppos)
 326 #elif LINUX_VERSION_CODE >= KERNEL_VER(2,1,0)
 327 static long zft_write(struct inode *ino, struct file *fp, const char *buff,
 328                       unsigned long req_len)
 329 #elif LINUX_VERSION_CODE >= KERNEL_VER(1,3,0)
 330 static int  zft_write(struct inode *ino, struct file *fp, const char *buff,
 331                       int req_len)
 332 #else
 333 static int  zft_write(struct inode *ino, struct file *fp, char *buff,
 334                       int req_len)
 335 #endif
 336 {
 337         int result = -EIO;
 338         sigset_t old_sigmask;
 339 #if LINUX_VERSION_CODE >= KERNEL_VER(2,1,60)
 340         struct inode *ino = fp->f_dentry->d_inode;
 341 #endif
 342         TRACE_FUN(ft_t_flow);
 343
 344         TRACE(ft_t_flow, "called with count: %ld", (unsigned long)req_len);
 345         if (!busy_flag || MINOR(ino->i_rdev) != zft_unit || ft_failure) {
 346                 TRACE_ABORT(-EIO, ft_t_err,
 347                             "failed: not busy, failure or wrong unit");
 348         }
 349         old_sigmask = current->blocked; /* save mask */
 350         sigfillset(&current->blocked);
 351         result = _zft_write(buff, req_len);
 352         current->blocked = old_sigmask; /* restore mask */
 353         TRACE(ft_t_data_flow, "return with count: %d", result);
 354         TRACE_EXIT result;
 355 }
 356
 357 /*                    END OF VFS INTERFACE
 358  *
 359  *****************************************************************************/
 360
 361 /*  driver/module initialization
 362  */
 363
 364 /*  the compression module has to call this function to hook into the zftape
 365  *  code
 366  */
 367 int zft_cmpr_register(struct zft_cmpr_ops *new_ops)
 368 {
 369         TRACE_FUN(ft_t_flow);
 370
 371         if (zft_cmpr_ops != NULL) {
 372                 TRACE_EXIT -EBUSY;
 373         } else {
 374                 zft_cmpr_ops = new_ops;
 375                 TRACE_EXIT 0;
 376         }
 377 }
 378
 379 struct zft_cmpr_ops *zft_cmpr_unregister(void)
 380 {
 381         struct zft_cmpr_ops *old_ops = zft_cmpr_ops;
 382         TRACE_FUN(ft_t_flow);
 383
 384         zft_cmpr_ops = NULL;
 385         TRACE_EXIT old_ops;
 386 }
 387
 388 /*  lock the zft-compressor() module.
 389  */
 390 int zft_cmpr_lock(int try_to_load)
 391 {
 392         if (zft_cmpr_ops == NULL) {
 393 #ifdef CONFIG_KMOD
 394                 if (try_to_load) {
 395                         request_module("zft-compressor");
 396                         if (zft_cmpr_ops == NULL) {
 397                                 return -ENOSYS;
 398                         }
 399                 } else {
 400                         return -ENOSYS;
 401                 }
 402 #else
 403                 return -ENOSYS;
 404 #endif
 405         }
 406         (*zft_cmpr_ops->lock)();
 407         return 0;
 408 }
 409
 410 #ifdef CONFIG_ZFT_COMPRESSOR
 411 extern int zft_compressor_init(void);
 412 #endif
 413
 414 /*  Called by modules package when installing the driver or by kernel
 415  *  during the initialization phase
 416  */
 417 int __init zft_init(void)
 418 {
 419         TRACE_FUN(ft_t_flow);
 420
 421 #ifdef MODULE
 422         printk(KERN_INFO ZFTAPE_VERSION "\n");
 423         if (TRACE_LEVEL >= ft_t_info) {
 424                 printk(
 425 KERN_INFO
 426 "(c) 1996, 1997 Claus-Justus Heine (claus@momo.math.rwth-aachen.de)\n"
 427 KERN_INFO
 428 "vfs interface for ftape floppy tape driver.\n"
 429 KERN_INFO
 430 "Support for QIC-113 compatible volume table, dynamic memory allocation\n"
 431 KERN_INFO
 432 "and builtin compression (lzrw3 algorithm).\n"
 433 KERN_INFO
 434 "Compiled for Linux version %s"
 435 #ifdef MODVERSIONS
 436                        " with versioned symbols"
 437 #endif
 438                        "\n", UTS_RELEASE);
 439         }
 440 #else /* !MODULE */
 441         /* print a short no-nonsense boot message */
 442         printk(KERN_INFO ZFTAPE_VERSION " for Linux " UTS_RELEASE "\n");
 443 #endif /* MODULE */
 444         TRACE(ft_t_info, "zft_init @ 0x%p", zft_init);
 445         TRACE(ft_t_info,
 446               "installing zftape VFS interface for ftape driver ...");
 447         TRACE_CATCH(register_chrdev(QIC117_TAPE_MAJOR, "zft", &zft_cdev),);
 448 #if LINUX_VERSION_CODE >= KERNEL_VER(1,2,0)
 449 # if LINUX_VERSION_CODE < KERNEL_VER(2,1,18)
 450         register_symtab(&zft_symbol_table); /* add global zftape symbols */
 451 # endif
 452 #endif
 453 #ifdef CONFIG_ZFT_COMPRESSOR
 454         (void)zft_compressor_init();
 455 #endif
 456         zft_status = ftape_get_status(); /*  fetch global data of ftape
 457                                           *  hardware driver
 458                                           */
 459         TRACE_EXIT 0;
 460 }
 461
 462
 463 #ifdef MODULE
 464 #if LINUX_VERSION_CODE <= KERNEL_VER(1,2,13) && defined(MODULE)
 465 char kernel_version[] = UTS_RELEASE;
 466 #endif
 467 #if LINUX_VERSION_CODE >= KERNEL_VER(2,1,18)
 468 /* Called by modules package before trying to unload the module
 469  */
 470 static int can_unload(void)
 471 {
 472         return (zft_dirty() || busy_flag) ? -EBUSY : 0;
 473 }
 474 #endif
 475 /* Called by modules package when installing the driver
 476  */
 477 int init_module(void)
 478 {
 479 #if LINUX_VERSION_CODE >= KERNEL_VER(2,1,18)
 480         if (!mod_member_present(&__this_module, can_unload)) {
 481                 return -EBUSY;
 482         }
 483         __this_module.can_unload = can_unload;
 484 #endif
 485         return zft_init();
 486 }
 487
 488 /* Called by modules package when removing the driver
 489  */
 490 void cleanup_module(void)
 491 {
 492         TRACE_FUN(ft_t_flow);
 493
 494         if (unregister_chrdev(QIC117_TAPE_MAJOR, "zft") != 0) {
 495                 TRACE(ft_t_warn, "failed");
 496         } else {
 497                 TRACE(ft_t_info, "successful");
 498         }
 499         zft_uninit_mem(); /* release remaining memory, if any */
 500         printk(KERN_INFO "zftape successfully unloaded.\n");
 501         TRACE_EXIT;
 502 }
 503
 504 #endif /* MODULE */