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                 vma->vm_file = filep;
 284                 filep->f_count++;
 285         }
 286         current->blocked = old_sigmask; /* restore mask */
 287         TRACE_EXIT result;
 288 }
 289
 290 /*      Read from floppy tape device
 291  */
 292 #if LINUX_VERSION_CODE >= KERNEL_VER(2,1,60)
 293 static ssize_t zft_read(struct file *fp, char *buff,
 294                         size_t req_len, loff_t *ppos)
 295 #elif LINUX_VERSION_CODE >= KERNEL_VER(2,1,0)
 296 static long zft_read(struct inode *ino, struct file *fp, char *buff,
 297                      unsigned long req_len)
 298 #else
 299 static int  zft_read(struct inode *ino, struct file *fp, char *buff,
 300                      int req_len)
 301 #endif
 302 {
 303         int result = -EIO;
 304         sigset_t old_sigmask;
 305 #if LINUX_VERSION_CODE >= KERNEL_VER(2,1,60)
 306         struct inode *ino = fp->f_dentry->d_inode;
 307 #endif
 308         TRACE_FUN(ft_t_flow);
 309
 310         TRACE(ft_t_data_flow, "called with count: %ld", (unsigned long)req_len);
 311         if (!busy_flag || MINOR(ino->i_rdev) != zft_unit || ft_failure) {
 312                 TRACE_ABORT(-EIO, ft_t_err,
 313                             "failed: not busy, failure or wrong unit");
 314         }
 315         old_sigmask = current->blocked; /* save mask */
 316         sigfillset(&current->blocked);
 317         result = _zft_read(buff, req_len);
 318         current->blocked = old_sigmask; /* restore mask */
 319         TRACE(ft_t_data_flow, "return with count: %d", result);
 320         TRACE_EXIT result;
 321 }
 322
 323 /*      Write to tape device
 324  */
 325 #if LINUX_VERSION_CODE >= KERNEL_VER(2,1,60)
 326 static ssize_t zft_write(struct file *fp, const char *buff,
 327                          size_t req_len, loff_t *ppos)
 328 #elif LINUX_VERSION_CODE >= KERNEL_VER(2,1,0)
 329 static long zft_write(struct inode *ino, struct file *fp, const char *buff,
 330                       unsigned long req_len)
 331 #elif LINUX_VERSION_CODE >= KERNEL_VER(1,3,0)
 332 static int  zft_write(struct inode *ino, struct file *fp, const char *buff,
 333                       int req_len)
 334 #else
 335 static int  zft_write(struct inode *ino, struct file *fp, char *buff,
 336                       int req_len)
 337 #endif
 338 {
 339         int result = -EIO;
 340         sigset_t old_sigmask;
 341 #if LINUX_VERSION_CODE >= KERNEL_VER(2,1,60)
 342         struct inode *ino = fp->f_dentry->d_inode;
 343 #endif
 344         TRACE_FUN(ft_t_flow);
 345
 346         TRACE(ft_t_flow, "called with count: %ld", (unsigned long)req_len);
 347         if (!busy_flag || MINOR(ino->i_rdev) != zft_unit || ft_failure) {
 348                 TRACE_ABORT(-EIO, ft_t_err,
 349                             "failed: not busy, failure or wrong unit");
 350         }
 351         old_sigmask = current->blocked; /* save mask */
 352         sigfillset(&current->blocked);
 353         result = _zft_write(buff, req_len);
 354         current->blocked = old_sigmask; /* restore mask */
 355         TRACE(ft_t_data_flow, "return with count: %d", result);
 356         TRACE_EXIT result;
 357 }
 358
 359 /*                    END OF VFS INTERFACE
 360  *
 361  *****************************************************************************/
 362
 363 /*  driver/module initialization
 364  */
 365
 366 /*  the compression module has to call this function to hook into the zftape
 367  *  code
 368  */
 369 int zft_cmpr_register(struct zft_cmpr_ops *new_ops)
 370 {
 371         TRACE_FUN(ft_t_flow);
 372
 373         if (zft_cmpr_ops != NULL) {
 374                 TRACE_EXIT -EBUSY;
 375         } else {
 376                 zft_cmpr_ops = new_ops;
 377                 TRACE_EXIT 0;
 378         }
 379 }
 380
 381 struct zft_cmpr_ops *zft_cmpr_unregister(void)
 382 {
 383         struct zft_cmpr_ops *old_ops = zft_cmpr_ops;
 384         TRACE_FUN(ft_t_flow);
 385
 386         zft_cmpr_ops = NULL;
 387         TRACE_EXIT old_ops;
 388 }
 389
 390 /*  lock the zft-compressor() module.
 391  */
 392 int zft_cmpr_lock(int try_to_load)
 393 {
 394         if (zft_cmpr_ops == NULL) {
 395 #ifdef CONFIG_KMOD
 396                 if (try_to_load) {
 397                         request_module("zft-compressor");
 398                         if (zft_cmpr_ops == NULL) {
 399                                 return -ENOSYS;
 400                         }
 401                 } else {
 402                         return -ENOSYS;
 403                 }
 404 #else
 405                 return -ENOSYS;
 406 #endif
 407         }
 408         (*zft_cmpr_ops->lock)();
 409         return 0;
 410 }
 411
 412 #ifdef CONFIG_ZFT_COMPRESSOR
 413 extern int zft_compressor_init(void);
 414 #endif
 415
 416 /*  Called by modules package when installing the driver or by kernel
 417  *  during the initialization phase
 418  */
 419 __initfunc(int zft_init(void))
 420 {
 421         TRACE_FUN(ft_t_flow);
 422
 423 #ifdef MODULE
 424         printk(KERN_INFO ZFTAPE_VERSION "\n");
 425         if (TRACE_LEVEL >= ft_t_info) {
 426                 printk(
 427 KERN_INFO
 428 "(c) 1996, 1997 Claus-Justus Heine (claus@momo.math.rwth-aachen.de)\n"
 429 KERN_INFO
 430 "vfs interface for ftape floppy tape driver.\n"
 431 KERN_INFO
 432 "Support for QIC-113 compatible volume table, dynamic memory allocation\n"
 433 KERN_INFO
 434 "and builtin compression (lzrw3 algorithm).\n"
 435 KERN_INFO
 436 "Compiled for Linux version %s"
 437 #ifdef MODVERSIONS
 438                        " with versioned symbols"
 439 #endif
 440                        "\n", UTS_RELEASE);
 441         }
 442 #else /* !MODULE */
 443         /* print a short no-nonsense boot message */
 444         printk(KERN_INFO ZFTAPE_VERSION " for Linux " UTS_RELEASE "\n");
 445 #endif /* MODULE */
 446         TRACE(ft_t_info, "zft_init @ 0x%p", zft_init);
 447         TRACE(ft_t_info,
 448               "installing zftape VFS interface for ftape driver ...");
 449         TRACE_CATCH(register_chrdev(QIC117_TAPE_MAJOR, "zft", &zft_cdev),);
 450 #if LINUX_VERSION_CODE >= KERNEL_VER(1,2,0)
 451 # if LINUX_VERSION_CODE < KERNEL_VER(2,1,18)
 452         register_symtab(&zft_symbol_table); /* add global zftape symbols */
 453 # endif
 454 #endif
 455 #ifdef CONFIG_ZFT_COMPRESSOR
 456         (void)zft_compressor_init();
 457 #endif
 458         zft_status = ftape_get_status(); /*  fetch global data of ftape
 459                                           *  hardware driver
 460                                           */
 461         TRACE_EXIT 0;
 462 }
 463
 464
 465 #ifdef MODULE
 466 #if LINUX_VERSION_CODE <= KERNEL_VER(1,2,13) && defined(MODULE)
 467 char kernel_version[] = UTS_RELEASE;
 468 #endif
 469 #if LINUX_VERSION_CODE >= KERNEL_VER(2,1,18)
 470 /* Called by modules package before trying to unload the module
 471  */
 472 static int can_unload(void)
 473 {
 474         return (zft_dirty() || busy_flag) ? -EBUSY : 0;
 475 }
 476 #endif
 477 /* Called by modules package when installing the driver
 478  */
 479 int init_module(void)
 480 {
 481 #if LINUX_VERSION_CODE >= KERNEL_VER(2,1,18)
 482         if (!mod_member_present(&__this_module, can_unload)) {
 483                 return -EBUSY;
 484         }
 485         __this_module.can_unload = can_unload;
 486 #endif
 487         return zft_init();
 488 }
 489
 490 /* Called by modules package when removing the driver
 491  */
 492 void cleanup_module(void)
 493 {
 494         TRACE_FUN(ft_t_flow);
 495
 496         if (unregister_chrdev(QIC117_TAPE_MAJOR, "zft") != 0) {
 497                 TRACE(ft_t_warn, "failed");
 498         } else {
 499                 TRACE(ft_t_info, "successful");
 500         }
 501         zft_uninit_mem(); /* release remaining memory, if any */
 502         printk(KERN_INFO "zftape successfully unloaded.\n");
 503         TRACE_EXIT;
 504 }
 505
 506 #endif /* MODULE */