git.gag.com Git - debian/amanda/blob - device-src/tape-device.c

   1 /*
   2  * Copyright (c) 2007, 2008, 2009, 2010 Zmanda, Inc.  All Rights Reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 as published
   6  * by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  10  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  11  * for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  16  *
  17  * Contact information: Zmanda Inc., 465 S. Mathilda Ave., Suite 300
  18  * Sunnyvale, CA 94085, USA, or: http://www.zmanda.com
  19  */
  20
  21 #include "amanda.h"
  22 #include "pipespawn.h"
  23 #include <string.h> /* memset() */
  24 #include "util.h"
  25 #include "device.h"
  26
  27 #ifdef HAVE_SYS_TAPE_H
  28 # include <sys/tape.h>
  29 #endif
  30 #ifdef HAVE_SYS_MTIO_H
  31 # include <sys/mtio.h>
  32 #endif
  33 #ifdef HAVE_LIMITS_H
  34 # include <limits.h>
  35 #endif
  36
  37 /* This is equal to 2*1024*1024*1024 - 16*1024*1024 - 1, but written
  38    explicitly to avoid overflow issues. */
  39 #define RESETOFS_THRESHOLD (0x7effffff)
  40
  41 /* Largest possible block size on SCSI systems. */
  42 #define LARGEST_BLOCK_ESTIMATE (16 * 1024 * 1024)
  43
  44 /*
  45  * Type checking and casting macros
  46  */
  47
  48 #define TYPE_TAPE_DEVICE        (tape_device_get_type())
  49 #define TAPE_DEVICE(obj)        G_TYPE_CHECK_INSTANCE_CAST((obj), tape_device_get_type(), TapeDevice)
  50 #define TAPE_DEVICE_CONST(obj)  G_TYPE_CHECK_INSTANCE_CAST((obj), tape_device_get_type(), TapeDevice const)
  51 #define TAPE_DEVICE_CLASS(klass)        G_TYPE_CHECK_CLASS_CAST((klass), tape_device_get_type(), TapeDeviceClass)
  52 #define IS_TAPE_DEVICE(obj)     G_TYPE_CHECK_INSTANCE_TYPE((obj), tape_device_get_type ())
  53 #define TAPE_DEVICE_GET_CLASS(obj)      G_TYPE_INSTANCE_GET_CLASS((obj), tape_device_get_type(), TapeDeviceClass)
  54 GType   tape_device_get_type    (void);
  55
  56 /*
  57  * Main object structure
  58  */
  59 typedef struct TapeDevicePrivate_s TapeDevicePrivate;
  60 typedef struct _TapeDevice {
  61     Device __parent__;
  62
  63     /* It should go without saying that all this stuff is
  64      * look-but-don't-touch. */
  65
  66     /* characteristics of the device */
  67     gboolean fsf, bsf, fsr, bsr, eom, bsf_after_eom, broken_gmt_online;
  68     gboolean leom;
  69     gboolean nonblocking_open, fsf_after_filemark;
  70     int final_filemarks;
  71
  72     /* 0 if we opened with O_RDWR; error otherwise. */
  73     gboolean write_open_errno;
  74     int fd;
  75
  76     TapeDevicePrivate * private;
  77 } TapeDevice;
  78
  79 struct TapeDevicePrivate_s {
  80     /* This holds the total number of bytes written to the device,
  81        modulus RESETOFS_THRESHOLD. */
  82     int write_count;
  83     char * device_filename;
  84     gsize read_block_size;
  85 };
  86
  87 /*
  88  * Class definition
  89  */
  90
  91 typedef struct _TapeDeviceClass TapeDeviceClass;
  92 struct _TapeDeviceClass {
  93         DeviceClass __parent__;
  94 };
  95
  96 void tape_device_register(void);
  97
  98 /* useful callback for tape ops */
  99 void tape_device_set_capabilities(TapeDevice *self,
 100         gboolean fsf, PropertySurety fsf_surety, PropertySource fsf_source,
 101         gboolean fsf_after_filemark, PropertySurety faf_surety, PropertySource faf_source,
 102         gboolean bsf, PropertySurety bsf_surety, PropertySource bsf_source,
 103         gboolean fsr, PropertySurety fsr_surety, PropertySource fsr_source,
 104         gboolean bsr, PropertySurety bsr_surety, PropertySource bsr_source,
 105         gboolean eom, PropertySurety eom_surety, PropertySource eom_source,
 106         gboolean leom, PropertySurety leom_surety, PropertySource leom_source,
 107         gboolean bsf_after_eom, PropertySurety bae_surety, PropertySource bae_source,
 108         guint final_filemarks, PropertySurety ff_surety, PropertySource ff_source);
 109
 110 /* Real Operations (always return FALSE if not implemented) */
 111 gboolean tape_rewind(int fd);
 112 gboolean tape_fsf(int fd, guint count);
 113 gboolean tape_bsf(int fd, guint count);
 114 gboolean tape_fsr(int fd, guint count);
 115 gboolean tape_bsr(int fd, guint count);
 116 gint tape_fileno(int fd);
 117
 118 /* tape_fileno returns tape position file number, or one of these: */
 119 #define TAPE_OP_ERROR -1
 120 #define TAPE_POSITION_UNKNOWN -2
 121
 122 /* Possible (abstracted) results from a system I/O operation. */
 123 typedef enum {
 124     RESULT_SUCCESS,
 125     RESULT_ERROR,        /* Undefined error (*errmsg set) */
 126     RESULT_SMALL_BUFFER, /* Tried to read with a buffer that is too
 127                             small. */
 128     RESULT_NO_DATA,      /* End of File, while reading */
 129     RESULT_NO_SPACE,     /* Out of space. Sometimes we don't know if
 130                             it was this or I/O error, but this is the
 131                             preferred explanation. */
 132     RESULT_MAX
 133 } IoResult;
 134
 135 /* returns a fileno like tape_fileno */
 136 gint tape_eod(int fd);
 137
 138 gboolean tape_weof(int fd, guint8 count);
 139 gboolean tape_setcompression(int fd, gboolean on);
 140
 141 gboolean tape_offl(int fd);
 142
 143 DeviceStatusFlags tape_is_tape_device(int fd);
 144 DeviceStatusFlags tape_is_ready(int fd, TapeDevice *t_self);
 145
 146 #define tape_device_read_size(self) \
 147     (((TapeDevice *)(self))->private->read_block_size? \
 148         ((TapeDevice *)(self))->private->read_block_size : ((Device *)(self))->block_size)
 149
 150 /*
 151  * Our device-specific properties.
 152  */
 153
 154 #define PROPERTY_BROKEN_GMT_ONLINE (device_property_broken_gmt_online.ID)
 155 #define PROPERTY_FSF (device_property_fsf.ID)
 156 #define PROPERTY_FSF_AFTER_FILEMARK (device_property_fsf_after_filemark.ID)
 157 #define PROPERTY_BSF (device_property_bsf.ID)
 158 #define PROPERTY_FSR (device_property_fsr.ID)
 159 #define PROPERTY_BSR (device_property_bsr.ID)
 160 #define PROPERTY_EOM (device_property_eom.ID)
 161 #define PROPERTY_BSF_AFTER_EOM (device_property_bsf_after_eom.ID)
 162 #define PROPERTY_NONBLOCKING_OPEN (device_property_nonblocking_open.ID)
 163 #define PROPERTY_FINAL_FILEMARKS (device_property_final_filemarks.ID)
 164
 165 static DevicePropertyBase device_property_broken_gmt_online;
 166 static DevicePropertyBase device_property_fsf;
 167 static DevicePropertyBase device_property_fsf_after_filemark;
 168 static DevicePropertyBase device_property_bsf;
 169 static DevicePropertyBase device_property_fsr;
 170 static DevicePropertyBase device_property_bsr;
 171 static DevicePropertyBase device_property_eom;
 172 static DevicePropertyBase device_property_bsf_after_eom;
 173 static DevicePropertyBase device_property_nonblocking_open;
 174 static DevicePropertyBase device_property_final_filemarks;
 175 static DevicePropertyBase device_property_read_buffer_size; /* old name for READ_BLOCK_SIZE */
 176
 177 /* here are local prototypes */
 178 static void tape_device_init (TapeDevice * o);
 179 static void tape_device_class_init (TapeDeviceClass * c);
 180 static void tape_device_base_init (TapeDeviceClass * c);
 181 static gboolean tape_device_set_feature_property_fn(Device *p_self, DevicePropertyBase *base,
 182                                     GValue *val, PropertySurety surety, PropertySource source);
 183 static gboolean tape_device_set_final_filemarks_fn(Device *p_self, DevicePropertyBase *base,
 184                                     GValue *val, PropertySurety surety, PropertySource source);
 185 static gboolean tape_device_set_compression_fn(Device *p_self, DevicePropertyBase *base,
 186                                     GValue *val, PropertySurety surety, PropertySource source);
 187 static gboolean tape_device_get_read_block_size_fn(Device *p_self, DevicePropertyBase *base,
 188                                     GValue *val, PropertySurety *surety, PropertySource *source);
 189 static gboolean tape_device_set_read_block_size_fn(Device *p_self, DevicePropertyBase *base,
 190                                     GValue *val, PropertySurety surety, PropertySource source);
 191 static void tape_device_open_device (Device * self, char * device_name, char * device_type, char * device_node);
 192 static Device * tape_device_factory (char * device_name, char * device_type, char * device_node);
 193 static DeviceStatusFlags tape_device_read_label(Device * self);
 194 static gboolean tape_device_write_block(Device * self, guint size, gpointer data);
 195 static int tape_device_read_block(Device * self,  gpointer buf,
 196                                        int * size_req);
 197 static gboolean tape_device_start (Device * self, DeviceAccessMode mode,
 198                                    char * label, char * timestamp);
 199 static gboolean tape_device_start_file (Device * self, dumpfile_t * ji);
 200 static gboolean tape_device_finish_file (Device * self);
 201 static dumpfile_t * tape_device_seek_file (Device * self, guint file);
 202 static gboolean tape_device_seek_block (Device * self, guint64 block);
 203 static gboolean tape_device_eject (Device * self);
 204 static gboolean tape_device_finish (Device * self);
 205 static IoResult tape_device_robust_read (TapeDevice * self, void * buf,
 206                                                int * count, char **errmsg);
 207 static IoResult tape_device_robust_write (TapeDevice * self, void * buf, int count, char **errmsg);
 208 static gboolean tape_device_fsf (TapeDevice * self, guint count);
 209 static gboolean tape_device_fsr (TapeDevice * self, guint count);
 210 static gboolean tape_device_bsr (TapeDevice * self, guint count, guint file, guint block);
 211 static gboolean tape_device_eod (TapeDevice * self);
 212
 213 /* pointer to the class of our parent */
 214 static DeviceClass *parent_class = NULL;
 215
 216 GType tape_device_get_type (void)
 217 {
 218     static GType type = 0;
 219
 220     if G_UNLIKELY(type == 0) {
 221         static const GTypeInfo info = {
 222             sizeof (TapeDeviceClass),
 223             (GBaseInitFunc) tape_device_base_init,
 224             (GBaseFinalizeFunc) NULL,
 225             (GClassInitFunc) tape_device_class_init,
 226             (GClassFinalizeFunc) NULL,
 227             NULL /* class_data */,
 228             sizeof (TapeDevice),
 229             0 /* n_preallocs */,
 230             (GInstanceInitFunc) tape_device_init,
 231             NULL
 232         };
 233
 234         type = g_type_register_static (TYPE_DEVICE, "TapeDevice",
 235                                        &info, (GTypeFlags)0);
 236     }
 237
 238     return type;
 239 }
 240
 241 static void
 242 tape_device_init (TapeDevice * self) {
 243     Device * d_self;
 244     GValue response;
 245
 246     d_self = DEVICE(self);
 247     bzero(&response, sizeof(response));
 248
 249     self->private = g_new0(TapeDevicePrivate, 1);
 250
 251     /* Clear all fields. */
 252     d_self->block_size = 32768;
 253     d_self->min_block_size = 32768;
 254     d_self->max_block_size = LARGEST_BLOCK_ESTIMATE;
 255     self->broken_gmt_online = FALSE;
 256
 257     self->fd = -1;
 258
 259     /* set all of the feature properties to an unsure default of FALSE */
 260     self->broken_gmt_online = FALSE;
 261     self->fsf = FALSE;
 262     self->bsf = FALSE;
 263     self->fsr = FALSE;
 264     self->bsr = FALSE;
 265     self->eom = FALSE;
 266     self->leom = FALSE;
 267     self->bsf_after_eom = FALSE;
 268
 269     g_value_init(&response, G_TYPE_BOOLEAN);
 270     g_value_set_boolean(&response, FALSE);
 271     device_set_simple_property(d_self, PROPERTY_BROKEN_GMT_ONLINE,
 272             &response, PROPERTY_SURETY_BAD, PROPERTY_SOURCE_DEFAULT);
 273     device_set_simple_property(d_self, PROPERTY_FSF,
 274             &response, PROPERTY_SURETY_BAD, PROPERTY_SOURCE_DEFAULT);
 275     device_set_simple_property(d_self, PROPERTY_FSF_AFTER_FILEMARK,
 276             &response, PROPERTY_SURETY_BAD, PROPERTY_SOURCE_DEFAULT);
 277     device_set_simple_property(d_self, PROPERTY_BSF,
 278             &response, PROPERTY_SURETY_BAD, PROPERTY_SOURCE_DEFAULT);
 279     device_set_simple_property(d_self, PROPERTY_FSR,
 280             &response, PROPERTY_SURETY_BAD, PROPERTY_SOURCE_DEFAULT);
 281     device_set_simple_property(d_self, PROPERTY_BSR,
 282             &response, PROPERTY_SURETY_BAD, PROPERTY_SOURCE_DEFAULT);
 283     device_set_simple_property(d_self, PROPERTY_EOM,
 284             &response, PROPERTY_SURETY_BAD, PROPERTY_SOURCE_DEFAULT);
 285     device_set_simple_property(d_self, PROPERTY_LEOM,
 286             &response, PROPERTY_SURETY_BAD, PROPERTY_SOURCE_DEFAULT);
 287     device_set_simple_property(d_self, PROPERTY_BSF_AFTER_EOM,
 288             &response, PROPERTY_SURETY_BAD, PROPERTY_SOURCE_DEFAULT);
 289
 290 #ifdef DEFAULT_TAPE_NON_BLOCKING_OPEN
 291     self->nonblocking_open = TRUE;
 292 #else
 293     self->nonblocking_open = FALSE;
 294 #endif
 295     g_value_set_boolean(&response, self->nonblocking_open);
 296     device_set_simple_property(d_self, PROPERTY_NONBLOCKING_OPEN,
 297             &response, PROPERTY_SURETY_BAD, PROPERTY_SOURCE_DEFAULT);
 298     g_value_unset(&response);
 299
 300     self->final_filemarks = 2;
 301     g_value_init(&response, G_TYPE_UINT);
 302     g_value_set_uint(&response, self->final_filemarks);
 303     device_set_simple_property(d_self, PROPERTY_FINAL_FILEMARKS,
 304             &response, PROPERTY_SURETY_BAD, PROPERTY_SOURCE_DEFAULT);
 305     g_value_unset(&response);
 306
 307     self->private->read_block_size = 0;
 308     g_value_init(&response, G_TYPE_UINT);
 309     g_value_set_uint(&response, self->private->read_block_size);
 310     device_set_simple_property(d_self, PROPERTY_READ_BLOCK_SIZE,
 311             &response, PROPERTY_SURETY_GOOD, PROPERTY_SOURCE_DEFAULT);
 312     g_value_unset(&response);
 313
 314     self->private->write_count = 0;
 315     self->private->device_filename = NULL;
 316
 317     /* Static properites */
 318     g_value_init(&response, CONCURRENCY_PARADIGM_TYPE);
 319     g_value_set_enum(&response, CONCURRENCY_PARADIGM_EXCLUSIVE);
 320     device_set_simple_property(d_self, PROPERTY_CONCURRENCY,
 321             &response, PROPERTY_SURETY_GOOD, PROPERTY_SOURCE_DETECTED);
 322     g_value_unset(&response);
 323
 324     g_value_init(&response, STREAMING_REQUIREMENT_TYPE);
 325     g_value_set_enum(&response, STREAMING_REQUIREMENT_DESIRED);
 326     device_set_simple_property(d_self, PROPERTY_STREAMING,
 327             &response, PROPERTY_SURETY_GOOD, PROPERTY_SOURCE_DETECTED);
 328     g_value_unset(&response);
 329
 330     g_value_init(&response, G_TYPE_BOOLEAN);
 331     g_value_set_boolean(&response, TRUE);
 332     device_set_simple_property(d_self, PROPERTY_APPENDABLE,
 333             &response, PROPERTY_SURETY_GOOD, PROPERTY_SOURCE_DETECTED);
 334     g_value_unset(&response);
 335
 336     g_value_init(&response, G_TYPE_BOOLEAN);
 337     g_value_set_boolean(&response, FALSE);
 338     device_set_simple_property(d_self, PROPERTY_PARTIAL_DELETION,
 339             &response, PROPERTY_SURETY_GOOD, PROPERTY_SOURCE_DETECTED);
 340     g_value_unset(&response);
 341
 342     g_value_init(&response, G_TYPE_BOOLEAN);
 343     g_value_set_boolean(&response, FALSE);
 344     device_set_simple_property(d_self, PROPERTY_FULL_DELETION,
 345             &response, PROPERTY_SURETY_GOOD, PROPERTY_SOURCE_DETECTED);
 346     g_value_unset(&response);
 347
 348     g_value_init(&response, MEDIA_ACCESS_MODE_TYPE);
 349     g_value_set_enum(&response, MEDIA_ACCESS_MODE_READ_WRITE);
 350     device_set_simple_property(d_self, PROPERTY_MEDIUM_ACCESS_TYPE,
 351             &response, PROPERTY_SURETY_GOOD, PROPERTY_SOURCE_DETECTED);
 352     g_value_unset(&response);
 353 }
 354
 355 static void tape_device_finalize(GObject * obj_self) {
 356     TapeDevice * self = TAPE_DEVICE(obj_self);
 357
 358     if(G_OBJECT_CLASS(parent_class)->finalize) \
 359            (* G_OBJECT_CLASS(parent_class)->finalize)(obj_self);
 360
 361     robust_close(self->fd);
 362     self->fd = -1;
 363     amfree(self->private->device_filename);
 364     amfree(self->private);
 365 }
 366
 367 static void
 368 tape_device_class_init (TapeDeviceClass * c)
 369 {
 370     DeviceClass *device_class = (DeviceClass *)c;
 371     GObjectClass *g_object_class = (GObjectClass *)c;
 372
 373     parent_class = g_type_class_ref (TYPE_DEVICE);
 374
 375     device_class->open_device = tape_device_open_device;
 376     device_class->read_label = tape_device_read_label;
 377     device_class->write_block = tape_device_write_block;
 378     device_class->read_block = tape_device_read_block;
 379     device_class->start = tape_device_start;
 380     device_class->start_file = tape_device_start_file;
 381     device_class->finish_file = tape_device_finish_file;
 382     device_class->seek_file = tape_device_seek_file;
 383     device_class->seek_block = tape_device_seek_block;
 384     device_class->eject = tape_device_eject;
 385     device_class->finish = tape_device_finish;
 386
 387     g_object_class->finalize = tape_device_finalize;
 388 }
 389
 390 static void
 391 tape_device_base_init (TapeDeviceClass * c)
 392 {
 393     DeviceClass *device_class = (DeviceClass *)c;
 394
 395     device_class_register_property(device_class, PROPERTY_BROKEN_GMT_ONLINE,
 396             PROPERTY_ACCESS_GET_MASK | PROPERTY_ACCESS_SET_BEFORE_START,
 397             device_simple_property_get_fn,
 398             tape_device_set_feature_property_fn);
 399
 400     device_class_register_property(device_class, PROPERTY_FSF,
 401             PROPERTY_ACCESS_GET_MASK | PROPERTY_ACCESS_SET_BEFORE_START,
 402             device_simple_property_get_fn,
 403             tape_device_set_feature_property_fn);
 404
 405     device_class_register_property(device_class, PROPERTY_FSF_AFTER_FILEMARK,
 406             PROPERTY_ACCESS_GET_MASK | PROPERTY_ACCESS_SET_BEFORE_START,
 407             device_simple_property_get_fn,
 408             tape_device_set_feature_property_fn);
 409
 410     device_class_register_property(device_class, PROPERTY_BSF,
 411             PROPERTY_ACCESS_GET_MASK | PROPERTY_ACCESS_SET_BEFORE_START,
 412             device_simple_property_get_fn,
 413             tape_device_set_feature_property_fn);
 414
 415     device_class_register_property(device_class, PROPERTY_FSR,
 416             PROPERTY_ACCESS_GET_MASK | PROPERTY_ACCESS_SET_BEFORE_START,
 417             device_simple_property_get_fn,
 418             tape_device_set_feature_property_fn);
 419
 420     device_class_register_property(device_class, PROPERTY_BSR,
 421             PROPERTY_ACCESS_GET_MASK | PROPERTY_ACCESS_SET_BEFORE_START,
 422             device_simple_property_get_fn,
 423             tape_device_set_feature_property_fn);
 424
 425     device_class_register_property(device_class, PROPERTY_EOM,
 426             PROPERTY_ACCESS_GET_MASK | PROPERTY_ACCESS_SET_BEFORE_START,
 427             device_simple_property_get_fn,
 428             tape_device_set_feature_property_fn);
 429
 430     device_class_register_property(device_class, PROPERTY_BSF_AFTER_EOM,
 431             PROPERTY_ACCESS_GET_MASK | PROPERTY_ACCESS_SET_BEFORE_START,
 432             device_simple_property_get_fn,
 433             tape_device_set_feature_property_fn);
 434
 435     device_class_register_property(device_class, PROPERTY_NONBLOCKING_OPEN,
 436             PROPERTY_ACCESS_GET_MASK | PROPERTY_ACCESS_SET_BEFORE_START,
 437             device_simple_property_get_fn,
 438             tape_device_set_feature_property_fn);
 439
 440     device_class_register_property(device_class, PROPERTY_FINAL_FILEMARKS,
 441             PROPERTY_ACCESS_GET_MASK | PROPERTY_ACCESS_SET_BEFORE_START,
 442             device_simple_property_get_fn,
 443             tape_device_set_final_filemarks_fn);
 444
 445     /* We don't (yet?) support reading the device's compression state, so not
 446      * gettable. */
 447     device_class_register_property(device_class, PROPERTY_COMPRESSION,
 448             PROPERTY_ACCESS_SET_MASK,
 449             NULL,
 450             tape_device_set_compression_fn);
 451
 452     device_class_register_property(device_class, PROPERTY_READ_BLOCK_SIZE,
 453             PROPERTY_ACCESS_GET_MASK | PROPERTY_ACCESS_SET_BEFORE_START,
 454             tape_device_get_read_block_size_fn,
 455             tape_device_set_read_block_size_fn);
 456
 457     device_class_register_property(device_class, device_property_read_buffer_size.ID,
 458             PROPERTY_ACCESS_GET_MASK | PROPERTY_ACCESS_SET_BEFORE_START,
 459             tape_device_get_read_block_size_fn,
 460             tape_device_set_read_block_size_fn);
 461
 462     /* add the ability to set LEOM to FALSE, for testing purposes */
 463     device_class_register_property(device_class, PROPERTY_LEOM,
 464             PROPERTY_ACCESS_GET_MASK | PROPERTY_ACCESS_SET_BEFORE_START,
 465             device_simple_property_get_fn,
 466             tape_device_set_feature_property_fn);
 467 }
 468
 469 static gboolean
 470 tape_device_set_feature_property_fn(Device *p_self, DevicePropertyBase *base,
 471     GValue *val, PropertySurety surety, PropertySource source)
 472 {
 473     TapeDevice *self = TAPE_DEVICE(p_self);
 474     GValue old_val;
 475     gboolean old_bool, new_bool;
 476     PropertySurety old_surety;
 477     PropertySource old_source;
 478
 479     new_bool = g_value_get_boolean(val);
 480
 481     /* get the old source and surety and see if we're willing to make this change */
 482     bzero(&old_val, sizeof(old_val));
 483     if (device_get_simple_property(p_self, base->ID, &old_val, &old_surety, &old_source)) {
 484         old_bool = g_value_get_boolean(&old_val);
 485
 486         if (old_surety == PROPERTY_SURETY_GOOD && old_source == PROPERTY_SOURCE_DETECTED) {
 487             if (new_bool != old_bool) {
 488                 device_set_error(p_self, vstrallocf(_(
 489                            "Value for property '%s' was autodetected and cannot be changed"),
 490                            base->name),
 491                     DEVICE_STATUS_DEVICE_ERROR);
 492                 return FALSE;
 493             } else {
 494                 /* pretend we set it, but don't change surety/source */
 495                 return TRUE;
 496             }
 497         }
 498     }
 499
 500     /* (note: PROPERTY_* are not constants, so we can't use switch) */
 501     if (base->ID == PROPERTY_BROKEN_GMT_ONLINE)
 502         self->broken_gmt_online = new_bool;
 503     else if (base->ID == PROPERTY_FSF)
 504         self->fsf = new_bool;
 505     else if (base->ID == PROPERTY_FSF_AFTER_FILEMARK)
 506         self->fsf_after_filemark = new_bool;
 507     else if (base->ID == PROPERTY_BSF)
 508         self->bsf = new_bool;
 509     else if (base->ID == PROPERTY_FSR)
 510         self->fsr = new_bool;
 511     else if (base->ID == PROPERTY_BSR)
 512         self->bsr = new_bool;
 513     else if (base->ID == PROPERTY_EOM)
 514         self->eom = new_bool;
 515     else if (base->ID == PROPERTY_BSF_AFTER_EOM)
 516         self->bsf_after_eom = new_bool;
 517     else if (base->ID == PROPERTY_NONBLOCKING_OPEN)
 518         self->nonblocking_open = new_bool;
 519     else if (base->ID == PROPERTY_LEOM)
 520         self->leom = new_bool;
 521     else
 522         return FALSE; /* shouldn't happen */
 523
 524     return device_simple_property_set_fn(p_self, base, val, surety, source);
 525 }
 526
 527 static gboolean
 528 tape_device_set_final_filemarks_fn(Device *p_self, DevicePropertyBase *base,
 529     GValue *val, PropertySurety surety, PropertySource source)
 530 {
 531     TapeDevice *self = TAPE_DEVICE(p_self);
 532     GValue old_val;
 533     gboolean old_int, new_int;
 534     PropertySurety old_surety;
 535     PropertySource old_source;
 536
 537     new_int = g_value_get_uint(val);
 538
 539     /* get the old source and surety and see if we're willing to make this change */
 540     bzero(&old_val, sizeof(old_val));
 541     if (device_get_simple_property(p_self, base->ID, &old_val, &old_surety, &old_source)) {
 542         old_int = g_value_get_uint(&old_val);
 543
 544         if (old_surety == PROPERTY_SURETY_GOOD && old_source == PROPERTY_SOURCE_DETECTED) {
 545             if (new_int != old_int) {
 546                 device_set_error(p_self, vstrallocf(_(
 547                            "Value for property '%s' was autodetected and cannot be changed"),
 548                            base->name),
 549                     DEVICE_STATUS_DEVICE_ERROR);
 550                 return FALSE;
 551             } else {
 552                 /* pretend we set it, but don't change surety/source */
 553                 return TRUE;
 554             }
 555         }
 556     }
 557
 558     self->final_filemarks = new_int;
 559
 560     return device_simple_property_set_fn(p_self, base, val, surety, source);
 561 }
 562
 563 static gboolean
 564 tape_device_set_compression_fn(Device *p_self, DevicePropertyBase *base,
 565     GValue *val, PropertySurety surety, PropertySource source)
 566 {
 567     TapeDevice *self = TAPE_DEVICE(p_self);
 568     gboolean request = g_value_get_boolean(val);
 569
 570     /* We allow this property to be set at any time. This is mostly
 571      * because setting compression is a hit-and-miss proposition
 572      * at any time; some drives accept the mode setting but don't
 573      * actually support compression, while others do support
 574      * compression but do it via density settings or some other
 575      * way. Set this property whenever you want, but all we'll do
 576      * is report whether or not the ioctl succeeded. */
 577     if (tape_setcompression(self->fd, request)) {
 578         /* looks good .. let's start the device over, though */
 579         device_clear_volume_details(p_self);
 580     } else {
 581         return FALSE;
 582     }
 583
 584     return device_simple_property_set_fn(p_self, base, val, surety, source);
 585 }
 586
 587 static gboolean
 588 tape_device_get_read_block_size_fn(Device *p_self, DevicePropertyBase *base G_GNUC_UNUSED,
 589     GValue *val, PropertySurety *surety, PropertySource *source)
 590 {
 591     /* use the READ_BLOCK_SIZE, even if we're invoked to get the old READ_BUFFER_SIZE */
 592     return device_simple_property_get_fn(p_self, &device_property_read_block_size,
 593                                         val, surety, source);
 594 }
 595
 596 static gboolean
 597 tape_device_set_read_block_size_fn(Device *p_self, DevicePropertyBase *base G_GNUC_UNUSED,
 598     GValue *val, PropertySurety surety, PropertySource source)
 599 {
 600     TapeDevice *self = TAPE_DEVICE(p_self);
 601     guint read_block_size = g_value_get_uint(val);
 602
 603     if (read_block_size != 0 &&
 604             ((gsize)read_block_size < p_self->block_size ||
 605              (gsize)read_block_size > p_self->max_block_size))
 606         return FALSE;
 607
 608     self->private->read_block_size = read_block_size;
 609
 610     /* use the READ_BLOCK_SIZE, even if we're invoked to get the old READ_BUFFER_SIZE */
 611     return device_simple_property_set_fn(p_self, &device_property_read_block_size,
 612                                         val, surety, source);
 613 }
 614
 615 void tape_device_register(void) {
 616     static const char * device_prefix_list[] = { "tape", NULL };
 617
 618     /* First register tape-specific properties */
 619     device_property_fill_and_register(&device_property_broken_gmt_online,
 620                                       G_TYPE_BOOLEAN, "broken_gmt_online",
 621       "Does this drive support the GMT_ONLINE macro?");
 622
 623     device_property_fill_and_register(&device_property_fsf,
 624                                       G_TYPE_BOOLEAN, "fsf",
 625       "Does this drive support the MTFSF command?");
 626
 627     device_property_fill_and_register(&device_property_fsf_after_filemark,
 628                                       G_TYPE_BOOLEAN, "fsf_after_filemark",
 629       "Does this drive needs a FSF if a filemark is already read?");
 630
 631     device_property_fill_and_register(&device_property_bsf,
 632                                       G_TYPE_BOOLEAN, "bsf",
 633       "Does this drive support the MTBSF command?" );
 634
 635     device_property_fill_and_register(&device_property_fsr,
 636                                       G_TYPE_BOOLEAN, "fsr",
 637       "Does this drive support the MTFSR command?");
 638
 639     device_property_fill_and_register(&device_property_bsr,
 640                                       G_TYPE_BOOLEAN, "bsr",
 641       "Does this drive support the MTBSR command?");
 642
 643     device_property_fill_and_register(&device_property_eom,
 644                                       G_TYPE_BOOLEAN, "eom",
 645       "Does this drive support the MTEOM command?");
 646
 647     device_property_fill_and_register(&device_property_bsf_after_eom,
 648                                       G_TYPE_BOOLEAN,
 649                                       "bsf_after_eom",
 650       "Does this drive require an MTBSF after MTEOM in order to append?" );
 651
 652     device_property_fill_and_register(&device_property_nonblocking_open,
 653                                       G_TYPE_BOOLEAN,
 654                                       "nonblocking_open",
 655       "Does this drive require a open with O_NONBLOCK?" );
 656
 657     device_property_fill_and_register(&device_property_final_filemarks,
 658                                       G_TYPE_UINT, "final_filemarks",
 659       "How many filemarks to write after the last tape file?" );
 660
 661     device_property_fill_and_register(&device_property_read_buffer_size,
 662                                       G_TYPE_UINT, "read_buffer_size",
 663       "(deprecated name for READ_BLOCK_SIZE)");
 664
 665     /* Then the device itself */
 666     register_device(tape_device_factory, device_prefix_list);
 667 }
 668
 669 /* Open the tape device, trying various combinations of O_RDWR and
 670    O_NONBLOCK.  Returns -1 and calls device_set_error for errors
 671    On Linux, with O_NONBLOCK, the kernel just checks the state once,
 672    whereas it checks it every second for ST_BLOCK_SECONDS if O_NONBLOCK is
 673    not given.  Amanda already have the code to poll, we want open to check
 674    the state only once. */
 675
 676 static int try_open_tape_device(TapeDevice * self, char * device_filename) {
 677     int fd;
 678     int save_errno;
 679     DeviceStatusFlags new_status;
 680
 681 #ifdef O_NONBLOCK
 682     int nonblocking = 0;
 683
 684     if (self->nonblocking_open) {
 685         nonblocking = O_NONBLOCK;
 686     }
 687 #endif
 688
 689 #ifdef O_NONBLOCK
 690     fd  = robust_open(device_filename, O_RDWR | nonblocking, 0);
 691     save_errno = errno;
 692     if (fd < 0 && nonblocking && (save_errno == EWOULDBLOCK || save_errno == EINVAL)) {
 693         /* Maybe we don't support O_NONBLOCK for tape devices. */
 694         fd = robust_open(device_filename, O_RDWR, 0);
 695         save_errno = errno;
 696     }
 697 #else
 698     fd = robust_open(device_filename, O_RDWR, 0);
 699     save_errno = errno;
 700 #endif
 701     if (fd >= 0) {
 702         self->write_open_errno = 0;
 703     } else {
 704         if (errno == EACCES || errno == EPERM
 705 #ifdef EROFS
 706                             || errno == EROFS
 707 #endif
 708            ) {
 709             /* Device is write-protected. */
 710             self->write_open_errno = errno;
 711 #ifdef O_NONBLOCK
 712             fd = robust_open(device_filename, O_RDONLY | nonblocking, 0);
 713             save_errno = errno;
 714             if (fd < 0 && nonblocking && (save_errno == EWOULDBLOCK || save_errno == EINVAL)) {
 715                 fd = robust_open(device_filename, O_RDONLY, 0);
 716                 save_errno = errno;
 717             }
 718 #else
 719             fd = robust_open(device_filename, O_RDONLY, 0);
 720             save_errno = errno;
 721 #endif
 722         }
 723     }
 724 #ifdef O_NONBLOCK
 725     /* Clear O_NONBLOCK for operations from now on. */
 726     if (fd >= 0 && nonblocking)
 727         fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) & ~O_NONBLOCK);
 728     errno = save_errno;
 729     /* function continues after #endif */
 730
 731 #endif /* O_NONBLOCK */
 732
 733     if (fd < 0) {
 734         DeviceStatusFlags status_flag = 0;
 735         if (errno == EBUSY)
 736             status_flag = DEVICE_STATUS_DEVICE_BUSY;
 737         else
 738             status_flag = DEVICE_STATUS_DEVICE_ERROR;
 739         device_set_error(DEVICE(self),
 740             vstrallocf(_("Can't open tape device %s: %s"), self->private->device_filename, strerror(errno)),
 741             status_flag);
 742         return -1;
 743     }
 744
 745     /* Check that this is actually a tape device. */
 746     new_status = tape_is_tape_device(fd);
 747     if (new_status & DEVICE_STATUS_DEVICE_ERROR) {
 748         device_set_error(DEVICE(self),
 749             vstrallocf(_("File %s is not a tape device"), self->private->device_filename),
 750             new_status);
 751         robust_close(fd);
 752         return -1;
 753     }
 754     if (new_status & DEVICE_STATUS_VOLUME_MISSING) {
 755         device_set_error(DEVICE(self),
 756             vstrallocf(_("Tape device %s is not ready or is empty"), self->private->device_filename),
 757             new_status);
 758         robust_close(fd);
 759         return -1;
 760     }
 761
 762     new_status = tape_is_ready(fd, self);
 763     if (new_status & DEVICE_STATUS_VOLUME_MISSING) {
 764         device_set_error(DEVICE(self),
 765             vstrallocf(_("Tape device %s is empty"), self->private->device_filename),
 766             new_status);
 767         robust_close(fd);
 768         return -1;
 769     }
 770     if (new_status != DEVICE_STATUS_SUCCESS) {
 771         device_set_error(DEVICE(self),
 772             vstrallocf(_("Tape device %s is not ready or is empty"), self->private->device_filename),
 773             new_status);
 774         robust_close(fd);
 775         return -1;
 776     }
 777
 778     return fd;
 779 }
 780
 781 static void
 782 tape_device_open_device (Device * dself, char * device_name,
 783                         char * device_type, char * device_node) {
 784     TapeDevice * self;
 785     GValue val;
 786
 787     self = TAPE_DEVICE(dself);
 788
 789     self->fd = -1;
 790     self->private->device_filename = stralloc(device_node);
 791
 792     /* Set tape drive/OS info */
 793     bzero(&val, sizeof(val));
 794     g_value_init(&val, G_TYPE_BOOLEAN);
 795
 796     self->fsf = TRUE;
 797     g_value_set_boolean(&val, self->fsf);
 798     device_set_simple_property(dself, PROPERTY_FSF, &val, PROPERTY_SURETY_BAD, PROPERTY_SOURCE_DEFAULT);
 799
 800     self->fsf_after_filemark = DEFAULT_FSF_AFTER_FILEMARK;
 801     g_value_set_boolean(&val, self->fsf_after_filemark);
 802     device_set_simple_property(dself, PROPERTY_FSF_AFTER_FILEMARK, &val, PROPERTY_SURETY_BAD, PROPERTY_SOURCE_DEFAULT);
 803
 804     self->bsf = TRUE;
 805     g_value_set_boolean(&val, self->bsf);
 806     device_set_simple_property(dself, PROPERTY_BSF, &val, PROPERTY_SURETY_BAD, PROPERTY_SOURCE_DEFAULT);
 807
 808     self->fsr = TRUE;
 809     g_value_set_boolean(&val, self->fsr);
 810     device_set_simple_property(dself, PROPERTY_FSR, &val, PROPERTY_SURETY_BAD, PROPERTY_SOURCE_DEFAULT);
 811
 812     self->bsr = TRUE;
 813     g_value_set_boolean(&val, self->bsr);
 814     device_set_simple_property(dself, PROPERTY_BSR, &val, PROPERTY_SURETY_BAD, PROPERTY_SOURCE_DEFAULT);
 815
 816     self->eom = TRUE;
 817     g_value_set_boolean(&val, self->eom);
 818     device_set_simple_property(dself, PROPERTY_EOM, &val, PROPERTY_SURETY_BAD, PROPERTY_SOURCE_DEFAULT);
 819
 820     self->leom = FALSE;
 821     g_value_set_boolean(&val, self->leom);
 822     device_set_simple_property(dself, PROPERTY_LEOM, &val, PROPERTY_SURETY_BAD, PROPERTY_SOURCE_DEFAULT);
 823
 824     self->bsf_after_eom = FALSE;
 825     g_value_set_boolean(&val, self->bsf_after_eom);
 826     device_set_simple_property(dself, PROPERTY_BSF_AFTER_EOM, &val, PROPERTY_SURETY_BAD, PROPERTY_SOURCE_DEFAULT);
 827
 828     g_value_unset(&val);
 829     g_value_init(&val, G_TYPE_UINT);
 830
 831     self->final_filemarks = 2;
 832     g_value_set_uint(&val, self->final_filemarks);
 833     device_set_simple_property(dself, PROPERTY_FINAL_FILEMARKS, &val, PROPERTY_SURETY_BAD, PROPERTY_SOURCE_DEFAULT);
 834
 835     g_value_unset(&val);
 836
 837     /* Chain up */
 838     if (parent_class->open_device) {
 839         parent_class->open_device(dself, device_name, device_type, device_node);
 840     }
 841 }
 842
 843
 844 static DeviceStatusFlags tape_device_read_label(Device * dself) {
 845     TapeDevice * self;
 846     char * header_buffer;
 847     int buffer_len;
 848     IoResult result;
 849     dumpfile_t *header;
 850     DeviceStatusFlags new_status;
 851     char *msg = NULL;
 852
 853     self = TAPE_DEVICE(dself);
 854
 855     amfree(dself->volume_label);
 856     amfree(dself->volume_time);
 857     dumpfile_free(dself->volume_header);
 858     dself->volume_header = NULL;
 859
 860     if (device_in_error(self)) return dself->status;
 861
 862     if (self->fd == -1) {
 863         self->fd = try_open_tape_device(self, self->private->device_filename);
 864         /* if the open failed, then try_open_tape_device already set the
 865          * approppriate error status */
 866         if (self->fd == -1)
 867             return dself->status;
 868     }
 869
 870     /* Rewind it. */
 871     if (!tape_rewind(self->fd)) {
 872         device_set_error(dself,
 873             vstrallocf(_("Error rewinding device %s to read label: %s"),
 874                     self->private->device_filename, strerror(errno)),
 875               DEVICE_STATUS_DEVICE_ERROR
 876             | DEVICE_STATUS_VOLUME_ERROR);
 877         return dself->status;
 878     }
 879
 880     buffer_len = tape_device_read_size(self);
 881     header_buffer = malloc(buffer_len);
 882     result = tape_device_robust_read(self, header_buffer, &buffer_len, &msg);
 883
 884     if (result != RESULT_SUCCESS) {
 885         free(header_buffer);
 886         tape_rewind(self->fd);
 887         /* I/O error. */
 888         switch (result) {
 889         case RESULT_NO_DATA:
 890             msg = stralloc(_("no data"));
 891             new_status = (DEVICE_STATUS_VOLUME_ERROR |
 892                           DEVICE_STATUS_VOLUME_UNLABELED);
 893             header = dself->volume_header = g_new(dumpfile_t, 1);
 894             fh_init(header);
 895             break;
 896
 897         case RESULT_SMALL_BUFFER:
 898             msg = stralloc(_("block size too small"));
 899             new_status = (DEVICE_STATUS_DEVICE_ERROR |
 900                           DEVICE_STATUS_VOLUME_ERROR);
 901             header = dself->volume_header = g_new(dumpfile_t, 1);
 902             fh_init(header);
 903             header->type = F_WEIRD;
 904             break;
 905
 906         default:
 907             msg = stralloc(_("unknown error"));
 908         case RESULT_ERROR:
 909             new_status = (DEVICE_STATUS_DEVICE_ERROR |
 910                           DEVICE_STATUS_VOLUME_ERROR |
 911                           DEVICE_STATUS_VOLUME_UNLABELED);
 912             break;
 913         }
 914         device_set_error(dself,
 915                  g_strdup_printf(_("Error reading Amanda header: %s"),
 916                         msg? msg : _("unknown error")),
 917                  new_status);
 918         amfree(msg);
 919         return dself->status;
 920     }
 921
 922     header = dself->volume_header = g_new(dumpfile_t, 1);
 923     fh_init(header);
 924
 925     parse_file_header(header_buffer, header, buffer_len);
 926     amfree(header_buffer);
 927     if (header->type != F_TAPESTART) {
 928         device_set_error(dself,
 929                 stralloc(_("No tapestart header -- unlabeled device?")),
 930                 DEVICE_STATUS_VOLUME_UNLABELED);
 931         return dself->status;
 932     }
 933
 934     dself->volume_label = g_strdup(header->name);
 935     dself->volume_time = g_strdup(header->datestamp);
 936     /* dself->volume_header is already set */
 937
 938     device_set_error(dself, NULL, DEVICE_STATUS_SUCCESS);
 939
 940     return dself->status;
 941 }
 942
 943 static gboolean
 944 tape_device_write_block(Device * pself, guint size, gpointer data) {
 945     TapeDevice * self;
 946     char *replacement_buffer = NULL;
 947     IoResult result;
 948     char *msg = NULL;
 949
 950     self = TAPE_DEVICE(pself);
 951
 952     g_assert(self->fd >= 0);
 953     if (device_in_error(self)) return FALSE;
 954
 955     /* zero out to the end of a short block -- tape devices only write
 956      * whole blocks. */
 957     if (size < pself->block_size) {
 958         replacement_buffer = malloc(pself->block_size);
 959         memcpy(replacement_buffer, data, size);
 960         bzero(replacement_buffer+size, pself->block_size-size);
 961
 962         data = replacement_buffer;
 963         size = pself->block_size;
 964     }
 965
 966     result = tape_device_robust_write(self, data, size, &msg);
 967     amfree(replacement_buffer);
 968
 969     switch (result) {
 970         case RESULT_SUCCESS:
 971             break;
 972
 973         case RESULT_NO_SPACE:
 974             device_set_error(pself,
 975                 stralloc(_("No space left on device")),
 976                 DEVICE_STATUS_VOLUME_ERROR);
 977             pself->is_eom = TRUE;
 978             return FALSE;
 979
 980         default:
 981             msg = stralloc(_("unknown error"));
 982         case RESULT_ERROR:
 983             device_set_error(pself,
 984                 g_strdup_printf(_("Error writing block: %s"), msg),
 985                 DEVICE_STATUS_DEVICE_ERROR);
 986             amfree(msg);
 987             return FALSE;
 988     }
 989
 990     pself->block++;
 991
 992     return TRUE;
 993 }
 994
 995 static int tape_device_read_block (Device * pself, gpointer buf,
 996                                    int * size_req) {
 997     TapeDevice * self;
 998     int size;
 999     IoResult result;
1000     gssize read_block_size = tape_device_read_size(pself);
1001     char *msg = NULL;
1002
1003     self = TAPE_DEVICE(pself);
1004
1005     g_assert(self->fd >= 0);
1006     if (device_in_error(self)) return -1;
1007
1008     g_assert(read_block_size < INT_MAX); /* data type mismatch */
1009     if (buf == NULL || *size_req < (int)read_block_size) {
1010         /* Just a size query. */
1011         *size_req = (int)read_block_size;
1012         return 0;
1013     }
1014
1015     size = *size_req;
1016     result = tape_device_robust_read(self, buf, &size, &msg);
1017     switch (result) {
1018     case RESULT_SUCCESS:
1019         *size_req = size;
1020         pself->block++;
1021         return size;
1022     case RESULT_SMALL_BUFFER: {
1023         gsize new_size;
1024         GValue newval;
1025
1026         /* If this happens, it means that we have:
1027          *     (next block size) > (buffer size) >= (read_block_size)
1028          * The solution is to ask for an even bigger buffer. We also play
1029          * some games to refrain from reading above the SCSI limit or from
1030          * integer overflow.  Note that not all devices will tell us about
1031          * this problem -- some will just discard the "extra" data. */
1032         new_size = MIN(INT_MAX/2 - 1, *size_req) * 2;
1033         if (new_size > LARGEST_BLOCK_ESTIMATE &&
1034             *size_req < LARGEST_BLOCK_ESTIMATE) {
1035             new_size = LARGEST_BLOCK_ESTIMATE;
1036         }
1037         g_assert (new_size > (gsize)*size_req);
1038
1039         g_info("Device %s indicated blocksize %zd was too small; using %zd.",
1040             pself->device_name, (gsize)*size_req, new_size);
1041         *size_req = (int)new_size;
1042         self->private->read_block_size = new_size;
1043
1044         bzero(&newval, sizeof(newval));
1045         g_value_init(&newval, G_TYPE_UINT);
1046         g_value_set_uint(&newval, self->private->read_block_size);
1047         device_set_simple_property(pself, PROPERTY_READ_BLOCK_SIZE,
1048                 &newval, PROPERTY_SURETY_GOOD, PROPERTY_SOURCE_DETECTED);
1049         g_value_unset(&newval);
1050
1051         return 0;
1052     }
1053     case RESULT_NO_DATA:
1054         pself->is_eof = TRUE;
1055         pself->in_file = FALSE;
1056         device_set_error(pself,
1057             stralloc(_("EOF")),
1058             DEVICE_STATUS_SUCCESS);
1059         return -1;
1060
1061     default:
1062         msg = stralloc(_("unknown error"));
1063     case RESULT_ERROR:
1064         device_set_error(pself,
1065             vstrallocf(_("Error reading from tape device: %s"), msg),
1066             DEVICE_STATUS_VOLUME_ERROR | DEVICE_STATUS_DEVICE_ERROR);
1067         amfree(msg);
1068         return -1;
1069     }
1070
1071     g_assert_not_reached();
1072 }
1073
1074 /* Just a helper function for tape_device_start(). */
1075 static gboolean write_tapestart_header(TapeDevice * self, char * label,
1076                                        char * timestamp) {
1077      IoResult result;
1078      dumpfile_t * header;
1079      char * header_buf;
1080      Device * d_self = (Device*)self;
1081      char *msg = NULL;
1082
1083      tape_rewind(self->fd);
1084
1085      header = make_tapestart_header(d_self, label, timestamp);
1086      g_assert(header != NULL);
1087      header_buf = device_build_amanda_header(d_self, header, NULL);
1088      if (header_buf == NULL) {
1089          device_set_error(d_self,
1090             stralloc(_("Tapestart header won't fit in a single block!")),
1091             DEVICE_STATUS_DEVICE_ERROR);
1092          dumpfile_free(header);
1093          return FALSE;
1094      }
1095      dumpfile_free(d_self->volume_header);
1096      d_self->volume_header = NULL;
1097
1098      result = tape_device_robust_write(self, header_buf, d_self->block_size, &msg);
1099      if (result != RESULT_SUCCESS) {
1100         device_set_error(d_self,
1101             g_strdup_printf(_("Error writing tapestart header: %s"),
1102                         (result == RESULT_ERROR)? msg : _("out of space")),
1103             DEVICE_STATUS_DEVICE_ERROR);
1104
1105         if (result == RESULT_NO_SPACE)
1106             d_self->is_eom = TRUE;
1107
1108         amfree(msg);
1109         dumpfile_free(header);
1110         amfree(header_buf);
1111         return FALSE;
1112      }
1113
1114      amfree(header_buf);
1115
1116      if (!tape_weof(self->fd, 1)) {
1117         device_set_error(d_self,
1118                          vstrallocf(_("Error writing filemark: %s"),
1119                                     strerror(errno)),
1120                          DEVICE_STATUS_DEVICE_ERROR|DEVICE_STATUS_VOLUME_ERROR);
1121         /* can't tell if this was EOM or not, so assume it is */
1122         d_self->is_eom = TRUE;
1123         dumpfile_free(header);
1124         return FALSE;
1125      }
1126
1127      d_self->volume_header = header;
1128      return TRUE;
1129 }
1130
1131 static gboolean
1132 tape_device_start (Device * d_self, DeviceAccessMode mode, char * label,
1133                    char * timestamp) {
1134     TapeDevice * self;
1135
1136     self = TAPE_DEVICE(d_self);
1137
1138     if (device_in_error(self)) return FALSE;
1139
1140     if (self->fd == -1) {
1141         self->fd = try_open_tape_device(self, self->private->device_filename);
1142         /* if the open failed, then try_open_tape_device already set the
1143          * approppriate error status */
1144         if (self->fd == -1)
1145             return FALSE;
1146     }
1147
1148     if (mode != ACCESS_WRITE && d_self->volume_label == NULL) {
1149         /* we need a labeled volume for APPEND and READ */
1150         if (tape_device_read_label(d_self) != DEVICE_STATUS_SUCCESS)
1151             return FALSE;
1152     }
1153
1154     d_self->access_mode = mode;
1155     d_self->in_file = FALSE;
1156
1157     if (IS_WRITABLE_ACCESS_MODE(mode)) {
1158         if (self->write_open_errno != 0) {
1159             /* We tried and failed to open the device in write mode. */
1160             device_set_error(d_self,
1161                 vstrallocf(_("Can't open tape device %s for writing: %s"),
1162                             self->private->device_filename, strerror(self->write_open_errno)),
1163                 DEVICE_STATUS_DEVICE_ERROR | DEVICE_STATUS_VOLUME_ERROR);
1164             return FALSE;
1165         } else if (!tape_rewind(self->fd)) {
1166             device_set_error(d_self,
1167                 vstrallocf(_("Error rewinding device to start: %s"), strerror(errno)),
1168                 DEVICE_STATUS_DEVICE_ERROR);
1169             return FALSE;
1170         }
1171     }
1172
1173     /* Position the tape */
1174     switch (mode) {
1175     case ACCESS_APPEND:
1176         if (d_self->volume_label == NULL && device_read_label(d_self) != DEVICE_STATUS_SUCCESS) {
1177             /* device_read_label already set our error message */
1178             return FALSE;
1179         }
1180
1181         if (!tape_device_eod(self)) {
1182             device_set_error(d_self,
1183                 vstrallocf(_("Couldn't seek to end of tape: %s"), strerror(errno)),
1184                 DEVICE_STATUS_DEVICE_ERROR);
1185             return FALSE;
1186         }
1187         break;
1188
1189     case ACCESS_READ:
1190         if (d_self->volume_label == NULL && device_read_label(d_self) != DEVICE_STATUS_SUCCESS) {
1191             /* device_read_label already set our error message */
1192             return FALSE;
1193         }
1194
1195         if (!tape_rewind(self->fd)) {
1196             device_set_error(d_self,
1197                 vstrallocf(_("Error rewinding device after reading label: %s"), strerror(errno)),
1198                 DEVICE_STATUS_DEVICE_ERROR);
1199             return FALSE;
1200         }
1201         d_self->file = 0;
1202         break;
1203
1204     case ACCESS_WRITE:
1205         if (!write_tapestart_header(self, label, timestamp)) {
1206             /* write_tapestart_header already set the error status */
1207             return FALSE;
1208         }
1209
1210         d_self->volume_label = newstralloc(d_self->volume_label, label);
1211         d_self->volume_time = newstralloc(d_self->volume_time, timestamp);
1212
1213         /* unset the VOLUME_UNLABELED flag, if it was set */
1214         device_set_error(d_self, NULL, DEVICE_STATUS_SUCCESS);
1215         d_self->file = 0;
1216         break;
1217
1218     default:
1219         g_assert_not_reached();
1220     }
1221
1222     return TRUE;
1223 }
1224
1225 static gboolean tape_device_start_file(Device * d_self,
1226                                        dumpfile_t * info) {
1227     TapeDevice * self;
1228     IoResult result;
1229     char * amanda_header;
1230     char *msg = NULL;
1231
1232     self = TAPE_DEVICE(d_self);
1233
1234     g_assert(self->fd >= 0);
1235     if (device_in_error(self)) return FALSE;
1236
1237     /* set the blocksize in the header properly */
1238     info->blocksize = d_self->block_size;
1239
1240     /* Make the Amanda header suitable for writing to the device. */
1241     /* Then write the damn thing. */
1242     amanda_header = device_build_amanda_header(d_self, info, NULL);
1243     if (amanda_header == NULL) {
1244         device_set_error(d_self,
1245             stralloc(_("Amanda file header won't fit in a single block!")),
1246             DEVICE_STATUS_DEVICE_ERROR);
1247         return FALSE;
1248     }
1249
1250     result = tape_device_robust_write(self, amanda_header, d_self->block_size, &msg);
1251     if (result != RESULT_SUCCESS) {
1252         device_set_error(d_self,
1253             vstrallocf(_("Error writing file header: %s"),
1254                         (result == RESULT_ERROR)? msg : _("out of space")),
1255             DEVICE_STATUS_DEVICE_ERROR);
1256
1257         if (result == RESULT_NO_SPACE)
1258             d_self->is_eom = TRUE;
1259
1260         amfree(amanda_header);
1261         amfree(msg);
1262         return FALSE;
1263     }
1264     amfree(amanda_header);
1265
1266     /* arrange the file numbers correctly */
1267     d_self->in_file = TRUE;
1268     d_self->block = 0;
1269     if (d_self->file >= 0)
1270         d_self->file ++;
1271     return TRUE;
1272 }
1273
1274 static gboolean
1275 tape_device_finish_file (Device * d_self) {
1276     TapeDevice * self;
1277
1278     self = TAPE_DEVICE(d_self);
1279     if (device_in_error(d_self)) return FALSE;
1280
1281     if (!tape_weof(self->fd, 1)) {
1282         device_set_error(d_self,
1283                 vstrallocf(_("Error writing filemark: %s"), strerror(errno)),
1284                 DEVICE_STATUS_DEVICE_ERROR | DEVICE_STATUS_VOLUME_ERROR);
1285         /* can't tell if this was EOM or not, so assume it is */
1286         d_self->is_eom = TRUE;
1287         return FALSE;
1288     }
1289
1290     d_self->in_file = FALSE;
1291     return TRUE;
1292 }
1293
1294 static dumpfile_t *
1295 tape_device_seek_file (Device * d_self, guint file) {
1296     TapeDevice * self;
1297     gint got_file;
1298     int difference;
1299     char * header_buffer;
1300     dumpfile_t * rval;
1301     int buffer_len;
1302     IoResult result;
1303     char *msg;
1304
1305     self = TAPE_DEVICE(d_self);
1306
1307     if (device_in_error(self)) return NULL;
1308
1309     difference = file - d_self->file;
1310
1311     /* Check if we already read a filemark. */
1312     /* If we already read a filemark and the drive automaticaly goes to the
1313        next file, then we must reduce the difference by one. */
1314     if (d_self->is_eof && !self->fsf_after_filemark) {
1315         difference --;
1316     }
1317
1318     d_self->in_file = FALSE;
1319     d_self->is_eof = FALSE;
1320     d_self->block = 0;
1321
1322 reseek:
1323     if (difference > 0) {
1324         /* Seeking forwards */
1325         if (!tape_device_fsf(self, difference)) {
1326             tape_rewind(self->fd);
1327             device_set_error(d_self,
1328                 vstrallocf(_("Could not seek forward to file %d"), file),
1329                 DEVICE_STATUS_VOLUME_ERROR | DEVICE_STATUS_DEVICE_ERROR);
1330             return NULL;
1331         }
1332     } else { /* (difference <= 0) */
1333         /* Seeking backwards, or to this file itself */
1334
1335         /* if the drive supports bsf, we can do this the fancy way */
1336         if (self->bsf) {
1337             /* bsf one more than the difference */
1338             if (!tape_bsf(self->fd, -difference + 1)) {
1339                 tape_rewind(self->fd);
1340                 device_set_error(d_self,
1341                     vstrallocf(_("Could not seek backward to file %d"), file),
1342                     DEVICE_STATUS_VOLUME_ERROR | DEVICE_STATUS_DEVICE_ERROR);
1343                 return NULL;
1344             }
1345
1346             /* now we are on the BOT side of the desired filemark, so FSF to get to the
1347              * EOT side of it */
1348             if (!tape_device_fsf(self, 1)) {
1349                 tape_rewind(self->fd);
1350                 device_set_error(d_self,
1351                     vstrallocf(_("Could not seek forward to file %d"), file),
1352                     DEVICE_STATUS_VOLUME_ERROR | DEVICE_STATUS_DEVICE_ERROR);
1353                 return NULL;
1354             }
1355         } else {
1356             /* no BSF, so just rewind and seek forward */
1357             if (!tape_rewind(self->fd)) {
1358                 device_set_error(d_self,
1359                     vstrallocf(_("Could not rewind device while emulating BSF")),
1360                     DEVICE_STATUS_VOLUME_ERROR | DEVICE_STATUS_DEVICE_ERROR);
1361                 return FALSE;
1362             }
1363
1364             if (!tape_device_fsf(self, file)) {
1365                 tape_rewind(self->fd);
1366                 device_set_error(d_self,
1367                     vstrallocf(_("Could not seek forward to file %d"), file),
1368                     DEVICE_STATUS_VOLUME_ERROR | DEVICE_STATUS_DEVICE_ERROR);
1369                 return NULL;
1370             }
1371         }
1372     }
1373
1374     /* double-check that we're on the right fileno, if possible.  This is most
1375      * likely a programming error if it occurs, but could also be due to a weird
1376      * tape drive or driver (and that would *never* happen, right?) */
1377     got_file = tape_fileno(self->fd);
1378     if (got_file >= 0 && (guint)got_file != file) {
1379         device_set_error(d_self,
1380                 vstrallocf(_("Could not seek to file %d correctly; got %d"),
1381                             file, got_file),
1382                 DEVICE_STATUS_DEVICE_ERROR);
1383         d_self->file = (guint)got_file;
1384         return NULL;
1385     }
1386
1387     buffer_len = tape_device_read_size(d_self);
1388     header_buffer = malloc(buffer_len);
1389     d_self->is_eof = FALSE;
1390     result = tape_device_robust_read(self, header_buffer, &buffer_len, &msg);
1391
1392     if (result != RESULT_SUCCESS) {
1393         free(header_buffer);
1394         tape_rewind(self->fd);
1395         switch (result) {
1396         case RESULT_NO_DATA:
1397             /* If we read 0 bytes, that means we encountered a double
1398              * filemark, which indicates end of tape. This should
1399              * work even with QIC tapes on operating systems with
1400              * proper support. */
1401             d_self->file = file; /* other attributes are already correct */
1402             return make_tapeend_header();
1403
1404         case RESULT_SMALL_BUFFER:
1405             msg = stralloc(_("block size too small"));
1406             break;
1407
1408         default:
1409             msg = stralloc(_("unknown error"));
1410         case RESULT_ERROR:
1411             break;
1412         }
1413         device_set_error(d_self,
1414             g_strdup_printf(_("Error reading Amanda header: %s"), msg),
1415             DEVICE_STATUS_DEVICE_ERROR | DEVICE_STATUS_VOLUME_ERROR);
1416         amfree(msg);
1417         return NULL;
1418     }
1419
1420     rval = g_new(dumpfile_t, 1);
1421     parse_file_header(header_buffer, rval, buffer_len);
1422     amfree(header_buffer);
1423     switch (rval->type) {
1424     case F_DUMPFILE:
1425     case F_CONT_DUMPFILE:
1426     case F_SPLIT_DUMPFILE:
1427         break;
1428
1429     case F_NOOP:
1430         /* a NOOP is written on QIC tapes to avoid writing two sequential
1431          * filemarks when closing a device in WRITE or APPEND mode.  In this
1432          * case, we just seek to the next file. */
1433         amfree(rval);
1434         file++;
1435         difference = 1;
1436         goto reseek;
1437
1438     default:
1439         tape_rewind(self->fd);
1440         device_set_error(d_self,
1441             stralloc(_("Invalid amanda header while reading file header")),
1442             DEVICE_STATUS_VOLUME_ERROR);
1443         amfree(rval);
1444         return NULL;
1445     }
1446
1447     d_self->in_file = TRUE;
1448     d_self->file = file;
1449
1450     return rval;
1451 }
1452
1453 static gboolean
1454 tape_device_seek_block (Device * d_self, guint64 block) {
1455     TapeDevice * self;
1456     int difference;
1457
1458     self = TAPE_DEVICE(d_self);
1459
1460     if (device_in_error(self)) return FALSE;
1461
1462     difference = block - d_self->block;
1463
1464     if (difference > 0) {
1465         if (!tape_device_fsr(self, difference)) {
1466             device_set_error(d_self,
1467                 vstrallocf(_("Could not seek forward to block %ju: %s"), (uintmax_t)block, strerror(errno)),
1468                 DEVICE_STATUS_VOLUME_ERROR | DEVICE_STATUS_DEVICE_ERROR);
1469             return FALSE;
1470         }
1471     } else if (difference < 0) {
1472         if (!tape_device_bsr(self, difference, d_self->file, d_self->block)) {
1473             device_set_error(d_self,
1474                 vstrallocf(_("Could not seek backward to block %ju: %s"), (uintmax_t)block, strerror(errno)),
1475                 DEVICE_STATUS_VOLUME_ERROR | DEVICE_STATUS_DEVICE_ERROR);
1476             return FALSE;
1477         }
1478     }
1479
1480     d_self->block = block;
1481     return TRUE;
1482 }
1483
1484 static gboolean
1485 tape_device_eject (Device * d_self) {
1486     TapeDevice * self;
1487
1488     self = TAPE_DEVICE(d_self);
1489
1490     if (device_in_error(self)) return FALSE;
1491
1492     /* Open the device if not already opened */
1493     if (self->fd == -1) {
1494         self->fd = try_open_tape_device(self, self->private->device_filename);
1495         /* if the open failed, then try_open_tape_device already set the
1496          * approppriate error status */
1497         if (self->fd == -1)
1498             return FALSE;
1499     }
1500
1501     /* Rewind it. */
1502     if (!tape_rewind(self->fd)) {
1503         device_set_error(d_self,
1504             vstrallocf(_("Error rewinding device %s before ejecting: %s"),
1505                        self->private->device_filename, strerror(errno)),
1506               DEVICE_STATUS_DEVICE_ERROR
1507             | DEVICE_STATUS_VOLUME_ERROR);
1508         return FALSE;
1509     }
1510
1511     if (tape_offl(self->fd))
1512         return TRUE;
1513
1514     device_set_error(d_self,
1515         vstrallocf(_("Error ejecting device %s: %s\n"),
1516                    self->private->device_filename, strerror(errno)),
1517           DEVICE_STATUS_DEVICE_ERROR);
1518
1519     return FALSE;
1520 }
1521
1522 static gboolean
1523 tape_device_finish (Device * d_self) {
1524     TapeDevice * self;
1525     char *msg = NULL;
1526
1527     self = TAPE_DEVICE(d_self);
1528
1529     if (device_in_error(self))
1530         goto finish_error;
1531
1532     /* if we're already in ACCESS_NULL, then there are no filemarks or anything
1533      * to worry about, but we need to release the kernel device */
1534     if (d_self->access_mode == ACCESS_NULL) {
1535         robust_close(self->fd);
1536         self->fd = -1;
1537         return TRUE;
1538     }
1539
1540     /* Polish off this file, if relevant. */
1541     if (d_self->in_file && IS_WRITABLE_ACCESS_MODE(d_self->access_mode)) {
1542         if (!device_finish_file(d_self))
1543             goto finish_error;
1544     }
1545
1546     /* Straighten out the filemarks.  We already wrote one in finish_file, and
1547      * the device driver will write another filemark when we rewind.  This means
1548      * that, if we do nothing, we'll get two filemarks.  If final_filemarks is
1549      * 1, this would be wrong, so in this case we insert a F_NOOP header between
1550      * the two filemarks. */
1551     if (self->final_filemarks == 1 &&
1552         IS_WRITABLE_ACCESS_MODE(d_self->access_mode)) {
1553         dumpfile_t file;
1554         char *header;
1555         int result;
1556
1557         /* write a F_NOOP header */
1558         fh_init(&file);
1559         file.type = F_NOOP;
1560         header = device_build_amanda_header(d_self, &file, NULL);
1561         if (!header) {
1562             device_set_error(d_self,
1563                 stralloc(_("Amanda file header won't fit in a single block!")),
1564                 DEVICE_STATUS_DEVICE_ERROR);
1565             goto finish_error;
1566         }
1567
1568         result = tape_device_robust_write(self, header, d_self->block_size, &msg);
1569         if (result != RESULT_SUCCESS) {
1570             device_set_error(d_self,
1571                 vstrallocf(_("Error writing file header: %s"),
1572                             (result == RESULT_ERROR)? msg : _("out of space")),
1573                 DEVICE_STATUS_DEVICE_ERROR);
1574             amfree(header);
1575             amfree(msg);
1576             goto finish_error;
1577         }
1578         amfree(header);
1579     }
1580
1581     /* Rewind (the kernel will write a filemark first) */
1582     if (!tape_rewind(self->fd)) {
1583         device_set_error(d_self,
1584             vstrallocf(_("Couldn't rewind device to finish: %s"), strerror(errno)),
1585             DEVICE_STATUS_DEVICE_ERROR);
1586         goto finish_error;
1587     }
1588
1589     d_self->is_eof = FALSE;
1590     d_self->access_mode = ACCESS_NULL;
1591
1592     /* release the kernel's device */
1593     robust_close(self->fd);
1594     self->fd = -1;
1595
1596     return TRUE;
1597
1598 finish_error:
1599     d_self->access_mode = ACCESS_NULL;
1600
1601     /* release the kernel's device */
1602     robust_close(self->fd);
1603     self->fd = -1;
1604
1605     return FALSE;
1606 }
1607
1608 /* Works just like read(), except for the following:
1609  * 1) Retries on EINTR & friends.
1610  * 2) Stores count in parameter, not return value.
1611  * 3) Provides explicit return result.
1612  * *errmsg is only set on RESULT_ERROR.
1613  */
1614 static IoResult
1615 tape_device_robust_read (TapeDevice * self, void * buf, int * count, char **errmsg) {
1616     Device * d_self;
1617     int result;
1618
1619     d_self = (Device*)self;
1620
1621     /* Callers should ensure this. */
1622     g_assert(*count >= 0);
1623
1624     for (;;) {
1625         result = read(self->fd, buf, *count);
1626         if (result > 0) {
1627             /* Success. By definition, we read a full block. */
1628             d_self->is_eof = FALSE;
1629             *count = result;
1630             return RESULT_SUCCESS;
1631         } else if (result == 0) {
1632             d_self->is_eof = TRUE;
1633             return RESULT_NO_DATA;
1634         } else {
1635             if (0
1636 #ifdef EAGAIN
1637                 || errno == EAGAIN
1638 #endif
1639 #ifdef EWOULDBLOCK
1640                 || errno == EWOULDBLOCK
1641 #endif
1642 #ifdef EINTR
1643                 || errno == EINTR
1644 #endif
1645                 ) {
1646                 /* Interrupted system call */
1647                 continue;
1648             } else if ((0
1649 #ifdef ENOMEM
1650                         || errno == ENOMEM /* bad user-space buffer */
1651 #endif
1652 #ifdef EOVERFLOW
1653                         || errno == EOVERFLOW /* bad kernel-space buffer */
1654 #endif
1655 #ifdef EINVAL
1656                         || errno == EINVAL /* ??? */
1657 #endif
1658                         )) {
1659                 /* Buffer too small. */
1660                 g_warning("Buffer is too small (%d bytes) from %s: %s",
1661                         *count, self->private->device_filename, strerror(errno));
1662                 return RESULT_SMALL_BUFFER;
1663             } else {
1664                 *errmsg = g_strdup_printf(_("Error reading %d bytes from %s: %s"),
1665                         *count, self->private->device_filename, strerror(errno));
1666                 return RESULT_ERROR;
1667             }
1668         }
1669     }
1670
1671     g_assert_not_reached();
1672 }
1673
1674 /* Kernel workaround: If needed, poke the kernel so it doesn't fail.
1675    at the 2GB boundry. Parameters are G_GNUC_UNUSED in case NEED_RESETOFS
1676    is not defined. */
1677 static void check_resetofs(TapeDevice * self G_GNUC_UNUSED,
1678                            int count G_GNUC_UNUSED) {
1679 #ifdef NEED_RESETOFS
1680     Device * d_self;
1681     int result;
1682
1683     d_self = (Device*)self;
1684
1685     self->private->write_count += count;
1686     if (self->private->write_count < RESETOFS_THRESHOLD) {
1687         return;
1688     }
1689
1690     result = lseek(self->fd, 0, SEEK_SET);
1691     if (result < 0) {
1692         g_warning(_("lseek() failed during kernel 2GB workaround: %s"),
1693                strerror(errno));
1694     }
1695 #endif
1696 }
1697
1698 /* *errmsg is only set on RESULT_ERROR */
1699 static IoResult
1700 tape_device_robust_write (TapeDevice * self, void * buf, int count, char **errmsg) {
1701     Device * d_self;
1702     int result;
1703     gboolean retry = FALSE;
1704
1705     d_self = (Device*)self;
1706
1707     check_resetofs(self, count);
1708
1709     for (;;) {
1710         result = write(self->fd, buf, count);
1711
1712         /* Success. */
1713         if (result == count)
1714             return RESULT_SUCCESS;
1715
1716         if (result > 0) {
1717             /* write() returned a short count. This should not happen if the block sizes
1718              * are properly aligned. */
1719             *errmsg = g_strdup_printf("Short write on tape device: Tried %d, got %d.  Is "
1720                             "the drive using a block size smaller than %d bytes?",
1721                                 count, result, count);
1722             return RESULT_ERROR;
1723         }
1724
1725         /* Detect LEOM (early warning) and handle properly
1726          *
1727          * FreeBSD: 0-length write; next write will succeed
1728          *   http://lists.freebsd.org/pipermail/freebsd-scsi/2010-June/004414.html
1729          *
1730          * Solaris: 0-length write; next write will succeed
1731          *   (from Matthew Jacob on FreeBSD thread)
1732          *
1733          * Linux: -1/ENOSPC; next write will succeed
1734          *   http://www.mjmwired.net/kernel/Documentation/scsi/st.txt
1735          *
1736          * HP/UX: -1/ENOSPC; next write will succeed
1737          *   http://www.adssasia.com/Manual/IBM%203581%20tape%20autoloader.pdf
1738          */
1739         if (result == 0
1740 #ifdef ENOSPC
1741                         || (result < 0 && errno == ENOSPC)
1742 #endif
1743         ) {
1744             /* if we've retried once already, then we're probably really out of space */
1745             if (retry)
1746                 return RESULT_NO_SPACE;
1747             retry = TRUE;
1748             d_self->is_eom = TRUE;
1749
1750             g_debug("empty write to tape; treating as LEOM early warning and retrying");
1751             continue;
1752         }
1753
1754         /* at this point result < 0, so an error occurred - sort out what */
1755
1756         if (0
1757 #ifdef EAGAIN
1758                    || errno == EAGAIN
1759 #endif
1760 #ifdef EWOULDBLOCK
1761                    || errno == EWOULDBLOCK
1762 #endif
1763 #ifdef EINTR
1764                    || errno == EINTR
1765 #endif
1766                    ) {
1767                 /* Interrupted system call */
1768             continue;
1769         } else if (0
1770 #ifdef ENOSPC
1771                    || errno == ENOSPC
1772 #endif
1773 #ifdef EIO
1774                    || errno == EIO
1775 #endif
1776                    ) {
1777             /* Probably EOT. Print a message if we got EIO. */
1778 #ifdef EIO
1779             if (errno == EIO) {
1780                 g_warning(_("Got EIO on %s, assuming end of tape"),
1781                         self->private->device_filename);
1782             }
1783 #endif
1784             return RESULT_NO_SPACE;
1785         } else {
1786             /* WTF */
1787             *errmsg = vstrallocf(_("Kernel gave unexpected write() result of \"%s\" on device %s"),
1788                             strerror(errno), self->private->device_filename);
1789             return RESULT_ERROR;
1790         }
1791     }
1792
1793     g_assert_not_reached();
1794 }
1795
1796 /* Reads some number of tape blocks into the bit-bucket. If the count
1797    is negative, then we read the rest of the entire file. Returns the
1798    number of blocks read, or -1 if an error occured. If we encounter
1799    EOF (as opposed to some other error) we return the number of blocks
1800    actually read. */
1801 static int drain_tape_blocks(TapeDevice * self, int count) {
1802     char * buffer;
1803     gsize buffer_size;
1804     int i;
1805
1806     buffer_size = tape_device_read_size(self);
1807
1808     buffer = malloc(buffer_size);
1809
1810     for (i = 0; i < count || count < 0;) {
1811         int result;
1812
1813         result = read(self->fd, buffer, buffer_size);
1814         if (result > 0) {
1815             i ++;
1816             continue;
1817         } else if (result == 0) {
1818             amfree(buffer);
1819             return i;
1820         } else {
1821             /* First check for interrupted system call. */
1822             if (0
1823 #ifdef EAGAIN
1824                 || errno == EAGAIN
1825 #endif
1826 #ifdef EWOULDBLOCK
1827                 || errno == EWOULDBLOCK
1828 #endif
1829 #ifdef EINTR
1830                 || errno == EINTR
1831 #endif
1832                 ) {
1833                 /* Interrupted system call */
1834                 continue;
1835             } else if (0
1836 #ifdef ENOSPC
1837                        || errno == ENOSPC /* bad user-space buffer */
1838 #endif
1839 #ifdef EOVERFLOW
1840                        || errno == EOVERFLOW /* bad kernel-space buffer */
1841 #endif
1842 #ifdef EINVAL
1843                        || errno == EINVAL /* ??? */
1844 #endif
1845                        ) {
1846                 /* The buffer may not be big enough. But the OS is not
1847                    100% clear. We double the buffer and try again, but
1848                    in no case allow a buffer bigger than 32 MB. */
1849                 buffer_size *= 2;
1850
1851                 if (buffer_size > 32*1024*1024) {
1852                     amfree(buffer);
1853                     return -1;
1854                 } else {
1855                     buffer = realloc(buffer, buffer_size);
1856                     continue;
1857                 }
1858             }
1859         }
1860     }
1861
1862     amfree(buffer);
1863     return count;
1864 }
1865
1866 static gboolean
1867 tape_device_fsf (TapeDevice * self, guint count) {
1868     if (self->fsf) {
1869         return tape_fsf(self->fd, count);
1870     } else {
1871         guint i;
1872         for (i = 0; i < count; i ++) {
1873             if (drain_tape_blocks(self, -1) < 0)
1874                 return FALSE;
1875         }
1876         return TRUE;
1877     }
1878 }
1879
1880
1881 static gboolean
1882 tape_device_fsr (TapeDevice * self, guint count) {
1883     if (self->fsr) {
1884         return tape_fsr(self->fd, count);
1885     } else {
1886         int result = drain_tape_blocks(self, count);
1887         return result > 0 && (int)count == result;
1888     }
1889 }
1890
1891 /* Seek back the given number of blocks to block number block within
1892  * the current file, numbered file. */
1893
1894 static gboolean
1895 tape_device_bsr (TapeDevice * self, guint count, guint file, guint block) {
1896     if (self->bsr) {
1897         return tape_bsr(self->fd, count);
1898     } else if (self->bsf && self->fsf) {
1899         /* BSF, FSF to the right side of the filemark, and then FSR. */
1900         if (!tape_bsf(self->fd, 1))
1901             return FALSE;
1902
1903         if (!tape_fsf(self->fd, 1))
1904             return FALSE;
1905
1906         return tape_device_fsr(self, block);
1907     } else {
1908         /* rewind, FSF, and FSR */
1909         if (!tape_rewind(self->fd))
1910             return FALSE;
1911
1912         if (!tape_device_fsf(self, file))
1913             return FALSE;
1914
1915         return tape_device_fsr(self, block);
1916     }
1917     g_assert_not_reached();
1918 }
1919
1920 /* Go to the right place to write more data, and update the file
1921    number if possible. */
1922 static gboolean
1923 tape_device_eod (TapeDevice * self) {
1924     Device * d_self;
1925     int count;
1926
1927     d_self = (Device*)self;
1928
1929     if (self->eom) {
1930         int result;
1931         result = tape_eod(self->fd);
1932         if (result == TAPE_OP_ERROR) {
1933             return FALSE;
1934         } else if (result != TAPE_POSITION_UNKNOWN) {
1935             /* great - we just fast-forwarded to EOD, but don't know where we are, so
1936              * now we have to rewind and drain all of that data.  Warn the user so that
1937              * we can skip the fast-forward-rewind stage on the next run */
1938             g_warning("Seek to end of tape does not give an accurate tape position; set "
1939                       "the EOM property to 0 to avoid useless tape movement.");
1940             /* and set the property so that next time *this* object is opened for
1941              * append, we skip this stage */
1942             self->eom = FALSE;
1943             /* fall through to draining blocks, below */
1944         } else {
1945             /* We drop by 1 because Device will increment the first
1946                time the user does start_file. */
1947             d_self->file = result - 1;
1948             return TRUE;
1949         }
1950     }
1951
1952     if (!tape_rewind(self->fd))
1953         return FALSE;
1954
1955     count = 0;
1956     for (;;) {
1957         /* We alternately read a block and FSF. If the read is
1958            successful, then we are not there yet and should FSF
1959            again. */
1960         int result;
1961         result = drain_tape_blocks(self, 1);
1962         if (result == 1) {
1963             /* More data, FSF. */
1964             tape_device_fsf(self, 1);
1965             count ++;
1966         } else if (result == 0) {
1967             /* Finished. */
1968             d_self->file = count - 1;
1969             return TRUE;
1970         } else {
1971             return FALSE;
1972         }
1973     }
1974 }
1975
1976 static Device *
1977 tape_device_factory (char * device_name, char * device_type, char * device_node) {
1978     Device * rval;
1979     g_assert(0 == strcmp(device_type, "tape"));
1980     rval = DEVICE(g_object_new(TYPE_TAPE_DEVICE, NULL));
1981     device_open_device(rval, device_name, device_type, device_node);
1982     return rval;
1983 }
1984
1985 /*
1986  * Tape Operations using the POSIX interface
1987  */
1988
1989 /* Having one name for every operation would be too easy. */
1990 #if !defined(MTCOMPRESSION) && defined(MTCOMP)
1991 # define MTCOMPRESSION MTCOMP
1992 #endif
1993
1994 #if !defined(MTSETBLK) && defined(MTSETBSIZ)
1995 # define MTSETBLK MTSETBSIZ
1996 #endif
1997
1998 #if !defined(MTEOM) && defined(MTEOD)
1999 # define MTEOM MTEOD
2000 #endif
2001
2002 gboolean tape_rewind(int fd) {
2003     int count = 5;
2004     time_t stop_time;
2005
2006     /* We will retry this for up to 30 seconds or 5 retries,
2007        whichever is less, because some hardware/software combinations
2008        (notably EXB-8200 on FreeBSD) can fail to rewind. */
2009     stop_time = time(NULL) + 30;
2010
2011     while (--count >= 0 && time(NULL) < stop_time) {
2012         struct mtop mt;
2013         mt.mt_op = MTREW;
2014         mt.mt_count = 1;
2015
2016         if (0 == ioctl(fd, MTIOCTOP, &mt))
2017             return TRUE;
2018
2019         sleep(3);
2020     }
2021
2022     return FALSE;
2023 }
2024
2025 gboolean tape_fsf(int fd, guint count) {
2026     struct mtop mt;
2027     mt.mt_op = MTFSF;
2028     mt.mt_count = count;
2029     return 0 == ioctl(fd, MTIOCTOP, &mt);
2030 }
2031
2032 gboolean tape_bsf(int fd, guint count) {
2033     struct mtop mt;
2034     mt.mt_op = MTBSF;
2035     mt.mt_count = count;
2036     return 0 == ioctl(fd, MTIOCTOP, &mt);
2037 }
2038
2039 gboolean tape_fsr(int fd, guint count) {
2040     struct mtop mt;
2041     mt.mt_op = MTFSR;
2042     mt.mt_count = count;
2043     return 0 == ioctl(fd, MTIOCTOP, &mt);
2044 }
2045
2046 gboolean tape_bsr(int fd, guint count) {
2047     struct mtop mt;
2048     mt.mt_op = MTBSR;
2049     mt.mt_count = count;
2050     return 0 == ioctl(fd, MTIOCTOP, &mt);
2051 }
2052
2053 gint tape_fileno(int fd) {
2054     struct mtget get;
2055
2056     if (0 != ioctl(fd, MTIOCGET, &get))
2057         return TAPE_POSITION_UNKNOWN;
2058     if (get.mt_fileno < 0)
2059         return TAPE_POSITION_UNKNOWN;
2060     else
2061         return get.mt_fileno;
2062 }
2063
2064 gint tape_eod(int fd) {
2065     struct mtop mt;
2066     struct mtget get;
2067     mt.mt_op = MTEOM;
2068     mt.mt_count = 1;
2069     if (0 != ioctl(fd, MTIOCTOP, &mt))
2070         return TAPE_OP_ERROR;
2071
2072     /* Ignored result. This is just to flush buffers. */
2073     mt.mt_op = MTNOP;
2074     ioctl(fd, MTIOCTOP, &mt);
2075
2076     if (0 != ioctl(fd, MTIOCGET, &get))
2077         return TAPE_POSITION_UNKNOWN;
2078     if (get.mt_fileno < 0)
2079         return TAPE_POSITION_UNKNOWN;
2080     else
2081         return get.mt_fileno;
2082 }
2083
2084 gboolean tape_weof(int fd, guint8 count) {
2085     struct mtop mt;
2086     mt.mt_op = MTWEOF;
2087     mt.mt_count = count;
2088     return 0 == ioctl(fd, MTIOCTOP, &mt);
2089 }
2090
2091 gboolean tape_setcompression(int fd G_GNUC_UNUSED,
2092         gboolean on G_GNUC_UNUSED) {
2093 #ifdef MTCOMPRESSION
2094     struct mtop mt;
2095     mt.mt_op = MTCOMPRESSION;
2096     mt.mt_count = on;
2097     return 0 == ioctl(fd, MTIOCTOP, &mt);
2098 #else
2099     return 0;
2100 #endif
2101 }
2102
2103 gboolean tape_offl(int fd) {
2104     struct mtop mt;
2105     int safe_errno;
2106
2107     mt.mt_op = MTOFFL;
2108     mt.mt_count = 1;
2109     if (0 == ioctl(fd, MTIOCTOP, &mt))
2110         return TRUE;
2111
2112     safe_errno = errno;
2113     g_debug("tape_off: ioctl(MTIOCTOP/MTOFFL) failed: %s", strerror(errno));
2114     errno = safe_errno;
2115
2116     return FALSE;
2117 }
2118
2119 DeviceStatusFlags tape_is_tape_device(int fd) {
2120     struct mtop mt;
2121     mt.mt_op = MTNOP;
2122     mt.mt_count = 1;
2123     if (0 == ioctl(fd, MTIOCTOP, &mt)) {
2124         return DEVICE_STATUS_SUCCESS;
2125 #ifdef ENOMEDIUM
2126     } else if (errno == ENOMEDIUM) {
2127         return DEVICE_STATUS_VOLUME_MISSING;
2128 #endif
2129     } else {
2130         g_debug("tape_is_tape_device: ioctl(MTIOCTOP/MTNOP) failed: %s",
2131                  strerror(errno));
2132         if (errno == EIO) {
2133             /* some devices return EIO while the drive is busy loading */
2134             return DEVICE_STATUS_DEVICE_ERROR|DEVICE_STATUS_DEVICE_BUSY;
2135         } else {
2136             return DEVICE_STATUS_DEVICE_ERROR;
2137         }
2138     }
2139 }
2140
2141 DeviceStatusFlags tape_is_ready(int fd, TapeDevice *t_self G_GNUC_UNUSED) {
2142     struct mtget get;
2143     if (0 == ioctl(fd, MTIOCGET, &get)) {
2144 #if defined(GMT_ONLINE) || defined(GMT_DR_OPEN)
2145         if (1
2146 #ifdef GMT_ONLINE
2147             && (t_self->broken_gmt_online || GMT_ONLINE(get.mt_gstat))
2148 #endif
2149 #ifdef GMT_DR_OPEN
2150             && !GMT_DR_OPEN(get.mt_gstat)
2151 #endif
2152             ) {
2153             return DEVICE_STATUS_SUCCESS;
2154         } else {
2155             return DEVICE_STATUS_VOLUME_MISSING;
2156         }
2157 #else /* Neither macro is defined. */
2158         return DEVICE_STATUS_SUCCESS;
2159 #endif
2160     } else {
2161         return DEVICE_STATUS_VOLUME_ERROR;
2162     }
2163 }
2164