drivers/scsi/sg.c

   1 /*
   2  *  History:
   3  *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
   4  *           to allow user process control of SCSI devices.
   5  *  Development Sponsored by Killy Corp. NY NY
   6  *
   7  * Original driver (sg.c):
   8  *        Copyright (C) 1992 Lawrence Foard
   9  * Version 2 and 3 extensions to driver:
  10  *        Copyright (C) 1998 - 2005 Douglas Gilbert
  11  *
  12  *  Modified  19-JAN-1998  Richard Gooch <rgooch@atnf.csiro.au>  Devfs support
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2, or (at your option)
  17  * any later version.
  18  *
  19  */
  20
  21 static int sg_version_num = 30534;      /* 2 digits for each component */
  22 #define SG_VERSION_STR "3.5.34"
  23
  24 /*
  25  *  D. P. Gilbert (dgilbert@interlog.com, dougg@triode.net.au), notes:
  26  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
  27  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
  28  *        (otherwise the macros compile to empty statements).
  29  *
  30  */
  31 #include <linux/module.h>
  32
  33 #include <linux/fs.h>
  34 #include <linux/kernel.h>
  35 #include <linux/sched.h>
  36 #include <linux/string.h>
  37 #include <linux/mm.h>
  38 #include <linux/errno.h>
  39 #include <linux/mtio.h>
  40 #include <linux/ioctl.h>
  41 #include <linux/slab.h>
  42 #include <linux/fcntl.h>
  43 #include <linux/init.h>
  44 #include <linux/poll.h>
  45 #include <linux/moduleparam.h>
  46 #include <linux/cdev.h>
  47 #include <linux/idr.h>
  48 #include <linux/seq_file.h>
  49 #include <linux/blkdev.h>
  50 #include <linux/delay.h>
  51 #include <linux/blktrace_api.h>
  52 #include <linux/mutex.h>
  53 #include <linux/ratelimit.h>
  54
  55 #include "scsi.h"
  56 #include <scsi/scsi_dbg.h>
  57 #include <scsi/scsi_host.h>
  58 #include <scsi/scsi_driver.h>
  59 #include <scsi/scsi_ioctl.h>
  60 #include <scsi/sg.h>
  61
  62 #include "scsi_logging.h"
  63
  64 #ifdef CONFIG_SCSI_PROC_FS
  65 #include <linux/proc_fs.h>
  66 static char *sg_version_date = "20061027";
  67
  68 static int sg_proc_init(void);
  69 static void sg_proc_cleanup(void);
  70 #endif
  71
  72 #define SG_ALLOW_DIO_DEF 0
  73
  74 #define SG_MAX_DEVS 32768
  75
  76 /*
  77  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
  78  * Then when using 32 bit integers x * m may overflow during the calculation.
  79  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
  80  * calculates the same, but prevents the overflow when both m and d
  81  * are "small" numbers (like HZ and USER_HZ).
  82  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
  83  * in 32 bits.
  84  */
  85 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
  86
  87 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  88
  89 int sg_big_buff = SG_DEF_RESERVED_SIZE;
  90 /* N.B. This variable is readable and writeable via
  91    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  92    of this size (or less if there is not enough memory) will be reserved
  93    for use by this file descriptor. [Deprecated usage: this variable is also
  94    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  95    the kernel (i.e. it is not a module).] */
  96 static int def_reserved_size = -1;      /* picks up init parameter */
  97 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
  98
  99 static int scatter_elem_sz = SG_SCATTER_SZ;
 100 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
 101
 102 #define SG_SECTOR_SZ 512
 103
 104 static int sg_add(struct device *, struct class_interface *);
 105 static void sg_remove(struct device *, struct class_interface *);
 106
 107 static DEFINE_MUTEX(sg_mutex);
 108
 109 static DEFINE_IDR(sg_index_idr);
 110 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
 111                                                            file descriptor list for device */
 112
 113 static struct class_interface sg_interface = {
 114         .add_dev        = sg_add,
 115         .remove_dev     = sg_remove,
 116 };
 117
 118 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 119         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 120         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 121         unsigned bufflen;       /* Size of (aggregate) data buffer */
 122         struct page **pages;
 123         int page_order;
 124         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 125         unsigned char cmd_opcode; /* first byte of command */
 126 } Sg_scatter_hold;
 127
 128 struct sg_device;               /* forward declarations */
 129 struct sg_fd;
 130
 131 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 132         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
 133         struct sg_fd *parentfp; /* NULL -> not in use */
 134         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 135         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 136         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 137         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 138         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 139         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 140         volatile char done;     /* 0->before bh, 1->before read, 2->read */
 141         struct request *rq;
 142         struct bio *bio;
 143         struct execute_work ew;
 144 } Sg_request;
 145
 146 typedef struct sg_fd {          /* holds the state of a file descriptor */
 147         struct list_head sfd_siblings;
 148         struct sg_device *parentdp;     /* owning device */
 149         wait_queue_head_t read_wait;    /* queue read until command done */
 150         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 151         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 152         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 153         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 154         unsigned save_scat_len; /* original length of trunc. scat. element */
 155         Sg_request *headrp;     /* head of request slist, NULL->empty */
 156         struct fasync_struct *async_qp; /* used by asynchronous notification */
 157         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 158         char low_dma;           /* as in parent but possibly overridden to 1 */
 159         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 160         volatile char closed;   /* 1 -> fd closed but request(s) outstanding */
 161         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 162         char next_cmd_len;      /* 0 -> automatic (def), >0 -> use on next write() */
 163         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 164         char mmap_called;       /* 0 -> mmap() never called on this fd */
 165         struct kref f_ref;
 166         struct execute_work ew;
 167 } Sg_fd;
 168
 169 typedef struct sg_device { /* holds the state of each scsi generic device */
 170         struct scsi_device *device;
 171         wait_queue_head_t o_excl_wait;  /* queue open() when O_EXCL in use */
 172         int sg_tablesize;       /* adapter's max scatter-gather table size */
 173         u32 index;              /* device index number */
 174         struct list_head sfds;
 175         volatile char detached; /* 0->attached, 1->detached pending removal */
 176         volatile char exclude;  /* opened for exclusive access */
 177         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 178         struct gendisk *disk;
 179         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 180         struct kref d_ref;
 181 } Sg_device;
 182
 183 /* tasklet or soft irq callback */
 184 static void sg_rq_end_io(struct request *rq, int uptodate);
 185 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 186 static int sg_finish_rem_req(Sg_request * srp);
 187 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 188 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 189                            Sg_request * srp);
 190 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 191                         const char __user *buf, size_t count, int blocking,
 192                         int read_only, int sg_io_owned, Sg_request **o_srp);
 193 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 194                            unsigned char *cmnd, int timeout, int blocking);
 195 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 196 static void sg_remove_scat(Sg_scatter_hold * schp);
 197 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 198 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 199 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 200 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
 201 static void sg_remove_sfp(struct kref *);
 202 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 203 static Sg_request *sg_add_request(Sg_fd * sfp);
 204 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 205 static int sg_res_in_use(Sg_fd * sfp);
 206 static Sg_device *sg_get_dev(int dev);
 207 static void sg_put_dev(Sg_device *sdp);
 208
 209 #define SZ_SG_HEADER sizeof(struct sg_header)
 210 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 211 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
 212 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 213
 214 static int sg_allow_access(struct file *filp, unsigned char *cmd)
 215 {
 216         struct sg_fd *sfp = filp->private_data;
 217
 218         if (sfp->parentdp->device->type == TYPE_SCANNER)
 219                 return 0;
 220
 221         return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE);
 222 }
 223
 224 static int
 225 sg_open(struct inode *inode, struct file *filp)
 226 {
 227         int dev = iminor(inode);
 228         int flags = filp->f_flags;
 229         struct request_queue *q;
 230         Sg_device *sdp;
 231         Sg_fd *sfp;
 232         int res;
 233         int retval;
 234
 235         mutex_lock(&sg_mutex);
 236         nonseekable_open(inode, filp);
 237         SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
 238         sdp = sg_get_dev(dev);
 239         if (IS_ERR(sdp)) {
 240                 retval = PTR_ERR(sdp);
 241                 sdp = NULL;
 242                 goto sg_put;
 243         }
 244
 245         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 246         /* Prevent the device driver from vanishing while we sleep */
 247         retval = scsi_device_get(sdp->device);
 248         if (retval)
 249                 goto sg_put;
 250
 251         retval = scsi_autopm_get_device(sdp->device);
 252         if (retval)
 253                 goto sdp_put;
 254
 255         if (!((flags & O_NONBLOCK) ||
 256               scsi_block_when_processing_errors(sdp->device))) {
 257                 retval = -ENXIO;
 258                 /* we are in error recovery for this device */
 259                 goto error_out;
 260         }
 261
 262         if (flags & O_EXCL) {
 263                 if (O_RDONLY == (flags & O_ACCMODE)) {
 264                         retval = -EPERM; /* Can't lock it with read only access */
 265                         goto error_out;
 266                 }
 267                 if (!list_empty(&sdp->sfds) && (flags & O_NONBLOCK)) {
 268                         retval = -EBUSY;
 269                         goto error_out;
 270                 }
 271                 res = 0;
 272                 __wait_event_interruptible(sdp->o_excl_wait,
 273                                            ((!list_empty(&sdp->sfds) || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
 274                 if (res) {
 275                         retval = res;   /* -ERESTARTSYS because signal hit process */
 276                         goto error_out;
 277                 }
 278         } else if (sdp->exclude) {      /* some other fd has an exclusive lock on dev */
 279                 if (flags & O_NONBLOCK) {
 280                         retval = -EBUSY;
 281                         goto error_out;
 282                 }
 283                 res = 0;
 284                 __wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
 285                                            res);
 286                 if (res) {
 287                         retval = res;   /* -ERESTARTSYS because signal hit process */
 288                         goto error_out;
 289                 }
 290         }
 291         if (sdp->detached) {
 292                 retval = -ENODEV;
 293                 goto error_out;
 294         }
 295         if (list_empty(&sdp->sfds)) {   /* no existing opens on this device */
 296                 sdp->sgdebug = 0;
 297                 q = sdp->device->request_queue;
 298                 sdp->sg_tablesize = queue_max_segments(q);
 299         }
 300         if ((sfp = sg_add_sfp(sdp, dev)))
 301                 filp->private_data = sfp;
 302         else {
 303                 if (flags & O_EXCL) {
 304                         sdp->exclude = 0;       /* undo if error */
 305                         wake_up_interruptible(&sdp->o_excl_wait);
 306                 }
 307                 retval = -ENOMEM;
 308                 goto error_out;
 309         }
 310         retval = 0;
 311 error_out:
 312         if (retval) {
 313                 scsi_autopm_put_device(sdp->device);
 314 sdp_put:
 315                 scsi_device_put(sdp->device);
 316         }
 317 sg_put:
 318         if (sdp)
 319                 sg_put_dev(sdp);
 320         mutex_unlock(&sg_mutex);
 321         return retval;
 322 }
 323
 324 /* Following function was formerly called 'sg_close' */
 325 static int
 326 sg_release(struct inode *inode, struct file *filp)
 327 {
 328         Sg_device *sdp;
 329         Sg_fd *sfp;
 330
 331         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 332                 return -ENXIO;
 333         SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
 334
 335         sfp->closed = 1;
 336
 337         sdp->exclude = 0;
 338         wake_up_interruptible(&sdp->o_excl_wait);
 339
 340         scsi_autopm_put_device(sdp->device);
 341         kref_put(&sfp->f_ref, sg_remove_sfp);
 342         return 0;
 343 }
 344
 345 static ssize_t
 346 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 347 {
 348         Sg_device *sdp;
 349         Sg_fd *sfp;
 350         Sg_request *srp;
 351         int req_pack_id = -1;
 352         sg_io_hdr_t *hp;
 353         struct sg_header *old_hdr = NULL;
 354         int retval = 0;
 355
 356         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 357                 return -ENXIO;
 358         SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
 359                                    sdp->disk->disk_name, (int) count));
 360
 361         if (!access_ok(VERIFY_WRITE, buf, count))
 362                 return -EFAULT;
 363         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 364                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 365                 if (!old_hdr)
 366                         return -ENOMEM;
 367                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
 368                         retval = -EFAULT;
 369                         goto free_old_hdr;
 370                 }
 371                 if (old_hdr->reply_len < 0) {
 372                         if (count >= SZ_SG_IO_HDR) {
 373                                 sg_io_hdr_t *new_hdr;
 374                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
 375                                 if (!new_hdr) {
 376                                         retval = -ENOMEM;
 377                                         goto free_old_hdr;
 378                                 }
 379                                 retval =__copy_from_user
 380                                     (new_hdr, buf, SZ_SG_IO_HDR);
 381                                 req_pack_id = new_hdr->pack_id;
 382                                 kfree(new_hdr);
 383                                 if (retval) {
 384                                         retval = -EFAULT;
 385                                         goto free_old_hdr;
 386                                 }
 387                         }
 388                 } else
 389                         req_pack_id = old_hdr->pack_id;
 390         }
 391         srp = sg_get_rq_mark(sfp, req_pack_id);
 392         if (!srp) {             /* now wait on packet to arrive */
 393                 if (sdp->detached) {
 394                         retval = -ENODEV;
 395                         goto free_old_hdr;
 396                 }
 397                 if (filp->f_flags & O_NONBLOCK) {
 398                         retval = -EAGAIN;
 399                         goto free_old_hdr;
 400                 }
 401                 while (1) {
 402                         retval = 0; /* following macro beats race condition */
 403                         __wait_event_interruptible(sfp->read_wait,
 404                                 (sdp->detached ||
 405                                 (srp = sg_get_rq_mark(sfp, req_pack_id))),
 406                                 retval);
 407                         if (sdp->detached) {
 408                                 retval = -ENODEV;
 409                                 goto free_old_hdr;
 410                         }
 411                         if (0 == retval)
 412                                 break;
 413
 414                         /* -ERESTARTSYS as signal hit process */
 415                         goto free_old_hdr;
 416                 }
 417         }
 418         if (srp->header.interface_id != '\0') {
 419                 retval = sg_new_read(sfp, buf, count, srp);
 420                 goto free_old_hdr;
 421         }
 422
 423         hp = &srp->header;
 424         if (old_hdr == NULL) {
 425                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 426                 if (! old_hdr) {
 427                         retval = -ENOMEM;
 428                         goto free_old_hdr;
 429                 }
 430         }
 431         memset(old_hdr, 0, SZ_SG_HEADER);
 432         old_hdr->reply_len = (int) hp->timeout;
 433         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 434         old_hdr->pack_id = hp->pack_id;
 435         old_hdr->twelve_byte =
 436             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 437         old_hdr->target_status = hp->masked_status;
 438         old_hdr->host_status = hp->host_status;
 439         old_hdr->driver_status = hp->driver_status;
 440         if ((CHECK_CONDITION & hp->masked_status) ||
 441             (DRIVER_SENSE & hp->driver_status))
 442                 memcpy(old_hdr->sense_buffer, srp->sense_b,
 443                        sizeof (old_hdr->sense_buffer));
 444         switch (hp->host_status) {
 445         /* This setup of 'result' is for backward compatibility and is best
 446            ignored by the user who should use target, host + driver status */
 447         case DID_OK:
 448         case DID_PASSTHROUGH:
 449         case DID_SOFT_ERROR:
 450                 old_hdr->result = 0;
 451                 break;
 452         case DID_NO_CONNECT:
 453         case DID_BUS_BUSY:
 454         case DID_TIME_OUT:
 455                 old_hdr->result = EBUSY;
 456                 break;
 457         case DID_BAD_TARGET:
 458         case DID_ABORT:
 459         case DID_PARITY:
 460         case DID_RESET:
 461         case DID_BAD_INTR:
 462                 old_hdr->result = EIO;
 463                 break;
 464         case DID_ERROR:
 465                 old_hdr->result = (srp->sense_b[0] == 0 &&
 466                                   hp->masked_status == GOOD) ? 0 : EIO;
 467                 break;
 468         default:
 469                 old_hdr->result = EIO;
 470                 break;
 471         }
 472
 473         /* Now copy the result back to the user buffer.  */
 474         if (count >= SZ_SG_HEADER) {
 475                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 476                         retval = -EFAULT;
 477                         goto free_old_hdr;
 478                 }
 479                 buf += SZ_SG_HEADER;
 480                 if (count > old_hdr->reply_len)
 481                         count = old_hdr->reply_len;
 482                 if (count > SZ_SG_HEADER) {
 483                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 484                                 retval = -EFAULT;
 485                                 goto free_old_hdr;
 486                         }
 487                 }
 488         } else
 489                 count = (old_hdr->result == 0) ? 0 : -EIO;
 490         sg_finish_rem_req(srp);
 491         retval = count;
 492 free_old_hdr:
 493         kfree(old_hdr);
 494         return retval;
 495 }
 496
 497 static ssize_t
 498 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 499 {
 500         sg_io_hdr_t *hp = &srp->header;
 501         int err = 0, err2;
 502         int len;
 503
 504         if (count < SZ_SG_IO_HDR) {
 505                 err = -EINVAL;
 506                 goto err_out;
 507         }
 508         hp->sb_len_wr = 0;
 509         if ((hp->mx_sb_len > 0) && hp->sbp) {
 510                 if ((CHECK_CONDITION & hp->masked_status) ||
 511                     (DRIVER_SENSE & hp->driver_status)) {
 512                         int sb_len = SCSI_SENSE_BUFFERSIZE;
 513                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 514                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 515                         len = (len > sb_len) ? sb_len : len;
 516                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 517                                 err = -EFAULT;
 518                                 goto err_out;
 519                         }
 520                         hp->sb_len_wr = len;
 521                 }
 522         }
 523         if (hp->masked_status || hp->host_status || hp->driver_status)
 524                 hp->info |= SG_INFO_CHECK;
 525         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 526                 err = -EFAULT;
 527                 goto err_out;
 528         }
 529 err_out:
 530         err2 = sg_finish_rem_req(srp);
 531         return err ? : err2 ? : count;
 532 }
 533
 534 static ssize_t
 535 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 536 {
 537         int mxsize, cmd_size, k;
 538         int input_size, blocking;
 539         unsigned char opcode;
 540         Sg_device *sdp;
 541         Sg_fd *sfp;
 542         Sg_request *srp;
 543         struct sg_header old_hdr;
 544         sg_io_hdr_t *hp;
 545         unsigned char cmnd[MAX_COMMAND_SIZE];
 546
 547         if (unlikely(segment_eq(get_fs(), KERNEL_DS)))
 548                 return -EINVAL;
 549
 550         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 551                 return -ENXIO;
 552         SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
 553                                    sdp->disk->disk_name, (int) count));
 554         if (sdp->detached)
 555                 return -ENODEV;
 556         if (!((filp->f_flags & O_NONBLOCK) ||
 557               scsi_block_when_processing_errors(sdp->device)))
 558                 return -ENXIO;
 559
 560         if (!access_ok(VERIFY_READ, buf, count))
 561                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 562         if (count < SZ_SG_HEADER)
 563                 return -EIO;
 564         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 565                 return -EFAULT;
 566         blocking = !(filp->f_flags & O_NONBLOCK);
 567         if (old_hdr.reply_len < 0)
 568                 return sg_new_write(sfp, filp, buf, count,
 569                                     blocking, 0, 0, NULL);
 570         if (count < (SZ_SG_HEADER + 6))
 571                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 572
 573         if (!(srp = sg_add_request(sfp))) {
 574                 SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
 575                 return -EDOM;
 576         }
 577         buf += SZ_SG_HEADER;
 578         __get_user(opcode, buf);
 579         if (sfp->next_cmd_len > 0) {
 580                 if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
 581                         SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
 582                         sfp->next_cmd_len = 0;
 583                         sg_remove_request(sfp, srp);
 584                         return -EIO;
 585                 }
 586                 cmd_size = sfp->next_cmd_len;
 587                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 588         } else {
 589                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 590                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 591                         cmd_size = 12;
 592         }
 593         SCSI_LOG_TIMEOUT(4, printk(
 594                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 595 /* Determine buffer size.  */
 596         input_size = count - cmd_size;
 597         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 598         mxsize -= SZ_SG_HEADER;
 599         input_size -= SZ_SG_HEADER;
 600         if (input_size < 0) {
 601                 sg_remove_request(sfp, srp);
 602                 return -EIO;    /* User did not pass enough bytes for this command. */
 603         }
 604         hp = &srp->header;
 605         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 606         hp->cmd_len = (unsigned char) cmd_size;
 607         hp->iovec_count = 0;
 608         hp->mx_sb_len = 0;
 609         if (input_size > 0)
 610                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 611                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 612         else
 613                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 614         hp->dxfer_len = mxsize;
 615         if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
 616             (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
 617                 hp->dxferp = (char __user *)buf + cmd_size;
 618         else
 619                 hp->dxferp = NULL;
 620         hp->sbp = NULL;
 621         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 622         hp->flags = input_size; /* structure abuse ... */
 623         hp->pack_id = old_hdr.pack_id;
 624         hp->usr_ptr = NULL;
 625         if (__copy_from_user(cmnd, buf, cmd_size))
 626                 return -EFAULT;
 627         /*
 628          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 629          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 630          * is a non-zero input_size, so emit a warning.
 631          */
 632         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 633                 static char cmd[TASK_COMM_LEN];
 634                 if (strcmp(current->comm, cmd)) {
 635                         printk_ratelimited(KERN_WARNING
 636                                            "sg_write: data in/out %d/%d bytes "
 637                                            "for SCSI command 0x%x-- guessing "
 638                                            "data in;\n   program %s not setting "
 639                                            "count and/or reply_len properly\n",
 640                                            old_hdr.reply_len - (int)SZ_SG_HEADER,
 641                                            input_size, (unsigned int) cmnd[0],
 642                                            current->comm);
 643                         strcpy(cmd, current->comm);
 644                 }
 645         }
 646         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 647         return (k < 0) ? k : count;
 648 }
 649
 650 static ssize_t
 651 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 652                  size_t count, int blocking, int read_only, int sg_io_owned,
 653                  Sg_request **o_srp)
 654 {
 655         int k;
 656         Sg_request *srp;
 657         sg_io_hdr_t *hp;
 658         unsigned char cmnd[MAX_COMMAND_SIZE];
 659         int timeout;
 660         unsigned long ul_timeout;
 661
 662         if (count < SZ_SG_IO_HDR)
 663                 return -EINVAL;
 664         if (!access_ok(VERIFY_READ, buf, count))
 665                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 666
 667         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 668         if (!(srp = sg_add_request(sfp))) {
 669                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
 670                 return -EDOM;
 671         }
 672         srp->sg_io_owned = sg_io_owned;
 673         hp = &srp->header;
 674         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 675                 sg_remove_request(sfp, srp);
 676                 return -EFAULT;
 677         }
 678         if (hp->interface_id != 'S') {
 679                 sg_remove_request(sfp, srp);
 680                 return -ENOSYS;
 681         }
 682         if (hp->flags & SG_FLAG_MMAP_IO) {
 683                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 684                         sg_remove_request(sfp, srp);
 685                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 686                 }
 687                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 688                         sg_remove_request(sfp, srp);
 689                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 690                 }
 691                 if (sg_res_in_use(sfp)) {
 692                         sg_remove_request(sfp, srp);
 693                         return -EBUSY;  /* reserve buffer already being used */
 694                 }
 695         }
 696         ul_timeout = msecs_to_jiffies(srp->header.timeout);
 697         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 698         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 699                 sg_remove_request(sfp, srp);
 700                 return -EMSGSIZE;
 701         }
 702         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
 703                 sg_remove_request(sfp, srp);
 704                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 705         }
 706         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 707                 sg_remove_request(sfp, srp);
 708                 return -EFAULT;
 709         }
 710         if (read_only && sg_allow_access(file, cmnd)) {
 711                 sg_remove_request(sfp, srp);
 712                 return -EPERM;
 713         }
 714         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 715         if (k < 0)
 716                 return k;
 717         if (o_srp)
 718                 *o_srp = srp;
 719         return count;
 720 }
 721
 722 static int
 723 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 724                 unsigned char *cmnd, int timeout, int blocking)
 725 {
 726         int k, data_dir;
 727         Sg_device *sdp = sfp->parentdp;
 728         sg_io_hdr_t *hp = &srp->header;
 729
 730         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 731         hp->status = 0;
 732         hp->masked_status = 0;
 733         hp->msg_status = 0;
 734         hp->info = 0;
 735         hp->host_status = 0;
 736         hp->driver_status = 0;
 737         hp->resid = 0;
 738         SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 739                           (int) cmnd[0], (int) hp->cmd_len));
 740
 741         k = sg_start_req(srp, cmnd);
 742         if (k) {
 743                 SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k));
 744                 sg_finish_rem_req(srp);
 745                 return k;       /* probably out of space --> ENOMEM */
 746         }
 747         if (sdp->detached) {
 748                 if (srp->bio) {
 749                         blk_end_request_all(srp->rq, -EIO);
 750                         srp->rq = NULL;
 751                 }
 752
 753                 sg_finish_rem_req(srp);
 754                 return -ENODEV;
 755         }
 756
 757         switch (hp->dxfer_direction) {
 758         case SG_DXFER_TO_FROM_DEV:
 759         case SG_DXFER_FROM_DEV:
 760                 data_dir = DMA_FROM_DEVICE;
 761                 break;
 762         case SG_DXFER_TO_DEV:
 763                 data_dir = DMA_TO_DEVICE;
 764                 break;
 765         case SG_DXFER_UNKNOWN:
 766                 data_dir = DMA_BIDIRECTIONAL;
 767                 break;
 768         default:
 769                 data_dir = DMA_NONE;
 770                 break;
 771         }
 772         hp->duration = jiffies_to_msecs(jiffies);
 773
 774         srp->rq->timeout = timeout;
 775         kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
 776         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 777                               srp->rq, 1, sg_rq_end_io);
 778         return 0;
 779 }
 780
 781 static int
 782 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 783 {
 784         void __user *p = (void __user *)arg;
 785         int __user *ip = p;
 786         int result, val, read_only;
 787         Sg_device *sdp;
 788         Sg_fd *sfp;
 789         Sg_request *srp;
 790         unsigned long iflags;
 791
 792         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 793                 return -ENXIO;
 794
 795         SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
 796                                    sdp->disk->disk_name, (int) cmd_in));
 797         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 798
 799         switch (cmd_in) {
 800         case SG_IO:
 801                 {
 802                         int blocking = 1;       /* ignore O_NONBLOCK flag */
 803
 804                         if (sdp->detached)
 805                                 return -ENODEV;
 806                         if (!scsi_block_when_processing_errors(sdp->device))
 807                                 return -ENXIO;
 808                         if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 809                                 return -EFAULT;
 810                         result =
 811                             sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 812                                          blocking, read_only, 1, &srp);
 813                         if (result < 0)
 814                                 return result;
 815                         while (1) {
 816                                 result = 0;     /* following macro to beat race condition */
 817                                 __wait_event_interruptible(sfp->read_wait,
 818                                         (srp->done || sdp->detached),
 819                                         result);
 820                                 if (sdp->detached)
 821                                         return -ENODEV;
 822                                 write_lock_irq(&sfp->rq_list_lock);
 823                                 if (srp->done) {
 824                                         srp->done = 2;
 825                                         write_unlock_irq(&sfp->rq_list_lock);
 826                                         break;
 827                                 }
 828                                 srp->orphan = 1;
 829                                 write_unlock_irq(&sfp->rq_list_lock);
 830                                 return result;  /* -ERESTARTSYS because signal hit process */
 831                         }
 832                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 833                         return (result < 0) ? result : 0;
 834                 }
 835         case SG_SET_TIMEOUT:
 836                 result = get_user(val, ip);
 837                 if (result)
 838                         return result;
 839                 if (val < 0)
 840                         return -EIO;
 841                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
 842                     val = MULDIV (INT_MAX, USER_HZ, HZ);
 843                 sfp->timeout_user = val;
 844                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
 845
 846                 return 0;
 847         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 848                                 /* strange ..., for backward compatibility */
 849                 return sfp->timeout_user;
 850         case SG_SET_FORCE_LOW_DMA:
 851                 result = get_user(val, ip);
 852                 if (result)
 853                         return result;
 854                 if (val) {
 855                         sfp->low_dma = 1;
 856                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
 857                                 val = (int) sfp->reserve.bufflen;
 858                                 sg_remove_scat(&sfp->reserve);
 859                                 sg_build_reserve(sfp, val);
 860                         }
 861                 } else {
 862                         if (sdp->detached)
 863                                 return -ENODEV;
 864                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
 865                 }
 866                 return 0;
 867         case SG_GET_LOW_DMA:
 868                 return put_user((int) sfp->low_dma, ip);
 869         case SG_GET_SCSI_ID:
 870                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 871                         return -EFAULT;
 872                 else {
 873                         sg_scsi_id_t __user *sg_idp = p;
 874
 875                         if (sdp->detached)
 876                                 return -ENODEV;
 877                         __put_user((int) sdp->device->host->host_no,
 878                                    &sg_idp->host_no);
 879                         __put_user((int) sdp->device->channel,
 880                                    &sg_idp->channel);
 881                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 882                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 883                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 884                         __put_user((short) sdp->device->host->cmd_per_lun,
 885                                    &sg_idp->h_cmd_per_lun);
 886                         __put_user((short) sdp->device->queue_depth,
 887                                    &sg_idp->d_queue_depth);
 888                         __put_user(0, &sg_idp->unused[0]);
 889                         __put_user(0, &sg_idp->unused[1]);
 890                         return 0;
 891                 }
 892         case SG_SET_FORCE_PACK_ID:
 893                 result = get_user(val, ip);
 894                 if (result)
 895                         return result;
 896                 sfp->force_packid = val ? 1 : 0;
 897                 return 0;
 898         case SG_GET_PACK_ID:
 899                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 900                         return -EFAULT;
 901                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 902                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
 903                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 904                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 905                                                        iflags);
 906                                 __put_user(srp->header.pack_id, ip);
 907                                 return 0;
 908                         }
 909                 }
 910                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 911                 __put_user(-1, ip);
 912                 return 0;
 913         case SG_GET_NUM_WAITING:
 914                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 915                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
 916                         if ((1 == srp->done) && (!srp->sg_io_owned))
 917                                 ++val;
 918                 }
 919                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 920                 return put_user(val, ip);
 921         case SG_GET_SG_TABLESIZE:
 922                 return put_user(sdp->sg_tablesize, ip);
 923         case SG_SET_RESERVED_SIZE:
 924                 result = get_user(val, ip);
 925                 if (result)
 926                         return result;
 927                 if (val < 0)
 928                         return -EINVAL;
 929                 val = min_t(int, val,
 930                             queue_max_sectors(sdp->device->request_queue) * 512);
 931                 if (val != sfp->reserve.bufflen) {
 932                         if (sg_res_in_use(sfp) || sfp->mmap_called)
 933                                 return -EBUSY;
 934                         sg_remove_scat(&sfp->reserve);
 935                         sg_build_reserve(sfp, val);
 936                 }
 937                 return 0;
 938         case SG_GET_RESERVED_SIZE:
 939                 val = min_t(int, sfp->reserve.bufflen,
 940                             queue_max_sectors(sdp->device->request_queue) * 512);
 941                 return put_user(val, ip);
 942         case SG_SET_COMMAND_Q:
 943                 result = get_user(val, ip);
 944                 if (result)
 945                         return result;
 946                 sfp->cmd_q = val ? 1 : 0;
 947                 return 0;
 948         case SG_GET_COMMAND_Q:
 949                 return put_user((int) sfp->cmd_q, ip);
 950         case SG_SET_KEEP_ORPHAN:
 951                 result = get_user(val, ip);
 952                 if (result)
 953                         return result;
 954                 sfp->keep_orphan = val;
 955                 return 0;
 956         case SG_GET_KEEP_ORPHAN:
 957                 return put_user((int) sfp->keep_orphan, ip);
 958         case SG_NEXT_CMD_LEN:
 959                 result = get_user(val, ip);
 960                 if (result)
 961                         return result;
 962                 sfp->next_cmd_len = (val > 0) ? val : 0;
 963                 return 0;
 964         case SG_GET_VERSION_NUM:
 965                 return put_user(sg_version_num, ip);
 966         case SG_GET_ACCESS_COUNT:
 967                 /* faked - we don't have a real access count anymore */
 968                 val = (sdp->device ? 1 : 0);
 969                 return put_user(val, ip);
 970         case SG_GET_REQUEST_TABLE:
 971                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
 972                         return -EFAULT;
 973                 else {
 974                         sg_req_info_t *rinfo;
 975                         unsigned int ms;
 976
 977                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
 978                                                                 GFP_KERNEL);
 979                         if (!rinfo)
 980                                 return -ENOMEM;
 981                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 982                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
 983                              ++val, srp = srp ? srp->nextrp : srp) {
 984                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
 985                                 if (srp) {
 986                                         rinfo[val].req_state = srp->done + 1;
 987                                         rinfo[val].problem =
 988                                             srp->header.masked_status &
 989                                             srp->header.host_status &
 990                                             srp->header.driver_status;
 991                                         if (srp->done)
 992                                                 rinfo[val].duration =
 993                                                         srp->header.duration;
 994                                         else {
 995                                                 ms = jiffies_to_msecs(jiffies);
 996                                                 rinfo[val].duration =
 997                                                     (ms > srp->header.duration) ?
 998                                                     (ms - srp->header.duration) : 0;
 999                                         }
1000                                         rinfo[val].orphan = srp->orphan;
1001                                         rinfo[val].sg_io_owned =
1002                                                         srp->sg_io_owned;
1003                                         rinfo[val].pack_id =
1004                                                         srp->header.pack_id;
1005                                         rinfo[val].usr_ptr =
1006                                                         srp->header.usr_ptr;
1007                                 }
1008                         }
1009                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1010                         result = __copy_to_user(p, rinfo,
1011                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1012                         result = result ? -EFAULT : 0;
1013                         kfree(rinfo);
1014                         return result;
1015                 }
1016         case SG_EMULATED_HOST:
1017                 if (sdp->detached)
1018                         return -ENODEV;
1019                 return put_user(sdp->device->host->hostt->emulated, ip);
1020         case SG_SCSI_RESET:
1021                 if (sdp->detached)
1022                         return -ENODEV;
1023                 if (filp->f_flags & O_NONBLOCK) {
1024                         if (scsi_host_in_recovery(sdp->device->host))
1025                                 return -EBUSY;
1026                 } else if (!scsi_block_when_processing_errors(sdp->device))
1027                         return -EBUSY;
1028                 result = get_user(val, ip);
1029                 if (result)
1030                         return result;
1031                 if (SG_SCSI_RESET_NOTHING == val)
1032                         return 0;
1033                 switch (val) {
1034                 case SG_SCSI_RESET_DEVICE:
1035                         val = SCSI_TRY_RESET_DEVICE;
1036                         break;
1037                 case SG_SCSI_RESET_TARGET:
1038                         val = SCSI_TRY_RESET_TARGET;
1039                         break;
1040                 case SG_SCSI_RESET_BUS:
1041                         val = SCSI_TRY_RESET_BUS;
1042                         break;
1043                 case SG_SCSI_RESET_HOST:
1044                         val = SCSI_TRY_RESET_HOST;
1045                         break;
1046                 default:
1047                         return -EINVAL;
1048                 }
1049                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1050                         return -EACCES;
1051                 return (scsi_reset_provider(sdp->device, val) ==
1052                         SUCCESS) ? 0 : -EIO;
1053         case SCSI_IOCTL_SEND_COMMAND:
1054                 if (sdp->detached)
1055                         return -ENODEV;
1056                 if (read_only) {
1057                         unsigned char opcode = WRITE_6;
1058                         Scsi_Ioctl_Command __user *siocp = p;
1059
1060                         if (copy_from_user(&opcode, siocp->data, 1))
1061                                 return -EFAULT;
1062                         if (sg_allow_access(filp, &opcode))
1063                                 return -EPERM;
1064                 }
1065                 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1066         case SG_SET_DEBUG:
1067                 result = get_user(val, ip);
1068                 if (result)
1069                         return result;
1070                 sdp->sgdebug = (char) val;
1071                 return 0;
1072         case SCSI_IOCTL_GET_IDLUN:
1073         case SCSI_IOCTL_GET_BUS_NUMBER:
1074         case SCSI_IOCTL_PROBE_HOST:
1075         case SG_GET_TRANSFORM:
1076                 if (sdp->detached)
1077                         return -ENODEV;
1078                 return scsi_ioctl(sdp->device, cmd_in, p);
1079         case BLKSECTGET:
1080                 return put_user(queue_max_sectors(sdp->device->request_queue) * 512,
1081                                 ip);
1082         case BLKTRACESETUP:
1083                 return blk_trace_setup(sdp->device->request_queue,
1084                                        sdp->disk->disk_name,
1085                                        MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1086                                        NULL,
1087                                        (char *)arg);
1088         case BLKTRACESTART:
1089                 return blk_trace_startstop(sdp->device->request_queue, 1);
1090         case BLKTRACESTOP:
1091                 return blk_trace_startstop(sdp->device->request_queue, 0);
1092         case BLKTRACETEARDOWN:
1093                 return blk_trace_remove(sdp->device->request_queue);
1094         default:
1095                 if (read_only)
1096                         return -EPERM;  /* don't know so take safe approach */
1097                 return scsi_ioctl(sdp->device, cmd_in, p);
1098         }
1099 }
1100
1101 static long
1102 sg_unlocked_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1103 {
1104         int ret;
1105
1106         mutex_lock(&sg_mutex);
1107         ret = sg_ioctl(filp, cmd_in, arg);
1108         mutex_unlock(&sg_mutex);
1109
1110         return ret;
1111 }
1112
1113 #ifdef CONFIG_COMPAT
1114 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1115 {
1116         Sg_device *sdp;
1117         Sg_fd *sfp;
1118         struct scsi_device *sdev;
1119
1120         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1121                 return -ENXIO;
1122
1123         sdev = sdp->device;
1124         if (sdev->host->hostt->compat_ioctl) {
1125                 int ret;
1126
1127                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1128
1129                 return ret;
1130         }
1131
1132         return -ENOIOCTLCMD;
1133 }
1134 #endif
1135
1136 static unsigned int
1137 sg_poll(struct file *filp, poll_table * wait)
1138 {
1139         unsigned int res = 0;
1140         Sg_device *sdp;
1141         Sg_fd *sfp;
1142         Sg_request *srp;
1143         int count = 0;
1144         unsigned long iflags;
1145
1146         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1147             || sfp->closed)
1148                 return POLLERR;
1149         poll_wait(filp, &sfp->read_wait, wait);
1150         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1151         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1152                 /* if any read waiting, flag it */
1153                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1154                         res = POLLIN | POLLRDNORM;
1155                 ++count;
1156         }
1157         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1158
1159         if (sdp->detached)
1160                 res |= POLLHUP;
1161         else if (!sfp->cmd_q) {
1162                 if (0 == count)
1163                         res |= POLLOUT | POLLWRNORM;
1164         } else if (count < SG_MAX_QUEUE)
1165                 res |= POLLOUT | POLLWRNORM;
1166         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1167                                    sdp->disk->disk_name, (int) res));
1168         return res;
1169 }
1170
1171 static int
1172 sg_fasync(int fd, struct file *filp, int mode)
1173 {
1174         Sg_device *sdp;
1175         Sg_fd *sfp;
1176
1177         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1178                 return -ENXIO;
1179         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1180                                    sdp->disk->disk_name, mode));
1181
1182         return fasync_helper(fd, filp, mode, &sfp->async_qp);
1183 }
1184
1185 static int
1186 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1187 {
1188         Sg_fd *sfp;
1189         unsigned long offset, len, sa;
1190         Sg_scatter_hold *rsv_schp;
1191         int k, length;
1192
1193         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1194                 return VM_FAULT_SIGBUS;
1195         rsv_schp = &sfp->reserve;
1196         offset = vmf->pgoff << PAGE_SHIFT;
1197         if (offset >= rsv_schp->bufflen)
1198                 return VM_FAULT_SIGBUS;
1199         SCSI_LOG_TIMEOUT(3, printk("sg_vma_fault: offset=%lu, scatg=%d\n",
1200                                    offset, rsv_schp->k_use_sg));
1201         sa = vma->vm_start;
1202         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1203         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1204                 len = vma->vm_end - sa;
1205                 len = (len < length) ? len : length;
1206                 if (offset < len) {
1207                         struct page *page = nth_page(rsv_schp->pages[k],
1208                                                      offset >> PAGE_SHIFT);
1209                         get_page(page); /* increment page count */
1210                         vmf->page = page;
1211                         return 0; /* success */
1212                 }
1213                 sa += len;
1214                 offset -= len;
1215         }
1216
1217         return VM_FAULT_SIGBUS;
1218 }
1219
1220 static const struct vm_operations_struct sg_mmap_vm_ops = {
1221         .fault = sg_vma_fault,
1222 };
1223
1224 static int
1225 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1226 {
1227         Sg_fd *sfp;
1228         unsigned long req_sz, len, sa;
1229         Sg_scatter_hold *rsv_schp;
1230         int k, length;
1231
1232         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1233                 return -ENXIO;
1234         req_sz = vma->vm_end - vma->vm_start;
1235         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1236                                    (void *) vma->vm_start, (int) req_sz));
1237         if (vma->vm_pgoff)
1238                 return -EINVAL; /* want no offset */
1239         rsv_schp = &sfp->reserve;
1240         if (req_sz > rsv_schp->bufflen)
1241                 return -ENOMEM; /* cannot map more than reserved buffer */
1242
1243         sa = vma->vm_start;
1244         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1245         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1246                 len = vma->vm_end - sa;
1247                 len = (len < length) ? len : length;
1248                 sa += len;
1249         }
1250
1251         sfp->mmap_called = 1;
1252         vma->vm_flags |= VM_RESERVED;
1253         vma->vm_private_data = sfp;
1254         vma->vm_ops = &sg_mmap_vm_ops;
1255         return 0;
1256 }
1257
1258 static void sg_rq_end_io_usercontext(struct work_struct *work)
1259 {
1260         struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1261         struct sg_fd *sfp = srp->parentfp;
1262
1263         sg_finish_rem_req(srp);
1264         kref_put(&sfp->f_ref, sg_remove_sfp);
1265 }
1266
1267 /*
1268  * This function is a "bottom half" handler that is called by the mid
1269  * level when a command is completed (or has failed).
1270  */
1271 static void sg_rq_end_io(struct request *rq, int uptodate)
1272 {
1273         struct sg_request *srp = rq->end_io_data;
1274         Sg_device *sdp;
1275         Sg_fd *sfp;
1276         unsigned long iflags;
1277         unsigned int ms;
1278         char *sense;
1279         int result, resid, done = 1;
1280
1281         if (WARN_ON(srp->done != 0))
1282                 return;
1283
1284         sfp = srp->parentfp;
1285         if (WARN_ON(sfp == NULL))
1286                 return;
1287
1288         sdp = sfp->parentdp;
1289         if (unlikely(sdp->detached))
1290                 printk(KERN_INFO "sg_rq_end_io: device detached\n");
1291
1292         sense = rq->sense;
1293         result = rq->errors;
1294         resid = rq->resid_len;
1295
1296         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1297                 sdp->disk->disk_name, srp->header.pack_id, result));
1298         srp->header.resid = resid;
1299         ms = jiffies_to_msecs(jiffies);
1300         srp->header.duration = (ms > srp->header.duration) ?
1301                                 (ms - srp->header.duration) : 0;
1302         if (0 != result) {
1303                 struct scsi_sense_hdr sshdr;
1304
1305                 srp->header.status = 0xff & result;
1306                 srp->header.masked_status = status_byte(result);
1307                 srp->header.msg_status = msg_byte(result);
1308                 srp->header.host_status = host_byte(result);
1309                 srp->header.driver_status = driver_byte(result);
1310                 if ((sdp->sgdebug > 0) &&
1311                     ((CHECK_CONDITION == srp->header.masked_status) ||
1312                      (COMMAND_TERMINATED == srp->header.masked_status)))
1313                         __scsi_print_sense("sg_cmd_done", sense,
1314                                            SCSI_SENSE_BUFFERSIZE);
1315
1316                 /* Following if statement is a patch supplied by Eric Youngdale */
1317                 if (driver_byte(result) != 0
1318                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1319                     && !scsi_sense_is_deferred(&sshdr)
1320                     && sshdr.sense_key == UNIT_ATTENTION
1321                     && sdp->device->removable) {
1322                         /* Detected possible disc change. Set the bit - this */
1323                         /* may be used if there are filesystems using this device */
1324                         sdp->device->changed = 1;
1325                 }
1326         }
1327         /* Rely on write phase to clean out srp status values, so no "else" */
1328
1329         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1330         if (unlikely(srp->orphan)) {
1331                 if (sfp->keep_orphan)
1332                         srp->sg_io_owned = 0;
1333                 else
1334                         done = 0;
1335         }
1336         srp->done = done;
1337         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1338
1339         if (likely(done)) {
1340                 /* Now wake up any sg_read() that is waiting for this
1341                  * packet.
1342                  */
1343                 wake_up_interruptible(&sfp->read_wait);
1344                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1345                 kref_put(&sfp->f_ref, sg_remove_sfp);
1346         } else {
1347                 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1348                 schedule_work(&srp->ew.work);
1349         }
1350 }
1351
1352 static const struct file_operations sg_fops = {
1353         .owner = THIS_MODULE,
1354         .read = sg_read,
1355         .write = sg_write,
1356         .poll = sg_poll,
1357         .unlocked_ioctl = sg_unlocked_ioctl,
1358 #ifdef CONFIG_COMPAT
1359         .compat_ioctl = sg_compat_ioctl,
1360 #endif
1361         .open = sg_open,
1362         .mmap = sg_mmap,
1363         .release = sg_release,
1364         .fasync = sg_fasync,
1365         .llseek = no_llseek,
1366 };
1367
1368 static struct class *sg_sysfs_class;
1369
1370 static int sg_sysfs_valid = 0;
1371
1372 static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1373 {
1374         struct request_queue *q = scsidp->request_queue;
1375         Sg_device *sdp;
1376         unsigned long iflags;
1377         int error;
1378         u32 k;
1379
1380         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1381         if (!sdp) {
1382                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1383                 return ERR_PTR(-ENOMEM);
1384         }
1385
1386         if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) {
1387                 printk(KERN_WARNING "idr expansion Sg_device failure\n");
1388                 error = -ENOMEM;
1389                 goto out;
1390         }
1391
1392         write_lock_irqsave(&sg_index_lock, iflags);
1393
1394         error = idr_get_new(&sg_index_idr, sdp, &k);
1395         if (error) {
1396                 write_unlock_irqrestore(&sg_index_lock, iflags);
1397                 printk(KERN_WARNING "idr allocation Sg_device failure: %d\n",
1398                        error);
1399                 goto out;
1400         }
1401
1402         if (unlikely(k >= SG_MAX_DEVS))
1403                 goto overflow;
1404
1405         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1406         sprintf(disk->disk_name, "sg%d", k);
1407         disk->first_minor = k;
1408         sdp->disk = disk;
1409         sdp->device = scsidp;
1410         INIT_LIST_HEAD(&sdp->sfds);
1411         init_waitqueue_head(&sdp->o_excl_wait);
1412         sdp->sg_tablesize = queue_max_segments(q);
1413         sdp->index = k;
1414         kref_init(&sdp->d_ref);
1415
1416         write_unlock_irqrestore(&sg_index_lock, iflags);
1417
1418         error = 0;
1419  out:
1420         if (error) {
1421                 kfree(sdp);
1422                 return ERR_PTR(error);
1423         }
1424         return sdp;
1425
1426  overflow:
1427         idr_remove(&sg_index_idr, k);
1428         write_unlock_irqrestore(&sg_index_lock, iflags);
1429         sdev_printk(KERN_WARNING, scsidp,
1430                     "Unable to attach sg device type=%d, minor "
1431                     "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1432         error = -ENODEV;
1433         goto out;
1434 }
1435
1436 static int
1437 sg_add(struct device *cl_dev, struct class_interface *cl_intf)
1438 {
1439         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1440         struct gendisk *disk;
1441         Sg_device *sdp = NULL;
1442         struct cdev * cdev = NULL;
1443         int error;
1444         unsigned long iflags;
1445
1446         disk = alloc_disk(1);
1447         if (!disk) {
1448                 printk(KERN_WARNING "alloc_disk failed\n");
1449                 return -ENOMEM;
1450         }
1451         disk->major = SCSI_GENERIC_MAJOR;
1452
1453         error = -ENOMEM;
1454         cdev = cdev_alloc();
1455         if (!cdev) {
1456                 printk(KERN_WARNING "cdev_alloc failed\n");
1457                 goto out;
1458         }
1459         cdev->owner = THIS_MODULE;
1460         cdev->ops = &sg_fops;
1461
1462         sdp = sg_alloc(disk, scsidp);
1463         if (IS_ERR(sdp)) {
1464                 printk(KERN_WARNING "sg_alloc failed\n");
1465                 error = PTR_ERR(sdp);
1466                 goto out;
1467         }
1468
1469         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1470         if (error)
1471                 goto cdev_add_err;
1472
1473         sdp->cdev = cdev;
1474         if (sg_sysfs_valid) {
1475                 struct device *sg_class_member;
1476
1477                 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1478                                                 MKDEV(SCSI_GENERIC_MAJOR,
1479                                                       sdp->index),
1480                                                 sdp, "%s", disk->disk_name);
1481                 if (IS_ERR(sg_class_member)) {
1482                         printk(KERN_ERR "sg_add: "
1483                                "device_create failed\n");
1484                         error = PTR_ERR(sg_class_member);
1485                         goto cdev_add_err;
1486                 }
1487                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1488                                           &sg_class_member->kobj, "generic");
1489                 if (error)
1490                         printk(KERN_ERR "sg_add: unable to make symlink "
1491                                         "'generic' back to sg%d\n", sdp->index);
1492         } else
1493                 printk(KERN_WARNING "sg_add: sg_sys Invalid\n");
1494
1495         sdev_printk(KERN_NOTICE, scsidp,
1496                     "Attached scsi generic sg%d type %d\n", sdp->index,
1497                     scsidp->type);
1498
1499         dev_set_drvdata(cl_dev, sdp);
1500
1501         return 0;
1502
1503 cdev_add_err:
1504         write_lock_irqsave(&sg_index_lock, iflags);
1505         idr_remove(&sg_index_idr, sdp->index);
1506         write_unlock_irqrestore(&sg_index_lock, iflags);
1507         kfree(sdp);
1508
1509 out:
1510         put_disk(disk);
1511         if (cdev)
1512                 cdev_del(cdev);
1513         return error;
1514 }
1515
1516 static void sg_device_destroy(struct kref *kref)
1517 {
1518         struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1519         unsigned long flags;
1520
1521         /* CAUTION!  Note that the device can still be found via idr_find()
1522          * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1523          * any other cleanup.
1524          */
1525
1526         write_lock_irqsave(&sg_index_lock, flags);
1527         idr_remove(&sg_index_idr, sdp->index);
1528         write_unlock_irqrestore(&sg_index_lock, flags);
1529
1530         SCSI_LOG_TIMEOUT(3,
1531                 printk("sg_device_destroy: %s\n",
1532                         sdp->disk->disk_name));
1533
1534         put_disk(sdp->disk);
1535         kfree(sdp);
1536 }
1537
1538 static void sg_remove(struct device *cl_dev, struct class_interface *cl_intf)
1539 {
1540         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1541         Sg_device *sdp = dev_get_drvdata(cl_dev);
1542         unsigned long iflags;
1543         Sg_fd *sfp;
1544
1545         if (!sdp || sdp->detached)
1546                 return;
1547
1548         SCSI_LOG_TIMEOUT(3, printk("sg_remove: %s\n", sdp->disk->disk_name));
1549
1550         /* Need a write lock to set sdp->detached. */
1551         write_lock_irqsave(&sg_index_lock, iflags);
1552         sdp->detached = 1;
1553         list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1554                 wake_up_interruptible(&sfp->read_wait);
1555                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1556         }
1557         write_unlock_irqrestore(&sg_index_lock, iflags);
1558
1559         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1560         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1561         cdev_del(sdp->cdev);
1562         sdp->cdev = NULL;
1563
1564         sg_put_dev(sdp);
1565 }
1566
1567 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1568 module_param_named(def_reserved_size, def_reserved_size, int,
1569                    S_IRUGO | S_IWUSR);
1570 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1571
1572 MODULE_AUTHOR("Douglas Gilbert");
1573 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1574 MODULE_LICENSE("GPL");
1575 MODULE_VERSION(SG_VERSION_STR);
1576 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1577
1578 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1579                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1580 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1581 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1582
1583 static int __init
1584 init_sg(void)
1585 {
1586         int rc;
1587
1588         if (scatter_elem_sz < PAGE_SIZE) {
1589                 scatter_elem_sz = PAGE_SIZE;
1590                 scatter_elem_sz_prev = scatter_elem_sz;
1591         }
1592         if (def_reserved_size >= 0)
1593                 sg_big_buff = def_reserved_size;
1594         else
1595                 def_reserved_size = sg_big_buff;
1596
1597         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1598                                     SG_MAX_DEVS, "sg");
1599         if (rc)
1600                 return rc;
1601         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1602         if ( IS_ERR(sg_sysfs_class) ) {
1603                 rc = PTR_ERR(sg_sysfs_class);
1604                 goto err_out;
1605         }
1606         sg_sysfs_valid = 1;
1607         rc = scsi_register_interface(&sg_interface);
1608         if (0 == rc) {
1609 #ifdef CONFIG_SCSI_PROC_FS
1610                 sg_proc_init();
1611 #endif                          /* CONFIG_SCSI_PROC_FS */
1612                 return 0;
1613         }
1614         class_destroy(sg_sysfs_class);
1615 err_out:
1616         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1617         return rc;
1618 }
1619
1620 static void __exit
1621 exit_sg(void)
1622 {
1623 #ifdef CONFIG_SCSI_PROC_FS
1624         sg_proc_cleanup();
1625 #endif                          /* CONFIG_SCSI_PROC_FS */
1626         scsi_unregister_interface(&sg_interface);
1627         class_destroy(sg_sysfs_class);
1628         sg_sysfs_valid = 0;
1629         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1630                                  SG_MAX_DEVS);
1631         idr_destroy(&sg_index_idr);
1632 }
1633
1634 static int sg_start_req(Sg_request *srp, unsigned char *cmd)
1635 {
1636         int res;
1637         struct request *rq;
1638         Sg_fd *sfp = srp->parentfp;
1639         sg_io_hdr_t *hp = &srp->header;
1640         int dxfer_len = (int) hp->dxfer_len;
1641         int dxfer_dir = hp->dxfer_direction;
1642         unsigned int iov_count = hp->iovec_count;
1643         Sg_scatter_hold *req_schp = &srp->data;
1644         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1645         struct request_queue *q = sfp->parentdp->device->request_queue;
1646         struct rq_map_data *md, map_data;
1647         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1648
1649         SCSI_LOG_TIMEOUT(4, printk(KERN_INFO "sg_start_req: dxfer_len=%d\n",
1650                                    dxfer_len));
1651
1652         rq = blk_get_request(q, rw, GFP_ATOMIC);
1653         if (!rq)
1654                 return -ENOMEM;
1655
1656         memcpy(rq->cmd, cmd, hp->cmd_len);
1657
1658         rq->cmd_len = hp->cmd_len;
1659         rq->cmd_type = REQ_TYPE_BLOCK_PC;
1660
1661         srp->rq = rq;
1662         rq->end_io_data = srp;
1663         rq->sense = srp->sense_b;
1664         rq->retries = SG_DEFAULT_RETRIES;
1665
1666         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1667                 return 0;
1668
1669         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1670             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1671             !sfp->parentdp->device->host->unchecked_isa_dma &&
1672             blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1673                 md = NULL;
1674         else
1675                 md = &map_data;
1676
1677         if (md) {
1678                 if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
1679                         sg_link_reserve(sfp, srp, dxfer_len);
1680                 else {
1681                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1682                         if (res)
1683                                 return res;
1684                 }
1685
1686                 md->pages = req_schp->pages;
1687                 md->page_order = req_schp->page_order;
1688                 md->nr_entries = req_schp->k_use_sg;
1689                 md->offset = 0;
1690                 md->null_mapped = hp->dxferp ? 0 : 1;
1691                 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1692                         md->from_user = 1;
1693                 else
1694                         md->from_user = 0;
1695         }
1696
1697         if (unlikely(iov_count > UIO_MAXIOV))
1698                 return -EINVAL;
1699
1700         if (iov_count) {
1701                 int len, size = sizeof(struct sg_iovec) * iov_count;
1702                 struct iovec *iov;
1703
1704                 iov = memdup_user(hp->dxferp, size);
1705                 if (IS_ERR(iov))
1706                         return PTR_ERR(iov);
1707
1708                 len = iov_length(iov, iov_count);
1709                 if (hp->dxfer_len < len) {
1710                         iov_count = iov_shorten(iov, iov_count, hp->dxfer_len);
1711                         len = hp->dxfer_len;
1712                 }
1713                 if (len == 0) {
1714                         kfree(iov);
1715                         return -EINVAL;
1716                 }
1717
1718                 res = blk_rq_map_user_iov(q, rq, md, (struct sg_iovec *)iov,
1719                                           iov_count,
1720                                           len, GFP_ATOMIC);
1721                 kfree(iov);
1722         } else
1723                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1724                                       hp->dxfer_len, GFP_ATOMIC);
1725
1726         if (!res) {
1727                 srp->bio = rq->bio;
1728
1729                 if (!md) {
1730                         req_schp->dio_in_use = 1;
1731                         hp->info |= SG_INFO_DIRECT_IO;
1732                 }
1733         }
1734         return res;
1735 }
1736
1737 static int sg_finish_rem_req(Sg_request * srp)
1738 {
1739         int ret = 0;
1740
1741         Sg_fd *sfp = srp->parentfp;
1742         Sg_scatter_hold *req_schp = &srp->data;
1743
1744         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1745         if (srp->rq) {
1746                 if (srp->bio)
1747                         ret = blk_rq_unmap_user(srp->bio);
1748
1749                 blk_put_request(srp->rq);
1750         }
1751
1752         if (srp->res_used)
1753                 sg_unlink_reserve(sfp, srp);
1754         else
1755                 sg_remove_scat(req_schp);
1756
1757         sg_remove_request(sfp, srp);
1758
1759         return ret;
1760 }
1761
1762 static int
1763 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1764 {
1765         int sg_bufflen = tablesize * sizeof(struct page *);
1766         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1767
1768         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1769         if (!schp->pages)
1770                 return -ENOMEM;
1771         schp->sglist_len = sg_bufflen;
1772         return tablesize;       /* number of scat_gath elements allocated */
1773 }
1774
1775 static int
1776 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1777 {
1778         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1779         int sg_tablesize = sfp->parentdp->sg_tablesize;
1780         int blk_size = buff_size, order;
1781         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1782
1783         if (blk_size < 0)
1784                 return -EFAULT;
1785         if (0 == blk_size)
1786                 ++blk_size;     /* don't know why */
1787         /* round request up to next highest SG_SECTOR_SZ byte boundary */
1788         blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1789         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1790                                    buff_size, blk_size));
1791
1792         /* N.B. ret_sz carried into this block ... */
1793         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1794         if (mx_sc_elems < 0)
1795                 return mx_sc_elems;     /* most likely -ENOMEM */
1796
1797         num = scatter_elem_sz;
1798         if (unlikely(num != scatter_elem_sz_prev)) {
1799                 if (num < PAGE_SIZE) {
1800                         scatter_elem_sz = PAGE_SIZE;
1801                         scatter_elem_sz_prev = PAGE_SIZE;
1802                 } else
1803                         scatter_elem_sz_prev = num;
1804         }
1805
1806         if (sfp->low_dma)
1807                 gfp_mask |= GFP_DMA;
1808
1809         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1810                 gfp_mask |= __GFP_ZERO;
1811
1812         order = get_order(num);
1813 retry:
1814         ret_sz = 1 << (PAGE_SHIFT + order);
1815
1816         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1817              k++, rem_sz -= ret_sz) {
1818
1819                 num = (rem_sz > scatter_elem_sz_prev) ?
1820                         scatter_elem_sz_prev : rem_sz;
1821
1822                 schp->pages[k] = alloc_pages(gfp_mask, order);
1823                 if (!schp->pages[k])
1824                         goto out;
1825
1826                 if (num == scatter_elem_sz_prev) {
1827                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1828                                 scatter_elem_sz = ret_sz;
1829                                 scatter_elem_sz_prev = ret_sz;
1830                         }
1831                 }
1832
1833                 SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
1834                                  "ret_sz=%d\n", k, num, ret_sz));
1835         }               /* end of for loop */
1836
1837         schp->page_order = order;
1838         schp->k_use_sg = k;
1839         SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
1840                          "rem_sz=%d\n", k, rem_sz));
1841
1842         schp->bufflen = blk_size;
1843         if (rem_sz > 0) /* must have failed */
1844                 return -ENOMEM;
1845         return 0;
1846 out:
1847         for (i = 0; i < k; i++)
1848                 __free_pages(schp->pages[i], order);
1849
1850         if (--order >= 0)
1851                 goto retry;
1852
1853         return -ENOMEM;
1854 }
1855
1856 static void
1857 sg_remove_scat(Sg_scatter_hold * schp)
1858 {
1859         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1860         if (schp->pages && schp->sglist_len > 0) {
1861                 if (!schp->dio_in_use) {
1862                         int k;
1863
1864                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1865                                 SCSI_LOG_TIMEOUT(5, printk(
1866                                     "sg_remove_scat: k=%d, pg=0x%p\n",
1867                                     k, schp->pages[k]));
1868                                 __free_pages(schp->pages[k], schp->page_order);
1869                         }
1870
1871                         kfree(schp->pages);
1872                 }
1873         }
1874         memset(schp, 0, sizeof (*schp));
1875 }
1876
1877 static int
1878 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1879 {
1880         Sg_scatter_hold *schp = &srp->data;
1881         int k, num;
1882
1883         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
1884                                    num_read_xfer));
1885         if ((!outp) || (num_read_xfer <= 0))
1886                 return 0;
1887
1888         num = 1 << (PAGE_SHIFT + schp->page_order);
1889         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1890                 if (num > num_read_xfer) {
1891                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1892                                            num_read_xfer))
1893                                 return -EFAULT;
1894                         break;
1895                 } else {
1896                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1897                                            num))
1898                                 return -EFAULT;
1899                         num_read_xfer -= num;
1900                         if (num_read_xfer <= 0)
1901                                 break;
1902                         outp += num;
1903                 }
1904         }
1905
1906         return 0;
1907 }
1908
1909 static void
1910 sg_build_reserve(Sg_fd * sfp, int req_size)
1911 {
1912         Sg_scatter_hold *schp = &sfp->reserve;
1913
1914         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
1915         do {
1916                 if (req_size < PAGE_SIZE)
1917                         req_size = PAGE_SIZE;
1918                 if (0 == sg_build_indirect(schp, sfp, req_size))
1919                         return;
1920                 else
1921                         sg_remove_scat(schp);
1922                 req_size >>= 1; /* divide by 2 */
1923         } while (req_size > (PAGE_SIZE / 2));
1924 }
1925
1926 static void
1927 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1928 {
1929         Sg_scatter_hold *req_schp = &srp->data;
1930         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1931         int k, num, rem;
1932
1933         srp->res_used = 1;
1934         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
1935         rem = size;
1936
1937         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1938         for (k = 0; k < rsv_schp->k_use_sg; k++) {
1939                 if (rem <= num) {
1940                         req_schp->k_use_sg = k + 1;
1941                         req_schp->sglist_len = rsv_schp->sglist_len;
1942                         req_schp->pages = rsv_schp->pages;
1943
1944                         req_schp->bufflen = size;
1945                         req_schp->page_order = rsv_schp->page_order;
1946                         break;
1947                 } else
1948                         rem -= num;
1949         }
1950
1951         if (k >= rsv_schp->k_use_sg)
1952                 SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
1953 }
1954
1955 static void
1956 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
1957 {
1958         Sg_scatter_hold *req_schp = &srp->data;
1959
1960         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
1961                                    (int) req_schp->k_use_sg));
1962         req_schp->k_use_sg = 0;
1963         req_schp->bufflen = 0;
1964         req_schp->pages = NULL;
1965         req_schp->page_order = 0;
1966         req_schp->sglist_len = 0;
1967         sfp->save_scat_len = 0;
1968         srp->res_used = 0;
1969 }
1970
1971 static Sg_request *
1972 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
1973 {
1974         Sg_request *resp;
1975         unsigned long iflags;
1976
1977         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1978         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
1979                 /* look for requests that are ready + not SG_IO owned */
1980                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
1981                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
1982                         resp->done = 2; /* guard against other readers */
1983                         break;
1984                 }
1985         }
1986         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1987         return resp;
1988 }
1989
1990 /* always adds to end of list */
1991 static Sg_request *
1992 sg_add_request(Sg_fd * sfp)
1993 {
1994         int k;
1995         unsigned long iflags;
1996         Sg_request *resp;
1997         Sg_request *rp = sfp->req_arr;
1998
1999         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2000         resp = sfp->headrp;
2001         if (!resp) {
2002                 memset(rp, 0, sizeof (Sg_request));
2003                 rp->parentfp = sfp;
2004                 resp = rp;
2005                 sfp->headrp = resp;
2006         } else {
2007                 if (0 == sfp->cmd_q)
2008                         resp = NULL;    /* command queuing disallowed */
2009                 else {
2010                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2011                                 if (!rp->parentfp)
2012                                         break;
2013                         }
2014                         if (k < SG_MAX_QUEUE) {
2015                                 memset(rp, 0, sizeof (Sg_request));
2016                                 rp->parentfp = sfp;
2017                                 while (resp->nextrp)
2018                                         resp = resp->nextrp;
2019                                 resp->nextrp = rp;
2020                                 resp = rp;
2021                         } else
2022                                 resp = NULL;
2023                 }
2024         }
2025         if (resp) {
2026                 resp->nextrp = NULL;
2027                 resp->header.duration = jiffies_to_msecs(jiffies);
2028         }
2029         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2030         return resp;
2031 }
2032
2033 /* Return of 1 for found; 0 for not found */
2034 static int
2035 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2036 {
2037         Sg_request *prev_rp;
2038         Sg_request *rp;
2039         unsigned long iflags;
2040         int res = 0;
2041
2042         if ((!sfp) || (!srp) || (!sfp->headrp))
2043                 return res;
2044         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2045         prev_rp = sfp->headrp;
2046         if (srp == prev_rp) {
2047                 sfp->headrp = prev_rp->nextrp;
2048                 prev_rp->parentfp = NULL;
2049                 res = 1;
2050         } else {
2051                 while ((rp = prev_rp->nextrp)) {
2052                         if (srp == rp) {
2053                                 prev_rp->nextrp = rp->nextrp;
2054                                 rp->parentfp = NULL;
2055                                 res = 1;
2056                                 break;
2057                         }
2058                         prev_rp = rp;
2059                 }
2060         }
2061         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2062         return res;
2063 }
2064
2065 static Sg_fd *
2066 sg_add_sfp(Sg_device * sdp, int dev)
2067 {
2068         Sg_fd *sfp;
2069         unsigned long iflags;
2070         int bufflen;
2071
2072         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2073         if (!sfp)
2074                 return NULL;
2075
2076         init_waitqueue_head(&sfp->read_wait);
2077         rwlock_init(&sfp->rq_list_lock);
2078
2079         kref_init(&sfp->f_ref);
2080         sfp->timeout = SG_DEFAULT_TIMEOUT;
2081         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2082         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2083         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2084             sdp->device->host->unchecked_isa_dma : 1;
2085         sfp->cmd_q = SG_DEF_COMMAND_Q;
2086         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2087         sfp->parentdp = sdp;
2088         write_lock_irqsave(&sg_index_lock, iflags);
2089         list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2090         write_unlock_irqrestore(&sg_index_lock, iflags);
2091         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2092         if (unlikely(sg_big_buff != def_reserved_size))
2093                 sg_big_buff = def_reserved_size;
2094
2095         bufflen = min_t(int, sg_big_buff,
2096                         queue_max_sectors(sdp->device->request_queue) * 512);
2097         sg_build_reserve(sfp, bufflen);
2098         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2099                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2100
2101         kref_get(&sdp->d_ref);
2102         __module_get(THIS_MODULE);
2103         return sfp;
2104 }
2105
2106 static void sg_remove_sfp_usercontext(struct work_struct *work)
2107 {
2108         struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2109         struct sg_device *sdp = sfp->parentdp;
2110
2111         /* Cleanup any responses which were never read(). */
2112         while (sfp->headrp)
2113                 sg_finish_rem_req(sfp->headrp);
2114
2115         if (sfp->reserve.bufflen > 0) {
2116                 SCSI_LOG_TIMEOUT(6,
2117                         printk("sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2118                                 (int) sfp->reserve.bufflen,
2119                                 (int) sfp->reserve.k_use_sg));
2120                 sg_remove_scat(&sfp->reserve);
2121         }
2122
2123         SCSI_LOG_TIMEOUT(6,
2124                 printk("sg_remove_sfp: %s, sfp=0x%p\n",
2125                         sdp->disk->disk_name,
2126                         sfp));
2127         kfree(sfp);
2128
2129         scsi_device_put(sdp->device);
2130         sg_put_dev(sdp);
2131         module_put(THIS_MODULE);
2132 }
2133
2134 static void sg_remove_sfp(struct kref *kref)
2135 {
2136         struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2137         struct sg_device *sdp = sfp->parentdp;
2138         unsigned long iflags;
2139
2140         write_lock_irqsave(&sg_index_lock, iflags);
2141         list_del(&sfp->sfd_siblings);
2142         write_unlock_irqrestore(&sg_index_lock, iflags);
2143         wake_up_interruptible(&sdp->o_excl_wait);
2144
2145         INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2146         schedule_work(&sfp->ew.work);
2147 }
2148
2149 static int
2150 sg_res_in_use(Sg_fd * sfp)
2151 {
2152         const Sg_request *srp;
2153         unsigned long iflags;
2154
2155         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2156         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2157                 if (srp->res_used)
2158                         break;
2159         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2160         return srp ? 1 : 0;
2161 }
2162
2163 #ifdef CONFIG_SCSI_PROC_FS
2164 static int
2165 sg_idr_max_id(int id, void *p, void *data)
2166 {
2167         int *k = data;
2168
2169         if (*k < id)
2170                 *k = id;
2171
2172         return 0;
2173 }
2174
2175 static int
2176 sg_last_dev(void)
2177 {
2178         int k = -1;
2179         unsigned long iflags;
2180
2181         read_lock_irqsave(&sg_index_lock, iflags);
2182         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2183         read_unlock_irqrestore(&sg_index_lock, iflags);
2184         return k + 1;           /* origin 1 */
2185 }
2186 #endif
2187
2188 /* must be called with sg_index_lock held */
2189 static Sg_device *sg_lookup_dev(int dev)
2190 {
2191         return idr_find(&sg_index_idr, dev);
2192 }
2193
2194 static Sg_device *sg_get_dev(int dev)
2195 {
2196         struct sg_device *sdp;
2197         unsigned long flags;
2198
2199         read_lock_irqsave(&sg_index_lock, flags);
2200         sdp = sg_lookup_dev(dev);
2201         if (!sdp)
2202                 sdp = ERR_PTR(-ENXIO);
2203         else if (sdp->detached) {
2204                 /* If sdp->detached, then the refcount may already be 0, in
2205                  * which case it would be a bug to do kref_get().
2206                  */
2207                 sdp = ERR_PTR(-ENODEV);
2208         } else
2209                 kref_get(&sdp->d_ref);
2210         read_unlock_irqrestore(&sg_index_lock, flags);
2211
2212         return sdp;
2213 }
2214
2215 static void sg_put_dev(struct sg_device *sdp)
2216 {
2217         kref_put(&sdp->d_ref, sg_device_destroy);
2218 }
2219
2220 #ifdef CONFIG_SCSI_PROC_FS
2221
2222 static struct proc_dir_entry *sg_proc_sgp = NULL;
2223
2224 static char sg_proc_sg_dirname[] = "scsi/sg";
2225
2226 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2227
2228 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2229 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2230                                   size_t count, loff_t *off);
2231 static const struct file_operations adio_fops = {
2232         .owner = THIS_MODULE,
2233         .open = sg_proc_single_open_adio,
2234         .read = seq_read,
2235         .llseek = seq_lseek,
2236         .write = sg_proc_write_adio,
2237         .release = single_release,
2238 };
2239
2240 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2241 static ssize_t sg_proc_write_dressz(struct file *filp,
2242                 const char __user *buffer, size_t count, loff_t *off);
2243 static const struct file_operations dressz_fops = {
2244         .owner = THIS_MODULE,
2245         .open = sg_proc_single_open_dressz,
2246         .read = seq_read,
2247         .llseek = seq_lseek,
2248         .write = sg_proc_write_dressz,
2249         .release = single_release,
2250 };
2251
2252 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2253 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2254 static const struct file_operations version_fops = {
2255         .owner = THIS_MODULE,
2256         .open = sg_proc_single_open_version,
2257         .read = seq_read,
2258         .llseek = seq_lseek,
2259         .release = single_release,
2260 };
2261
2262 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2263 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2264 static const struct file_operations devhdr_fops = {
2265         .owner = THIS_MODULE,
2266         .open = sg_proc_single_open_devhdr,
2267         .read = seq_read,
2268         .llseek = seq_lseek,
2269         .release = single_release,
2270 };
2271
2272 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2273 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2274 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2275 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2276 static void dev_seq_stop(struct seq_file *s, void *v);
2277 static const struct file_operations dev_fops = {
2278         .owner = THIS_MODULE,
2279         .open = sg_proc_open_dev,
2280         .read = seq_read,
2281         .llseek = seq_lseek,
2282         .release = seq_release,
2283 };
2284 static const struct seq_operations dev_seq_ops = {
2285         .start = dev_seq_start,
2286         .next  = dev_seq_next,
2287         .stop  = dev_seq_stop,
2288         .show  = sg_proc_seq_show_dev,
2289 };
2290
2291 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2292 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2293 static const struct file_operations devstrs_fops = {
2294         .owner = THIS_MODULE,
2295         .open = sg_proc_open_devstrs,
2296         .read = seq_read,
2297         .llseek = seq_lseek,
2298         .release = seq_release,
2299 };
2300 static const struct seq_operations devstrs_seq_ops = {
2301         .start = dev_seq_start,
2302         .next  = dev_seq_next,
2303         .stop  = dev_seq_stop,
2304         .show  = sg_proc_seq_show_devstrs,
2305 };
2306
2307 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2308 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2309 static const struct file_operations debug_fops = {
2310         .owner = THIS_MODULE,
2311         .open = sg_proc_open_debug,
2312         .read = seq_read,
2313         .llseek = seq_lseek,
2314         .release = seq_release,
2315 };
2316 static const struct seq_operations debug_seq_ops = {
2317         .start = dev_seq_start,
2318         .next  = dev_seq_next,
2319         .stop  = dev_seq_stop,
2320         .show  = sg_proc_seq_show_debug,
2321 };
2322
2323
2324 struct sg_proc_leaf {
2325         const char * name;
2326         const struct file_operations * fops;
2327 };
2328
2329 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2330         {"allow_dio", &adio_fops},
2331         {"debug", &debug_fops},
2332         {"def_reserved_size", &dressz_fops},
2333         {"device_hdr", &devhdr_fops},
2334         {"devices", &dev_fops},
2335         {"device_strs", &devstrs_fops},
2336         {"version", &version_fops}
2337 };
2338
2339 static int
2340 sg_proc_init(void)
2341 {
2342         int k, mask;
2343         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2344         struct sg_proc_leaf * leaf;
2345
2346         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2347         if (!sg_proc_sgp)
2348                 return 1;
2349         for (k = 0; k < num_leaves; ++k) {
2350                 leaf = &sg_proc_leaf_arr[k];
2351                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2352                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2353         }
2354         return 0;
2355 }
2356
2357 static void
2358 sg_proc_cleanup(void)
2359 {
2360         int k;
2361         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2362
2363         if (!sg_proc_sgp)
2364                 return;
2365         for (k = 0; k < num_leaves; ++k)
2366                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2367         remove_proc_entry(sg_proc_sg_dirname, NULL);
2368 }
2369
2370
2371 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2372 {
2373         seq_printf(s, "%d\n", *((int *)s->private));
2374         return 0;
2375 }
2376
2377 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2378 {
2379         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2380 }
2381
2382 static ssize_t
2383 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2384                    size_t count, loff_t *off)
2385 {
2386         int num;
2387         char buff[11];
2388
2389         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2390                 return -EACCES;
2391         num = (count < 10) ? count : 10;
2392         if (copy_from_user(buff, buffer, num))
2393                 return -EFAULT;
2394         buff[num] = '\0';
2395         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2396         return count;
2397 }
2398
2399 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2400 {
2401         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2402 }
2403
2404 static ssize_t
2405 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2406                      size_t count, loff_t *off)
2407 {
2408         int num;
2409         unsigned long k = ULONG_MAX;
2410         char buff[11];
2411
2412         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2413                 return -EACCES;
2414         num = (count < 10) ? count : 10;
2415         if (copy_from_user(buff, buffer, num))
2416                 return -EFAULT;
2417         buff[num] = '\0';
2418         k = simple_strtoul(buff, NULL, 10);
2419         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2420                 sg_big_buff = k;
2421                 return count;
2422         }
2423         return -ERANGE;
2424 }
2425
2426 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2427 {
2428         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2429                    sg_version_date);
2430         return 0;
2431 }
2432
2433 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2434 {
2435         return single_open(file, sg_proc_seq_show_version, NULL);
2436 }
2437
2438 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2439 {
2440         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2441                    "online\n");
2442         return 0;
2443 }
2444
2445 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2446 {
2447         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2448 }
2449
2450 struct sg_proc_deviter {
2451         loff_t  index;
2452         size_t  max;
2453 };
2454
2455 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2456 {
2457         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2458
2459         s->private = it;
2460         if (! it)
2461                 return NULL;
2462
2463         it->index = *pos;
2464         it->max = sg_last_dev();
2465         if (it->index >= it->max)
2466                 return NULL;
2467         return it;
2468 }
2469
2470 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2471 {
2472         struct sg_proc_deviter * it = s->private;
2473
2474         *pos = ++it->index;
2475         return (it->index < it->max) ? it : NULL;
2476 }
2477
2478 static void dev_seq_stop(struct seq_file *s, void *v)
2479 {
2480         kfree(s->private);
2481 }
2482
2483 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2484 {
2485         return seq_open(file, &dev_seq_ops);
2486 }
2487
2488 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2489 {
2490         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2491         Sg_device *sdp;
2492         struct scsi_device *scsidp;
2493         unsigned long iflags;
2494
2495         read_lock_irqsave(&sg_index_lock, iflags);
2496         sdp = it ? sg_lookup_dev(it->index) : NULL;
2497         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2498                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2499                               scsidp->host->host_no, scsidp->channel,
2500                               scsidp->id, scsidp->lun, (int) scsidp->type,
2501                               1,
2502                               (int) scsidp->queue_depth,
2503                               (int) scsidp->device_busy,
2504                               (int) scsi_device_online(scsidp));
2505         else
2506                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2507         read_unlock_irqrestore(&sg_index_lock, iflags);
2508         return 0;
2509 }
2510
2511 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2512 {
2513         return seq_open(file, &devstrs_seq_ops);
2514 }
2515
2516 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2517 {
2518         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2519         Sg_device *sdp;
2520         struct scsi_device *scsidp;
2521         unsigned long iflags;
2522
2523         read_lock_irqsave(&sg_index_lock, iflags);
2524         sdp = it ? sg_lookup_dev(it->index) : NULL;
2525         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2526                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2527                            scsidp->vendor, scsidp->model, scsidp->rev);
2528         else
2529                 seq_printf(s, "<no active device>\n");
2530         read_unlock_irqrestore(&sg_index_lock, iflags);
2531         return 0;
2532 }
2533
2534 /* must be called while holding sg_index_lock */
2535 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2536 {
2537         int k, m, new_interface, blen, usg;
2538         Sg_request *srp;
2539         Sg_fd *fp;
2540         const sg_io_hdr_t *hp;
2541         const char * cp;
2542         unsigned int ms;
2543
2544         k = 0;
2545         list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2546                 k++;
2547                 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2548                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2549                            "(res)sgat=%d low_dma=%d\n", k,
2550                            jiffies_to_msecs(fp->timeout),
2551                            fp->reserve.bufflen,
2552                            (int) fp->reserve.k_use_sg,
2553                            (int) fp->low_dma);
2554                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2555                            (int) fp->cmd_q, (int) fp->force_packid,
2556                            (int) fp->keep_orphan, (int) fp->closed);
2557                 for (m = 0, srp = fp->headrp;
2558                                 srp != NULL;
2559                                 ++m, srp = srp->nextrp) {
2560                         hp = &srp->header;
2561                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2562                         if (srp->res_used) {
2563                                 if (new_interface &&
2564                                     (SG_FLAG_MMAP_IO & hp->flags))
2565                                         cp = "     mmap>> ";
2566                                 else
2567                                         cp = "     rb>> ";
2568                         } else {
2569                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2570                                         cp = "     dio>> ";
2571                                 else
2572                                         cp = "     ";
2573                         }
2574                         seq_printf(s, cp);
2575                         blen = srp->data.bufflen;
2576                         usg = srp->data.k_use_sg;
2577                         seq_printf(s, srp->done ?
2578                                    ((1 == srp->done) ?  "rcv:" : "fin:")
2579                                    : "act:");
2580                         seq_printf(s, " id=%d blen=%d",
2581                                    srp->header.pack_id, blen);
2582                         if (srp->done)
2583                                 seq_printf(s, " dur=%d", hp->duration);
2584                         else {
2585                                 ms = jiffies_to_msecs(jiffies);
2586                                 seq_printf(s, " t_o/elap=%d/%d",
2587                                         (new_interface ? hp->timeout :
2588                                                   jiffies_to_msecs(fp->timeout)),
2589                                         (ms > hp->duration ? ms - hp->duration : 0));
2590                         }
2591                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2592                                    (int) srp->data.cmd_opcode);
2593                 }
2594                 if (0 == m)
2595                         seq_printf(s, "     No requests active\n");
2596                 read_unlock(&fp->rq_list_lock);
2597         }
2598 }
2599
2600 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2601 {
2602         return seq_open(file, &debug_seq_ops);
2603 }
2604
2605 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2606 {
2607         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2608         Sg_device *sdp;
2609         unsigned long iflags;
2610
2611         if (it && (0 == it->index)) {
2612                 seq_printf(s, "max_active_device=%d(origin 1)\n",
2613                            (int)it->max);
2614                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2615         }
2616
2617         read_lock_irqsave(&sg_index_lock, iflags);
2618         sdp = it ? sg_lookup_dev(it->index) : NULL;
2619         if (sdp && !list_empty(&sdp->sfds)) {
2620                 struct scsi_device *scsidp = sdp->device;
2621
2622                 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2623                 if (sdp->detached)
2624                         seq_printf(s, "detached pending close ");
2625                 else
2626                         seq_printf
2627                             (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2628                              scsidp->host->host_no,
2629                              scsidp->channel, scsidp->id,
2630                              scsidp->lun,
2631                              scsidp->host->hostt->emulated);
2632                 seq_printf(s, " sg_tablesize=%d excl=%d\n",
2633                            sdp->sg_tablesize, sdp->exclude);
2634                 sg_proc_debug_helper(s, sdp);
2635         }
2636         read_unlock_irqrestore(&sg_index_lock, iflags);
2637         return 0;
2638 }
2639
2640 #endif                          /* CONFIG_SCSI_PROC_FS */
2641
2642 module_init(init_sg);
2643 module_exit(exit_sg);