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