git.oblomov.eu Git - linux-2.6/blob - 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/fcntl.h>
  42 #include <linux/init.h>
  43 #include <linux/poll.h>
  44 #include <linux/moduleparam.h>
  45 #include <linux/cdev.h>
  46 #include <linux/idr.h>
  47 #include <linux/seq_file.h>
  48 #include <linux/blkdev.h>
  49 #include <linux/delay.h>
  50 #include <linux/blktrace_api.h>
  51 #include <linux/smp_lock.h>
  52
  53 #include "scsi.h"
  54 #include <scsi/scsi_dbg.h>
  55 #include <scsi/scsi_host.h>
  56 #include <scsi/scsi_driver.h>
  57 #include <scsi/scsi_ioctl.h>
  58 #include <scsi/sg.h>
  59
  60 #include "scsi_logging.h"
  61
  62 #ifdef CONFIG_SCSI_PROC_FS
  63 #include <linux/proc_fs.h>
  64 static char *sg_version_date = "20061027";
  65
  66 static int sg_proc_init(void);
  67 static void sg_proc_cleanup(void);
  68 #endif
  69
  70 #define SG_ALLOW_DIO_DEF 0
  71
  72 #define SG_MAX_DEVS 32768
  73
  74 /*
  75  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
  76  * Then when using 32 bit integers x * m may overflow during the calculation.
  77  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
  78  * calculates the same, but prevents the overflow when both m and d
  79  * are "small" numbers (like HZ and USER_HZ).
  80  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
  81  * in 32 bits.
  82  */
  83 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
  84
  85 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  86
  87 int sg_big_buff = SG_DEF_RESERVED_SIZE;
  88 /* N.B. This variable is readable and writeable via
  89    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  90    of this size (or less if there is not enough memory) will be reserved
  91    for use by this file descriptor. [Deprecated usage: this variable is also
  92    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  93    the kernel (i.e. it is not a module).] */
  94 static int def_reserved_size = -1;      /* picks up init parameter */
  95 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
  96
  97 static int scatter_elem_sz = SG_SCATTER_SZ;
  98 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
  99
 100 #define SG_SECTOR_SZ 512
 101
 102 static int sg_add(struct device *, struct class_interface *);
 103 static void sg_remove(struct device *, struct class_interface *);
 104
 105 static DEFINE_IDR(sg_index_idr);
 106 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
 107                                                            file descriptor list for device */
 108
 109 static struct class_interface sg_interface = {
 110         .add_dev        = sg_add,
 111         .remove_dev     = sg_remove,
 112 };
 113
 114 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 115         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 116         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 117         unsigned bufflen;       /* Size of (aggregate) data buffer */
 118         struct page **pages;
 119         int page_order;
 120         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 121         unsigned char cmd_opcode; /* first byte of command */
 122 } Sg_scatter_hold;
 123
 124 struct sg_device;               /* forward declarations */
 125 struct sg_fd;
 126
 127 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 128         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
 129         struct sg_fd *parentfp; /* NULL -> not in use */
 130         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 131         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 132         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 133         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 134         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 135         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 136         volatile char done;     /* 0->before bh, 1->before read, 2->read */
 137         struct request *rq;
 138         struct bio *bio;
 139         struct execute_work ew;
 140 } Sg_request;
 141
 142 typedef struct sg_fd {          /* holds the state of a file descriptor */
 143         struct list_head sfd_siblings;
 144         struct sg_device *parentdp;     /* owning device */
 145         wait_queue_head_t read_wait;    /* queue read until command done */
 146         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 147         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 148         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 149         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 150         unsigned save_scat_len; /* original length of trunc. scat. element */
 151         Sg_request *headrp;     /* head of request slist, NULL->empty */
 152         struct fasync_struct *async_qp; /* used by asynchronous notification */
 153         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 154         char low_dma;           /* as in parent but possibly overridden to 1 */
 155         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 156         volatile char closed;   /* 1 -> fd closed but request(s) outstanding */
 157         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 158         char next_cmd_len;      /* 0 -> automatic (def), >0 -> use on next write() */
 159         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 160         char mmap_called;       /* 0 -> mmap() never called on this fd */
 161         struct kref f_ref;
 162         struct execute_work ew;
 163 } Sg_fd;
 164
 165 typedef struct sg_device { /* holds the state of each scsi generic device */
 166         struct scsi_device *device;
 167         wait_queue_head_t o_excl_wait;  /* queue open() when O_EXCL in use */
 168         int sg_tablesize;       /* adapter's max scatter-gather table size */
 169         u32 index;              /* device index number */
 170         struct list_head sfds;
 171         volatile char detached; /* 0->attached, 1->detached pending removal */
 172         volatile char exclude;  /* opened for exclusive access */
 173         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 174         struct gendisk *disk;
 175         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 176         struct kref d_ref;
 177 } Sg_device;
 178
 179 /* tasklet or soft irq callback */
 180 static void sg_rq_end_io(struct request *rq, int uptodate);
 181 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 182 static void sg_finish_rem_req(Sg_request * srp);
 183 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 184 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 185                            Sg_request * srp);
 186 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 187                         const char __user *buf, size_t count, int blocking,
 188                         int read_only, int sg_io_owned, Sg_request **o_srp);
 189 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 190                            unsigned char *cmnd, int timeout, int blocking);
 191 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 192 static void sg_remove_scat(Sg_scatter_hold * schp);
 193 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 194 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 195 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 196 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
 197 static void sg_remove_sfp(struct kref *);
 198 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 199 static Sg_request *sg_add_request(Sg_fd * sfp);
 200 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 201 static int sg_res_in_use(Sg_fd * sfp);
 202 static Sg_device *sg_get_dev(int dev);
 203 static void sg_put_dev(Sg_device *sdp);
 204
 205 #define SZ_SG_HEADER sizeof(struct sg_header)
 206 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 207 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
 208 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 209
 210 static int sg_allow_access(struct file *filp, unsigned char *cmd)
 211 {
 212         struct sg_fd *sfp = (struct sg_fd *)filp->private_data;
 213         struct request_queue *q = sfp->parentdp->device->request_queue;
 214
 215         if (sfp->parentdp->device->type == TYPE_SCANNER)
 216                 return 0;
 217
 218         return blk_verify_command(&q->cmd_filter,
 219                                   cmd, filp->f_mode & FMODE_WRITE);
 220 }
 221
 222 static int
 223 sg_open(struct inode *inode, struct file *filp)
 224 {
 225         int dev = iminor(inode);
 226         int flags = filp->f_flags;
 227         struct request_queue *q;
 228         Sg_device *sdp;
 229         Sg_fd *sfp;
 230         int res;
 231         int retval;
 232
 233         lock_kernel();
 234         nonseekable_open(inode, filp);
 235         SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
 236         sdp = sg_get_dev(dev);
 237         if (IS_ERR(sdp)) {
 238                 retval = PTR_ERR(sdp);
 239                 sdp = NULL;
 240                 goto sg_put;
 241         }
 242
 243         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 244         /* Prevent the device driver from vanishing while we sleep */
 245         retval = scsi_device_get(sdp->device);
 246         if (retval)
 247                 goto sg_put;
 248
 249         if (!((flags & O_NONBLOCK) ||
 250               scsi_block_when_processing_errors(sdp->device))) {
 251                 retval = -ENXIO;
 252                 /* we are in error recovery for this device */
 253                 goto error_out;
 254         }
 255
 256         if (flags & O_EXCL) {
 257                 if (O_RDONLY == (flags & O_ACCMODE)) {
 258                         retval = -EPERM; /* Can't lock it with read only access */
 259                         goto error_out;
 260                 }
 261                 if (!list_empty(&sdp->sfds) && (flags & O_NONBLOCK)) {
 262                         retval = -EBUSY;
 263                         goto error_out;
 264                 }
 265                 res = 0;
 266                 __wait_event_interruptible(sdp->o_excl_wait,
 267                                            ((!list_empty(&sdp->sfds) || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
 268                 if (res) {
 269                         retval = res;   /* -ERESTARTSYS because signal hit process */
 270                         goto error_out;
 271                 }
 272         } else if (sdp->exclude) {      /* some other fd has an exclusive lock on dev */
 273                 if (flags & O_NONBLOCK) {
 274                         retval = -EBUSY;
 275                         goto error_out;
 276                 }
 277                 res = 0;
 278                 __wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
 279                                            res);
 280                 if (res) {
 281                         retval = res;   /* -ERESTARTSYS because signal hit process */
 282                         goto error_out;
 283                 }
 284         }
 285         if (sdp->detached) {
 286                 retval = -ENODEV;
 287                 goto error_out;
 288         }
 289         if (list_empty(&sdp->sfds)) {   /* no existing opens on this device */
 290                 sdp->sgdebug = 0;
 291                 q = sdp->device->request_queue;
 292                 sdp->sg_tablesize = min(q->max_hw_segments,
 293                                         q->max_phys_segments);
 294         }
 295         if ((sfp = sg_add_sfp(sdp, dev)))
 296                 filp->private_data = sfp;
 297         else {
 298                 if (flags & O_EXCL) {
 299                         sdp->exclude = 0;       /* undo if error */
 300                         wake_up_interruptible(&sdp->o_excl_wait);
 301                 }
 302                 retval = -ENOMEM;
 303                 goto error_out;
 304         }
 305         retval = 0;
 306 error_out:
 307         if (retval)
 308                 scsi_device_put(sdp->device);
 309 sg_put:
 310         if (sdp)
 311                 sg_put_dev(sdp);
 312         unlock_kernel();
 313         return retval;
 314 }
 315
 316 /* Following function was formerly called 'sg_close' */
 317 static int
 318 sg_release(struct inode *inode, struct file *filp)
 319 {
 320         Sg_device *sdp;
 321         Sg_fd *sfp;
 322
 323         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 324                 return -ENXIO;
 325         SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
 326
 327         sfp->closed = 1;
 328
 329         sdp->exclude = 0;
 330         wake_up_interruptible(&sdp->o_excl_wait);
 331
 332         kref_put(&sfp->f_ref, sg_remove_sfp);
 333         return 0;
 334 }
 335
 336 static ssize_t
 337 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 338 {
 339         Sg_device *sdp;
 340         Sg_fd *sfp;
 341         Sg_request *srp;
 342         int req_pack_id = -1;
 343         sg_io_hdr_t *hp;
 344         struct sg_header *old_hdr = NULL;
 345         int retval = 0;
 346
 347         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 348                 return -ENXIO;
 349         SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
 350                                    sdp->disk->disk_name, (int) count));
 351
 352         if (!access_ok(VERIFY_WRITE, buf, count))
 353                 return -EFAULT;
 354         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 355                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 356                 if (!old_hdr)
 357                         return -ENOMEM;
 358                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
 359                         retval = -EFAULT;
 360                         goto free_old_hdr;
 361                 }
 362                 if (old_hdr->reply_len < 0) {
 363                         if (count >= SZ_SG_IO_HDR) {
 364                                 sg_io_hdr_t *new_hdr;
 365                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
 366                                 if (!new_hdr) {
 367                                         retval = -ENOMEM;
 368                                         goto free_old_hdr;
 369                                 }
 370                                 retval =__copy_from_user
 371                                     (new_hdr, buf, SZ_SG_IO_HDR);
 372                                 req_pack_id = new_hdr->pack_id;
 373                                 kfree(new_hdr);
 374                                 if (retval) {
 375                                         retval = -EFAULT;
 376                                         goto free_old_hdr;
 377                                 }
 378                         }
 379                 } else
 380                         req_pack_id = old_hdr->pack_id;
 381         }
 382         srp = sg_get_rq_mark(sfp, req_pack_id);
 383         if (!srp) {             /* now wait on packet to arrive */
 384                 if (sdp->detached) {
 385                         retval = -ENODEV;
 386                         goto free_old_hdr;
 387                 }
 388                 if (filp->f_flags & O_NONBLOCK) {
 389                         retval = -EAGAIN;
 390                         goto free_old_hdr;
 391                 }
 392                 while (1) {
 393                         retval = 0; /* following macro beats race condition */
 394                         __wait_event_interruptible(sfp->read_wait,
 395                                 (sdp->detached ||
 396                                 (srp = sg_get_rq_mark(sfp, req_pack_id))),
 397                                 retval);
 398                         if (sdp->detached) {
 399                                 retval = -ENODEV;
 400                                 goto free_old_hdr;
 401                         }
 402                         if (0 == retval)
 403                                 break;
 404
 405                         /* -ERESTARTSYS as signal hit process */
 406                         goto free_old_hdr;
 407                 }
 408         }
 409         if (srp->header.interface_id != '\0') {
 410                 retval = sg_new_read(sfp, buf, count, srp);
 411                 goto free_old_hdr;
 412         }
 413
 414         hp = &srp->header;
 415         if (old_hdr == NULL) {
 416                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 417                 if (! old_hdr) {
 418                         retval = -ENOMEM;
 419                         goto free_old_hdr;
 420                 }
 421         }
 422         memset(old_hdr, 0, SZ_SG_HEADER);
 423         old_hdr->reply_len = (int) hp->timeout;
 424         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 425         old_hdr->pack_id = hp->pack_id;
 426         old_hdr->twelve_byte =
 427             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 428         old_hdr->target_status = hp->masked_status;
 429         old_hdr->host_status = hp->host_status;
 430         old_hdr->driver_status = hp->driver_status;
 431         if ((CHECK_CONDITION & hp->masked_status) ||
 432             (DRIVER_SENSE & hp->driver_status))
 433                 memcpy(old_hdr->sense_buffer, srp->sense_b,
 434                        sizeof (old_hdr->sense_buffer));
 435         switch (hp->host_status) {
 436         /* This setup of 'result' is for backward compatibility and is best
 437            ignored by the user who should use target, host + driver status */
 438         case DID_OK:
 439         case DID_PASSTHROUGH:
 440         case DID_SOFT_ERROR:
 441                 old_hdr->result = 0;
 442                 break;
 443         case DID_NO_CONNECT:
 444         case DID_BUS_BUSY:
 445         case DID_TIME_OUT:
 446                 old_hdr->result = EBUSY;
 447                 break;
 448         case DID_BAD_TARGET:
 449         case DID_ABORT:
 450         case DID_PARITY:
 451         case DID_RESET:
 452         case DID_BAD_INTR:
 453                 old_hdr->result = EIO;
 454                 break;
 455         case DID_ERROR:
 456                 old_hdr->result = (srp->sense_b[0] == 0 &&
 457                                   hp->masked_status == GOOD) ? 0 : EIO;
 458                 break;
 459         default:
 460                 old_hdr->result = EIO;
 461                 break;
 462         }
 463
 464         /* Now copy the result back to the user buffer.  */
 465         if (count >= SZ_SG_HEADER) {
 466                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 467                         retval = -EFAULT;
 468                         goto free_old_hdr;
 469                 }
 470                 buf += SZ_SG_HEADER;
 471                 if (count > old_hdr->reply_len)
 472                         count = old_hdr->reply_len;
 473                 if (count > SZ_SG_HEADER) {
 474                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 475                                 retval = -EFAULT;
 476                                 goto free_old_hdr;
 477                         }
 478                 }
 479         } else
 480                 count = (old_hdr->result == 0) ? 0 : -EIO;
 481         sg_finish_rem_req(srp);
 482         retval = count;
 483 free_old_hdr:
 484         kfree(old_hdr);
 485         return retval;
 486 }
 487
 488 static ssize_t
 489 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 490 {
 491         sg_io_hdr_t *hp = &srp->header;
 492         int err = 0;
 493         int len;
 494
 495         if (count < SZ_SG_IO_HDR) {
 496                 err = -EINVAL;
 497                 goto err_out;
 498         }
 499         hp->sb_len_wr = 0;
 500         if ((hp->mx_sb_len > 0) && hp->sbp) {
 501                 if ((CHECK_CONDITION & hp->masked_status) ||
 502                     (DRIVER_SENSE & hp->driver_status)) {
 503                         int sb_len = SCSI_SENSE_BUFFERSIZE;
 504                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 505                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 506                         len = (len > sb_len) ? sb_len : len;
 507                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 508                                 err = -EFAULT;
 509                                 goto err_out;
 510                         }
 511                         hp->sb_len_wr = len;
 512                 }
 513         }
 514         if (hp->masked_status || hp->host_status || hp->driver_status)
 515                 hp->info |= SG_INFO_CHECK;
 516         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 517                 err = -EFAULT;
 518                 goto err_out;
 519         }
 520 err_out:
 521         sg_finish_rem_req(srp);
 522         return (0 == err) ? count : err;
 523 }
 524
 525 static ssize_t
 526 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 527 {
 528         int mxsize, cmd_size, k;
 529         int input_size, blocking;
 530         unsigned char opcode;
 531         Sg_device *sdp;
 532         Sg_fd *sfp;
 533         Sg_request *srp;
 534         struct sg_header old_hdr;
 535         sg_io_hdr_t *hp;
 536         unsigned char cmnd[MAX_COMMAND_SIZE];
 537
 538         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 539                 return -ENXIO;
 540         SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
 541                                    sdp->disk->disk_name, (int) count));
 542         if (sdp->detached)
 543                 return -ENODEV;
 544         if (!((filp->f_flags & O_NONBLOCK) ||
 545               scsi_block_when_processing_errors(sdp->device)))
 546                 return -ENXIO;
 547
 548         if (!access_ok(VERIFY_READ, buf, count))
 549                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 550         if (count < SZ_SG_HEADER)
 551                 return -EIO;
 552         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 553                 return -EFAULT;
 554         blocking = !(filp->f_flags & O_NONBLOCK);
 555         if (old_hdr.reply_len < 0)
 556                 return sg_new_write(sfp, filp, buf, count,
 557                                     blocking, 0, 0, NULL);
 558         if (count < (SZ_SG_HEADER + 6))
 559                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 560
 561         if (!(srp = sg_add_request(sfp))) {
 562                 SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
 563                 return -EDOM;
 564         }
 565         buf += SZ_SG_HEADER;
 566         __get_user(opcode, buf);
 567         if (sfp->next_cmd_len > 0) {
 568                 if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
 569                         SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
 570                         sfp->next_cmd_len = 0;
 571                         sg_remove_request(sfp, srp);
 572                         return -EIO;
 573                 }
 574                 cmd_size = sfp->next_cmd_len;
 575                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 576         } else {
 577                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 578                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 579                         cmd_size = 12;
 580         }
 581         SCSI_LOG_TIMEOUT(4, printk(
 582                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 583 /* Determine buffer size.  */
 584         input_size = count - cmd_size;
 585         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 586         mxsize -= SZ_SG_HEADER;
 587         input_size -= SZ_SG_HEADER;
 588         if (input_size < 0) {
 589                 sg_remove_request(sfp, srp);
 590                 return -EIO;    /* User did not pass enough bytes for this command. */
 591         }
 592         hp = &srp->header;
 593         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 594         hp->cmd_len = (unsigned char) cmd_size;
 595         hp->iovec_count = 0;
 596         hp->mx_sb_len = 0;
 597         if (input_size > 0)
 598                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 599                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 600         else
 601                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 602         hp->dxfer_len = mxsize;
 603         if (hp->dxfer_direction == SG_DXFER_TO_DEV)
 604                 hp->dxferp = (char __user *)buf + cmd_size;
 605         else
 606                 hp->dxferp = NULL;
 607         hp->sbp = NULL;
 608         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 609         hp->flags = input_size; /* structure abuse ... */
 610         hp->pack_id = old_hdr.pack_id;
 611         hp->usr_ptr = NULL;
 612         if (__copy_from_user(cmnd, buf, cmd_size))
 613                 return -EFAULT;
 614         /*
 615          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 616          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 617          * is a non-zero input_size, so emit a warning.
 618          */
 619         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 620                 static char cmd[TASK_COMM_LEN];
 621                 if (strcmp(current->comm, cmd) && printk_ratelimit()) {
 622                         printk(KERN_WARNING
 623                                "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
 624                                "guessing data in;\n" KERN_WARNING "   "
 625                                "program %s not setting count and/or reply_len properly\n",
 626                                old_hdr.reply_len - (int)SZ_SG_HEADER,
 627                                input_size, (unsigned int) cmnd[0],
 628                                current->comm);
 629                         strcpy(cmd, current->comm);
 630                 }
 631         }
 632         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 633         return (k < 0) ? k : count;
 634 }
 635
 636 static ssize_t
 637 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 638                  size_t count, int blocking, int read_only, int sg_io_owned,
 639                  Sg_request **o_srp)
 640 {
 641         int k;
 642         Sg_request *srp;
 643         sg_io_hdr_t *hp;
 644         unsigned char cmnd[MAX_COMMAND_SIZE];
 645         int timeout;
 646         unsigned long ul_timeout;
 647
 648         if (count < SZ_SG_IO_HDR)
 649                 return -EINVAL;
 650         if (!access_ok(VERIFY_READ, buf, count))
 651                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 652
 653         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 654         if (!(srp = sg_add_request(sfp))) {
 655                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
 656                 return -EDOM;
 657         }
 658         srp->sg_io_owned = sg_io_owned;
 659         hp = &srp->header;
 660         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 661                 sg_remove_request(sfp, srp);
 662                 return -EFAULT;
 663         }
 664         if (hp->interface_id != 'S') {
 665                 sg_remove_request(sfp, srp);
 666                 return -ENOSYS;
 667         }
 668         if (hp->flags & SG_FLAG_MMAP_IO) {
 669                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 670                         sg_remove_request(sfp, srp);
 671                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 672                 }
 673                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 674                         sg_remove_request(sfp, srp);
 675                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 676                 }
 677                 if (sg_res_in_use(sfp)) {
 678                         sg_remove_request(sfp, srp);
 679                         return -EBUSY;  /* reserve buffer already being used */
 680                 }
 681         }
 682         ul_timeout = msecs_to_jiffies(srp->header.timeout);
 683         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 684         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 685                 sg_remove_request(sfp, srp);
 686                 return -EMSGSIZE;
 687         }
 688         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
 689                 sg_remove_request(sfp, srp);
 690                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 691         }
 692         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 693                 sg_remove_request(sfp, srp);
 694                 return -EFAULT;
 695         }
 696         if (read_only && sg_allow_access(file, cmnd)) {
 697                 sg_remove_request(sfp, srp);
 698                 return -EPERM;
 699         }
 700         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 701         if (k < 0)
 702                 return k;
 703         if (o_srp)
 704                 *o_srp = srp;
 705         return count;
 706 }
 707
 708 static int
 709 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 710                 unsigned char *cmnd, int timeout, int blocking)
 711 {
 712         int k, data_dir;
 713         Sg_device *sdp = sfp->parentdp;
 714         sg_io_hdr_t *hp = &srp->header;
 715
 716         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 717         hp->status = 0;
 718         hp->masked_status = 0;
 719         hp->msg_status = 0;
 720         hp->info = 0;
 721         hp->host_status = 0;
 722         hp->driver_status = 0;
 723         hp->resid = 0;
 724         SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 725                           (int) cmnd[0], (int) hp->cmd_len));
 726
 727         k = sg_start_req(srp, cmnd);
 728         if (k) {
 729                 SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k));
 730                 sg_finish_rem_req(srp);
 731                 return k;       /* probably out of space --> ENOMEM */
 732         }
 733         if (sdp->detached) {
 734                 sg_finish_rem_req(srp);
 735                 return -ENODEV;
 736         }
 737
 738         switch (hp->dxfer_direction) {
 739         case SG_DXFER_TO_FROM_DEV:
 740         case SG_DXFER_FROM_DEV:
 741                 data_dir = DMA_FROM_DEVICE;
 742                 break;
 743         case SG_DXFER_TO_DEV:
 744                 data_dir = DMA_TO_DEVICE;
 745                 break;
 746         case SG_DXFER_UNKNOWN:
 747                 data_dir = DMA_BIDIRECTIONAL;
 748                 break;
 749         default:
 750                 data_dir = DMA_NONE;
 751                 break;
 752         }
 753         hp->duration = jiffies_to_msecs(jiffies);
 754
 755         srp->rq->timeout = timeout;
 756         kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
 757         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 758                               srp->rq, 1, sg_rq_end_io);
 759         return 0;
 760 }
 761
 762 static int
 763 sg_ioctl(struct inode *inode, struct file *filp,
 764          unsigned int cmd_in, unsigned long arg)
 765 {
 766         void __user *p = (void __user *)arg;
 767         int __user *ip = p;
 768         int result, val, read_only;
 769         Sg_device *sdp;
 770         Sg_fd *sfp;
 771         Sg_request *srp;
 772         unsigned long iflags;
 773
 774         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 775                 return -ENXIO;
 776
 777         SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
 778                                    sdp->disk->disk_name, (int) cmd_in));
 779         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 780
 781         switch (cmd_in) {
 782         case SG_IO:
 783                 {
 784                         int blocking = 1;       /* ignore O_NONBLOCK flag */
 785
 786                         if (sdp->detached)
 787                                 return -ENODEV;
 788                         if (!scsi_block_when_processing_errors(sdp->device))
 789                                 return -ENXIO;
 790                         if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 791                                 return -EFAULT;
 792                         result =
 793                             sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 794                                          blocking, read_only, 1, &srp);
 795                         if (result < 0)
 796                                 return result;
 797                         while (1) {
 798                                 result = 0;     /* following macro to beat race condition */
 799                                 __wait_event_interruptible(sfp->read_wait,
 800                                         (srp->done || sdp->detached),
 801                                         result);
 802                                 if (sdp->detached)
 803                                         return -ENODEV;
 804                                 write_lock_irq(&sfp->rq_list_lock);
 805                                 if (srp->done) {
 806                                         srp->done = 2;
 807                                         write_unlock_irq(&sfp->rq_list_lock);
 808                                         break;
 809                                 }
 810                                 srp->orphan = 1;
 811                                 write_unlock_irq(&sfp->rq_list_lock);
 812                                 return result;  /* -ERESTARTSYS because signal hit process */
 813                         }
 814                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 815                         return (result < 0) ? result : 0;
 816                 }
 817         case SG_SET_TIMEOUT:
 818                 result = get_user(val, ip);
 819                 if (result)
 820                         return result;
 821                 if (val < 0)
 822                         return -EIO;
 823                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
 824                     val = MULDIV (INT_MAX, USER_HZ, HZ);
 825                 sfp->timeout_user = val;
 826                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
 827
 828                 return 0;
 829         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 830                                 /* strange ..., for backward compatibility */
 831                 return sfp->timeout_user;
 832         case SG_SET_FORCE_LOW_DMA:
 833                 result = get_user(val, ip);
 834                 if (result)
 835                         return result;
 836                 if (val) {
 837                         sfp->low_dma = 1;
 838                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
 839                                 val = (int) sfp->reserve.bufflen;
 840                                 sg_remove_scat(&sfp->reserve);
 841                                 sg_build_reserve(sfp, val);
 842                         }
 843                 } else {
 844                         if (sdp->detached)
 845                                 return -ENODEV;
 846                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
 847                 }
 848                 return 0;
 849         case SG_GET_LOW_DMA:
 850                 return put_user((int) sfp->low_dma, ip);
 851         case SG_GET_SCSI_ID:
 852                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 853                         return -EFAULT;
 854                 else {
 855                         sg_scsi_id_t __user *sg_idp = p;
 856
 857                         if (sdp->detached)
 858                                 return -ENODEV;
 859                         __put_user((int) sdp->device->host->host_no,
 860                                    &sg_idp->host_no);
 861                         __put_user((int) sdp->device->channel,
 862                                    &sg_idp->channel);
 863                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 864                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 865                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 866                         __put_user((short) sdp->device->host->cmd_per_lun,
 867                                    &sg_idp->h_cmd_per_lun);
 868                         __put_user((short) sdp->device->queue_depth,
 869                                    &sg_idp->d_queue_depth);
 870                         __put_user(0, &sg_idp->unused[0]);
 871                         __put_user(0, &sg_idp->unused[1]);
 872                         return 0;
 873                 }
 874         case SG_SET_FORCE_PACK_ID:
 875                 result = get_user(val, ip);
 876                 if (result)
 877                         return result;
 878                 sfp->force_packid = val ? 1 : 0;
 879                 return 0;
 880         case SG_GET_PACK_ID:
 881                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 882                         return -EFAULT;
 883                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 884                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
 885                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 886                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 887                                                        iflags);
 888                                 __put_user(srp->header.pack_id, ip);
 889                                 return 0;
 890                         }
 891                 }
 892                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 893                 __put_user(-1, ip);
 894                 return 0;
 895         case SG_GET_NUM_WAITING:
 896                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 897                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
 898                         if ((1 == srp->done) && (!srp->sg_io_owned))
 899                                 ++val;
 900                 }
 901                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 902                 return put_user(val, ip);
 903         case SG_GET_SG_TABLESIZE:
 904                 return put_user(sdp->sg_tablesize, ip);
 905         case SG_SET_RESERVED_SIZE:
 906                 result = get_user(val, ip);
 907                 if (result)
 908                         return result;
 909                 if (val < 0)
 910                         return -EINVAL;
 911                 val = min_t(int, val,
 912                                 sdp->device->request_queue->max_sectors * 512);
 913                 if (val != sfp->reserve.bufflen) {
 914                         if (sg_res_in_use(sfp) || sfp->mmap_called)
 915                                 return -EBUSY;
 916                         sg_remove_scat(&sfp->reserve);
 917                         sg_build_reserve(sfp, val);
 918                 }
 919                 return 0;
 920         case SG_GET_RESERVED_SIZE:
 921                 val = min_t(int, sfp->reserve.bufflen,
 922                                 sdp->device->request_queue->max_sectors * 512);
 923                 return put_user(val, ip);
 924         case SG_SET_COMMAND_Q:
 925                 result = get_user(val, ip);
 926                 if (result)
 927                         return result;
 928                 sfp->cmd_q = val ? 1 : 0;
 929                 return 0;
 930         case SG_GET_COMMAND_Q:
 931                 return put_user((int) sfp->cmd_q, ip);
 932         case SG_SET_KEEP_ORPHAN:
 933                 result = get_user(val, ip);
 934                 if (result)
 935                         return result;
 936                 sfp->keep_orphan = val;
 937                 return 0;
 938         case SG_GET_KEEP_ORPHAN:
 939                 return put_user((int) sfp->keep_orphan, ip);
 940         case SG_NEXT_CMD_LEN:
 941                 result = get_user(val, ip);
 942                 if (result)
 943                         return result;
 944                 sfp->next_cmd_len = (val > 0) ? val : 0;
 945                 return 0;
 946         case SG_GET_VERSION_NUM:
 947                 return put_user(sg_version_num, ip);
 948         case SG_GET_ACCESS_COUNT:
 949                 /* faked - we don't have a real access count anymore */
 950                 val = (sdp->device ? 1 : 0);
 951                 return put_user(val, ip);
 952         case SG_GET_REQUEST_TABLE:
 953                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
 954                         return -EFAULT;
 955                 else {
 956                         sg_req_info_t *rinfo;
 957                         unsigned int ms;
 958
 959                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
 960                                                                 GFP_KERNEL);
 961                         if (!rinfo)
 962                                 return -ENOMEM;
 963                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 964                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
 965                              ++val, srp = srp ? srp->nextrp : srp) {
 966                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
 967                                 if (srp) {
 968                                         rinfo[val].req_state = srp->done + 1;
 969                                         rinfo[val].problem =
 970                                             srp->header.masked_status &
 971                                             srp->header.host_status &
 972                                             srp->header.driver_status;
 973                                         if (srp->done)
 974                                                 rinfo[val].duration =
 975                                                         srp->header.duration;
 976                                         else {
 977                                                 ms = jiffies_to_msecs(jiffies);
 978                                                 rinfo[val].duration =
 979                                                     (ms > srp->header.duration) ?
 980                                                     (ms - srp->header.duration) : 0;
 981                                         }
 982                                         rinfo[val].orphan = srp->orphan;
 983                                         rinfo[val].sg_io_owned =
 984                                                         srp->sg_io_owned;
 985                                         rinfo[val].pack_id =
 986                                                         srp->header.pack_id;
 987                                         rinfo[val].usr_ptr =
 988                                                         srp->header.usr_ptr;
 989                                 }
 990                         }
 991                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 992                         result = __copy_to_user(p, rinfo,
 993                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
 994                         result = result ? -EFAULT : 0;
 995                         kfree(rinfo);
 996                         return result;
 997                 }
 998         case SG_EMULATED_HOST:
 999                 if (sdp->detached)
1000                         return -ENODEV;
1001                 return put_user(sdp->device->host->hostt->emulated, ip);
1002         case SG_SCSI_RESET:
1003                 if (sdp->detached)
1004                         return -ENODEV;
1005                 if (filp->f_flags & O_NONBLOCK) {
1006                         if (scsi_host_in_recovery(sdp->device->host))
1007                                 return -EBUSY;
1008                 } else if (!scsi_block_when_processing_errors(sdp->device))
1009                         return -EBUSY;
1010                 result = get_user(val, ip);
1011                 if (result)
1012                         return result;
1013                 if (SG_SCSI_RESET_NOTHING == val)
1014                         return 0;
1015                 switch (val) {
1016                 case SG_SCSI_RESET_DEVICE:
1017                         val = SCSI_TRY_RESET_DEVICE;
1018                         break;
1019                 case SG_SCSI_RESET_TARGET:
1020                         val = SCSI_TRY_RESET_TARGET;
1021                         break;
1022                 case SG_SCSI_RESET_BUS:
1023                         val = SCSI_TRY_RESET_BUS;
1024                         break;
1025                 case SG_SCSI_RESET_HOST:
1026                         val = SCSI_TRY_RESET_HOST;
1027                         break;
1028                 default:
1029                         return -EINVAL;
1030                 }
1031                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1032                         return -EACCES;
1033                 return (scsi_reset_provider(sdp->device, val) ==
1034                         SUCCESS) ? 0 : -EIO;
1035         case SCSI_IOCTL_SEND_COMMAND:
1036                 if (sdp->detached)
1037                         return -ENODEV;
1038                 if (read_only) {
1039                         unsigned char opcode = WRITE_6;
1040                         Scsi_Ioctl_Command __user *siocp = p;
1041
1042                         if (copy_from_user(&opcode, siocp->data, 1))
1043                                 return -EFAULT;
1044                         if (sg_allow_access(filp, &opcode))
1045                                 return -EPERM;
1046                 }
1047                 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1048         case SG_SET_DEBUG:
1049                 result = get_user(val, ip);
1050                 if (result)
1051                         return result;
1052                 sdp->sgdebug = (char) val;
1053                 return 0;
1054         case SCSI_IOCTL_GET_IDLUN:
1055         case SCSI_IOCTL_GET_BUS_NUMBER:
1056         case SCSI_IOCTL_PROBE_HOST:
1057         case SG_GET_TRANSFORM:
1058                 if (sdp->detached)
1059                         return -ENODEV;
1060                 return scsi_ioctl(sdp->device, cmd_in, p);
1061         case BLKSECTGET:
1062                 return put_user(sdp->device->request_queue->max_sectors * 512,
1063                                 ip);
1064         case BLKTRACESETUP:
1065                 return blk_trace_setup(sdp->device->request_queue,
1066                                        sdp->disk->disk_name,
1067                                        MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1068                                        (char *)arg);
1069         case BLKTRACESTART:
1070                 return blk_trace_startstop(sdp->device->request_queue, 1);
1071         case BLKTRACESTOP:
1072                 return blk_trace_startstop(sdp->device->request_queue, 0);
1073         case BLKTRACETEARDOWN:
1074                 return blk_trace_remove(sdp->device->request_queue);
1075         default:
1076                 if (read_only)
1077                         return -EPERM;  /* don't know so take safe approach */
1078                 return scsi_ioctl(sdp->device, cmd_in, p);
1079         }
1080 }
1081
1082 #ifdef CONFIG_COMPAT
1083 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1084 {
1085         Sg_device *sdp;
1086         Sg_fd *sfp;
1087         struct scsi_device *sdev;
1088
1089         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1090                 return -ENXIO;
1091
1092         sdev = sdp->device;
1093         if (sdev->host->hostt->compat_ioctl) {
1094                 int ret;
1095
1096                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1097
1098                 return ret;
1099         }
1100
1101         return -ENOIOCTLCMD;
1102 }
1103 #endif
1104
1105 static unsigned int
1106 sg_poll(struct file *filp, poll_table * wait)
1107 {
1108         unsigned int res = 0;
1109         Sg_device *sdp;
1110         Sg_fd *sfp;
1111         Sg_request *srp;
1112         int count = 0;
1113         unsigned long iflags;
1114
1115         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1116             || sfp->closed)
1117                 return POLLERR;
1118         poll_wait(filp, &sfp->read_wait, wait);
1119         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1120         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1121                 /* if any read waiting, flag it */
1122                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1123                         res = POLLIN | POLLRDNORM;
1124                 ++count;
1125         }
1126         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1127
1128         if (sdp->detached)
1129                 res |= POLLHUP;
1130         else if (!sfp->cmd_q) {
1131                 if (0 == count)
1132                         res |= POLLOUT | POLLWRNORM;
1133         } else if (count < SG_MAX_QUEUE)
1134                 res |= POLLOUT | POLLWRNORM;
1135         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1136                                    sdp->disk->disk_name, (int) res));
1137         return res;
1138 }
1139
1140 static int
1141 sg_fasync(int fd, struct file *filp, int mode)
1142 {
1143         Sg_device *sdp;
1144         Sg_fd *sfp;
1145
1146         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1147                 return -ENXIO;
1148         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1149                                    sdp->disk->disk_name, mode));
1150
1151         return fasync_helper(fd, filp, mode, &sfp->async_qp);
1152 }
1153
1154 static int
1155 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1156 {
1157         Sg_fd *sfp;
1158         unsigned long offset, len, sa;
1159         Sg_scatter_hold *rsv_schp;
1160         int k, length;
1161
1162         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1163                 return VM_FAULT_SIGBUS;
1164         rsv_schp = &sfp->reserve;
1165         offset = vmf->pgoff << PAGE_SHIFT;
1166         if (offset >= rsv_schp->bufflen)
1167                 return VM_FAULT_SIGBUS;
1168         SCSI_LOG_TIMEOUT(3, printk("sg_vma_fault: offset=%lu, scatg=%d\n",
1169                                    offset, rsv_schp->k_use_sg));
1170         sa = vma->vm_start;
1171         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1172         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1173                 len = vma->vm_end - sa;
1174                 len = (len < length) ? len : length;
1175                 if (offset < len) {
1176                         struct page *page = nth_page(rsv_schp->pages[k],
1177                                                      offset >> PAGE_SHIFT);
1178                         get_page(page); /* increment page count */
1179                         vmf->page = page;
1180                         return 0; /* success */
1181                 }
1182                 sa += len;
1183                 offset -= len;
1184         }
1185
1186         return VM_FAULT_SIGBUS;
1187 }
1188
1189 static struct vm_operations_struct sg_mmap_vm_ops = {
1190         .fault = sg_vma_fault,
1191 };
1192
1193 static int
1194 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1195 {
1196         Sg_fd *sfp;
1197         unsigned long req_sz, len, sa;
1198         Sg_scatter_hold *rsv_schp;
1199         int k, length;
1200
1201         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1202                 return -ENXIO;
1203         req_sz = vma->vm_end - vma->vm_start;
1204         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1205                                    (void *) vma->vm_start, (int) req_sz));
1206         if (vma->vm_pgoff)
1207                 return -EINVAL; /* want no offset */
1208         rsv_schp = &sfp->reserve;
1209         if (req_sz > rsv_schp->bufflen)
1210                 return -ENOMEM; /* cannot map more than reserved buffer */
1211
1212         sa = vma->vm_start;
1213         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1214         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1215                 len = vma->vm_end - sa;
1216                 len = (len < length) ? len : length;
1217                 sa += len;
1218         }
1219
1220         sfp->mmap_called = 1;
1221         vma->vm_flags |= VM_RESERVED;
1222         vma->vm_private_data = sfp;
1223         vma->vm_ops = &sg_mmap_vm_ops;
1224         return 0;
1225 }
1226
1227 static void sg_rq_end_io_usercontext(struct work_struct *work)
1228 {
1229         struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1230         struct sg_fd *sfp = srp->parentfp;
1231
1232         sg_finish_rem_req(srp);
1233         kref_put(&sfp->f_ref, sg_remove_sfp);
1234 }
1235
1236 /*
1237  * This function is a "bottom half" handler that is called by the mid
1238  * level when a command is completed (or has failed).
1239  */
1240 static void sg_rq_end_io(struct request *rq, int uptodate)
1241 {
1242         struct sg_request *srp = rq->end_io_data;
1243         Sg_device *sdp;
1244         Sg_fd *sfp;
1245         unsigned long iflags;
1246         unsigned int ms;
1247         char *sense;
1248         int result, resid, done = 1;
1249
1250         if (WARN_ON(srp->done != 0))
1251                 return;
1252
1253         sfp = srp->parentfp;
1254         if (WARN_ON(sfp == NULL))
1255                 return;
1256
1257         sdp = sfp->parentdp;
1258         if (unlikely(sdp->detached))
1259                 printk(KERN_INFO "sg_rq_end_io: device detached\n");
1260
1261         sense = rq->sense;
1262         result = rq->errors;
1263         resid = rq->data_len;
1264
1265         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1266                 sdp->disk->disk_name, srp->header.pack_id, result));
1267         srp->header.resid = resid;
1268         ms = jiffies_to_msecs(jiffies);
1269         srp->header.duration = (ms > srp->header.duration) ?
1270                                 (ms - srp->header.duration) : 0;
1271         if (0 != result) {
1272                 struct scsi_sense_hdr sshdr;
1273
1274                 srp->header.status = 0xff & result;
1275                 srp->header.masked_status = status_byte(result);
1276                 srp->header.msg_status = msg_byte(result);
1277                 srp->header.host_status = host_byte(result);
1278                 srp->header.driver_status = driver_byte(result);
1279                 if ((sdp->sgdebug > 0) &&
1280                     ((CHECK_CONDITION == srp->header.masked_status) ||
1281                      (COMMAND_TERMINATED == srp->header.masked_status)))
1282                         __scsi_print_sense("sg_cmd_done", sense,
1283                                            SCSI_SENSE_BUFFERSIZE);
1284
1285                 /* Following if statement is a patch supplied by Eric Youngdale */
1286                 if (driver_byte(result) != 0
1287                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1288                     && !scsi_sense_is_deferred(&sshdr)
1289                     && sshdr.sense_key == UNIT_ATTENTION
1290                     && sdp->device->removable) {
1291                         /* Detected possible disc change. Set the bit - this */
1292                         /* may be used if there are filesystems using this device */
1293                         sdp->device->changed = 1;
1294                 }
1295         }
1296         /* Rely on write phase to clean out srp status values, so no "else" */
1297
1298         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1299         if (unlikely(srp->orphan)) {
1300                 if (sfp->keep_orphan)
1301                         srp->sg_io_owned = 0;
1302                 else
1303                         done = 0;
1304         }
1305         srp->done = done;
1306         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1307
1308         if (likely(done)) {
1309                 /* Now wake up any sg_read() that is waiting for this
1310                  * packet.
1311                  */
1312                 wake_up_interruptible(&sfp->read_wait);
1313                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1314                 kref_put(&sfp->f_ref, sg_remove_sfp);
1315         } else
1316                 execute_in_process_context(sg_rq_end_io_usercontext, &srp->ew);
1317 }
1318
1319 static struct file_operations sg_fops = {
1320         .owner = THIS_MODULE,
1321         .read = sg_read,
1322         .write = sg_write,
1323         .poll = sg_poll,
1324         .ioctl = sg_ioctl,
1325 #ifdef CONFIG_COMPAT
1326         .compat_ioctl = sg_compat_ioctl,
1327 #endif
1328         .open = sg_open,
1329         .mmap = sg_mmap,
1330         .release = sg_release,
1331         .fasync = sg_fasync,
1332 };
1333
1334 static struct class *sg_sysfs_class;
1335
1336 static int sg_sysfs_valid = 0;
1337
1338 static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1339 {
1340         struct request_queue *q = scsidp->request_queue;
1341         Sg_device *sdp;
1342         unsigned long iflags;
1343         int error;
1344         u32 k;
1345
1346         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1347         if (!sdp) {
1348                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1349                 return ERR_PTR(-ENOMEM);
1350         }
1351
1352         if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) {
1353                 printk(KERN_WARNING "idr expansion Sg_device failure\n");
1354                 error = -ENOMEM;
1355                 goto out;
1356         }
1357
1358         write_lock_irqsave(&sg_index_lock, iflags);
1359
1360         error = idr_get_new(&sg_index_idr, sdp, &k);
1361         if (error) {
1362                 write_unlock_irqrestore(&sg_index_lock, iflags);
1363                 printk(KERN_WARNING "idr allocation Sg_device failure: %d\n",
1364                        error);
1365                 goto out;
1366         }
1367
1368         if (unlikely(k >= SG_MAX_DEVS))
1369                 goto overflow;
1370
1371         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1372         sprintf(disk->disk_name, "sg%d", k);
1373         disk->first_minor = k;
1374         sdp->disk = disk;
1375         sdp->device = scsidp;
1376         INIT_LIST_HEAD(&sdp->sfds);
1377         init_waitqueue_head(&sdp->o_excl_wait);
1378         sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments);
1379         sdp->index = k;
1380         kref_init(&sdp->d_ref);
1381
1382         write_unlock_irqrestore(&sg_index_lock, iflags);
1383
1384         error = 0;
1385  out:
1386         if (error) {
1387                 kfree(sdp);
1388                 return ERR_PTR(error);
1389         }
1390         return sdp;
1391
1392  overflow:
1393         idr_remove(&sg_index_idr, k);
1394         write_unlock_irqrestore(&sg_index_lock, iflags);
1395         sdev_printk(KERN_WARNING, scsidp,
1396                     "Unable to attach sg device type=%d, minor "
1397                     "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1398         error = -ENODEV;
1399         goto out;
1400 }
1401
1402 static int
1403 sg_add(struct device *cl_dev, struct class_interface *cl_intf)
1404 {
1405         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1406         struct gendisk *disk;
1407         Sg_device *sdp = NULL;
1408         struct cdev * cdev = NULL;
1409         int error;
1410         unsigned long iflags;
1411
1412         disk = alloc_disk(1);
1413         if (!disk) {
1414                 printk(KERN_WARNING "alloc_disk failed\n");
1415                 return -ENOMEM;
1416         }
1417         disk->major = SCSI_GENERIC_MAJOR;
1418
1419         error = -ENOMEM;
1420         cdev = cdev_alloc();
1421         if (!cdev) {
1422                 printk(KERN_WARNING "cdev_alloc failed\n");
1423                 goto out;
1424         }
1425         cdev->owner = THIS_MODULE;
1426         cdev->ops = &sg_fops;
1427
1428         sdp = sg_alloc(disk, scsidp);
1429         if (IS_ERR(sdp)) {
1430                 printk(KERN_WARNING "sg_alloc failed\n");
1431                 error = PTR_ERR(sdp);
1432                 goto out;
1433         }
1434
1435         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1436         if (error)
1437                 goto cdev_add_err;
1438
1439         sdp->cdev = cdev;
1440         if (sg_sysfs_valid) {
1441                 struct device *sg_class_member;
1442
1443                 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1444                                                 MKDEV(SCSI_GENERIC_MAJOR,
1445                                                       sdp->index),
1446                                                 sdp, "%s", disk->disk_name);
1447                 if (IS_ERR(sg_class_member)) {
1448                         printk(KERN_ERR "sg_add: "
1449                                "device_create failed\n");
1450                         error = PTR_ERR(sg_class_member);
1451                         goto cdev_add_err;
1452                 }
1453                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1454                                           &sg_class_member->kobj, "generic");
1455                 if (error)
1456                         printk(KERN_ERR "sg_add: unable to make symlink "
1457                                         "'generic' back to sg%d\n", sdp->index);
1458         } else
1459                 printk(KERN_WARNING "sg_add: sg_sys Invalid\n");
1460
1461         sdev_printk(KERN_NOTICE, scsidp,
1462                     "Attached scsi generic sg%d type %d\n", sdp->index,
1463                     scsidp->type);
1464
1465         dev_set_drvdata(cl_dev, sdp);
1466
1467         return 0;
1468
1469 cdev_add_err:
1470         write_lock_irqsave(&sg_index_lock, iflags);
1471         idr_remove(&sg_index_idr, sdp->index);
1472         write_unlock_irqrestore(&sg_index_lock, iflags);
1473         kfree(sdp);
1474
1475 out:
1476         put_disk(disk);
1477         if (cdev)
1478                 cdev_del(cdev);
1479         return error;
1480 }
1481
1482 static void sg_device_destroy(struct kref *kref)
1483 {
1484         struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1485         unsigned long flags;
1486
1487         /* CAUTION!  Note that the device can still be found via idr_find()
1488          * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1489          * any other cleanup.
1490          */
1491
1492         write_lock_irqsave(&sg_index_lock, flags);
1493         idr_remove(&sg_index_idr, sdp->index);
1494         write_unlock_irqrestore(&sg_index_lock, flags);
1495
1496         SCSI_LOG_TIMEOUT(3,
1497                 printk("sg_device_destroy: %s\n",
1498                         sdp->disk->disk_name));
1499
1500         put_disk(sdp->disk);
1501         kfree(sdp);
1502 }
1503
1504 static void sg_remove(struct device *cl_dev, struct class_interface *cl_intf)
1505 {
1506         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1507         Sg_device *sdp = dev_get_drvdata(cl_dev);
1508         unsigned long iflags;
1509         Sg_fd *sfp;
1510
1511         if (!sdp || sdp->detached)
1512                 return;
1513
1514         SCSI_LOG_TIMEOUT(3, printk("sg_remove: %s\n", sdp->disk->disk_name));
1515
1516         /* Need a write lock to set sdp->detached. */
1517         write_lock_irqsave(&sg_index_lock, iflags);
1518         sdp->detached = 1;
1519         list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1520                 wake_up_interruptible(&sfp->read_wait);
1521                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1522         }
1523         write_unlock_irqrestore(&sg_index_lock, iflags);
1524
1525         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1526         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1527         cdev_del(sdp->cdev);
1528         sdp->cdev = NULL;
1529
1530         sg_put_dev(sdp);
1531 }
1532
1533 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1534 module_param_named(def_reserved_size, def_reserved_size, int,
1535                    S_IRUGO | S_IWUSR);
1536 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1537
1538 MODULE_AUTHOR("Douglas Gilbert");
1539 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1540 MODULE_LICENSE("GPL");
1541 MODULE_VERSION(SG_VERSION_STR);
1542 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1543
1544 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1545                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1546 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1547 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1548
1549 static int __init
1550 init_sg(void)
1551 {
1552         int rc;
1553
1554         if (scatter_elem_sz < PAGE_SIZE) {
1555                 scatter_elem_sz = PAGE_SIZE;
1556                 scatter_elem_sz_prev = scatter_elem_sz;
1557         }
1558         if (def_reserved_size >= 0)
1559                 sg_big_buff = def_reserved_size;
1560         else
1561                 def_reserved_size = sg_big_buff;
1562
1563         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1564                                     SG_MAX_DEVS, "sg");
1565         if (rc)
1566                 return rc;
1567         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1568         if ( IS_ERR(sg_sysfs_class) ) {
1569                 rc = PTR_ERR(sg_sysfs_class);
1570                 goto err_out;
1571         }
1572         sg_sysfs_valid = 1;
1573         rc = scsi_register_interface(&sg_interface);
1574         if (0 == rc) {
1575 #ifdef CONFIG_SCSI_PROC_FS
1576                 sg_proc_init();
1577 #endif                          /* CONFIG_SCSI_PROC_FS */
1578                 return 0;
1579         }
1580         class_destroy(sg_sysfs_class);
1581 err_out:
1582         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1583         return rc;
1584 }
1585
1586 static void __exit
1587 exit_sg(void)
1588 {
1589 #ifdef CONFIG_SCSI_PROC_FS
1590         sg_proc_cleanup();
1591 #endif                          /* CONFIG_SCSI_PROC_FS */
1592         scsi_unregister_interface(&sg_interface);
1593         class_destroy(sg_sysfs_class);
1594         sg_sysfs_valid = 0;
1595         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1596                                  SG_MAX_DEVS);
1597         idr_destroy(&sg_index_idr);
1598 }
1599
1600 static int sg_start_req(Sg_request *srp, unsigned char *cmd)
1601 {
1602         int res;
1603         struct request *rq;
1604         Sg_fd *sfp = srp->parentfp;
1605         sg_io_hdr_t *hp = &srp->header;
1606         int dxfer_len = (int) hp->dxfer_len;
1607         int dxfer_dir = hp->dxfer_direction;
1608         unsigned int iov_count = hp->iovec_count;
1609         Sg_scatter_hold *req_schp = &srp->data;
1610         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1611         struct request_queue *q = sfp->parentdp->device->request_queue;
1612         struct rq_map_data *md, map_data;
1613         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1614
1615         SCSI_LOG_TIMEOUT(4, printk(KERN_INFO "sg_start_req: dxfer_len=%d\n",
1616                                    dxfer_len));
1617
1618         rq = blk_get_request(q, rw, GFP_ATOMIC);
1619         if (!rq)
1620                 return -ENOMEM;
1621
1622         memcpy(rq->cmd, cmd, hp->cmd_len);
1623
1624         rq->cmd_len = hp->cmd_len;
1625         rq->cmd_type = REQ_TYPE_BLOCK_PC;
1626
1627         srp->rq = rq;
1628         rq->end_io_data = srp;
1629         rq->sense = srp->sense_b;
1630         rq->retries = SG_DEFAULT_RETRIES;
1631
1632         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1633                 return 0;
1634
1635         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1636             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1637             !sfp->parentdp->device->host->unchecked_isa_dma &&
1638             blk_rq_aligned(q, hp->dxferp, dxfer_len))
1639                 md = NULL;
1640         else
1641                 md = &map_data;
1642
1643         if (md) {
1644                 if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
1645                         sg_link_reserve(sfp, srp, dxfer_len);
1646                 else {
1647                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1648                         if (res)
1649                                 return res;
1650                 }
1651
1652                 md->pages = req_schp->pages;
1653                 md->page_order = req_schp->page_order;
1654                 md->nr_entries = req_schp->k_use_sg;
1655                 md->offset = 0;
1656                 md->null_mapped = hp->dxferp ? 0 : 1;
1657         }
1658
1659         if (iov_count)
1660                 res = blk_rq_map_user_iov(q, rq, md, hp->dxferp, iov_count,
1661                                           hp->dxfer_len, GFP_ATOMIC);
1662         else
1663                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1664                                       hp->dxfer_len, GFP_ATOMIC);
1665
1666         if (!res) {
1667                 srp->bio = rq->bio;
1668
1669                 if (!md) {
1670                         req_schp->dio_in_use = 1;
1671                         hp->info |= SG_INFO_DIRECT_IO;
1672                 }
1673         }
1674         return res;
1675 }
1676
1677 static void
1678 sg_finish_rem_req(Sg_request * srp)
1679 {
1680         Sg_fd *sfp = srp->parentfp;
1681         Sg_scatter_hold *req_schp = &srp->data;
1682
1683         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1684         if (srp->res_used)
1685                 sg_unlink_reserve(sfp, srp);
1686         else
1687                 sg_remove_scat(req_schp);
1688
1689         if (srp->rq) {
1690                 if (srp->bio)
1691                         blk_rq_unmap_user(srp->bio);
1692
1693                 blk_put_request(srp->rq);
1694         }
1695
1696         sg_remove_request(sfp, srp);
1697 }
1698
1699 static int
1700 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1701 {
1702         int sg_bufflen = tablesize * sizeof(struct page *);
1703         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1704
1705         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1706         if (!schp->pages)
1707                 return -ENOMEM;
1708         schp->sglist_len = sg_bufflen;
1709         return tablesize;       /* number of scat_gath elements allocated */
1710 }
1711
1712 static int
1713 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1714 {
1715         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1716         int sg_tablesize = sfp->parentdp->sg_tablesize;
1717         int blk_size = buff_size, order;
1718         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1719
1720         if (blk_size < 0)
1721                 return -EFAULT;
1722         if (0 == blk_size)
1723                 ++blk_size;     /* don't know why */
1724         /* round request up to next highest SG_SECTOR_SZ byte boundary */
1725         blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1726         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1727                                    buff_size, blk_size));
1728
1729         /* N.B. ret_sz carried into this block ... */
1730         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1731         if (mx_sc_elems < 0)
1732                 return mx_sc_elems;     /* most likely -ENOMEM */
1733
1734         num = scatter_elem_sz;
1735         if (unlikely(num != scatter_elem_sz_prev)) {
1736                 if (num < PAGE_SIZE) {
1737                         scatter_elem_sz = PAGE_SIZE;
1738                         scatter_elem_sz_prev = PAGE_SIZE;
1739                 } else
1740                         scatter_elem_sz_prev = num;
1741         }
1742
1743         if (sfp->low_dma)
1744                 gfp_mask |= GFP_DMA;
1745
1746         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1747                 gfp_mask |= __GFP_ZERO;
1748
1749         order = get_order(num);
1750 retry:
1751         ret_sz = 1 << (PAGE_SHIFT + order);
1752
1753         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1754              k++, rem_sz -= ret_sz) {
1755
1756                 num = (rem_sz > scatter_elem_sz_prev) ?
1757                         scatter_elem_sz_prev : rem_sz;
1758
1759                 schp->pages[k] = alloc_pages(gfp_mask, order);
1760                 if (!schp->pages[k])
1761                         goto out;
1762
1763                 if (num == scatter_elem_sz_prev) {
1764                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1765                                 scatter_elem_sz = ret_sz;
1766                                 scatter_elem_sz_prev = ret_sz;
1767                         }
1768                 }
1769
1770                 SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
1771                                  "ret_sz=%d\n", k, num, ret_sz));
1772         }               /* end of for loop */
1773
1774         schp->page_order = order;
1775         schp->k_use_sg = k;
1776         SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
1777                          "rem_sz=%d\n", k, rem_sz));
1778
1779         schp->bufflen = blk_size;
1780         if (rem_sz > 0) /* must have failed */
1781                 return -ENOMEM;
1782         return 0;
1783 out:
1784         for (i = 0; i < k; i++)
1785                 __free_pages(schp->pages[k], order);
1786
1787         if (--order >= 0)
1788                 goto retry;
1789
1790         return -ENOMEM;
1791 }
1792
1793 static void
1794 sg_remove_scat(Sg_scatter_hold * schp)
1795 {
1796         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1797         if (schp->pages && schp->sglist_len > 0) {
1798                 if (!schp->dio_in_use) {
1799                         int k;
1800
1801                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1802                                 SCSI_LOG_TIMEOUT(5, printk(
1803                                     "sg_remove_scat: k=%d, pg=0x%p\n",
1804                                     k, schp->pages[k]));
1805                                 __free_pages(schp->pages[k], schp->page_order);
1806                         }
1807
1808                         kfree(schp->pages);
1809                 }
1810         }
1811         memset(schp, 0, sizeof (*schp));
1812 }
1813
1814 static int
1815 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1816 {
1817         Sg_scatter_hold *schp = &srp->data;
1818         int k, num;
1819
1820         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
1821                                    num_read_xfer));
1822         if ((!outp) || (num_read_xfer <= 0))
1823                 return 0;
1824
1825         num = 1 << (PAGE_SHIFT + schp->page_order);
1826         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1827                 if (num > num_read_xfer) {
1828                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1829                                            num_read_xfer))
1830                                 return -EFAULT;
1831                         break;
1832                 } else {
1833                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1834                                            num))
1835                                 return -EFAULT;
1836                         num_read_xfer -= num;
1837                         if (num_read_xfer <= 0)
1838                                 break;
1839                         outp += num;
1840                 }
1841         }
1842
1843         return 0;
1844 }
1845
1846 static void
1847 sg_build_reserve(Sg_fd * sfp, int req_size)
1848 {
1849         Sg_scatter_hold *schp = &sfp->reserve;
1850
1851         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
1852         do {
1853                 if (req_size < PAGE_SIZE)
1854                         req_size = PAGE_SIZE;
1855                 if (0 == sg_build_indirect(schp, sfp, req_size))
1856                         return;
1857                 else
1858                         sg_remove_scat(schp);
1859                 req_size >>= 1; /* divide by 2 */
1860         } while (req_size > (PAGE_SIZE / 2));
1861 }
1862
1863 static void
1864 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1865 {
1866         Sg_scatter_hold *req_schp = &srp->data;
1867         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1868         int k, num, rem;
1869
1870         srp->res_used = 1;
1871         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
1872         rem = size;
1873
1874         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1875         for (k = 0; k < rsv_schp->k_use_sg; k++) {
1876                 if (rem <= num) {
1877                         req_schp->k_use_sg = k + 1;
1878                         req_schp->sglist_len = rsv_schp->sglist_len;
1879                         req_schp->pages = rsv_schp->pages;
1880
1881                         req_schp->bufflen = size;
1882                         req_schp->page_order = rsv_schp->page_order;
1883                         break;
1884                 } else
1885                         rem -= num;
1886         }
1887
1888         if (k >= rsv_schp->k_use_sg)
1889                 SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
1890 }
1891
1892 static void
1893 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
1894 {
1895         Sg_scatter_hold *req_schp = &srp->data;
1896
1897         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
1898                                    (int) req_schp->k_use_sg));
1899         req_schp->k_use_sg = 0;
1900         req_schp->bufflen = 0;
1901         req_schp->pages = NULL;
1902         req_schp->page_order = 0;
1903         req_schp->sglist_len = 0;
1904         sfp->save_scat_len = 0;
1905         srp->res_used = 0;
1906 }
1907
1908 static Sg_request *
1909 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
1910 {
1911         Sg_request *resp;
1912         unsigned long iflags;
1913
1914         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1915         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
1916                 /* look for requests that are ready + not SG_IO owned */
1917                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
1918                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
1919                         resp->done = 2; /* guard against other readers */
1920                         break;
1921                 }
1922         }
1923         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1924         return resp;
1925 }
1926
1927 /* always adds to end of list */
1928 static Sg_request *
1929 sg_add_request(Sg_fd * sfp)
1930 {
1931         int k;
1932         unsigned long iflags;
1933         Sg_request *resp;
1934         Sg_request *rp = sfp->req_arr;
1935
1936         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1937         resp = sfp->headrp;
1938         if (!resp) {
1939                 memset(rp, 0, sizeof (Sg_request));
1940                 rp->parentfp = sfp;
1941                 resp = rp;
1942                 sfp->headrp = resp;
1943         } else {
1944                 if (0 == sfp->cmd_q)
1945                         resp = NULL;    /* command queuing disallowed */
1946                 else {
1947                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
1948                                 if (!rp->parentfp)
1949                                         break;
1950                         }
1951                         if (k < SG_MAX_QUEUE) {
1952                                 memset(rp, 0, sizeof (Sg_request));
1953                                 rp->parentfp = sfp;
1954                                 while (resp->nextrp)
1955                                         resp = resp->nextrp;
1956                                 resp->nextrp = rp;
1957                                 resp = rp;
1958                         } else
1959                                 resp = NULL;
1960                 }
1961         }
1962         if (resp) {
1963                 resp->nextrp = NULL;
1964                 resp->header.duration = jiffies_to_msecs(jiffies);
1965         }
1966         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1967         return resp;
1968 }
1969
1970 /* Return of 1 for found; 0 for not found */
1971 static int
1972 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
1973 {
1974         Sg_request *prev_rp;
1975         Sg_request *rp;
1976         unsigned long iflags;
1977         int res = 0;
1978
1979         if ((!sfp) || (!srp) || (!sfp->headrp))
1980                 return res;
1981         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1982         prev_rp = sfp->headrp;
1983         if (srp == prev_rp) {
1984                 sfp->headrp = prev_rp->nextrp;
1985                 prev_rp->parentfp = NULL;
1986                 res = 1;
1987         } else {
1988                 while ((rp = prev_rp->nextrp)) {
1989                         if (srp == rp) {
1990                                 prev_rp->nextrp = rp->nextrp;
1991                                 rp->parentfp = NULL;
1992                                 res = 1;
1993                                 break;
1994                         }
1995                         prev_rp = rp;
1996                 }
1997         }
1998         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1999         return res;
2000 }
2001
2002 static Sg_fd *
2003 sg_add_sfp(Sg_device * sdp, int dev)
2004 {
2005         Sg_fd *sfp;
2006         unsigned long iflags;
2007         int bufflen;
2008
2009         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2010         if (!sfp)
2011                 return NULL;
2012
2013         init_waitqueue_head(&sfp->read_wait);
2014         rwlock_init(&sfp->rq_list_lock);
2015
2016         kref_init(&sfp->f_ref);
2017         sfp->timeout = SG_DEFAULT_TIMEOUT;
2018         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2019         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2020         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2021             sdp->device->host->unchecked_isa_dma : 1;
2022         sfp->cmd_q = SG_DEF_COMMAND_Q;
2023         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2024         sfp->parentdp = sdp;
2025         write_lock_irqsave(&sg_index_lock, iflags);
2026         list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2027         write_unlock_irqrestore(&sg_index_lock, iflags);
2028         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2029         if (unlikely(sg_big_buff != def_reserved_size))
2030                 sg_big_buff = def_reserved_size;
2031
2032         bufflen = min_t(int, sg_big_buff,
2033                         sdp->device->request_queue->max_sectors * 512);
2034         sg_build_reserve(sfp, bufflen);
2035         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2036                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2037
2038         kref_get(&sdp->d_ref);
2039         __module_get(THIS_MODULE);
2040         return sfp;
2041 }
2042
2043 static void sg_remove_sfp_usercontext(struct work_struct *work)
2044 {
2045         struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2046         struct sg_device *sdp = sfp->parentdp;
2047
2048         /* Cleanup any responses which were never read(). */
2049         while (sfp->headrp)
2050                 sg_finish_rem_req(sfp->headrp);
2051
2052         if (sfp->reserve.bufflen > 0) {
2053                 SCSI_LOG_TIMEOUT(6,
2054                         printk("sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2055                                 (int) sfp->reserve.bufflen,
2056                                 (int) sfp->reserve.k_use_sg));
2057                 sg_remove_scat(&sfp->reserve);
2058         }
2059
2060         SCSI_LOG_TIMEOUT(6,
2061                 printk("sg_remove_sfp: %s, sfp=0x%p\n",
2062                         sdp->disk->disk_name,
2063                         sfp));
2064         kfree(sfp);
2065
2066         scsi_device_put(sdp->device);
2067         sg_put_dev(sdp);
2068         module_put(THIS_MODULE);
2069 }
2070
2071 static void sg_remove_sfp(struct kref *kref)
2072 {
2073         struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2074         struct sg_device *sdp = sfp->parentdp;
2075         unsigned long iflags;
2076
2077         write_lock_irqsave(&sg_index_lock, iflags);
2078         list_del(&sfp->sfd_siblings);
2079         write_unlock_irqrestore(&sg_index_lock, iflags);
2080         wake_up_interruptible(&sdp->o_excl_wait);
2081
2082         execute_in_process_context(sg_remove_sfp_usercontext, &sfp->ew);
2083 }
2084
2085 static int
2086 sg_res_in_use(Sg_fd * sfp)
2087 {
2088         const Sg_request *srp;
2089         unsigned long iflags;
2090
2091         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2092         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2093                 if (srp->res_used)
2094                         break;
2095         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2096         return srp ? 1 : 0;
2097 }
2098
2099 #ifdef CONFIG_SCSI_PROC_FS
2100 static int
2101 sg_idr_max_id(int id, void *p, void *data)
2102 {
2103         int *k = data;
2104
2105         if (*k < id)
2106                 *k = id;
2107
2108         return 0;
2109 }
2110
2111 static int
2112 sg_last_dev(void)
2113 {
2114         int k = -1;
2115         unsigned long iflags;
2116
2117         read_lock_irqsave(&sg_index_lock, iflags);
2118         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2119         read_unlock_irqrestore(&sg_index_lock, iflags);
2120         return k + 1;           /* origin 1 */
2121 }
2122 #endif
2123
2124 /* must be called with sg_index_lock held */
2125 static Sg_device *sg_lookup_dev(int dev)
2126 {
2127         return idr_find(&sg_index_idr, dev);
2128 }
2129
2130 static Sg_device *sg_get_dev(int dev)
2131 {
2132         struct sg_device *sdp;
2133         unsigned long flags;
2134
2135         read_lock_irqsave(&sg_index_lock, flags);
2136         sdp = sg_lookup_dev(dev);
2137         if (!sdp)
2138                 sdp = ERR_PTR(-ENXIO);
2139         else if (sdp->detached) {
2140                 /* If sdp->detached, then the refcount may already be 0, in
2141                  * which case it would be a bug to do kref_get().
2142                  */
2143                 sdp = ERR_PTR(-ENODEV);
2144         } else
2145                 kref_get(&sdp->d_ref);
2146         read_unlock_irqrestore(&sg_index_lock, flags);
2147
2148         return sdp;
2149 }
2150
2151 static void sg_put_dev(struct sg_device *sdp)
2152 {
2153         kref_put(&sdp->d_ref, sg_device_destroy);
2154 }
2155
2156 #ifdef CONFIG_SCSI_PROC_FS
2157
2158 static struct proc_dir_entry *sg_proc_sgp = NULL;
2159
2160 static char sg_proc_sg_dirname[] = "scsi/sg";
2161
2162 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2163
2164 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2165 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2166                                   size_t count, loff_t *off);
2167 static struct file_operations adio_fops = {
2168         /* .owner, .read and .llseek added in sg_proc_init() */
2169         .open = sg_proc_single_open_adio,
2170         .write = sg_proc_write_adio,
2171         .release = single_release,
2172 };
2173
2174 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2175 static ssize_t sg_proc_write_dressz(struct file *filp,
2176                 const char __user *buffer, size_t count, loff_t *off);
2177 static struct file_operations dressz_fops = {
2178         .open = sg_proc_single_open_dressz,
2179         .write = sg_proc_write_dressz,
2180         .release = single_release,
2181 };
2182
2183 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2184 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2185 static struct file_operations version_fops = {
2186         .open = sg_proc_single_open_version,
2187         .release = single_release,
2188 };
2189
2190 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2191 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2192 static struct file_operations devhdr_fops = {
2193         .open = sg_proc_single_open_devhdr,
2194         .release = single_release,
2195 };
2196
2197 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2198 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2199 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2200 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2201 static void dev_seq_stop(struct seq_file *s, void *v);
2202 static struct file_operations dev_fops = {
2203         .open = sg_proc_open_dev,
2204         .release = seq_release,
2205 };
2206 static struct seq_operations dev_seq_ops = {
2207         .start = dev_seq_start,
2208         .next  = dev_seq_next,
2209         .stop  = dev_seq_stop,
2210         .show  = sg_proc_seq_show_dev,
2211 };
2212
2213 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2214 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2215 static struct file_operations devstrs_fops = {
2216         .open = sg_proc_open_devstrs,
2217         .release = seq_release,
2218 };
2219 static struct seq_operations devstrs_seq_ops = {
2220         .start = dev_seq_start,
2221         .next  = dev_seq_next,
2222         .stop  = dev_seq_stop,
2223         .show  = sg_proc_seq_show_devstrs,
2224 };
2225
2226 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2227 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2228 static struct file_operations debug_fops = {
2229         .open = sg_proc_open_debug,
2230         .release = seq_release,
2231 };
2232 static struct seq_operations debug_seq_ops = {
2233         .start = dev_seq_start,
2234         .next  = dev_seq_next,
2235         .stop  = dev_seq_stop,
2236         .show  = sg_proc_seq_show_debug,
2237 };
2238
2239
2240 struct sg_proc_leaf {
2241         const char * name;
2242         struct file_operations * fops;
2243 };
2244
2245 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2246         {"allow_dio", &adio_fops},
2247         {"debug", &debug_fops},
2248         {"def_reserved_size", &dressz_fops},
2249         {"device_hdr", &devhdr_fops},
2250         {"devices", &dev_fops},
2251         {"device_strs", &devstrs_fops},
2252         {"version", &version_fops}
2253 };
2254
2255 static int
2256 sg_proc_init(void)
2257 {
2258         int k, mask;
2259         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2260         struct sg_proc_leaf * leaf;
2261
2262         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2263         if (!sg_proc_sgp)
2264                 return 1;
2265         for (k = 0; k < num_leaves; ++k) {
2266                 leaf = &sg_proc_leaf_arr[k];
2267                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2268                 leaf->fops->owner = THIS_MODULE;
2269                 leaf->fops->read = seq_read;
2270                 leaf->fops->llseek = seq_lseek;
2271                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2272         }
2273         return 0;
2274 }
2275
2276 static void
2277 sg_proc_cleanup(void)
2278 {
2279         int k;
2280         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2281
2282         if (!sg_proc_sgp)
2283                 return;
2284         for (k = 0; k < num_leaves; ++k)
2285                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2286         remove_proc_entry(sg_proc_sg_dirname, NULL);
2287 }
2288
2289
2290 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2291 {
2292         seq_printf(s, "%d\n", *((int *)s->private));
2293         return 0;
2294 }
2295
2296 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2297 {
2298         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2299 }
2300
2301 static ssize_t
2302 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2303                    size_t count, loff_t *off)
2304 {
2305         int num;
2306         char buff[11];
2307
2308         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2309                 return -EACCES;
2310         num = (count < 10) ? count : 10;
2311         if (copy_from_user(buff, buffer, num))
2312                 return -EFAULT;
2313         buff[num] = '\0';
2314         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2315         return count;
2316 }
2317
2318 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2319 {
2320         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2321 }
2322
2323 static ssize_t
2324 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2325                      size_t count, loff_t *off)
2326 {
2327         int num;
2328         unsigned long k = ULONG_MAX;
2329         char buff[11];
2330
2331         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2332                 return -EACCES;
2333         num = (count < 10) ? count : 10;
2334         if (copy_from_user(buff, buffer, num))
2335                 return -EFAULT;
2336         buff[num] = '\0';
2337         k = simple_strtoul(buff, NULL, 10);
2338         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2339                 sg_big_buff = k;
2340                 return count;
2341         }
2342         return -ERANGE;
2343 }
2344
2345 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2346 {
2347         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2348                    sg_version_date);
2349         return 0;
2350 }
2351
2352 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2353 {
2354         return single_open(file, sg_proc_seq_show_version, NULL);
2355 }
2356
2357 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2358 {
2359         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2360                    "online\n");
2361         return 0;
2362 }
2363
2364 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2365 {
2366         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2367 }
2368
2369 struct sg_proc_deviter {
2370         loff_t  index;
2371         size_t  max;
2372 };
2373
2374 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2375 {
2376         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2377
2378         s->private = it;
2379         if (! it)
2380                 return NULL;
2381
2382         it->index = *pos;
2383         it->max = sg_last_dev();
2384         if (it->index >= it->max)
2385                 return NULL;
2386         return it;
2387 }
2388
2389 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2390 {
2391         struct sg_proc_deviter * it = s->private;
2392
2393         *pos = ++it->index;
2394         return (it->index < it->max) ? it : NULL;
2395 }
2396
2397 static void dev_seq_stop(struct seq_file *s, void *v)
2398 {
2399         kfree(s->private);
2400 }
2401
2402 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2403 {
2404         return seq_open(file, &dev_seq_ops);
2405 }
2406
2407 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2408 {
2409         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2410         Sg_device *sdp;
2411         struct scsi_device *scsidp;
2412         unsigned long iflags;
2413
2414         read_lock_irqsave(&sg_index_lock, iflags);
2415         sdp = it ? sg_lookup_dev(it->index) : NULL;
2416         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2417                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2418                               scsidp->host->host_no, scsidp->channel,
2419                               scsidp->id, scsidp->lun, (int) scsidp->type,
2420                               1,
2421                               (int) scsidp->queue_depth,
2422                               (int) scsidp->device_busy,
2423                               (int) scsi_device_online(scsidp));
2424         else
2425                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2426         read_unlock_irqrestore(&sg_index_lock, iflags);
2427         return 0;
2428 }
2429
2430 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2431 {
2432         return seq_open(file, &devstrs_seq_ops);
2433 }
2434
2435 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2436 {
2437         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2438         Sg_device *sdp;
2439         struct scsi_device *scsidp;
2440         unsigned long iflags;
2441
2442         read_lock_irqsave(&sg_index_lock, iflags);
2443         sdp = it ? sg_lookup_dev(it->index) : NULL;
2444         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2445                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2446                            scsidp->vendor, scsidp->model, scsidp->rev);
2447         else
2448                 seq_printf(s, "<no active device>\n");
2449         read_unlock_irqrestore(&sg_index_lock, iflags);
2450         return 0;
2451 }
2452
2453 /* must be called while holding sg_index_lock */
2454 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2455 {
2456         int k, m, new_interface, blen, usg;
2457         Sg_request *srp;
2458         Sg_fd *fp;
2459         const sg_io_hdr_t *hp;
2460         const char * cp;
2461         unsigned int ms;
2462
2463         k = 0;
2464         list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2465                 k++;
2466                 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2467                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2468                            "(res)sgat=%d low_dma=%d\n", k,
2469                            jiffies_to_msecs(fp->timeout),
2470                            fp->reserve.bufflen,
2471                            (int) fp->reserve.k_use_sg,
2472                            (int) fp->low_dma);
2473                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2474                            (int) fp->cmd_q, (int) fp->force_packid,
2475                            (int) fp->keep_orphan, (int) fp->closed);
2476                 for (m = 0, srp = fp->headrp;
2477                                 srp != NULL;
2478                                 ++m, srp = srp->nextrp) {
2479                         hp = &srp->header;
2480                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2481                         if (srp->res_used) {
2482                                 if (new_interface &&
2483                                     (SG_FLAG_MMAP_IO & hp->flags))
2484                                         cp = "     mmap>> ";
2485                                 else
2486                                         cp = "     rb>> ";
2487                         } else {
2488                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2489                                         cp = "     dio>> ";
2490                                 else
2491                                         cp = "     ";
2492                         }
2493                         seq_printf(s, cp);
2494                         blen = srp->data.bufflen;
2495                         usg = srp->data.k_use_sg;
2496                         seq_printf(s, srp->done ?
2497                                    ((1 == srp->done) ?  "rcv:" : "fin:")
2498                                    : "act:");
2499                         seq_printf(s, " id=%d blen=%d",
2500                                    srp->header.pack_id, blen);
2501                         if (srp->done)
2502                                 seq_printf(s, " dur=%d", hp->duration);
2503                         else {
2504                                 ms = jiffies_to_msecs(jiffies);
2505                                 seq_printf(s, " t_o/elap=%d/%d",
2506                                         (new_interface ? hp->timeout :
2507                                                   jiffies_to_msecs(fp->timeout)),
2508                                         (ms > hp->duration ? ms - hp->duration : 0));
2509                         }
2510                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2511                                    (int) srp->data.cmd_opcode);
2512                 }
2513                 if (0 == m)
2514                         seq_printf(s, "     No requests active\n");
2515                 read_unlock(&fp->rq_list_lock);
2516         }
2517 }
2518
2519 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2520 {
2521         return seq_open(file, &debug_seq_ops);
2522 }
2523
2524 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2525 {
2526         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2527         Sg_device *sdp;
2528         unsigned long iflags;
2529
2530         if (it && (0 == it->index)) {
2531                 seq_printf(s, "max_active_device=%d(origin 1)\n",
2532                            (int)it->max);
2533                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2534         }
2535
2536         read_lock_irqsave(&sg_index_lock, iflags);
2537         sdp = it ? sg_lookup_dev(it->index) : NULL;
2538         if (sdp && !list_empty(&sdp->sfds)) {
2539                 struct scsi_device *scsidp = sdp->device;
2540
2541                 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2542                 if (sdp->detached)
2543                         seq_printf(s, "detached pending close ");
2544                 else
2545                         seq_printf
2546                             (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2547                              scsidp->host->host_no,
2548                              scsidp->channel, scsidp->id,
2549                              scsidp->lun,
2550                              scsidp->host->hostt->emulated);
2551                 seq_printf(s, " sg_tablesize=%d excl=%d\n",
2552                            sdp->sg_tablesize, sdp->exclude);
2553                 sg_proc_debug_helper(s, sdp);
2554         }
2555         read_unlock_irqrestore(&sg_index_lock, iflags);
2556         return 0;
2557 }
2558
2559 #endif                          /* CONFIG_SCSI_PROC_FS */
2560
2561 module_init(init_sg);
2562 module_exit(exit_sg);