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 #define SG_SECTOR_MSK (SG_SECTOR_SZ - 1)
 102
 103 static int sg_add(struct device *, struct class_interface *);
 104 static void sg_remove(struct device *, struct class_interface *);
 105
 106 static DEFINE_IDR(sg_index_idr);
 107 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
 108                                                            file descriptor list for device */
 109
 110 static struct class_interface sg_interface = {
 111         .add_dev        = sg_add,
 112         .remove_dev     = sg_remove,
 113 };
 114
 115 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 116         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 117         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 118         unsigned bufflen;       /* Size of (aggregate) data buffer */
 119         struct page **pages;
 120         int page_order;
 121         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 122         unsigned char cmd_opcode; /* first byte of command */
 123 } Sg_scatter_hold;
 124
 125 struct sg_device;               /* forward declarations */
 126 struct sg_fd;
 127
 128 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 129         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
 130         struct sg_fd *parentfp; /* NULL -> not in use */
 131         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 132         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 133         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 134         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 135         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 136         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 137         volatile char done;     /* 0->before bh, 1->before read, 2->read */
 138         struct request *rq;
 139         struct bio *bio;
 140 } Sg_request;
 141
 142 typedef struct sg_fd {          /* holds the state of a file descriptor */
 143         struct sg_fd *nextfp;   /* NULL when last opened fd on this device */
 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 } Sg_fd;
 162
 163 typedef struct sg_device { /* holds the state of each scsi generic device */
 164         struct scsi_device *device;
 165         wait_queue_head_t o_excl_wait;  /* queue open() when O_EXCL in use */
 166         int sg_tablesize;       /* adapter's max scatter-gather table size */
 167         u32 index;              /* device index number */
 168         Sg_fd *headfp;          /* first open fd belonging to this device */
 169         volatile char detached; /* 0->attached, 1->detached pending removal */
 170         volatile char exclude;  /* opened for exclusive access */
 171         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 172         struct gendisk *disk;
 173         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 174 } Sg_device;
 175
 176 static int sg_fasync(int fd, struct file *filp, int mode);
 177 /* tasklet or soft irq callback */
 178 static void sg_rq_end_io(struct request *rq, int uptodate);
 179 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 180 static void sg_finish_rem_req(Sg_request * srp);
 181 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 182 static int sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp,
 183                          int tablesize);
 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, 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_write_xfer(Sg_request * srp);
 192 static int sg_read_xfer(Sg_request * srp);
 193 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 194 static void sg_remove_scat(Sg_scatter_hold * schp);
 195 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 196 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 197 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 198 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
 199 static int sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
 200 static void __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
 201 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 202 static Sg_request *sg_add_request(Sg_fd * sfp);
 203 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 204 static int sg_res_in_use(Sg_fd * sfp);
 205 static Sg_device *sg_get_dev(int dev);
 206 #ifdef CONFIG_SCSI_PROC_FS
 207 static int sg_last_dev(void);
 208 #endif
 209
 210 #define SZ_SG_HEADER sizeof(struct sg_header)
 211 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 212 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
 213 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 214
 215 static int sg_allow_access(struct file *filp, unsigned char *cmd)
 216 {
 217         struct sg_fd *sfp = (struct sg_fd *)filp->private_data;
 218         struct request_queue *q = sfp->parentdp->device->request_queue;
 219
 220         if (sfp->parentdp->device->type == TYPE_SCANNER)
 221                 return 0;
 222
 223         return blk_verify_command(&q->cmd_filter,
 224                                   cmd, filp->f_mode & FMODE_WRITE);
 225 }
 226
 227 static int
 228 sg_open(struct inode *inode, struct file *filp)
 229 {
 230         int dev = iminor(inode);
 231         int flags = filp->f_flags;
 232         struct request_queue *q;
 233         Sg_device *sdp;
 234         Sg_fd *sfp;
 235         int res;
 236         int retval;
 237
 238         lock_kernel();
 239         nonseekable_open(inode, filp);
 240         SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
 241         sdp = sg_get_dev(dev);
 242         if ((!sdp) || (!sdp->device)) {
 243                 unlock_kernel();
 244                 return -ENXIO;
 245         }
 246         if (sdp->detached) {
 247                 unlock_kernel();
 248                 return -ENODEV;
 249         }
 250
 251         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 252         /* Prevent the device driver from vanishing while we sleep */
 253         retval = scsi_device_get(sdp->device);
 254         if (retval) {
 255                 unlock_kernel();
 256                 return retval;
 257         }
 258
 259         if (!((flags & O_NONBLOCK) ||
 260               scsi_block_when_processing_errors(sdp->device))) {
 261                 retval = -ENXIO;
 262                 /* we are in error recovery for this device */
 263                 goto error_out;
 264         }
 265
 266         if (flags & O_EXCL) {
 267                 if (O_RDONLY == (flags & O_ACCMODE)) {
 268                         retval = -EPERM; /* Can't lock it with read only access */
 269                         goto error_out;
 270                 }
 271                 if (sdp->headfp && (flags & O_NONBLOCK)) {
 272                         retval = -EBUSY;
 273                         goto error_out;
 274                 }
 275                 res = 0;
 276                 __wait_event_interruptible(sdp->o_excl_wait,
 277                         ((sdp->headfp || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
 278                 if (res) {
 279                         retval = res;   /* -ERESTARTSYS because signal hit process */
 280                         goto error_out;
 281                 }
 282         } else if (sdp->exclude) {      /* some other fd has an exclusive lock on dev */
 283                 if (flags & O_NONBLOCK) {
 284                         retval = -EBUSY;
 285                         goto error_out;
 286                 }
 287                 res = 0;
 288                 __wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
 289                                            res);
 290                 if (res) {
 291                         retval = res;   /* -ERESTARTSYS because signal hit process */
 292                         goto error_out;
 293                 }
 294         }
 295         if (sdp->detached) {
 296                 retval = -ENODEV;
 297                 goto error_out;
 298         }
 299         if (!sdp->headfp) {     /* no existing opens on this device */
 300                 sdp->sgdebug = 0;
 301                 q = sdp->device->request_queue;
 302                 sdp->sg_tablesize = min(q->max_hw_segments,
 303                                         q->max_phys_segments);
 304         }
 305         if ((sfp = sg_add_sfp(sdp, dev)))
 306                 filp->private_data = sfp;
 307         else {
 308                 if (flags & O_EXCL)
 309                         sdp->exclude = 0;       /* undo if error */
 310                 retval = -ENOMEM;
 311                 goto error_out;
 312         }
 313         unlock_kernel();
 314         return 0;
 315
 316       error_out:
 317         scsi_device_put(sdp->device);
 318         unlock_kernel();
 319         return retval;
 320 }
 321
 322 /* Following function was formerly called 'sg_close' */
 323 static int
 324 sg_release(struct inode *inode, struct file *filp)
 325 {
 326         Sg_device *sdp;
 327         Sg_fd *sfp;
 328
 329         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 330                 return -ENXIO;
 331         SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
 332         sg_fasync(-1, filp, 0); /* remove filp from async notification list */
 333         if (0 == sg_remove_sfp(sdp, sfp)) {     /* Returns 1 when sdp gone */
 334                 if (!sdp->detached) {
 335                         scsi_device_put(sdp->device);
 336                 }
 337                 sdp->exclude = 0;
 338                 wake_up_interruptible(&sdp->o_excl_wait);
 339         }
 340         return 0;
 341 }
 342
 343 static ssize_t
 344 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 345 {
 346         Sg_device *sdp;
 347         Sg_fd *sfp;
 348         Sg_request *srp;
 349         int req_pack_id = -1;
 350         sg_io_hdr_t *hp;
 351         struct sg_header *old_hdr = NULL;
 352         int retval = 0;
 353
 354         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 355                 return -ENXIO;
 356         SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
 357                                    sdp->disk->disk_name, (int) count));
 358
 359         if (!access_ok(VERIFY_WRITE, buf, count))
 360                 return -EFAULT;
 361         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 362                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 363                 if (!old_hdr)
 364                         return -ENOMEM;
 365                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
 366                         retval = -EFAULT;
 367                         goto free_old_hdr;
 368                 }
 369                 if (old_hdr->reply_len < 0) {
 370                         if (count >= SZ_SG_IO_HDR) {
 371                                 sg_io_hdr_t *new_hdr;
 372                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
 373                                 if (!new_hdr) {
 374                                         retval = -ENOMEM;
 375                                         goto free_old_hdr;
 376                                 }
 377                                 retval =__copy_from_user
 378                                     (new_hdr, buf, SZ_SG_IO_HDR);
 379                                 req_pack_id = new_hdr->pack_id;
 380                                 kfree(new_hdr);
 381                                 if (retval) {
 382                                         retval = -EFAULT;
 383                                         goto free_old_hdr;
 384                                 }
 385                         }
 386                 } else
 387                         req_pack_id = old_hdr->pack_id;
 388         }
 389         srp = sg_get_rq_mark(sfp, req_pack_id);
 390         if (!srp) {             /* now wait on packet to arrive */
 391                 if (sdp->detached) {
 392                         retval = -ENODEV;
 393                         goto free_old_hdr;
 394                 }
 395                 if (filp->f_flags & O_NONBLOCK) {
 396                         retval = -EAGAIN;
 397                         goto free_old_hdr;
 398                 }
 399                 while (1) {
 400                         retval = 0; /* following macro beats race condition */
 401                         __wait_event_interruptible(sfp->read_wait,
 402                                 (sdp->detached ||
 403                                 (srp = sg_get_rq_mark(sfp, req_pack_id))),
 404                                 retval);
 405                         if (sdp->detached) {
 406                                 retval = -ENODEV;
 407                                 goto free_old_hdr;
 408                         }
 409                         if (0 == retval)
 410                                 break;
 411
 412                         /* -ERESTARTSYS as signal hit process */
 413                         goto free_old_hdr;
 414                 }
 415         }
 416         if (srp->header.interface_id != '\0') {
 417                 retval = sg_new_read(sfp, buf, count, srp);
 418                 goto free_old_hdr;
 419         }
 420
 421         hp = &srp->header;
 422         if (old_hdr == NULL) {
 423                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 424                 if (! old_hdr) {
 425                         retval = -ENOMEM;
 426                         goto free_old_hdr;
 427                 }
 428         }
 429         memset(old_hdr, 0, SZ_SG_HEADER);
 430         old_hdr->reply_len = (int) hp->timeout;
 431         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 432         old_hdr->pack_id = hp->pack_id;
 433         old_hdr->twelve_byte =
 434             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 435         old_hdr->target_status = hp->masked_status;
 436         old_hdr->host_status = hp->host_status;
 437         old_hdr->driver_status = hp->driver_status;
 438         if ((CHECK_CONDITION & hp->masked_status) ||
 439             (DRIVER_SENSE & hp->driver_status))
 440                 memcpy(old_hdr->sense_buffer, srp->sense_b,
 441                        sizeof (old_hdr->sense_buffer));
 442         switch (hp->host_status) {
 443         /* This setup of 'result' is for backward compatibility and is best
 444            ignored by the user who should use target, host + driver status */
 445         case DID_OK:
 446         case DID_PASSTHROUGH:
 447         case DID_SOFT_ERROR:
 448                 old_hdr->result = 0;
 449                 break;
 450         case DID_NO_CONNECT:
 451         case DID_BUS_BUSY:
 452         case DID_TIME_OUT:
 453                 old_hdr->result = EBUSY;
 454                 break;
 455         case DID_BAD_TARGET:
 456         case DID_ABORT:
 457         case DID_PARITY:
 458         case DID_RESET:
 459         case DID_BAD_INTR:
 460                 old_hdr->result = EIO;
 461                 break;
 462         case DID_ERROR:
 463                 old_hdr->result = (srp->sense_b[0] == 0 &&
 464                                   hp->masked_status == GOOD) ? 0 : EIO;
 465                 break;
 466         default:
 467                 old_hdr->result = EIO;
 468                 break;
 469         }
 470
 471         /* Now copy the result back to the user buffer.  */
 472         if (count >= SZ_SG_HEADER) {
 473                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 474                         retval = -EFAULT;
 475                         goto free_old_hdr;
 476                 }
 477                 buf += SZ_SG_HEADER;
 478                 if (count > old_hdr->reply_len)
 479                         count = old_hdr->reply_len;
 480                 if (count > SZ_SG_HEADER) {
 481                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 482                                 retval = -EFAULT;
 483                                 goto free_old_hdr;
 484                         }
 485                 }
 486         } else
 487                 count = (old_hdr->result == 0) ? 0 : -EIO;
 488         sg_finish_rem_req(srp);
 489         retval = count;
 490 free_old_hdr:
 491         kfree(old_hdr);
 492         return retval;
 493 }
 494
 495 static ssize_t
 496 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 497 {
 498         sg_io_hdr_t *hp = &srp->header;
 499         int err = 0;
 500         int len;
 501
 502         if (count < SZ_SG_IO_HDR) {
 503                 err = -EINVAL;
 504                 goto err_out;
 505         }
 506         hp->sb_len_wr = 0;
 507         if ((hp->mx_sb_len > 0) && hp->sbp) {
 508                 if ((CHECK_CONDITION & hp->masked_status) ||
 509                     (DRIVER_SENSE & hp->driver_status)) {
 510                         int sb_len = SCSI_SENSE_BUFFERSIZE;
 511                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 512                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 513                         len = (len > sb_len) ? sb_len : len;
 514                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 515                                 err = -EFAULT;
 516                                 goto err_out;
 517                         }
 518                         hp->sb_len_wr = len;
 519                 }
 520         }
 521         if (hp->masked_status || hp->host_status || hp->driver_status)
 522                 hp->info |= SG_INFO_CHECK;
 523         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 524                 err = -EFAULT;
 525                 goto err_out;
 526         }
 527         err = sg_read_xfer(srp);
 528       err_out:
 529         sg_finish_rem_req(srp);
 530         return (0 == err) ? count : err;
 531 }
 532
 533 static ssize_t
 534 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 535 {
 536         int mxsize, cmd_size, k;
 537         int input_size, blocking;
 538         unsigned char opcode;
 539         Sg_device *sdp;
 540         Sg_fd *sfp;
 541         Sg_request *srp;
 542         struct sg_header old_hdr;
 543         sg_io_hdr_t *hp;
 544         unsigned char cmnd[MAX_COMMAND_SIZE];
 545
 546         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 547                 return -ENXIO;
 548         SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
 549                                    sdp->disk->disk_name, (int) count));
 550         if (sdp->detached)
 551                 return -ENODEV;
 552         if (!((filp->f_flags & O_NONBLOCK) ||
 553               scsi_block_when_processing_errors(sdp->device)))
 554                 return -ENXIO;
 555
 556         if (!access_ok(VERIFY_READ, buf, count))
 557                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 558         if (count < SZ_SG_HEADER)
 559                 return -EIO;
 560         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 561                 return -EFAULT;
 562         blocking = !(filp->f_flags & O_NONBLOCK);
 563         if (old_hdr.reply_len < 0)
 564                 return sg_new_write(sfp, filp, buf, count, blocking, 0, NULL);
 565         if (count < (SZ_SG_HEADER + 6))
 566                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 567
 568         if (!(srp = sg_add_request(sfp))) {
 569                 SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
 570                 return -EDOM;
 571         }
 572         buf += SZ_SG_HEADER;
 573         __get_user(opcode, buf);
 574         if (sfp->next_cmd_len > 0) {
 575                 if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
 576                         SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
 577                         sfp->next_cmd_len = 0;
 578                         sg_remove_request(sfp, srp);
 579                         return -EIO;
 580                 }
 581                 cmd_size = sfp->next_cmd_len;
 582                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 583         } else {
 584                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 585                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 586                         cmd_size = 12;
 587         }
 588         SCSI_LOG_TIMEOUT(4, printk(
 589                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 590 /* Determine buffer size.  */
 591         input_size = count - cmd_size;
 592         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 593         mxsize -= SZ_SG_HEADER;
 594         input_size -= SZ_SG_HEADER;
 595         if (input_size < 0) {
 596                 sg_remove_request(sfp, srp);
 597                 return -EIO;    /* User did not pass enough bytes for this command. */
 598         }
 599         hp = &srp->header;
 600         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 601         hp->cmd_len = (unsigned char) cmd_size;
 602         hp->iovec_count = 0;
 603         hp->mx_sb_len = 0;
 604         if (input_size > 0)
 605                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 606                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 607         else
 608                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 609         hp->dxfer_len = mxsize;
 610         if (hp->dxfer_direction == SG_DXFER_TO_DEV)
 611                 hp->dxferp = (char __user *)buf + cmd_size;
 612         else
 613                 hp->dxferp = NULL;
 614         hp->sbp = NULL;
 615         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 616         hp->flags = input_size; /* structure abuse ... */
 617         hp->pack_id = old_hdr.pack_id;
 618         hp->usr_ptr = NULL;
 619         if (__copy_from_user(cmnd, buf, cmd_size))
 620                 return -EFAULT;
 621         /*
 622          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 623          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 624          * is a non-zero input_size, so emit a warning.
 625          */
 626         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 627                 static char cmd[TASK_COMM_LEN];
 628                 if (strcmp(current->comm, cmd) && printk_ratelimit()) {
 629                         printk(KERN_WARNING
 630                                "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
 631                                "guessing data in;\n" KERN_WARNING "   "
 632                                "program %s not setting count and/or reply_len properly\n",
 633                                old_hdr.reply_len - (int)SZ_SG_HEADER,
 634                                input_size, (unsigned int) cmnd[0],
 635                                current->comm);
 636                         strcpy(cmd, current->comm);
 637                 }
 638         }
 639         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 640         return (k < 0) ? k : count;
 641 }
 642
 643 static ssize_t
 644 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 645                  size_t count, int blocking, int read_only,
 646                  Sg_request **o_srp)
 647 {
 648         int k;
 649         Sg_request *srp;
 650         sg_io_hdr_t *hp;
 651         unsigned char cmnd[MAX_COMMAND_SIZE];
 652         int timeout;
 653         unsigned long ul_timeout;
 654
 655         if (count < SZ_SG_IO_HDR)
 656                 return -EINVAL;
 657         if (!access_ok(VERIFY_READ, buf, count))
 658                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 659
 660         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 661         if (!(srp = sg_add_request(sfp))) {
 662                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
 663                 return -EDOM;
 664         }
 665         hp = &srp->header;
 666         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 667                 sg_remove_request(sfp, srp);
 668                 return -EFAULT;
 669         }
 670         if (hp->interface_id != 'S') {
 671                 sg_remove_request(sfp, srp);
 672                 return -ENOSYS;
 673         }
 674         if (hp->flags & SG_FLAG_MMAP_IO) {
 675                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 676                         sg_remove_request(sfp, srp);
 677                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 678                 }
 679                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 680                         sg_remove_request(sfp, srp);
 681                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 682                 }
 683                 if (sg_res_in_use(sfp)) {
 684                         sg_remove_request(sfp, srp);
 685                         return -EBUSY;  /* reserve buffer already being used */
 686                 }
 687         }
 688         ul_timeout = msecs_to_jiffies(srp->header.timeout);
 689         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 690         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 691                 sg_remove_request(sfp, srp);
 692                 return -EMSGSIZE;
 693         }
 694         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
 695                 sg_remove_request(sfp, srp);
 696                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 697         }
 698         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 699                 sg_remove_request(sfp, srp);
 700                 return -EFAULT;
 701         }
 702         if (read_only && sg_allow_access(file, cmnd)) {
 703                 sg_remove_request(sfp, srp);
 704                 return -EPERM;
 705         }
 706         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 707         if (k < 0)
 708                 return k;
 709         if (o_srp)
 710                 *o_srp = srp;
 711         return count;
 712 }
 713
 714 static int
 715 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 716                 unsigned char *cmnd, int timeout, int blocking)
 717 {
 718         int k, data_dir;
 719         Sg_device *sdp = sfp->parentdp;
 720         sg_io_hdr_t *hp = &srp->header;
 721
 722         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 723         hp->status = 0;
 724         hp->masked_status = 0;
 725         hp->msg_status = 0;
 726         hp->info = 0;
 727         hp->host_status = 0;
 728         hp->driver_status = 0;
 729         hp->resid = 0;
 730         SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 731                           (int) cmnd[0], (int) hp->cmd_len));
 732
 733         k = sg_start_req(srp, cmnd);
 734         if (k) {
 735                 SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k));
 736                 sg_finish_rem_req(srp);
 737                 return k;       /* probably out of space --> ENOMEM */
 738         }
 739         if ((k = sg_write_xfer(srp))) {
 740                 SCSI_LOG_TIMEOUT(1, printk("sg_common_write: write_xfer, bad address\n"));
 741                 sg_finish_rem_req(srp);
 742                 return k;
 743         }
 744         if (sdp->detached) {
 745                 sg_finish_rem_req(srp);
 746                 return -ENODEV;
 747         }
 748
 749         switch (hp->dxfer_direction) {
 750         case SG_DXFER_TO_FROM_DEV:
 751         case SG_DXFER_FROM_DEV:
 752                 data_dir = DMA_FROM_DEVICE;
 753                 break;
 754         case SG_DXFER_TO_DEV:
 755                 data_dir = DMA_TO_DEVICE;
 756                 break;
 757         case SG_DXFER_UNKNOWN:
 758                 data_dir = DMA_BIDIRECTIONAL;
 759                 break;
 760         default:
 761                 data_dir = DMA_NONE;
 762                 break;
 763         }
 764         hp->duration = jiffies_to_msecs(jiffies);
 765
 766         srp->rq->timeout = timeout;
 767         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 768                               srp->rq, 1, sg_rq_end_io);
 769         return 0;
 770 }
 771
 772 static int
 773 sg_srp_done(Sg_request *srp, Sg_fd *sfp)
 774 {
 775         unsigned long iflags;
 776         int done;
 777
 778         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 779         done = srp->done;
 780         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 781         return done;
 782 }
 783
 784 static int
 785 sg_ioctl(struct inode *inode, struct file *filp,
 786          unsigned int cmd_in, unsigned long arg)
 787 {
 788         void __user *p = (void __user *)arg;
 789         int __user *ip = p;
 790         int result, val, read_only;
 791         Sg_device *sdp;
 792         Sg_fd *sfp;
 793         Sg_request *srp;
 794         unsigned long iflags;
 795
 796         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 797                 return -ENXIO;
 798
 799         SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
 800                                    sdp->disk->disk_name, (int) cmd_in));
 801         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 802
 803         switch (cmd_in) {
 804         case SG_IO:
 805                 {
 806                         int blocking = 1;       /* ignore O_NONBLOCK flag */
 807
 808                         if (sdp->detached)
 809                                 return -ENODEV;
 810                         if (!scsi_block_when_processing_errors(sdp->device))
 811                                 return -ENXIO;
 812                         if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 813                                 return -EFAULT;
 814                         result =
 815                             sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 816                                          blocking, read_only, &srp);
 817                         if (result < 0)
 818                                 return result;
 819                         srp->sg_io_owned = 1;
 820                         while (1) {
 821                                 result = 0;     /* following macro to beat race condition */
 822                                 __wait_event_interruptible(sfp->read_wait,
 823                                         (sdp->detached || sfp->closed || sg_srp_done(srp, sfp)),
 824                                                            result);
 825                                 if (sdp->detached)
 826                                         return -ENODEV;
 827                                 if (sfp->closed)
 828                                         return 0;       /* request packet dropped already */
 829                                 if (0 == result)
 830                                         break;
 831                                 srp->orphan = 1;
 832                                 return result;  /* -ERESTARTSYS because signal hit process */
 833                         }
 834                         write_lock_irqsave(&sfp->rq_list_lock, iflags);
 835                         srp->done = 2;
 836                         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 837                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 838                         return (result < 0) ? result : 0;
 839                 }
 840         case SG_SET_TIMEOUT:
 841                 result = get_user(val, ip);
 842                 if (result)
 843                         return result;
 844                 if (val < 0)
 845                         return -EIO;
 846                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
 847                     val = MULDIV (INT_MAX, USER_HZ, HZ);
 848                 sfp->timeout_user = val;
 849                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
 850
 851                 return 0;
 852         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 853                                 /* strange ..., for backward compatibility */
 854                 return sfp->timeout_user;
 855         case SG_SET_FORCE_LOW_DMA:
 856                 result = get_user(val, ip);
 857                 if (result)
 858                         return result;
 859                 if (val) {
 860                         sfp->low_dma = 1;
 861                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
 862                                 val = (int) sfp->reserve.bufflen;
 863                                 sg_remove_scat(&sfp->reserve);
 864                                 sg_build_reserve(sfp, val);
 865                         }
 866                 } else {
 867                         if (sdp->detached)
 868                                 return -ENODEV;
 869                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
 870                 }
 871                 return 0;
 872         case SG_GET_LOW_DMA:
 873                 return put_user((int) sfp->low_dma, ip);
 874         case SG_GET_SCSI_ID:
 875                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 876                         return -EFAULT;
 877                 else {
 878                         sg_scsi_id_t __user *sg_idp = p;
 879
 880                         if (sdp->detached)
 881                                 return -ENODEV;
 882                         __put_user((int) sdp->device->host->host_no,
 883                                    &sg_idp->host_no);
 884                         __put_user((int) sdp->device->channel,
 885                                    &sg_idp->channel);
 886                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 887                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 888                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 889                         __put_user((short) sdp->device->host->cmd_per_lun,
 890                                    &sg_idp->h_cmd_per_lun);
 891                         __put_user((short) sdp->device->queue_depth,
 892                                    &sg_idp->d_queue_depth);
 893                         __put_user(0, &sg_idp->unused[0]);
 894                         __put_user(0, &sg_idp->unused[1]);
 895                         return 0;
 896                 }
 897         case SG_SET_FORCE_PACK_ID:
 898                 result = get_user(val, ip);
 899                 if (result)
 900                         return result;
 901                 sfp->force_packid = val ? 1 : 0;
 902                 return 0;
 903         case SG_GET_PACK_ID:
 904                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 905                         return -EFAULT;
 906                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 907                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
 908                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 909                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 910                                                        iflags);
 911                                 __put_user(srp->header.pack_id, ip);
 912                                 return 0;
 913                         }
 914                 }
 915                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 916                 __put_user(-1, ip);
 917                 return 0;
 918         case SG_GET_NUM_WAITING:
 919                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 920                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
 921                         if ((1 == srp->done) && (!srp->sg_io_owned))
 922                                 ++val;
 923                 }
 924                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 925                 return put_user(val, ip);
 926         case SG_GET_SG_TABLESIZE:
 927                 return put_user(sdp->sg_tablesize, ip);
 928         case SG_SET_RESERVED_SIZE:
 929                 result = get_user(val, ip);
 930                 if (result)
 931                         return result;
 932                 if (val < 0)
 933                         return -EINVAL;
 934                 val = min_t(int, val,
 935                                 sdp->device->request_queue->max_sectors * 512);
 936                 if (val != sfp->reserve.bufflen) {
 937                         if (sg_res_in_use(sfp) || sfp->mmap_called)
 938                                 return -EBUSY;
 939                         sg_remove_scat(&sfp->reserve);
 940                         sg_build_reserve(sfp, val);
 941                 }
 942                 return 0;
 943         case SG_GET_RESERVED_SIZE:
 944                 val = min_t(int, sfp->reserve.bufflen,
 945                                 sdp->device->request_queue->max_sectors * 512);
 946                 return put_user(val, ip);
 947         case SG_SET_COMMAND_Q:
 948                 result = get_user(val, ip);
 949                 if (result)
 950                         return result;
 951                 sfp->cmd_q = val ? 1 : 0;
 952                 return 0;
 953         case SG_GET_COMMAND_Q:
 954                 return put_user((int) sfp->cmd_q, ip);
 955         case SG_SET_KEEP_ORPHAN:
 956                 result = get_user(val, ip);
 957                 if (result)
 958                         return result;
 959                 sfp->keep_orphan = val;
 960                 return 0;
 961         case SG_GET_KEEP_ORPHAN:
 962                 return put_user((int) sfp->keep_orphan, ip);
 963         case SG_NEXT_CMD_LEN:
 964                 result = get_user(val, ip);
 965                 if (result)
 966                         return result;
 967                 sfp->next_cmd_len = (val > 0) ? val : 0;
 968                 return 0;
 969         case SG_GET_VERSION_NUM:
 970                 return put_user(sg_version_num, ip);
 971         case SG_GET_ACCESS_COUNT:
 972                 /* faked - we don't have a real access count anymore */
 973                 val = (sdp->device ? 1 : 0);
 974                 return put_user(val, ip);
 975         case SG_GET_REQUEST_TABLE:
 976                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
 977                         return -EFAULT;
 978                 else {
 979                         sg_req_info_t *rinfo;
 980                         unsigned int ms;
 981
 982                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
 983                                                                 GFP_KERNEL);
 984                         if (!rinfo)
 985                                 return -ENOMEM;
 986                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 987                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
 988                              ++val, srp = srp ? srp->nextrp : srp) {
 989                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
 990                                 if (srp) {
 991                                         rinfo[val].req_state = srp->done + 1;
 992                                         rinfo[val].problem =
 993                                             srp->header.masked_status &
 994                                             srp->header.host_status &
 995                                             srp->header.driver_status;
 996                                         if (srp->done)
 997                                                 rinfo[val].duration =
 998                                                         srp->header.duration;
 999                                         else {
1000                                                 ms = jiffies_to_msecs(jiffies);
1001                                                 rinfo[val].duration =
1002                                                     (ms > srp->header.duration) ?
1003                                                     (ms - srp->header.duration) : 0;
1004                                         }
1005                                         rinfo[val].orphan = srp->orphan;
1006                                         rinfo[val].sg_io_owned =
1007                                                         srp->sg_io_owned;
1008                                         rinfo[val].pack_id =
1009                                                         srp->header.pack_id;
1010                                         rinfo[val].usr_ptr =
1011                                                         srp->header.usr_ptr;
1012                                 }
1013                         }
1014                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1015                         result = __copy_to_user(p, rinfo,
1016                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1017                         result = result ? -EFAULT : 0;
1018                         kfree(rinfo);
1019                         return result;
1020                 }
1021         case SG_EMULATED_HOST:
1022                 if (sdp->detached)
1023                         return -ENODEV;
1024                 return put_user(sdp->device->host->hostt->emulated, ip);
1025         case SG_SCSI_RESET:
1026                 if (sdp->detached)
1027                         return -ENODEV;
1028                 if (filp->f_flags & O_NONBLOCK) {
1029                         if (scsi_host_in_recovery(sdp->device->host))
1030                                 return -EBUSY;
1031                 } else if (!scsi_block_when_processing_errors(sdp->device))
1032                         return -EBUSY;
1033                 result = get_user(val, ip);
1034                 if (result)
1035                         return result;
1036                 if (SG_SCSI_RESET_NOTHING == val)
1037                         return 0;
1038                 switch (val) {
1039                 case SG_SCSI_RESET_DEVICE:
1040                         val = SCSI_TRY_RESET_DEVICE;
1041                         break;
1042                 case SG_SCSI_RESET_TARGET:
1043                         val = SCSI_TRY_RESET_TARGET;
1044                         break;
1045                 case SG_SCSI_RESET_BUS:
1046                         val = SCSI_TRY_RESET_BUS;
1047                         break;
1048                 case SG_SCSI_RESET_HOST:
1049                         val = SCSI_TRY_RESET_HOST;
1050                         break;
1051                 default:
1052                         return -EINVAL;
1053                 }
1054                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1055                         return -EACCES;
1056                 return (scsi_reset_provider(sdp->device, val) ==
1057                         SUCCESS) ? 0 : -EIO;
1058         case SCSI_IOCTL_SEND_COMMAND:
1059                 if (sdp->detached)
1060                         return -ENODEV;
1061                 if (read_only) {
1062                         unsigned char opcode = WRITE_6;
1063                         Scsi_Ioctl_Command __user *siocp = p;
1064
1065                         if (copy_from_user(&opcode, siocp->data, 1))
1066                                 return -EFAULT;
1067                         if (sg_allow_access(filp, &opcode))
1068                                 return -EPERM;
1069                 }
1070                 return sg_scsi_ioctl(filp, sdp->device->request_queue, NULL, p);
1071         case SG_SET_DEBUG:
1072                 result = get_user(val, ip);
1073                 if (result)
1074                         return result;
1075                 sdp->sgdebug = (char) val;
1076                 return 0;
1077         case SCSI_IOCTL_GET_IDLUN:
1078         case SCSI_IOCTL_GET_BUS_NUMBER:
1079         case SCSI_IOCTL_PROBE_HOST:
1080         case SG_GET_TRANSFORM:
1081                 if (sdp->detached)
1082                         return -ENODEV;
1083                 return scsi_ioctl(sdp->device, cmd_in, p);
1084         case BLKSECTGET:
1085                 return put_user(sdp->device->request_queue->max_sectors * 512,
1086                                 ip);
1087         case BLKTRACESETUP:
1088                 return blk_trace_setup(sdp->device->request_queue,
1089                                        sdp->disk->disk_name,
1090                                        sdp->device->sdev_gendev.devt,
1091                                        (char *)arg);
1092         case BLKTRACESTART:
1093                 return blk_trace_startstop(sdp->device->request_queue, 1);
1094         case BLKTRACESTOP:
1095                 return blk_trace_startstop(sdp->device->request_queue, 0);
1096         case BLKTRACETEARDOWN:
1097                 return blk_trace_remove(sdp->device->request_queue);
1098         default:
1099                 if (read_only)
1100                         return -EPERM;  /* don't know so take safe approach */
1101                 return scsi_ioctl(sdp->device, cmd_in, p);
1102         }
1103 }
1104
1105 #ifdef CONFIG_COMPAT
1106 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1107 {
1108         Sg_device *sdp;
1109         Sg_fd *sfp;
1110         struct scsi_device *sdev;
1111
1112         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1113                 return -ENXIO;
1114
1115         sdev = sdp->device;
1116         if (sdev->host->hostt->compat_ioctl) {
1117                 int ret;
1118
1119                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1120
1121                 return ret;
1122         }
1123
1124         return -ENOIOCTLCMD;
1125 }
1126 #endif
1127
1128 static unsigned int
1129 sg_poll(struct file *filp, poll_table * wait)
1130 {
1131         unsigned int res = 0;
1132         Sg_device *sdp;
1133         Sg_fd *sfp;
1134         Sg_request *srp;
1135         int count = 0;
1136         unsigned long iflags;
1137
1138         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1139             || sfp->closed)
1140                 return POLLERR;
1141         poll_wait(filp, &sfp->read_wait, wait);
1142         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1143         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1144                 /* if any read waiting, flag it */
1145                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1146                         res = POLLIN | POLLRDNORM;
1147                 ++count;
1148         }
1149         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1150
1151         if (sdp->detached)
1152                 res |= POLLHUP;
1153         else if (!sfp->cmd_q) {
1154                 if (0 == count)
1155                         res |= POLLOUT | POLLWRNORM;
1156         } else if (count < SG_MAX_QUEUE)
1157                 res |= POLLOUT | POLLWRNORM;
1158         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1159                                    sdp->disk->disk_name, (int) res));
1160         return res;
1161 }
1162
1163 static int
1164 sg_fasync(int fd, struct file *filp, int mode)
1165 {
1166         int retval;
1167         Sg_device *sdp;
1168         Sg_fd *sfp;
1169
1170         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1171                 return -ENXIO;
1172         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1173                                    sdp->disk->disk_name, mode));
1174
1175         retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
1176         return (retval < 0) ? retval : 0;
1177 }
1178
1179 static int
1180 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1181 {
1182         Sg_fd *sfp;
1183         unsigned long offset, len, sa;
1184         Sg_scatter_hold *rsv_schp;
1185         int k, length;
1186
1187         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1188                 return VM_FAULT_SIGBUS;
1189         rsv_schp = &sfp->reserve;
1190         offset = vmf->pgoff << PAGE_SHIFT;
1191         if (offset >= rsv_schp->bufflen)
1192                 return VM_FAULT_SIGBUS;
1193         SCSI_LOG_TIMEOUT(3, printk("sg_vma_fault: offset=%lu, scatg=%d\n",
1194                                    offset, rsv_schp->k_use_sg));
1195         sa = vma->vm_start;
1196         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1197         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1198                 len = vma->vm_end - sa;
1199                 len = (len < length) ? len : length;
1200                 if (offset < len) {
1201                         struct page *page = nth_page(rsv_schp->pages[k],
1202                                                      offset >> PAGE_SHIFT);
1203                         get_page(page); /* increment page count */
1204                         vmf->page = page;
1205                         return 0; /* success */
1206                 }
1207                 sa += len;
1208                 offset -= len;
1209         }
1210
1211         return VM_FAULT_SIGBUS;
1212 }
1213
1214 static struct vm_operations_struct sg_mmap_vm_ops = {
1215         .fault = sg_vma_fault,
1216 };
1217
1218 static int
1219 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1220 {
1221         Sg_fd *sfp;
1222         unsigned long req_sz, len, sa;
1223         Sg_scatter_hold *rsv_schp;
1224         int k, length;
1225
1226         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1227                 return -ENXIO;
1228         req_sz = vma->vm_end - vma->vm_start;
1229         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1230                                    (void *) vma->vm_start, (int) req_sz));
1231         if (vma->vm_pgoff)
1232                 return -EINVAL; /* want no offset */
1233         rsv_schp = &sfp->reserve;
1234         if (req_sz > rsv_schp->bufflen)
1235                 return -ENOMEM; /* cannot map more than reserved buffer */
1236
1237         sa = vma->vm_start;
1238         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1239         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1240                 len = vma->vm_end - sa;
1241                 len = (len < length) ? len : length;
1242                 sa += len;
1243         }
1244
1245         sfp->mmap_called = 1;
1246         vma->vm_flags |= VM_RESERVED;
1247         vma->vm_private_data = sfp;
1248         vma->vm_ops = &sg_mmap_vm_ops;
1249         return 0;
1250 }
1251
1252 /*
1253  * This function is a "bottom half" handler that is called by the mid
1254  * level when a command is completed (or has failed).
1255  */
1256 static void sg_rq_end_io(struct request *rq, int uptodate)
1257 {
1258         struct sg_request *srp = rq->end_io_data;
1259         Sg_device *sdp = NULL;
1260         Sg_fd *sfp;
1261         unsigned long iflags;
1262         unsigned int ms;
1263         char *sense;
1264         int result, resid;
1265
1266         if (NULL == srp) {
1267                 printk(KERN_ERR "sg_cmd_done: NULL request\n");
1268                 return;
1269         }
1270         sfp = srp->parentfp;
1271         if (sfp)
1272                 sdp = sfp->parentdp;
1273         if ((NULL == sdp) || sdp->detached) {
1274                 printk(KERN_INFO "sg_cmd_done: device detached\n");
1275                 return;
1276         }
1277
1278         sense = rq->sense;
1279         result = rq->errors;
1280         resid = rq->data_len;
1281
1282         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1283                 sdp->disk->disk_name, srp->header.pack_id, result));
1284         srp->header.resid = resid;
1285         ms = jiffies_to_msecs(jiffies);
1286         srp->header.duration = (ms > srp->header.duration) ?
1287                                 (ms - srp->header.duration) : 0;
1288         if (0 != result) {
1289                 struct scsi_sense_hdr sshdr;
1290
1291                 srp->header.status = 0xff & result;
1292                 srp->header.masked_status = status_byte(result);
1293                 srp->header.msg_status = msg_byte(result);
1294                 srp->header.host_status = host_byte(result);
1295                 srp->header.driver_status = driver_byte(result);
1296                 if ((sdp->sgdebug > 0) &&
1297                     ((CHECK_CONDITION == srp->header.masked_status) ||
1298                      (COMMAND_TERMINATED == srp->header.masked_status)))
1299                         __scsi_print_sense("sg_cmd_done", sense,
1300                                            SCSI_SENSE_BUFFERSIZE);
1301
1302                 /* Following if statement is a patch supplied by Eric Youngdale */
1303                 if (driver_byte(result) != 0
1304                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1305                     && !scsi_sense_is_deferred(&sshdr)
1306                     && sshdr.sense_key == UNIT_ATTENTION
1307                     && sdp->device->removable) {
1308                         /* Detected possible disc change. Set the bit - this */
1309                         /* may be used if there are filesystems using this device */
1310                         sdp->device->changed = 1;
1311                 }
1312         }
1313         /* Rely on write phase to clean out srp status values, so no "else" */
1314
1315         if (sfp->closed) {      /* whoops this fd already released, cleanup */
1316                 SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1317                 sg_finish_rem_req(srp);
1318                 srp = NULL;
1319                 if (NULL == sfp->headrp) {
1320                         SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, final cleanup\n"));
1321                         if (0 == sg_remove_sfp(sdp, sfp)) {     /* device still present */
1322                                 scsi_device_put(sdp->device);
1323                         }
1324                         sfp = NULL;
1325                 }
1326         } else if (srp && srp->orphan) {
1327                 if (sfp->keep_orphan)
1328                         srp->sg_io_owned = 0;
1329                 else {
1330                         sg_finish_rem_req(srp);
1331                         srp = NULL;
1332                 }
1333         }
1334         if (sfp && srp) {
1335                 /* Now wake up any sg_read() that is waiting for this packet. */
1336                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1337                 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1338                 srp->done = 1;
1339                 wake_up_interruptible(&sfp->read_wait);
1340                 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1341         }
1342 }
1343
1344 static struct file_operations sg_fops = {
1345         .owner = THIS_MODULE,
1346         .read = sg_read,
1347         .write = sg_write,
1348         .poll = sg_poll,
1349         .ioctl = sg_ioctl,
1350 #ifdef CONFIG_COMPAT
1351         .compat_ioctl = sg_compat_ioctl,
1352 #endif
1353         .open = sg_open,
1354         .mmap = sg_mmap,
1355         .release = sg_release,
1356         .fasync = sg_fasync,
1357 };
1358
1359 static struct class *sg_sysfs_class;
1360
1361 static int sg_sysfs_valid = 0;
1362
1363 static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1364 {
1365         struct request_queue *q = scsidp->request_queue;
1366         Sg_device *sdp;
1367         unsigned long iflags;
1368         int error;
1369         u32 k;
1370
1371         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1372         if (!sdp) {
1373                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1374                 return ERR_PTR(-ENOMEM);
1375         }
1376         error = -ENOMEM;
1377         if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) {
1378                 printk(KERN_WARNING "idr expansion Sg_device failure\n");
1379                 goto out;
1380         }
1381
1382         write_lock_irqsave(&sg_index_lock, iflags);
1383         error = idr_get_new(&sg_index_idr, sdp, &k);
1384         write_unlock_irqrestore(&sg_index_lock, iflags);
1385
1386         if (error) {
1387                 printk(KERN_WARNING "idr allocation Sg_device failure: %d\n",
1388                        error);
1389                 goto out;
1390         }
1391
1392         if (unlikely(k >= SG_MAX_DEVS))
1393                 goto overflow;
1394
1395         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1396         sprintf(disk->disk_name, "sg%d", k);
1397         disk->first_minor = k;
1398         sdp->disk = disk;
1399         sdp->device = scsidp;
1400         init_waitqueue_head(&sdp->o_excl_wait);
1401         sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments);
1402         sdp->index = k;
1403
1404         error = 0;
1405  out:
1406         if (error) {
1407                 kfree(sdp);
1408                 return ERR_PTR(error);
1409         }
1410         return sdp;
1411
1412  overflow:
1413         sdev_printk(KERN_WARNING, scsidp,
1414                     "Unable to attach sg device type=%d, minor "
1415                     "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1416         error = -ENODEV;
1417         goto out;
1418 }
1419
1420 static int
1421 sg_add(struct device *cl_dev, struct class_interface *cl_intf)
1422 {
1423         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1424         struct gendisk *disk;
1425         Sg_device *sdp = NULL;
1426         struct cdev * cdev = NULL;
1427         int error;
1428         unsigned long iflags;
1429
1430         disk = alloc_disk(1);
1431         if (!disk) {
1432                 printk(KERN_WARNING "alloc_disk failed\n");
1433                 return -ENOMEM;
1434         }
1435         disk->major = SCSI_GENERIC_MAJOR;
1436
1437         error = -ENOMEM;
1438         cdev = cdev_alloc();
1439         if (!cdev) {
1440                 printk(KERN_WARNING "cdev_alloc failed\n");
1441                 goto out;
1442         }
1443         cdev->owner = THIS_MODULE;
1444         cdev->ops = &sg_fops;
1445
1446         sdp = sg_alloc(disk, scsidp);
1447         if (IS_ERR(sdp)) {
1448                 printk(KERN_WARNING "sg_alloc failed\n");
1449                 error = PTR_ERR(sdp);
1450                 goto out;
1451         }
1452
1453         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1454         if (error)
1455                 goto cdev_add_err;
1456
1457         sdp->cdev = cdev;
1458         if (sg_sysfs_valid) {
1459                 struct device *sg_class_member;
1460
1461                 sg_class_member = device_create_drvdata(sg_sysfs_class,
1462                                                         cl_dev->parent,
1463                                                         MKDEV(SCSI_GENERIC_MAJOR,
1464                                                               sdp->index),
1465                                                         sdp,
1466                                                         "%s", disk->disk_name);
1467                 if (IS_ERR(sg_class_member)) {
1468                         printk(KERN_ERR "sg_add: "
1469                                "device_create failed\n");
1470                         error = PTR_ERR(sg_class_member);
1471                         goto cdev_add_err;
1472                 }
1473                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1474                                           &sg_class_member->kobj, "generic");
1475                 if (error)
1476                         printk(KERN_ERR "sg_add: unable to make symlink "
1477                                         "'generic' back to sg%d\n", sdp->index);
1478         } else
1479                 printk(KERN_WARNING "sg_add: sg_sys Invalid\n");
1480
1481         sdev_printk(KERN_NOTICE, scsidp,
1482                     "Attached scsi generic sg%d type %d\n", sdp->index,
1483                     scsidp->type);
1484
1485         dev_set_drvdata(cl_dev, sdp);
1486
1487         return 0;
1488
1489 cdev_add_err:
1490         write_lock_irqsave(&sg_index_lock, iflags);
1491         idr_remove(&sg_index_idr, sdp->index);
1492         write_unlock_irqrestore(&sg_index_lock, iflags);
1493         kfree(sdp);
1494
1495 out:
1496         put_disk(disk);
1497         if (cdev)
1498                 cdev_del(cdev);
1499         return error;
1500 }
1501
1502 static void
1503 sg_remove(struct device *cl_dev, struct class_interface *cl_intf)
1504 {
1505         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1506         Sg_device *sdp = dev_get_drvdata(cl_dev);
1507         unsigned long iflags;
1508         Sg_fd *sfp;
1509         Sg_fd *tsfp;
1510         Sg_request *srp;
1511         Sg_request *tsrp;
1512         int delay;
1513
1514         if (!sdp)
1515                 return;
1516
1517         delay = 0;
1518         write_lock_irqsave(&sg_index_lock, iflags);
1519         if (sdp->headfp) {
1520                 sdp->detached = 1;
1521                 for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1522                         tsfp = sfp->nextfp;
1523                         for (srp = sfp->headrp; srp; srp = tsrp) {
1524                                 tsrp = srp->nextrp;
1525                                 if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
1526                                         sg_finish_rem_req(srp);
1527                         }
1528                         if (sfp->closed) {
1529                                 scsi_device_put(sdp->device);
1530                                 __sg_remove_sfp(sdp, sfp);
1531                         } else {
1532                                 delay = 1;
1533                                 wake_up_interruptible(&sfp->read_wait);
1534                                 kill_fasync(&sfp->async_qp, SIGPOLL,
1535                                             POLL_HUP);
1536                         }
1537                 }
1538                 SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d, dirty\n", sdp->index));
1539                 if (NULL == sdp->headfp) {
1540                         idr_remove(&sg_index_idr, sdp->index);
1541                 }
1542         } else {        /* nothing active, simple case */
1543                 SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d\n", sdp->index));
1544                 idr_remove(&sg_index_idr, sdp->index);
1545         }
1546         write_unlock_irqrestore(&sg_index_lock, iflags);
1547
1548         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1549         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1550         cdev_del(sdp->cdev);
1551         sdp->cdev = NULL;
1552         put_disk(sdp->disk);
1553         sdp->disk = NULL;
1554         if (NULL == sdp->headfp)
1555                 kfree(sdp);
1556
1557         if (delay)
1558                 msleep(10);     /* dirty detach so delay device destruction */
1559 }
1560
1561 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1562 module_param_named(def_reserved_size, def_reserved_size, int,
1563                    S_IRUGO | S_IWUSR);
1564 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1565
1566 MODULE_AUTHOR("Douglas Gilbert");
1567 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1568 MODULE_LICENSE("GPL");
1569 MODULE_VERSION(SG_VERSION_STR);
1570 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1571
1572 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1573                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1574 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1575 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1576
1577 static int __init
1578 init_sg(void)
1579 {
1580         int rc;
1581
1582         if (scatter_elem_sz < PAGE_SIZE) {
1583                 scatter_elem_sz = PAGE_SIZE;
1584                 scatter_elem_sz_prev = scatter_elem_sz;
1585         }
1586         if (def_reserved_size >= 0)
1587                 sg_big_buff = def_reserved_size;
1588         else
1589                 def_reserved_size = sg_big_buff;
1590
1591         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1592                                     SG_MAX_DEVS, "sg");
1593         if (rc)
1594                 return rc;
1595         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1596         if ( IS_ERR(sg_sysfs_class) ) {
1597                 rc = PTR_ERR(sg_sysfs_class);
1598                 goto err_out;
1599         }
1600         sg_sysfs_valid = 1;
1601         rc = scsi_register_interface(&sg_interface);
1602         if (0 == rc) {
1603 #ifdef CONFIG_SCSI_PROC_FS
1604                 sg_proc_init();
1605 #endif                          /* CONFIG_SCSI_PROC_FS */
1606                 return 0;
1607         }
1608         class_destroy(sg_sysfs_class);
1609 err_out:
1610         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1611         return rc;
1612 }
1613
1614 static void __exit
1615 exit_sg(void)
1616 {
1617 #ifdef CONFIG_SCSI_PROC_FS
1618         sg_proc_cleanup();
1619 #endif                          /* CONFIG_SCSI_PROC_FS */
1620         scsi_unregister_interface(&sg_interface);
1621         class_destroy(sg_sysfs_class);
1622         sg_sysfs_valid = 0;
1623         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1624                                  SG_MAX_DEVS);
1625         idr_destroy(&sg_index_idr);
1626 }
1627
1628 static int sg_start_req(Sg_request *srp, unsigned char *cmd)
1629 {
1630         int res;
1631         struct request *rq;
1632         Sg_fd *sfp = srp->parentfp;
1633         sg_io_hdr_t *hp = &srp->header;
1634         int dxfer_len = (int) hp->dxfer_len;
1635         int dxfer_dir = hp->dxfer_direction;
1636         unsigned int iov_count = hp->iovec_count;
1637         Sg_scatter_hold *req_schp = &srp->data;
1638         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1639         struct request_queue *q = sfp->parentdp->device->request_queue;
1640         struct rq_map_data *md, map_data;
1641         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1642
1643         SCSI_LOG_TIMEOUT(4, printk(KERN_INFO "sg_start_req: dxfer_len=%d\n",
1644                                    dxfer_len));
1645
1646         rq = blk_get_request(q, rw, GFP_ATOMIC);
1647         if (!rq)
1648                 return -ENOMEM;
1649
1650         memcpy(rq->cmd, cmd, hp->cmd_len);
1651
1652         rq->cmd_len = hp->cmd_len;
1653         rq->cmd_type = REQ_TYPE_BLOCK_PC;
1654
1655         srp->rq = rq;
1656         rq->end_io_data = srp;
1657         rq->sense = srp->sense_b;
1658         rq->retries = SG_DEFAULT_RETRIES;
1659
1660         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1661                 return 0;
1662
1663         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1664             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1665             !sfp->parentdp->device->host->unchecked_isa_dma &&
1666             blk_rq_aligned(q, hp->dxferp, dxfer_len))
1667                 md = NULL;
1668         else
1669                 md = &map_data;
1670
1671         if (md) {
1672                 if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
1673                         sg_link_reserve(sfp, srp, dxfer_len);
1674                 else {
1675                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1676                         if (res)
1677                                 return res;
1678                 }
1679
1680                 md->pages = req_schp->pages;
1681                 md->page_order = req_schp->page_order;
1682                 md->nr_entries = req_schp->k_use_sg;
1683         }
1684
1685         if (iov_count)
1686                 res = blk_rq_map_user_iov(q, rq, md, hp->dxferp, iov_count,
1687                                           hp->dxfer_len, GFP_ATOMIC);
1688         else
1689                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1690                                       hp->dxfer_len, GFP_ATOMIC);
1691
1692         if (!res) {
1693                 srp->bio = rq->bio;
1694
1695                 if (!md) {
1696                         req_schp->dio_in_use = 1;
1697                         hp->info |= SG_INFO_DIRECT_IO;
1698                 }
1699         }
1700         return res;
1701 }
1702
1703 static void
1704 sg_finish_rem_req(Sg_request * srp)
1705 {
1706         Sg_fd *sfp = srp->parentfp;
1707         Sg_scatter_hold *req_schp = &srp->data;
1708
1709         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1710         if (srp->res_used)
1711                 sg_unlink_reserve(sfp, srp);
1712         else
1713                 sg_remove_scat(req_schp);
1714
1715         if (srp->rq) {
1716                 if (srp->bio)
1717                         blk_rq_unmap_user(srp->bio);
1718
1719                 blk_put_request(srp->rq);
1720         }
1721
1722         sg_remove_request(sfp, srp);
1723 }
1724
1725 static int
1726 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1727 {
1728         int sg_bufflen = tablesize * sizeof(struct page *);
1729         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1730
1731         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1732         if (!schp->pages)
1733                 return -ENOMEM;
1734         schp->sglist_len = sg_bufflen;
1735         return tablesize;       /* number of scat_gath elements allocated */
1736 }
1737
1738 static int
1739 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1740 {
1741         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1742         int sg_tablesize = sfp->parentdp->sg_tablesize;
1743         int blk_size = buff_size, order;
1744         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1745
1746         if (blk_size < 0)
1747                 return -EFAULT;
1748         if (0 == blk_size)
1749                 ++blk_size;     /* don't know why */
1750 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1751         blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1752         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1753                                    buff_size, blk_size));
1754
1755         /* N.B. ret_sz carried into this block ... */
1756         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1757         if (mx_sc_elems < 0)
1758                 return mx_sc_elems;     /* most likely -ENOMEM */
1759
1760         num = scatter_elem_sz;
1761         if (unlikely(num != scatter_elem_sz_prev)) {
1762                 if (num < PAGE_SIZE) {
1763                         scatter_elem_sz = PAGE_SIZE;
1764                         scatter_elem_sz_prev = PAGE_SIZE;
1765                 } else
1766                         scatter_elem_sz_prev = num;
1767         }
1768
1769         if (sfp->low_dma)
1770                 gfp_mask |= GFP_DMA;
1771
1772         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1773                 gfp_mask |= __GFP_ZERO;
1774
1775         order = get_order(num);
1776 retry:
1777         ret_sz = 1 << (PAGE_SHIFT + order);
1778
1779         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1780              k++, rem_sz -= ret_sz) {
1781
1782                 num = (rem_sz > scatter_elem_sz_prev) ?
1783                         scatter_elem_sz_prev : rem_sz;
1784
1785                 schp->pages[k] = alloc_pages(gfp_mask, order);
1786                 if (!schp->pages[k])
1787                         goto out;
1788
1789                 if (num == scatter_elem_sz_prev) {
1790                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1791                                 scatter_elem_sz = ret_sz;
1792                                 scatter_elem_sz_prev = ret_sz;
1793                         }
1794                 }
1795
1796                 SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
1797                                  "ret_sz=%d\n", k, num, ret_sz));
1798         }               /* end of for loop */
1799
1800         schp->page_order = order;
1801         schp->k_use_sg = k;
1802         SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
1803                          "rem_sz=%d\n", k, rem_sz));
1804
1805         schp->bufflen = blk_size;
1806         if (rem_sz > 0) /* must have failed */
1807                 return -ENOMEM;
1808         return 0;
1809 out:
1810         for (i = 0; i < k; i++)
1811                 __free_pages(schp->pages[k], order);
1812
1813         if (--order >= 0)
1814                 goto retry;
1815
1816         return -ENOMEM;
1817 }
1818
1819 static int
1820 sg_write_xfer(Sg_request * srp)
1821 {
1822         sg_io_hdr_t *hp = &srp->header;
1823         Sg_scatter_hold *schp = &srp->data;
1824         int num_xfer = 0;
1825         int dxfer_dir = hp->dxfer_direction;
1826         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1827
1828         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_TO_DEV == dxfer_dir) ||
1829             (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1830                 num_xfer = (int) (new_interface ? hp->dxfer_len : hp->flags);
1831                 if (schp->bufflen < num_xfer)
1832                         num_xfer = schp->bufflen;
1833         }
1834         if ((num_xfer <= 0) || (schp->dio_in_use) ||
1835             (new_interface
1836              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1837                 return 0;
1838
1839         SCSI_LOG_TIMEOUT(4, printk("sg_write_xfer: num_xfer=%d, k_use_sg=%d\n",
1840                           num_xfer, schp->k_use_sg));
1841
1842         return 0;
1843 }
1844
1845 static void
1846 sg_remove_scat(Sg_scatter_hold * schp)
1847 {
1848         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1849         if (schp->pages && schp->sglist_len > 0) {
1850                 if (!schp->dio_in_use) {
1851                         int k;
1852
1853                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1854                                 SCSI_LOG_TIMEOUT(5, printk(
1855                                     "sg_remove_scat: k=%d, pg=0x%p\n",
1856                                     k, schp->pages[k]));
1857                                 __free_pages(schp->pages[k], schp->page_order);
1858                         }
1859
1860                         kfree(schp->pages);
1861                 }
1862         }
1863         memset(schp, 0, sizeof (*schp));
1864 }
1865
1866 static int
1867 sg_read_xfer(Sg_request * srp)
1868 {
1869         sg_io_hdr_t *hp = &srp->header;
1870         Sg_scatter_hold *schp = &srp->data;
1871         int num_xfer = 0;
1872         int dxfer_dir = hp->dxfer_direction;
1873         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1874
1875         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_FROM_DEV == dxfer_dir)
1876             || (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1877                 num_xfer = hp->dxfer_len;
1878                 if (schp->bufflen < num_xfer)
1879                         num_xfer = schp->bufflen;
1880         }
1881         if ((num_xfer <= 0) || (schp->dio_in_use) ||
1882             (new_interface
1883              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1884                 return 0;
1885
1886         SCSI_LOG_TIMEOUT(4, printk("sg_read_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
1887                           num_xfer, (int)hp->iovec_count, schp->k_use_sg));
1888         return 0;
1889 }
1890
1891 static int
1892 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1893 {
1894         Sg_scatter_hold *schp = &srp->data;
1895         int k, num;
1896
1897         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
1898                                    num_read_xfer));
1899         if ((!outp) || (num_read_xfer <= 0))
1900                 return 0;
1901
1902         blk_rq_unmap_user(srp->bio);
1903         srp->bio = NULL;
1904
1905         num = 1 << (PAGE_SHIFT + schp->page_order);
1906         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1907                 if (num > num_read_xfer) {
1908                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1909                                            num_read_xfer))
1910                                 return -EFAULT;
1911                         break;
1912                 } else {
1913                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1914                                            num))
1915                                 return -EFAULT;
1916                         num_read_xfer -= num;
1917                         if (num_read_xfer <= 0)
1918                                 break;
1919                         outp += num;
1920                 }
1921         }
1922
1923         return 0;
1924 }
1925
1926 static void
1927 sg_build_reserve(Sg_fd * sfp, int req_size)
1928 {
1929         Sg_scatter_hold *schp = &sfp->reserve;
1930
1931         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
1932         do {
1933                 if (req_size < PAGE_SIZE)
1934                         req_size = PAGE_SIZE;
1935                 if (0 == sg_build_indirect(schp, sfp, req_size))
1936                         return;
1937                 else
1938                         sg_remove_scat(schp);
1939                 req_size >>= 1; /* divide by 2 */
1940         } while (req_size > (PAGE_SIZE / 2));
1941 }
1942
1943 static void
1944 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1945 {
1946         Sg_scatter_hold *req_schp = &srp->data;
1947         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1948         int k, num, rem;
1949
1950         srp->res_used = 1;
1951         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
1952         rem = size;
1953
1954         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1955         for (k = 0; k < rsv_schp->k_use_sg; k++) {
1956                 if (rem <= num) {
1957                         req_schp->k_use_sg = k + 1;
1958                         req_schp->sglist_len = rsv_schp->sglist_len;
1959                         req_schp->pages = rsv_schp->pages;
1960
1961                         req_schp->bufflen = size;
1962                         req_schp->page_order = rsv_schp->page_order;
1963                         break;
1964                 } else
1965                         rem -= num;
1966         }
1967
1968         if (k >= rsv_schp->k_use_sg)
1969                 SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
1970 }
1971
1972 static void
1973 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
1974 {
1975         Sg_scatter_hold *req_schp = &srp->data;
1976
1977         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
1978                                    (int) req_schp->k_use_sg));
1979         req_schp->k_use_sg = 0;
1980         req_schp->bufflen = 0;
1981         req_schp->pages = NULL;
1982         req_schp->page_order = 0;
1983         req_schp->sglist_len = 0;
1984         sfp->save_scat_len = 0;
1985         srp->res_used = 0;
1986 }
1987
1988 static Sg_request *
1989 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
1990 {
1991         Sg_request *resp;
1992         unsigned long iflags;
1993
1994         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1995         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
1996                 /* look for requests that are ready + not SG_IO owned */
1997                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
1998                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
1999                         resp->done = 2; /* guard against other readers */
2000                         break;
2001                 }
2002         }
2003         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2004         return resp;
2005 }
2006
2007 #ifdef CONFIG_SCSI_PROC_FS
2008 static Sg_request *
2009 sg_get_nth_request(Sg_fd * sfp, int nth)
2010 {
2011         Sg_request *resp;
2012         unsigned long iflags;
2013         int k;
2014
2015         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2016         for (k = 0, resp = sfp->headrp; resp && (k < nth);
2017              ++k, resp = resp->nextrp) ;
2018         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2019         return resp;
2020 }
2021 #endif
2022
2023 /* always adds to end of list */
2024 static Sg_request *
2025 sg_add_request(Sg_fd * sfp)
2026 {
2027         int k;
2028         unsigned long iflags;
2029         Sg_request *resp;
2030         Sg_request *rp = sfp->req_arr;
2031
2032         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2033         resp = sfp->headrp;
2034         if (!resp) {
2035                 memset(rp, 0, sizeof (Sg_request));
2036                 rp->parentfp = sfp;
2037                 resp = rp;
2038                 sfp->headrp = resp;
2039         } else {
2040                 if (0 == sfp->cmd_q)
2041                         resp = NULL;    /* command queuing disallowed */
2042                 else {
2043                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2044                                 if (!rp->parentfp)
2045                                         break;
2046                         }
2047                         if (k < SG_MAX_QUEUE) {
2048                                 memset(rp, 0, sizeof (Sg_request));
2049                                 rp->parentfp = sfp;
2050                                 while (resp->nextrp)
2051                                         resp = resp->nextrp;
2052                                 resp->nextrp = rp;
2053                                 resp = rp;
2054                         } else
2055                                 resp = NULL;
2056                 }
2057         }
2058         if (resp) {
2059                 resp->nextrp = NULL;
2060                 resp->header.duration = jiffies_to_msecs(jiffies);
2061         }
2062         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2063         return resp;
2064 }
2065
2066 /* Return of 1 for found; 0 for not found */
2067 static int
2068 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2069 {
2070         Sg_request *prev_rp;
2071         Sg_request *rp;
2072         unsigned long iflags;
2073         int res = 0;
2074
2075         if ((!sfp) || (!srp) || (!sfp->headrp))
2076                 return res;
2077         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2078         prev_rp = sfp->headrp;
2079         if (srp == prev_rp) {
2080                 sfp->headrp = prev_rp->nextrp;
2081                 prev_rp->parentfp = NULL;
2082                 res = 1;
2083         } else {
2084                 while ((rp = prev_rp->nextrp)) {
2085                         if (srp == rp) {
2086                                 prev_rp->nextrp = rp->nextrp;
2087                                 rp->parentfp = NULL;
2088                                 res = 1;
2089                                 break;
2090                         }
2091                         prev_rp = rp;
2092                 }
2093         }
2094         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2095         return res;
2096 }
2097
2098 #ifdef CONFIG_SCSI_PROC_FS
2099 static Sg_fd *
2100 sg_get_nth_sfp(Sg_device * sdp, int nth)
2101 {
2102         Sg_fd *resp;
2103         unsigned long iflags;
2104         int k;
2105
2106         read_lock_irqsave(&sg_index_lock, iflags);
2107         for (k = 0, resp = sdp->headfp; resp && (k < nth);
2108              ++k, resp = resp->nextfp) ;
2109         read_unlock_irqrestore(&sg_index_lock, iflags);
2110         return resp;
2111 }
2112 #endif
2113
2114 static Sg_fd *
2115 sg_add_sfp(Sg_device * sdp, int dev)
2116 {
2117         Sg_fd *sfp;
2118         unsigned long iflags;
2119         int bufflen;
2120
2121         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2122         if (!sfp)
2123                 return NULL;
2124
2125         init_waitqueue_head(&sfp->read_wait);
2126         rwlock_init(&sfp->rq_list_lock);
2127
2128         sfp->timeout = SG_DEFAULT_TIMEOUT;
2129         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2130         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2131         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2132             sdp->device->host->unchecked_isa_dma : 1;
2133         sfp->cmd_q = SG_DEF_COMMAND_Q;
2134         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2135         sfp->parentdp = sdp;
2136         write_lock_irqsave(&sg_index_lock, iflags);
2137         if (!sdp->headfp)
2138                 sdp->headfp = sfp;
2139         else {                  /* add to tail of existing list */
2140                 Sg_fd *pfp = sdp->headfp;
2141                 while (pfp->nextfp)
2142                         pfp = pfp->nextfp;
2143                 pfp->nextfp = sfp;
2144         }
2145         write_unlock_irqrestore(&sg_index_lock, iflags);
2146         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2147         if (unlikely(sg_big_buff != def_reserved_size))
2148                 sg_big_buff = def_reserved_size;
2149
2150         bufflen = min_t(int, sg_big_buff,
2151                         sdp->device->request_queue->max_sectors * 512);
2152         sg_build_reserve(sfp, bufflen);
2153         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2154                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2155         return sfp;
2156 }
2157
2158 static void
2159 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2160 {
2161         Sg_fd *fp;
2162         Sg_fd *prev_fp;
2163
2164         prev_fp = sdp->headfp;
2165         if (sfp == prev_fp)
2166                 sdp->headfp = prev_fp->nextfp;
2167         else {
2168                 while ((fp = prev_fp->nextfp)) {
2169                         if (sfp == fp) {
2170                                 prev_fp->nextfp = fp->nextfp;
2171                                 break;
2172                         }
2173                         prev_fp = fp;
2174                 }
2175         }
2176         if (sfp->reserve.bufflen > 0) {
2177                 SCSI_LOG_TIMEOUT(6,
2178                         printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2179                         (int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2180                 sg_remove_scat(&sfp->reserve);
2181         }
2182         sfp->parentdp = NULL;
2183         SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2184         kfree(sfp);
2185 }
2186
2187 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2188 static int
2189 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2190 {
2191         Sg_request *srp;
2192         Sg_request *tsrp;
2193         int dirty = 0;
2194         int res = 0;
2195
2196         for (srp = sfp->headrp; srp; srp = tsrp) {
2197                 tsrp = srp->nextrp;
2198                 if (sg_srp_done(srp, sfp))
2199                         sg_finish_rem_req(srp);
2200                 else
2201                         ++dirty;
2202         }
2203         if (0 == dirty) {
2204                 unsigned long iflags;
2205
2206                 write_lock_irqsave(&sg_index_lock, iflags);
2207                 __sg_remove_sfp(sdp, sfp);
2208                 if (sdp->detached && (NULL == sdp->headfp)) {
2209                         idr_remove(&sg_index_idr, sdp->index);
2210                         kfree(sdp);
2211                         res = 1;
2212                 }
2213                 write_unlock_irqrestore(&sg_index_lock, iflags);
2214         } else {
2215                 /* MOD_INC's to inhibit unloading sg and associated adapter driver */
2216                 /* only bump the access_count if we actually succeeded in
2217                  * throwing another counter on the host module */
2218                 scsi_device_get(sdp->device);   /* XXX: retval ignored? */
2219                 sfp->closed = 1;        /* flag dirty state on this fd */
2220                 SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2221                                   dirty));
2222         }
2223         return res;
2224 }
2225
2226 static int
2227 sg_res_in_use(Sg_fd * sfp)
2228 {
2229         const Sg_request *srp;
2230         unsigned long iflags;
2231
2232         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2233         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2234                 if (srp->res_used)
2235                         break;
2236         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2237         return srp ? 1 : 0;
2238 }
2239
2240 #ifdef CONFIG_SCSI_PROC_FS
2241 static int
2242 sg_idr_max_id(int id, void *p, void *data)
2243 {
2244         int *k = data;
2245
2246         if (*k < id)
2247                 *k = id;
2248
2249         return 0;
2250 }
2251
2252 static int
2253 sg_last_dev(void)
2254 {
2255         int k = -1;
2256         unsigned long iflags;
2257
2258         read_lock_irqsave(&sg_index_lock, iflags);
2259         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2260         read_unlock_irqrestore(&sg_index_lock, iflags);
2261         return k + 1;           /* origin 1 */
2262 }
2263 #endif
2264
2265 static Sg_device *
2266 sg_get_dev(int dev)
2267 {
2268         Sg_device *sdp;
2269         unsigned long iflags;
2270
2271         read_lock_irqsave(&sg_index_lock, iflags);
2272         sdp = idr_find(&sg_index_idr, dev);
2273         read_unlock_irqrestore(&sg_index_lock, iflags);
2274
2275         return sdp;
2276 }
2277
2278 #ifdef CONFIG_SCSI_PROC_FS
2279
2280 static struct proc_dir_entry *sg_proc_sgp = NULL;
2281
2282 static char sg_proc_sg_dirname[] = "scsi/sg";
2283
2284 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2285
2286 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2287 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2288                                   size_t count, loff_t *off);
2289 static struct file_operations adio_fops = {
2290         /* .owner, .read and .llseek added in sg_proc_init() */
2291         .open = sg_proc_single_open_adio,
2292         .write = sg_proc_write_adio,
2293         .release = single_release,
2294 };
2295
2296 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2297 static ssize_t sg_proc_write_dressz(struct file *filp,
2298                 const char __user *buffer, size_t count, loff_t *off);
2299 static struct file_operations dressz_fops = {
2300         .open = sg_proc_single_open_dressz,
2301         .write = sg_proc_write_dressz,
2302         .release = single_release,
2303 };
2304
2305 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2306 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2307 static struct file_operations version_fops = {
2308         .open = sg_proc_single_open_version,
2309         .release = single_release,
2310 };
2311
2312 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2313 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2314 static struct file_operations devhdr_fops = {
2315         .open = sg_proc_single_open_devhdr,
2316         .release = single_release,
2317 };
2318
2319 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2320 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2321 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2322 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2323 static void dev_seq_stop(struct seq_file *s, void *v);
2324 static struct file_operations dev_fops = {
2325         .open = sg_proc_open_dev,
2326         .release = seq_release,
2327 };
2328 static struct seq_operations dev_seq_ops = {
2329         .start = dev_seq_start,
2330         .next  = dev_seq_next,
2331         .stop  = dev_seq_stop,
2332         .show  = sg_proc_seq_show_dev,
2333 };
2334
2335 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2336 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2337 static struct file_operations devstrs_fops = {
2338         .open = sg_proc_open_devstrs,
2339         .release = seq_release,
2340 };
2341 static struct seq_operations devstrs_seq_ops = {
2342         .start = dev_seq_start,
2343         .next  = dev_seq_next,
2344         .stop  = dev_seq_stop,
2345         .show  = sg_proc_seq_show_devstrs,
2346 };
2347
2348 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2349 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2350 static struct file_operations debug_fops = {
2351         .open = sg_proc_open_debug,
2352         .release = seq_release,
2353 };
2354 static struct seq_operations debug_seq_ops = {
2355         .start = dev_seq_start,
2356         .next  = dev_seq_next,
2357         .stop  = dev_seq_stop,
2358         .show  = sg_proc_seq_show_debug,
2359 };
2360
2361
2362 struct sg_proc_leaf {
2363         const char * name;
2364         struct file_operations * fops;
2365 };
2366
2367 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2368         {"allow_dio", &adio_fops},
2369         {"debug", &debug_fops},
2370         {"def_reserved_size", &dressz_fops},
2371         {"device_hdr", &devhdr_fops},
2372         {"devices", &dev_fops},
2373         {"device_strs", &devstrs_fops},
2374         {"version", &version_fops}
2375 };
2376
2377 static int
2378 sg_proc_init(void)
2379 {
2380         int k, mask;
2381         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2382         struct sg_proc_leaf * leaf;
2383
2384         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2385         if (!sg_proc_sgp)
2386                 return 1;
2387         for (k = 0; k < num_leaves; ++k) {
2388                 leaf = &sg_proc_leaf_arr[k];
2389                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2390                 leaf->fops->owner = THIS_MODULE;
2391                 leaf->fops->read = seq_read;
2392                 leaf->fops->llseek = seq_lseek;
2393                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2394         }
2395         return 0;
2396 }
2397
2398 static void
2399 sg_proc_cleanup(void)
2400 {
2401         int k;
2402         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2403
2404         if (!sg_proc_sgp)
2405                 return;
2406         for (k = 0; k < num_leaves; ++k)
2407                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2408         remove_proc_entry(sg_proc_sg_dirname, NULL);
2409 }
2410
2411
2412 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2413 {
2414         seq_printf(s, "%d\n", *((int *)s->private));
2415         return 0;
2416 }
2417
2418 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2419 {
2420         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2421 }
2422
2423 static ssize_t
2424 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2425                    size_t count, loff_t *off)
2426 {
2427         int num;
2428         char buff[11];
2429
2430         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2431                 return -EACCES;
2432         num = (count < 10) ? count : 10;
2433         if (copy_from_user(buff, buffer, num))
2434                 return -EFAULT;
2435         buff[num] = '\0';
2436         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2437         return count;
2438 }
2439
2440 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2441 {
2442         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2443 }
2444
2445 static ssize_t
2446 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2447                      size_t count, loff_t *off)
2448 {
2449         int num;
2450         unsigned long k = ULONG_MAX;
2451         char buff[11];
2452
2453         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2454                 return -EACCES;
2455         num = (count < 10) ? count : 10;
2456         if (copy_from_user(buff, buffer, num))
2457                 return -EFAULT;
2458         buff[num] = '\0';
2459         k = simple_strtoul(buff, NULL, 10);
2460         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2461                 sg_big_buff = k;
2462                 return count;
2463         }
2464         return -ERANGE;
2465 }
2466
2467 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2468 {
2469         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2470                    sg_version_date);
2471         return 0;
2472 }
2473
2474 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2475 {
2476         return single_open(file, sg_proc_seq_show_version, NULL);
2477 }
2478
2479 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2480 {
2481         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2482                    "online\n");
2483         return 0;
2484 }
2485
2486 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2487 {
2488         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2489 }
2490
2491 struct sg_proc_deviter {
2492         loff_t  index;
2493         size_t  max;
2494 };
2495
2496 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2497 {
2498         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2499
2500         s->private = it;
2501         if (! it)
2502                 return NULL;
2503
2504         it->index = *pos;
2505         it->max = sg_last_dev();
2506         if (it->index >= it->max)
2507                 return NULL;
2508         return it;
2509 }
2510
2511 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2512 {
2513         struct sg_proc_deviter * it = s->private;
2514
2515         *pos = ++it->index;
2516         return (it->index < it->max) ? it : NULL;
2517 }
2518
2519 static void dev_seq_stop(struct seq_file *s, void *v)
2520 {
2521         kfree(s->private);
2522 }
2523
2524 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2525 {
2526         return seq_open(file, &dev_seq_ops);
2527 }
2528
2529 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2530 {
2531         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2532         Sg_device *sdp;
2533         struct scsi_device *scsidp;
2534
2535         sdp = it ? sg_get_dev(it->index) : NULL;
2536         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2537                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2538                               scsidp->host->host_no, scsidp->channel,
2539                               scsidp->id, scsidp->lun, (int) scsidp->type,
2540                               1,
2541                               (int) scsidp->queue_depth,
2542                               (int) scsidp->device_busy,
2543                               (int) scsi_device_online(scsidp));
2544         else
2545                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2546         return 0;
2547 }
2548
2549 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2550 {
2551         return seq_open(file, &devstrs_seq_ops);
2552 }
2553
2554 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2555 {
2556         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2557         Sg_device *sdp;
2558         struct scsi_device *scsidp;
2559
2560         sdp = it ? sg_get_dev(it->index) : NULL;
2561         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2562                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2563                            scsidp->vendor, scsidp->model, scsidp->rev);
2564         else
2565                 seq_printf(s, "<no active device>\n");
2566         return 0;
2567 }
2568
2569 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2570 {
2571         int k, m, new_interface, blen, usg;
2572         Sg_request *srp;
2573         Sg_fd *fp;
2574         const sg_io_hdr_t *hp;
2575         const char * cp;
2576         unsigned int ms;
2577
2578         for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
2579                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2580                            "(res)sgat=%d low_dma=%d\n", k + 1,
2581                            jiffies_to_msecs(fp->timeout),
2582                            fp->reserve.bufflen,
2583                            (int) fp->reserve.k_use_sg,
2584                            (int) fp->low_dma);
2585                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2586                            (int) fp->cmd_q, (int) fp->force_packid,
2587                            (int) fp->keep_orphan, (int) fp->closed);
2588                 for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
2589                         hp = &srp->header;
2590                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2591                         if (srp->res_used) {
2592                                 if (new_interface &&
2593                                     (SG_FLAG_MMAP_IO & hp->flags))
2594                                         cp = "     mmap>> ";
2595                                 else
2596                                         cp = "     rb>> ";
2597                         } else {
2598                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2599                                         cp = "     dio>> ";
2600                                 else
2601                                         cp = "     ";
2602                         }
2603                         seq_printf(s, cp);
2604                         blen = srp->data.bufflen;
2605                         usg = srp->data.k_use_sg;
2606                         seq_printf(s, srp->done ?
2607                                    ((1 == srp->done) ?  "rcv:" : "fin:")
2608                                    : "act:");
2609                         seq_printf(s, " id=%d blen=%d",
2610                                    srp->header.pack_id, blen);
2611                         if (srp->done)
2612                                 seq_printf(s, " dur=%d", hp->duration);
2613                         else {
2614                                 ms = jiffies_to_msecs(jiffies);
2615                                 seq_printf(s, " t_o/elap=%d/%d",
2616                                         (new_interface ? hp->timeout :
2617                                                   jiffies_to_msecs(fp->timeout)),
2618                                         (ms > hp->duration ? ms - hp->duration : 0));
2619                         }
2620                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2621                                    (int) srp->data.cmd_opcode);
2622                 }
2623                 if (0 == m)
2624                         seq_printf(s, "     No requests active\n");
2625         }
2626 }
2627
2628 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2629 {
2630         return seq_open(file, &debug_seq_ops);
2631 }
2632
2633 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2634 {
2635         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2636         Sg_device *sdp;
2637
2638         if (it && (0 == it->index)) {
2639                 seq_printf(s, "max_active_device=%d(origin 1)\n",
2640                            (int)it->max);
2641                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2642         }
2643         sdp = it ? sg_get_dev(it->index) : NULL;
2644         if (sdp) {
2645                 struct scsi_device *scsidp = sdp->device;
2646
2647                 if (NULL == scsidp) {
2648                         seq_printf(s, "device %d detached ??\n",
2649                                    (int)it->index);
2650                         return 0;
2651                 }
2652
2653                 if (sg_get_nth_sfp(sdp, 0)) {
2654                         seq_printf(s, " >>> device=%s ",
2655                                 sdp->disk->disk_name);
2656                         if (sdp->detached)
2657                                 seq_printf(s, "detached pending close ");
2658                         else
2659                                 seq_printf
2660                                     (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2661                                      scsidp->host->host_no,
2662                                      scsidp->channel, scsidp->id,
2663                                      scsidp->lun,
2664                                      scsidp->host->hostt->emulated);
2665                         seq_printf(s, " sg_tablesize=%d excl=%d\n",
2666                                    sdp->sg_tablesize, sdp->exclude);
2667                 }
2668                 sg_proc_debug_helper(s, sdp);
2669         }
2670         return 0;
2671 }
2672
2673 #endif                          /* CONFIG_SCSI_PROC_FS */
2674
2675 module_init(init_sg);
2676 module_exit(exit_sg);