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 = 30532;      /* 2 digits for each component */
  22 #define SG_VERSION_STR "3.5.32"
  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/config.h>
  32 #include <linux/module.h>
  33
  34 #include <linux/fs.h>
  35 #include <linux/kernel.h>
  36 #include <linux/sched.h>
  37 #include <linux/string.h>
  38 #include <linux/mm.h>
  39 #include <linux/errno.h>
  40 #include <linux/mtio.h>
  41 #include <linux/ioctl.h>
  42 #include <linux/fcntl.h>
  43 #include <linux/init.h>
  44 #include <linux/poll.h>
  45 #include <linux/smp_lock.h>
  46 #include <linux/moduleparam.h>
  47 #include <linux/devfs_fs_kernel.h>
  48 #include <linux/cdev.h>
  49 #include <linux/seq_file.h>
  50 #include <linux/blkdev.h>
  51 #include <linux/delay.h>
  52
  53 #include "scsi.h"
  54 #include <scsi/scsi_host.h>
  55 #include <scsi/scsi_driver.h>
  56 #include <scsi/scsi_ioctl.h>
  57 #include <scsi/sg.h>
  58
  59 #include "scsi_logging.h"
  60
  61 #ifdef CONFIG_SCSI_PROC_FS
  62 #include <linux/proc_fs.h>
  63 static char *sg_version_date = "20050117";
  64
  65 static int sg_proc_init(void);
  66 static void sg_proc_cleanup(void);
  67 #endif
  68
  69 #ifndef LINUX_VERSION_CODE
  70 #include <linux/version.h>
  71 #endif                          /* LINUX_VERSION_CODE */
  72
  73 #define SG_ALLOW_DIO_DEF 0
  74 #define SG_ALLOW_DIO_CODE /* compile out by commenting this define */
  75
  76 #define SG_MAX_DEVS 32768
  77
  78 /*
  79  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
  80  * Then when using 32 bit integers x * m may overflow during the calculation.
  81  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
  82  * calculates the same, but prevents the overflow when both m and d
  83  * are "small" numbers (like HZ and USER_HZ).
  84  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
  85  * in 32 bits.
  86  */
  87 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
  88
  89 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  90
  91 int sg_big_buff = SG_DEF_RESERVED_SIZE;
  92 /* N.B. This variable is readable and writeable via
  93    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  94    of this size (or less if there is not enough memory) will be reserved
  95    for use by this file descriptor. [Deprecated usage: this variable is also
  96    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  97    the kernel (i.e. it is not a module).] */
  98 static int def_reserved_size = -1;      /* picks up init parameter */
  99 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
 100
 101 #define SG_SECTOR_SZ 512
 102 #define SG_SECTOR_MSK (SG_SECTOR_SZ - 1)
 103
 104 #define SG_DEV_ARR_LUMP 32      /* amount to over allocate sg_dev_arr by */
 105
 106 static int sg_add(struct class_device *);
 107 static void sg_remove(struct class_device *);
 108
 109 static Scsi_Request *dummy_cmdp;        /* only used for sizeof */
 110
 111 static DEFINE_RWLOCK(sg_dev_arr_lock);  /* Also used to lock
 112                                                            file descriptor list for device */
 113
 114 static struct class_interface sg_interface = {
 115         .add            = sg_add,
 116         .remove         = sg_remove,
 117 };
 118
 119 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 120         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 121         unsigned short sglist_len; /* size of malloc'd scatter-gather list ++ */
 122         unsigned bufflen;       /* Size of (aggregate) data buffer */
 123         unsigned b_malloc_len;  /* actual len malloc'ed in buffer */
 124         void *buffer;           /* Data buffer or scatter list (k_use_sg>0) */
 125         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 126         unsigned char cmd_opcode; /* first byte of command */
 127 } Sg_scatter_hold;
 128
 129 struct sg_device;               /* forward declarations */
 130 struct sg_fd;
 131
 132 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 133         Scsi_Request *my_cmdp;  /* != 0  when request with lower levels */
 134         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
 135         struct sg_fd *parentfp; /* NULL -> not in use */
 136         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 137         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 138         unsigned char sense_b[sizeof (dummy_cmdp->sr_sense_buffer)];
 139         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 140         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 141         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 142         volatile char done;     /* 0->before bh, 1->before read, 2->read */
 143 } Sg_request;
 144
 145 typedef struct sg_fd {          /* holds the state of a file descriptor */
 146         struct sg_fd *nextfp;   /* NULL when last opened fd on this device */
 147         struct sg_device *parentdp;     /* owning device */
 148         wait_queue_head_t read_wait;    /* queue read until command done */
 149         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 150         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 151         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 152         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 153         unsigned save_scat_len; /* original length of trunc. scat. element */
 154         Sg_request *headrp;     /* head of request slist, NULL->empty */
 155         struct fasync_struct *async_qp; /* used by asynchronous notification */
 156         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 157         char low_dma;           /* as in parent but possibly overridden to 1 */
 158         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 159         volatile char closed;   /* 1 -> fd closed but request(s) outstanding */
 160         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 161         char next_cmd_len;      /* 0 -> automatic (def), >0 -> use on next write() */
 162         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 163         char mmap_called;       /* 0 -> mmap() never called on this fd */
 164 } Sg_fd;
 165
 166 typedef struct sg_device { /* holds the state of each scsi generic device */
 167         struct scsi_device *device;
 168         wait_queue_head_t o_excl_wait;  /* queue open() when O_EXCL in use */
 169         int sg_tablesize;       /* adapter's max scatter-gather table size */
 170         Sg_fd *headfp;          /* first open fd belonging to this device */
 171         volatile char detached; /* 0->attached, 1->detached pending removal */
 172         volatile char exclude;  /* opened for exclusive access */
 173         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 174         struct gendisk *disk;
 175         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 176 } Sg_device;
 177
 178 static int sg_fasync(int fd, struct file *filp, int mode);
 179 static void sg_cmd_done(Scsi_Cmnd * SCpnt);     /* tasklet or soft irq callback */
 180 static int sg_start_req(Sg_request * srp);
 181 static void sg_finish_rem_req(Sg_request * srp);
 182 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 183 static int sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp,
 184                          int tablesize);
 185 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 186                            Sg_request * srp);
 187 static ssize_t sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
 188                             int blocking, 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_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
 192                       int wr_xf, int *countp, unsigned char __user **up);
 193 static int sg_write_xfer(Sg_request * srp);
 194 static int sg_read_xfer(Sg_request * srp);
 195 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 196 static void sg_remove_scat(Sg_scatter_hold * schp);
 197 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 198 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 199 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 200 static char *sg_page_malloc(int rqSz, int lowDma, int *retSzp);
 201 static void sg_page_free(char *buff, int size);
 202 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
 203 static int sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
 204 static void __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
 205 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 206 static Sg_request *sg_add_request(Sg_fd * sfp);
 207 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 208 static int sg_res_in_use(Sg_fd * sfp);
 209 static int sg_allow_access(unsigned char opcode, char dev_type);
 210 static int sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len);
 211 static Sg_device *sg_get_dev(int dev);
 212 static inline unsigned char *sg_scatg2virt(const struct scatterlist *sclp);
 213 #ifdef CONFIG_SCSI_PROC_FS
 214 static int sg_last_dev(void);
 215 #endif
 216
 217 static Sg_device **sg_dev_arr = NULL;
 218 static int sg_dev_max;
 219 static int sg_nr_dev;
 220
 221 #define SZ_SG_HEADER sizeof(struct sg_header)
 222 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 223 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
 224 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 225
 226 static int
 227 sg_open(struct inode *inode, struct file *filp)
 228 {
 229         int dev = iminor(inode);
 230         int flags = filp->f_flags;
 231         Sg_device *sdp;
 232         Sg_fd *sfp;
 233         int res;
 234         int retval;
 235
 236         nonseekable_open(inode, filp);
 237         SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
 238         sdp = sg_get_dev(dev);
 239         if ((!sdp) || (!sdp->device))
 240                 return -ENXIO;
 241         if (sdp->detached)
 242                 return -ENODEV;
 243
 244         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 245         /* Prevent the device driver from vanishing while we sleep */
 246         retval = scsi_device_get(sdp->device);
 247         if (retval)
 248                 return retval;
 249
 250         if (!((flags & O_NONBLOCK) ||
 251               scsi_block_when_processing_errors(sdp->device))) {
 252                 retval = -ENXIO;
 253                 /* we are in error recovery for this device */
 254                 goto error_out;
 255         }
 256
 257         if (flags & O_EXCL) {
 258                 if (O_RDONLY == (flags & O_ACCMODE)) {
 259                         retval = -EPERM; /* Can't lock it with read only access */
 260                         goto error_out;
 261                 }
 262                 if (sdp->headfp && (flags & O_NONBLOCK)) {
 263                         retval = -EBUSY;
 264                         goto error_out;
 265                 }
 266                 res = 0;
 267                 __wait_event_interruptible(sdp->o_excl_wait,
 268                         ((sdp->headfp || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
 269                 if (res) {
 270                         retval = res;   /* -ERESTARTSYS because signal hit process */
 271                         goto error_out;
 272                 }
 273         } else if (sdp->exclude) {      /* some other fd has an exclusive lock on dev */
 274                 if (flags & O_NONBLOCK) {
 275                         retval = -EBUSY;
 276                         goto error_out;
 277                 }
 278                 res = 0;
 279                 __wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
 280                                            res);
 281                 if (res) {
 282                         retval = res;   /* -ERESTARTSYS because signal hit process */
 283                         goto error_out;
 284                 }
 285         }
 286         if (sdp->detached) {
 287                 retval = -ENODEV;
 288                 goto error_out;
 289         }
 290         if (!sdp->headfp) {     /* no existing opens on this device */
 291                 sdp->sgdebug = 0;
 292                 sdp->sg_tablesize = sdp->device->host->sg_tablesize;
 293         }
 294         if ((sfp = sg_add_sfp(sdp, dev)))
 295                 filp->private_data = sfp;
 296         else {
 297                 if (flags & O_EXCL)
 298                         sdp->exclude = 0;       /* undo if error */
 299                 retval = -ENOMEM;
 300                 goto error_out;
 301         }
 302         return 0;
 303
 304       error_out:
 305         scsi_device_put(sdp->device);
 306         return retval;
 307 }
 308
 309 /* Following function was formerly called 'sg_close' */
 310 static int
 311 sg_release(struct inode *inode, struct file *filp)
 312 {
 313         Sg_device *sdp;
 314         Sg_fd *sfp;
 315
 316         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 317                 return -ENXIO;
 318         SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
 319         sg_fasync(-1, filp, 0); /* remove filp from async notification list */
 320         if (0 == sg_remove_sfp(sdp, sfp)) {     /* Returns 1 when sdp gone */
 321                 if (!sdp->detached) {
 322                         scsi_device_put(sdp->device);
 323                 }
 324                 sdp->exclude = 0;
 325                 wake_up_interruptible(&sdp->o_excl_wait);
 326         }
 327         return 0;
 328 }
 329
 330 static ssize_t
 331 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 332 {
 333         int k, res;
 334         Sg_device *sdp;
 335         Sg_fd *sfp;
 336         Sg_request *srp;
 337         int req_pack_id = -1;
 338         struct sg_header old_hdr;
 339         sg_io_hdr_t new_hdr;
 340         sg_io_hdr_t *hp;
 341
 342         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 343                 return -ENXIO;
 344         SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
 345                                    sdp->disk->disk_name, (int) count));
 346         if ((k = verify_area(VERIFY_WRITE, buf, count)))
 347                 return k;
 348         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 349                 if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 350                         return -EFAULT;
 351                 if (old_hdr.reply_len < 0) {
 352                         if (count >= SZ_SG_IO_HDR) {
 353                                 if (__copy_from_user
 354                                     (&new_hdr, buf, SZ_SG_IO_HDR))
 355                                         return -EFAULT;
 356                                 req_pack_id = new_hdr.pack_id;
 357                         }
 358                 } else
 359                         req_pack_id = old_hdr.pack_id;
 360         }
 361         srp = sg_get_rq_mark(sfp, req_pack_id);
 362         if (!srp) {             /* now wait on packet to arrive */
 363                 if (sdp->detached)
 364                         return -ENODEV;
 365                 if (filp->f_flags & O_NONBLOCK)
 366                         return -EAGAIN;
 367                 while (1) {
 368                         res = 0;        /* following is a macro that beats race condition */
 369                         __wait_event_interruptible(sfp->read_wait,
 370                                 (sdp->detached || (srp = sg_get_rq_mark(sfp, req_pack_id))),
 371                                                    res);
 372                         if (sdp->detached)
 373                                 return -ENODEV;
 374                         if (0 == res)
 375                                 break;
 376                         return res;     /* -ERESTARTSYS because signal hit process */
 377                 }
 378         }
 379         if (srp->header.interface_id != '\0')
 380                 return sg_new_read(sfp, buf, count, srp);
 381
 382         hp = &srp->header;
 383         memset(&old_hdr, 0, SZ_SG_HEADER);
 384         old_hdr.reply_len = (int) hp->timeout;
 385         old_hdr.pack_len = old_hdr.reply_len; /* very old, strange behaviour */
 386         old_hdr.pack_id = hp->pack_id;
 387         old_hdr.twelve_byte =
 388             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 389         old_hdr.target_status = hp->masked_status;
 390         old_hdr.host_status = hp->host_status;
 391         old_hdr.driver_status = hp->driver_status;
 392         if ((CHECK_CONDITION & hp->masked_status) ||
 393             (DRIVER_SENSE & hp->driver_status))
 394                 memcpy(old_hdr.sense_buffer, srp->sense_b,
 395                        sizeof (old_hdr.sense_buffer));
 396         switch (hp->host_status) {
 397         /* This setup of 'result' is for backward compatibility and is best
 398            ignored by the user who should use target, host + driver status */
 399         case DID_OK:
 400         case DID_PASSTHROUGH:
 401         case DID_SOFT_ERROR:
 402                 old_hdr.result = 0;
 403                 break;
 404         case DID_NO_CONNECT:
 405         case DID_BUS_BUSY:
 406         case DID_TIME_OUT:
 407                 old_hdr.result = EBUSY;
 408                 break;
 409         case DID_BAD_TARGET:
 410         case DID_ABORT:
 411         case DID_PARITY:
 412         case DID_RESET:
 413         case DID_BAD_INTR:
 414                 old_hdr.result = EIO;
 415                 break;
 416         case DID_ERROR:
 417                 old_hdr.result = (srp->sense_b[0] == 0 &&
 418                                   hp->masked_status == GOOD) ? 0 : EIO;
 419                 break;
 420         default:
 421                 old_hdr.result = EIO;
 422                 break;
 423         }
 424
 425         /* Now copy the result back to the user buffer.  */
 426         if (count >= SZ_SG_HEADER) {
 427                 if (__copy_to_user(buf, &old_hdr, SZ_SG_HEADER))
 428                         return -EFAULT;
 429                 buf += SZ_SG_HEADER;
 430                 if (count > old_hdr.reply_len)
 431                         count = old_hdr.reply_len;
 432                 if (count > SZ_SG_HEADER) {
 433                         if ((res =
 434                              sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)))
 435                                 return -EFAULT;
 436                 }
 437         } else
 438                 count = (old_hdr.result == 0) ? 0 : -EIO;
 439         sg_finish_rem_req(srp);
 440         return count;
 441 }
 442
 443 static ssize_t
 444 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 445 {
 446         sg_io_hdr_t *hp = &srp->header;
 447         int err = 0;
 448         int len;
 449
 450         if (count < SZ_SG_IO_HDR) {
 451                 err = -EINVAL;
 452                 goto err_out;
 453         }
 454         hp->sb_len_wr = 0;
 455         if ((hp->mx_sb_len > 0) && hp->sbp) {
 456                 if ((CHECK_CONDITION & hp->masked_status) ||
 457                     (DRIVER_SENSE & hp->driver_status)) {
 458                         int sb_len = sizeof (dummy_cmdp->sr_sense_buffer);
 459                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 460                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 461                         len = (len > sb_len) ? sb_len : len;
 462                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 463                                 err = -EFAULT;
 464                                 goto err_out;
 465                         }
 466                         hp->sb_len_wr = len;
 467                 }
 468         }
 469         if (hp->masked_status || hp->host_status || hp->driver_status)
 470                 hp->info |= SG_INFO_CHECK;
 471         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 472                 err = -EFAULT;
 473                 goto err_out;
 474         }
 475         err = sg_read_xfer(srp);
 476       err_out:
 477         sg_finish_rem_req(srp);
 478         return (0 == err) ? count : err;
 479 }
 480
 481 static ssize_t
 482 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 483 {
 484         int mxsize, cmd_size, k;
 485         int input_size, blocking;
 486         unsigned char opcode;
 487         Sg_device *sdp;
 488         Sg_fd *sfp;
 489         Sg_request *srp;
 490         struct sg_header old_hdr;
 491         sg_io_hdr_t *hp;
 492         unsigned char cmnd[sizeof (dummy_cmdp->sr_cmnd)];
 493
 494         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 495                 return -ENXIO;
 496         SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
 497                                    sdp->disk->disk_name, (int) count));
 498         if (sdp->detached)
 499                 return -ENODEV;
 500         if (!((filp->f_flags & O_NONBLOCK) ||
 501               scsi_block_when_processing_errors(sdp->device)))
 502                 return -ENXIO;
 503
 504         if ((k = verify_area(VERIFY_READ, buf, count)))
 505                 return k;       /* protects following copy_from_user()s + get_user()s */
 506         if (count < SZ_SG_HEADER)
 507                 return -EIO;
 508         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 509                 return -EFAULT;
 510         blocking = !(filp->f_flags & O_NONBLOCK);
 511         if (old_hdr.reply_len < 0)
 512                 return sg_new_write(sfp, buf, count, blocking, 0, NULL);
 513         if (count < (SZ_SG_HEADER + 6))
 514                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 515
 516         if (!(srp = sg_add_request(sfp))) {
 517                 SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
 518                 return -EDOM;
 519         }
 520         buf += SZ_SG_HEADER;
 521         __get_user(opcode, buf);
 522         if (sfp->next_cmd_len > 0) {
 523                 if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
 524                         SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
 525                         sfp->next_cmd_len = 0;
 526                         sg_remove_request(sfp, srp);
 527                         return -EIO;
 528                 }
 529                 cmd_size = sfp->next_cmd_len;
 530                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 531         } else {
 532                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 533                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 534                         cmd_size = 12;
 535         }
 536         SCSI_LOG_TIMEOUT(4, printk(
 537                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 538 /* Determine buffer size.  */
 539         input_size = count - cmd_size;
 540         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 541         mxsize -= SZ_SG_HEADER;
 542         input_size -= SZ_SG_HEADER;
 543         if (input_size < 0) {
 544                 sg_remove_request(sfp, srp);
 545                 return -EIO;    /* User did not pass enough bytes for this command. */
 546         }
 547         hp = &srp->header;
 548         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 549         hp->cmd_len = (unsigned char) cmd_size;
 550         hp->iovec_count = 0;
 551         hp->mx_sb_len = 0;
 552         if (input_size > 0)
 553                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 554                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 555         else
 556                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 557         hp->dxfer_len = mxsize;
 558         hp->dxferp = (char __user *)buf + cmd_size;
 559         hp->sbp = NULL;
 560         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 561         hp->flags = input_size; /* structure abuse ... */
 562         hp->pack_id = old_hdr.pack_id;
 563         hp->usr_ptr = NULL;
 564         if (__copy_from_user(cmnd, buf, cmd_size))
 565                 return -EFAULT;
 566         /*
 567          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 568          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 569          * is a non-zero input_size, so emit a warning.
 570          */
 571         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV)
 572                 if (printk_ratelimit())
 573                         printk(KERN_WARNING
 574                                "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
 575                                "guessing data in;\n" KERN_WARNING "   "
 576                                "program %s not setting count and/or reply_len properly\n",
 577                                old_hdr.reply_len - (int)SZ_SG_HEADER,
 578                                input_size, (unsigned int) cmnd[0],
 579                                current->comm);
 580         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 581         return (k < 0) ? k : count;
 582 }
 583
 584 static ssize_t
 585 sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
 586              int blocking, int read_only, Sg_request ** o_srp)
 587 {
 588         int k;
 589         Sg_request *srp;
 590         sg_io_hdr_t *hp;
 591         unsigned char cmnd[sizeof (dummy_cmdp->sr_cmnd)];
 592         int timeout;
 593         unsigned long ul_timeout;
 594
 595         if (count < SZ_SG_IO_HDR)
 596                 return -EINVAL;
 597         if ((k = verify_area(VERIFY_READ, buf, count)))
 598                 return k; /* protects following copy_from_user()s + get_user()s */
 599
 600         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 601         if (!(srp = sg_add_request(sfp))) {
 602                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
 603                 return -EDOM;
 604         }
 605         hp = &srp->header;
 606         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 607                 sg_remove_request(sfp, srp);
 608                 return -EFAULT;
 609         }
 610         if (hp->interface_id != 'S') {
 611                 sg_remove_request(sfp, srp);
 612                 return -ENOSYS;
 613         }
 614         if (hp->flags & SG_FLAG_MMAP_IO) {
 615                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 616                         sg_remove_request(sfp, srp);
 617                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 618                 }
 619                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 620                         sg_remove_request(sfp, srp);
 621                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 622                 }
 623                 if (sg_res_in_use(sfp)) {
 624                         sg_remove_request(sfp, srp);
 625                         return -EBUSY;  /* reserve buffer already being used */
 626                 }
 627         }
 628         ul_timeout = msecs_to_jiffies(srp->header.timeout);
 629         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 630         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 631                 sg_remove_request(sfp, srp);
 632                 return -EMSGSIZE;
 633         }
 634         if ((k = verify_area(VERIFY_READ, hp->cmdp, hp->cmd_len))) {
 635                 sg_remove_request(sfp, srp);
 636                 return k;       /* protects following copy_from_user()s + get_user()s */
 637         }
 638         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 639                 sg_remove_request(sfp, srp);
 640                 return -EFAULT;
 641         }
 642         if (read_only &&
 643             (!sg_allow_access(cmnd[0], sfp->parentdp->device->type))) {
 644                 sg_remove_request(sfp, srp);
 645                 return -EPERM;
 646         }
 647         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 648         if (k < 0)
 649                 return k;
 650         if (o_srp)
 651                 *o_srp = srp;
 652         return count;
 653 }
 654
 655 static int
 656 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 657                 unsigned char *cmnd, int timeout, int blocking)
 658 {
 659         int k;
 660         Scsi_Request *SRpnt;
 661         Sg_device *sdp = sfp->parentdp;
 662         sg_io_hdr_t *hp = &srp->header;
 663         request_queue_t *q;
 664
 665         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 666         hp->status = 0;
 667         hp->masked_status = 0;
 668         hp->msg_status = 0;
 669         hp->info = 0;
 670         hp->host_status = 0;
 671         hp->driver_status = 0;
 672         hp->resid = 0;
 673         SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 674                           (int) cmnd[0], (int) hp->cmd_len));
 675
 676         if ((k = sg_start_req(srp))) {
 677                 SCSI_LOG_TIMEOUT(1, printk("sg_write: start_req err=%d\n", k));
 678                 sg_finish_rem_req(srp);
 679                 return k;       /* probably out of space --> ENOMEM */
 680         }
 681         if ((k = sg_write_xfer(srp))) {
 682                 SCSI_LOG_TIMEOUT(1, printk("sg_write: write_xfer, bad address\n"));
 683                 sg_finish_rem_req(srp);
 684                 return k;
 685         }
 686         if (sdp->detached) {
 687                 sg_finish_rem_req(srp);
 688                 return -ENODEV;
 689         }
 690         SRpnt = scsi_allocate_request(sdp->device, GFP_ATOMIC);
 691         if (SRpnt == NULL) {
 692                 SCSI_LOG_TIMEOUT(1, printk("sg_write: no mem\n"));
 693                 sg_finish_rem_req(srp);
 694                 return -ENOMEM;
 695         }
 696
 697         srp->my_cmdp = SRpnt;
 698         q = SRpnt->sr_device->request_queue;
 699         SRpnt->sr_request->rq_disk = sdp->disk;
 700         SRpnt->sr_sense_buffer[0] = 0;
 701         SRpnt->sr_cmd_len = hp->cmd_len;
 702         SRpnt->sr_use_sg = srp->data.k_use_sg;
 703         SRpnt->sr_sglist_len = srp->data.sglist_len;
 704         SRpnt->sr_bufflen = srp->data.bufflen;
 705         SRpnt->sr_underflow = 0;
 706         SRpnt->sr_buffer = srp->data.buffer;
 707         switch (hp->dxfer_direction) {
 708         case SG_DXFER_TO_FROM_DEV:
 709         case SG_DXFER_FROM_DEV:
 710                 SRpnt->sr_data_direction = SCSI_DATA_READ;
 711                 break;
 712         case SG_DXFER_TO_DEV:
 713                 SRpnt->sr_data_direction = SCSI_DATA_WRITE;
 714                 break;
 715         case SG_DXFER_UNKNOWN:
 716                 SRpnt->sr_data_direction = SCSI_DATA_UNKNOWN;
 717                 break;
 718         default:
 719                 SRpnt->sr_data_direction = SCSI_DATA_NONE;
 720                 break;
 721         }
 722         SRpnt->upper_private_data = srp;
 723         srp->data.k_use_sg = 0;
 724         srp->data.sglist_len = 0;
 725         srp->data.bufflen = 0;
 726         srp->data.buffer = NULL;
 727         hp->duration = jiffies; /* unit jiffies now, millisecs after done */
 728 /* Now send everything of to mid-level. The next time we hear about this
 729    packet is when sg_cmd_done() is called (i.e. a callback). */
 730         scsi_do_req(SRpnt, (void *) cmnd,
 731                     (void *) SRpnt->sr_buffer, hp->dxfer_len,
 732                     sg_cmd_done, timeout, SG_DEFAULT_RETRIES);
 733         /* dxfer_len overwrites SRpnt->sr_bufflen, hence need for b_malloc_len */
 734         return 0;
 735 }
 736
 737 static int
 738 sg_srp_done(Sg_request *srp, Sg_fd *sfp)
 739 {
 740         unsigned long iflags;
 741         int done;
 742
 743         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 744         done = srp->done;
 745         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 746         return done;
 747 }
 748
 749 static int
 750 sg_ioctl(struct inode *inode, struct file *filp,
 751          unsigned int cmd_in, unsigned long arg)
 752 {
 753         void __user *p = (void __user *)arg;
 754         int __user *ip = p;
 755         int result, val, read_only;
 756         Sg_device *sdp;
 757         Sg_fd *sfp;
 758         Sg_request *srp;
 759         unsigned long iflags;
 760
 761         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 762                 return -ENXIO;
 763         SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
 764                                    sdp->disk->disk_name, (int) cmd_in));
 765         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 766
 767         switch (cmd_in) {
 768         case SG_IO:
 769                 {
 770                         int blocking = 1;       /* ignore O_NONBLOCK flag */
 771
 772                         if (sdp->detached)
 773                                 return -ENODEV;
 774                         if (!scsi_block_when_processing_errors(sdp->device))
 775                                 return -ENXIO;
 776                         result = verify_area(VERIFY_WRITE, p, SZ_SG_IO_HDR);
 777                         if (result)
 778                                 return result;
 779                         result =
 780                             sg_new_write(sfp, p, SZ_SG_IO_HDR,
 781                                          blocking, read_only, &srp);
 782                         if (result < 0)
 783                                 return result;
 784                         srp->sg_io_owned = 1;
 785                         while (1) {
 786                                 result = 0;     /* following macro to beat race condition */
 787                                 __wait_event_interruptible(sfp->read_wait,
 788                                         (sdp->detached || sfp->closed || sg_srp_done(srp, sfp)),
 789                                                            result);
 790                                 if (sdp->detached)
 791                                         return -ENODEV;
 792                                 if (sfp->closed)
 793                                         return 0;       /* request packet dropped already */
 794                                 if (0 == result)
 795                                         break;
 796                                 srp->orphan = 1;
 797                                 return result;  /* -ERESTARTSYS because signal hit process */
 798                         }
 799                         write_lock_irqsave(&sfp->rq_list_lock, iflags);
 800                         srp->done = 2;
 801                         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 802                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 803                         return (result < 0) ? result : 0;
 804                 }
 805         case SG_SET_TIMEOUT:
 806                 result = get_user(val, ip);
 807                 if (result)
 808                         return result;
 809                 if (val < 0)
 810                         return -EIO;
 811                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
 812                     val = MULDIV (INT_MAX, USER_HZ, HZ);
 813                 sfp->timeout_user = val;
 814                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
 815
 816                 return 0;
 817         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 818                                 /* strange ..., for backward compatibility */
 819                 return sfp->timeout_user;
 820         case SG_SET_FORCE_LOW_DMA:
 821                 result = get_user(val, ip);
 822                 if (result)
 823                         return result;
 824                 if (val) {
 825                         sfp->low_dma = 1;
 826                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
 827                                 val = (int) sfp->reserve.bufflen;
 828                                 sg_remove_scat(&sfp->reserve);
 829                                 sg_build_reserve(sfp, val);
 830                         }
 831                 } else {
 832                         if (sdp->detached)
 833                                 return -ENODEV;
 834                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
 835                 }
 836                 return 0;
 837         case SG_GET_LOW_DMA:
 838                 return put_user((int) sfp->low_dma, ip);
 839         case SG_GET_SCSI_ID:
 840                 result =
 841                     verify_area(VERIFY_WRITE, p, sizeof (sg_scsi_id_t));
 842                 if (result)
 843                         return result;
 844                 else {
 845                         sg_scsi_id_t __user *sg_idp = p;
 846
 847                         if (sdp->detached)
 848                                 return -ENODEV;
 849                         __put_user((int) sdp->device->host->host_no,
 850                                    &sg_idp->host_no);
 851                         __put_user((int) sdp->device->channel,
 852                                    &sg_idp->channel);
 853                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 854                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 855                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 856                         __put_user((short) sdp->device->host->cmd_per_lun,
 857                                    &sg_idp->h_cmd_per_lun);
 858                         __put_user((short) sdp->device->queue_depth,
 859                                    &sg_idp->d_queue_depth);
 860                         __put_user(0, &sg_idp->unused[0]);
 861                         __put_user(0, &sg_idp->unused[1]);
 862                         return 0;
 863                 }
 864         case SG_SET_FORCE_PACK_ID:
 865                 result = get_user(val, ip);
 866                 if (result)
 867                         return result;
 868                 sfp->force_packid = val ? 1 : 0;
 869                 return 0;
 870         case SG_GET_PACK_ID:
 871                 result = verify_area(VERIFY_WRITE, ip, sizeof (int));
 872                 if (result)
 873                         return result;
 874                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 875                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
 876                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 877                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 878                                                        iflags);
 879                                 __put_user(srp->header.pack_id, ip);
 880                                 return 0;
 881                         }
 882                 }
 883                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 884                 __put_user(-1, ip);
 885                 return 0;
 886         case SG_GET_NUM_WAITING:
 887                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 888                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
 889                         if ((1 == srp->done) && (!srp->sg_io_owned))
 890                                 ++val;
 891                 }
 892                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 893                 return put_user(val, ip);
 894         case SG_GET_SG_TABLESIZE:
 895                 return put_user(sdp->sg_tablesize, ip);
 896         case SG_SET_RESERVED_SIZE:
 897                 result = get_user(val, ip);
 898                 if (result)
 899                         return result;
 900                 if (val < 0)
 901                         return -EINVAL;
 902                 if (val != sfp->reserve.bufflen) {
 903                         if (sg_res_in_use(sfp) || sfp->mmap_called)
 904                                 return -EBUSY;
 905                         sg_remove_scat(&sfp->reserve);
 906                         sg_build_reserve(sfp, val);
 907                 }
 908                 return 0;
 909         case SG_GET_RESERVED_SIZE:
 910                 val = (int) sfp->reserve.bufflen;
 911                 return put_user(val, ip);
 912         case SG_SET_COMMAND_Q:
 913                 result = get_user(val, ip);
 914                 if (result)
 915                         return result;
 916                 sfp->cmd_q = val ? 1 : 0;
 917                 return 0;
 918         case SG_GET_COMMAND_Q:
 919                 return put_user((int) sfp->cmd_q, ip);
 920         case SG_SET_KEEP_ORPHAN:
 921                 result = get_user(val, ip);
 922                 if (result)
 923                         return result;
 924                 sfp->keep_orphan = val;
 925                 return 0;
 926         case SG_GET_KEEP_ORPHAN:
 927                 return put_user((int) sfp->keep_orphan, ip);
 928         case SG_NEXT_CMD_LEN:
 929                 result = get_user(val, ip);
 930                 if (result)
 931                         return result;
 932                 sfp->next_cmd_len = (val > 0) ? val : 0;
 933                 return 0;
 934         case SG_GET_VERSION_NUM:
 935                 return put_user(sg_version_num, ip);
 936         case SG_GET_ACCESS_COUNT:
 937                 /* faked - we don't have a real access count anymore */
 938                 val = (sdp->device ? 1 : 0);
 939                 return put_user(val, ip);
 940         case SG_GET_REQUEST_TABLE:
 941                 result = verify_area(VERIFY_WRITE, p,
 942                                      SZ_SG_REQ_INFO * SG_MAX_QUEUE);
 943                 if (result)
 944                         return result;
 945                 else {
 946                         sg_req_info_t rinfo[SG_MAX_QUEUE];
 947                         Sg_request *srp;
 948                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 949                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
 950                              ++val, srp = srp ? srp->nextrp : srp) {
 951                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
 952                                 if (srp) {
 953                                         rinfo[val].req_state = srp->done + 1;
 954                                         rinfo[val].problem =
 955                                             srp->header.masked_status &
 956                                             srp->header.host_status &
 957                                             srp->header.driver_status;
 958                                         rinfo[val].duration =
 959                                             srp->done ? srp->header.duration :
 960                                             jiffies_to_msecs(
 961                                                 jiffies - srp->header.duration);
 962                                         rinfo[val].orphan = srp->orphan;
 963                                         rinfo[val].sg_io_owned = srp->sg_io_owned;
 964                                         rinfo[val].pack_id = srp->header.pack_id;
 965                                         rinfo[val].usr_ptr = srp->header.usr_ptr;
 966                                 }
 967                         }
 968                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 969                         return (__copy_to_user(p, rinfo,
 970                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE) ? -EFAULT : 0);
 971                 }
 972         case SG_EMULATED_HOST:
 973                 if (sdp->detached)
 974                         return -ENODEV;
 975                 return put_user(sdp->device->host->hostt->emulated, ip);
 976         case SG_SCSI_RESET:
 977                 if (sdp->detached)
 978                         return -ENODEV;
 979                 if (filp->f_flags & O_NONBLOCK) {
 980                         if (test_bit(SHOST_RECOVERY,
 981                                      &sdp->device->host->shost_state))
 982                                 return -EBUSY;
 983                 } else if (!scsi_block_when_processing_errors(sdp->device))
 984                         return -EBUSY;
 985                 result = get_user(val, ip);
 986                 if (result)
 987                         return result;
 988                 if (SG_SCSI_RESET_NOTHING == val)
 989                         return 0;
 990                 switch (val) {
 991                 case SG_SCSI_RESET_DEVICE:
 992                         val = SCSI_TRY_RESET_DEVICE;
 993                         break;
 994                 case SG_SCSI_RESET_BUS:
 995                         val = SCSI_TRY_RESET_BUS;
 996                         break;
 997                 case SG_SCSI_RESET_HOST:
 998                         val = SCSI_TRY_RESET_HOST;
 999                         break;
1000                 default:
1001                         return -EINVAL;
1002                 }
1003                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1004                         return -EACCES;
1005                 return (scsi_reset_provider(sdp->device, val) ==
1006                         SUCCESS) ? 0 : -EIO;
1007         case SCSI_IOCTL_SEND_COMMAND:
1008                 if (sdp->detached)
1009                         return -ENODEV;
1010                 if (read_only) {
1011                         unsigned char opcode = WRITE_6;
1012                         Scsi_Ioctl_Command __user *siocp = p;
1013
1014                         if (copy_from_user(&opcode, siocp->data, 1))
1015                                 return -EFAULT;
1016                         if (!sg_allow_access(opcode, sdp->device->type))
1017                                 return -EPERM;
1018                 }
1019                 return scsi_ioctl_send_command(sdp->device, p);
1020         case SG_SET_DEBUG:
1021                 result = get_user(val, ip);
1022                 if (result)
1023                         return result;
1024                 sdp->sgdebug = (char) val;
1025                 return 0;
1026         case SCSI_IOCTL_GET_IDLUN:
1027         case SCSI_IOCTL_GET_BUS_NUMBER:
1028         case SCSI_IOCTL_PROBE_HOST:
1029         case SG_GET_TRANSFORM:
1030                 if (sdp->detached)
1031                         return -ENODEV;
1032                 return scsi_ioctl(sdp->device, cmd_in, p);
1033         default:
1034                 if (read_only)
1035                         return -EPERM;  /* don't know so take safe approach */
1036                 return scsi_ioctl(sdp->device, cmd_in, p);
1037         }
1038 }
1039
1040 static unsigned int
1041 sg_poll(struct file *filp, poll_table * wait)
1042 {
1043         unsigned int res = 0;
1044         Sg_device *sdp;
1045         Sg_fd *sfp;
1046         Sg_request *srp;
1047         int count = 0;
1048         unsigned long iflags;
1049
1050         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1051             || sfp->closed)
1052                 return POLLERR;
1053         poll_wait(filp, &sfp->read_wait, wait);
1054         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1055         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1056                 /* if any read waiting, flag it */
1057                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1058                         res = POLLIN | POLLRDNORM;
1059                 ++count;
1060         }
1061         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1062
1063         if (sdp->detached)
1064                 res |= POLLHUP;
1065         else if (!sfp->cmd_q) {
1066                 if (0 == count)
1067                         res |= POLLOUT | POLLWRNORM;
1068         } else if (count < SG_MAX_QUEUE)
1069                 res |= POLLOUT | POLLWRNORM;
1070         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1071                                    sdp->disk->disk_name, (int) res));
1072         return res;
1073 }
1074
1075 static int
1076 sg_fasync(int fd, struct file *filp, int mode)
1077 {
1078         int retval;
1079         Sg_device *sdp;
1080         Sg_fd *sfp;
1081
1082         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1083                 return -ENXIO;
1084         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1085                                    sdp->disk->disk_name, mode));
1086
1087         retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
1088         return (retval < 0) ? retval : 0;
1089 }
1090
1091 static inline unsigned char *
1092 sg_scatg2virt(const struct scatterlist *sclp)
1093 {
1094         return (sclp && sclp->page) ?
1095             (unsigned char *) page_address(sclp->page) + sclp->offset : NULL;
1096 }
1097
1098 /* When startFinish==1 increments page counts for pages other than the
1099    first of scatter gather elements obtained from __get_free_pages().
1100    When startFinish==0 decrements ... */
1101 static void
1102 sg_rb_correct4mmap(Sg_scatter_hold * rsv_schp, int startFinish)
1103 {
1104         void *page_ptr;
1105         struct page *page;
1106         int k, m;
1107
1108         SCSI_LOG_TIMEOUT(3, printk("sg_rb_correct4mmap: startFinish=%d, scatg=%d\n",
1109                                    startFinish, rsv_schp->k_use_sg));
1110         /* N.B. correction _not_ applied to base page of each allocation */
1111         if (rsv_schp->k_use_sg) {       /* reserve buffer is a scatter gather list */
1112                 struct scatterlist *sclp = rsv_schp->buffer;
1113
1114                 for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sclp) {
1115                         for (m = PAGE_SIZE; m < sclp->length; m += PAGE_SIZE) {
1116                                 page_ptr = sg_scatg2virt(sclp) + m;
1117                                 page = virt_to_page(page_ptr);
1118                                 if (startFinish)
1119                                         get_page(page);
1120                                 else {
1121                                         if (page_count(page) > 0)
1122                                                 __put_page(page);
1123                                 }
1124                         }
1125                 }
1126         } else {                /* reserve buffer is just a single allocation */
1127                 for (m = PAGE_SIZE; m < rsv_schp->bufflen; m += PAGE_SIZE) {
1128                         page_ptr = (unsigned char *) rsv_schp->buffer + m;
1129                         page = virt_to_page(page_ptr);
1130                         if (startFinish)
1131                                 get_page(page);
1132                         else {
1133                                 if (page_count(page) > 0)
1134                                         __put_page(page);
1135                         }
1136                 }
1137         }
1138 }
1139
1140 static struct page *
1141 sg_vma_nopage(struct vm_area_struct *vma, unsigned long addr, int *type)
1142 {
1143         Sg_fd *sfp;
1144         struct page *page = NOPAGE_SIGBUS;
1145         void *page_ptr = NULL;
1146         unsigned long offset;
1147         Sg_scatter_hold *rsv_schp;
1148
1149         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1150                 return page;
1151         rsv_schp = &sfp->reserve;
1152         offset = addr - vma->vm_start;
1153         if (offset >= rsv_schp->bufflen)
1154                 return page;
1155         SCSI_LOG_TIMEOUT(3, printk("sg_vma_nopage: offset=%lu, scatg=%d\n",
1156                                    offset, rsv_schp->k_use_sg));
1157         if (rsv_schp->k_use_sg) {       /* reserve buffer is a scatter gather list */
1158                 int k;
1159                 unsigned long sa = vma->vm_start;
1160                 unsigned long len;
1161                 struct scatterlist *sclp = rsv_schp->buffer;
1162
1163                 for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1164                      ++k, ++sclp) {
1165                         len = vma->vm_end - sa;
1166                         len = (len < sclp->length) ? len : sclp->length;
1167                         if (offset < len) {
1168                                 page_ptr = sg_scatg2virt(sclp) + offset;
1169                                 page = virt_to_page(page_ptr);
1170                                 get_page(page); /* increment page count */
1171                                 break;
1172                         }
1173                         sa += len;
1174                         offset -= len;
1175                 }
1176         } else {                /* reserve buffer is just a single allocation */
1177                 page_ptr = (unsigned char *) rsv_schp->buffer + offset;
1178                 page = virt_to_page(page_ptr);
1179                 get_page(page); /* increment page count */
1180         }
1181         if (type)
1182                 *type = VM_FAULT_MINOR;
1183         return page;
1184 }
1185
1186 static struct vm_operations_struct sg_mmap_vm_ops = {
1187         .nopage = sg_vma_nopage,
1188 };
1189
1190 static int
1191 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1192 {
1193         Sg_fd *sfp;
1194         unsigned long req_sz = vma->vm_end - vma->vm_start;
1195         Sg_scatter_hold *rsv_schp;
1196
1197         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1198                 return -ENXIO;
1199         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1200                                    (void *) vma->vm_start, (int) req_sz));
1201         if (vma->vm_pgoff)
1202                 return -EINVAL; /* want no offset */
1203         rsv_schp = &sfp->reserve;
1204         if (req_sz > rsv_schp->bufflen)
1205                 return -ENOMEM; /* cannot map more than reserved buffer */
1206
1207         if (rsv_schp->k_use_sg) { /* reserve buffer is a scatter gather list */
1208                 int k;
1209                 unsigned long sa = vma->vm_start;
1210                 unsigned long len;
1211                 struct scatterlist *sclp = rsv_schp->buffer;
1212
1213                 for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1214                      ++k, ++sclp) {
1215                         if (0 != sclp->offset)
1216                                 return -EFAULT; /* non page aligned memory ?? */
1217                         len = vma->vm_end - sa;
1218                         len = (len < sclp->length) ? len : sclp->length;
1219                         sa += len;
1220                 }
1221         } else {        /* reserve buffer is just a single allocation */
1222                 if ((unsigned long) rsv_schp->buffer & (PAGE_SIZE - 1))
1223                         return -EFAULT; /* non page aligned memory ?? */
1224         }
1225         if (0 == sfp->mmap_called) {
1226                 sg_rb_correct4mmap(rsv_schp, 1);        /* do only once per fd lifetime */
1227                 sfp->mmap_called = 1;
1228         }
1229         vma->vm_flags |= (VM_RESERVED | VM_IO);
1230         vma->vm_private_data = sfp;
1231         vma->vm_ops = &sg_mmap_vm_ops;
1232         return 0;
1233 }
1234
1235 /* This function is a "bottom half" handler that is called by the
1236  * mid level when a command is completed (or has failed). */
1237 static void
1238 sg_cmd_done(Scsi_Cmnd * SCpnt)
1239 {
1240         Scsi_Request *SRpnt = NULL;
1241         Sg_device *sdp = NULL;
1242         Sg_fd *sfp;
1243         Sg_request *srp = NULL;
1244         unsigned long iflags;
1245
1246         if (SCpnt && (SRpnt = SCpnt->sc_request))
1247                 srp = (Sg_request *) SRpnt->upper_private_data;
1248         if (NULL == srp) {
1249                 printk(KERN_ERR "sg_cmd_done: NULL request\n");
1250                 if (SRpnt)
1251                         scsi_release_request(SRpnt);
1252                 return;
1253         }
1254         sfp = srp->parentfp;
1255         if (sfp)
1256                 sdp = sfp->parentdp;
1257         if ((NULL == sdp) || sdp->detached) {
1258                 printk(KERN_INFO "sg_cmd_done: device detached\n");
1259                 scsi_release_request(SRpnt);
1260                 return;
1261         }
1262
1263         /* First transfer ownership of data buffers to sg_device object. */
1264         srp->data.k_use_sg = SRpnt->sr_use_sg;
1265         srp->data.sglist_len = SRpnt->sr_sglist_len;
1266         srp->data.bufflen = SRpnt->sr_bufflen;
1267         srp->data.buffer = SRpnt->sr_buffer;
1268         /* now clear out request structure */
1269         SRpnt->sr_use_sg = 0;
1270         SRpnt->sr_sglist_len = 0;
1271         SRpnt->sr_bufflen = 0;
1272         SRpnt->sr_buffer = NULL;
1273         SRpnt->sr_underflow = 0;
1274         SRpnt->sr_request->rq_disk = NULL; /* "sg" _disowns_ request blk */
1275
1276         srp->my_cmdp = NULL;
1277
1278         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1279                 sdp->disk->disk_name, srp->header.pack_id, (int) SRpnt->sr_result));
1280         srp->header.resid = SCpnt->resid;
1281         /* N.B. unit of duration changes here from jiffies to millisecs */
1282         srp->header.duration =
1283             jiffies_to_msecs(jiffies - srp->header.duration);
1284         if (0 != SRpnt->sr_result) {
1285                 struct scsi_sense_hdr sshdr;
1286
1287                 memcpy(srp->sense_b, SRpnt->sr_sense_buffer,
1288                        sizeof (srp->sense_b));
1289                 srp->header.status = 0xff & SRpnt->sr_result;
1290                 srp->header.masked_status = status_byte(SRpnt->sr_result);
1291                 srp->header.msg_status = msg_byte(SRpnt->sr_result);
1292                 srp->header.host_status = host_byte(SRpnt->sr_result);
1293                 srp->header.driver_status = driver_byte(SRpnt->sr_result);
1294                 if ((sdp->sgdebug > 0) &&
1295                     ((CHECK_CONDITION == srp->header.masked_status) ||
1296                      (COMMAND_TERMINATED == srp->header.masked_status)))
1297                         print_req_sense("sg_cmd_done", SRpnt);
1298
1299                 /* Following if statement is a patch supplied by Eric Youngdale */
1300                 if (driver_byte(SRpnt->sr_result) != 0
1301                     && scsi_command_normalize_sense(SCpnt, &sshdr)
1302                     && !scsi_sense_is_deferred(&sshdr)
1303                     && sshdr.sense_key == UNIT_ATTENTION
1304                     && sdp->device->removable) {
1305                         /* Detected possible disc change. Set the bit - this */
1306                         /* may be used if there are filesystems using this device */
1307                         sdp->device->changed = 1;
1308                 }
1309         }
1310         /* Rely on write phase to clean out srp status values, so no "else" */
1311
1312         scsi_release_request(SRpnt);
1313         SRpnt = NULL;
1314         if (sfp->closed) {      /* whoops this fd already released, cleanup */
1315                 SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1316                 sg_finish_rem_req(srp);
1317                 srp = NULL;
1318                 if (NULL == sfp->headrp) {
1319                         SCSI_LOG_TIMEOUT(1, printk("sg...bh: already closed, final cleanup\n"));
1320                         if (0 == sg_remove_sfp(sdp, sfp)) {     /* device still present */
1321                                 scsi_device_put(sdp->device);
1322                         }
1323                         sfp = NULL;
1324                 }
1325         } else if (srp && srp->orphan) {
1326                 if (sfp->keep_orphan)
1327                         srp->sg_io_owned = 0;
1328                 else {
1329                         sg_finish_rem_req(srp);
1330                         srp = NULL;
1331                 }
1332         }
1333         if (sfp && srp) {
1334                 /* Now wake up any sg_read() that is waiting for this packet. */
1335                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1336                 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1337                 srp->done = 1;
1338                 wake_up_interruptible(&sfp->read_wait);
1339                 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1340         }
1341 }
1342
1343 static struct file_operations sg_fops = {
1344         .owner = THIS_MODULE,
1345         .read = sg_read,
1346         .write = sg_write,
1347         .poll = sg_poll,
1348         .ioctl = sg_ioctl,
1349         .open = sg_open,
1350         .mmap = sg_mmap,
1351         .release = sg_release,
1352         .fasync = sg_fasync,
1353 };
1354
1355 static struct class_simple * sg_sysfs_class;
1356
1357 static int sg_sysfs_valid = 0;
1358
1359 static int sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1360 {
1361         Sg_device *sdp;
1362         unsigned long iflags;
1363         void *old_sg_dev_arr = NULL;
1364         int k, error;
1365
1366         sdp = kmalloc(sizeof(Sg_device), GFP_KERNEL);
1367         if (!sdp) {
1368                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1369                 return -ENOMEM;
1370         }
1371
1372         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1373         if (unlikely(sg_nr_dev >= sg_dev_max)) {        /* try to resize */
1374                 Sg_device **tmp_da;
1375                 int tmp_dev_max = sg_nr_dev + SG_DEV_ARR_LUMP;
1376                 write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1377
1378                 tmp_da = kmalloc(tmp_dev_max * sizeof(Sg_device *), GFP_KERNEL);
1379                 if (unlikely(!tmp_da))
1380                         goto expand_failed;
1381
1382                 write_lock_irqsave(&sg_dev_arr_lock, iflags);
1383                 memset(tmp_da, 0, tmp_dev_max * sizeof(Sg_device *));
1384                 memcpy(tmp_da, sg_dev_arr, sg_dev_max * sizeof(Sg_device *));
1385                 old_sg_dev_arr = sg_dev_arr;
1386                 sg_dev_arr = tmp_da;
1387                 sg_dev_max = tmp_dev_max;
1388         }
1389
1390         for (k = 0; k < sg_dev_max; k++)
1391                 if (!sg_dev_arr[k])
1392                         break;
1393         if (unlikely(k >= SG_MAX_DEVS))
1394                 goto overflow;
1395
1396         memset(sdp, 0, sizeof(*sdp));
1397         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1398         sprintf(disk->disk_name, "sg%d", k);
1399         disk->first_minor = k;
1400         sdp->disk = disk;
1401         sdp->device = scsidp;
1402         init_waitqueue_head(&sdp->o_excl_wait);
1403         sdp->sg_tablesize = scsidp->host ? scsidp->host->sg_tablesize : 0;
1404
1405         sg_nr_dev++;
1406         sg_dev_arr[k] = sdp;
1407         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1408         error = k;
1409
1410  out:
1411         if (error < 0)
1412                 kfree(sdp);
1413         kfree(old_sg_dev_arr);
1414         return error;
1415
1416  expand_failed:
1417         printk(KERN_WARNING "sg_alloc: device array cannot be resized\n");
1418         error = -ENOMEM;
1419         goto out;
1420
1421  overflow:
1422         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1423         printk(KERN_WARNING
1424                "Unable to attach sg device <%d, %d, %d, %d> type=%d, minor "
1425                "number exceeds %d\n", scsidp->host->host_no, scsidp->channel,
1426                scsidp->id, scsidp->lun, scsidp->type, SG_MAX_DEVS - 1);
1427         error = -ENODEV;
1428         goto out;
1429 }
1430
1431 static int
1432 sg_add(struct class_device *cl_dev)
1433 {
1434         struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1435         struct gendisk *disk;
1436         Sg_device *sdp = NULL;
1437         struct cdev * cdev = NULL;
1438         int error, k;
1439
1440         disk = alloc_disk(1);
1441         if (!disk) {
1442                 printk(KERN_WARNING "alloc_disk failed\n");
1443                 return -ENOMEM;
1444         }
1445         disk->major = SCSI_GENERIC_MAJOR;
1446
1447         error = -ENOMEM;
1448         cdev = cdev_alloc();
1449         if (!cdev) {
1450                 printk(KERN_WARNING "cdev_alloc failed\n");
1451                 goto out;
1452         }
1453         cdev->owner = THIS_MODULE;
1454         cdev->ops = &sg_fops;
1455
1456         error = sg_alloc(disk, scsidp);
1457         if (error < 0) {
1458                 printk(KERN_WARNING "sg_alloc failed\n");
1459                 goto out;
1460         }
1461         k = error;
1462         sdp = sg_dev_arr[k];
1463
1464         devfs_mk_cdev(MKDEV(SCSI_GENERIC_MAJOR, k),
1465                         S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP,
1466                         "%s/generic", scsidp->devfs_name);
1467         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, k), 1);
1468         if (error) {
1469                 devfs_remove("%s/generic", scsidp->devfs_name);
1470                 goto out;
1471         }
1472         sdp->cdev = cdev;
1473         if (sg_sysfs_valid) {
1474                 struct class_device * sg_class_member;
1475
1476                 sg_class_member = class_simple_device_add(sg_sysfs_class,
1477                                 MKDEV(SCSI_GENERIC_MAJOR, k),
1478                                 cl_dev->dev, "%s",
1479                                 disk->disk_name);
1480                 if (IS_ERR(sg_class_member))
1481                         printk(KERN_WARNING "sg_add: "
1482                                 "class_simple_device_add failed\n");
1483                 class_set_devdata(sg_class_member, sdp);
1484                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1485                                           &sg_class_member->kobj, "generic");
1486                 if (error)
1487                         printk(KERN_ERR "sg_add: unable to make symlink "
1488                                         "'generic' back to sg%d\n", k);
1489         } else
1490                 printk(KERN_WARNING "sg_add: sg_sys INvalid\n");
1491
1492         printk(KERN_NOTICE
1493                "Attached scsi generic sg%d at scsi%d, channel"
1494                " %d, id %d, lun %d,  type %d\n", k,
1495                scsidp->host->host_no, scsidp->channel, scsidp->id,
1496                scsidp->lun, scsidp->type);
1497
1498         return 0;
1499
1500 out:
1501         put_disk(disk);
1502         if (cdev)
1503                 cdev_del(cdev);
1504         return error;
1505 }
1506
1507 static void
1508 sg_remove(struct class_device *cl_dev)
1509 {
1510         struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1511         Sg_device *sdp = NULL;
1512         unsigned long iflags;
1513         Sg_fd *sfp;
1514         Sg_fd *tsfp;
1515         Sg_request *srp;
1516         Sg_request *tsrp;
1517         int k, delay;
1518
1519         if (NULL == sg_dev_arr)
1520                 return;
1521         delay = 0;
1522         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1523         for (k = 0; k < sg_dev_max; k++) {
1524                 sdp = sg_dev_arr[k];
1525                 if ((NULL == sdp) || (sdp->device != scsidp))
1526                         continue;       /* dirty but lowers nesting */
1527                 if (sdp->headfp) {
1528                         sdp->detached = 1;
1529                         for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1530                                 tsfp = sfp->nextfp;
1531                                 for (srp = sfp->headrp; srp; srp = tsrp) {
1532                                         tsrp = srp->nextrp;
1533                                         if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
1534                                                 sg_finish_rem_req(srp);
1535                                 }
1536                                 if (sfp->closed) {
1537                                         scsi_device_put(sdp->device);
1538                                         __sg_remove_sfp(sdp, sfp);
1539                                 } else {
1540                                         delay = 1;
1541                                         wake_up_interruptible(&sfp->read_wait);
1542                                         kill_fasync(&sfp->async_qp, SIGPOLL,
1543                                                     POLL_HUP);
1544                                 }
1545                         }
1546                         SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d, dirty\n", k));
1547                         if (NULL == sdp->headfp) {
1548                                 sg_dev_arr[k] = NULL;
1549                         }
1550                 } else {        /* nothing active, simple case */
1551                         SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d\n", k));
1552                         sg_dev_arr[k] = NULL;
1553                 }
1554                 sg_nr_dev--;
1555                 break;
1556         }
1557         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1558
1559         if (sdp) {
1560                 sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1561                 class_simple_device_remove(MKDEV(SCSI_GENERIC_MAJOR, k));
1562                 cdev_del(sdp->cdev);
1563                 sdp->cdev = NULL;
1564                 devfs_remove("%s/generic", scsidp->devfs_name);
1565                 put_disk(sdp->disk);
1566                 sdp->disk = NULL;
1567                 if (NULL == sdp->headfp)
1568                         kfree((char *) sdp);
1569         }
1570
1571         if (delay)
1572                 msleep(10);     /* dirty detach so delay device destruction */
1573 }
1574
1575 /* Set 'perm' (4th argument) to 0 to disable module_param's definition
1576  * of sysfs parameters (which module_param doesn't yet support).
1577  * Sysfs parameters defined explicitly below.
1578  */
1579 module_param_named(def_reserved_size, def_reserved_size, int, S_IRUGO);
1580 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1581
1582 MODULE_AUTHOR("Douglas Gilbert");
1583 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1584 MODULE_LICENSE("GPL");
1585 MODULE_VERSION(SG_VERSION_STR);
1586
1587 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1588 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1589
1590 static int __init
1591 init_sg(void)
1592 {
1593         int rc;
1594
1595         if (def_reserved_size >= 0)
1596                 sg_big_buff = def_reserved_size;
1597
1598         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1599                                     SG_MAX_DEVS, "sg");
1600         if (rc)
1601                 return rc;
1602         sg_sysfs_class = class_simple_create(THIS_MODULE, "scsi_generic");
1603         if ( IS_ERR(sg_sysfs_class) ) {
1604                 rc = PTR_ERR(sg_sysfs_class);
1605                 goto err_out;
1606         }
1607         sg_sysfs_valid = 1;
1608         rc = scsi_register_interface(&sg_interface);
1609         if (0 == rc) {
1610 #ifdef CONFIG_SCSI_PROC_FS
1611                 sg_proc_init();
1612 #endif                          /* CONFIG_SCSI_PROC_FS */
1613                 return 0;
1614         }
1615         class_simple_destroy(sg_sysfs_class);
1616 err_out:
1617         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1618         return rc;
1619 }
1620
1621 static void __exit
1622 exit_sg(void)
1623 {
1624 #ifdef CONFIG_SCSI_PROC_FS
1625         sg_proc_cleanup();
1626 #endif                          /* CONFIG_SCSI_PROC_FS */
1627         scsi_unregister_interface(&sg_interface);
1628         class_simple_destroy(sg_sysfs_class);
1629         sg_sysfs_valid = 0;
1630         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1631                                  SG_MAX_DEVS);
1632         if (sg_dev_arr != NULL) {
1633                 kfree((char *) sg_dev_arr);
1634                 sg_dev_arr = NULL;
1635         }
1636         sg_dev_max = 0;
1637 }
1638
1639 static int
1640 sg_start_req(Sg_request * srp)
1641 {
1642         int res;
1643         Sg_fd *sfp = srp->parentfp;
1644         sg_io_hdr_t *hp = &srp->header;
1645         int dxfer_len = (int) hp->dxfer_len;
1646         int dxfer_dir = hp->dxfer_direction;
1647         Sg_scatter_hold *req_schp = &srp->data;
1648         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1649
1650         SCSI_LOG_TIMEOUT(4, printk("sg_start_req: dxfer_len=%d\n", dxfer_len));
1651         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1652                 return 0;
1653         if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
1654             (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) &&
1655             (!sfp->parentdp->device->host->unchecked_isa_dma)) {
1656                 res = sg_build_direct(srp, sfp, dxfer_len);
1657                 if (res <= 0)   /* -ve -> error, 0 -> done, 1 -> try indirect */
1658                         return res;
1659         }
1660         if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen))
1661                 sg_link_reserve(sfp, srp, dxfer_len);
1662         else {
1663                 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1664                 if (res) {
1665                         sg_remove_scat(req_schp);
1666                         return res;
1667                 }
1668         }
1669         return 0;
1670 }
1671
1672 static void
1673 sg_finish_rem_req(Sg_request * srp)
1674 {
1675         Sg_fd *sfp = srp->parentfp;
1676         Sg_scatter_hold *req_schp = &srp->data;
1677
1678         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1679         if (srp->res_used)
1680                 sg_unlink_reserve(sfp, srp);
1681         else
1682                 sg_remove_scat(req_schp);
1683         sg_remove_request(sfp, srp);
1684 }
1685
1686 static int
1687 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1688 {
1689         int ret_sz;
1690         int elem_sz = sizeof (struct scatterlist);
1691         int sg_bufflen = tablesize * elem_sz;
1692         int mx_sc_elems = tablesize;
1693
1694         schp->buffer = sg_page_malloc(sg_bufflen, sfp->low_dma, &ret_sz);
1695         if (!schp->buffer)
1696                 return -ENOMEM;
1697         else if (ret_sz != sg_bufflen) {
1698                 sg_bufflen = ret_sz;
1699                 mx_sc_elems = sg_bufflen / elem_sz;
1700         }
1701         schp->sglist_len = sg_bufflen;
1702         memset(schp->buffer, 0, sg_bufflen);
1703         return mx_sc_elems;     /* number of scat_gath elements allocated */
1704 }
1705
1706 #ifdef SG_ALLOW_DIO_CODE
1707 /* vvvvvvvv  following code borrowed from st driver's direct IO vvvvvvvvv */
1708         /* hopefully this generic code will moved to a library */
1709
1710 /* Pin down user pages and put them into a scatter gather list. Returns <= 0 if
1711    - mapping of all pages not successful
1712    - any page is above max_pfn
1713    (i.e., either completely successful or fails)
1714 */
1715 static int
1716 st_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages,
1717                   unsigned long uaddr, size_t count, int rw,
1718                   unsigned long max_pfn)
1719 {
1720         int res, i, j;
1721         unsigned int nr_pages;
1722         struct page **pages;
1723
1724         nr_pages = ((uaddr & ~PAGE_MASK) + count + ~PAGE_MASK) >> PAGE_SHIFT;
1725
1726         /* User attempted Overflow! */
1727         if ((uaddr + count) < uaddr)
1728                 return -EINVAL;
1729
1730         /* Too big */
1731         if (nr_pages > max_pages)
1732                 return -ENOMEM;
1733
1734         /* Hmm? */
1735         if (count == 0)
1736                 return 0;
1737
1738         if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_ATOMIC)) == NULL)
1739                 return -ENOMEM;
1740
1741         /* Try to fault in all of the necessary pages */
1742         down_read(&current->mm->mmap_sem);
1743         /* rw==READ means read from drive, write into memory area */
1744         res = get_user_pages(
1745                 current,
1746                 current->mm,
1747                 uaddr,
1748                 nr_pages,
1749                 rw == READ,
1750                 0, /* don't force */
1751                 pages,
1752                 NULL);
1753         up_read(&current->mm->mmap_sem);
1754
1755         /* Errors and no page mapped should return here */
1756         if (res < nr_pages)
1757                 goto out_unmap;
1758
1759         for (i=0; i < nr_pages; i++) {
1760                 /* FIXME: flush superflous for rw==READ,
1761                  * probably wrong function for rw==WRITE
1762                  */
1763                 flush_dcache_page(pages[i]);
1764                 if (page_to_pfn(pages[i]) > max_pfn)
1765                         goto out_unlock;
1766                 /* ?? Is locking needed? I don't think so */
1767                 /* if (TestSetPageLocked(pages[i]))
1768                    goto out_unlock; */
1769         }
1770
1771         /* Populate the scatter/gather list */
1772         sgl[0].page = pages[0];
1773         sgl[0].offset = uaddr & ~PAGE_MASK;
1774         if (nr_pages > 1) {
1775                 sgl[0].length = PAGE_SIZE - sgl[0].offset;
1776                 count -= sgl[0].length;
1777                 for (i=1; i < nr_pages ; i++) {
1778                         sgl[i].offset = 0;
1779                         sgl[i].page = pages[i];
1780                         sgl[i].length = count < PAGE_SIZE ? count : PAGE_SIZE;
1781                         count -= PAGE_SIZE;
1782                 }
1783         }
1784         else {
1785                 sgl[0].length = count;
1786         }
1787
1788         kfree(pages);
1789         return nr_pages;
1790
1791  out_unlock:
1792         /* for (j=0; j < i; j++)
1793            unlock_page(pages[j]); */
1794         res = 0;
1795  out_unmap:
1796         if (res > 0)
1797                 for (j=0; j < res; j++)
1798                         page_cache_release(pages[j]);
1799         kfree(pages);
1800         return res;
1801 }
1802
1803
1804 /* And unmap them... */
1805 static int
1806 st_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_pages,
1807                     int dirtied)
1808 {
1809         int i;
1810
1811         for (i=0; i < nr_pages; i++) {
1812                 if (dirtied && !PageReserved(sgl[i].page))
1813                         SetPageDirty(sgl[i].page);
1814                 /* unlock_page(sgl[i].page); */
1815                 /* FIXME: cache flush missing for rw==READ
1816                  * FIXME: call the correct reference counting function
1817                  */
1818                 page_cache_release(sgl[i].page);
1819         }
1820
1821         return 0;
1822 }
1823
1824 /* ^^^^^^^^  above code borrowed from st driver's direct IO ^^^^^^^^^ */
1825 #endif
1826
1827
1828 /* Returns: -ve -> error, 0 -> done, 1 -> try indirect */
1829 static int
1830 sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
1831 {
1832 #ifdef SG_ALLOW_DIO_CODE
1833         sg_io_hdr_t *hp = &srp->header;
1834         Sg_scatter_hold *schp = &srp->data;
1835         int sg_tablesize = sfp->parentdp->sg_tablesize;
1836         struct scatterlist *sgl;
1837         int mx_sc_elems, res;
1838         struct scsi_device *sdev = sfp->parentdp->device;
1839
1840         if (((unsigned long)hp->dxferp &
1841                         queue_dma_alignment(sdev->request_queue)) != 0)
1842                 return 1;
1843         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1844         if (mx_sc_elems <= 0) {
1845                 return 1;
1846         }
1847         sgl = (struct scatterlist *)schp->buffer;
1848         res = st_map_user_pages(sgl, mx_sc_elems, (unsigned long)hp->dxferp, dxfer_len,
1849                                 (SG_DXFER_TO_DEV == hp->dxfer_direction) ? 1 : 0, ULONG_MAX);
1850         if (res <= 0)
1851                 return 1;
1852         schp->k_use_sg = res;
1853         schp->dio_in_use = 1;
1854         hp->info |= SG_INFO_DIRECT_IO;
1855         return 0;
1856 #else
1857         return 1;
1858 #endif
1859 }
1860
1861 static int
1862 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1863 {
1864         int ret_sz;
1865         int blk_size = buff_size;
1866         unsigned char *p = NULL;
1867
1868         if ((blk_size < 0) || (!sfp))
1869                 return -EFAULT;
1870         if (0 == blk_size)
1871                 ++blk_size;     /* don't know why */
1872 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1873         blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1874         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1875                                    buff_size, blk_size));
1876         if (blk_size <= SG_SCATTER_SZ) {
1877                 p = sg_page_malloc(blk_size, sfp->low_dma, &ret_sz);
1878                 if (!p)
1879                         return -ENOMEM;
1880                 if (blk_size == ret_sz) {       /* got it on the first attempt */
1881                         schp->k_use_sg = 0;
1882                         schp->buffer = p;
1883                         schp->bufflen = blk_size;
1884                         schp->b_malloc_len = blk_size;
1885                         return 0;
1886                 }
1887         } else {
1888                 p = sg_page_malloc(SG_SCATTER_SZ, sfp->low_dma, &ret_sz);
1889                 if (!p)
1890                         return -ENOMEM;
1891         }
1892 /* Want some local declarations, so start new block ... */
1893         {                       /* lets try and build a scatter gather list */
1894                 struct scatterlist *sclp;
1895                 int k, rem_sz, num;
1896                 int mx_sc_elems;
1897                 int sg_tablesize = sfp->parentdp->sg_tablesize;
1898                 int first = 1;
1899
1900                 /* N.B. ret_sz carried into this block ... */
1901                 mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1902                 if (mx_sc_elems < 0)
1903                         return mx_sc_elems;     /* most likely -ENOMEM */
1904
1905                 for (k = 0, sclp = schp->buffer, rem_sz = blk_size;
1906                      (rem_sz > 0) && (k < mx_sc_elems);
1907                      ++k, rem_sz -= ret_sz, ++sclp) {
1908                         if (first)
1909                                 first = 0;
1910                         else {
1911                                 num =
1912                                     (rem_sz >
1913                                      SG_SCATTER_SZ) ? SG_SCATTER_SZ : rem_sz;
1914                                 p = sg_page_malloc(num, sfp->low_dma, &ret_sz);
1915                                 if (!p)
1916                                         break;
1917                         }
1918                         sclp->page = virt_to_page(p);
1919                         sclp->offset = offset_in_page(p);
1920                         sclp->length = ret_sz;
1921
1922                         SCSI_LOG_TIMEOUT(5, printk("sg_build_build: k=%d, a=0x%p, len=%d\n",
1923                                           k, sg_scatg2virt(sclp), ret_sz));
1924                 }               /* end of for loop */
1925                 schp->k_use_sg = k;
1926                 SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, rem_sz=%d\n", k, rem_sz));
1927                 schp->bufflen = blk_size;
1928                 if (rem_sz > 0) /* must have failed */
1929                         return -ENOMEM;
1930         }
1931         return 0;
1932 }
1933
1934 static int
1935 sg_write_xfer(Sg_request * srp)
1936 {
1937         sg_io_hdr_t *hp = &srp->header;
1938         Sg_scatter_hold *schp = &srp->data;
1939         int num_xfer = 0;
1940         int j, k, onum, usglen, ksglen, res;
1941         int iovec_count = (int) hp->iovec_count;
1942         int dxfer_dir = hp->dxfer_direction;
1943         unsigned char *p;
1944         unsigned char __user *up;
1945         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1946
1947         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_TO_DEV == dxfer_dir) ||
1948             (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1949                 num_xfer = (int) (new_interface ? hp->dxfer_len : hp->flags);
1950                 if (schp->bufflen < num_xfer)
1951                         num_xfer = schp->bufflen;
1952         }
1953         if ((num_xfer <= 0) || (schp->dio_in_use) ||
1954             (new_interface
1955              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1956                 return 0;
1957
1958         SCSI_LOG_TIMEOUT(4, printk("sg_write_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
1959                           num_xfer, iovec_count, schp->k_use_sg));
1960         if (iovec_count) {
1961                 onum = iovec_count;
1962                 if ((k = verify_area(VERIFY_READ, hp->dxferp,
1963                                      SZ_SG_IOVEC * onum)))
1964                         return k;
1965         } else
1966                 onum = 1;
1967
1968         if (0 == schp->k_use_sg) {      /* kernel has single buffer */
1969                 for (j = 0, p = schp->buffer; j < onum; ++j) {
1970                         res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
1971                         if (res)
1972                                 return res;
1973                         usglen = (num_xfer > usglen) ? usglen : num_xfer;
1974                         if (__copy_from_user(p, up, usglen))
1975                                 return -EFAULT;
1976                         p += usglen;
1977                         num_xfer -= usglen;
1978                         if (num_xfer <= 0)
1979                                 return 0;
1980                 }
1981         } else {                /* kernel using scatter gather list */
1982                 struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
1983
1984                 ksglen = (int) sclp->length;
1985                 p = sg_scatg2virt(sclp);
1986                 for (j = 0, k = 0; j < onum; ++j) {
1987                         res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
1988                         if (res)
1989                                 return res;
1990
1991                         for (; p; ++sclp, ksglen = (int) sclp->length,
1992                                   p = sg_scatg2virt(sclp)) {
1993                                 if (usglen <= 0)
1994                                         break;
1995                                 if (ksglen > usglen) {
1996                                         if (usglen >= num_xfer) {
1997                                                 if (__copy_from_user
1998                                                     (p, up, num_xfer))
1999                                                         return -EFAULT;
2000                                                 return 0;
2001                                         }
2002                                         if (__copy_from_user(p, up, usglen))
2003                                                 return -EFAULT;
2004                                         p += usglen;
2005                                         ksglen -= usglen;
2006                                         break;
2007                                 } else {
2008                                         if (ksglen >= num_xfer) {
2009                                                 if (__copy_from_user
2010                                                     (p, up, num_xfer))
2011                                                         return -EFAULT;
2012                                                 return 0;
2013                                         }
2014                                         if (__copy_from_user(p, up, ksglen))
2015                                                 return -EFAULT;
2016                                         up += ksglen;
2017                                         usglen -= ksglen;
2018                                 }
2019                                 ++k;
2020                                 if (k >= schp->k_use_sg)
2021                                         return 0;
2022                         }
2023                 }
2024         }
2025         return 0;
2026 }
2027
2028 static int
2029 sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
2030            int wr_xf, int *countp, unsigned char __user **up)
2031 {
2032         int num_xfer = (int) hp->dxfer_len;
2033         unsigned char __user *p = hp->dxferp;
2034         int count, k;
2035
2036         if (0 == sg_num) {
2037                 if (wr_xf && ('\0' == hp->interface_id))
2038                         count = (int) hp->flags;        /* holds "old" input_size */
2039                 else
2040                         count = num_xfer;
2041         } else {
2042                 sg_iovec_t iovec;
2043                 if (__copy_from_user(&iovec, p + ind*SZ_SG_IOVEC, SZ_SG_IOVEC))
2044                         return -EFAULT;
2045                 p = iovec.iov_base;
2046                 count = (int) iovec.iov_len;
2047         }
2048         if ((k = verify_area(wr_xf ? VERIFY_READ : VERIFY_WRITE, p, count)))
2049                 return k;
2050         if (up)
2051                 *up = p;
2052         if (countp)
2053                 *countp = count;
2054         return 0;
2055 }
2056
2057 static void
2058 sg_remove_scat(Sg_scatter_hold * schp)
2059 {
2060         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
2061         if (schp->buffer && (schp->sglist_len > 0)) {
2062                 struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2063
2064                 if (schp->dio_in_use) {
2065 #ifdef SG_ALLOW_DIO_CODE
2066                         st_unmap_user_pages(sclp, schp->k_use_sg, TRUE);
2067 #endif
2068                 } else {
2069                         int k;
2070
2071                         for (k = 0; (k < schp->k_use_sg) && sg_scatg2virt(sclp);
2072                              ++k, ++sclp) {
2073                                 SCSI_LOG_TIMEOUT(5, printk(
2074                                     "sg_remove_scat: k=%d, a=0x%p, len=%d\n",
2075                                     k, sg_scatg2virt(sclp), sclp->length));
2076                                 sg_page_free(sg_scatg2virt(sclp), sclp->length);
2077                                 sclp->page = NULL;
2078                                 sclp->offset = 0;
2079                                 sclp->length = 0;
2080                         }
2081                 }
2082                 sg_page_free(schp->buffer, schp->sglist_len);
2083         } else if (schp->buffer)
2084                 sg_page_free(schp->buffer, schp->b_malloc_len);
2085         memset(schp, 0, sizeof (*schp));
2086 }
2087
2088 static int
2089 sg_read_xfer(Sg_request * srp)
2090 {
2091         sg_io_hdr_t *hp = &srp->header;
2092         Sg_scatter_hold *schp = &srp->data;
2093         int num_xfer = 0;
2094         int j, k, onum, usglen, ksglen, res;
2095         int iovec_count = (int) hp->iovec_count;
2096         int dxfer_dir = hp->dxfer_direction;
2097         unsigned char *p;
2098         unsigned char __user *up;
2099         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
2100
2101         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_FROM_DEV == dxfer_dir)
2102             || (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
2103                 num_xfer = hp->dxfer_len;
2104                 if (schp->bufflen < num_xfer)
2105                         num_xfer = schp->bufflen;
2106         }
2107         if ((num_xfer <= 0) || (schp->dio_in_use) ||
2108             (new_interface
2109              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
2110                 return 0;
2111
2112         SCSI_LOG_TIMEOUT(4, printk("sg_read_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
2113                           num_xfer, iovec_count, schp->k_use_sg));
2114         if (iovec_count) {
2115                 onum = iovec_count;
2116                 if ((k = verify_area(VERIFY_READ, hp->dxferp,
2117                                      SZ_SG_IOVEC * onum)))
2118                         return k;
2119         } else
2120                 onum = 1;
2121
2122         if (0 == schp->k_use_sg) {      /* kernel has single buffer */
2123                 for (j = 0, p = schp->buffer; j < onum; ++j) {
2124                         res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2125                         if (res)
2126                                 return res;
2127                         usglen = (num_xfer > usglen) ? usglen : num_xfer;
2128                         if (__copy_to_user(up, p, usglen))
2129                                 return -EFAULT;
2130                         p += usglen;
2131                         num_xfer -= usglen;
2132                         if (num_xfer <= 0)
2133                                 return 0;
2134                 }
2135         } else {                /* kernel using scatter gather list */
2136                 struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2137
2138                 ksglen = (int) sclp->length;
2139                 p = sg_scatg2virt(sclp);
2140                 for (j = 0, k = 0; j < onum; ++j) {
2141                         res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2142                         if (res)
2143                                 return res;
2144
2145                         for (; p; ++sclp, ksglen = (int) sclp->length,
2146                                   p = sg_scatg2virt(sclp)) {
2147                                 if (usglen <= 0)
2148                                         break;
2149                                 if (ksglen > usglen) {
2150                                         if (usglen >= num_xfer) {
2151                                                 if (__copy_to_user
2152                                                     (up, p, num_xfer))
2153                                                         return -EFAULT;
2154                                                 return 0;
2155                                         }
2156                                         if (__copy_to_user(up, p, usglen))
2157                                                 return -EFAULT;
2158                                         p += usglen;
2159                                         ksglen -= usglen;
2160                                         break;
2161                                 } else {
2162                                         if (ksglen >= num_xfer) {
2163                                                 if (__copy_to_user
2164                                                     (up, p, num_xfer))
2165                                                         return -EFAULT;
2166                                                 return 0;
2167                                         }
2168                                         if (__copy_to_user(up, p, ksglen))
2169                                                 return -EFAULT;
2170                                         up += ksglen;
2171                                         usglen -= ksglen;
2172                                 }
2173                                 ++k;
2174                                 if (k >= schp->k_use_sg)
2175                                         return 0;
2176                         }
2177                 }
2178         }
2179         return 0;
2180 }
2181
2182 static int
2183 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
2184 {
2185         Sg_scatter_hold *schp = &srp->data;
2186
2187         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
2188                                    num_read_xfer));
2189         if ((!outp) || (num_read_xfer <= 0))
2190                 return 0;
2191         if (schp->k_use_sg > 0) {
2192                 int k, num;
2193                 struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2194
2195                 for (k = 0; (k < schp->k_use_sg) && sg_scatg2virt(sclp);
2196                      ++k, ++sclp) {
2197                         num = (int) sclp->length;
2198                         if (num > num_read_xfer) {
2199                                 if (__copy_to_user
2200                                     (outp, sg_scatg2virt(sclp), num_read_xfer))
2201                                         return -EFAULT;
2202                                 break;
2203                         } else {
2204                                 if (__copy_to_user
2205                                     (outp, sg_scatg2virt(sclp), num))
2206                                         return -EFAULT;
2207                                 num_read_xfer -= num;
2208                                 if (num_read_xfer <= 0)
2209                                         break;
2210                                 outp += num;
2211                         }
2212                 }
2213         } else {
2214                 if (__copy_to_user(outp, schp->buffer, num_read_xfer))
2215                         return -EFAULT;
2216         }
2217         return 0;
2218 }
2219
2220 static void
2221 sg_build_reserve(Sg_fd * sfp, int req_size)
2222 {
2223         Sg_scatter_hold *schp = &sfp->reserve;
2224
2225         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
2226         do {
2227                 if (req_size < PAGE_SIZE)
2228                         req_size = PAGE_SIZE;
2229                 if (0 == sg_build_indirect(schp, sfp, req_size))
2230                         return;
2231                 else
2232                         sg_remove_scat(schp);
2233                 req_size >>= 1; /* divide by 2 */
2234         } while (req_size > (PAGE_SIZE / 2));
2235 }
2236
2237 static void
2238 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2239 {
2240         Sg_scatter_hold *req_schp = &srp->data;
2241         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2242
2243         srp->res_used = 1;
2244         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
2245         size = (size + 1) & (~1);       /* round to even for aha1542 */
2246         if (rsv_schp->k_use_sg > 0) {
2247                 int k, num;
2248                 int rem = size;
2249                 struct scatterlist *sclp =
2250                     (struct scatterlist *) rsv_schp->buffer;
2251
2252                 for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sclp) {
2253                         num = (int) sclp->length;
2254                         if (rem <= num) {
2255                                 if (0 == k) {
2256                                         req_schp->k_use_sg = 0;
2257                                         req_schp->buffer = sg_scatg2virt(sclp);
2258                                 } else {
2259                                         sfp->save_scat_len = num;
2260                                         sclp->length = (unsigned) rem;
2261                                         req_schp->k_use_sg = k + 1;
2262                                         req_schp->sglist_len =
2263                                             rsv_schp->sglist_len;
2264                                         req_schp->buffer = rsv_schp->buffer;
2265                                 }
2266                                 req_schp->bufflen = size;
2267                                 req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2268                                 break;
2269                         } else
2270                                 rem -= num;
2271                 }
2272                 if (k >= rsv_schp->k_use_sg)
2273                         SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
2274         } else {
2275                 req_schp->k_use_sg = 0;
2276                 req_schp->bufflen = size;
2277                 req_schp->buffer = rsv_schp->buffer;
2278                 req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2279         }
2280 }
2281
2282 static void
2283 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2284 {
2285         Sg_scatter_hold *req_schp = &srp->data;
2286         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2287
2288         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
2289                                    (int) req_schp->k_use_sg));
2290         if ((rsv_schp->k_use_sg > 0) && (req_schp->k_use_sg > 0)) {
2291                 struct scatterlist *sclp =
2292                     (struct scatterlist *) rsv_schp->buffer;
2293
2294                 if (sfp->save_scat_len > 0)
2295                         (sclp + (req_schp->k_use_sg - 1))->length =
2296                             (unsigned) sfp->save_scat_len;
2297                 else
2298                         SCSI_LOG_TIMEOUT(1, printk ("sg_unlink_reserve: BAD save_scat_len\n"));
2299         }
2300         req_schp->k_use_sg = 0;
2301         req_schp->bufflen = 0;
2302         req_schp->buffer = NULL;
2303         req_schp->sglist_len = 0;
2304         sfp->save_scat_len = 0;
2305         srp->res_used = 0;
2306 }
2307
2308 static Sg_request *
2309 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2310 {
2311         Sg_request *resp;
2312         unsigned long iflags;
2313
2314         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2315         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2316                 /* look for requests that are ready + not SG_IO owned */
2317                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2318                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2319                         resp->done = 2; /* guard against other readers */
2320                         break;
2321                 }
2322         }
2323         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2324         return resp;
2325 }
2326
2327 #ifdef CONFIG_SCSI_PROC_FS
2328 static Sg_request *
2329 sg_get_nth_request(Sg_fd * sfp, int nth)
2330 {
2331         Sg_request *resp;
2332         unsigned long iflags;
2333         int k;
2334
2335         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2336         for (k = 0, resp = sfp->headrp; resp && (k < nth);
2337              ++k, resp = resp->nextrp) ;
2338         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2339         return resp;
2340 }
2341 #endif
2342
2343 /* always adds to end of list */
2344 static Sg_request *
2345 sg_add_request(Sg_fd * sfp)
2346 {
2347         int k;
2348         unsigned long iflags;
2349         Sg_request *resp;
2350         Sg_request *rp = sfp->req_arr;
2351
2352         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2353         resp = sfp->headrp;
2354         if (!resp) {
2355                 memset(rp, 0, sizeof (Sg_request));
2356                 rp->parentfp = sfp;
2357                 resp = rp;
2358                 sfp->headrp = resp;
2359         } else {
2360                 if (0 == sfp->cmd_q)
2361                         resp = NULL;    /* command queuing disallowed */
2362                 else {
2363                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2364                                 if (!rp->parentfp)
2365                                         break;
2366                         }
2367                         if (k < SG_MAX_QUEUE) {
2368                                 memset(rp, 0, sizeof (Sg_request));
2369                                 rp->parentfp = sfp;
2370                                 while (resp->nextrp)
2371                                         resp = resp->nextrp;
2372                                 resp->nextrp = rp;
2373                                 resp = rp;
2374                         } else
2375                                 resp = NULL;
2376                 }
2377         }
2378         if (resp) {
2379                 resp->nextrp = NULL;
2380                 resp->header.duration = jiffies;
2381                 resp->my_cmdp = NULL;
2382         }
2383         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2384         return resp;
2385 }
2386
2387 /* Return of 1 for found; 0 for not found */
2388 static int
2389 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2390 {
2391         Sg_request *prev_rp;
2392         Sg_request *rp;
2393         unsigned long iflags;
2394         int res = 0;
2395
2396         if ((!sfp) || (!srp) || (!sfp->headrp))
2397                 return res;
2398         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2399         prev_rp = sfp->headrp;
2400         if (srp == prev_rp) {
2401                 sfp->headrp = prev_rp->nextrp;
2402                 prev_rp->parentfp = NULL;
2403                 res = 1;
2404         } else {
2405                 while ((rp = prev_rp->nextrp)) {
2406                         if (srp == rp) {
2407                                 prev_rp->nextrp = rp->nextrp;
2408                                 rp->parentfp = NULL;
2409                                 res = 1;
2410                                 break;
2411                         }
2412                         prev_rp = rp;
2413                 }
2414         }
2415         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2416         return res;
2417 }
2418
2419 #ifdef CONFIG_SCSI_PROC_FS
2420 static Sg_fd *
2421 sg_get_nth_sfp(Sg_device * sdp, int nth)
2422 {
2423         Sg_fd *resp;
2424         unsigned long iflags;
2425         int k;
2426
2427         read_lock_irqsave(&sg_dev_arr_lock, iflags);
2428         for (k = 0, resp = sdp->headfp; resp && (k < nth);
2429              ++k, resp = resp->nextfp) ;
2430         read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2431         return resp;
2432 }
2433 #endif
2434
2435 static Sg_fd *
2436 sg_add_sfp(Sg_device * sdp, int dev)
2437 {
2438         Sg_fd *sfp;
2439         unsigned long iflags;
2440
2441         sfp = (Sg_fd *) sg_page_malloc(sizeof (Sg_fd), 0, NULL);
2442         if (!sfp)
2443                 return NULL;
2444         memset(sfp, 0, sizeof (Sg_fd));
2445         init_waitqueue_head(&sfp->read_wait);
2446         rwlock_init(&sfp->rq_list_lock);
2447
2448         sfp->timeout = SG_DEFAULT_TIMEOUT;
2449         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2450         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2451         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2452             sdp->device->host->unchecked_isa_dma : 1;
2453         sfp->cmd_q = SG_DEF_COMMAND_Q;
2454         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2455         sfp->parentdp = sdp;
2456         write_lock_irqsave(&sg_dev_arr_lock, iflags);
2457         if (!sdp->headfp)
2458                 sdp->headfp = sfp;
2459         else {                  /* add to tail of existing list */
2460                 Sg_fd *pfp = sdp->headfp;
2461                 while (pfp->nextfp)
2462                         pfp = pfp->nextfp;
2463                 pfp->nextfp = sfp;
2464         }
2465         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2466         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2467         sg_build_reserve(sfp, sg_big_buff);
2468         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2469                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2470         return sfp;
2471 }
2472
2473 static void
2474 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2475 {
2476         Sg_fd *fp;
2477         Sg_fd *prev_fp;
2478
2479         prev_fp = sdp->headfp;
2480         if (sfp == prev_fp)
2481                 sdp->headfp = prev_fp->nextfp;
2482         else {
2483                 while ((fp = prev_fp->nextfp)) {
2484                         if (sfp == fp) {
2485                                 prev_fp->nextfp = fp->nextfp;
2486                                 break;
2487                         }
2488                         prev_fp = fp;
2489                 }
2490         }
2491         if (sfp->reserve.bufflen > 0) {
2492                 SCSI_LOG_TIMEOUT(6,
2493                         printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2494                         (int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2495                 if (sfp->mmap_called)
2496                         sg_rb_correct4mmap(&sfp->reserve, 0);   /* undo correction */
2497                 sg_remove_scat(&sfp->reserve);
2498         }
2499         sfp->parentdp = NULL;
2500         SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2501         sg_page_free((char *) sfp, sizeof (Sg_fd));
2502 }
2503
2504 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2505 static int
2506 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2507 {
2508         Sg_request *srp;
2509         Sg_request *tsrp;
2510         int dirty = 0;
2511         int res = 0;
2512
2513         for (srp = sfp->headrp; srp; srp = tsrp) {
2514                 tsrp = srp->nextrp;
2515                 if (sg_srp_done(srp, sfp))
2516                         sg_finish_rem_req(srp);
2517                 else
2518                         ++dirty;
2519         }
2520         if (0 == dirty) {
2521                 unsigned long iflags;
2522
2523                 write_lock_irqsave(&sg_dev_arr_lock, iflags);
2524                 __sg_remove_sfp(sdp, sfp);
2525                 if (sdp->detached && (NULL == sdp->headfp)) {
2526                         int k, maxd;
2527
2528                         maxd = sg_dev_max;
2529                         for (k = 0; k < maxd; ++k) {
2530                                 if (sdp == sg_dev_arr[k])
2531                                         break;
2532                         }
2533                         if (k < maxd)
2534                                 sg_dev_arr[k] = NULL;
2535                         kfree((char *) sdp);
2536                         res = 1;
2537                 }
2538                 write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2539         } else {
2540                 /* MOD_INC's to inhibit unloading sg and associated adapter driver */
2541                 /* only bump the access_count if we actually succeeded in
2542                  * throwing another counter on the host module */
2543                 scsi_device_get(sdp->device);   /* XXX: retval ignored? */
2544                 sfp->closed = 1;        /* flag dirty state on this fd */
2545                 SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2546                                   dirty));
2547         }
2548         return res;
2549 }
2550
2551 static int
2552 sg_res_in_use(Sg_fd * sfp)
2553 {
2554         const Sg_request *srp;
2555         unsigned long iflags;
2556
2557         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2558         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2559                 if (srp->res_used)
2560                         break;
2561         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2562         return srp ? 1 : 0;
2563 }
2564
2565 /* If retSzp==NULL want exact size or fail */
2566 static char *
2567 sg_page_malloc(int rqSz, int lowDma, int *retSzp)
2568 {
2569         char *resp = NULL;
2570         int page_mask;
2571         int order, a_size;
2572         int resSz = rqSz;
2573
2574         if (rqSz <= 0)
2575                 return resp;
2576
2577         if (lowDma)
2578                 page_mask = GFP_ATOMIC | GFP_DMA | __GFP_NOWARN;
2579         else
2580                 page_mask = GFP_ATOMIC | __GFP_NOWARN;
2581
2582         for (order = 0, a_size = PAGE_SIZE; a_size < rqSz;
2583              order++, a_size <<= 1) ;
2584         resp = (char *) __get_free_pages(page_mask, order);
2585         while ((!resp) && order && retSzp) {
2586                 --order;
2587                 a_size >>= 1;   /* divide by 2, until PAGE_SIZE */
2588                 resp = (char *) __get_free_pages(page_mask, order);     /* try half */
2589                 resSz = a_size;
2590         }
2591         if (resp) {
2592                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2593                         memset(resp, 0, resSz);
2594                 if (retSzp)
2595                         *retSzp = resSz;
2596         }
2597         return resp;
2598 }
2599
2600 static void
2601 sg_page_free(char *buff, int size)
2602 {
2603         int order, a_size;
2604
2605         if (!buff)
2606                 return;
2607         for (order = 0, a_size = PAGE_SIZE; a_size < size;
2608              order++, a_size <<= 1) ;
2609         free_pages((unsigned long) buff, order);
2610 }
2611
2612 #ifndef MAINTENANCE_IN_CMD
2613 #define MAINTENANCE_IN_CMD 0xa3
2614 #endif
2615
2616 static unsigned char allow_ops[] = { TEST_UNIT_READY, REQUEST_SENSE,
2617         INQUIRY, READ_CAPACITY, READ_BUFFER, READ_6, READ_10, READ_12,
2618         READ_16, MODE_SENSE, MODE_SENSE_10, LOG_SENSE, REPORT_LUNS,
2619         SERVICE_ACTION_IN, RECEIVE_DIAGNOSTIC, READ_LONG, MAINTENANCE_IN_CMD
2620 };
2621
2622 static int
2623 sg_allow_access(unsigned char opcode, char dev_type)
2624 {
2625         int k;
2626
2627         if (TYPE_SCANNER == dev_type)   /* TYPE_ROM maybe burner */
2628                 return 1;
2629         for (k = 0; k < sizeof (allow_ops); ++k) {
2630                 if (opcode == allow_ops[k])
2631                         return 1;
2632         }
2633         return 0;
2634 }
2635
2636 #ifdef CONFIG_SCSI_PROC_FS
2637 static int
2638 sg_last_dev(void)
2639 {
2640         int k;
2641         unsigned long iflags;
2642
2643         read_lock_irqsave(&sg_dev_arr_lock, iflags);
2644         for (k = sg_dev_max - 1; k >= 0; --k)
2645                 if (sg_dev_arr[k] && sg_dev_arr[k]->device)
2646                         break;
2647         read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2648         return k + 1;           /* origin 1 */
2649 }
2650 #endif
2651
2652 static Sg_device *
2653 sg_get_dev(int dev)
2654 {
2655         Sg_device *sdp = NULL;
2656         unsigned long iflags;
2657
2658         if (sg_dev_arr && (dev >= 0)) {
2659                 read_lock_irqsave(&sg_dev_arr_lock, iflags);
2660                 if (dev < sg_dev_max)
2661                         sdp = sg_dev_arr[dev];
2662                 read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2663         }
2664         return sdp;
2665 }
2666
2667 #ifdef CONFIG_SCSI_PROC_FS
2668
2669 static struct proc_dir_entry *sg_proc_sgp = NULL;
2670
2671 static char sg_proc_sg_dirname[] = "scsi/sg";
2672
2673 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2674
2675 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2676 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2677                                   size_t count, loff_t *off);
2678 static struct file_operations adio_fops = {
2679         /* .owner, .read and .llseek added in sg_proc_init() */
2680         .open = sg_proc_single_open_adio,
2681         .write = sg_proc_write_adio,
2682         .release = single_release,
2683 };
2684
2685 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2686 static ssize_t sg_proc_write_dressz(struct file *filp,
2687                 const char __user *buffer, size_t count, loff_t *off);
2688 static struct file_operations dressz_fops = {
2689         .open = sg_proc_single_open_dressz,
2690         .write = sg_proc_write_dressz,
2691         .release = single_release,
2692 };
2693
2694 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2695 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2696 static struct file_operations version_fops = {
2697         .open = sg_proc_single_open_version,
2698         .release = single_release,
2699 };
2700
2701 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2702 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2703 static struct file_operations devhdr_fops = {
2704         .open = sg_proc_single_open_devhdr,
2705         .release = single_release,
2706 };
2707
2708 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2709 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2710 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2711 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2712 static void dev_seq_stop(struct seq_file *s, void *v);
2713 static struct file_operations dev_fops = {
2714         .open = sg_proc_open_dev,
2715         .release = seq_release,
2716 };
2717 static struct seq_operations dev_seq_ops = {
2718         .start = dev_seq_start,
2719         .next  = dev_seq_next,
2720         .stop  = dev_seq_stop,
2721         .show  = sg_proc_seq_show_dev,
2722 };
2723
2724 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2725 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2726 static struct file_operations devstrs_fops = {
2727         .open = sg_proc_open_devstrs,
2728         .release = seq_release,
2729 };
2730 static struct seq_operations devstrs_seq_ops = {
2731         .start = dev_seq_start,
2732         .next  = dev_seq_next,
2733         .stop  = dev_seq_stop,
2734         .show  = sg_proc_seq_show_devstrs,
2735 };
2736
2737 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2738 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2739 static struct file_operations debug_fops = {
2740         .open = sg_proc_open_debug,
2741         .release = seq_release,
2742 };
2743 static struct seq_operations debug_seq_ops = {
2744         .start = dev_seq_start,
2745         .next  = dev_seq_next,
2746         .stop  = dev_seq_stop,
2747         .show  = sg_proc_seq_show_debug,
2748 };
2749
2750
2751 struct sg_proc_leaf {
2752         const char * name;
2753         struct file_operations * fops;
2754 };
2755
2756 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2757         {"allow_dio", &adio_fops},
2758         {"debug", &debug_fops},
2759         {"def_reserved_size", &dressz_fops},
2760         {"device_hdr", &devhdr_fops},
2761         {"devices", &dev_fops},
2762         {"device_strs", &devstrs_fops},
2763         {"version", &version_fops}
2764 };
2765
2766 static int
2767 sg_proc_init(void)
2768 {
2769         int k, mask;
2770         int num_leaves =
2771             sizeof (sg_proc_leaf_arr) / sizeof (sg_proc_leaf_arr[0]);
2772         struct proc_dir_entry *pdep;
2773         struct sg_proc_leaf * leaf;
2774
2775         sg_proc_sgp = create_proc_entry(sg_proc_sg_dirname,
2776                                         S_IFDIR | S_IRUGO | S_IXUGO, NULL);
2777         if (!sg_proc_sgp)
2778                 return 1;
2779         for (k = 0; k < num_leaves; ++k) {
2780                 leaf = &sg_proc_leaf_arr[k];
2781                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2782                 pdep = create_proc_entry(leaf->name, mask, sg_proc_sgp);
2783                 if (pdep) {
2784                         leaf->fops->owner = THIS_MODULE,
2785                         leaf->fops->read = seq_read,
2786                         leaf->fops->llseek = seq_lseek,
2787                         pdep->proc_fops = leaf->fops;
2788                 }
2789         }
2790         return 0;
2791 }
2792
2793 static void
2794 sg_proc_cleanup(void)
2795 {
2796         int k;
2797         int num_leaves =
2798             sizeof (sg_proc_leaf_arr) / sizeof (sg_proc_leaf_arr[0]);
2799
2800         if (!sg_proc_sgp)
2801                 return;
2802         for (k = 0; k < num_leaves; ++k)
2803                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2804         remove_proc_entry(sg_proc_sg_dirname, NULL);
2805 }
2806
2807
2808 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2809 {
2810         seq_printf(s, "%d\n", *((int *)s->private));
2811         return 0;
2812 }
2813
2814 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2815 {
2816         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2817 }
2818
2819 static ssize_t
2820 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2821                    size_t count, loff_t *off)
2822 {
2823         int num;
2824         char buff[11];
2825
2826         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2827                 return -EACCES;
2828         num = (count < 10) ? count : 10;
2829         if (copy_from_user(buff, buffer, num))
2830                 return -EFAULT;
2831         buff[num] = '\0';
2832         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2833         return count;
2834 }
2835
2836 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2837 {
2838         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2839 }
2840
2841 static ssize_t
2842 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2843                      size_t count, loff_t *off)
2844 {
2845         int num;
2846         unsigned long k = ULONG_MAX;
2847         char buff[11];
2848
2849         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2850                 return -EACCES;
2851         num = (count < 10) ? count : 10;
2852         if (copy_from_user(buff, buffer, num))
2853                 return -EFAULT;
2854         buff[num] = '\0';
2855         k = simple_strtoul(buff, NULL, 10);
2856         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2857                 sg_big_buff = k;
2858                 return count;
2859         }
2860         return -ERANGE;
2861 }
2862
2863 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2864 {
2865         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2866                    sg_version_date);
2867         return 0;
2868 }
2869
2870 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2871 {
2872         return single_open(file, sg_proc_seq_show_version, NULL);
2873 }
2874
2875 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2876 {
2877         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2878                    "online\n");
2879         return 0;
2880 }
2881
2882 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2883 {
2884         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2885 }
2886
2887 struct sg_proc_deviter {
2888         loff_t  index;
2889         size_t  max;
2890 };
2891
2892 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2893 {
2894         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2895
2896         if (! it)
2897                 return NULL;
2898         if (NULL == sg_dev_arr)
2899                 goto err1;
2900         it->index = *pos;
2901         it->max = sg_last_dev();
2902         if (it->index >= it->max)
2903                 goto err1;
2904         return it;
2905 err1:
2906         kfree(it);
2907         return NULL;
2908 }
2909
2910 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2911 {
2912         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2913
2914         *pos = ++it->index;
2915         return (it->index < it->max) ? it : NULL;
2916 }
2917
2918 static void dev_seq_stop(struct seq_file *s, void *v)
2919 {
2920         kfree (v);
2921 }
2922
2923 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2924 {
2925         return seq_open(file, &dev_seq_ops);
2926 }
2927
2928 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2929 {
2930         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2931         Sg_device *sdp;
2932         struct scsi_device *scsidp;
2933
2934         sdp = it ? sg_get_dev(it->index) : NULL;
2935         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2936                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2937                               scsidp->host->host_no, scsidp->channel,
2938                               scsidp->id, scsidp->lun, (int) scsidp->type,
2939                               1,
2940                               (int) scsidp->queue_depth,
2941                               (int) scsidp->device_busy,
2942                               (int) scsi_device_online(scsidp));
2943         else
2944                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2945         return 0;
2946 }
2947
2948 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2949 {
2950         return seq_open(file, &devstrs_seq_ops);
2951 }
2952
2953 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2954 {
2955         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2956         Sg_device *sdp;
2957         struct scsi_device *scsidp;
2958
2959         sdp = it ? sg_get_dev(it->index) : NULL;
2960         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2961                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2962                            scsidp->vendor, scsidp->model, scsidp->rev);
2963         else
2964                 seq_printf(s, "<no active device>\n");
2965         return 0;
2966 }
2967
2968 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2969 {
2970         int k, m, new_interface, blen, usg;
2971         Sg_request *srp;
2972         Sg_fd *fp;
2973         const sg_io_hdr_t *hp;
2974         const char * cp;
2975
2976         for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
2977                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2978                            "(res)sgat=%d low_dma=%d\n", k + 1,
2979                            jiffies_to_msecs(fp->timeout),
2980                            fp->reserve.bufflen,
2981                            (int) fp->reserve.k_use_sg,
2982                            (int) fp->low_dma);
2983                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2984                            (int) fp->cmd_q, (int) fp->force_packid,
2985                            (int) fp->keep_orphan, (int) fp->closed);
2986                 for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
2987                         hp = &srp->header;
2988                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2989                         if (srp->res_used) {
2990                                 if (new_interface &&
2991                                     (SG_FLAG_MMAP_IO & hp->flags))
2992                                         cp = "     mmap>> ";
2993                                 else
2994                                         cp = "     rb>> ";
2995                         } else {
2996                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2997                                         cp = "     dio>> ";
2998                                 else
2999                                         cp = "     ";
3000                         }
3001                         seq_printf(s, cp);
3002                         blen = srp->my_cmdp ?
3003                                 srp->my_cmdp->sr_bufflen : srp->data.bufflen;
3004                         usg = srp->my_cmdp ?
3005                                 srp->my_cmdp->sr_use_sg : srp->data.k_use_sg;
3006                         seq_printf(s, srp->done ?
3007                                    ((1 == srp->done) ?  "rcv:" : "fin:")
3008                                    : (srp->my_cmdp ? "act:" : "prior:"));
3009                         seq_printf(s, " id=%d blen=%d",
3010                                    srp->header.pack_id, blen);
3011                         if (srp->done)
3012                                 seq_printf(s, " dur=%d", hp->duration);
3013                         else
3014                                 seq_printf(s, " t_o/elap=%d/%d",
3015                                   new_interface ? hp->timeout : jiffies_to_msecs(fp->timeout),
3016                                   jiffies_to_msecs(hp->duration ? (jiffies - hp->duration) : 0));
3017                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
3018                                    (int) srp->data.cmd_opcode);
3019                 }
3020                 if (0 == m)
3021                         seq_printf(s, "     No requests active\n");
3022         }
3023 }
3024
3025 static int sg_proc_open_debug(struct inode *inode, struct file *file)
3026 {
3027         return seq_open(file, &debug_seq_ops);
3028 }
3029
3030 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
3031 {
3032         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
3033         Sg_device *sdp;
3034
3035         if (it && (0 == it->index)) {
3036                 seq_printf(s, "dev_max(currently)=%d max_active_device=%d "
3037                            "(origin 1)\n", sg_dev_max, (int)it->max);
3038                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
3039         }
3040         sdp = it ? sg_get_dev(it->index) : NULL;
3041         if (sdp) {
3042                 struct scsi_device *scsidp = sdp->device;
3043
3044                 if (NULL == scsidp) {
3045                         seq_printf(s, "device %d detached ??\n",
3046                                    (int)it->index);
3047                         return 0;
3048                 }
3049
3050                 if (sg_get_nth_sfp(sdp, 0)) {
3051                         seq_printf(s, " >>> device=%s ",
3052                                 sdp->disk->disk_name);
3053                         if (sdp->detached)
3054                                 seq_printf(s, "detached pending close ");
3055                         else
3056                                 seq_printf
3057                                     (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
3058                                      scsidp->host->host_no,
3059                                      scsidp->channel, scsidp->id,
3060                                      scsidp->lun,
3061                                      scsidp->host->hostt->emulated);
3062                         seq_printf(s, " sg_tablesize=%d excl=%d\n",
3063                                    sdp->sg_tablesize, sdp->exclude);
3064                 }
3065                 sg_proc_debug_helper(s, sdp);
3066         }
3067         return 0;
3068 }
3069
3070 #endif                          /* CONFIG_SCSI_PROC_FS */
3071
3072 module_init(init_sg);
3073 module_exit(exit_sg);
3074 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);