git.oblomov.eu Git - linux-2.6/blob - drivers/scsi/sg.c

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