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   1 /*
   2  *  History:
   3  *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
   4  *           to allow user process control of SCSI devices.
   5  *  Development Sponsored by Killy Corp. NY NY
   6  *
   7  * Original driver (sg.c):
   8  *        Copyright (C) 1992 Lawrence Foard
   9  * Version 2 and 3 extensions to driver:
  10  *        Copyright (C) 1998 - 2005 Douglas Gilbert
  11  *
  12  *  Modified  19-JAN-1998  Richard Gooch <rgooch@atnf.csiro.au>  Devfs support
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2, or (at your option)
  17  * any later version.
  18  *
  19  */
  20
  21 static int sg_version_num = 30534;      /* 2 digits for each component */
  22 #define SG_VERSION_STR "3.5.34"
  23
  24 /*
  25  *  D. P. Gilbert (dgilbert@interlog.com, dougg@triode.net.au), notes:
  26  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
  27  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
  28  *        (otherwise the macros compile to empty statements).
  29  *
  30  */
  31 #include <linux/module.h>
  32
  33 #include <linux/fs.h>
  34 #include <linux/kernel.h>
  35 #include <linux/sched.h>
  36 #include <linux/string.h>
  37 #include <linux/mm.h>
  38 #include <linux/errno.h>
  39 #include <linux/mtio.h>
  40 #include <linux/ioctl.h>
  41 #include <linux/fcntl.h>
  42 #include <linux/init.h>
  43 #include <linux/poll.h>
  44 #include <linux/moduleparam.h>
  45 #include <linux/cdev.h>
  46 #include <linux/idr.h>
  47 #include <linux/seq_file.h>
  48 #include <linux/blkdev.h>
  49 #include <linux/delay.h>
  50 #include <linux/blktrace_api.h>
  51 #include <linux/smp_lock.h>
  52
  53 #include "scsi.h"
  54 #include <scsi/scsi_dbg.h>
  55 #include <scsi/scsi_host.h>
  56 #include <scsi/scsi_driver.h>
  57 #include <scsi/scsi_ioctl.h>
  58 #include <scsi/sg.h>
  59
  60 #include "scsi_logging.h"
  61
  62 #ifdef CONFIG_SCSI_PROC_FS
  63 #include <linux/proc_fs.h>
  64 static char *sg_version_date = "20061027";
  65
  66 static int sg_proc_init(void);
  67 static void sg_proc_cleanup(void);
  68 #endif
  69
  70 #define SG_ALLOW_DIO_DEF 0
  71
  72 #define SG_MAX_DEVS 32768
  73
  74 /*
  75  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
  76  * Then when using 32 bit integers x * m may overflow during the calculation.
  77  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
  78  * calculates the same, but prevents the overflow when both m and d
  79  * are "small" numbers (like HZ and USER_HZ).
  80  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
  81  * in 32 bits.
  82  */
  83 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
  84
  85 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  86
  87 int sg_big_buff = SG_DEF_RESERVED_SIZE;
  88 /* N.B. This variable is readable and writeable via
  89    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  90    of this size (or less if there is not enough memory) will be reserved
  91    for use by this file descriptor. [Deprecated usage: this variable is also
  92    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  93    the kernel (i.e. it is not a module).] */
  94 static int def_reserved_size = -1;      /* picks up init parameter */
  95 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
  96
  97 static int scatter_elem_sz = SG_SCATTER_SZ;
  98 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
  99
 100 #define SG_SECTOR_SZ 512
 101 #define SG_SECTOR_MSK (SG_SECTOR_SZ - 1)
 102
 103 static int sg_add(struct device *, struct class_interface *);
 104 static void sg_remove(struct device *, struct class_interface *);
 105
 106 static DEFINE_IDR(sg_index_idr);
 107 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
 108                                                            file descriptor list for device */
 109
 110 static struct class_interface sg_interface = {
 111         .add_dev        = sg_add,
 112         .remove_dev     = sg_remove,
 113 };
 114
 115 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 116         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 117         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 118         unsigned bufflen;       /* Size of (aggregate) data buffer */
 119         struct page **pages;
 120         int page_order;
 121         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 122         unsigned char cmd_opcode; /* first byte of command */
 123 } Sg_scatter_hold;
 124
 125 struct sg_device;               /* forward declarations */
 126 struct sg_fd;
 127
 128 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 129         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
 130         struct sg_fd *parentfp; /* NULL -> not in use */
 131         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 132         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 133         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 134         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 135         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 136         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 137         volatile char done;     /* 0->before bh, 1->before read, 2->read */
 138         struct request *rq;
 139         struct bio *bio;
 140 } Sg_request;
 141
 142 typedef struct sg_fd {          /* holds the state of a file descriptor */
 143         struct sg_fd *nextfp;   /* NULL when last opened fd on this device */
 144         struct sg_device *parentdp;     /* owning device */
 145         wait_queue_head_t read_wait;    /* queue read until command done */
 146         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 147         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 148         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 149         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 150         unsigned save_scat_len; /* original length of trunc. scat. element */
 151         Sg_request *headrp;     /* head of request slist, NULL->empty */
 152         struct fasync_struct *async_qp; /* used by asynchronous notification */
 153         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 154         char low_dma;           /* as in parent but possibly overridden to 1 */
 155         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 156         volatile char closed;   /* 1 -> fd closed but request(s) outstanding */
 157         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 158         char next_cmd_len;      /* 0 -> automatic (def), >0 -> use on next write() */
 159         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 160         char mmap_called;       /* 0 -> mmap() never called on this fd */
 161 } Sg_fd;
 162
 163 typedef struct sg_device { /* holds the state of each scsi generic device */
 164         struct scsi_device *device;
 165         wait_queue_head_t o_excl_wait;  /* queue open() when O_EXCL in use */
 166         int sg_tablesize;       /* adapter's max scatter-gather table size */
 167         u32 index;              /* device index number */
 168         Sg_fd *headfp;          /* first open fd belonging to this device */
 169         volatile char detached; /* 0->attached, 1->detached pending removal */
 170         volatile char exclude;  /* opened for exclusive access */
 171         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 172         struct gendisk *disk;
 173         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 174 } Sg_device;
 175
 176 static int sg_fasync(int fd, struct file *filp, int mode);
 177 /* tasklet or soft irq callback */
 178 static void sg_rq_end_io(struct request *rq, int uptodate);
 179 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 180 static void sg_finish_rem_req(Sg_request * srp);
 181 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 182 static int sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp,
 183                          int tablesize);
 184 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 185                            Sg_request * srp);
 186 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 187                         const char __user *buf, size_t count, int blocking,
 188                         int read_only, Sg_request **o_srp);
 189 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 190                            unsigned char *cmnd, int timeout, int blocking);
 191 static int sg_write_xfer(Sg_request * srp);
 192 static int sg_read_xfer(Sg_request * srp);
 193 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 194 static void sg_remove_scat(Sg_scatter_hold * schp);
 195 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 196 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 197 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 198 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
 199 static int sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
 200 static void __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
 201 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 202 static Sg_request *sg_add_request(Sg_fd * sfp);
 203 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 204 static int sg_res_in_use(Sg_fd * sfp);
 205 static int sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len);
 206 static Sg_device *sg_get_dev(int dev);
 207 #ifdef CONFIG_SCSI_PROC_FS
 208 static int sg_last_dev(void);
 209 #endif
 210
 211 #define SZ_SG_HEADER sizeof(struct sg_header)
 212 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 213 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
 214 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 215
 216 static int sg_allow_access(struct file *filp, unsigned char *cmd)
 217 {
 218         struct sg_fd *sfp = (struct sg_fd *)filp->private_data;
 219         struct request_queue *q = sfp->parentdp->device->request_queue;
 220
 221         if (sfp->parentdp->device->type == TYPE_SCANNER)
 222                 return 0;
 223
 224         return blk_verify_command(&q->cmd_filter,
 225                                   cmd, filp->f_mode & FMODE_WRITE);
 226 }
 227
 228 static int
 229 sg_open(struct inode *inode, struct file *filp)
 230 {
 231         int dev = iminor(inode);
 232         int flags = filp->f_flags;
 233         struct request_queue *q;
 234         Sg_device *sdp;
 235         Sg_fd *sfp;
 236         int res;
 237         int retval;
 238
 239         lock_kernel();
 240         nonseekable_open(inode, filp);
 241         SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
 242         sdp = sg_get_dev(dev);
 243         if ((!sdp) || (!sdp->device)) {
 244                 unlock_kernel();
 245                 return -ENXIO;
 246         }
 247         if (sdp->detached) {
 248                 unlock_kernel();
 249                 return -ENODEV;
 250         }
 251
 252         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 253         /* Prevent the device driver from vanishing while we sleep */
 254         retval = scsi_device_get(sdp->device);
 255         if (retval) {
 256                 unlock_kernel();
 257                 return retval;
 258         }
 259
 260         if (!((flags & O_NONBLOCK) ||
 261               scsi_block_when_processing_errors(sdp->device))) {
 262                 retval = -ENXIO;
 263                 /* we are in error recovery for this device */
 264                 goto error_out;
 265         }
 266
 267         if (flags & O_EXCL) {
 268                 if (O_RDONLY == (flags & O_ACCMODE)) {
 269                         retval = -EPERM; /* Can't lock it with read only access */
 270                         goto error_out;
 271                 }
 272                 if (sdp->headfp && (flags & O_NONBLOCK)) {
 273                         retval = -EBUSY;
 274                         goto error_out;
 275                 }
 276                 res = 0;
 277                 __wait_event_interruptible(sdp->o_excl_wait,
 278                         ((sdp->headfp || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
 279                 if (res) {
 280                         retval = res;   /* -ERESTARTSYS because signal hit process */
 281                         goto error_out;
 282                 }
 283         } else if (sdp->exclude) {      /* some other fd has an exclusive lock on dev */
 284                 if (flags & O_NONBLOCK) {
 285                         retval = -EBUSY;
 286                         goto error_out;
 287                 }
 288                 res = 0;
 289                 __wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
 290                                            res);
 291                 if (res) {
 292                         retval = res;   /* -ERESTARTSYS because signal hit process */
 293                         goto error_out;
 294                 }
 295         }
 296         if (sdp->detached) {
 297                 retval = -ENODEV;
 298                 goto error_out;
 299         }
 300         if (!sdp->headfp) {     /* no existing opens on this device */
 301                 sdp->sgdebug = 0;
 302                 q = sdp->device->request_queue;
 303                 sdp->sg_tablesize = min(q->max_hw_segments,
 304                                         q->max_phys_segments);
 305         }
 306         if ((sfp = sg_add_sfp(sdp, dev)))
 307                 filp->private_data = sfp;
 308         else {
 309                 if (flags & O_EXCL)
 310                         sdp->exclude = 0;       /* undo if error */
 311                 retval = -ENOMEM;
 312                 goto error_out;
 313         }
 314         unlock_kernel();
 315         return 0;
 316
 317       error_out:
 318         scsi_device_put(sdp->device);
 319         unlock_kernel();
 320         return retval;
 321 }
 322
 323 /* Following function was formerly called 'sg_close' */
 324 static int
 325 sg_release(struct inode *inode, struct file *filp)
 326 {
 327         Sg_device *sdp;
 328         Sg_fd *sfp;
 329
 330         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 331                 return -ENXIO;
 332         SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
 333         sg_fasync(-1, filp, 0); /* remove filp from async notification list */
 334         if (0 == sg_remove_sfp(sdp, sfp)) {     /* Returns 1 when sdp gone */
 335                 if (!sdp->detached) {
 336                         scsi_device_put(sdp->device);
 337                 }
 338                 sdp->exclude = 0;
 339                 wake_up_interruptible(&sdp->o_excl_wait);
 340         }
 341         return 0;
 342 }
 343
 344 static ssize_t
 345 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 346 {
 347         Sg_device *sdp;
 348         Sg_fd *sfp;
 349         Sg_request *srp;
 350         int req_pack_id = -1;
 351         sg_io_hdr_t *hp;
 352         struct sg_header *old_hdr = NULL;
 353         int retval = 0;
 354
 355         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 356                 return -ENXIO;
 357         SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
 358                                    sdp->disk->disk_name, (int) count));
 359
 360         if (!access_ok(VERIFY_WRITE, buf, count))
 361                 return -EFAULT;
 362         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 363                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 364                 if (!old_hdr)
 365                         return -ENOMEM;
 366                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
 367                         retval = -EFAULT;
 368                         goto free_old_hdr;
 369                 }
 370                 if (old_hdr->reply_len < 0) {
 371                         if (count >= SZ_SG_IO_HDR) {
 372                                 sg_io_hdr_t *new_hdr;
 373                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
 374                                 if (!new_hdr) {
 375                                         retval = -ENOMEM;
 376                                         goto free_old_hdr;
 377                                 }
 378                                 retval =__copy_from_user
 379                                     (new_hdr, buf, SZ_SG_IO_HDR);
 380                                 req_pack_id = new_hdr->pack_id;
 381                                 kfree(new_hdr);
 382                                 if (retval) {
 383                                         retval = -EFAULT;
 384                                         goto free_old_hdr;
 385                                 }
 386                         }
 387                 } else
 388                         req_pack_id = old_hdr->pack_id;
 389         }
 390         srp = sg_get_rq_mark(sfp, req_pack_id);
 391         if (!srp) {             /* now wait on packet to arrive */
 392                 if (sdp->detached) {
 393                         retval = -ENODEV;
 394                         goto free_old_hdr;
 395                 }
 396                 if (filp->f_flags & O_NONBLOCK) {
 397                         retval = -EAGAIN;
 398                         goto free_old_hdr;
 399                 }
 400                 while (1) {
 401                         retval = 0; /* following macro beats race condition */
 402                         __wait_event_interruptible(sfp->read_wait,
 403                                 (sdp->detached ||
 404                                 (srp = sg_get_rq_mark(sfp, req_pack_id))),
 405                                 retval);
 406                         if (sdp->detached) {
 407                                 retval = -ENODEV;
 408                                 goto free_old_hdr;
 409                         }
 410                         if (0 == retval)
 411                                 break;
 412
 413                         /* -ERESTARTSYS as signal hit process */
 414                         goto free_old_hdr;
 415                 }
 416         }
 417         if (srp->header.interface_id != '\0') {
 418                 retval = sg_new_read(sfp, buf, count, srp);
 419                 goto free_old_hdr;
 420         }
 421
 422         hp = &srp->header;
 423         if (old_hdr == NULL) {
 424                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 425                 if (! old_hdr) {
 426                         retval = -ENOMEM;
 427                         goto free_old_hdr;
 428                 }
 429         }
 430         memset(old_hdr, 0, SZ_SG_HEADER);
 431         old_hdr->reply_len = (int) hp->timeout;
 432         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 433         old_hdr->pack_id = hp->pack_id;
 434         old_hdr->twelve_byte =
 435             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 436         old_hdr->target_status = hp->masked_status;
 437         old_hdr->host_status = hp->host_status;
 438         old_hdr->driver_status = hp->driver_status;
 439         if ((CHECK_CONDITION & hp->masked_status) ||
 440             (DRIVER_SENSE & hp->driver_status))
 441                 memcpy(old_hdr->sense_buffer, srp->sense_b,
 442                        sizeof (old_hdr->sense_buffer));
 443         switch (hp->host_status) {
 444         /* This setup of 'result' is for backward compatibility and is best
 445            ignored by the user who should use target, host + driver status */
 446         case DID_OK:
 447         case DID_PASSTHROUGH:
 448         case DID_SOFT_ERROR:
 449                 old_hdr->result = 0;
 450                 break;
 451         case DID_NO_CONNECT:
 452         case DID_BUS_BUSY:
 453         case DID_TIME_OUT:
 454                 old_hdr->result = EBUSY;
 455                 break;
 456         case DID_BAD_TARGET:
 457         case DID_ABORT:
 458         case DID_PARITY:
 459         case DID_RESET:
 460         case DID_BAD_INTR:
 461                 old_hdr->result = EIO;
 462                 break;
 463         case DID_ERROR:
 464                 old_hdr->result = (srp->sense_b[0] == 0 &&
 465                                   hp->masked_status == GOOD) ? 0 : EIO;
 466                 break;
 467         default:
 468                 old_hdr->result = EIO;
 469                 break;
 470         }
 471
 472         /* Now copy the result back to the user buffer.  */
 473         if (count >= SZ_SG_HEADER) {
 474                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 475                         retval = -EFAULT;
 476                         goto free_old_hdr;
 477                 }
 478                 buf += SZ_SG_HEADER;
 479                 if (count > old_hdr->reply_len)
 480                         count = old_hdr->reply_len;
 481                 if (count > SZ_SG_HEADER) {
 482                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 483                                 retval = -EFAULT;
 484                                 goto free_old_hdr;
 485                         }
 486                 }
 487         } else
 488                 count = (old_hdr->result == 0) ? 0 : -EIO;
 489         sg_finish_rem_req(srp);
 490         retval = count;
 491 free_old_hdr:
 492         kfree(old_hdr);
 493         return retval;
 494 }
 495
 496 static ssize_t
 497 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 498 {
 499         sg_io_hdr_t *hp = &srp->header;
 500         int err = 0;
 501         int len;
 502
 503         if (count < SZ_SG_IO_HDR) {
 504                 err = -EINVAL;
 505                 goto err_out;
 506         }
 507         hp->sb_len_wr = 0;
 508         if ((hp->mx_sb_len > 0) && hp->sbp) {
 509                 if ((CHECK_CONDITION & hp->masked_status) ||
 510                     (DRIVER_SENSE & hp->driver_status)) {
 511                         int sb_len = SCSI_SENSE_BUFFERSIZE;
 512                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 513                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 514                         len = (len > sb_len) ? sb_len : len;
 515                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 516                                 err = -EFAULT;
 517                                 goto err_out;
 518                         }
 519                         hp->sb_len_wr = len;
 520                 }
 521         }
 522         if (hp->masked_status || hp->host_status || hp->driver_status)
 523                 hp->info |= SG_INFO_CHECK;
 524         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 525                 err = -EFAULT;
 526                 goto err_out;
 527         }
 528         err = sg_read_xfer(srp);
 529       err_out:
 530         sg_finish_rem_req(srp);
 531         return (0 == err) ? count : err;
 532 }
 533
 534 static ssize_t
 535 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 536 {
 537         int mxsize, cmd_size, k;
 538         int input_size, blocking;
 539         unsigned char opcode;
 540         Sg_device *sdp;
 541         Sg_fd *sfp;
 542         Sg_request *srp;
 543         struct sg_header old_hdr;
 544         sg_io_hdr_t *hp;
 545         unsigned char cmnd[MAX_COMMAND_SIZE];
 546
 547         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 548                 return -ENXIO;
 549         SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
 550                                    sdp->disk->disk_name, (int) count));
 551         if (sdp->detached)
 552                 return -ENODEV;
 553         if (!((filp->f_flags & O_NONBLOCK) ||
 554               scsi_block_when_processing_errors(sdp->device)))
 555                 return -ENXIO;
 556
 557         if (!access_ok(VERIFY_READ, buf, count))
 558                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 559         if (count < SZ_SG_HEADER)
 560                 return -EIO;
 561         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 562                 return -EFAULT;
 563         blocking = !(filp->f_flags & O_NONBLOCK);
 564         if (old_hdr.reply_len < 0)
 565                 return sg_new_write(sfp, filp, buf, count, blocking, 0, NULL);
 566         if (count < (SZ_SG_HEADER + 6))
 567                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 568
 569         if (!(srp = sg_add_request(sfp))) {
 570                 SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
 571                 return -EDOM;
 572         }
 573         buf += SZ_SG_HEADER;
 574         __get_user(opcode, buf);
 575         if (sfp->next_cmd_len > 0) {
 576                 if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
 577                         SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
 578                         sfp->next_cmd_len = 0;
 579                         sg_remove_request(sfp, srp);
 580                         return -EIO;
 581                 }
 582                 cmd_size = sfp->next_cmd_len;
 583                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 584         } else {
 585                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 586                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 587                         cmd_size = 12;
 588         }
 589         SCSI_LOG_TIMEOUT(4, printk(
 590                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 591 /* Determine buffer size.  */
 592         input_size = count - cmd_size;
 593         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 594         mxsize -= SZ_SG_HEADER;
 595         input_size -= SZ_SG_HEADER;
 596         if (input_size < 0) {
 597                 sg_remove_request(sfp, srp);
 598                 return -EIO;    /* User did not pass enough bytes for this command. */
 599         }
 600         hp = &srp->header;
 601         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 602         hp->cmd_len = (unsigned char) cmd_size;
 603         hp->iovec_count = 0;
 604         hp->mx_sb_len = 0;
 605         if (input_size > 0)
 606                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 607                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 608         else
 609                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 610         hp->dxfer_len = mxsize;
 611         if (hp->dxfer_direction == SG_DXFER_TO_DEV)
 612                 hp->dxferp = (char __user *)buf + cmd_size;
 613         else
 614                 hp->dxferp = NULL;
 615         hp->sbp = NULL;
 616         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 617         hp->flags = input_size; /* structure abuse ... */
 618         hp->pack_id = old_hdr.pack_id;
 619         hp->usr_ptr = NULL;
 620         if (__copy_from_user(cmnd, buf, cmd_size))
 621                 return -EFAULT;
 622         /*
 623          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 624          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 625          * is a non-zero input_size, so emit a warning.
 626          */
 627         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 628                 static char cmd[TASK_COMM_LEN];
 629                 if (strcmp(current->comm, cmd) && printk_ratelimit()) {
 630                         printk(KERN_WARNING
 631                                "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
 632                                "guessing data in;\n" KERN_WARNING "   "
 633                                "program %s not setting count and/or reply_len properly\n",
 634                                old_hdr.reply_len - (int)SZ_SG_HEADER,
 635                                input_size, (unsigned int) cmnd[0],
 636                                current->comm);
 637                         strcpy(cmd, current->comm);
 638                 }
 639         }
 640         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 641         return (k < 0) ? k : count;
 642 }
 643
 644 static ssize_t
 645 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 646                  size_t count, int blocking, int read_only,
 647                  Sg_request **o_srp)
 648 {
 649         int k;
 650         Sg_request *srp;
 651         sg_io_hdr_t *hp;
 652         unsigned char cmnd[MAX_COMMAND_SIZE];
 653         int timeout;
 654         unsigned long ul_timeout;
 655
 656         if (count < SZ_SG_IO_HDR)
 657                 return -EINVAL;
 658         if (!access_ok(VERIFY_READ, buf, count))
 659                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 660
 661         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 662         if (!(srp = sg_add_request(sfp))) {
 663                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
 664                 return -EDOM;
 665         }
 666         hp = &srp->header;
 667         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 668                 sg_remove_request(sfp, srp);
 669                 return -EFAULT;
 670         }
 671         if (hp->interface_id != 'S') {
 672                 sg_remove_request(sfp, srp);
 673                 return -ENOSYS;
 674         }
 675         if (hp->flags & SG_FLAG_MMAP_IO) {
 676                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 677                         sg_remove_request(sfp, srp);
 678                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 679                 }
 680                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 681                         sg_remove_request(sfp, srp);
 682                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 683                 }
 684                 if (sg_res_in_use(sfp)) {
 685                         sg_remove_request(sfp, srp);
 686                         return -EBUSY;  /* reserve buffer already being used */
 687                 }
 688         }
 689         ul_timeout = msecs_to_jiffies(srp->header.timeout);
 690         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 691         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 692                 sg_remove_request(sfp, srp);
 693                 return -EMSGSIZE;
 694         }
 695         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
 696                 sg_remove_request(sfp, srp);
 697                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 698         }
 699         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 700                 sg_remove_request(sfp, srp);
 701                 return -EFAULT;
 702         }
 703         if (read_only && sg_allow_access(file, cmnd)) {
 704                 sg_remove_request(sfp, srp);
 705                 return -EPERM;
 706         }
 707         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 708         if (k < 0)
 709                 return k;
 710         if (o_srp)
 711                 *o_srp = srp;
 712         return count;
 713 }
 714
 715 static int
 716 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 717                 unsigned char *cmnd, int timeout, int blocking)
 718 {
 719         int k, data_dir;
 720         Sg_device *sdp = sfp->parentdp;
 721         sg_io_hdr_t *hp = &srp->header;
 722
 723         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 724         hp->status = 0;
 725         hp->masked_status = 0;
 726         hp->msg_status = 0;
 727         hp->info = 0;
 728         hp->host_status = 0;
 729         hp->driver_status = 0;
 730         hp->resid = 0;
 731         SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 732                           (int) cmnd[0], (int) hp->cmd_len));
 733
 734         k = sg_start_req(srp, cmnd);
 735         if (k) {
 736                 SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k));
 737                 sg_finish_rem_req(srp);
 738                 return k;       /* probably out of space --> ENOMEM */
 739         }
 740         if ((k = sg_write_xfer(srp))) {
 741                 SCSI_LOG_TIMEOUT(1, printk("sg_common_write: write_xfer, bad address\n"));
 742                 sg_finish_rem_req(srp);
 743                 return k;
 744         }
 745         if (sdp->detached) {
 746                 sg_finish_rem_req(srp);
 747                 return -ENODEV;
 748         }
 749
 750         switch (hp->dxfer_direction) {
 751         case SG_DXFER_TO_FROM_DEV:
 752         case SG_DXFER_FROM_DEV:
 753                 data_dir = DMA_FROM_DEVICE;
 754                 break;
 755         case SG_DXFER_TO_DEV:
 756                 data_dir = DMA_TO_DEVICE;
 757                 break;
 758         case SG_DXFER_UNKNOWN:
 759                 data_dir = DMA_BIDIRECTIONAL;
 760                 break;
 761         default:
 762                 data_dir = DMA_NONE;
 763                 break;
 764         }
 765         hp->duration = jiffies_to_msecs(jiffies);
 766
 767         srp->rq->timeout = timeout;
 768         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 769                               srp->rq, 1, sg_rq_end_io);
 770         return 0;
 771 }
 772
 773 static int
 774 sg_srp_done(Sg_request *srp, Sg_fd *sfp)
 775 {
 776         unsigned long iflags;
 777         int done;
 778
 779         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 780         done = srp->done;
 781         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 782         return done;
 783 }
 784
 785 static int
 786 sg_ioctl(struct inode *inode, struct file *filp,
 787          unsigned int cmd_in, unsigned long arg)
 788 {
 789         void __user *p = (void __user *)arg;
 790         int __user *ip = p;
 791         int result, val, read_only;
 792         Sg_device *sdp;
 793         Sg_fd *sfp;
 794         Sg_request *srp;
 795         unsigned long iflags;
 796
 797         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 798                 return -ENXIO;
 799
 800         SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
 801                                    sdp->disk->disk_name, (int) cmd_in));
 802         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 803
 804         switch (cmd_in) {
 805         case SG_IO:
 806                 {
 807                         int blocking = 1;       /* ignore O_NONBLOCK flag */
 808
 809                         if (sdp->detached)
 810                                 return -ENODEV;
 811                         if (!scsi_block_when_processing_errors(sdp->device))
 812                                 return -ENXIO;
 813                         if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 814                                 return -EFAULT;
 815                         result =
 816                             sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 817                                          blocking, read_only, &srp);
 818                         if (result < 0)
 819                                 return result;
 820                         srp->sg_io_owned = 1;
 821                         while (1) {
 822                                 result = 0;     /* following macro to beat race condition */
 823                                 __wait_event_interruptible(sfp->read_wait,
 824                                         (sdp->detached || sfp->closed || sg_srp_done(srp, sfp)),
 825                                                            result);
 826                                 if (sdp->detached)
 827                                         return -ENODEV;
 828                                 if (sfp->closed)
 829                                         return 0;       /* request packet dropped already */
 830                                 if (0 == result)
 831                                         break;
 832                                 srp->orphan = 1;
 833                                 return result;  /* -ERESTARTSYS because signal hit process */
 834                         }
 835                         write_lock_irqsave(&sfp->rq_list_lock, iflags);
 836                         srp->done = 2;
 837                         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 838                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 839                         return (result < 0) ? result : 0;
 840                 }
 841         case SG_SET_TIMEOUT:
 842                 result = get_user(val, ip);
 843                 if (result)
 844                         return result;
 845                 if (val < 0)
 846                         return -EIO;
 847                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
 848                     val = MULDIV (INT_MAX, USER_HZ, HZ);
 849                 sfp->timeout_user = val;
 850                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
 851
 852                 return 0;
 853         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 854                                 /* strange ..., for backward compatibility */
 855                 return sfp->timeout_user;
 856         case SG_SET_FORCE_LOW_DMA:
 857                 result = get_user(val, ip);
 858                 if (result)
 859                         return result;
 860                 if (val) {
 861                         sfp->low_dma = 1;
 862                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
 863                                 val = (int) sfp->reserve.bufflen;
 864                                 sg_remove_scat(&sfp->reserve);
 865                                 sg_build_reserve(sfp, val);
 866                         }
 867                 } else {
 868                         if (sdp->detached)
 869                                 return -ENODEV;
 870                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
 871                 }
 872                 return 0;
 873         case SG_GET_LOW_DMA:
 874                 return put_user((int) sfp->low_dma, ip);
 875         case SG_GET_SCSI_ID:
 876                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 877                         return -EFAULT;
 878                 else {
 879                         sg_scsi_id_t __user *sg_idp = p;
 880
 881                         if (sdp->detached)
 882                                 return -ENODEV;
 883                         __put_user((int) sdp->device->host->host_no,
 884                                    &sg_idp->host_no);
 885                         __put_user((int) sdp->device->channel,
 886                                    &sg_idp->channel);
 887                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 888                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 889                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 890                         __put_user((short) sdp->device->host->cmd_per_lun,
 891                                    &sg_idp->h_cmd_per_lun);
 892                         __put_user((short) sdp->device->queue_depth,
 893                                    &sg_idp->d_queue_depth);
 894                         __put_user(0, &sg_idp->unused[0]);
 895                         __put_user(0, &sg_idp->unused[1]);
 896                         return 0;
 897                 }
 898         case SG_SET_FORCE_PACK_ID:
 899                 result = get_user(val, ip);
 900                 if (result)
 901                         return result;
 902                 sfp->force_packid = val ? 1 : 0;
 903                 return 0;
 904         case SG_GET_PACK_ID:
 905                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 906                         return -EFAULT;
 907                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 908                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
 909                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 910                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 911                                                        iflags);
 912                                 __put_user(srp->header.pack_id, ip);
 913                                 return 0;
 914                         }
 915                 }
 916                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 917                 __put_user(-1, ip);
 918                 return 0;
 919         case SG_GET_NUM_WAITING:
 920                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 921                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
 922                         if ((1 == srp->done) && (!srp->sg_io_owned))
 923                                 ++val;
 924                 }
 925                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 926                 return put_user(val, ip);
 927         case SG_GET_SG_TABLESIZE:
 928                 return put_user(sdp->sg_tablesize, ip);
 929         case SG_SET_RESERVED_SIZE:
 930                 result = get_user(val, ip);
 931                 if (result)
 932                         return result;
 933                 if (val < 0)
 934                         return -EINVAL;
 935                 val = min_t(int, val,
 936                                 sdp->device->request_queue->max_sectors * 512);
 937                 if (val != sfp->reserve.bufflen) {
 938                         if (sg_res_in_use(sfp) || sfp->mmap_called)
 939                                 return -EBUSY;
 940                         sg_remove_scat(&sfp->reserve);
 941                         sg_build_reserve(sfp, val);
 942                 }
 943                 return 0;
 944         case SG_GET_RESERVED_SIZE:
 945                 val = min_t(int, sfp->reserve.bufflen,
 946                                 sdp->device->request_queue->max_sectors * 512);
 947                 return put_user(val, ip);
 948         case SG_SET_COMMAND_Q:
 949                 result = get_user(val, ip);
 950                 if (result)
 951                         return result;
 952                 sfp->cmd_q = val ? 1 : 0;
 953                 return 0;
 954         case SG_GET_COMMAND_Q:
 955                 return put_user((int) sfp->cmd_q, ip);
 956         case SG_SET_KEEP_ORPHAN:
 957                 result = get_user(val, ip);
 958                 if (result)
 959                         return result;
 960                 sfp->keep_orphan = val;
 961                 return 0;
 962         case SG_GET_KEEP_ORPHAN:
 963                 return put_user((int) sfp->keep_orphan, ip);
 964         case SG_NEXT_CMD_LEN:
 965                 result = get_user(val, ip);
 966                 if (result)
 967                         return result;
 968                 sfp->next_cmd_len = (val > 0) ? val : 0;
 969                 return 0;
 970         case SG_GET_VERSION_NUM:
 971                 return put_user(sg_version_num, ip);
 972         case SG_GET_ACCESS_COUNT:
 973                 /* faked - we don't have a real access count anymore */
 974                 val = (sdp->device ? 1 : 0);
 975                 return put_user(val, ip);
 976         case SG_GET_REQUEST_TABLE:
 977                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
 978                         return -EFAULT;
 979                 else {
 980                         sg_req_info_t *rinfo;
 981                         unsigned int ms;
 982
 983                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
 984                                                                 GFP_KERNEL);
 985                         if (!rinfo)
 986                                 return -ENOMEM;
 987                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 988                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
 989                              ++val, srp = srp ? srp->nextrp : srp) {
 990                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
 991                                 if (srp) {
 992                                         rinfo[val].req_state = srp->done + 1;
 993                                         rinfo[val].problem =
 994                                             srp->header.masked_status &
 995                                             srp->header.host_status &
 996                                             srp->header.driver_status;
 997                                         if (srp->done)
 998                                                 rinfo[val].duration =
 999                                                         srp->header.duration;
1000                                         else {
1001                                                 ms = jiffies_to_msecs(jiffies);
1002                                                 rinfo[val].duration =
1003                                                     (ms > srp->header.duration) ?
1004                                                     (ms - srp->header.duration) : 0;
1005                                         }
1006                                         rinfo[val].orphan = srp->orphan;
1007                                         rinfo[val].sg_io_owned =
1008                                                         srp->sg_io_owned;
1009                                         rinfo[val].pack_id =
1010                                                         srp->header.pack_id;
1011                                         rinfo[val].usr_ptr =
1012                                                         srp->header.usr_ptr;
1013                                 }
1014                         }
1015                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1016                         result = __copy_to_user(p, rinfo,
1017                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1018                         result = result ? -EFAULT : 0;
1019                         kfree(rinfo);
1020                         return result;
1021                 }
1022         case SG_EMULATED_HOST:
1023                 if (sdp->detached)
1024                         return -ENODEV;
1025                 return put_user(sdp->device->host->hostt->emulated, ip);
1026         case SG_SCSI_RESET:
1027                 if (sdp->detached)
1028                         return -ENODEV;
1029                 if (filp->f_flags & O_NONBLOCK) {
1030                         if (scsi_host_in_recovery(sdp->device->host))
1031                                 return -EBUSY;
1032                 } else if (!scsi_block_when_processing_errors(sdp->device))
1033                         return -EBUSY;
1034                 result = get_user(val, ip);
1035                 if (result)
1036                         return result;
1037                 if (SG_SCSI_RESET_NOTHING == val)
1038                         return 0;
1039                 switch (val) {
1040                 case SG_SCSI_RESET_DEVICE:
1041                         val = SCSI_TRY_RESET_DEVICE;
1042                         break;
1043                 case SG_SCSI_RESET_TARGET:
1044                         val = SCSI_TRY_RESET_TARGET;
1045                         break;
1046                 case SG_SCSI_RESET_BUS:
1047                         val = SCSI_TRY_RESET_BUS;
1048                         break;
1049                 case SG_SCSI_RESET_HOST:
1050                         val = SCSI_TRY_RESET_HOST;
1051                         break;
1052                 default:
1053                         return -EINVAL;
1054                 }
1055                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1056                         return -EACCES;
1057                 return (scsi_reset_provider(sdp->device, val) ==
1058                         SUCCESS) ? 0 : -EIO;
1059         case SCSI_IOCTL_SEND_COMMAND:
1060                 if (sdp->detached)
1061                         return -ENODEV;
1062                 if (read_only) {
1063                         unsigned char opcode = WRITE_6;
1064                         Scsi_Ioctl_Command __user *siocp = p;
1065
1066                         if (copy_from_user(&opcode, siocp->data, 1))
1067                                 return -EFAULT;
1068                         if (sg_allow_access(filp, &opcode))
1069                                 return -EPERM;
1070                 }
1071                 return sg_scsi_ioctl(filp, sdp->device->request_queue, NULL, p);
1072         case SG_SET_DEBUG:
1073                 result = get_user(val, ip);
1074                 if (result)
1075                         return result;
1076                 sdp->sgdebug = (char) val;
1077                 return 0;
1078         case SCSI_IOCTL_GET_IDLUN:
1079         case SCSI_IOCTL_GET_BUS_NUMBER:
1080         case SCSI_IOCTL_PROBE_HOST:
1081         case SG_GET_TRANSFORM:
1082                 if (sdp->detached)
1083                         return -ENODEV;
1084                 return scsi_ioctl(sdp->device, cmd_in, p);
1085         case BLKSECTGET:
1086                 return put_user(sdp->device->request_queue->max_sectors * 512,
1087                                 ip);
1088         case BLKTRACESETUP:
1089                 return blk_trace_setup(sdp->device->request_queue,
1090                                        sdp->disk->disk_name,
1091                                        sdp->device->sdev_gendev.devt,
1092                                        (char *)arg);
1093         case BLKTRACESTART:
1094                 return blk_trace_startstop(sdp->device->request_queue, 1);
1095         case BLKTRACESTOP:
1096                 return blk_trace_startstop(sdp->device->request_queue, 0);
1097         case BLKTRACETEARDOWN:
1098                 return blk_trace_remove(sdp->device->request_queue);
1099         default:
1100                 if (read_only)
1101                         return -EPERM;  /* don't know so take safe approach */
1102                 return scsi_ioctl(sdp->device, cmd_in, p);
1103         }
1104 }
1105
1106 #ifdef CONFIG_COMPAT
1107 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1108 {
1109         Sg_device *sdp;
1110         Sg_fd *sfp;
1111         struct scsi_device *sdev;
1112
1113         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1114                 return -ENXIO;
1115
1116         sdev = sdp->device;
1117         if (sdev->host->hostt->compat_ioctl) {
1118                 int ret;
1119
1120                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1121
1122                 return ret;
1123         }
1124
1125         return -ENOIOCTLCMD;
1126 }
1127 #endif
1128
1129 static unsigned int
1130 sg_poll(struct file *filp, poll_table * wait)
1131 {
1132         unsigned int res = 0;
1133         Sg_device *sdp;
1134         Sg_fd *sfp;
1135         Sg_request *srp;
1136         int count = 0;
1137         unsigned long iflags;
1138
1139         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1140             || sfp->closed)
1141                 return POLLERR;
1142         poll_wait(filp, &sfp->read_wait, wait);
1143         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1144         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1145                 /* if any read waiting, flag it */
1146                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1147                         res = POLLIN | POLLRDNORM;
1148                 ++count;
1149         }
1150         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1151
1152         if (sdp->detached)
1153                 res |= POLLHUP;
1154         else if (!sfp->cmd_q) {
1155                 if (0 == count)
1156                         res |= POLLOUT | POLLWRNORM;
1157         } else if (count < SG_MAX_QUEUE)
1158                 res |= POLLOUT | POLLWRNORM;
1159         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1160                                    sdp->disk->disk_name, (int) res));
1161         return res;
1162 }
1163
1164 static int
1165 sg_fasync(int fd, struct file *filp, int mode)
1166 {
1167         int retval;
1168         Sg_device *sdp;
1169         Sg_fd *sfp;
1170
1171         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1172                 return -ENXIO;
1173         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1174                                    sdp->disk->disk_name, mode));
1175
1176         retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
1177         return (retval < 0) ? retval : 0;
1178 }
1179
1180 static int
1181 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1182 {
1183         Sg_fd *sfp;
1184         unsigned long offset, len, sa;
1185         Sg_scatter_hold *rsv_schp;
1186         int k, length;
1187
1188         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1189                 return VM_FAULT_SIGBUS;
1190         rsv_schp = &sfp->reserve;
1191         offset = vmf->pgoff << PAGE_SHIFT;
1192         if (offset >= rsv_schp->bufflen)
1193                 return VM_FAULT_SIGBUS;
1194         SCSI_LOG_TIMEOUT(3, printk("sg_vma_fault: offset=%lu, scatg=%d\n",
1195                                    offset, rsv_schp->k_use_sg));
1196         sa = vma->vm_start;
1197         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1198         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1199                 len = vma->vm_end - sa;
1200                 len = (len < length) ? len : length;
1201                 if (offset < len) {
1202                         struct page *page = nth_page(rsv_schp->pages[k],
1203                                                      offset >> PAGE_SHIFT);
1204                         get_page(page); /* increment page count */
1205                         vmf->page = page;
1206                         return 0; /* success */
1207                 }
1208                 sa += len;
1209                 offset -= len;
1210         }
1211
1212         return VM_FAULT_SIGBUS;
1213 }
1214
1215 static struct vm_operations_struct sg_mmap_vm_ops = {
1216         .fault = sg_vma_fault,
1217 };
1218
1219 static int
1220 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1221 {
1222         Sg_fd *sfp;
1223         unsigned long req_sz, len, sa;
1224         Sg_scatter_hold *rsv_schp;
1225         int k, length;
1226
1227         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1228                 return -ENXIO;
1229         req_sz = vma->vm_end - vma->vm_start;
1230         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1231                                    (void *) vma->vm_start, (int) req_sz));
1232         if (vma->vm_pgoff)
1233                 return -EINVAL; /* want no offset */
1234         rsv_schp = &sfp->reserve;
1235         if (req_sz > rsv_schp->bufflen)
1236                 return -ENOMEM; /* cannot map more than reserved buffer */
1237
1238         sa = vma->vm_start;
1239         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1240         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1241                 len = vma->vm_end - sa;
1242                 len = (len < length) ? len : length;
1243                 sa += len;
1244         }
1245
1246         sfp->mmap_called = 1;
1247         vma->vm_flags |= VM_RESERVED;
1248         vma->vm_private_data = sfp;
1249         vma->vm_ops = &sg_mmap_vm_ops;
1250         return 0;
1251 }
1252
1253 /*
1254  * This function is a "bottom half" handler that is called by the mid
1255  * level when a command is completed (or has failed).
1256  */
1257 static void sg_rq_end_io(struct request *rq, int uptodate)
1258 {
1259         struct sg_request *srp = rq->end_io_data;
1260         Sg_device *sdp = NULL;
1261         Sg_fd *sfp;
1262         unsigned long iflags;
1263         unsigned int ms;
1264         char *sense;
1265         int result, resid;
1266
1267         if (NULL == srp) {
1268                 printk(KERN_ERR "sg_cmd_done: NULL request\n");
1269                 return;
1270         }
1271         sfp = srp->parentfp;
1272         if (sfp)
1273                 sdp = sfp->parentdp;
1274         if ((NULL == sdp) || sdp->detached) {
1275                 printk(KERN_INFO "sg_cmd_done: device detached\n");
1276                 return;
1277         }
1278
1279         sense = rq->sense;
1280         result = rq->errors;
1281         resid = rq->data_len;
1282
1283         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1284                 sdp->disk->disk_name, srp->header.pack_id, result));
1285         srp->header.resid = resid;
1286         ms = jiffies_to_msecs(jiffies);
1287         srp->header.duration = (ms > srp->header.duration) ?
1288                                 (ms - srp->header.duration) : 0;
1289         if (0 != result) {
1290                 struct scsi_sense_hdr sshdr;
1291
1292                 srp->header.status = 0xff & result;
1293                 srp->header.masked_status = status_byte(result);
1294                 srp->header.msg_status = msg_byte(result);
1295                 srp->header.host_status = host_byte(result);
1296                 srp->header.driver_status = driver_byte(result);
1297                 if ((sdp->sgdebug > 0) &&
1298                     ((CHECK_CONDITION == srp->header.masked_status) ||
1299                      (COMMAND_TERMINATED == srp->header.masked_status)))
1300                         __scsi_print_sense("sg_cmd_done", sense,
1301                                            SCSI_SENSE_BUFFERSIZE);
1302
1303                 /* Following if statement is a patch supplied by Eric Youngdale */
1304                 if (driver_byte(result) != 0
1305                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1306                     && !scsi_sense_is_deferred(&sshdr)
1307                     && sshdr.sense_key == UNIT_ATTENTION
1308                     && sdp->device->removable) {
1309                         /* Detected possible disc change. Set the bit - this */
1310                         /* may be used if there are filesystems using this device */
1311                         sdp->device->changed = 1;
1312                 }
1313         }
1314         /* Rely on write phase to clean out srp status values, so no "else" */
1315
1316         if (sfp->closed) {      /* whoops this fd already released, cleanup */
1317                 SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1318                 sg_finish_rem_req(srp);
1319                 srp = NULL;
1320                 if (NULL == sfp->headrp) {
1321                         SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, final cleanup\n"));
1322                         if (0 == sg_remove_sfp(sdp, sfp)) {     /* device still present */
1323                                 scsi_device_put(sdp->device);
1324                         }
1325                         sfp = NULL;
1326                 }
1327         } else if (srp && srp->orphan) {
1328                 if (sfp->keep_orphan)
1329                         srp->sg_io_owned = 0;
1330                 else {
1331                         sg_finish_rem_req(srp);
1332                         srp = NULL;
1333                 }
1334         }
1335         if (sfp && srp) {
1336                 /* Now wake up any sg_read() that is waiting for this packet. */
1337                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1338                 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1339                 srp->done = 1;
1340                 wake_up_interruptible(&sfp->read_wait);
1341                 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1342         }
1343 }
1344
1345 static struct file_operations sg_fops = {
1346         .owner = THIS_MODULE,
1347         .read = sg_read,
1348         .write = sg_write,
1349         .poll = sg_poll,
1350         .ioctl = sg_ioctl,
1351 #ifdef CONFIG_COMPAT
1352         .compat_ioctl = sg_compat_ioctl,
1353 #endif
1354         .open = sg_open,
1355         .mmap = sg_mmap,
1356         .release = sg_release,
1357         .fasync = sg_fasync,
1358 };
1359
1360 static struct class *sg_sysfs_class;
1361
1362 static int sg_sysfs_valid = 0;
1363
1364 static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1365 {
1366         struct request_queue *q = scsidp->request_queue;
1367         Sg_device *sdp;
1368         unsigned long iflags;
1369         int error;
1370         u32 k;
1371
1372         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1373         if (!sdp) {
1374                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1375                 return ERR_PTR(-ENOMEM);
1376         }
1377         error = -ENOMEM;
1378         if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) {
1379                 printk(KERN_WARNING "idr expansion Sg_device failure\n");
1380                 goto out;
1381         }
1382
1383         write_lock_irqsave(&sg_index_lock, iflags);
1384         error = idr_get_new(&sg_index_idr, sdp, &k);
1385         write_unlock_irqrestore(&sg_index_lock, iflags);
1386
1387         if (error) {
1388                 printk(KERN_WARNING "idr allocation Sg_device failure: %d\n",
1389                        error);
1390                 goto out;
1391         }
1392
1393         if (unlikely(k >= SG_MAX_DEVS))
1394                 goto overflow;
1395
1396         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1397         sprintf(disk->disk_name, "sg%d", k);
1398         disk->first_minor = k;
1399         sdp->disk = disk;
1400         sdp->device = scsidp;
1401         init_waitqueue_head(&sdp->o_excl_wait);
1402         sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments);
1403         sdp->index = k;
1404
1405         error = 0;
1406  out:
1407         if (error) {
1408                 kfree(sdp);
1409                 return ERR_PTR(error);
1410         }
1411         return sdp;
1412
1413  overflow:
1414         sdev_printk(KERN_WARNING, scsidp,
1415                     "Unable to attach sg device type=%d, minor "
1416                     "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1417         error = -ENODEV;
1418         goto out;
1419 }
1420
1421 static int
1422 sg_add(struct device *cl_dev, struct class_interface *cl_intf)
1423 {
1424         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1425         struct gendisk *disk;
1426         Sg_device *sdp = NULL;
1427         struct cdev * cdev = NULL;
1428         int error;
1429         unsigned long iflags;
1430
1431         disk = alloc_disk(1);
1432         if (!disk) {
1433                 printk(KERN_WARNING "alloc_disk failed\n");
1434                 return -ENOMEM;
1435         }
1436         disk->major = SCSI_GENERIC_MAJOR;
1437
1438         error = -ENOMEM;
1439         cdev = cdev_alloc();
1440         if (!cdev) {
1441                 printk(KERN_WARNING "cdev_alloc failed\n");
1442                 goto out;
1443         }
1444         cdev->owner = THIS_MODULE;
1445         cdev->ops = &sg_fops;
1446
1447         sdp = sg_alloc(disk, scsidp);
1448         if (IS_ERR(sdp)) {
1449                 printk(KERN_WARNING "sg_alloc failed\n");
1450                 error = PTR_ERR(sdp);
1451                 goto out;
1452         }
1453
1454         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1455         if (error)
1456                 goto cdev_add_err;
1457
1458         sdp->cdev = cdev;
1459         if (sg_sysfs_valid) {
1460                 struct device *sg_class_member;
1461
1462                 sg_class_member = device_create_drvdata(sg_sysfs_class,
1463                                                         cl_dev->parent,
1464                                                         MKDEV(SCSI_GENERIC_MAJOR,
1465                                                               sdp->index),
1466                                                         sdp,
1467                                                         "%s", disk->disk_name);
1468                 if (IS_ERR(sg_class_member)) {
1469                         printk(KERN_ERR "sg_add: "
1470                                "device_create failed\n");
1471                         error = PTR_ERR(sg_class_member);
1472                         goto cdev_add_err;
1473                 }
1474                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1475                                           &sg_class_member->kobj, "generic");
1476                 if (error)
1477                         printk(KERN_ERR "sg_add: unable to make symlink "
1478                                         "'generic' back to sg%d\n", sdp->index);
1479         } else
1480                 printk(KERN_WARNING "sg_add: sg_sys Invalid\n");
1481
1482         sdev_printk(KERN_NOTICE, scsidp,
1483                     "Attached scsi generic sg%d type %d\n", sdp->index,
1484                     scsidp->type);
1485
1486         dev_set_drvdata(cl_dev, sdp);
1487
1488         return 0;
1489
1490 cdev_add_err:
1491         write_lock_irqsave(&sg_index_lock, iflags);
1492         idr_remove(&sg_index_idr, sdp->index);
1493         write_unlock_irqrestore(&sg_index_lock, iflags);
1494         kfree(sdp);
1495
1496 out:
1497         put_disk(disk);
1498         if (cdev)
1499                 cdev_del(cdev);
1500         return error;
1501 }
1502
1503 static void
1504 sg_remove(struct device *cl_dev, struct class_interface *cl_intf)
1505 {
1506         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1507         Sg_device *sdp = dev_get_drvdata(cl_dev);
1508         unsigned long iflags;
1509         Sg_fd *sfp;
1510         Sg_fd *tsfp;
1511         Sg_request *srp;
1512         Sg_request *tsrp;
1513         int delay;
1514
1515         if (!sdp)
1516                 return;
1517
1518         delay = 0;
1519         write_lock_irqsave(&sg_index_lock, iflags);
1520         if (sdp->headfp) {
1521                 sdp->detached = 1;
1522                 for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1523                         tsfp = sfp->nextfp;
1524                         for (srp = sfp->headrp; srp; srp = tsrp) {
1525                                 tsrp = srp->nextrp;
1526                                 if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
1527                                         sg_finish_rem_req(srp);
1528                         }
1529                         if (sfp->closed) {
1530                                 scsi_device_put(sdp->device);
1531                                 __sg_remove_sfp(sdp, sfp);
1532                         } else {
1533                                 delay = 1;
1534                                 wake_up_interruptible(&sfp->read_wait);
1535                                 kill_fasync(&sfp->async_qp, SIGPOLL,
1536                                             POLL_HUP);
1537                         }
1538                 }
1539                 SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d, dirty\n", sdp->index));
1540                 if (NULL == sdp->headfp) {
1541                         idr_remove(&sg_index_idr, sdp->index);
1542                 }
1543         } else {        /* nothing active, simple case */
1544                 SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d\n", sdp->index));
1545                 idr_remove(&sg_index_idr, sdp->index);
1546         }
1547         write_unlock_irqrestore(&sg_index_lock, iflags);
1548
1549         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1550         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1551         cdev_del(sdp->cdev);
1552         sdp->cdev = NULL;
1553         put_disk(sdp->disk);
1554         sdp->disk = NULL;
1555         if (NULL == sdp->headfp)
1556                 kfree(sdp);
1557
1558         if (delay)
1559                 msleep(10);     /* dirty detach so delay device destruction */
1560 }
1561
1562 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1563 module_param_named(def_reserved_size, def_reserved_size, int,
1564                    S_IRUGO | S_IWUSR);
1565 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1566
1567 MODULE_AUTHOR("Douglas Gilbert");
1568 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1569 MODULE_LICENSE("GPL");
1570 MODULE_VERSION(SG_VERSION_STR);
1571 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1572
1573 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1574                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1575 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1576 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1577
1578 static int __init
1579 init_sg(void)
1580 {
1581         int rc;
1582
1583         if (scatter_elem_sz < PAGE_SIZE) {
1584                 scatter_elem_sz = PAGE_SIZE;
1585                 scatter_elem_sz_prev = scatter_elem_sz;
1586         }
1587         if (def_reserved_size >= 0)
1588                 sg_big_buff = def_reserved_size;
1589         else
1590                 def_reserved_size = sg_big_buff;
1591
1592         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1593                                     SG_MAX_DEVS, "sg");
1594         if (rc)
1595                 return rc;
1596         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1597         if ( IS_ERR(sg_sysfs_class) ) {
1598                 rc = PTR_ERR(sg_sysfs_class);
1599                 goto err_out;
1600         }
1601         sg_sysfs_valid = 1;
1602         rc = scsi_register_interface(&sg_interface);
1603         if (0 == rc) {
1604 #ifdef CONFIG_SCSI_PROC_FS
1605                 sg_proc_init();
1606 #endif                          /* CONFIG_SCSI_PROC_FS */
1607                 return 0;
1608         }
1609         class_destroy(sg_sysfs_class);
1610 err_out:
1611         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1612         return rc;
1613 }
1614
1615 static void __exit
1616 exit_sg(void)
1617 {
1618 #ifdef CONFIG_SCSI_PROC_FS
1619         sg_proc_cleanup();
1620 #endif                          /* CONFIG_SCSI_PROC_FS */
1621         scsi_unregister_interface(&sg_interface);
1622         class_destroy(sg_sysfs_class);
1623         sg_sysfs_valid = 0;
1624         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1625                                  SG_MAX_DEVS);
1626         idr_destroy(&sg_index_idr);
1627 }
1628
1629 static int sg_start_req(Sg_request *srp, unsigned char *cmd)
1630 {
1631         int res = 0;
1632         struct request *rq;
1633         Sg_fd *sfp = srp->parentfp;
1634         sg_io_hdr_t *hp = &srp->header;
1635         int dxfer_len = (int) hp->dxfer_len;
1636         int dxfer_dir = hp->dxfer_direction;
1637         Sg_scatter_hold *req_schp = &srp->data;
1638         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1639         struct request_queue *q = sfp->parentdp->device->request_queue;
1640         struct rq_map_data map_data;
1641         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1642
1643         SCSI_LOG_TIMEOUT(4, printk(KERN_INFO "sg_start_req: dxfer_len=%d\n",
1644                                    dxfer_len));
1645
1646         rq = blk_get_request(q, rw, GFP_ATOMIC);
1647         if (!rq)
1648                 return -ENOMEM;
1649
1650         memcpy(rq->cmd, cmd, hp->cmd_len);
1651
1652         rq->cmd_len = hp->cmd_len;
1653         rq->cmd_type = REQ_TYPE_BLOCK_PC;
1654
1655         srp->rq = rq;
1656         rq->end_io_data = srp;
1657         rq->sense = srp->sense_b;
1658         rq->retries = SG_DEFAULT_RETRIES;
1659
1660         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1661                 return 0;
1662
1663         if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
1664             (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) &&
1665             (!sfp->parentdp->device->host->unchecked_isa_dma) &&
1666             blk_rq_aligned(q, hp->dxferp, dxfer_len))
1667                 return sg_build_direct(srp, sfp, dxfer_len);
1668
1669         if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen))
1670                 sg_link_reserve(sfp, srp, dxfer_len);
1671         else
1672                 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1673
1674         if (!res) {
1675                 struct request *rq = srp->rq;
1676                 Sg_scatter_hold *schp = &srp->data;
1677                 int iovec_count = (int) hp->iovec_count;
1678
1679                 map_data.pages = schp->pages;
1680                 map_data.page_order = schp->page_order;
1681                 map_data.nr_entries = schp->k_use_sg;
1682
1683                 if (iovec_count)
1684                         res = blk_rq_map_user_iov(q, rq, &map_data, hp->dxferp,
1685                                                   iovec_count,
1686                                                   hp->dxfer_len, GFP_ATOMIC);
1687                 else
1688                         res = blk_rq_map_user(q, rq, &map_data, hp->dxferp,
1689                                               hp->dxfer_len, GFP_ATOMIC);
1690
1691                 if (!res)
1692                         srp->bio = rq->bio;
1693         }
1694
1695         return res;
1696 }
1697
1698 static void
1699 sg_finish_rem_req(Sg_request * srp)
1700 {
1701         Sg_fd *sfp = srp->parentfp;
1702         Sg_scatter_hold *req_schp = &srp->data;
1703
1704         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1705         if (srp->res_used)
1706                 sg_unlink_reserve(sfp, srp);
1707         else
1708                 sg_remove_scat(req_schp);
1709
1710         if (srp->rq) {
1711                 if (srp->bio)
1712                         blk_rq_unmap_user(srp->bio);
1713
1714                 blk_put_request(srp->rq);
1715         }
1716
1717         sg_remove_request(sfp, srp);
1718 }
1719
1720 static int
1721 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1722 {
1723         int sg_bufflen = tablesize * sizeof(struct page *);
1724         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1725
1726         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1727         if (!schp->pages)
1728                 return -ENOMEM;
1729         schp->sglist_len = sg_bufflen;
1730         return tablesize;       /* number of scat_gath elements allocated */
1731 }
1732
1733 /* Returns: -ve -> error, 0 -> done, 1 -> try indirect */
1734 static int
1735 sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
1736 {
1737         sg_io_hdr_t *hp = &srp->header;
1738         Sg_scatter_hold *schp = &srp->data;
1739         int res;
1740         struct request *rq = srp->rq;
1741         struct request_queue *q = sfp->parentdp->device->request_queue;
1742
1743         res = blk_rq_map_user(q, rq, NULL, hp->dxferp, dxfer_len, GFP_ATOMIC);
1744         if (res)
1745                 return res;
1746         srp->bio = rq->bio;
1747         schp->dio_in_use = 1;
1748         hp->info |= SG_INFO_DIRECT_IO;
1749         return 0;
1750 }
1751
1752 static int
1753 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1754 {
1755         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1756         int sg_tablesize = sfp->parentdp->sg_tablesize;
1757         int blk_size = buff_size, order;
1758         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1759
1760         if (blk_size < 0)
1761                 return -EFAULT;
1762         if (0 == blk_size)
1763                 ++blk_size;     /* don't know why */
1764 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1765         blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1766         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1767                                    buff_size, blk_size));
1768
1769         /* N.B. ret_sz carried into this block ... */
1770         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1771         if (mx_sc_elems < 0)
1772                 return mx_sc_elems;     /* most likely -ENOMEM */
1773
1774         num = scatter_elem_sz;
1775         if (unlikely(num != scatter_elem_sz_prev)) {
1776                 if (num < PAGE_SIZE) {
1777                         scatter_elem_sz = PAGE_SIZE;
1778                         scatter_elem_sz_prev = PAGE_SIZE;
1779                 } else
1780                         scatter_elem_sz_prev = num;
1781         }
1782
1783         if (sfp->low_dma)
1784                 gfp_mask |= GFP_DMA;
1785
1786         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1787                 gfp_mask |= __GFP_ZERO;
1788
1789         order = get_order(num);
1790 retry:
1791         ret_sz = 1 << (PAGE_SHIFT + order);
1792
1793         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1794              k++, rem_sz -= ret_sz) {
1795
1796                 num = (rem_sz > scatter_elem_sz_prev) ?
1797                         scatter_elem_sz_prev : rem_sz;
1798
1799                 schp->pages[k] = alloc_pages(gfp_mask, order);
1800                 if (!schp->pages[k])
1801                         goto out;
1802
1803                 if (num == scatter_elem_sz_prev) {
1804                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1805                                 scatter_elem_sz = ret_sz;
1806                                 scatter_elem_sz_prev = ret_sz;
1807                         }
1808                 }
1809
1810                 SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
1811                                  "ret_sz=%d\n", k, num, ret_sz));
1812         }               /* end of for loop */
1813
1814         schp->page_order = order;
1815         schp->k_use_sg = k;
1816         SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
1817                          "rem_sz=%d\n", k, rem_sz));
1818
1819         schp->bufflen = blk_size;
1820         if (rem_sz > 0) /* must have failed */
1821                 return -ENOMEM;
1822         return 0;
1823 out:
1824         for (i = 0; i < k; i++)
1825                 __free_pages(schp->pages[k], order);
1826
1827         if (--order >= 0)
1828                 goto retry;
1829
1830         return -ENOMEM;
1831 }
1832
1833 static int
1834 sg_write_xfer(Sg_request * srp)
1835 {
1836         sg_io_hdr_t *hp = &srp->header;
1837         Sg_scatter_hold *schp = &srp->data;
1838         int num_xfer = 0;
1839         int dxfer_dir = hp->dxfer_direction;
1840         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1841
1842         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_TO_DEV == dxfer_dir) ||
1843             (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1844                 num_xfer = (int) (new_interface ? hp->dxfer_len : hp->flags);
1845                 if (schp->bufflen < num_xfer)
1846                         num_xfer = schp->bufflen;
1847         }
1848         if ((num_xfer <= 0) || (schp->dio_in_use) ||
1849             (new_interface
1850              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1851                 return 0;
1852
1853         SCSI_LOG_TIMEOUT(4, printk("sg_write_xfer: num_xfer=%d, k_use_sg=%d\n",
1854                           num_xfer, schp->k_use_sg));
1855
1856         return 0;
1857 }
1858
1859 static void
1860 sg_remove_scat(Sg_scatter_hold * schp)
1861 {
1862         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1863         if (schp->pages && schp->sglist_len > 0) {
1864                 if (!schp->dio_in_use) {
1865                         int k;
1866
1867                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1868                                 SCSI_LOG_TIMEOUT(5, printk(
1869                                     "sg_remove_scat: k=%d, pg=0x%p\n",
1870                                     k, schp->pages[k]));
1871                                 __free_pages(schp->pages[k], schp->page_order);
1872                         }
1873
1874                         kfree(schp->pages);
1875                 }
1876         }
1877         memset(schp, 0, sizeof (*schp));
1878 }
1879
1880 static int
1881 sg_read_xfer(Sg_request * srp)
1882 {
1883         sg_io_hdr_t *hp = &srp->header;
1884         Sg_scatter_hold *schp = &srp->data;
1885         int num_xfer = 0;
1886         int dxfer_dir = hp->dxfer_direction;
1887         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1888
1889         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_FROM_DEV == dxfer_dir)
1890             || (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1891                 num_xfer = hp->dxfer_len;
1892                 if (schp->bufflen < num_xfer)
1893                         num_xfer = schp->bufflen;
1894         }
1895         if ((num_xfer <= 0) || (schp->dio_in_use) ||
1896             (new_interface
1897              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1898                 return 0;
1899
1900         SCSI_LOG_TIMEOUT(4, printk("sg_read_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
1901                           num_xfer, (int)hp->iovec_count, schp->k_use_sg));
1902         return 0;
1903 }
1904
1905 static int
1906 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1907 {
1908         Sg_scatter_hold *schp = &srp->data;
1909         int k, num;
1910
1911         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
1912                                    num_read_xfer));
1913         if ((!outp) || (num_read_xfer <= 0))
1914                 return 0;
1915
1916         blk_rq_unmap_user(srp->bio);
1917         srp->bio = NULL;
1918
1919         num = 1 << (PAGE_SHIFT + schp->page_order);
1920         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1921                 if (num > num_read_xfer) {
1922                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1923                                            num_read_xfer))
1924                                 return -EFAULT;
1925                         break;
1926                 } else {
1927                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1928                                            num))
1929                                 return -EFAULT;
1930                         num_read_xfer -= num;
1931                         if (num_read_xfer <= 0)
1932                                 break;
1933                         outp += num;
1934                 }
1935         }
1936
1937         return 0;
1938 }
1939
1940 static void
1941 sg_build_reserve(Sg_fd * sfp, int req_size)
1942 {
1943         Sg_scatter_hold *schp = &sfp->reserve;
1944
1945         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
1946         do {
1947                 if (req_size < PAGE_SIZE)
1948                         req_size = PAGE_SIZE;
1949                 if (0 == sg_build_indirect(schp, sfp, req_size))
1950                         return;
1951                 else
1952                         sg_remove_scat(schp);
1953                 req_size >>= 1; /* divide by 2 */
1954         } while (req_size > (PAGE_SIZE / 2));
1955 }
1956
1957 static void
1958 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1959 {
1960         Sg_scatter_hold *req_schp = &srp->data;
1961         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1962         int k, num, rem;
1963
1964         srp->res_used = 1;
1965         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
1966         rem = size;
1967
1968         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1969         for (k = 0; k < rsv_schp->k_use_sg; k++) {
1970                 if (rem <= num) {
1971                         req_schp->k_use_sg = k + 1;
1972                         req_schp->sglist_len = rsv_schp->sglist_len;
1973                         req_schp->pages = rsv_schp->pages;
1974
1975                         req_schp->bufflen = size;
1976                         req_schp->page_order = rsv_schp->page_order;
1977                         break;
1978                 } else
1979                         rem -= num;
1980         }
1981
1982         if (k >= rsv_schp->k_use_sg)
1983                 SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
1984 }
1985
1986 static void
1987 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
1988 {
1989         Sg_scatter_hold *req_schp = &srp->data;
1990
1991         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
1992                                    (int) req_schp->k_use_sg));
1993         req_schp->k_use_sg = 0;
1994         req_schp->bufflen = 0;
1995         req_schp->pages = NULL;
1996         req_schp->page_order = 0;
1997         req_schp->sglist_len = 0;
1998         sfp->save_scat_len = 0;
1999         srp->res_used = 0;
2000 }
2001
2002 static Sg_request *
2003 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2004 {
2005         Sg_request *resp;
2006         unsigned long iflags;
2007
2008         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2009         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2010                 /* look for requests that are ready + not SG_IO owned */
2011                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2012                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2013                         resp->done = 2; /* guard against other readers */
2014                         break;
2015                 }
2016         }
2017         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2018         return resp;
2019 }
2020
2021 #ifdef CONFIG_SCSI_PROC_FS
2022 static Sg_request *
2023 sg_get_nth_request(Sg_fd * sfp, int nth)
2024 {
2025         Sg_request *resp;
2026         unsigned long iflags;
2027         int k;
2028
2029         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2030         for (k = 0, resp = sfp->headrp; resp && (k < nth);
2031              ++k, resp = resp->nextrp) ;
2032         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2033         return resp;
2034 }
2035 #endif
2036
2037 /* always adds to end of list */
2038 static Sg_request *
2039 sg_add_request(Sg_fd * sfp)
2040 {
2041         int k;
2042         unsigned long iflags;
2043         Sg_request *resp;
2044         Sg_request *rp = sfp->req_arr;
2045
2046         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2047         resp = sfp->headrp;
2048         if (!resp) {
2049                 memset(rp, 0, sizeof (Sg_request));
2050                 rp->parentfp = sfp;
2051                 resp = rp;
2052                 sfp->headrp = resp;
2053         } else {
2054                 if (0 == sfp->cmd_q)
2055                         resp = NULL;    /* command queuing disallowed */
2056                 else {
2057                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2058                                 if (!rp->parentfp)
2059                                         break;
2060                         }
2061                         if (k < SG_MAX_QUEUE) {
2062                                 memset(rp, 0, sizeof (Sg_request));
2063                                 rp->parentfp = sfp;
2064                                 while (resp->nextrp)
2065                                         resp = resp->nextrp;
2066                                 resp->nextrp = rp;
2067                                 resp = rp;
2068                         } else
2069                                 resp = NULL;
2070                 }
2071         }
2072         if (resp) {
2073                 resp->nextrp = NULL;
2074                 resp->header.duration = jiffies_to_msecs(jiffies);
2075         }
2076         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2077         return resp;
2078 }
2079
2080 /* Return of 1 for found; 0 for not found */
2081 static int
2082 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2083 {
2084         Sg_request *prev_rp;
2085         Sg_request *rp;
2086         unsigned long iflags;
2087         int res = 0;
2088
2089         if ((!sfp) || (!srp) || (!sfp->headrp))
2090                 return res;
2091         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2092         prev_rp = sfp->headrp;
2093         if (srp == prev_rp) {
2094                 sfp->headrp = prev_rp->nextrp;
2095                 prev_rp->parentfp = NULL;
2096                 res = 1;
2097         } else {
2098                 while ((rp = prev_rp->nextrp)) {
2099                         if (srp == rp) {
2100                                 prev_rp->nextrp = rp->nextrp;
2101                                 rp->parentfp = NULL;
2102                                 res = 1;
2103                                 break;
2104                         }
2105                         prev_rp = rp;
2106                 }
2107         }
2108         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2109         return res;
2110 }
2111
2112 #ifdef CONFIG_SCSI_PROC_FS
2113 static Sg_fd *
2114 sg_get_nth_sfp(Sg_device * sdp, int nth)
2115 {
2116         Sg_fd *resp;
2117         unsigned long iflags;
2118         int k;
2119
2120         read_lock_irqsave(&sg_index_lock, iflags);
2121         for (k = 0, resp = sdp->headfp; resp && (k < nth);
2122              ++k, resp = resp->nextfp) ;
2123         read_unlock_irqrestore(&sg_index_lock, iflags);
2124         return resp;
2125 }
2126 #endif
2127
2128 static Sg_fd *
2129 sg_add_sfp(Sg_device * sdp, int dev)
2130 {
2131         Sg_fd *sfp;
2132         unsigned long iflags;
2133         int bufflen;
2134
2135         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2136         if (!sfp)
2137                 return NULL;
2138
2139         init_waitqueue_head(&sfp->read_wait);
2140         rwlock_init(&sfp->rq_list_lock);
2141
2142         sfp->timeout = SG_DEFAULT_TIMEOUT;
2143         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2144         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2145         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2146             sdp->device->host->unchecked_isa_dma : 1;
2147         sfp->cmd_q = SG_DEF_COMMAND_Q;
2148         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2149         sfp->parentdp = sdp;
2150         write_lock_irqsave(&sg_index_lock, iflags);
2151         if (!sdp->headfp)
2152                 sdp->headfp = sfp;
2153         else {                  /* add to tail of existing list */
2154                 Sg_fd *pfp = sdp->headfp;
2155                 while (pfp->nextfp)
2156                         pfp = pfp->nextfp;
2157                 pfp->nextfp = sfp;
2158         }
2159         write_unlock_irqrestore(&sg_index_lock, iflags);
2160         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2161         if (unlikely(sg_big_buff != def_reserved_size))
2162                 sg_big_buff = def_reserved_size;
2163
2164         bufflen = min_t(int, sg_big_buff,
2165                         sdp->device->request_queue->max_sectors * 512);
2166         sg_build_reserve(sfp, bufflen);
2167         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2168                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2169         return sfp;
2170 }
2171
2172 static void
2173 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2174 {
2175         Sg_fd *fp;
2176         Sg_fd *prev_fp;
2177
2178         prev_fp = sdp->headfp;
2179         if (sfp == prev_fp)
2180                 sdp->headfp = prev_fp->nextfp;
2181         else {
2182                 while ((fp = prev_fp->nextfp)) {
2183                         if (sfp == fp) {
2184                                 prev_fp->nextfp = fp->nextfp;
2185                                 break;
2186                         }
2187                         prev_fp = fp;
2188                 }
2189         }
2190         if (sfp->reserve.bufflen > 0) {
2191                 SCSI_LOG_TIMEOUT(6,
2192                         printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2193                         (int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2194                 sg_remove_scat(&sfp->reserve);
2195         }
2196         sfp->parentdp = NULL;
2197         SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2198         kfree(sfp);
2199 }
2200
2201 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2202 static int
2203 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2204 {
2205         Sg_request *srp;
2206         Sg_request *tsrp;
2207         int dirty = 0;
2208         int res = 0;
2209
2210         for (srp = sfp->headrp; srp; srp = tsrp) {
2211                 tsrp = srp->nextrp;
2212                 if (sg_srp_done(srp, sfp))
2213                         sg_finish_rem_req(srp);
2214                 else
2215                         ++dirty;
2216         }
2217         if (0 == dirty) {
2218                 unsigned long iflags;
2219
2220                 write_lock_irqsave(&sg_index_lock, iflags);
2221                 __sg_remove_sfp(sdp, sfp);
2222                 if (sdp->detached && (NULL == sdp->headfp)) {
2223                         idr_remove(&sg_index_idr, sdp->index);
2224                         kfree(sdp);
2225                         res = 1;
2226                 }
2227                 write_unlock_irqrestore(&sg_index_lock, iflags);
2228         } else {
2229                 /* MOD_INC's to inhibit unloading sg and associated adapter driver */
2230                 /* only bump the access_count if we actually succeeded in
2231                  * throwing another counter on the host module */
2232                 scsi_device_get(sdp->device);   /* XXX: retval ignored? */
2233                 sfp->closed = 1;        /* flag dirty state on this fd */
2234                 SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2235                                   dirty));
2236         }
2237         return res;
2238 }
2239
2240 static int
2241 sg_res_in_use(Sg_fd * sfp)
2242 {
2243         const Sg_request *srp;
2244         unsigned long iflags;
2245
2246         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2247         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2248                 if (srp->res_used)
2249                         break;
2250         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2251         return srp ? 1 : 0;
2252 }
2253
2254 #ifdef CONFIG_SCSI_PROC_FS
2255 static int
2256 sg_idr_max_id(int id, void *p, void *data)
2257 {
2258         int *k = data;
2259
2260         if (*k < id)
2261                 *k = id;
2262
2263         return 0;
2264 }
2265
2266 static int
2267 sg_last_dev(void)
2268 {
2269         int k = -1;
2270         unsigned long iflags;
2271
2272         read_lock_irqsave(&sg_index_lock, iflags);
2273         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2274         read_unlock_irqrestore(&sg_index_lock, iflags);
2275         return k + 1;           /* origin 1 */
2276 }
2277 #endif
2278
2279 static Sg_device *
2280 sg_get_dev(int dev)
2281 {
2282         Sg_device *sdp;
2283         unsigned long iflags;
2284
2285         read_lock_irqsave(&sg_index_lock, iflags);
2286         sdp = idr_find(&sg_index_idr, dev);
2287         read_unlock_irqrestore(&sg_index_lock, iflags);
2288
2289         return sdp;
2290 }
2291
2292 #ifdef CONFIG_SCSI_PROC_FS
2293
2294 static struct proc_dir_entry *sg_proc_sgp = NULL;
2295
2296 static char sg_proc_sg_dirname[] = "scsi/sg";
2297
2298 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2299
2300 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2301 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2302                                   size_t count, loff_t *off);
2303 static struct file_operations adio_fops = {
2304         /* .owner, .read and .llseek added in sg_proc_init() */
2305         .open = sg_proc_single_open_adio,
2306         .write = sg_proc_write_adio,
2307         .release = single_release,
2308 };
2309
2310 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2311 static ssize_t sg_proc_write_dressz(struct file *filp,
2312                 const char __user *buffer, size_t count, loff_t *off);
2313 static struct file_operations dressz_fops = {
2314         .open = sg_proc_single_open_dressz,
2315         .write = sg_proc_write_dressz,
2316         .release = single_release,
2317 };
2318
2319 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2320 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2321 static struct file_operations version_fops = {
2322         .open = sg_proc_single_open_version,
2323         .release = single_release,
2324 };
2325
2326 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2327 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2328 static struct file_operations devhdr_fops = {
2329         .open = sg_proc_single_open_devhdr,
2330         .release = single_release,
2331 };
2332
2333 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2334 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2335 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2336 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2337 static void dev_seq_stop(struct seq_file *s, void *v);
2338 static struct file_operations dev_fops = {
2339         .open = sg_proc_open_dev,
2340         .release = seq_release,
2341 };
2342 static struct seq_operations dev_seq_ops = {
2343         .start = dev_seq_start,
2344         .next  = dev_seq_next,
2345         .stop  = dev_seq_stop,
2346         .show  = sg_proc_seq_show_dev,
2347 };
2348
2349 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2350 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2351 static struct file_operations devstrs_fops = {
2352         .open = sg_proc_open_devstrs,
2353         .release = seq_release,
2354 };
2355 static struct seq_operations devstrs_seq_ops = {
2356         .start = dev_seq_start,
2357         .next  = dev_seq_next,
2358         .stop  = dev_seq_stop,
2359         .show  = sg_proc_seq_show_devstrs,
2360 };
2361
2362 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2363 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2364 static struct file_operations debug_fops = {
2365         .open = sg_proc_open_debug,
2366         .release = seq_release,
2367 };
2368 static struct seq_operations debug_seq_ops = {
2369         .start = dev_seq_start,
2370         .next  = dev_seq_next,
2371         .stop  = dev_seq_stop,
2372         .show  = sg_proc_seq_show_debug,
2373 };
2374
2375
2376 struct sg_proc_leaf {
2377         const char * name;
2378         struct file_operations * fops;
2379 };
2380
2381 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2382         {"allow_dio", &adio_fops},
2383         {"debug", &debug_fops},
2384         {"def_reserved_size", &dressz_fops},
2385         {"device_hdr", &devhdr_fops},
2386         {"devices", &dev_fops},
2387         {"device_strs", &devstrs_fops},
2388         {"version", &version_fops}
2389 };
2390
2391 static int
2392 sg_proc_init(void)
2393 {
2394         int k, mask;
2395         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2396         struct sg_proc_leaf * leaf;
2397
2398         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2399         if (!sg_proc_sgp)
2400                 return 1;
2401         for (k = 0; k < num_leaves; ++k) {
2402                 leaf = &sg_proc_leaf_arr[k];
2403                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2404                 leaf->fops->owner = THIS_MODULE;
2405                 leaf->fops->read = seq_read;
2406                 leaf->fops->llseek = seq_lseek;
2407                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2408         }
2409         return 0;
2410 }
2411
2412 static void
2413 sg_proc_cleanup(void)
2414 {
2415         int k;
2416         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2417
2418         if (!sg_proc_sgp)
2419                 return;
2420         for (k = 0; k < num_leaves; ++k)
2421                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2422         remove_proc_entry(sg_proc_sg_dirname, NULL);
2423 }
2424
2425
2426 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2427 {
2428         seq_printf(s, "%d\n", *((int *)s->private));
2429         return 0;
2430 }
2431
2432 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2433 {
2434         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2435 }
2436
2437 static ssize_t
2438 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2439                    size_t count, loff_t *off)
2440 {
2441         int num;
2442         char buff[11];
2443
2444         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2445                 return -EACCES;
2446         num = (count < 10) ? count : 10;
2447         if (copy_from_user(buff, buffer, num))
2448                 return -EFAULT;
2449         buff[num] = '\0';
2450         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2451         return count;
2452 }
2453
2454 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2455 {
2456         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2457 }
2458
2459 static ssize_t
2460 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2461                      size_t count, loff_t *off)
2462 {
2463         int num;
2464         unsigned long k = ULONG_MAX;
2465         char buff[11];
2466
2467         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2468                 return -EACCES;
2469         num = (count < 10) ? count : 10;
2470         if (copy_from_user(buff, buffer, num))
2471                 return -EFAULT;
2472         buff[num] = '\0';
2473         k = simple_strtoul(buff, NULL, 10);
2474         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2475                 sg_big_buff = k;
2476                 return count;
2477         }
2478         return -ERANGE;
2479 }
2480
2481 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2482 {
2483         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2484                    sg_version_date);
2485         return 0;
2486 }
2487
2488 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2489 {
2490         return single_open(file, sg_proc_seq_show_version, NULL);
2491 }
2492
2493 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2494 {
2495         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2496                    "online\n");
2497         return 0;
2498 }
2499
2500 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2501 {
2502         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2503 }
2504
2505 struct sg_proc_deviter {
2506         loff_t  index;
2507         size_t  max;
2508 };
2509
2510 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2511 {
2512         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2513
2514         s->private = it;
2515         if (! it)
2516                 return NULL;
2517
2518         it->index = *pos;
2519         it->max = sg_last_dev();
2520         if (it->index >= it->max)
2521                 return NULL;
2522         return it;
2523 }
2524
2525 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2526 {
2527         struct sg_proc_deviter * it = s->private;
2528
2529         *pos = ++it->index;
2530         return (it->index < it->max) ? it : NULL;
2531 }
2532
2533 static void dev_seq_stop(struct seq_file *s, void *v)
2534 {
2535         kfree(s->private);
2536 }
2537
2538 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2539 {
2540         return seq_open(file, &dev_seq_ops);
2541 }
2542
2543 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2544 {
2545         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2546         Sg_device *sdp;
2547         struct scsi_device *scsidp;
2548
2549         sdp = it ? sg_get_dev(it->index) : NULL;
2550         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2551                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2552                               scsidp->host->host_no, scsidp->channel,
2553                               scsidp->id, scsidp->lun, (int) scsidp->type,
2554                               1,
2555                               (int) scsidp->queue_depth,
2556                               (int) scsidp->device_busy,
2557                               (int) scsi_device_online(scsidp));
2558         else
2559                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2560         return 0;
2561 }
2562
2563 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2564 {
2565         return seq_open(file, &devstrs_seq_ops);
2566 }
2567
2568 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2569 {
2570         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2571         Sg_device *sdp;
2572         struct scsi_device *scsidp;
2573
2574         sdp = it ? sg_get_dev(it->index) : NULL;
2575         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2576                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2577                            scsidp->vendor, scsidp->model, scsidp->rev);
2578         else
2579                 seq_printf(s, "<no active device>\n");
2580         return 0;
2581 }
2582
2583 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2584 {
2585         int k, m, new_interface, blen, usg;
2586         Sg_request *srp;
2587         Sg_fd *fp;
2588         const sg_io_hdr_t *hp;
2589         const char * cp;
2590         unsigned int ms;
2591
2592         for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
2593                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2594                            "(res)sgat=%d low_dma=%d\n", k + 1,
2595                            jiffies_to_msecs(fp->timeout),
2596                            fp->reserve.bufflen,
2597                            (int) fp->reserve.k_use_sg,
2598                            (int) fp->low_dma);
2599                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2600                            (int) fp->cmd_q, (int) fp->force_packid,
2601                            (int) fp->keep_orphan, (int) fp->closed);
2602                 for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
2603                         hp = &srp->header;
2604                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2605                         if (srp->res_used) {
2606                                 if (new_interface &&
2607                                     (SG_FLAG_MMAP_IO & hp->flags))
2608                                         cp = "     mmap>> ";
2609                                 else
2610                                         cp = "     rb>> ";
2611                         } else {
2612                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2613                                         cp = "     dio>> ";
2614                                 else
2615                                         cp = "     ";
2616                         }
2617                         seq_printf(s, cp);
2618                         blen = srp->data.bufflen;
2619                         usg = srp->data.k_use_sg;
2620                         seq_printf(s, srp->done ?
2621                                    ((1 == srp->done) ?  "rcv:" : "fin:")
2622                                    : "act:");
2623                         seq_printf(s, " id=%d blen=%d",
2624                                    srp->header.pack_id, blen);
2625                         if (srp->done)
2626                                 seq_printf(s, " dur=%d", hp->duration);
2627                         else {
2628                                 ms = jiffies_to_msecs(jiffies);
2629                                 seq_printf(s, " t_o/elap=%d/%d",
2630                                         (new_interface ? hp->timeout :
2631                                                   jiffies_to_msecs(fp->timeout)),
2632                                         (ms > hp->duration ? ms - hp->duration : 0));
2633                         }
2634                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2635                                    (int) srp->data.cmd_opcode);
2636                 }
2637                 if (0 == m)
2638                         seq_printf(s, "     No requests active\n");
2639         }
2640 }
2641
2642 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2643 {
2644         return seq_open(file, &debug_seq_ops);
2645 }
2646
2647 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2648 {
2649         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2650         Sg_device *sdp;
2651
2652         if (it && (0 == it->index)) {
2653                 seq_printf(s, "max_active_device=%d(origin 1)\n",
2654                            (int)it->max);
2655                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2656         }
2657         sdp = it ? sg_get_dev(it->index) : NULL;
2658         if (sdp) {
2659                 struct scsi_device *scsidp = sdp->device;
2660
2661                 if (NULL == scsidp) {
2662                         seq_printf(s, "device %d detached ??\n",
2663                                    (int)it->index);
2664                         return 0;
2665                 }
2666
2667                 if (sg_get_nth_sfp(sdp, 0)) {
2668                         seq_printf(s, " >>> device=%s ",
2669                                 sdp->disk->disk_name);
2670                         if (sdp->detached)
2671                                 seq_printf(s, "detached pending close ");
2672                         else
2673                                 seq_printf
2674                                     (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2675                                      scsidp->host->host_no,
2676                                      scsidp->channel, scsidp->id,
2677                                      scsidp->lun,
2678                                      scsidp->host->hostt->emulated);
2679                         seq_printf(s, " sg_tablesize=%d excl=%d\n",
2680                                    sdp->sg_tablesize, sdp->exclude);
2681                 }
2682                 sg_proc_debug_helper(s, sdp);
2683         }
2684         return 0;
2685 }
2686
2687 #endif                          /* CONFIG_SCSI_PROC_FS */
2688
2689 module_init(init_sg);
2690 module_exit(exit_sg);