drivers/scsi/sg.c

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