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