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