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