drivers/scsi/sg.c

   1 /*
   2  *  History:
   3  *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
   4  *           to allow user process control of SCSI devices.
   5  *  Development Sponsored by Killy Corp. NY NY
   6  *
   7  * Original driver (sg.c):
   8  *        Copyright (C) 1992 Lawrence Foard
   9  * Version 2 and 3 extensions to driver:
  10  *        Copyright (C) 1998 - 2005 Douglas Gilbert
  11  *
  12  *  Modified  19-JAN-1998  Richard Gooch <rgooch@atnf.csiro.au>  Devfs support
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2, or (at your option)
  17  * any later version.
  18  *
  19  */
  20
  21 static int sg_version_num = 30534;      /* 2 digits for each component */
  22 #define SG_VERSION_STR "3.5.34"
  23
  24 /*
  25  *  D. P. Gilbert (dgilbert@interlog.com, dougg@triode.net.au), notes:
  26  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
  27  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
  28  *        (otherwise the macros compile to empty statements).
  29  *
  30  */
  31 #include <linux/module.h>
  32
  33 #include <linux/fs.h>
  34 #include <linux/kernel.h>
  35 #include <linux/sched.h>
  36 #include <linux/string.h>
  37 #include <linux/mm.h>
  38 #include <linux/errno.h>
  39 #include <linux/mtio.h>
  40 #include <linux/ioctl.h>
  41 #include <linux/slab.h>
  42 #include <linux/fcntl.h>
  43 #include <linux/init.h>
  44 #include <linux/poll.h>
  45 #include <linux/moduleparam.h>
  46 #include <linux/cdev.h>
  47 #include <linux/idr.h>
  48 #include <linux/seq_file.h>
  49 #include <linux/blkdev.h>
  50 #include <linux/delay.h>
  51 #include <linux/blktrace_api.h>
  52 #include <linux/mutex.h>
  53 #include <linux/ratelimit.h>
  54
  55 #include "scsi.h"
  56 #include <scsi/scsi_dbg.h>
  57 #include <scsi/scsi_host.h>
  58 #include <scsi/scsi_driver.h>
  59 #include <scsi/scsi_ioctl.h>
  60 #include <scsi/sg.h>
  61
  62 #include "scsi_logging.h"
  63
  64 #ifdef CONFIG_SCSI_PROC_FS
  65 #include <linux/proc_fs.h>
  66 static char *sg_version_date = "20061027";
  67
  68 static int sg_proc_init(void);
  69 static void sg_proc_cleanup(void);
  70 #endif
  71
  72 #define SG_ALLOW_DIO_DEF 0
  73
  74 #define SG_MAX_DEVS 32768
  75
  76 /*
  77  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
  78  * Then when using 32 bit integers x * m may overflow during the calculation.
  79  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
  80  * calculates the same, but prevents the overflow when both m and d
  81  * are "small" numbers (like HZ and USER_HZ).
  82  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
  83  * in 32 bits.
  84  */
  85 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
  86
  87 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  88
  89 int sg_big_buff = SG_DEF_RESERVED_SIZE;
  90 /* N.B. This variable is readable and writeable via
  91    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  92    of this size (or less if there is not enough memory) will be reserved
  93    for use by this file descriptor. [Deprecated usage: this variable is also
  94    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  95    the kernel (i.e. it is not a module).] */
  96 static int def_reserved_size = -1;      /* picks up init parameter */
  97 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
  98
  99 static int scatter_elem_sz = SG_SCATTER_SZ;
 100 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
 101
 102 #define SG_SECTOR_SZ 512
 103
 104 static int sg_add(struct device *, struct class_interface *);
 105 static void sg_remove(struct device *, struct class_interface *);
 106
 107 static DEFINE_MUTEX(sg_mutex);
 108
 109 static DEFINE_IDR(sg_index_idr);
 110 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
 111                                                            file descriptor list for device */
 112
 113 static struct class_interface sg_interface = {
 114         .add_dev        = sg_add,
 115         .remove_dev     = sg_remove,
 116 };
 117
 118 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 119         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 120         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 121         unsigned bufflen;       /* Size of (aggregate) data buffer */
 122         struct page **pages;
 123         int page_order;
 124         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 125         unsigned char cmd_opcode; /* first byte of command */
 126 } Sg_scatter_hold;
 127
 128 struct sg_device;               /* forward declarations */
 129 struct sg_fd;
 130
 131 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 132         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
 133         struct sg_fd *parentfp; /* NULL -> not in use */
 134         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 135         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 136         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 137         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 138         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 139         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 140         volatile 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         struct list_head sfd_siblings;
 148         struct sg_device *parentdp;     /* owning device */
 149         wait_queue_head_t read_wait;    /* queue read until command done */
 150         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 151         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 152         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 153         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 154         unsigned save_scat_len; /* original length of trunc. scat. element */
 155         Sg_request *headrp;     /* head of request slist, NULL->empty */
 156         struct fasync_struct *async_qp; /* used by asynchronous notification */
 157         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 158         char low_dma;           /* as in parent but possibly overridden to 1 */
 159         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 160         volatile char closed;   /* 1 -> fd closed but request(s) outstanding */
 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         wait_queue_head_t o_excl_wait;  /* queue open() when O_EXCL in use */
 172         int sg_tablesize;       /* adapter's max scatter-gather table size */
 173         u32 index;              /* device index number */
 174         struct list_head sfds;
 175         volatile char detached; /* 0->attached, 1->detached pending removal */
 176         volatile char exclude;  /* opened for exclusive access */
 177         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 178         struct gendisk *disk;
 179         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 180         struct kref d_ref;
 181 } Sg_device;
 182
 183 /* tasklet or soft irq callback */
 184 static void sg_rq_end_io(struct request *rq, int uptodate);
 185 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 186 static int sg_finish_rem_req(Sg_request * srp);
 187 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 188 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 189                            Sg_request * srp);
 190 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 191                         const char __user *buf, size_t count, int blocking,
 192                         int read_only, int sg_io_owned, Sg_request **o_srp);
 193 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 194                            unsigned char *cmnd, int timeout, int blocking);
 195 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 196 static void sg_remove_scat(Sg_scatter_hold * schp);
 197 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 198 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 199 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 200 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
 201 static void sg_remove_sfp(struct kref *);
 202 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 203 static Sg_request *sg_add_request(Sg_fd * sfp);
 204 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 205 static int sg_res_in_use(Sg_fd * sfp);
 206 static Sg_device *sg_get_dev(int dev);
 207 static void sg_put_dev(Sg_device *sdp);
 208
 209 #define SZ_SG_HEADER sizeof(struct sg_header)
 210 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 211 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
 212 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 213
 214 static int sg_allow_access(struct file *filp, unsigned char *cmd)
 215 {
 216         struct sg_fd *sfp = filp->private_data;
 217
 218         if (sfp->parentdp->device->type == TYPE_SCANNER)
 219                 return 0;
 220
 221         return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE);
 222 }
 223
 224 static int
 225 sg_open(struct inode *inode, struct file *filp)
 226 {
 227         int dev = iminor(inode);
 228         int flags = filp->f_flags;
 229         struct request_queue *q;
 230         Sg_device *sdp;
 231         Sg_fd *sfp;
 232         int res;
 233         int retval;
 234
 235         mutex_lock(&sg_mutex);
 236         nonseekable_open(inode, filp);
 237         SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
 238         sdp = sg_get_dev(dev);
 239         if (IS_ERR(sdp)) {
 240                 retval = PTR_ERR(sdp);
 241                 sdp = NULL;
 242                 goto sg_put;
 243         }
 244
 245         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 246         /* Prevent the device driver from vanishing while we sleep */
 247         retval = scsi_device_get(sdp->device);
 248         if (retval)
 249                 goto sg_put;
 250
 251         retval = scsi_autopm_get_device(sdp->device);
 252         if (retval)
 253                 goto sdp_put;
 254
 255         if (!((flags & O_NONBLOCK) ||
 256               scsi_block_when_processing_errors(sdp->device))) {
 257                 retval = -ENXIO;
 258                 /* we are in error recovery for this device */
 259                 goto error_out;
 260         }
 261
 262         if (flags & O_EXCL) {
 263                 if (O_RDONLY == (flags & O_ACCMODE)) {
 264                         retval = -EPERM; /* Can't lock it with read only access */
 265                         goto error_out;
 266                 }
 267                 if (!list_empty(&sdp->sfds) && (flags & O_NONBLOCK)) {
 268                         retval = -EBUSY;
 269                         goto error_out;
 270                 }
 271                 res = 0;
 272                 __wait_event_interruptible(sdp->o_excl_wait,
 273                                            ((!list_empty(&sdp->sfds) || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
 274                 if (res) {
 275                         retval = res;   /* -ERESTARTSYS because signal hit process */
 276                         goto error_out;
 277                 }
 278         } else if (sdp->exclude) {      /* some other fd has an exclusive lock on dev */
 279                 if (flags & O_NONBLOCK) {
 280                         retval = -EBUSY;
 281                         goto error_out;
 282                 }
 283                 res = 0;
 284                 __wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
 285                                            res);
 286                 if (res) {
 287                         retval = res;   /* -ERESTARTSYS because signal hit process */
 288                         goto error_out;
 289                 }
 290         }
 291         if (sdp->detached) {
 292                 retval = -ENODEV;
 293                 goto error_out;
 294         }
 295         if (list_empty(&sdp->sfds)) {   /* no existing opens on this device */
 296                 sdp->sgdebug = 0;
 297                 q = sdp->device->request_queue;
 298                 sdp->sg_tablesize = queue_max_segments(q);
 299         }
 300         if ((sfp = sg_add_sfp(sdp, dev)))
 301                 filp->private_data = sfp;
 302         else {
 303                 if (flags & O_EXCL) {
 304                         sdp->exclude = 0;       /* undo if error */
 305                         wake_up_interruptible(&sdp->o_excl_wait);
 306                 }
 307                 retval = -ENOMEM;
 308                 goto error_out;
 309         }
 310         retval = 0;
 311 error_out:
 312         if (retval) {
 313                 scsi_autopm_put_device(sdp->device);
 314 sdp_put:
 315                 scsi_device_put(sdp->device);
 316         }
 317 sg_put:
 318         if (sdp)
 319                 sg_put_dev(sdp);
 320         mutex_unlock(&sg_mutex);
 321         return retval;
 322 }
 323
 324 /* Following function was formerly called 'sg_close' */
 325 static int
 326 sg_release(struct inode *inode, struct file *filp)
 327 {
 328         Sg_device *sdp;
 329         Sg_fd *sfp;
 330
 331         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 332                 return -ENXIO;
 333         SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
 334
 335         sfp->closed = 1;
 336
 337         sdp->exclude = 0;
 338         wake_up_interruptible(&sdp->o_excl_wait);
 339
 340         scsi_autopm_put_device(sdp->device);
 341         kref_put(&sfp->f_ref, sg_remove_sfp);
 342         return 0;
 343 }
 344
 345 static ssize_t
 346 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 347 {
 348         Sg_device *sdp;
 349         Sg_fd *sfp;
 350         Sg_request *srp;
 351         int req_pack_id = -1;
 352         sg_io_hdr_t *hp;
 353         struct sg_header *old_hdr = NULL;
 354         int retval = 0;
 355
 356         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 357                 return -ENXIO;
 358         SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
 359                                    sdp->disk->disk_name, (int) count));
 360
 361         if (!access_ok(VERIFY_WRITE, buf, count))
 362                 return -EFAULT;
 363         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 364                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 365                 if (!old_hdr)
 366                         return -ENOMEM;
 367                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
 368                         retval = -EFAULT;
 369                         goto free_old_hdr;
 370                 }
 371                 if (old_hdr->reply_len < 0) {
 372                         if (count >= SZ_SG_IO_HDR) {
 373                                 sg_io_hdr_t *new_hdr;
 374                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
 375                                 if (!new_hdr) {
 376                                         retval = -ENOMEM;
 377                                         goto free_old_hdr;
 378                                 }
 379                                 retval =__copy_from_user
 380                                     (new_hdr, buf, SZ_SG_IO_HDR);
 381                                 req_pack_id = new_hdr->pack_id;
 382                                 kfree(new_hdr);
 383                                 if (retval) {
 384                                         retval = -EFAULT;
 385                                         goto free_old_hdr;
 386                                 }
 387                         }
 388                 } else
 389                         req_pack_id = old_hdr->pack_id;
 390         }
 391         srp = sg_get_rq_mark(sfp, req_pack_id);
 392         if (!srp) {             /* now wait on packet to arrive */
 393                 if (sdp->detached) {
 394                         retval = -ENODEV;
 395                         goto free_old_hdr;
 396                 }
 397                 if (filp->f_flags & O_NONBLOCK) {
 398                         retval = -EAGAIN;
 399                         goto free_old_hdr;
 400                 }
 401                 while (1) {
 402                         retval = 0; /* following macro beats race condition */
 403                         __wait_event_interruptible(sfp->read_wait,
 404                                 (sdp->detached ||
 405                                 (srp = sg_get_rq_mark(sfp, req_pack_id))),
 406                                 retval);
 407                         if (sdp->detached) {
 408                                 retval = -ENODEV;
 409                                 goto free_old_hdr;
 410                         }
 411                         if (0 == retval)
 412                                 break;
 413
 414                         /* -ERESTARTSYS as signal hit process */
 415                         goto free_old_hdr;
 416                 }
 417         }
 418         if (srp->header.interface_id != '\0') {
 419                 retval = sg_new_read(sfp, buf, count, srp);
 420                 goto free_old_hdr;
 421         }
 422
 423         hp = &srp->header;
 424         if (old_hdr == NULL) {
 425                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 426                 if (! old_hdr) {
 427                         retval = -ENOMEM;
 428                         goto free_old_hdr;
 429                 }
 430         }
 431         memset(old_hdr, 0, SZ_SG_HEADER);
 432         old_hdr->reply_len = (int) hp->timeout;
 433         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 434         old_hdr->pack_id = hp->pack_id;
 435         old_hdr->twelve_byte =
 436             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 437         old_hdr->target_status = hp->masked_status;
 438         old_hdr->host_status = hp->host_status;
 439         old_hdr->driver_status = hp->driver_status;
 440         if ((CHECK_CONDITION & hp->masked_status) ||
 441             (DRIVER_SENSE & hp->driver_status))
 442                 memcpy(old_hdr->sense_buffer, srp->sense_b,
 443                        sizeof (old_hdr->sense_buffer));
 444         switch (hp->host_status) {
 445         /* This setup of 'result' is for backward compatibility and is best
 446            ignored by the user who should use target, host + driver status */
 447         case DID_OK:
 448         case DID_PASSTHROUGH:
 449         case DID_SOFT_ERROR:
 450                 old_hdr->result = 0;
 451                 break;
 452         case DID_NO_CONNECT:
 453         case DID_BUS_BUSY:
 454         case DID_TIME_OUT:
 455                 old_hdr->result = EBUSY;
 456                 break;
 457         case DID_BAD_TARGET:
 458         case DID_ABORT:
 459         case DID_PARITY:
 460         case DID_RESET:
 461         case DID_BAD_INTR:
 462                 old_hdr->result = EIO;
 463                 break;
 464         case DID_ERROR:
 465                 old_hdr->result = (srp->sense_b[0] == 0 &&
 466                                   hp->masked_status == GOOD) ? 0 : EIO;
 467                 break;
 468         default:
 469                 old_hdr->result = EIO;
 470                 break;
 471         }
 472
 473         /* Now copy the result back to the user buffer.  */
 474         if (count >= SZ_SG_HEADER) {
 475                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 476                         retval = -EFAULT;
 477                         goto free_old_hdr;
 478                 }
 479                 buf += SZ_SG_HEADER;
 480                 if (count > old_hdr->reply_len)
 481                         count = old_hdr->reply_len;
 482                 if (count > SZ_SG_HEADER) {
 483                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 484                                 retval = -EFAULT;
 485                                 goto free_old_hdr;
 486                         }
 487                 }
 488         } else
 489                 count = (old_hdr->result == 0) ? 0 : -EIO;
 490         sg_finish_rem_req(srp);
 491         retval = count;
 492 free_old_hdr:
 493         kfree(old_hdr);
 494         return retval;
 495 }
 496
 497 static ssize_t
 498 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 499 {
 500         sg_io_hdr_t *hp = &srp->header;
 501         int err = 0, err2;
 502         int len;
 503
 504         if (count < SZ_SG_IO_HDR) {
 505                 err = -EINVAL;
 506                 goto err_out;
 507         }
 508         hp->sb_len_wr = 0;
 509         if ((hp->mx_sb_len > 0) && hp->sbp) {
 510                 if ((CHECK_CONDITION & hp->masked_status) ||
 511                     (DRIVER_SENSE & hp->driver_status)) {
 512                         int sb_len = SCSI_SENSE_BUFFERSIZE;
 513                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 514                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 515                         len = (len > sb_len) ? sb_len : len;
 516                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 517                                 err = -EFAULT;
 518                                 goto err_out;
 519                         }
 520                         hp->sb_len_wr = len;
 521                 }
 522         }
 523         if (hp->masked_status || hp->host_status || hp->driver_status)
 524                 hp->info |= SG_INFO_CHECK;
 525         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 526                 err = -EFAULT;
 527                 goto err_out;
 528         }
 529 err_out:
 530         err2 = sg_finish_rem_req(srp);
 531         return err ? : err2 ? : count;
 532 }
 533
 534 static ssize_t
 535 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 536 {
 537         int mxsize, cmd_size, k;
 538         int input_size, blocking;
 539         unsigned char opcode;
 540         Sg_device *sdp;
 541         Sg_fd *sfp;
 542         Sg_request *srp;
 543         struct sg_header old_hdr;
 544         sg_io_hdr_t *hp;
 545         unsigned char cmnd[MAX_COMMAND_SIZE];
 546
 547         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 548                 return -ENXIO;
 549         SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
 550                                    sdp->disk->disk_name, (int) count));
 551         if (sdp->detached)
 552                 return -ENODEV;
 553         if (!((filp->f_flags & O_NONBLOCK) ||
 554               scsi_block_when_processing_errors(sdp->device)))
 555                 return -ENXIO;
 556
 557         if (!access_ok(VERIFY_READ, buf, count))
 558                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 559         if (count < SZ_SG_HEADER)
 560                 return -EIO;
 561         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 562                 return -EFAULT;
 563         blocking = !(filp->f_flags & O_NONBLOCK);
 564         if (old_hdr.reply_len < 0)
 565                 return sg_new_write(sfp, filp, buf, count,
 566                                     blocking, 0, 0, NULL);
 567         if (count < (SZ_SG_HEADER + 6))
 568                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 569
 570         if (!(srp = sg_add_request(sfp))) {
 571                 SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
 572                 return -EDOM;
 573         }
 574         buf += SZ_SG_HEADER;
 575         __get_user(opcode, buf);
 576         if (sfp->next_cmd_len > 0) {
 577                 if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
 578                         SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
 579                         sfp->next_cmd_len = 0;
 580                         sg_remove_request(sfp, srp);
 581                         return -EIO;
 582                 }
 583                 cmd_size = sfp->next_cmd_len;
 584                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 585         } else {
 586                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 587                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 588                         cmd_size = 12;
 589         }
 590         SCSI_LOG_TIMEOUT(4, printk(
 591                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 592 /* Determine buffer size.  */
 593         input_size = count - cmd_size;
 594         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 595         mxsize -= SZ_SG_HEADER;
 596         input_size -= SZ_SG_HEADER;
 597         if (input_size < 0) {
 598                 sg_remove_request(sfp, srp);
 599                 return -EIO;    /* User did not pass enough bytes for this command. */
 600         }
 601         hp = &srp->header;
 602         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 603         hp->cmd_len = (unsigned char) cmd_size;
 604         hp->iovec_count = 0;
 605         hp->mx_sb_len = 0;
 606         if (input_size > 0)
 607                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 608                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 609         else
 610                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 611         hp->dxfer_len = mxsize;
 612         if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
 613             (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
 614                 hp->dxferp = (char __user *)buf + cmd_size;
 615         else
 616                 hp->dxferp = NULL;
 617         hp->sbp = NULL;
 618         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 619         hp->flags = input_size; /* structure abuse ... */
 620         hp->pack_id = old_hdr.pack_id;
 621         hp->usr_ptr = NULL;
 622         if (__copy_from_user(cmnd, buf, cmd_size))
 623                 return -EFAULT;
 624         /*
 625          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 626          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 627          * is a non-zero input_size, so emit a warning.
 628          */
 629         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 630                 static char cmd[TASK_COMM_LEN];
 631                 if (strcmp(current->comm, cmd)) {
 632                         printk_ratelimited(KERN_WARNING
 633                                            "sg_write: data in/out %d/%d bytes "
 634                                            "for SCSI command 0x%x-- guessing "
 635                                            "data in;\n   program %s not setting "
 636                                            "count and/or reply_len properly\n",
 637                                            old_hdr.reply_len - (int)SZ_SG_HEADER,
 638                                            input_size, (unsigned int) cmnd[0],
 639                                            current->comm);
 640                         strcpy(cmd, current->comm);
 641                 }
 642         }
 643         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 644         return (k < 0) ? k : count;
 645 }
 646
 647 static ssize_t
 648 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 649                  size_t count, int blocking, int read_only, int sg_io_owned,
 650                  Sg_request **o_srp)
 651 {
 652         int k;
 653         Sg_request *srp;
 654         sg_io_hdr_t *hp;
 655         unsigned char cmnd[MAX_COMMAND_SIZE];
 656         int timeout;
 657         unsigned long ul_timeout;
 658
 659         if (count < SZ_SG_IO_HDR)
 660                 return -EINVAL;
 661         if (!access_ok(VERIFY_READ, buf, count))
 662                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 663
 664         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 665         if (!(srp = sg_add_request(sfp))) {
 666                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
 667                 return -EDOM;
 668         }
 669         srp->sg_io_owned = sg_io_owned;
 670         hp = &srp->header;
 671         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 672                 sg_remove_request(sfp, srp);
 673                 return -EFAULT;
 674         }
 675         if (hp->interface_id != 'S') {
 676                 sg_remove_request(sfp, srp);
 677                 return -ENOSYS;
 678         }
 679         if (hp->flags & SG_FLAG_MMAP_IO) {
 680                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 681                         sg_remove_request(sfp, srp);
 682                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 683                 }
 684                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 685                         sg_remove_request(sfp, srp);
 686                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 687                 }
 688                 if (sg_res_in_use(sfp)) {
 689                         sg_remove_request(sfp, srp);
 690                         return -EBUSY;  /* reserve buffer already being used */
 691                 }
 692         }
 693         ul_timeout = msecs_to_jiffies(srp->header.timeout);
 694         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 695         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 696                 sg_remove_request(sfp, srp);
 697                 return -EMSGSIZE;
 698         }
 699         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
 700                 sg_remove_request(sfp, srp);
 701                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 702         }
 703         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 704                 sg_remove_request(sfp, srp);
 705                 return -EFAULT;
 706         }
 707         if (read_only && sg_allow_access(file, cmnd)) {
 708                 sg_remove_request(sfp, srp);
 709                 return -EPERM;
 710         }
 711         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 712         if (k < 0)
 713                 return k;
 714         if (o_srp)
 715                 *o_srp = srp;
 716         return count;
 717 }
 718
 719 static int
 720 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 721                 unsigned char *cmnd, int timeout, int blocking)
 722 {
 723         int k, data_dir;
 724         Sg_device *sdp = sfp->parentdp;
 725         sg_io_hdr_t *hp = &srp->header;
 726
 727         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 728         hp->status = 0;
 729         hp->masked_status = 0;
 730         hp->msg_status = 0;
 731         hp->info = 0;
 732         hp->host_status = 0;
 733         hp->driver_status = 0;
 734         hp->resid = 0;
 735         SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 736                           (int) cmnd[0], (int) hp->cmd_len));
 737
 738         k = sg_start_req(srp, cmnd);
 739         if (k) {
 740                 SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k));
 741                 sg_finish_rem_req(srp);
 742                 return k;       /* probably out of space --> ENOMEM */
 743         }
 744         if (sdp->detached) {
 745                 if (srp->bio)
 746                         blk_end_request_all(srp->rq, -EIO);
 747                 sg_finish_rem_req(srp);
 748                 return -ENODEV;
 749         }
 750
 751         switch (hp->dxfer_direction) {
 752         case SG_DXFER_TO_FROM_DEV:
 753         case SG_DXFER_FROM_DEV:
 754                 data_dir = DMA_FROM_DEVICE;
 755                 break;
 756         case SG_DXFER_TO_DEV:
 757                 data_dir = DMA_TO_DEVICE;
 758                 break;
 759         case SG_DXFER_UNKNOWN:
 760                 data_dir = DMA_BIDIRECTIONAL;
 761                 break;
 762         default:
 763                 data_dir = DMA_NONE;
 764                 break;
 765         }
 766         hp->duration = jiffies_to_msecs(jiffies);
 767
 768         srp->rq->timeout = timeout;
 769         kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
 770         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 771                               srp->rq, 1, sg_rq_end_io);
 772         return 0;
 773 }
 774
 775 static int
 776 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 777 {
 778         void __user *p = (void __user *)arg;
 779         int __user *ip = p;
 780         int result, val, read_only;
 781         Sg_device *sdp;
 782         Sg_fd *sfp;
 783         Sg_request *srp;
 784         unsigned long iflags;
 785
 786         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 787                 return -ENXIO;
 788
 789         SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
 790                                    sdp->disk->disk_name, (int) cmd_in));
 791         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 792
 793         switch (cmd_in) {
 794         case SG_IO:
 795                 {
 796                         int blocking = 1;       /* ignore O_NONBLOCK flag */
 797
 798                         if (sdp->detached)
 799                                 return -ENODEV;
 800                         if (!scsi_block_when_processing_errors(sdp->device))
 801                                 return -ENXIO;
 802                         if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 803                                 return -EFAULT;
 804                         result =
 805                             sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 806                                          blocking, read_only, 1, &srp);
 807                         if (result < 0)
 808                                 return result;
 809                         while (1) {
 810                                 result = 0;     /* following macro to beat race condition */
 811                                 __wait_event_interruptible(sfp->read_wait,
 812                                         (srp->done || sdp->detached),
 813                                         result);
 814                                 if (sdp->detached)
 815                                         return -ENODEV;
 816                                 write_lock_irq(&sfp->rq_list_lock);
 817                                 if (srp->done) {
 818                                         srp->done = 2;
 819                                         write_unlock_irq(&sfp->rq_list_lock);
 820                                         break;
 821                                 }
 822                                 srp->orphan = 1;
 823                                 write_unlock_irq(&sfp->rq_list_lock);
 824                                 return result;  /* -ERESTARTSYS because signal hit process */
 825                         }
 826                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 827                         return (result < 0) ? result : 0;
 828                 }
 829         case SG_SET_TIMEOUT:
 830                 result = get_user(val, ip);
 831                 if (result)
 832                         return result;
 833                 if (val < 0)
 834                         return -EIO;
 835                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
 836                     val = MULDIV (INT_MAX, USER_HZ, HZ);
 837                 sfp->timeout_user = val;
 838                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
 839
 840                 return 0;
 841         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 842                                 /* strange ..., for backward compatibility */
 843                 return sfp->timeout_user;
 844         case SG_SET_FORCE_LOW_DMA:
 845                 result = get_user(val, ip);
 846                 if (result)
 847                         return result;
 848                 if (val) {
 849                         sfp->low_dma = 1;
 850                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
 851                                 val = (int) sfp->reserve.bufflen;
 852                                 sg_remove_scat(&sfp->reserve);
 853                                 sg_build_reserve(sfp, val);
 854                         }
 855                 } else {
 856                         if (sdp->detached)
 857                                 return -ENODEV;
 858                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
 859                 }
 860                 return 0;
 861         case SG_GET_LOW_DMA:
 862                 return put_user((int) sfp->low_dma, ip);
 863         case SG_GET_SCSI_ID:
 864                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 865                         return -EFAULT;
 866                 else {
 867                         sg_scsi_id_t __user *sg_idp = p;
 868
 869                         if (sdp->detached)
 870                                 return -ENODEV;
 871                         __put_user((int) sdp->device->host->host_no,
 872                                    &sg_idp->host_no);
 873                         __put_user((int) sdp->device->channel,
 874                                    &sg_idp->channel);
 875                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 876                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 877                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 878                         __put_user((short) sdp->device->host->cmd_per_lun,
 879                                    &sg_idp->h_cmd_per_lun);
 880                         __put_user((short) sdp->device->queue_depth,
 881                                    &sg_idp->d_queue_depth);
 882                         __put_user(0, &sg_idp->unused[0]);
 883                         __put_user(0, &sg_idp->unused[1]);
 884                         return 0;
 885                 }
 886         case SG_SET_FORCE_PACK_ID:
 887                 result = get_user(val, ip);
 888                 if (result)
 889                         return result;
 890                 sfp->force_packid = val ? 1 : 0;
 891                 return 0;
 892         case SG_GET_PACK_ID:
 893                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 894                         return -EFAULT;
 895                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 896                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
 897                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 898                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 899                                                        iflags);
 900                                 __put_user(srp->header.pack_id, ip);
 901                                 return 0;
 902                         }
 903                 }
 904                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 905                 __put_user(-1, ip);
 906                 return 0;
 907         case SG_GET_NUM_WAITING:
 908                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 909                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
 910                         if ((1 == srp->done) && (!srp->sg_io_owned))
 911                                 ++val;
 912                 }
 913                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 914                 return put_user(val, ip);
 915         case SG_GET_SG_TABLESIZE:
 916                 return put_user(sdp->sg_tablesize, ip);
 917         case SG_SET_RESERVED_SIZE:
 918                 result = get_user(val, ip);
 919                 if (result)
 920                         return result;
 921                 if (val < 0)
 922                         return -EINVAL;
 923                 val = min_t(int, val,
 924                             queue_max_sectors(sdp->device->request_queue) * 512);
 925                 if (val != sfp->reserve.bufflen) {
 926                         if (sg_res_in_use(sfp) || sfp->mmap_called)
 927                                 return -EBUSY;
 928                         sg_remove_scat(&sfp->reserve);
 929                         sg_build_reserve(sfp, val);
 930                 }
 931                 return 0;
 932         case SG_GET_RESERVED_SIZE:
 933                 val = min_t(int, sfp->reserve.bufflen,
 934                             queue_max_sectors(sdp->device->request_queue) * 512);
 935                 return put_user(val, ip);
 936         case SG_SET_COMMAND_Q:
 937                 result = get_user(val, ip);
 938                 if (result)
 939                         return result;
 940                 sfp->cmd_q = val ? 1 : 0;
 941                 return 0;
 942         case SG_GET_COMMAND_Q:
 943                 return put_user((int) sfp->cmd_q, ip);
 944         case SG_SET_KEEP_ORPHAN:
 945                 result = get_user(val, ip);
 946                 if (result)
 947                         return result;
 948                 sfp->keep_orphan = val;
 949                 return 0;
 950         case SG_GET_KEEP_ORPHAN:
 951                 return put_user((int) sfp->keep_orphan, ip);
 952         case SG_NEXT_CMD_LEN:
 953                 result = get_user(val, ip);
 954                 if (result)
 955                         return result;
 956                 sfp->next_cmd_len = (val > 0) ? val : 0;
 957                 return 0;
 958         case SG_GET_VERSION_NUM:
 959                 return put_user(sg_version_num, ip);
 960         case SG_GET_ACCESS_COUNT:
 961                 /* faked - we don't have a real access count anymore */
 962                 val = (sdp->device ? 1 : 0);
 963                 return put_user(val, ip);
 964         case SG_GET_REQUEST_TABLE:
 965                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
 966                         return -EFAULT;
 967                 else {
 968                         sg_req_info_t *rinfo;
 969                         unsigned int ms;
 970
 971                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
 972                                                                 GFP_KERNEL);
 973                         if (!rinfo)
 974                                 return -ENOMEM;
 975                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 976                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
 977                              ++val, srp = srp ? srp->nextrp : srp) {
 978                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
 979                                 if (srp) {
 980                                         rinfo[val].req_state = srp->done + 1;
 981                                         rinfo[val].problem =
 982                                             srp->header.masked_status &
 983                                             srp->header.host_status &
 984                                             srp->header.driver_status;
 985                                         if (srp->done)
 986                                                 rinfo[val].duration =
 987                                                         srp->header.duration;
 988                                         else {
 989                                                 ms = jiffies_to_msecs(jiffies);
 990                                                 rinfo[val].duration =
 991                                                     (ms > srp->header.duration) ?
 992                                                     (ms - srp->header.duration) : 0;
 993                                         }
 994                                         rinfo[val].orphan = srp->orphan;
 995                                         rinfo[val].sg_io_owned =
 996                                                         srp->sg_io_owned;
 997                                         rinfo[val].pack_id =
 998                                                         srp->header.pack_id;
 999                                         rinfo[val].usr_ptr =
1000                                                         srp->header.usr_ptr;
1001                                 }
1002                         }
1003                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1004                         result = __copy_to_user(p, rinfo,
1005                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1006                         result = result ? -EFAULT : 0;
1007                         kfree(rinfo);
1008                         return result;
1009                 }
1010         case SG_EMULATED_HOST:
1011                 if (sdp->detached)
1012                         return -ENODEV;
1013                 return put_user(sdp->device->host->hostt->emulated, ip);
1014         case SG_SCSI_RESET:
1015                 if (sdp->detached)
1016                         return -ENODEV;
1017                 if (filp->f_flags & O_NONBLOCK) {
1018                         if (scsi_host_in_recovery(sdp->device->host))
1019                                 return -EBUSY;
1020                 } else if (!scsi_block_when_processing_errors(sdp->device))
1021                         return -EBUSY;
1022                 result = get_user(val, ip);
1023                 if (result)
1024                         return result;
1025                 if (SG_SCSI_RESET_NOTHING == val)
1026                         return 0;
1027                 switch (val) {
1028                 case SG_SCSI_RESET_DEVICE:
1029                         val = SCSI_TRY_RESET_DEVICE;
1030                         break;
1031                 case SG_SCSI_RESET_TARGET:
1032                         val = SCSI_TRY_RESET_TARGET;
1033                         break;
1034                 case SG_SCSI_RESET_BUS:
1035                         val = SCSI_TRY_RESET_BUS;
1036                         break;
1037                 case SG_SCSI_RESET_HOST:
1038                         val = SCSI_TRY_RESET_HOST;
1039                         break;
1040                 default:
1041                         return -EINVAL;
1042                 }
1043                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1044                         return -EACCES;
1045                 return (scsi_reset_provider(sdp->device, val) ==
1046                         SUCCESS) ? 0 : -EIO;
1047         case SCSI_IOCTL_SEND_COMMAND:
1048                 if (sdp->detached)
1049                         return -ENODEV;
1050                 if (read_only) {
1051                         unsigned char opcode = WRITE_6;
1052                         Scsi_Ioctl_Command __user *siocp = p;
1053
1054                         if (copy_from_user(&opcode, siocp->data, 1))
1055                                 return -EFAULT;
1056                         if (sg_allow_access(filp, &opcode))
1057                                 return -EPERM;
1058                 }
1059                 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1060         case SG_SET_DEBUG:
1061                 result = get_user(val, ip);
1062                 if (result)
1063                         return result;
1064                 sdp->sgdebug = (char) val;
1065                 return 0;
1066         case SCSI_IOCTL_GET_IDLUN:
1067         case SCSI_IOCTL_GET_BUS_NUMBER:
1068         case SCSI_IOCTL_PROBE_HOST:
1069         case SG_GET_TRANSFORM:
1070                 if (sdp->detached)
1071                         return -ENODEV;
1072                 return scsi_ioctl(sdp->device, cmd_in, p);
1073         case BLKSECTGET:
1074                 return put_user(queue_max_sectors(sdp->device->request_queue) * 512,
1075                                 ip);
1076         case BLKTRACESETUP:
1077                 return blk_trace_setup(sdp->device->request_queue,
1078                                        sdp->disk->disk_name,
1079                                        MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1080                                        NULL,
1081                                        (char *)arg);
1082         case BLKTRACESTART:
1083                 return blk_trace_startstop(sdp->device->request_queue, 1);
1084         case BLKTRACESTOP:
1085                 return blk_trace_startstop(sdp->device->request_queue, 0);
1086         case BLKTRACETEARDOWN:
1087                 return blk_trace_remove(sdp->device->request_queue);
1088         default:
1089                 if (read_only)
1090                         return -EPERM;  /* don't know so take safe approach */
1091                 return scsi_ioctl(sdp->device, cmd_in, p);
1092         }
1093 }
1094
1095 static long
1096 sg_unlocked_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1097 {
1098         int ret;
1099
1100         mutex_lock(&sg_mutex);
1101         ret = sg_ioctl(filp, cmd_in, arg);
1102         mutex_unlock(&sg_mutex);
1103
1104         return ret;
1105 }
1106
1107 #ifdef CONFIG_COMPAT
1108 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1109 {
1110         Sg_device *sdp;
1111         Sg_fd *sfp;
1112         struct scsi_device *sdev;
1113
1114         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1115                 return -ENXIO;
1116
1117         sdev = sdp->device;
1118         if (sdev->host->hostt->compat_ioctl) {
1119                 int ret;
1120
1121                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1122
1123                 return ret;
1124         }
1125
1126         return -ENOIOCTLCMD;
1127 }
1128 #endif
1129
1130 static unsigned int
1131 sg_poll(struct file *filp, poll_table * wait)
1132 {
1133         unsigned int res = 0;
1134         Sg_device *sdp;
1135         Sg_fd *sfp;
1136         Sg_request *srp;
1137         int count = 0;
1138         unsigned long iflags;
1139
1140         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1141             || sfp->closed)
1142                 return POLLERR;
1143         poll_wait(filp, &sfp->read_wait, wait);
1144         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1145         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1146                 /* if any read waiting, flag it */
1147                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1148                         res = POLLIN | POLLRDNORM;
1149                 ++count;
1150         }
1151         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1152
1153         if (sdp->detached)
1154                 res |= POLLHUP;
1155         else if (!sfp->cmd_q) {
1156                 if (0 == count)
1157                         res |= POLLOUT | POLLWRNORM;
1158         } else if (count < SG_MAX_QUEUE)
1159                 res |= POLLOUT | POLLWRNORM;
1160         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1161                                    sdp->disk->disk_name, (int) res));
1162         return res;
1163 }
1164
1165 static int
1166 sg_fasync(int fd, struct file *filp, int mode)
1167 {
1168         Sg_device *sdp;
1169         Sg_fd *sfp;
1170
1171         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1172                 return -ENXIO;
1173         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1174                                    sdp->disk->disk_name, mode));
1175
1176         return fasync_helper(fd, filp, mode, &sfp->async_qp);
1177 }
1178
1179 static int
1180 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1181 {
1182         Sg_fd *sfp;
1183         unsigned long offset, len, sa;
1184         Sg_scatter_hold *rsv_schp;
1185         int k, length;
1186
1187         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1188                 return VM_FAULT_SIGBUS;
1189         rsv_schp = &sfp->reserve;
1190         offset = vmf->pgoff << PAGE_SHIFT;
1191         if (offset >= rsv_schp->bufflen)
1192                 return VM_FAULT_SIGBUS;
1193         SCSI_LOG_TIMEOUT(3, printk("sg_vma_fault: offset=%lu, scatg=%d\n",
1194                                    offset, rsv_schp->k_use_sg));
1195         sa = vma->vm_start;
1196         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1197         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1198                 len = vma->vm_end - sa;
1199                 len = (len < length) ? len : length;
1200                 if (offset < len) {
1201                         struct page *page = nth_page(rsv_schp->pages[k],
1202                                                      offset >> PAGE_SHIFT);
1203                         get_page(page); /* increment page count */
1204                         vmf->page = page;
1205                         return 0; /* success */
1206                 }
1207                 sa += len;
1208                 offset -= len;
1209         }
1210
1211         return VM_FAULT_SIGBUS;
1212 }
1213
1214 static const struct vm_operations_struct sg_mmap_vm_ops = {
1215         .fault = sg_vma_fault,
1216 };
1217
1218 static int
1219 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1220 {
1221         Sg_fd *sfp;
1222         unsigned long req_sz, len, sa;
1223         Sg_scatter_hold *rsv_schp;
1224         int k, length;
1225
1226         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1227                 return -ENXIO;
1228         req_sz = vma->vm_end - vma->vm_start;
1229         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1230                                    (void *) vma->vm_start, (int) req_sz));
1231         if (vma->vm_pgoff)
1232                 return -EINVAL; /* want no offset */
1233         rsv_schp = &sfp->reserve;
1234         if (req_sz > rsv_schp->bufflen)
1235                 return -ENOMEM; /* cannot map more than reserved buffer */
1236
1237         sa = vma->vm_start;
1238         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1239         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1240                 len = vma->vm_end - sa;
1241                 len = (len < length) ? len : length;
1242                 sa += len;
1243         }
1244
1245         sfp->mmap_called = 1;
1246         vma->vm_flags |= VM_RESERVED;
1247         vma->vm_private_data = sfp;
1248         vma->vm_ops = &sg_mmap_vm_ops;
1249         return 0;
1250 }
1251
1252 static void sg_rq_end_io_usercontext(struct work_struct *work)
1253 {
1254         struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1255         struct sg_fd *sfp = srp->parentfp;
1256
1257         sg_finish_rem_req(srp);
1258         kref_put(&sfp->f_ref, sg_remove_sfp);
1259 }
1260
1261 /*
1262  * This function is a "bottom half" handler that is called by the mid
1263  * level when a command is completed (or has failed).
1264  */
1265 static void sg_rq_end_io(struct request *rq, int uptodate)
1266 {
1267         struct sg_request *srp = rq->end_io_data;
1268         Sg_device *sdp;
1269         Sg_fd *sfp;
1270         unsigned long iflags;
1271         unsigned int ms;
1272         char *sense;
1273         int result, resid, done = 1;
1274
1275         if (WARN_ON(srp->done != 0))
1276                 return;
1277
1278         sfp = srp->parentfp;
1279         if (WARN_ON(sfp == NULL))
1280                 return;
1281
1282         sdp = sfp->parentdp;
1283         if (unlikely(sdp->detached))
1284                 printk(KERN_INFO "sg_rq_end_io: device detached\n");
1285
1286         sense = rq->sense;
1287         result = rq->errors;
1288         resid = rq->resid_len;
1289
1290         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1291                 sdp->disk->disk_name, srp->header.pack_id, result));
1292         srp->header.resid = resid;
1293         ms = jiffies_to_msecs(jiffies);
1294         srp->header.duration = (ms > srp->header.duration) ?
1295                                 (ms - srp->header.duration) : 0;
1296         if (0 != result) {
1297                 struct scsi_sense_hdr sshdr;
1298
1299                 srp->header.status = 0xff & result;
1300                 srp->header.masked_status = status_byte(result);
1301                 srp->header.msg_status = msg_byte(result);
1302                 srp->header.host_status = host_byte(result);
1303                 srp->header.driver_status = driver_byte(result);
1304                 if ((sdp->sgdebug > 0) &&
1305                     ((CHECK_CONDITION == srp->header.masked_status) ||
1306                      (COMMAND_TERMINATED == srp->header.masked_status)))
1307                         __scsi_print_sense("sg_cmd_done", sense,
1308                                            SCSI_SENSE_BUFFERSIZE);
1309
1310                 /* Following if statement is a patch supplied by Eric Youngdale */
1311                 if (driver_byte(result) != 0
1312                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1313                     && !scsi_sense_is_deferred(&sshdr)
1314                     && sshdr.sense_key == UNIT_ATTENTION
1315                     && sdp->device->removable) {
1316                         /* Detected possible disc change. Set the bit - this */
1317                         /* may be used if there are filesystems using this device */
1318                         sdp->device->changed = 1;
1319                 }
1320         }
1321         /* Rely on write phase to clean out srp status values, so no "else" */
1322
1323         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1324         if (unlikely(srp->orphan)) {
1325                 if (sfp->keep_orphan)
1326                         srp->sg_io_owned = 0;
1327                 else
1328                         done = 0;
1329         }
1330         srp->done = done;
1331         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1332
1333         if (likely(done)) {
1334                 /* Now wake up any sg_read() that is waiting for this
1335                  * packet.
1336                  */
1337                 wake_up_interruptible(&sfp->read_wait);
1338                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1339                 kref_put(&sfp->f_ref, sg_remove_sfp);
1340         } else {
1341                 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1342                 schedule_work(&srp->ew.work);
1343         }
1344 }
1345
1346 static const struct file_operations sg_fops = {
1347         .owner = THIS_MODULE,
1348         .read = sg_read,
1349         .write = sg_write,
1350         .poll = sg_poll,
1351         .unlocked_ioctl = sg_unlocked_ioctl,
1352 #ifdef CONFIG_COMPAT
1353         .compat_ioctl = sg_compat_ioctl,
1354 #endif
1355         .open = sg_open,
1356         .mmap = sg_mmap,
1357         .release = sg_release,
1358         .fasync = sg_fasync,
1359         .llseek = no_llseek,
1360 };
1361
1362 static struct class *sg_sysfs_class;
1363
1364 static int sg_sysfs_valid = 0;
1365
1366 static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1367 {
1368         struct request_queue *q = scsidp->request_queue;
1369         Sg_device *sdp;
1370         unsigned long iflags;
1371         int error;
1372         u32 k;
1373
1374         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1375         if (!sdp) {
1376                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1377                 return ERR_PTR(-ENOMEM);
1378         }
1379
1380         if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) {
1381                 printk(KERN_WARNING "idr expansion Sg_device failure\n");
1382                 error = -ENOMEM;
1383                 goto out;
1384         }
1385
1386         write_lock_irqsave(&sg_index_lock, iflags);
1387
1388         error = idr_get_new(&sg_index_idr, sdp, &k);
1389         if (error) {
1390                 write_unlock_irqrestore(&sg_index_lock, iflags);
1391                 printk(KERN_WARNING "idr allocation Sg_device failure: %d\n",
1392                        error);
1393                 goto out;
1394         }
1395
1396         if (unlikely(k >= SG_MAX_DEVS))
1397                 goto overflow;
1398
1399         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1400         sprintf(disk->disk_name, "sg%d", k);
1401         disk->first_minor = k;
1402         sdp->disk = disk;
1403         sdp->device = scsidp;
1404         INIT_LIST_HEAD(&sdp->sfds);
1405         init_waitqueue_head(&sdp->o_excl_wait);
1406         sdp->sg_tablesize = queue_max_segments(q);
1407         sdp->index = k;
1408         kref_init(&sdp->d_ref);
1409
1410         write_unlock_irqrestore(&sg_index_lock, iflags);
1411
1412         error = 0;
1413  out:
1414         if (error) {
1415                 kfree(sdp);
1416                 return ERR_PTR(error);
1417         }
1418         return sdp;
1419
1420  overflow:
1421         idr_remove(&sg_index_idr, k);
1422         write_unlock_irqrestore(&sg_index_lock, iflags);
1423         sdev_printk(KERN_WARNING, scsidp,
1424                     "Unable to attach sg device type=%d, minor "
1425                     "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1426         error = -ENODEV;
1427         goto out;
1428 }
1429
1430 static int
1431 sg_add(struct device *cl_dev, struct class_interface *cl_intf)
1432 {
1433         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1434         struct gendisk *disk;
1435         Sg_device *sdp = NULL;
1436         struct cdev * cdev = NULL;
1437         int error;
1438         unsigned long iflags;
1439
1440         disk = alloc_disk(1);
1441         if (!disk) {
1442                 printk(KERN_WARNING "alloc_disk failed\n");
1443                 return -ENOMEM;
1444         }
1445         disk->major = SCSI_GENERIC_MAJOR;
1446
1447         error = -ENOMEM;
1448         cdev = cdev_alloc();
1449         if (!cdev) {
1450                 printk(KERN_WARNING "cdev_alloc failed\n");
1451                 goto out;
1452         }
1453         cdev->owner = THIS_MODULE;
1454         cdev->ops = &sg_fops;
1455
1456         sdp = sg_alloc(disk, scsidp);
1457         if (IS_ERR(sdp)) {
1458                 printk(KERN_WARNING "sg_alloc failed\n");
1459                 error = PTR_ERR(sdp);
1460                 goto out;
1461         }
1462
1463         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1464         if (error)
1465                 goto cdev_add_err;
1466
1467         sdp->cdev = cdev;
1468         if (sg_sysfs_valid) {
1469                 struct device *sg_class_member;
1470
1471                 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1472                                                 MKDEV(SCSI_GENERIC_MAJOR,
1473                                                       sdp->index),
1474                                                 sdp, "%s", disk->disk_name);
1475                 if (IS_ERR(sg_class_member)) {
1476                         printk(KERN_ERR "sg_add: "
1477                                "device_create failed\n");
1478                         error = PTR_ERR(sg_class_member);
1479                         goto cdev_add_err;
1480                 }
1481                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1482                                           &sg_class_member->kobj, "generic");
1483                 if (error)
1484                         printk(KERN_ERR "sg_add: unable to make symlink "
1485                                         "'generic' back to sg%d\n", sdp->index);
1486         } else
1487                 printk(KERN_WARNING "sg_add: sg_sys Invalid\n");
1488
1489         sdev_printk(KERN_NOTICE, scsidp,
1490                     "Attached scsi generic sg%d type %d\n", sdp->index,
1491                     scsidp->type);
1492
1493         dev_set_drvdata(cl_dev, sdp);
1494
1495         return 0;
1496
1497 cdev_add_err:
1498         write_lock_irqsave(&sg_index_lock, iflags);
1499         idr_remove(&sg_index_idr, sdp->index);
1500         write_unlock_irqrestore(&sg_index_lock, iflags);
1501         kfree(sdp);
1502
1503 out:
1504         put_disk(disk);
1505         if (cdev)
1506                 cdev_del(cdev);
1507         return error;
1508 }
1509
1510 static void sg_device_destroy(struct kref *kref)
1511 {
1512         struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1513         unsigned long flags;
1514
1515         /* CAUTION!  Note that the device can still be found via idr_find()
1516          * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1517          * any other cleanup.
1518          */
1519
1520         write_lock_irqsave(&sg_index_lock, flags);
1521         idr_remove(&sg_index_idr, sdp->index);
1522         write_unlock_irqrestore(&sg_index_lock, flags);
1523
1524         SCSI_LOG_TIMEOUT(3,
1525                 printk("sg_device_destroy: %s\n",
1526                         sdp->disk->disk_name));
1527
1528         put_disk(sdp->disk);
1529         kfree(sdp);
1530 }
1531
1532 static void sg_remove(struct device *cl_dev, struct class_interface *cl_intf)
1533 {
1534         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1535         Sg_device *sdp = dev_get_drvdata(cl_dev);
1536         unsigned long iflags;
1537         Sg_fd *sfp;
1538
1539         if (!sdp || sdp->detached)
1540                 return;
1541
1542         SCSI_LOG_TIMEOUT(3, printk("sg_remove: %s\n", sdp->disk->disk_name));
1543
1544         /* Need a write lock to set sdp->detached. */
1545         write_lock_irqsave(&sg_index_lock, iflags);
1546         sdp->detached = 1;
1547         list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1548                 wake_up_interruptible(&sfp->read_wait);
1549                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1550         }
1551         write_unlock_irqrestore(&sg_index_lock, iflags);
1552
1553         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1554         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1555         cdev_del(sdp->cdev);
1556         sdp->cdev = NULL;
1557
1558         sg_put_dev(sdp);
1559 }
1560
1561 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1562 module_param_named(def_reserved_size, def_reserved_size, int,
1563                    S_IRUGO | S_IWUSR);
1564 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1565
1566 MODULE_AUTHOR("Douglas Gilbert");
1567 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1568 MODULE_LICENSE("GPL");
1569 MODULE_VERSION(SG_VERSION_STR);
1570 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1571
1572 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1573                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1574 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1575 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1576
1577 static int __init
1578 init_sg(void)
1579 {
1580         int rc;
1581
1582         if (scatter_elem_sz < PAGE_SIZE) {
1583                 scatter_elem_sz = PAGE_SIZE;
1584                 scatter_elem_sz_prev = scatter_elem_sz;
1585         }
1586         if (def_reserved_size >= 0)
1587                 sg_big_buff = def_reserved_size;
1588         else
1589                 def_reserved_size = sg_big_buff;
1590
1591         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1592                                     SG_MAX_DEVS, "sg");
1593         if (rc)
1594                 return rc;
1595         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1596         if ( IS_ERR(sg_sysfs_class) ) {
1597                 rc = PTR_ERR(sg_sysfs_class);
1598                 goto err_out;
1599         }
1600         sg_sysfs_valid = 1;
1601         rc = scsi_register_interface(&sg_interface);
1602         if (0 == rc) {
1603 #ifdef CONFIG_SCSI_PROC_FS
1604                 sg_proc_init();
1605 #endif                          /* CONFIG_SCSI_PROC_FS */
1606                 return 0;
1607         }
1608         class_destroy(sg_sysfs_class);
1609 err_out:
1610         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1611         return rc;
1612 }
1613
1614 static void __exit
1615 exit_sg(void)
1616 {
1617 #ifdef CONFIG_SCSI_PROC_FS
1618         sg_proc_cleanup();
1619 #endif                          /* CONFIG_SCSI_PROC_FS */
1620         scsi_unregister_interface(&sg_interface);
1621         class_destroy(sg_sysfs_class);
1622         sg_sysfs_valid = 0;
1623         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1624                                  SG_MAX_DEVS);
1625         idr_destroy(&sg_index_idr);
1626 }
1627
1628 static int sg_start_req(Sg_request *srp, unsigned char *cmd)
1629 {
1630         int res;
1631         struct request *rq;
1632         Sg_fd *sfp = srp->parentfp;
1633         sg_io_hdr_t *hp = &srp->header;
1634         int dxfer_len = (int) hp->dxfer_len;
1635         int dxfer_dir = hp->dxfer_direction;
1636         unsigned int iov_count = hp->iovec_count;
1637         Sg_scatter_hold *req_schp = &srp->data;
1638         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1639         struct request_queue *q = sfp->parentdp->device->request_queue;
1640         struct rq_map_data *md, map_data;
1641         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1642
1643         SCSI_LOG_TIMEOUT(4, printk(KERN_INFO "sg_start_req: dxfer_len=%d\n",
1644                                    dxfer_len));
1645
1646         rq = blk_get_request(q, rw, GFP_ATOMIC);
1647         if (!rq)
1648                 return -ENOMEM;
1649
1650         memcpy(rq->cmd, cmd, hp->cmd_len);
1651
1652         rq->cmd_len = hp->cmd_len;
1653         rq->cmd_type = REQ_TYPE_BLOCK_PC;
1654
1655         srp->rq = rq;
1656         rq->end_io_data = srp;
1657         rq->sense = srp->sense_b;
1658         rq->retries = SG_DEFAULT_RETRIES;
1659
1660         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1661                 return 0;
1662
1663         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1664             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1665             !sfp->parentdp->device->host->unchecked_isa_dma &&
1666             blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1667                 md = NULL;
1668         else
1669                 md = &map_data;
1670
1671         if (md) {
1672                 if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
1673                         sg_link_reserve(sfp, srp, dxfer_len);
1674                 else {
1675                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1676                         if (res)
1677                                 return res;
1678                 }
1679
1680                 md->pages = req_schp->pages;
1681                 md->page_order = req_schp->page_order;
1682                 md->nr_entries = req_schp->k_use_sg;
1683                 md->offset = 0;
1684                 md->null_mapped = hp->dxferp ? 0 : 1;
1685                 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1686                         md->from_user = 1;
1687                 else
1688                         md->from_user = 0;
1689         }
1690
1691         if (unlikely(iov_count > UIO_MAXIOV))
1692                 return -EINVAL;
1693
1694         if (iov_count) {
1695                 int len, size = sizeof(struct sg_iovec) * iov_count;
1696                 struct iovec *iov;
1697
1698                 iov = memdup_user(hp->dxferp, size);
1699                 if (IS_ERR(iov))
1700                         return PTR_ERR(iov);
1701
1702                 len = iov_length(iov, iov_count);
1703                 if (hp->dxfer_len < len) {
1704                         iov_count = iov_shorten(iov, iov_count, hp->dxfer_len);
1705                         len = hp->dxfer_len;
1706                 }
1707
1708                 res = blk_rq_map_user_iov(q, rq, md, (struct sg_iovec *)iov,
1709                                           iov_count,
1710                                           len, GFP_ATOMIC);
1711                 kfree(iov);
1712         } else
1713                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1714                                       hp->dxfer_len, GFP_ATOMIC);
1715
1716         if (!res) {
1717                 srp->bio = rq->bio;
1718
1719                 if (!md) {
1720                         req_schp->dio_in_use = 1;
1721                         hp->info |= SG_INFO_DIRECT_IO;
1722                 }
1723         }
1724         return res;
1725 }
1726
1727 static int sg_finish_rem_req(Sg_request * srp)
1728 {
1729         int ret = 0;
1730
1731         Sg_fd *sfp = srp->parentfp;
1732         Sg_scatter_hold *req_schp = &srp->data;
1733
1734         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1735         if (srp->rq) {
1736                 if (srp->bio)
1737                         ret = blk_rq_unmap_user(srp->bio);
1738
1739                 blk_put_request(srp->rq);
1740         }
1741
1742         if (srp->res_used)
1743                 sg_unlink_reserve(sfp, srp);
1744         else
1745                 sg_remove_scat(req_schp);
1746
1747         sg_remove_request(sfp, srp);
1748
1749         return ret;
1750 }
1751
1752 static int
1753 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1754 {
1755         int sg_bufflen = tablesize * sizeof(struct page *);
1756         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1757
1758         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1759         if (!schp->pages)
1760                 return -ENOMEM;
1761         schp->sglist_len = sg_bufflen;
1762         return tablesize;       /* number of scat_gath elements allocated */
1763 }
1764
1765 static int
1766 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1767 {
1768         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1769         int sg_tablesize = sfp->parentdp->sg_tablesize;
1770         int blk_size = buff_size, order;
1771         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1772
1773         if (blk_size < 0)
1774                 return -EFAULT;
1775         if (0 == blk_size)
1776                 ++blk_size;     /* don't know why */
1777         /* round request up to next highest SG_SECTOR_SZ byte boundary */
1778         blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1779         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1780                                    buff_size, blk_size));
1781
1782         /* N.B. ret_sz carried into this block ... */
1783         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1784         if (mx_sc_elems < 0)
1785                 return mx_sc_elems;     /* most likely -ENOMEM */
1786
1787         num = scatter_elem_sz;
1788         if (unlikely(num != scatter_elem_sz_prev)) {
1789                 if (num < PAGE_SIZE) {
1790                         scatter_elem_sz = PAGE_SIZE;
1791                         scatter_elem_sz_prev = PAGE_SIZE;
1792                 } else
1793                         scatter_elem_sz_prev = num;
1794         }
1795
1796         if (sfp->low_dma)
1797                 gfp_mask |= GFP_DMA;
1798
1799         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1800                 gfp_mask |= __GFP_ZERO;
1801
1802         order = get_order(num);
1803 retry:
1804         ret_sz = 1 << (PAGE_SHIFT + order);
1805
1806         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1807              k++, rem_sz -= ret_sz) {
1808
1809                 num = (rem_sz > scatter_elem_sz_prev) ?
1810                         scatter_elem_sz_prev : rem_sz;
1811
1812                 schp->pages[k] = alloc_pages(gfp_mask, order);
1813                 if (!schp->pages[k])
1814                         goto out;
1815
1816                 if (num == scatter_elem_sz_prev) {
1817                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1818                                 scatter_elem_sz = ret_sz;
1819                                 scatter_elem_sz_prev = ret_sz;
1820                         }
1821                 }
1822
1823                 SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
1824                                  "ret_sz=%d\n", k, num, ret_sz));
1825         }               /* end of for loop */
1826
1827         schp->page_order = order;
1828         schp->k_use_sg = k;
1829         SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
1830                          "rem_sz=%d\n", k, rem_sz));
1831
1832         schp->bufflen = blk_size;
1833         if (rem_sz > 0) /* must have failed */
1834                 return -ENOMEM;
1835         return 0;
1836 out:
1837         for (i = 0; i < k; i++)
1838                 __free_pages(schp->pages[i], order);
1839
1840         if (--order >= 0)
1841                 goto retry;
1842
1843         return -ENOMEM;
1844 }
1845
1846 static void
1847 sg_remove_scat(Sg_scatter_hold * schp)
1848 {
1849         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1850         if (schp->pages && schp->sglist_len > 0) {
1851                 if (!schp->dio_in_use) {
1852                         int k;
1853
1854                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1855                                 SCSI_LOG_TIMEOUT(5, printk(
1856                                     "sg_remove_scat: k=%d, pg=0x%p\n",
1857                                     k, schp->pages[k]));
1858                                 __free_pages(schp->pages[k], schp->page_order);
1859                         }
1860
1861                         kfree(schp->pages);
1862                 }
1863         }
1864         memset(schp, 0, sizeof (*schp));
1865 }
1866
1867 static int
1868 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1869 {
1870         Sg_scatter_hold *schp = &srp->data;
1871         int k, num;
1872
1873         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
1874                                    num_read_xfer));
1875         if ((!outp) || (num_read_xfer <= 0))
1876                 return 0;
1877
1878         num = 1 << (PAGE_SHIFT + schp->page_order);
1879         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1880                 if (num > num_read_xfer) {
1881                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1882                                            num_read_xfer))
1883                                 return -EFAULT;
1884                         break;
1885                 } else {
1886                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1887                                            num))
1888                                 return -EFAULT;
1889                         num_read_xfer -= num;
1890                         if (num_read_xfer <= 0)
1891                                 break;
1892                         outp += num;
1893                 }
1894         }
1895
1896         return 0;
1897 }
1898
1899 static void
1900 sg_build_reserve(Sg_fd * sfp, int req_size)
1901 {
1902         Sg_scatter_hold *schp = &sfp->reserve;
1903
1904         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
1905         do {
1906                 if (req_size < PAGE_SIZE)
1907                         req_size = PAGE_SIZE;
1908                 if (0 == sg_build_indirect(schp, sfp, req_size))
1909                         return;
1910                 else
1911                         sg_remove_scat(schp);
1912                 req_size >>= 1; /* divide by 2 */
1913         } while (req_size > (PAGE_SIZE / 2));
1914 }
1915
1916 static void
1917 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1918 {
1919         Sg_scatter_hold *req_schp = &srp->data;
1920         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1921         int k, num, rem;
1922
1923         srp->res_used = 1;
1924         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
1925         rem = size;
1926
1927         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1928         for (k = 0; k < rsv_schp->k_use_sg; k++) {
1929                 if (rem <= num) {
1930                         req_schp->k_use_sg = k + 1;
1931                         req_schp->sglist_len = rsv_schp->sglist_len;
1932                         req_schp->pages = rsv_schp->pages;
1933
1934                         req_schp->bufflen = size;
1935                         req_schp->page_order = rsv_schp->page_order;
1936                         break;
1937                 } else
1938                         rem -= num;
1939         }
1940
1941         if (k >= rsv_schp->k_use_sg)
1942                 SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
1943 }
1944
1945 static void
1946 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
1947 {
1948         Sg_scatter_hold *req_schp = &srp->data;
1949
1950         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
1951                                    (int) req_schp->k_use_sg));
1952         req_schp->k_use_sg = 0;
1953         req_schp->bufflen = 0;
1954         req_schp->pages = NULL;
1955         req_schp->page_order = 0;
1956         req_schp->sglist_len = 0;
1957         sfp->save_scat_len = 0;
1958         srp->res_used = 0;
1959 }
1960
1961 static Sg_request *
1962 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
1963 {
1964         Sg_request *resp;
1965         unsigned long iflags;
1966
1967         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1968         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
1969                 /* look for requests that are ready + not SG_IO owned */
1970                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
1971                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
1972                         resp->done = 2; /* guard against other readers */
1973                         break;
1974                 }
1975         }
1976         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1977         return resp;
1978 }
1979
1980 /* always adds to end of list */
1981 static Sg_request *
1982 sg_add_request(Sg_fd * sfp)
1983 {
1984         int k;
1985         unsigned long iflags;
1986         Sg_request *resp;
1987         Sg_request *rp = sfp->req_arr;
1988
1989         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1990         resp = sfp->headrp;
1991         if (!resp) {
1992                 memset(rp, 0, sizeof (Sg_request));
1993                 rp->parentfp = sfp;
1994                 resp = rp;
1995                 sfp->headrp = resp;
1996         } else {
1997                 if (0 == sfp->cmd_q)
1998                         resp = NULL;    /* command queuing disallowed */
1999                 else {
2000                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2001                                 if (!rp->parentfp)
2002                                         break;
2003                         }
2004                         if (k < SG_MAX_QUEUE) {
2005                                 memset(rp, 0, sizeof (Sg_request));
2006                                 rp->parentfp = sfp;
2007                                 while (resp->nextrp)
2008                                         resp = resp->nextrp;
2009                                 resp->nextrp = rp;
2010                                 resp = rp;
2011                         } else
2012                                 resp = NULL;
2013                 }
2014         }
2015         if (resp) {
2016                 resp->nextrp = NULL;
2017                 resp->header.duration = jiffies_to_msecs(jiffies);
2018         }
2019         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2020         return resp;
2021 }
2022
2023 /* Return of 1 for found; 0 for not found */
2024 static int
2025 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2026 {
2027         Sg_request *prev_rp;
2028         Sg_request *rp;
2029         unsigned long iflags;
2030         int res = 0;
2031
2032         if ((!sfp) || (!srp) || (!sfp->headrp))
2033                 return res;
2034         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2035         prev_rp = sfp->headrp;
2036         if (srp == prev_rp) {
2037                 sfp->headrp = prev_rp->nextrp;
2038                 prev_rp->parentfp = NULL;
2039                 res = 1;
2040         } else {
2041                 while ((rp = prev_rp->nextrp)) {
2042                         if (srp == rp) {
2043                                 prev_rp->nextrp = rp->nextrp;
2044                                 rp->parentfp = NULL;
2045                                 res = 1;
2046                                 break;
2047                         }
2048                         prev_rp = rp;
2049                 }
2050         }
2051         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2052         return res;
2053 }
2054
2055 static Sg_fd *
2056 sg_add_sfp(Sg_device * sdp, int dev)
2057 {
2058         Sg_fd *sfp;
2059         unsigned long iflags;
2060         int bufflen;
2061
2062         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2063         if (!sfp)
2064                 return NULL;
2065
2066         init_waitqueue_head(&sfp->read_wait);
2067         rwlock_init(&sfp->rq_list_lock);
2068
2069         kref_init(&sfp->f_ref);
2070         sfp->timeout = SG_DEFAULT_TIMEOUT;
2071         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2072         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2073         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2074             sdp->device->host->unchecked_isa_dma : 1;
2075         sfp->cmd_q = SG_DEF_COMMAND_Q;
2076         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2077         sfp->parentdp = sdp;
2078         write_lock_irqsave(&sg_index_lock, iflags);
2079         list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2080         write_unlock_irqrestore(&sg_index_lock, iflags);
2081         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2082         if (unlikely(sg_big_buff != def_reserved_size))
2083                 sg_big_buff = def_reserved_size;
2084
2085         bufflen = min_t(int, sg_big_buff,
2086                         queue_max_sectors(sdp->device->request_queue) * 512);
2087         sg_build_reserve(sfp, bufflen);
2088         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2089                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2090
2091         kref_get(&sdp->d_ref);
2092         __module_get(THIS_MODULE);
2093         return sfp;
2094 }
2095
2096 static void sg_remove_sfp_usercontext(struct work_struct *work)
2097 {
2098         struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2099         struct sg_device *sdp = sfp->parentdp;
2100
2101         /* Cleanup any responses which were never read(). */
2102         while (sfp->headrp)
2103                 sg_finish_rem_req(sfp->headrp);
2104
2105         if (sfp->reserve.bufflen > 0) {
2106                 SCSI_LOG_TIMEOUT(6,
2107                         printk("sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2108                                 (int) sfp->reserve.bufflen,
2109                                 (int) sfp->reserve.k_use_sg));
2110                 sg_remove_scat(&sfp->reserve);
2111         }
2112
2113         SCSI_LOG_TIMEOUT(6,
2114                 printk("sg_remove_sfp: %s, sfp=0x%p\n",
2115                         sdp->disk->disk_name,
2116                         sfp));
2117         kfree(sfp);
2118
2119         scsi_device_put(sdp->device);
2120         sg_put_dev(sdp);
2121         module_put(THIS_MODULE);
2122 }
2123
2124 static void sg_remove_sfp(struct kref *kref)
2125 {
2126         struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2127         struct sg_device *sdp = sfp->parentdp;
2128         unsigned long iflags;
2129
2130         write_lock_irqsave(&sg_index_lock, iflags);
2131         list_del(&sfp->sfd_siblings);
2132         write_unlock_irqrestore(&sg_index_lock, iflags);
2133         wake_up_interruptible(&sdp->o_excl_wait);
2134
2135         INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2136         schedule_work(&sfp->ew.work);
2137 }
2138
2139 static int
2140 sg_res_in_use(Sg_fd * sfp)
2141 {
2142         const Sg_request *srp;
2143         unsigned long iflags;
2144
2145         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2146         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2147                 if (srp->res_used)
2148                         break;
2149         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2150         return srp ? 1 : 0;
2151 }
2152
2153 #ifdef CONFIG_SCSI_PROC_FS
2154 static int
2155 sg_idr_max_id(int id, void *p, void *data)
2156 {
2157         int *k = data;
2158
2159         if (*k < id)
2160                 *k = id;
2161
2162         return 0;
2163 }
2164
2165 static int
2166 sg_last_dev(void)
2167 {
2168         int k = -1;
2169         unsigned long iflags;
2170
2171         read_lock_irqsave(&sg_index_lock, iflags);
2172         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2173         read_unlock_irqrestore(&sg_index_lock, iflags);
2174         return k + 1;           /* origin 1 */
2175 }
2176 #endif
2177
2178 /* must be called with sg_index_lock held */
2179 static Sg_device *sg_lookup_dev(int dev)
2180 {
2181         return idr_find(&sg_index_idr, dev);
2182 }
2183
2184 static Sg_device *sg_get_dev(int dev)
2185 {
2186         struct sg_device *sdp;
2187         unsigned long flags;
2188
2189         read_lock_irqsave(&sg_index_lock, flags);
2190         sdp = sg_lookup_dev(dev);
2191         if (!sdp)
2192                 sdp = ERR_PTR(-ENXIO);
2193         else if (sdp->detached) {
2194                 /* If sdp->detached, then the refcount may already be 0, in
2195                  * which case it would be a bug to do kref_get().
2196                  */
2197                 sdp = ERR_PTR(-ENODEV);
2198         } else
2199                 kref_get(&sdp->d_ref);
2200         read_unlock_irqrestore(&sg_index_lock, flags);
2201
2202         return sdp;
2203 }
2204
2205 static void sg_put_dev(struct sg_device *sdp)
2206 {
2207         kref_put(&sdp->d_ref, sg_device_destroy);
2208 }
2209
2210 #ifdef CONFIG_SCSI_PROC_FS
2211
2212 static struct proc_dir_entry *sg_proc_sgp = NULL;
2213
2214 static char sg_proc_sg_dirname[] = "scsi/sg";
2215
2216 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2217
2218 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2219 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2220                                   size_t count, loff_t *off);
2221 static const struct file_operations adio_fops = {
2222         .owner = THIS_MODULE,
2223         .open = sg_proc_single_open_adio,
2224         .read = seq_read,
2225         .llseek = seq_lseek,
2226         .write = sg_proc_write_adio,
2227         .release = single_release,
2228 };
2229
2230 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2231 static ssize_t sg_proc_write_dressz(struct file *filp,
2232                 const char __user *buffer, size_t count, loff_t *off);
2233 static const struct file_operations dressz_fops = {
2234         .owner = THIS_MODULE,
2235         .open = sg_proc_single_open_dressz,
2236         .read = seq_read,
2237         .llseek = seq_lseek,
2238         .write = sg_proc_write_dressz,
2239         .release = single_release,
2240 };
2241
2242 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2243 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2244 static const struct file_operations version_fops = {
2245         .owner = THIS_MODULE,
2246         .open = sg_proc_single_open_version,
2247         .read = seq_read,
2248         .llseek = seq_lseek,
2249         .release = single_release,
2250 };
2251
2252 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2253 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2254 static const struct file_operations devhdr_fops = {
2255         .owner = THIS_MODULE,
2256         .open = sg_proc_single_open_devhdr,
2257         .read = seq_read,
2258         .llseek = seq_lseek,
2259         .release = single_release,
2260 };
2261
2262 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2263 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2264 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2265 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2266 static void dev_seq_stop(struct seq_file *s, void *v);
2267 static const struct file_operations dev_fops = {
2268         .owner = THIS_MODULE,
2269         .open = sg_proc_open_dev,
2270         .read = seq_read,
2271         .llseek = seq_lseek,
2272         .release = seq_release,
2273 };
2274 static const struct seq_operations dev_seq_ops = {
2275         .start = dev_seq_start,
2276         .next  = dev_seq_next,
2277         .stop  = dev_seq_stop,
2278         .show  = sg_proc_seq_show_dev,
2279 };
2280
2281 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2282 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2283 static const struct file_operations devstrs_fops = {
2284         .owner = THIS_MODULE,
2285         .open = sg_proc_open_devstrs,
2286         .read = seq_read,
2287         .llseek = seq_lseek,
2288         .release = seq_release,
2289 };
2290 static const struct seq_operations devstrs_seq_ops = {
2291         .start = dev_seq_start,
2292         .next  = dev_seq_next,
2293         .stop  = dev_seq_stop,
2294         .show  = sg_proc_seq_show_devstrs,
2295 };
2296
2297 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2298 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2299 static const struct file_operations debug_fops = {
2300         .owner = THIS_MODULE,
2301         .open = sg_proc_open_debug,
2302         .read = seq_read,
2303         .llseek = seq_lseek,
2304         .release = seq_release,
2305 };
2306 static const struct seq_operations debug_seq_ops = {
2307         .start = dev_seq_start,
2308         .next  = dev_seq_next,
2309         .stop  = dev_seq_stop,
2310         .show  = sg_proc_seq_show_debug,
2311 };
2312
2313
2314 struct sg_proc_leaf {
2315         const char * name;
2316         const struct file_operations * fops;
2317 };
2318
2319 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2320         {"allow_dio", &adio_fops},
2321         {"debug", &debug_fops},
2322         {"def_reserved_size", &dressz_fops},
2323         {"device_hdr", &devhdr_fops},
2324         {"devices", &dev_fops},
2325         {"device_strs", &devstrs_fops},
2326         {"version", &version_fops}
2327 };
2328
2329 static int
2330 sg_proc_init(void)
2331 {
2332         int k, mask;
2333         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2334         struct sg_proc_leaf * leaf;
2335
2336         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2337         if (!sg_proc_sgp)
2338                 return 1;
2339         for (k = 0; k < num_leaves; ++k) {
2340                 leaf = &sg_proc_leaf_arr[k];
2341                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2342                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2343         }
2344         return 0;
2345 }
2346
2347 static void
2348 sg_proc_cleanup(void)
2349 {
2350         int k;
2351         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2352
2353         if (!sg_proc_sgp)
2354                 return;
2355         for (k = 0; k < num_leaves; ++k)
2356                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2357         remove_proc_entry(sg_proc_sg_dirname, NULL);
2358 }
2359
2360
2361 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2362 {
2363         seq_printf(s, "%d\n", *((int *)s->private));
2364         return 0;
2365 }
2366
2367 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2368 {
2369         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2370 }
2371
2372 static ssize_t
2373 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2374                    size_t count, loff_t *off)
2375 {
2376         int num;
2377         char buff[11];
2378
2379         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2380                 return -EACCES;
2381         num = (count < 10) ? count : 10;
2382         if (copy_from_user(buff, buffer, num))
2383                 return -EFAULT;
2384         buff[num] = '\0';
2385         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2386         return count;
2387 }
2388
2389 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2390 {
2391         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2392 }
2393
2394 static ssize_t
2395 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2396                      size_t count, loff_t *off)
2397 {
2398         int num;
2399         unsigned long k = ULONG_MAX;
2400         char buff[11];
2401
2402         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2403                 return -EACCES;
2404         num = (count < 10) ? count : 10;
2405         if (copy_from_user(buff, buffer, num))
2406                 return -EFAULT;
2407         buff[num] = '\0';
2408         k = simple_strtoul(buff, NULL, 10);
2409         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2410                 sg_big_buff = k;
2411                 return count;
2412         }
2413         return -ERANGE;
2414 }
2415
2416 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2417 {
2418         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2419                    sg_version_date);
2420         return 0;
2421 }
2422
2423 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2424 {
2425         return single_open(file, sg_proc_seq_show_version, NULL);
2426 }
2427
2428 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2429 {
2430         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2431                    "online\n");
2432         return 0;
2433 }
2434
2435 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2436 {
2437         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2438 }
2439
2440 struct sg_proc_deviter {
2441         loff_t  index;
2442         size_t  max;
2443 };
2444
2445 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2446 {
2447         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2448
2449         s->private = it;
2450         if (! it)
2451                 return NULL;
2452
2453         it->index = *pos;
2454         it->max = sg_last_dev();
2455         if (it->index >= it->max)
2456                 return NULL;
2457         return it;
2458 }
2459
2460 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2461 {
2462         struct sg_proc_deviter * it = s->private;
2463
2464         *pos = ++it->index;
2465         return (it->index < it->max) ? it : NULL;
2466 }
2467
2468 static void dev_seq_stop(struct seq_file *s, void *v)
2469 {
2470         kfree(s->private);
2471 }
2472
2473 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2474 {
2475         return seq_open(file, &dev_seq_ops);
2476 }
2477
2478 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2479 {
2480         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2481         Sg_device *sdp;
2482         struct scsi_device *scsidp;
2483         unsigned long iflags;
2484
2485         read_lock_irqsave(&sg_index_lock, iflags);
2486         sdp = it ? sg_lookup_dev(it->index) : NULL;
2487         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2488                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2489                               scsidp->host->host_no, scsidp->channel,
2490                               scsidp->id, scsidp->lun, (int) scsidp->type,
2491                               1,
2492                               (int) scsidp->queue_depth,
2493                               (int) scsidp->device_busy,
2494                               (int) scsi_device_online(scsidp));
2495         else
2496                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2497         read_unlock_irqrestore(&sg_index_lock, iflags);
2498         return 0;
2499 }
2500
2501 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2502 {
2503         return seq_open(file, &devstrs_seq_ops);
2504 }
2505
2506 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2507 {
2508         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2509         Sg_device *sdp;
2510         struct scsi_device *scsidp;
2511         unsigned long iflags;
2512
2513         read_lock_irqsave(&sg_index_lock, iflags);
2514         sdp = it ? sg_lookup_dev(it->index) : NULL;
2515         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2516                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2517                            scsidp->vendor, scsidp->model, scsidp->rev);
2518         else
2519                 seq_printf(s, "<no active device>\n");
2520         read_unlock_irqrestore(&sg_index_lock, iflags);
2521         return 0;
2522 }
2523
2524 /* must be called while holding sg_index_lock */
2525 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2526 {
2527         int k, m, new_interface, blen, usg;
2528         Sg_request *srp;
2529         Sg_fd *fp;
2530         const sg_io_hdr_t *hp;
2531         const char * cp;
2532         unsigned int ms;
2533
2534         k = 0;
2535         list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2536                 k++;
2537                 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2538                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2539                            "(res)sgat=%d low_dma=%d\n", k,
2540                            jiffies_to_msecs(fp->timeout),
2541                            fp->reserve.bufflen,
2542                            (int) fp->reserve.k_use_sg,
2543                            (int) fp->low_dma);
2544                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2545                            (int) fp->cmd_q, (int) fp->force_packid,
2546                            (int) fp->keep_orphan, (int) fp->closed);
2547                 for (m = 0, srp = fp->headrp;
2548                                 srp != NULL;
2549                                 ++m, srp = srp->nextrp) {
2550                         hp = &srp->header;
2551                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2552                         if (srp->res_used) {
2553                                 if (new_interface &&
2554                                     (SG_FLAG_MMAP_IO & hp->flags))
2555                                         cp = "     mmap>> ";
2556                                 else
2557                                         cp = "     rb>> ";
2558                         } else {
2559                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2560                                         cp = "     dio>> ";
2561                                 else
2562                                         cp = "     ";
2563                         }
2564                         seq_printf(s, cp);
2565                         blen = srp->data.bufflen;
2566                         usg = srp->data.k_use_sg;
2567                         seq_printf(s, srp->done ?
2568                                    ((1 == srp->done) ?  "rcv:" : "fin:")
2569                                    : "act:");
2570                         seq_printf(s, " id=%d blen=%d",
2571                                    srp->header.pack_id, blen);
2572                         if (srp->done)
2573                                 seq_printf(s, " dur=%d", hp->duration);
2574                         else {
2575                                 ms = jiffies_to_msecs(jiffies);
2576                                 seq_printf(s, " t_o/elap=%d/%d",
2577                                         (new_interface ? hp->timeout :
2578                                                   jiffies_to_msecs(fp->timeout)),
2579                                         (ms > hp->duration ? ms - hp->duration : 0));
2580                         }
2581                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2582                                    (int) srp->data.cmd_opcode);
2583                 }
2584                 if (0 == m)
2585                         seq_printf(s, "     No requests active\n");
2586                 read_unlock(&fp->rq_list_lock);
2587         }
2588 }
2589
2590 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2591 {
2592         return seq_open(file, &debug_seq_ops);
2593 }
2594
2595 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2596 {
2597         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2598         Sg_device *sdp;
2599         unsigned long iflags;
2600
2601         if (it && (0 == it->index)) {
2602                 seq_printf(s, "max_active_device=%d(origin 1)\n",
2603                            (int)it->max);
2604                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2605         }
2606
2607         read_lock_irqsave(&sg_index_lock, iflags);
2608         sdp = it ? sg_lookup_dev(it->index) : NULL;
2609         if (sdp && !list_empty(&sdp->sfds)) {
2610                 struct scsi_device *scsidp = sdp->device;
2611
2612                 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2613                 if (sdp->detached)
2614                         seq_printf(s, "detached pending close ");
2615                 else
2616                         seq_printf
2617                             (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2618                              scsidp->host->host_no,
2619                              scsidp->channel, scsidp->id,
2620                              scsidp->lun,
2621                              scsidp->host->hostt->emulated);
2622                 seq_printf(s, " sg_tablesize=%d excl=%d\n",
2623                            sdp->sg_tablesize, sdp->exclude);
2624                 sg_proc_debug_helper(s, sdp);
2625         }
2626         read_unlock_irqrestore(&sg_index_lock, iflags);
2627         return 0;
2628 }
2629
2630 #endif                          /* CONFIG_SCSI_PROC_FS */
2631
2632 module_init(init_sg);
2633 module_exit(exit_sg);