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/fcntl.h>
  42 #include <linux/init.h>
  43 #include <linux/poll.h>
  44 #include <linux/moduleparam.h>
  45 #include <linux/cdev.h>
  46 #include <linux/idr.h>
  47 #include <linux/seq_file.h>
  48 #include <linux/blkdev.h>
  49 #include <linux/delay.h>
  50 #include <linux/blktrace_api.h>
  51 #include <linux/smp_lock.h>
  52
  53 #include "scsi.h"
  54 #include <scsi/scsi_dbg.h>
  55 #include <scsi/scsi_host.h>
  56 #include <scsi/scsi_driver.h>
  57 #include <scsi/scsi_ioctl.h>
  58 #include <scsi/sg.h>
  59
  60 #include "scsi_logging.h"
  61
  62 #ifdef CONFIG_SCSI_PROC_FS
  63 #include <linux/proc_fs.h>
  64 static char *sg_version_date = "20061027";
  65
  66 static int sg_proc_init(void);
  67 static void sg_proc_cleanup(void);
  68 #endif
  69
  70 #define SG_ALLOW_DIO_DEF 0
  71 #define SG_ALLOW_DIO_CODE /* compile out by commenting this define */
  72
  73 #define SG_MAX_DEVS 32768
  74
  75 /*
  76  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
  77  * Then when using 32 bit integers x * m may overflow during the calculation.
  78  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
  79  * calculates the same, but prevents the overflow when both m and d
  80  * are "small" numbers (like HZ and USER_HZ).
  81  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
  82  * in 32 bits.
  83  */
  84 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
  85
  86 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  87
  88 int sg_big_buff = SG_DEF_RESERVED_SIZE;
  89 /* N.B. This variable is readable and writeable via
  90    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  91    of this size (or less if there is not enough memory) will be reserved
  92    for use by this file descriptor. [Deprecated usage: this variable is also
  93    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  94    the kernel (i.e. it is not a module).] */
  95 static int def_reserved_size = -1;      /* picks up init parameter */
  96 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
  97
  98 static int scatter_elem_sz = SG_SCATTER_SZ;
  99 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
 100
 101 #define SG_SECTOR_SZ 512
 102 #define SG_SECTOR_MSK (SG_SECTOR_SZ - 1)
 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_IDR(sg_index_idr);
 108 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
 109                                                            file descriptor list for device */
 110
 111 static struct class_interface sg_interface = {
 112         .add_dev        = sg_add,
 113         .remove_dev     = sg_remove,
 114 };
 115
 116 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 117         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 118         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 119         unsigned bufflen;       /* Size of (aggregate) data buffer */
 120         unsigned b_malloc_len;  /* actual len malloc'ed in buffer */
 121         struct page **pages;
 122         int page_order;
 123         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 124         unsigned char cmd_opcode; /* first byte of command */
 125 } Sg_scatter_hold;
 126
 127 struct sg_device;               /* forward declarations */
 128 struct sg_fd;
 129
 130 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 131         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
 132         struct sg_fd *parentfp; /* NULL -> not in use */
 133         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 134         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 135         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 136         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 137         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 138         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 139         volatile char done;     /* 0->before bh, 1->before read, 2->read */
 140         struct request *rq;
 141         struct bio *bio;
 142 } Sg_request;
 143
 144 typedef struct sg_fd {          /* holds the state of a file descriptor */
 145         struct sg_fd *nextfp;   /* NULL when last opened fd on this device */
 146         struct sg_device *parentdp;     /* owning device */
 147         wait_queue_head_t read_wait;    /* queue read until command done */
 148         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 149         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 150         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 151         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 152         unsigned save_scat_len; /* original length of trunc. scat. element */
 153         Sg_request *headrp;     /* head of request slist, NULL->empty */
 154         struct fasync_struct *async_qp; /* used by asynchronous notification */
 155         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 156         char low_dma;           /* as in parent but possibly overridden to 1 */
 157         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 158         volatile char closed;   /* 1 -> fd closed but request(s) outstanding */
 159         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 160         char next_cmd_len;      /* 0 -> automatic (def), >0 -> use on next write() */
 161         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 162         char mmap_called;       /* 0 -> mmap() never called on this fd */
 163 } Sg_fd;
 164
 165 typedef struct sg_device { /* holds the state of each scsi generic device */
 166         struct scsi_device *device;
 167         wait_queue_head_t o_excl_wait;  /* queue open() when O_EXCL in use */
 168         int sg_tablesize;       /* adapter's max scatter-gather table size */
 169         u32 index;              /* device index number */
 170         Sg_fd *headfp;          /* first open fd belonging to this device */
 171         volatile char detached; /* 0->attached, 1->detached pending removal */
 172         volatile char exclude;  /* opened for exclusive access */
 173         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 174         struct gendisk *disk;
 175         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 176 } Sg_device;
 177
 178 static int sg_fasync(int fd, struct file *filp, int mode);
 179 /* tasklet or soft irq callback */
 180 static void sg_cmd_done(void *data, char *sense, int result, int resid);
 181 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 182 static void sg_finish_rem_req(Sg_request * srp);
 183 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 184 static int sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp,
 185                          int tablesize);
 186 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 187                            Sg_request * srp);
 188 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 189                         const char __user *buf, size_t count, int blocking,
 190                         int read_only, Sg_request **o_srp);
 191 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 192                            unsigned char *cmnd, int timeout, int blocking);
 193 static int sg_write_xfer(Sg_request * srp);
 194 static int sg_read_xfer(Sg_request * srp);
 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 int sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
 202 static void __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
 203 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 204 static Sg_request *sg_add_request(Sg_fd * sfp);
 205 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 206 static int sg_res_in_use(Sg_fd * sfp);
 207 static int sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len);
 208 static Sg_device *sg_get_dev(int dev);
 209 #ifdef CONFIG_SCSI_PROC_FS
 210 static int sg_last_dev(void);
 211 #endif
 212
 213 #define SZ_SG_HEADER sizeof(struct sg_header)
 214 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 215 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
 216 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 217
 218 static int sg_allow_access(struct file *filp, unsigned char *cmd)
 219 {
 220         struct sg_fd *sfp = (struct sg_fd *)filp->private_data;
 221         struct request_queue *q = sfp->parentdp->device->request_queue;
 222
 223         if (sfp->parentdp->device->type == TYPE_SCANNER)
 224                 return 0;
 225
 226         return blk_verify_command(&q->cmd_filter,
 227                                   cmd, filp->f_mode & FMODE_WRITE);
 228 }
 229
 230 static void sg_rq_end_io(struct request *rq, int uptodate)
 231 {
 232         sg_cmd_done(rq->end_io_data, rq->sense, rq->errors, rq->data_len);
 233 }
 234
 235 static int
 236 sg_open(struct inode *inode, struct file *filp)
 237 {
 238         int dev = iminor(inode);
 239         int flags = filp->f_flags;
 240         struct request_queue *q;
 241         Sg_device *sdp;
 242         Sg_fd *sfp;
 243         int res;
 244         int retval;
 245
 246         lock_kernel();
 247         nonseekable_open(inode, filp);
 248         SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
 249         sdp = sg_get_dev(dev);
 250         if ((!sdp) || (!sdp->device)) {
 251                 unlock_kernel();
 252                 return -ENXIO;
 253         }
 254         if (sdp->detached) {
 255                 unlock_kernel();
 256                 return -ENODEV;
 257         }
 258
 259         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 260         /* Prevent the device driver from vanishing while we sleep */
 261         retval = scsi_device_get(sdp->device);
 262         if (retval) {
 263                 unlock_kernel();
 264                 return retval;
 265         }
 266
 267         if (!((flags & O_NONBLOCK) ||
 268               scsi_block_when_processing_errors(sdp->device))) {
 269                 retval = -ENXIO;
 270                 /* we are in error recovery for this device */
 271                 goto error_out;
 272         }
 273
 274         if (flags & O_EXCL) {
 275                 if (O_RDONLY == (flags & O_ACCMODE)) {
 276                         retval = -EPERM; /* Can't lock it with read only access */
 277                         goto error_out;
 278                 }
 279                 if (sdp->headfp && (flags & O_NONBLOCK)) {
 280                         retval = -EBUSY;
 281                         goto error_out;
 282                 }
 283                 res = 0;
 284                 __wait_event_interruptible(sdp->o_excl_wait,
 285                         ((sdp->headfp || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
 286                 if (res) {
 287                         retval = res;   /* -ERESTARTSYS because signal hit process */
 288                         goto error_out;
 289                 }
 290         } else if (sdp->exclude) {      /* some other fd has an exclusive lock on dev */
 291                 if (flags & O_NONBLOCK) {
 292                         retval = -EBUSY;
 293                         goto error_out;
 294                 }
 295                 res = 0;
 296                 __wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
 297                                            res);
 298                 if (res) {
 299                         retval = res;   /* -ERESTARTSYS because signal hit process */
 300                         goto error_out;
 301                 }
 302         }
 303         if (sdp->detached) {
 304                 retval = -ENODEV;
 305                 goto error_out;
 306         }
 307         if (!sdp->headfp) {     /* no existing opens on this device */
 308                 sdp->sgdebug = 0;
 309                 q = sdp->device->request_queue;
 310                 sdp->sg_tablesize = min(q->max_hw_segments,
 311                                         q->max_phys_segments);
 312         }
 313         if ((sfp = sg_add_sfp(sdp, dev)))
 314                 filp->private_data = sfp;
 315         else {
 316                 if (flags & O_EXCL)
 317                         sdp->exclude = 0;       /* undo if error */
 318                 retval = -ENOMEM;
 319                 goto error_out;
 320         }
 321         unlock_kernel();
 322         return 0;
 323
 324       error_out:
 325         scsi_device_put(sdp->device);
 326         unlock_kernel();
 327         return retval;
 328 }
 329
 330 /* Following function was formerly called 'sg_close' */
 331 static int
 332 sg_release(struct inode *inode, struct file *filp)
 333 {
 334         Sg_device *sdp;
 335         Sg_fd *sfp;
 336
 337         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 338                 return -ENXIO;
 339         SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
 340         sg_fasync(-1, filp, 0); /* remove filp from async notification list */
 341         if (0 == sg_remove_sfp(sdp, sfp)) {     /* Returns 1 when sdp gone */
 342                 if (!sdp->detached) {
 343                         scsi_device_put(sdp->device);
 344                 }
 345                 sdp->exclude = 0;
 346                 wake_up_interruptible(&sdp->o_excl_wait);
 347         }
 348         return 0;
 349 }
 350
 351 static ssize_t
 352 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 353 {
 354         Sg_device *sdp;
 355         Sg_fd *sfp;
 356         Sg_request *srp;
 357         int req_pack_id = -1;
 358         sg_io_hdr_t *hp;
 359         struct sg_header *old_hdr = NULL;
 360         int retval = 0;
 361
 362         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 363                 return -ENXIO;
 364         SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
 365                                    sdp->disk->disk_name, (int) count));
 366
 367         if (!access_ok(VERIFY_WRITE, buf, count))
 368                 return -EFAULT;
 369         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 370                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 371                 if (!old_hdr)
 372                         return -ENOMEM;
 373                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
 374                         retval = -EFAULT;
 375                         goto free_old_hdr;
 376                 }
 377                 if (old_hdr->reply_len < 0) {
 378                         if (count >= SZ_SG_IO_HDR) {
 379                                 sg_io_hdr_t *new_hdr;
 380                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
 381                                 if (!new_hdr) {
 382                                         retval = -ENOMEM;
 383                                         goto free_old_hdr;
 384                                 }
 385                                 retval =__copy_from_user
 386                                     (new_hdr, buf, SZ_SG_IO_HDR);
 387                                 req_pack_id = new_hdr->pack_id;
 388                                 kfree(new_hdr);
 389                                 if (retval) {
 390                                         retval = -EFAULT;
 391                                         goto free_old_hdr;
 392                                 }
 393                         }
 394                 } else
 395                         req_pack_id = old_hdr->pack_id;
 396         }
 397         srp = sg_get_rq_mark(sfp, req_pack_id);
 398         if (!srp) {             /* now wait on packet to arrive */
 399                 if (sdp->detached) {
 400                         retval = -ENODEV;
 401                         goto free_old_hdr;
 402                 }
 403                 if (filp->f_flags & O_NONBLOCK) {
 404                         retval = -EAGAIN;
 405                         goto free_old_hdr;
 406                 }
 407                 while (1) {
 408                         retval = 0; /* following macro beats race condition */
 409                         __wait_event_interruptible(sfp->read_wait,
 410                                 (sdp->detached ||
 411                                 (srp = sg_get_rq_mark(sfp, req_pack_id))),
 412                                 retval);
 413                         if (sdp->detached) {
 414                                 retval = -ENODEV;
 415                                 goto free_old_hdr;
 416                         }
 417                         if (0 == retval)
 418                                 break;
 419
 420                         /* -ERESTARTSYS as signal hit process */
 421                         goto free_old_hdr;
 422                 }
 423         }
 424         if (srp->header.interface_id != '\0') {
 425                 retval = sg_new_read(sfp, buf, count, srp);
 426                 goto free_old_hdr;
 427         }
 428
 429         hp = &srp->header;
 430         if (old_hdr == NULL) {
 431                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 432                 if (! old_hdr) {
 433                         retval = -ENOMEM;
 434                         goto free_old_hdr;
 435                 }
 436         }
 437         memset(old_hdr, 0, SZ_SG_HEADER);
 438         old_hdr->reply_len = (int) hp->timeout;
 439         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 440         old_hdr->pack_id = hp->pack_id;
 441         old_hdr->twelve_byte =
 442             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 443         old_hdr->target_status = hp->masked_status;
 444         old_hdr->host_status = hp->host_status;
 445         old_hdr->driver_status = hp->driver_status;
 446         if ((CHECK_CONDITION & hp->masked_status) ||
 447             (DRIVER_SENSE & hp->driver_status))
 448                 memcpy(old_hdr->sense_buffer, srp->sense_b,
 449                        sizeof (old_hdr->sense_buffer));
 450         switch (hp->host_status) {
 451         /* This setup of 'result' is for backward compatibility and is best
 452            ignored by the user who should use target, host + driver status */
 453         case DID_OK:
 454         case DID_PASSTHROUGH:
 455         case DID_SOFT_ERROR:
 456                 old_hdr->result = 0;
 457                 break;
 458         case DID_NO_CONNECT:
 459         case DID_BUS_BUSY:
 460         case DID_TIME_OUT:
 461                 old_hdr->result = EBUSY;
 462                 break;
 463         case DID_BAD_TARGET:
 464         case DID_ABORT:
 465         case DID_PARITY:
 466         case DID_RESET:
 467         case DID_BAD_INTR:
 468                 old_hdr->result = EIO;
 469                 break;
 470         case DID_ERROR:
 471                 old_hdr->result = (srp->sense_b[0] == 0 &&
 472                                   hp->masked_status == GOOD) ? 0 : EIO;
 473                 break;
 474         default:
 475                 old_hdr->result = EIO;
 476                 break;
 477         }
 478
 479         /* Now copy the result back to the user buffer.  */
 480         if (count >= SZ_SG_HEADER) {
 481                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 482                         retval = -EFAULT;
 483                         goto free_old_hdr;
 484                 }
 485                 buf += SZ_SG_HEADER;
 486                 if (count > old_hdr->reply_len)
 487                         count = old_hdr->reply_len;
 488                 if (count > SZ_SG_HEADER) {
 489                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 490                                 retval = -EFAULT;
 491                                 goto free_old_hdr;
 492                         }
 493                 }
 494         } else
 495                 count = (old_hdr->result == 0) ? 0 : -EIO;
 496         sg_finish_rem_req(srp);
 497         retval = count;
 498 free_old_hdr:
 499         kfree(old_hdr);
 500         return retval;
 501 }
 502
 503 static ssize_t
 504 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 505 {
 506         sg_io_hdr_t *hp = &srp->header;
 507         int err = 0;
 508         int len;
 509
 510         if (count < SZ_SG_IO_HDR) {
 511                 err = -EINVAL;
 512                 goto err_out;
 513         }
 514         hp->sb_len_wr = 0;
 515         if ((hp->mx_sb_len > 0) && hp->sbp) {
 516                 if ((CHECK_CONDITION & hp->masked_status) ||
 517                     (DRIVER_SENSE & hp->driver_status)) {
 518                         int sb_len = SCSI_SENSE_BUFFERSIZE;
 519                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 520                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 521                         len = (len > sb_len) ? sb_len : len;
 522                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 523                                 err = -EFAULT;
 524                                 goto err_out;
 525                         }
 526                         hp->sb_len_wr = len;
 527                 }
 528         }
 529         if (hp->masked_status || hp->host_status || hp->driver_status)
 530                 hp->info |= SG_INFO_CHECK;
 531         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 532                 err = -EFAULT;
 533                 goto err_out;
 534         }
 535         err = sg_read_xfer(srp);
 536       err_out:
 537         sg_finish_rem_req(srp);
 538         return (0 == err) ? count : err;
 539 }
 540
 541 static ssize_t
 542 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 543 {
 544         int mxsize, cmd_size, k;
 545         int input_size, blocking;
 546         unsigned char opcode;
 547         Sg_device *sdp;
 548         Sg_fd *sfp;
 549         Sg_request *srp;
 550         struct sg_header old_hdr;
 551         sg_io_hdr_t *hp;
 552         unsigned char cmnd[MAX_COMMAND_SIZE];
 553
 554         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 555                 return -ENXIO;
 556         SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
 557                                    sdp->disk->disk_name, (int) count));
 558         if (sdp->detached)
 559                 return -ENODEV;
 560         if (!((filp->f_flags & O_NONBLOCK) ||
 561               scsi_block_when_processing_errors(sdp->device)))
 562                 return -ENXIO;
 563
 564         if (!access_ok(VERIFY_READ, buf, count))
 565                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 566         if (count < SZ_SG_HEADER)
 567                 return -EIO;
 568         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 569                 return -EFAULT;
 570         blocking = !(filp->f_flags & O_NONBLOCK);
 571         if (old_hdr.reply_len < 0)
 572                 return sg_new_write(sfp, filp, buf, count, blocking, 0, NULL);
 573         if (count < (SZ_SG_HEADER + 6))
 574                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 575
 576         if (!(srp = sg_add_request(sfp))) {
 577                 SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
 578                 return -EDOM;
 579         }
 580         buf += SZ_SG_HEADER;
 581         __get_user(opcode, buf);
 582         if (sfp->next_cmd_len > 0) {
 583                 if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
 584                         SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
 585                         sfp->next_cmd_len = 0;
 586                         sg_remove_request(sfp, srp);
 587                         return -EIO;
 588                 }
 589                 cmd_size = sfp->next_cmd_len;
 590                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 591         } else {
 592                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 593                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 594                         cmd_size = 12;
 595         }
 596         SCSI_LOG_TIMEOUT(4, printk(
 597                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 598 /* Determine buffer size.  */
 599         input_size = count - cmd_size;
 600         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 601         mxsize -= SZ_SG_HEADER;
 602         input_size -= SZ_SG_HEADER;
 603         if (input_size < 0) {
 604                 sg_remove_request(sfp, srp);
 605                 return -EIO;    /* User did not pass enough bytes for this command. */
 606         }
 607         hp = &srp->header;
 608         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 609         hp->cmd_len = (unsigned char) cmd_size;
 610         hp->iovec_count = 0;
 611         hp->mx_sb_len = 0;
 612         if (input_size > 0)
 613                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 614                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 615         else
 616                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 617         hp->dxfer_len = mxsize;
 618         hp->dxferp = (char __user *)buf + cmd_size;
 619         hp->sbp = NULL;
 620         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 621         hp->flags = input_size; /* structure abuse ... */
 622         hp->pack_id = old_hdr.pack_id;
 623         hp->usr_ptr = NULL;
 624         if (__copy_from_user(cmnd, buf, cmd_size))
 625                 return -EFAULT;
 626         /*
 627          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 628          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 629          * is a non-zero input_size, so emit a warning.
 630          */
 631         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 632                 static char cmd[TASK_COMM_LEN];
 633                 if (strcmp(current->comm, cmd) && printk_ratelimit()) {
 634                         printk(KERN_WARNING
 635                                "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
 636                                "guessing data in;\n" KERN_WARNING "   "
 637                                "program %s not setting count and/or reply_len properly\n",
 638                                old_hdr.reply_len - (int)SZ_SG_HEADER,
 639                                input_size, (unsigned int) cmnd[0],
 640                                current->comm);
 641                         strcpy(cmd, current->comm);
 642                 }
 643         }
 644         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 645         return (k < 0) ? k : count;
 646 }
 647
 648 static ssize_t
 649 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 650                  size_t count, int blocking, int read_only,
 651                  Sg_request **o_srp)
 652 {
 653         int k;
 654         Sg_request *srp;
 655         sg_io_hdr_t *hp;
 656         unsigned char cmnd[MAX_COMMAND_SIZE];
 657         int timeout;
 658         unsigned long ul_timeout;
 659
 660         if (count < SZ_SG_IO_HDR)
 661                 return -EINVAL;
 662         if (!access_ok(VERIFY_READ, buf, count))
 663                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 664
 665         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 666         if (!(srp = sg_add_request(sfp))) {
 667                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
 668                 return -EDOM;
 669         }
 670         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 ((k = sg_write_xfer(srp))) {
 745                 SCSI_LOG_TIMEOUT(1, printk("sg_common_write: write_xfer, bad address\n"));
 746                 sg_finish_rem_req(srp);
 747                 return k;
 748         }
 749         if (sdp->detached) {
 750                 sg_finish_rem_req(srp);
 751                 return -ENODEV;
 752         }
 753
 754         switch (hp->dxfer_direction) {
 755         case SG_DXFER_TO_FROM_DEV:
 756         case SG_DXFER_FROM_DEV:
 757                 data_dir = DMA_FROM_DEVICE;
 758                 break;
 759         case SG_DXFER_TO_DEV:
 760                 data_dir = DMA_TO_DEVICE;
 761                 break;
 762         case SG_DXFER_UNKNOWN:
 763                 data_dir = DMA_BIDIRECTIONAL;
 764                 break;
 765         default:
 766                 data_dir = DMA_NONE;
 767                 break;
 768         }
 769         hp->duration = jiffies_to_msecs(jiffies);
 770
 771         srp->rq->timeout = timeout;
 772         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 773                               srp->rq, 1, sg_rq_end_io);
 774         return 0;
 775 }
 776
 777 static int
 778 sg_srp_done(Sg_request *srp, Sg_fd *sfp)
 779 {
 780         unsigned long iflags;
 781         int done;
 782
 783         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 784         done = srp->done;
 785         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 786         return done;
 787 }
 788
 789 static int
 790 sg_ioctl(struct inode *inode, struct file *filp,
 791          unsigned int cmd_in, unsigned long arg)
 792 {
 793         void __user *p = (void __user *)arg;
 794         int __user *ip = p;
 795         int result, val, read_only;
 796         Sg_device *sdp;
 797         Sg_fd *sfp;
 798         Sg_request *srp;
 799         unsigned long iflags;
 800
 801         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 802                 return -ENXIO;
 803
 804         SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
 805                                    sdp->disk->disk_name, (int) cmd_in));
 806         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 807
 808         switch (cmd_in) {
 809         case SG_IO:
 810                 {
 811                         int blocking = 1;       /* ignore O_NONBLOCK flag */
 812
 813                         if (sdp->detached)
 814                                 return -ENODEV;
 815                         if (!scsi_block_when_processing_errors(sdp->device))
 816                                 return -ENXIO;
 817                         if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 818                                 return -EFAULT;
 819                         result =
 820                             sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 821                                          blocking, read_only, &srp);
 822                         if (result < 0)
 823                                 return result;
 824                         srp->sg_io_owned = 1;
 825                         while (1) {
 826                                 result = 0;     /* following macro to beat race condition */
 827                                 __wait_event_interruptible(sfp->read_wait,
 828                                         (sdp->detached || sfp->closed || sg_srp_done(srp, sfp)),
 829                                                            result);
 830                                 if (sdp->detached)
 831                                         return -ENODEV;
 832                                 if (sfp->closed)
 833                                         return 0;       /* request packet dropped already */
 834                                 if (0 == result)
 835                                         break;
 836                                 srp->orphan = 1;
 837                                 return result;  /* -ERESTARTSYS because signal hit process */
 838                         }
 839                         write_lock_irqsave(&sfp->rq_list_lock, iflags);
 840                         srp->done = 2;
 841                         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 842                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 843                         return (result < 0) ? result : 0;
 844                 }
 845         case SG_SET_TIMEOUT:
 846                 result = get_user(val, ip);
 847                 if (result)
 848                         return result;
 849                 if (val < 0)
 850                         return -EIO;
 851                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
 852                     val = MULDIV (INT_MAX, USER_HZ, HZ);
 853                 sfp->timeout_user = val;
 854                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
 855
 856                 return 0;
 857         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 858                                 /* strange ..., for backward compatibility */
 859                 return sfp->timeout_user;
 860         case SG_SET_FORCE_LOW_DMA:
 861                 result = get_user(val, ip);
 862                 if (result)
 863                         return result;
 864                 if (val) {
 865                         sfp->low_dma = 1;
 866                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
 867                                 val = (int) sfp->reserve.bufflen;
 868                                 sg_remove_scat(&sfp->reserve);
 869                                 sg_build_reserve(sfp, val);
 870                         }
 871                 } else {
 872                         if (sdp->detached)
 873                                 return -ENODEV;
 874                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
 875                 }
 876                 return 0;
 877         case SG_GET_LOW_DMA:
 878                 return put_user((int) sfp->low_dma, ip);
 879         case SG_GET_SCSI_ID:
 880                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 881                         return -EFAULT;
 882                 else {
 883                         sg_scsi_id_t __user *sg_idp = p;
 884
 885                         if (sdp->detached)
 886                                 return -ENODEV;
 887                         __put_user((int) sdp->device->host->host_no,
 888                                    &sg_idp->host_no);
 889                         __put_user((int) sdp->device->channel,
 890                                    &sg_idp->channel);
 891                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 892                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 893                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 894                         __put_user((short) sdp->device->host->cmd_per_lun,
 895                                    &sg_idp->h_cmd_per_lun);
 896                         __put_user((short) sdp->device->queue_depth,
 897                                    &sg_idp->d_queue_depth);
 898                         __put_user(0, &sg_idp->unused[0]);
 899                         __put_user(0, &sg_idp->unused[1]);
 900                         return 0;
 901                 }
 902         case SG_SET_FORCE_PACK_ID:
 903                 result = get_user(val, ip);
 904                 if (result)
 905                         return result;
 906                 sfp->force_packid = val ? 1 : 0;
 907                 return 0;
 908         case SG_GET_PACK_ID:
 909                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 910                         return -EFAULT;
 911                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 912                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
 913                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 914                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 915                                                        iflags);
 916                                 __put_user(srp->header.pack_id, ip);
 917                                 return 0;
 918                         }
 919                 }
 920                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 921                 __put_user(-1, ip);
 922                 return 0;
 923         case SG_GET_NUM_WAITING:
 924                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 925                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
 926                         if ((1 == srp->done) && (!srp->sg_io_owned))
 927                                 ++val;
 928                 }
 929                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 930                 return put_user(val, ip);
 931         case SG_GET_SG_TABLESIZE:
 932                 return put_user(sdp->sg_tablesize, ip);
 933         case SG_SET_RESERVED_SIZE:
 934                 result = get_user(val, ip);
 935                 if (result)
 936                         return result;
 937                 if (val < 0)
 938                         return -EINVAL;
 939                 val = min_t(int, val,
 940                                 sdp->device->request_queue->max_sectors * 512);
 941                 if (val != sfp->reserve.bufflen) {
 942                         if (sg_res_in_use(sfp) || sfp->mmap_called)
 943                                 return -EBUSY;
 944                         sg_remove_scat(&sfp->reserve);
 945                         sg_build_reserve(sfp, val);
 946                 }
 947                 return 0;
 948         case SG_GET_RESERVED_SIZE:
 949                 val = min_t(int, sfp->reserve.bufflen,
 950                                 sdp->device->request_queue->max_sectors * 512);
 951                 return put_user(val, ip);
 952         case SG_SET_COMMAND_Q:
 953                 result = get_user(val, ip);
 954                 if (result)
 955                         return result;
 956                 sfp->cmd_q = val ? 1 : 0;
 957                 return 0;
 958         case SG_GET_COMMAND_Q:
 959                 return put_user((int) sfp->cmd_q, ip);
 960         case SG_SET_KEEP_ORPHAN:
 961                 result = get_user(val, ip);
 962                 if (result)
 963                         return result;
 964                 sfp->keep_orphan = val;
 965                 return 0;
 966         case SG_GET_KEEP_ORPHAN:
 967                 return put_user((int) sfp->keep_orphan, ip);
 968         case SG_NEXT_CMD_LEN:
 969                 result = get_user(val, ip);
 970                 if (result)
 971                         return result;
 972                 sfp->next_cmd_len = (val > 0) ? val : 0;
 973                 return 0;
 974         case SG_GET_VERSION_NUM:
 975                 return put_user(sg_version_num, ip);
 976         case SG_GET_ACCESS_COUNT:
 977                 /* faked - we don't have a real access count anymore */
 978                 val = (sdp->device ? 1 : 0);
 979                 return put_user(val, ip);
 980         case SG_GET_REQUEST_TABLE:
 981                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
 982                         return -EFAULT;
 983                 else {
 984                         sg_req_info_t *rinfo;
 985                         unsigned int ms;
 986
 987                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
 988                                                                 GFP_KERNEL);
 989                         if (!rinfo)
 990                                 return -ENOMEM;
 991                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 992                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
 993                              ++val, srp = srp ? srp->nextrp : srp) {
 994                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
 995                                 if (srp) {
 996                                         rinfo[val].req_state = srp->done + 1;
 997                                         rinfo[val].problem =
 998                                             srp->header.masked_status &
 999                                             srp->header.host_status &
1000                                             srp->header.driver_status;
1001                                         if (srp->done)
1002                                                 rinfo[val].duration =
1003                                                         srp->header.duration;
1004                                         else {
1005                                                 ms = jiffies_to_msecs(jiffies);
1006                                                 rinfo[val].duration =
1007                                                     (ms > srp->header.duration) ?
1008                                                     (ms - srp->header.duration) : 0;
1009                                         }
1010                                         rinfo[val].orphan = srp->orphan;
1011                                         rinfo[val].sg_io_owned =
1012                                                         srp->sg_io_owned;
1013                                         rinfo[val].pack_id =
1014                                                         srp->header.pack_id;
1015                                         rinfo[val].usr_ptr =
1016                                                         srp->header.usr_ptr;
1017                                 }
1018                         }
1019                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1020                         result = __copy_to_user(p, rinfo,
1021                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1022                         result = result ? -EFAULT : 0;
1023                         kfree(rinfo);
1024                         return result;
1025                 }
1026         case SG_EMULATED_HOST:
1027                 if (sdp->detached)
1028                         return -ENODEV;
1029                 return put_user(sdp->device->host->hostt->emulated, ip);
1030         case SG_SCSI_RESET:
1031                 if (sdp->detached)
1032                         return -ENODEV;
1033                 if (filp->f_flags & O_NONBLOCK) {
1034                         if (scsi_host_in_recovery(sdp->device->host))
1035                                 return -EBUSY;
1036                 } else if (!scsi_block_when_processing_errors(sdp->device))
1037                         return -EBUSY;
1038                 result = get_user(val, ip);
1039                 if (result)
1040                         return result;
1041                 if (SG_SCSI_RESET_NOTHING == val)
1042                         return 0;
1043                 switch (val) {
1044                 case SG_SCSI_RESET_DEVICE:
1045                         val = SCSI_TRY_RESET_DEVICE;
1046                         break;
1047                 case SG_SCSI_RESET_TARGET:
1048                         val = SCSI_TRY_RESET_TARGET;
1049                         break;
1050                 case SG_SCSI_RESET_BUS:
1051                         val = SCSI_TRY_RESET_BUS;
1052                         break;
1053                 case SG_SCSI_RESET_HOST:
1054                         val = SCSI_TRY_RESET_HOST;
1055                         break;
1056                 default:
1057                         return -EINVAL;
1058                 }
1059                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1060                         return -EACCES;
1061                 return (scsi_reset_provider(sdp->device, val) ==
1062                         SUCCESS) ? 0 : -EIO;
1063         case SCSI_IOCTL_SEND_COMMAND:
1064                 if (sdp->detached)
1065                         return -ENODEV;
1066                 if (read_only) {
1067                         unsigned char opcode = WRITE_6;
1068                         Scsi_Ioctl_Command __user *siocp = p;
1069
1070                         if (copy_from_user(&opcode, siocp->data, 1))
1071                                 return -EFAULT;
1072                         if (sg_allow_access(filp, &opcode))
1073                                 return -EPERM;
1074                 }
1075                 return sg_scsi_ioctl(filp, sdp->device->request_queue, NULL, p);
1076         case SG_SET_DEBUG:
1077                 result = get_user(val, ip);
1078                 if (result)
1079                         return result;
1080                 sdp->sgdebug = (char) val;
1081                 return 0;
1082         case SCSI_IOCTL_GET_IDLUN:
1083         case SCSI_IOCTL_GET_BUS_NUMBER:
1084         case SCSI_IOCTL_PROBE_HOST:
1085         case SG_GET_TRANSFORM:
1086                 if (sdp->detached)
1087                         return -ENODEV;
1088                 return scsi_ioctl(sdp->device, cmd_in, p);
1089         case BLKSECTGET:
1090                 return put_user(sdp->device->request_queue->max_sectors * 512,
1091                                 ip);
1092         case BLKTRACESETUP:
1093                 return blk_trace_setup(sdp->device->request_queue,
1094                                        sdp->disk->disk_name,
1095                                        sdp->device->sdev_gendev.devt,
1096                                        (char *)arg);
1097         case BLKTRACESTART:
1098                 return blk_trace_startstop(sdp->device->request_queue, 1);
1099         case BLKTRACESTOP:
1100                 return blk_trace_startstop(sdp->device->request_queue, 0);
1101         case BLKTRACETEARDOWN:
1102                 return blk_trace_remove(sdp->device->request_queue);
1103         default:
1104                 if (read_only)
1105                         return -EPERM;  /* don't know so take safe approach */
1106                 return scsi_ioctl(sdp->device, cmd_in, p);
1107         }
1108 }
1109
1110 #ifdef CONFIG_COMPAT
1111 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1112 {
1113         Sg_device *sdp;
1114         Sg_fd *sfp;
1115         struct scsi_device *sdev;
1116
1117         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1118                 return -ENXIO;
1119
1120         sdev = sdp->device;
1121         if (sdev->host->hostt->compat_ioctl) {
1122                 int ret;
1123
1124                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1125
1126                 return ret;
1127         }
1128
1129         return -ENOIOCTLCMD;
1130 }
1131 #endif
1132
1133 static unsigned int
1134 sg_poll(struct file *filp, poll_table * wait)
1135 {
1136         unsigned int res = 0;
1137         Sg_device *sdp;
1138         Sg_fd *sfp;
1139         Sg_request *srp;
1140         int count = 0;
1141         unsigned long iflags;
1142
1143         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1144             || sfp->closed)
1145                 return POLLERR;
1146         poll_wait(filp, &sfp->read_wait, wait);
1147         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1148         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1149                 /* if any read waiting, flag it */
1150                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1151                         res = POLLIN | POLLRDNORM;
1152                 ++count;
1153         }
1154         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1155
1156         if (sdp->detached)
1157                 res |= POLLHUP;
1158         else if (!sfp->cmd_q) {
1159                 if (0 == count)
1160                         res |= POLLOUT | POLLWRNORM;
1161         } else if (count < SG_MAX_QUEUE)
1162                 res |= POLLOUT | POLLWRNORM;
1163         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1164                                    sdp->disk->disk_name, (int) res));
1165         return res;
1166 }
1167
1168 static int
1169 sg_fasync(int fd, struct file *filp, int mode)
1170 {
1171         int retval;
1172         Sg_device *sdp;
1173         Sg_fd *sfp;
1174
1175         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1176                 return -ENXIO;
1177         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1178                                    sdp->disk->disk_name, mode));
1179
1180         retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
1181         return (retval < 0) ? retval : 0;
1182 }
1183
1184 static int
1185 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1186 {
1187         Sg_fd *sfp;
1188         unsigned long offset, len, sa;
1189         Sg_scatter_hold *rsv_schp;
1190         int k, length;
1191
1192         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1193                 return VM_FAULT_SIGBUS;
1194         rsv_schp = &sfp->reserve;
1195         offset = vmf->pgoff << PAGE_SHIFT;
1196         if (offset >= rsv_schp->bufflen)
1197                 return VM_FAULT_SIGBUS;
1198         SCSI_LOG_TIMEOUT(3, printk("sg_vma_fault: offset=%lu, scatg=%d\n",
1199                                    offset, rsv_schp->k_use_sg));
1200         sa = vma->vm_start;
1201         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1202         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1203                 len = vma->vm_end - sa;
1204                 len = (len < length) ? len : length;
1205                 if (offset < len) {
1206                         struct page *page = nth_page(rsv_schp->pages[k],
1207                                                      offset >> PAGE_SHIFT);
1208                         get_page(page); /* increment page count */
1209                         vmf->page = page;
1210                         return 0; /* success */
1211                 }
1212                 sa += len;
1213                 offset -= len;
1214         }
1215
1216         return VM_FAULT_SIGBUS;
1217 }
1218
1219 static struct vm_operations_struct sg_mmap_vm_ops = {
1220         .fault = sg_vma_fault,
1221 };
1222
1223 static int
1224 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1225 {
1226         Sg_fd *sfp;
1227         unsigned long req_sz, len, sa;
1228         Sg_scatter_hold *rsv_schp;
1229         int k, length;
1230
1231         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1232                 return -ENXIO;
1233         req_sz = vma->vm_end - vma->vm_start;
1234         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1235                                    (void *) vma->vm_start, (int) req_sz));
1236         if (vma->vm_pgoff)
1237                 return -EINVAL; /* want no offset */
1238         rsv_schp = &sfp->reserve;
1239         if (req_sz > rsv_schp->bufflen)
1240                 return -ENOMEM; /* cannot map more than reserved buffer */
1241
1242         sa = vma->vm_start;
1243         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1244         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1245                 len = vma->vm_end - sa;
1246                 len = (len < length) ? len : length;
1247                 sa += len;
1248         }
1249
1250         sfp->mmap_called = 1;
1251         vma->vm_flags |= VM_RESERVED;
1252         vma->vm_private_data = sfp;
1253         vma->vm_ops = &sg_mmap_vm_ops;
1254         return 0;
1255 }
1256
1257 /* This function is a "bottom half" handler that is called by the
1258  * mid level when a command is completed (or has failed). */
1259 static void
1260 sg_cmd_done(void *data, char *sense, int result, int resid)
1261 {
1262         Sg_request *srp = data;
1263         Sg_device *sdp = NULL;
1264         Sg_fd *sfp;
1265         unsigned long iflags;
1266         unsigned int ms;
1267
1268         if (NULL == srp) {
1269                 printk(KERN_ERR "sg_cmd_done: NULL request\n");
1270                 return;
1271         }
1272         sfp = srp->parentfp;
1273         if (sfp)
1274                 sdp = sfp->parentdp;
1275         if ((NULL == sdp) || sdp->detached) {
1276                 printk(KERN_INFO "sg_cmd_done: device detached\n");
1277                 return;
1278         }
1279
1280
1281         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1282                 sdp->disk->disk_name, srp->header.pack_id, result));
1283         srp->header.resid = resid;
1284         ms = jiffies_to_msecs(jiffies);
1285         srp->header.duration = (ms > srp->header.duration) ?
1286                                 (ms - srp->header.duration) : 0;
1287         if (0 != result) {
1288                 struct scsi_sense_hdr sshdr;
1289
1290                 srp->header.status = 0xff & result;
1291                 srp->header.masked_status = status_byte(result);
1292                 srp->header.msg_status = msg_byte(result);
1293                 srp->header.host_status = host_byte(result);
1294                 srp->header.driver_status = driver_byte(result);
1295                 if ((sdp->sgdebug > 0) &&
1296                     ((CHECK_CONDITION == srp->header.masked_status) ||
1297                      (COMMAND_TERMINATED == srp->header.masked_status)))
1298                         __scsi_print_sense("sg_cmd_done", sense,
1299                                            SCSI_SENSE_BUFFERSIZE);
1300
1301                 /* Following if statement is a patch supplied by Eric Youngdale */
1302                 if (driver_byte(result) != 0
1303                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1304                     && !scsi_sense_is_deferred(&sshdr)
1305                     && sshdr.sense_key == UNIT_ATTENTION
1306                     && sdp->device->removable) {
1307                         /* Detected possible disc change. Set the bit - this */
1308                         /* may be used if there are filesystems using this device */
1309                         sdp->device->changed = 1;
1310                 }
1311         }
1312         /* Rely on write phase to clean out srp status values, so no "else" */
1313
1314         if (sfp->closed) {      /* whoops this fd already released, cleanup */
1315                 SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1316                 sg_finish_rem_req(srp);
1317                 srp = NULL;
1318                 if (NULL == sfp->headrp) {
1319                         SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, final cleanup\n"));
1320                         if (0 == sg_remove_sfp(sdp, sfp)) {     /* device still present */
1321                                 scsi_device_put(sdp->device);
1322                         }
1323                         sfp = NULL;
1324                 }
1325         } else if (srp && srp->orphan) {
1326                 if (sfp->keep_orphan)
1327                         srp->sg_io_owned = 0;
1328                 else {
1329                         sg_finish_rem_req(srp);
1330                         srp = NULL;
1331                 }
1332         }
1333         if (sfp && srp) {
1334                 /* Now wake up any sg_read() that is waiting for this packet. */
1335                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1336                 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1337                 srp->done = 1;
1338                 wake_up_interruptible(&sfp->read_wait);
1339                 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1340         }
1341 }
1342
1343 static struct file_operations sg_fops = {
1344         .owner = THIS_MODULE,
1345         .read = sg_read,
1346         .write = sg_write,
1347         .poll = sg_poll,
1348         .ioctl = sg_ioctl,
1349 #ifdef CONFIG_COMPAT
1350         .compat_ioctl = sg_compat_ioctl,
1351 #endif
1352         .open = sg_open,
1353         .mmap = sg_mmap,
1354         .release = sg_release,
1355         .fasync = sg_fasync,
1356 };
1357
1358 static struct class *sg_sysfs_class;
1359
1360 static int sg_sysfs_valid = 0;
1361
1362 static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1363 {
1364         struct request_queue *q = scsidp->request_queue;
1365         Sg_device *sdp;
1366         unsigned long iflags;
1367         int error;
1368         u32 k;
1369
1370         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1371         if (!sdp) {
1372                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1373                 return ERR_PTR(-ENOMEM);
1374         }
1375         error = -ENOMEM;
1376         if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) {
1377                 printk(KERN_WARNING "idr expansion Sg_device failure\n");
1378                 goto out;
1379         }
1380
1381         write_lock_irqsave(&sg_index_lock, iflags);
1382         error = idr_get_new(&sg_index_idr, sdp, &k);
1383         write_unlock_irqrestore(&sg_index_lock, iflags);
1384
1385         if (error) {
1386                 printk(KERN_WARNING "idr allocation Sg_device failure: %d\n",
1387                        error);
1388                 goto out;
1389         }
1390
1391         if (unlikely(k >= SG_MAX_DEVS))
1392                 goto overflow;
1393
1394         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1395         sprintf(disk->disk_name, "sg%d", k);
1396         disk->first_minor = k;
1397         sdp->disk = disk;
1398         sdp->device = scsidp;
1399         init_waitqueue_head(&sdp->o_excl_wait);
1400         sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments);
1401         sdp->index = k;
1402
1403         error = 0;
1404  out:
1405         if (error) {
1406                 kfree(sdp);
1407                 return ERR_PTR(error);
1408         }
1409         return sdp;
1410
1411  overflow:
1412         sdev_printk(KERN_WARNING, scsidp,
1413                     "Unable to attach sg device type=%d, minor "
1414                     "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1415         error = -ENODEV;
1416         goto out;
1417 }
1418
1419 static int
1420 sg_add(struct device *cl_dev, struct class_interface *cl_intf)
1421 {
1422         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1423         struct gendisk *disk;
1424         Sg_device *sdp = NULL;
1425         struct cdev * cdev = NULL;
1426         int error;
1427         unsigned long iflags;
1428
1429         disk = alloc_disk(1);
1430         if (!disk) {
1431                 printk(KERN_WARNING "alloc_disk failed\n");
1432                 return -ENOMEM;
1433         }
1434         disk->major = SCSI_GENERIC_MAJOR;
1435
1436         error = -ENOMEM;
1437         cdev = cdev_alloc();
1438         if (!cdev) {
1439                 printk(KERN_WARNING "cdev_alloc failed\n");
1440                 goto out;
1441         }
1442         cdev->owner = THIS_MODULE;
1443         cdev->ops = &sg_fops;
1444
1445         sdp = sg_alloc(disk, scsidp);
1446         if (IS_ERR(sdp)) {
1447                 printk(KERN_WARNING "sg_alloc failed\n");
1448                 error = PTR_ERR(sdp);
1449                 goto out;
1450         }
1451
1452         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1453         if (error)
1454                 goto cdev_add_err;
1455
1456         sdp->cdev = cdev;
1457         if (sg_sysfs_valid) {
1458                 struct device *sg_class_member;
1459
1460                 sg_class_member = device_create_drvdata(sg_sysfs_class,
1461                                                         cl_dev->parent,
1462                                                         MKDEV(SCSI_GENERIC_MAJOR,
1463                                                               sdp->index),
1464                                                         sdp,
1465                                                         "%s", disk->disk_name);
1466                 if (IS_ERR(sg_class_member)) {
1467                         printk(KERN_ERR "sg_add: "
1468                                "device_create failed\n");
1469                         error = PTR_ERR(sg_class_member);
1470                         goto cdev_add_err;
1471                 }
1472                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1473                                           &sg_class_member->kobj, "generic");
1474                 if (error)
1475                         printk(KERN_ERR "sg_add: unable to make symlink "
1476                                         "'generic' back to sg%d\n", sdp->index);
1477         } else
1478                 printk(KERN_WARNING "sg_add: sg_sys Invalid\n");
1479
1480         sdev_printk(KERN_NOTICE, scsidp,
1481                     "Attached scsi generic sg%d type %d\n", sdp->index,
1482                     scsidp->type);
1483
1484         dev_set_drvdata(cl_dev, sdp);
1485
1486         return 0;
1487
1488 cdev_add_err:
1489         write_lock_irqsave(&sg_index_lock, iflags);
1490         idr_remove(&sg_index_idr, sdp->index);
1491         write_unlock_irqrestore(&sg_index_lock, iflags);
1492         kfree(sdp);
1493
1494 out:
1495         put_disk(disk);
1496         if (cdev)
1497                 cdev_del(cdev);
1498         return error;
1499 }
1500
1501 static void
1502 sg_remove(struct device *cl_dev, struct class_interface *cl_intf)
1503 {
1504         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1505         Sg_device *sdp = dev_get_drvdata(cl_dev);
1506         unsigned long iflags;
1507         Sg_fd *sfp;
1508         Sg_fd *tsfp;
1509         Sg_request *srp;
1510         Sg_request *tsrp;
1511         int delay;
1512
1513         if (!sdp)
1514                 return;
1515
1516         delay = 0;
1517         write_lock_irqsave(&sg_index_lock, iflags);
1518         if (sdp->headfp) {
1519                 sdp->detached = 1;
1520                 for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1521                         tsfp = sfp->nextfp;
1522                         for (srp = sfp->headrp; srp; srp = tsrp) {
1523                                 tsrp = srp->nextrp;
1524                                 if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
1525                                         sg_finish_rem_req(srp);
1526                         }
1527                         if (sfp->closed) {
1528                                 scsi_device_put(sdp->device);
1529                                 __sg_remove_sfp(sdp, sfp);
1530                         } else {
1531                                 delay = 1;
1532                                 wake_up_interruptible(&sfp->read_wait);
1533                                 kill_fasync(&sfp->async_qp, SIGPOLL,
1534                                             POLL_HUP);
1535                         }
1536                 }
1537                 SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d, dirty\n", sdp->index));
1538                 if (NULL == sdp->headfp) {
1539                         idr_remove(&sg_index_idr, sdp->index);
1540                 }
1541         } else {        /* nothing active, simple case */
1542                 SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d\n", sdp->index));
1543                 idr_remove(&sg_index_idr, sdp->index);
1544         }
1545         write_unlock_irqrestore(&sg_index_lock, iflags);
1546
1547         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1548         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1549         cdev_del(sdp->cdev);
1550         sdp->cdev = NULL;
1551         put_disk(sdp->disk);
1552         sdp->disk = NULL;
1553         if (NULL == sdp->headfp)
1554                 kfree(sdp);
1555
1556         if (delay)
1557                 msleep(10);     /* dirty detach so delay device destruction */
1558 }
1559
1560 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1561 module_param_named(def_reserved_size, def_reserved_size, int,
1562                    S_IRUGO | S_IWUSR);
1563 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1564
1565 MODULE_AUTHOR("Douglas Gilbert");
1566 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1567 MODULE_LICENSE("GPL");
1568 MODULE_VERSION(SG_VERSION_STR);
1569 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1570
1571 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1572                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1573 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1574 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1575
1576 static int __init
1577 init_sg(void)
1578 {
1579         int rc;
1580
1581         if (scatter_elem_sz < PAGE_SIZE) {
1582                 scatter_elem_sz = PAGE_SIZE;
1583                 scatter_elem_sz_prev = scatter_elem_sz;
1584         }
1585         if (def_reserved_size >= 0)
1586                 sg_big_buff = def_reserved_size;
1587         else
1588                 def_reserved_size = sg_big_buff;
1589
1590         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1591                                     SG_MAX_DEVS, "sg");
1592         if (rc)
1593                 return rc;
1594         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1595         if ( IS_ERR(sg_sysfs_class) ) {
1596                 rc = PTR_ERR(sg_sysfs_class);
1597                 goto err_out;
1598         }
1599         sg_sysfs_valid = 1;
1600         rc = scsi_register_interface(&sg_interface);
1601         if (0 == rc) {
1602 #ifdef CONFIG_SCSI_PROC_FS
1603                 sg_proc_init();
1604 #endif                          /* CONFIG_SCSI_PROC_FS */
1605                 return 0;
1606         }
1607         class_destroy(sg_sysfs_class);
1608 err_out:
1609         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1610         return rc;
1611 }
1612
1613 static void __exit
1614 exit_sg(void)
1615 {
1616 #ifdef CONFIG_SCSI_PROC_FS
1617         sg_proc_cleanup();
1618 #endif                          /* CONFIG_SCSI_PROC_FS */
1619         scsi_unregister_interface(&sg_interface);
1620         class_destroy(sg_sysfs_class);
1621         sg_sysfs_valid = 0;
1622         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1623                                  SG_MAX_DEVS);
1624         idr_destroy(&sg_index_idr);
1625 }
1626
1627 static int __sg_start_req(struct sg_request *srp, struct sg_io_hdr *hp,
1628                           unsigned char *cmd)
1629 {
1630         struct sg_fd *sfp = srp->parentfp;
1631         struct request_queue *q = sfp->parentdp->device->request_queue;
1632         struct request *rq;
1633         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1634
1635         rq = blk_get_request(q, rw, GFP_ATOMIC);
1636         if (!rq)
1637                 return -ENOMEM;
1638
1639         memcpy(rq->cmd, cmd, hp->cmd_len);
1640
1641         rq->cmd_len = hp->cmd_len;
1642         rq->cmd_type = REQ_TYPE_BLOCK_PC;
1643
1644         srp->rq = rq;
1645         rq->end_io_data = srp;
1646         rq->sense = srp->sense_b;
1647         rq->retries = SG_DEFAULT_RETRIES;
1648
1649         return 0;
1650 }
1651
1652 static int sg_start_req(Sg_request *srp, unsigned char *cmd)
1653 {
1654         int res;
1655         Sg_fd *sfp = srp->parentfp;
1656         sg_io_hdr_t *hp = &srp->header;
1657         int dxfer_len = (int) hp->dxfer_len;
1658         int dxfer_dir = hp->dxfer_direction;
1659         unsigned long uaddr = (unsigned long)hp->dxferp;
1660         Sg_scatter_hold *req_schp = &srp->data;
1661         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1662         struct request_queue *q = sfp->parentdp->device->request_queue;
1663         unsigned long alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1664         struct rq_map_data map_data;
1665
1666         SCSI_LOG_TIMEOUT(4, printk("sg_start_req: dxfer_len=%d\n", dxfer_len));
1667
1668         res = __sg_start_req(srp, hp, cmd);
1669         if (res)
1670                 return res;
1671
1672         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1673                 return 0;
1674
1675 #ifdef SG_ALLOW_DIO_CODE
1676         if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
1677             (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) &&
1678             (!sfp->parentdp->device->host->unchecked_isa_dma) &&
1679             !(uaddr & alignment) && !(dxfer_len & alignment))
1680                 return sg_build_direct(srp, sfp, dxfer_len);
1681 #endif
1682         if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen))
1683                 sg_link_reserve(sfp, srp, dxfer_len);
1684         else
1685                 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1686
1687         if (!res) {
1688                 struct request *rq = srp->rq;
1689                 Sg_scatter_hold *schp = &srp->data;
1690                 int iovec_count = (int) hp->iovec_count;
1691
1692                 map_data.pages = schp->pages;
1693                 map_data.page_order = schp->page_order;
1694                 map_data.nr_entries = schp->k_use_sg;
1695
1696                 if (iovec_count)
1697                         res = blk_rq_map_user_iov(q, rq, &map_data, hp->dxferp,
1698                                                   iovec_count,
1699                                                   hp->dxfer_len, GFP_ATOMIC);
1700                 else
1701                         res = blk_rq_map_user(q, rq, &map_data, hp->dxferp,
1702                                               hp->dxfer_len, GFP_ATOMIC);
1703
1704                 if (!res)
1705                         srp->bio = rq->bio;
1706         }
1707
1708         return res;
1709 }
1710
1711 static void
1712 sg_finish_rem_req(Sg_request * srp)
1713 {
1714         Sg_fd *sfp = srp->parentfp;
1715         Sg_scatter_hold *req_schp = &srp->data;
1716
1717         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1718         if (srp->res_used)
1719                 sg_unlink_reserve(sfp, srp);
1720         else
1721                 sg_remove_scat(req_schp);
1722
1723         if (srp->rq) {
1724                 if (srp->bio)
1725                         blk_rq_unmap_user(srp->bio);
1726
1727                 blk_put_request(srp->rq);
1728         }
1729
1730         sg_remove_request(sfp, srp);
1731 }
1732
1733 static int
1734 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1735 {
1736         int sg_bufflen = tablesize * sizeof(struct page *);
1737         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1738
1739         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1740         if (!schp->pages)
1741                 return -ENOMEM;
1742         schp->sglist_len = sg_bufflen;
1743         return tablesize;       /* number of scat_gath elements allocated */
1744 }
1745
1746 /* Returns: -ve -> error, 0 -> done, 1 -> try indirect */
1747 static int
1748 sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
1749 {
1750         sg_io_hdr_t *hp = &srp->header;
1751         Sg_scatter_hold *schp = &srp->data;
1752         int res;
1753         struct request *rq = srp->rq;
1754         struct request_queue *q = sfp->parentdp->device->request_queue;
1755
1756         res = blk_rq_map_user(q, rq, NULL, hp->dxferp, dxfer_len, GFP_ATOMIC);
1757         if (res)
1758                 return res;
1759         srp->bio = rq->bio;
1760         schp->dio_in_use = 1;
1761         hp->info |= SG_INFO_DIRECT_IO;
1762         return 0;
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 = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
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[k], order);
1839
1840         if (--order >= 0)
1841                 goto retry;
1842
1843         return -ENOMEM;
1844 }
1845
1846 static int
1847 sg_write_xfer(Sg_request * srp)
1848 {
1849         sg_io_hdr_t *hp = &srp->header;
1850         Sg_scatter_hold *schp = &srp->data;
1851         int num_xfer = 0;
1852         int dxfer_dir = hp->dxfer_direction;
1853         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1854
1855         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_TO_DEV == dxfer_dir) ||
1856             (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1857                 num_xfer = (int) (new_interface ? hp->dxfer_len : hp->flags);
1858                 if (schp->bufflen < num_xfer)
1859                         num_xfer = schp->bufflen;
1860         }
1861         if ((num_xfer <= 0) || (schp->dio_in_use) ||
1862             (new_interface
1863              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1864                 return 0;
1865
1866         SCSI_LOG_TIMEOUT(4, printk("sg_write_xfer: num_xfer=%d, k_use_sg=%d\n",
1867                           num_xfer, schp->k_use_sg));
1868
1869         return 0;
1870 }
1871
1872 static void
1873 sg_remove_scat(Sg_scatter_hold * schp)
1874 {
1875         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1876         if (schp->pages && schp->sglist_len > 0) {
1877                 if (!schp->dio_in_use) {
1878                         int k;
1879
1880                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1881                                 SCSI_LOG_TIMEOUT(5, printk(
1882                                     "sg_remove_scat: k=%d, pg=0x%p\n",
1883                                     k, schp->pages[k]));
1884                                 __free_pages(schp->pages[k], schp->page_order);
1885                         }
1886
1887                         kfree(schp->pages);
1888                 }
1889         }
1890         memset(schp, 0, sizeof (*schp));
1891 }
1892
1893 static int
1894 sg_read_xfer(Sg_request * srp)
1895 {
1896         sg_io_hdr_t *hp = &srp->header;
1897         Sg_scatter_hold *schp = &srp->data;
1898         int num_xfer = 0;
1899         int dxfer_dir = hp->dxfer_direction;
1900         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1901
1902         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_FROM_DEV == dxfer_dir)
1903             || (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1904                 num_xfer = hp->dxfer_len;
1905                 if (schp->bufflen < num_xfer)
1906                         num_xfer = schp->bufflen;
1907         }
1908         if ((num_xfer <= 0) || (schp->dio_in_use) ||
1909             (new_interface
1910              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1911                 return 0;
1912
1913         SCSI_LOG_TIMEOUT(4, printk("sg_read_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
1914                           num_xfer, (int)hp->iovec_count, schp->k_use_sg));
1915         return 0;
1916 }
1917
1918 static int
1919 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1920 {
1921         Sg_scatter_hold *schp = &srp->data;
1922         int k, num;
1923
1924         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
1925                                    num_read_xfer));
1926         if ((!outp) || (num_read_xfer <= 0))
1927                 return 0;
1928
1929         blk_rq_unmap_user(srp->bio);
1930         srp->bio = NULL;
1931
1932         num = 1 << (PAGE_SHIFT + schp->page_order);
1933         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1934                 if (num > num_read_xfer) {
1935                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1936                                            num_read_xfer))
1937                                 return -EFAULT;
1938                         break;
1939                 } else {
1940                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1941                                            num))
1942                                 return -EFAULT;
1943                         num_read_xfer -= num;
1944                         if (num_read_xfer <= 0)
1945                                 break;
1946                         outp += num;
1947                 }
1948         }
1949
1950         return 0;
1951 }
1952
1953 static void
1954 sg_build_reserve(Sg_fd * sfp, int req_size)
1955 {
1956         Sg_scatter_hold *schp = &sfp->reserve;
1957
1958         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
1959         do {
1960                 if (req_size < PAGE_SIZE)
1961                         req_size = PAGE_SIZE;
1962                 if (0 == sg_build_indirect(schp, sfp, req_size))
1963                         return;
1964                 else
1965                         sg_remove_scat(schp);
1966                 req_size >>= 1; /* divide by 2 */
1967         } while (req_size > (PAGE_SIZE / 2));
1968 }
1969
1970 static void
1971 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1972 {
1973         Sg_scatter_hold *req_schp = &srp->data;
1974         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1975         int k, num, rem;
1976
1977         srp->res_used = 1;
1978         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
1979         rem = size;
1980
1981         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1982         for (k = 0; k < rsv_schp->k_use_sg; k++) {
1983                 if (rem <= num) {
1984                         req_schp->k_use_sg = k + 1;
1985                         req_schp->sglist_len = rsv_schp->sglist_len;
1986                         req_schp->pages = rsv_schp->pages;
1987
1988                         req_schp->bufflen = size;
1989                         req_schp->b_malloc_len = rsv_schp->b_malloc_len;
1990                         req_schp->page_order = rsv_schp->page_order;
1991                         break;
1992                 } else
1993                         rem -= num;
1994         }
1995
1996         if (k >= rsv_schp->k_use_sg)
1997                 SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
1998 }
1999
2000 static void
2001 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2002 {
2003         Sg_scatter_hold *req_schp = &srp->data;
2004
2005         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
2006                                    (int) req_schp->k_use_sg));
2007         req_schp->k_use_sg = 0;
2008         req_schp->bufflen = 0;
2009         req_schp->pages = NULL;
2010         req_schp->page_order = 0;
2011         req_schp->sglist_len = 0;
2012         sfp->save_scat_len = 0;
2013         srp->res_used = 0;
2014 }
2015
2016 static Sg_request *
2017 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2018 {
2019         Sg_request *resp;
2020         unsigned long iflags;
2021
2022         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2023         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2024                 /* look for requests that are ready + not SG_IO owned */
2025                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2026                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2027                         resp->done = 2; /* guard against other readers */
2028                         break;
2029                 }
2030         }
2031         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2032         return resp;
2033 }
2034
2035 #ifdef CONFIG_SCSI_PROC_FS
2036 static Sg_request *
2037 sg_get_nth_request(Sg_fd * sfp, int nth)
2038 {
2039         Sg_request *resp;
2040         unsigned long iflags;
2041         int k;
2042
2043         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2044         for (k = 0, resp = sfp->headrp; resp && (k < nth);
2045              ++k, resp = resp->nextrp) ;
2046         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2047         return resp;
2048 }
2049 #endif
2050
2051 /* always adds to end of list */
2052 static Sg_request *
2053 sg_add_request(Sg_fd * sfp)
2054 {
2055         int k;
2056         unsigned long iflags;
2057         Sg_request *resp;
2058         Sg_request *rp = sfp->req_arr;
2059
2060         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2061         resp = sfp->headrp;
2062         if (!resp) {
2063                 memset(rp, 0, sizeof (Sg_request));
2064                 rp->parentfp = sfp;
2065                 resp = rp;
2066                 sfp->headrp = resp;
2067         } else {
2068                 if (0 == sfp->cmd_q)
2069                         resp = NULL;    /* command queuing disallowed */
2070                 else {
2071                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2072                                 if (!rp->parentfp)
2073                                         break;
2074                         }
2075                         if (k < SG_MAX_QUEUE) {
2076                                 memset(rp, 0, sizeof (Sg_request));
2077                                 rp->parentfp = sfp;
2078                                 while (resp->nextrp)
2079                                         resp = resp->nextrp;
2080                                 resp->nextrp = rp;
2081                                 resp = rp;
2082                         } else
2083                                 resp = NULL;
2084                 }
2085         }
2086         if (resp) {
2087                 resp->nextrp = NULL;
2088                 resp->header.duration = jiffies_to_msecs(jiffies);
2089         }
2090         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2091         return resp;
2092 }
2093
2094 /* Return of 1 for found; 0 for not found */
2095 static int
2096 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2097 {
2098         Sg_request *prev_rp;
2099         Sg_request *rp;
2100         unsigned long iflags;
2101         int res = 0;
2102
2103         if ((!sfp) || (!srp) || (!sfp->headrp))
2104                 return res;
2105         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2106         prev_rp = sfp->headrp;
2107         if (srp == prev_rp) {
2108                 sfp->headrp = prev_rp->nextrp;
2109                 prev_rp->parentfp = NULL;
2110                 res = 1;
2111         } else {
2112                 while ((rp = prev_rp->nextrp)) {
2113                         if (srp == rp) {
2114                                 prev_rp->nextrp = rp->nextrp;
2115                                 rp->parentfp = NULL;
2116                                 res = 1;
2117                                 break;
2118                         }
2119                         prev_rp = rp;
2120                 }
2121         }
2122         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2123         return res;
2124 }
2125
2126 #ifdef CONFIG_SCSI_PROC_FS
2127 static Sg_fd *
2128 sg_get_nth_sfp(Sg_device * sdp, int nth)
2129 {
2130         Sg_fd *resp;
2131         unsigned long iflags;
2132         int k;
2133
2134         read_lock_irqsave(&sg_index_lock, iflags);
2135         for (k = 0, resp = sdp->headfp; resp && (k < nth);
2136              ++k, resp = resp->nextfp) ;
2137         read_unlock_irqrestore(&sg_index_lock, iflags);
2138         return resp;
2139 }
2140 #endif
2141
2142 static Sg_fd *
2143 sg_add_sfp(Sg_device * sdp, int dev)
2144 {
2145         Sg_fd *sfp;
2146         unsigned long iflags;
2147         int bufflen;
2148
2149         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2150         if (!sfp)
2151                 return NULL;
2152
2153         init_waitqueue_head(&sfp->read_wait);
2154         rwlock_init(&sfp->rq_list_lock);
2155
2156         sfp->timeout = SG_DEFAULT_TIMEOUT;
2157         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2158         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2159         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2160             sdp->device->host->unchecked_isa_dma : 1;
2161         sfp->cmd_q = SG_DEF_COMMAND_Q;
2162         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2163         sfp->parentdp = sdp;
2164         write_lock_irqsave(&sg_index_lock, iflags);
2165         if (!sdp->headfp)
2166                 sdp->headfp = sfp;
2167         else {                  /* add to tail of existing list */
2168                 Sg_fd *pfp = sdp->headfp;
2169                 while (pfp->nextfp)
2170                         pfp = pfp->nextfp;
2171                 pfp->nextfp = sfp;
2172         }
2173         write_unlock_irqrestore(&sg_index_lock, iflags);
2174         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2175         if (unlikely(sg_big_buff != def_reserved_size))
2176                 sg_big_buff = def_reserved_size;
2177
2178         bufflen = min_t(int, sg_big_buff,
2179                         sdp->device->request_queue->max_sectors * 512);
2180         sg_build_reserve(sfp, bufflen);
2181         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2182                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2183         return sfp;
2184 }
2185
2186 static void
2187 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2188 {
2189         Sg_fd *fp;
2190         Sg_fd *prev_fp;
2191
2192         prev_fp = sdp->headfp;
2193         if (sfp == prev_fp)
2194                 sdp->headfp = prev_fp->nextfp;
2195         else {
2196                 while ((fp = prev_fp->nextfp)) {
2197                         if (sfp == fp) {
2198                                 prev_fp->nextfp = fp->nextfp;
2199                                 break;
2200                         }
2201                         prev_fp = fp;
2202                 }
2203         }
2204         if (sfp->reserve.bufflen > 0) {
2205                 SCSI_LOG_TIMEOUT(6,
2206                         printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2207                         (int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2208                 sg_remove_scat(&sfp->reserve);
2209         }
2210         sfp->parentdp = NULL;
2211         SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2212         kfree(sfp);
2213 }
2214
2215 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2216 static int
2217 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2218 {
2219         Sg_request *srp;
2220         Sg_request *tsrp;
2221         int dirty = 0;
2222         int res = 0;
2223
2224         for (srp = sfp->headrp; srp; srp = tsrp) {
2225                 tsrp = srp->nextrp;
2226                 if (sg_srp_done(srp, sfp))
2227                         sg_finish_rem_req(srp);
2228                 else
2229                         ++dirty;
2230         }
2231         if (0 == dirty) {
2232                 unsigned long iflags;
2233
2234                 write_lock_irqsave(&sg_index_lock, iflags);
2235                 __sg_remove_sfp(sdp, sfp);
2236                 if (sdp->detached && (NULL == sdp->headfp)) {
2237                         idr_remove(&sg_index_idr, sdp->index);
2238                         kfree(sdp);
2239                         res = 1;
2240                 }
2241                 write_unlock_irqrestore(&sg_index_lock, iflags);
2242         } else {
2243                 /* MOD_INC's to inhibit unloading sg and associated adapter driver */
2244                 /* only bump the access_count if we actually succeeded in
2245                  * throwing another counter on the host module */
2246                 scsi_device_get(sdp->device);   /* XXX: retval ignored? */
2247                 sfp->closed = 1;        /* flag dirty state on this fd */
2248                 SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2249                                   dirty));
2250         }
2251         return res;
2252 }
2253
2254 static int
2255 sg_res_in_use(Sg_fd * sfp)
2256 {
2257         const Sg_request *srp;
2258         unsigned long iflags;
2259
2260         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2261         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2262                 if (srp->res_used)
2263                         break;
2264         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2265         return srp ? 1 : 0;
2266 }
2267
2268 #ifdef CONFIG_SCSI_PROC_FS
2269 static int
2270 sg_idr_max_id(int id, void *p, void *data)
2271 {
2272         int *k = data;
2273
2274         if (*k < id)
2275                 *k = id;
2276
2277         return 0;
2278 }
2279
2280 static int
2281 sg_last_dev(void)
2282 {
2283         int k = -1;
2284         unsigned long iflags;
2285
2286         read_lock_irqsave(&sg_index_lock, iflags);
2287         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2288         read_unlock_irqrestore(&sg_index_lock, iflags);
2289         return k + 1;           /* origin 1 */
2290 }
2291 #endif
2292
2293 static Sg_device *
2294 sg_get_dev(int dev)
2295 {
2296         Sg_device *sdp;
2297         unsigned long iflags;
2298
2299         read_lock_irqsave(&sg_index_lock, iflags);
2300         sdp = idr_find(&sg_index_idr, dev);
2301         read_unlock_irqrestore(&sg_index_lock, iflags);
2302
2303         return sdp;
2304 }
2305
2306 #ifdef CONFIG_SCSI_PROC_FS
2307
2308 static struct proc_dir_entry *sg_proc_sgp = NULL;
2309
2310 static char sg_proc_sg_dirname[] = "scsi/sg";
2311
2312 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2313
2314 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2315 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2316                                   size_t count, loff_t *off);
2317 static struct file_operations adio_fops = {
2318         /* .owner, .read and .llseek added in sg_proc_init() */
2319         .open = sg_proc_single_open_adio,
2320         .write = sg_proc_write_adio,
2321         .release = single_release,
2322 };
2323
2324 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2325 static ssize_t sg_proc_write_dressz(struct file *filp,
2326                 const char __user *buffer, size_t count, loff_t *off);
2327 static struct file_operations dressz_fops = {
2328         .open = sg_proc_single_open_dressz,
2329         .write = sg_proc_write_dressz,
2330         .release = single_release,
2331 };
2332
2333 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2334 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2335 static struct file_operations version_fops = {
2336         .open = sg_proc_single_open_version,
2337         .release = single_release,
2338 };
2339
2340 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2341 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2342 static struct file_operations devhdr_fops = {
2343         .open = sg_proc_single_open_devhdr,
2344         .release = single_release,
2345 };
2346
2347 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2348 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2349 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2350 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2351 static void dev_seq_stop(struct seq_file *s, void *v);
2352 static struct file_operations dev_fops = {
2353         .open = sg_proc_open_dev,
2354         .release = seq_release,
2355 };
2356 static struct seq_operations dev_seq_ops = {
2357         .start = dev_seq_start,
2358         .next  = dev_seq_next,
2359         .stop  = dev_seq_stop,
2360         .show  = sg_proc_seq_show_dev,
2361 };
2362
2363 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2364 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2365 static struct file_operations devstrs_fops = {
2366         .open = sg_proc_open_devstrs,
2367         .release = seq_release,
2368 };
2369 static struct seq_operations devstrs_seq_ops = {
2370         .start = dev_seq_start,
2371         .next  = dev_seq_next,
2372         .stop  = dev_seq_stop,
2373         .show  = sg_proc_seq_show_devstrs,
2374 };
2375
2376 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2377 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2378 static struct file_operations debug_fops = {
2379         .open = sg_proc_open_debug,
2380         .release = seq_release,
2381 };
2382 static struct seq_operations debug_seq_ops = {
2383         .start = dev_seq_start,
2384         .next  = dev_seq_next,
2385         .stop  = dev_seq_stop,
2386         .show  = sg_proc_seq_show_debug,
2387 };
2388
2389
2390 struct sg_proc_leaf {
2391         const char * name;
2392         struct file_operations * fops;
2393 };
2394
2395 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2396         {"allow_dio", &adio_fops},
2397         {"debug", &debug_fops},
2398         {"def_reserved_size", &dressz_fops},
2399         {"device_hdr", &devhdr_fops},
2400         {"devices", &dev_fops},
2401         {"device_strs", &devstrs_fops},
2402         {"version", &version_fops}
2403 };
2404
2405 static int
2406 sg_proc_init(void)
2407 {
2408         int k, mask;
2409         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2410         struct sg_proc_leaf * leaf;
2411
2412         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2413         if (!sg_proc_sgp)
2414                 return 1;
2415         for (k = 0; k < num_leaves; ++k) {
2416                 leaf = &sg_proc_leaf_arr[k];
2417                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2418                 leaf->fops->owner = THIS_MODULE;
2419                 leaf->fops->read = seq_read;
2420                 leaf->fops->llseek = seq_lseek;
2421                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2422         }
2423         return 0;
2424 }
2425
2426 static void
2427 sg_proc_cleanup(void)
2428 {
2429         int k;
2430         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2431
2432         if (!sg_proc_sgp)
2433                 return;
2434         for (k = 0; k < num_leaves; ++k)
2435                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2436         remove_proc_entry(sg_proc_sg_dirname, NULL);
2437 }
2438
2439
2440 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2441 {
2442         seq_printf(s, "%d\n", *((int *)s->private));
2443         return 0;
2444 }
2445
2446 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2447 {
2448         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2449 }
2450
2451 static ssize_t
2452 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2453                    size_t count, loff_t *off)
2454 {
2455         int num;
2456         char buff[11];
2457
2458         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2459                 return -EACCES;
2460         num = (count < 10) ? count : 10;
2461         if (copy_from_user(buff, buffer, num))
2462                 return -EFAULT;
2463         buff[num] = '\0';
2464         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2465         return count;
2466 }
2467
2468 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2469 {
2470         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2471 }
2472
2473 static ssize_t
2474 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2475                      size_t count, loff_t *off)
2476 {
2477         int num;
2478         unsigned long k = ULONG_MAX;
2479         char buff[11];
2480
2481         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2482                 return -EACCES;
2483         num = (count < 10) ? count : 10;
2484         if (copy_from_user(buff, buffer, num))
2485                 return -EFAULT;
2486         buff[num] = '\0';
2487         k = simple_strtoul(buff, NULL, 10);
2488         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2489                 sg_big_buff = k;
2490                 return count;
2491         }
2492         return -ERANGE;
2493 }
2494
2495 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2496 {
2497         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2498                    sg_version_date);
2499         return 0;
2500 }
2501
2502 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2503 {
2504         return single_open(file, sg_proc_seq_show_version, NULL);
2505 }
2506
2507 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2508 {
2509         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2510                    "online\n");
2511         return 0;
2512 }
2513
2514 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2515 {
2516         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2517 }
2518
2519 struct sg_proc_deviter {
2520         loff_t  index;
2521         size_t  max;
2522 };
2523
2524 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2525 {
2526         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2527
2528         s->private = it;
2529         if (! it)
2530                 return NULL;
2531
2532         it->index = *pos;
2533         it->max = sg_last_dev();
2534         if (it->index >= it->max)
2535                 return NULL;
2536         return it;
2537 }
2538
2539 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2540 {
2541         struct sg_proc_deviter * it = s->private;
2542
2543         *pos = ++it->index;
2544         return (it->index < it->max) ? it : NULL;
2545 }
2546
2547 static void dev_seq_stop(struct seq_file *s, void *v)
2548 {
2549         kfree(s->private);
2550 }
2551
2552 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2553 {
2554         return seq_open(file, &dev_seq_ops);
2555 }
2556
2557 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2558 {
2559         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2560         Sg_device *sdp;
2561         struct scsi_device *scsidp;
2562
2563         sdp = it ? sg_get_dev(it->index) : NULL;
2564         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2565                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2566                               scsidp->host->host_no, scsidp->channel,
2567                               scsidp->id, scsidp->lun, (int) scsidp->type,
2568                               1,
2569                               (int) scsidp->queue_depth,
2570                               (int) scsidp->device_busy,
2571                               (int) scsi_device_online(scsidp));
2572         else
2573                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2574         return 0;
2575 }
2576
2577 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2578 {
2579         return seq_open(file, &devstrs_seq_ops);
2580 }
2581
2582 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2583 {
2584         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2585         Sg_device *sdp;
2586         struct scsi_device *scsidp;
2587
2588         sdp = it ? sg_get_dev(it->index) : NULL;
2589         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2590                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2591                            scsidp->vendor, scsidp->model, scsidp->rev);
2592         else
2593                 seq_printf(s, "<no active device>\n");
2594         return 0;
2595 }
2596
2597 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2598 {
2599         int k, m, new_interface, blen, usg;
2600         Sg_request *srp;
2601         Sg_fd *fp;
2602         const sg_io_hdr_t *hp;
2603         const char * cp;
2604         unsigned int ms;
2605
2606         for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
2607                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2608                            "(res)sgat=%d low_dma=%d\n", k + 1,
2609                            jiffies_to_msecs(fp->timeout),
2610                            fp->reserve.bufflen,
2611                            (int) fp->reserve.k_use_sg,
2612                            (int) fp->low_dma);
2613                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2614                            (int) fp->cmd_q, (int) fp->force_packid,
2615                            (int) fp->keep_orphan, (int) fp->closed);
2616                 for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
2617                         hp = &srp->header;
2618                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2619                         if (srp->res_used) {
2620                                 if (new_interface &&
2621                                     (SG_FLAG_MMAP_IO & hp->flags))
2622                                         cp = "     mmap>> ";
2623                                 else
2624                                         cp = "     rb>> ";
2625                         } else {
2626                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2627                                         cp = "     dio>> ";
2628                                 else
2629                                         cp = "     ";
2630                         }
2631                         seq_printf(s, cp);
2632                         blen = srp->data.bufflen;
2633                         usg = srp->data.k_use_sg;
2634                         seq_printf(s, srp->done ?
2635                                    ((1 == srp->done) ?  "rcv:" : "fin:")
2636                                    : "act:");
2637                         seq_printf(s, " id=%d blen=%d",
2638                                    srp->header.pack_id, blen);
2639                         if (srp->done)
2640                                 seq_printf(s, " dur=%d", hp->duration);
2641                         else {
2642                                 ms = jiffies_to_msecs(jiffies);
2643                                 seq_printf(s, " t_o/elap=%d/%d",
2644                                         (new_interface ? hp->timeout :
2645                                                   jiffies_to_msecs(fp->timeout)),
2646                                         (ms > hp->duration ? ms - hp->duration : 0));
2647                         }
2648                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2649                                    (int) srp->data.cmd_opcode);
2650                 }
2651                 if (0 == m)
2652                         seq_printf(s, "     No requests active\n");
2653         }
2654 }
2655
2656 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2657 {
2658         return seq_open(file, &debug_seq_ops);
2659 }
2660
2661 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2662 {
2663         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2664         Sg_device *sdp;
2665
2666         if (it && (0 == it->index)) {
2667                 seq_printf(s, "max_active_device=%d(origin 1)\n",
2668                            (int)it->max);
2669                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2670         }
2671         sdp = it ? sg_get_dev(it->index) : NULL;
2672         if (sdp) {
2673                 struct scsi_device *scsidp = sdp->device;
2674
2675                 if (NULL == scsidp) {
2676                         seq_printf(s, "device %d detached ??\n",
2677                                    (int)it->index);
2678                         return 0;
2679                 }
2680
2681                 if (sg_get_nth_sfp(sdp, 0)) {
2682                         seq_printf(s, " >>> device=%s ",
2683                                 sdp->disk->disk_name);
2684                         if (sdp->detached)
2685                                 seq_printf(s, "detached pending close ");
2686                         else
2687                                 seq_printf
2688                                     (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2689                                      scsidp->host->host_no,
2690                                      scsidp->channel, scsidp->id,
2691                                      scsidp->lun,
2692                                      scsidp->host->hostt->emulated);
2693                         seq_printf(s, " sg_tablesize=%d excl=%d\n",
2694                                    sdp->sg_tablesize, sdp->exclude);
2695                 }
2696                 sg_proc_debug_helper(s, sdp);
2697         }
2698         return 0;
2699 }
2700
2701 #endif                          /* CONFIG_SCSI_PROC_FS */
2702
2703 module_init(init_sg);
2704 module_exit(exit_sg);