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   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         if (hp->dxfer_direction == SG_DXFER_TO_DEV)
 619                 hp->dxferp = (char __user *)buf + cmd_size;
 620         else
 621                 hp->dxferp = NULL;
 622         hp->sbp = NULL;
 623         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 624         hp->flags = input_size; /* structure abuse ... */
 625         hp->pack_id = old_hdr.pack_id;
 626         hp->usr_ptr = NULL;
 627         if (__copy_from_user(cmnd, buf, cmd_size))
 628                 return -EFAULT;
 629         /*
 630          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 631          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 632          * is a non-zero input_size, so emit a warning.
 633          */
 634         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 635                 static char cmd[TASK_COMM_LEN];
 636                 if (strcmp(current->comm, cmd) && printk_ratelimit()) {
 637                         printk(KERN_WARNING
 638                                "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
 639                                "guessing data in;\n" KERN_WARNING "   "
 640                                "program %s not setting count and/or reply_len properly\n",
 641                                old_hdr.reply_len - (int)SZ_SG_HEADER,
 642                                input_size, (unsigned int) cmnd[0],
 643                                current->comm);
 644                         strcpy(cmd, current->comm);
 645                 }
 646         }
 647         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 648         return (k < 0) ? k : count;
 649 }
 650
 651 static ssize_t
 652 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 653                  size_t count, int blocking, int read_only,
 654                  Sg_request **o_srp)
 655 {
 656         int k;
 657         Sg_request *srp;
 658         sg_io_hdr_t *hp;
 659         unsigned char cmnd[MAX_COMMAND_SIZE];
 660         int timeout;
 661         unsigned long ul_timeout;
 662
 663         if (count < SZ_SG_IO_HDR)
 664                 return -EINVAL;
 665         if (!access_ok(VERIFY_READ, buf, count))
 666                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 667
 668         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 669         if (!(srp = sg_add_request(sfp))) {
 670                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
 671                 return -EDOM;
 672         }
 673         hp = &srp->header;
 674         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 675                 sg_remove_request(sfp, srp);
 676                 return -EFAULT;
 677         }
 678         if (hp->interface_id != 'S') {
 679                 sg_remove_request(sfp, srp);
 680                 return -ENOSYS;
 681         }
 682         if (hp->flags & SG_FLAG_MMAP_IO) {
 683                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 684                         sg_remove_request(sfp, srp);
 685                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 686                 }
 687                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 688                         sg_remove_request(sfp, srp);
 689                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 690                 }
 691                 if (sg_res_in_use(sfp)) {
 692                         sg_remove_request(sfp, srp);
 693                         return -EBUSY;  /* reserve buffer already being used */
 694                 }
 695         }
 696         ul_timeout = msecs_to_jiffies(srp->header.timeout);
 697         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 698         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 699                 sg_remove_request(sfp, srp);
 700                 return -EMSGSIZE;
 701         }
 702         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
 703                 sg_remove_request(sfp, srp);
 704                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 705         }
 706         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 707                 sg_remove_request(sfp, srp);
 708                 return -EFAULT;
 709         }
 710         if (read_only && sg_allow_access(file, cmnd)) {
 711                 sg_remove_request(sfp, srp);
 712                 return -EPERM;
 713         }
 714         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 715         if (k < 0)
 716                 return k;
 717         if (o_srp)
 718                 *o_srp = srp;
 719         return count;
 720 }
 721
 722 static int
 723 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 724                 unsigned char *cmnd, int timeout, int blocking)
 725 {
 726         int k, data_dir;
 727         Sg_device *sdp = sfp->parentdp;
 728         sg_io_hdr_t *hp = &srp->header;
 729
 730         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 731         hp->status = 0;
 732         hp->masked_status = 0;
 733         hp->msg_status = 0;
 734         hp->info = 0;
 735         hp->host_status = 0;
 736         hp->driver_status = 0;
 737         hp->resid = 0;
 738         SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 739                           (int) cmnd[0], (int) hp->cmd_len));
 740
 741         k = sg_start_req(srp, cmnd);
 742         if (k) {
 743                 SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k));
 744                 sg_finish_rem_req(srp);
 745                 return k;       /* probably out of space --> ENOMEM */
 746         }
 747         if ((k = sg_write_xfer(srp))) {
 748                 SCSI_LOG_TIMEOUT(1, printk("sg_common_write: write_xfer, bad address\n"));
 749                 sg_finish_rem_req(srp);
 750                 return k;
 751         }
 752         if (sdp->detached) {
 753                 sg_finish_rem_req(srp);
 754                 return -ENODEV;
 755         }
 756
 757         switch (hp->dxfer_direction) {
 758         case SG_DXFER_TO_FROM_DEV:
 759         case SG_DXFER_FROM_DEV:
 760                 data_dir = DMA_FROM_DEVICE;
 761                 break;
 762         case SG_DXFER_TO_DEV:
 763                 data_dir = DMA_TO_DEVICE;
 764                 break;
 765         case SG_DXFER_UNKNOWN:
 766                 data_dir = DMA_BIDIRECTIONAL;
 767                 break;
 768         default:
 769                 data_dir = DMA_NONE;
 770                 break;
 771         }
 772         hp->duration = jiffies_to_msecs(jiffies);
 773
 774         srp->rq->timeout = timeout;
 775         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 776                               srp->rq, 1, sg_rq_end_io);
 777         return 0;
 778 }
 779
 780 static int
 781 sg_srp_done(Sg_request *srp, Sg_fd *sfp)
 782 {
 783         unsigned long iflags;
 784         int done;
 785
 786         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 787         done = srp->done;
 788         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 789         return done;
 790 }
 791
 792 static int
 793 sg_ioctl(struct inode *inode, struct file *filp,
 794          unsigned int cmd_in, unsigned long arg)
 795 {
 796         void __user *p = (void __user *)arg;
 797         int __user *ip = p;
 798         int result, val, read_only;
 799         Sg_device *sdp;
 800         Sg_fd *sfp;
 801         Sg_request *srp;
 802         unsigned long iflags;
 803
 804         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 805                 return -ENXIO;
 806
 807         SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
 808                                    sdp->disk->disk_name, (int) cmd_in));
 809         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 810
 811         switch (cmd_in) {
 812         case SG_IO:
 813                 {
 814                         int blocking = 1;       /* ignore O_NONBLOCK flag */
 815
 816                         if (sdp->detached)
 817                                 return -ENODEV;
 818                         if (!scsi_block_when_processing_errors(sdp->device))
 819                                 return -ENXIO;
 820                         if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 821                                 return -EFAULT;
 822                         result =
 823                             sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 824                                          blocking, read_only, &srp);
 825                         if (result < 0)
 826                                 return result;
 827                         srp->sg_io_owned = 1;
 828                         while (1) {
 829                                 result = 0;     /* following macro to beat race condition */
 830                                 __wait_event_interruptible(sfp->read_wait,
 831                                         (sdp->detached || sfp->closed || sg_srp_done(srp, sfp)),
 832                                                            result);
 833                                 if (sdp->detached)
 834                                         return -ENODEV;
 835                                 if (sfp->closed)
 836                                         return 0;       /* request packet dropped already */
 837                                 if (0 == result)
 838                                         break;
 839                                 srp->orphan = 1;
 840                                 return result;  /* -ERESTARTSYS because signal hit process */
 841                         }
 842                         write_lock_irqsave(&sfp->rq_list_lock, iflags);
 843                         srp->done = 2;
 844                         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 845                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 846                         return (result < 0) ? result : 0;
 847                 }
 848         case SG_SET_TIMEOUT:
 849                 result = get_user(val, ip);
 850                 if (result)
 851                         return result;
 852                 if (val < 0)
 853                         return -EIO;
 854                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
 855                     val = MULDIV (INT_MAX, USER_HZ, HZ);
 856                 sfp->timeout_user = val;
 857                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
 858
 859                 return 0;
 860         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 861                                 /* strange ..., for backward compatibility */
 862                 return sfp->timeout_user;
 863         case SG_SET_FORCE_LOW_DMA:
 864                 result = get_user(val, ip);
 865                 if (result)
 866                         return result;
 867                 if (val) {
 868                         sfp->low_dma = 1;
 869                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
 870                                 val = (int) sfp->reserve.bufflen;
 871                                 sg_remove_scat(&sfp->reserve);
 872                                 sg_build_reserve(sfp, val);
 873                         }
 874                 } else {
 875                         if (sdp->detached)
 876                                 return -ENODEV;
 877                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
 878                 }
 879                 return 0;
 880         case SG_GET_LOW_DMA:
 881                 return put_user((int) sfp->low_dma, ip);
 882         case SG_GET_SCSI_ID:
 883                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 884                         return -EFAULT;
 885                 else {
 886                         sg_scsi_id_t __user *sg_idp = p;
 887
 888                         if (sdp->detached)
 889                                 return -ENODEV;
 890                         __put_user((int) sdp->device->host->host_no,
 891                                    &sg_idp->host_no);
 892                         __put_user((int) sdp->device->channel,
 893                                    &sg_idp->channel);
 894                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 895                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 896                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 897                         __put_user((short) sdp->device->host->cmd_per_lun,
 898                                    &sg_idp->h_cmd_per_lun);
 899                         __put_user((short) sdp->device->queue_depth,
 900                                    &sg_idp->d_queue_depth);
 901                         __put_user(0, &sg_idp->unused[0]);
 902                         __put_user(0, &sg_idp->unused[1]);
 903                         return 0;
 904                 }
 905         case SG_SET_FORCE_PACK_ID:
 906                 result = get_user(val, ip);
 907                 if (result)
 908                         return result;
 909                 sfp->force_packid = val ? 1 : 0;
 910                 return 0;
 911         case SG_GET_PACK_ID:
 912                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 913                         return -EFAULT;
 914                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 915                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
 916                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 917                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 918                                                        iflags);
 919                                 __put_user(srp->header.pack_id, ip);
 920                                 return 0;
 921                         }
 922                 }
 923                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 924                 __put_user(-1, ip);
 925                 return 0;
 926         case SG_GET_NUM_WAITING:
 927                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 928                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
 929                         if ((1 == srp->done) && (!srp->sg_io_owned))
 930                                 ++val;
 931                 }
 932                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 933                 return put_user(val, ip);
 934         case SG_GET_SG_TABLESIZE:
 935                 return put_user(sdp->sg_tablesize, ip);
 936         case SG_SET_RESERVED_SIZE:
 937                 result = get_user(val, ip);
 938                 if (result)
 939                         return result;
 940                 if (val < 0)
 941                         return -EINVAL;
 942                 val = min_t(int, val,
 943                                 sdp->device->request_queue->max_sectors * 512);
 944                 if (val != sfp->reserve.bufflen) {
 945                         if (sg_res_in_use(sfp) || sfp->mmap_called)
 946                                 return -EBUSY;
 947                         sg_remove_scat(&sfp->reserve);
 948                         sg_build_reserve(sfp, val);
 949                 }
 950                 return 0;
 951         case SG_GET_RESERVED_SIZE:
 952                 val = min_t(int, sfp->reserve.bufflen,
 953                                 sdp->device->request_queue->max_sectors * 512);
 954                 return put_user(val, ip);
 955         case SG_SET_COMMAND_Q:
 956                 result = get_user(val, ip);
 957                 if (result)
 958                         return result;
 959                 sfp->cmd_q = val ? 1 : 0;
 960                 return 0;
 961         case SG_GET_COMMAND_Q:
 962                 return put_user((int) sfp->cmd_q, ip);
 963         case SG_SET_KEEP_ORPHAN:
 964                 result = get_user(val, ip);
 965                 if (result)
 966                         return result;
 967                 sfp->keep_orphan = val;
 968                 return 0;
 969         case SG_GET_KEEP_ORPHAN:
 970                 return put_user((int) sfp->keep_orphan, ip);
 971         case SG_NEXT_CMD_LEN:
 972                 result = get_user(val, ip);
 973                 if (result)
 974                         return result;
 975                 sfp->next_cmd_len = (val > 0) ? val : 0;
 976                 return 0;
 977         case SG_GET_VERSION_NUM:
 978                 return put_user(sg_version_num, ip);
 979         case SG_GET_ACCESS_COUNT:
 980                 /* faked - we don't have a real access count anymore */
 981                 val = (sdp->device ? 1 : 0);
 982                 return put_user(val, ip);
 983         case SG_GET_REQUEST_TABLE:
 984                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
 985                         return -EFAULT;
 986                 else {
 987                         sg_req_info_t *rinfo;
 988                         unsigned int ms;
 989
 990                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
 991                                                                 GFP_KERNEL);
 992                         if (!rinfo)
 993                                 return -ENOMEM;
 994                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 995                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
 996                              ++val, srp = srp ? srp->nextrp : srp) {
 997                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
 998                                 if (srp) {
 999                                         rinfo[val].req_state = srp->done + 1;
1000                                         rinfo[val].problem =
1001                                             srp->header.masked_status &
1002                                             srp->header.host_status &
1003                                             srp->header.driver_status;
1004                                         if (srp->done)
1005                                                 rinfo[val].duration =
1006                                                         srp->header.duration;
1007                                         else {
1008                                                 ms = jiffies_to_msecs(jiffies);
1009                                                 rinfo[val].duration =
1010                                                     (ms > srp->header.duration) ?
1011                                                     (ms - srp->header.duration) : 0;
1012                                         }
1013                                         rinfo[val].orphan = srp->orphan;
1014                                         rinfo[val].sg_io_owned =
1015                                                         srp->sg_io_owned;
1016                                         rinfo[val].pack_id =
1017                                                         srp->header.pack_id;
1018                                         rinfo[val].usr_ptr =
1019                                                         srp->header.usr_ptr;
1020                                 }
1021                         }
1022                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1023                         result = __copy_to_user(p, rinfo,
1024                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1025                         result = result ? -EFAULT : 0;
1026                         kfree(rinfo);
1027                         return result;
1028                 }
1029         case SG_EMULATED_HOST:
1030                 if (sdp->detached)
1031                         return -ENODEV;
1032                 return put_user(sdp->device->host->hostt->emulated, ip);
1033         case SG_SCSI_RESET:
1034                 if (sdp->detached)
1035                         return -ENODEV;
1036                 if (filp->f_flags & O_NONBLOCK) {
1037                         if (scsi_host_in_recovery(sdp->device->host))
1038                                 return -EBUSY;
1039                 } else if (!scsi_block_when_processing_errors(sdp->device))
1040                         return -EBUSY;
1041                 result = get_user(val, ip);
1042                 if (result)
1043                         return result;
1044                 if (SG_SCSI_RESET_NOTHING == val)
1045                         return 0;
1046                 switch (val) {
1047                 case SG_SCSI_RESET_DEVICE:
1048                         val = SCSI_TRY_RESET_DEVICE;
1049                         break;
1050                 case SG_SCSI_RESET_TARGET:
1051                         val = SCSI_TRY_RESET_TARGET;
1052                         break;
1053                 case SG_SCSI_RESET_BUS:
1054                         val = SCSI_TRY_RESET_BUS;
1055                         break;
1056                 case SG_SCSI_RESET_HOST:
1057                         val = SCSI_TRY_RESET_HOST;
1058                         break;
1059                 default:
1060                         return -EINVAL;
1061                 }
1062                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1063                         return -EACCES;
1064                 return (scsi_reset_provider(sdp->device, val) ==
1065                         SUCCESS) ? 0 : -EIO;
1066         case SCSI_IOCTL_SEND_COMMAND:
1067                 if (sdp->detached)
1068                         return -ENODEV;
1069                 if (read_only) {
1070                         unsigned char opcode = WRITE_6;
1071                         Scsi_Ioctl_Command __user *siocp = p;
1072
1073                         if (copy_from_user(&opcode, siocp->data, 1))
1074                                 return -EFAULT;
1075                         if (sg_allow_access(filp, &opcode))
1076                                 return -EPERM;
1077                 }
1078                 return sg_scsi_ioctl(filp, sdp->device->request_queue, NULL, p);
1079         case SG_SET_DEBUG:
1080                 result = get_user(val, ip);
1081                 if (result)
1082                         return result;
1083                 sdp->sgdebug = (char) val;
1084                 return 0;
1085         case SCSI_IOCTL_GET_IDLUN:
1086         case SCSI_IOCTL_GET_BUS_NUMBER:
1087         case SCSI_IOCTL_PROBE_HOST:
1088         case SG_GET_TRANSFORM:
1089                 if (sdp->detached)
1090                         return -ENODEV;
1091                 return scsi_ioctl(sdp->device, cmd_in, p);
1092         case BLKSECTGET:
1093                 return put_user(sdp->device->request_queue->max_sectors * 512,
1094                                 ip);
1095         case BLKTRACESETUP:
1096                 return blk_trace_setup(sdp->device->request_queue,
1097                                        sdp->disk->disk_name,
1098                                        sdp->device->sdev_gendev.devt,
1099                                        (char *)arg);
1100         case BLKTRACESTART:
1101                 return blk_trace_startstop(sdp->device->request_queue, 1);
1102         case BLKTRACESTOP:
1103                 return blk_trace_startstop(sdp->device->request_queue, 0);
1104         case BLKTRACETEARDOWN:
1105                 return blk_trace_remove(sdp->device->request_queue);
1106         default:
1107                 if (read_only)
1108                         return -EPERM;  /* don't know so take safe approach */
1109                 return scsi_ioctl(sdp->device, cmd_in, p);
1110         }
1111 }
1112
1113 #ifdef CONFIG_COMPAT
1114 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1115 {
1116         Sg_device *sdp;
1117         Sg_fd *sfp;
1118         struct scsi_device *sdev;
1119
1120         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1121                 return -ENXIO;
1122
1123         sdev = sdp->device;
1124         if (sdev->host->hostt->compat_ioctl) {
1125                 int ret;
1126
1127                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1128
1129                 return ret;
1130         }
1131
1132         return -ENOIOCTLCMD;
1133 }
1134 #endif
1135
1136 static unsigned int
1137 sg_poll(struct file *filp, poll_table * wait)
1138 {
1139         unsigned int res = 0;
1140         Sg_device *sdp;
1141         Sg_fd *sfp;
1142         Sg_request *srp;
1143         int count = 0;
1144         unsigned long iflags;
1145
1146         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1147             || sfp->closed)
1148                 return POLLERR;
1149         poll_wait(filp, &sfp->read_wait, wait);
1150         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1151         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1152                 /* if any read waiting, flag it */
1153                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1154                         res = POLLIN | POLLRDNORM;
1155                 ++count;
1156         }
1157         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1158
1159         if (sdp->detached)
1160                 res |= POLLHUP;
1161         else if (!sfp->cmd_q) {
1162                 if (0 == count)
1163                         res |= POLLOUT | POLLWRNORM;
1164         } else if (count < SG_MAX_QUEUE)
1165                 res |= POLLOUT | POLLWRNORM;
1166         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1167                                    sdp->disk->disk_name, (int) res));
1168         return res;
1169 }
1170
1171 static int
1172 sg_fasync(int fd, struct file *filp, int mode)
1173 {
1174         int retval;
1175         Sg_device *sdp;
1176         Sg_fd *sfp;
1177
1178         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1179                 return -ENXIO;
1180         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1181                                    sdp->disk->disk_name, mode));
1182
1183         retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
1184         return (retval < 0) ? retval : 0;
1185 }
1186
1187 static int
1188 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1189 {
1190         Sg_fd *sfp;
1191         unsigned long offset, len, sa;
1192         Sg_scatter_hold *rsv_schp;
1193         int k, length;
1194
1195         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1196                 return VM_FAULT_SIGBUS;
1197         rsv_schp = &sfp->reserve;
1198         offset = vmf->pgoff << PAGE_SHIFT;
1199         if (offset >= rsv_schp->bufflen)
1200                 return VM_FAULT_SIGBUS;
1201         SCSI_LOG_TIMEOUT(3, printk("sg_vma_fault: offset=%lu, scatg=%d\n",
1202                                    offset, rsv_schp->k_use_sg));
1203         sa = vma->vm_start;
1204         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1205         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1206                 len = vma->vm_end - sa;
1207                 len = (len < length) ? len : length;
1208                 if (offset < len) {
1209                         struct page *page = nth_page(rsv_schp->pages[k],
1210                                                      offset >> PAGE_SHIFT);
1211                         get_page(page); /* increment page count */
1212                         vmf->page = page;
1213                         return 0; /* success */
1214                 }
1215                 sa += len;
1216                 offset -= len;
1217         }
1218
1219         return VM_FAULT_SIGBUS;
1220 }
1221
1222 static struct vm_operations_struct sg_mmap_vm_ops = {
1223         .fault = sg_vma_fault,
1224 };
1225
1226 static int
1227 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1228 {
1229         Sg_fd *sfp;
1230         unsigned long req_sz, len, sa;
1231         Sg_scatter_hold *rsv_schp;
1232         int k, length;
1233
1234         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1235                 return -ENXIO;
1236         req_sz = vma->vm_end - vma->vm_start;
1237         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1238                                    (void *) vma->vm_start, (int) req_sz));
1239         if (vma->vm_pgoff)
1240                 return -EINVAL; /* want no offset */
1241         rsv_schp = &sfp->reserve;
1242         if (req_sz > rsv_schp->bufflen)
1243                 return -ENOMEM; /* cannot map more than reserved buffer */
1244
1245         sa = vma->vm_start;
1246         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1247         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1248                 len = vma->vm_end - sa;
1249                 len = (len < length) ? len : length;
1250                 sa += len;
1251         }
1252
1253         sfp->mmap_called = 1;
1254         vma->vm_flags |= VM_RESERVED;
1255         vma->vm_private_data = sfp;
1256         vma->vm_ops = &sg_mmap_vm_ops;
1257         return 0;
1258 }
1259
1260 /* This function is a "bottom half" handler that is called by the
1261  * mid level when a command is completed (or has failed). */
1262 static void
1263 sg_cmd_done(void *data, char *sense, int result, int resid)
1264 {
1265         Sg_request *srp = data;
1266         Sg_device *sdp = NULL;
1267         Sg_fd *sfp;
1268         unsigned long iflags;
1269         unsigned int ms;
1270
1271         if (NULL == srp) {
1272                 printk(KERN_ERR "sg_cmd_done: NULL request\n");
1273                 return;
1274         }
1275         sfp = srp->parentfp;
1276         if (sfp)
1277                 sdp = sfp->parentdp;
1278         if ((NULL == sdp) || sdp->detached) {
1279                 printk(KERN_INFO "sg_cmd_done: device detached\n");
1280                 return;
1281         }
1282
1283
1284         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1285                 sdp->disk->disk_name, srp->header.pack_id, result));
1286         srp->header.resid = resid;
1287         ms = jiffies_to_msecs(jiffies);
1288         srp->header.duration = (ms > srp->header.duration) ?
1289                                 (ms - srp->header.duration) : 0;
1290         if (0 != result) {
1291                 struct scsi_sense_hdr sshdr;
1292
1293                 srp->header.status = 0xff & result;
1294                 srp->header.masked_status = status_byte(result);
1295                 srp->header.msg_status = msg_byte(result);
1296                 srp->header.host_status = host_byte(result);
1297                 srp->header.driver_status = driver_byte(result);
1298                 if ((sdp->sgdebug > 0) &&
1299                     ((CHECK_CONDITION == srp->header.masked_status) ||
1300                      (COMMAND_TERMINATED == srp->header.masked_status)))
1301                         __scsi_print_sense("sg_cmd_done", sense,
1302                                            SCSI_SENSE_BUFFERSIZE);
1303
1304                 /* Following if statement is a patch supplied by Eric Youngdale */
1305                 if (driver_byte(result) != 0
1306                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1307                     && !scsi_sense_is_deferred(&sshdr)
1308                     && sshdr.sense_key == UNIT_ATTENTION
1309                     && sdp->device->removable) {
1310                         /* Detected possible disc change. Set the bit - this */
1311                         /* may be used if there are filesystems using this device */
1312                         sdp->device->changed = 1;
1313                 }
1314         }
1315         /* Rely on write phase to clean out srp status values, so no "else" */
1316
1317         if (sfp->closed) {      /* whoops this fd already released, cleanup */
1318                 SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1319                 sg_finish_rem_req(srp);
1320                 srp = NULL;
1321                 if (NULL == sfp->headrp) {
1322                         SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, final cleanup\n"));
1323                         if (0 == sg_remove_sfp(sdp, sfp)) {     /* device still present */
1324                                 scsi_device_put(sdp->device);
1325                         }
1326                         sfp = NULL;
1327                 }
1328         } else if (srp && srp->orphan) {
1329                 if (sfp->keep_orphan)
1330                         srp->sg_io_owned = 0;
1331                 else {
1332                         sg_finish_rem_req(srp);
1333                         srp = NULL;
1334                 }
1335         }
1336         if (sfp && srp) {
1337                 /* Now wake up any sg_read() that is waiting for this packet. */
1338                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1339                 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1340                 srp->done = 1;
1341                 wake_up_interruptible(&sfp->read_wait);
1342                 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1343         }
1344 }
1345
1346 static struct file_operations sg_fops = {
1347         .owner = THIS_MODULE,
1348         .read = sg_read,
1349         .write = sg_write,
1350         .poll = sg_poll,
1351         .ioctl = sg_ioctl,
1352 #ifdef CONFIG_COMPAT
1353         .compat_ioctl = sg_compat_ioctl,
1354 #endif
1355         .open = sg_open,
1356         .mmap = sg_mmap,
1357         .release = sg_release,
1358         .fasync = sg_fasync,
1359 };
1360
1361 static struct class *sg_sysfs_class;
1362
1363 static int sg_sysfs_valid = 0;
1364
1365 static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1366 {
1367         struct request_queue *q = scsidp->request_queue;
1368         Sg_device *sdp;
1369         unsigned long iflags;
1370         int error;
1371         u32 k;
1372
1373         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1374         if (!sdp) {
1375                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1376                 return ERR_PTR(-ENOMEM);
1377         }
1378         error = -ENOMEM;
1379         if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) {
1380                 printk(KERN_WARNING "idr expansion Sg_device failure\n");
1381                 goto out;
1382         }
1383
1384         write_lock_irqsave(&sg_index_lock, iflags);
1385         error = idr_get_new(&sg_index_idr, sdp, &k);
1386         write_unlock_irqrestore(&sg_index_lock, iflags);
1387
1388         if (error) {
1389                 printk(KERN_WARNING "idr allocation Sg_device failure: %d\n",
1390                        error);
1391                 goto out;
1392         }
1393
1394         if (unlikely(k >= SG_MAX_DEVS))
1395                 goto overflow;
1396
1397         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1398         sprintf(disk->disk_name, "sg%d", k);
1399         disk->first_minor = k;
1400         sdp->disk = disk;
1401         sdp->device = scsidp;
1402         init_waitqueue_head(&sdp->o_excl_wait);
1403         sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments);
1404         sdp->index = k;
1405
1406         error = 0;
1407  out:
1408         if (error) {
1409                 kfree(sdp);
1410                 return ERR_PTR(error);
1411         }
1412         return sdp;
1413
1414  overflow:
1415         sdev_printk(KERN_WARNING, scsidp,
1416                     "Unable to attach sg device type=%d, minor "
1417                     "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1418         error = -ENODEV;
1419         goto out;
1420 }
1421
1422 static int
1423 sg_add(struct device *cl_dev, struct class_interface *cl_intf)
1424 {
1425         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1426         struct gendisk *disk;
1427         Sg_device *sdp = NULL;
1428         struct cdev * cdev = NULL;
1429         int error;
1430         unsigned long iflags;
1431
1432         disk = alloc_disk(1);
1433         if (!disk) {
1434                 printk(KERN_WARNING "alloc_disk failed\n");
1435                 return -ENOMEM;
1436         }
1437         disk->major = SCSI_GENERIC_MAJOR;
1438
1439         error = -ENOMEM;
1440         cdev = cdev_alloc();
1441         if (!cdev) {
1442                 printk(KERN_WARNING "cdev_alloc failed\n");
1443                 goto out;
1444         }
1445         cdev->owner = THIS_MODULE;
1446         cdev->ops = &sg_fops;
1447
1448         sdp = sg_alloc(disk, scsidp);
1449         if (IS_ERR(sdp)) {
1450                 printk(KERN_WARNING "sg_alloc failed\n");
1451                 error = PTR_ERR(sdp);
1452                 goto out;
1453         }
1454
1455         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1456         if (error)
1457                 goto cdev_add_err;
1458
1459         sdp->cdev = cdev;
1460         if (sg_sysfs_valid) {
1461                 struct device *sg_class_member;
1462
1463                 sg_class_member = device_create_drvdata(sg_sysfs_class,
1464                                                         cl_dev->parent,
1465                                                         MKDEV(SCSI_GENERIC_MAJOR,
1466                                                               sdp->index),
1467                                                         sdp,
1468                                                         "%s", disk->disk_name);
1469                 if (IS_ERR(sg_class_member)) {
1470                         printk(KERN_ERR "sg_add: "
1471                                "device_create failed\n");
1472                         error = PTR_ERR(sg_class_member);
1473                         goto cdev_add_err;
1474                 }
1475                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1476                                           &sg_class_member->kobj, "generic");
1477                 if (error)
1478                         printk(KERN_ERR "sg_add: unable to make symlink "
1479                                         "'generic' back to sg%d\n", sdp->index);
1480         } else
1481                 printk(KERN_WARNING "sg_add: sg_sys Invalid\n");
1482
1483         sdev_printk(KERN_NOTICE, scsidp,
1484                     "Attached scsi generic sg%d type %d\n", sdp->index,
1485                     scsidp->type);
1486
1487         dev_set_drvdata(cl_dev, sdp);
1488
1489         return 0;
1490
1491 cdev_add_err:
1492         write_lock_irqsave(&sg_index_lock, iflags);
1493         idr_remove(&sg_index_idr, sdp->index);
1494         write_unlock_irqrestore(&sg_index_lock, iflags);
1495         kfree(sdp);
1496
1497 out:
1498         put_disk(disk);
1499         if (cdev)
1500                 cdev_del(cdev);
1501         return error;
1502 }
1503
1504 static void
1505 sg_remove(struct device *cl_dev, struct class_interface *cl_intf)
1506 {
1507         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1508         Sg_device *sdp = dev_get_drvdata(cl_dev);
1509         unsigned long iflags;
1510         Sg_fd *sfp;
1511         Sg_fd *tsfp;
1512         Sg_request *srp;
1513         Sg_request *tsrp;
1514         int delay;
1515
1516         if (!sdp)
1517                 return;
1518
1519         delay = 0;
1520         write_lock_irqsave(&sg_index_lock, iflags);
1521         if (sdp->headfp) {
1522                 sdp->detached = 1;
1523                 for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1524                         tsfp = sfp->nextfp;
1525                         for (srp = sfp->headrp; srp; srp = tsrp) {
1526                                 tsrp = srp->nextrp;
1527                                 if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
1528                                         sg_finish_rem_req(srp);
1529                         }
1530                         if (sfp->closed) {
1531                                 scsi_device_put(sdp->device);
1532                                 __sg_remove_sfp(sdp, sfp);
1533                         } else {
1534                                 delay = 1;
1535                                 wake_up_interruptible(&sfp->read_wait);
1536                                 kill_fasync(&sfp->async_qp, SIGPOLL,
1537                                             POLL_HUP);
1538                         }
1539                 }
1540                 SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d, dirty\n", sdp->index));
1541                 if (NULL == sdp->headfp) {
1542                         idr_remove(&sg_index_idr, sdp->index);
1543                 }
1544         } else {        /* nothing active, simple case */
1545                 SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d\n", sdp->index));
1546                 idr_remove(&sg_index_idr, sdp->index);
1547         }
1548         write_unlock_irqrestore(&sg_index_lock, iflags);
1549
1550         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1551         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1552         cdev_del(sdp->cdev);
1553         sdp->cdev = NULL;
1554         put_disk(sdp->disk);
1555         sdp->disk = NULL;
1556         if (NULL == sdp->headfp)
1557                 kfree(sdp);
1558
1559         if (delay)
1560                 msleep(10);     /* dirty detach so delay device destruction */
1561 }
1562
1563 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1564 module_param_named(def_reserved_size, def_reserved_size, int,
1565                    S_IRUGO | S_IWUSR);
1566 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1567
1568 MODULE_AUTHOR("Douglas Gilbert");
1569 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1570 MODULE_LICENSE("GPL");
1571 MODULE_VERSION(SG_VERSION_STR);
1572 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1573
1574 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1575                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1576 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1577 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1578
1579 static int __init
1580 init_sg(void)
1581 {
1582         int rc;
1583
1584         if (scatter_elem_sz < PAGE_SIZE) {
1585                 scatter_elem_sz = PAGE_SIZE;
1586                 scatter_elem_sz_prev = scatter_elem_sz;
1587         }
1588         if (def_reserved_size >= 0)
1589                 sg_big_buff = def_reserved_size;
1590         else
1591                 def_reserved_size = sg_big_buff;
1592
1593         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1594                                     SG_MAX_DEVS, "sg");
1595         if (rc)
1596                 return rc;
1597         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1598         if ( IS_ERR(sg_sysfs_class) ) {
1599                 rc = PTR_ERR(sg_sysfs_class);
1600                 goto err_out;
1601         }
1602         sg_sysfs_valid = 1;
1603         rc = scsi_register_interface(&sg_interface);
1604         if (0 == rc) {
1605 #ifdef CONFIG_SCSI_PROC_FS
1606                 sg_proc_init();
1607 #endif                          /* CONFIG_SCSI_PROC_FS */
1608                 return 0;
1609         }
1610         class_destroy(sg_sysfs_class);
1611 err_out:
1612         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1613         return rc;
1614 }
1615
1616 static void __exit
1617 exit_sg(void)
1618 {
1619 #ifdef CONFIG_SCSI_PROC_FS
1620         sg_proc_cleanup();
1621 #endif                          /* CONFIG_SCSI_PROC_FS */
1622         scsi_unregister_interface(&sg_interface);
1623         class_destroy(sg_sysfs_class);
1624         sg_sysfs_valid = 0;
1625         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1626                                  SG_MAX_DEVS);
1627         idr_destroy(&sg_index_idr);
1628 }
1629
1630 static int __sg_start_req(struct sg_request *srp, struct sg_io_hdr *hp,
1631                           unsigned char *cmd)
1632 {
1633         struct sg_fd *sfp = srp->parentfp;
1634         struct request_queue *q = sfp->parentdp->device->request_queue;
1635         struct request *rq;
1636         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1637
1638         rq = blk_get_request(q, rw, GFP_ATOMIC);
1639         if (!rq)
1640                 return -ENOMEM;
1641
1642         memcpy(rq->cmd, cmd, hp->cmd_len);
1643
1644         rq->cmd_len = hp->cmd_len;
1645         rq->cmd_type = REQ_TYPE_BLOCK_PC;
1646
1647         srp->rq = rq;
1648         rq->end_io_data = srp;
1649         rq->sense = srp->sense_b;
1650         rq->retries = SG_DEFAULT_RETRIES;
1651
1652         return 0;
1653 }
1654
1655 static int sg_start_req(Sg_request *srp, unsigned char *cmd)
1656 {
1657         int res;
1658         Sg_fd *sfp = srp->parentfp;
1659         sg_io_hdr_t *hp = &srp->header;
1660         int dxfer_len = (int) hp->dxfer_len;
1661         int dxfer_dir = hp->dxfer_direction;
1662         Sg_scatter_hold *req_schp = &srp->data;
1663         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1664         struct request_queue *q = sfp->parentdp->device->request_queue;
1665         struct rq_map_data map_data;
1666
1667         SCSI_LOG_TIMEOUT(4, printk("sg_start_req: dxfer_len=%d\n", dxfer_len));
1668
1669         res = __sg_start_req(srp, hp, cmd);
1670         if (res)
1671                 return res;
1672
1673         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1674                 return 0;
1675
1676 #ifdef SG_ALLOW_DIO_CODE
1677         if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
1678             (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) &&
1679             (!sfp->parentdp->device->host->unchecked_isa_dma) &&
1680             blk_rq_aligned(q, hp->dxferp, dxfer_len))
1681                 return sg_build_direct(srp, sfp, dxfer_len);
1682 #endif
1683         if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen))
1684                 sg_link_reserve(sfp, srp, dxfer_len);
1685         else
1686                 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1687
1688         if (!res) {
1689                 struct request *rq = srp->rq;
1690                 Sg_scatter_hold *schp = &srp->data;
1691                 int iovec_count = (int) hp->iovec_count;
1692
1693                 map_data.pages = schp->pages;
1694                 map_data.page_order = schp->page_order;
1695                 map_data.nr_entries = schp->k_use_sg;
1696
1697                 if (iovec_count)
1698                         res = blk_rq_map_user_iov(q, rq, &map_data, hp->dxferp,
1699                                                   iovec_count,
1700                                                   hp->dxfer_len, GFP_ATOMIC);
1701                 else
1702                         res = blk_rq_map_user(q, rq, &map_data, hp->dxferp,
1703                                               hp->dxfer_len, GFP_ATOMIC);
1704
1705                 if (!res)
1706                         srp->bio = rq->bio;
1707         }
1708
1709         return res;
1710 }
1711
1712 static void
1713 sg_finish_rem_req(Sg_request * srp)
1714 {
1715         Sg_fd *sfp = srp->parentfp;
1716         Sg_scatter_hold *req_schp = &srp->data;
1717
1718         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1719         if (srp->res_used)
1720                 sg_unlink_reserve(sfp, srp);
1721         else
1722                 sg_remove_scat(req_schp);
1723
1724         if (srp->rq) {
1725                 if (srp->bio)
1726                         blk_rq_unmap_user(srp->bio);
1727
1728                 blk_put_request(srp->rq);
1729         }
1730
1731         sg_remove_request(sfp, srp);
1732 }
1733
1734 static int
1735 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1736 {
1737         int sg_bufflen = tablesize * sizeof(struct page *);
1738         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1739
1740         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1741         if (!schp->pages)
1742                 return -ENOMEM;
1743         schp->sglist_len = sg_bufflen;
1744         return tablesize;       /* number of scat_gath elements allocated */
1745 }
1746
1747 /* Returns: -ve -> error, 0 -> done, 1 -> try indirect */
1748 static int
1749 sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
1750 {
1751         sg_io_hdr_t *hp = &srp->header;
1752         Sg_scatter_hold *schp = &srp->data;
1753         int res;
1754         struct request *rq = srp->rq;
1755         struct request_queue *q = sfp->parentdp->device->request_queue;
1756
1757         res = blk_rq_map_user(q, rq, NULL, hp->dxferp, dxfer_len, GFP_ATOMIC);
1758         if (res)
1759                 return res;
1760         srp->bio = rq->bio;
1761         schp->dio_in_use = 1;
1762         hp->info |= SG_INFO_DIRECT_IO;
1763         return 0;
1764 }
1765
1766 static int
1767 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1768 {
1769         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1770         int sg_tablesize = sfp->parentdp->sg_tablesize;
1771         int blk_size = buff_size, order;
1772         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1773
1774         if (blk_size < 0)
1775                 return -EFAULT;
1776         if (0 == blk_size)
1777                 ++blk_size;     /* don't know why */
1778 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1779         blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1780         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1781                                    buff_size, blk_size));
1782
1783         /* N.B. ret_sz carried into this block ... */
1784         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1785         if (mx_sc_elems < 0)
1786                 return mx_sc_elems;     /* most likely -ENOMEM */
1787
1788         num = scatter_elem_sz;
1789         if (unlikely(num != scatter_elem_sz_prev)) {
1790                 if (num < PAGE_SIZE) {
1791                         scatter_elem_sz = PAGE_SIZE;
1792                         scatter_elem_sz_prev = PAGE_SIZE;
1793                 } else
1794                         scatter_elem_sz_prev = num;
1795         }
1796
1797         if (sfp->low_dma)
1798                 gfp_mask |= GFP_DMA;
1799
1800         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1801                 gfp_mask |= __GFP_ZERO;
1802
1803         order = get_order(num);
1804 retry:
1805         ret_sz = 1 << (PAGE_SHIFT + order);
1806
1807         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1808              k++, rem_sz -= ret_sz) {
1809
1810                 num = (rem_sz > scatter_elem_sz_prev) ?
1811                         scatter_elem_sz_prev : rem_sz;
1812
1813                 schp->pages[k] = alloc_pages(gfp_mask, order);
1814                 if (!schp->pages[k])
1815                         goto out;
1816
1817                 if (num == scatter_elem_sz_prev) {
1818                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1819                                 scatter_elem_sz = ret_sz;
1820                                 scatter_elem_sz_prev = ret_sz;
1821                         }
1822                 }
1823
1824                 SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
1825                                  "ret_sz=%d\n", k, num, ret_sz));
1826         }               /* end of for loop */
1827
1828         schp->page_order = order;
1829         schp->k_use_sg = k;
1830         SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
1831                          "rem_sz=%d\n", k, rem_sz));
1832
1833         schp->bufflen = blk_size;
1834         if (rem_sz > 0) /* must have failed */
1835                 return -ENOMEM;
1836         return 0;
1837 out:
1838         for (i = 0; i < k; i++)
1839                 __free_pages(schp->pages[k], order);
1840
1841         if (--order >= 0)
1842                 goto retry;
1843
1844         return -ENOMEM;
1845 }
1846
1847 static int
1848 sg_write_xfer(Sg_request * srp)
1849 {
1850         sg_io_hdr_t *hp = &srp->header;
1851         Sg_scatter_hold *schp = &srp->data;
1852         int num_xfer = 0;
1853         int dxfer_dir = hp->dxfer_direction;
1854         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1855
1856         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_TO_DEV == dxfer_dir) ||
1857             (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1858                 num_xfer = (int) (new_interface ? hp->dxfer_len : hp->flags);
1859                 if (schp->bufflen < num_xfer)
1860                         num_xfer = schp->bufflen;
1861         }
1862         if ((num_xfer <= 0) || (schp->dio_in_use) ||
1863             (new_interface
1864              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1865                 return 0;
1866
1867         SCSI_LOG_TIMEOUT(4, printk("sg_write_xfer: num_xfer=%d, k_use_sg=%d\n",
1868                           num_xfer, schp->k_use_sg));
1869
1870         return 0;
1871 }
1872
1873 static void
1874 sg_remove_scat(Sg_scatter_hold * schp)
1875 {
1876         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1877         if (schp->pages && schp->sglist_len > 0) {
1878                 if (!schp->dio_in_use) {
1879                         int k;
1880
1881                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1882                                 SCSI_LOG_TIMEOUT(5, printk(
1883                                     "sg_remove_scat: k=%d, pg=0x%p\n",
1884                                     k, schp->pages[k]));
1885                                 __free_pages(schp->pages[k], schp->page_order);
1886                         }
1887
1888                         kfree(schp->pages);
1889                 }
1890         }
1891         memset(schp, 0, sizeof (*schp));
1892 }
1893
1894 static int
1895 sg_read_xfer(Sg_request * srp)
1896 {
1897         sg_io_hdr_t *hp = &srp->header;
1898         Sg_scatter_hold *schp = &srp->data;
1899         int num_xfer = 0;
1900         int dxfer_dir = hp->dxfer_direction;
1901         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1902
1903         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_FROM_DEV == dxfer_dir)
1904             || (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1905                 num_xfer = hp->dxfer_len;
1906                 if (schp->bufflen < num_xfer)
1907                         num_xfer = schp->bufflen;
1908         }
1909         if ((num_xfer <= 0) || (schp->dio_in_use) ||
1910             (new_interface
1911              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1912                 return 0;
1913
1914         SCSI_LOG_TIMEOUT(4, printk("sg_read_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
1915                           num_xfer, (int)hp->iovec_count, schp->k_use_sg));
1916         return 0;
1917 }
1918
1919 static int
1920 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1921 {
1922         Sg_scatter_hold *schp = &srp->data;
1923         int k, num;
1924
1925         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
1926                                    num_read_xfer));
1927         if ((!outp) || (num_read_xfer <= 0))
1928                 return 0;
1929
1930         blk_rq_unmap_user(srp->bio);
1931         srp->bio = NULL;
1932
1933         num = 1 << (PAGE_SHIFT + schp->page_order);
1934         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1935                 if (num > num_read_xfer) {
1936                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1937                                            num_read_xfer))
1938                                 return -EFAULT;
1939                         break;
1940                 } else {
1941                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1942                                            num))
1943                                 return -EFAULT;
1944                         num_read_xfer -= num;
1945                         if (num_read_xfer <= 0)
1946                                 break;
1947                         outp += num;
1948                 }
1949         }
1950
1951         return 0;
1952 }
1953
1954 static void
1955 sg_build_reserve(Sg_fd * sfp, int req_size)
1956 {
1957         Sg_scatter_hold *schp = &sfp->reserve;
1958
1959         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
1960         do {
1961                 if (req_size < PAGE_SIZE)
1962                         req_size = PAGE_SIZE;
1963                 if (0 == sg_build_indirect(schp, sfp, req_size))
1964                         return;
1965                 else
1966                         sg_remove_scat(schp);
1967                 req_size >>= 1; /* divide by 2 */
1968         } while (req_size > (PAGE_SIZE / 2));
1969 }
1970
1971 static void
1972 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1973 {
1974         Sg_scatter_hold *req_schp = &srp->data;
1975         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1976         int k, num, rem;
1977
1978         srp->res_used = 1;
1979         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
1980         rem = size;
1981
1982         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1983         for (k = 0; k < rsv_schp->k_use_sg; k++) {
1984                 if (rem <= num) {
1985                         req_schp->k_use_sg = k + 1;
1986                         req_schp->sglist_len = rsv_schp->sglist_len;
1987                         req_schp->pages = rsv_schp->pages;
1988
1989                         req_schp->bufflen = size;
1990                         req_schp->b_malloc_len = rsv_schp->b_malloc_len;
1991                         req_schp->page_order = rsv_schp->page_order;
1992                         break;
1993                 } else
1994                         rem -= num;
1995         }
1996
1997         if (k >= rsv_schp->k_use_sg)
1998                 SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
1999 }
2000
2001 static void
2002 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2003 {
2004         Sg_scatter_hold *req_schp = &srp->data;
2005
2006         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
2007                                    (int) req_schp->k_use_sg));
2008         req_schp->k_use_sg = 0;
2009         req_schp->bufflen = 0;
2010         req_schp->pages = NULL;
2011         req_schp->page_order = 0;
2012         req_schp->sglist_len = 0;
2013         sfp->save_scat_len = 0;
2014         srp->res_used = 0;
2015 }
2016
2017 static Sg_request *
2018 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2019 {
2020         Sg_request *resp;
2021         unsigned long iflags;
2022
2023         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2024         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2025                 /* look for requests that are ready + not SG_IO owned */
2026                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2027                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2028                         resp->done = 2; /* guard against other readers */
2029                         break;
2030                 }
2031         }
2032         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2033         return resp;
2034 }
2035
2036 #ifdef CONFIG_SCSI_PROC_FS
2037 static Sg_request *
2038 sg_get_nth_request(Sg_fd * sfp, int nth)
2039 {
2040         Sg_request *resp;
2041         unsigned long iflags;
2042         int k;
2043
2044         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2045         for (k = 0, resp = sfp->headrp; resp && (k < nth);
2046              ++k, resp = resp->nextrp) ;
2047         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2048         return resp;
2049 }
2050 #endif
2051
2052 /* always adds to end of list */
2053 static Sg_request *
2054 sg_add_request(Sg_fd * sfp)
2055 {
2056         int k;
2057         unsigned long iflags;
2058         Sg_request *resp;
2059         Sg_request *rp = sfp->req_arr;
2060
2061         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2062         resp = sfp->headrp;
2063         if (!resp) {
2064                 memset(rp, 0, sizeof (Sg_request));
2065                 rp->parentfp = sfp;
2066                 resp = rp;
2067                 sfp->headrp = resp;
2068         } else {
2069                 if (0 == sfp->cmd_q)
2070                         resp = NULL;    /* command queuing disallowed */
2071                 else {
2072                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2073                                 if (!rp->parentfp)
2074                                         break;
2075                         }
2076                         if (k < SG_MAX_QUEUE) {
2077                                 memset(rp, 0, sizeof (Sg_request));
2078                                 rp->parentfp = sfp;
2079                                 while (resp->nextrp)
2080                                         resp = resp->nextrp;
2081                                 resp->nextrp = rp;
2082                                 resp = rp;
2083                         } else
2084                                 resp = NULL;
2085                 }
2086         }
2087         if (resp) {
2088                 resp->nextrp = NULL;
2089                 resp->header.duration = jiffies_to_msecs(jiffies);
2090         }
2091         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2092         return resp;
2093 }
2094
2095 /* Return of 1 for found; 0 for not found */
2096 static int
2097 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2098 {
2099         Sg_request *prev_rp;
2100         Sg_request *rp;
2101         unsigned long iflags;
2102         int res = 0;
2103
2104         if ((!sfp) || (!srp) || (!sfp->headrp))
2105                 return res;
2106         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2107         prev_rp = sfp->headrp;
2108         if (srp == prev_rp) {
2109                 sfp->headrp = prev_rp->nextrp;
2110                 prev_rp->parentfp = NULL;
2111                 res = 1;
2112         } else {
2113                 while ((rp = prev_rp->nextrp)) {
2114                         if (srp == rp) {
2115                                 prev_rp->nextrp = rp->nextrp;
2116                                 rp->parentfp = NULL;
2117                                 res = 1;
2118                                 break;
2119                         }
2120                         prev_rp = rp;
2121                 }
2122         }
2123         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2124         return res;
2125 }
2126
2127 #ifdef CONFIG_SCSI_PROC_FS
2128 static Sg_fd *
2129 sg_get_nth_sfp(Sg_device * sdp, int nth)
2130 {
2131         Sg_fd *resp;
2132         unsigned long iflags;
2133         int k;
2134
2135         read_lock_irqsave(&sg_index_lock, iflags);
2136         for (k = 0, resp = sdp->headfp; resp && (k < nth);
2137              ++k, resp = resp->nextfp) ;
2138         read_unlock_irqrestore(&sg_index_lock, iflags);
2139         return resp;
2140 }
2141 #endif
2142
2143 static Sg_fd *
2144 sg_add_sfp(Sg_device * sdp, int dev)
2145 {
2146         Sg_fd *sfp;
2147         unsigned long iflags;
2148         int bufflen;
2149
2150         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2151         if (!sfp)
2152                 return NULL;
2153
2154         init_waitqueue_head(&sfp->read_wait);
2155         rwlock_init(&sfp->rq_list_lock);
2156
2157         sfp->timeout = SG_DEFAULT_TIMEOUT;
2158         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2159         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2160         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2161             sdp->device->host->unchecked_isa_dma : 1;
2162         sfp->cmd_q = SG_DEF_COMMAND_Q;
2163         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2164         sfp->parentdp = sdp;
2165         write_lock_irqsave(&sg_index_lock, iflags);
2166         if (!sdp->headfp)
2167                 sdp->headfp = sfp;
2168         else {                  /* add to tail of existing list */
2169                 Sg_fd *pfp = sdp->headfp;
2170                 while (pfp->nextfp)
2171                         pfp = pfp->nextfp;
2172                 pfp->nextfp = sfp;
2173         }
2174         write_unlock_irqrestore(&sg_index_lock, iflags);
2175         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2176         if (unlikely(sg_big_buff != def_reserved_size))
2177                 sg_big_buff = def_reserved_size;
2178
2179         bufflen = min_t(int, sg_big_buff,
2180                         sdp->device->request_queue->max_sectors * 512);
2181         sg_build_reserve(sfp, bufflen);
2182         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2183                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2184         return sfp;
2185 }
2186
2187 static void
2188 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2189 {
2190         Sg_fd *fp;
2191         Sg_fd *prev_fp;
2192
2193         prev_fp = sdp->headfp;
2194         if (sfp == prev_fp)
2195                 sdp->headfp = prev_fp->nextfp;
2196         else {
2197                 while ((fp = prev_fp->nextfp)) {
2198                         if (sfp == fp) {
2199                                 prev_fp->nextfp = fp->nextfp;
2200                                 break;
2201                         }
2202                         prev_fp = fp;
2203                 }
2204         }
2205         if (sfp->reserve.bufflen > 0) {
2206                 SCSI_LOG_TIMEOUT(6,
2207                         printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2208                         (int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2209                 sg_remove_scat(&sfp->reserve);
2210         }
2211         sfp->parentdp = NULL;
2212         SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2213         kfree(sfp);
2214 }
2215
2216 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2217 static int
2218 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2219 {
2220         Sg_request *srp;
2221         Sg_request *tsrp;
2222         int dirty = 0;
2223         int res = 0;
2224
2225         for (srp = sfp->headrp; srp; srp = tsrp) {
2226                 tsrp = srp->nextrp;
2227                 if (sg_srp_done(srp, sfp))
2228                         sg_finish_rem_req(srp);
2229                 else
2230                         ++dirty;
2231         }
2232         if (0 == dirty) {
2233                 unsigned long iflags;
2234
2235                 write_lock_irqsave(&sg_index_lock, iflags);
2236                 __sg_remove_sfp(sdp, sfp);
2237                 if (sdp->detached && (NULL == sdp->headfp)) {
2238                         idr_remove(&sg_index_idr, sdp->index);
2239                         kfree(sdp);
2240                         res = 1;
2241                 }
2242                 write_unlock_irqrestore(&sg_index_lock, iflags);
2243         } else {
2244                 /* MOD_INC's to inhibit unloading sg and associated adapter driver */
2245                 /* only bump the access_count if we actually succeeded in
2246                  * throwing another counter on the host module */
2247                 scsi_device_get(sdp->device);   /* XXX: retval ignored? */
2248                 sfp->closed = 1;        /* flag dirty state on this fd */
2249                 SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2250                                   dirty));
2251         }
2252         return res;
2253 }
2254
2255 static int
2256 sg_res_in_use(Sg_fd * sfp)
2257 {
2258         const Sg_request *srp;
2259         unsigned long iflags;
2260
2261         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2262         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2263                 if (srp->res_used)
2264                         break;
2265         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2266         return srp ? 1 : 0;
2267 }
2268
2269 #ifdef CONFIG_SCSI_PROC_FS
2270 static int
2271 sg_idr_max_id(int id, void *p, void *data)
2272 {
2273         int *k = data;
2274
2275         if (*k < id)
2276                 *k = id;
2277
2278         return 0;
2279 }
2280
2281 static int
2282 sg_last_dev(void)
2283 {
2284         int k = -1;
2285         unsigned long iflags;
2286
2287         read_lock_irqsave(&sg_index_lock, iflags);
2288         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2289         read_unlock_irqrestore(&sg_index_lock, iflags);
2290         return k + 1;           /* origin 1 */
2291 }
2292 #endif
2293
2294 static Sg_device *
2295 sg_get_dev(int dev)
2296 {
2297         Sg_device *sdp;
2298         unsigned long iflags;
2299
2300         read_lock_irqsave(&sg_index_lock, iflags);
2301         sdp = idr_find(&sg_index_idr, dev);
2302         read_unlock_irqrestore(&sg_index_lock, iflags);
2303
2304         return sdp;
2305 }
2306
2307 #ifdef CONFIG_SCSI_PROC_FS
2308
2309 static struct proc_dir_entry *sg_proc_sgp = NULL;
2310
2311 static char sg_proc_sg_dirname[] = "scsi/sg";
2312
2313 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2314
2315 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2316 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2317                                   size_t count, loff_t *off);
2318 static struct file_operations adio_fops = {
2319         /* .owner, .read and .llseek added in sg_proc_init() */
2320         .open = sg_proc_single_open_adio,
2321         .write = sg_proc_write_adio,
2322         .release = single_release,
2323 };
2324
2325 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2326 static ssize_t sg_proc_write_dressz(struct file *filp,
2327                 const char __user *buffer, size_t count, loff_t *off);
2328 static struct file_operations dressz_fops = {
2329         .open = sg_proc_single_open_dressz,
2330         .write = sg_proc_write_dressz,
2331         .release = single_release,
2332 };
2333
2334 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2335 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2336 static struct file_operations version_fops = {
2337         .open = sg_proc_single_open_version,
2338         .release = single_release,
2339 };
2340
2341 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2342 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2343 static struct file_operations devhdr_fops = {
2344         .open = sg_proc_single_open_devhdr,
2345         .release = single_release,
2346 };
2347
2348 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2349 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2350 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2351 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2352 static void dev_seq_stop(struct seq_file *s, void *v);
2353 static struct file_operations dev_fops = {
2354         .open = sg_proc_open_dev,
2355         .release = seq_release,
2356 };
2357 static struct seq_operations dev_seq_ops = {
2358         .start = dev_seq_start,
2359         .next  = dev_seq_next,
2360         .stop  = dev_seq_stop,
2361         .show  = sg_proc_seq_show_dev,
2362 };
2363
2364 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2365 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2366 static struct file_operations devstrs_fops = {
2367         .open = sg_proc_open_devstrs,
2368         .release = seq_release,
2369 };
2370 static struct seq_operations devstrs_seq_ops = {
2371         .start = dev_seq_start,
2372         .next  = dev_seq_next,
2373         .stop  = dev_seq_stop,
2374         .show  = sg_proc_seq_show_devstrs,
2375 };
2376
2377 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2378 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2379 static struct file_operations debug_fops = {
2380         .open = sg_proc_open_debug,
2381         .release = seq_release,
2382 };
2383 static struct seq_operations debug_seq_ops = {
2384         .start = dev_seq_start,
2385         .next  = dev_seq_next,
2386         .stop  = dev_seq_stop,
2387         .show  = sg_proc_seq_show_debug,
2388 };
2389
2390
2391 struct sg_proc_leaf {
2392         const char * name;
2393         struct file_operations * fops;
2394 };
2395
2396 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2397         {"allow_dio", &adio_fops},
2398         {"debug", &debug_fops},
2399         {"def_reserved_size", &dressz_fops},
2400         {"device_hdr", &devhdr_fops},
2401         {"devices", &dev_fops},
2402         {"device_strs", &devstrs_fops},
2403         {"version", &version_fops}
2404 };
2405
2406 static int
2407 sg_proc_init(void)
2408 {
2409         int k, mask;
2410         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2411         struct sg_proc_leaf * leaf;
2412
2413         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2414         if (!sg_proc_sgp)
2415                 return 1;
2416         for (k = 0; k < num_leaves; ++k) {
2417                 leaf = &sg_proc_leaf_arr[k];
2418                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2419                 leaf->fops->owner = THIS_MODULE;
2420                 leaf->fops->read = seq_read;
2421                 leaf->fops->llseek = seq_lseek;
2422                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2423         }
2424         return 0;
2425 }
2426
2427 static void
2428 sg_proc_cleanup(void)
2429 {
2430         int k;
2431         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2432
2433         if (!sg_proc_sgp)
2434                 return;
2435         for (k = 0; k < num_leaves; ++k)
2436                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2437         remove_proc_entry(sg_proc_sg_dirname, NULL);
2438 }
2439
2440
2441 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2442 {
2443         seq_printf(s, "%d\n", *((int *)s->private));
2444         return 0;
2445 }
2446
2447 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2448 {
2449         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2450 }
2451
2452 static ssize_t
2453 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2454                    size_t count, loff_t *off)
2455 {
2456         int num;
2457         char buff[11];
2458
2459         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2460                 return -EACCES;
2461         num = (count < 10) ? count : 10;
2462         if (copy_from_user(buff, buffer, num))
2463                 return -EFAULT;
2464         buff[num] = '\0';
2465         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2466         return count;
2467 }
2468
2469 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2470 {
2471         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2472 }
2473
2474 static ssize_t
2475 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2476                      size_t count, loff_t *off)
2477 {
2478         int num;
2479         unsigned long k = ULONG_MAX;
2480         char buff[11];
2481
2482         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2483                 return -EACCES;
2484         num = (count < 10) ? count : 10;
2485         if (copy_from_user(buff, buffer, num))
2486                 return -EFAULT;
2487         buff[num] = '\0';
2488         k = simple_strtoul(buff, NULL, 10);
2489         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2490                 sg_big_buff = k;
2491                 return count;
2492         }
2493         return -ERANGE;
2494 }
2495
2496 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2497 {
2498         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2499                    sg_version_date);
2500         return 0;
2501 }
2502
2503 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2504 {
2505         return single_open(file, sg_proc_seq_show_version, NULL);
2506 }
2507
2508 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2509 {
2510         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2511                    "online\n");
2512         return 0;
2513 }
2514
2515 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2516 {
2517         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2518 }
2519
2520 struct sg_proc_deviter {
2521         loff_t  index;
2522         size_t  max;
2523 };
2524
2525 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2526 {
2527         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2528
2529         s->private = it;
2530         if (! it)
2531                 return NULL;
2532
2533         it->index = *pos;
2534         it->max = sg_last_dev();
2535         if (it->index >= it->max)
2536                 return NULL;
2537         return it;
2538 }
2539
2540 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2541 {
2542         struct sg_proc_deviter * it = s->private;
2543
2544         *pos = ++it->index;
2545         return (it->index < it->max) ? it : NULL;
2546 }
2547
2548 static void dev_seq_stop(struct seq_file *s, void *v)
2549 {
2550         kfree(s->private);
2551 }
2552
2553 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2554 {
2555         return seq_open(file, &dev_seq_ops);
2556 }
2557
2558 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2559 {
2560         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2561         Sg_device *sdp;
2562         struct scsi_device *scsidp;
2563
2564         sdp = it ? sg_get_dev(it->index) : NULL;
2565         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2566                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2567                               scsidp->host->host_no, scsidp->channel,
2568                               scsidp->id, scsidp->lun, (int) scsidp->type,
2569                               1,
2570                               (int) scsidp->queue_depth,
2571                               (int) scsidp->device_busy,
2572                               (int) scsi_device_online(scsidp));
2573         else
2574                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2575         return 0;
2576 }
2577
2578 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2579 {
2580         return seq_open(file, &devstrs_seq_ops);
2581 }
2582
2583 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2584 {
2585         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2586         Sg_device *sdp;
2587         struct scsi_device *scsidp;
2588
2589         sdp = it ? sg_get_dev(it->index) : NULL;
2590         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2591                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2592                            scsidp->vendor, scsidp->model, scsidp->rev);
2593         else
2594                 seq_printf(s, "<no active device>\n");
2595         return 0;
2596 }
2597
2598 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2599 {
2600         int k, m, new_interface, blen, usg;
2601         Sg_request *srp;
2602         Sg_fd *fp;
2603         const sg_io_hdr_t *hp;
2604         const char * cp;
2605         unsigned int ms;
2606
2607         for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
2608                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2609                            "(res)sgat=%d low_dma=%d\n", k + 1,
2610                            jiffies_to_msecs(fp->timeout),
2611                            fp->reserve.bufflen,
2612                            (int) fp->reserve.k_use_sg,
2613                            (int) fp->low_dma);
2614                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2615                            (int) fp->cmd_q, (int) fp->force_packid,
2616                            (int) fp->keep_orphan, (int) fp->closed);
2617                 for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
2618                         hp = &srp->header;
2619                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2620                         if (srp->res_used) {
2621                                 if (new_interface &&
2622                                     (SG_FLAG_MMAP_IO & hp->flags))
2623                                         cp = "     mmap>> ";
2624                                 else
2625                                         cp = "     rb>> ";
2626                         } else {
2627                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2628                                         cp = "     dio>> ";
2629                                 else
2630                                         cp = "     ";
2631                         }
2632                         seq_printf(s, cp);
2633                         blen = srp->data.bufflen;
2634                         usg = srp->data.k_use_sg;
2635                         seq_printf(s, srp->done ?
2636                                    ((1 == srp->done) ?  "rcv:" : "fin:")
2637                                    : "act:");
2638                         seq_printf(s, " id=%d blen=%d",
2639                                    srp->header.pack_id, blen);
2640                         if (srp->done)
2641                                 seq_printf(s, " dur=%d", hp->duration);
2642                         else {
2643                                 ms = jiffies_to_msecs(jiffies);
2644                                 seq_printf(s, " t_o/elap=%d/%d",
2645                                         (new_interface ? hp->timeout :
2646                                                   jiffies_to_msecs(fp->timeout)),
2647                                         (ms > hp->duration ? ms - hp->duration : 0));
2648                         }
2649                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2650                                    (int) srp->data.cmd_opcode);
2651                 }
2652                 if (0 == m)
2653                         seq_printf(s, "     No requests active\n");
2654         }
2655 }
2656
2657 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2658 {
2659         return seq_open(file, &debug_seq_ops);
2660 }
2661
2662 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2663 {
2664         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2665         Sg_device *sdp;
2666
2667         if (it && (0 == it->index)) {
2668                 seq_printf(s, "max_active_device=%d(origin 1)\n",
2669                            (int)it->max);
2670                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2671         }
2672         sdp = it ? sg_get_dev(it->index) : NULL;
2673         if (sdp) {
2674                 struct scsi_device *scsidp = sdp->device;
2675
2676                 if (NULL == scsidp) {
2677                         seq_printf(s, "device %d detached ??\n",
2678                                    (int)it->index);
2679                         return 0;
2680                 }
2681
2682                 if (sg_get_nth_sfp(sdp, 0)) {
2683                         seq_printf(s, " >>> device=%s ",
2684                                 sdp->disk->disk_name);
2685                         if (sdp->detached)
2686                                 seq_printf(s, "detached pending close ");
2687                         else
2688                                 seq_printf
2689                                     (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2690                                      scsidp->host->host_no,
2691                                      scsidp->channel, scsidp->id,
2692                                      scsidp->lun,
2693                                      scsidp->host->hostt->emulated);
2694                         seq_printf(s, " sg_tablesize=%d excl=%d\n",
2695                                    sdp->sg_tablesize, sdp->exclude);
2696                 }
2697                 sg_proc_debug_helper(s, sdp);
2698         }
2699         return 0;
2700 }
2701
2702 #endif                          /* CONFIG_SCSI_PROC_FS */
2703
2704 module_init(init_sg);
2705 module_exit(exit_sg);