drivers/scsi/sg.c

   1 /*
   2  *  History:
   3  *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
   4  *           to allow user process control of SCSI devices.
   5  *  Development Sponsored by Killy Corp. NY NY
   6  *
   7  * Original driver (sg.c):
   8  *        Copyright (C) 1992 Lawrence Foard
   9  * Version 2 and 3 extensions to driver:
  10  *        Copyright (C) 1998 - 2005 Douglas Gilbert
  11  *
  12  *  Modified  19-JAN-1998  Richard Gooch <rgooch@atnf.csiro.au>  Devfs support
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2, or (at your option)
  17  * any later version.
  18  *
  19  */
  20
  21 static int sg_version_num = 30534;      /* 2 digits for each component */
  22 #define SG_VERSION_STR "3.5.34"
  23
  24 /*
  25  *  D. P. Gilbert (dgilbert@interlog.com, dougg@triode.net.au), notes:
  26  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
  27  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
  28  *        (otherwise the macros compile to empty statements).
  29  *
  30  */
  31 #include <linux/module.h>
  32
  33 #include <linux/fs.h>
  34 #include <linux/kernel.h>
  35 #include <linux/sched.h>
  36 #include <linux/string.h>
  37 #include <linux/mm.h>
  38 #include <linux/errno.h>
  39 #include <linux/mtio.h>
  40 #include <linux/ioctl.h>
  41 #include <linux/fcntl.h>
  42 #include <linux/init.h>
  43 #include <linux/poll.h>
  44 #include <linux/moduleparam.h>
  45 #include <linux/cdev.h>
  46 #include <linux/idr.h>
  47 #include <linux/seq_file.h>
  48 #include <linux/blkdev.h>
  49 #include <linux/delay.h>
  50 #include <linux/blktrace_api.h>
  51 #include <linux/smp_lock.h>
  52
  53 #include "scsi.h"
  54 #include <scsi/scsi_dbg.h>
  55 #include <scsi/scsi_host.h>
  56 #include <scsi/scsi_driver.h>
  57 #include <scsi/scsi_ioctl.h>
  58 #include <scsi/sg.h>
  59
  60 #include "scsi_logging.h"
  61
  62 #ifdef CONFIG_SCSI_PROC_FS
  63 #include <linux/proc_fs.h>
  64 static char *sg_version_date = "20061027";
  65
  66 static int sg_proc_init(void);
  67 static void sg_proc_cleanup(void);
  68 #endif
  69
  70 #define SG_ALLOW_DIO_DEF 0
  71 #define SG_ALLOW_DIO_CODE /* compile out by commenting this define */
  72
  73 #define SG_MAX_DEVS 32768
  74
  75 /*
  76  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
  77  * Then when using 32 bit integers x * m may overflow during the calculation.
  78  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
  79  * calculates the same, but prevents the overflow when both m and d
  80  * are "small" numbers (like HZ and USER_HZ).
  81  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
  82  * in 32 bits.
  83  */
  84 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
  85
  86 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  87
  88 int sg_big_buff = SG_DEF_RESERVED_SIZE;
  89 /* N.B. This variable is readable and writeable via
  90    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  91    of this size (or less if there is not enough memory) will be reserved
  92    for use by this file descriptor. [Deprecated usage: this variable is also
  93    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  94    the kernel (i.e. it is not a module).] */
  95 static int def_reserved_size = -1;      /* picks up init parameter */
  96 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
  97
  98 static int scatter_elem_sz = SG_SCATTER_SZ;
  99 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
 100
 101 #define SG_SECTOR_SZ 512
 102 #define SG_SECTOR_MSK (SG_SECTOR_SZ - 1)
 103
 104 static int sg_add(struct device *, struct class_interface *);
 105 static void sg_remove(struct device *, struct class_interface *);
 106
 107 static DEFINE_IDR(sg_index_idr);
 108 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
 109                                                            file descriptor list for device */
 110
 111 static struct class_interface sg_interface = {
 112         .add_dev        = sg_add,
 113         .remove_dev     = sg_remove,
 114 };
 115
 116 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 117         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 118         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 119         unsigned bufflen;       /* Size of (aggregate) data buffer */
 120         unsigned b_malloc_len;  /* actual len malloc'ed in buffer */
 121         struct page **pages;
 122         int page_order;
 123         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 124         unsigned char cmd_opcode; /* first byte of command */
 125 } Sg_scatter_hold;
 126
 127 struct sg_device;               /* forward declarations */
 128 struct sg_fd;
 129
 130 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 131         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
 132         struct sg_fd *parentfp; /* NULL -> not in use */
 133         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 134         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 135         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 136         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 137         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 138         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 139         volatile char done;     /* 0->before bh, 1->before read, 2->read */
 140         struct request *rq;
 141         struct bio *bio;
 142 } Sg_request;
 143
 144 typedef struct sg_fd {          /* holds the state of a file descriptor */
 145         struct sg_fd *nextfp;   /* NULL when last opened fd on this device */
 146         struct sg_device *parentdp;     /* owning device */
 147         wait_queue_head_t read_wait;    /* queue read until command done */
 148         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 149         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 150         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 151         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 152         unsigned save_scat_len; /* original length of trunc. scat. element */
 153         Sg_request *headrp;     /* head of request slist, NULL->empty */
 154         struct fasync_struct *async_qp; /* used by asynchronous notification */
 155         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 156         char low_dma;           /* as in parent but possibly overridden to 1 */
 157         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 158         volatile char closed;   /* 1 -> fd closed but request(s) outstanding */
 159         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 160         char next_cmd_len;      /* 0 -> automatic (def), >0 -> use on next write() */
 161         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 162         char mmap_called;       /* 0 -> mmap() never called on this fd */
 163 } Sg_fd;
 164
 165 typedef struct sg_device { /* holds the state of each scsi generic device */
 166         struct scsi_device *device;
 167         wait_queue_head_t o_excl_wait;  /* queue open() when O_EXCL in use */
 168         int sg_tablesize;       /* adapter's max scatter-gather table size */
 169         u32 index;              /* device index number */
 170         Sg_fd *headfp;          /* first open fd belonging to this device */
 171         volatile char detached; /* 0->attached, 1->detached pending removal */
 172         volatile char exclude;  /* opened for exclusive access */
 173         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 174         struct gendisk *disk;
 175         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 176 } Sg_device;
 177
 178 static int sg_fasync(int fd, struct file *filp, int mode);
 179 /* tasklet or soft irq callback */
 180 static void sg_rq_end_io(struct request *rq, int uptodate);
 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 int
 231 sg_open(struct inode *inode, struct file *filp)
 232 {
 233         int dev = iminor(inode);
 234         int flags = filp->f_flags;
 235         struct request_queue *q;
 236         Sg_device *sdp;
 237         Sg_fd *sfp;
 238         int res;
 239         int retval;
 240
 241         lock_kernel();
 242         nonseekable_open(inode, filp);
 243         SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
 244         sdp = sg_get_dev(dev);
 245         if ((!sdp) || (!sdp->device)) {
 246                 unlock_kernel();
 247                 return -ENXIO;
 248         }
 249         if (sdp->detached) {
 250                 unlock_kernel();
 251                 return -ENODEV;
 252         }
 253
 254         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 255         /* Prevent the device driver from vanishing while we sleep */
 256         retval = scsi_device_get(sdp->device);
 257         if (retval) {
 258                 unlock_kernel();
 259                 return retval;
 260         }
 261
 262         if (!((flags & O_NONBLOCK) ||
 263               scsi_block_when_processing_errors(sdp->device))) {
 264                 retval = -ENXIO;
 265                 /* we are in error recovery for this device */
 266                 goto error_out;
 267         }
 268
 269         if (flags & O_EXCL) {
 270                 if (O_RDONLY == (flags & O_ACCMODE)) {
 271                         retval = -EPERM; /* Can't lock it with read only access */
 272                         goto error_out;
 273                 }
 274                 if (sdp->headfp && (flags & O_NONBLOCK)) {
 275                         retval = -EBUSY;
 276                         goto error_out;
 277                 }
 278                 res = 0;
 279                 __wait_event_interruptible(sdp->o_excl_wait,
 280                         ((sdp->headfp || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
 281                 if (res) {
 282                         retval = res;   /* -ERESTARTSYS because signal hit process */
 283                         goto error_out;
 284                 }
 285         } else if (sdp->exclude) {      /* some other fd has an exclusive lock on dev */
 286                 if (flags & O_NONBLOCK) {
 287                         retval = -EBUSY;
 288                         goto error_out;
 289                 }
 290                 res = 0;
 291                 __wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
 292                                            res);
 293                 if (res) {
 294                         retval = res;   /* -ERESTARTSYS because signal hit process */
 295                         goto error_out;
 296                 }
 297         }
 298         if (sdp->detached) {
 299                 retval = -ENODEV;
 300                 goto error_out;
 301         }
 302         if (!sdp->headfp) {     /* no existing opens on this device */
 303                 sdp->sgdebug = 0;
 304                 q = sdp->device->request_queue;
 305                 sdp->sg_tablesize = min(q->max_hw_segments,
 306                                         q->max_phys_segments);
 307         }
 308         if ((sfp = sg_add_sfp(sdp, dev)))
 309                 filp->private_data = sfp;
 310         else {
 311                 if (flags & O_EXCL)
 312                         sdp->exclude = 0;       /* undo if error */
 313                 retval = -ENOMEM;
 314                 goto error_out;
 315         }
 316         unlock_kernel();
 317         return 0;
 318
 319       error_out:
 320         scsi_device_put(sdp->device);
 321         unlock_kernel();
 322         return retval;
 323 }
 324
 325 /* Following function was formerly called 'sg_close' */
 326 static int
 327 sg_release(struct inode *inode, struct file *filp)
 328 {
 329         Sg_device *sdp;
 330         Sg_fd *sfp;
 331
 332         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 333                 return -ENXIO;
 334         SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
 335         sg_fasync(-1, filp, 0); /* remove filp from async notification list */
 336         if (0 == sg_remove_sfp(sdp, sfp)) {     /* Returns 1 when sdp gone */
 337                 if (!sdp->detached) {
 338                         scsi_device_put(sdp->device);
 339                 }
 340                 sdp->exclude = 0;
 341                 wake_up_interruptible(&sdp->o_excl_wait);
 342         }
 343         return 0;
 344 }
 345
 346 static ssize_t
 347 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 348 {
 349         Sg_device *sdp;
 350         Sg_fd *sfp;
 351         Sg_request *srp;
 352         int req_pack_id = -1;
 353         sg_io_hdr_t *hp;
 354         struct sg_header *old_hdr = NULL;
 355         int retval = 0;
 356
 357         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 358                 return -ENXIO;
 359         SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
 360                                    sdp->disk->disk_name, (int) count));
 361
 362         if (!access_ok(VERIFY_WRITE, buf, count))
 363                 return -EFAULT;
 364         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 365                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 366                 if (!old_hdr)
 367                         return -ENOMEM;
 368                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
 369                         retval = -EFAULT;
 370                         goto free_old_hdr;
 371                 }
 372                 if (old_hdr->reply_len < 0) {
 373                         if (count >= SZ_SG_IO_HDR) {
 374                                 sg_io_hdr_t *new_hdr;
 375                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
 376                                 if (!new_hdr) {
 377                                         retval = -ENOMEM;
 378                                         goto free_old_hdr;
 379                                 }
 380                                 retval =__copy_from_user
 381                                     (new_hdr, buf, SZ_SG_IO_HDR);
 382                                 req_pack_id = new_hdr->pack_id;
 383                                 kfree(new_hdr);
 384                                 if (retval) {
 385                                         retval = -EFAULT;
 386                                         goto free_old_hdr;
 387                                 }
 388                         }
 389                 } else
 390                         req_pack_id = old_hdr->pack_id;
 391         }
 392         srp = sg_get_rq_mark(sfp, req_pack_id);
 393         if (!srp) {             /* now wait on packet to arrive */
 394                 if (sdp->detached) {
 395                         retval = -ENODEV;
 396                         goto free_old_hdr;
 397                 }
 398                 if (filp->f_flags & O_NONBLOCK) {
 399                         retval = -EAGAIN;
 400                         goto free_old_hdr;
 401                 }
 402                 while (1) {
 403                         retval = 0; /* following macro beats race condition */
 404                         __wait_event_interruptible(sfp->read_wait,
 405                                 (sdp->detached ||
 406                                 (srp = sg_get_rq_mark(sfp, req_pack_id))),
 407                                 retval);
 408                         if (sdp->detached) {
 409                                 retval = -ENODEV;
 410                                 goto free_old_hdr;
 411                         }
 412                         if (0 == retval)
 413                                 break;
 414
 415                         /* -ERESTARTSYS as signal hit process */
 416                         goto free_old_hdr;
 417                 }
 418         }
 419         if (srp->header.interface_id != '\0') {
 420                 retval = sg_new_read(sfp, buf, count, srp);
 421                 goto free_old_hdr;
 422         }
 423
 424         hp = &srp->header;
 425         if (old_hdr == NULL) {
 426                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 427                 if (! old_hdr) {
 428                         retval = -ENOMEM;
 429                         goto free_old_hdr;
 430                 }
 431         }
 432         memset(old_hdr, 0, SZ_SG_HEADER);
 433         old_hdr->reply_len = (int) hp->timeout;
 434         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 435         old_hdr->pack_id = hp->pack_id;
 436         old_hdr->twelve_byte =
 437             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 438         old_hdr->target_status = hp->masked_status;
 439         old_hdr->host_status = hp->host_status;
 440         old_hdr->driver_status = hp->driver_status;
 441         if ((CHECK_CONDITION & hp->masked_status) ||
 442             (DRIVER_SENSE & hp->driver_status))
 443                 memcpy(old_hdr->sense_buffer, srp->sense_b,
 444                        sizeof (old_hdr->sense_buffer));
 445         switch (hp->host_status) {
 446         /* This setup of 'result' is for backward compatibility and is best
 447            ignored by the user who should use target, host + driver status */
 448         case DID_OK:
 449         case DID_PASSTHROUGH:
 450         case DID_SOFT_ERROR:
 451                 old_hdr->result = 0;
 452                 break;
 453         case DID_NO_CONNECT:
 454         case DID_BUS_BUSY:
 455         case DID_TIME_OUT:
 456                 old_hdr->result = EBUSY;
 457                 break;
 458         case DID_BAD_TARGET:
 459         case DID_ABORT:
 460         case DID_PARITY:
 461         case DID_RESET:
 462         case DID_BAD_INTR:
 463                 old_hdr->result = EIO;
 464                 break;
 465         case DID_ERROR:
 466                 old_hdr->result = (srp->sense_b[0] == 0 &&
 467                                   hp->masked_status == GOOD) ? 0 : EIO;
 468                 break;
 469         default:
 470                 old_hdr->result = EIO;
 471                 break;
 472         }
 473
 474         /* Now copy the result back to the user buffer.  */
 475         if (count >= SZ_SG_HEADER) {
 476                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 477                         retval = -EFAULT;
 478                         goto free_old_hdr;
 479                 }
 480                 buf += SZ_SG_HEADER;
 481                 if (count > old_hdr->reply_len)
 482                         count = old_hdr->reply_len;
 483                 if (count > SZ_SG_HEADER) {
 484                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 485                                 retval = -EFAULT;
 486                                 goto free_old_hdr;
 487                         }
 488                 }
 489         } else
 490                 count = (old_hdr->result == 0) ? 0 : -EIO;
 491         sg_finish_rem_req(srp);
 492         retval = count;
 493 free_old_hdr:
 494         kfree(old_hdr);
 495         return retval;
 496 }
 497
 498 static ssize_t
 499 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 500 {
 501         sg_io_hdr_t *hp = &srp->header;
 502         int err = 0;
 503         int len;
 504
 505         if (count < SZ_SG_IO_HDR) {
 506                 err = -EINVAL;
 507                 goto err_out;
 508         }
 509         hp->sb_len_wr = 0;
 510         if ((hp->mx_sb_len > 0) && hp->sbp) {
 511                 if ((CHECK_CONDITION & hp->masked_status) ||
 512                     (DRIVER_SENSE & hp->driver_status)) {
 513                         int sb_len = SCSI_SENSE_BUFFERSIZE;
 514                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 515                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 516                         len = (len > sb_len) ? sb_len : len;
 517                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 518                                 err = -EFAULT;
 519                                 goto err_out;
 520                         }
 521                         hp->sb_len_wr = len;
 522                 }
 523         }
 524         if (hp->masked_status || hp->host_status || hp->driver_status)
 525                 hp->info |= SG_INFO_CHECK;
 526         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 527                 err = -EFAULT;
 528                 goto err_out;
 529         }
 530         err = sg_read_xfer(srp);
 531       err_out:
 532         sg_finish_rem_req(srp);
 533         return (0 == err) ? count : err;
 534 }
 535
 536 static ssize_t
 537 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 538 {
 539         int mxsize, cmd_size, k;
 540         int input_size, blocking;
 541         unsigned char opcode;
 542         Sg_device *sdp;
 543         Sg_fd *sfp;
 544         Sg_request *srp;
 545         struct sg_header old_hdr;
 546         sg_io_hdr_t *hp;
 547         unsigned char cmnd[MAX_COMMAND_SIZE];
 548
 549         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 550                 return -ENXIO;
 551         SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
 552                                    sdp->disk->disk_name, (int) count));
 553         if (sdp->detached)
 554                 return -ENODEV;
 555         if (!((filp->f_flags & O_NONBLOCK) ||
 556               scsi_block_when_processing_errors(sdp->device)))
 557                 return -ENXIO;
 558
 559         if (!access_ok(VERIFY_READ, buf, count))
 560                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 561         if (count < SZ_SG_HEADER)
 562                 return -EIO;
 563         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 564                 return -EFAULT;
 565         blocking = !(filp->f_flags & O_NONBLOCK);
 566         if (old_hdr.reply_len < 0)
 567                 return sg_new_write(sfp, filp, buf, count, blocking, 0, NULL);
 568         if (count < (SZ_SG_HEADER + 6))
 569                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 570
 571         if (!(srp = sg_add_request(sfp))) {
 572                 SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
 573                 return -EDOM;
 574         }
 575         buf += SZ_SG_HEADER;
 576         __get_user(opcode, buf);
 577         if (sfp->next_cmd_len > 0) {
 578                 if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
 579                         SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
 580                         sfp->next_cmd_len = 0;
 581                         sg_remove_request(sfp, srp);
 582                         return -EIO;
 583                 }
 584                 cmd_size = sfp->next_cmd_len;
 585                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 586         } else {
 587                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 588                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 589                         cmd_size = 12;
 590         }
 591         SCSI_LOG_TIMEOUT(4, printk(
 592                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 593 /* Determine buffer size.  */
 594         input_size = count - cmd_size;
 595         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 596         mxsize -= SZ_SG_HEADER;
 597         input_size -= SZ_SG_HEADER;
 598         if (input_size < 0) {
 599                 sg_remove_request(sfp, srp);
 600                 return -EIO;    /* User did not pass enough bytes for this command. */
 601         }
 602         hp = &srp->header;
 603         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 604         hp->cmd_len = (unsigned char) cmd_size;
 605         hp->iovec_count = 0;
 606         hp->mx_sb_len = 0;
 607         if (input_size > 0)
 608                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 609                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 610         else
 611                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 612         hp->dxfer_len = mxsize;
 613         if (hp->dxfer_direction == SG_DXFER_TO_DEV)
 614                 hp->dxferp = (char __user *)buf + cmd_size;
 615         else
 616                 hp->dxferp = NULL;
 617         hp->sbp = NULL;
 618         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 619         hp->flags = input_size; /* structure abuse ... */
 620         hp->pack_id = old_hdr.pack_id;
 621         hp->usr_ptr = NULL;
 622         if (__copy_from_user(cmnd, buf, cmd_size))
 623                 return -EFAULT;
 624         /*
 625          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 626          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 627          * is a non-zero input_size, so emit a warning.
 628          */
 629         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 630                 static char cmd[TASK_COMM_LEN];
 631                 if (strcmp(current->comm, cmd) && printk_ratelimit()) {
 632                         printk(KERN_WARNING
 633                                "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
 634                                "guessing data in;\n" KERN_WARNING "   "
 635                                "program %s not setting count and/or reply_len properly\n",
 636                                old_hdr.reply_len - (int)SZ_SG_HEADER,
 637                                input_size, (unsigned int) cmnd[0],
 638                                current->comm);
 639                         strcpy(cmd, current->comm);
 640                 }
 641         }
 642         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 643         return (k < 0) ? k : count;
 644 }
 645
 646 static ssize_t
 647 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 648                  size_t count, int blocking, int read_only,
 649                  Sg_request **o_srp)
 650 {
 651         int k;
 652         Sg_request *srp;
 653         sg_io_hdr_t *hp;
 654         unsigned char cmnd[MAX_COMMAND_SIZE];
 655         int timeout;
 656         unsigned long ul_timeout;
 657
 658         if (count < SZ_SG_IO_HDR)
 659                 return -EINVAL;
 660         if (!access_ok(VERIFY_READ, buf, count))
 661                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 662
 663         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 664         if (!(srp = sg_add_request(sfp))) {
 665                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
 666                 return -EDOM;
 667         }
 668         hp = &srp->header;
 669         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 670                 sg_remove_request(sfp, srp);
 671                 return -EFAULT;
 672         }
 673         if (hp->interface_id != 'S') {
 674                 sg_remove_request(sfp, srp);
 675                 return -ENOSYS;
 676         }
 677         if (hp->flags & SG_FLAG_MMAP_IO) {
 678                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 679                         sg_remove_request(sfp, srp);
 680                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 681                 }
 682                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 683                         sg_remove_request(sfp, srp);
 684                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 685                 }
 686                 if (sg_res_in_use(sfp)) {
 687                         sg_remove_request(sfp, srp);
 688                         return -EBUSY;  /* reserve buffer already being used */
 689                 }
 690         }
 691         ul_timeout = msecs_to_jiffies(srp->header.timeout);
 692         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 693         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 694                 sg_remove_request(sfp, srp);
 695                 return -EMSGSIZE;
 696         }
 697         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
 698                 sg_remove_request(sfp, srp);
 699                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 700         }
 701         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 702                 sg_remove_request(sfp, srp);
 703                 return -EFAULT;
 704         }
 705         if (read_only && sg_allow_access(file, cmnd)) {
 706                 sg_remove_request(sfp, srp);
 707                 return -EPERM;
 708         }
 709         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 710         if (k < 0)
 711                 return k;
 712         if (o_srp)
 713                 *o_srp = srp;
 714         return count;
 715 }
 716
 717 static int
 718 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 719                 unsigned char *cmnd, int timeout, int blocking)
 720 {
 721         int k, data_dir;
 722         Sg_device *sdp = sfp->parentdp;
 723         sg_io_hdr_t *hp = &srp->header;
 724
 725         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 726         hp->status = 0;
 727         hp->masked_status = 0;
 728         hp->msg_status = 0;
 729         hp->info = 0;
 730         hp->host_status = 0;
 731         hp->driver_status = 0;
 732         hp->resid = 0;
 733         SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 734                           (int) cmnd[0], (int) hp->cmd_len));
 735
 736         k = sg_start_req(srp, cmnd);
 737         if (k) {
 738                 SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k));
 739                 sg_finish_rem_req(srp);
 740                 return k;       /* probably out of space --> ENOMEM */
 741         }
 742         if ((k = sg_write_xfer(srp))) {
 743                 SCSI_LOG_TIMEOUT(1, printk("sg_common_write: write_xfer, bad address\n"));
 744                 sg_finish_rem_req(srp);
 745                 return k;
 746         }
 747         if (sdp->detached) {
 748                 sg_finish_rem_req(srp);
 749                 return -ENODEV;
 750         }
 751
 752         switch (hp->dxfer_direction) {
 753         case SG_DXFER_TO_FROM_DEV:
 754         case SG_DXFER_FROM_DEV:
 755                 data_dir = DMA_FROM_DEVICE;
 756                 break;
 757         case SG_DXFER_TO_DEV:
 758                 data_dir = DMA_TO_DEVICE;
 759                 break;
 760         case SG_DXFER_UNKNOWN:
 761                 data_dir = DMA_BIDIRECTIONAL;
 762                 break;
 763         default:
 764                 data_dir = DMA_NONE;
 765                 break;
 766         }
 767         hp->duration = jiffies_to_msecs(jiffies);
 768
 769         srp->rq->timeout = timeout;
 770         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 771                               srp->rq, 1, sg_rq_end_io);
 772         return 0;
 773 }
 774
 775 static int
 776 sg_srp_done(Sg_request *srp, Sg_fd *sfp)
 777 {
 778         unsigned long iflags;
 779         int done;
 780
 781         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 782         done = srp->done;
 783         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 784         return done;
 785 }
 786
 787 static int
 788 sg_ioctl(struct inode *inode, struct file *filp,
 789          unsigned int cmd_in, unsigned long arg)
 790 {
 791         void __user *p = (void __user *)arg;
 792         int __user *ip = p;
 793         int result, val, read_only;
 794         Sg_device *sdp;
 795         Sg_fd *sfp;
 796         Sg_request *srp;
 797         unsigned long iflags;
 798
 799         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 800                 return -ENXIO;
 801
 802         SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
 803                                    sdp->disk->disk_name, (int) cmd_in));
 804         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 805
 806         switch (cmd_in) {
 807         case SG_IO:
 808                 {
 809                         int blocking = 1;       /* ignore O_NONBLOCK flag */
 810
 811                         if (sdp->detached)
 812                                 return -ENODEV;
 813                         if (!scsi_block_when_processing_errors(sdp->device))
 814                                 return -ENXIO;
 815                         if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 816                                 return -EFAULT;
 817                         result =
 818                             sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 819                                          blocking, read_only, &srp);
 820                         if (result < 0)
 821                                 return result;
 822                         srp->sg_io_owned = 1;
 823                         while (1) {
 824                                 result = 0;     /* following macro to beat race condition */
 825                                 __wait_event_interruptible(sfp->read_wait,
 826                                         (sdp->detached || sfp->closed || sg_srp_done(srp, sfp)),
 827                                                            result);
 828                                 if (sdp->detached)
 829                                         return -ENODEV;
 830                                 if (sfp->closed)
 831                                         return 0;       /* request packet dropped already */
 832                                 if (0 == result)
 833                                         break;
 834                                 srp->orphan = 1;
 835                                 return result;  /* -ERESTARTSYS because signal hit process */
 836                         }
 837                         write_lock_irqsave(&sfp->rq_list_lock, iflags);
 838                         srp->done = 2;
 839                         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 840                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 841                         return (result < 0) ? result : 0;
 842                 }
 843         case SG_SET_TIMEOUT:
 844                 result = get_user(val, ip);
 845                 if (result)
 846                         return result;
 847                 if (val < 0)
 848                         return -EIO;
 849                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
 850                     val = MULDIV (INT_MAX, USER_HZ, HZ);
 851                 sfp->timeout_user = val;
 852                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
 853
 854                 return 0;
 855         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 856                                 /* strange ..., for backward compatibility */
 857                 return sfp->timeout_user;
 858         case SG_SET_FORCE_LOW_DMA:
 859                 result = get_user(val, ip);
 860                 if (result)
 861                         return result;
 862                 if (val) {
 863                         sfp->low_dma = 1;
 864                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
 865                                 val = (int) sfp->reserve.bufflen;
 866                                 sg_remove_scat(&sfp->reserve);
 867                                 sg_build_reserve(sfp, val);
 868                         }
 869                 } else {
 870                         if (sdp->detached)
 871                                 return -ENODEV;
 872                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
 873                 }
 874                 return 0;
 875         case SG_GET_LOW_DMA:
 876                 return put_user((int) sfp->low_dma, ip);
 877         case SG_GET_SCSI_ID:
 878                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 879                         return -EFAULT;
 880                 else {
 881                         sg_scsi_id_t __user *sg_idp = p;
 882
 883                         if (sdp->detached)
 884                                 return -ENODEV;
 885                         __put_user((int) sdp->device->host->host_no,
 886                                    &sg_idp->host_no);
 887                         __put_user((int) sdp->device->channel,
 888                                    &sg_idp->channel);
 889                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 890                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 891                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 892                         __put_user((short) sdp->device->host->cmd_per_lun,
 893                                    &sg_idp->h_cmd_per_lun);
 894                         __put_user((short) sdp->device->queue_depth,
 895                                    &sg_idp->d_queue_depth);
 896                         __put_user(0, &sg_idp->unused[0]);
 897                         __put_user(0, &sg_idp->unused[1]);
 898                         return 0;
 899                 }
 900         case SG_SET_FORCE_PACK_ID:
 901                 result = get_user(val, ip);
 902                 if (result)
 903                         return result;
 904                 sfp->force_packid = val ? 1 : 0;
 905                 return 0;
 906         case SG_GET_PACK_ID:
 907                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 908                         return -EFAULT;
 909                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 910                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
 911                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 912                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 913                                                        iflags);
 914                                 __put_user(srp->header.pack_id, ip);
 915                                 return 0;
 916                         }
 917                 }
 918                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 919                 __put_user(-1, ip);
 920                 return 0;
 921         case SG_GET_NUM_WAITING:
 922                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 923                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
 924                         if ((1 == srp->done) && (!srp->sg_io_owned))
 925                                 ++val;
 926                 }
 927                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 928                 return put_user(val, ip);
 929         case SG_GET_SG_TABLESIZE:
 930                 return put_user(sdp->sg_tablesize, ip);
 931         case SG_SET_RESERVED_SIZE:
 932                 result = get_user(val, ip);
 933                 if (result)
 934                         return result;
 935                 if (val < 0)
 936                         return -EINVAL;
 937                 val = min_t(int, val,
 938                                 sdp->device->request_queue->max_sectors * 512);
 939                 if (val != sfp->reserve.bufflen) {
 940                         if (sg_res_in_use(sfp) || sfp->mmap_called)
 941                                 return -EBUSY;
 942                         sg_remove_scat(&sfp->reserve);
 943                         sg_build_reserve(sfp, val);
 944                 }
 945                 return 0;
 946         case SG_GET_RESERVED_SIZE:
 947                 val = min_t(int, sfp->reserve.bufflen,
 948                                 sdp->device->request_queue->max_sectors * 512);
 949                 return put_user(val, ip);
 950         case SG_SET_COMMAND_Q:
 951                 result = get_user(val, ip);
 952                 if (result)
 953                         return result;
 954                 sfp->cmd_q = val ? 1 : 0;
 955                 return 0;
 956         case SG_GET_COMMAND_Q:
 957                 return put_user((int) sfp->cmd_q, ip);
 958         case SG_SET_KEEP_ORPHAN:
 959                 result = get_user(val, ip);
 960                 if (result)
 961                         return result;
 962                 sfp->keep_orphan = val;
 963                 return 0;
 964         case SG_GET_KEEP_ORPHAN:
 965                 return put_user((int) sfp->keep_orphan, ip);
 966         case SG_NEXT_CMD_LEN:
 967                 result = get_user(val, ip);
 968                 if (result)
 969                         return result;
 970                 sfp->next_cmd_len = (val > 0) ? val : 0;
 971                 return 0;
 972         case SG_GET_VERSION_NUM:
 973                 return put_user(sg_version_num, ip);
 974         case SG_GET_ACCESS_COUNT:
 975                 /* faked - we don't have a real access count anymore */
 976                 val = (sdp->device ? 1 : 0);
 977                 return put_user(val, ip);
 978         case SG_GET_REQUEST_TABLE:
 979                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
 980                         return -EFAULT;
 981                 else {
 982                         sg_req_info_t *rinfo;
 983                         unsigned int ms;
 984
 985                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
 986                                                                 GFP_KERNEL);
 987                         if (!rinfo)
 988                                 return -ENOMEM;
 989                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 990                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
 991                              ++val, srp = srp ? srp->nextrp : srp) {
 992                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
 993                                 if (srp) {
 994                                         rinfo[val].req_state = srp->done + 1;
 995                                         rinfo[val].problem =
 996                                             srp->header.masked_status &
 997                                             srp->header.host_status &
 998                                             srp->header.driver_status;
 999                                         if (srp->done)
1000                                                 rinfo[val].duration =
1001                                                         srp->header.duration;
1002                                         else {
1003                                                 ms = jiffies_to_msecs(jiffies);
1004                                                 rinfo[val].duration =
1005                                                     (ms > srp->header.duration) ?
1006                                                     (ms - srp->header.duration) : 0;
1007                                         }
1008                                         rinfo[val].orphan = srp->orphan;
1009                                         rinfo[val].sg_io_owned =
1010                                                         srp->sg_io_owned;
1011                                         rinfo[val].pack_id =
1012                                                         srp->header.pack_id;
1013                                         rinfo[val].usr_ptr =
1014                                                         srp->header.usr_ptr;
1015                                 }
1016                         }
1017                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1018                         result = __copy_to_user(p, rinfo,
1019                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1020                         result = result ? -EFAULT : 0;
1021                         kfree(rinfo);
1022                         return result;
1023                 }
1024         case SG_EMULATED_HOST:
1025                 if (sdp->detached)
1026                         return -ENODEV;
1027                 return put_user(sdp->device->host->hostt->emulated, ip);
1028         case SG_SCSI_RESET:
1029                 if (sdp->detached)
1030                         return -ENODEV;
1031                 if (filp->f_flags & O_NONBLOCK) {
1032                         if (scsi_host_in_recovery(sdp->device->host))
1033                                 return -EBUSY;
1034                 } else if (!scsi_block_when_processing_errors(sdp->device))
1035                         return -EBUSY;
1036                 result = get_user(val, ip);
1037                 if (result)
1038                         return result;
1039                 if (SG_SCSI_RESET_NOTHING == val)
1040                         return 0;
1041                 switch (val) {
1042                 case SG_SCSI_RESET_DEVICE:
1043                         val = SCSI_TRY_RESET_DEVICE;
1044                         break;
1045                 case SG_SCSI_RESET_TARGET:
1046                         val = SCSI_TRY_RESET_TARGET;
1047                         break;
1048                 case SG_SCSI_RESET_BUS:
1049                         val = SCSI_TRY_RESET_BUS;
1050                         break;
1051                 case SG_SCSI_RESET_HOST:
1052                         val = SCSI_TRY_RESET_HOST;
1053                         break;
1054                 default:
1055                         return -EINVAL;
1056                 }
1057                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1058                         return -EACCES;
1059                 return (scsi_reset_provider(sdp->device, val) ==
1060                         SUCCESS) ? 0 : -EIO;
1061         case SCSI_IOCTL_SEND_COMMAND:
1062                 if (sdp->detached)
1063                         return -ENODEV;
1064                 if (read_only) {
1065                         unsigned char opcode = WRITE_6;
1066                         Scsi_Ioctl_Command __user *siocp = p;
1067
1068                         if (copy_from_user(&opcode, siocp->data, 1))
1069                                 return -EFAULT;
1070                         if (sg_allow_access(filp, &opcode))
1071                                 return -EPERM;
1072                 }
1073                 return sg_scsi_ioctl(filp, sdp->device->request_queue, NULL, p);
1074         case SG_SET_DEBUG:
1075                 result = get_user(val, ip);
1076                 if (result)
1077                         return result;
1078                 sdp->sgdebug = (char) val;
1079                 return 0;
1080         case SCSI_IOCTL_GET_IDLUN:
1081         case SCSI_IOCTL_GET_BUS_NUMBER:
1082         case SCSI_IOCTL_PROBE_HOST:
1083         case SG_GET_TRANSFORM:
1084                 if (sdp->detached)
1085                         return -ENODEV;
1086                 return scsi_ioctl(sdp->device, cmd_in, p);
1087         case BLKSECTGET:
1088                 return put_user(sdp->device->request_queue->max_sectors * 512,
1089                                 ip);
1090         case BLKTRACESETUP:
1091                 return blk_trace_setup(sdp->device->request_queue,
1092                                        sdp->disk->disk_name,
1093                                        sdp->device->sdev_gendev.devt,
1094                                        (char *)arg);
1095         case BLKTRACESTART:
1096                 return blk_trace_startstop(sdp->device->request_queue, 1);
1097         case BLKTRACESTOP:
1098                 return blk_trace_startstop(sdp->device->request_queue, 0);
1099         case BLKTRACETEARDOWN:
1100                 return blk_trace_remove(sdp->device->request_queue);
1101         default:
1102                 if (read_only)
1103                         return -EPERM;  /* don't know so take safe approach */
1104                 return scsi_ioctl(sdp->device, cmd_in, p);
1105         }
1106 }
1107
1108 #ifdef CONFIG_COMPAT
1109 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1110 {
1111         Sg_device *sdp;
1112         Sg_fd *sfp;
1113         struct scsi_device *sdev;
1114
1115         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1116                 return -ENXIO;
1117
1118         sdev = sdp->device;
1119         if (sdev->host->hostt->compat_ioctl) {
1120                 int ret;
1121
1122                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1123
1124                 return ret;
1125         }
1126
1127         return -ENOIOCTLCMD;
1128 }
1129 #endif
1130
1131 static unsigned int
1132 sg_poll(struct file *filp, poll_table * wait)
1133 {
1134         unsigned int res = 0;
1135         Sg_device *sdp;
1136         Sg_fd *sfp;
1137         Sg_request *srp;
1138         int count = 0;
1139         unsigned long iflags;
1140
1141         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1142             || sfp->closed)
1143                 return POLLERR;
1144         poll_wait(filp, &sfp->read_wait, wait);
1145         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1146         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1147                 /* if any read waiting, flag it */
1148                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1149                         res = POLLIN | POLLRDNORM;
1150                 ++count;
1151         }
1152         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1153
1154         if (sdp->detached)
1155                 res |= POLLHUP;
1156         else if (!sfp->cmd_q) {
1157                 if (0 == count)
1158                         res |= POLLOUT | POLLWRNORM;
1159         } else if (count < SG_MAX_QUEUE)
1160                 res |= POLLOUT | POLLWRNORM;
1161         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1162                                    sdp->disk->disk_name, (int) res));
1163         return res;
1164 }
1165
1166 static int
1167 sg_fasync(int fd, struct file *filp, int mode)
1168 {
1169         int retval;
1170         Sg_device *sdp;
1171         Sg_fd *sfp;
1172
1173         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1174                 return -ENXIO;
1175         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1176                                    sdp->disk->disk_name, mode));
1177
1178         retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
1179         return (retval < 0) ? retval : 0;
1180 }
1181
1182 static int
1183 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1184 {
1185         Sg_fd *sfp;
1186         unsigned long offset, len, sa;
1187         Sg_scatter_hold *rsv_schp;
1188         int k, length;
1189
1190         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1191                 return VM_FAULT_SIGBUS;
1192         rsv_schp = &sfp->reserve;
1193         offset = vmf->pgoff << PAGE_SHIFT;
1194         if (offset >= rsv_schp->bufflen)
1195                 return VM_FAULT_SIGBUS;
1196         SCSI_LOG_TIMEOUT(3, printk("sg_vma_fault: offset=%lu, scatg=%d\n",
1197                                    offset, rsv_schp->k_use_sg));
1198         sa = vma->vm_start;
1199         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1200         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1201                 len = vma->vm_end - sa;
1202                 len = (len < length) ? len : length;
1203                 if (offset < len) {
1204                         struct page *page = nth_page(rsv_schp->pages[k],
1205                                                      offset >> PAGE_SHIFT);
1206                         get_page(page); /* increment page count */
1207                         vmf->page = page;
1208                         return 0; /* success */
1209                 }
1210                 sa += len;
1211                 offset -= len;
1212         }
1213
1214         return VM_FAULT_SIGBUS;
1215 }
1216
1217 static struct vm_operations_struct sg_mmap_vm_ops = {
1218         .fault = sg_vma_fault,
1219 };
1220
1221 static int
1222 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1223 {
1224         Sg_fd *sfp;
1225         unsigned long req_sz, len, sa;
1226         Sg_scatter_hold *rsv_schp;
1227         int k, length;
1228
1229         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1230                 return -ENXIO;
1231         req_sz = vma->vm_end - vma->vm_start;
1232         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1233                                    (void *) vma->vm_start, (int) req_sz));
1234         if (vma->vm_pgoff)
1235                 return -EINVAL; /* want no offset */
1236         rsv_schp = &sfp->reserve;
1237         if (req_sz > rsv_schp->bufflen)
1238                 return -ENOMEM; /* cannot map more than reserved buffer */
1239
1240         sa = vma->vm_start;
1241         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1242         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1243                 len = vma->vm_end - sa;
1244                 len = (len < length) ? len : length;
1245                 sa += len;
1246         }
1247
1248         sfp->mmap_called = 1;
1249         vma->vm_flags |= VM_RESERVED;
1250         vma->vm_private_data = sfp;
1251         vma->vm_ops = &sg_mmap_vm_ops;
1252         return 0;
1253 }
1254
1255 /*
1256  * This function is a "bottom half" handler that is called by the mid
1257  * level when a command is completed (or has failed).
1258  */
1259 static void sg_rq_end_io(struct request *rq, int uptodate)
1260 {
1261         struct sg_request *srp = rq->end_io_data;
1262         Sg_device *sdp = NULL;
1263         Sg_fd *sfp;
1264         unsigned long iflags;
1265         unsigned int ms;
1266         char *sense;
1267         int result, resid;
1268
1269         if (NULL == srp) {
1270                 printk(KERN_ERR "sg_cmd_done: NULL request\n");
1271                 return;
1272         }
1273         sfp = srp->parentfp;
1274         if (sfp)
1275                 sdp = sfp->parentdp;
1276         if ((NULL == sdp) || sdp->detached) {
1277                 printk(KERN_INFO "sg_cmd_done: device detached\n");
1278                 return;
1279         }
1280
1281         sense = rq->sense;
1282         result = rq->errors;
1283         resid = rq->data_len;
1284
1285         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1286                 sdp->disk->disk_name, srp->header.pack_id, result));
1287         srp->header.resid = resid;
1288         ms = jiffies_to_msecs(jiffies);
1289         srp->header.duration = (ms > srp->header.duration) ?
1290                                 (ms - srp->header.duration) : 0;
1291         if (0 != result) {
1292                 struct scsi_sense_hdr sshdr;
1293
1294                 srp->header.status = 0xff & result;
1295                 srp->header.masked_status = status_byte(result);
1296                 srp->header.msg_status = msg_byte(result);
1297                 srp->header.host_status = host_byte(result);
1298                 srp->header.driver_status = driver_byte(result);
1299                 if ((sdp->sgdebug > 0) &&
1300                     ((CHECK_CONDITION == srp->header.masked_status) ||
1301                      (COMMAND_TERMINATED == srp->header.masked_status)))
1302                         __scsi_print_sense("sg_cmd_done", sense,
1303                                            SCSI_SENSE_BUFFERSIZE);
1304
1305                 /* Following if statement is a patch supplied by Eric Youngdale */
1306                 if (driver_byte(result) != 0
1307                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1308                     && !scsi_sense_is_deferred(&sshdr)
1309                     && sshdr.sense_key == UNIT_ATTENTION
1310                     && sdp->device->removable) {
1311                         /* Detected possible disc change. Set the bit - this */
1312                         /* may be used if there are filesystems using this device */
1313                         sdp->device->changed = 1;
1314                 }
1315         }
1316         /* Rely on write phase to clean out srp status values, so no "else" */
1317
1318         if (sfp->closed) {      /* whoops this fd already released, cleanup */
1319                 SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1320                 sg_finish_rem_req(srp);
1321                 srp = NULL;
1322                 if (NULL == sfp->headrp) {
1323                         SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, final cleanup\n"));
1324                         if (0 == sg_remove_sfp(sdp, sfp)) {     /* device still present */
1325                                 scsi_device_put(sdp->device);
1326                         }
1327                         sfp = NULL;
1328                 }
1329         } else if (srp && srp->orphan) {
1330                 if (sfp->keep_orphan)
1331                         srp->sg_io_owned = 0;
1332                 else {
1333                         sg_finish_rem_req(srp);
1334                         srp = NULL;
1335                 }
1336         }
1337         if (sfp && srp) {
1338                 /* Now wake up any sg_read() that is waiting for this packet. */
1339                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1340                 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1341                 srp->done = 1;
1342                 wake_up_interruptible(&sfp->read_wait);
1343                 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1344         }
1345 }
1346
1347 static struct file_operations sg_fops = {
1348         .owner = THIS_MODULE,
1349         .read = sg_read,
1350         .write = sg_write,
1351         .poll = sg_poll,
1352         .ioctl = sg_ioctl,
1353 #ifdef CONFIG_COMPAT
1354         .compat_ioctl = sg_compat_ioctl,
1355 #endif
1356         .open = sg_open,
1357         .mmap = sg_mmap,
1358         .release = sg_release,
1359         .fasync = sg_fasync,
1360 };
1361
1362 static struct class *sg_sysfs_class;
1363
1364 static int sg_sysfs_valid = 0;
1365
1366 static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1367 {
1368         struct request_queue *q = scsidp->request_queue;
1369         Sg_device *sdp;
1370         unsigned long iflags;
1371         int error;
1372         u32 k;
1373
1374         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1375         if (!sdp) {
1376                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1377                 return ERR_PTR(-ENOMEM);
1378         }
1379         error = -ENOMEM;
1380         if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) {
1381                 printk(KERN_WARNING "idr expansion Sg_device failure\n");
1382                 goto out;
1383         }
1384
1385         write_lock_irqsave(&sg_index_lock, iflags);
1386         error = idr_get_new(&sg_index_idr, sdp, &k);
1387         write_unlock_irqrestore(&sg_index_lock, iflags);
1388
1389         if (error) {
1390                 printk(KERN_WARNING "idr allocation Sg_device failure: %d\n",
1391                        error);
1392                 goto out;
1393         }
1394
1395         if (unlikely(k >= SG_MAX_DEVS))
1396                 goto overflow;
1397
1398         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1399         sprintf(disk->disk_name, "sg%d", k);
1400         disk->first_minor = k;
1401         sdp->disk = disk;
1402         sdp->device = scsidp;
1403         init_waitqueue_head(&sdp->o_excl_wait);
1404         sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments);
1405         sdp->index = k;
1406
1407         error = 0;
1408  out:
1409         if (error) {
1410                 kfree(sdp);
1411                 return ERR_PTR(error);
1412         }
1413         return sdp;
1414
1415  overflow:
1416         sdev_printk(KERN_WARNING, scsidp,
1417                     "Unable to attach sg device type=%d, minor "
1418                     "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1419         error = -ENODEV;
1420         goto out;
1421 }
1422
1423 static int
1424 sg_add(struct device *cl_dev, struct class_interface *cl_intf)
1425 {
1426         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1427         struct gendisk *disk;
1428         Sg_device *sdp = NULL;
1429         struct cdev * cdev = NULL;
1430         int error;
1431         unsigned long iflags;
1432
1433         disk = alloc_disk(1);
1434         if (!disk) {
1435                 printk(KERN_WARNING "alloc_disk failed\n");
1436                 return -ENOMEM;
1437         }
1438         disk->major = SCSI_GENERIC_MAJOR;
1439
1440         error = -ENOMEM;
1441         cdev = cdev_alloc();
1442         if (!cdev) {
1443                 printk(KERN_WARNING "cdev_alloc failed\n");
1444                 goto out;
1445         }
1446         cdev->owner = THIS_MODULE;
1447         cdev->ops = &sg_fops;
1448
1449         sdp = sg_alloc(disk, scsidp);
1450         if (IS_ERR(sdp)) {
1451                 printk(KERN_WARNING "sg_alloc failed\n");
1452                 error = PTR_ERR(sdp);
1453                 goto out;
1454         }
1455
1456         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1457         if (error)
1458                 goto cdev_add_err;
1459
1460         sdp->cdev = cdev;
1461         if (sg_sysfs_valid) {
1462                 struct device *sg_class_member;
1463
1464                 sg_class_member = device_create_drvdata(sg_sysfs_class,
1465                                                         cl_dev->parent,
1466                                                         MKDEV(SCSI_GENERIC_MAJOR,
1467                                                               sdp->index),
1468                                                         sdp,
1469                                                         "%s", disk->disk_name);
1470                 if (IS_ERR(sg_class_member)) {
1471                         printk(KERN_ERR "sg_add: "
1472                                "device_create failed\n");
1473                         error = PTR_ERR(sg_class_member);
1474                         goto cdev_add_err;
1475                 }
1476                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1477                                           &sg_class_member->kobj, "generic");
1478                 if (error)
1479                         printk(KERN_ERR "sg_add: unable to make symlink "
1480                                         "'generic' back to sg%d\n", sdp->index);
1481         } else
1482                 printk(KERN_WARNING "sg_add: sg_sys Invalid\n");
1483
1484         sdev_printk(KERN_NOTICE, scsidp,
1485                     "Attached scsi generic sg%d type %d\n", sdp->index,
1486                     scsidp->type);
1487
1488         dev_set_drvdata(cl_dev, sdp);
1489
1490         return 0;
1491
1492 cdev_add_err:
1493         write_lock_irqsave(&sg_index_lock, iflags);
1494         idr_remove(&sg_index_idr, sdp->index);
1495         write_unlock_irqrestore(&sg_index_lock, iflags);
1496         kfree(sdp);
1497
1498 out:
1499         put_disk(disk);
1500         if (cdev)
1501                 cdev_del(cdev);
1502         return error;
1503 }
1504
1505 static void
1506 sg_remove(struct device *cl_dev, struct class_interface *cl_intf)
1507 {
1508         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1509         Sg_device *sdp = dev_get_drvdata(cl_dev);
1510         unsigned long iflags;
1511         Sg_fd *sfp;
1512         Sg_fd *tsfp;
1513         Sg_request *srp;
1514         Sg_request *tsrp;
1515         int delay;
1516
1517         if (!sdp)
1518                 return;
1519
1520         delay = 0;
1521         write_lock_irqsave(&sg_index_lock, iflags);
1522         if (sdp->headfp) {
1523                 sdp->detached = 1;
1524                 for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1525                         tsfp = sfp->nextfp;
1526                         for (srp = sfp->headrp; srp; srp = tsrp) {
1527                                 tsrp = srp->nextrp;
1528                                 if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
1529                                         sg_finish_rem_req(srp);
1530                         }
1531                         if (sfp->closed) {
1532                                 scsi_device_put(sdp->device);
1533                                 __sg_remove_sfp(sdp, sfp);
1534                         } else {
1535                                 delay = 1;
1536                                 wake_up_interruptible(&sfp->read_wait);
1537                                 kill_fasync(&sfp->async_qp, SIGPOLL,
1538                                             POLL_HUP);
1539                         }
1540                 }
1541                 SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d, dirty\n", sdp->index));
1542                 if (NULL == sdp->headfp) {
1543                         idr_remove(&sg_index_idr, sdp->index);
1544                 }
1545         } else {        /* nothing active, simple case */
1546                 SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d\n", sdp->index));
1547                 idr_remove(&sg_index_idr, sdp->index);
1548         }
1549         write_unlock_irqrestore(&sg_index_lock, iflags);
1550
1551         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1552         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1553         cdev_del(sdp->cdev);
1554         sdp->cdev = NULL;
1555         put_disk(sdp->disk);
1556         sdp->disk = NULL;
1557         if (NULL == sdp->headfp)
1558                 kfree(sdp);
1559
1560         if (delay)
1561                 msleep(10);     /* dirty detach so delay device destruction */
1562 }
1563
1564 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1565 module_param_named(def_reserved_size, def_reserved_size, int,
1566                    S_IRUGO | S_IWUSR);
1567 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1568
1569 MODULE_AUTHOR("Douglas Gilbert");
1570 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1571 MODULE_LICENSE("GPL");
1572 MODULE_VERSION(SG_VERSION_STR);
1573 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1574
1575 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1576                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1577 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1578 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1579
1580 static int __init
1581 init_sg(void)
1582 {
1583         int rc;
1584
1585         if (scatter_elem_sz < PAGE_SIZE) {
1586                 scatter_elem_sz = PAGE_SIZE;
1587                 scatter_elem_sz_prev = scatter_elem_sz;
1588         }
1589         if (def_reserved_size >= 0)
1590                 sg_big_buff = def_reserved_size;
1591         else
1592                 def_reserved_size = sg_big_buff;
1593
1594         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1595                                     SG_MAX_DEVS, "sg");
1596         if (rc)
1597                 return rc;
1598         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1599         if ( IS_ERR(sg_sysfs_class) ) {
1600                 rc = PTR_ERR(sg_sysfs_class);
1601                 goto err_out;
1602         }
1603         sg_sysfs_valid = 1;
1604         rc = scsi_register_interface(&sg_interface);
1605         if (0 == rc) {
1606 #ifdef CONFIG_SCSI_PROC_FS
1607                 sg_proc_init();
1608 #endif                          /* CONFIG_SCSI_PROC_FS */
1609                 return 0;
1610         }
1611         class_destroy(sg_sysfs_class);
1612 err_out:
1613         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1614         return rc;
1615 }
1616
1617 static void __exit
1618 exit_sg(void)
1619 {
1620 #ifdef CONFIG_SCSI_PROC_FS
1621         sg_proc_cleanup();
1622 #endif                          /* CONFIG_SCSI_PROC_FS */
1623         scsi_unregister_interface(&sg_interface);
1624         class_destroy(sg_sysfs_class);
1625         sg_sysfs_valid = 0;
1626         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1627                                  SG_MAX_DEVS);
1628         idr_destroy(&sg_index_idr);
1629 }
1630
1631 static int __sg_start_req(struct sg_request *srp, struct sg_io_hdr *hp,
1632                           unsigned char *cmd)
1633 {
1634         struct sg_fd *sfp = srp->parentfp;
1635         struct request_queue *q = sfp->parentdp->device->request_queue;
1636         struct request *rq;
1637         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1638
1639         rq = blk_get_request(q, rw, GFP_ATOMIC);
1640         if (!rq)
1641                 return -ENOMEM;
1642
1643         memcpy(rq->cmd, cmd, hp->cmd_len);
1644
1645         rq->cmd_len = hp->cmd_len;
1646         rq->cmd_type = REQ_TYPE_BLOCK_PC;
1647
1648         srp->rq = rq;
1649         rq->end_io_data = srp;
1650         rq->sense = srp->sense_b;
1651         rq->retries = SG_DEFAULT_RETRIES;
1652
1653         return 0;
1654 }
1655
1656 static int sg_start_req(Sg_request *srp, unsigned char *cmd)
1657 {
1658         int res;
1659         Sg_fd *sfp = srp->parentfp;
1660         sg_io_hdr_t *hp = &srp->header;
1661         int dxfer_len = (int) hp->dxfer_len;
1662         int dxfer_dir = hp->dxfer_direction;
1663         Sg_scatter_hold *req_schp = &srp->data;
1664         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1665         struct request_queue *q = sfp->parentdp->device->request_queue;
1666         struct rq_map_data map_data;
1667
1668         SCSI_LOG_TIMEOUT(4, printk("sg_start_req: dxfer_len=%d\n", dxfer_len));
1669
1670         res = __sg_start_req(srp, hp, cmd);
1671         if (res)
1672                 return res;
1673
1674         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1675                 return 0;
1676
1677 #ifdef SG_ALLOW_DIO_CODE
1678         if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
1679             (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) &&
1680             (!sfp->parentdp->device->host->unchecked_isa_dma) &&
1681             blk_rq_aligned(q, hp->dxferp, dxfer_len))
1682                 return sg_build_direct(srp, sfp, dxfer_len);
1683 #endif
1684         if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen))
1685                 sg_link_reserve(sfp, srp, dxfer_len);
1686         else
1687                 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1688
1689         if (!res) {
1690                 struct request *rq = srp->rq;
1691                 Sg_scatter_hold *schp = &srp->data;
1692                 int iovec_count = (int) hp->iovec_count;
1693
1694                 map_data.pages = schp->pages;
1695                 map_data.page_order = schp->page_order;
1696                 map_data.nr_entries = schp->k_use_sg;
1697
1698                 if (iovec_count)
1699                         res = blk_rq_map_user_iov(q, rq, &map_data, hp->dxferp,
1700                                                   iovec_count,
1701                                                   hp->dxfer_len, GFP_ATOMIC);
1702                 else
1703                         res = blk_rq_map_user(q, rq, &map_data, hp->dxferp,
1704                                               hp->dxfer_len, GFP_ATOMIC);
1705
1706                 if (!res)
1707                         srp->bio = rq->bio;
1708         }
1709
1710         return res;
1711 }
1712
1713 static void
1714 sg_finish_rem_req(Sg_request * srp)
1715 {
1716         Sg_fd *sfp = srp->parentfp;
1717         Sg_scatter_hold *req_schp = &srp->data;
1718
1719         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1720         if (srp->res_used)
1721                 sg_unlink_reserve(sfp, srp);
1722         else
1723                 sg_remove_scat(req_schp);
1724
1725         if (srp->rq) {
1726                 if (srp->bio)
1727                         blk_rq_unmap_user(srp->bio);
1728
1729                 blk_put_request(srp->rq);
1730         }
1731
1732         sg_remove_request(sfp, srp);
1733 }
1734
1735 static int
1736 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1737 {
1738         int sg_bufflen = tablesize * sizeof(struct page *);
1739         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1740
1741         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1742         if (!schp->pages)
1743                 return -ENOMEM;
1744         schp->sglist_len = sg_bufflen;
1745         return tablesize;       /* number of scat_gath elements allocated */
1746 }
1747
1748 /* Returns: -ve -> error, 0 -> done, 1 -> try indirect */
1749 static int
1750 sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
1751 {
1752         sg_io_hdr_t *hp = &srp->header;
1753         Sg_scatter_hold *schp = &srp->data;
1754         int res;
1755         struct request *rq = srp->rq;
1756         struct request_queue *q = sfp->parentdp->device->request_queue;
1757
1758         res = blk_rq_map_user(q, rq, NULL, hp->dxferp, dxfer_len, GFP_ATOMIC);
1759         if (res)
1760                 return res;
1761         srp->bio = rq->bio;
1762         schp->dio_in_use = 1;
1763         hp->info |= SG_INFO_DIRECT_IO;
1764         return 0;
1765 }
1766
1767 static int
1768 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1769 {
1770         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1771         int sg_tablesize = sfp->parentdp->sg_tablesize;
1772         int blk_size = buff_size, order;
1773         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1774
1775         if (blk_size < 0)
1776                 return -EFAULT;
1777         if (0 == blk_size)
1778                 ++blk_size;     /* don't know why */
1779 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1780         blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1781         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1782                                    buff_size, blk_size));
1783
1784         /* N.B. ret_sz carried into this block ... */
1785         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1786         if (mx_sc_elems < 0)
1787                 return mx_sc_elems;     /* most likely -ENOMEM */
1788
1789         num = scatter_elem_sz;
1790         if (unlikely(num != scatter_elem_sz_prev)) {
1791                 if (num < PAGE_SIZE) {
1792                         scatter_elem_sz = PAGE_SIZE;
1793                         scatter_elem_sz_prev = PAGE_SIZE;
1794                 } else
1795                         scatter_elem_sz_prev = num;
1796         }
1797
1798         if (sfp->low_dma)
1799                 gfp_mask |= GFP_DMA;
1800
1801         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1802                 gfp_mask |= __GFP_ZERO;
1803
1804         order = get_order(num);
1805 retry:
1806         ret_sz = 1 << (PAGE_SHIFT + order);
1807
1808         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1809              k++, rem_sz -= ret_sz) {
1810
1811                 num = (rem_sz > scatter_elem_sz_prev) ?
1812                         scatter_elem_sz_prev : rem_sz;
1813
1814                 schp->pages[k] = alloc_pages(gfp_mask, order);
1815                 if (!schp->pages[k])
1816                         goto out;
1817
1818                 if (num == scatter_elem_sz_prev) {
1819                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1820                                 scatter_elem_sz = ret_sz;
1821                                 scatter_elem_sz_prev = ret_sz;
1822                         }
1823                 }
1824
1825                 SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
1826                                  "ret_sz=%d\n", k, num, ret_sz));
1827         }               /* end of for loop */
1828
1829         schp->page_order = order;
1830         schp->k_use_sg = k;
1831         SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
1832                          "rem_sz=%d\n", k, rem_sz));
1833
1834         schp->bufflen = blk_size;
1835         if (rem_sz > 0) /* must have failed */
1836                 return -ENOMEM;
1837         return 0;
1838 out:
1839         for (i = 0; i < k; i++)
1840                 __free_pages(schp->pages[k], order);
1841
1842         if (--order >= 0)
1843                 goto retry;
1844
1845         return -ENOMEM;
1846 }
1847
1848 static int
1849 sg_write_xfer(Sg_request * srp)
1850 {
1851         sg_io_hdr_t *hp = &srp->header;
1852         Sg_scatter_hold *schp = &srp->data;
1853         int num_xfer = 0;
1854         int dxfer_dir = hp->dxfer_direction;
1855         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1856
1857         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_TO_DEV == dxfer_dir) ||
1858             (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1859                 num_xfer = (int) (new_interface ? hp->dxfer_len : hp->flags);
1860                 if (schp->bufflen < num_xfer)
1861                         num_xfer = schp->bufflen;
1862         }
1863         if ((num_xfer <= 0) || (schp->dio_in_use) ||
1864             (new_interface
1865              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1866                 return 0;
1867
1868         SCSI_LOG_TIMEOUT(4, printk("sg_write_xfer: num_xfer=%d, k_use_sg=%d\n",
1869                           num_xfer, schp->k_use_sg));
1870
1871         return 0;
1872 }
1873
1874 static void
1875 sg_remove_scat(Sg_scatter_hold * schp)
1876 {
1877         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1878         if (schp->pages && schp->sglist_len > 0) {
1879                 if (!schp->dio_in_use) {
1880                         int k;
1881
1882                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1883                                 SCSI_LOG_TIMEOUT(5, printk(
1884                                     "sg_remove_scat: k=%d, pg=0x%p\n",
1885                                     k, schp->pages[k]));
1886                                 __free_pages(schp->pages[k], schp->page_order);
1887                         }
1888
1889                         kfree(schp->pages);
1890                 }
1891         }
1892         memset(schp, 0, sizeof (*schp));
1893 }
1894
1895 static int
1896 sg_read_xfer(Sg_request * srp)
1897 {
1898         sg_io_hdr_t *hp = &srp->header;
1899         Sg_scatter_hold *schp = &srp->data;
1900         int num_xfer = 0;
1901         int dxfer_dir = hp->dxfer_direction;
1902         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1903
1904         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_FROM_DEV == dxfer_dir)
1905             || (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1906                 num_xfer = hp->dxfer_len;
1907                 if (schp->bufflen < num_xfer)
1908                         num_xfer = schp->bufflen;
1909         }
1910         if ((num_xfer <= 0) || (schp->dio_in_use) ||
1911             (new_interface
1912              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1913                 return 0;
1914
1915         SCSI_LOG_TIMEOUT(4, printk("sg_read_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
1916                           num_xfer, (int)hp->iovec_count, schp->k_use_sg));
1917         return 0;
1918 }
1919
1920 static int
1921 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1922 {
1923         Sg_scatter_hold *schp = &srp->data;
1924         int k, num;
1925
1926         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
1927                                    num_read_xfer));
1928         if ((!outp) || (num_read_xfer <= 0))
1929                 return 0;
1930
1931         blk_rq_unmap_user(srp->bio);
1932         srp->bio = NULL;
1933
1934         num = 1 << (PAGE_SHIFT + schp->page_order);
1935         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1936                 if (num > num_read_xfer) {
1937                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1938                                            num_read_xfer))
1939                                 return -EFAULT;
1940                         break;
1941                 } else {
1942                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1943                                            num))
1944                                 return -EFAULT;
1945                         num_read_xfer -= num;
1946                         if (num_read_xfer <= 0)
1947                                 break;
1948                         outp += num;
1949                 }
1950         }
1951
1952         return 0;
1953 }
1954
1955 static void
1956 sg_build_reserve(Sg_fd * sfp, int req_size)
1957 {
1958         Sg_scatter_hold *schp = &sfp->reserve;
1959
1960         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
1961         do {
1962                 if (req_size < PAGE_SIZE)
1963                         req_size = PAGE_SIZE;
1964                 if (0 == sg_build_indirect(schp, sfp, req_size))
1965                         return;
1966                 else
1967                         sg_remove_scat(schp);
1968                 req_size >>= 1; /* divide by 2 */
1969         } while (req_size > (PAGE_SIZE / 2));
1970 }
1971
1972 static void
1973 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1974 {
1975         Sg_scatter_hold *req_schp = &srp->data;
1976         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1977         int k, num, rem;
1978
1979         srp->res_used = 1;
1980         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
1981         rem = size;
1982
1983         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1984         for (k = 0; k < rsv_schp->k_use_sg; k++) {
1985                 if (rem <= num) {
1986                         req_schp->k_use_sg = k + 1;
1987                         req_schp->sglist_len = rsv_schp->sglist_len;
1988                         req_schp->pages = rsv_schp->pages;
1989
1990                         req_schp->bufflen = size;
1991                         req_schp->b_malloc_len = rsv_schp->b_malloc_len;
1992                         req_schp->page_order = rsv_schp->page_order;
1993                         break;
1994                 } else
1995                         rem -= num;
1996         }
1997
1998         if (k >= rsv_schp->k_use_sg)
1999                 SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
2000 }
2001
2002 static void
2003 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2004 {
2005         Sg_scatter_hold *req_schp = &srp->data;
2006
2007         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
2008                                    (int) req_schp->k_use_sg));
2009         req_schp->k_use_sg = 0;
2010         req_schp->bufflen = 0;
2011         req_schp->pages = NULL;
2012         req_schp->page_order = 0;
2013         req_schp->sglist_len = 0;
2014         sfp->save_scat_len = 0;
2015         srp->res_used = 0;
2016 }
2017
2018 static Sg_request *
2019 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2020 {
2021         Sg_request *resp;
2022         unsigned long iflags;
2023
2024         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2025         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2026                 /* look for requests that are ready + not SG_IO owned */
2027                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2028                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2029                         resp->done = 2; /* guard against other readers */
2030                         break;
2031                 }
2032         }
2033         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2034         return resp;
2035 }
2036
2037 #ifdef CONFIG_SCSI_PROC_FS
2038 static Sg_request *
2039 sg_get_nth_request(Sg_fd * sfp, int nth)
2040 {
2041         Sg_request *resp;
2042         unsigned long iflags;
2043         int k;
2044
2045         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2046         for (k = 0, resp = sfp->headrp; resp && (k < nth);
2047              ++k, resp = resp->nextrp) ;
2048         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2049         return resp;
2050 }
2051 #endif
2052
2053 /* always adds to end of list */
2054 static Sg_request *
2055 sg_add_request(Sg_fd * sfp)
2056 {
2057         int k;
2058         unsigned long iflags;
2059         Sg_request *resp;
2060         Sg_request *rp = sfp->req_arr;
2061
2062         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2063         resp = sfp->headrp;
2064         if (!resp) {
2065                 memset(rp, 0, sizeof (Sg_request));
2066                 rp->parentfp = sfp;
2067                 resp = rp;
2068                 sfp->headrp = resp;
2069         } else {
2070                 if (0 == sfp->cmd_q)
2071                         resp = NULL;    /* command queuing disallowed */
2072                 else {
2073                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2074                                 if (!rp->parentfp)
2075                                         break;
2076                         }
2077                         if (k < SG_MAX_QUEUE) {
2078                                 memset(rp, 0, sizeof (Sg_request));
2079                                 rp->parentfp = sfp;
2080                                 while (resp->nextrp)
2081                                         resp = resp->nextrp;
2082                                 resp->nextrp = rp;
2083                                 resp = rp;
2084                         } else
2085                                 resp = NULL;
2086                 }
2087         }
2088         if (resp) {
2089                 resp->nextrp = NULL;
2090                 resp->header.duration = jiffies_to_msecs(jiffies);
2091         }
2092         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2093         return resp;
2094 }
2095
2096 /* Return of 1 for found; 0 for not found */
2097 static int
2098 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2099 {
2100         Sg_request *prev_rp;
2101         Sg_request *rp;
2102         unsigned long iflags;
2103         int res = 0;
2104
2105         if ((!sfp) || (!srp) || (!sfp->headrp))
2106                 return res;
2107         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2108         prev_rp = sfp->headrp;
2109         if (srp == prev_rp) {
2110                 sfp->headrp = prev_rp->nextrp;
2111                 prev_rp->parentfp = NULL;
2112                 res = 1;
2113         } else {
2114                 while ((rp = prev_rp->nextrp)) {
2115                         if (srp == rp) {
2116                                 prev_rp->nextrp = rp->nextrp;
2117                                 rp->parentfp = NULL;
2118                                 res = 1;
2119                                 break;
2120                         }
2121                         prev_rp = rp;
2122                 }
2123         }
2124         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2125         return res;
2126 }
2127
2128 #ifdef CONFIG_SCSI_PROC_FS
2129 static Sg_fd *
2130 sg_get_nth_sfp(Sg_device * sdp, int nth)
2131 {
2132         Sg_fd *resp;
2133         unsigned long iflags;
2134         int k;
2135
2136         read_lock_irqsave(&sg_index_lock, iflags);
2137         for (k = 0, resp = sdp->headfp; resp && (k < nth);
2138              ++k, resp = resp->nextfp) ;
2139         read_unlock_irqrestore(&sg_index_lock, iflags);
2140         return resp;
2141 }
2142 #endif
2143
2144 static Sg_fd *
2145 sg_add_sfp(Sg_device * sdp, int dev)
2146 {
2147         Sg_fd *sfp;
2148         unsigned long iflags;
2149         int bufflen;
2150
2151         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2152         if (!sfp)
2153                 return NULL;
2154
2155         init_waitqueue_head(&sfp->read_wait);
2156         rwlock_init(&sfp->rq_list_lock);
2157
2158         sfp->timeout = SG_DEFAULT_TIMEOUT;
2159         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2160         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2161         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2162             sdp->device->host->unchecked_isa_dma : 1;
2163         sfp->cmd_q = SG_DEF_COMMAND_Q;
2164         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2165         sfp->parentdp = sdp;
2166         write_lock_irqsave(&sg_index_lock, iflags);
2167         if (!sdp->headfp)
2168                 sdp->headfp = sfp;
2169         else {                  /* add to tail of existing list */
2170                 Sg_fd *pfp = sdp->headfp;
2171                 while (pfp->nextfp)
2172                         pfp = pfp->nextfp;
2173                 pfp->nextfp = sfp;
2174         }
2175         write_unlock_irqrestore(&sg_index_lock, iflags);
2176         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2177         if (unlikely(sg_big_buff != def_reserved_size))
2178                 sg_big_buff = def_reserved_size;
2179
2180         bufflen = min_t(int, sg_big_buff,
2181                         sdp->device->request_queue->max_sectors * 512);
2182         sg_build_reserve(sfp, bufflen);
2183         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2184                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2185         return sfp;
2186 }
2187
2188 static void
2189 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2190 {
2191         Sg_fd *fp;
2192         Sg_fd *prev_fp;
2193
2194         prev_fp = sdp->headfp;
2195         if (sfp == prev_fp)
2196                 sdp->headfp = prev_fp->nextfp;
2197         else {
2198                 while ((fp = prev_fp->nextfp)) {
2199                         if (sfp == fp) {
2200                                 prev_fp->nextfp = fp->nextfp;
2201                                 break;
2202                         }
2203                         prev_fp = fp;
2204                 }
2205         }
2206         if (sfp->reserve.bufflen > 0) {
2207                 SCSI_LOG_TIMEOUT(6,
2208                         printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2209                         (int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2210                 sg_remove_scat(&sfp->reserve);
2211         }
2212         sfp->parentdp = NULL;
2213         SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2214         kfree(sfp);
2215 }
2216
2217 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2218 static int
2219 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2220 {
2221         Sg_request *srp;
2222         Sg_request *tsrp;
2223         int dirty = 0;
2224         int res = 0;
2225
2226         for (srp = sfp->headrp; srp; srp = tsrp) {
2227                 tsrp = srp->nextrp;
2228                 if (sg_srp_done(srp, sfp))
2229                         sg_finish_rem_req(srp);
2230                 else
2231                         ++dirty;
2232         }
2233         if (0 == dirty) {
2234                 unsigned long iflags;
2235
2236                 write_lock_irqsave(&sg_index_lock, iflags);
2237                 __sg_remove_sfp(sdp, sfp);
2238                 if (sdp->detached && (NULL == sdp->headfp)) {
2239                         idr_remove(&sg_index_idr, sdp->index);
2240                         kfree(sdp);
2241                         res = 1;
2242                 }
2243                 write_unlock_irqrestore(&sg_index_lock, iflags);
2244         } else {
2245                 /* MOD_INC's to inhibit unloading sg and associated adapter driver */
2246                 /* only bump the access_count if we actually succeeded in
2247                  * throwing another counter on the host module */
2248                 scsi_device_get(sdp->device);   /* XXX: retval ignored? */
2249                 sfp->closed = 1;        /* flag dirty state on this fd */
2250                 SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2251                                   dirty));
2252         }
2253         return res;
2254 }
2255
2256 static int
2257 sg_res_in_use(Sg_fd * sfp)
2258 {
2259         const Sg_request *srp;
2260         unsigned long iflags;
2261
2262         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2263         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2264                 if (srp->res_used)
2265                         break;
2266         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2267         return srp ? 1 : 0;
2268 }
2269
2270 #ifdef CONFIG_SCSI_PROC_FS
2271 static int
2272 sg_idr_max_id(int id, void *p, void *data)
2273 {
2274         int *k = data;
2275
2276         if (*k < id)
2277                 *k = id;
2278
2279         return 0;
2280 }
2281
2282 static int
2283 sg_last_dev(void)
2284 {
2285         int k = -1;
2286         unsigned long iflags;
2287
2288         read_lock_irqsave(&sg_index_lock, iflags);
2289         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2290         read_unlock_irqrestore(&sg_index_lock, iflags);
2291         return k + 1;           /* origin 1 */
2292 }
2293 #endif
2294
2295 static Sg_device *
2296 sg_get_dev(int dev)
2297 {
2298         Sg_device *sdp;
2299         unsigned long iflags;
2300
2301         read_lock_irqsave(&sg_index_lock, iflags);
2302         sdp = idr_find(&sg_index_idr, dev);
2303         read_unlock_irqrestore(&sg_index_lock, iflags);
2304
2305         return sdp;
2306 }
2307
2308 #ifdef CONFIG_SCSI_PROC_FS
2309
2310 static struct proc_dir_entry *sg_proc_sgp = NULL;
2311
2312 static char sg_proc_sg_dirname[] = "scsi/sg";
2313
2314 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2315
2316 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2317 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2318                                   size_t count, loff_t *off);
2319 static struct file_operations adio_fops = {
2320         /* .owner, .read and .llseek added in sg_proc_init() */
2321         .open = sg_proc_single_open_adio,
2322         .write = sg_proc_write_adio,
2323         .release = single_release,
2324 };
2325
2326 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2327 static ssize_t sg_proc_write_dressz(struct file *filp,
2328                 const char __user *buffer, size_t count, loff_t *off);
2329 static struct file_operations dressz_fops = {
2330         .open = sg_proc_single_open_dressz,
2331         .write = sg_proc_write_dressz,
2332         .release = single_release,
2333 };
2334
2335 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2336 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2337 static struct file_operations version_fops = {
2338         .open = sg_proc_single_open_version,
2339         .release = single_release,
2340 };
2341
2342 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2343 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2344 static struct file_operations devhdr_fops = {
2345         .open = sg_proc_single_open_devhdr,
2346         .release = single_release,
2347 };
2348
2349 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2350 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2351 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2352 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2353 static void dev_seq_stop(struct seq_file *s, void *v);
2354 static struct file_operations dev_fops = {
2355         .open = sg_proc_open_dev,
2356         .release = seq_release,
2357 };
2358 static struct seq_operations dev_seq_ops = {
2359         .start = dev_seq_start,
2360         .next  = dev_seq_next,
2361         .stop  = dev_seq_stop,
2362         .show  = sg_proc_seq_show_dev,
2363 };
2364
2365 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2366 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2367 static struct file_operations devstrs_fops = {
2368         .open = sg_proc_open_devstrs,
2369         .release = seq_release,
2370 };
2371 static struct seq_operations devstrs_seq_ops = {
2372         .start = dev_seq_start,
2373         .next  = dev_seq_next,
2374         .stop  = dev_seq_stop,
2375         .show  = sg_proc_seq_show_devstrs,
2376 };
2377
2378 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2379 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2380 static struct file_operations debug_fops = {
2381         .open = sg_proc_open_debug,
2382         .release = seq_release,
2383 };
2384 static struct seq_operations debug_seq_ops = {
2385         .start = dev_seq_start,
2386         .next  = dev_seq_next,
2387         .stop  = dev_seq_stop,
2388         .show  = sg_proc_seq_show_debug,
2389 };
2390
2391
2392 struct sg_proc_leaf {
2393         const char * name;
2394         struct file_operations * fops;
2395 };
2396
2397 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2398         {"allow_dio", &adio_fops},
2399         {"debug", &debug_fops},
2400         {"def_reserved_size", &dressz_fops},
2401         {"device_hdr", &devhdr_fops},
2402         {"devices", &dev_fops},
2403         {"device_strs", &devstrs_fops},
2404         {"version", &version_fops}
2405 };
2406
2407 static int
2408 sg_proc_init(void)
2409 {
2410         int k, mask;
2411         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2412         struct sg_proc_leaf * leaf;
2413
2414         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2415         if (!sg_proc_sgp)
2416                 return 1;
2417         for (k = 0; k < num_leaves; ++k) {
2418                 leaf = &sg_proc_leaf_arr[k];
2419                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2420                 leaf->fops->owner = THIS_MODULE;
2421                 leaf->fops->read = seq_read;
2422                 leaf->fops->llseek = seq_lseek;
2423                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2424         }
2425         return 0;
2426 }
2427
2428 static void
2429 sg_proc_cleanup(void)
2430 {
2431         int k;
2432         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2433
2434         if (!sg_proc_sgp)
2435                 return;
2436         for (k = 0; k < num_leaves; ++k)
2437                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2438         remove_proc_entry(sg_proc_sg_dirname, NULL);
2439 }
2440
2441
2442 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2443 {
2444         seq_printf(s, "%d\n", *((int *)s->private));
2445         return 0;
2446 }
2447
2448 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2449 {
2450         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2451 }
2452
2453 static ssize_t
2454 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2455                    size_t count, loff_t *off)
2456 {
2457         int num;
2458         char buff[11];
2459
2460         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2461                 return -EACCES;
2462         num = (count < 10) ? count : 10;
2463         if (copy_from_user(buff, buffer, num))
2464                 return -EFAULT;
2465         buff[num] = '\0';
2466         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2467         return count;
2468 }
2469
2470 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2471 {
2472         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2473 }
2474
2475 static ssize_t
2476 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2477                      size_t count, loff_t *off)
2478 {
2479         int num;
2480         unsigned long k = ULONG_MAX;
2481         char buff[11];
2482
2483         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2484                 return -EACCES;
2485         num = (count < 10) ? count : 10;
2486         if (copy_from_user(buff, buffer, num))
2487                 return -EFAULT;
2488         buff[num] = '\0';
2489         k = simple_strtoul(buff, NULL, 10);
2490         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2491                 sg_big_buff = k;
2492                 return count;
2493         }
2494         return -ERANGE;
2495 }
2496
2497 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2498 {
2499         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2500                    sg_version_date);
2501         return 0;
2502 }
2503
2504 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2505 {
2506         return single_open(file, sg_proc_seq_show_version, NULL);
2507 }
2508
2509 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2510 {
2511         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2512                    "online\n");
2513         return 0;
2514 }
2515
2516 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2517 {
2518         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2519 }
2520
2521 struct sg_proc_deviter {
2522         loff_t  index;
2523         size_t  max;
2524 };
2525
2526 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2527 {
2528         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2529
2530         s->private = it;
2531         if (! it)
2532                 return NULL;
2533
2534         it->index = *pos;
2535         it->max = sg_last_dev();
2536         if (it->index >= it->max)
2537                 return NULL;
2538         return it;
2539 }
2540
2541 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2542 {
2543         struct sg_proc_deviter * it = s->private;
2544
2545         *pos = ++it->index;
2546         return (it->index < it->max) ? it : NULL;
2547 }
2548
2549 static void dev_seq_stop(struct seq_file *s, void *v)
2550 {
2551         kfree(s->private);
2552 }
2553
2554 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2555 {
2556         return seq_open(file, &dev_seq_ops);
2557 }
2558
2559 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2560 {
2561         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2562         Sg_device *sdp;
2563         struct scsi_device *scsidp;
2564
2565         sdp = it ? sg_get_dev(it->index) : NULL;
2566         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2567                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2568                               scsidp->host->host_no, scsidp->channel,
2569                               scsidp->id, scsidp->lun, (int) scsidp->type,
2570                               1,
2571                               (int) scsidp->queue_depth,
2572                               (int) scsidp->device_busy,
2573                               (int) scsi_device_online(scsidp));
2574         else
2575                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2576         return 0;
2577 }
2578
2579 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2580 {
2581         return seq_open(file, &devstrs_seq_ops);
2582 }
2583
2584 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2585 {
2586         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2587         Sg_device *sdp;
2588         struct scsi_device *scsidp;
2589
2590         sdp = it ? sg_get_dev(it->index) : NULL;
2591         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2592                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2593                            scsidp->vendor, scsidp->model, scsidp->rev);
2594         else
2595                 seq_printf(s, "<no active device>\n");
2596         return 0;
2597 }
2598
2599 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2600 {
2601         int k, m, new_interface, blen, usg;
2602         Sg_request *srp;
2603         Sg_fd *fp;
2604         const sg_io_hdr_t *hp;
2605         const char * cp;
2606         unsigned int ms;
2607
2608         for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
2609                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2610                            "(res)sgat=%d low_dma=%d\n", k + 1,
2611                            jiffies_to_msecs(fp->timeout),
2612                            fp->reserve.bufflen,
2613                            (int) fp->reserve.k_use_sg,
2614                            (int) fp->low_dma);
2615                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2616                            (int) fp->cmd_q, (int) fp->force_packid,
2617                            (int) fp->keep_orphan, (int) fp->closed);
2618                 for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
2619                         hp = &srp->header;
2620                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2621                         if (srp->res_used) {
2622                                 if (new_interface &&
2623                                     (SG_FLAG_MMAP_IO & hp->flags))
2624                                         cp = "     mmap>> ";
2625                                 else
2626                                         cp = "     rb>> ";
2627                         } else {
2628                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2629                                         cp = "     dio>> ";
2630                                 else
2631                                         cp = "     ";
2632                         }
2633                         seq_printf(s, cp);
2634                         blen = srp->data.bufflen;
2635                         usg = srp->data.k_use_sg;
2636                         seq_printf(s, srp->done ?
2637                                    ((1 == srp->done) ?  "rcv:" : "fin:")
2638                                    : "act:");
2639                         seq_printf(s, " id=%d blen=%d",
2640                                    srp->header.pack_id, blen);
2641                         if (srp->done)
2642                                 seq_printf(s, " dur=%d", hp->duration);
2643                         else {
2644                                 ms = jiffies_to_msecs(jiffies);
2645                                 seq_printf(s, " t_o/elap=%d/%d",
2646                                         (new_interface ? hp->timeout :
2647                                                   jiffies_to_msecs(fp->timeout)),
2648                                         (ms > hp->duration ? ms - hp->duration : 0));
2649                         }
2650                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2651                                    (int) srp->data.cmd_opcode);
2652                 }
2653                 if (0 == m)
2654                         seq_printf(s, "     No requests active\n");
2655         }
2656 }
2657
2658 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2659 {
2660         return seq_open(file, &debug_seq_ops);
2661 }
2662
2663 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2664 {
2665         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2666         Sg_device *sdp;
2667
2668         if (it && (0 == it->index)) {
2669                 seq_printf(s, "max_active_device=%d(origin 1)\n",
2670                            (int)it->max);
2671                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2672         }
2673         sdp = it ? sg_get_dev(it->index) : NULL;
2674         if (sdp) {
2675                 struct scsi_device *scsidp = sdp->device;
2676
2677                 if (NULL == scsidp) {
2678                         seq_printf(s, "device %d detached ??\n",
2679                                    (int)it->index);
2680                         return 0;
2681                 }
2682
2683                 if (sg_get_nth_sfp(sdp, 0)) {
2684                         seq_printf(s, " >>> device=%s ",
2685                                 sdp->disk->disk_name);
2686                         if (sdp->detached)
2687                                 seq_printf(s, "detached pending close ");
2688                         else
2689                                 seq_printf
2690                                     (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2691                                      scsidp->host->host_no,
2692                                      scsidp->channel, scsidp->id,
2693                                      scsidp->lun,
2694                                      scsidp->host->hostt->emulated);
2695                         seq_printf(s, " sg_tablesize=%d excl=%d\n",
2696                                    sdp->sg_tablesize, sdp->exclude);
2697                 }
2698                 sg_proc_debug_helper(s, sdp);
2699         }
2700         return 0;
2701 }
2702
2703 #endif                          /* CONFIG_SCSI_PROC_FS */
2704
2705 module_init(init_sg);
2706 module_exit(exit_sg);