kernel/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 - 2014 Douglas Gilbert
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2, or (at your option)
  15  * any later version.
  16  *
  17  */
  18
  19 static int sg_version_num = 30536;      /* 2 digits for each component */
  20 #define SG_VERSION_STR "3.5.36"
  21
  22 /*
  23  *  D. P. Gilbert (dgilbert@interlog.com), notes:
  24  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
  25  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
  26  *        (otherwise the macros compile to empty statements).
  27  *
  28  */
  29 #include <linux/module.h>
  30
  31 #include <linux/fs.h>
  32 #include <linux/kernel.h>
  33 #include <linux/sched.h>
  34 #include <linux/string.h>
  35 #include <linux/mm.h>
  36 #include <linux/errno.h>
  37 #include <linux/mtio.h>
  38 #include <linux/ioctl.h>
  39 #include <linux/slab.h>
  40 #include <linux/fcntl.h>
  41 #include <linux/init.h>
  42 #include <linux/poll.h>
  43 #include <linux/moduleparam.h>
  44 #include <linux/cdev.h>
  45 #include <linux/idr.h>
  46 #include <linux/seq_file.h>
  47 #include <linux/blkdev.h>
  48 #include <linux/delay.h>
  49 #include <linux/blktrace_api.h>
  50 #include <linux/mutex.h>
  51 #include <linux/atomic.h>
  52 #include <linux/ratelimit.h>
  53 #include <linux/uio.h>
  54
  55 #include "scsi.h"
  56 #include <scsi/scsi_dbg.h>
  57 #include <scsi/scsi_host.h>
  58 #include <scsi/scsi_driver.h>
  59 #include <scsi/scsi_ioctl.h>
  60 #include <scsi/sg.h>
  61
  62 #include "scsi_logging.h"
  63
  64 #ifdef CONFIG_SCSI_PROC_FS
  65 #include <linux/proc_fs.h>
  66 static char *sg_version_date = "20140603";
  67
  68 static int sg_proc_init(void);
  69 static void sg_proc_cleanup(void);
  70 #endif
  71
  72 #define SG_ALLOW_DIO_DEF 0
  73
  74 #define SG_MAX_DEVS 32768
  75
  76 /* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
  77  * of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
  78  * than 16 bytes are "variable length" whose length is a multiple of 4
  79  */
  80 #define SG_MAX_CDB_SIZE 252
  81
  82 /*
  83  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
  84  * Then when using 32 bit integers x * m may overflow during the calculation.
  85  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
  86  * calculates the same, but prevents the overflow when both m and d
  87  * are "small" numbers (like HZ and USER_HZ).
  88  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
  89  * in 32 bits.
  90  */
  91 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
  92
  93 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  94
  95 int sg_big_buff = SG_DEF_RESERVED_SIZE;
  96 /* N.B. This variable is readable and writeable via
  97    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  98    of this size (or less if there is not enough memory) will be reserved
  99    for use by this file descriptor. [Deprecated usage: this variable is also
 100    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
 101    the kernel (i.e. it is not a module).] */
 102 static int def_reserved_size = -1;      /* picks up init parameter */
 103 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
 104
 105 static int scatter_elem_sz = SG_SCATTER_SZ;
 106 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
 107
 108 #define SG_SECTOR_SZ 512
 109
 110 static int sg_add_device(struct device *, struct class_interface *);
 111 static void sg_remove_device(struct device *, struct class_interface *);
 112
 113 static DEFINE_IDR(sg_index_idr);
 114 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
 115                                                            file descriptor list for device */
 116
 117 static struct class_interface sg_interface = {
 118         .add_dev        = sg_add_device,
 119         .remove_dev     = sg_remove_device,
 120 };
 121
 122 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 123         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 124         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 125         unsigned bufflen;       /* Size of (aggregate) data buffer */
 126         struct page **pages;
 127         int page_order;
 128         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 129         unsigned char cmd_opcode; /* first byte of command */
 130 } Sg_scatter_hold;
 131
 132 struct sg_device;               /* forward declarations */
 133 struct sg_fd;
 134
 135 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 136         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
 137         struct sg_fd *parentfp; /* NULL -> not in use */
 138         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 139         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 140         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 141         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 142         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 143         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 144         /* done protected by rq_list_lock */
 145         char done;              /* 0->before bh, 1->before read, 2->read */
 146         struct request *rq;
 147         struct bio *bio;
 148         struct execute_work ew;
 149 } Sg_request;
 150
 151 typedef struct sg_fd {          /* holds the state of a file descriptor */
 152         struct list_head sfd_siblings;  /* protected by device's sfd_lock */
 153         struct sg_device *parentdp;     /* owning device */
 154         wait_queue_head_t read_wait;    /* queue read until command done */
 155         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 156         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 157         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 158         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 159         unsigned save_scat_len; /* original length of trunc. scat. element */
 160         Sg_request *headrp;     /* head of request slist, NULL->empty */
 161         struct fasync_struct *async_qp; /* used by asynchronous notification */
 162         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 163         char low_dma;           /* as in parent but possibly overridden to 1 */
 164         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 165         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 166         unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */
 167         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 168         char mmap_called;       /* 0 -> mmap() never called on this fd */
 169         struct kref f_ref;
 170         struct execute_work ew;
 171 } Sg_fd;
 172
 173 typedef struct sg_device { /* holds the state of each scsi generic device */
 174         struct scsi_device *device;
 175         wait_queue_head_t open_wait;    /* queue open() when O_EXCL present */
 176         struct mutex open_rel_lock;     /* held when in open() or release() */
 177         int sg_tablesize;       /* adapter's max scatter-gather table size */
 178         u32 index;              /* device index number */
 179         struct list_head sfds;
 180         rwlock_t sfd_lock;      /* protect access to sfd list */
 181         atomic_t detaching;     /* 0->device usable, 1->device detaching */
 182         bool exclude;           /* 1->open(O_EXCL) succeeded and is active */
 183         int open_cnt;           /* count of opens (perhaps < num(sfds) ) */
 184         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 185         struct gendisk *disk;
 186         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 187         struct kref d_ref;
 188 } Sg_device;
 189
 190 /* tasklet or soft irq callback */
 191 static void sg_rq_end_io(struct request *rq, int uptodate);
 192 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 193 static int sg_finish_rem_req(Sg_request * srp);
 194 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 195 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 196                            Sg_request * srp);
 197 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 198                         const char __user *buf, size_t count, int blocking,
 199                         int read_only, int sg_io_owned, Sg_request **o_srp);
 200 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 201                            unsigned char *cmnd, int timeout, int blocking);
 202 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 203 static void sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp);
 204 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 205 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 206 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 207 static Sg_fd *sg_add_sfp(Sg_device * sdp);
 208 static void sg_remove_sfp(struct kref *);
 209 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 210 static Sg_request *sg_add_request(Sg_fd * sfp);
 211 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 212 static int sg_res_in_use(Sg_fd * sfp);
 213 static Sg_device *sg_get_dev(int dev);
 214 static void sg_device_destroy(struct kref *kref);
 215
 216 #define SZ_SG_HEADER sizeof(struct sg_header)
 217 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 218 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
 219 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 220
 221 #define sg_printk(prefix, sdp, fmt, a...) \
 222         sdev_prefix_printk(prefix, (sdp)->device,               \
 223                            (sdp)->disk->disk_name, fmt, ##a)
 224
 225 static int sg_allow_access(struct file *filp, unsigned char *cmd)
 226 {
 227         struct sg_fd *sfp = filp->private_data;
 228
 229         if (sfp->parentdp->device->type == TYPE_SCANNER)
 230                 return 0;
 231
 232         return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE);
 233 }
 234
 235 static int
 236 open_wait(Sg_device *sdp, int flags)
 237 {
 238         int retval = 0;
 239
 240         if (flags & O_EXCL) {
 241                 while (sdp->open_cnt > 0) {
 242                         mutex_unlock(&sdp->open_rel_lock);
 243                         retval = wait_event_interruptible(sdp->open_wait,
 244                                         (atomic_read(&sdp->detaching) ||
 245                                          !sdp->open_cnt));
 246                         mutex_lock(&sdp->open_rel_lock);
 247
 248                         if (retval) /* -ERESTARTSYS */
 249                                 return retval;
 250                         if (atomic_read(&sdp->detaching))
 251                                 return -ENODEV;
 252                 }
 253         } else {
 254                 while (sdp->exclude) {
 255                         mutex_unlock(&sdp->open_rel_lock);
 256                         retval = wait_event_interruptible(sdp->open_wait,
 257                                         (atomic_read(&sdp->detaching) ||
 258                                          !sdp->exclude));
 259                         mutex_lock(&sdp->open_rel_lock);
 260
 261                         if (retval) /* -ERESTARTSYS */
 262                                 return retval;
 263                         if (atomic_read(&sdp->detaching))
 264                                 return -ENODEV;
 265                 }
 266         }
 267
 268         return retval;
 269 }
 270
 271 /* Returns 0 on success, else a negated errno value */
 272 static int
 273 sg_open(struct inode *inode, struct file *filp)
 274 {
 275         int dev = iminor(inode);
 276         int flags = filp->f_flags;
 277         struct request_queue *q;
 278         Sg_device *sdp;
 279         Sg_fd *sfp;
 280         int retval;
 281
 282         nonseekable_open(inode, filp);
 283         if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
 284                 return -EPERM; /* Can't lock it with read only access */
 285         sdp = sg_get_dev(dev);
 286         if (IS_ERR(sdp))
 287                 return PTR_ERR(sdp);
 288
 289         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 290                                       "sg_open: flags=0x%x\n", flags));
 291
 292         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 293         /* Prevent the device driver from vanishing while we sleep */
 294         retval = scsi_device_get(sdp->device);
 295         if (retval)
 296                 goto sg_put;
 297
 298         retval = scsi_autopm_get_device(sdp->device);
 299         if (retval)
 300                 goto sdp_put;
 301
 302         /* scsi_block_when_processing_errors() may block so bypass
 303          * check if O_NONBLOCK. Permits SCSI commands to be issued
 304          * during error recovery. Tread carefully. */
 305         if (!((flags & O_NONBLOCK) ||
 306               scsi_block_when_processing_errors(sdp->device))) {
 307                 retval = -ENXIO;
 308                 /* we are in error recovery for this device */
 309                 goto error_out;
 310         }
 311
 312         mutex_lock(&sdp->open_rel_lock);
 313         if (flags & O_NONBLOCK) {
 314                 if (flags & O_EXCL) {
 315                         if (sdp->open_cnt > 0) {
 316                                 retval = -EBUSY;
 317                                 goto error_mutex_locked;
 318                         }
 319                 } else {
 320                         if (sdp->exclude) {
 321                                 retval = -EBUSY;
 322                                 goto error_mutex_locked;
 323                         }
 324                 }
 325         } else {
 326                 retval = open_wait(sdp, flags);
 327                 if (retval) /* -ERESTARTSYS or -ENODEV */
 328                         goto error_mutex_locked;
 329         }
 330
 331         /* N.B. at this point we are holding the open_rel_lock */
 332         if (flags & O_EXCL)
 333                 sdp->exclude = true;
 334
 335         if (sdp->open_cnt < 1) {  /* no existing opens */
 336                 sdp->sgdebug = 0;
 337                 q = sdp->device->request_queue;
 338                 sdp->sg_tablesize = queue_max_segments(q);
 339         }
 340         sfp = sg_add_sfp(sdp);
 341         if (IS_ERR(sfp)) {
 342                 retval = PTR_ERR(sfp);
 343                 goto out_undo;
 344         }
 345
 346         filp->private_data = sfp;
 347         sdp->open_cnt++;
 348         mutex_unlock(&sdp->open_rel_lock);
 349
 350         retval = 0;
 351 sg_put:
 352         kref_put(&sdp->d_ref, sg_device_destroy);
 353         return retval;
 354
 355 out_undo:
 356         if (flags & O_EXCL) {
 357                 sdp->exclude = false;   /* undo if error */
 358                 wake_up_interruptible(&sdp->open_wait);
 359         }
 360 error_mutex_locked:
 361         mutex_unlock(&sdp->open_rel_lock);
 362 error_out:
 363         scsi_autopm_put_device(sdp->device);
 364 sdp_put:
 365         scsi_device_put(sdp->device);
 366         goto sg_put;
 367 }
 368
 369 /* Release resources associated with a successful sg_open()
 370  * Returns 0 on success, else a negated errno value */
 371 static int
 372 sg_release(struct inode *inode, struct file *filp)
 373 {
 374         Sg_device *sdp;
 375         Sg_fd *sfp;
 376
 377         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 378                 return -ENXIO;
 379         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
 380
 381         mutex_lock(&sdp->open_rel_lock);
 382         scsi_autopm_put_device(sdp->device);
 383         kref_put(&sfp->f_ref, sg_remove_sfp);
 384         sdp->open_cnt--;
 385
 386         /* possibly many open()s waiting on exlude clearing, start many;
 387          * only open(O_EXCL)s wait on 0==open_cnt so only start one */
 388         if (sdp->exclude) {
 389                 sdp->exclude = false;
 390                 wake_up_interruptible_all(&sdp->open_wait);
 391         } else if (0 == sdp->open_cnt) {
 392                 wake_up_interruptible(&sdp->open_wait);
 393         }
 394         mutex_unlock(&sdp->open_rel_lock);
 395         return 0;
 396 }
 397
 398 static ssize_t
 399 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 400 {
 401         Sg_device *sdp;
 402         Sg_fd *sfp;
 403         Sg_request *srp;
 404         int req_pack_id = -1;
 405         sg_io_hdr_t *hp;
 406         struct sg_header *old_hdr = NULL;
 407         int retval = 0;
 408
 409         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 410                 return -ENXIO;
 411         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 412                                       "sg_read: count=%d\n", (int) count));
 413
 414         if (!access_ok(VERIFY_WRITE, buf, count))
 415                 return -EFAULT;
 416         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 417                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 418                 if (!old_hdr)
 419                         return -ENOMEM;
 420                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
 421                         retval = -EFAULT;
 422                         goto free_old_hdr;
 423                 }
 424                 if (old_hdr->reply_len < 0) {
 425                         if (count >= SZ_SG_IO_HDR) {
 426                                 sg_io_hdr_t *new_hdr;
 427                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
 428                                 if (!new_hdr) {
 429                                         retval = -ENOMEM;
 430                                         goto free_old_hdr;
 431                                 }
 432                                 retval =__copy_from_user
 433                                     (new_hdr, buf, SZ_SG_IO_HDR);
 434                                 req_pack_id = new_hdr->pack_id;
 435                                 kfree(new_hdr);
 436                                 if (retval) {
 437                                         retval = -EFAULT;
 438                                         goto free_old_hdr;
 439                                 }
 440                         }
 441                 } else
 442                         req_pack_id = old_hdr->pack_id;
 443         }
 444         srp = sg_get_rq_mark(sfp, req_pack_id);
 445         if (!srp) {             /* now wait on packet to arrive */
 446                 if (atomic_read(&sdp->detaching)) {
 447                         retval = -ENODEV;
 448                         goto free_old_hdr;
 449                 }
 450                 if (filp->f_flags & O_NONBLOCK) {
 451                         retval = -EAGAIN;
 452                         goto free_old_hdr;
 453                 }
 454                 retval = wait_event_interruptible(sfp->read_wait,
 455                         (atomic_read(&sdp->detaching) ||
 456                         (srp = sg_get_rq_mark(sfp, req_pack_id))));
 457                 if (atomic_read(&sdp->detaching)) {
 458                         retval = -ENODEV;
 459                         goto free_old_hdr;
 460                 }
 461                 if (retval) {
 462                         /* -ERESTARTSYS as signal hit process */
 463                         goto free_old_hdr;
 464                 }
 465         }
 466         if (srp->header.interface_id != '\0') {
 467                 retval = sg_new_read(sfp, buf, count, srp);
 468                 goto free_old_hdr;
 469         }
 470
 471         hp = &srp->header;
 472         if (old_hdr == NULL) {
 473                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 474                 if (! old_hdr) {
 475                         retval = -ENOMEM;
 476                         goto free_old_hdr;
 477                 }
 478         }
 479         memset(old_hdr, 0, SZ_SG_HEADER);
 480         old_hdr->reply_len = (int) hp->timeout;
 481         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 482         old_hdr->pack_id = hp->pack_id;
 483         old_hdr->twelve_byte =
 484             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 485         old_hdr->target_status = hp->masked_status;
 486         old_hdr->host_status = hp->host_status;
 487         old_hdr->driver_status = hp->driver_status;
 488         if ((CHECK_CONDITION & hp->masked_status) ||
 489             (DRIVER_SENSE & hp->driver_status))
 490                 memcpy(old_hdr->sense_buffer, srp->sense_b,
 491                        sizeof (old_hdr->sense_buffer));
 492         switch (hp->host_status) {
 493         /* This setup of 'result' is for backward compatibility and is best
 494            ignored by the user who should use target, host + driver status */
 495         case DID_OK:
 496         case DID_PASSTHROUGH:
 497         case DID_SOFT_ERROR:
 498                 old_hdr->result = 0;
 499                 break;
 500         case DID_NO_CONNECT:
 501         case DID_BUS_BUSY:
 502         case DID_TIME_OUT:
 503                 old_hdr->result = EBUSY;
 504                 break;
 505         case DID_BAD_TARGET:
 506         case DID_ABORT:
 507         case DID_PARITY:
 508         case DID_RESET:
 509         case DID_BAD_INTR:
 510                 old_hdr->result = EIO;
 511                 break;
 512         case DID_ERROR:
 513                 old_hdr->result = (srp->sense_b[0] == 0 &&
 514                                   hp->masked_status == GOOD) ? 0 : EIO;
 515                 break;
 516         default:
 517                 old_hdr->result = EIO;
 518                 break;
 519         }
 520
 521         /* Now copy the result back to the user buffer.  */
 522         if (count >= SZ_SG_HEADER) {
 523                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 524                         retval = -EFAULT;
 525                         goto free_old_hdr;
 526                 }
 527                 buf += SZ_SG_HEADER;
 528                 if (count > old_hdr->reply_len)
 529                         count = old_hdr->reply_len;
 530                 if (count > SZ_SG_HEADER) {
 531                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 532                                 retval = -EFAULT;
 533                                 goto free_old_hdr;
 534                         }
 535                 }
 536         } else
 537                 count = (old_hdr->result == 0) ? 0 : -EIO;
 538         sg_finish_rem_req(srp);
 539         retval = count;
 540 free_old_hdr:
 541         kfree(old_hdr);
 542         return retval;
 543 }
 544
 545 static ssize_t
 546 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 547 {
 548         sg_io_hdr_t *hp = &srp->header;
 549         int err = 0, err2;
 550         int len;
 551
 552         if (count < SZ_SG_IO_HDR) {
 553                 err = -EINVAL;
 554                 goto err_out;
 555         }
 556         hp->sb_len_wr = 0;
 557         if ((hp->mx_sb_len > 0) && hp->sbp) {
 558                 if ((CHECK_CONDITION & hp->masked_status) ||
 559                     (DRIVER_SENSE & hp->driver_status)) {
 560                         int sb_len = SCSI_SENSE_BUFFERSIZE;
 561                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 562                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 563                         len = (len > sb_len) ? sb_len : len;
 564                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 565                                 err = -EFAULT;
 566                                 goto err_out;
 567                         }
 568                         hp->sb_len_wr = len;
 569                 }
 570         }
 571         if (hp->masked_status || hp->host_status || hp->driver_status)
 572                 hp->info |= SG_INFO_CHECK;
 573         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 574                 err = -EFAULT;
 575                 goto err_out;
 576         }
 577 err_out:
 578         err2 = sg_finish_rem_req(srp);
 579         return err ? : err2 ? : count;
 580 }
 581
 582 static ssize_t
 583 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 584 {
 585         int mxsize, cmd_size, k;
 586         int input_size, blocking;
 587         unsigned char opcode;
 588         Sg_device *sdp;
 589         Sg_fd *sfp;
 590         Sg_request *srp;
 591         struct sg_header old_hdr;
 592         sg_io_hdr_t *hp;
 593         unsigned char cmnd[SG_MAX_CDB_SIZE];
 594
 595         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 596                 return -ENXIO;
 597         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 598                                       "sg_write: count=%d\n", (int) count));
 599         if (atomic_read(&sdp->detaching))
 600                 return -ENODEV;
 601         if (!((filp->f_flags & O_NONBLOCK) ||
 602               scsi_block_when_processing_errors(sdp->device)))
 603                 return -ENXIO;
 604
 605         if (!access_ok(VERIFY_READ, buf, count))
 606                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 607         if (count < SZ_SG_HEADER)
 608                 return -EIO;
 609         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 610                 return -EFAULT;
 611         blocking = !(filp->f_flags & O_NONBLOCK);
 612         if (old_hdr.reply_len < 0)
 613                 return sg_new_write(sfp, filp, buf, count,
 614                                     blocking, 0, 0, NULL);
 615         if (count < (SZ_SG_HEADER + 6))
 616                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 617
 618         if (!(srp = sg_add_request(sfp))) {
 619                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
 620                                               "sg_write: queue full\n"));
 621                 return -EDOM;
 622         }
 623         buf += SZ_SG_HEADER;
 624         __get_user(opcode, buf);
 625         if (sfp->next_cmd_len > 0) {
 626                 cmd_size = sfp->next_cmd_len;
 627                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 628         } else {
 629                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 630                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 631                         cmd_size = 12;
 632         }
 633         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
 634                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 635 /* Determine buffer size.  */
 636         input_size = count - cmd_size;
 637         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 638         mxsize -= SZ_SG_HEADER;
 639         input_size -= SZ_SG_HEADER;
 640         if (input_size < 0) {
 641                 sg_remove_request(sfp, srp);
 642                 return -EIO;    /* User did not pass enough bytes for this command. */
 643         }
 644         hp = &srp->header;
 645         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 646         hp->cmd_len = (unsigned char) cmd_size;
 647         hp->iovec_count = 0;
 648         hp->mx_sb_len = 0;
 649         if (input_size > 0)
 650                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 651                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 652         else
 653                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 654         hp->dxfer_len = mxsize;
 655         if (hp->dxfer_direction == SG_DXFER_TO_DEV)
 656                 hp->dxferp = (char __user *)buf + cmd_size;
 657         else
 658                 hp->dxferp = NULL;
 659         hp->sbp = NULL;
 660         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 661         hp->flags = input_size; /* structure abuse ... */
 662         hp->pack_id = old_hdr.pack_id;
 663         hp->usr_ptr = NULL;
 664         if (__copy_from_user(cmnd, buf, cmd_size))
 665                 return -EFAULT;
 666         /*
 667          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 668          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 669          * is a non-zero input_size, so emit a warning.
 670          */
 671         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 672                 static char cmd[TASK_COMM_LEN];
 673                 if (strcmp(current->comm, cmd)) {
 674                         printk_ratelimited(KERN_WARNING
 675                                            "sg_write: data in/out %d/%d bytes "
 676                                            "for SCSI command 0x%x-- guessing "
 677                                            "data in;\n   program %s not setting "
 678                                            "count and/or reply_len properly\n",
 679                                            old_hdr.reply_len - (int)SZ_SG_HEADER,
 680                                            input_size, (unsigned int) cmnd[0],
 681                                            current->comm);
 682                         strcpy(cmd, current->comm);
 683                 }
 684         }
 685         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 686         return (k < 0) ? k : count;
 687 }
 688
 689 static ssize_t
 690 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 691                  size_t count, int blocking, int read_only, int sg_io_owned,
 692                  Sg_request **o_srp)
 693 {
 694         int k;
 695         Sg_request *srp;
 696         sg_io_hdr_t *hp;
 697         unsigned char cmnd[SG_MAX_CDB_SIZE];
 698         int timeout;
 699         unsigned long ul_timeout;
 700
 701         if (count < SZ_SG_IO_HDR)
 702                 return -EINVAL;
 703         if (!access_ok(VERIFY_READ, buf, count))
 704                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 705
 706         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 707         if (!(srp = sg_add_request(sfp))) {
 708                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 709                                               "sg_new_write: queue full\n"));
 710                 return -EDOM;
 711         }
 712         srp->sg_io_owned = sg_io_owned;
 713         hp = &srp->header;
 714         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 715                 sg_remove_request(sfp, srp);
 716                 return -EFAULT;
 717         }
 718         if (hp->interface_id != 'S') {
 719                 sg_remove_request(sfp, srp);
 720                 return -ENOSYS;
 721         }
 722         if (hp->flags & SG_FLAG_MMAP_IO) {
 723                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 724                         sg_remove_request(sfp, srp);
 725                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 726                 }
 727                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 728                         sg_remove_request(sfp, srp);
 729                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 730                 }
 731                 if (sg_res_in_use(sfp)) {
 732                         sg_remove_request(sfp, srp);
 733                         return -EBUSY;  /* reserve buffer already being used */
 734                 }
 735         }
 736         ul_timeout = msecs_to_jiffies(srp->header.timeout);
 737         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 738         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 739                 sg_remove_request(sfp, srp);
 740                 return -EMSGSIZE;
 741         }
 742         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
 743                 sg_remove_request(sfp, srp);
 744                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 745         }
 746         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 747                 sg_remove_request(sfp, srp);
 748                 return -EFAULT;
 749         }
 750         if (read_only && sg_allow_access(file, cmnd)) {
 751                 sg_remove_request(sfp, srp);
 752                 return -EPERM;
 753         }
 754         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 755         if (k < 0)
 756                 return k;
 757         if (o_srp)
 758                 *o_srp = srp;
 759         return count;
 760 }
 761
 762 static int
 763 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 764                 unsigned char *cmnd, int timeout, int blocking)
 765 {
 766         int k, at_head;
 767         Sg_device *sdp = sfp->parentdp;
 768         sg_io_hdr_t *hp = &srp->header;
 769
 770         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 771         hp->status = 0;
 772         hp->masked_status = 0;
 773         hp->msg_status = 0;
 774         hp->info = 0;
 775         hp->host_status = 0;
 776         hp->driver_status = 0;
 777         hp->resid = 0;
 778         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
 779                         "sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 780                         (int) cmnd[0], (int) hp->cmd_len));
 781
 782         k = sg_start_req(srp, cmnd);
 783         if (k) {
 784                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 785                         "sg_common_write: start_req err=%d\n", k));
 786                 sg_finish_rem_req(srp);
 787                 return k;       /* probably out of space --> ENOMEM */
 788         }
 789         if (atomic_read(&sdp->detaching)) {
 790                 if (srp->bio)
 791                         blk_end_request_all(srp->rq, -EIO);
 792                 sg_finish_rem_req(srp);
 793                 return -ENODEV;
 794         }
 795
 796         hp->duration = jiffies_to_msecs(jiffies);
 797         if (hp->interface_id != '\0' && /* v3 (or later) interface */
 798             (SG_FLAG_Q_AT_TAIL & hp->flags))
 799                 at_head = 0;
 800         else
 801                 at_head = 1;
 802
 803         srp->rq->timeout = timeout;
 804         kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
 805         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 806                               srp->rq, at_head, sg_rq_end_io);
 807         return 0;
 808 }
 809
 810 static int srp_done(Sg_fd *sfp, Sg_request *srp)
 811 {
 812         unsigned long flags;
 813         int ret;
 814
 815         read_lock_irqsave(&sfp->rq_list_lock, flags);
 816         ret = srp->done;
 817         read_unlock_irqrestore(&sfp->rq_list_lock, flags);
 818         return ret;
 819 }
 820
 821 static int max_sectors_bytes(struct request_queue *q)
 822 {
 823         unsigned int max_sectors = queue_max_sectors(q);
 824
 825         max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
 826
 827         return max_sectors << 9;
 828 }
 829
 830 static long
 831 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 832 {
 833         void __user *p = (void __user *)arg;
 834         int __user *ip = p;
 835         int result, val, read_only;
 836         Sg_device *sdp;
 837         Sg_fd *sfp;
 838         Sg_request *srp;
 839         unsigned long iflags;
 840
 841         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 842                 return -ENXIO;
 843
 844         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 845                                    "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
 846         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 847
 848         switch (cmd_in) {
 849         case SG_IO:
 850                 if (atomic_read(&sdp->detaching))
 851                         return -ENODEV;
 852                 if (!scsi_block_when_processing_errors(sdp->device))
 853                         return -ENXIO;
 854                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 855                         return -EFAULT;
 856                 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 857                                  1, read_only, 1, &srp);
 858                 if (result < 0)
 859                         return result;
 860                 result = wait_event_interruptible(sfp->read_wait,
 861                         (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
 862                 if (atomic_read(&sdp->detaching))
 863                         return -ENODEV;
 864                 write_lock_irq(&sfp->rq_list_lock);
 865                 if (srp->done) {
 866                         srp->done = 2;
 867                         write_unlock_irq(&sfp->rq_list_lock);
 868                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 869                         return (result < 0) ? result : 0;
 870                 }
 871                 srp->orphan = 1;
 872                 write_unlock_irq(&sfp->rq_list_lock);
 873                 return result;  /* -ERESTARTSYS because signal hit process */
 874         case SG_SET_TIMEOUT:
 875                 result = get_user(val, ip);
 876                 if (result)
 877                         return result;
 878                 if (val < 0)
 879                         return -EIO;
 880                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
 881                     val = MULDIV (INT_MAX, USER_HZ, HZ);
 882                 sfp->timeout_user = val;
 883                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
 884
 885                 return 0;
 886         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 887                                 /* strange ..., for backward compatibility */
 888                 return sfp->timeout_user;
 889         case SG_SET_FORCE_LOW_DMA:
 890                 result = get_user(val, ip);
 891                 if (result)
 892                         return result;
 893                 if (val) {
 894                         sfp->low_dma = 1;
 895                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
 896                                 val = (int) sfp->reserve.bufflen;
 897                                 sg_remove_scat(sfp, &sfp->reserve);
 898                                 sg_build_reserve(sfp, val);
 899                         }
 900                 } else {
 901                         if (atomic_read(&sdp->detaching))
 902                                 return -ENODEV;
 903                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
 904                 }
 905                 return 0;
 906         case SG_GET_LOW_DMA:
 907                 return put_user((int) sfp->low_dma, ip);
 908         case SG_GET_SCSI_ID:
 909                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 910                         return -EFAULT;
 911                 else {
 912                         sg_scsi_id_t __user *sg_idp = p;
 913
 914                         if (atomic_read(&sdp->detaching))
 915                                 return -ENODEV;
 916                         __put_user((int) sdp->device->host->host_no,
 917                                    &sg_idp->host_no);
 918                         __put_user((int) sdp->device->channel,
 919                                    &sg_idp->channel);
 920                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 921                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 922                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 923                         __put_user((short) sdp->device->host->cmd_per_lun,
 924                                    &sg_idp->h_cmd_per_lun);
 925                         __put_user((short) sdp->device->queue_depth,
 926                                    &sg_idp->d_queue_depth);
 927                         __put_user(0, &sg_idp->unused[0]);
 928                         __put_user(0, &sg_idp->unused[1]);
 929                         return 0;
 930                 }
 931         case SG_SET_FORCE_PACK_ID:
 932                 result = get_user(val, ip);
 933                 if (result)
 934                         return result;
 935                 sfp->force_packid = val ? 1 : 0;
 936                 return 0;
 937         case SG_GET_PACK_ID:
 938                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 939                         return -EFAULT;
 940                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 941                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
 942                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 943                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 944                                                        iflags);
 945                                 __put_user(srp->header.pack_id, ip);
 946                                 return 0;
 947                         }
 948                 }
 949                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 950                 __put_user(-1, ip);
 951                 return 0;
 952         case SG_GET_NUM_WAITING:
 953                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 954                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
 955                         if ((1 == srp->done) && (!srp->sg_io_owned))
 956                                 ++val;
 957                 }
 958                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 959                 return put_user(val, ip);
 960         case SG_GET_SG_TABLESIZE:
 961                 return put_user(sdp->sg_tablesize, ip);
 962         case SG_SET_RESERVED_SIZE:
 963                 result = get_user(val, ip);
 964                 if (result)
 965                         return result;
 966                 if (val < 0)
 967                         return -EINVAL;
 968                 val = min_t(int, val,
 969                             max_sectors_bytes(sdp->device->request_queue));
 970                 if (val != sfp->reserve.bufflen) {
 971                         if (sg_res_in_use(sfp) || sfp->mmap_called)
 972                                 return -EBUSY;
 973                         sg_remove_scat(sfp, &sfp->reserve);
 974                         sg_build_reserve(sfp, val);
 975                 }
 976                 return 0;
 977         case SG_GET_RESERVED_SIZE:
 978                 val = min_t(int, sfp->reserve.bufflen,
 979                             max_sectors_bytes(sdp->device->request_queue));
 980                 return put_user(val, ip);
 981         case SG_SET_COMMAND_Q:
 982                 result = get_user(val, ip);
 983                 if (result)
 984                         return result;
 985                 sfp->cmd_q = val ? 1 : 0;
 986                 return 0;
 987         case SG_GET_COMMAND_Q:
 988                 return put_user((int) sfp->cmd_q, ip);
 989         case SG_SET_KEEP_ORPHAN:
 990                 result = get_user(val, ip);
 991                 if (result)
 992                         return result;
 993                 sfp->keep_orphan = val;
 994                 return 0;
 995         case SG_GET_KEEP_ORPHAN:
 996                 return put_user((int) sfp->keep_orphan, ip);
 997         case SG_NEXT_CMD_LEN:
 998                 result = get_user(val, ip);
 999                 if (result)
1000                         return result;
1001                 sfp->next_cmd_len = (val > 0) ? val : 0;
1002                 return 0;
1003         case SG_GET_VERSION_NUM:
1004                 return put_user(sg_version_num, ip);
1005         case SG_GET_ACCESS_COUNT:
1006                 /* faked - we don't have a real access count anymore */
1007                 val = (sdp->device ? 1 : 0);
1008                 return put_user(val, ip);
1009         case SG_GET_REQUEST_TABLE:
1010                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
1011                         return -EFAULT;
1012                 else {
1013                         sg_req_info_t *rinfo;
1014                         unsigned int ms;
1015
1016                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
1017                                                                 GFP_KERNEL);
1018                         if (!rinfo)
1019                                 return -ENOMEM;
1020                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1021                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
1022                              ++val, srp = srp ? srp->nextrp : srp) {
1023                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
1024                                 if (srp) {
1025                                         rinfo[val].req_state = srp->done + 1;
1026                                         rinfo[val].problem =
1027                                             srp->header.masked_status &
1028                                             srp->header.host_status &
1029                                             srp->header.driver_status;
1030                                         if (srp->done)
1031                                                 rinfo[val].duration =
1032                                                         srp->header.duration;
1033                                         else {
1034                                                 ms = jiffies_to_msecs(jiffies);
1035                                                 rinfo[val].duration =
1036                                                     (ms > srp->header.duration) ?
1037                                                     (ms - srp->header.duration) : 0;
1038                                         }
1039                                         rinfo[val].orphan = srp->orphan;
1040                                         rinfo[val].sg_io_owned =
1041                                                         srp->sg_io_owned;
1042                                         rinfo[val].pack_id =
1043                                                         srp->header.pack_id;
1044                                         rinfo[val].usr_ptr =
1045                                                         srp->header.usr_ptr;
1046                                 }
1047                         }
1048                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1049                         result = __copy_to_user(p, rinfo,
1050                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1051                         result = result ? -EFAULT : 0;
1052                         kfree(rinfo);
1053                         return result;
1054                 }
1055         case SG_EMULATED_HOST:
1056                 if (atomic_read(&sdp->detaching))
1057                         return -ENODEV;
1058                 return put_user(sdp->device->host->hostt->emulated, ip);
1059         case SCSI_IOCTL_SEND_COMMAND:
1060                 if (atomic_read(&sdp->detaching))
1061                         return -ENODEV;
1062                 if (read_only) {
1063                         unsigned char opcode = WRITE_6;
1064                         Scsi_Ioctl_Command __user *siocp = p;
1065
1066                         if (copy_from_user(&opcode, siocp->data, 1))
1067                                 return -EFAULT;
1068                         if (sg_allow_access(filp, &opcode))
1069                                 return -EPERM;
1070                 }
1071                 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1072         case SG_SET_DEBUG:
1073                 result = get_user(val, ip);
1074                 if (result)
1075                         return result;
1076                 sdp->sgdebug = (char) val;
1077                 return 0;
1078         case BLKSECTGET:
1079                 return put_user(max_sectors_bytes(sdp->device->request_queue),
1080                                 ip);
1081         case BLKTRACESETUP:
1082                 return blk_trace_setup(sdp->device->request_queue,
1083                                        sdp->disk->disk_name,
1084                                        MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1085                                        NULL,
1086                                        (char *)arg);
1087         case BLKTRACESTART:
1088                 return blk_trace_startstop(sdp->device->request_queue, 1);
1089         case BLKTRACESTOP:
1090                 return blk_trace_startstop(sdp->device->request_queue, 0);
1091         case BLKTRACETEARDOWN:
1092                 return blk_trace_remove(sdp->device->request_queue);
1093         case SCSI_IOCTL_GET_IDLUN:
1094         case SCSI_IOCTL_GET_BUS_NUMBER:
1095         case SCSI_IOCTL_PROBE_HOST:
1096         case SG_GET_TRANSFORM:
1097         case SG_SCSI_RESET:
1098                 if (atomic_read(&sdp->detaching))
1099                         return -ENODEV;
1100                 break;
1101         default:
1102                 if (read_only)
1103                         return -EPERM;  /* don't know so take safe approach */
1104                 break;
1105         }
1106
1107         result = scsi_ioctl_block_when_processing_errors(sdp->device,
1108                         cmd_in, filp->f_flags & O_NDELAY);
1109         if (result)
1110                 return result;
1111         return scsi_ioctl(sdp->device, cmd_in, p);
1112 }
1113
1114 #ifdef CONFIG_COMPAT
1115 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1116 {
1117         Sg_device *sdp;
1118         Sg_fd *sfp;
1119         struct scsi_device *sdev;
1120
1121         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1122                 return -ENXIO;
1123
1124         sdev = sdp->device;
1125         if (sdev->host->hostt->compat_ioctl) {
1126                 int ret;
1127
1128                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1129
1130                 return ret;
1131         }
1132
1133         return -ENOIOCTLCMD;
1134 }
1135 #endif
1136
1137 static unsigned int
1138 sg_poll(struct file *filp, poll_table * wait)
1139 {
1140         unsigned int res = 0;
1141         Sg_device *sdp;
1142         Sg_fd *sfp;
1143         Sg_request *srp;
1144         int count = 0;
1145         unsigned long iflags;
1146
1147         sfp = filp->private_data;
1148         if (!sfp)
1149                 return POLLERR;
1150         sdp = sfp->parentdp;
1151         if (!sdp)
1152                 return POLLERR;
1153         poll_wait(filp, &sfp->read_wait, wait);
1154         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1155         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1156                 /* if any read waiting, flag it */
1157                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1158                         res = POLLIN | POLLRDNORM;
1159                 ++count;
1160         }
1161         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1162
1163         if (atomic_read(&sdp->detaching))
1164                 res |= POLLHUP;
1165         else if (!sfp->cmd_q) {
1166                 if (0 == count)
1167                         res |= POLLOUT | POLLWRNORM;
1168         } else if (count < SG_MAX_QUEUE)
1169                 res |= POLLOUT | POLLWRNORM;
1170         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1171                                       "sg_poll: res=0x%x\n", (int) res));
1172         return res;
1173 }
1174
1175 static int
1176 sg_fasync(int fd, struct file *filp, int mode)
1177 {
1178         Sg_device *sdp;
1179         Sg_fd *sfp;
1180
1181         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1182                 return -ENXIO;
1183         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1184                                       "sg_fasync: mode=%d\n", mode));
1185
1186         return fasync_helper(fd, filp, mode, &sfp->async_qp);
1187 }
1188
1189 static int
1190 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1191 {
1192         Sg_fd *sfp;
1193         unsigned long offset, len, sa;
1194         Sg_scatter_hold *rsv_schp;
1195         int k, length;
1196
1197         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1198                 return VM_FAULT_SIGBUS;
1199         rsv_schp = &sfp->reserve;
1200         offset = vmf->pgoff << PAGE_SHIFT;
1201         if (offset >= rsv_schp->bufflen)
1202                 return VM_FAULT_SIGBUS;
1203         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1204                                       "sg_vma_fault: offset=%lu, scatg=%d\n",
1205                                       offset, rsv_schp->k_use_sg));
1206         sa = vma->vm_start;
1207         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1208         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1209                 len = vma->vm_end - sa;
1210                 len = (len < length) ? len : length;
1211                 if (offset < len) {
1212                         struct page *page = nth_page(rsv_schp->pages[k],
1213                                                      offset >> PAGE_SHIFT);
1214                         get_page(page); /* increment page count */
1215                         vmf->page = page;
1216                         return 0; /* success */
1217                 }
1218                 sa += len;
1219                 offset -= len;
1220         }
1221
1222         return VM_FAULT_SIGBUS;
1223 }
1224
1225 static const struct vm_operations_struct sg_mmap_vm_ops = {
1226         .fault = sg_vma_fault,
1227 };
1228
1229 static int
1230 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1231 {
1232         Sg_fd *sfp;
1233         unsigned long req_sz, len, sa;
1234         Sg_scatter_hold *rsv_schp;
1235         int k, length;
1236
1237         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1238                 return -ENXIO;
1239         req_sz = vma->vm_end - vma->vm_start;
1240         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1241                                       "sg_mmap starting, vm_start=%p, len=%d\n",
1242                                       (void *) vma->vm_start, (int) req_sz));
1243         if (vma->vm_pgoff)
1244                 return -EINVAL; /* want no offset */
1245         rsv_schp = &sfp->reserve;
1246         if (req_sz > rsv_schp->bufflen)
1247                 return -ENOMEM; /* cannot map more than reserved buffer */
1248
1249         sa = vma->vm_start;
1250         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1251         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1252                 len = vma->vm_end - sa;
1253                 len = (len < length) ? len : length;
1254                 sa += len;
1255         }
1256
1257         sfp->mmap_called = 1;
1258         vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
1259         vma->vm_private_data = sfp;
1260         vma->vm_ops = &sg_mmap_vm_ops;
1261         return 0;
1262 }
1263
1264 static void
1265 sg_rq_end_io_usercontext(struct work_struct *work)
1266 {
1267         struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1268         struct sg_fd *sfp = srp->parentfp;
1269
1270         sg_finish_rem_req(srp);
1271         kref_put(&sfp->f_ref, sg_remove_sfp);
1272 }
1273
1274 /*
1275  * This function is a "bottom half" handler that is called by the mid
1276  * level when a command is completed (or has failed).
1277  */
1278 static void
1279 sg_rq_end_io(struct request *rq, int uptodate)
1280 {
1281         struct sg_request *srp = rq->end_io_data;
1282         Sg_device *sdp;
1283         Sg_fd *sfp;
1284         unsigned long iflags;
1285         unsigned int ms;
1286         char *sense;
1287         int result, resid, done = 1;
1288
1289         if (WARN_ON(srp->done != 0))
1290                 return;
1291
1292         sfp = srp->parentfp;
1293         if (WARN_ON(sfp == NULL))
1294                 return;
1295
1296         sdp = sfp->parentdp;
1297         if (unlikely(atomic_read(&sdp->detaching)))
1298                 pr_info("%s: device detaching\n", __func__);
1299
1300         sense = rq->sense;
1301         result = rq->errors;
1302         resid = rq->resid_len;
1303
1304         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1305                                       "sg_cmd_done: pack_id=%d, res=0x%x\n",
1306                                       srp->header.pack_id, result));
1307         srp->header.resid = resid;
1308         ms = jiffies_to_msecs(jiffies);
1309         srp->header.duration = (ms > srp->header.duration) ?
1310                                 (ms - srp->header.duration) : 0;
1311         if (0 != result) {
1312                 struct scsi_sense_hdr sshdr;
1313
1314                 srp->header.status = 0xff & result;
1315                 srp->header.masked_status = status_byte(result);
1316                 srp->header.msg_status = msg_byte(result);
1317                 srp->header.host_status = host_byte(result);
1318                 srp->header.driver_status = driver_byte(result);
1319                 if ((sdp->sgdebug > 0) &&
1320                     ((CHECK_CONDITION == srp->header.masked_status) ||
1321                      (COMMAND_TERMINATED == srp->header.masked_status)))
1322                         __scsi_print_sense(sdp->device, __func__, sense,
1323                                            SCSI_SENSE_BUFFERSIZE);
1324
1325                 /* Following if statement is a patch supplied by Eric Youngdale */
1326                 if (driver_byte(result) != 0
1327                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1328                     && !scsi_sense_is_deferred(&sshdr)
1329                     && sshdr.sense_key == UNIT_ATTENTION
1330                     && sdp->device->removable) {
1331                         /* Detected possible disc change. Set the bit - this */
1332                         /* may be used if there are filesystems using this device */
1333                         sdp->device->changed = 1;
1334                 }
1335         }
1336         /* Rely on write phase to clean out srp status values, so no "else" */
1337
1338         /*
1339          * Free the request as soon as it is complete so that its resources
1340          * can be reused without waiting for userspace to read() the
1341          * result.  But keep the associated bio (if any) around until
1342          * blk_rq_unmap_user() can be called from user context.
1343          */
1344         srp->rq = NULL;
1345         if (rq->cmd != rq->__cmd)
1346                 kfree(rq->cmd);
1347         __blk_put_request(rq->q, rq);
1348
1349         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1350         if (unlikely(srp->orphan)) {
1351                 if (sfp->keep_orphan)
1352                         srp->sg_io_owned = 0;
1353                 else
1354                         done = 0;
1355         }
1356         srp->done = done;
1357         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1358
1359         if (likely(done)) {
1360                 /* Now wake up any sg_read() that is waiting for this
1361                  * packet.
1362                  */
1363                 wake_up_interruptible(&sfp->read_wait);
1364                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1365                 kref_put(&sfp->f_ref, sg_remove_sfp);
1366         } else {
1367                 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1368                 schedule_work(&srp->ew.work);
1369         }
1370 }
1371
1372 static const struct file_operations sg_fops = {
1373         .owner = THIS_MODULE,
1374         .read = sg_read,
1375         .write = sg_write,
1376         .poll = sg_poll,
1377         .unlocked_ioctl = sg_ioctl,
1378 #ifdef CONFIG_COMPAT
1379         .compat_ioctl = sg_compat_ioctl,
1380 #endif
1381         .open = sg_open,
1382         .mmap = sg_mmap,
1383         .release = sg_release,
1384         .fasync = sg_fasync,
1385         .llseek = no_llseek,
1386 };
1387
1388 static struct class *sg_sysfs_class;
1389
1390 static int sg_sysfs_valid = 0;
1391
1392 static Sg_device *
1393 sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1394 {
1395         struct request_queue *q = scsidp->request_queue;
1396         Sg_device *sdp;
1397         unsigned long iflags;
1398         int error;
1399         u32 k;
1400
1401         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1402         if (!sdp) {
1403                 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1404                             "failure\n", __func__);
1405                 return ERR_PTR(-ENOMEM);
1406         }
1407
1408         idr_preload(GFP_KERNEL);
1409         write_lock_irqsave(&sg_index_lock, iflags);
1410
1411         error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1412         if (error < 0) {
1413                 if (error == -ENOSPC) {
1414                         sdev_printk(KERN_WARNING, scsidp,
1415                                     "Unable to attach sg device type=%d, minor number exceeds %d\n",
1416                                     scsidp->type, SG_MAX_DEVS - 1);
1417                         error = -ENODEV;
1418                 } else {
1419                         sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1420                                     "allocation Sg_device failure: %d\n",
1421                                     __func__, error);
1422                 }
1423                 goto out_unlock;
1424         }
1425         k = error;
1426
1427         SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1428                                         "sg_alloc: dev=%d \n", k));
1429         sprintf(disk->disk_name, "sg%d", k);
1430         disk->first_minor = k;
1431         sdp->disk = disk;
1432         sdp->device = scsidp;
1433         mutex_init(&sdp->open_rel_lock);
1434         INIT_LIST_HEAD(&sdp->sfds);
1435         init_waitqueue_head(&sdp->open_wait);
1436         atomic_set(&sdp->detaching, 0);
1437         rwlock_init(&sdp->sfd_lock);
1438         sdp->sg_tablesize = queue_max_segments(q);
1439         sdp->index = k;
1440         kref_init(&sdp->d_ref);
1441         error = 0;
1442
1443 out_unlock:
1444         write_unlock_irqrestore(&sg_index_lock, iflags);
1445         idr_preload_end();
1446
1447         if (error) {
1448                 kfree(sdp);
1449                 return ERR_PTR(error);
1450         }
1451         return sdp;
1452 }
1453
1454 static int
1455 sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1456 {
1457         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1458         struct gendisk *disk;
1459         Sg_device *sdp = NULL;
1460         struct cdev * cdev = NULL;
1461         int error;
1462         unsigned long iflags;
1463
1464         disk = alloc_disk(1);
1465         if (!disk) {
1466                 pr_warn("%s: alloc_disk failed\n", __func__);
1467                 return -ENOMEM;
1468         }
1469         disk->major = SCSI_GENERIC_MAJOR;
1470
1471         error = -ENOMEM;
1472         cdev = cdev_alloc();
1473         if (!cdev) {
1474                 pr_warn("%s: cdev_alloc failed\n", __func__);
1475                 goto out;
1476         }
1477         cdev->owner = THIS_MODULE;
1478         cdev->ops = &sg_fops;
1479
1480         sdp = sg_alloc(disk, scsidp);
1481         if (IS_ERR(sdp)) {
1482                 pr_warn("%s: sg_alloc failed\n", __func__);
1483                 error = PTR_ERR(sdp);
1484                 goto out;
1485         }
1486
1487         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1488         if (error)
1489                 goto cdev_add_err;
1490
1491         sdp->cdev = cdev;
1492         if (sg_sysfs_valid) {
1493                 struct device *sg_class_member;
1494
1495                 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1496                                                 MKDEV(SCSI_GENERIC_MAJOR,
1497                                                       sdp->index),
1498                                                 sdp, "%s", disk->disk_name);
1499                 if (IS_ERR(sg_class_member)) {
1500                         pr_err("%s: device_create failed\n", __func__);
1501                         error = PTR_ERR(sg_class_member);
1502                         goto cdev_add_err;
1503                 }
1504                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1505                                           &sg_class_member->kobj, "generic");
1506                 if (error)
1507                         pr_err("%s: unable to make symlink 'generic' back "
1508                                "to sg%d\n", __func__, sdp->index);
1509         } else
1510                 pr_warn("%s: sg_sys Invalid\n", __func__);
1511
1512         sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1513                     "type %d\n", sdp->index, scsidp->type);
1514
1515         dev_set_drvdata(cl_dev, sdp);
1516
1517         return 0;
1518
1519 cdev_add_err:
1520         write_lock_irqsave(&sg_index_lock, iflags);
1521         idr_remove(&sg_index_idr, sdp->index);
1522         write_unlock_irqrestore(&sg_index_lock, iflags);
1523         kfree(sdp);
1524
1525 out:
1526         put_disk(disk);
1527         if (cdev)
1528                 cdev_del(cdev);
1529         return error;
1530 }
1531
1532 static void
1533 sg_device_destroy(struct kref *kref)
1534 {
1535         struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1536         unsigned long flags;
1537
1538         /* CAUTION!  Note that the device can still be found via idr_find()
1539          * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1540          * any other cleanup.
1541          */
1542
1543         write_lock_irqsave(&sg_index_lock, flags);
1544         idr_remove(&sg_index_idr, sdp->index);
1545         write_unlock_irqrestore(&sg_index_lock, flags);
1546
1547         SCSI_LOG_TIMEOUT(3,
1548                 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1549
1550         put_disk(sdp->disk);
1551         kfree(sdp);
1552 }
1553
1554 static void
1555 sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1556 {
1557         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1558         Sg_device *sdp = dev_get_drvdata(cl_dev);
1559         unsigned long iflags;
1560         Sg_fd *sfp;
1561         int val;
1562
1563         if (!sdp)
1564                 return;
1565         /* want sdp->detaching non-zero as soon as possible */
1566         val = atomic_inc_return(&sdp->detaching);
1567         if (val > 1)
1568                 return; /* only want to do following once per device */
1569
1570         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1571                                       "%s\n", __func__));
1572
1573         read_lock_irqsave(&sdp->sfd_lock, iflags);
1574         list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1575                 wake_up_interruptible_all(&sfp->read_wait);
1576                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1577         }
1578         wake_up_interruptible_all(&sdp->open_wait);
1579         read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1580
1581         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1582         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1583         cdev_del(sdp->cdev);
1584         sdp->cdev = NULL;
1585
1586         kref_put(&sdp->d_ref, sg_device_destroy);
1587 }
1588
1589 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1590 module_param_named(def_reserved_size, def_reserved_size, int,
1591                    S_IRUGO | S_IWUSR);
1592 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1593
1594 MODULE_AUTHOR("Douglas Gilbert");
1595 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1596 MODULE_LICENSE("GPL");
1597 MODULE_VERSION(SG_VERSION_STR);
1598 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1599
1600 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1601                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1602 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1603 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1604
1605 static int __init
1606 init_sg(void)
1607 {
1608         int rc;
1609
1610         if (scatter_elem_sz < PAGE_SIZE) {
1611                 scatter_elem_sz = PAGE_SIZE;
1612                 scatter_elem_sz_prev = scatter_elem_sz;
1613         }
1614         if (def_reserved_size >= 0)
1615                 sg_big_buff = def_reserved_size;
1616         else
1617                 def_reserved_size = sg_big_buff;
1618
1619         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1620                                     SG_MAX_DEVS, "sg");
1621         if (rc)
1622                 return rc;
1623         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1624         if ( IS_ERR(sg_sysfs_class) ) {
1625                 rc = PTR_ERR(sg_sysfs_class);
1626                 goto err_out;
1627         }
1628         sg_sysfs_valid = 1;
1629         rc = scsi_register_interface(&sg_interface);
1630         if (0 == rc) {
1631 #ifdef CONFIG_SCSI_PROC_FS
1632                 sg_proc_init();
1633 #endif                          /* CONFIG_SCSI_PROC_FS */
1634                 return 0;
1635         }
1636         class_destroy(sg_sysfs_class);
1637 err_out:
1638         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1639         return rc;
1640 }
1641
1642 static void __exit
1643 exit_sg(void)
1644 {
1645 #ifdef CONFIG_SCSI_PROC_FS
1646         sg_proc_cleanup();
1647 #endif                          /* CONFIG_SCSI_PROC_FS */
1648         scsi_unregister_interface(&sg_interface);
1649         class_destroy(sg_sysfs_class);
1650         sg_sysfs_valid = 0;
1651         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1652                                  SG_MAX_DEVS);
1653         idr_destroy(&sg_index_idr);
1654 }
1655
1656 static int
1657 sg_start_req(Sg_request *srp, unsigned char *cmd)
1658 {
1659         int res;
1660         struct request *rq;
1661         Sg_fd *sfp = srp->parentfp;
1662         sg_io_hdr_t *hp = &srp->header;
1663         int dxfer_len = (int) hp->dxfer_len;
1664         int dxfer_dir = hp->dxfer_direction;
1665         unsigned int iov_count = hp->iovec_count;
1666         Sg_scatter_hold *req_schp = &srp->data;
1667         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1668         struct request_queue *q = sfp->parentdp->device->request_queue;
1669         struct rq_map_data *md, map_data;
1670         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1671         unsigned char *long_cmdp = NULL;
1672
1673         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1674                                       "sg_start_req: dxfer_len=%d\n",
1675                                       dxfer_len));
1676
1677         if (hp->cmd_len > BLK_MAX_CDB) {
1678                 long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1679                 if (!long_cmdp)
1680                         return -ENOMEM;
1681         }
1682
1683         /*
1684          * NOTE
1685          *
1686          * With scsi-mq enabled, there are a fixed number of preallocated
1687          * requests equal in number to shost->can_queue.  If all of the
1688          * preallocated requests are already in use, then using GFP_ATOMIC with
1689          * blk_get_request() will return -EWOULDBLOCK, whereas using GFP_KERNEL
1690          * will cause blk_get_request() to sleep until an active command
1691          * completes, freeing up a request.  Neither option is ideal, but
1692          * GFP_KERNEL is the better choice to prevent userspace from getting an
1693          * unexpected EWOULDBLOCK.
1694          *
1695          * With scsi-mq disabled, blk_get_request() with GFP_KERNEL usually
1696          * does not sleep except under memory pressure.
1697          */
1698         rq = blk_get_request(q, rw, GFP_KERNEL);
1699         if (IS_ERR(rq)) {
1700                 kfree(long_cmdp);
1701                 return PTR_ERR(rq);
1702         }
1703
1704         blk_rq_set_block_pc(rq);
1705
1706         if (hp->cmd_len > BLK_MAX_CDB)
1707                 rq->cmd = long_cmdp;
1708         memcpy(rq->cmd, cmd, hp->cmd_len);
1709         rq->cmd_len = hp->cmd_len;
1710
1711         srp->rq = rq;
1712         rq->end_io_data = srp;
1713         rq->sense = srp->sense_b;
1714         rq->retries = SG_DEFAULT_RETRIES;
1715
1716         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1717                 return 0;
1718
1719         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1720             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1721             !sfp->parentdp->device->host->unchecked_isa_dma &&
1722             blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1723                 md = NULL;
1724         else
1725                 md = &map_data;
1726
1727         if (md) {
1728                 if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
1729                         sg_link_reserve(sfp, srp, dxfer_len);
1730                 else {
1731                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1732                         if (res)
1733                                 return res;
1734                 }
1735
1736                 md->pages = req_schp->pages;
1737                 md->page_order = req_schp->page_order;
1738                 md->nr_entries = req_schp->k_use_sg;
1739                 md->offset = 0;
1740                 md->null_mapped = hp->dxferp ? 0 : 1;
1741                 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1742                         md->from_user = 1;
1743                 else
1744                         md->from_user = 0;
1745         }
1746
1747         if (iov_count) {
1748                 struct iovec *iov = NULL;
1749                 struct iov_iter i;
1750
1751                 res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i);
1752                 if (res < 0)
1753                         return res;
1754
1755                 iov_iter_truncate(&i, hp->dxfer_len);
1756
1757                 res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
1758                 kfree(iov);
1759         } else
1760                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1761                                       hp->dxfer_len, GFP_ATOMIC);
1762
1763         if (!res) {
1764                 srp->bio = rq->bio;
1765
1766                 if (!md) {
1767                         req_schp->dio_in_use = 1;
1768                         hp->info |= SG_INFO_DIRECT_IO;
1769                 }
1770         }
1771         return res;
1772 }
1773
1774 static int
1775 sg_finish_rem_req(Sg_request *srp)
1776 {
1777         int ret = 0;
1778
1779         Sg_fd *sfp = srp->parentfp;
1780         Sg_scatter_hold *req_schp = &srp->data;
1781
1782         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1783                                       "sg_finish_rem_req: res_used=%d\n",
1784                                       (int) srp->res_used));
1785         if (srp->bio)
1786                 ret = blk_rq_unmap_user(srp->bio);
1787
1788         if (srp->rq) {
1789                 if (srp->rq->cmd != srp->rq->__cmd)
1790                         kfree(srp->rq->cmd);
1791                 blk_put_request(srp->rq);
1792         }
1793
1794         if (srp->res_used)
1795                 sg_unlink_reserve(sfp, srp);
1796         else
1797                 sg_remove_scat(sfp, req_schp);
1798
1799         sg_remove_request(sfp, srp);
1800
1801         return ret;
1802 }
1803
1804 static int
1805 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1806 {
1807         int sg_bufflen = tablesize * sizeof(struct page *);
1808         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1809
1810         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1811         if (!schp->pages)
1812                 return -ENOMEM;
1813         schp->sglist_len = sg_bufflen;
1814         return tablesize;       /* number of scat_gath elements allocated */
1815 }
1816
1817 static int
1818 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1819 {
1820         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1821         int sg_tablesize = sfp->parentdp->sg_tablesize;
1822         int blk_size = buff_size, order;
1823         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1824
1825         if (blk_size < 0)
1826                 return -EFAULT;
1827         if (0 == blk_size)
1828                 ++blk_size;     /* don't know why */
1829         /* round request up to next highest SG_SECTOR_SZ byte boundary */
1830         blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1831         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1832                 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1833                 buff_size, blk_size));
1834
1835         /* N.B. ret_sz carried into this block ... */
1836         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1837         if (mx_sc_elems < 0)
1838                 return mx_sc_elems;     /* most likely -ENOMEM */
1839
1840         num = scatter_elem_sz;
1841         if (unlikely(num != scatter_elem_sz_prev)) {
1842                 if (num < PAGE_SIZE) {
1843                         scatter_elem_sz = PAGE_SIZE;
1844                         scatter_elem_sz_prev = PAGE_SIZE;
1845                 } else
1846                         scatter_elem_sz_prev = num;
1847         }
1848
1849         if (sfp->low_dma)
1850                 gfp_mask |= GFP_DMA;
1851
1852         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1853                 gfp_mask |= __GFP_ZERO;
1854
1855         order = get_order(num);
1856 retry:
1857         ret_sz = 1 << (PAGE_SHIFT + order);
1858
1859         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1860              k++, rem_sz -= ret_sz) {
1861
1862                 num = (rem_sz > scatter_elem_sz_prev) ?
1863                         scatter_elem_sz_prev : rem_sz;
1864
1865                 schp->pages[k] = alloc_pages(gfp_mask, order);
1866                 if (!schp->pages[k])
1867                         goto out;
1868
1869                 if (num == scatter_elem_sz_prev) {
1870                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1871                                 scatter_elem_sz = ret_sz;
1872                                 scatter_elem_sz_prev = ret_sz;
1873                         }
1874                 }
1875
1876                 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1877                                  "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1878                                  k, num, ret_sz));
1879         }               /* end of for loop */
1880
1881         schp->page_order = order;
1882         schp->k_use_sg = k;
1883         SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1884                          "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1885                          k, rem_sz));
1886
1887         schp->bufflen = blk_size;
1888         if (rem_sz > 0) /* must have failed */
1889                 return -ENOMEM;
1890         return 0;
1891 out:
1892         for (i = 0; i < k; i++)
1893                 __free_pages(schp->pages[i], order);
1894
1895         if (--order >= 0)
1896                 goto retry;
1897
1898         return -ENOMEM;
1899 }
1900
1901 static void
1902 sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1903 {
1904         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1905                          "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1906         if (schp->pages && schp->sglist_len > 0) {
1907                 if (!schp->dio_in_use) {
1908                         int k;
1909
1910                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1911                                 SCSI_LOG_TIMEOUT(5,
1912                                         sg_printk(KERN_INFO, sfp->parentdp,
1913                                         "sg_remove_scat: k=%d, pg=0x%p\n",
1914                                         k, schp->pages[k]));
1915                                 __free_pages(schp->pages[k], schp->page_order);
1916                         }
1917
1918                         kfree(schp->pages);
1919                 }
1920         }
1921         memset(schp, 0, sizeof (*schp));
1922 }
1923
1924 static int
1925 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1926 {
1927         Sg_scatter_hold *schp = &srp->data;
1928         int k, num;
1929
1930         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1931                          "sg_read_oxfer: num_read_xfer=%d\n",
1932                          num_read_xfer));
1933         if ((!outp) || (num_read_xfer <= 0))
1934                 return 0;
1935
1936         num = 1 << (PAGE_SHIFT + schp->page_order);
1937         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1938                 if (num > num_read_xfer) {
1939                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1940                                            num_read_xfer))
1941                                 return -EFAULT;
1942                         break;
1943                 } else {
1944                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1945                                            num))
1946                                 return -EFAULT;
1947                         num_read_xfer -= num;
1948                         if (num_read_xfer <= 0)
1949                                 break;
1950                         outp += num;
1951                 }
1952         }
1953
1954         return 0;
1955 }
1956
1957 static void
1958 sg_build_reserve(Sg_fd * sfp, int req_size)
1959 {
1960         Sg_scatter_hold *schp = &sfp->reserve;
1961
1962         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1963                          "sg_build_reserve: req_size=%d\n", req_size));
1964         do {
1965                 if (req_size < PAGE_SIZE)
1966                         req_size = PAGE_SIZE;
1967                 if (0 == sg_build_indirect(schp, sfp, req_size))
1968                         return;
1969                 else
1970                         sg_remove_scat(sfp, schp);
1971                 req_size >>= 1; /* divide by 2 */
1972         } while (req_size > (PAGE_SIZE / 2));
1973 }
1974
1975 static void
1976 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1977 {
1978         Sg_scatter_hold *req_schp = &srp->data;
1979         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1980         int k, num, rem;
1981
1982         srp->res_used = 1;
1983         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1984                          "sg_link_reserve: size=%d\n", size));
1985         rem = size;
1986
1987         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1988         for (k = 0; k < rsv_schp->k_use_sg; k++) {
1989                 if (rem <= num) {
1990                         req_schp->k_use_sg = k + 1;
1991                         req_schp->sglist_len = rsv_schp->sglist_len;
1992                         req_schp->pages = rsv_schp->pages;
1993
1994                         req_schp->bufflen = size;
1995                         req_schp->page_order = rsv_schp->page_order;
1996                         break;
1997                 } else
1998                         rem -= num;
1999         }
2000
2001         if (k >= rsv_schp->k_use_sg)
2002                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2003                                  "sg_link_reserve: BAD size\n"));
2004 }
2005
2006 static void
2007 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2008 {
2009         Sg_scatter_hold *req_schp = &srp->data;
2010
2011         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2012                                       "sg_unlink_reserve: req->k_use_sg=%d\n",
2013                                       (int) req_schp->k_use_sg));
2014         req_schp->k_use_sg = 0;
2015         req_schp->bufflen = 0;
2016         req_schp->pages = NULL;
2017         req_schp->page_order = 0;
2018         req_schp->sglist_len = 0;
2019         sfp->save_scat_len = 0;
2020         srp->res_used = 0;
2021 }
2022
2023 static Sg_request *
2024 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2025 {
2026         Sg_request *resp;
2027         unsigned long iflags;
2028
2029         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2030         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2031                 /* look for requests that are ready + not SG_IO owned */
2032                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2033                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2034                         resp->done = 2; /* guard against other readers */
2035                         break;
2036                 }
2037         }
2038         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2039         return resp;
2040 }
2041
2042 /* always adds to end of list */
2043 static Sg_request *
2044 sg_add_request(Sg_fd * sfp)
2045 {
2046         int k;
2047         unsigned long iflags;
2048         Sg_request *resp;
2049         Sg_request *rp = sfp->req_arr;
2050
2051         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2052         resp = sfp->headrp;
2053         if (!resp) {
2054                 memset(rp, 0, sizeof (Sg_request));
2055                 rp->parentfp = sfp;
2056                 resp = rp;
2057                 sfp->headrp = resp;
2058         } else {
2059                 if (0 == sfp->cmd_q)
2060                         resp = NULL;    /* command queuing disallowed */
2061                 else {
2062                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2063                                 if (!rp->parentfp)
2064                                         break;
2065                         }
2066                         if (k < SG_MAX_QUEUE) {
2067                                 memset(rp, 0, sizeof (Sg_request));
2068                                 rp->parentfp = sfp;
2069                                 while (resp->nextrp)
2070                                         resp = resp->nextrp;
2071                                 resp->nextrp = rp;
2072                                 resp = rp;
2073                         } else
2074                                 resp = NULL;
2075                 }
2076         }
2077         if (resp) {
2078                 resp->nextrp = NULL;
2079                 resp->header.duration = jiffies_to_msecs(jiffies);
2080         }
2081         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2082         return resp;
2083 }
2084
2085 /* Return of 1 for found; 0 for not found */
2086 static int
2087 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2088 {
2089         Sg_request *prev_rp;
2090         Sg_request *rp;
2091         unsigned long iflags;
2092         int res = 0;
2093
2094         if ((!sfp) || (!srp) || (!sfp->headrp))
2095                 return res;
2096         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2097         prev_rp = sfp->headrp;
2098         if (srp == prev_rp) {
2099                 sfp->headrp = prev_rp->nextrp;
2100                 prev_rp->parentfp = NULL;
2101                 res = 1;
2102         } else {
2103                 while ((rp = prev_rp->nextrp)) {
2104                         if (srp == rp) {
2105                                 prev_rp->nextrp = rp->nextrp;
2106                                 rp->parentfp = NULL;
2107                                 res = 1;
2108                                 break;
2109                         }
2110                         prev_rp = rp;
2111                 }
2112         }
2113         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2114         return res;
2115 }
2116
2117 static Sg_fd *
2118 sg_add_sfp(Sg_device * sdp)
2119 {
2120         Sg_fd *sfp;
2121         unsigned long iflags;
2122         int bufflen;
2123
2124         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2125         if (!sfp)
2126                 return ERR_PTR(-ENOMEM);
2127
2128         init_waitqueue_head(&sfp->read_wait);
2129         rwlock_init(&sfp->rq_list_lock);
2130
2131         kref_init(&sfp->f_ref);
2132         sfp->timeout = SG_DEFAULT_TIMEOUT;
2133         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2134         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2135         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2136             sdp->device->host->unchecked_isa_dma : 1;
2137         sfp->cmd_q = SG_DEF_COMMAND_Q;
2138         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2139         sfp->parentdp = sdp;
2140         write_lock_irqsave(&sdp->sfd_lock, iflags);
2141         if (atomic_read(&sdp->detaching)) {
2142                 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2143                 return ERR_PTR(-ENODEV);
2144         }
2145         list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2146         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2147         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2148                                       "sg_add_sfp: sfp=0x%p\n", sfp));
2149         if (unlikely(sg_big_buff != def_reserved_size))
2150                 sg_big_buff = def_reserved_size;
2151
2152         bufflen = min_t(int, sg_big_buff,
2153                         max_sectors_bytes(sdp->device->request_queue));
2154         sg_build_reserve(sfp, bufflen);
2155         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2156                                       "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2157                                       sfp->reserve.bufflen,
2158                                       sfp->reserve.k_use_sg));
2159
2160         kref_get(&sdp->d_ref);
2161         __module_get(THIS_MODULE);
2162         return sfp;
2163 }
2164
2165 static void
2166 sg_remove_sfp_usercontext(struct work_struct *work)
2167 {
2168         struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2169         struct sg_device *sdp = sfp->parentdp;
2170
2171         /* Cleanup any responses which were never read(). */
2172         while (sfp->headrp)
2173                 sg_finish_rem_req(sfp->headrp);
2174
2175         if (sfp->reserve.bufflen > 0) {
2176                 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2177                                 "sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2178                                 (int) sfp->reserve.bufflen,
2179                                 (int) sfp->reserve.k_use_sg));
2180                 sg_remove_scat(sfp, &sfp->reserve);
2181         }
2182
2183         SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2184                         "sg_remove_sfp: sfp=0x%p\n", sfp));
2185         kfree(sfp);
2186
2187         scsi_device_put(sdp->device);
2188         kref_put(&sdp->d_ref, sg_device_destroy);
2189         module_put(THIS_MODULE);
2190 }
2191
2192 static void
2193 sg_remove_sfp(struct kref *kref)
2194 {
2195         struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2196         struct sg_device *sdp = sfp->parentdp;
2197         unsigned long iflags;
2198
2199         write_lock_irqsave(&sdp->sfd_lock, iflags);
2200         list_del(&sfp->sfd_siblings);
2201         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2202
2203         INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2204         schedule_work(&sfp->ew.work);
2205 }
2206
2207 static int
2208 sg_res_in_use(Sg_fd * sfp)
2209 {
2210         const Sg_request *srp;
2211         unsigned long iflags;
2212
2213         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2214         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2215                 if (srp->res_used)
2216                         break;
2217         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2218         return srp ? 1 : 0;
2219 }
2220
2221 #ifdef CONFIG_SCSI_PROC_FS
2222 static int
2223 sg_idr_max_id(int id, void *p, void *data)
2224 {
2225         int *k = data;
2226
2227         if (*k < id)
2228                 *k = id;
2229
2230         return 0;
2231 }
2232
2233 static int
2234 sg_last_dev(void)
2235 {
2236         int k = -1;
2237         unsigned long iflags;
2238
2239         read_lock_irqsave(&sg_index_lock, iflags);
2240         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2241         read_unlock_irqrestore(&sg_index_lock, iflags);
2242         return k + 1;           /* origin 1 */
2243 }
2244 #endif
2245
2246 /* must be called with sg_index_lock held */
2247 static Sg_device *sg_lookup_dev(int dev)
2248 {
2249         return idr_find(&sg_index_idr, dev);
2250 }
2251
2252 static Sg_device *
2253 sg_get_dev(int dev)
2254 {
2255         struct sg_device *sdp;
2256         unsigned long flags;
2257
2258         read_lock_irqsave(&sg_index_lock, flags);
2259         sdp = sg_lookup_dev(dev);
2260         if (!sdp)
2261                 sdp = ERR_PTR(-ENXIO);
2262         else if (atomic_read(&sdp->detaching)) {
2263                 /* If sdp->detaching, then the refcount may already be 0, in
2264                  * which case it would be a bug to do kref_get().
2265                  */
2266                 sdp = ERR_PTR(-ENODEV);
2267         } else
2268                 kref_get(&sdp->d_ref);
2269         read_unlock_irqrestore(&sg_index_lock, flags);
2270
2271         return sdp;
2272 }
2273
2274 #ifdef CONFIG_SCSI_PROC_FS
2275
2276 static struct proc_dir_entry *sg_proc_sgp = NULL;
2277
2278 static char sg_proc_sg_dirname[] = "scsi/sg";
2279
2280 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2281
2282 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2283 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2284                                   size_t count, loff_t *off);
2285 static const struct file_operations adio_fops = {
2286         .owner = THIS_MODULE,
2287         .open = sg_proc_single_open_adio,
2288         .read = seq_read,
2289         .llseek = seq_lseek,
2290         .write = sg_proc_write_adio,
2291         .release = single_release,
2292 };
2293
2294 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2295 static ssize_t sg_proc_write_dressz(struct file *filp,
2296                 const char __user *buffer, size_t count, loff_t *off);
2297 static const struct file_operations dressz_fops = {
2298         .owner = THIS_MODULE,
2299         .open = sg_proc_single_open_dressz,
2300         .read = seq_read,
2301         .llseek = seq_lseek,
2302         .write = sg_proc_write_dressz,
2303         .release = single_release,
2304 };
2305
2306 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2307 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2308 static const struct file_operations version_fops = {
2309         .owner = THIS_MODULE,
2310         .open = sg_proc_single_open_version,
2311         .read = seq_read,
2312         .llseek = seq_lseek,
2313         .release = single_release,
2314 };
2315
2316 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2317 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2318 static const struct file_operations devhdr_fops = {
2319         .owner = THIS_MODULE,
2320         .open = sg_proc_single_open_devhdr,
2321         .read = seq_read,
2322         .llseek = seq_lseek,
2323         .release = single_release,
2324 };
2325
2326 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2327 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2328 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2329 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2330 static void dev_seq_stop(struct seq_file *s, void *v);
2331 static const struct file_operations dev_fops = {
2332         .owner = THIS_MODULE,
2333         .open = sg_proc_open_dev,
2334         .read = seq_read,
2335         .llseek = seq_lseek,
2336         .release = seq_release,
2337 };
2338 static const struct seq_operations dev_seq_ops = {
2339         .start = dev_seq_start,
2340         .next  = dev_seq_next,
2341         .stop  = dev_seq_stop,
2342         .show  = sg_proc_seq_show_dev,
2343 };
2344
2345 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2346 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2347 static const struct file_operations devstrs_fops = {
2348         .owner = THIS_MODULE,
2349         .open = sg_proc_open_devstrs,
2350         .read = seq_read,
2351         .llseek = seq_lseek,
2352         .release = seq_release,
2353 };
2354 static const struct seq_operations devstrs_seq_ops = {
2355         .start = dev_seq_start,
2356         .next  = dev_seq_next,
2357         .stop  = dev_seq_stop,
2358         .show  = sg_proc_seq_show_devstrs,
2359 };
2360
2361 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2362 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2363 static const struct file_operations debug_fops = {
2364         .owner = THIS_MODULE,
2365         .open = sg_proc_open_debug,
2366         .read = seq_read,
2367         .llseek = seq_lseek,
2368         .release = seq_release,
2369 };
2370 static const struct seq_operations debug_seq_ops = {
2371         .start = dev_seq_start,
2372         .next  = dev_seq_next,
2373         .stop  = dev_seq_stop,
2374         .show  = sg_proc_seq_show_debug,
2375 };
2376
2377
2378 struct sg_proc_leaf {
2379         const char * name;
2380         const struct file_operations * fops;
2381 };
2382
2383 static const struct sg_proc_leaf sg_proc_leaf_arr[] = {
2384         {"allow_dio", &adio_fops},
2385         {"debug", &debug_fops},
2386         {"def_reserved_size", &dressz_fops},
2387         {"device_hdr", &devhdr_fops},
2388         {"devices", &dev_fops},
2389         {"device_strs", &devstrs_fops},
2390         {"version", &version_fops}
2391 };
2392
2393 static int
2394 sg_proc_init(void)
2395 {
2396         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2397         int k;
2398
2399         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2400         if (!sg_proc_sgp)
2401                 return 1;
2402         for (k = 0; k < num_leaves; ++k) {
2403                 const struct sg_proc_leaf *leaf = &sg_proc_leaf_arr[k];
2404                 umode_t mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2405                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2406         }
2407         return 0;
2408 }
2409
2410 static void
2411 sg_proc_cleanup(void)
2412 {
2413         int k;
2414         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2415
2416         if (!sg_proc_sgp)
2417                 return;
2418         for (k = 0; k < num_leaves; ++k)
2419                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2420         remove_proc_entry(sg_proc_sg_dirname, NULL);
2421 }
2422
2423
2424 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2425 {
2426         seq_printf(s, "%d\n", *((int *)s->private));
2427         return 0;
2428 }
2429
2430 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2431 {
2432         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2433 }
2434
2435 static ssize_t
2436 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2437                    size_t count, loff_t *off)
2438 {
2439         int err;
2440         unsigned long num;
2441
2442         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2443                 return -EACCES;
2444         err = kstrtoul_from_user(buffer, count, 0, &num);
2445         if (err)
2446                 return err;
2447         sg_allow_dio = num ? 1 : 0;
2448         return count;
2449 }
2450
2451 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2452 {
2453         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2454 }
2455
2456 static ssize_t
2457 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2458                      size_t count, loff_t *off)
2459 {
2460         int err;
2461         unsigned long k = ULONG_MAX;
2462
2463         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2464                 return -EACCES;
2465
2466         err = kstrtoul_from_user(buffer, count, 0, &k);
2467         if (err)
2468                 return err;
2469         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2470                 sg_big_buff = k;
2471                 return count;
2472         }
2473         return -ERANGE;
2474 }
2475
2476 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2477 {
2478         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2479                    sg_version_date);
2480         return 0;
2481 }
2482
2483 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2484 {
2485         return single_open(file, sg_proc_seq_show_version, NULL);
2486 }
2487
2488 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2489 {
2490         seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2491         return 0;
2492 }
2493
2494 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2495 {
2496         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2497 }
2498
2499 struct sg_proc_deviter {
2500         loff_t  index;
2501         size_t  max;
2502 };
2503
2504 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2505 {
2506         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2507
2508         s->private = it;
2509         if (! it)
2510                 return NULL;
2511
2512         it->index = *pos;
2513         it->max = sg_last_dev();
2514         if (it->index >= it->max)
2515                 return NULL;
2516         return it;
2517 }
2518
2519 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2520 {
2521         struct sg_proc_deviter * it = s->private;
2522
2523         *pos = ++it->index;
2524         return (it->index < it->max) ? it : NULL;
2525 }
2526
2527 static void dev_seq_stop(struct seq_file *s, void *v)
2528 {
2529         kfree(s->private);
2530 }
2531
2532 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2533 {
2534         return seq_open(file, &dev_seq_ops);
2535 }
2536
2537 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2538 {
2539         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2540         Sg_device *sdp;
2541         struct scsi_device *scsidp;
2542         unsigned long iflags;
2543
2544         read_lock_irqsave(&sg_index_lock, iflags);
2545         sdp = it ? sg_lookup_dev(it->index) : NULL;
2546         if ((NULL == sdp) || (NULL == sdp->device) ||
2547             (atomic_read(&sdp->detaching)))
2548                 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2549         else {
2550                 scsidp = sdp->device;
2551                 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2552                               scsidp->host->host_no, scsidp->channel,
2553                               scsidp->id, scsidp->lun, (int) scsidp->type,
2554                               1,
2555                               (int) scsidp->queue_depth,
2556                               (int) atomic_read(&scsidp->device_busy),
2557                               (int) scsi_device_online(scsidp));
2558         }
2559         read_unlock_irqrestore(&sg_index_lock, iflags);
2560         return 0;
2561 }
2562
2563 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2564 {
2565         return seq_open(file, &devstrs_seq_ops);
2566 }
2567
2568 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2569 {
2570         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2571         Sg_device *sdp;
2572         struct scsi_device *scsidp;
2573         unsigned long iflags;
2574
2575         read_lock_irqsave(&sg_index_lock, iflags);
2576         sdp = it ? sg_lookup_dev(it->index) : NULL;
2577         scsidp = sdp ? sdp->device : NULL;
2578         if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2579                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2580                            scsidp->vendor, scsidp->model, scsidp->rev);
2581         else
2582                 seq_puts(s, "<no active device>\n");
2583         read_unlock_irqrestore(&sg_index_lock, iflags);
2584         return 0;
2585 }
2586
2587 /* must be called while holding sg_index_lock */
2588 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2589 {
2590         int k, m, new_interface, blen, usg;
2591         Sg_request *srp;
2592         Sg_fd *fp;
2593         const sg_io_hdr_t *hp;
2594         const char * cp;
2595         unsigned int ms;
2596
2597         k = 0;
2598         list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2599                 k++;
2600                 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2601                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2602                            "(res)sgat=%d low_dma=%d\n", k,
2603                            jiffies_to_msecs(fp->timeout),
2604                            fp->reserve.bufflen,
2605                            (int) fp->reserve.k_use_sg,
2606                            (int) fp->low_dma);
2607                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2608                            (int) fp->cmd_q, (int) fp->force_packid,
2609                            (int) fp->keep_orphan);
2610                 for (m = 0, srp = fp->headrp;
2611                                 srp != NULL;
2612                                 ++m, srp = srp->nextrp) {
2613                         hp = &srp->header;
2614                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2615                         if (srp->res_used) {
2616                                 if (new_interface &&
2617                                     (SG_FLAG_MMAP_IO & hp->flags))
2618                                         cp = "     mmap>> ";
2619                                 else
2620                                         cp = "     rb>> ";
2621                         } else {
2622                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2623                                         cp = "     dio>> ";
2624                                 else
2625                                         cp = "     ";
2626                         }
2627                         seq_puts(s, cp);
2628                         blen = srp->data.bufflen;
2629                         usg = srp->data.k_use_sg;
2630                         seq_puts(s, srp->done ?
2631                                  ((1 == srp->done) ?  "rcv:" : "fin:")
2632                                   : "act:");
2633                         seq_printf(s, " id=%d blen=%d",
2634                                    srp->header.pack_id, blen);
2635                         if (srp->done)
2636                                 seq_printf(s, " dur=%d", hp->duration);
2637                         else {
2638                                 ms = jiffies_to_msecs(jiffies);
2639                                 seq_printf(s, " t_o/elap=%d/%d",
2640                                         (new_interface ? hp->timeout :
2641                                                   jiffies_to_msecs(fp->timeout)),
2642                                         (ms > hp->duration ? ms - hp->duration : 0));
2643                         }
2644                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2645                                    (int) srp->data.cmd_opcode);
2646                 }
2647                 if (0 == m)
2648                         seq_puts(s, "     No requests active\n");
2649                 read_unlock(&fp->rq_list_lock);
2650         }
2651 }
2652
2653 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2654 {
2655         return seq_open(file, &debug_seq_ops);
2656 }
2657
2658 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2659 {
2660         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2661         Sg_device *sdp;
2662         unsigned long iflags;
2663
2664         if (it && (0 == it->index))
2665                 seq_printf(s, "max_active_device=%d  def_reserved_size=%d\n",
2666                            (int)it->max, sg_big_buff);
2667
2668         read_lock_irqsave(&sg_index_lock, iflags);
2669         sdp = it ? sg_lookup_dev(it->index) : NULL;
2670         if (NULL == sdp)
2671                 goto skip;
2672         read_lock(&sdp->sfd_lock);
2673         if (!list_empty(&sdp->sfds)) {
2674                 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2675                 if (atomic_read(&sdp->detaching))
2676                         seq_puts(s, "detaching pending close ");
2677                 else if (sdp->device) {
2678                         struct scsi_device *scsidp = sdp->device;
2679
2680                         seq_printf(s, "%d:%d:%d:%llu   em=%d",
2681                                    scsidp->host->host_no,
2682                                    scsidp->channel, scsidp->id,
2683                                    scsidp->lun,
2684                                    scsidp->host->hostt->emulated);
2685                 }
2686                 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2687                            sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2688                 sg_proc_debug_helper(s, sdp);
2689         }
2690         read_unlock(&sdp->sfd_lock);
2691 skip:
2692         read_unlock_irqrestore(&sg_index_lock, iflags);
2693         return 0;
2694 }
2695
2696 #endif                          /* CONFIG_SCSI_PROC_FS */
2697
2698 module_init(init_sg);
2699 module_exit(exit_sg);