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 #define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  83
  84 int sg_big_buff = SG_DEF_RESERVED_SIZE;
  85 /* N.B. This variable is readable and writeable via
  86    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  87    of this size (or less if there is not enough memory) will be reserved
  88    for use by this file descriptor. [Deprecated usage: this variable is also
  89    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  90    the kernel (i.e. it is not a module).] */
  91 static int def_reserved_size = -1;      /* picks up init parameter */
  92 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
  93
  94 static int scatter_elem_sz = SG_SCATTER_SZ;
  95 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
  96
  97 #define SG_SECTOR_SZ 512
  98
  99 static int sg_add_device(struct device *, struct class_interface *);
 100 static void sg_remove_device(struct device *, struct class_interface *);
 101
 102 static DEFINE_IDR(sg_index_idr);
 103 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
 104                                                            file descriptor list for device */
 105
 106 static struct class_interface sg_interface = {
 107         .add_dev        = sg_add_device,
 108         .remove_dev     = sg_remove_device,
 109 };
 110
 111 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 112         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 113         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 114         unsigned bufflen;       /* Size of (aggregate) data buffer */
 115         struct page **pages;
 116         int page_order;
 117         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 118         unsigned char cmd_opcode; /* first byte of command */
 119 } Sg_scatter_hold;
 120
 121 struct sg_device;               /* forward declarations */
 122 struct sg_fd;
 123
 124 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 125         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
 126         struct sg_fd *parentfp; /* NULL -> not in use */
 127         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 128         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 129         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 130         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 131         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 132         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 133         /* done protected by rq_list_lock */
 134         char done;              /* 0->before bh, 1->before read, 2->read */
 135         struct request *rq;
 136         struct bio *bio;
 137         struct execute_work ew;
 138 } Sg_request;
 139
 140 typedef struct sg_fd {          /* holds the state of a file descriptor */
 141         struct list_head sfd_siblings;  /* protected by device's sfd_lock */
 142         struct sg_device *parentdp;     /* owning device */
 143         wait_queue_head_t read_wait;    /* queue read until command done */
 144         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 145         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 146         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 147         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 148         unsigned save_scat_len; /* original length of trunc. scat. element */
 149         Sg_request *headrp;     /* head of request slist, NULL->empty */
 150         struct fasync_struct *async_qp; /* used by asynchronous notification */
 151         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 152         char low_dma;           /* as in parent but possibly overridden to 1 */
 153         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 154         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 155         unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */
 156         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 157         char mmap_called;       /* 0 -> mmap() never called on this fd */
 158         struct kref f_ref;
 159         struct execute_work ew;
 160 } Sg_fd;
 161
 162 typedef struct sg_device { /* holds the state of each scsi generic device */
 163         struct scsi_device *device;
 164         wait_queue_head_t open_wait;    /* queue open() when O_EXCL present */
 165         struct mutex open_rel_lock;     /* held when in open() or release() */
 166         int sg_tablesize;       /* adapter's max scatter-gather table size */
 167         u32 index;              /* device index number */
 168         struct list_head sfds;
 169         rwlock_t sfd_lock;      /* protect access to sfd list */
 170         atomic_t detaching;     /* 0->device usable, 1->device detaching */
 171         bool exclude;           /* 1->open(O_EXCL) succeeded and is active */
 172         int open_cnt;           /* count of opens (perhaps < num(sfds) ) */
 173         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 174         struct gendisk *disk;
 175         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 176         struct kref d_ref;
 177 } Sg_device;
 178
 179 /* tasklet or soft irq callback */
 180 static void sg_rq_end_io(struct request *rq, int uptodate);
 181 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 182 static int sg_finish_rem_req(Sg_request * srp);
 183 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 184 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 185                            Sg_request * srp);
 186 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 187                         const char __user *buf, size_t count, int blocking,
 188                         int read_only, int sg_io_owned, Sg_request **o_srp);
 189 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 190                            unsigned char *cmnd, int timeout, int blocking);
 191 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 192 static void sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp);
 193 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 194 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 195 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 196 static Sg_fd *sg_add_sfp(Sg_device * sdp);
 197 static void sg_remove_sfp(struct kref *);
 198 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 199 static Sg_request *sg_add_request(Sg_fd * sfp);
 200 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 201 static int sg_res_in_use(Sg_fd * sfp);
 202 static Sg_device *sg_get_dev(int dev);
 203 static void sg_device_destroy(struct kref *kref);
 204
 205 #define SZ_SG_HEADER sizeof(struct sg_header)
 206 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 207 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
 208 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 209
 210 #define sg_printk(prefix, sdp, fmt, a...) \
 211         sdev_prefix_printk(prefix, (sdp)->device,               \
 212                            (sdp)->disk->disk_name, fmt, ##a)
 213
 214 static int sg_allow_access(struct file *filp, unsigned char *cmd)
 215 {
 216         struct sg_fd *sfp = filp->private_data;
 217
 218         if (sfp->parentdp->device->type == TYPE_SCANNER)
 219                 return 0;
 220
 221         return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE);
 222 }
 223
 224 static int
 225 open_wait(Sg_device *sdp, int flags)
 226 {
 227         int retval = 0;
 228
 229         if (flags & O_EXCL) {
 230                 while (sdp->open_cnt > 0) {
 231                         mutex_unlock(&sdp->open_rel_lock);
 232                         retval = wait_event_interruptible(sdp->open_wait,
 233                                         (atomic_read(&sdp->detaching) ||
 234                                          !sdp->open_cnt));
 235                         mutex_lock(&sdp->open_rel_lock);
 236
 237                         if (retval) /* -ERESTARTSYS */
 238                                 return retval;
 239                         if (atomic_read(&sdp->detaching))
 240                                 return -ENODEV;
 241                 }
 242         } else {
 243                 while (sdp->exclude) {
 244                         mutex_unlock(&sdp->open_rel_lock);
 245                         retval = wait_event_interruptible(sdp->open_wait,
 246                                         (atomic_read(&sdp->detaching) ||
 247                                          !sdp->exclude));
 248                         mutex_lock(&sdp->open_rel_lock);
 249
 250                         if (retval) /* -ERESTARTSYS */
 251                                 return retval;
 252                         if (atomic_read(&sdp->detaching))
 253                                 return -ENODEV;
 254                 }
 255         }
 256
 257         return retval;
 258 }
 259
 260 /* Returns 0 on success, else a negated errno value */
 261 static int
 262 sg_open(struct inode *inode, struct file *filp)
 263 {
 264         int dev = iminor(inode);
 265         int flags = filp->f_flags;
 266         struct request_queue *q;
 267         Sg_device *sdp;
 268         Sg_fd *sfp;
 269         int retval;
 270
 271         nonseekable_open(inode, filp);
 272         if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
 273                 return -EPERM; /* Can't lock it with read only access */
 274         sdp = sg_get_dev(dev);
 275         if (IS_ERR(sdp))
 276                 return PTR_ERR(sdp);
 277
 278         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 279                                       "sg_open: flags=0x%x\n", flags));
 280
 281         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 282         /* Prevent the device driver from vanishing while we sleep */
 283         retval = scsi_device_get(sdp->device);
 284         if (retval)
 285                 goto sg_put;
 286
 287         retval = scsi_autopm_get_device(sdp->device);
 288         if (retval)
 289                 goto sdp_put;
 290
 291         /* scsi_block_when_processing_errors() may block so bypass
 292          * check if O_NONBLOCK. Permits SCSI commands to be issued
 293          * during error recovery. Tread carefully. */
 294         if (!((flags & O_NONBLOCK) ||
 295               scsi_block_when_processing_errors(sdp->device))) {
 296                 retval = -ENXIO;
 297                 /* we are in error recovery for this device */
 298                 goto error_out;
 299         }
 300
 301         mutex_lock(&sdp->open_rel_lock);
 302         if (flags & O_NONBLOCK) {
 303                 if (flags & O_EXCL) {
 304                         if (sdp->open_cnt > 0) {
 305                                 retval = -EBUSY;
 306                                 goto error_mutex_locked;
 307                         }
 308                 } else {
 309                         if (sdp->exclude) {
 310                                 retval = -EBUSY;
 311                                 goto error_mutex_locked;
 312                         }
 313                 }
 314         } else {
 315                 retval = open_wait(sdp, flags);
 316                 if (retval) /* -ERESTARTSYS or -ENODEV */
 317                         goto error_mutex_locked;
 318         }
 319
 320         /* N.B. at this point we are holding the open_rel_lock */
 321         if (flags & O_EXCL)
 322                 sdp->exclude = true;
 323
 324         if (sdp->open_cnt < 1) {  /* no existing opens */
 325                 sdp->sgdebug = 0;
 326                 q = sdp->device->request_queue;
 327                 sdp->sg_tablesize = queue_max_segments(q);
 328         }
 329         sfp = sg_add_sfp(sdp);
 330         if (IS_ERR(sfp)) {
 331                 retval = PTR_ERR(sfp);
 332                 goto out_undo;
 333         }
 334
 335         filp->private_data = sfp;
 336         sdp->open_cnt++;
 337         mutex_unlock(&sdp->open_rel_lock);
 338
 339         retval = 0;
 340 sg_put:
 341         kref_put(&sdp->d_ref, sg_device_destroy);
 342         return retval;
 343
 344 out_undo:
 345         if (flags & O_EXCL) {
 346                 sdp->exclude = false;   /* undo if error */
 347                 wake_up_interruptible(&sdp->open_wait);
 348         }
 349 error_mutex_locked:
 350         mutex_unlock(&sdp->open_rel_lock);
 351 error_out:
 352         scsi_autopm_put_device(sdp->device);
 353 sdp_put:
 354         scsi_device_put(sdp->device);
 355         goto sg_put;
 356 }
 357
 358 /* Release resources associated with a successful sg_open()
 359  * Returns 0 on success, else a negated errno value */
 360 static int
 361 sg_release(struct inode *inode, struct file *filp)
 362 {
 363         Sg_device *sdp;
 364         Sg_fd *sfp;
 365
 366         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 367                 return -ENXIO;
 368         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
 369
 370         mutex_lock(&sdp->open_rel_lock);
 371         scsi_autopm_put_device(sdp->device);
 372         kref_put(&sfp->f_ref, sg_remove_sfp);
 373         sdp->open_cnt--;
 374
 375         /* possibly many open()s waiting on exlude clearing, start many;
 376          * only open(O_EXCL)s wait on 0==open_cnt so only start one */
 377         if (sdp->exclude) {
 378                 sdp->exclude = false;
 379                 wake_up_interruptible_all(&sdp->open_wait);
 380         } else if (0 == sdp->open_cnt) {
 381                 wake_up_interruptible(&sdp->open_wait);
 382         }
 383         mutex_unlock(&sdp->open_rel_lock);
 384         return 0;
 385 }
 386
 387 static ssize_t
 388 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 389 {
 390         Sg_device *sdp;
 391         Sg_fd *sfp;
 392         Sg_request *srp;
 393         int req_pack_id = -1;
 394         sg_io_hdr_t *hp;
 395         struct sg_header *old_hdr = NULL;
 396         int retval = 0;
 397
 398         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 399                 return -ENXIO;
 400         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 401                                       "sg_read: count=%d\n", (int) count));
 402
 403         if (!access_ok(VERIFY_WRITE, buf, count))
 404                 return -EFAULT;
 405         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 406                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 407                 if (!old_hdr)
 408                         return -ENOMEM;
 409                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
 410                         retval = -EFAULT;
 411                         goto free_old_hdr;
 412                 }
 413                 if (old_hdr->reply_len < 0) {
 414                         if (count >= SZ_SG_IO_HDR) {
 415                                 sg_io_hdr_t *new_hdr;
 416                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
 417                                 if (!new_hdr) {
 418                                         retval = -ENOMEM;
 419                                         goto free_old_hdr;
 420                                 }
 421                                 retval =__copy_from_user
 422                                     (new_hdr, buf, SZ_SG_IO_HDR);
 423                                 req_pack_id = new_hdr->pack_id;
 424                                 kfree(new_hdr);
 425                                 if (retval) {
 426                                         retval = -EFAULT;
 427                                         goto free_old_hdr;
 428                                 }
 429                         }
 430                 } else
 431                         req_pack_id = old_hdr->pack_id;
 432         }
 433         srp = sg_get_rq_mark(sfp, req_pack_id);
 434         if (!srp) {             /* now wait on packet to arrive */
 435                 if (atomic_read(&sdp->detaching)) {
 436                         retval = -ENODEV;
 437                         goto free_old_hdr;
 438                 }
 439                 if (filp->f_flags & O_NONBLOCK) {
 440                         retval = -EAGAIN;
 441                         goto free_old_hdr;
 442                 }
 443                 retval = wait_event_interruptible(sfp->read_wait,
 444                         (atomic_read(&sdp->detaching) ||
 445                         (srp = sg_get_rq_mark(sfp, req_pack_id))));
 446                 if (atomic_read(&sdp->detaching)) {
 447                         retval = -ENODEV;
 448                         goto free_old_hdr;
 449                 }
 450                 if (retval) {
 451                         /* -ERESTARTSYS as signal hit process */
 452                         goto free_old_hdr;
 453                 }
 454         }
 455         if (srp->header.interface_id != '\0') {
 456                 retval = sg_new_read(sfp, buf, count, srp);
 457                 goto free_old_hdr;
 458         }
 459
 460         hp = &srp->header;
 461         if (old_hdr == NULL) {
 462                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 463                 if (! old_hdr) {
 464                         retval = -ENOMEM;
 465                         goto free_old_hdr;
 466                 }
 467         }
 468         memset(old_hdr, 0, SZ_SG_HEADER);
 469         old_hdr->reply_len = (int) hp->timeout;
 470         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 471         old_hdr->pack_id = hp->pack_id;
 472         old_hdr->twelve_byte =
 473             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 474         old_hdr->target_status = hp->masked_status;
 475         old_hdr->host_status = hp->host_status;
 476         old_hdr->driver_status = hp->driver_status;
 477         if ((CHECK_CONDITION & hp->masked_status) ||
 478             (DRIVER_SENSE & hp->driver_status))
 479                 memcpy(old_hdr->sense_buffer, srp->sense_b,
 480                        sizeof (old_hdr->sense_buffer));
 481         switch (hp->host_status) {
 482         /* This setup of 'result' is for backward compatibility and is best
 483            ignored by the user who should use target, host + driver status */
 484         case DID_OK:
 485         case DID_PASSTHROUGH:
 486         case DID_SOFT_ERROR:
 487                 old_hdr->result = 0;
 488                 break;
 489         case DID_NO_CONNECT:
 490         case DID_BUS_BUSY:
 491         case DID_TIME_OUT:
 492                 old_hdr->result = EBUSY;
 493                 break;
 494         case DID_BAD_TARGET:
 495         case DID_ABORT:
 496         case DID_PARITY:
 497         case DID_RESET:
 498         case DID_BAD_INTR:
 499                 old_hdr->result = EIO;
 500                 break;
 501         case DID_ERROR:
 502                 old_hdr->result = (srp->sense_b[0] == 0 &&
 503                                   hp->masked_status == GOOD) ? 0 : EIO;
 504                 break;
 505         default:
 506                 old_hdr->result = EIO;
 507                 break;
 508         }
 509
 510         /* Now copy the result back to the user buffer.  */
 511         if (count >= SZ_SG_HEADER) {
 512                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 513                         retval = -EFAULT;
 514                         goto free_old_hdr;
 515                 }
 516                 buf += SZ_SG_HEADER;
 517                 if (count > old_hdr->reply_len)
 518                         count = old_hdr->reply_len;
 519                 if (count > SZ_SG_HEADER) {
 520                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 521                                 retval = -EFAULT;
 522                                 goto free_old_hdr;
 523                         }
 524                 }
 525         } else
 526                 count = (old_hdr->result == 0) ? 0 : -EIO;
 527         sg_finish_rem_req(srp);
 528         retval = count;
 529 free_old_hdr:
 530         kfree(old_hdr);
 531         return retval;
 532 }
 533
 534 static ssize_t
 535 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 536 {
 537         sg_io_hdr_t *hp = &srp->header;
 538         int err = 0, err2;
 539         int len;
 540
 541         if (count < SZ_SG_IO_HDR) {
 542                 err = -EINVAL;
 543                 goto err_out;
 544         }
 545         hp->sb_len_wr = 0;
 546         if ((hp->mx_sb_len > 0) && hp->sbp) {
 547                 if ((CHECK_CONDITION & hp->masked_status) ||
 548                     (DRIVER_SENSE & hp->driver_status)) {
 549                         int sb_len = SCSI_SENSE_BUFFERSIZE;
 550                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 551                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 552                         len = (len > sb_len) ? sb_len : len;
 553                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 554                                 err = -EFAULT;
 555                                 goto err_out;
 556                         }
 557                         hp->sb_len_wr = len;
 558                 }
 559         }
 560         if (hp->masked_status || hp->host_status || hp->driver_status)
 561                 hp->info |= SG_INFO_CHECK;
 562         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 563                 err = -EFAULT;
 564                 goto err_out;
 565         }
 566 err_out:
 567         err2 = sg_finish_rem_req(srp);
 568         return err ? : err2 ? : count;
 569 }
 570
 571 static ssize_t
 572 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 573 {
 574         int mxsize, cmd_size, k;
 575         int input_size, blocking;
 576         unsigned char opcode;
 577         Sg_device *sdp;
 578         Sg_fd *sfp;
 579         Sg_request *srp;
 580         struct sg_header old_hdr;
 581         sg_io_hdr_t *hp;
 582         unsigned char cmnd[SG_MAX_CDB_SIZE];
 583
 584         if (unlikely(segment_eq(get_fs(), KERNEL_DS)))
 585                 return -EINVAL;
 586
 587         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 588                 return -ENXIO;
 589         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 590                                       "sg_write: count=%d\n", (int) count));
 591         if (atomic_read(&sdp->detaching))
 592                 return -ENODEV;
 593         if (!((filp->f_flags & O_NONBLOCK) ||
 594               scsi_block_when_processing_errors(sdp->device)))
 595                 return -ENXIO;
 596
 597         if (!access_ok(VERIFY_READ, buf, count))
 598                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 599         if (count < SZ_SG_HEADER)
 600                 return -EIO;
 601         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 602                 return -EFAULT;
 603         blocking = !(filp->f_flags & O_NONBLOCK);
 604         if (old_hdr.reply_len < 0)
 605                 return sg_new_write(sfp, filp, buf, count,
 606                                     blocking, 0, 0, NULL);
 607         if (count < (SZ_SG_HEADER + 6))
 608                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 609
 610         if (!(srp = sg_add_request(sfp))) {
 611                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
 612                                               "sg_write: queue full\n"));
 613                 return -EDOM;
 614         }
 615         buf += SZ_SG_HEADER;
 616         __get_user(opcode, buf);
 617         if (sfp->next_cmd_len > 0) {
 618                 cmd_size = sfp->next_cmd_len;
 619                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 620         } else {
 621                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 622                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 623                         cmd_size = 12;
 624         }
 625         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
 626                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 627 /* Determine buffer size.  */
 628         input_size = count - cmd_size;
 629         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 630         mxsize -= SZ_SG_HEADER;
 631         input_size -= SZ_SG_HEADER;
 632         if (input_size < 0) {
 633                 sg_remove_request(sfp, srp);
 634                 return -EIO;    /* User did not pass enough bytes for this command. */
 635         }
 636         hp = &srp->header;
 637         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 638         hp->cmd_len = (unsigned char) cmd_size;
 639         hp->iovec_count = 0;
 640         hp->mx_sb_len = 0;
 641         if (input_size > 0)
 642                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 643                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 644         else
 645                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 646         hp->dxfer_len = mxsize;
 647         if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
 648             (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
 649                 hp->dxferp = (char __user *)buf + cmd_size;
 650         else
 651                 hp->dxferp = NULL;
 652         hp->sbp = NULL;
 653         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 654         hp->flags = input_size; /* structure abuse ... */
 655         hp->pack_id = old_hdr.pack_id;
 656         hp->usr_ptr = NULL;
 657         if (__copy_from_user(cmnd, buf, cmd_size))
 658                 return -EFAULT;
 659         /*
 660          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 661          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 662          * is a non-zero input_size, so emit a warning.
 663          */
 664         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 665                 static char cmd[TASK_COMM_LEN];
 666                 if (strcmp(current->comm, cmd)) {
 667                         printk_ratelimited(KERN_WARNING
 668                                            "sg_write: data in/out %d/%d bytes "
 669                                            "for SCSI command 0x%x-- guessing "
 670                                            "data in;\n   program %s not setting "
 671                                            "count and/or reply_len properly\n",
 672                                            old_hdr.reply_len - (int)SZ_SG_HEADER,
 673                                            input_size, (unsigned int) cmnd[0],
 674                                            current->comm);
 675                         strcpy(cmd, current->comm);
 676                 }
 677         }
 678         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 679         return (k < 0) ? k : count;
 680 }
 681
 682 static ssize_t
 683 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 684                  size_t count, int blocking, int read_only, int sg_io_owned,
 685                  Sg_request **o_srp)
 686 {
 687         int k;
 688         Sg_request *srp;
 689         sg_io_hdr_t *hp;
 690         unsigned char cmnd[SG_MAX_CDB_SIZE];
 691         int timeout;
 692         unsigned long ul_timeout;
 693
 694         if (count < SZ_SG_IO_HDR)
 695                 return -EINVAL;
 696         if (!access_ok(VERIFY_READ, buf, count))
 697                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 698
 699         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 700         if (!(srp = sg_add_request(sfp))) {
 701                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 702                                               "sg_new_write: queue full\n"));
 703                 return -EDOM;
 704         }
 705         srp->sg_io_owned = sg_io_owned;
 706         hp = &srp->header;
 707         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 708                 sg_remove_request(sfp, srp);
 709                 return -EFAULT;
 710         }
 711         if (hp->interface_id != 'S') {
 712                 sg_remove_request(sfp, srp);
 713                 return -ENOSYS;
 714         }
 715         if (hp->flags & SG_FLAG_MMAP_IO) {
 716                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 717                         sg_remove_request(sfp, srp);
 718                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 719                 }
 720                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 721                         sg_remove_request(sfp, srp);
 722                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 723                 }
 724                 if (sg_res_in_use(sfp)) {
 725                         sg_remove_request(sfp, srp);
 726                         return -EBUSY;  /* reserve buffer already being used */
 727                 }
 728         }
 729         ul_timeout = msecs_to_jiffies(srp->header.timeout);
 730         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 731         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 732                 sg_remove_request(sfp, srp);
 733                 return -EMSGSIZE;
 734         }
 735         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
 736                 sg_remove_request(sfp, srp);
 737                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 738         }
 739         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 740                 sg_remove_request(sfp, srp);
 741                 return -EFAULT;
 742         }
 743         if (read_only && sg_allow_access(file, cmnd)) {
 744                 sg_remove_request(sfp, srp);
 745                 return -EPERM;
 746         }
 747         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 748         if (k < 0)
 749                 return k;
 750         if (o_srp)
 751                 *o_srp = srp;
 752         return count;
 753 }
 754
 755 static int
 756 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 757                 unsigned char *cmnd, int timeout, int blocking)
 758 {
 759         int k, at_head;
 760         Sg_device *sdp = sfp->parentdp;
 761         sg_io_hdr_t *hp = &srp->header;
 762
 763         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 764         hp->status = 0;
 765         hp->masked_status = 0;
 766         hp->msg_status = 0;
 767         hp->info = 0;
 768         hp->host_status = 0;
 769         hp->driver_status = 0;
 770         hp->resid = 0;
 771         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
 772                         "sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 773                         (int) cmnd[0], (int) hp->cmd_len));
 774
 775         k = sg_start_req(srp, cmnd);
 776         if (k) {
 777                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 778                         "sg_common_write: start_req err=%d\n", k));
 779                 sg_finish_rem_req(srp);
 780                 return k;       /* probably out of space --> ENOMEM */
 781         }
 782         if (atomic_read(&sdp->detaching)) {
 783                 if (srp->bio) {
 784                         scsi_req_free_cmd(scsi_req(srp->rq));
 785                         blk_end_request_all(srp->rq, -EIO);
 786                         srp->rq = NULL;
 787                 }
 788
 789                 sg_finish_rem_req(srp);
 790                 return -ENODEV;
 791         }
 792
 793         hp->duration = jiffies_to_msecs(jiffies);
 794         if (hp->interface_id != '\0' && /* v3 (or later) interface */
 795             (SG_FLAG_Q_AT_TAIL & hp->flags))
 796                 at_head = 0;
 797         else
 798                 at_head = 1;
 799
 800         srp->rq->timeout = timeout;
 801         kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
 802         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 803                               srp->rq, at_head, sg_rq_end_io);
 804         return 0;
 805 }
 806
 807 static int srp_done(Sg_fd *sfp, Sg_request *srp)
 808 {
 809         unsigned long flags;
 810         int ret;
 811
 812         read_lock_irqsave(&sfp->rq_list_lock, flags);
 813         ret = srp->done;
 814         read_unlock_irqrestore(&sfp->rq_list_lock, flags);
 815         return ret;
 816 }
 817
 818 static int max_sectors_bytes(struct request_queue *q)
 819 {
 820         unsigned int max_sectors = queue_max_sectors(q);
 821
 822         max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
 823
 824         return max_sectors << 9;
 825 }
 826
 827 static long
 828 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 829 {
 830         void __user *p = (void __user *)arg;
 831         int __user *ip = p;
 832         int result, val, read_only;
 833         Sg_device *sdp;
 834         Sg_fd *sfp;
 835         Sg_request *srp;
 836         unsigned long iflags;
 837
 838         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 839                 return -ENXIO;
 840
 841         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 842                                    "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
 843         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 844
 845         switch (cmd_in) {
 846         case SG_IO:
 847                 if (atomic_read(&sdp->detaching))
 848                         return -ENODEV;
 849                 if (!scsi_block_when_processing_errors(sdp->device))
 850                         return -ENXIO;
 851                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 852                         return -EFAULT;
 853                 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 854                                  1, read_only, 1, &srp);
 855                 if (result < 0)
 856                         return result;
 857                 result = wait_event_interruptible(sfp->read_wait,
 858                         (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
 859                 if (atomic_read(&sdp->detaching))
 860                         return -ENODEV;
 861                 write_lock_irq(&sfp->rq_list_lock);
 862                 if (srp->done) {
 863                         srp->done = 2;
 864                         write_unlock_irq(&sfp->rq_list_lock);
 865                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 866                         return (result < 0) ? result : 0;
 867                 }
 868                 srp->orphan = 1;
 869                 write_unlock_irq(&sfp->rq_list_lock);
 870                 return result;  /* -ERESTARTSYS because signal hit process */
 871         case SG_SET_TIMEOUT:
 872                 result = get_user(val, ip);
 873                 if (result)
 874                         return result;
 875                 if (val < 0)
 876                         return -EIO;
 877                 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
 878                         val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
 879                                     INT_MAX);
 880                 sfp->timeout_user = val;
 881                 sfp->timeout = mult_frac(val, HZ, USER_HZ);
 882
 883                 return 0;
 884         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 885                                 /* strange ..., for backward compatibility */
 886                 return sfp->timeout_user;
 887         case SG_SET_FORCE_LOW_DMA:
 888                 result = get_user(val, ip);
 889                 if (result)
 890                         return result;
 891                 if (val) {
 892                         sfp->low_dma = 1;
 893                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
 894                                 val = (int) sfp->reserve.bufflen;
 895                                 sg_remove_scat(sfp, &sfp->reserve);
 896                                 sg_build_reserve(sfp, val);
 897                         }
 898                 } else {
 899                         if (atomic_read(&sdp->detaching))
 900                                 return -ENODEV;
 901                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
 902                 }
 903                 return 0;
 904         case SG_GET_LOW_DMA:
 905                 return put_user((int) sfp->low_dma, ip);
 906         case SG_GET_SCSI_ID:
 907                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 908                         return -EFAULT;
 909                 else {
 910                         sg_scsi_id_t __user *sg_idp = p;
 911
 912                         if (atomic_read(&sdp->detaching))
 913                                 return -ENODEV;
 914                         __put_user((int) sdp->device->host->host_no,
 915                                    &sg_idp->host_no);
 916                         __put_user((int) sdp->device->channel,
 917                                    &sg_idp->channel);
 918                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 919                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 920                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 921                         __put_user((short) sdp->device->host->cmd_per_lun,
 922                                    &sg_idp->h_cmd_per_lun);
 923                         __put_user((short) sdp->device->queue_depth,
 924                                    &sg_idp->d_queue_depth);
 925                         __put_user(0, &sg_idp->unused[0]);
 926                         __put_user(0, &sg_idp->unused[1]);
 927                         return 0;
 928                 }
 929         case SG_SET_FORCE_PACK_ID:
 930                 result = get_user(val, ip);
 931                 if (result)
 932                         return result;
 933                 sfp->force_packid = val ? 1 : 0;
 934                 return 0;
 935         case SG_GET_PACK_ID:
 936                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 937                         return -EFAULT;
 938                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 939                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
 940                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 941                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 942                                                        iflags);
 943                                 __put_user(srp->header.pack_id, ip);
 944                                 return 0;
 945                         }
 946                 }
 947                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 948                 __put_user(-1, ip);
 949                 return 0;
 950         case SG_GET_NUM_WAITING:
 951                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 952                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
 953                         if ((1 == srp->done) && (!srp->sg_io_owned))
 954                                 ++val;
 955                 }
 956                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 957                 return put_user(val, ip);
 958         case SG_GET_SG_TABLESIZE:
 959                 return put_user(sdp->sg_tablesize, ip);
 960         case SG_SET_RESERVED_SIZE:
 961                 result = get_user(val, ip);
 962                 if (result)
 963                         return result;
 964                 if (val < 0)
 965                         return -EINVAL;
 966                 val = min_t(int, val,
 967                             max_sectors_bytes(sdp->device->request_queue));
 968                 if (val != sfp->reserve.bufflen) {
 969                         if (sg_res_in_use(sfp) || sfp->mmap_called)
 970                                 return -EBUSY;
 971                         sg_remove_scat(sfp, &sfp->reserve);
 972                         sg_build_reserve(sfp, val);
 973                 }
 974                 return 0;
 975         case SG_GET_RESERVED_SIZE:
 976                 val = min_t(int, sfp->reserve.bufflen,
 977                             max_sectors_bytes(sdp->device->request_queue));
 978                 return put_user(val, ip);
 979         case SG_SET_COMMAND_Q:
 980                 result = get_user(val, ip);
 981                 if (result)
 982                         return result;
 983                 sfp->cmd_q = val ? 1 : 0;
 984                 return 0;
 985         case SG_GET_COMMAND_Q:
 986                 return put_user((int) sfp->cmd_q, ip);
 987         case SG_SET_KEEP_ORPHAN:
 988                 result = get_user(val, ip);
 989                 if (result)
 990                         return result;
 991                 sfp->keep_orphan = val;
 992                 return 0;
 993         case SG_GET_KEEP_ORPHAN:
 994                 return put_user((int) sfp->keep_orphan, ip);
 995         case SG_NEXT_CMD_LEN:
 996                 result = get_user(val, ip);
 997                 if (result)
 998                         return result;
 999                 sfp->next_cmd_len = (val > 0) ? val : 0;
1000                 return 0;
1001         case SG_GET_VERSION_NUM:
1002                 return put_user(sg_version_num, ip);
1003         case SG_GET_ACCESS_COUNT:
1004                 /* faked - we don't have a real access count anymore */
1005                 val = (sdp->device ? 1 : 0);
1006                 return put_user(val, ip);
1007         case SG_GET_REQUEST_TABLE:
1008                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
1009                         return -EFAULT;
1010                 else {
1011                         sg_req_info_t *rinfo;
1012                         unsigned int ms;
1013
1014                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
1015                                                                 GFP_KERNEL);
1016                         if (!rinfo)
1017                                 return -ENOMEM;
1018                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1019                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
1020                              ++val, srp = srp ? srp->nextrp : srp) {
1021                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
1022                                 if (srp) {
1023                                         rinfo[val].req_state = srp->done + 1;
1024                                         rinfo[val].problem =
1025                                             srp->header.masked_status &
1026                                             srp->header.host_status &
1027                                             srp->header.driver_status;
1028                                         if (srp->done)
1029                                                 rinfo[val].duration =
1030                                                         srp->header.duration;
1031                                         else {
1032                                                 ms = jiffies_to_msecs(jiffies);
1033                                                 rinfo[val].duration =
1034                                                     (ms > srp->header.duration) ?
1035                                                     (ms - srp->header.duration) : 0;
1036                                         }
1037                                         rinfo[val].orphan = srp->orphan;
1038                                         rinfo[val].sg_io_owned =
1039                                                         srp->sg_io_owned;
1040                                         rinfo[val].pack_id =
1041                                                         srp->header.pack_id;
1042                                         rinfo[val].usr_ptr =
1043                                                         srp->header.usr_ptr;
1044                                 }
1045                         }
1046                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1047                         result = __copy_to_user(p, rinfo,
1048                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1049                         result = result ? -EFAULT : 0;
1050                         kfree(rinfo);
1051                         return result;
1052                 }
1053         case SG_EMULATED_HOST:
1054                 if (atomic_read(&sdp->detaching))
1055                         return -ENODEV;
1056                 return put_user(sdp->device->host->hostt->emulated, ip);
1057         case SCSI_IOCTL_SEND_COMMAND:
1058                 if (atomic_read(&sdp->detaching))
1059                         return -ENODEV;
1060                 if (read_only) {
1061                         unsigned char opcode = WRITE_6;
1062                         Scsi_Ioctl_Command __user *siocp = p;
1063
1064                         if (copy_from_user(&opcode, siocp->data, 1))
1065                                 return -EFAULT;
1066                         if (sg_allow_access(filp, &opcode))
1067                                 return -EPERM;
1068                 }
1069                 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1070         case SG_SET_DEBUG:
1071                 result = get_user(val, ip);
1072                 if (result)
1073                         return result;
1074                 sdp->sgdebug = (char) val;
1075                 return 0;
1076         case BLKSECTGET:
1077                 return put_user(max_sectors_bytes(sdp->device->request_queue),
1078                                 ip);
1079         case BLKTRACESETUP:
1080                 return blk_trace_setup(sdp->device->request_queue,
1081                                        sdp->disk->disk_name,
1082                                        MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1083                                        NULL,
1084                                        (char *)arg);
1085         case BLKTRACESTART:
1086                 return blk_trace_startstop(sdp->device->request_queue, 1);
1087         case BLKTRACESTOP:
1088                 return blk_trace_startstop(sdp->device->request_queue, 0);
1089         case BLKTRACETEARDOWN:
1090                 return blk_trace_remove(sdp->device->request_queue);
1091         case SCSI_IOCTL_GET_IDLUN:
1092         case SCSI_IOCTL_GET_BUS_NUMBER:
1093         case SCSI_IOCTL_PROBE_HOST:
1094         case SG_GET_TRANSFORM:
1095         case SG_SCSI_RESET:
1096                 if (atomic_read(&sdp->detaching))
1097                         return -ENODEV;
1098                 break;
1099         default:
1100                 if (read_only)
1101                         return -EPERM;  /* don't know so take safe approach */
1102                 break;
1103         }
1104
1105         result = scsi_ioctl_block_when_processing_errors(sdp->device,
1106                         cmd_in, filp->f_flags & O_NDELAY);
1107         if (result)
1108                 return result;
1109         return scsi_ioctl(sdp->device, cmd_in, p);
1110 }
1111
1112 #ifdef CONFIG_COMPAT
1113 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1114 {
1115         Sg_device *sdp;
1116         Sg_fd *sfp;
1117         struct scsi_device *sdev;
1118
1119         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1120                 return -ENXIO;
1121
1122         sdev = sdp->device;
1123         if (sdev->host->hostt->compat_ioctl) {
1124                 int ret;
1125
1126                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1127
1128                 return ret;
1129         }
1130
1131         return -ENOIOCTLCMD;
1132 }
1133 #endif
1134
1135 static unsigned int
1136 sg_poll(struct file *filp, poll_table * wait)
1137 {
1138         unsigned int res = 0;
1139         Sg_device *sdp;
1140         Sg_fd *sfp;
1141         Sg_request *srp;
1142         int count = 0;
1143         unsigned long iflags;
1144
1145         sfp = filp->private_data;
1146         if (!sfp)
1147                 return POLLERR;
1148         sdp = sfp->parentdp;
1149         if (!sdp)
1150                 return POLLERR;
1151         poll_wait(filp, &sfp->read_wait, wait);
1152         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1153         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1154                 /* if any read waiting, flag it */
1155                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1156                         res = POLLIN | POLLRDNORM;
1157                 ++count;
1158         }
1159         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1160
1161         if (atomic_read(&sdp->detaching))
1162                 res |= POLLHUP;
1163         else if (!sfp->cmd_q) {
1164                 if (0 == count)
1165                         res |= POLLOUT | POLLWRNORM;
1166         } else if (count < SG_MAX_QUEUE)
1167                 res |= POLLOUT | POLLWRNORM;
1168         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1169                                       "sg_poll: res=0x%x\n", (int) res));
1170         return res;
1171 }
1172
1173 static int
1174 sg_fasync(int fd, struct file *filp, int mode)
1175 {
1176         Sg_device *sdp;
1177         Sg_fd *sfp;
1178
1179         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1180                 return -ENXIO;
1181         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1182                                       "sg_fasync: mode=%d\n", mode));
1183
1184         return fasync_helper(fd, filp, mode, &sfp->async_qp);
1185 }
1186
1187 static int
1188 sg_vma_fault(struct vm_fault *vmf)
1189 {
1190         struct vm_area_struct *vma = vmf->vma;
1191         Sg_fd *sfp;
1192         unsigned long offset, len, sa;
1193         Sg_scatter_hold *rsv_schp;
1194         int k, length;
1195
1196         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1197                 return VM_FAULT_SIGBUS;
1198         rsv_schp = &sfp->reserve;
1199         offset = vmf->pgoff << PAGE_SHIFT;
1200         if (offset >= rsv_schp->bufflen)
1201                 return VM_FAULT_SIGBUS;
1202         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1203                                       "sg_vma_fault: offset=%lu, scatg=%d\n",
1204                                       offset, rsv_schp->k_use_sg));
1205         sa = vma->vm_start;
1206         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1207         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1208                 len = vma->vm_end - sa;
1209                 len = (len < length) ? len : length;
1210                 if (offset < len) {
1211                         struct page *page = nth_page(rsv_schp->pages[k],
1212                                                      offset >> PAGE_SHIFT);
1213                         get_page(page); /* increment page count */
1214                         vmf->page = page;
1215                         return 0; /* success */
1216                 }
1217                 sa += len;
1218                 offset -= len;
1219         }
1220
1221         return VM_FAULT_SIGBUS;
1222 }
1223
1224 static const struct vm_operations_struct sg_mmap_vm_ops = {
1225         .fault = sg_vma_fault,
1226 };
1227
1228 static int
1229 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1230 {
1231         Sg_fd *sfp;
1232         unsigned long req_sz, len, sa;
1233         Sg_scatter_hold *rsv_schp;
1234         int k, length;
1235
1236         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1237                 return -ENXIO;
1238         req_sz = vma->vm_end - vma->vm_start;
1239         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1240                                       "sg_mmap starting, vm_start=%p, len=%d\n",
1241                                       (void *) vma->vm_start, (int) req_sz));
1242         if (vma->vm_pgoff)
1243                 return -EINVAL; /* want no offset */
1244         rsv_schp = &sfp->reserve;
1245         if (req_sz > rsv_schp->bufflen)
1246                 return -ENOMEM; /* cannot map more than reserved buffer */
1247
1248         sa = vma->vm_start;
1249         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1250         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1251                 len = vma->vm_end - sa;
1252                 len = (len < length) ? len : length;
1253                 sa += len;
1254         }
1255
1256         sfp->mmap_called = 1;
1257         vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
1258         vma->vm_private_data = sfp;
1259         vma->vm_ops = &sg_mmap_vm_ops;
1260         return 0;
1261 }
1262
1263 static void
1264 sg_rq_end_io_usercontext(struct work_struct *work)
1265 {
1266         struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1267         struct sg_fd *sfp = srp->parentfp;
1268
1269         sg_finish_rem_req(srp);
1270         kref_put(&sfp->f_ref, sg_remove_sfp);
1271 }
1272
1273 /*
1274  * This function is a "bottom half" handler that is called by the mid
1275  * level when a command is completed (or has failed).
1276  */
1277 static void
1278 sg_rq_end_io(struct request *rq, int uptodate)
1279 {
1280         struct sg_request *srp = rq->end_io_data;
1281         struct scsi_request *req = scsi_req(rq);
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 = req->sense;
1301         result = rq->errors;
1302         resid = req->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
1337         if (req->sense_len)
1338                 memcpy(srp->sense_b, req->sense, SCSI_SENSE_BUFFERSIZE);
1339
1340         /* Rely on write phase to clean out srp status values, so no "else" */
1341
1342         /*
1343          * Free the request as soon as it is complete so that its resources
1344          * can be reused without waiting for userspace to read() the
1345          * result.  But keep the associated bio (if any) around until
1346          * blk_rq_unmap_user() can be called from user context.
1347          */
1348         srp->rq = NULL;
1349         scsi_req_free_cmd(scsi_req(rq));
1350         __blk_put_request(rq->q, rq);
1351
1352         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1353         if (unlikely(srp->orphan)) {
1354                 if (sfp->keep_orphan)
1355                         srp->sg_io_owned = 0;
1356                 else
1357                         done = 0;
1358         }
1359         srp->done = done;
1360         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1361
1362         if (likely(done)) {
1363                 /* Now wake up any sg_read() that is waiting for this
1364                  * packet.
1365                  */
1366                 wake_up_interruptible(&sfp->read_wait);
1367                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1368                 kref_put(&sfp->f_ref, sg_remove_sfp);
1369         } else {
1370                 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1371                 schedule_work(&srp->ew.work);
1372         }
1373 }
1374
1375 static const struct file_operations sg_fops = {
1376         .owner = THIS_MODULE,
1377         .read = sg_read,
1378         .write = sg_write,
1379         .poll = sg_poll,
1380         .unlocked_ioctl = sg_ioctl,
1381 #ifdef CONFIG_COMPAT
1382         .compat_ioctl = sg_compat_ioctl,
1383 #endif
1384         .open = sg_open,
1385         .mmap = sg_mmap,
1386         .release = sg_release,
1387         .fasync = sg_fasync,
1388         .llseek = no_llseek,
1389 };
1390
1391 static struct class *sg_sysfs_class;
1392
1393 static int sg_sysfs_valid = 0;
1394
1395 static Sg_device *
1396 sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1397 {
1398         struct request_queue *q = scsidp->request_queue;
1399         Sg_device *sdp;
1400         unsigned long iflags;
1401         int error;
1402         u32 k;
1403
1404         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1405         if (!sdp) {
1406                 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1407                             "failure\n", __func__);
1408                 return ERR_PTR(-ENOMEM);
1409         }
1410
1411         idr_preload(GFP_KERNEL);
1412         write_lock_irqsave(&sg_index_lock, iflags);
1413
1414         error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1415         if (error < 0) {
1416                 if (error == -ENOSPC) {
1417                         sdev_printk(KERN_WARNING, scsidp,
1418                                     "Unable to attach sg device type=%d, minor number exceeds %d\n",
1419                                     scsidp->type, SG_MAX_DEVS - 1);
1420                         error = -ENODEV;
1421                 } else {
1422                         sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1423                                     "allocation Sg_device failure: %d\n",
1424                                     __func__, error);
1425                 }
1426                 goto out_unlock;
1427         }
1428         k = error;
1429
1430         SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1431                                         "sg_alloc: dev=%d \n", k));
1432         sprintf(disk->disk_name, "sg%d", k);
1433         disk->first_minor = k;
1434         sdp->disk = disk;
1435         sdp->device = scsidp;
1436         mutex_init(&sdp->open_rel_lock);
1437         INIT_LIST_HEAD(&sdp->sfds);
1438         init_waitqueue_head(&sdp->open_wait);
1439         atomic_set(&sdp->detaching, 0);
1440         rwlock_init(&sdp->sfd_lock);
1441         sdp->sg_tablesize = queue_max_segments(q);
1442         sdp->index = k;
1443         kref_init(&sdp->d_ref);
1444         error = 0;
1445
1446 out_unlock:
1447         write_unlock_irqrestore(&sg_index_lock, iflags);
1448         idr_preload_end();
1449
1450         if (error) {
1451                 kfree(sdp);
1452                 return ERR_PTR(error);
1453         }
1454         return sdp;
1455 }
1456
1457 static int
1458 sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1459 {
1460         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1461         struct gendisk *disk;
1462         Sg_device *sdp = NULL;
1463         struct cdev * cdev = NULL;
1464         int error;
1465         unsigned long iflags;
1466
1467         disk = alloc_disk(1);
1468         if (!disk) {
1469                 pr_warn("%s: alloc_disk failed\n", __func__);
1470                 return -ENOMEM;
1471         }
1472         disk->major = SCSI_GENERIC_MAJOR;
1473
1474         error = -ENOMEM;
1475         cdev = cdev_alloc();
1476         if (!cdev) {
1477                 pr_warn("%s: cdev_alloc failed\n", __func__);
1478                 goto out;
1479         }
1480         cdev->owner = THIS_MODULE;
1481         cdev->ops = &sg_fops;
1482
1483         sdp = sg_alloc(disk, scsidp);
1484         if (IS_ERR(sdp)) {
1485                 pr_warn("%s: sg_alloc failed\n", __func__);
1486                 error = PTR_ERR(sdp);
1487                 goto out;
1488         }
1489
1490         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1491         if (error)
1492                 goto cdev_add_err;
1493
1494         sdp->cdev = cdev;
1495         if (sg_sysfs_valid) {
1496                 struct device *sg_class_member;
1497
1498                 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1499                                                 MKDEV(SCSI_GENERIC_MAJOR,
1500                                                       sdp->index),
1501                                                 sdp, "%s", disk->disk_name);
1502                 if (IS_ERR(sg_class_member)) {
1503                         pr_err("%s: device_create failed\n", __func__);
1504                         error = PTR_ERR(sg_class_member);
1505                         goto cdev_add_err;
1506                 }
1507                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1508                                           &sg_class_member->kobj, "generic");
1509                 if (error)
1510                         pr_err("%s: unable to make symlink 'generic' back "
1511                                "to sg%d\n", __func__, sdp->index);
1512         } else
1513                 pr_warn("%s: sg_sys Invalid\n", __func__);
1514
1515         sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1516                     "type %d\n", sdp->index, scsidp->type);
1517
1518         dev_set_drvdata(cl_dev, sdp);
1519
1520         return 0;
1521
1522 cdev_add_err:
1523         write_lock_irqsave(&sg_index_lock, iflags);
1524         idr_remove(&sg_index_idr, sdp->index);
1525         write_unlock_irqrestore(&sg_index_lock, iflags);
1526         kfree(sdp);
1527
1528 out:
1529         put_disk(disk);
1530         if (cdev)
1531                 cdev_del(cdev);
1532         return error;
1533 }
1534
1535 static void
1536 sg_device_destroy(struct kref *kref)
1537 {
1538         struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1539         unsigned long flags;
1540
1541         /* CAUTION!  Note that the device can still be found via idr_find()
1542          * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1543          * any other cleanup.
1544          */
1545
1546         write_lock_irqsave(&sg_index_lock, flags);
1547         idr_remove(&sg_index_idr, sdp->index);
1548         write_unlock_irqrestore(&sg_index_lock, flags);
1549
1550         SCSI_LOG_TIMEOUT(3,
1551                 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1552
1553         put_disk(sdp->disk);
1554         kfree(sdp);
1555 }
1556
1557 static void
1558 sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1559 {
1560         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1561         Sg_device *sdp = dev_get_drvdata(cl_dev);
1562         unsigned long iflags;
1563         Sg_fd *sfp;
1564         int val;
1565
1566         if (!sdp)
1567                 return;
1568         /* want sdp->detaching non-zero as soon as possible */
1569         val = atomic_inc_return(&sdp->detaching);
1570         if (val > 1)
1571                 return; /* only want to do following once per device */
1572
1573         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1574                                       "%s\n", __func__));
1575
1576         read_lock_irqsave(&sdp->sfd_lock, iflags);
1577         list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1578                 wake_up_interruptible_all(&sfp->read_wait);
1579                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1580         }
1581         wake_up_interruptible_all(&sdp->open_wait);
1582         read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1583
1584         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1585         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1586         cdev_del(sdp->cdev);
1587         sdp->cdev = NULL;
1588
1589         kref_put(&sdp->d_ref, sg_device_destroy);
1590 }
1591
1592 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1593 module_param_named(def_reserved_size, def_reserved_size, int,
1594                    S_IRUGO | S_IWUSR);
1595 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1596
1597 MODULE_AUTHOR("Douglas Gilbert");
1598 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1599 MODULE_LICENSE("GPL");
1600 MODULE_VERSION(SG_VERSION_STR);
1601 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1602
1603 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1604                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1605 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1606 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1607
1608 static int __init
1609 init_sg(void)
1610 {
1611         int rc;
1612
1613         if (scatter_elem_sz < PAGE_SIZE) {
1614                 scatter_elem_sz = PAGE_SIZE;
1615                 scatter_elem_sz_prev = scatter_elem_sz;
1616         }
1617         if (def_reserved_size >= 0)
1618                 sg_big_buff = def_reserved_size;
1619         else
1620                 def_reserved_size = sg_big_buff;
1621
1622         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1623                                     SG_MAX_DEVS, "sg");
1624         if (rc)
1625                 return rc;
1626         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1627         if ( IS_ERR(sg_sysfs_class) ) {
1628                 rc = PTR_ERR(sg_sysfs_class);
1629                 goto err_out;
1630         }
1631         sg_sysfs_valid = 1;
1632         rc = scsi_register_interface(&sg_interface);
1633         if (0 == rc) {
1634 #ifdef CONFIG_SCSI_PROC_FS
1635                 sg_proc_init();
1636 #endif                          /* CONFIG_SCSI_PROC_FS */
1637                 return 0;
1638         }
1639         class_destroy(sg_sysfs_class);
1640 err_out:
1641         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1642         return rc;
1643 }
1644
1645 static void __exit
1646 exit_sg(void)
1647 {
1648 #ifdef CONFIG_SCSI_PROC_FS
1649         sg_proc_cleanup();
1650 #endif                          /* CONFIG_SCSI_PROC_FS */
1651         scsi_unregister_interface(&sg_interface);
1652         class_destroy(sg_sysfs_class);
1653         sg_sysfs_valid = 0;
1654         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1655                                  SG_MAX_DEVS);
1656         idr_destroy(&sg_index_idr);
1657 }
1658
1659 static int
1660 sg_start_req(Sg_request *srp, unsigned char *cmd)
1661 {
1662         int res;
1663         struct request *rq;
1664         struct scsi_request *req;
1665         Sg_fd *sfp = srp->parentfp;
1666         sg_io_hdr_t *hp = &srp->header;
1667         int dxfer_len = (int) hp->dxfer_len;
1668         int dxfer_dir = hp->dxfer_direction;
1669         unsigned int iov_count = hp->iovec_count;
1670         Sg_scatter_hold *req_schp = &srp->data;
1671         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1672         struct request_queue *q = sfp->parentdp->device->request_queue;
1673         struct rq_map_data *md, map_data;
1674         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1675         unsigned char *long_cmdp = NULL;
1676
1677         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1678                                       "sg_start_req: dxfer_len=%d\n",
1679                                       dxfer_len));
1680
1681         if (hp->cmd_len > BLK_MAX_CDB) {
1682                 long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1683                 if (!long_cmdp)
1684                         return -ENOMEM;
1685         }
1686
1687         /*
1688          * NOTE
1689          *
1690          * With scsi-mq enabled, there are a fixed number of preallocated
1691          * requests equal in number to shost->can_queue.  If all of the
1692          * preallocated requests are already in use, then using GFP_ATOMIC with
1693          * blk_get_request() will return -EWOULDBLOCK, whereas using GFP_KERNEL
1694          * will cause blk_get_request() to sleep until an active command
1695          * completes, freeing up a request.  Neither option is ideal, but
1696          * GFP_KERNEL is the better choice to prevent userspace from getting an
1697          * unexpected EWOULDBLOCK.
1698          *
1699          * With scsi-mq disabled, blk_get_request() with GFP_KERNEL usually
1700          * does not sleep except under memory pressure.
1701          */
1702         rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1703                         REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, GFP_KERNEL);
1704         if (IS_ERR(rq)) {
1705                 kfree(long_cmdp);
1706                 return PTR_ERR(rq);
1707         }
1708         req = scsi_req(rq);
1709
1710         scsi_req_init(rq);
1711
1712         if (hp->cmd_len > BLK_MAX_CDB)
1713                 req->cmd = long_cmdp;
1714         memcpy(req->cmd, cmd, hp->cmd_len);
1715         req->cmd_len = hp->cmd_len;
1716
1717         srp->rq = rq;
1718         rq->end_io_data = srp;
1719         rq->retries = SG_DEFAULT_RETRIES;
1720
1721         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1722                 return 0;
1723
1724         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1725             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1726             !sfp->parentdp->device->host->unchecked_isa_dma &&
1727             blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1728                 md = NULL;
1729         else
1730                 md = &map_data;
1731
1732         if (md) {
1733                 if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
1734                         sg_link_reserve(sfp, srp, dxfer_len);
1735                 else {
1736                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1737                         if (res)
1738                                 return res;
1739                 }
1740
1741                 md->pages = req_schp->pages;
1742                 md->page_order = req_schp->page_order;
1743                 md->nr_entries = req_schp->k_use_sg;
1744                 md->offset = 0;
1745                 md->null_mapped = hp->dxferp ? 0 : 1;
1746                 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1747                         md->from_user = 1;
1748                 else
1749                         md->from_user = 0;
1750         }
1751
1752         if (iov_count) {
1753                 struct iovec *iov = NULL;
1754                 struct iov_iter i;
1755
1756                 res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i);
1757                 if (res < 0)
1758                         return res;
1759
1760                 iov_iter_truncate(&i, hp->dxfer_len);
1761                 if (!iov_iter_count(&i)) {
1762                         kfree(iov);
1763                         return -EINVAL;
1764                 }
1765
1766                 res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
1767                 kfree(iov);
1768         } else
1769                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1770                                       hp->dxfer_len, GFP_ATOMIC);
1771
1772         if (!res) {
1773                 srp->bio = rq->bio;
1774
1775                 if (!md) {
1776                         req_schp->dio_in_use = 1;
1777                         hp->info |= SG_INFO_DIRECT_IO;
1778                 }
1779         }
1780         return res;
1781 }
1782
1783 static int
1784 sg_finish_rem_req(Sg_request *srp)
1785 {
1786         int ret = 0;
1787
1788         Sg_fd *sfp = srp->parentfp;
1789         Sg_scatter_hold *req_schp = &srp->data;
1790
1791         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1792                                       "sg_finish_rem_req: res_used=%d\n",
1793                                       (int) srp->res_used));
1794         if (srp->bio)
1795                 ret = blk_rq_unmap_user(srp->bio);
1796
1797         if (srp->rq) {
1798                 scsi_req_free_cmd(scsi_req(srp->rq));
1799                 blk_put_request(srp->rq);
1800         }
1801
1802         if (srp->res_used)
1803                 sg_unlink_reserve(sfp, srp);
1804         else
1805                 sg_remove_scat(sfp, req_schp);
1806
1807         sg_remove_request(sfp, srp);
1808
1809         return ret;
1810 }
1811
1812 static int
1813 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1814 {
1815         int sg_bufflen = tablesize * sizeof(struct page *);
1816         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1817
1818         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1819         if (!schp->pages)
1820                 return -ENOMEM;
1821         schp->sglist_len = sg_bufflen;
1822         return tablesize;       /* number of scat_gath elements allocated */
1823 }
1824
1825 static int
1826 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1827 {
1828         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1829         int sg_tablesize = sfp->parentdp->sg_tablesize;
1830         int blk_size = buff_size, order;
1831         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1832
1833         if (blk_size < 0)
1834                 return -EFAULT;
1835         if (0 == blk_size)
1836                 ++blk_size;     /* don't know why */
1837         /* round request up to next highest SG_SECTOR_SZ byte boundary */
1838         blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1839         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1840                 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1841                 buff_size, blk_size));
1842
1843         /* N.B. ret_sz carried into this block ... */
1844         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1845         if (mx_sc_elems < 0)
1846                 return mx_sc_elems;     /* most likely -ENOMEM */
1847
1848         num = scatter_elem_sz;
1849         if (unlikely(num != scatter_elem_sz_prev)) {
1850                 if (num < PAGE_SIZE) {
1851                         scatter_elem_sz = PAGE_SIZE;
1852                         scatter_elem_sz_prev = PAGE_SIZE;
1853                 } else
1854                         scatter_elem_sz_prev = num;
1855         }
1856
1857         if (sfp->low_dma)
1858                 gfp_mask |= GFP_DMA;
1859
1860         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1861                 gfp_mask |= __GFP_ZERO;
1862
1863         order = get_order(num);
1864 retry:
1865         ret_sz = 1 << (PAGE_SHIFT + order);
1866
1867         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1868              k++, rem_sz -= ret_sz) {
1869
1870                 num = (rem_sz > scatter_elem_sz_prev) ?
1871                         scatter_elem_sz_prev : rem_sz;
1872
1873                 schp->pages[k] = alloc_pages(gfp_mask, order);
1874                 if (!schp->pages[k])
1875                         goto out;
1876
1877                 if (num == scatter_elem_sz_prev) {
1878                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1879                                 scatter_elem_sz = ret_sz;
1880                                 scatter_elem_sz_prev = ret_sz;
1881                         }
1882                 }
1883
1884                 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1885                                  "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1886                                  k, num, ret_sz));
1887         }               /* end of for loop */
1888
1889         schp->page_order = order;
1890         schp->k_use_sg = k;
1891         SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1892                          "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1893                          k, rem_sz));
1894
1895         schp->bufflen = blk_size;
1896         if (rem_sz > 0) /* must have failed */
1897                 return -ENOMEM;
1898         return 0;
1899 out:
1900         for (i = 0; i < k; i++)
1901                 __free_pages(schp->pages[i], order);
1902
1903         if (--order >= 0)
1904                 goto retry;
1905
1906         return -ENOMEM;
1907 }
1908
1909 static void
1910 sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1911 {
1912         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1913                          "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1914         if (schp->pages && schp->sglist_len > 0) {
1915                 if (!schp->dio_in_use) {
1916                         int k;
1917
1918                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1919                                 SCSI_LOG_TIMEOUT(5,
1920                                         sg_printk(KERN_INFO, sfp->parentdp,
1921                                         "sg_remove_scat: k=%d, pg=0x%p\n",
1922                                         k, schp->pages[k]));
1923                                 __free_pages(schp->pages[k], schp->page_order);
1924                         }
1925
1926                         kfree(schp->pages);
1927                 }
1928         }
1929         memset(schp, 0, sizeof (*schp));
1930 }
1931
1932 static int
1933 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1934 {
1935         Sg_scatter_hold *schp = &srp->data;
1936         int k, num;
1937
1938         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1939                          "sg_read_oxfer: num_read_xfer=%d\n",
1940                          num_read_xfer));
1941         if ((!outp) || (num_read_xfer <= 0))
1942                 return 0;
1943
1944         num = 1 << (PAGE_SHIFT + schp->page_order);
1945         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1946                 if (num > num_read_xfer) {
1947                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1948                                            num_read_xfer))
1949                                 return -EFAULT;
1950                         break;
1951                 } else {
1952                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1953                                            num))
1954                                 return -EFAULT;
1955                         num_read_xfer -= num;
1956                         if (num_read_xfer <= 0)
1957                                 break;
1958                         outp += num;
1959                 }
1960         }
1961
1962         return 0;
1963 }
1964
1965 static void
1966 sg_build_reserve(Sg_fd * sfp, int req_size)
1967 {
1968         Sg_scatter_hold *schp = &sfp->reserve;
1969
1970         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1971                          "sg_build_reserve: req_size=%d\n", req_size));
1972         do {
1973                 if (req_size < PAGE_SIZE)
1974                         req_size = PAGE_SIZE;
1975                 if (0 == sg_build_indirect(schp, sfp, req_size))
1976                         return;
1977                 else
1978                         sg_remove_scat(sfp, schp);
1979                 req_size >>= 1; /* divide by 2 */
1980         } while (req_size > (PAGE_SIZE / 2));
1981 }
1982
1983 static void
1984 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1985 {
1986         Sg_scatter_hold *req_schp = &srp->data;
1987         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1988         int k, num, rem;
1989
1990         srp->res_used = 1;
1991         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1992                          "sg_link_reserve: size=%d\n", size));
1993         rem = size;
1994
1995         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1996         for (k = 0; k < rsv_schp->k_use_sg; k++) {
1997                 if (rem <= num) {
1998                         req_schp->k_use_sg = k + 1;
1999                         req_schp->sglist_len = rsv_schp->sglist_len;
2000                         req_schp->pages = rsv_schp->pages;
2001
2002                         req_schp->bufflen = size;
2003                         req_schp->page_order = rsv_schp->page_order;
2004                         break;
2005                 } else
2006                         rem -= num;
2007         }
2008
2009         if (k >= rsv_schp->k_use_sg)
2010                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2011                                  "sg_link_reserve: BAD size\n"));
2012 }
2013
2014 static void
2015 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2016 {
2017         Sg_scatter_hold *req_schp = &srp->data;
2018
2019         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2020                                       "sg_unlink_reserve: req->k_use_sg=%d\n",
2021                                       (int) req_schp->k_use_sg));
2022         req_schp->k_use_sg = 0;
2023         req_schp->bufflen = 0;
2024         req_schp->pages = NULL;
2025         req_schp->page_order = 0;
2026         req_schp->sglist_len = 0;
2027         sfp->save_scat_len = 0;
2028         srp->res_used = 0;
2029 }
2030
2031 static Sg_request *
2032 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2033 {
2034         Sg_request *resp;
2035         unsigned long iflags;
2036
2037         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2038         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2039                 /* look for requests that are ready + not SG_IO owned */
2040                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2041                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2042                         resp->done = 2; /* guard against other readers */
2043                         break;
2044                 }
2045         }
2046         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2047         return resp;
2048 }
2049
2050 /* always adds to end of list */
2051 static Sg_request *
2052 sg_add_request(Sg_fd * sfp)
2053 {
2054         int k;
2055         unsigned long iflags;
2056         Sg_request *resp;
2057         Sg_request *rp = sfp->req_arr;
2058
2059         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2060         resp = sfp->headrp;
2061         if (!resp) {
2062                 memset(rp, 0, sizeof (Sg_request));
2063                 rp->parentfp = sfp;
2064                 resp = rp;
2065                 sfp->headrp = resp;
2066         } else {
2067                 if (0 == sfp->cmd_q)
2068                         resp = NULL;    /* command queuing disallowed */
2069                 else {
2070                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2071                                 if (!rp->parentfp)
2072                                         break;
2073                         }
2074                         if (k < SG_MAX_QUEUE) {
2075                                 memset(rp, 0, sizeof (Sg_request));
2076                                 rp->parentfp = sfp;
2077                                 while (resp->nextrp)
2078                                         resp = resp->nextrp;
2079                                 resp->nextrp = rp;
2080                                 resp = rp;
2081                         } else
2082                                 resp = NULL;
2083                 }
2084         }
2085         if (resp) {
2086                 resp->nextrp = NULL;
2087                 resp->header.duration = jiffies_to_msecs(jiffies);
2088         }
2089         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2090         return resp;
2091 }
2092
2093 /* Return of 1 for found; 0 for not found */
2094 static int
2095 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2096 {
2097         Sg_request *prev_rp;
2098         Sg_request *rp;
2099         unsigned long iflags;
2100         int res = 0;
2101
2102         if ((!sfp) || (!srp) || (!sfp->headrp))
2103                 return res;
2104         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2105         prev_rp = sfp->headrp;
2106         if (srp == prev_rp) {
2107                 sfp->headrp = prev_rp->nextrp;
2108                 prev_rp->parentfp = NULL;
2109                 res = 1;
2110         } else {
2111                 while ((rp = prev_rp->nextrp)) {
2112                         if (srp == rp) {
2113                                 prev_rp->nextrp = rp->nextrp;
2114                                 rp->parentfp = NULL;
2115                                 res = 1;
2116                                 break;
2117                         }
2118                         prev_rp = rp;
2119                 }
2120         }
2121         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2122         return res;
2123 }
2124
2125 static Sg_fd *
2126 sg_add_sfp(Sg_device * sdp)
2127 {
2128         Sg_fd *sfp;
2129         unsigned long iflags;
2130         int bufflen;
2131
2132         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2133         if (!sfp)
2134                 return ERR_PTR(-ENOMEM);
2135
2136         init_waitqueue_head(&sfp->read_wait);
2137         rwlock_init(&sfp->rq_list_lock);
2138
2139         kref_init(&sfp->f_ref);
2140         sfp->timeout = SG_DEFAULT_TIMEOUT;
2141         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2142         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2143         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2144             sdp->device->host->unchecked_isa_dma : 1;
2145         sfp->cmd_q = SG_DEF_COMMAND_Q;
2146         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2147         sfp->parentdp = sdp;
2148         write_lock_irqsave(&sdp->sfd_lock, iflags);
2149         if (atomic_read(&sdp->detaching)) {
2150                 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2151                 return ERR_PTR(-ENODEV);
2152         }
2153         list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2154         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2155         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2156                                       "sg_add_sfp: sfp=0x%p\n", sfp));
2157         if (unlikely(sg_big_buff != def_reserved_size))
2158                 sg_big_buff = def_reserved_size;
2159
2160         bufflen = min_t(int, sg_big_buff,
2161                         max_sectors_bytes(sdp->device->request_queue));
2162         sg_build_reserve(sfp, bufflen);
2163         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2164                                       "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2165                                       sfp->reserve.bufflen,
2166                                       sfp->reserve.k_use_sg));
2167
2168         kref_get(&sdp->d_ref);
2169         __module_get(THIS_MODULE);
2170         return sfp;
2171 }
2172
2173 static void
2174 sg_remove_sfp_usercontext(struct work_struct *work)
2175 {
2176         struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2177         struct sg_device *sdp = sfp->parentdp;
2178
2179         /* Cleanup any responses which were never read(). */
2180         while (sfp->headrp)
2181                 sg_finish_rem_req(sfp->headrp);
2182
2183         if (sfp->reserve.bufflen > 0) {
2184                 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2185                                 "sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2186                                 (int) sfp->reserve.bufflen,
2187                                 (int) sfp->reserve.k_use_sg));
2188                 sg_remove_scat(sfp, &sfp->reserve);
2189         }
2190
2191         SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2192                         "sg_remove_sfp: sfp=0x%p\n", sfp));
2193         kfree(sfp);
2194
2195         scsi_device_put(sdp->device);
2196         kref_put(&sdp->d_ref, sg_device_destroy);
2197         module_put(THIS_MODULE);
2198 }
2199
2200 static void
2201 sg_remove_sfp(struct kref *kref)
2202 {
2203         struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2204         struct sg_device *sdp = sfp->parentdp;
2205         unsigned long iflags;
2206
2207         write_lock_irqsave(&sdp->sfd_lock, iflags);
2208         list_del(&sfp->sfd_siblings);
2209         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2210
2211         INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2212         schedule_work(&sfp->ew.work);
2213 }
2214
2215 static int
2216 sg_res_in_use(Sg_fd * sfp)
2217 {
2218         const Sg_request *srp;
2219         unsigned long iflags;
2220
2221         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2222         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2223                 if (srp->res_used)
2224                         break;
2225         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2226         return srp ? 1 : 0;
2227 }
2228
2229 #ifdef CONFIG_SCSI_PROC_FS
2230 static int
2231 sg_idr_max_id(int id, void *p, void *data)
2232 {
2233         int *k = data;
2234
2235         if (*k < id)
2236                 *k = id;
2237
2238         return 0;
2239 }
2240
2241 static int
2242 sg_last_dev(void)
2243 {
2244         int k = -1;
2245         unsigned long iflags;
2246
2247         read_lock_irqsave(&sg_index_lock, iflags);
2248         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2249         read_unlock_irqrestore(&sg_index_lock, iflags);
2250         return k + 1;           /* origin 1 */
2251 }
2252 #endif
2253
2254 /* must be called with sg_index_lock held */
2255 static Sg_device *sg_lookup_dev(int dev)
2256 {
2257         return idr_find(&sg_index_idr, dev);
2258 }
2259
2260 static Sg_device *
2261 sg_get_dev(int dev)
2262 {
2263         struct sg_device *sdp;
2264         unsigned long flags;
2265
2266         read_lock_irqsave(&sg_index_lock, flags);
2267         sdp = sg_lookup_dev(dev);
2268         if (!sdp)
2269                 sdp = ERR_PTR(-ENXIO);
2270         else if (atomic_read(&sdp->detaching)) {
2271                 /* If sdp->detaching, then the refcount may already be 0, in
2272                  * which case it would be a bug to do kref_get().
2273                  */
2274                 sdp = ERR_PTR(-ENODEV);
2275         } else
2276                 kref_get(&sdp->d_ref);
2277         read_unlock_irqrestore(&sg_index_lock, flags);
2278
2279         return sdp;
2280 }
2281
2282 #ifdef CONFIG_SCSI_PROC_FS
2283
2284 static struct proc_dir_entry *sg_proc_sgp = NULL;
2285
2286 static char sg_proc_sg_dirname[] = "scsi/sg";
2287
2288 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2289
2290 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2291 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2292                                   size_t count, loff_t *off);
2293 static const struct file_operations adio_fops = {
2294         .owner = THIS_MODULE,
2295         .open = sg_proc_single_open_adio,
2296         .read = seq_read,
2297         .llseek = seq_lseek,
2298         .write = sg_proc_write_adio,
2299         .release = single_release,
2300 };
2301
2302 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2303 static ssize_t sg_proc_write_dressz(struct file *filp,
2304                 const char __user *buffer, size_t count, loff_t *off);
2305 static const struct file_operations dressz_fops = {
2306         .owner = THIS_MODULE,
2307         .open = sg_proc_single_open_dressz,
2308         .read = seq_read,
2309         .llseek = seq_lseek,
2310         .write = sg_proc_write_dressz,
2311         .release = single_release,
2312 };
2313
2314 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2315 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2316 static const struct file_operations version_fops = {
2317         .owner = THIS_MODULE,
2318         .open = sg_proc_single_open_version,
2319         .read = seq_read,
2320         .llseek = seq_lseek,
2321         .release = single_release,
2322 };
2323
2324 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2325 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2326 static const struct file_operations devhdr_fops = {
2327         .owner = THIS_MODULE,
2328         .open = sg_proc_single_open_devhdr,
2329         .read = seq_read,
2330         .llseek = seq_lseek,
2331         .release = single_release,
2332 };
2333
2334 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2335 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2336 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2337 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2338 static void dev_seq_stop(struct seq_file *s, void *v);
2339 static const struct file_operations dev_fops = {
2340         .owner = THIS_MODULE,
2341         .open = sg_proc_open_dev,
2342         .read = seq_read,
2343         .llseek = seq_lseek,
2344         .release = seq_release,
2345 };
2346 static const struct seq_operations dev_seq_ops = {
2347         .start = dev_seq_start,
2348         .next  = dev_seq_next,
2349         .stop  = dev_seq_stop,
2350         .show  = sg_proc_seq_show_dev,
2351 };
2352
2353 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2354 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2355 static const struct file_operations devstrs_fops = {
2356         .owner = THIS_MODULE,
2357         .open = sg_proc_open_devstrs,
2358         .read = seq_read,
2359         .llseek = seq_lseek,
2360         .release = seq_release,
2361 };
2362 static const struct seq_operations devstrs_seq_ops = {
2363         .start = dev_seq_start,
2364         .next  = dev_seq_next,
2365         .stop  = dev_seq_stop,
2366         .show  = sg_proc_seq_show_devstrs,
2367 };
2368
2369 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2370 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2371 static const struct file_operations debug_fops = {
2372         .owner = THIS_MODULE,
2373         .open = sg_proc_open_debug,
2374         .read = seq_read,
2375         .llseek = seq_lseek,
2376         .release = seq_release,
2377 };
2378 static const struct seq_operations debug_seq_ops = {
2379         .start = dev_seq_start,
2380         .next  = dev_seq_next,
2381         .stop  = dev_seq_stop,
2382         .show  = sg_proc_seq_show_debug,
2383 };
2384
2385
2386 struct sg_proc_leaf {
2387         const char * name;
2388         const struct file_operations * fops;
2389 };
2390
2391 static const struct sg_proc_leaf sg_proc_leaf_arr[] = {
2392         {"allow_dio", &adio_fops},
2393         {"debug", &debug_fops},
2394         {"def_reserved_size", &dressz_fops},
2395         {"device_hdr", &devhdr_fops},
2396         {"devices", &dev_fops},
2397         {"device_strs", &devstrs_fops},
2398         {"version", &version_fops}
2399 };
2400
2401 static int
2402 sg_proc_init(void)
2403 {
2404         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2405         int k;
2406
2407         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2408         if (!sg_proc_sgp)
2409                 return 1;
2410         for (k = 0; k < num_leaves; ++k) {
2411                 const struct sg_proc_leaf *leaf = &sg_proc_leaf_arr[k];
2412                 umode_t mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2413                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2414         }
2415         return 0;
2416 }
2417
2418 static void
2419 sg_proc_cleanup(void)
2420 {
2421         int k;
2422         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2423
2424         if (!sg_proc_sgp)
2425                 return;
2426         for (k = 0; k < num_leaves; ++k)
2427                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2428         remove_proc_entry(sg_proc_sg_dirname, NULL);
2429 }
2430
2431
2432 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2433 {
2434         seq_printf(s, "%d\n", *((int *)s->private));
2435         return 0;
2436 }
2437
2438 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2439 {
2440         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2441 }
2442
2443 static ssize_t
2444 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2445                    size_t count, loff_t *off)
2446 {
2447         int err;
2448         unsigned long num;
2449
2450         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2451                 return -EACCES;
2452         err = kstrtoul_from_user(buffer, count, 0, &num);
2453         if (err)
2454                 return err;
2455         sg_allow_dio = num ? 1 : 0;
2456         return count;
2457 }
2458
2459 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2460 {
2461         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2462 }
2463
2464 static ssize_t
2465 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2466                      size_t count, loff_t *off)
2467 {
2468         int err;
2469         unsigned long k = ULONG_MAX;
2470
2471         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2472                 return -EACCES;
2473
2474         err = kstrtoul_from_user(buffer, count, 0, &k);
2475         if (err)
2476                 return err;
2477         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2478                 sg_big_buff = k;
2479                 return count;
2480         }
2481         return -ERANGE;
2482 }
2483
2484 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2485 {
2486         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2487                    sg_version_date);
2488         return 0;
2489 }
2490
2491 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2492 {
2493         return single_open(file, sg_proc_seq_show_version, NULL);
2494 }
2495
2496 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2497 {
2498         seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2499         return 0;
2500 }
2501
2502 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2503 {
2504         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2505 }
2506
2507 struct sg_proc_deviter {
2508         loff_t  index;
2509         size_t  max;
2510 };
2511
2512 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2513 {
2514         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2515
2516         s->private = it;
2517         if (! it)
2518                 return NULL;
2519
2520         it->index = *pos;
2521         it->max = sg_last_dev();
2522         if (it->index >= it->max)
2523                 return NULL;
2524         return it;
2525 }
2526
2527 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2528 {
2529         struct sg_proc_deviter * it = s->private;
2530
2531         *pos = ++it->index;
2532         return (it->index < it->max) ? it : NULL;
2533 }
2534
2535 static void dev_seq_stop(struct seq_file *s, void *v)
2536 {
2537         kfree(s->private);
2538 }
2539
2540 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2541 {
2542         return seq_open(file, &dev_seq_ops);
2543 }
2544
2545 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2546 {
2547         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2548         Sg_device *sdp;
2549         struct scsi_device *scsidp;
2550         unsigned long iflags;
2551
2552         read_lock_irqsave(&sg_index_lock, iflags);
2553         sdp = it ? sg_lookup_dev(it->index) : NULL;
2554         if ((NULL == sdp) || (NULL == sdp->device) ||
2555             (atomic_read(&sdp->detaching)))
2556                 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2557         else {
2558                 scsidp = sdp->device;
2559                 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2560                               scsidp->host->host_no, scsidp->channel,
2561                               scsidp->id, scsidp->lun, (int) scsidp->type,
2562                               1,
2563                               (int) scsidp->queue_depth,
2564                               (int) atomic_read(&scsidp->device_busy),
2565                               (int) scsi_device_online(scsidp));
2566         }
2567         read_unlock_irqrestore(&sg_index_lock, iflags);
2568         return 0;
2569 }
2570
2571 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2572 {
2573         return seq_open(file, &devstrs_seq_ops);
2574 }
2575
2576 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2577 {
2578         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2579         Sg_device *sdp;
2580         struct scsi_device *scsidp;
2581         unsigned long iflags;
2582
2583         read_lock_irqsave(&sg_index_lock, iflags);
2584         sdp = it ? sg_lookup_dev(it->index) : NULL;
2585         scsidp = sdp ? sdp->device : NULL;
2586         if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2587                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2588                            scsidp->vendor, scsidp->model, scsidp->rev);
2589         else
2590                 seq_puts(s, "<no active device>\n");
2591         read_unlock_irqrestore(&sg_index_lock, iflags);
2592         return 0;
2593 }
2594
2595 /* must be called while holding sg_index_lock */
2596 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2597 {
2598         int k, m, new_interface, blen, usg;
2599         Sg_request *srp;
2600         Sg_fd *fp;
2601         const sg_io_hdr_t *hp;
2602         const char * cp;
2603         unsigned int ms;
2604
2605         k = 0;
2606         list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2607                 k++;
2608                 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2609                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2610                            "(res)sgat=%d low_dma=%d\n", k,
2611                            jiffies_to_msecs(fp->timeout),
2612                            fp->reserve.bufflen,
2613                            (int) fp->reserve.k_use_sg,
2614                            (int) fp->low_dma);
2615                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2616                            (int) fp->cmd_q, (int) fp->force_packid,
2617                            (int) fp->keep_orphan);
2618                 for (m = 0, srp = fp->headrp;
2619                                 srp != NULL;
2620                                 ++m, srp = srp->nextrp) {
2621                         hp = &srp->header;
2622                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2623                         if (srp->res_used) {
2624                                 if (new_interface &&
2625                                     (SG_FLAG_MMAP_IO & hp->flags))
2626                                         cp = "     mmap>> ";
2627                                 else
2628                                         cp = "     rb>> ";
2629                         } else {
2630                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2631                                         cp = "     dio>> ";
2632                                 else
2633                                         cp = "     ";
2634                         }
2635                         seq_puts(s, cp);
2636                         blen = srp->data.bufflen;
2637                         usg = srp->data.k_use_sg;
2638                         seq_puts(s, srp->done ?
2639                                  ((1 == srp->done) ?  "rcv:" : "fin:")
2640                                   : "act:");
2641                         seq_printf(s, " id=%d blen=%d",
2642                                    srp->header.pack_id, blen);
2643                         if (srp->done)
2644                                 seq_printf(s, " dur=%d", hp->duration);
2645                         else {
2646                                 ms = jiffies_to_msecs(jiffies);
2647                                 seq_printf(s, " t_o/elap=%d/%d",
2648                                         (new_interface ? hp->timeout :
2649                                                   jiffies_to_msecs(fp->timeout)),
2650                                         (ms > hp->duration ? ms - hp->duration : 0));
2651                         }
2652                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2653                                    (int) srp->data.cmd_opcode);
2654                 }
2655                 if (0 == m)
2656                         seq_puts(s, "     No requests active\n");
2657                 read_unlock(&fp->rq_list_lock);
2658         }
2659 }
2660
2661 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2662 {
2663         return seq_open(file, &debug_seq_ops);
2664 }
2665
2666 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2667 {
2668         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2669         Sg_device *sdp;
2670         unsigned long iflags;
2671
2672         if (it && (0 == it->index))
2673                 seq_printf(s, "max_active_device=%d  def_reserved_size=%d\n",
2674                            (int)it->max, sg_big_buff);
2675
2676         read_lock_irqsave(&sg_index_lock, iflags);
2677         sdp = it ? sg_lookup_dev(it->index) : NULL;
2678         if (NULL == sdp)
2679                 goto skip;
2680         read_lock(&sdp->sfd_lock);
2681         if (!list_empty(&sdp->sfds)) {
2682                 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2683                 if (atomic_read(&sdp->detaching))
2684                         seq_puts(s, "detaching pending close ");
2685                 else if (sdp->device) {
2686                         struct scsi_device *scsidp = sdp->device;
2687
2688                         seq_printf(s, "%d:%d:%d:%llu   em=%d",
2689                                    scsidp->host->host_no,
2690                                    scsidp->channel, scsidp->id,
2691                                    scsidp->lun,
2692                                    scsidp->host->hostt->emulated);
2693                 }
2694                 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2695                            sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2696                 sg_proc_debug_helper(s, sdp);
2697         }
2698         read_unlock(&sdp->sfd_lock);
2699 skip:
2700         read_unlock_irqrestore(&sg_index_lock, iflags);
2701         return 0;
2702 }
2703
2704 #endif                          /* CONFIG_SCSI_PROC_FS */
2705
2706 module_init(init_sg);
2707 module_exit(exit_sg);