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 #endif
  70
  71 #define SG_ALLOW_DIO_DEF 0
  72
  73 #define SG_MAX_DEVS 32768
  74
  75 /* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
  76  * of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
  77  * than 16 bytes are "variable length" whose length is a multiple of 4
  78  */
  79 #define SG_MAX_CDB_SIZE 252
  80
  81 #define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  82
  83 int sg_big_buff = SG_DEF_RESERVED_SIZE;
  84 /* N.B. This variable is readable and writeable via
  85    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  86    of this size (or less if there is not enough memory) will be reserved
  87    for use by this file descriptor. [Deprecated usage: this variable is also
  88    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  89    the kernel (i.e. it is not a module).] */
  90 static int def_reserved_size = -1;      /* picks up init parameter */
  91 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
  92
  93 static int scatter_elem_sz = SG_SCATTER_SZ;
  94 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
  95
  96 #define SG_SECTOR_SZ 512
  97
  98 static int sg_add_device(struct device *, struct class_interface *);
  99 static void sg_remove_device(struct device *, struct class_interface *);
 100
 101 static DEFINE_IDR(sg_index_idr);
 102 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
 103                                                            file descriptor list for device */
 104
 105 static struct class_interface sg_interface = {
 106         .add_dev        = sg_add_device,
 107         .remove_dev     = sg_remove_device,
 108 };
 109
 110 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 111         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 112         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 113         unsigned bufflen;       /* Size of (aggregate) data buffer */
 114         struct page **pages;
 115         int page_order;
 116         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 117         unsigned char cmd_opcode; /* first byte of command */
 118 } Sg_scatter_hold;
 119
 120 struct sg_device;               /* forward declarations */
 121 struct sg_fd;
 122
 123 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 124         struct list_head entry; /* list entry */
 125         struct sg_fd *parentfp; /* NULL -> not in use */
 126         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 127         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 128         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 129         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 130         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 131         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 132         /* done protected by rq_list_lock */
 133         char done;              /* 0->before bh, 1->before read, 2->read */
 134         struct request *rq;
 135         struct bio *bio;
 136         struct execute_work ew;
 137 } Sg_request;
 138
 139 typedef struct sg_fd {          /* holds the state of a file descriptor */
 140         struct list_head sfd_siblings;  /* protected by device's sfd_lock */
 141         struct sg_device *parentdp;     /* owning device */
 142         wait_queue_head_t read_wait;    /* queue read until command done */
 143         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 144         struct mutex f_mutex;   /* protect against changes in this fd */
 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         struct list_head rq_list; /* head of request list */
 149         struct fasync_struct *async_qp; /* used by asynchronous notification */
 150         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 151         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 152         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 153         unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */
 154         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 155         char mmap_called;       /* 0 -> mmap() never called on this fd */
 156         char res_in_use;        /* 1 -> 'reserve' array in use */
 157         struct kref f_ref;
 158         struct execute_work ew;
 159 } Sg_fd;
 160
 161 typedef struct sg_device { /* holds the state of each scsi generic device */
 162         struct scsi_device *device;
 163         wait_queue_head_t open_wait;    /* queue open() when O_EXCL present */
 164         struct mutex open_rel_lock;     /* held when in open() or release() */
 165         int sg_tablesize;       /* adapter's max scatter-gather table size */
 166         u32 index;              /* device index number */
 167         struct list_head sfds;
 168         rwlock_t sfd_lock;      /* protect access to sfd list */
 169         atomic_t detaching;     /* 0->device usable, 1->device detaching */
 170         bool exclude;           /* 1->open(O_EXCL) succeeded and is active */
 171         int open_cnt;           /* count of opens (perhaps < num(sfds) ) */
 172         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 173         struct gendisk *disk;
 174         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 175         struct kref d_ref;
 176 } Sg_device;
 177
 178 /* tasklet or soft irq callback */
 179 static void sg_rq_end_io(struct request *rq, blk_status_t status);
 180 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 181 static int sg_finish_rem_req(Sg_request * srp);
 182 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 183 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 184                            Sg_request * srp);
 185 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 186                         const char __user *buf, size_t count, int blocking,
 187                         int read_only, int sg_io_owned, Sg_request **o_srp);
 188 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 189                            unsigned char *cmnd, int timeout, int blocking);
 190 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 191 static void sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp);
 192 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 193 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 194 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 195 static Sg_fd *sg_add_sfp(Sg_device * sdp);
 196 static void sg_remove_sfp(struct kref *);
 197 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 198 static Sg_request *sg_add_request(Sg_fd * sfp);
 199 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 200 static Sg_device *sg_get_dev(int dev);
 201 static void sg_device_destroy(struct kref *kref);
 202
 203 #define SZ_SG_HEADER sizeof(struct sg_header)
 204 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 205 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
 206 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 207
 208 #define sg_printk(prefix, sdp, fmt, a...) \
 209         sdev_prefix_printk(prefix, (sdp)->device,               \
 210                            (sdp)->disk->disk_name, fmt, ##a)
 211
 212 static int sg_allow_access(struct file *filp, unsigned char *cmd)
 213 {
 214         struct sg_fd *sfp = filp->private_data;
 215
 216         if (sfp->parentdp->device->type == TYPE_SCANNER)
 217                 return 0;
 218
 219         return blk_verify_command(cmd, filp->f_mode);
 220 }
 221
 222 static int
 223 open_wait(Sg_device *sdp, int flags)
 224 {
 225         int retval = 0;
 226
 227         if (flags & O_EXCL) {
 228                 while (sdp->open_cnt > 0) {
 229                         mutex_unlock(&sdp->open_rel_lock);
 230                         retval = wait_event_interruptible(sdp->open_wait,
 231                                         (atomic_read(&sdp->detaching) ||
 232                                          !sdp->open_cnt));
 233                         mutex_lock(&sdp->open_rel_lock);
 234
 235                         if (retval) /* -ERESTARTSYS */
 236                                 return retval;
 237                         if (atomic_read(&sdp->detaching))
 238                                 return -ENODEV;
 239                 }
 240         } else {
 241                 while (sdp->exclude) {
 242                         mutex_unlock(&sdp->open_rel_lock);
 243                         retval = wait_event_interruptible(sdp->open_wait,
 244                                         (atomic_read(&sdp->detaching) ||
 245                                          !sdp->exclude));
 246                         mutex_lock(&sdp->open_rel_lock);
 247
 248                         if (retval) /* -ERESTARTSYS */
 249                                 return retval;
 250                         if (atomic_read(&sdp->detaching))
 251                                 return -ENODEV;
 252                 }
 253         }
 254
 255         return retval;
 256 }
 257
 258 /* Returns 0 on success, else a negated errno value */
 259 static int
 260 sg_open(struct inode *inode, struct file *filp)
 261 {
 262         int dev = iminor(inode);
 263         int flags = filp->f_flags;
 264         struct request_queue *q;
 265         Sg_device *sdp;
 266         Sg_fd *sfp;
 267         int retval;
 268
 269         nonseekable_open(inode, filp);
 270         if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
 271                 return -EPERM; /* Can't lock it with read only access */
 272         sdp = sg_get_dev(dev);
 273         if (IS_ERR(sdp))
 274                 return PTR_ERR(sdp);
 275
 276         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 277                                       "sg_open: flags=0x%x\n", flags));
 278
 279         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 280         /* Prevent the device driver from vanishing while we sleep */
 281         retval = scsi_device_get(sdp->device);
 282         if (retval)
 283                 goto sg_put;
 284
 285         retval = scsi_autopm_get_device(sdp->device);
 286         if (retval)
 287                 goto sdp_put;
 288
 289         /* scsi_block_when_processing_errors() may block so bypass
 290          * check if O_NONBLOCK. Permits SCSI commands to be issued
 291          * during error recovery. Tread carefully. */
 292         if (!((flags & O_NONBLOCK) ||
 293               scsi_block_when_processing_errors(sdp->device))) {
 294                 retval = -ENXIO;
 295                 /* we are in error recovery for this device */
 296                 goto error_out;
 297         }
 298
 299         mutex_lock(&sdp->open_rel_lock);
 300         if (flags & O_NONBLOCK) {
 301                 if (flags & O_EXCL) {
 302                         if (sdp->open_cnt > 0) {
 303                                 retval = -EBUSY;
 304                                 goto error_mutex_locked;
 305                         }
 306                 } else {
 307                         if (sdp->exclude) {
 308                                 retval = -EBUSY;
 309                                 goto error_mutex_locked;
 310                         }
 311                 }
 312         } else {
 313                 retval = open_wait(sdp, flags);
 314                 if (retval) /* -ERESTARTSYS or -ENODEV */
 315                         goto error_mutex_locked;
 316         }
 317
 318         /* N.B. at this point we are holding the open_rel_lock */
 319         if (flags & O_EXCL)
 320                 sdp->exclude = true;
 321
 322         if (sdp->open_cnt < 1) {  /* no existing opens */
 323                 sdp->sgdebug = 0;
 324                 q = sdp->device->request_queue;
 325                 sdp->sg_tablesize = queue_max_segments(q);
 326         }
 327         sfp = sg_add_sfp(sdp);
 328         if (IS_ERR(sfp)) {
 329                 retval = PTR_ERR(sfp);
 330                 goto out_undo;
 331         }
 332
 333         filp->private_data = sfp;
 334         sdp->open_cnt++;
 335         mutex_unlock(&sdp->open_rel_lock);
 336
 337         retval = 0;
 338 sg_put:
 339         kref_put(&sdp->d_ref, sg_device_destroy);
 340         return retval;
 341
 342 out_undo:
 343         if (flags & O_EXCL) {
 344                 sdp->exclude = false;   /* undo if error */
 345                 wake_up_interruptible(&sdp->open_wait);
 346         }
 347 error_mutex_locked:
 348         mutex_unlock(&sdp->open_rel_lock);
 349 error_out:
 350         scsi_autopm_put_device(sdp->device);
 351 sdp_put:
 352         scsi_device_put(sdp->device);
 353         goto sg_put;
 354 }
 355
 356 /* Release resources associated with a successful sg_open()
 357  * Returns 0 on success, else a negated errno value */
 358 static int
 359 sg_release(struct inode *inode, struct file *filp)
 360 {
 361         Sg_device *sdp;
 362         Sg_fd *sfp;
 363
 364         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 365                 return -ENXIO;
 366         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
 367
 368         mutex_lock(&sdp->open_rel_lock);
 369         scsi_autopm_put_device(sdp->device);
 370         kref_put(&sfp->f_ref, sg_remove_sfp);
 371         sdp->open_cnt--;
 372
 373         /* possibly many open()s waiting on exlude clearing, start many;
 374          * only open(O_EXCL)s wait on 0==open_cnt so only start one */
 375         if (sdp->exclude) {
 376                 sdp->exclude = false;
 377                 wake_up_interruptible_all(&sdp->open_wait);
 378         } else if (0 == sdp->open_cnt) {
 379                 wake_up_interruptible(&sdp->open_wait);
 380         }
 381         mutex_unlock(&sdp->open_rel_lock);
 382         return 0;
 383 }
 384
 385 static ssize_t
 386 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 387 {
 388         Sg_device *sdp;
 389         Sg_fd *sfp;
 390         Sg_request *srp;
 391         int req_pack_id = -1;
 392         sg_io_hdr_t *hp;
 393         struct sg_header *old_hdr = NULL;
 394         int retval = 0;
 395
 396         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 397                 return -ENXIO;
 398         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 399                                       "sg_read: count=%d\n", (int) count));
 400
 401         if (!access_ok(VERIFY_WRITE, buf, count))
 402                 return -EFAULT;
 403         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 404                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 405                 if (!old_hdr)
 406                         return -ENOMEM;
 407                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
 408                         retval = -EFAULT;
 409                         goto free_old_hdr;
 410                 }
 411                 if (old_hdr->reply_len < 0) {
 412                         if (count >= SZ_SG_IO_HDR) {
 413                                 sg_io_hdr_t *new_hdr;
 414                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
 415                                 if (!new_hdr) {
 416                                         retval = -ENOMEM;
 417                                         goto free_old_hdr;
 418                                 }
 419                                 retval =__copy_from_user
 420                                     (new_hdr, buf, SZ_SG_IO_HDR);
 421                                 req_pack_id = new_hdr->pack_id;
 422                                 kfree(new_hdr);
 423                                 if (retval) {
 424                                         retval = -EFAULT;
 425                                         goto free_old_hdr;
 426                                 }
 427                         }
 428                 } else
 429                         req_pack_id = old_hdr->pack_id;
 430         }
 431         srp = sg_get_rq_mark(sfp, req_pack_id);
 432         if (!srp) {             /* now wait on packet to arrive */
 433                 if (atomic_read(&sdp->detaching)) {
 434                         retval = -ENODEV;
 435                         goto free_old_hdr;
 436                 }
 437                 if (filp->f_flags & O_NONBLOCK) {
 438                         retval = -EAGAIN;
 439                         goto free_old_hdr;
 440                 }
 441                 retval = wait_event_interruptible(sfp->read_wait,
 442                         (atomic_read(&sdp->detaching) ||
 443                         (srp = sg_get_rq_mark(sfp, req_pack_id))));
 444                 if (atomic_read(&sdp->detaching)) {
 445                         retval = -ENODEV;
 446                         goto free_old_hdr;
 447                 }
 448                 if (retval) {
 449                         /* -ERESTARTSYS as signal hit process */
 450                         goto free_old_hdr;
 451                 }
 452         }
 453         if (srp->header.interface_id != '\0') {
 454                 retval = sg_new_read(sfp, buf, count, srp);
 455                 goto free_old_hdr;
 456         }
 457
 458         hp = &srp->header;
 459         if (old_hdr == NULL) {
 460                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 461                 if (! old_hdr) {
 462                         retval = -ENOMEM;
 463                         goto free_old_hdr;
 464                 }
 465         }
 466         memset(old_hdr, 0, SZ_SG_HEADER);
 467         old_hdr->reply_len = (int) hp->timeout;
 468         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 469         old_hdr->pack_id = hp->pack_id;
 470         old_hdr->twelve_byte =
 471             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 472         old_hdr->target_status = hp->masked_status;
 473         old_hdr->host_status = hp->host_status;
 474         old_hdr->driver_status = hp->driver_status;
 475         if ((CHECK_CONDITION & hp->masked_status) ||
 476             (DRIVER_SENSE & hp->driver_status))
 477                 memcpy(old_hdr->sense_buffer, srp->sense_b,
 478                        sizeof (old_hdr->sense_buffer));
 479         switch (hp->host_status) {
 480         /* This setup of 'result' is for backward compatibility and is best
 481            ignored by the user who should use target, host + driver status */
 482         case DID_OK:
 483         case DID_PASSTHROUGH:
 484         case DID_SOFT_ERROR:
 485                 old_hdr->result = 0;
 486                 break;
 487         case DID_NO_CONNECT:
 488         case DID_BUS_BUSY:
 489         case DID_TIME_OUT:
 490                 old_hdr->result = EBUSY;
 491                 break;
 492         case DID_BAD_TARGET:
 493         case DID_ABORT:
 494         case DID_PARITY:
 495         case DID_RESET:
 496         case DID_BAD_INTR:
 497                 old_hdr->result = EIO;
 498                 break;
 499         case DID_ERROR:
 500                 old_hdr->result = (srp->sense_b[0] == 0 &&
 501                                   hp->masked_status == GOOD) ? 0 : EIO;
 502                 break;
 503         default:
 504                 old_hdr->result = EIO;
 505                 break;
 506         }
 507
 508         /* Now copy the result back to the user buffer.  */
 509         if (count >= SZ_SG_HEADER) {
 510                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 511                         retval = -EFAULT;
 512                         goto free_old_hdr;
 513                 }
 514                 buf += SZ_SG_HEADER;
 515                 if (count > old_hdr->reply_len)
 516                         count = old_hdr->reply_len;
 517                 if (count > SZ_SG_HEADER) {
 518                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 519                                 retval = -EFAULT;
 520                                 goto free_old_hdr;
 521                         }
 522                 }
 523         } else
 524                 count = (old_hdr->result == 0) ? 0 : -EIO;
 525         sg_finish_rem_req(srp);
 526         sg_remove_request(sfp, srp);
 527         retval = count;
 528 free_old_hdr:
 529         kfree(old_hdr);
 530         return retval;
 531 }
 532
 533 static ssize_t
 534 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 535 {
 536         sg_io_hdr_t *hp = &srp->header;
 537         int err = 0, err2;
 538         int len;
 539
 540         if (count < SZ_SG_IO_HDR) {
 541                 err = -EINVAL;
 542                 goto err_out;
 543         }
 544         hp->sb_len_wr = 0;
 545         if ((hp->mx_sb_len > 0) && hp->sbp) {
 546                 if ((CHECK_CONDITION & hp->masked_status) ||
 547                     (DRIVER_SENSE & hp->driver_status)) {
 548                         int sb_len = SCSI_SENSE_BUFFERSIZE;
 549                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 550                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 551                         len = (len > sb_len) ? sb_len : len;
 552                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 553                                 err = -EFAULT;
 554                                 goto err_out;
 555                         }
 556                         hp->sb_len_wr = len;
 557                 }
 558         }
 559         if (hp->masked_status || hp->host_status || hp->driver_status)
 560                 hp->info |= SG_INFO_CHECK;
 561         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 562                 err = -EFAULT;
 563                 goto err_out;
 564         }
 565 err_out:
 566         err2 = sg_finish_rem_req(srp);
 567         sg_remove_request(sfp, 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(uaccess_kernel()))
 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         mutex_lock(&sfp->f_mutex);
 618         if (sfp->next_cmd_len > 0) {
 619                 cmd_size = sfp->next_cmd_len;
 620                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 621         } else {
 622                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 623                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 624                         cmd_size = 12;
 625         }
 626         mutex_unlock(&sfp->f_mutex);
 627         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
 628                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 629 /* Determine buffer size.  */
 630         input_size = count - cmd_size;
 631         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 632         mxsize -= SZ_SG_HEADER;
 633         input_size -= SZ_SG_HEADER;
 634         if (input_size < 0) {
 635                 sg_remove_request(sfp, srp);
 636                 return -EIO;    /* User did not pass enough bytes for this command. */
 637         }
 638         hp = &srp->header;
 639         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 640         hp->cmd_len = (unsigned char) cmd_size;
 641         hp->iovec_count = 0;
 642         hp->mx_sb_len = 0;
 643         if (input_size > 0)
 644                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 645                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 646         else
 647                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 648         hp->dxfer_len = mxsize;
 649         if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
 650             (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
 651                 hp->dxferp = (char __user *)buf + cmd_size;
 652         else
 653                 hp->dxferp = NULL;
 654         hp->sbp = NULL;
 655         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 656         hp->flags = input_size; /* structure abuse ... */
 657         hp->pack_id = old_hdr.pack_id;
 658         hp->usr_ptr = NULL;
 659         if (__copy_from_user(cmnd, buf, cmd_size))
 660                 return -EFAULT;
 661         /*
 662          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 663          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 664          * is a non-zero input_size, so emit a warning.
 665          */
 666         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 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         }
 676         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 677         return (k < 0) ? k : count;
 678 }
 679
 680 static ssize_t
 681 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 682                  size_t count, int blocking, int read_only, int sg_io_owned,
 683                  Sg_request **o_srp)
 684 {
 685         int k;
 686         Sg_request *srp;
 687         sg_io_hdr_t *hp;
 688         unsigned char cmnd[SG_MAX_CDB_SIZE];
 689         int timeout;
 690         unsigned long ul_timeout;
 691
 692         if (count < SZ_SG_IO_HDR)
 693                 return -EINVAL;
 694         if (!access_ok(VERIFY_READ, buf, count))
 695                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 696
 697         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 698         if (!(srp = sg_add_request(sfp))) {
 699                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 700                                               "sg_new_write: queue full\n"));
 701                 return -EDOM;
 702         }
 703         srp->sg_io_owned = sg_io_owned;
 704         hp = &srp->header;
 705         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 706                 sg_remove_request(sfp, srp);
 707                 return -EFAULT;
 708         }
 709         if (hp->interface_id != 'S') {
 710                 sg_remove_request(sfp, srp);
 711                 return -ENOSYS;
 712         }
 713         if (hp->flags & SG_FLAG_MMAP_IO) {
 714                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 715                         sg_remove_request(sfp, srp);
 716                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 717                 }
 718                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 719                         sg_remove_request(sfp, srp);
 720                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 721                 }
 722                 if (sfp->res_in_use) {
 723                         sg_remove_request(sfp, srp);
 724                         return -EBUSY;  /* reserve buffer already being used */
 725                 }
 726         }
 727         ul_timeout = msecs_to_jiffies(srp->header.timeout);
 728         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 729         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 730                 sg_remove_request(sfp, srp);
 731                 return -EMSGSIZE;
 732         }
 733         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
 734                 sg_remove_request(sfp, srp);
 735                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 736         }
 737         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 738                 sg_remove_request(sfp, srp);
 739                 return -EFAULT;
 740         }
 741         if (read_only && sg_allow_access(file, cmnd)) {
 742                 sg_remove_request(sfp, srp);
 743                 return -EPERM;
 744         }
 745         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 746         if (k < 0)
 747                 return k;
 748         if (o_srp)
 749                 *o_srp = srp;
 750         return count;
 751 }
 752
 753 static int
 754 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 755                 unsigned char *cmnd, int timeout, int blocking)
 756 {
 757         int k, at_head;
 758         Sg_device *sdp = sfp->parentdp;
 759         sg_io_hdr_t *hp = &srp->header;
 760
 761         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 762         hp->status = 0;
 763         hp->masked_status = 0;
 764         hp->msg_status = 0;
 765         hp->info = 0;
 766         hp->host_status = 0;
 767         hp->driver_status = 0;
 768         hp->resid = 0;
 769         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
 770                         "sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 771                         (int) cmnd[0], (int) hp->cmd_len));
 772
 773         if (hp->dxfer_len >= SZ_256M)
 774                 return -EINVAL;
 775
 776         k = sg_start_req(srp, cmnd);
 777         if (k) {
 778                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 779                         "sg_common_write: start_req err=%d\n", k));
 780                 sg_finish_rem_req(srp);
 781                 sg_remove_request(sfp, srp);
 782                 return k;       /* probably out of space --> ENOMEM */
 783         }
 784         if (atomic_read(&sdp->detaching)) {
 785                 if (srp->bio) {
 786                         scsi_req_free_cmd(scsi_req(srp->rq));
 787                         blk_end_request_all(srp->rq, BLK_STS_IOERR);
 788                         srp->rq = NULL;
 789                 }
 790
 791                 sg_finish_rem_req(srp);
 792                 sg_remove_request(sfp, srp);
 793                 return -ENODEV;
 794         }
 795
 796         hp->duration = jiffies_to_msecs(jiffies);
 797         if (hp->interface_id != '\0' && /* v3 (or later) interface */
 798             (SG_FLAG_Q_AT_TAIL & hp->flags))
 799                 at_head = 0;
 800         else
 801                 at_head = 1;
 802
 803         srp->rq->timeout = timeout;
 804         kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
 805         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 806                               srp->rq, at_head, sg_rq_end_io);
 807         return 0;
 808 }
 809
 810 static int srp_done(Sg_fd *sfp, Sg_request *srp)
 811 {
 812         unsigned long flags;
 813         int ret;
 814
 815         read_lock_irqsave(&sfp->rq_list_lock, flags);
 816         ret = srp->done;
 817         read_unlock_irqrestore(&sfp->rq_list_lock, flags);
 818         return ret;
 819 }
 820
 821 static int max_sectors_bytes(struct request_queue *q)
 822 {
 823         unsigned int max_sectors = queue_max_sectors(q);
 824
 825         max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
 826
 827         return max_sectors << 9;
 828 }
 829
 830 static void
 831 sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
 832 {
 833         Sg_request *srp;
 834         int val;
 835         unsigned int ms;
 836
 837         val = 0;
 838         list_for_each_entry(srp, &sfp->rq_list, entry) {
 839                 if (val >= SG_MAX_QUEUE)
 840                         break;
 841                 rinfo[val].req_state = srp->done + 1;
 842                 rinfo[val].problem =
 843                         srp->header.masked_status &
 844                         srp->header.host_status &
 845                         srp->header.driver_status;
 846                 if (srp->done)
 847                         rinfo[val].duration =
 848                                 srp->header.duration;
 849                 else {
 850                         ms = jiffies_to_msecs(jiffies);
 851                         rinfo[val].duration =
 852                                 (ms > srp->header.duration) ?
 853                                 (ms - srp->header.duration) : 0;
 854                 }
 855                 rinfo[val].orphan = srp->orphan;
 856                 rinfo[val].sg_io_owned = srp->sg_io_owned;
 857                 rinfo[val].pack_id = srp->header.pack_id;
 858                 rinfo[val].usr_ptr = srp->header.usr_ptr;
 859                 val++;
 860         }
 861 }
 862
 863 static long
 864 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 865 {
 866         void __user *p = (void __user *)arg;
 867         int __user *ip = p;
 868         int result, val, read_only;
 869         Sg_device *sdp;
 870         Sg_fd *sfp;
 871         Sg_request *srp;
 872         unsigned long iflags;
 873
 874         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 875                 return -ENXIO;
 876
 877         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 878                                    "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
 879         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 880
 881         switch (cmd_in) {
 882         case SG_IO:
 883                 if (atomic_read(&sdp->detaching))
 884                         return -ENODEV;
 885                 if (!scsi_block_when_processing_errors(sdp->device))
 886                         return -ENXIO;
 887                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 888                         return -EFAULT;
 889                 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 890                                  1, read_only, 1, &srp);
 891                 if (result < 0)
 892                         return result;
 893                 result = wait_event_interruptible(sfp->read_wait,
 894                         (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
 895                 if (atomic_read(&sdp->detaching))
 896                         return -ENODEV;
 897                 write_lock_irq(&sfp->rq_list_lock);
 898                 if (srp->done) {
 899                         srp->done = 2;
 900                         write_unlock_irq(&sfp->rq_list_lock);
 901                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 902                         return (result < 0) ? result : 0;
 903                 }
 904                 srp->orphan = 1;
 905                 write_unlock_irq(&sfp->rq_list_lock);
 906                 return result;  /* -ERESTARTSYS because signal hit process */
 907         case SG_SET_TIMEOUT:
 908                 result = get_user(val, ip);
 909                 if (result)
 910                         return result;
 911                 if (val < 0)
 912                         return -EIO;
 913                 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
 914                         val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
 915                                     INT_MAX);
 916                 sfp->timeout_user = val;
 917                 sfp->timeout = mult_frac(val, HZ, USER_HZ);
 918
 919                 return 0;
 920         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 921                                 /* strange ..., for backward compatibility */
 922                 return sfp->timeout_user;
 923         case SG_SET_FORCE_LOW_DMA:
 924                 /*
 925                  * N.B. This ioctl never worked properly, but failed to
 926                  * return an error value. So returning '0' to keep compability
 927                  * with legacy applications.
 928                  */
 929                 return 0;
 930         case SG_GET_LOW_DMA:
 931                 return put_user((int) sdp->device->host->unchecked_isa_dma, ip);
 932         case SG_GET_SCSI_ID:
 933                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 934                         return -EFAULT;
 935                 else {
 936                         sg_scsi_id_t __user *sg_idp = p;
 937
 938                         if (atomic_read(&sdp->detaching))
 939                                 return -ENODEV;
 940                         __put_user((int) sdp->device->host->host_no,
 941                                    &sg_idp->host_no);
 942                         __put_user((int) sdp->device->channel,
 943                                    &sg_idp->channel);
 944                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 945                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 946                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 947                         __put_user((short) sdp->device->host->cmd_per_lun,
 948                                    &sg_idp->h_cmd_per_lun);
 949                         __put_user((short) sdp->device->queue_depth,
 950                                    &sg_idp->d_queue_depth);
 951                         __put_user(0, &sg_idp->unused[0]);
 952                         __put_user(0, &sg_idp->unused[1]);
 953                         return 0;
 954                 }
 955         case SG_SET_FORCE_PACK_ID:
 956                 result = get_user(val, ip);
 957                 if (result)
 958                         return result;
 959                 sfp->force_packid = val ? 1 : 0;
 960                 return 0;
 961         case SG_GET_PACK_ID:
 962                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 963                         return -EFAULT;
 964                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 965                 list_for_each_entry(srp, &sfp->rq_list, entry) {
 966                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 967                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 968                                                        iflags);
 969                                 __put_user(srp->header.pack_id, ip);
 970                                 return 0;
 971                         }
 972                 }
 973                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 974                 __put_user(-1, ip);
 975                 return 0;
 976         case SG_GET_NUM_WAITING:
 977                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 978                 val = 0;
 979                 list_for_each_entry(srp, &sfp->rq_list, entry) {
 980                         if ((1 == srp->done) && (!srp->sg_io_owned))
 981                                 ++val;
 982                 }
 983                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 984                 return put_user(val, ip);
 985         case SG_GET_SG_TABLESIZE:
 986                 return put_user(sdp->sg_tablesize, ip);
 987         case SG_SET_RESERVED_SIZE:
 988                 result = get_user(val, ip);
 989                 if (result)
 990                         return result;
 991                 if (val < 0)
 992                         return -EINVAL;
 993                 val = min_t(int, val,
 994                             max_sectors_bytes(sdp->device->request_queue));
 995                 mutex_lock(&sfp->f_mutex);
 996                 if (val != sfp->reserve.bufflen) {
 997                         if (sfp->mmap_called ||
 998                             sfp->res_in_use) {
 999                                 mutex_unlock(&sfp->f_mutex);
1000                                 return -EBUSY;
1001                         }
1002
1003                         sg_remove_scat(sfp, &sfp->reserve);
1004                         sg_build_reserve(sfp, val);
1005                 }
1006                 mutex_unlock(&sfp->f_mutex);
1007                 return 0;
1008         case SG_GET_RESERVED_SIZE:
1009                 val = min_t(int, sfp->reserve.bufflen,
1010                             max_sectors_bytes(sdp->device->request_queue));
1011                 return put_user(val, ip);
1012         case SG_SET_COMMAND_Q:
1013                 result = get_user(val, ip);
1014                 if (result)
1015                         return result;
1016                 sfp->cmd_q = val ? 1 : 0;
1017                 return 0;
1018         case SG_GET_COMMAND_Q:
1019                 return put_user((int) sfp->cmd_q, ip);
1020         case SG_SET_KEEP_ORPHAN:
1021                 result = get_user(val, ip);
1022                 if (result)
1023                         return result;
1024                 sfp->keep_orphan = val;
1025                 return 0;
1026         case SG_GET_KEEP_ORPHAN:
1027                 return put_user((int) sfp->keep_orphan, ip);
1028         case SG_NEXT_CMD_LEN:
1029                 result = get_user(val, ip);
1030                 if (result)
1031                         return result;
1032                 if (val > SG_MAX_CDB_SIZE)
1033                         return -ENOMEM;
1034                 sfp->next_cmd_len = (val > 0) ? val : 0;
1035                 return 0;
1036         case SG_GET_VERSION_NUM:
1037                 return put_user(sg_version_num, ip);
1038         case SG_GET_ACCESS_COUNT:
1039                 /* faked - we don't have a real access count anymore */
1040                 val = (sdp->device ? 1 : 0);
1041                 return put_user(val, ip);
1042         case SG_GET_REQUEST_TABLE:
1043                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
1044                         return -EFAULT;
1045                 else {
1046                         sg_req_info_t *rinfo;
1047
1048                         rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
1049                                         GFP_KERNEL);
1050                         if (!rinfo)
1051                                 return -ENOMEM;
1052                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1053                         sg_fill_request_table(sfp, rinfo);
1054                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1055                         result = __copy_to_user(p, rinfo,
1056                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1057                         result = result ? -EFAULT : 0;
1058                         kfree(rinfo);
1059                         return result;
1060                 }
1061         case SG_EMULATED_HOST:
1062                 if (atomic_read(&sdp->detaching))
1063                         return -ENODEV;
1064                 return put_user(sdp->device->host->hostt->emulated, ip);
1065         case SCSI_IOCTL_SEND_COMMAND:
1066                 if (atomic_read(&sdp->detaching))
1067                         return -ENODEV;
1068                 if (read_only) {
1069                         unsigned char opcode = WRITE_6;
1070                         Scsi_Ioctl_Command __user *siocp = p;
1071
1072                         if (copy_from_user(&opcode, siocp->data, 1))
1073                                 return -EFAULT;
1074                         if (sg_allow_access(filp, &opcode))
1075                                 return -EPERM;
1076                 }
1077                 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1078         case SG_SET_DEBUG:
1079                 result = get_user(val, ip);
1080                 if (result)
1081                         return result;
1082                 sdp->sgdebug = (char) val;
1083                 return 0;
1084         case BLKSECTGET:
1085                 return put_user(max_sectors_bytes(sdp->device->request_queue),
1086                                 ip);
1087         case BLKTRACESETUP:
1088                 return blk_trace_setup(sdp->device->request_queue,
1089                                        sdp->disk->disk_name,
1090                                        MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1091                                        NULL, p);
1092         case BLKTRACESTART:
1093                 return blk_trace_startstop(sdp->device->request_queue, 1);
1094         case BLKTRACESTOP:
1095                 return blk_trace_startstop(sdp->device->request_queue, 0);
1096         case BLKTRACETEARDOWN:
1097                 return blk_trace_remove(sdp->device->request_queue);
1098         case SCSI_IOCTL_GET_IDLUN:
1099         case SCSI_IOCTL_GET_BUS_NUMBER:
1100         case SCSI_IOCTL_PROBE_HOST:
1101         case SG_GET_TRANSFORM:
1102         case SG_SCSI_RESET:
1103                 if (atomic_read(&sdp->detaching))
1104                         return -ENODEV;
1105                 break;
1106         default:
1107                 if (read_only)
1108                         return -EPERM;  /* don't know so take safe approach */
1109                 break;
1110         }
1111
1112         result = scsi_ioctl_block_when_processing_errors(sdp->device,
1113                         cmd_in, filp->f_flags & O_NDELAY);
1114         if (result)
1115                 return result;
1116         return scsi_ioctl(sdp->device, cmd_in, p);
1117 }
1118
1119 #ifdef CONFIG_COMPAT
1120 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1121 {
1122         Sg_device *sdp;
1123         Sg_fd *sfp;
1124         struct scsi_device *sdev;
1125
1126         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1127                 return -ENXIO;
1128
1129         sdev = sdp->device;
1130         if (sdev->host->hostt->compat_ioctl) {
1131                 int ret;
1132
1133                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1134
1135                 return ret;
1136         }
1137
1138         return -ENOIOCTLCMD;
1139 }
1140 #endif
1141
1142 static __poll_t
1143 sg_poll(struct file *filp, poll_table * wait)
1144 {
1145         __poll_t res = 0;
1146         Sg_device *sdp;
1147         Sg_fd *sfp;
1148         Sg_request *srp;
1149         int count = 0;
1150         unsigned long iflags;
1151
1152         sfp = filp->private_data;
1153         if (!sfp)
1154                 return EPOLLERR;
1155         sdp = sfp->parentdp;
1156         if (!sdp)
1157                 return EPOLLERR;
1158         poll_wait(filp, &sfp->read_wait, wait);
1159         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1160         list_for_each_entry(srp, &sfp->rq_list, entry) {
1161                 /* if any read waiting, flag it */
1162                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1163                         res = EPOLLIN | EPOLLRDNORM;
1164                 ++count;
1165         }
1166         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1167
1168         if (atomic_read(&sdp->detaching))
1169                 res |= EPOLLHUP;
1170         else if (!sfp->cmd_q) {
1171                 if (0 == count)
1172                         res |= EPOLLOUT | EPOLLWRNORM;
1173         } else if (count < SG_MAX_QUEUE)
1174                 res |= EPOLLOUT | EPOLLWRNORM;
1175         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1176                                       "sg_poll: res=0x%x\n", (__force u32) res));
1177         return res;
1178 }
1179
1180 static int
1181 sg_fasync(int fd, struct file *filp, int mode)
1182 {
1183         Sg_device *sdp;
1184         Sg_fd *sfp;
1185
1186         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1187                 return -ENXIO;
1188         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1189                                       "sg_fasync: mode=%d\n", mode));
1190
1191         return fasync_helper(fd, filp, mode, &sfp->async_qp);
1192 }
1193
1194 static vm_fault_t
1195 sg_vma_fault(struct vm_fault *vmf)
1196 {
1197         struct vm_area_struct *vma = vmf->vma;
1198         Sg_fd *sfp;
1199         unsigned long offset, len, sa;
1200         Sg_scatter_hold *rsv_schp;
1201         int k, length;
1202
1203         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1204                 return VM_FAULT_SIGBUS;
1205         rsv_schp = &sfp->reserve;
1206         offset = vmf->pgoff << PAGE_SHIFT;
1207         if (offset >= rsv_schp->bufflen)
1208                 return VM_FAULT_SIGBUS;
1209         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1210                                       "sg_vma_fault: offset=%lu, scatg=%d\n",
1211                                       offset, rsv_schp->k_use_sg));
1212         sa = vma->vm_start;
1213         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1214         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1215                 len = vma->vm_end - sa;
1216                 len = (len < length) ? len : length;
1217                 if (offset < len) {
1218                         struct page *page = nth_page(rsv_schp->pages[k],
1219                                                      offset >> PAGE_SHIFT);
1220                         get_page(page); /* increment page count */
1221                         vmf->page = page;
1222                         return 0; /* success */
1223                 }
1224                 sa += len;
1225                 offset -= len;
1226         }
1227
1228         return VM_FAULT_SIGBUS;
1229 }
1230
1231 static const struct vm_operations_struct sg_mmap_vm_ops = {
1232         .fault = sg_vma_fault,
1233 };
1234
1235 static int
1236 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1237 {
1238         Sg_fd *sfp;
1239         unsigned long req_sz, len, sa;
1240         Sg_scatter_hold *rsv_schp;
1241         int k, length;
1242         int ret = 0;
1243
1244         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1245                 return -ENXIO;
1246         req_sz = vma->vm_end - vma->vm_start;
1247         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1248                                       "sg_mmap starting, vm_start=%p, len=%d\n",
1249                                       (void *) vma->vm_start, (int) req_sz));
1250         if (vma->vm_pgoff)
1251                 return -EINVAL; /* want no offset */
1252         rsv_schp = &sfp->reserve;
1253         mutex_lock(&sfp->f_mutex);
1254         if (req_sz > rsv_schp->bufflen) {
1255                 ret = -ENOMEM;  /* cannot map more than reserved buffer */
1256                 goto out;
1257         }
1258
1259         sa = vma->vm_start;
1260         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1261         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1262                 len = vma->vm_end - sa;
1263                 len = (len < length) ? len : length;
1264                 sa += len;
1265         }
1266
1267         sfp->mmap_called = 1;
1268         vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
1269         vma->vm_private_data = sfp;
1270         vma->vm_ops = &sg_mmap_vm_ops;
1271 out:
1272         mutex_unlock(&sfp->f_mutex);
1273         return ret;
1274 }
1275
1276 static void
1277 sg_rq_end_io_usercontext(struct work_struct *work)
1278 {
1279         struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1280         struct sg_fd *sfp = srp->parentfp;
1281
1282         sg_finish_rem_req(srp);
1283         sg_remove_request(sfp, srp);
1284         kref_put(&sfp->f_ref, sg_remove_sfp);
1285 }
1286
1287 /*
1288  * This function is a "bottom half" handler that is called by the mid
1289  * level when a command is completed (or has failed).
1290  */
1291 static void
1292 sg_rq_end_io(struct request *rq, blk_status_t status)
1293 {
1294         struct sg_request *srp = rq->end_io_data;
1295         struct scsi_request *req = scsi_req(rq);
1296         Sg_device *sdp;
1297         Sg_fd *sfp;
1298         unsigned long iflags;
1299         unsigned int ms;
1300         char *sense;
1301         int result, resid, done = 1;
1302
1303         if (WARN_ON(srp->done != 0))
1304                 return;
1305
1306         sfp = srp->parentfp;
1307         if (WARN_ON(sfp == NULL))
1308                 return;
1309
1310         sdp = sfp->parentdp;
1311         if (unlikely(atomic_read(&sdp->detaching)))
1312                 pr_info("%s: device detaching\n", __func__);
1313
1314         sense = req->sense;
1315         result = req->result;
1316         resid = req->resid_len;
1317
1318         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1319                                       "sg_cmd_done: pack_id=%d, res=0x%x\n",
1320                                       srp->header.pack_id, result));
1321         srp->header.resid = resid;
1322         ms = jiffies_to_msecs(jiffies);
1323         srp->header.duration = (ms > srp->header.duration) ?
1324                                 (ms - srp->header.duration) : 0;
1325         if (0 != result) {
1326                 struct scsi_sense_hdr sshdr;
1327
1328                 srp->header.status = 0xff & result;
1329                 srp->header.masked_status = status_byte(result);
1330                 srp->header.msg_status = msg_byte(result);
1331                 srp->header.host_status = host_byte(result);
1332                 srp->header.driver_status = driver_byte(result);
1333                 if ((sdp->sgdebug > 0) &&
1334                     ((CHECK_CONDITION == srp->header.masked_status) ||
1335                      (COMMAND_TERMINATED == srp->header.masked_status)))
1336                         __scsi_print_sense(sdp->device, __func__, sense,
1337                                            SCSI_SENSE_BUFFERSIZE);
1338
1339                 /* Following if statement is a patch supplied by Eric Youngdale */
1340                 if (driver_byte(result) != 0
1341                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1342                     && !scsi_sense_is_deferred(&sshdr)
1343                     && sshdr.sense_key == UNIT_ATTENTION
1344                     && sdp->device->removable) {
1345                         /* Detected possible disc change. Set the bit - this */
1346                         /* may be used if there are filesystems using this device */
1347                         sdp->device->changed = 1;
1348                 }
1349         }
1350
1351         if (req->sense_len)
1352                 memcpy(srp->sense_b, req->sense, SCSI_SENSE_BUFFERSIZE);
1353
1354         /* Rely on write phase to clean out srp status values, so no "else" */
1355
1356         /*
1357          * Free the request as soon as it is complete so that its resources
1358          * can be reused without waiting for userspace to read() the
1359          * result.  But keep the associated bio (if any) around until
1360          * blk_rq_unmap_user() can be called from user context.
1361          */
1362         srp->rq = NULL;
1363         scsi_req_free_cmd(scsi_req(rq));
1364         __blk_put_request(rq->q, rq);
1365
1366         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1367         if (unlikely(srp->orphan)) {
1368                 if (sfp->keep_orphan)
1369                         srp->sg_io_owned = 0;
1370                 else
1371                         done = 0;
1372         }
1373         srp->done = done;
1374         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1375
1376         if (likely(done)) {
1377                 /* Now wake up any sg_read() that is waiting for this
1378                  * packet.
1379                  */
1380                 wake_up_interruptible(&sfp->read_wait);
1381                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1382                 kref_put(&sfp->f_ref, sg_remove_sfp);
1383         } else {
1384                 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1385                 schedule_work(&srp->ew.work);
1386         }
1387 }
1388
1389 static const struct file_operations sg_fops = {
1390         .owner = THIS_MODULE,
1391         .read = sg_read,
1392         .write = sg_write,
1393         .poll = sg_poll,
1394         .unlocked_ioctl = sg_ioctl,
1395 #ifdef CONFIG_COMPAT
1396         .compat_ioctl = sg_compat_ioctl,
1397 #endif
1398         .open = sg_open,
1399         .mmap = sg_mmap,
1400         .release = sg_release,
1401         .fasync = sg_fasync,
1402         .llseek = no_llseek,
1403 };
1404
1405 static struct class *sg_sysfs_class;
1406
1407 static int sg_sysfs_valid = 0;
1408
1409 static Sg_device *
1410 sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1411 {
1412         struct request_queue *q = scsidp->request_queue;
1413         Sg_device *sdp;
1414         unsigned long iflags;
1415         int error;
1416         u32 k;
1417
1418         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1419         if (!sdp) {
1420                 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1421                             "failure\n", __func__);
1422                 return ERR_PTR(-ENOMEM);
1423         }
1424
1425         idr_preload(GFP_KERNEL);
1426         write_lock_irqsave(&sg_index_lock, iflags);
1427
1428         error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1429         if (error < 0) {
1430                 if (error == -ENOSPC) {
1431                         sdev_printk(KERN_WARNING, scsidp,
1432                                     "Unable to attach sg device type=%d, minor number exceeds %d\n",
1433                                     scsidp->type, SG_MAX_DEVS - 1);
1434                         error = -ENODEV;
1435                 } else {
1436                         sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1437                                     "allocation Sg_device failure: %d\n",
1438                                     __func__, error);
1439                 }
1440                 goto out_unlock;
1441         }
1442         k = error;
1443
1444         SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1445                                         "sg_alloc: dev=%d \n", k));
1446         sprintf(disk->disk_name, "sg%d", k);
1447         disk->first_minor = k;
1448         sdp->disk = disk;
1449         sdp->device = scsidp;
1450         mutex_init(&sdp->open_rel_lock);
1451         INIT_LIST_HEAD(&sdp->sfds);
1452         init_waitqueue_head(&sdp->open_wait);
1453         atomic_set(&sdp->detaching, 0);
1454         rwlock_init(&sdp->sfd_lock);
1455         sdp->sg_tablesize = queue_max_segments(q);
1456         sdp->index = k;
1457         kref_init(&sdp->d_ref);
1458         error = 0;
1459
1460 out_unlock:
1461         write_unlock_irqrestore(&sg_index_lock, iflags);
1462         idr_preload_end();
1463
1464         if (error) {
1465                 kfree(sdp);
1466                 return ERR_PTR(error);
1467         }
1468         return sdp;
1469 }
1470
1471 static int
1472 sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1473 {
1474         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1475         struct gendisk *disk;
1476         Sg_device *sdp = NULL;
1477         struct cdev * cdev = NULL;
1478         int error;
1479         unsigned long iflags;
1480
1481         disk = alloc_disk(1);
1482         if (!disk) {
1483                 pr_warn("%s: alloc_disk failed\n", __func__);
1484                 return -ENOMEM;
1485         }
1486         disk->major = SCSI_GENERIC_MAJOR;
1487
1488         error = -ENOMEM;
1489         cdev = cdev_alloc();
1490         if (!cdev) {
1491                 pr_warn("%s: cdev_alloc failed\n", __func__);
1492                 goto out;
1493         }
1494         cdev->owner = THIS_MODULE;
1495         cdev->ops = &sg_fops;
1496
1497         sdp = sg_alloc(disk, scsidp);
1498         if (IS_ERR(sdp)) {
1499                 pr_warn("%s: sg_alloc failed\n", __func__);
1500                 error = PTR_ERR(sdp);
1501                 goto out;
1502         }
1503
1504         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1505         if (error)
1506                 goto cdev_add_err;
1507
1508         sdp->cdev = cdev;
1509         if (sg_sysfs_valid) {
1510                 struct device *sg_class_member;
1511
1512                 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1513                                                 MKDEV(SCSI_GENERIC_MAJOR,
1514                                                       sdp->index),
1515                                                 sdp, "%s", disk->disk_name);
1516                 if (IS_ERR(sg_class_member)) {
1517                         pr_err("%s: device_create failed\n", __func__);
1518                         error = PTR_ERR(sg_class_member);
1519                         goto cdev_add_err;
1520                 }
1521                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1522                                           &sg_class_member->kobj, "generic");
1523                 if (error)
1524                         pr_err("%s: unable to make symlink 'generic' back "
1525                                "to sg%d\n", __func__, sdp->index);
1526         } else
1527                 pr_warn("%s: sg_sys Invalid\n", __func__);
1528
1529         sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1530                     "type %d\n", sdp->index, scsidp->type);
1531
1532         dev_set_drvdata(cl_dev, sdp);
1533
1534         return 0;
1535
1536 cdev_add_err:
1537         write_lock_irqsave(&sg_index_lock, iflags);
1538         idr_remove(&sg_index_idr, sdp->index);
1539         write_unlock_irqrestore(&sg_index_lock, iflags);
1540         kfree(sdp);
1541
1542 out:
1543         put_disk(disk);
1544         if (cdev)
1545                 cdev_del(cdev);
1546         return error;
1547 }
1548
1549 static void
1550 sg_device_destroy(struct kref *kref)
1551 {
1552         struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1553         unsigned long flags;
1554
1555         /* CAUTION!  Note that the device can still be found via idr_find()
1556          * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1557          * any other cleanup.
1558          */
1559
1560         write_lock_irqsave(&sg_index_lock, flags);
1561         idr_remove(&sg_index_idr, sdp->index);
1562         write_unlock_irqrestore(&sg_index_lock, flags);
1563
1564         SCSI_LOG_TIMEOUT(3,
1565                 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1566
1567         put_disk(sdp->disk);
1568         kfree(sdp);
1569 }
1570
1571 static void
1572 sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1573 {
1574         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1575         Sg_device *sdp = dev_get_drvdata(cl_dev);
1576         unsigned long iflags;
1577         Sg_fd *sfp;
1578         int val;
1579
1580         if (!sdp)
1581                 return;
1582         /* want sdp->detaching non-zero as soon as possible */
1583         val = atomic_inc_return(&sdp->detaching);
1584         if (val > 1)
1585                 return; /* only want to do following once per device */
1586
1587         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1588                                       "%s\n", __func__));
1589
1590         read_lock_irqsave(&sdp->sfd_lock, iflags);
1591         list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1592                 wake_up_interruptible_all(&sfp->read_wait);
1593                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1594         }
1595         wake_up_interruptible_all(&sdp->open_wait);
1596         read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1597
1598         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1599         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1600         cdev_del(sdp->cdev);
1601         sdp->cdev = NULL;
1602
1603         kref_put(&sdp->d_ref, sg_device_destroy);
1604 }
1605
1606 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1607 module_param_named(def_reserved_size, def_reserved_size, int,
1608                    S_IRUGO | S_IWUSR);
1609 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1610
1611 MODULE_AUTHOR("Douglas Gilbert");
1612 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1613 MODULE_LICENSE("GPL");
1614 MODULE_VERSION(SG_VERSION_STR);
1615 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1616
1617 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1618                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1619 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1620 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1621
1622 static int __init
1623 init_sg(void)
1624 {
1625         int rc;
1626
1627         if (scatter_elem_sz < PAGE_SIZE) {
1628                 scatter_elem_sz = PAGE_SIZE;
1629                 scatter_elem_sz_prev = scatter_elem_sz;
1630         }
1631         if (def_reserved_size >= 0)
1632                 sg_big_buff = def_reserved_size;
1633         else
1634                 def_reserved_size = sg_big_buff;
1635
1636         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1637                                     SG_MAX_DEVS, "sg");
1638         if (rc)
1639                 return rc;
1640         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1641         if ( IS_ERR(sg_sysfs_class) ) {
1642                 rc = PTR_ERR(sg_sysfs_class);
1643                 goto err_out;
1644         }
1645         sg_sysfs_valid = 1;
1646         rc = scsi_register_interface(&sg_interface);
1647         if (0 == rc) {
1648 #ifdef CONFIG_SCSI_PROC_FS
1649                 sg_proc_init();
1650 #endif                          /* CONFIG_SCSI_PROC_FS */
1651                 return 0;
1652         }
1653         class_destroy(sg_sysfs_class);
1654 err_out:
1655         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1656         return rc;
1657 }
1658
1659 static void __exit
1660 exit_sg(void)
1661 {
1662 #ifdef CONFIG_SCSI_PROC_FS
1663         remove_proc_subtree("scsi/sg", NULL);
1664 #endif                          /* CONFIG_SCSI_PROC_FS */
1665         scsi_unregister_interface(&sg_interface);
1666         class_destroy(sg_sysfs_class);
1667         sg_sysfs_valid = 0;
1668         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1669                                  SG_MAX_DEVS);
1670         idr_destroy(&sg_index_idr);
1671 }
1672
1673 static int
1674 sg_start_req(Sg_request *srp, unsigned char *cmd)
1675 {
1676         int res;
1677         struct request *rq;
1678         struct scsi_request *req;
1679         Sg_fd *sfp = srp->parentfp;
1680         sg_io_hdr_t *hp = &srp->header;
1681         int dxfer_len = (int) hp->dxfer_len;
1682         int dxfer_dir = hp->dxfer_direction;
1683         unsigned int iov_count = hp->iovec_count;
1684         Sg_scatter_hold *req_schp = &srp->data;
1685         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1686         struct request_queue *q = sfp->parentdp->device->request_queue;
1687         struct rq_map_data *md, map_data;
1688         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1689         unsigned char *long_cmdp = NULL;
1690
1691         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1692                                       "sg_start_req: dxfer_len=%d\n",
1693                                       dxfer_len));
1694
1695         if (hp->cmd_len > BLK_MAX_CDB) {
1696                 long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1697                 if (!long_cmdp)
1698                         return -ENOMEM;
1699         }
1700
1701         /*
1702          * NOTE
1703          *
1704          * With scsi-mq enabled, there are a fixed number of preallocated
1705          * requests equal in number to shost->can_queue.  If all of the
1706          * preallocated requests are already in use, then using GFP_ATOMIC with
1707          * blk_get_request() will return -EWOULDBLOCK, whereas using GFP_KERNEL
1708          * will cause blk_get_request() to sleep until an active command
1709          * completes, freeing up a request.  Neither option is ideal, but
1710          * GFP_KERNEL is the better choice to prevent userspace from getting an
1711          * unexpected EWOULDBLOCK.
1712          *
1713          * With scsi-mq disabled, blk_get_request() with GFP_KERNEL usually
1714          * does not sleep except under memory pressure.
1715          */
1716         rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1717                         REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
1718         if (IS_ERR(rq)) {
1719                 kfree(long_cmdp);
1720                 return PTR_ERR(rq);
1721         }
1722         req = scsi_req(rq);
1723
1724         if (hp->cmd_len > BLK_MAX_CDB)
1725                 req->cmd = long_cmdp;
1726         memcpy(req->cmd, cmd, hp->cmd_len);
1727         req->cmd_len = hp->cmd_len;
1728
1729         srp->rq = rq;
1730         rq->end_io_data = srp;
1731         req->retries = SG_DEFAULT_RETRIES;
1732
1733         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1734                 return 0;
1735
1736         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1737             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1738             !sfp->parentdp->device->host->unchecked_isa_dma &&
1739             blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1740                 md = NULL;
1741         else
1742                 md = &map_data;
1743
1744         if (md) {
1745                 mutex_lock(&sfp->f_mutex);
1746                 if (dxfer_len <= rsv_schp->bufflen &&
1747                     !sfp->res_in_use) {
1748                         sfp->res_in_use = 1;
1749                         sg_link_reserve(sfp, srp, dxfer_len);
1750                 } else if (hp->flags & SG_FLAG_MMAP_IO) {
1751                         res = -EBUSY; /* sfp->res_in_use == 1 */
1752                         if (dxfer_len > rsv_schp->bufflen)
1753                                 res = -ENOMEM;
1754                         mutex_unlock(&sfp->f_mutex);
1755                         return res;
1756                 } else {
1757                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1758                         if (res) {
1759                                 mutex_unlock(&sfp->f_mutex);
1760                                 return res;
1761                         }
1762                 }
1763                 mutex_unlock(&sfp->f_mutex);
1764
1765                 md->pages = req_schp->pages;
1766                 md->page_order = req_schp->page_order;
1767                 md->nr_entries = req_schp->k_use_sg;
1768                 md->offset = 0;
1769                 md->null_mapped = hp->dxferp ? 0 : 1;
1770                 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1771                         md->from_user = 1;
1772                 else
1773                         md->from_user = 0;
1774         }
1775
1776         if (iov_count) {
1777                 struct iovec *iov = NULL;
1778                 struct iov_iter i;
1779
1780                 res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i);
1781                 if (res < 0)
1782                         return res;
1783
1784                 iov_iter_truncate(&i, hp->dxfer_len);
1785                 if (!iov_iter_count(&i)) {
1786                         kfree(iov);
1787                         return -EINVAL;
1788                 }
1789
1790                 res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
1791                 kfree(iov);
1792         } else
1793                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1794                                       hp->dxfer_len, GFP_ATOMIC);
1795
1796         if (!res) {
1797                 srp->bio = rq->bio;
1798
1799                 if (!md) {
1800                         req_schp->dio_in_use = 1;
1801                         hp->info |= SG_INFO_DIRECT_IO;
1802                 }
1803         }
1804         return res;
1805 }
1806
1807 static int
1808 sg_finish_rem_req(Sg_request *srp)
1809 {
1810         int ret = 0;
1811
1812         Sg_fd *sfp = srp->parentfp;
1813         Sg_scatter_hold *req_schp = &srp->data;
1814
1815         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1816                                       "sg_finish_rem_req: res_used=%d\n",
1817                                       (int) srp->res_used));
1818         if (srp->bio)
1819                 ret = blk_rq_unmap_user(srp->bio);
1820
1821         if (srp->rq) {
1822                 scsi_req_free_cmd(scsi_req(srp->rq));
1823                 blk_put_request(srp->rq);
1824         }
1825
1826         if (srp->res_used)
1827                 sg_unlink_reserve(sfp, srp);
1828         else
1829                 sg_remove_scat(sfp, req_schp);
1830
1831         return ret;
1832 }
1833
1834 static int
1835 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1836 {
1837         int sg_bufflen = tablesize * sizeof(struct page *);
1838         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1839
1840         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1841         if (!schp->pages)
1842                 return -ENOMEM;
1843         schp->sglist_len = sg_bufflen;
1844         return tablesize;       /* number of scat_gath elements allocated */
1845 }
1846
1847 static int
1848 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1849 {
1850         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1851         int sg_tablesize = sfp->parentdp->sg_tablesize;
1852         int blk_size = buff_size, order;
1853         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1854         struct sg_device *sdp = sfp->parentdp;
1855
1856         if (blk_size < 0)
1857                 return -EFAULT;
1858         if (0 == blk_size)
1859                 ++blk_size;     /* don't know why */
1860         /* round request up to next highest SG_SECTOR_SZ byte boundary */
1861         blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1862         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1863                 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1864                 buff_size, blk_size));
1865
1866         /* N.B. ret_sz carried into this block ... */
1867         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1868         if (mx_sc_elems < 0)
1869                 return mx_sc_elems;     /* most likely -ENOMEM */
1870
1871         num = scatter_elem_sz;
1872         if (unlikely(num != scatter_elem_sz_prev)) {
1873                 if (num < PAGE_SIZE) {
1874                         scatter_elem_sz = PAGE_SIZE;
1875                         scatter_elem_sz_prev = PAGE_SIZE;
1876                 } else
1877                         scatter_elem_sz_prev = num;
1878         }
1879
1880         if (sdp->device->host->unchecked_isa_dma)
1881                 gfp_mask |= GFP_DMA;
1882
1883         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1884                 gfp_mask |= __GFP_ZERO;
1885
1886         order = get_order(num);
1887 retry:
1888         ret_sz = 1 << (PAGE_SHIFT + order);
1889
1890         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1891              k++, rem_sz -= ret_sz) {
1892
1893                 num = (rem_sz > scatter_elem_sz_prev) ?
1894                         scatter_elem_sz_prev : rem_sz;
1895
1896                 schp->pages[k] = alloc_pages(gfp_mask | __GFP_ZERO, order);
1897                 if (!schp->pages[k])
1898                         goto out;
1899
1900                 if (num == scatter_elem_sz_prev) {
1901                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1902                                 scatter_elem_sz = ret_sz;
1903                                 scatter_elem_sz_prev = ret_sz;
1904                         }
1905                 }
1906
1907                 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1908                                  "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1909                                  k, num, ret_sz));
1910         }               /* end of for loop */
1911
1912         schp->page_order = order;
1913         schp->k_use_sg = k;
1914         SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1915                          "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1916                          k, rem_sz));
1917
1918         schp->bufflen = blk_size;
1919         if (rem_sz > 0) /* must have failed */
1920                 return -ENOMEM;
1921         return 0;
1922 out:
1923         for (i = 0; i < k; i++)
1924                 __free_pages(schp->pages[i], order);
1925
1926         if (--order >= 0)
1927                 goto retry;
1928
1929         return -ENOMEM;
1930 }
1931
1932 static void
1933 sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1934 {
1935         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1936                          "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1937         if (schp->pages && schp->sglist_len > 0) {
1938                 if (!schp->dio_in_use) {
1939                         int k;
1940
1941                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1942                                 SCSI_LOG_TIMEOUT(5,
1943                                         sg_printk(KERN_INFO, sfp->parentdp,
1944                                         "sg_remove_scat: k=%d, pg=0x%p\n",
1945                                         k, schp->pages[k]));
1946                                 __free_pages(schp->pages[k], schp->page_order);
1947                         }
1948
1949                         kfree(schp->pages);
1950                 }
1951         }
1952         memset(schp, 0, sizeof (*schp));
1953 }
1954
1955 static int
1956 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1957 {
1958         Sg_scatter_hold *schp = &srp->data;
1959         int k, num;
1960
1961         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1962                          "sg_read_oxfer: num_read_xfer=%d\n",
1963                          num_read_xfer));
1964         if ((!outp) || (num_read_xfer <= 0))
1965                 return 0;
1966
1967         num = 1 << (PAGE_SHIFT + schp->page_order);
1968         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1969                 if (num > num_read_xfer) {
1970                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1971                                            num_read_xfer))
1972                                 return -EFAULT;
1973                         break;
1974                 } else {
1975                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1976                                            num))
1977                                 return -EFAULT;
1978                         num_read_xfer -= num;
1979                         if (num_read_xfer <= 0)
1980                                 break;
1981                         outp += num;
1982                 }
1983         }
1984
1985         return 0;
1986 }
1987
1988 static void
1989 sg_build_reserve(Sg_fd * sfp, int req_size)
1990 {
1991         Sg_scatter_hold *schp = &sfp->reserve;
1992
1993         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1994                          "sg_build_reserve: req_size=%d\n", req_size));
1995         do {
1996                 if (req_size < PAGE_SIZE)
1997                         req_size = PAGE_SIZE;
1998                 if (0 == sg_build_indirect(schp, sfp, req_size))
1999                         return;
2000                 else
2001                         sg_remove_scat(sfp, schp);
2002                 req_size >>= 1; /* divide by 2 */
2003         } while (req_size > (PAGE_SIZE / 2));
2004 }
2005
2006 static void
2007 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2008 {
2009         Sg_scatter_hold *req_schp = &srp->data;
2010         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2011         int k, num, rem;
2012
2013         srp->res_used = 1;
2014         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2015                          "sg_link_reserve: size=%d\n", size));
2016         rem = size;
2017
2018         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2019         for (k = 0; k < rsv_schp->k_use_sg; k++) {
2020                 if (rem <= num) {
2021                         req_schp->k_use_sg = k + 1;
2022                         req_schp->sglist_len = rsv_schp->sglist_len;
2023                         req_schp->pages = rsv_schp->pages;
2024
2025                         req_schp->bufflen = size;
2026                         req_schp->page_order = rsv_schp->page_order;
2027                         break;
2028                 } else
2029                         rem -= num;
2030         }
2031
2032         if (k >= rsv_schp->k_use_sg)
2033                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2034                                  "sg_link_reserve: BAD size\n"));
2035 }
2036
2037 static void
2038 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2039 {
2040         Sg_scatter_hold *req_schp = &srp->data;
2041
2042         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2043                                       "sg_unlink_reserve: req->k_use_sg=%d\n",
2044                                       (int) req_schp->k_use_sg));
2045         req_schp->k_use_sg = 0;
2046         req_schp->bufflen = 0;
2047         req_schp->pages = NULL;
2048         req_schp->page_order = 0;
2049         req_schp->sglist_len = 0;
2050         srp->res_used = 0;
2051         /* Called without mutex lock to avoid deadlock */
2052         sfp->res_in_use = 0;
2053 }
2054
2055 static Sg_request *
2056 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2057 {
2058         Sg_request *resp;
2059         unsigned long iflags;
2060
2061         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2062         list_for_each_entry(resp, &sfp->rq_list, entry) {
2063                 /* look for requests that are ready + not SG_IO owned */
2064                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2065                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2066                         resp->done = 2; /* guard against other readers */
2067                         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2068                         return resp;
2069                 }
2070         }
2071         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2072         return NULL;
2073 }
2074
2075 /* always adds to end of list */
2076 static Sg_request *
2077 sg_add_request(Sg_fd * sfp)
2078 {
2079         int k;
2080         unsigned long iflags;
2081         Sg_request *rp = sfp->req_arr;
2082
2083         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2084         if (!list_empty(&sfp->rq_list)) {
2085                 if (!sfp->cmd_q)
2086                         goto out_unlock;
2087
2088                 for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2089                         if (!rp->parentfp)
2090                                 break;
2091                 }
2092                 if (k >= SG_MAX_QUEUE)
2093                         goto out_unlock;
2094         }
2095         memset(rp, 0, sizeof (Sg_request));
2096         rp->parentfp = sfp;
2097         rp->header.duration = jiffies_to_msecs(jiffies);
2098         list_add_tail(&rp->entry, &sfp->rq_list);
2099         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2100         return rp;
2101 out_unlock:
2102         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2103         return NULL;
2104 }
2105
2106 /* Return of 1 for found; 0 for not found */
2107 static int
2108 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2109 {
2110         unsigned long iflags;
2111         int res = 0;
2112
2113         if (!sfp || !srp || list_empty(&sfp->rq_list))
2114                 return res;
2115         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2116         if (!list_empty(&srp->entry)) {
2117                 list_del(&srp->entry);
2118                 srp->parentfp = NULL;
2119                 res = 1;
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         INIT_LIST_HEAD(&sfp->rq_list);
2139         kref_init(&sfp->f_ref);
2140         mutex_init(&sfp->f_mutex);
2141         sfp->timeout = SG_DEFAULT_TIMEOUT;
2142         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2143         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2144         sfp->cmd_q = SG_DEF_COMMAND_Q;
2145         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2146         sfp->parentdp = sdp;
2147         write_lock_irqsave(&sdp->sfd_lock, iflags);
2148         if (atomic_read(&sdp->detaching)) {
2149                 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2150                 return ERR_PTR(-ENODEV);
2151         }
2152         list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2153         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2154         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2155                                       "sg_add_sfp: sfp=0x%p\n", sfp));
2156         if (unlikely(sg_big_buff != def_reserved_size))
2157                 sg_big_buff = def_reserved_size;
2158
2159         bufflen = min_t(int, sg_big_buff,
2160                         max_sectors_bytes(sdp->device->request_queue));
2161         sg_build_reserve(sfp, bufflen);
2162         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2163                                       "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2164                                       sfp->reserve.bufflen,
2165                                       sfp->reserve.k_use_sg));
2166
2167         kref_get(&sdp->d_ref);
2168         __module_get(THIS_MODULE);
2169         return sfp;
2170 }
2171
2172 static void
2173 sg_remove_sfp_usercontext(struct work_struct *work)
2174 {
2175         struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2176         struct sg_device *sdp = sfp->parentdp;
2177         Sg_request *srp;
2178         unsigned long iflags;
2179
2180         /* Cleanup any responses which were never read(). */
2181         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2182         while (!list_empty(&sfp->rq_list)) {
2183                 srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2184                 sg_finish_rem_req(srp);
2185                 list_del(&srp->entry);
2186                 srp->parentfp = NULL;
2187         }
2188         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2189
2190         if (sfp->reserve.bufflen > 0) {
2191                 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2192                                 "sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2193                                 (int) sfp->reserve.bufflen,
2194                                 (int) sfp->reserve.k_use_sg));
2195                 sg_remove_scat(sfp, &sfp->reserve);
2196         }
2197
2198         SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2199                         "sg_remove_sfp: sfp=0x%p\n", sfp));
2200         kfree(sfp);
2201
2202         scsi_device_put(sdp->device);
2203         kref_put(&sdp->d_ref, sg_device_destroy);
2204         module_put(THIS_MODULE);
2205 }
2206
2207 static void
2208 sg_remove_sfp(struct kref *kref)
2209 {
2210         struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2211         struct sg_device *sdp = sfp->parentdp;
2212         unsigned long iflags;
2213
2214         write_lock_irqsave(&sdp->sfd_lock, iflags);
2215         list_del(&sfp->sfd_siblings);
2216         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2217
2218         INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2219         schedule_work(&sfp->ew.work);
2220 }
2221
2222 #ifdef CONFIG_SCSI_PROC_FS
2223 static int
2224 sg_idr_max_id(int id, void *p, void *data)
2225 {
2226         int *k = data;
2227
2228         if (*k < id)
2229                 *k = id;
2230
2231         return 0;
2232 }
2233
2234 static int
2235 sg_last_dev(void)
2236 {
2237         int k = -1;
2238         unsigned long iflags;
2239
2240         read_lock_irqsave(&sg_index_lock, iflags);
2241         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2242         read_unlock_irqrestore(&sg_index_lock, iflags);
2243         return k + 1;           /* origin 1 */
2244 }
2245 #endif
2246
2247 /* must be called with sg_index_lock held */
2248 static Sg_device *sg_lookup_dev(int dev)
2249 {
2250         return idr_find(&sg_index_idr, dev);
2251 }
2252
2253 static Sg_device *
2254 sg_get_dev(int dev)
2255 {
2256         struct sg_device *sdp;
2257         unsigned long flags;
2258
2259         read_lock_irqsave(&sg_index_lock, flags);
2260         sdp = sg_lookup_dev(dev);
2261         if (!sdp)
2262                 sdp = ERR_PTR(-ENXIO);
2263         else if (atomic_read(&sdp->detaching)) {
2264                 /* If sdp->detaching, then the refcount may already be 0, in
2265                  * which case it would be a bug to do kref_get().
2266                  */
2267                 sdp = ERR_PTR(-ENODEV);
2268         } else
2269                 kref_get(&sdp->d_ref);
2270         read_unlock_irqrestore(&sg_index_lock, flags);
2271
2272         return sdp;
2273 }
2274
2275 #ifdef CONFIG_SCSI_PROC_FS
2276 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2277
2278 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2279 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2280                                   size_t count, loff_t *off);
2281 static const struct file_operations adio_fops = {
2282         .owner = THIS_MODULE,
2283         .open = sg_proc_single_open_adio,
2284         .read = seq_read,
2285         .llseek = seq_lseek,
2286         .write = sg_proc_write_adio,
2287         .release = single_release,
2288 };
2289
2290 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2291 static ssize_t sg_proc_write_dressz(struct file *filp,
2292                 const char __user *buffer, size_t count, loff_t *off);
2293 static const struct file_operations dressz_fops = {
2294         .owner = THIS_MODULE,
2295         .open = sg_proc_single_open_dressz,
2296         .read = seq_read,
2297         .llseek = seq_lseek,
2298         .write = sg_proc_write_dressz,
2299         .release = single_release,
2300 };
2301
2302 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2303 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2304 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2305 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2306 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2307 static void dev_seq_stop(struct seq_file *s, void *v);
2308 static const struct seq_operations dev_seq_ops = {
2309         .start = dev_seq_start,
2310         .next  = dev_seq_next,
2311         .stop  = dev_seq_stop,
2312         .show  = sg_proc_seq_show_dev,
2313 };
2314
2315 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2316 static const struct seq_operations devstrs_seq_ops = {
2317         .start = dev_seq_start,
2318         .next  = dev_seq_next,
2319         .stop  = dev_seq_stop,
2320         .show  = sg_proc_seq_show_devstrs,
2321 };
2322
2323 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2324 static const struct seq_operations debug_seq_ops = {
2325         .start = dev_seq_start,
2326         .next  = dev_seq_next,
2327         .stop  = dev_seq_stop,
2328         .show  = sg_proc_seq_show_debug,
2329 };
2330
2331 static int
2332 sg_proc_init(void)
2333 {
2334         struct proc_dir_entry *p;
2335
2336         p = proc_mkdir("scsi/sg", NULL);
2337         if (!p)
2338                 return 1;
2339
2340         proc_create("allow_dio", S_IRUGO | S_IWUSR, p, &adio_fops);
2341         proc_create_seq("debug", S_IRUGO, p, &debug_seq_ops);
2342         proc_create("def_reserved_size", S_IRUGO | S_IWUSR, p, &dressz_fops);
2343         proc_create_single("device_hdr", S_IRUGO, p, sg_proc_seq_show_devhdr);
2344         proc_create_seq("devices", S_IRUGO, p, &dev_seq_ops);
2345         proc_create_seq("device_strs", S_IRUGO, p, &devstrs_seq_ops);
2346         proc_create_single("version", S_IRUGO, p, sg_proc_seq_show_version);
2347         return 0;
2348 }
2349
2350
2351 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2352 {
2353         seq_printf(s, "%d\n", *((int *)s->private));
2354         return 0;
2355 }
2356
2357 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2358 {
2359         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2360 }
2361
2362 static ssize_t
2363 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2364                    size_t count, loff_t *off)
2365 {
2366         int err;
2367         unsigned long num;
2368
2369         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2370                 return -EACCES;
2371         err = kstrtoul_from_user(buffer, count, 0, &num);
2372         if (err)
2373                 return err;
2374         sg_allow_dio = num ? 1 : 0;
2375         return count;
2376 }
2377
2378 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2379 {
2380         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2381 }
2382
2383 static ssize_t
2384 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2385                      size_t count, loff_t *off)
2386 {
2387         int err;
2388         unsigned long k = ULONG_MAX;
2389
2390         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2391                 return -EACCES;
2392
2393         err = kstrtoul_from_user(buffer, count, 0, &k);
2394         if (err)
2395                 return err;
2396         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2397                 sg_big_buff = k;
2398                 return count;
2399         }
2400         return -ERANGE;
2401 }
2402
2403 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2404 {
2405         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2406                    sg_version_date);
2407         return 0;
2408 }
2409
2410 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2411 {
2412         seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2413         return 0;
2414 }
2415
2416 struct sg_proc_deviter {
2417         loff_t  index;
2418         size_t  max;
2419 };
2420
2421 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2422 {
2423         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2424
2425         s->private = it;
2426         if (! it)
2427                 return NULL;
2428
2429         it->index = *pos;
2430         it->max = sg_last_dev();
2431         if (it->index >= it->max)
2432                 return NULL;
2433         return it;
2434 }
2435
2436 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2437 {
2438         struct sg_proc_deviter * it = s->private;
2439
2440         *pos = ++it->index;
2441         return (it->index < it->max) ? it : NULL;
2442 }
2443
2444 static void dev_seq_stop(struct seq_file *s, void *v)
2445 {
2446         kfree(s->private);
2447 }
2448
2449 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2450 {
2451         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2452         Sg_device *sdp;
2453         struct scsi_device *scsidp;
2454         unsigned long iflags;
2455
2456         read_lock_irqsave(&sg_index_lock, iflags);
2457         sdp = it ? sg_lookup_dev(it->index) : NULL;
2458         if ((NULL == sdp) || (NULL == sdp->device) ||
2459             (atomic_read(&sdp->detaching)))
2460                 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2461         else {
2462                 scsidp = sdp->device;
2463                 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2464                               scsidp->host->host_no, scsidp->channel,
2465                               scsidp->id, scsidp->lun, (int) scsidp->type,
2466                               1,
2467                               (int) scsidp->queue_depth,
2468                               (int) atomic_read(&scsidp->device_busy),
2469                               (int) scsi_device_online(scsidp));
2470         }
2471         read_unlock_irqrestore(&sg_index_lock, iflags);
2472         return 0;
2473 }
2474
2475 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2476 {
2477         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2478         Sg_device *sdp;
2479         struct scsi_device *scsidp;
2480         unsigned long iflags;
2481
2482         read_lock_irqsave(&sg_index_lock, iflags);
2483         sdp = it ? sg_lookup_dev(it->index) : NULL;
2484         scsidp = sdp ? sdp->device : NULL;
2485         if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2486                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2487                            scsidp->vendor, scsidp->model, scsidp->rev);
2488         else
2489                 seq_puts(s, "<no active device>\n");
2490         read_unlock_irqrestore(&sg_index_lock, iflags);
2491         return 0;
2492 }
2493
2494 /* must be called while holding sg_index_lock */
2495 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2496 {
2497         int k, new_interface, blen, usg;
2498         Sg_request *srp;
2499         Sg_fd *fp;
2500         const sg_io_hdr_t *hp;
2501         const char * cp;
2502         unsigned int ms;
2503
2504         k = 0;
2505         list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2506                 k++;
2507                 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2508                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2509                            "(res)sgat=%d low_dma=%d\n", k,
2510                            jiffies_to_msecs(fp->timeout),
2511                            fp->reserve.bufflen,
2512                            (int) fp->reserve.k_use_sg,
2513                            (int) sdp->device->host->unchecked_isa_dma);
2514                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2515                            (int) fp->cmd_q, (int) fp->force_packid,
2516                            (int) fp->keep_orphan);
2517                 list_for_each_entry(srp, &fp->rq_list, entry) {
2518                         hp = &srp->header;
2519                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2520                         if (srp->res_used) {
2521                                 if (new_interface &&
2522                                     (SG_FLAG_MMAP_IO & hp->flags))
2523                                         cp = "     mmap>> ";
2524                                 else
2525                                         cp = "     rb>> ";
2526                         } else {
2527                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2528                                         cp = "     dio>> ";
2529                                 else
2530                                         cp = "     ";
2531                         }
2532                         seq_puts(s, cp);
2533                         blen = srp->data.bufflen;
2534                         usg = srp->data.k_use_sg;
2535                         seq_puts(s, srp->done ?
2536                                  ((1 == srp->done) ?  "rcv:" : "fin:")
2537                                   : "act:");
2538                         seq_printf(s, " id=%d blen=%d",
2539                                    srp->header.pack_id, blen);
2540                         if (srp->done)
2541                                 seq_printf(s, " dur=%d", hp->duration);
2542                         else {
2543                                 ms = jiffies_to_msecs(jiffies);
2544                                 seq_printf(s, " t_o/elap=%d/%d",
2545                                         (new_interface ? hp->timeout :
2546                                                   jiffies_to_msecs(fp->timeout)),
2547                                         (ms > hp->duration ? ms - hp->duration : 0));
2548                         }
2549                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2550                                    (int) srp->data.cmd_opcode);
2551                 }
2552                 if (list_empty(&fp->rq_list))
2553                         seq_puts(s, "     No requests active\n");
2554                 read_unlock(&fp->rq_list_lock);
2555         }
2556 }
2557
2558 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2559 {
2560         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2561         Sg_device *sdp;
2562         unsigned long iflags;
2563
2564         if (it && (0 == it->index))
2565                 seq_printf(s, "max_active_device=%d  def_reserved_size=%d\n",
2566                            (int)it->max, sg_big_buff);
2567
2568         read_lock_irqsave(&sg_index_lock, iflags);
2569         sdp = it ? sg_lookup_dev(it->index) : NULL;
2570         if (NULL == sdp)
2571                 goto skip;
2572         read_lock(&sdp->sfd_lock);
2573         if (!list_empty(&sdp->sfds)) {
2574                 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2575                 if (atomic_read(&sdp->detaching))
2576                         seq_puts(s, "detaching pending close ");
2577                 else if (sdp->device) {
2578                         struct scsi_device *scsidp = sdp->device;
2579
2580                         seq_printf(s, "%d:%d:%d:%llu   em=%d",
2581                                    scsidp->host->host_no,
2582                                    scsidp->channel, scsidp->id,
2583                                    scsidp->lun,
2584                                    scsidp->host->hostt->emulated);
2585                 }
2586                 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2587                            sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2588                 sg_proc_debug_helper(s, sdp);
2589         }
2590         read_unlock(&sdp->sfd_lock);
2591 skip:
2592         read_unlock_irqrestore(&sg_index_lock, iflags);
2593         return 0;
2594 }
2595
2596 #endif                          /* CONFIG_SCSI_PROC_FS */
2597
2598 module_init(init_sg);
2599 module_exit(exit_sg);