drivers/scsi/sg.c

   1 /*
   2  *  History:
   3  *  Started: Aug 9 by Lawrence Foard ([email protected]),
   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 ([email protected]), notes:
  24  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
  25  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
  26  *        (otherwise the macros compile to empty statements).
  27  *
  28  */
  29 #include <linux/module.h>
  30
  31 #include <linux/fs.h>
  32 #include <linux/kernel.h>
  33 #include <linux/sched.h>
  34 #include <linux/string.h>
  35 #include <linux/mm.h>
  36 #include <linux/errno.h>
  37 #include <linux/mtio.h>
  38 #include <linux/ioctl.h>
  39 #include <linux/slab.h>
  40 #include <linux/fcntl.h>
  41 #include <linux/init.h>
  42 #include <linux/poll.h>
  43 #include <linux/moduleparam.h>
  44 #include <linux/cdev.h>
  45 #include <linux/idr.h>
  46 #include <linux/seq_file.h>
  47 #include <linux/blkdev.h>
  48 #include <linux/delay.h>
  49 #include <linux/blktrace_api.h>
  50 #include <linux/mutex.h>
  51 #include <linux/atomic.h>
  52 #include <linux/ratelimit.h>
  53 #include <linux/uio.h>
  54
  55 #include "scsi.h"
  56 #include <scsi/scsi_dbg.h>
  57 #include <scsi/scsi_host.h>
  58 #include <scsi/scsi_driver.h>
  59 #include <scsi/scsi_ioctl.h>
  60 #include <scsi/sg.h>
  61
  62 #include "scsi_logging.h"
  63
  64 #ifdef CONFIG_SCSI_PROC_FS
  65 #include <linux/proc_fs.h>
  66 static char *sg_version_date = "20140603";
  67
  68 static int sg_proc_init(void);
  69 static void sg_proc_cleanup(void);
  70 #endif
  71
  72 #define SG_ALLOW_DIO_DEF 0
  73
  74 #define SG_MAX_DEVS 32768
  75
  76 /* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
  77  * of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
  78  * than 16 bytes are "variable length" whose length is a multiple of 4
  79  */
  80 #define SG_MAX_CDB_SIZE 252
  81
  82 #define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  83
  84 int sg_big_buff = SG_DEF_RESERVED_SIZE;
  85 /* N.B. This variable is readable and writeable via
  86    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  87    of this size (or less if there is not enough memory) will be reserved
  88    for use by this file descriptor. [Deprecated usage: this variable is also
  89    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  90    the kernel (i.e. it is not a module).] */
  91 static int def_reserved_size = -1;      /* picks up init parameter */
  92 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
  93
  94 static int scatter_elem_sz = SG_SCATTER_SZ;
  95 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
  96
  97 #define SG_SECTOR_SZ 512
  98
  99 static int sg_add_device(struct device *, struct class_interface *);
 100 static void sg_remove_device(struct device *, struct class_interface *);
 101
 102 static DEFINE_IDR(sg_index_idr);
 103 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
 104                                                            file descriptor list for device */
 105
 106 static struct class_interface sg_interface = {
 107         .add_dev        = sg_add_device,
 108         .remove_dev     = sg_remove_device,
 109 };
 110
 111 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 112         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 113         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 114         unsigned bufflen;       /* Size of (aggregate) data buffer */
 115         struct page **pages;
 116         int page_order;
 117         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 118         unsigned char cmd_opcode; /* first byte of command */
 119 } Sg_scatter_hold;
 120
 121 struct sg_device;               /* forward declarations */
 122 struct sg_fd;
 123
 124 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 125         struct list_head entry; /* list entry */
 126         struct sg_fd *parentfp; /* NULL -> not in use */
 127         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 128         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 129         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 130         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 131         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 132         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 133         /* done protected by rq_list_lock */
 134         char done;              /* 0->before bh, 1->before read, 2->read */
 135         struct request *rq;
 136         struct bio *bio;
 137         struct execute_work ew;
 138 } Sg_request;
 139
 140 typedef struct sg_fd {          /* holds the state of a file descriptor */
 141         struct list_head sfd_siblings;  /* protected by device's sfd_lock */
 142         struct sg_device *parentdp;     /* owning device */
 143         wait_queue_head_t read_wait;    /* queue read until command done */
 144         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 145         struct mutex f_mutex;   /* protect against changes in this fd */
 146         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 147         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 148         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 149         struct list_head rq_list; /* head of request list */
 150         struct fasync_struct *async_qp; /* used by asynchronous notification */
 151         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 152         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 153         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 154         unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */
 155         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 156         char mmap_called;       /* 0 -> mmap() never called on this fd */
 157         char res_in_use;        /* 1 -> 'reserve' array in use */
 158         struct kref f_ref;
 159         struct execute_work ew;
 160 } Sg_fd;
 161
 162 typedef struct sg_device { /* holds the state of each scsi generic device */
 163         struct scsi_device *device;
 164         wait_queue_head_t open_wait;    /* queue open() when O_EXCL present */
 165         struct mutex open_rel_lock;     /* held when in open() or release() */
 166         int sg_tablesize;       /* adapter's max scatter-gather table size */
 167         u32 index;              /* device index number */
 168         struct list_head sfds;
 169         rwlock_t sfd_lock;      /* protect access to sfd list */
 170         atomic_t detaching;     /* 0->device usable, 1->device detaching */
 171         bool exclude;           /* 1->open(O_EXCL) succeeded and is active */
 172         int open_cnt;           /* count of opens (perhaps < num(sfds) ) */
 173         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 174         struct gendisk *disk;
 175         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 176         struct kref d_ref;
 177 } Sg_device;
 178
 179 /* tasklet or soft irq callback */
 180 static void sg_rq_end_io(struct request *rq, blk_status_t status);
 181 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 182 static int sg_finish_rem_req(Sg_request * srp);
 183 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 184 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 185                            Sg_request * srp);
 186 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 187                         const char __user *buf, size_t count, int blocking,
 188                         int read_only, int sg_io_owned, Sg_request **o_srp);
 189 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 190                            unsigned char *cmnd, int timeout, int blocking);
 191 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 192 static void sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp);
 193 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 194 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 195 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 196 static Sg_fd *sg_add_sfp(Sg_device * sdp);
 197 static void sg_remove_sfp(struct kref *);
 198 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 199 static Sg_request *sg_add_request(Sg_fd * sfp);
 200 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 201 static Sg_device *sg_get_dev(int dev);
 202 static void sg_device_destroy(struct kref *kref);
 203
 204 #define SZ_SG_HEADER sizeof(struct sg_header)
 205 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 206 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
 207 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 208
 209 #define sg_printk(prefix, sdp, fmt, a...) \
 210         sdev_prefix_printk(prefix, (sdp)->device,               \
 211                            (sdp)->disk->disk_name, fmt, ##a)
 212
 213 static int sg_allow_access(struct file *filp, unsigned char *cmd)
 214 {
 215         struct sg_fd *sfp = filp->private_data;
 216
 217         if (sfp->parentdp->device->type == TYPE_SCANNER)
 218                 return 0;
 219
 220         return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE);
 221 }
 222
 223 static int
 224 open_wait(Sg_device *sdp, int flags)
 225 {
 226         int retval = 0;
 227
 228         if (flags & O_EXCL) {
 229                 while (sdp->open_cnt > 0) {
 230                         mutex_unlock(&sdp->open_rel_lock);
 231                         retval = wait_event_interruptible(sdp->open_wait,
 232                                         (atomic_read(&sdp->detaching) ||
 233                                          !sdp->open_cnt));
 234                         mutex_lock(&sdp->open_rel_lock);
 235
 236                         if (retval) /* -ERESTARTSYS */
 237                                 return retval;
 238                         if (atomic_read(&sdp->detaching))
 239                                 return -ENODEV;
 240                 }
 241         } else {
 242                 while (sdp->exclude) {
 243                         mutex_unlock(&sdp->open_rel_lock);
 244                         retval = wait_event_interruptible(sdp->open_wait,
 245                                         (atomic_read(&sdp->detaching) ||
 246                                          !sdp->exclude));
 247                         mutex_lock(&sdp->open_rel_lock);
 248
 249                         if (retval) /* -ERESTARTSYS */
 250                                 return retval;
 251                         if (atomic_read(&sdp->detaching))
 252                                 return -ENODEV;
 253                 }
 254         }
 255
 256         return retval;
 257 }
 258
 259 /* Returns 0 on success, else a negated errno value */
 260 static int
 261 sg_open(struct inode *inode, struct file *filp)
 262 {
 263         int dev = iminor(inode);
 264         int flags = filp->f_flags;
 265         struct request_queue *q;
 266         Sg_device *sdp;
 267         Sg_fd *sfp;
 268         int retval;
 269
 270         nonseekable_open(inode, filp);
 271         if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
 272                 return -EPERM; /* Can't lock it with read only access */
 273         sdp = sg_get_dev(dev);
 274         if (IS_ERR(sdp))
 275                 return PTR_ERR(sdp);
 276
 277         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 278                                       "sg_open: flags=0x%x\n", flags));
 279
 280         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 281         /* Prevent the device driver from vanishing while we sleep */
 282         retval = scsi_device_get(sdp->device);
 283         if (retval)
 284                 goto sg_put;
 285
 286         retval = scsi_autopm_get_device(sdp->device);
 287         if (retval)
 288                 goto sdp_put;
 289
 290         /* scsi_block_when_processing_errors() may block so bypass
 291          * check if O_NONBLOCK. Permits SCSI commands to be issued
 292          * during error recovery. Tread carefully. */
 293         if (!((flags & O_NONBLOCK) ||
 294               scsi_block_when_processing_errors(sdp->device))) {
 295                 retval = -ENXIO;
 296                 /* we are in error recovery for this device */
 297                 goto error_out;
 298         }
 299
 300         mutex_lock(&sdp->open_rel_lock);
 301         if (flags & O_NONBLOCK) {
 302                 if (flags & O_EXCL) {
 303                         if (sdp->open_cnt > 0) {
 304                                 retval = -EBUSY;
 305                                 goto error_mutex_locked;
 306                         }
 307                 } else {
 308                         if (sdp->exclude) {
 309                                 retval = -EBUSY;
 310                                 goto error_mutex_locked;
 311                         }
 312                 }
 313         } else {
 314                 retval = open_wait(sdp, flags);
 315                 if (retval) /* -ERESTARTSYS or -ENODEV */
 316                         goto error_mutex_locked;
 317         }
 318
 319         /* N.B. at this point we are holding the open_rel_lock */
 320         if (flags & O_EXCL)
 321                 sdp->exclude = true;
 322
 323         if (sdp->open_cnt < 1) {  /* no existing opens */
 324                 sdp->sgdebug = 0;
 325                 q = sdp->device->request_queue;
 326                 sdp->sg_tablesize = queue_max_segments(q);
 327         }
 328         sfp = sg_add_sfp(sdp);
 329         if (IS_ERR(sfp)) {
 330                 retval = PTR_ERR(sfp);
 331                 goto out_undo;
 332         }
 333
 334         filp->private_data = sfp;
 335         sdp->open_cnt++;
 336         mutex_unlock(&sdp->open_rel_lock);
 337
 338         retval = 0;
 339 sg_put:
 340         kref_put(&sdp->d_ref, sg_device_destroy);
 341         return retval;
 342
 343 out_undo:
 344         if (flags & O_EXCL) {
 345                 sdp->exclude = false;   /* undo if error */
 346                 wake_up_interruptible(&sdp->open_wait);
 347         }
 348 error_mutex_locked:
 349         mutex_unlock(&sdp->open_rel_lock);
 350 error_out:
 351         scsi_autopm_put_device(sdp->device);
 352 sdp_put:
 353         scsi_device_put(sdp->device);
 354         goto sg_put;
 355 }
 356
 357 /* Release resources associated with a successful sg_open()
 358  * Returns 0 on success, else a negated errno value */
 359 static int
 360 sg_release(struct inode *inode, struct file *filp)
 361 {
 362         Sg_device *sdp;
 363         Sg_fd *sfp;
 364
 365         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 366                 return -ENXIO;
 367         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
 368
 369         mutex_lock(&sdp->open_rel_lock);
 370         scsi_autopm_put_device(sdp->device);
 371         kref_put(&sfp->f_ref, sg_remove_sfp);
 372         sdp->open_cnt--;
 373
 374         /* possibly many open()s waiting on exlude clearing, start many;
 375          * only open(O_EXCL)s wait on 0==open_cnt so only start one */
 376         if (sdp->exclude) {
 377                 sdp->exclude = false;
 378                 wake_up_interruptible_all(&sdp->open_wait);
 379         } else if (0 == sdp->open_cnt) {
 380                 wake_up_interruptible(&sdp->open_wait);
 381         }
 382         mutex_unlock(&sdp->open_rel_lock);
 383         return 0;
 384 }
 385
 386 static ssize_t
 387 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 388 {
 389         Sg_device *sdp;
 390         Sg_fd *sfp;
 391         Sg_request *srp;
 392         int req_pack_id = -1;
 393         sg_io_hdr_t *hp;
 394         struct sg_header *old_hdr = NULL;
 395         int retval = 0;
 396
 397         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 398                 return -ENXIO;
 399         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 400                                       "sg_read: count=%d\n", (int) count));
 401
 402         if (!access_ok(VERIFY_WRITE, buf, count))
 403                 return -EFAULT;
 404         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 405                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 406                 if (!old_hdr)
 407                         return -ENOMEM;
 408                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
 409                         retval = -EFAULT;
 410                         goto free_old_hdr;
 411                 }
 412                 if (old_hdr->reply_len < 0) {
 413                         if (count >= SZ_SG_IO_HDR) {
 414                                 sg_io_hdr_t *new_hdr;
 415                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
 416                                 if (!new_hdr) {
 417                                         retval = -ENOMEM;
 418                                         goto free_old_hdr;
 419                                 }
 420                                 retval =__copy_from_user
 421                                     (new_hdr, buf, SZ_SG_IO_HDR);
 422                                 req_pack_id = new_hdr->pack_id;
 423                                 kfree(new_hdr);
 424                                 if (retval) {
 425                                         retval = -EFAULT;
 426                                         goto free_old_hdr;
 427                                 }
 428                         }
 429                 } else
 430                         req_pack_id = old_hdr->pack_id;
 431         }
 432         srp = sg_get_rq_mark(sfp, req_pack_id);
 433         if (!srp) {             /* now wait on packet to arrive */
 434                 if (atomic_read(&sdp->detaching)) {
 435                         retval = -ENODEV;
 436                         goto free_old_hdr;
 437                 }
 438                 if (filp->f_flags & O_NONBLOCK) {
 439                         retval = -EAGAIN;
 440                         goto free_old_hdr;
 441                 }
 442                 retval = wait_event_interruptible(sfp->read_wait,
 443                         (atomic_read(&sdp->detaching) ||
 444                         (srp = sg_get_rq_mark(sfp, req_pack_id))));
 445                 if (atomic_read(&sdp->detaching)) {
 446                         retval = -ENODEV;
 447                         goto free_old_hdr;
 448                 }
 449                 if (retval) {
 450                         /* -ERESTARTSYS as signal hit process */
 451                         goto free_old_hdr;
 452                 }
 453         }
 454         if (srp->header.interface_id != '\0') {
 455                 retval = sg_new_read(sfp, buf, count, srp);
 456                 goto free_old_hdr;
 457         }
 458
 459         hp = &srp->header;
 460         if (old_hdr == NULL) {
 461                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 462                 if (! old_hdr) {
 463                         retval = -ENOMEM;
 464                         goto free_old_hdr;
 465                 }
 466         }
 467         memset(old_hdr, 0, SZ_SG_HEADER);
 468         old_hdr->reply_len = (int) hp->timeout;
 469         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 470         old_hdr->pack_id = hp->pack_id;
 471         old_hdr->twelve_byte =
 472             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 473         old_hdr->target_status = hp->masked_status;
 474         old_hdr->host_status = hp->host_status;
 475         old_hdr->driver_status = hp->driver_status;
 476         if ((CHECK_CONDITION & hp->masked_status) ||
 477             (DRIVER_SENSE & hp->driver_status))
 478                 memcpy(old_hdr->sense_buffer, srp->sense_b,
 479                        sizeof (old_hdr->sense_buffer));
 480         switch (hp->host_status) {
 481         /* This setup of 'result' is for backward compatibility and is best
 482            ignored by the user who should use target, host + driver status */
 483         case DID_OK:
 484         case DID_PASSTHROUGH:
 485         case DID_SOFT_ERROR:
 486                 old_hdr->result = 0;
 487                 break;
 488         case DID_NO_CONNECT:
 489         case DID_BUS_BUSY:
 490         case DID_TIME_OUT:
 491                 old_hdr->result = EBUSY;
 492                 break;
 493         case DID_BAD_TARGET:
 494         case DID_ABORT:
 495         case DID_PARITY:
 496         case DID_RESET:
 497         case DID_BAD_INTR:
 498                 old_hdr->result = EIO;
 499                 break;
 500         case DID_ERROR:
 501                 old_hdr->result = (srp->sense_b[0] == 0 &&
 502                                   hp->masked_status == GOOD) ? 0 : EIO;
 503                 break;
 504         default:
 505                 old_hdr->result = EIO;
 506                 break;
 507         }
 508
 509         /* Now copy the result back to the user buffer.  */
 510         if (count >= SZ_SG_HEADER) {
 511                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 512                         retval = -EFAULT;
 513                         goto free_old_hdr;
 514                 }
 515                 buf += SZ_SG_HEADER;
 516                 if (count > old_hdr->reply_len)
 517                         count = old_hdr->reply_len;
 518                 if (count > SZ_SG_HEADER) {
 519                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 520                                 retval = -EFAULT;
 521                                 goto free_old_hdr;
 522                         }
 523                 }
 524         } else
 525                 count = (old_hdr->result == 0) ? 0 : -EIO;
 526         sg_finish_rem_req(srp);
 527         sg_remove_request(sfp, srp);
 528         retval = count;
 529 free_old_hdr:
 530         kfree(old_hdr);
 531         return retval;
 532 }
 533
 534 static ssize_t
 535 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 536 {
 537         sg_io_hdr_t *hp = &srp->header;
 538         int err = 0, err2;
 539         int len;
 540
 541         if (count < SZ_SG_IO_HDR) {
 542                 err = -EINVAL;
 543                 goto err_out;
 544         }
 545         hp->sb_len_wr = 0;
 546         if ((hp->mx_sb_len > 0) && hp->sbp) {
 547                 if ((CHECK_CONDITION & hp->masked_status) ||
 548                     (DRIVER_SENSE & hp->driver_status)) {
 549                         int sb_len = SCSI_SENSE_BUFFERSIZE;
 550                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 551                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 552                         len = (len > sb_len) ? sb_len : len;
 553                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 554                                 err = -EFAULT;
 555                                 goto err_out;
 556                         }
 557                         hp->sb_len_wr = len;
 558                 }
 559         }
 560         if (hp->masked_status || hp->host_status || hp->driver_status)
 561                 hp->info |= SG_INFO_CHECK;
 562         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 563                 err = -EFAULT;
 564                 goto err_out;
 565         }
 566 err_out:
 567         err2 = sg_finish_rem_req(srp);
 568         sg_remove_request(sfp, srp);
 569         return err ? : err2 ? : count;
 570 }
 571
 572 static ssize_t
 573 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 574 {
 575         int mxsize, cmd_size, k;
 576         int input_size, blocking;
 577         unsigned char opcode;
 578         Sg_device *sdp;
 579         Sg_fd *sfp;
 580         Sg_request *srp;
 581         struct sg_header old_hdr;
 582         sg_io_hdr_t *hp;
 583         unsigned char cmnd[SG_MAX_CDB_SIZE];
 584
 585         if (unlikely(uaccess_kernel()))
 586                 return -EINVAL;
 587
 588         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 589                 return -ENXIO;
 590         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 591                                       "sg_write: count=%d\n", (int) count));
 592         if (atomic_read(&sdp->detaching))
 593                 return -ENODEV;
 594         if (!((filp->f_flags & O_NONBLOCK) ||
 595               scsi_block_when_processing_errors(sdp->device)))
 596                 return -ENXIO;
 597
 598         if (!access_ok(VERIFY_READ, buf, count))
 599                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 600         if (count < SZ_SG_HEADER)
 601                 return -EIO;
 602         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 603                 return -EFAULT;
 604         blocking = !(filp->f_flags & O_NONBLOCK);
 605         if (old_hdr.reply_len < 0)
 606                 return sg_new_write(sfp, filp, buf, count,
 607                                     blocking, 0, 0, NULL);
 608         if (count < (SZ_SG_HEADER + 6))
 609                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 610
 611         if (!(srp = sg_add_request(sfp))) {
 612                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
 613                                               "sg_write: queue full\n"));
 614                 return -EDOM;
 615         }
 616         buf += SZ_SG_HEADER;
 617         __get_user(opcode, buf);
 618         mutex_lock(&sfp->f_mutex);
 619         if (sfp->next_cmd_len > 0) {
 620                 cmd_size = sfp->next_cmd_len;
 621                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 622         } else {
 623                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 624                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 625                         cmd_size = 12;
 626         }
 627         mutex_unlock(&sfp->f_mutex);
 628         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
 629                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 630 /* Determine buffer size.  */
 631         input_size = count - cmd_size;
 632         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 633         mxsize -= SZ_SG_HEADER;
 634         input_size -= SZ_SG_HEADER;
 635         if (input_size < 0) {
 636                 sg_remove_request(sfp, srp);
 637                 return -EIO;    /* User did not pass enough bytes for this command. */
 638         }
 639         hp = &srp->header;
 640         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 641         hp->cmd_len = (unsigned char) cmd_size;
 642         hp->iovec_count = 0;
 643         hp->mx_sb_len = 0;
 644         if (input_size > 0)
 645                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 646                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 647         else
 648                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 649         hp->dxfer_len = mxsize;
 650         if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
 651             (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
 652                 hp->dxferp = (char __user *)buf + cmd_size;
 653         else
 654                 hp->dxferp = NULL;
 655         hp->sbp = NULL;
 656         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 657         hp->flags = input_size; /* structure abuse ... */
 658         hp->pack_id = old_hdr.pack_id;
 659         hp->usr_ptr = NULL;
 660         if (__copy_from_user(cmnd, buf, cmd_size))
 661                 return -EFAULT;
 662         /*
 663          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 664          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 665          * is a non-zero input_size, so emit a warning.
 666          */
 667         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 668                 printk_ratelimited(KERN_WARNING
 669                                    "sg_write: data in/out %d/%d bytes "
 670                                    "for SCSI command 0x%x-- guessing "
 671                                    "data in;\n   program %s not setting "
 672                                    "count and/or reply_len properly\n",
 673                                    old_hdr.reply_len - (int)SZ_SG_HEADER,
 674                                    input_size, (unsigned int) cmnd[0],
 675                                    current->comm);
 676         }
 677         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 678         return (k < 0) ? k : count;
 679 }
 680
 681 static ssize_t
 682 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 683                  size_t count, int blocking, int read_only, int sg_io_owned,
 684                  Sg_request **o_srp)
 685 {
 686         int k;
 687         Sg_request *srp;
 688         sg_io_hdr_t *hp;
 689         unsigned char cmnd[SG_MAX_CDB_SIZE];
 690         int timeout;
 691         unsigned long ul_timeout;
 692
 693         if (count < SZ_SG_IO_HDR)
 694                 return -EINVAL;
 695         if (!access_ok(VERIFY_READ, buf, count))
 696                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 697
 698         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 699         if (!(srp = sg_add_request(sfp))) {
 700                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 701                                               "sg_new_write: queue full\n"));
 702                 return -EDOM;
 703         }
 704         srp->sg_io_owned = sg_io_owned;
 705         hp = &srp->header;
 706         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 707                 sg_remove_request(sfp, srp);
 708                 return -EFAULT;
 709         }
 710         if (hp->interface_id != 'S') {
 711                 sg_remove_request(sfp, srp);
 712                 return -ENOSYS;
 713         }
 714         if (hp->flags & SG_FLAG_MMAP_IO) {
 715                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 716                         sg_remove_request(sfp, srp);
 717                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 718                 }
 719                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 720                         sg_remove_request(sfp, srp);
 721                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 722                 }
 723                 if (sfp->res_in_use) {
 724                         sg_remove_request(sfp, srp);
 725                         return -EBUSY;  /* reserve buffer already being used */
 726                 }
 727         }
 728         ul_timeout = msecs_to_jiffies(srp->header.timeout);
 729         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 730         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 731                 sg_remove_request(sfp, srp);
 732                 return -EMSGSIZE;
 733         }
 734         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
 735                 sg_remove_request(sfp, srp);
 736                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 737         }
 738         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 739                 sg_remove_request(sfp, srp);
 740                 return -EFAULT;
 741         }
 742         if (read_only && sg_allow_access(file, cmnd)) {
 743                 sg_remove_request(sfp, srp);
 744                 return -EPERM;
 745         }
 746         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 747         if (k < 0)
 748                 return k;
 749         if (o_srp)
 750                 *o_srp = srp;
 751         return count;
 752 }
 753
 754 static bool sg_is_valid_dxfer(sg_io_hdr_t *hp)
 755 {
 756         switch (hp->dxfer_direction) {
 757         case SG_DXFER_NONE:
 758                 if (hp->dxferp || hp->dxfer_len > 0)
 759                         return false;
 760                 return true;
 761         case SG_DXFER_TO_DEV:
 762         case SG_DXFER_FROM_DEV:
 763         case SG_DXFER_TO_FROM_DEV:
 764                 if (!hp->dxferp || hp->dxfer_len == 0)
 765                         return false;
 766                 return true;
 767         case SG_DXFER_UNKNOWN:
 768                 if ((!hp->dxferp && hp->dxfer_len) ||
 769                     (hp->dxferp && hp->dxfer_len == 0))
 770                         return false;
 771                 return true;
 772         default:
 773                 return false;
 774         }
 775 }
 776
 777 static int
 778 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 779                 unsigned char *cmnd, int timeout, int blocking)
 780 {
 781         int k, at_head;
 782         Sg_device *sdp = sfp->parentdp;
 783         sg_io_hdr_t *hp = &srp->header;
 784
 785         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 786         hp->status = 0;
 787         hp->masked_status = 0;
 788         hp->msg_status = 0;
 789         hp->info = 0;
 790         hp->host_status = 0;
 791         hp->driver_status = 0;
 792         hp->resid = 0;
 793         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
 794                         "sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 795                         (int) cmnd[0], (int) hp->cmd_len));
 796
 797         if (!sg_is_valid_dxfer(hp))
 798                 return -EINVAL;
 799
 800         k = sg_start_req(srp, cmnd);
 801         if (k) {
 802                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 803                         "sg_common_write: start_req err=%d\n", k));
 804                 sg_finish_rem_req(srp);
 805                 sg_remove_request(sfp, srp);
 806                 return k;       /* probably out of space --> ENOMEM */
 807         }
 808         if (atomic_read(&sdp->detaching)) {
 809                 if (srp->bio) {
 810                         scsi_req_free_cmd(scsi_req(srp->rq));
 811                         blk_end_request_all(srp->rq, BLK_STS_IOERR);
 812                         srp->rq = NULL;
 813                 }
 814
 815                 sg_finish_rem_req(srp);
 816                 sg_remove_request(sfp, srp);
 817                 return -ENODEV;
 818         }
 819
 820         hp->duration = jiffies_to_msecs(jiffies);
 821         if (hp->interface_id != '\0' && /* v3 (or later) interface */
 822             (SG_FLAG_Q_AT_TAIL & hp->flags))
 823                 at_head = 0;
 824         else
 825                 at_head = 1;
 826
 827         srp->rq->timeout = timeout;
 828         kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
 829         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 830                               srp->rq, at_head, sg_rq_end_io);
 831         return 0;
 832 }
 833
 834 static int srp_done(Sg_fd *sfp, Sg_request *srp)
 835 {
 836         unsigned long flags;
 837         int ret;
 838
 839         read_lock_irqsave(&sfp->rq_list_lock, flags);
 840         ret = srp->done;
 841         read_unlock_irqrestore(&sfp->rq_list_lock, flags);
 842         return ret;
 843 }
 844
 845 static int max_sectors_bytes(struct request_queue *q)
 846 {
 847         unsigned int max_sectors = queue_max_sectors(q);
 848
 849         max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
 850
 851         return max_sectors << 9;
 852 }
 853
 854 static long
 855 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 856 {
 857         void __user *p = (void __user *)arg;
 858         int __user *ip = p;
 859         int result, val, read_only;
 860         Sg_device *sdp;
 861         Sg_fd *sfp;
 862         Sg_request *srp;
 863         unsigned long iflags;
 864
 865         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 866                 return -ENXIO;
 867
 868         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 869                                    "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
 870         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 871
 872         switch (cmd_in) {
 873         case SG_IO:
 874                 if (atomic_read(&sdp->detaching))
 875                         return -ENODEV;
 876                 if (!scsi_block_when_processing_errors(sdp->device))
 877                         return -ENXIO;
 878                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 879                         return -EFAULT;
 880                 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 881                                  1, read_only, 1, &srp);
 882                 if (result < 0)
 883                         return result;
 884                 result = wait_event_interruptible(sfp->read_wait,
 885                         (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
 886                 if (atomic_read(&sdp->detaching))
 887                         return -ENODEV;
 888                 write_lock_irq(&sfp->rq_list_lock);
 889                 if (srp->done) {
 890                         srp->done = 2;
 891                         write_unlock_irq(&sfp->rq_list_lock);
 892                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 893                         return (result < 0) ? result : 0;
 894                 }
 895                 srp->orphan = 1;
 896                 write_unlock_irq(&sfp->rq_list_lock);
 897                 return result;  /* -ERESTARTSYS because signal hit process */
 898         case SG_SET_TIMEOUT:
 899                 result = get_user(val, ip);
 900                 if (result)
 901                         return result;
 902                 if (val < 0)
 903                         return -EIO;
 904                 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
 905                         val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
 906                                     INT_MAX);
 907                 sfp->timeout_user = val;
 908                 sfp->timeout = mult_frac(val, HZ, USER_HZ);
 909
 910                 return 0;
 911         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 912                                 /* strange ..., for backward compatibility */
 913                 return sfp->timeout_user;
 914         case SG_SET_FORCE_LOW_DMA:
 915                 /*
 916                  * N.B. This ioctl never worked properly, but failed to
 917                  * return an error value. So returning '0' to keep compability
 918                  * with legacy applications.
 919                  */
 920                 return 0;
 921         case SG_GET_LOW_DMA:
 922                 return put_user((int) sdp->device->host->unchecked_isa_dma, ip);
 923         case SG_GET_SCSI_ID:
 924                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 925                         return -EFAULT;
 926                 else {
 927                         sg_scsi_id_t __user *sg_idp = p;
 928
 929                         if (atomic_read(&sdp->detaching))
 930                                 return -ENODEV;
 931                         __put_user((int) sdp->device->host->host_no,
 932                                    &sg_idp->host_no);
 933                         __put_user((int) sdp->device->channel,
 934                                    &sg_idp->channel);
 935                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 936                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 937                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 938                         __put_user((short) sdp->device->host->cmd_per_lun,
 939                                    &sg_idp->h_cmd_per_lun);
 940                         __put_user((short) sdp->device->queue_depth,
 941                                    &sg_idp->d_queue_depth);
 942                         __put_user(0, &sg_idp->unused[0]);
 943                         __put_user(0, &sg_idp->unused[1]);
 944                         return 0;
 945                 }
 946         case SG_SET_FORCE_PACK_ID:
 947                 result = get_user(val, ip);
 948                 if (result)
 949                         return result;
 950                 sfp->force_packid = val ? 1 : 0;
 951                 return 0;
 952         case SG_GET_PACK_ID:
 953                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 954                         return -EFAULT;
 955                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 956                 list_for_each_entry(srp, &sfp->rq_list, entry) {
 957                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 958                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 959                                                        iflags);
 960                                 __put_user(srp->header.pack_id, ip);
 961                                 return 0;
 962                         }
 963                 }
 964                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 965                 __put_user(-1, ip);
 966                 return 0;
 967         case SG_GET_NUM_WAITING:
 968                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 969                 val = 0;
 970                 list_for_each_entry(srp, &sfp->rq_list, entry) {
 971                         if ((1 == srp->done) && (!srp->sg_io_owned))
 972                                 ++val;
 973                 }
 974                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 975                 return put_user(val, ip);
 976         case SG_GET_SG_TABLESIZE:
 977                 return put_user(sdp->sg_tablesize, ip);
 978         case SG_SET_RESERVED_SIZE:
 979                 result = get_user(val, ip);
 980                 if (result)
 981                         return result;
 982                 if (val < 0)
 983                         return -EINVAL;
 984                 val = min_t(int, val,
 985                             max_sectors_bytes(sdp->device->request_queue));
 986                 mutex_lock(&sfp->f_mutex);
 987                 if (val != sfp->reserve.bufflen) {
 988                         if (sfp->mmap_called ||
 989                             sfp->res_in_use) {
 990                                 mutex_unlock(&sfp->f_mutex);
 991                                 return -EBUSY;
 992                         }
 993
 994                         sg_remove_scat(sfp, &sfp->reserve);
 995                         sg_build_reserve(sfp, val);
 996                 }
 997                 mutex_unlock(&sfp->f_mutex);
 998                 return 0;
 999         case SG_GET_RESERVED_SIZE:
1000                 val = min_t(int, sfp->reserve.bufflen,
1001                             max_sectors_bytes(sdp->device->request_queue));
1002                 return put_user(val, ip);
1003         case SG_SET_COMMAND_Q:
1004                 result = get_user(val, ip);
1005                 if (result)
1006                         return result;
1007                 sfp->cmd_q = val ? 1 : 0;
1008                 return 0;
1009         case SG_GET_COMMAND_Q:
1010                 return put_user((int) sfp->cmd_q, ip);
1011         case SG_SET_KEEP_ORPHAN:
1012                 result = get_user(val, ip);
1013                 if (result)
1014                         return result;
1015                 sfp->keep_orphan = val;
1016                 return 0;
1017         case SG_GET_KEEP_ORPHAN:
1018                 return put_user((int) sfp->keep_orphan, ip);
1019         case SG_NEXT_CMD_LEN:
1020                 result = get_user(val, ip);
1021                 if (result)
1022                         return result;
1023                 if (val > SG_MAX_CDB_SIZE)
1024                         return -ENOMEM;
1025                 sfp->next_cmd_len = (val > 0) ? val : 0;
1026                 return 0;
1027         case SG_GET_VERSION_NUM:
1028                 return put_user(sg_version_num, ip);
1029         case SG_GET_ACCESS_COUNT:
1030                 /* faked - we don't have a real access count anymore */
1031                 val = (sdp->device ? 1 : 0);
1032                 return put_user(val, ip);
1033         case SG_GET_REQUEST_TABLE:
1034                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
1035                         return -EFAULT;
1036                 else {
1037                         sg_req_info_t *rinfo;
1038                         unsigned int ms;
1039
1040                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
1041                                                                 GFP_KERNEL);
1042                         if (!rinfo)
1043                                 return -ENOMEM;
1044                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1045                         val = 0;
1046                         list_for_each_entry(srp, &sfp->rq_list, entry) {
1047                                 if (val > SG_MAX_QUEUE)
1048                                         break;
1049                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
1050                                 rinfo[val].req_state = srp->done + 1;
1051                                 rinfo[val].problem =
1052                                         srp->header.masked_status &
1053                                         srp->header.host_status &
1054                                         srp->header.driver_status;
1055                                 if (srp->done)
1056                                         rinfo[val].duration =
1057                                                 srp->header.duration;
1058                                 else {
1059                                         ms = jiffies_to_msecs(jiffies);
1060                                         rinfo[val].duration =
1061                                                 (ms > srp->header.duration) ?
1062                                                 (ms - srp->header.duration) : 0;
1063                                 }
1064                                 rinfo[val].orphan = srp->orphan;
1065                                 rinfo[val].sg_io_owned = srp->sg_io_owned;
1066                                 rinfo[val].pack_id = srp->header.pack_id;
1067                                 rinfo[val].usr_ptr = srp->header.usr_ptr;
1068                                 val++;
1069                         }
1070                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1071                         result = __copy_to_user(p, rinfo,
1072                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1073                         result = result ? -EFAULT : 0;
1074                         kfree(rinfo);
1075                         return result;
1076                 }
1077         case SG_EMULATED_HOST:
1078                 if (atomic_read(&sdp->detaching))
1079                         return -ENODEV;
1080                 return put_user(sdp->device->host->hostt->emulated, ip);
1081         case SCSI_IOCTL_SEND_COMMAND:
1082                 if (atomic_read(&sdp->detaching))
1083                         return -ENODEV;
1084                 if (read_only) {
1085                         unsigned char opcode = WRITE_6;
1086                         Scsi_Ioctl_Command __user *siocp = p;
1087
1088                         if (copy_from_user(&opcode, siocp->data, 1))
1089                                 return -EFAULT;
1090                         if (sg_allow_access(filp, &opcode))
1091                                 return -EPERM;
1092                 }
1093                 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1094         case SG_SET_DEBUG:
1095                 result = get_user(val, ip);
1096                 if (result)
1097                         return result;
1098                 sdp->sgdebug = (char) val;
1099                 return 0;
1100         case BLKSECTGET:
1101                 return put_user(max_sectors_bytes(sdp->device->request_queue),
1102                                 ip);
1103         case BLKTRACESETUP:
1104                 return blk_trace_setup(sdp->device->request_queue,
1105                                        sdp->disk->disk_name,
1106                                        MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1107                                        NULL,
1108                                        (char *)arg);
1109         case BLKTRACESTART:
1110                 return blk_trace_startstop(sdp->device->request_queue, 1);
1111         case BLKTRACESTOP:
1112                 return blk_trace_startstop(sdp->device->request_queue, 0);
1113         case BLKTRACETEARDOWN:
1114                 return blk_trace_remove(sdp->device->request_queue);
1115         case SCSI_IOCTL_GET_IDLUN:
1116         case SCSI_IOCTL_GET_BUS_NUMBER:
1117         case SCSI_IOCTL_PROBE_HOST:
1118         case SG_GET_TRANSFORM:
1119         case SG_SCSI_RESET:
1120                 if (atomic_read(&sdp->detaching))
1121                         return -ENODEV;
1122                 break;
1123         default:
1124                 if (read_only)
1125                         return -EPERM;  /* don't know so take safe approach */
1126                 break;
1127         }
1128
1129         result = scsi_ioctl_block_when_processing_errors(sdp->device,
1130                         cmd_in, filp->f_flags & O_NDELAY);
1131         if (result)
1132                 return result;
1133         return scsi_ioctl(sdp->device, cmd_in, p);
1134 }
1135
1136 #ifdef CONFIG_COMPAT
1137 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1138 {
1139         Sg_device *sdp;
1140         Sg_fd *sfp;
1141         struct scsi_device *sdev;
1142
1143         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1144                 return -ENXIO;
1145
1146         sdev = sdp->device;
1147         if (sdev->host->hostt->compat_ioctl) {
1148                 int ret;
1149
1150                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1151
1152                 return ret;
1153         }
1154
1155         return -ENOIOCTLCMD;
1156 }
1157 #endif
1158
1159 static unsigned int
1160 sg_poll(struct file *filp, poll_table * wait)
1161 {
1162         unsigned int res = 0;
1163         Sg_device *sdp;
1164         Sg_fd *sfp;
1165         Sg_request *srp;
1166         int count = 0;
1167         unsigned long iflags;
1168
1169         sfp = filp->private_data;
1170         if (!sfp)
1171                 return POLLERR;
1172         sdp = sfp->parentdp;
1173         if (!sdp)
1174                 return POLLERR;
1175         poll_wait(filp, &sfp->read_wait, wait);
1176         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1177         list_for_each_entry(srp, &sfp->rq_list, entry) {
1178                 /* if any read waiting, flag it */
1179                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1180                         res = POLLIN | POLLRDNORM;
1181                 ++count;
1182         }
1183         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1184
1185         if (atomic_read(&sdp->detaching))
1186                 res |= POLLHUP;
1187         else if (!sfp->cmd_q) {
1188                 if (0 == count)
1189                         res |= POLLOUT | POLLWRNORM;
1190         } else if (count < SG_MAX_QUEUE)
1191                 res |= POLLOUT | POLLWRNORM;
1192         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1193                                       "sg_poll: res=0x%x\n", (int) res));
1194         return res;
1195 }
1196
1197 static int
1198 sg_fasync(int fd, struct file *filp, int mode)
1199 {
1200         Sg_device *sdp;
1201         Sg_fd *sfp;
1202
1203         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1204                 return -ENXIO;
1205         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1206                                       "sg_fasync: mode=%d\n", mode));
1207
1208         return fasync_helper(fd, filp, mode, &sfp->async_qp);
1209 }
1210
1211 static int
1212 sg_vma_fault(struct vm_fault *vmf)
1213 {
1214         struct vm_area_struct *vma = vmf->vma;
1215         Sg_fd *sfp;
1216         unsigned long offset, len, sa;
1217         Sg_scatter_hold *rsv_schp;
1218         int k, length;
1219
1220         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1221                 return VM_FAULT_SIGBUS;
1222         rsv_schp = &sfp->reserve;
1223         offset = vmf->pgoff << PAGE_SHIFT;
1224         if (offset >= rsv_schp->bufflen)
1225                 return VM_FAULT_SIGBUS;
1226         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1227                                       "sg_vma_fault: offset=%lu, scatg=%d\n",
1228                                       offset, rsv_schp->k_use_sg));
1229         sa = vma->vm_start;
1230         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1231         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1232                 len = vma->vm_end - sa;
1233                 len = (len < length) ? len : length;
1234                 if (offset < len) {
1235                         struct page *page = nth_page(rsv_schp->pages[k],
1236                                                      offset >> PAGE_SHIFT);
1237                         get_page(page); /* increment page count */
1238                         vmf->page = page;
1239                         return 0; /* success */
1240                 }
1241                 sa += len;
1242                 offset -= len;
1243         }
1244
1245         return VM_FAULT_SIGBUS;
1246 }
1247
1248 static const struct vm_operations_struct sg_mmap_vm_ops = {
1249         .fault = sg_vma_fault,
1250 };
1251
1252 static int
1253 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1254 {
1255         Sg_fd *sfp;
1256         unsigned long req_sz, len, sa;
1257         Sg_scatter_hold *rsv_schp;
1258         int k, length;
1259
1260         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1261                 return -ENXIO;
1262         req_sz = vma->vm_end - vma->vm_start;
1263         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1264                                       "sg_mmap starting, vm_start=%p, len=%d\n",
1265                                       (void *) vma->vm_start, (int) req_sz));
1266         if (vma->vm_pgoff)
1267                 return -EINVAL; /* want no offset */
1268         rsv_schp = &sfp->reserve;
1269         if (req_sz > rsv_schp->bufflen)
1270                 return -ENOMEM; /* cannot map more than reserved buffer */
1271
1272         sa = vma->vm_start;
1273         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1274         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1275                 len = vma->vm_end - sa;
1276                 len = (len < length) ? len : length;
1277                 sa += len;
1278         }
1279
1280         sfp->mmap_called = 1;
1281         vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
1282         vma->vm_private_data = sfp;
1283         vma->vm_ops = &sg_mmap_vm_ops;
1284         return 0;
1285 }
1286
1287 static void
1288 sg_rq_end_io_usercontext(struct work_struct *work)
1289 {
1290         struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1291         struct sg_fd *sfp = srp->parentfp;
1292
1293         sg_finish_rem_req(srp);
1294         sg_remove_request(sfp, srp);
1295         kref_put(&sfp->f_ref, sg_remove_sfp);
1296 }
1297
1298 /*
1299  * This function is a "bottom half" handler that is called by the mid
1300  * level when a command is completed (or has failed).
1301  */
1302 static void
1303 sg_rq_end_io(struct request *rq, blk_status_t status)
1304 {
1305         struct sg_request *srp = rq->end_io_data;
1306         struct scsi_request *req = scsi_req(rq);
1307         Sg_device *sdp;
1308         Sg_fd *sfp;
1309         unsigned long iflags;
1310         unsigned int ms;
1311         char *sense;
1312         int result, resid, done = 1;
1313
1314         if (WARN_ON(srp->done != 0))
1315                 return;
1316
1317         sfp = srp->parentfp;
1318         if (WARN_ON(sfp == NULL))
1319                 return;
1320
1321         sdp = sfp->parentdp;
1322         if (unlikely(atomic_read(&sdp->detaching)))
1323                 pr_info("%s: device detaching\n", __func__);
1324
1325         sense = req->sense;
1326         result = req->result;
1327         resid = req->resid_len;
1328
1329         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1330                                       "sg_cmd_done: pack_id=%d, res=0x%x\n",
1331                                       srp->header.pack_id, result));
1332         srp->header.resid = resid;
1333         ms = jiffies_to_msecs(jiffies);
1334         srp->header.duration = (ms > srp->header.duration) ?
1335                                 (ms - srp->header.duration) : 0;
1336         if (0 != result) {
1337                 struct scsi_sense_hdr sshdr;
1338
1339                 srp->header.status = 0xff & result;
1340                 srp->header.masked_status = status_byte(result);
1341                 srp->header.msg_status = msg_byte(result);
1342                 srp->header.host_status = host_byte(result);
1343                 srp->header.driver_status = driver_byte(result);
1344                 if ((sdp->sgdebug > 0) &&
1345                     ((CHECK_CONDITION == srp->header.masked_status) ||
1346                      (COMMAND_TERMINATED == srp->header.masked_status)))
1347                         __scsi_print_sense(sdp->device, __func__, sense,
1348                                            SCSI_SENSE_BUFFERSIZE);
1349
1350                 /* Following if statement is a patch supplied by Eric Youngdale */
1351                 if (driver_byte(result) != 0
1352                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1353                     && !scsi_sense_is_deferred(&sshdr)
1354                     && sshdr.sense_key == UNIT_ATTENTION
1355                     && sdp->device->removable) {
1356                         /* Detected possible disc change. Set the bit - this */
1357                         /* may be used if there are filesystems using this device */
1358                         sdp->device->changed = 1;
1359                 }
1360         }
1361
1362         if (req->sense_len)
1363                 memcpy(srp->sense_b, req->sense, SCSI_SENSE_BUFFERSIZE);
1364
1365         /* Rely on write phase to clean out srp status values, so no "else" */
1366
1367         /*
1368          * Free the request as soon as it is complete so that its resources
1369          * can be reused without waiting for userspace to read() the
1370          * result.  But keep the associated bio (if any) around until
1371          * blk_rq_unmap_user() can be called from user context.
1372          */
1373         srp->rq = NULL;
1374         scsi_req_free_cmd(scsi_req(rq));
1375         __blk_put_request(rq->q, rq);
1376
1377         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1378         if (unlikely(srp->orphan)) {
1379                 if (sfp->keep_orphan)
1380                         srp->sg_io_owned = 0;
1381                 else
1382                         done = 0;
1383         }
1384         srp->done = done;
1385         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1386
1387         if (likely(done)) {
1388                 /* Now wake up any sg_read() that is waiting for this
1389                  * packet.
1390                  */
1391                 wake_up_interruptible(&sfp->read_wait);
1392                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1393                 kref_put(&sfp->f_ref, sg_remove_sfp);
1394         } else {
1395                 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1396                 schedule_work(&srp->ew.work);
1397         }
1398 }
1399
1400 static const struct file_operations sg_fops = {
1401         .owner = THIS_MODULE,
1402         .read = sg_read,
1403         .write = sg_write,
1404         .poll = sg_poll,
1405         .unlocked_ioctl = sg_ioctl,
1406 #ifdef CONFIG_COMPAT
1407         .compat_ioctl = sg_compat_ioctl,
1408 #endif
1409         .open = sg_open,
1410         .mmap = sg_mmap,
1411         .release = sg_release,
1412         .fasync = sg_fasync,
1413         .llseek = no_llseek,
1414 };
1415
1416 static struct class *sg_sysfs_class;
1417
1418 static int sg_sysfs_valid = 0;
1419
1420 static Sg_device *
1421 sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1422 {
1423         struct request_queue *q = scsidp->request_queue;
1424         Sg_device *sdp;
1425         unsigned long iflags;
1426         int error;
1427         u32 k;
1428
1429         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1430         if (!sdp) {
1431                 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1432                             "failure\n", __func__);
1433                 return ERR_PTR(-ENOMEM);
1434         }
1435
1436         idr_preload(GFP_KERNEL);
1437         write_lock_irqsave(&sg_index_lock, iflags);
1438
1439         error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1440         if (error < 0) {
1441                 if (error == -ENOSPC) {
1442                         sdev_printk(KERN_WARNING, scsidp,
1443                                     "Unable to attach sg device type=%d, minor number exceeds %d\n",
1444                                     scsidp->type, SG_MAX_DEVS - 1);
1445                         error = -ENODEV;
1446                 } else {
1447                         sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1448                                     "allocation Sg_device failure: %d\n",
1449                                     __func__, error);
1450                 }
1451                 goto out_unlock;
1452         }
1453         k = error;
1454
1455         SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1456                                         "sg_alloc: dev=%d \n", k));
1457         sprintf(disk->disk_name, "sg%d", k);
1458         disk->first_minor = k;
1459         sdp->disk = disk;
1460         sdp->device = scsidp;
1461         mutex_init(&sdp->open_rel_lock);
1462         INIT_LIST_HEAD(&sdp->sfds);
1463         init_waitqueue_head(&sdp->open_wait);
1464         atomic_set(&sdp->detaching, 0);
1465         rwlock_init(&sdp->sfd_lock);
1466         sdp->sg_tablesize = queue_max_segments(q);
1467         sdp->index = k;
1468         kref_init(&sdp->d_ref);
1469         error = 0;
1470
1471 out_unlock:
1472         write_unlock_irqrestore(&sg_index_lock, iflags);
1473         idr_preload_end();
1474
1475         if (error) {
1476                 kfree(sdp);
1477                 return ERR_PTR(error);
1478         }
1479         return sdp;
1480 }
1481
1482 static int
1483 sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1484 {
1485         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1486         struct gendisk *disk;
1487         Sg_device *sdp = NULL;
1488         struct cdev * cdev = NULL;
1489         int error;
1490         unsigned long iflags;
1491
1492         disk = alloc_disk(1);
1493         if (!disk) {
1494                 pr_warn("%s: alloc_disk failed\n", __func__);
1495                 return -ENOMEM;
1496         }
1497         disk->major = SCSI_GENERIC_MAJOR;
1498
1499         error = -ENOMEM;
1500         cdev = cdev_alloc();
1501         if (!cdev) {
1502                 pr_warn("%s: cdev_alloc failed\n", __func__);
1503                 goto out;
1504         }
1505         cdev->owner = THIS_MODULE;
1506         cdev->ops = &sg_fops;
1507
1508         sdp = sg_alloc(disk, scsidp);
1509         if (IS_ERR(sdp)) {
1510                 pr_warn("%s: sg_alloc failed\n", __func__);
1511                 error = PTR_ERR(sdp);
1512                 goto out;
1513         }
1514
1515         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1516         if (error)
1517                 goto cdev_add_err;
1518
1519         sdp->cdev = cdev;
1520         if (sg_sysfs_valid) {
1521                 struct device *sg_class_member;
1522
1523                 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1524                                                 MKDEV(SCSI_GENERIC_MAJOR,
1525                                                       sdp->index),
1526                                                 sdp, "%s", disk->disk_name);
1527                 if (IS_ERR(sg_class_member)) {
1528                         pr_err("%s: device_create failed\n", __func__);
1529                         error = PTR_ERR(sg_class_member);
1530                         goto cdev_add_err;
1531                 }
1532                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1533                                           &sg_class_member->kobj, "generic");
1534                 if (error)
1535                         pr_err("%s: unable to make symlink 'generic' back "
1536                                "to sg%d\n", __func__, sdp->index);
1537         } else
1538                 pr_warn("%s: sg_sys Invalid\n", __func__);
1539
1540         sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1541                     "type %d\n", sdp->index, scsidp->type);
1542
1543         dev_set_drvdata(cl_dev, sdp);
1544
1545         return 0;
1546
1547 cdev_add_err:
1548         write_lock_irqsave(&sg_index_lock, iflags);
1549         idr_remove(&sg_index_idr, sdp->index);
1550         write_unlock_irqrestore(&sg_index_lock, iflags);
1551         kfree(sdp);
1552
1553 out:
1554         put_disk(disk);
1555         if (cdev)
1556                 cdev_del(cdev);
1557         return error;
1558 }
1559
1560 static void
1561 sg_device_destroy(struct kref *kref)
1562 {
1563         struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1564         unsigned long flags;
1565
1566         /* CAUTION!  Note that the device can still be found via idr_find()
1567          * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1568          * any other cleanup.
1569          */
1570
1571         write_lock_irqsave(&sg_index_lock, flags);
1572         idr_remove(&sg_index_idr, sdp->index);
1573         write_unlock_irqrestore(&sg_index_lock, flags);
1574
1575         SCSI_LOG_TIMEOUT(3,
1576                 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1577
1578         put_disk(sdp->disk);
1579         kfree(sdp);
1580 }
1581
1582 static void
1583 sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1584 {
1585         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1586         Sg_device *sdp = dev_get_drvdata(cl_dev);
1587         unsigned long iflags;
1588         Sg_fd *sfp;
1589         int val;
1590
1591         if (!sdp)
1592                 return;
1593         /* want sdp->detaching non-zero as soon as possible */
1594         val = atomic_inc_return(&sdp->detaching);
1595         if (val > 1)
1596                 return; /* only want to do following once per device */
1597
1598         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1599                                       "%s\n", __func__));
1600
1601         read_lock_irqsave(&sdp->sfd_lock, iflags);
1602         list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1603                 wake_up_interruptible_all(&sfp->read_wait);
1604                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1605         }
1606         wake_up_interruptible_all(&sdp->open_wait);
1607         read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1608
1609         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1610         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1611         cdev_del(sdp->cdev);
1612         sdp->cdev = NULL;
1613
1614         kref_put(&sdp->d_ref, sg_device_destroy);
1615 }
1616
1617 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1618 module_param_named(def_reserved_size, def_reserved_size, int,
1619                    S_IRUGO | S_IWUSR);
1620 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1621
1622 MODULE_AUTHOR("Douglas Gilbert");
1623 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1624 MODULE_LICENSE("GPL");
1625 MODULE_VERSION(SG_VERSION_STR);
1626 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1627
1628 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1629                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1630 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1631 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1632
1633 static int __init
1634 init_sg(void)
1635 {
1636         int rc;
1637
1638         if (scatter_elem_sz < PAGE_SIZE) {
1639                 scatter_elem_sz = PAGE_SIZE;
1640                 scatter_elem_sz_prev = scatter_elem_sz;
1641         }
1642         if (def_reserved_size >= 0)
1643                 sg_big_buff = def_reserved_size;
1644         else
1645                 def_reserved_size = sg_big_buff;
1646
1647         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1648                                     SG_MAX_DEVS, "sg");
1649         if (rc)
1650                 return rc;
1651         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1652         if ( IS_ERR(sg_sysfs_class) ) {
1653                 rc = PTR_ERR(sg_sysfs_class);
1654                 goto err_out;
1655         }
1656         sg_sysfs_valid = 1;
1657         rc = scsi_register_interface(&sg_interface);
1658         if (0 == rc) {
1659 #ifdef CONFIG_SCSI_PROC_FS
1660                 sg_proc_init();
1661 #endif                          /* CONFIG_SCSI_PROC_FS */
1662                 return 0;
1663         }
1664         class_destroy(sg_sysfs_class);
1665 err_out:
1666         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1667         return rc;
1668 }
1669
1670 static void __exit
1671 exit_sg(void)
1672 {
1673 #ifdef CONFIG_SCSI_PROC_FS
1674         sg_proc_cleanup();
1675 #endif                          /* CONFIG_SCSI_PROC_FS */
1676         scsi_unregister_interface(&sg_interface);
1677         class_destroy(sg_sysfs_class);
1678         sg_sysfs_valid = 0;
1679         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1680                                  SG_MAX_DEVS);
1681         idr_destroy(&sg_index_idr);
1682 }
1683
1684 static int
1685 sg_start_req(Sg_request *srp, unsigned char *cmd)
1686 {
1687         int res;
1688         struct request *rq;
1689         struct scsi_request *req;
1690         Sg_fd *sfp = srp->parentfp;
1691         sg_io_hdr_t *hp = &srp->header;
1692         int dxfer_len = (int) hp->dxfer_len;
1693         int dxfer_dir = hp->dxfer_direction;
1694         unsigned int iov_count = hp->iovec_count;
1695         Sg_scatter_hold *req_schp = &srp->data;
1696         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1697         struct request_queue *q = sfp->parentdp->device->request_queue;
1698         struct rq_map_data *md, map_data;
1699         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1700         unsigned char *long_cmdp = NULL;
1701
1702         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1703                                       "sg_start_req: dxfer_len=%d\n",
1704                                       dxfer_len));
1705
1706         if (hp->cmd_len > BLK_MAX_CDB) {
1707                 long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1708                 if (!long_cmdp)
1709                         return -ENOMEM;
1710         }
1711
1712         /*
1713          * NOTE
1714          *
1715          * With scsi-mq enabled, there are a fixed number of preallocated
1716          * requests equal in number to shost->can_queue.  If all of the
1717          * preallocated requests are already in use, then using GFP_ATOMIC with
1718          * blk_get_request() will return -EWOULDBLOCK, whereas using GFP_KERNEL
1719          * will cause blk_get_request() to sleep until an active command
1720          * completes, freeing up a request.  Neither option is ideal, but
1721          * GFP_KERNEL is the better choice to prevent userspace from getting an
1722          * unexpected EWOULDBLOCK.
1723          *
1724          * With scsi-mq disabled, blk_get_request() with GFP_KERNEL usually
1725          * does not sleep except under memory pressure.
1726          */
1727         rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1728                         REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, GFP_KERNEL);
1729         if (IS_ERR(rq)) {
1730                 kfree(long_cmdp);
1731                 return PTR_ERR(rq);
1732         }
1733         req = scsi_req(rq);
1734
1735         if (hp->cmd_len > BLK_MAX_CDB)
1736                 req->cmd = long_cmdp;
1737         memcpy(req->cmd, cmd, hp->cmd_len);
1738         req->cmd_len = hp->cmd_len;
1739
1740         srp->rq = rq;
1741         rq->end_io_data = srp;
1742         req->retries = SG_DEFAULT_RETRIES;
1743
1744         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1745                 return 0;
1746
1747         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1748             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1749             !sfp->parentdp->device->host->unchecked_isa_dma &&
1750             blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1751                 md = NULL;
1752         else
1753                 md = &map_data;
1754
1755         if (md) {
1756                 mutex_lock(&sfp->f_mutex);
1757                 if (dxfer_len <= rsv_schp->bufflen &&
1758                     !sfp->res_in_use) {
1759                         sfp->res_in_use = 1;
1760                         sg_link_reserve(sfp, srp, dxfer_len);
1761                 } else if ((hp->flags & SG_FLAG_MMAP_IO) && sfp->res_in_use) {
1762                         mutex_unlock(&sfp->f_mutex);
1763                         return -EBUSY;
1764                 } else {
1765                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1766                         if (res) {
1767                                 mutex_unlock(&sfp->f_mutex);
1768                                 return res;
1769                         }
1770                 }
1771                 mutex_unlock(&sfp->f_mutex);
1772
1773                 md->pages = req_schp->pages;
1774                 md->page_order = req_schp->page_order;
1775                 md->nr_entries = req_schp->k_use_sg;
1776                 md->offset = 0;
1777                 md->null_mapped = hp->dxferp ? 0 : 1;
1778                 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1779                         md->from_user = 1;
1780                 else
1781                         md->from_user = 0;
1782         }
1783
1784         if (iov_count) {
1785                 struct iovec *iov = NULL;
1786                 struct iov_iter i;
1787
1788                 res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i);
1789                 if (res < 0)
1790                         return res;
1791
1792                 iov_iter_truncate(&i, hp->dxfer_len);
1793                 if (!iov_iter_count(&i)) {
1794                         kfree(iov);
1795                         return -EINVAL;
1796                 }
1797
1798                 res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
1799                 kfree(iov);
1800         } else
1801                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1802                                       hp->dxfer_len, GFP_ATOMIC);
1803
1804         if (!res) {
1805                 srp->bio = rq->bio;
1806
1807                 if (!md) {
1808                         req_schp->dio_in_use = 1;
1809                         hp->info |= SG_INFO_DIRECT_IO;
1810                 }
1811         }
1812         return res;
1813 }
1814
1815 static int
1816 sg_finish_rem_req(Sg_request *srp)
1817 {
1818         int ret = 0;
1819
1820         Sg_fd *sfp = srp->parentfp;
1821         Sg_scatter_hold *req_schp = &srp->data;
1822
1823         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1824                                       "sg_finish_rem_req: res_used=%d\n",
1825                                       (int) srp->res_used));
1826         if (srp->bio)
1827                 ret = blk_rq_unmap_user(srp->bio);
1828
1829         if (srp->rq) {
1830                 scsi_req_free_cmd(scsi_req(srp->rq));
1831                 blk_put_request(srp->rq);
1832         }
1833
1834         if (srp->res_used)
1835                 sg_unlink_reserve(sfp, srp);
1836         else
1837                 sg_remove_scat(sfp, req_schp);
1838
1839         return ret;
1840 }
1841
1842 static int
1843 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1844 {
1845         int sg_bufflen = tablesize * sizeof(struct page *);
1846         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1847
1848         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1849         if (!schp->pages)
1850                 return -ENOMEM;
1851         schp->sglist_len = sg_bufflen;
1852         return tablesize;       /* number of scat_gath elements allocated */
1853 }
1854
1855 static int
1856 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1857 {
1858         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1859         int sg_tablesize = sfp->parentdp->sg_tablesize;
1860         int blk_size = buff_size, order;
1861         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1862         struct sg_device *sdp = sfp->parentdp;
1863
1864         if (blk_size < 0)
1865                 return -EFAULT;
1866         if (0 == blk_size)
1867                 ++blk_size;     /* don't know why */
1868         /* round request up to next highest SG_SECTOR_SZ byte boundary */
1869         blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1870         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1871                 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1872                 buff_size, blk_size));
1873
1874         /* N.B. ret_sz carried into this block ... */
1875         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1876         if (mx_sc_elems < 0)
1877                 return mx_sc_elems;     /* most likely -ENOMEM */
1878
1879         num = scatter_elem_sz;
1880         if (unlikely(num != scatter_elem_sz_prev)) {
1881                 if (num < PAGE_SIZE) {
1882                         scatter_elem_sz = PAGE_SIZE;
1883                         scatter_elem_sz_prev = PAGE_SIZE;
1884                 } else
1885                         scatter_elem_sz_prev = num;
1886         }
1887
1888         if (sdp->device->host->unchecked_isa_dma)
1889                 gfp_mask |= GFP_DMA;
1890
1891         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1892                 gfp_mask |= __GFP_ZERO;
1893
1894         order = get_order(num);
1895 retry:
1896         ret_sz = 1 << (PAGE_SHIFT + order);
1897
1898         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1899              k++, rem_sz -= ret_sz) {
1900
1901                 num = (rem_sz > scatter_elem_sz_prev) ?
1902                         scatter_elem_sz_prev : rem_sz;
1903
1904                 schp->pages[k] = alloc_pages(gfp_mask, order);
1905                 if (!schp->pages[k])
1906                         goto out;
1907
1908                 if (num == scatter_elem_sz_prev) {
1909                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1910                                 scatter_elem_sz = ret_sz;
1911                                 scatter_elem_sz_prev = ret_sz;
1912                         }
1913                 }
1914
1915                 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1916                                  "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1917                                  k, num, ret_sz));
1918         }               /* end of for loop */
1919
1920         schp->page_order = order;
1921         schp->k_use_sg = k;
1922         SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1923                          "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1924                          k, rem_sz));
1925
1926         schp->bufflen = blk_size;
1927         if (rem_sz > 0) /* must have failed */
1928                 return -ENOMEM;
1929         return 0;
1930 out:
1931         for (i = 0; i < k; i++)
1932                 __free_pages(schp->pages[i], order);
1933
1934         if (--order >= 0)
1935                 goto retry;
1936
1937         return -ENOMEM;
1938 }
1939
1940 static void
1941 sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1942 {
1943         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1944                          "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1945         if (schp->pages && schp->sglist_len > 0) {
1946                 if (!schp->dio_in_use) {
1947                         int k;
1948
1949                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1950                                 SCSI_LOG_TIMEOUT(5,
1951                                         sg_printk(KERN_INFO, sfp->parentdp,
1952                                         "sg_remove_scat: k=%d, pg=0x%p\n",
1953                                         k, schp->pages[k]));
1954                                 __free_pages(schp->pages[k], schp->page_order);
1955                         }
1956
1957                         kfree(schp->pages);
1958                 }
1959         }
1960         memset(schp, 0, sizeof (*schp));
1961 }
1962
1963 static int
1964 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1965 {
1966         Sg_scatter_hold *schp = &srp->data;
1967         int k, num;
1968
1969         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1970                          "sg_read_oxfer: num_read_xfer=%d\n",
1971                          num_read_xfer));
1972         if ((!outp) || (num_read_xfer <= 0))
1973                 return 0;
1974
1975         num = 1 << (PAGE_SHIFT + schp->page_order);
1976         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1977                 if (num > num_read_xfer) {
1978                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1979                                            num_read_xfer))
1980                                 return -EFAULT;
1981                         break;
1982                 } else {
1983                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1984                                            num))
1985                                 return -EFAULT;
1986                         num_read_xfer -= num;
1987                         if (num_read_xfer <= 0)
1988                                 break;
1989                         outp += num;
1990                 }
1991         }
1992
1993         return 0;
1994 }
1995
1996 static void
1997 sg_build_reserve(Sg_fd * sfp, int req_size)
1998 {
1999         Sg_scatter_hold *schp = &sfp->reserve;
2000
2001         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2002                          "sg_build_reserve: req_size=%d\n", req_size));
2003         do {
2004                 if (req_size < PAGE_SIZE)
2005                         req_size = PAGE_SIZE;
2006                 if (0 == sg_build_indirect(schp, sfp, req_size))
2007                         return;
2008                 else
2009                         sg_remove_scat(sfp, schp);
2010                 req_size >>= 1; /* divide by 2 */
2011         } while (req_size > (PAGE_SIZE / 2));
2012 }
2013
2014 static void
2015 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2016 {
2017         Sg_scatter_hold *req_schp = &srp->data;
2018         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2019         int k, num, rem;
2020
2021         srp->res_used = 1;
2022         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2023                          "sg_link_reserve: size=%d\n", size));
2024         rem = size;
2025
2026         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2027         for (k = 0; k < rsv_schp->k_use_sg; k++) {
2028                 if (rem <= num) {
2029                         req_schp->k_use_sg = k + 1;
2030                         req_schp->sglist_len = rsv_schp->sglist_len;
2031                         req_schp->pages = rsv_schp->pages;
2032
2033                         req_schp->bufflen = size;
2034                         req_schp->page_order = rsv_schp->page_order;
2035                         break;
2036                 } else
2037                         rem -= num;
2038         }
2039
2040         if (k >= rsv_schp->k_use_sg)
2041                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2042                                  "sg_link_reserve: BAD size\n"));
2043 }
2044
2045 static void
2046 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2047 {
2048         Sg_scatter_hold *req_schp = &srp->data;
2049
2050         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2051                                       "sg_unlink_reserve: req->k_use_sg=%d\n",
2052                                       (int) req_schp->k_use_sg));
2053         req_schp->k_use_sg = 0;
2054         req_schp->bufflen = 0;
2055         req_schp->pages = NULL;
2056         req_schp->page_order = 0;
2057         req_schp->sglist_len = 0;
2058         srp->res_used = 0;
2059         /* Called without mutex lock to avoid deadlock */
2060         sfp->res_in_use = 0;
2061 }
2062
2063 static Sg_request *
2064 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2065 {
2066         Sg_request *resp;
2067         unsigned long iflags;
2068
2069         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2070         list_for_each_entry(resp, &sfp->rq_list, entry) {
2071                 /* look for requests that are ready + not SG_IO owned */
2072                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2073                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2074                         resp->done = 2; /* guard against other readers */
2075                         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2076                         return resp;
2077                 }
2078         }
2079         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2080         return NULL;
2081 }
2082
2083 /* always adds to end of list */
2084 static Sg_request *
2085 sg_add_request(Sg_fd * sfp)
2086 {
2087         int k;
2088         unsigned long iflags;
2089         Sg_request *rp = sfp->req_arr;
2090
2091         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2092         if (!list_empty(&sfp->rq_list)) {
2093                 if (!sfp->cmd_q)
2094                         goto out_unlock;
2095
2096                 for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2097                         if (!rp->parentfp)
2098                                 break;
2099                 }
2100                 if (k >= SG_MAX_QUEUE)
2101                         goto out_unlock;
2102         }
2103         memset(rp, 0, sizeof (Sg_request));
2104         rp->parentfp = sfp;
2105         rp->header.duration = jiffies_to_msecs(jiffies);
2106         list_add_tail(&rp->entry, &sfp->rq_list);
2107         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2108         return rp;
2109 out_unlock:
2110         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2111         return NULL;
2112 }
2113
2114 /* Return of 1 for found; 0 for not found */
2115 static int
2116 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2117 {
2118         unsigned long iflags;
2119         int res = 0;
2120
2121         if (!sfp || !srp || list_empty(&sfp->rq_list))
2122                 return res;
2123         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2124         if (!list_empty(&srp->entry)) {
2125                 list_del(&srp->entry);
2126                 srp->parentfp = NULL;
2127                 res = 1;
2128         }
2129         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2130         return res;
2131 }
2132
2133 static Sg_fd *
2134 sg_add_sfp(Sg_device * sdp)
2135 {
2136         Sg_fd *sfp;
2137         unsigned long iflags;
2138         int bufflen;
2139
2140         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2141         if (!sfp)
2142                 return ERR_PTR(-ENOMEM);
2143
2144         init_waitqueue_head(&sfp->read_wait);
2145         rwlock_init(&sfp->rq_list_lock);
2146         INIT_LIST_HEAD(&sfp->rq_list);
2147         kref_init(&sfp->f_ref);
2148         mutex_init(&sfp->f_mutex);
2149         sfp->timeout = SG_DEFAULT_TIMEOUT;
2150         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2151         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2152         sfp->cmd_q = SG_DEF_COMMAND_Q;
2153         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2154         sfp->parentdp = sdp;
2155         write_lock_irqsave(&sdp->sfd_lock, iflags);
2156         if (atomic_read(&sdp->detaching)) {
2157                 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2158                 return ERR_PTR(-ENODEV);
2159         }
2160         list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2161         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2162         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2163                                       "sg_add_sfp: sfp=0x%p\n", sfp));
2164         if (unlikely(sg_big_buff != def_reserved_size))
2165                 sg_big_buff = def_reserved_size;
2166
2167         bufflen = min_t(int, sg_big_buff,
2168                         max_sectors_bytes(sdp->device->request_queue));
2169         sg_build_reserve(sfp, bufflen);
2170         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2171                                       "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2172                                       sfp->reserve.bufflen,
2173                                       sfp->reserve.k_use_sg));
2174
2175         kref_get(&sdp->d_ref);
2176         __module_get(THIS_MODULE);
2177         return sfp;
2178 }
2179
2180 static void
2181 sg_remove_sfp_usercontext(struct work_struct *work)
2182 {
2183         struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2184         struct sg_device *sdp = sfp->parentdp;
2185         Sg_request *srp;
2186         unsigned long iflags;
2187
2188         /* Cleanup any responses which were never read(). */
2189         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2190         while (!list_empty(&sfp->rq_list)) {
2191                 srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2192                 sg_finish_rem_req(srp);
2193                 list_del(&srp->entry);
2194                 srp->parentfp = NULL;
2195         }
2196         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2197
2198         if (sfp->reserve.bufflen > 0) {
2199                 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2200                                 "sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2201                                 (int) sfp->reserve.bufflen,
2202                                 (int) sfp->reserve.k_use_sg));
2203                 sg_remove_scat(sfp, &sfp->reserve);
2204         }
2205
2206         SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2207                         "sg_remove_sfp: sfp=0x%p\n", sfp));
2208         kfree(sfp);
2209
2210         scsi_device_put(sdp->device);
2211         kref_put(&sdp->d_ref, sg_device_destroy);
2212         module_put(THIS_MODULE);
2213 }
2214
2215 static void
2216 sg_remove_sfp(struct kref *kref)
2217 {
2218         struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2219         struct sg_device *sdp = sfp->parentdp;
2220         unsigned long iflags;
2221
2222         write_lock_irqsave(&sdp->sfd_lock, iflags);
2223         list_del(&sfp->sfd_siblings);
2224         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2225
2226         INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2227         schedule_work(&sfp->ew.work);
2228 }
2229
2230 #ifdef CONFIG_SCSI_PROC_FS
2231 static int
2232 sg_idr_max_id(int id, void *p, void *data)
2233 {
2234         int *k = data;
2235
2236         if (*k < id)
2237                 *k = id;
2238
2239         return 0;
2240 }
2241
2242 static int
2243 sg_last_dev(void)
2244 {
2245         int k = -1;
2246         unsigned long iflags;
2247
2248         read_lock_irqsave(&sg_index_lock, iflags);
2249         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2250         read_unlock_irqrestore(&sg_index_lock, iflags);
2251         return k + 1;           /* origin 1 */
2252 }
2253 #endif
2254
2255 /* must be called with sg_index_lock held */
2256 static Sg_device *sg_lookup_dev(int dev)
2257 {
2258         return idr_find(&sg_index_idr, dev);
2259 }
2260
2261 static Sg_device *
2262 sg_get_dev(int dev)
2263 {
2264         struct sg_device *sdp;
2265         unsigned long flags;
2266
2267         read_lock_irqsave(&sg_index_lock, flags);
2268         sdp = sg_lookup_dev(dev);
2269         if (!sdp)
2270                 sdp = ERR_PTR(-ENXIO);
2271         else if (atomic_read(&sdp->detaching)) {
2272                 /* If sdp->detaching, then the refcount may already be 0, in
2273                  * which case it would be a bug to do kref_get().
2274                  */
2275                 sdp = ERR_PTR(-ENODEV);
2276         } else
2277                 kref_get(&sdp->d_ref);
2278         read_unlock_irqrestore(&sg_index_lock, flags);
2279
2280         return sdp;
2281 }
2282
2283 #ifdef CONFIG_SCSI_PROC_FS
2284
2285 static struct proc_dir_entry *sg_proc_sgp = NULL;
2286
2287 static char sg_proc_sg_dirname[] = "scsi/sg";
2288
2289 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2290
2291 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2292 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2293                                   size_t count, loff_t *off);
2294 static const struct file_operations adio_fops = {
2295         .owner = THIS_MODULE,
2296         .open = sg_proc_single_open_adio,
2297         .read = seq_read,
2298         .llseek = seq_lseek,
2299         .write = sg_proc_write_adio,
2300         .release = single_release,
2301 };
2302
2303 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2304 static ssize_t sg_proc_write_dressz(struct file *filp,
2305                 const char __user *buffer, size_t count, loff_t *off);
2306 static const struct file_operations dressz_fops = {
2307         .owner = THIS_MODULE,
2308         .open = sg_proc_single_open_dressz,
2309         .read = seq_read,
2310         .llseek = seq_lseek,
2311         .write = sg_proc_write_dressz,
2312         .release = single_release,
2313 };
2314
2315 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2316 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2317 static const struct file_operations version_fops = {
2318         .owner = THIS_MODULE,
2319         .open = sg_proc_single_open_version,
2320         .read = seq_read,
2321         .llseek = seq_lseek,
2322         .release = single_release,
2323 };
2324
2325 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2326 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2327 static const struct file_operations devhdr_fops = {
2328         .owner = THIS_MODULE,
2329         .open = sg_proc_single_open_devhdr,
2330         .read = seq_read,
2331         .llseek = seq_lseek,
2332         .release = single_release,
2333 };
2334
2335 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2336 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2337 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2338 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2339 static void dev_seq_stop(struct seq_file *s, void *v);
2340 static const struct file_operations dev_fops = {
2341         .owner = THIS_MODULE,
2342         .open = sg_proc_open_dev,
2343         .read = seq_read,
2344         .llseek = seq_lseek,
2345         .release = seq_release,
2346 };
2347 static const struct seq_operations dev_seq_ops = {
2348         .start = dev_seq_start,
2349         .next  = dev_seq_next,
2350         .stop  = dev_seq_stop,
2351         .show  = sg_proc_seq_show_dev,
2352 };
2353
2354 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2355 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2356 static const struct file_operations devstrs_fops = {
2357         .owner = THIS_MODULE,
2358         .open = sg_proc_open_devstrs,
2359         .read = seq_read,
2360         .llseek = seq_lseek,
2361         .release = seq_release,
2362 };
2363 static const struct seq_operations devstrs_seq_ops = {
2364         .start = dev_seq_start,
2365         .next  = dev_seq_next,
2366         .stop  = dev_seq_stop,
2367         .show  = sg_proc_seq_show_devstrs,
2368 };
2369
2370 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2371 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2372 static const struct file_operations debug_fops = {
2373         .owner = THIS_MODULE,
2374         .open = sg_proc_open_debug,
2375         .read = seq_read,
2376         .llseek = seq_lseek,
2377         .release = seq_release,
2378 };
2379 static const struct seq_operations debug_seq_ops = {
2380         .start = dev_seq_start,
2381         .next  = dev_seq_next,
2382         .stop  = dev_seq_stop,
2383         .show  = sg_proc_seq_show_debug,
2384 };
2385
2386
2387 struct sg_proc_leaf {
2388         const char * name;
2389         const struct file_operations * fops;
2390 };
2391
2392 static const struct sg_proc_leaf sg_proc_leaf_arr[] = {
2393         {"allow_dio", &adio_fops},
2394         {"debug", &debug_fops},
2395         {"def_reserved_size", &dressz_fops},
2396         {"device_hdr", &devhdr_fops},
2397         {"devices", &dev_fops},
2398         {"device_strs", &devstrs_fops},
2399         {"version", &version_fops}
2400 };
2401
2402 static int
2403 sg_proc_init(void)
2404 {
2405         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2406         int k;
2407
2408         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2409         if (!sg_proc_sgp)
2410                 return 1;
2411         for (k = 0; k < num_leaves; ++k) {
2412                 const struct sg_proc_leaf *leaf = &sg_proc_leaf_arr[k];
2413                 umode_t mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2414                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2415         }
2416         return 0;
2417 }
2418
2419 static void
2420 sg_proc_cleanup(void)
2421 {
2422         int k;
2423         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2424
2425         if (!sg_proc_sgp)
2426                 return;
2427         for (k = 0; k < num_leaves; ++k)
2428                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2429         remove_proc_entry(sg_proc_sg_dirname, NULL);
2430 }
2431
2432
2433 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2434 {
2435         seq_printf(s, "%d\n", *((int *)s->private));
2436         return 0;
2437 }
2438
2439 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2440 {
2441         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2442 }
2443
2444 static ssize_t
2445 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2446                    size_t count, loff_t *off)
2447 {
2448         int err;
2449         unsigned long num;
2450
2451         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2452                 return -EACCES;
2453         err = kstrtoul_from_user(buffer, count, 0, &num);
2454         if (err)
2455                 return err;
2456         sg_allow_dio = num ? 1 : 0;
2457         return count;
2458 }
2459
2460 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2461 {
2462         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2463 }
2464
2465 static ssize_t
2466 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2467                      size_t count, loff_t *off)
2468 {
2469         int err;
2470         unsigned long k = ULONG_MAX;
2471
2472         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2473                 return -EACCES;
2474
2475         err = kstrtoul_from_user(buffer, count, 0, &k);
2476         if (err)
2477                 return err;
2478         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2479                 sg_big_buff = k;
2480                 return count;
2481         }
2482         return -ERANGE;
2483 }
2484
2485 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2486 {
2487         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2488                    sg_version_date);
2489         return 0;
2490 }
2491
2492 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2493 {
2494         return single_open(file, sg_proc_seq_show_version, NULL);
2495 }
2496
2497 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2498 {
2499         seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2500         return 0;
2501 }
2502
2503 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2504 {
2505         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2506 }
2507
2508 struct sg_proc_deviter {
2509         loff_t  index;
2510         size_t  max;
2511 };
2512
2513 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2514 {
2515         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2516
2517         s->private = it;
2518         if (! it)
2519                 return NULL;
2520
2521         it->index = *pos;
2522         it->max = sg_last_dev();
2523         if (it->index >= it->max)
2524                 return NULL;
2525         return it;
2526 }
2527
2528 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2529 {
2530         struct sg_proc_deviter * it = s->private;
2531
2532         *pos = ++it->index;
2533         return (it->index < it->max) ? it : NULL;
2534 }
2535
2536 static void dev_seq_stop(struct seq_file *s, void *v)
2537 {
2538         kfree(s->private);
2539 }
2540
2541 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2542 {
2543         return seq_open(file, &dev_seq_ops);
2544 }
2545
2546 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2547 {
2548         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2549         Sg_device *sdp;
2550         struct scsi_device *scsidp;
2551         unsigned long iflags;
2552
2553         read_lock_irqsave(&sg_index_lock, iflags);
2554         sdp = it ? sg_lookup_dev(it->index) : NULL;
2555         if ((NULL == sdp) || (NULL == sdp->device) ||
2556             (atomic_read(&sdp->detaching)))
2557                 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2558         else {
2559                 scsidp = sdp->device;
2560                 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2561                               scsidp->host->host_no, scsidp->channel,
2562                               scsidp->id, scsidp->lun, (int) scsidp->type,
2563                               1,
2564                               (int) scsidp->queue_depth,
2565                               (int) atomic_read(&scsidp->device_busy),
2566                               (int) scsi_device_online(scsidp));
2567         }
2568         read_unlock_irqrestore(&sg_index_lock, iflags);
2569         return 0;
2570 }
2571
2572 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2573 {
2574         return seq_open(file, &devstrs_seq_ops);
2575 }
2576
2577 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2578 {
2579         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2580         Sg_device *sdp;
2581         struct scsi_device *scsidp;
2582         unsigned long iflags;
2583
2584         read_lock_irqsave(&sg_index_lock, iflags);
2585         sdp = it ? sg_lookup_dev(it->index) : NULL;
2586         scsidp = sdp ? sdp->device : NULL;
2587         if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2588                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2589                            scsidp->vendor, scsidp->model, scsidp->rev);
2590         else
2591                 seq_puts(s, "<no active device>\n");
2592         read_unlock_irqrestore(&sg_index_lock, iflags);
2593         return 0;
2594 }
2595
2596 /* must be called while holding sg_index_lock */
2597 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2598 {
2599         int k, new_interface, blen, usg;
2600         Sg_request *srp;
2601         Sg_fd *fp;
2602         const sg_io_hdr_t *hp;
2603         const char * cp;
2604         unsigned int ms;
2605
2606         k = 0;
2607         list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2608                 k++;
2609                 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2610                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2611                            "(res)sgat=%d low_dma=%d\n", k,
2612                            jiffies_to_msecs(fp->timeout),
2613                            fp->reserve.bufflen,
2614                            (int) fp->reserve.k_use_sg,
2615                            (int) sdp->device->host->unchecked_isa_dma);
2616                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2617                            (int) fp->cmd_q, (int) fp->force_packid,
2618                            (int) fp->keep_orphan);
2619                 list_for_each_entry(srp, &fp->rq_list, entry) {
2620                         hp = &srp->header;
2621                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2622                         if (srp->res_used) {
2623                                 if (new_interface &&
2624                                     (SG_FLAG_MMAP_IO & hp->flags))
2625                                         cp = "     mmap>> ";
2626                                 else
2627                                         cp = "     rb>> ";
2628                         } else {
2629                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2630                                         cp = "     dio>> ";
2631                                 else
2632                                         cp = "     ";
2633                         }
2634                         seq_puts(s, cp);
2635                         blen = srp->data.bufflen;
2636                         usg = srp->data.k_use_sg;
2637                         seq_puts(s, srp->done ?
2638                                  ((1 == srp->done) ?  "rcv:" : "fin:")
2639                                   : "act:");
2640                         seq_printf(s, " id=%d blen=%d",
2641                                    srp->header.pack_id, blen);
2642                         if (srp->done)
2643                                 seq_printf(s, " dur=%d", hp->duration);
2644                         else {
2645                                 ms = jiffies_to_msecs(jiffies);
2646                                 seq_printf(s, " t_o/elap=%d/%d",
2647                                         (new_interface ? hp->timeout :
2648                                                   jiffies_to_msecs(fp->timeout)),
2649                                         (ms > hp->duration ? ms - hp->duration : 0));
2650                         }
2651                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2652                                    (int) srp->data.cmd_opcode);
2653                 }
2654                 if (list_empty(&fp->rq_list))
2655                         seq_puts(s, "     No requests active\n");
2656                 read_unlock(&fp->rq_list_lock);
2657         }
2658 }
2659
2660 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2661 {
2662         return seq_open(file, &debug_seq_ops);
2663 }
2664
2665 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2666 {
2667         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2668         Sg_device *sdp;
2669         unsigned long iflags;
2670
2671         if (it && (0 == it->index))
2672                 seq_printf(s, "max_active_device=%d  def_reserved_size=%d\n",
2673                            (int)it->max, sg_big_buff);
2674
2675         read_lock_irqsave(&sg_index_lock, iflags);
2676         sdp = it ? sg_lookup_dev(it->index) : NULL;
2677         if (NULL == sdp)
2678                 goto skip;
2679         read_lock(&sdp->sfd_lock);
2680         if (!list_empty(&sdp->sfds)) {
2681                 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2682                 if (atomic_read(&sdp->detaching))
2683                         seq_puts(s, "detaching pending close ");
2684                 else if (sdp->device) {
2685                         struct scsi_device *scsidp = sdp->device;
2686
2687                         seq_printf(s, "%d:%d:%d:%llu   em=%d",
2688                                    scsidp->host->host_no,
2689                                    scsidp->channel, scsidp->id,
2690                                    scsidp->lun,
2691                                    scsidp->host->hostt->emulated);
2692                 }
2693                 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2694                            sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2695                 sg_proc_debug_helper(s, sdp);
2696         }
2697         read_unlock(&sdp->sfd_lock);
2698 skip:
2699         read_unlock_irqrestore(&sg_index_lock, iflags);
2700         return 0;
2701 }
2702
2703 #endif                          /* CONFIG_SCSI_PROC_FS */
2704
2705 module_init(init_sg);
2706 module_exit(exit_sg);