drivers/scsi/sg.c

   1 /*
   2  *  History:
   3  *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
   4  *           to allow user process control of SCSI devices.
   5  *  Development Sponsored by Killy Corp. NY NY
   6  *
   7  * Original driver (sg.c):
   8  *        Copyright (C) 1992 Lawrence Foard
   9  * Version 2 and 3 extensions to driver:
  10  *        Copyright (C) 1998 - 2014 Douglas Gilbert
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2, or (at your option)
  15  * any later version.
  16  *
  17  */
  18
  19 static int sg_version_num = 30536;      /* 2 digits for each component */
  20 #define SG_VERSION_STR "3.5.36"
  21
  22 /*
  23  *  D. P. Gilbert (dgilbert@interlog.com), notes:
  24  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
  25  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
  26  *        (otherwise the macros compile to empty statements).
  27  *
  28  */
  29 #include <linux/module.h>
  30
  31 #include <linux/fs.h>
  32 #include <linux/kernel.h>
  33 #include <linux/sched.h>
  34 #include <linux/string.h>
  35 #include <linux/mm.h>
  36 #include <linux/errno.h>
  37 #include <linux/mtio.h>
  38 #include <linux/ioctl.h>
  39 #include <linux/slab.h>
  40 #include <linux/fcntl.h>
  41 #include <linux/init.h>
  42 #include <linux/poll.h>
  43 #include <linux/moduleparam.h>
  44 #include <linux/cdev.h>
  45 #include <linux/idr.h>
  46 #include <linux/seq_file.h>
  47 #include <linux/blkdev.h>
  48 #include <linux/delay.h>
  49 #include <linux/blktrace_api.h>
  50 #include <linux/mutex.h>
  51 #include <linux/atomic.h>
  52 #include <linux/ratelimit.h>
  53 #include <linux/uio.h>
  54
  55 #include "scsi.h"
  56 #include <scsi/scsi_dbg.h>
  57 #include <scsi/scsi_host.h>
  58 #include <scsi/scsi_driver.h>
  59 #include <scsi/scsi_ioctl.h>
  60 #include <scsi/sg.h>
  61
  62 #include "scsi_logging.h"
  63
  64 #ifdef CONFIG_SCSI_PROC_FS
  65 #include <linux/proc_fs.h>
  66 static char *sg_version_date = "20140603";
  67
  68 static int sg_proc_init(void);
  69 static void sg_proc_cleanup(void);
  70 #endif
  71
  72 #define SG_ALLOW_DIO_DEF 0
  73
  74 #define SG_MAX_DEVS 32768
  75
  76 /* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
  77  * of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
  78  * than 16 bytes are "variable length" whose length is a multiple of 4
  79  */
  80 #define SG_MAX_CDB_SIZE 252
  81
  82 #define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  83
  84 int sg_big_buff = SG_DEF_RESERVED_SIZE;
  85 /* N.B. This variable is readable and writeable via
  86    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  87    of this size (or less if there is not enough memory) will be reserved
  88    for use by this file descriptor. [Deprecated usage: this variable is also
  89    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  90    the kernel (i.e. it is not a module).] */
  91 static int def_reserved_size = -1;      /* picks up init parameter */
  92 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
  93
  94 static int scatter_elem_sz = SG_SCATTER_SZ;
  95 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
  96
  97 #define SG_SECTOR_SZ 512
  98
  99 static int sg_add_device(struct device *, struct class_interface *);
 100 static void sg_remove_device(struct device *, struct class_interface *);
 101
 102 static DEFINE_IDR(sg_index_idr);
 103 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
 104                                                            file descriptor list for device */
 105
 106 static struct class_interface sg_interface = {
 107         .add_dev        = sg_add_device,
 108         .remove_dev     = sg_remove_device,
 109 };
 110
 111 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 112         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 113         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 114         unsigned bufflen;       /* Size of (aggregate) data buffer */
 115         struct page **pages;
 116         int page_order;
 117         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 118         unsigned char cmd_opcode; /* first byte of command */
 119 } Sg_scatter_hold;
 120
 121 struct sg_device;               /* forward declarations */
 122 struct sg_fd;
 123
 124 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 125         struct 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 int
 755 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 756                 unsigned char *cmnd, int timeout, int blocking)
 757 {
 758         int k, at_head;
 759         Sg_device *sdp = sfp->parentdp;
 760         sg_io_hdr_t *hp = &srp->header;
 761
 762         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 763         hp->status = 0;
 764         hp->masked_status = 0;
 765         hp->msg_status = 0;
 766         hp->info = 0;
 767         hp->host_status = 0;
 768         hp->driver_status = 0;
 769         hp->resid = 0;
 770         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
 771                         "sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 772                         (int) cmnd[0], (int) hp->cmd_len));
 773
 774         if (hp->dxfer_len >= SZ_256M)
 775                 return -EINVAL;
 776
 777         k = sg_start_req(srp, cmnd);
 778         if (k) {
 779                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 780                         "sg_common_write: start_req err=%d\n", k));
 781                 sg_finish_rem_req(srp);
 782                 sg_remove_request(sfp, srp);
 783                 return k;       /* probably out of space --> ENOMEM */
 784         }
 785         if (atomic_read(&sdp->detaching)) {
 786                 if (srp->bio) {
 787                         scsi_req_free_cmd(scsi_req(srp->rq));
 788                         blk_end_request_all(srp->rq, BLK_STS_IOERR);
 789                         srp->rq = NULL;
 790                 }
 791
 792                 sg_finish_rem_req(srp);
 793                 sg_remove_request(sfp, srp);
 794                 return -ENODEV;
 795         }
 796
 797         hp->duration = jiffies_to_msecs(jiffies);
 798         if (hp->interface_id != '\0' && /* v3 (or later) interface */
 799             (SG_FLAG_Q_AT_TAIL & hp->flags))
 800                 at_head = 0;
 801         else
 802                 at_head = 1;
 803
 804         srp->rq->timeout = timeout;
 805         kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
 806         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 807                               srp->rq, at_head, sg_rq_end_io);
 808         return 0;
 809 }
 810
 811 static int srp_done(Sg_fd *sfp, Sg_request *srp)
 812 {
 813         unsigned long flags;
 814         int ret;
 815
 816         read_lock_irqsave(&sfp->rq_list_lock, flags);
 817         ret = srp->done;
 818         read_unlock_irqrestore(&sfp->rq_list_lock, flags);
 819         return ret;
 820 }
 821
 822 static int max_sectors_bytes(struct request_queue *q)
 823 {
 824         unsigned int max_sectors = queue_max_sectors(q);
 825
 826         max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
 827
 828         return max_sectors << 9;
 829 }
 830
 831 static void
 832 sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
 833 {
 834         Sg_request *srp;
 835         int val;
 836         unsigned int ms;
 837
 838         val = 0;
 839         list_for_each_entry(srp, &sfp->rq_list, entry) {
 840                 if (val > SG_MAX_QUEUE)
 841                         break;
 842                 rinfo[val].req_state = srp->done + 1;
 843                 rinfo[val].problem =
 844                         srp->header.masked_status &
 845                         srp->header.host_status &
 846                         srp->header.driver_status;
 847                 if (srp->done)
 848                         rinfo[val].duration =
 849                                 srp->header.duration;
 850                 else {
 851                         ms = jiffies_to_msecs(jiffies);
 852                         rinfo[val].duration =
 853                                 (ms > srp->header.duration) ?
 854                                 (ms - srp->header.duration) : 0;
 855                 }
 856                 rinfo[val].orphan = srp->orphan;
 857                 rinfo[val].sg_io_owned = srp->sg_io_owned;
 858                 rinfo[val].pack_id = srp->header.pack_id;
 859                 rinfo[val].usr_ptr = srp->header.usr_ptr;
 860                 val++;
 861         }
 862 }
 863
 864 static long
 865 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 866 {
 867         void __user *p = (void __user *)arg;
 868         int __user *ip = p;
 869         int result, val, read_only;
 870         Sg_device *sdp;
 871         Sg_fd *sfp;
 872         Sg_request *srp;
 873         unsigned long iflags;
 874
 875         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 876                 return -ENXIO;
 877
 878         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 879                                    "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
 880         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 881
 882         switch (cmd_in) {
 883         case SG_IO:
 884                 if (atomic_read(&sdp->detaching))
 885                         return -ENODEV;
 886                 if (!scsi_block_when_processing_errors(sdp->device))
 887                         return -ENXIO;
 888                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 889                         return -EFAULT;
 890                 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 891                                  1, read_only, 1, &srp);
 892                 if (result < 0)
 893                         return result;
 894                 result = wait_event_interruptible(sfp->read_wait,
 895                         (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
 896                 if (atomic_read(&sdp->detaching))
 897                         return -ENODEV;
 898                 write_lock_irq(&sfp->rq_list_lock);
 899                 if (srp->done) {
 900                         srp->done = 2;
 901                         write_unlock_irq(&sfp->rq_list_lock);
 902                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 903                         return (result < 0) ? result : 0;
 904                 }
 905                 srp->orphan = 1;
 906                 write_unlock_irq(&sfp->rq_list_lock);
 907                 return result;  /* -ERESTARTSYS because signal hit process */
 908         case SG_SET_TIMEOUT:
 909                 result = get_user(val, ip);
 910                 if (result)
 911                         return result;
 912                 if (val < 0)
 913                         return -EIO;
 914                 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
 915                         val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
 916                                     INT_MAX);
 917                 sfp->timeout_user = val;
 918                 sfp->timeout = mult_frac(val, HZ, USER_HZ);
 919
 920                 return 0;
 921         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 922                                 /* strange ..., for backward compatibility */
 923                 return sfp->timeout_user;
 924         case SG_SET_FORCE_LOW_DMA:
 925                 /*
 926                  * N.B. This ioctl never worked properly, but failed to
 927                  * return an error value. So returning '0' to keep compability
 928                  * with legacy applications.
 929                  */
 930                 return 0;
 931         case SG_GET_LOW_DMA:
 932                 return put_user((int) sdp->device->host->unchecked_isa_dma, ip);
 933         case SG_GET_SCSI_ID:
 934                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 935                         return -EFAULT;
 936                 else {
 937                         sg_scsi_id_t __user *sg_idp = p;
 938
 939                         if (atomic_read(&sdp->detaching))
 940                                 return -ENODEV;
 941                         __put_user((int) sdp->device->host->host_no,
 942                                    &sg_idp->host_no);
 943                         __put_user((int) sdp->device->channel,
 944                                    &sg_idp->channel);
 945                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 946                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 947                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 948                         __put_user((short) sdp->device->host->cmd_per_lun,
 949                                    &sg_idp->h_cmd_per_lun);
 950                         __put_user((short) sdp->device->queue_depth,
 951                                    &sg_idp->d_queue_depth);
 952                         __put_user(0, &sg_idp->unused[0]);
 953                         __put_user(0, &sg_idp->unused[1]);
 954                         return 0;
 955                 }
 956         case SG_SET_FORCE_PACK_ID:
 957                 result = get_user(val, ip);
 958                 if (result)
 959                         return result;
 960                 sfp->force_packid = val ? 1 : 0;
 961                 return 0;
 962         case SG_GET_PACK_ID:
 963                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 964                         return -EFAULT;
 965                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 966                 list_for_each_entry(srp, &sfp->rq_list, entry) {
 967                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 968                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 969                                                        iflags);
 970                                 __put_user(srp->header.pack_id, ip);
 971                                 return 0;
 972                         }
 973                 }
 974                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 975                 __put_user(-1, ip);
 976                 return 0;
 977         case SG_GET_NUM_WAITING:
 978                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 979                 val = 0;
 980                 list_for_each_entry(srp, &sfp->rq_list, entry) {
 981                         if ((1 == srp->done) && (!srp->sg_io_owned))
 982                                 ++val;
 983                 }
 984                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 985                 return put_user(val, ip);
 986         case SG_GET_SG_TABLESIZE:
 987                 return put_user(sdp->sg_tablesize, ip);
 988         case SG_SET_RESERVED_SIZE:
 989                 result = get_user(val, ip);
 990                 if (result)
 991                         return result;
 992                 if (val < 0)
 993                         return -EINVAL;
 994                 val = min_t(int, val,
 995                             max_sectors_bytes(sdp->device->request_queue));
 996                 mutex_lock(&sfp->f_mutex);
 997                 if (val != sfp->reserve.bufflen) {
 998                         if (sfp->mmap_called ||
 999                             sfp->res_in_use) {
1000                                 mutex_unlock(&sfp->f_mutex);
1001                                 return -EBUSY;
1002                         }
1003
1004                         sg_remove_scat(sfp, &sfp->reserve);
1005                         sg_build_reserve(sfp, val);
1006                 }
1007                 mutex_unlock(&sfp->f_mutex);
1008                 return 0;
1009         case SG_GET_RESERVED_SIZE:
1010                 val = min_t(int, sfp->reserve.bufflen,
1011                             max_sectors_bytes(sdp->device->request_queue));
1012                 return put_user(val, ip);
1013         case SG_SET_COMMAND_Q:
1014                 result = get_user(val, ip);
1015                 if (result)
1016                         return result;
1017                 sfp->cmd_q = val ? 1 : 0;
1018                 return 0;
1019         case SG_GET_COMMAND_Q:
1020                 return put_user((int) sfp->cmd_q, ip);
1021         case SG_SET_KEEP_ORPHAN:
1022                 result = get_user(val, ip);
1023                 if (result)
1024                         return result;
1025                 sfp->keep_orphan = val;
1026                 return 0;
1027         case SG_GET_KEEP_ORPHAN:
1028                 return put_user((int) sfp->keep_orphan, ip);
1029         case SG_NEXT_CMD_LEN:
1030                 result = get_user(val, ip);
1031                 if (result)
1032                         return result;
1033                 if (val > SG_MAX_CDB_SIZE)
1034                         return -ENOMEM;
1035                 sfp->next_cmd_len = (val > 0) ? val : 0;
1036                 return 0;
1037         case SG_GET_VERSION_NUM:
1038                 return put_user(sg_version_num, ip);
1039         case SG_GET_ACCESS_COUNT:
1040                 /* faked - we don't have a real access count anymore */
1041                 val = (sdp->device ? 1 : 0);
1042                 return put_user(val, ip);
1043         case SG_GET_REQUEST_TABLE:
1044                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
1045                         return -EFAULT;
1046                 else {
1047                         sg_req_info_t *rinfo;
1048
1049                         rinfo = kzalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
1050                                         GFP_KERNEL);
1051                         if (!rinfo)
1052                                 return -ENOMEM;
1053                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1054                         sg_fill_request_table(sfp, rinfo);
1055                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1056                         result = __copy_to_user(p, rinfo,
1057                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1058                         result = result ? -EFAULT : 0;
1059                         kfree(rinfo);
1060                         return result;
1061                 }
1062         case SG_EMULATED_HOST:
1063                 if (atomic_read(&sdp->detaching))
1064                         return -ENODEV;
1065                 return put_user(sdp->device->host->hostt->emulated, ip);
1066         case SCSI_IOCTL_SEND_COMMAND:
1067                 if (atomic_read(&sdp->detaching))
1068                         return -ENODEV;
1069                 if (read_only) {
1070                         unsigned char opcode = WRITE_6;
1071                         Scsi_Ioctl_Command __user *siocp = p;
1072
1073                         if (copy_from_user(&opcode, siocp->data, 1))
1074                                 return -EFAULT;
1075                         if (sg_allow_access(filp, &opcode))
1076                                 return -EPERM;
1077                 }
1078                 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1079         case SG_SET_DEBUG:
1080                 result = get_user(val, ip);
1081                 if (result)
1082                         return result;
1083                 sdp->sgdebug = (char) val;
1084                 return 0;
1085         case BLKSECTGET:
1086                 return put_user(max_sectors_bytes(sdp->device->request_queue),
1087                                 ip);
1088         case BLKTRACESETUP:
1089                 return blk_trace_setup(sdp->device->request_queue,
1090                                        sdp->disk->disk_name,
1091                                        MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1092                                        NULL, p);
1093         case BLKTRACESTART:
1094                 return blk_trace_startstop(sdp->device->request_queue, 1);
1095         case BLKTRACESTOP:
1096                 return blk_trace_startstop(sdp->device->request_queue, 0);
1097         case BLKTRACETEARDOWN:
1098                 return blk_trace_remove(sdp->device->request_queue);
1099         case SCSI_IOCTL_GET_IDLUN:
1100         case SCSI_IOCTL_GET_BUS_NUMBER:
1101         case SCSI_IOCTL_PROBE_HOST:
1102         case SG_GET_TRANSFORM:
1103         case SG_SCSI_RESET:
1104                 if (atomic_read(&sdp->detaching))
1105                         return -ENODEV;
1106                 break;
1107         default:
1108                 if (read_only)
1109                         return -EPERM;  /* don't know so take safe approach */
1110                 break;
1111         }
1112
1113         result = scsi_ioctl_block_when_processing_errors(sdp->device,
1114                         cmd_in, filp->f_flags & O_NDELAY);
1115         if (result)
1116                 return result;
1117         return scsi_ioctl(sdp->device, cmd_in, p);
1118 }
1119
1120 #ifdef CONFIG_COMPAT
1121 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1122 {
1123         Sg_device *sdp;
1124         Sg_fd *sfp;
1125         struct scsi_device *sdev;
1126
1127         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1128                 return -ENXIO;
1129
1130         sdev = sdp->device;
1131         if (sdev->host->hostt->compat_ioctl) {
1132                 int ret;
1133
1134                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1135
1136                 return ret;
1137         }
1138
1139         return -ENOIOCTLCMD;
1140 }
1141 #endif
1142
1143 static unsigned int
1144 sg_poll(struct file *filp, poll_table * wait)
1145 {
1146         unsigned int res = 0;
1147         Sg_device *sdp;
1148         Sg_fd *sfp;
1149         Sg_request *srp;
1150         int count = 0;
1151         unsigned long iflags;
1152
1153         sfp = filp->private_data;
1154         if (!sfp)
1155                 return POLLERR;
1156         sdp = sfp->parentdp;
1157         if (!sdp)
1158                 return POLLERR;
1159         poll_wait(filp, &sfp->read_wait, wait);
1160         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1161         list_for_each_entry(srp, &sfp->rq_list, entry) {
1162                 /* if any read waiting, flag it */
1163                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1164                         res = POLLIN | POLLRDNORM;
1165                 ++count;
1166         }
1167         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1168
1169         if (atomic_read(&sdp->detaching))
1170                 res |= POLLHUP;
1171         else if (!sfp->cmd_q) {
1172                 if (0 == count)
1173                         res |= POLLOUT | POLLWRNORM;
1174         } else if (count < SG_MAX_QUEUE)
1175                 res |= POLLOUT | POLLWRNORM;
1176         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1177                                       "sg_poll: res=0x%x\n", (int) res));
1178         return res;
1179 }
1180
1181 static int
1182 sg_fasync(int fd, struct file *filp, int mode)
1183 {
1184         Sg_device *sdp;
1185         Sg_fd *sfp;
1186
1187         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1188                 return -ENXIO;
1189         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1190                                       "sg_fasync: mode=%d\n", mode));
1191
1192         return fasync_helper(fd, filp, mode, &sfp->async_qp);
1193 }
1194
1195 static int
1196 sg_vma_fault(struct vm_fault *vmf)
1197 {
1198         struct vm_area_struct *vma = vmf->vma;
1199         Sg_fd *sfp;
1200         unsigned long offset, len, sa;
1201         Sg_scatter_hold *rsv_schp;
1202         int k, length;
1203
1204         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1205                 return VM_FAULT_SIGBUS;
1206         rsv_schp = &sfp->reserve;
1207         offset = vmf->pgoff << PAGE_SHIFT;
1208         if (offset >= rsv_schp->bufflen)
1209                 return VM_FAULT_SIGBUS;
1210         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1211                                       "sg_vma_fault: offset=%lu, scatg=%d\n",
1212                                       offset, rsv_schp->k_use_sg));
1213         sa = vma->vm_start;
1214         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1215         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1216                 len = vma->vm_end - sa;
1217                 len = (len < length) ? len : length;
1218                 if (offset < len) {
1219                         struct page *page = nth_page(rsv_schp->pages[k],
1220                                                      offset >> PAGE_SHIFT);
1221                         get_page(page); /* increment page count */
1222                         vmf->page = page;
1223                         return 0; /* success */
1224                 }
1225                 sa += len;
1226                 offset -= len;
1227         }
1228
1229         return VM_FAULT_SIGBUS;
1230 }
1231
1232 static const struct vm_operations_struct sg_mmap_vm_ops = {
1233         .fault = sg_vma_fault,
1234 };
1235
1236 static int
1237 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1238 {
1239         Sg_fd *sfp;
1240         unsigned long req_sz, len, sa;
1241         Sg_scatter_hold *rsv_schp;
1242         int k, length;
1243         int ret = 0;
1244
1245         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1246                 return -ENXIO;
1247         req_sz = vma->vm_end - vma->vm_start;
1248         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1249                                       "sg_mmap starting, vm_start=%p, len=%d\n",
1250                                       (void *) vma->vm_start, (int) req_sz));
1251         if (vma->vm_pgoff)
1252                 return -EINVAL; /* want no offset */
1253         rsv_schp = &sfp->reserve;
1254         mutex_lock(&sfp->f_mutex);
1255         if (req_sz > rsv_schp->bufflen) {
1256                 ret = -ENOMEM;  /* cannot map more than reserved buffer */
1257                 goto out;
1258         }
1259
1260         sa = vma->vm_start;
1261         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1262         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1263                 len = vma->vm_end - sa;
1264                 len = (len < length) ? len : length;
1265                 sa += len;
1266         }
1267
1268         sfp->mmap_called = 1;
1269         vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
1270         vma->vm_private_data = sfp;
1271         vma->vm_ops = &sg_mmap_vm_ops;
1272 out:
1273         mutex_unlock(&sfp->f_mutex);
1274         return ret;
1275 }
1276
1277 static void
1278 sg_rq_end_io_usercontext(struct work_struct *work)
1279 {
1280         struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1281         struct sg_fd *sfp = srp->parentfp;
1282
1283         sg_finish_rem_req(srp);
1284         sg_remove_request(sfp, srp);
1285         kref_put(&sfp->f_ref, sg_remove_sfp);
1286 }
1287
1288 /*
1289  * This function is a "bottom half" handler that is called by the mid
1290  * level when a command is completed (or has failed).
1291  */
1292 static void
1293 sg_rq_end_io(struct request *rq, blk_status_t status)
1294 {
1295         struct sg_request *srp = rq->end_io_data;
1296         struct scsi_request *req = scsi_req(rq);
1297         Sg_device *sdp;
1298         Sg_fd *sfp;
1299         unsigned long iflags;
1300         unsigned int ms;
1301         char *sense;
1302         int result, resid, done = 1;
1303
1304         if (WARN_ON(srp->done != 0))
1305                 return;
1306
1307         sfp = srp->parentfp;
1308         if (WARN_ON(sfp == NULL))
1309                 return;
1310
1311         sdp = sfp->parentdp;
1312         if (unlikely(atomic_read(&sdp->detaching)))
1313                 pr_info("%s: device detaching\n", __func__);
1314
1315         sense = req->sense;
1316         result = req->result;
1317         resid = req->resid_len;
1318
1319         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1320                                       "sg_cmd_done: pack_id=%d, res=0x%x\n",
1321                                       srp->header.pack_id, result));
1322         srp->header.resid = resid;
1323         ms = jiffies_to_msecs(jiffies);
1324         srp->header.duration = (ms > srp->header.duration) ?
1325                                 (ms - srp->header.duration) : 0;
1326         if (0 != result) {
1327                 struct scsi_sense_hdr sshdr;
1328
1329                 srp->header.status = 0xff & result;
1330                 srp->header.masked_status = status_byte(result);
1331                 srp->header.msg_status = msg_byte(result);
1332                 srp->header.host_status = host_byte(result);
1333                 srp->header.driver_status = driver_byte(result);
1334                 if ((sdp->sgdebug > 0) &&
1335                     ((CHECK_CONDITION == srp->header.masked_status) ||
1336                      (COMMAND_TERMINATED == srp->header.masked_status)))
1337                         __scsi_print_sense(sdp->device, __func__, sense,
1338                                            SCSI_SENSE_BUFFERSIZE);
1339
1340                 /* Following if statement is a patch supplied by Eric Youngdale */
1341                 if (driver_byte(result) != 0
1342                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1343                     && !scsi_sense_is_deferred(&sshdr)
1344                     && sshdr.sense_key == UNIT_ATTENTION
1345                     && sdp->device->removable) {
1346                         /* Detected possible disc change. Set the bit - this */
1347                         /* may be used if there are filesystems using this device */
1348                         sdp->device->changed = 1;
1349                 }
1350         }
1351
1352         if (req->sense_len)
1353                 memcpy(srp->sense_b, req->sense, SCSI_SENSE_BUFFERSIZE);
1354
1355         /* Rely on write phase to clean out srp status values, so no "else" */
1356
1357         /*
1358          * Free the request as soon as it is complete so that its resources
1359          * can be reused without waiting for userspace to read() the
1360          * result.  But keep the associated bio (if any) around until
1361          * blk_rq_unmap_user() can be called from user context.
1362          */
1363         srp->rq = NULL;
1364         scsi_req_free_cmd(scsi_req(rq));
1365         __blk_put_request(rq->q, rq);
1366
1367         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1368         if (unlikely(srp->orphan)) {
1369                 if (sfp->keep_orphan)
1370                         srp->sg_io_owned = 0;
1371                 else
1372                         done = 0;
1373         }
1374         srp->done = done;
1375         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1376
1377         if (likely(done)) {
1378                 /* Now wake up any sg_read() that is waiting for this
1379                  * packet.
1380                  */
1381                 wake_up_interruptible(&sfp->read_wait);
1382                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1383                 kref_put(&sfp->f_ref, sg_remove_sfp);
1384         } else {
1385                 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1386                 schedule_work(&srp->ew.work);
1387         }
1388 }
1389
1390 static const struct file_operations sg_fops = {
1391         .owner = THIS_MODULE,
1392         .read = sg_read,
1393         .write = sg_write,
1394         .poll = sg_poll,
1395         .unlocked_ioctl = sg_ioctl,
1396 #ifdef CONFIG_COMPAT
1397         .compat_ioctl = sg_compat_ioctl,
1398 #endif
1399         .open = sg_open,
1400         .mmap = sg_mmap,
1401         .release = sg_release,
1402         .fasync = sg_fasync,
1403         .llseek = no_llseek,
1404 };
1405
1406 static struct class *sg_sysfs_class;
1407
1408 static int sg_sysfs_valid = 0;
1409
1410 static Sg_device *
1411 sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1412 {
1413         struct request_queue *q = scsidp->request_queue;
1414         Sg_device *sdp;
1415         unsigned long iflags;
1416         int error;
1417         u32 k;
1418
1419         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1420         if (!sdp) {
1421                 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1422                             "failure\n", __func__);
1423                 return ERR_PTR(-ENOMEM);
1424         }
1425
1426         idr_preload(GFP_KERNEL);
1427         write_lock_irqsave(&sg_index_lock, iflags);
1428
1429         error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1430         if (error < 0) {
1431                 if (error == -ENOSPC) {
1432                         sdev_printk(KERN_WARNING, scsidp,
1433                                     "Unable to attach sg device type=%d, minor number exceeds %d\n",
1434                                     scsidp->type, SG_MAX_DEVS - 1);
1435                         error = -ENODEV;
1436                 } else {
1437                         sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1438                                     "allocation Sg_device failure: %d\n",
1439                                     __func__, error);
1440                 }
1441                 goto out_unlock;
1442         }
1443         k = error;
1444
1445         SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1446                                         "sg_alloc: dev=%d \n", k));
1447         sprintf(disk->disk_name, "sg%d", k);
1448         disk->first_minor = k;
1449         sdp->disk = disk;
1450         sdp->device = scsidp;
1451         mutex_init(&sdp->open_rel_lock);
1452         INIT_LIST_HEAD(&sdp->sfds);
1453         init_waitqueue_head(&sdp->open_wait);
1454         atomic_set(&sdp->detaching, 0);
1455         rwlock_init(&sdp->sfd_lock);
1456         sdp->sg_tablesize = queue_max_segments(q);
1457         sdp->index = k;
1458         kref_init(&sdp->d_ref);
1459         error = 0;
1460
1461 out_unlock:
1462         write_unlock_irqrestore(&sg_index_lock, iflags);
1463         idr_preload_end();
1464
1465         if (error) {
1466                 kfree(sdp);
1467                 return ERR_PTR(error);
1468         }
1469         return sdp;
1470 }
1471
1472 static int
1473 sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1474 {
1475         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1476         struct gendisk *disk;
1477         Sg_device *sdp = NULL;
1478         struct cdev * cdev = NULL;
1479         int error;
1480         unsigned long iflags;
1481
1482         disk = alloc_disk(1);
1483         if (!disk) {
1484                 pr_warn("%s: alloc_disk failed\n", __func__);
1485                 return -ENOMEM;
1486         }
1487         disk->major = SCSI_GENERIC_MAJOR;
1488
1489         error = -ENOMEM;
1490         cdev = cdev_alloc();
1491         if (!cdev) {
1492                 pr_warn("%s: cdev_alloc failed\n", __func__);
1493                 goto out;
1494         }
1495         cdev->owner = THIS_MODULE;
1496         cdev->ops = &sg_fops;
1497
1498         sdp = sg_alloc(disk, scsidp);
1499         if (IS_ERR(sdp)) {
1500                 pr_warn("%s: sg_alloc failed\n", __func__);
1501                 error = PTR_ERR(sdp);
1502                 goto out;
1503         }
1504
1505         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1506         if (error)
1507                 goto cdev_add_err;
1508
1509         sdp->cdev = cdev;
1510         if (sg_sysfs_valid) {
1511                 struct device *sg_class_member;
1512
1513                 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1514                                                 MKDEV(SCSI_GENERIC_MAJOR,
1515                                                       sdp->index),
1516                                                 sdp, "%s", disk->disk_name);
1517                 if (IS_ERR(sg_class_member)) {
1518                         pr_err("%s: device_create failed\n", __func__);
1519                         error = PTR_ERR(sg_class_member);
1520                         goto cdev_add_err;
1521                 }
1522                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1523                                           &sg_class_member->kobj, "generic");
1524                 if (error)
1525                         pr_err("%s: unable to make symlink 'generic' back "
1526                                "to sg%d\n", __func__, sdp->index);
1527         } else
1528                 pr_warn("%s: sg_sys Invalid\n", __func__);
1529
1530         sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1531                     "type %d\n", sdp->index, scsidp->type);
1532
1533         dev_set_drvdata(cl_dev, sdp);
1534
1535         return 0;
1536
1537 cdev_add_err:
1538         write_lock_irqsave(&sg_index_lock, iflags);
1539         idr_remove(&sg_index_idr, sdp->index);
1540         write_unlock_irqrestore(&sg_index_lock, iflags);
1541         kfree(sdp);
1542
1543 out:
1544         put_disk(disk);
1545         if (cdev)
1546                 cdev_del(cdev);
1547         return error;
1548 }
1549
1550 static void
1551 sg_device_destroy(struct kref *kref)
1552 {
1553         struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1554         unsigned long flags;
1555
1556         /* CAUTION!  Note that the device can still be found via idr_find()
1557          * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1558          * any other cleanup.
1559          */
1560
1561         write_lock_irqsave(&sg_index_lock, flags);
1562         idr_remove(&sg_index_idr, sdp->index);
1563         write_unlock_irqrestore(&sg_index_lock, flags);
1564
1565         SCSI_LOG_TIMEOUT(3,
1566                 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1567
1568         put_disk(sdp->disk);
1569         kfree(sdp);
1570 }
1571
1572 static void
1573 sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1574 {
1575         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1576         Sg_device *sdp = dev_get_drvdata(cl_dev);
1577         unsigned long iflags;
1578         Sg_fd *sfp;
1579         int val;
1580
1581         if (!sdp)
1582                 return;
1583         /* want sdp->detaching non-zero as soon as possible */
1584         val = atomic_inc_return(&sdp->detaching);
1585         if (val > 1)
1586                 return; /* only want to do following once per device */
1587
1588         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1589                                       "%s\n", __func__));
1590
1591         read_lock_irqsave(&sdp->sfd_lock, iflags);
1592         list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1593                 wake_up_interruptible_all(&sfp->read_wait);
1594                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1595         }
1596         wake_up_interruptible_all(&sdp->open_wait);
1597         read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1598
1599         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1600         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1601         cdev_del(sdp->cdev);
1602         sdp->cdev = NULL;
1603
1604         kref_put(&sdp->d_ref, sg_device_destroy);
1605 }
1606
1607 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1608 module_param_named(def_reserved_size, def_reserved_size, int,
1609                    S_IRUGO | S_IWUSR);
1610 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1611
1612 MODULE_AUTHOR("Douglas Gilbert");
1613 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1614 MODULE_LICENSE("GPL");
1615 MODULE_VERSION(SG_VERSION_STR);
1616 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1617
1618 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1619                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1620 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1621 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1622
1623 static int __init
1624 init_sg(void)
1625 {
1626         int rc;
1627
1628         if (scatter_elem_sz < PAGE_SIZE) {
1629                 scatter_elem_sz = PAGE_SIZE;
1630                 scatter_elem_sz_prev = scatter_elem_sz;
1631         }
1632         if (def_reserved_size >= 0)
1633                 sg_big_buff = def_reserved_size;
1634         else
1635                 def_reserved_size = sg_big_buff;
1636
1637         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1638                                     SG_MAX_DEVS, "sg");
1639         if (rc)
1640                 return rc;
1641         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1642         if ( IS_ERR(sg_sysfs_class) ) {
1643                 rc = PTR_ERR(sg_sysfs_class);
1644                 goto err_out;
1645         }
1646         sg_sysfs_valid = 1;
1647         rc = scsi_register_interface(&sg_interface);
1648         if (0 == rc) {
1649 #ifdef CONFIG_SCSI_PROC_FS
1650                 sg_proc_init();
1651 #endif                          /* CONFIG_SCSI_PROC_FS */
1652                 return 0;
1653         }
1654         class_destroy(sg_sysfs_class);
1655 err_out:
1656         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1657         return rc;
1658 }
1659
1660 static void __exit
1661 exit_sg(void)
1662 {
1663 #ifdef CONFIG_SCSI_PROC_FS
1664         sg_proc_cleanup();
1665 #endif                          /* CONFIG_SCSI_PROC_FS */
1666         scsi_unregister_interface(&sg_interface);
1667         class_destroy(sg_sysfs_class);
1668         sg_sysfs_valid = 0;
1669         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1670                                  SG_MAX_DEVS);
1671         idr_destroy(&sg_index_idr);
1672 }
1673
1674 static int
1675 sg_start_req(Sg_request *srp, unsigned char *cmd)
1676 {
1677         int res;
1678         struct request *rq;
1679         struct scsi_request *req;
1680         Sg_fd *sfp = srp->parentfp;
1681         sg_io_hdr_t *hp = &srp->header;
1682         int dxfer_len = (int) hp->dxfer_len;
1683         int dxfer_dir = hp->dxfer_direction;
1684         unsigned int iov_count = hp->iovec_count;
1685         Sg_scatter_hold *req_schp = &srp->data;
1686         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1687         struct request_queue *q = sfp->parentdp->device->request_queue;
1688         struct rq_map_data *md, map_data;
1689         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1690         unsigned char *long_cmdp = NULL;
1691
1692         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1693                                       "sg_start_req: dxfer_len=%d\n",
1694                                       dxfer_len));
1695
1696         if (hp->cmd_len > BLK_MAX_CDB) {
1697                 long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1698                 if (!long_cmdp)
1699                         return -ENOMEM;
1700         }
1701
1702         /*
1703          * NOTE
1704          *
1705          * With scsi-mq enabled, there are a fixed number of preallocated
1706          * requests equal in number to shost->can_queue.  If all of the
1707          * preallocated requests are already in use, then using GFP_ATOMIC with
1708          * blk_get_request() will return -EWOULDBLOCK, whereas using GFP_KERNEL
1709          * will cause blk_get_request() to sleep until an active command
1710          * completes, freeing up a request.  Neither option is ideal, but
1711          * GFP_KERNEL is the better choice to prevent userspace from getting an
1712          * unexpected EWOULDBLOCK.
1713          *
1714          * With scsi-mq disabled, blk_get_request() with GFP_KERNEL usually
1715          * does not sleep except under memory pressure.
1716          */
1717         rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1718                         REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, GFP_KERNEL);
1719         if (IS_ERR(rq)) {
1720                 kfree(long_cmdp);
1721                 return PTR_ERR(rq);
1722         }
1723         req = scsi_req(rq);
1724
1725         if (hp->cmd_len > BLK_MAX_CDB)
1726                 req->cmd = long_cmdp;
1727         memcpy(req->cmd, cmd, hp->cmd_len);
1728         req->cmd_len = hp->cmd_len;
1729
1730         srp->rq = rq;
1731         rq->end_io_data = srp;
1732         req->retries = SG_DEFAULT_RETRIES;
1733
1734         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1735                 return 0;
1736
1737         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1738             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1739             !sfp->parentdp->device->host->unchecked_isa_dma &&
1740             blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1741                 md = NULL;
1742         else
1743                 md = &map_data;
1744
1745         if (md) {
1746                 mutex_lock(&sfp->f_mutex);
1747                 if (dxfer_len <= rsv_schp->bufflen &&
1748                     !sfp->res_in_use) {
1749                         sfp->res_in_use = 1;
1750                         sg_link_reserve(sfp, srp, dxfer_len);
1751                 } else if (hp->flags & SG_FLAG_MMAP_IO) {
1752                         res = -EBUSY; /* sfp->res_in_use == 1 */
1753                         if (dxfer_len > rsv_schp->bufflen)
1754                                 res = -ENOMEM;
1755                         mutex_unlock(&sfp->f_mutex);
1756                         return res;
1757                 } else {
1758                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1759                         if (res) {
1760                                 mutex_unlock(&sfp->f_mutex);
1761                                 return res;
1762                         }
1763                 }
1764                 mutex_unlock(&sfp->f_mutex);
1765
1766                 md->pages = req_schp->pages;
1767                 md->page_order = req_schp->page_order;
1768                 md->nr_entries = req_schp->k_use_sg;
1769                 md->offset = 0;
1770                 md->null_mapped = hp->dxferp ? 0 : 1;
1771                 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1772                         md->from_user = 1;
1773                 else
1774                         md->from_user = 0;
1775         }
1776
1777         if (iov_count) {
1778                 struct iovec *iov = NULL;
1779                 struct iov_iter i;
1780
1781                 res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i);
1782                 if (res < 0)
1783                         return res;
1784
1785                 iov_iter_truncate(&i, hp->dxfer_len);
1786                 if (!iov_iter_count(&i)) {
1787                         kfree(iov);
1788                         return -EINVAL;
1789                 }
1790
1791                 res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
1792                 kfree(iov);
1793         } else
1794                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1795                                       hp->dxfer_len, GFP_ATOMIC);
1796
1797         if (!res) {
1798                 srp->bio = rq->bio;
1799
1800                 if (!md) {
1801                         req_schp->dio_in_use = 1;
1802                         hp->info |= SG_INFO_DIRECT_IO;
1803                 }
1804         }
1805         return res;
1806 }
1807
1808 static int
1809 sg_finish_rem_req(Sg_request *srp)
1810 {
1811         int ret = 0;
1812
1813         Sg_fd *sfp = srp->parentfp;
1814         Sg_scatter_hold *req_schp = &srp->data;
1815
1816         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1817                                       "sg_finish_rem_req: res_used=%d\n",
1818                                       (int) srp->res_used));
1819         if (srp->bio)
1820                 ret = blk_rq_unmap_user(srp->bio);
1821
1822         if (srp->rq) {
1823                 scsi_req_free_cmd(scsi_req(srp->rq));
1824                 blk_put_request(srp->rq);
1825         }
1826
1827         if (srp->res_used)
1828                 sg_unlink_reserve(sfp, srp);
1829         else
1830                 sg_remove_scat(sfp, req_schp);
1831
1832         return ret;
1833 }
1834
1835 static int
1836 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1837 {
1838         int sg_bufflen = tablesize * sizeof(struct page *);
1839         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1840
1841         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1842         if (!schp->pages)
1843                 return -ENOMEM;
1844         schp->sglist_len = sg_bufflen;
1845         return tablesize;       /* number of scat_gath elements allocated */
1846 }
1847
1848 static int
1849 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1850 {
1851         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1852         int sg_tablesize = sfp->parentdp->sg_tablesize;
1853         int blk_size = buff_size, order;
1854         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1855         struct sg_device *sdp = sfp->parentdp;
1856
1857         if (blk_size < 0)
1858                 return -EFAULT;
1859         if (0 == blk_size)
1860                 ++blk_size;     /* don't know why */
1861         /* round request up to next highest SG_SECTOR_SZ byte boundary */
1862         blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1863         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1864                 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1865                 buff_size, blk_size));
1866
1867         /* N.B. ret_sz carried into this block ... */
1868         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1869         if (mx_sc_elems < 0)
1870                 return mx_sc_elems;     /* most likely -ENOMEM */
1871
1872         num = scatter_elem_sz;
1873         if (unlikely(num != scatter_elem_sz_prev)) {
1874                 if (num < PAGE_SIZE) {
1875                         scatter_elem_sz = PAGE_SIZE;
1876                         scatter_elem_sz_prev = PAGE_SIZE;
1877                 } else
1878                         scatter_elem_sz_prev = num;
1879         }
1880
1881         if (sdp->device->host->unchecked_isa_dma)
1882                 gfp_mask |= GFP_DMA;
1883
1884         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1885                 gfp_mask |= __GFP_ZERO;
1886
1887         order = get_order(num);
1888 retry:
1889         ret_sz = 1 << (PAGE_SHIFT + order);
1890
1891         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1892              k++, rem_sz -= ret_sz) {
1893
1894                 num = (rem_sz > scatter_elem_sz_prev) ?
1895                         scatter_elem_sz_prev : rem_sz;
1896
1897                 schp->pages[k] = alloc_pages(gfp_mask, order);
1898                 if (!schp->pages[k])
1899                         goto out;
1900
1901                 if (num == scatter_elem_sz_prev) {
1902                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1903                                 scatter_elem_sz = ret_sz;
1904                                 scatter_elem_sz_prev = ret_sz;
1905                         }
1906                 }
1907
1908                 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1909                                  "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1910                                  k, num, ret_sz));
1911         }               /* end of for loop */
1912
1913         schp->page_order = order;
1914         schp->k_use_sg = k;
1915         SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1916                          "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1917                          k, rem_sz));
1918
1919         schp->bufflen = blk_size;
1920         if (rem_sz > 0) /* must have failed */
1921                 return -ENOMEM;
1922         return 0;
1923 out:
1924         for (i = 0; i < k; i++)
1925                 __free_pages(schp->pages[i], order);
1926
1927         if (--order >= 0)
1928                 goto retry;
1929
1930         return -ENOMEM;
1931 }
1932
1933 static void
1934 sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1935 {
1936         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1937                          "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1938         if (schp->pages && schp->sglist_len > 0) {
1939                 if (!schp->dio_in_use) {
1940                         int k;
1941
1942                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1943                                 SCSI_LOG_TIMEOUT(5,
1944                                         sg_printk(KERN_INFO, sfp->parentdp,
1945                                         "sg_remove_scat: k=%d, pg=0x%p\n",
1946                                         k, schp->pages[k]));
1947                                 __free_pages(schp->pages[k], schp->page_order);
1948                         }
1949
1950                         kfree(schp->pages);
1951                 }
1952         }
1953         memset(schp, 0, sizeof (*schp));
1954 }
1955
1956 static int
1957 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1958 {
1959         Sg_scatter_hold *schp = &srp->data;
1960         int k, num;
1961
1962         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1963                          "sg_read_oxfer: num_read_xfer=%d\n",
1964                          num_read_xfer));
1965         if ((!outp) || (num_read_xfer <= 0))
1966                 return 0;
1967
1968         num = 1 << (PAGE_SHIFT + schp->page_order);
1969         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1970                 if (num > num_read_xfer) {
1971                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1972                                            num_read_xfer))
1973                                 return -EFAULT;
1974                         break;
1975                 } else {
1976                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1977                                            num))
1978                                 return -EFAULT;
1979                         num_read_xfer -= num;
1980                         if (num_read_xfer <= 0)
1981                                 break;
1982                         outp += num;
1983                 }
1984         }
1985
1986         return 0;
1987 }
1988
1989 static void
1990 sg_build_reserve(Sg_fd * sfp, int req_size)
1991 {
1992         Sg_scatter_hold *schp = &sfp->reserve;
1993
1994         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1995                          "sg_build_reserve: req_size=%d\n", req_size));
1996         do {
1997                 if (req_size < PAGE_SIZE)
1998                         req_size = PAGE_SIZE;
1999                 if (0 == sg_build_indirect(schp, sfp, req_size))
2000                         return;
2001                 else
2002                         sg_remove_scat(sfp, schp);
2003                 req_size >>= 1; /* divide by 2 */
2004         } while (req_size > (PAGE_SIZE / 2));
2005 }
2006
2007 static void
2008 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2009 {
2010         Sg_scatter_hold *req_schp = &srp->data;
2011         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2012         int k, num, rem;
2013
2014         srp->res_used = 1;
2015         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2016                          "sg_link_reserve: size=%d\n", size));
2017         rem = size;
2018
2019         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2020         for (k = 0; k < rsv_schp->k_use_sg; k++) {
2021                 if (rem <= num) {
2022                         req_schp->k_use_sg = k + 1;
2023                         req_schp->sglist_len = rsv_schp->sglist_len;
2024                         req_schp->pages = rsv_schp->pages;
2025
2026                         req_schp->bufflen = size;
2027                         req_schp->page_order = rsv_schp->page_order;
2028                         break;
2029                 } else
2030                         rem -= num;
2031         }
2032
2033         if (k >= rsv_schp->k_use_sg)
2034                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2035                                  "sg_link_reserve: BAD size\n"));
2036 }
2037
2038 static void
2039 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2040 {
2041         Sg_scatter_hold *req_schp = &srp->data;
2042
2043         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2044                                       "sg_unlink_reserve: req->k_use_sg=%d\n",
2045                                       (int) req_schp->k_use_sg));
2046         req_schp->k_use_sg = 0;
2047         req_schp->bufflen = 0;
2048         req_schp->pages = NULL;
2049         req_schp->page_order = 0;
2050         req_schp->sglist_len = 0;
2051         srp->res_used = 0;
2052         /* Called without mutex lock to avoid deadlock */
2053         sfp->res_in_use = 0;
2054 }
2055
2056 static Sg_request *
2057 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2058 {
2059         Sg_request *resp;
2060         unsigned long iflags;
2061
2062         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2063         list_for_each_entry(resp, &sfp->rq_list, entry) {
2064                 /* look for requests that are ready + not SG_IO owned */
2065                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2066                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2067                         resp->done = 2; /* guard against other readers */
2068                         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2069                         return resp;
2070                 }
2071         }
2072         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2073         return NULL;
2074 }
2075
2076 /* always adds to end of list */
2077 static Sg_request *
2078 sg_add_request(Sg_fd * sfp)
2079 {
2080         int k;
2081         unsigned long iflags;
2082         Sg_request *rp = sfp->req_arr;
2083
2084         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2085         if (!list_empty(&sfp->rq_list)) {
2086                 if (!sfp->cmd_q)
2087                         goto out_unlock;
2088
2089                 for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2090                         if (!rp->parentfp)
2091                                 break;
2092                 }
2093                 if (k >= SG_MAX_QUEUE)
2094                         goto out_unlock;
2095         }
2096         memset(rp, 0, sizeof (Sg_request));
2097         rp->parentfp = sfp;
2098         rp->header.duration = jiffies_to_msecs(jiffies);
2099         list_add_tail(&rp->entry, &sfp->rq_list);
2100         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2101         return rp;
2102 out_unlock:
2103         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2104         return NULL;
2105 }
2106
2107 /* Return of 1 for found; 0 for not found */
2108 static int
2109 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2110 {
2111         unsigned long iflags;
2112         int res = 0;
2113
2114         if (!sfp || !srp || list_empty(&sfp->rq_list))
2115                 return res;
2116         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2117         if (!list_empty(&srp->entry)) {
2118                 list_del(&srp->entry);
2119                 srp->parentfp = NULL;
2120                 res = 1;
2121         }
2122         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2123         return res;
2124 }
2125
2126 static Sg_fd *
2127 sg_add_sfp(Sg_device * sdp)
2128 {
2129         Sg_fd *sfp;
2130         unsigned long iflags;
2131         int bufflen;
2132
2133         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2134         if (!sfp)
2135                 return ERR_PTR(-ENOMEM);
2136
2137         init_waitqueue_head(&sfp->read_wait);
2138         rwlock_init(&sfp->rq_list_lock);
2139         INIT_LIST_HEAD(&sfp->rq_list);
2140         kref_init(&sfp->f_ref);
2141         mutex_init(&sfp->f_mutex);
2142         sfp->timeout = SG_DEFAULT_TIMEOUT;
2143         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2144         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2145         sfp->cmd_q = SG_DEF_COMMAND_Q;
2146         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2147         sfp->parentdp = sdp;
2148         write_lock_irqsave(&sdp->sfd_lock, iflags);
2149         if (atomic_read(&sdp->detaching)) {
2150                 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2151                 return ERR_PTR(-ENODEV);
2152         }
2153         list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2154         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2155         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2156                                       "sg_add_sfp: sfp=0x%p\n", sfp));
2157         if (unlikely(sg_big_buff != def_reserved_size))
2158                 sg_big_buff = def_reserved_size;
2159
2160         bufflen = min_t(int, sg_big_buff,
2161                         max_sectors_bytes(sdp->device->request_queue));
2162         sg_build_reserve(sfp, bufflen);
2163         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2164                                       "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2165                                       sfp->reserve.bufflen,
2166                                       sfp->reserve.k_use_sg));
2167
2168         kref_get(&sdp->d_ref);
2169         __module_get(THIS_MODULE);
2170         return sfp;
2171 }
2172
2173 static void
2174 sg_remove_sfp_usercontext(struct work_struct *work)
2175 {
2176         struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2177         struct sg_device *sdp = sfp->parentdp;
2178         Sg_request *srp;
2179         unsigned long iflags;
2180
2181         /* Cleanup any responses which were never read(). */
2182         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2183         while (!list_empty(&sfp->rq_list)) {
2184                 srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2185                 sg_finish_rem_req(srp);
2186                 list_del(&srp->entry);
2187                 srp->parentfp = NULL;
2188         }
2189         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2190
2191         if (sfp->reserve.bufflen > 0) {
2192                 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2193                                 "sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2194                                 (int) sfp->reserve.bufflen,
2195                                 (int) sfp->reserve.k_use_sg));
2196                 sg_remove_scat(sfp, &sfp->reserve);
2197         }
2198
2199         SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2200                         "sg_remove_sfp: sfp=0x%p\n", sfp));
2201         kfree(sfp);
2202
2203         scsi_device_put(sdp->device);
2204         kref_put(&sdp->d_ref, sg_device_destroy);
2205         module_put(THIS_MODULE);
2206 }
2207
2208 static void
2209 sg_remove_sfp(struct kref *kref)
2210 {
2211         struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2212         struct sg_device *sdp = sfp->parentdp;
2213         unsigned long iflags;
2214
2215         write_lock_irqsave(&sdp->sfd_lock, iflags);
2216         list_del(&sfp->sfd_siblings);
2217         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2218
2219         INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2220         schedule_work(&sfp->ew.work);
2221 }
2222
2223 #ifdef CONFIG_SCSI_PROC_FS
2224 static int
2225 sg_idr_max_id(int id, void *p, void *data)
2226 {
2227         int *k = data;
2228
2229         if (*k < id)
2230                 *k = id;
2231
2232         return 0;
2233 }
2234
2235 static int
2236 sg_last_dev(void)
2237 {
2238         int k = -1;
2239         unsigned long iflags;
2240
2241         read_lock_irqsave(&sg_index_lock, iflags);
2242         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2243         read_unlock_irqrestore(&sg_index_lock, iflags);
2244         return k + 1;           /* origin 1 */
2245 }
2246 #endif
2247
2248 /* must be called with sg_index_lock held */
2249 static Sg_device *sg_lookup_dev(int dev)
2250 {
2251         return idr_find(&sg_index_idr, dev);
2252 }
2253
2254 static Sg_device *
2255 sg_get_dev(int dev)
2256 {
2257         struct sg_device *sdp;
2258         unsigned long flags;
2259
2260         read_lock_irqsave(&sg_index_lock, flags);
2261         sdp = sg_lookup_dev(dev);
2262         if (!sdp)
2263                 sdp = ERR_PTR(-ENXIO);
2264         else if (atomic_read(&sdp->detaching)) {
2265                 /* If sdp->detaching, then the refcount may already be 0, in
2266                  * which case it would be a bug to do kref_get().
2267                  */
2268                 sdp = ERR_PTR(-ENODEV);
2269         } else
2270                 kref_get(&sdp->d_ref);
2271         read_unlock_irqrestore(&sg_index_lock, flags);
2272
2273         return sdp;
2274 }
2275
2276 #ifdef CONFIG_SCSI_PROC_FS
2277
2278 static struct proc_dir_entry *sg_proc_sgp = NULL;
2279
2280 static char sg_proc_sg_dirname[] = "scsi/sg";
2281
2282 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2283
2284 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2285 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2286                                   size_t count, loff_t *off);
2287 static const struct file_operations adio_fops = {
2288         .owner = THIS_MODULE,
2289         .open = sg_proc_single_open_adio,
2290         .read = seq_read,
2291         .llseek = seq_lseek,
2292         .write = sg_proc_write_adio,
2293         .release = single_release,
2294 };
2295
2296 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2297 static ssize_t sg_proc_write_dressz(struct file *filp,
2298                 const char __user *buffer, size_t count, loff_t *off);
2299 static const struct file_operations dressz_fops = {
2300         .owner = THIS_MODULE,
2301         .open = sg_proc_single_open_dressz,
2302         .read = seq_read,
2303         .llseek = seq_lseek,
2304         .write = sg_proc_write_dressz,
2305         .release = single_release,
2306 };
2307
2308 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2309 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2310 static const struct file_operations version_fops = {
2311         .owner = THIS_MODULE,
2312         .open = sg_proc_single_open_version,
2313         .read = seq_read,
2314         .llseek = seq_lseek,
2315         .release = single_release,
2316 };
2317
2318 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2319 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2320 static const struct file_operations devhdr_fops = {
2321         .owner = THIS_MODULE,
2322         .open = sg_proc_single_open_devhdr,
2323         .read = seq_read,
2324         .llseek = seq_lseek,
2325         .release = single_release,
2326 };
2327
2328 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2329 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2330 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2331 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2332 static void dev_seq_stop(struct seq_file *s, void *v);
2333 static const struct file_operations dev_fops = {
2334         .owner = THIS_MODULE,
2335         .open = sg_proc_open_dev,
2336         .read = seq_read,
2337         .llseek = seq_lseek,
2338         .release = seq_release,
2339 };
2340 static const struct seq_operations dev_seq_ops = {
2341         .start = dev_seq_start,
2342         .next  = dev_seq_next,
2343         .stop  = dev_seq_stop,
2344         .show  = sg_proc_seq_show_dev,
2345 };
2346
2347 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2348 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2349 static const struct file_operations devstrs_fops = {
2350         .owner = THIS_MODULE,
2351         .open = sg_proc_open_devstrs,
2352         .read = seq_read,
2353         .llseek = seq_lseek,
2354         .release = seq_release,
2355 };
2356 static const struct seq_operations devstrs_seq_ops = {
2357         .start = dev_seq_start,
2358         .next  = dev_seq_next,
2359         .stop  = dev_seq_stop,
2360         .show  = sg_proc_seq_show_devstrs,
2361 };
2362
2363 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2364 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2365 static const struct file_operations debug_fops = {
2366         .owner = THIS_MODULE,
2367         .open = sg_proc_open_debug,
2368         .read = seq_read,
2369         .llseek = seq_lseek,
2370         .release = seq_release,
2371 };
2372 static const struct seq_operations debug_seq_ops = {
2373         .start = dev_seq_start,
2374         .next  = dev_seq_next,
2375         .stop  = dev_seq_stop,
2376         .show  = sg_proc_seq_show_debug,
2377 };
2378
2379
2380 struct sg_proc_leaf {
2381         const char * name;
2382         const struct file_operations * fops;
2383 };
2384
2385 static const struct sg_proc_leaf sg_proc_leaf_arr[] = {
2386         {"allow_dio", &adio_fops},
2387         {"debug", &debug_fops},
2388         {"def_reserved_size", &dressz_fops},
2389         {"device_hdr", &devhdr_fops},
2390         {"devices", &dev_fops},
2391         {"device_strs", &devstrs_fops},
2392         {"version", &version_fops}
2393 };
2394
2395 static int
2396 sg_proc_init(void)
2397 {
2398         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2399         int k;
2400
2401         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2402         if (!sg_proc_sgp)
2403                 return 1;
2404         for (k = 0; k < num_leaves; ++k) {
2405                 const struct sg_proc_leaf *leaf = &sg_proc_leaf_arr[k];
2406                 umode_t mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2407                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2408         }
2409         return 0;
2410 }
2411
2412 static void
2413 sg_proc_cleanup(void)
2414 {
2415         int k;
2416         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2417
2418         if (!sg_proc_sgp)
2419                 return;
2420         for (k = 0; k < num_leaves; ++k)
2421                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2422         remove_proc_entry(sg_proc_sg_dirname, NULL);
2423 }
2424
2425
2426 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2427 {
2428         seq_printf(s, "%d\n", *((int *)s->private));
2429         return 0;
2430 }
2431
2432 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2433 {
2434         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2435 }
2436
2437 static ssize_t
2438 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2439                    size_t count, loff_t *off)
2440 {
2441         int err;
2442         unsigned long num;
2443
2444         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2445                 return -EACCES;
2446         err = kstrtoul_from_user(buffer, count, 0, &num);
2447         if (err)
2448                 return err;
2449         sg_allow_dio = num ? 1 : 0;
2450         return count;
2451 }
2452
2453 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2454 {
2455         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2456 }
2457
2458 static ssize_t
2459 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2460                      size_t count, loff_t *off)
2461 {
2462         int err;
2463         unsigned long k = ULONG_MAX;
2464
2465         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2466                 return -EACCES;
2467
2468         err = kstrtoul_from_user(buffer, count, 0, &k);
2469         if (err)
2470                 return err;
2471         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2472                 sg_big_buff = k;
2473                 return count;
2474         }
2475         return -ERANGE;
2476 }
2477
2478 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2479 {
2480         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2481                    sg_version_date);
2482         return 0;
2483 }
2484
2485 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2486 {
2487         return single_open(file, sg_proc_seq_show_version, NULL);
2488 }
2489
2490 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2491 {
2492         seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2493         return 0;
2494 }
2495
2496 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2497 {
2498         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2499 }
2500
2501 struct sg_proc_deviter {
2502         loff_t  index;
2503         size_t  max;
2504 };
2505
2506 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2507 {
2508         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2509
2510         s->private = it;
2511         if (! it)
2512                 return NULL;
2513
2514         it->index = *pos;
2515         it->max = sg_last_dev();
2516         if (it->index >= it->max)
2517                 return NULL;
2518         return it;
2519 }
2520
2521 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2522 {
2523         struct sg_proc_deviter * it = s->private;
2524
2525         *pos = ++it->index;
2526         return (it->index < it->max) ? it : NULL;
2527 }
2528
2529 static void dev_seq_stop(struct seq_file *s, void *v)
2530 {
2531         kfree(s->private);
2532 }
2533
2534 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2535 {
2536         return seq_open(file, &dev_seq_ops);
2537 }
2538
2539 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2540 {
2541         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2542         Sg_device *sdp;
2543         struct scsi_device *scsidp;
2544         unsigned long iflags;
2545
2546         read_lock_irqsave(&sg_index_lock, iflags);
2547         sdp = it ? sg_lookup_dev(it->index) : NULL;
2548         if ((NULL == sdp) || (NULL == sdp->device) ||
2549             (atomic_read(&sdp->detaching)))
2550                 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2551         else {
2552                 scsidp = sdp->device;
2553                 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2554                               scsidp->host->host_no, scsidp->channel,
2555                               scsidp->id, scsidp->lun, (int) scsidp->type,
2556                               1,
2557                               (int) scsidp->queue_depth,
2558                               (int) atomic_read(&scsidp->device_busy),
2559                               (int) scsi_device_online(scsidp));
2560         }
2561         read_unlock_irqrestore(&sg_index_lock, iflags);
2562         return 0;
2563 }
2564
2565 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2566 {
2567         return seq_open(file, &devstrs_seq_ops);
2568 }
2569
2570 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2571 {
2572         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2573         Sg_device *sdp;
2574         struct scsi_device *scsidp;
2575         unsigned long iflags;
2576
2577         read_lock_irqsave(&sg_index_lock, iflags);
2578         sdp = it ? sg_lookup_dev(it->index) : NULL;
2579         scsidp = sdp ? sdp->device : NULL;
2580         if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2581                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2582                            scsidp->vendor, scsidp->model, scsidp->rev);
2583         else
2584                 seq_puts(s, "<no active device>\n");
2585         read_unlock_irqrestore(&sg_index_lock, iflags);
2586         return 0;
2587 }
2588
2589 /* must be called while holding sg_index_lock */
2590 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2591 {
2592         int k, new_interface, blen, usg;
2593         Sg_request *srp;
2594         Sg_fd *fp;
2595         const sg_io_hdr_t *hp;
2596         const char * cp;
2597         unsigned int ms;
2598
2599         k = 0;
2600         list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2601                 k++;
2602                 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2603                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2604                            "(res)sgat=%d low_dma=%d\n", k,
2605                            jiffies_to_msecs(fp->timeout),
2606                            fp->reserve.bufflen,
2607                            (int) fp->reserve.k_use_sg,
2608                            (int) sdp->device->host->unchecked_isa_dma);
2609                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2610                            (int) fp->cmd_q, (int) fp->force_packid,
2611                            (int) fp->keep_orphan);
2612                 list_for_each_entry(srp, &fp->rq_list, entry) {
2613                         hp = &srp->header;
2614                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2615                         if (srp->res_used) {
2616                                 if (new_interface &&
2617                                     (SG_FLAG_MMAP_IO & hp->flags))
2618                                         cp = "     mmap>> ";
2619                                 else
2620                                         cp = "     rb>> ";
2621                         } else {
2622                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2623                                         cp = "     dio>> ";
2624                                 else
2625                                         cp = "     ";
2626                         }
2627                         seq_puts(s, cp);
2628                         blen = srp->data.bufflen;
2629                         usg = srp->data.k_use_sg;
2630                         seq_puts(s, srp->done ?
2631                                  ((1 == srp->done) ?  "rcv:" : "fin:")
2632                                   : "act:");
2633                         seq_printf(s, " id=%d blen=%d",
2634                                    srp->header.pack_id, blen);
2635                         if (srp->done)
2636                                 seq_printf(s, " dur=%d", hp->duration);
2637                         else {
2638                                 ms = jiffies_to_msecs(jiffies);
2639                                 seq_printf(s, " t_o/elap=%d/%d",
2640                                         (new_interface ? hp->timeout :
2641                                                   jiffies_to_msecs(fp->timeout)),
2642                                         (ms > hp->duration ? ms - hp->duration : 0));
2643                         }
2644                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2645                                    (int) srp->data.cmd_opcode);
2646                 }
2647                 if (list_empty(&fp->rq_list))
2648                         seq_puts(s, "     No requests active\n");
2649                 read_unlock(&fp->rq_list_lock);
2650         }
2651 }
2652
2653 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2654 {
2655         return seq_open(file, &debug_seq_ops);
2656 }
2657
2658 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2659 {
2660         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2661         Sg_device *sdp;
2662         unsigned long iflags;
2663
2664         if (it && (0 == it->index))
2665                 seq_printf(s, "max_active_device=%d  def_reserved_size=%d\n",
2666                            (int)it->max, sg_big_buff);
2667
2668         read_lock_irqsave(&sg_index_lock, iflags);
2669         sdp = it ? sg_lookup_dev(it->index) : NULL;
2670         if (NULL == sdp)
2671                 goto skip;
2672         read_lock(&sdp->sfd_lock);
2673         if (!list_empty(&sdp->sfds)) {
2674                 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2675                 if (atomic_read(&sdp->detaching))
2676                         seq_puts(s, "detaching pending close ");
2677                 else if (sdp->device) {
2678                         struct scsi_device *scsidp = sdp->device;
2679
2680                         seq_printf(s, "%d:%d:%d:%llu   em=%d",
2681                                    scsidp->host->host_no,
2682                                    scsidp->channel, scsidp->id,
2683                                    scsidp->lun,
2684                                    scsidp->host->hostt->emulated);
2685                 }
2686                 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2687                            sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2688                 sg_proc_debug_helper(s, sdp);
2689         }
2690         read_unlock(&sdp->sfd_lock);
2691 skip:
2692         read_unlock_irqrestore(&sg_index_lock, iflags);
2693         return 0;
2694 }
2695
2696 #endif                          /* CONFIG_SCSI_PROC_FS */
2697
2698 module_init(init_sg);
2699 module_exit(exit_sg);